Merge pull request #446 from giuseppe/tag-1.15

release 1.15

.clang-format

@@ -0,0 +1,111 @@
+---
+BasedOnStyle:  GNU
+AccessModifierOffset: -2
+AlignAfterOpenBracket: Align
+AlignConsecutiveMacros: false
+AlignConsecutiveAssignments: false
+AlignConsecutiveDeclarations: false
+AlignEscapedNewlines: Left
+AlignOperands:   true
+AlignTrailingComments: true
+AllowAllArgumentsOnNextLine: true
+AllowAllConstructorInitializersOnNextLine: true
+AllowAllParametersOfDeclarationOnNextLine: true
+AllowShortBlocksOnASingleLine: Never
+AllowShortCaseLabelsOnASingleLine: false
+AllowShortFunctionsOnASingleLine: All
+AllowShortLambdasOnASingleLine: All
+AllowShortIfStatementsOnASingleLine: Never
+AllowShortLoopsOnASingleLine: false
+AlwaysBreakAfterDefinitionReturnType: All
+AlwaysBreakAfterReturnType: AllDefinitions
+AlwaysBreakBeforeMultilineStrings: false
+AlwaysBreakTemplateDeclarations: MultiLine
+BinPackArguments: true
+BinPackParameters: true
+BraceWrapping:
+  AfterCaseLabel:  true
+  AfterClass:      true
+  AfterControlStatement: true
+  AfterEnum:       true
+  AfterFunction:   true
+  AfterNamespace:  true
+  AfterObjCDeclaration: true
+  AfterStruct:     true
+  AfterUnion:      true
+  BeforeCatch:     true
+  BeforeElse:      true
+  IndentBraces:    true
+  SplitEmptyFunction: true
+  SplitEmptyRecord: true
+  SplitEmptyNamespace: true
+BreakBeforeBinaryOperators: All
+BreakBeforeBraces: Custom
+BreakBeforeInheritanceComma: false
+BreakInheritanceList: BeforeColon
+BreakBeforeTernaryOperators: true
+BreakConstructorInitializersBeforeComma: false
+BreakConstructorInitializers: BeforeColon
+BreakAfterJavaFieldAnnotations: false
+BreakStringLiterals: true
+ColumnLimit: 0
+ContinuationIndentWidth: 4
+DeriveLineEnding: true
+DerivePointerAlignment: false
+DisableFormat:   false
+ExperimentalAutoDetectBinPacking: false
+FixNamespaceComments: false
+ForEachMacros:
+  - foreach
+  - Q_FOREACH
+  - BOOST_FOREACH
+IncludeBlocks:   Preserve
+IncludeIsMainRegex: '(Test)?$'
+IncludeIsMainSourceRegex: ''
+IndentCaseLabels: false
+IndentGotoLabels: true
+IndentPPDirectives: AfterHash
+IndentWidth:     2
+IndentWrappedFunctionNames: false
+JavaScriptQuotes: Leave
+JavaScriptWrapImports: true
+KeepEmptyLinesAtTheStartOfBlocks: true
+MacroBlockBegin: ''
+MacroBlockEnd:   ''
+MaxEmptyLinesToKeep: 1
+NamespaceIndentation: None
+ObjCBinPackProtocolList: Auto
+ObjCBlockIndentWidth: 2
+ObjCSpaceAfterProperty: false
+ObjCSpaceBeforeProtocolList: true
+PenaltyBreakAssignment: 2
+PenaltyBreakBeforeFirstCallParameter: 19
+PenaltyBreakComment: 300
+PenaltyBreakFirstLessLess: 120
+PenaltyBreakString: 1000
+PenaltyBreakTemplateDeclaration: 10
+PenaltyExcessCharacter: 1000000
+PenaltyReturnTypeOnItsOwnLine: 60
+PointerAlignment: Right
+ReflowComments:  true
+SortIncludes:    false
+SortUsingDeclarations: true
+SpaceAfterCStyleCast: true
+SpaceAfterLogicalNot: true
+SpaceAfterTemplateKeyword: true
+SpaceBeforeAssignmentOperators: true
+SpaceBeforeParens: Always
+SpaceInEmptyBlock: false
+SpaceInEmptyParentheses: false
+SpacesBeforeTrailingComments: 1
+SpacesInAngles:  false
+SpacesInConditionalStatement: false
+SpacesInContainerLiterals: true
+SpacesInCStyleCastParentheses: false
+SpacesInParentheses: false
+SpacesInSquareBrackets: false
+SpaceBeforeSquareBrackets: false
+TabWidth:        8
+UseCRLF:         false
+UseTab:          Never
+...

.dockerignore

@@ -0,0 +1,10 @@
+*
+
+!lib
+!m4
+!*.sh
+!*.ac
+!*.am
+!*.md
+!*.h
+!*.c

.github/workflows/release.yaml

@@ -0,0 +1,77 @@
+name: Release
+on:
+  push:
+  pull_request:
+
+jobs:
+  release:
+    runs-on: ubuntu-latest
+    steps:
+    - uses: actions/checkout@v4
+      with:
+        # Reproduce the exact commit hash value
+        fetch-depth: 0
+        ref: ${{ github.event.pull_request.head.sha }}
+    - run: echo "SOURCE_DATE_EPOCH=$(git log -1 --pretty=%ct)" >> $GITHUB_ENV
+    - uses: docker/setup-buildx-action@v2
+    - name: Cache var-cache-apt
+      uses: actions/cache@v3
+      with:
+        path: var-cache-apt
+        key: var-cache-apt-${{ hashFiles('Containerfile.cross') }}
+    - name: Cache var-lib-apt
+      uses: actions/cache@v3
+      with:
+        path: var-lib-apt
+        key: var-lib-apt-${{ hashFiles('Containerfile.cross') }}
+    - name: inject var-cache-apt into docker
+      uses: reproducible-containers/buildkit-cache-dance@v2.1.2
+      with:
+        cache-source: var-cache-apt
+        cache-target: /var/cache/apt
+    - name: inject var-lib-apt into docker
+      uses: reproducible-containers/buildkit-cache-dance@v2.1.2
+      with:
+        cache-source: var-lib-apt
+        cache-target: /var/lib/apt
+    - name: "Build binaries from Containerfile.cross"
+      run: docker buildx build -o /tmp/fuse-overlayfs-builds --build-arg SOURCE_DATE_EPOCH --platform=amd64,arm64,arm,s390x,ppc64le,riscv64 -f Containerfile.cross .
+    - name: "Create /tmp/artifact"
+      run: |
+        mkdir -p /tmp/artifact
+        mv /tmp/fuse-overlayfs-builds/linux_amd64/fuse-overlayfs   /tmp/artifact/fuse-overlayfs-x86_64
+        mv /tmp/fuse-overlayfs-builds/linux_arm64/fuse-overlayfs   /tmp/artifact/fuse-overlayfs-aarch64
+        mv /tmp/fuse-overlayfs-builds/linux_arm_v7/fuse-overlayfs  /tmp/artifact/fuse-overlayfs-armv7l
+        mv /tmp/fuse-overlayfs-builds/linux_s390x/fuse-overlayfs   /tmp/artifact/fuse-overlayfs-s390x
+        mv /tmp/fuse-overlayfs-builds/linux_ppc64le/fuse-overlayfs /tmp/artifact/fuse-overlayfs-ppc64le
+        mv /tmp/fuse-overlayfs-builds/linux_riscv64/fuse-overlayfs /tmp/artifact/fuse-overlayfs-riscv64
+        echo "${SOURCE_DATE_EPOCH}" >/tmp/artifact/SOURCE_DATE_EPOCH
+    - name: "SHA256SUMS"
+      run: (cd /tmp/artifact; sha256sum *) | tee /tmp/SHA256SUMS
+    - name: "The sha256sum of the SHA256SUMS file"
+      run: sha256sum /tmp/SHA256SUMS
+    - name: "Prepare the release note"
+      run: |
+        cat << EOF | tee /tmp/release-note.txt
+        #### About the binaries
+        The binaries were built automatically on GitHub Actions.
+        The build log is available for 90 days: https://github.com/${{ github.repository }}/actions/runs/${{ github.run_id }}
+
+        The binaries should be reproducible with the following command:
+        \`\`\`
+        docker buildx build \
+          -o /tmp/fuse-overlayfs-builds \
+          --build-arg SOURCE_DATE_EPOCH=${SOURCE_DATE_EPOCH} \
+          --build-arg BUILDKIT_CONTEXT_KEEP_GIT_DIR=1 \
+          --platform=amd64,arm64,arm,s390x,ppc64le,riscv64 \
+          -f Containerfile.cross \
+          "https://github.com/${{ github.repository }}.git#${tag}"
+        \`\`\`
+        EOF
+    - name: "Create release"
+      if: github.event_name == 'push' && startsWith(github.ref, 'refs/tags/v')
+      env:
+        GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
+      run: |
+        tag="${GITHUB_REF##*/}"
+        gh release create -F /tmp/release-note.txt --draft --title "${tag}" "${tag}" /tmp/artifact/* /tmp/SHA256SUMS

.github/workflows/test.yaml

@@ -0,0 +1,120 @@
+name: Test
+
+on: [push, pull_request]
+
+jobs:
+  build_job:
+    runs-on: ubuntu-latest
+    name: Build on ${{ matrix.arch }}
+
+    strategy:
+      matrix:
+        include:
+          - arch: armv7
+            distro: ubuntu_latest
+          - arch: aarch64
+            distro: ubuntu_latest
+          - arch: s390x
+            distro: ubuntu_latest
+          - arch: ppc64le
+            distro: ubuntu_latest
+    steps:
+      - uses: actions/checkout@v4
+      - uses: uraimo/run-on-arch-action@v3.0.1
+        name: Build
+        id: build
+        with:
+          arch: ${{ matrix.arch }}
+          distro: ${{ matrix.distro }}
+
+          githubToken: ${{ github.token }}
+
+          setup: |
+            git submodule update --init --recursive
+
+          install: |
+            apt-get update -q -y
+            apt-get install -q -y attr automake autotools-dev git make gcc pkg-config xz-utils python3 g++ python3-setuptools libdevmapper-dev btrfs-progs libbtrfs-dev go-md2man parallel libfuse3-dev bats
+
+          run: |
+            ./autogen.sh
+            LIBS="-ldl" LDFLAGS="-static" ./configure
+            make -j $(nproc)
+
+      - name: Archive build artifacts
+        uses: actions/upload-artifact@v4.6.2
+        with:
+          name: fuse-overlayfs-${{ matrix.arch }}-${{ matrix.distro }}
+          path: |
+            fuse-overlayfs
+
+  Test:
+    runs-on: ubuntu-latest
+    strategy:
+      fail-fast: false
+      matrix:
+        include:
+          - test: no-ovl-whiteouts
+          - test: ovl-whiteouts
+    env:
+      GOPATH: /root/go
+      TAGS: exclude_graphdriver_devicemapper exclude_graphdriver_btrfs no_libsubid
+    steps:
+    - name: checkout
+      uses: actions/checkout@v4
+
+    - name: install dependencies
+      run: |
+            sudo apt-get update -q -y
+            sudo apt-get install -q -y attr automake autotools-dev git make gcc pkg-config xz-utils python3 g++ python3-setuptools libdevmapper-dev btrfs-progs libbtrfs-dev go-md2man parallel wget libfuse3-dev bats
+
+            sudo mkdir -p /lower /upper /mnt $GOPATH/src/github.com/containers
+            sudo sh -c "cd $GOPATH/src/github.com/containers; git clone --depth=1 https://github.com/containers/storage"
+            sudo TAGS="$TAGS" GOPATH=$GOPATH sh -c "(cd $GOPATH/src/github.com/containers/storage; sed -i -e 's|^AUTOTAGS.*$|AUTOTAGS := $TAGS|' Makefile; make GO111MODULE=on containers-storage)"
+            sudo sh -c "(cd /; git clone https://github.com/amir73il/unionmount-testsuite.git)"
+
+    - name: run autogen.sh
+      run: |
+        ./autogen.sh
+
+    - name: run configure
+      run: |
+        LIBS="-ldl" LDFLAGS="-static" ./configure
+
+    - name: build and install
+      run: |
+        make -j $(nproc)
+        sudo make -j install
+        sudo cp fuse-overlayfs /sbin
+
+    - name: Archive build artifacts
+      uses: actions/upload-artifact@v4.6.2
+      with:
+        name: fuse-overlayfs-x86_64-ubuntu-latest
+        path: |
+          fuse-overlayfs
+      if: ${{ matrix.test == 'ovl-whiteouts' }}
+
+    - name: run test
+      run: |
+        sudo sysctl -w kernel.apparmor_restrict_unprivileged_userns=0
+        sudo sysctl -w kernel.apparmor_restrict_unprivileged_unconfined=0
+
+        case "${{ matrix.test }}" in
+            ovl-whiteouts)
+                sudo sh -c "(cd /unionmount-testsuite; unshare -m ./run --ov --fuse=fuse-overlayfs --xdev)"
+                sudo tests/fedora-installs.sh
+                sudo tests/unlink.sh
+                sudo tests/alpine.sh
+                sudo sh -c "(cd /root/go/src/github.com/containers/storage/tests; JOBS=1 STORAGE_OPTION=overlay.mount_program=/sbin/fuse-overlayfs STORAGE_DRIVER=overlay unshare -m ./test_runner.bash)"
+                tests/unpriv.sh
+            ;;
+            no-ovl-whiteouts)
+                sudo sh -c "(cd /unionmount-testsuite; FUSE_OVERLAYFS_DISABLE_OVL_WHITEOUT=1 unshare -m ./run --ov --fuse=fuse-overlayfs --xdev)"
+                sudo FUSE_OVERLAYFS_DISABLE_OVL_WHITEOUT=1 tests/fedora-installs.sh
+                sudo FUSE_OVERLAYFS_DISABLE_OVL_WHITEOUT=1 tests/unlink.sh
+                sudo FUSE_OVERLAYFS_DISABLE_OVL_WHITEOUT=1 tests/alpine.sh
+                sudo sh -c "(cd /root/go/src/github.com/containers/storage/tests; JOBS=1 FUSE_OVERLAYFS_DISABLE_OVL_WHITEOUT=1 STORAGE_OPTION=overlay.mount_program=/sbin/fuse-overlayfs STORAGE_DRIVER=overlay unshare -m ./test_runner.bash)"
+                FUSE_OVERLAYFS_DISABLE_OVL_WHITEOUT=1 tests/unpriv.sh
+            ;;
+        esac

.gitignore

@@ -0,0 +1,20 @@
+*.a
+*.cache
+*.o
+.deps
+Makefile
+Makefile.in
+aclocal.m4
+build-aux
+config.h
+config.h.in
+config.log
+config.status
+configure
+fuse-overlayfs
+lib/.deps
+lib/Makefile
+lib/Makefile.in
+lib/limits.h
+lib/sys/types.h
+stamp-h1

.lgtm.yml

@@ -0,0 +1,16 @@
+extraction:
+  cpp:
+    prepare:
+      packages:
+        - xz-utils
+        - ninja-build
+        - meson
+        - libudev-dev
+        - libudev1
+        - udev
+    after_prepare:
+        - (wget https://github.com/libfuse/libfuse/releases/download/fuse-3.6.2/fuse-3.6.2.tar.xz; tar xf fuse-3.6.2.tar.xz; cd fuse-3.6.2; mkdir build; cd build; meson .. --prefix $LGTM_WORKSPACE/usr && ninja && ninja -j1 install || true)
+    configure:
+        command:
+        - ./autogen.sh
+        - ./configure PKG_CONFIG_PATH=$LGTM_WORKSPACE/usr/lib/x86_64-linux-gnu/pkgconfig

.travis.yml

@@ -1,45 +0,0 @@
-services:
-  - docker
-env:
-  - GOPATH=$HOME/go GOROOT=/usr/local/go GO=/usr/local/go/bin/go
-language: c
-sudo: required
-dist: xenial
-addons:
-  apt:
-    packages:
-      - automake
-      - autotools-dev
-      - git
-      - make
-      - gcc
-      - pkg-config
-      - wget
-      - xz-utils
-      - python3.5
-      - g++
-      - python3-setuptools
-      - libdevmapper-dev
-      - btrfs-tools
-      - go-md2man
-before_install:
-  - docker pull fedora &
-  - (wget https://dl.google.com/go/go1.10.8.linux-amd64.tar.gz && tar xf go1.10.8.linux-amd64.tar.gz && sudo mv go /usr/local)
-  - sudo mkdir -p /lower /upper /mnt
-  - (cd /; sudo git clone https://github.com/amir73il/unionmount-testsuite.git)
-  - (git clone git://github.com/ninja-build/ninja.git && cd ninja && python3.5 ./bootstrap.py && sudo cp ninja /usr/bin)
-  - (git clone https://github.com/mesonbuild/meson.git; cd meson; sudo python3.5 ./setup.py install)
-  - (git clone https://github.com/sstephenson/bats.git; cd bats; sudo ./install.sh /usr/local)
-  - (go get github.com/containers/storage; cd $GOPATH/src/github.com/containers/storage; sed -i -e 's|^AUTOTAGS.*$|AUTOTAGS := exclude_graphdriver_devicemapper exclude_graphdriver_btrfs|' Makefile; make GO=$GO containers-storage)
-  - (wget https://github.com/libfuse/libfuse/releases/download/fuse-3.2.4/fuse-3.2.4.tar.xz; tar xf fuse-3.2.4.tar.xz; cd fuse-3.2.4; mkdir build; cd build; meson .. --prefix /usr && ninja && sudo ninja install)
-script:
-  - ./autogen.sh || travis_terminate 1;
-  - ./configure || travis_terminate 1;
-  - make -j $(nproc) || travis_terminate 1;
-  - sudo make -j install; sudo cp fuse-overlayfs /sbin || travis_terminate 1;
-  - (cd /unionmount-testsuite; sudo unshare -m ./run --ov --fuse=fuse-overlayfs --xdev) || travis_terminate 1;
-  - (cd /unionmount-testsuite; sudo FUSE_OVERLAYFS_DISABLE_OVL_WHITEOUT=1 unshare -m ./run --ov --fuse=fuse-overlayfs --xdev) || travis_terminate 1;
-  - sudo tests/fedora-installs.sh || travis_terminate 1;
-  - sudo tests/unlink.sh || travis_terminate 1;
-  - (cd $GOPATH/src/github.com/containers/storage/tests; sudo STORAGE_OPTION=overlay.mount_program=/sbin/fuse-overlayfs STORAGE_DRIVER=overlay unshare -m ./test_runner.bash) || travis_terminate 1;
-  - (cd $GOPATH/src/github.com/containers/storage/tests; sudo FUSE_OVERLAYFS_DISABLE_OVL_WHITEOUT=1 STORAGE_OPTION=overlay.mount_program=/sbin/fuse-overlayfs STORAGE_DRIVER=overlay unshare -m ./test_runner.bash) || travis_terminate 1;

CODE-OF-CONDUCT.md

@@ -0,0 +1,3 @@
+## The fuse-overlayfs Project Community Code of Conduct
+
+The fuse-overlayfs project follows the [Containers Community Code of Conduct](https://github.com/containers/common/blob/master/CODE-OF-CONDUCT.md).

COPYING

@@ -1,622 +1,281 @@
                     GNU GENERAL PUBLIC LICENSE
-                       Version 3, 29 June 2007
+                       Version 2, June 1991
 
- Copyright (C) 2007 Free Software Foundation, Inc. <http://fsf.org/>
+ Copyright (C) 1989, 1991 Free Software Foundation, Inc.,
+ 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
  Everyone is permitted to copy and distribute verbatim copies
  of this license document, but changing it is not allowed.
 
                             Preamble
 
-  The GNU General Public License is a free, copyleft license for
-software and other kinds of works.
-
-  The licenses for most software and other practical works are designed
-to take away your freedom to share and change the works.  By contrast,
-the GNU General Public License is intended to guarantee your freedom to
-share and change all versions of a program--to make sure it remains free
-software for all its users.  We, the Free Software Foundation, use the
-GNU General Public License for most of our software; it applies also to
-any other work released this way by its authors.  You can apply it to
+  The licenses for most software are designed to take away your
+freedom to share and change it.  By contrast, the GNU General Public
+License is intended to guarantee your freedom to share and change free
+software--to make sure the software is free for all its users.  This
+General Public License applies to most of the Free Software
+Foundation's software and to any other program whose authors commit to
+using it.  (Some other Free Software Foundation software is covered by
+the GNU Lesser General Public License instead.)  You can apply it to
 your programs, too.
 
   When we speak of free software, we are referring to freedom, not
 price.  Our General Public Licenses are designed to make sure that you
 have the freedom to distribute copies of free software (and charge for
-them if you wish), that you receive source code or can get it if you
-want it, that you can change the software or use pieces of it in new
-free programs, and that you know you can do these things.
+this service if you wish), that you receive source code or can get it
+if you want it, that you can change the software or use pieces of it
+in new free programs; and that you know you can do these things.
 
-  To protect your rights, we need to prevent others from denying you
-these rights or asking you to surrender the rights.  Therefore, you have
-certain responsibilities if you distribute copies of the software, or if
-you modify it: responsibilities to respect the freedom of others.
+  To protect your rights, we need to make restrictions that forbid
+anyone to deny you these rights or to ask you to surrender the rights.
+These restrictions translate to certain responsibilities for you if you
+distribute copies of the software, or if you modify it.
 
   For example, if you distribute copies of such a program, whether
-gratis or for a fee, you must pass on to the recipients the same
-freedoms that you received.  You must make sure that they, too, receive
-or can get the source code.  And you must show them these terms so they
-know their rights.
+gratis or for a fee, you must give the recipients all the rights that
+you have.  You must make sure that they, too, receive or can get the
+source code.  And you must show them these terms so they know their
+rights.
 
-  Developers that use the GNU GPL protect your rights with two steps:
-(1) assert copyright on the software, and (2) offer you this License
-giving you legal permission to copy, distribute and/or modify it.
+  We protect your rights with two steps: (1) copyright the software, and
+(2) offer you this license which gives you legal permission to copy,
+distribute and/or modify the software.
 
-  For the developers' and authors' protection, the GPL clearly explains
-that there is no warranty for this free software.  For both users' and
-authors' sake, the GPL requires that modified versions be marked as
-changed, so that their problems will not be attributed erroneously to
-authors of previous versions.
+  Also, for each author's protection and ours, we want to make certain
+that everyone understands that there is no warranty for this free
+software.  If the software is modified by someone else and passed on, we
+want its recipients to know that what they have is not the original, so
+that any problems introduced by others will not reflect on the original
+authors' reputations.
 
-  Some devices are designed to deny users access to install or run
-modified versions of the software inside them, although the manufacturer
-can do so.  This is fundamentally incompatible with the aim of
-protecting users' freedom to change the software.  The systematic
-pattern of such abuse occurs in the area of products for individuals to
-use, which is precisely where it is most unacceptable.  Therefore, we
-have designed this version of the GPL to prohibit the practice for those
-products.  If such problems arise substantially in other domains, we
-stand ready to extend this provision to those domains in future versions
-of the GPL, as needed to protect the freedom of users.
-
-  Finally, every program is threatened constantly by software patents.
-States should not allow patents to restrict development and use of
-software on general-purpose computers, but in those that do, we wish to
-avoid the special danger that patents applied to a free program could
-make it effectively proprietary.  To prevent this, the GPL assures that
-patents cannot be used to render the program non-free.
+  Finally, any free program is threatened constantly by software
+patents.  We wish to avoid the danger that redistributors of a free
+program will individually obtain patent licenses, in effect making the
+program proprietary.  To prevent this, we have made it clear that any
+patent must be licensed for everyone's free use or not licensed at all.
 
   The precise terms and conditions for copying, distribution and
 modification follow.
 
-                       TERMS AND CONDITIONS
-
-  0. Definitions.
-
-  "This License" refers to version 3 of the GNU General Public License.
-
-  "Copyright" also means copyright-like laws that apply to other kinds of
-works, such as semiconductor masks.
-
-  "The Program" refers to any copyrightable work licensed under this
-License.  Each licensee is addressed as "you".  "Licensees" and
-"recipients" may be individuals or organizations.
-
-  To "modify" a work means to copy from or adapt all or part of the work
-in a fashion requiring copyright permission, other than the making of an
-exact copy.  The resulting work is called a "modified version" of the
-earlier work or a work "based on" the earlier work.
-
-  A "covered work" means either the unmodified Program or a work based
-on the Program.
-
-  To "propagate" a work means to do anything with it that, without
-permission, would make you directly or secondarily liable for
-infringement under applicable copyright law, except executing it on a
-computer or modifying a private copy.  Propagation includes copying,
-distribution (with or without modification), making available to the
-public, and in some countries other activities as well.
-
-  To "convey" a work means any kind of propagation that enables other
-parties to make or receive copies.  Mere interaction with a user through
-a computer network, with no transfer of a copy, is not conveying.
-
-  An interactive user interface displays "Appropriate Legal Notices"
-to the extent that it includes a convenient and prominently visible
-feature that (1) displays an appropriate copyright notice, and (2)
-tells the user that there is no warranty for the work (except to the
-extent that warranties are provided), that licensees may convey the
-work under this License, and how to view a copy of this License.  If
-the interface presents a list of user commands or options, such as a
-menu, a prominent item in the list meets this criterion.
-
-  1. Source Code.
-
-  The "source code" for a work means the preferred form of the work
-for making modifications to it.  "Object code" means any non-source
-form of a work.
-
-  A "Standard Interface" means an interface that either is an official
-standard defined by a recognized standards body, or, in the case of
-interfaces specified for a particular programming language, one that
-is widely used among developers working in that language.
-
-  The "System Libraries" of an executable work include anything, other
-than the work as a whole, that (a) is included in the normal form of
-packaging a Major Component, but which is not part of that Major
-Component, and (b) serves only to enable use of the work with that
-Major Component, or to implement a Standard Interface for which an
-implementation is available to the public in source code form.  A
-"Major Component", in this context, means a major essential component
-(kernel, window system, and so on) of the specific operating system
-(if any) on which the executable work runs, or a compiler used to
-produce the work, or an object code interpreter used to run it.
-
-  The "Corresponding Source" for a work in object code form means all
-the source code needed to generate, install, and (for an executable
-work) run the object code and to modify the work, including scripts to
-control those activities.  However, it does not include the work's
-System Libraries, or general-purpose tools or generally available free
-programs which are used unmodified in performing those activities but
-which are not part of the work.  For example, Corresponding Source
-includes interface definition files associated with source files for
-the work, and the source code for shared libraries and dynamically
-linked subprograms that the work is specifically designed to require,
-such as by intimate data communication or control flow between those
-subprograms and other parts of the work.
-
-  The Corresponding Source need not include anything that users
-can regenerate automatically from other parts of the Corresponding
-Source.
-
-  The Corresponding Source for a work in source code form is that
-same work.
-
-  2. Basic Permissions.
-
-  All rights granted under this License are granted for the term of
-copyright on the Program, and are irrevocable provided the stated
-conditions are met.  This License explicitly affirms your unlimited
-permission to run the unmodified Program.  The output from running a
-covered work is covered by this License only if the output, given its
-content, constitutes a covered work.  This License acknowledges your
-rights of fair use or other equivalent, as provided by copyright law.
-
-  You may make, run and propagate covered works that you do not
-convey, without conditions so long as your license otherwise remains
-in force.  You may convey covered works to others for the sole purpose
-of having them make modifications exclusively for you, or provide you
-with facilities for running those works, provided that you comply with
-the terms of this License in conveying all material for which you do
-not control copyright.  Those thus making or running the covered works
-for you must do so exclusively on your behalf, under your direction
-and control, on terms that prohibit them from making any copies of
-your copyrighted material outside their relationship with you.
-
-  Conveying under any other circumstances is permitted solely under
-the conditions stated below.  Sublicensing is not allowed; section 10
-makes it unnecessary.
-
-  3. Protecting Users' Legal Rights From Anti-Circumvention Law.
-
-  No covered work shall be deemed part of an effective technological
-measure under any applicable law fulfilling obligations under article
-11 of the WIPO copyright treaty adopted on 20 December 1996, or
-similar laws prohibiting or restricting circumvention of such
-measures.
-
-  When you convey a covered work, you waive any legal power to forbid
-circumvention of technological measures to the extent such circumvention
-is effected by exercising rights under this License with respect to
-the covered work, and you disclaim any intention to limit operation or
-modification of the work as a means of enforcing, against the work's
-users, your or third parties' legal rights to forbid circumvention of
-technological measures.
-
-  4. Conveying Verbatim Copies.
-
-  You may convey verbatim copies of the Program's source code as you
-receive it, in any medium, provided that you conspicuously and
-appropriately publish on each copy an appropriate copyright notice;
-keep intact all notices stating that this License and any
-non-permissive terms added in accord with section 7 apply to the code;
-keep intact all notices of the absence of any warranty; and give all
-recipients a copy of this License along with the Program.
-
-  You may charge any price or no price for each copy that you convey,
-and you may offer support or warranty protection for a fee.
-
-  5. Conveying Modified Source Versions.
-
-  You may convey a work based on the Program, or the modifications to
-produce it from the Program, in the form of source code under the
-terms of section 4, provided that you also meet all of these conditions:
-
-    a) The work must carry prominent notices stating that you modified
-    it, and giving a relevant date.
-
-    b) The work must carry prominent notices stating that it is
-    released under this License and any conditions added under section
-    7.  This requirement modifies the requirement in section 4 to
-    "keep intact all notices".
-
-    c) You must license the entire work, as a whole, under this
-    License to anyone who comes into possession of a copy.  This
-    License will therefore apply, along with any applicable section 7
-    additional terms, to the whole of the work, and all its parts,
-    regardless of how they are packaged.  This License gives no
-    permission to license the work in any other way, but it does not
-    invalidate such permission if you have separately received it.
-
-    d) If the work has interactive user interfaces, each must display
-    Appropriate Legal Notices; however, if the Program has interactive
-    interfaces that do not display Appropriate Legal Notices, your
-    work need not make them do so.
-
-  A compilation of a covered work with other separate and independent
-works, which are not by their nature extensions of the covered work,
-and which are not combined with it such as to form a larger program,
-in or on a volume of a storage or distribution medium, is called an
-"aggregate" if the compilation and its resulting copyright are not
-used to limit the access or legal rights of the compilation's users
-beyond what the individual works permit.  Inclusion of a covered work
-in an aggregate does not cause this License to apply to the other
-parts of the aggregate.
-
-  6. Conveying Non-Source Forms.
-
-  You may convey a covered work in object code form under the terms
-of sections 4 and 5, provided that you also convey the
-machine-readable Corresponding Source under the terms of this License,
-in one of these ways:
-
-    a) Convey the object code in, or embodied in, a physical product
-    (including a physical distribution medium), accompanied by the
-    Corresponding Source fixed on a durable physical medium
-    customarily used for software interchange.
-
-    b) Convey the object code in, or embodied in, a physical product
-    (including a physical distribution medium), accompanied by a
-    written offer, valid for at least three years and valid for as
-    long as you offer spare parts or customer support for that product
-    model, to give anyone who possesses the object code either (1) a
-    copy of the Corresponding Source for all the software in the
-    product that is covered by this License, on a durable physical
-    medium customarily used for software interchange, for a price no
-    more than your reasonable cost of physically performing this
-    conveying of source, or (2) access to copy the
-    Corresponding Source from a network server at no charge.
-
-    c) Convey individual copies of the object code with a copy of the
-    written offer to provide the Corresponding Source.  This
-    alternative is allowed only occasionally and noncommercially, and
-    only if you received the object code with such an offer, in accord
-    with subsection 6b.
-
-    d) Convey the object code by offering access from a designated
-    place (gratis or for a charge), and offer equivalent access to the
-    Corresponding Source in the same way through the same place at no
-    further charge.  You need not require recipients to copy the
-    Corresponding Source along with the object code.  If the place to
-    copy the object code is a network server, the Corresponding Source
-    may be on a different server (operated by you or a third party)
-    that supports equivalent copying facilities, provided you maintain
-    clear directions next to the object code saying where to find the
-    Corresponding Source.  Regardless of what server hosts the
-    Corresponding Source, you remain obligated to ensure that it is
-    available for as long as needed to satisfy these requirements.
-
-    e) Convey the object code using peer-to-peer transmission, provided
-    you inform other peers where the object code and Corresponding
-    Source of the work are being offered to the general public at no
-    charge under subsection 6d.
-
-  A separable portion of the object code, whose source code is excluded
-from the Corresponding Source as a System Library, need not be
-included in conveying the object code work.
-
-  A "User Product" is either (1) a "consumer product", which means any
-tangible personal property which is normally used for personal, family,
-or household purposes, or (2) anything designed or sold for incorporation
-into a dwelling.  In determining whether a product is a consumer product,
-doubtful cases shall be resolved in favor of coverage.  For a particular
-product received by a particular user, "normally used" refers to a
-typical or common use of that class of product, regardless of the status
-of the particular user or of the way in which the particular user
-actually uses, or expects or is expected to use, the product.  A product
-is a consumer product regardless of whether the product has substantial
-commercial, industrial or non-consumer uses, unless such uses represent
-the only significant mode of use of the product.
-
-  "Installation Information" for a User Product means any methods,
-procedures, authorization keys, or other information required to install
-and execute modified versions of a covered work in that User Product from
-a modified version of its Corresponding Source.  The information must
-suffice to ensure that the continued functioning of the modified object
-code is in no case prevented or interfered with solely because
-modification has been made.
-
-  If you convey an object code work under this section in, or with, or
-specifically for use in, a User Product, and the conveying occurs as
-part of a transaction in which the right of possession and use of the
-User Product is transferred to the recipient in perpetuity or for a
-fixed term (regardless of how the transaction is characterized), the
-Corresponding Source conveyed under this section must be accompanied
-by the Installation Information.  But this requirement does not apply
-if neither you nor any third party retains the ability to install
-modified object code on the User Product (for example, the work has
-been installed in ROM).
-
-  The requirement to provide Installation Information does not include a
-requirement to continue to provide support service, warranty, or updates
-for a work that has been modified or installed by the recipient, or for
-the User Product in which it has been modified or installed.  Access to a
-network may be denied when the modification itself materially and
-adversely affects the operation of the network or violates the rules and
-protocols for communication across the network.
-
-  Corresponding Source conveyed, and Installation Information provided,
-in accord with this section must be in a format that is publicly
-documented (and with an implementation available to the public in
-source code form), and must require no special password or key for
-unpacking, reading or copying.
-
-  7. Additional Terms.
-
-  "Additional permissions" are terms that supplement the terms of this
-License by making exceptions from one or more of its conditions.
-Additional permissions that are applicable to the entire Program shall
-be treated as though they were included in this License, to the extent
-that they are valid under applicable law.  If additional permissions
-apply only to part of the Program, that part may be used separately
-under those permissions, but the entire Program remains governed by
-this License without regard to the additional permissions.
-
-  When you convey a copy of a covered work, you may at your option
-remove any additional permissions from that copy, or from any part of
-it.  (Additional permissions may be written to require their own
-removal in certain cases when you modify the work.)  You may place
-additional permissions on material, added by you to a covered work,
-for which you have or can give appropriate copyright permission.
-
-  Notwithstanding any other provision of this License, for material you
-add to a covered work, you may (if authorized by the copyright holders of
-that material) supplement the terms of this License with terms:
-
-    a) Disclaiming warranty or limiting liability differently from the
-    terms of sections 15 and 16 of this License; or
-
-    b) Requiring preservation of specified reasonable legal notices or
-    author attributions in that material or in the Appropriate Legal
-    Notices displayed by works containing it; or
-
-    c) Prohibiting misrepresentation of the origin of that material, or
-    requiring that modified versions of such material be marked in
-    reasonable ways as different from the original version; or
-
-    d) Limiting the use for publicity purposes of names of licensors or
-    authors of the material; or
-
-    e) Declining to grant rights under trademark law for use of some
-    trade names, trademarks, or service marks; or
-
-    f) Requiring indemnification of licensors and authors of that
-    material by anyone who conveys the material (or modified versions of
-    it) with contractual assumptions of liability to the recipient, for
-    any liability that these contractual assumptions directly impose on
-    those licensors and authors.
-
-  All other non-permissive additional terms are considered "further
-restrictions" within the meaning of section 10.  If the Program as you
-received it, or any part of it, contains a notice stating that it is
-governed by this License along with a term that is a further
-restriction, you may remove that term.  If a license document contains
-a further restriction but permits relicensing or conveying under this
-License, you may add to a covered work material governed by the terms
-of that license document, provided that the further restriction does
-not survive such relicensing or conveying.
-
-  If you add terms to a covered work in accord with this section, you
-must place, in the relevant source files, a statement of the
-additional terms that apply to those files, or a notice indicating
-where to find the applicable terms.
-
-  Additional terms, permissive or non-permissive, may be stated in the
-form of a separately written license, or stated as exceptions;
-the above requirements apply either way.
-
-  8. Termination.
-
-  You may not propagate or modify a covered work except as expressly
-provided under this License.  Any attempt otherwise to propagate or
-modify it is void, and will automatically terminate your rights under
-this License (including any patent licenses granted under the third
-paragraph of section 11).
-
-  However, if you cease all violation of this License, then your
-license from a particular copyright holder is reinstated (a)
-provisionally, unless and until the copyright holder explicitly and
-finally terminates your license, and (b) permanently, if the copyright
-holder fails to notify you of the violation by some reasonable means
-prior to 60 days after the cessation.
-
-  Moreover, your license from a particular copyright holder is
-reinstated permanently if the copyright holder notifies you of the
-violation by some reasonable means, this is the first time you have
-received notice of violation of this License (for any work) from that
-copyright holder, and you cure the violation prior to 30 days after
-your receipt of the notice.
-
-  Termination of your rights under this section does not terminate the
-licenses of parties who have received copies or rights from you under
-this License.  If your rights have been terminated and not permanently
-reinstated, you do not qualify to receive new licenses for the same
-material under section 10.
-
-  9. Acceptance Not Required for Having Copies.
-
-  You are not required to accept this License in order to receive or
-run a copy of the Program.  Ancillary propagation of a covered work
-occurring solely as a consequence of using peer-to-peer transmission
-to receive a copy likewise does not require acceptance.  However,
-nothing other than this License grants you permission to propagate or
-modify any covered work.  These actions infringe copyright if you do
-not accept this License.  Therefore, by modifying or propagating a
-covered work, you indicate your acceptance of this License to do so.
-
-  10. Automatic Licensing of Downstream Recipients.
-
-  Each time you convey a covered work, the recipient automatically
-receives a license from the original licensors, to run, modify and
-propagate that work, subject to this License.  You are not responsible
-for enforcing compliance by third parties with this License.
-
-  An "entity transaction" is a transaction transferring control of an
-organization, or substantially all assets of one, or subdividing an
-organization, or merging organizations.  If propagation of a covered
-work results from an entity transaction, each party to that
-transaction who receives a copy of the work also receives whatever
-licenses to the work the party's predecessor in interest had or could
-give under the previous paragraph, plus a right to possession of the
-Corresponding Source of the work from the predecessor in interest, if
-the predecessor has it or can get it with reasonable efforts.
-
-  You may not impose any further restrictions on the exercise of the
-rights granted or affirmed under this License.  For example, you may
-not impose a license fee, royalty, or other charge for exercise of
-rights granted under this License, and you may not initiate litigation
-(including a cross-claim or counterclaim in a lawsuit) alleging that
-any patent claim is infringed by making, using, selling, offering for
-sale, or importing the Program or any portion of it.
-
-  11. Patents.
-
-  A "contributor" is a copyright holder who authorizes use under this
-License of the Program or a work on which the Program is based.  The
-work thus licensed is called the contributor's "contributor version".
-
-  A contributor's "essential patent claims" are all patent claims
-owned or controlled by the contributor, whether already acquired or
-hereafter acquired, that would be infringed by some manner, permitted
-by this License, of making, using, or selling its contributor version,
-but do not include claims that would be infringed only as a
-consequence of further modification of the contributor version.  For
-purposes of this definition, "control" includes the right to grant
-patent sublicenses in a manner consistent with the requirements of
+                    GNU GENERAL PUBLIC LICENSE
+   TERMS AND CONDITIONS FOR COPYING, DISTRIBUTION AND MODIFICATION
+
+  0. This License applies to any program or other work which contains
+a notice placed by the copyright holder saying it may be distributed
+under the terms of this General Public License.  The "Program", below,
+refers to any such program or work, and a "work based on the Program"
+means either the Program or any derivative work under copyright law:
+that is to say, a work containing the Program or a portion of it,
+either verbatim or with modifications and/or translated into another
+language.  (Hereinafter, translation is included without limitation in
+the term "modification".)  Each licensee is addressed as "you".
+
+Activities other than copying, distribution and modification are not
+covered by this License; they are outside its scope.  The act of
+running the Program is not restricted, and the output from the Program
+is covered only if its contents constitute a work based on the
+Program (independent of having been made by running the Program).
+Whether that is true depends on what the Program does.
+
+  1. You may copy and distribute verbatim copies of the Program's
+source code as you receive it, in any medium, provided that you
+conspicuously and appropriately publish on each copy an appropriate
+copyright notice and disclaimer of warranty; keep intact all the
+notices that refer to this License and to the absence of any warranty;
+and give any other recipients of the Program a copy of this License
+along with the Program.
+
+You may charge a fee for the physical act of transferring a copy, and
+you may at your option offer warranty protection in exchange for a fee.
+
+  2. You may modify your copy or copies of the Program or any portion
+of it, thus forming a work based on the Program, and copy and
+distribute such modifications or work under the terms of Section 1
+above, provided that you also meet all of these conditions:
+
+    a) You must cause the modified files to carry prominent notices
+    stating that you changed the files and the date of any change.
+
+    b) You must cause any work that you distribute or publish, that in
+    whole or in part contains or is derived from the Program or any
+    part thereof, to be licensed as a whole at no charge to all third
+    parties under the terms of this License.
+
+    c) If the modified program normally reads commands interactively
+    when run, you must cause it, when started running for such
+    interactive use in the most ordinary way, to print or display an
+    announcement including an appropriate copyright notice and a
+    notice that there is no warranty (or else, saying that you provide
+    a warranty) and that users may redistribute the program under
+    these conditions, and telling the user how to view a copy of this
+    License.  (Exception: if the Program itself is interactive but
+    does not normally print such an announcement, your work based on
+    the Program is not required to print an announcement.)
+
+These requirements apply to the modified work as a whole.  If
+identifiable sections of that work are not derived from the Program,
+and can be reasonably considered independent and separate works in
+themselves, then this License, and its terms, do not apply to those
+sections when you distribute them as separate works.  But when you
+distribute the same sections as part of a whole which is a work based
+on the Program, the distribution of the whole must be on the terms of
+this License, whose permissions for other licensees extend to the
+entire whole, and thus to each and every part regardless of who wrote it.
+
+Thus, it is not the intent of this section to claim rights or contest
+your rights to work written entirely by you; rather, the intent is to
+exercise the right to control the distribution of derivative or
+collective works based on the Program.
+
+In addition, mere aggregation of another work not based on the Program
+with the Program (or with a work based on the Program) on a volume of
+a storage or distribution medium does not bring the other work under
+the scope of this License.
+
+  3. You may copy and distribute the Program (or a work based on it,
+under Section 2) in object code or executable form under the terms of
+Sections 1 and 2 above provided that you also do one of the following:
+
+    a) Accompany it with the complete corresponding machine-readable
+    source code, which must be distributed under the terms of Sections
+    1 and 2 above on a medium customarily used for software interchange; or,
+
+    b) Accompany it with a written offer, valid for at least three
+    years, to give any third party, for a charge no more than your
+    cost of physically performing source distribution, a complete
+    machine-readable copy of the corresponding source code, to be
+    distributed under the terms of Sections 1 and 2 above on a medium
+    customarily used for software interchange; or,
+
+    c) Accompany it with the information you received as to the offer
+    to distribute corresponding source code.  (This alternative is
+    allowed only for noncommercial distribution and only if you
+    received the program in object code or executable form with such
+    an offer, in accord with Subsection b above.)
+
+The source code for a work means the preferred form of the work for
+making modifications to it.  For an executable work, complete source
+code means all the source code for all modules it contains, plus any
+associated interface definition files, plus the scripts used to
+control compilation and installation of the executable.  However, as a
+special exception, the source code distributed need not include
+anything that is normally distributed (in either source or binary
+form) with the major components (compiler, kernel, and so on) of the
+operating system on which the executable runs, unless that component
+itself accompanies the executable.
+
+If distribution of executable or object code is made by offering
+access to copy from a designated place, then offering equivalent
+access to copy the source code from the same place counts as
+distribution of the source code, even though third parties are not
+compelled to copy the source along with the object code.
+
+  4. You may not copy, modify, sublicense, or distribute the Program
+except as expressly provided under this License.  Any attempt
+otherwise to copy, modify, sublicense or distribute the Program is
+void, and will automatically terminate your rights under this License.
+However, parties who have received copies, or rights, from you under
+this License will not have their licenses terminated so long as such
+parties remain in full compliance.
+
+  5. You are not required to accept this License, since you have not
+signed it.  However, nothing else grants you permission to modify or
+distribute the Program or its derivative works.  These actions are
+prohibited by law if you do not accept this License.  Therefore, by
+modifying or distributing the Program (or any work based on the
+Program), you indicate your acceptance of this License to do so, and
+all its terms and conditions for copying, distributing or modifying
+the Program or works based on it.
+
+  6. Each time you redistribute the Program (or any work based on the
+Program), the recipient automatically receives a license from the
+original licensor to copy, distribute or modify the Program subject to
+these terms and conditions.  You may not impose any further
+restrictions on the recipients' exercise of the rights granted herein.
+You are not responsible for enforcing compliance by third parties to
 this License.
 
-  Each contributor grants you a non-exclusive, worldwide, royalty-free
-patent license under the contributor's essential patent claims, to
-make, use, sell, offer for sale, import and otherwise run, modify and
-propagate the contents of its contributor version.
-
-  In the following three paragraphs, a "patent license" is any express
-agreement or commitment, however denominated, not to enforce a patent
-(such as an express permission to practice a patent or covenant not to
-sue for patent infringement).  To "grant" such a patent license to a
-party means to make such an agreement or commitment not to enforce a
-patent against the party.
-
-  If you convey a covered work, knowingly relying on a patent license,
-and the Corresponding Source of the work is not available for anyone
-to copy, free of charge and under the terms of this License, through a
-publicly available network server or other readily accessible means,
-then you must either (1) cause the Corresponding Source to be so
-available, or (2) arrange to deprive yourself of the benefit of the
-patent license for this particular work, or (3) arrange, in a manner
-consistent with the requirements of this License, to extend the patent
-license to downstream recipients.  "Knowingly relying" means you have
-actual knowledge that, but for the patent license, your conveying the
-covered work in a country, or your recipient's use of the covered work
-in a country, would infringe one or more identifiable patents in that
-country that you have reason to believe are valid.
-
-  If, pursuant to or in connection with a single transaction or
-arrangement, you convey, or propagate by procuring conveyance of, a
-covered work, and grant a patent license to some of the parties
-receiving the covered work authorizing them to use, propagate, modify
-or convey a specific copy of the covered work, then the patent license
-you grant is automatically extended to all recipients of the covered
-work and works based on it.
-
-  A patent license is "discriminatory" if it does not include within
-the scope of its coverage, prohibits the exercise of, or is
-conditioned on the non-exercise of one or more of the rights that are
-specifically granted under this License.  You may not convey a covered
-work if you are a party to an arrangement with a third party that is
-in the business of distributing software, under which you make payment
-to the third party based on the extent of your activity of conveying
-the work, and under which the third party grants, to any of the
-parties who would receive the covered work from you, a discriminatory
-patent license (a) in connection with copies of the covered work
-conveyed by you (or copies made from those copies), or (b) primarily
-for and in connection with specific products or compilations that
-contain the covered work, unless you entered into that arrangement,
-or that patent license was granted, prior to 28 March 2007.
-
-  Nothing in this License shall be construed as excluding or limiting
-any implied license or other defenses to infringement that may
-otherwise be available to you under applicable patent law.
-
-  12. No Surrender of Others' Freedom.
-
-  If conditions are imposed on you (whether by court order, agreement or
+  7. If, as a consequence of a court judgment or allegation of patent
+infringement or for any other reason (not limited to patent issues),
+conditions are imposed on you (whether by court order, agreement or
 otherwise) that contradict the conditions of this License, they do not
-excuse you from the conditions of this License.  If you cannot convey a
-covered work so as to satisfy simultaneously your obligations under this
-License and any other pertinent obligations, then as a consequence you may
-not convey it at all.  For example, if you agree to terms that obligate you
-to collect a royalty for further conveying from those to whom you convey
-the Program, the only way you could satisfy both those terms and this
-License would be to refrain entirely from conveying the Program.
+excuse you from the conditions of this License.  If you cannot
+distribute so as to satisfy simultaneously your obligations under this
+License and any other pertinent obligations, then as a consequence you
+may not distribute the Program at all.  For example, if a patent
+license would not permit royalty-free redistribution of the Program by
+all those who receive copies directly or indirectly through you, then
+the only way you could satisfy both it and this License would be to
+refrain entirely from distribution of the Program.
 
-  13. Use with the GNU Affero General Public License.
+If any portion of this section is held invalid or unenforceable under
+any particular circumstance, the balance of the section is intended to
+apply and the section as a whole is intended to apply in other
+circumstances.
 
-  Notwithstanding any other provision of this License, you have
-permission to link or combine any covered work with a work licensed
-under version 3 of the GNU Affero General Public License into a single
-combined work, and to convey the resulting work.  The terms of this
-License will continue to apply to the part which is the covered work,
-but the special requirements of the GNU Affero General Public License,
-section 13, concerning interaction through a network will apply to the
-combination as such.
+It is not the purpose of this section to induce you to infringe any
+patents or other property right claims or to contest validity of any
+such claims; this section has the sole purpose of protecting the
+integrity of the free software distribution system, which is
+implemented by public license practices.  Many people have made
+generous contributions to the wide range of software distributed
+through that system in reliance on consistent application of that
+system; it is up to the author/donor to decide if he or she is willing
+to distribute software through any other system and a licensee cannot
+impose that choice.
 
-  14. Revised Versions of this License.
+This section is intended to make thoroughly clear what is believed to
+be a consequence of the rest of this License.
 
-  The Free Software Foundation may publish revised and/or new versions of
-the GNU General Public License from time to time.  Such new versions will
+  8. If the distribution and/or use of the Program is restricted in
+certain countries either by patents or by copyrighted interfaces, the
+original copyright holder who places the Program under this License
+may add an explicit geographical distribution limitation excluding
+those countries, so that distribution is permitted only in or among
+countries not thus excluded.  In such case, this License incorporates
+the limitation as if written in the body of this License.
+
+  9. The Free Software Foundation may publish revised and/or new versions
+of the General Public License from time to time.  Such new versions will
 be similar in spirit to the present version, but may differ in detail to
 address new problems or concerns.
 
-  Each version is given a distinguishing version number.  If the
-Program specifies that a certain numbered version of the GNU General
-Public License "or any later version" applies to it, you have the
-option of following the terms and conditions either of that numbered
-version or of any later version published by the Free Software
-Foundation.  If the Program does not specify a version number of the
-GNU General Public License, you may choose any version ever published
-by the Free Software Foundation.
+Each version is given a distinguishing version number.  If the Program
+specifies a version number of this License which applies to it and "any
+later version", you have the option of following the terms and conditions
+either of that version or of any later version published by the Free
+Software Foundation.  If the Program does not specify a version number of
+this License, you may choose any version ever published by the Free Software
+Foundation.
 
-  If the Program specifies that a proxy can decide which future
-versions of the GNU General Public License can be used, that proxy's
-public statement of acceptance of a version permanently authorizes you
-to choose that version for the Program.
+  10. If you wish to incorporate parts of the Program into other free
+programs whose distribution conditions are different, write to the author
+to ask for permission.  For software which is copyrighted by the Free
+Software Foundation, write to the Free Software Foundation; we sometimes
+make exceptions for this.  Our decision will be guided by the two goals
+of preserving the free status of all derivatives of our free software and
+of promoting the sharing and reuse of software generally.
 
-  Later license versions may give you additional or different
-permissions.  However, no additional obligations are imposed on any
-author or copyright holder as a result of your choosing to follow a
-later version.
+                            NO WARRANTY
 
-  15. Disclaimer of Warranty.
+  11. BECAUSE THE PROGRAM IS LICENSED FREE OF CHARGE, THERE IS NO WARRANTY
+FOR THE PROGRAM, TO THE EXTENT PERMITTED BY APPLICABLE LAW.  EXCEPT WHEN
+OTHERWISE STATED IN WRITING THE COPYRIGHT HOLDERS AND/OR OTHER PARTIES
+PROVIDE THE PROGRAM "AS IS" WITHOUT WARRANTY OF ANY KIND, EITHER EXPRESSED
+OR IMPLIED, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
+MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.  THE ENTIRE RISK AS
+TO THE QUALITY AND PERFORMANCE OF THE PROGRAM IS WITH YOU.  SHOULD THE
+PROGRAM PROVE DEFECTIVE, YOU ASSUME THE COST OF ALL NECESSARY SERVICING,
+REPAIR OR CORRECTION.
 
-  THERE IS NO WARRANTY FOR THE PROGRAM, TO THE EXTENT PERMITTED BY
-APPLICABLE LAW.  EXCEPT WHEN OTHERWISE STATED IN WRITING THE COPYRIGHT
-HOLDERS AND/OR OTHER PARTIES PROVIDE THE PROGRAM "AS IS" WITHOUT WARRANTY
-OF ANY KIND, EITHER EXPRESSED OR IMPLIED, INCLUDING, BUT NOT LIMITED TO,
-THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
-PURPOSE.  THE ENTIRE RISK AS TO THE QUALITY AND PERFORMANCE OF THE PROGRAM
-IS WITH YOU.  SHOULD THE PROGRAM PROVE DEFECTIVE, YOU ASSUME THE COST OF
-ALL NECESSARY SERVICING, REPAIR OR CORRECTION.
-
-  16. Limitation of Liability.
-
-  IN NO EVENT UNLESS REQUIRED BY APPLICABLE LAW OR AGREED TO IN WRITING
-WILL ANY COPYRIGHT HOLDER, OR ANY OTHER PARTY WHO MODIFIES AND/OR CONVEYS
-THE PROGRAM AS PERMITTED ABOVE, BE LIABLE TO YOU FOR DAMAGES, INCLUDING ANY
-GENERAL, SPECIAL, INCIDENTAL OR CONSEQUENTIAL DAMAGES ARISING OUT OF THE
-USE OR INABILITY TO USE THE PROGRAM (INCLUDING BUT NOT LIMITED TO LOSS OF
-DATA OR DATA BEING RENDERED INACCURATE OR LOSSES SUSTAINED BY YOU OR THIRD
-PARTIES OR A FAILURE OF THE PROGRAM TO OPERATE WITH ANY OTHER PROGRAMS),
-EVEN IF SUCH HOLDER OR OTHER PARTY HAS BEEN ADVISED OF THE POSSIBILITY OF
-SUCH DAMAGES.
-
-  17. Interpretation of Sections 15 and 16.
-
-  If the disclaimer of warranty and limitation of liability provided
-above cannot be given local legal effect according to their terms,
-reviewing courts shall apply local law that most closely approximates
-an absolute waiver of all civil liability in connection with the
-Program, unless a warranty or assumption of liability accompanies a
-copy of the Program in return for a fee.
+  12. IN NO EVENT UNLESS REQUIRED BY APPLICABLE LAW OR AGREED TO IN WRITING
+WILL ANY COPYRIGHT HOLDER, OR ANY OTHER PARTY WHO MAY MODIFY AND/OR
+REDISTRIBUTE THE PROGRAM AS PERMITTED ABOVE, BE LIABLE TO YOU FOR DAMAGES,
+INCLUDING ANY GENERAL, SPECIAL, INCIDENTAL OR CONSEQUENTIAL DAMAGES ARISING
+OUT OF THE USE OR INABILITY TO USE THE PROGRAM (INCLUDING BUT NOT LIMITED
+TO LOSS OF DATA OR DATA BEING RENDERED INACCURATE OR LOSSES SUSTAINED BY
+YOU OR THIRD PARTIES OR A FAILURE OF THE PROGRAM TO OPERATE WITH ANY OTHER
+PROGRAMS), EVEN IF SUCH HOLDER OR OTHER PARTY HAS BEEN ADVISED OF THE
+POSSIBILITY OF SUCH DAMAGES.
 
                      END OF TERMS AND CONDITIONS
 
@@ -628,15 +287,15 @@ free software which everyone can redistribute and change under these terms.
 
   To do so, attach the following notices to the program.  It is safest
 to attach them to the start of each source file to most effectively
-state the exclusion of warranty; and each file should have at least
+convey the exclusion of warranty; and each file should have at least
 the "copyright" line and a pointer to where the full notice is found.
 
     <one line to give the program's name and a brief idea of what it does.>
     Copyright (C) <year>  <name of author>
 
-    This program is free software: you can redistribute it and/or modify
+    This program is free software; you can redistribute it and/or modify
     it under the terms of the GNU General Public License as published by
-    the Free Software Foundation, either version 3 of the License, or
+    the Free Software Foundation; either version 2 of the License, or
     (at your option) any later version.
 
     This program is distributed in the hope that it will be useful,
@@ -644,31 +303,37 @@ the "copyright" line and a pointer to where the full notice is found.
     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
     GNU General Public License for more details.
 
-    You should have received a copy of the GNU General Public License
-    along with this program.  If not, see <http://www.gnu.org/licenses/>.
+    You should have received a copy of the GNU General Public License along
+    with this program; if not, write to the Free Software Foundation, Inc.,
+    51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
 
 Also add information on how to contact you by electronic and paper mail.
 
-  If the program does terminal interaction, make it output a short
-notice like this when it starts in an interactive mode:
+If the program is interactive, make it output a short notice like this
+when it starts in an interactive mode:
 
-    <program>  Copyright (C) <year>  <name of author>
-    This program comes with ABSOLUTELY NO WARRANTY; for details type `show w'.
+    Gnomovision version 69, Copyright (C) year name of author
+    Gnomovision comes with ABSOLUTELY NO WARRANTY; for details type `show w'.
     This is free software, and you are welcome to redistribute it
     under certain conditions; type `show c' for details.
 
 The hypothetical commands `show w' and `show c' should show the appropriate
-parts of the General Public License.  Of course, your program's commands
-might be different; for a GUI interface, you would use an "about box".
+parts of the General Public License.  Of course, the commands you use may
+be called something other than `show w' and `show c'; they could even be
+mouse-clicks or menu items--whatever suits your program.
 
-  You should also get your employer (if you work as a programmer) or school,
-if any, to sign a "copyright disclaimer" for the program, if necessary.
-For more information on this, and how to apply and follow the GNU GPL, see
-<http://www.gnu.org/licenses/>.
+You should also get your employer (if you work as a programmer) or your
+school, if any, to sign a "copyright disclaimer" for the program, if
+necessary.  Here is a sample; alter the names:
 
-  The GNU General Public License does not permit incorporating your program
-into proprietary programs.  If your program is a subroutine library, you
-may consider it more useful to permit linking proprietary applications with
-the library.  If this is what you want to do, use the GNU Lesser General
-Public License instead of this License.  But first, please read
-<http://www.gnu.org/philosophy/why-not-lgpl.html>.
+  Yoyodyne, Inc., hereby disclaims all copyright interest in the program
+  `Gnomovision' (which makes passes at compilers) written by James Hacker.
+
+  <signature of Ty Coon>, 1 April 1989
+  Ty Coon, President of Vice
+
+This General Public License does not permit incorporating your program into
+proprietary programs.  If your program is a subroutine library, you may
+consider it more useful to permit linking proprietary applications with the
+library.  If this is what you want to do, use the GNU Lesser General
+Public License instead of this License.

Containerfile.alpine

@@ -0,0 +1,23 @@
+FROM alpine
+WORKDIR /build
+RUN apk add git make gcc libc-dev musl-dev glib-static gettext eudev-dev \
+	linux-headers automake autoconf cmake meson ninja clang go-md2man
+
+RUN git clone https://github.com/libfuse/libfuse -b fuse-3.16.2 && \
+    cd libfuse && \
+    mkdir build && \
+    cd build && \
+    LDFLAGS="-lpthread -s -w -static" meson --prefix /usr -D default_library=static .. && \
+    ninja && \
+    ninja install
+
+COPY . /build/fuse-overlayfs
+RUN cd fuse-overlayfs && \
+    ./autogen.sh && \
+    LIBS="-ldl" LDFLAGS="-s -w -static" ./configure --prefix /usr && \
+    make clean && \
+    make && \
+    make install
+
+USER nobody
+ENTRYPOINT ["/usr/bin/fuse-overlayfs","-f"]

Containerfile.cross

@@ -0,0 +1,42 @@
+# Usage:
+# docker buildx build \
+#   -o /tmp/fuse-overlayfs-builds \
+#   --build-arg SOURCE_DATE_EPOCH=$(git log -1 --pretty=%ct) \
+#   --platform=amd64,arm64,arm,s390x,ppc64le,riscv64 \
+#   -f Containerfile.cross .
+FROM --platform=$BUILDPLATFORM tonistiigi/xx:1.2.1 AS xx
+FROM --platform=$BUILDPLATFORM ubuntu:jammy-20230804 AS fuse-overlayfs
+ADD --chmod=0755 \
+  https://raw.githubusercontent.com/reproducible-containers/repro-sources-list.sh/v0.1.0/repro-sources-list.sh \
+  /usr/local/bin/repro-sources-list.sh
+RUN \
+  --mount=type=cache,target=/var/cache/apt,sharing=locked \
+  --mount=type=cache,target=/var/lib/apt,sharing=locked \
+  repro-sources-list.sh && \
+  apt-get update && \
+  apt-get install --no-install-recommends -y \
+  git make automake autoconf pkgconf file go-md2man
+# Set SOURCE_DATE_EPOCH after running repro-sources-list.sh, for cache efficiency
+ARG SOURCE_DATE_EPOCH
+COPY . /fuse-overlayfs
+WORKDIR /fuse-overlayfs
+COPY --from=xx / /
+ARG TARGETPLATFORM
+ENV DEBIAN_FRONTEND=noninteractive
+# xx-apt-get cannot be used, as it clobbers /etc/apt/sources.list created by repro-sources-list.sh
+RUN \
+  --mount=type=cache,target=/var/cache/apt,sharing=locked \
+  --mount=type=cache,target=/var/lib/apt,sharing=locked \
+  darch="$(xx-info debian-arch)" && \
+  dpkg --add-architecture ${darch} && \
+  apt-get update && \
+  gcc="gcc" && \
+  if xx-info is-cross; then gcc="gcc-$(xx-info triple)"; fi; \
+  apt-get install -y "${gcc}" "libfuse3-dev:${darch}"
+RUN ./autogen.sh && \
+  LIBS="-ldl" LDFLAGS="-static" ./configure --host=$(xx-info) && \
+  make && mkdir /out && cp fuse-overlayfs /out && \
+  file /out/fuse-overlayfs | grep "statically linked"
+
+FROM scratch
+COPY --from=fuse-overlayfs /out/fuse-overlayfs /fuse-overlayfs

Containerfile.static.fedora

@@ -3,7 +3,7 @@ WORKDIR /build
 RUN dnf update -y && \
     dnf install -y git make automake autoconf gcc glibc-static meson ninja-build clang
 
-RUN git clone https://github.com/libfuse/libfuse && \
+RUN git clone https://github.com/libfuse/libfuse -b fuse-3.16.2 && \
     cd libfuse && \
     mkdir build && \
     cd build && \

Containerfile.static.ubuntu

@@ -0,0 +1,11 @@
+FROM docker.io/ubuntu:rolling
+WORKDIR /build
+RUN apt-get update && \
+    apt-get install --no-install-recommends -y \
+        libc6-dev gcc g++ make automake autoconf clang pkgconf libfuse3-dev
+
+RUN cd fuse-overlayfs && \
+    sh autogen.sh && \
+    LIBS="-ldl" LDFLAGS="-static" ./configure --prefix /usr && \
+    make
+

Makefile.am

@@ -4,21 +4,23 @@ bin_PROGRAMS = fuse-overlayfs
 
 ACLOCAL_AMFLAGS = -Im4
 
-EXTRA_DIST = m4/gnulib-cache.m4 rpm/fuse-overlayfs.spec.template autogen.sh fuse-overlayfs.1.md utils.h
+EXTRA_DIST = m4/gnulib-cache.m4 rpm/fuse-overlayfs.spec.template autogen.sh fuse-overlayfs.1.md utils.h NEWS tests/suid-test.c plugin.h plugin-manager.h fuse-overlayfs.h fuse_overlayfs_error.h
 
-CLEANFILES = fuse-overlayfs.1
+AM_CPPFLAGS = -DPKGLIBEXECDIR='"$(pkglibexecdir)"'
 
 fuse_overlayfs_CFLAGS = -I . -I $(abs_srcdir)/lib $(FUSE_CFLAGS)
 fuse_overlayfs_LDFLAGS =
 fuse_overlayfs_LDADD = lib/libgnu.a $(FUSE_LIBS)
-fuse_overlayfs_SOURCES = main.c
+fuse_overlayfs_SOURCES = main.c direct.c utils.c plugin-manager.c
 
 WD := $(shell pwd)
 
 man1_MANS = fuse-overlayfs.1
 
 fuse-overlayfs.1:
+if HAVE_MD2MAN
 	go-md2man -in $(abs_srcdir)/fuse-overlayfs.1.md -out fuse-overlayfs.1
+endif HAVE_MD2MAN
 
 generate-man: fuse-overlayfs.1
 
@@ -34,3 +36,6 @@ srpm: dist-gzip fuse-overlayfs.spec
 	echo $(VERSION)
 	$(MAKE) -C $(WD) dist-xz
 	rpmbuild -bs --define "_sourcedir $(WD)" --define "_specdir $(WD)" --define "_builddir $(WD)" --define "_srcrpmdir $(WD)" --define "_rpmdir $(WD)" --define "_buildrootdir $(WD)/.build" fuse-overlayfs.spec
+
+clang-format:
+	git ls-files | grep -E "\\.[hc]$$" | grep -v "^lib/" | xargs clang-format -style=file -i

NEWS

@@ -0,0 +1,217 @@
+* fuse-overlayfs-1.15
+
+- main: lookup upperdir only for created directories.
+- main: allow escaped colons in directory paths.
+- main: use extended override xattr to support devices.
+- remove unsupported option "lazytime".
+
+* fuse-overlayfs-1.14
+
+- isolate security xattrs for STAT_OVERRIDE_CONTAINERS.  Prefix all
+  security xattrs with XATTR_CONTAINERS_OVERRIDE_PREFIX.
+- prefer user.containers.override_stat over user.fuseoverlayfs.
+- do not force -1 for owner overriding extended attributes.  Otherwise
+  the value is written to the override extended attribute.
+- fix file owner retrieval for chmod.
+- honor umask with xattr_permissions.
+- honor mode for devices with xattr_permissions.
+- propagate extended attributes permissions with copyup.
+
+* fuse-overlayfs-1.13
+
+- fix a performance issue when dealing with big directories.
+
+* fuse-overlayfs-1.12
+
+- change license to GPL-2.0-or-later.
+
+- main: if a lower layer doesn't support ACLs do not enable them.
+
+* fuse-overlayfs-1.11
+
+- main: if a lower layer doesn't support ACLs do not enable them.
+
+* fuse-overlayfs-1.10
+
+- main: use /proc/self/fd to read xattrs.
+- main: inherit ACLs for new files/dirs.
+- main: fix passing noatime.
+- main: add checks for valid /proc mount.
+- main: fix copy_file_range for deleted files.
+- main: fix creating links of just deleted files.
+
+* fuse-overlayfs-1.9
+
+- main: fix setting attributes on file without permissions.
+- main: ignore EOVERFLOW when copying xattrs.
+- main: set the correct value for RENAME_NOREPLACE when it is not already
+  defined in the system headers.
+- main: create source whiteout only when needed
+- main: fix missing source whiteout when destination is whiteout
+
+* fuse-overlayfs-1.8.2
+
+- main: fix lookup if underlying path is a symlink, but a directory on
+  a upper directory.
+
+* fuse-overlayfs-1.8.1
+
+- main: fix race when looking up an inode that was renamed.
+- main: fix type used for ioctl.
+
+* fuse-overlayfs-1.8
+
+- main: honor user.overlay. xattrs.  Native overlay uses user.overlay
+  to store the overlay metadata instead of trusted.overlay, let's
+  honor it as well.
+- main: add a mount flag to disable ACLs.
+
+* fuse-overlayfs-1.7.1
+
+- set FUSE_CAP_POSIX_ACL only when it is supported by FUSE.
+- treat statx failure with EINVAL as ENOSYS, so that the fallback
+  is attempted.
+
+* fuse-overlayfs-1.7
+
+- fix read xattrs for device files
+- don't create whiteout files in opaque dirs.
+- fix reading files when running with euid != 0.
+- enable POSIX ACLs.
+
+* fuse-overlayfs-1.6
+
+- fix an invalid access when filtering internal xattrs that could
+  deal to a segfault.
+
+* fuse-overlayfs-1.5
+
+- honor FUSE_OVERLAYFS_DISABLE_OVL_WHITEOUT also for renames
+- use strncpy instead of strcpy
+- fix renameat2(RENAME_NOREPLACE) on older kernels that lack
+  device whiteouts for unprivileged users.
+- fix creating a symlink on top of a removed file.
+- fix copyup of xattrs longer than 256 bytes.
+
+* fuse-overlayfs-1.4
+
+- add squash_to_uid and squash_to_gid
+
+* fuse-overlayfs-1.3
+
+- add squash_to_root mount option.
+- honor option "volatile".
+- when writing mode to xattr, create files with mode 0755.
+- support ID mapping when using xattr permissions.
+- allow opening not accessible but still referenced files.
+- invalidate directory cache on create/rename.
+
+* fuse-overlayfs-1.2
+
+- fix segfault if no mountpoint specified
+- fix file_exists_at musl compatibility
+- introduce extended attribute to override gid/uid/mode.
+- support writing uid/gid/mode to an extended attribute.
+- fix a memory leak, where inodes are maintained in memory even if not needed.
+
+* fuse-overlayfs-1.1.2
+
+- fix build issues with libmusl.
+- fix memory leak when creating whiteout files.
+
+* fuse-overlayfs-1.1.1
+
+- fix lookup for overflow uid when it is different than the overflow gid.
+
+* fuse-overlayfs-1.1.0
+
+- use openat2(2) when available.
+- accept "ro" as mount option.
+- fix set mtime for a symlink.
+- fix some issues reported by static analysis.
+- fix potential infinite loop on a short read.
+- fix creating a directory if the destination already exists in the upper layer.
+
+* fuse-overlayfs-1.0.0
+
+- fix portability issue to 32 bits archs.
+
+* fuse-overlayfs-0.7.8
+
+- report correctly the number of links for a directory also for subsequent stat calls.
+- stop looking up the ino in the lower layers if the file could not be opened.
+
+* fuse-overlayfs-0.7.7
+
+- make sure the destination is deleted before doing a rename(2).  It prevents a left
+  over directory to cause delete to fail with EEXIST.
+- honor --debug.
+
+* fuse-overlayfs-0.7.6
+
+- do not look in lower layers for the ino if there is no origin xattr set.
+- attempt to use the file path if the operation on the fd fails with ENXIO.
+
+* fuse-overlayfs-0.7.5
+
+- do not expose internal xattrs through listxattr and getxattr.
+
+* fuse-overlayfs-0.7.4
+
+- fix fallocate for deleted files.
+- ignore O_DIRECT.  It causes issues with libfuse not using an aligned buffer, causing
+  write(2) to fail with EINVAL.
+- on copyup, do not copy the opaque xattr.
+- fix a wrong lookup for whiteout files, that could happen on a double unlink.
+
+* fuse-overlayfs-0.7.3
+
+- fix build with -fno-common
+- fix possible segmentation fault in direct_fsync()
+- use the data store to create missing whiteouts.
+- after a rename, force a directory reload.
+
+* fuse-overlayfs-0.7.2
+
+- drop special handling for security.capability.
+
+* fuse-overlayfs-0.7.1
+
+- fix an issue where a whiteout in the parent directory could hide
+  files in the sub directories.
+
+* fuse-overlayfs-0.7
+
+- plugins support.  It allows to read the lower layers from a different data source.
+- support running without an upper layer in read only mode.
+- honor opaque whiteouts.
+
+* fuse-overlayfs-0.6.5
+
+- stat reports correctly the number of links for a directory.
+
+* fuse-overlayfs-0.6.4
+
+- do not lose the setuid bit after a write when the writeback cache is used.
+- skip creating a whiteout if the node is present only on the upper layer.
+
+* fuse-overlayfs-0.6.3
+
+- correctly delete an existing whiteout when the file is recreated (regression introduced with 0.5).
+- fix ioctl on directories.
+
+* fuse-overlayfs-0.6.2
+
+- avoid ino lookup if not necessary.
+- include st_dev in the hash key.  Now the same inode number can be safely used by lower
+  directories on different file systems.
+
+* fuse-overlayfs-0.6.1
+
+- fix a regression introduced with 0.6 where UNIX sockets could not be correctly created.
+
+* fuse-overlayfs-0.6
+
+- fix an issue where changes to an inode would not be visible from another hard link.
+  The issue was always present but was made easier to reproduce with fuse-overlayfs 0.5
+  that enables FUSE writeback by default.

README.md

@@ -3,12 +3,6 @@ fuse-overlayfs
 
 An implementation of overlay+shiftfs in FUSE for rootless containers.
 
-Limitations:
-=======================================================
-
-Read-only mode is not supported, so it is always required to specify
-an upperdir and a workingdir.
-
 Usage:
 =======================================================
 
@@ -22,16 +16,43 @@ Specify a different UID/GID mapping:
 $ fuse-overlayfs -o uidmapping=0:10:100:100:10000:2000,gidmapping=0:10:100:100:10000:2000,lowerdir=lowerdir/a:lowerdir/b,upperdir=up,workdir=workdir merged
 ```
 
-Build Requirements:
+Requirements:
 =======================================================
 
-fuse-overlayfs requires libfuse > v3.2.1
+If you are not using the static build as explained in the next chapter, your system needs `libfuse` > v3.2.1.
 
-On Fedora: `dnf install fuse3-devel`
+* On Fedora: `dnf install fuse3-devel`
+* On Ubuntu > v19.04: `apt install libfuse3-dev`
+
+Also, please note that, when using `fuse-overlayfs` **from a user namespace** 
+(for example, when using rootless `podman`) a Linux Kernel > v4.18.0 is required.
 
 
 Static Build:
 =======================================================
 
-`buildah bud -t fuse-overlayfs -f ./Dockerfile.static .`
+This project provides a convenient way to automatically perform a static build using a container.
+The result is a self-contained binary without dependencies, that can be copied across hosts.
+
+1. Install `buildah` as explained [here](https://github.com/containers/buildah/blob/master/install.md);
+
+2. Both the build and deploy host require the special device `/dev/fuse`; there are a few ways to obtain it:
+
+  * install `fuse2` or `fuse3` using the package manager of your choice (dnf, apt, pacman, etc): 
+the install script will usually create the device automatically; or
+  * manually create the device with the command `mknod /dev/fuse -m 0666 c 10 229` 
+(see [this code](https://github.com/libfuse/libfuse/blob/f0e08cc700d629da2d46def8b620b0ed858cc0d9/util/install_helper.sh#L35))
+
+3. Clone this repository, and switch to the top-level folder containing the file "`Containerfile.static.ubuntu`";
+
+4. Launch the build with the command (note the single dot `.` at the end): 
+```
+buildah bud -v $PWD:/build/fuse-overlayfs -t fuse-overlayfs -f ./Containerfile.static.ubuntu .
+```
+
+5. Copy the resulting binary to your host:
+
+```
+sudo cp fuse-overlayfs /usr/bin/
+```
 

SECURITY.md

@@ -0,0 +1,3 @@
+## Security and Disclosure Information Policy for the fuse-overlayfs Project
+
+The fuse-overlayfs Project follows the [Security and Disclosure Information Policy](https://github.com/containers/common/blob/master/SECURITY.md) for the Containers Projects.

configure.ac

@@ -1,5 +1,5 @@
 AC_PREREQ([2.69])
-AC_INIT([fuse-overlayfs], [0.4.1], [giuseppe@scrivano.org])
+AC_INIT([fuse-overlayfs], [1.16-dev], [giuseppe@scrivano.org])
 AC_CONFIG_SRCDIR([main.c])
 AC_CONFIG_HEADERS([config.h])
 
@@ -28,11 +28,57 @@ AC_TYPE_UINT64_T
 AC_TYPE_UINT8_T
 AC_CHECK_TYPES([ptrdiff_t])
 
-PKG_CHECK_MODULES([FUSE], [fuse3 >= 3.2.1], [AC_DEFINE([HAVE_FUSE], 1, [Define if libfuse is available])], [AC_MSG_ERROR([*** libfuse not found])]])
+AC_DEFINE([USE_DIFF_HASH], 1, [Use the same hashing function as GNU diff])
+
+PKG_CHECK_MODULES([FUSE], [fuse3 >= 3.2.1], [AC_DEFINE([HAVE_FUSE], 1, [Define if libfuse3 is available])], [AC_MSG_ERROR([*** libfuse3 not found])]])
+
+old_CFLAGS=$CFLAGS
+old_LDFLAGS=$LDFLAGS
+CFLAGS=$pkg_cv_FUSE_CFLAGS
+LDFLAGS=$pkg_cv_FUSE_LDFLAGS
+AC_COMPILE_IFELSE(
+[
+AC_LANG_SOURCE([
+#define FUSE_USE_VERSION 32
+#include <fuse_lowlevel.h>
+void foo()
+{
+        struct fuse_file_info fi;
+        fi.cache_readdir = 1;
+}])
+],
+[cache_readdir=1],
+[cache_readdir=0])
+
+
+AC_COMPILE_IFELSE(
+[
+AC_LANG_SOURCE([
+#define FUSE_USE_VERSION 32
+#include <fuse_lowlevel.h>
+void foo()
+{
+        struct fuse_lowlevel_ops ops;
+        ops.copy_file_range = 0;
+}])
+],
+[fuse_has_copy_file_range=1],
+[fuse_has_copy_file_range=0])
+
+
+CFLAGS=$old_CFLAGS
+LDFLAGS=$old_LDFLAGS
+
+AC_PATH_PROG(MD2MAN, go-md2man)
+AM_CONDITIONAL([HAVE_MD2MAN], [test "x$ac_cv_path_MD2MAN" != x])
+
+AC_DEFINE_UNQUOTED([HAVE_FUSE_CACHE_READDIR], $cache_readdir, [Define if libfuse cache_readdir is available])
+AC_DEFINE_UNQUOTED([HAVE_FUSE_COPY_FILE_RANGE], $fuse_has_copy_file_range, [Define if libfuse has copy_file_range is available])
+
+AC_SEARCH_LIBS([dlopen], [dl], [], [AC_MSG_ERROR([unable to find dlopen()])])
 
 AC_FUNC_ERROR_AT_LINE
-AC_FUNC_MALLOC
-AC_CHECK_FUNCS([open_by_handle_at error memset strdup])
+AC_CHECK_FUNCS([malloc open_by_handle_at error memset strdup copy_file_range statx])
 
 AC_CONFIG_FILES([Makefile lib/Makefile])
 AC_OUTPUT

contrib/fix-mode.py

@@ -0,0 +1,51 @@
+#!/bin/python
+
+import os
+import sys
+import stat
+import errno
+
+XATTR_OVERRIDE_STAT_PRIVILEGED = "security.fuseoverlayfs.override_stat"
+XATTR_OVERRIDE_CONTAINERS_STAT = "user.fuseoverlayfs.override_stat"
+
+if os.geteuid() == 0:
+    xattr_name = XATTR_OVERRIDE_STAT_PRIVILEGED
+else:
+    xattr_name = XATTR_OVERRIDE_CONTAINERS_STAT
+
+cwd_fd = os.open(".", os.O_PATH)
+
+def fix_path(path):
+    st = os.lstat(path)
+    content = "%s:%s:%o" % (st.st_uid, st.st_gid,  stat.S_IMODE(st.st_mode))
+
+    try:
+        os.setxattr(path, xattr_name, str.encode(content), flags=os.XATTR_CREATE, follow_symlinks=False)
+    except Exception as e:
+        if e.errno == errno.EEXIST:
+            print("attr %s already present for %s: %s" % (xattr_name, path, e.errno))
+            return
+        raise e
+
+    fd = os.open(path, os.O_PATH|os.O_NOFOLLOW|os.O_NONBLOCK)
+    try:
+        proc_path = "/proc/self/fd/%d" % fd
+        os.chmod(proc_path, 0o755)
+    except Exception as e:
+        if e.errno != errno.ENOTSUP:
+            raise e
+    finally:
+        os.close(fd)
+
+
+def fix_mode_directory(d):
+    for root, dirs, files in os.walk(d, topdown=False):
+        for i in dirs+files:
+            path = os.path.join(root, i)
+            fix_path(path)
+    fix_path(d)
+
+for i in sys.argv[1:]:
+    fix_mode_directory(i)
+
+        

direct.c

@@ -0,0 +1,233 @@
+/* fuse-overlayfs: Overlay Filesystem in Userspace
+
+   Copyright (C) 2018 Giuseppe Scrivano <giuseppe@scrivano.org>
+   Copyright (C) 2018-2019 Red Hat Inc.
+   Copyright (C) 2001-2007  Miklos Szeredi <miklos@szeredi.hu>
+
+   This program is free software: you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation; either version 2 of the License, or
+   (at your option) any later version.
+
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with this program.  If not, see <http://www.gnu.org/licenses/>.
+*/
+
+#define _GNU_SOURCE
+#define _FILE_OFFSET_BITS 64
+
+#include <config.h>
+
+#include "fuse-overlayfs.h"
+
+#include "limits.h"
+#include <unistd.h>
+#include <fcntl.h>
+#include <errno.h>
+
+#include <sys/xattr.h>
+
+#include "utils.h"
+
+static int
+direct_file_exists (struct ovl_layer *l, const char *pathname)
+{
+  return file_exists_at (l->fd, pathname);
+}
+
+static int
+direct_listxattr (struct ovl_layer *l, const char *path, char *buf, size_t size)
+{
+  char full_path[PATH_MAX];
+  int ret;
+  ret = snprintf (full_path, sizeof (full_path), "/proc/self/fd/%d/%s", l->fd, path);
+  if (ret >= sizeof (full_path))
+    {
+      errno = ENAMETOOLONG;
+      return -1;
+    }
+
+  return llistxattr (full_path, buf, size);
+}
+
+static int
+direct_getxattr (struct ovl_layer *l, const char *path, const char *name, char *buf, size_t size)
+{
+  char full_path[PATH_MAX];
+  int ret;
+  ret = snprintf (full_path, sizeof (full_path), "/proc/self/fd/%d/%s", l->fd, path);
+  if (ret >= sizeof (full_path))
+    {
+      errno = ENAMETOOLONG;
+      return -1;
+    }
+  return lgetxattr (full_path, name, buf, size);
+}
+
+static int
+direct_fstat (struct ovl_layer *l, int fd, const char *path, unsigned int mask, struct stat *st)
+{
+  int ret;
+#ifdef HAVE_STATX
+  struct statx stx;
+
+  ret = statx (fd, "", AT_STATX_DONT_SYNC | AT_EMPTY_PATH, mask, &stx);
+  if (ret < 0 && (errno == ENOSYS || errno == EINVAL))
+    goto fallback;
+  if (ret == 0)
+    {
+      statx_to_stat (&stx, st);
+      return override_mode (l, fd, NULL, path, st);
+    }
+
+  return ret;
+#endif
+
+fallback:
+  ret = fstat (fd, st);
+  if (ret != 0)
+    return ret;
+
+  return override_mode (l, fd, NULL, path, st);
+}
+
+static int
+direct_statat (struct ovl_layer *l, const char *path, struct stat *st, int flags, unsigned int mask)
+{
+  int ret;
+#ifdef HAVE_STATX
+  struct statx stx;
+
+  ret = statx (l->fd, path, AT_STATX_DONT_SYNC | flags, mask, &stx);
+  if (ret < 0 && (errno == ENOSYS || errno == EINVAL))
+    goto fallback;
+  if (ret == 0)
+    {
+      statx_to_stat (&stx, st);
+      return override_mode (l, -1, NULL, path, st);
+    }
+
+  return ret;
+#endif
+fallback:
+  ret = fstatat (l->fd, path, st, flags);
+  if (ret != 0)
+    return ret;
+
+  return override_mode (l, -1, NULL, path, st);
+}
+
+static struct dirent *
+direct_readdir (void *dirp)
+{
+  return readdir (dirp);
+}
+
+static void *
+direct_opendir (struct ovl_layer *l, const char *path)
+{
+  cleanup_close int cleanup_fd = -1;
+  DIR *dp = NULL;
+
+  cleanup_fd = TEMP_FAILURE_RETRY (safe_openat (l->fd, path, O_DIRECTORY, 0));
+  if (cleanup_fd < 0)
+    return NULL;
+
+  dp = fdopendir (cleanup_fd);
+  if (dp == NULL)
+    return NULL;
+
+  cleanup_fd = -1;
+
+  return dp;
+}
+
+static int
+direct_closedir (void *dirp)
+{
+  return closedir (dirp);
+}
+
+static int
+direct_openat (struct ovl_layer *l, const char *path, int flags, mode_t mode)
+{
+  return TEMP_FAILURE_RETRY (safe_openat (l->fd, path, flags, mode));
+}
+
+static ssize_t
+direct_readlinkat (struct ovl_layer *l, const char *path, char *buf, size_t bufsiz)
+{
+  return TEMP_FAILURE_RETRY (readlinkat (l->fd, path, buf, bufsiz));
+}
+
+static int
+direct_load_data_source (struct ovl_layer *l, const char *opaque, const char *path, int n_layer)
+{
+  char tmp[64];
+  l->path = realpath (path, NULL);
+  if (l->path == NULL)
+    {
+      fprintf (stderr, "cannot resolve path %s\n", path);
+      return -1;
+    }
+
+  l->fd = open (path, O_DIRECTORY);
+  if (l->fd < 0)
+    {
+      free (l->path);
+      l->path = NULL;
+      return l->fd;
+    }
+
+  if (fgetxattr (l->fd, XATTR_PRIVILEGED_OVERRIDE_STAT, tmp, sizeof (tmp)) >= 0)
+    l->stat_override_mode = STAT_OVERRIDE_PRIVILEGED;
+  else if (fgetxattr (l->fd, XATTR_OVERRIDE_CONTAINERS_STAT, tmp, sizeof (tmp)) >= 0)
+    l->stat_override_mode = STAT_OVERRIDE_CONTAINERS;
+  else if (fgetxattr (l->fd, XATTR_OVERRIDE_STAT, tmp, sizeof (tmp)) >= 0)
+    l->stat_override_mode = STAT_OVERRIDE_USER;
+
+  return 0;
+}
+
+static int
+direct_cleanup (struct ovl_layer *l)
+{
+  return 0;
+}
+
+static int
+direct_num_of_layers (const char *opaque, const char *path)
+{
+  return 1;
+}
+
+static bool
+direct_support_acls (struct ovl_layer *l)
+{
+  char value[32];
+
+  return fgetxattr (l->fd, ACL_XATTR, value, sizeof (value)) >= 0
+         || errno != ENOTSUP;
+}
+
+struct data_source direct_access_ds = {
+  .num_of_layers = direct_num_of_layers,
+  .load_data_source = direct_load_data_source,
+  .cleanup = direct_cleanup,
+  .file_exists = direct_file_exists,
+  .statat = direct_statat,
+  .fstat = direct_fstat,
+  .opendir = direct_opendir,
+  .readdir = direct_readdir,
+  .closedir = direct_closedir,
+  .openat = direct_openat,
+  .getxattr = direct_getxattr,
+  .listxattr = direct_listxattr,
+  .readlinkat = direct_readlinkat,
+  .support_acls = direct_support_acls,
+};

fuse-overlayfs.1

@@ -1,60 +1,56 @@
-.TH fuse\-overlayfs 1 "User Commands"
+.nh
+.TH fuse-overlayfs 1 "User Commands"
 
 .SH NAME
 .PP
-fuse\-overlayfs \- overlayfs FUSE implementation
+fuse-overlayfs - overlayfs FUSE implementation
 
 
 .SH SYNOPSIS
 .PP
 mounting
-    fuse\-overlayfs [\-f] [\-\-debug] [\-o OPTS] MOUNT\_TARGET
+    fuse-overlayfs [-f] [--debug] [-o OPTS] MOUNT_TARGET
 
 .PP
 unmounting
-    fusermount \-u mountpoint
+    fusermount -u mountpoint
 
 
 .SH DESCRIPTION
 .PP
-fuse\-overlayfs provides an overlayfs FUSE implementation so that it
+fuse-overlayfs provides an overlayfs FUSE implementation so that it
 can be used since Linux 4.18 by unprivileged users in an user
 namespace.
 
 
 .SH OPTIONS
 .PP
-\fB\-\-debug\fP
+\fB--debug\fP
 Enable debugging mode, can be very noisy.
 
 .PP
-\fB\-o lowerdir=low1[:low2...]\fP
+\fB-o lowerdir=low1[:low2...]\fP
 A list of directories separated by \fB\fC:\fR\&.  Their content is merged.
 
 .PP
-\fB\-o upperdir=upperdir\fP
+\fB-o upperdir=upperdir\fP
 A directory merged on top of all the lowerdirs where all the changes
 done to the file system will be written.
 
 .PP
-\fB\-o workdir=workdir\fP
-A directory used internally by fuse\-overlays, must be on the same file
+\fB-o workdir=workdir\fP
+A directory used internally by fuse-overlays, must be on the same file
 system as the upper dir.
 
 .PP
-\fB\-o workdir=workdir\fP
-A directory used internally by fuse\-overlays, must be on the same file
-system as the upper dir.
-
-.PP
-\fB\-o uidmapping=UID:MAPPED\-UID:LEN[,UID2:MAPPED\-UID2:LEN2]\fP
-\fB\-o gidmapping=GID:MAPPED\-GID:LEN[,GID2:MAPPED\-GID2:LEN2]\fP
-Specifies the dynamic UID/GID mapping used by fuse\-overlayfs when
+\fB-o uidmapping=UID:MAPPED-UID:LEN[,UID2:MAPPED-UID2:LEN2]\fP
+\fB-o gidmapping=GID:MAPPED-GID:LEN[,GID2:MAPPED-GID2:LEN2]\fP
+Specifies the dynamic UID/GID mapping used by fuse-overlayfs when
 reading/writing files to the system.
 
 .PP
-The fuse\-overlayfs dynamic mapping is an alternative and cheaper way
-to chown'ing the files on the host to accomodate the user namespace
+The fuse-overlayfs dynamic mapping is an alternative and cheaper way
+to chown'ing the files on the host to accommodate the user namespace
 settings.
 
 .PP
@@ -66,13 +62,13 @@ without requiring to chown the files.
 For example, given on the host two files like:
 
 .PP
-$ stat \-c %u:%g lower/a lower/b
+$ stat -c %u:%g lower/a lower/b
 0:0
 1:1
 
 .PP
 When we run in a user namespace with the following configuration:
-$ cat /proc/self/uid\_map
+$ cat /proc/self/uid_map
          0       1000          1
          1     110000      65536
 
@@ -80,7 +76,7 @@ $ cat /proc/self/uid\_map
 We would see:
 
 .PP
-$ stat \-c %u:%g merged/a merged/b
+$ stat -c %u:%g merged/a merged/b
 65534:65534
 65534:65534
 
@@ -90,27 +86,52 @@ user namespace.  This happens because both users 0:0 and 1:1 are not
 mapped.
 
 .PP
-In the above example, if we mount the fuse\-overlayfs file system using:
-\fB\fC\-ouidmapping=0:1000:1:1:110000:65536,gidmapping=0:1000:1:1:110000:65536\fR,
+In the above example, if we mount the fuse-overlayfs file system using:
+\fB\fC-ouidmapping=0:1000:1:1:110000:65536,gidmapping=0:1000:1:1:110000:65536\fR,
 which is the namespace configuration specified on a single line, we'd
 see from the same user namespace:
 
 .PP
-$ stat \-c %u:%g merged/a merged/b
+$ stat -c %u:%g merged/a merged/b
 0:0
 1:1
 
 .PP
 Those are the same IDs visible from outside the user namespace.
 
+.PP
+\fB-o squash_to_root\fP
+Every file and directory is owned by the root user (0:0).
+
+.PP
+\fB-o squash_to_uid=uid\fP
+\fB-o squash_to_gid=gid\fP
+Every file and directory is owned by the specified uid or gid.
+
+.PP
+It has higher precedence over \fBsquash_to_root\fP\&.
+
+.PP
+\fB-o static_nlink\fP
+Set st_nlink to the static value 1 for all directories.
+
+.PP
+This can be useful for higher latency file systems such as NFS, where
+counting the number of hard links for a directory with many files can
+be a slow operation. With this option enabled, the number of hard
+links reported when running stat for any directory is 1.
+
+.PP
+\fB-o noacl\fP
+Disable ACL support in the FUSE file system.
+
 
 .SH SEE ALSO
 .PP
-\fBfuse\fP(8), \fBmount\fP(8), \fBuser\_namespaces\fP(7)
+\fBfuse\fP(8), \fBmount\fP(8), \fBuser_namespaces\fP(7)
 
 
 .SH AVAILABILITY
 .PP
-The slirp4netns command is available from
-\fB
-\[la]https://github.com/containers/fuse-overlayfs\[ra]\fP under GNU GENERAL PUBLIC LICENSE Version 3 or later.
+The fuse-overlayfs command is available from
+\fBhttps://github.com/containers/fuse-overlayfs\fP under GNU GENERAL PUBLIC LICENSE Version 3 or later.

fuse-overlayfs.1.md

@@ -35,17 +35,13 @@ done to the file system will be written.
 A directory used internally by fuse-overlays, must be on the same file
 system as the upper dir.
 
-**-o workdir=workdir**
-A directory used internally by fuse-overlays, must be on the same file
-system as the upper dir.
-
 **-o uidmapping=UID:MAPPED-UID:LEN[,UID2:MAPPED-UID2:LEN2]**
 **-o gidmapping=GID:MAPPED-GID:LEN[,GID2:MAPPED-GID2:LEN2]**
 Specifies the dynamic UID/GID mapping used by fuse-overlayfs when
 reading/writing files to the system.
 
 The fuse-overlayfs dynamic mapping is an alternative and cheaper way
-to chown'ing the files on the host to accomodate the user namespace
+to chown'ing the files on the host to accommodate the user namespace
 settings.
 
 It is useful to share the same storage among different user namespaces
@@ -84,11 +80,31 @@ $ stat -c %u:%g merged/a merged/b
 
 Those are the same IDs visible from outside the user namespace.
 
+**-o squash_to_root**
+Every file and directory is owned by the root user (0:0).
+
+**-o squash_to_uid=uid**
+**-o squash_to_gid=gid**
+Every file and directory is owned by the specified uid or gid.
+
+It has higher precedence over **squash_to_root**.
+
+**-o static_nlink**
+Set st_nlink to the static value 1 for all directories.
+
+This can be useful for higher latency file systems such as NFS, where
+counting the number of hard links for a directory with many files can
+be a slow operation. With this option enabled, the number of hard
+links reported when running stat for any directory is 1.
+
+**-o noacl**
+Disable ACL support in the FUSE file system.
+
 # SEE ALSO
 
 **fuse**(8), **mount**(8), **user_namespaces**(7)
 
 # AVAILABILITY
 
-The slirp4netns command is available from
+The fuse-overlayfs command is available from
 **https://github.com/containers/fuse-overlayfs** under GNU GENERAL PUBLIC LICENSE Version 3 or later.

fuse-overlayfs.h

@@ -0,0 +1,181 @@
+/* fuse-overlayfs: Overlay Filesystem in Userspace
+
+   Copyright (C) 2019 Red Hat Inc.
+
+   This program is free software: you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation; either version 2 of the License, or
+   (at your option) any later version.
+
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with this program.  If not, see <http://www.gnu.org/licenses/>.
+*/
+#ifndef FUSE_OVERLAYFS_H
+#define FUSE_OVERLAYFS_H
+#define _GNU_SOURCE
+
+#include <sys/stat.h>
+#include <plugin-manager.h>
+#include <stdbool.h>
+#include <sys/types.h>
+
+#define ACL_XATTR "system.posix_acl_default"
+
+typedef struct hash_table Hash_table;
+
+struct ovl_ino
+{
+  struct ovl_node *node;
+  ino_t ino;
+  dev_t dev;
+  int lookups;
+  mode_t mode;
+};
+
+struct ovl_node
+{
+  struct ovl_node *parent;
+  Hash_table *children;
+  struct ovl_layer *layer, *last_layer;
+  ino_t tmp_ino;
+  dev_t tmp_dev;
+  char *path;
+  char *name;
+  int hidden_dirfd;
+  int node_lookups;
+  size_t name_hash;
+  Hash_table *inodes;
+  struct ovl_ino *ino;
+  struct ovl_node *next_link;
+  unsigned int in_readdir;
+
+  size_t n_links;
+
+  unsigned int do_unlink : 1;
+  unsigned int do_rmdir : 1;
+  unsigned int hidden : 1;
+  unsigned int whiteout : 1;
+  unsigned int loaded : 1;
+};
+
+struct ovl_mapping
+{
+  struct ovl_mapping *next;
+  unsigned int host;
+  unsigned int to;
+  unsigned int len;
+};
+
+struct ovl_data
+{
+  struct fuse_session *se;
+  char *uid_str;
+  char *gid_str;
+  struct ovl_mapping *uid_mappings;
+  struct ovl_mapping *gid_mappings;
+  char *mountpoint;
+  char *lowerdir;
+  char *context;
+  char *upperdir;
+  char *workdir;
+  char *redirect_dir;
+  char *plugins;
+  int workdir_fd;
+  int debug;
+  struct ovl_layer *layers;
+
+  Hash_table *inodes;
+
+  struct ovl_node *root;
+  char *timeout_str;
+  double timeout;
+  int threaded;
+  int fsync;
+  int noacl;
+  int fast_ino_check;
+  int writeback;
+  int disable_xattrs;
+  int xattr_permissions;
+  int squash_to_root;
+  int squash_to_uid;
+  int squash_to_gid;
+  int static_nlink;
+
+  int volatile_mode;
+
+  /* current uid/gid*/
+  uid_t uid;
+  uid_t gid;
+
+  /* process euid. */
+  uid_t euid;
+
+  struct ovl_plugin_context *plugins_ctx;
+};
+
+enum stat_override_mode
+{
+  STAT_OVERRIDE_NONE,
+  STAT_OVERRIDE_USER,
+  STAT_OVERRIDE_PRIVILEGED,
+  STAT_OVERRIDE_CONTAINERS,
+};
+
+struct ovl_layer
+{
+  struct ovl_layer *next;
+  struct data_source *ds;
+  struct ovl_data *ovl_data;
+  char *path;
+  int fd;
+  bool low;
+
+  void *data_source_private_data;
+  int stat_override_mode;
+};
+
+/* a data_source defines the methods for accessing a lower layer.  */
+struct data_source
+{
+  int (*num_of_layers) (const char *opaque, const char *path);
+  int (*load_data_source) (struct ovl_layer *l, const char *opaque, const char *path, int n_layer);
+  int (*cleanup) (struct ovl_layer *l);
+  int (*file_exists) (struct ovl_layer *l, const char *pathname);
+  int (*statat) (struct ovl_layer *l, const char *path, struct stat *st, int flags, unsigned int mask);
+  int (*fstat) (struct ovl_layer *l, int fd, const char *path, unsigned int mask, struct stat *st);
+  void *(*opendir) (struct ovl_layer *l, const char *path);
+  struct dirent *(*readdir) (void *dirp);
+  int (*closedir) (void *dirp);
+  int (*openat) (struct ovl_layer *l, const char *path, int flags, mode_t mode);
+  int (*listxattr) (struct ovl_layer *l, const char *path, char *buf, size_t size);
+  int (*getxattr) (struct ovl_layer *l, const char *path, const char *name, char *buf, size_t size);
+  ssize_t (*readlinkat) (struct ovl_layer *l, const char *path, char *buf, size_t bufsiz);
+  bool (*support_acls) (struct ovl_layer *l);
+};
+
+/* passthrough to the file system.  */
+extern struct data_source direct_access_ds;
+
+#ifndef HAVE_STATX
+#  define STATX_TYPE 0x00000001U        /* Want/got stx_mode & S_IFMT */
+#  define STATX_MODE 0x00000002U        /* Want/got stx_mode & ~S_IFMT */
+#  define STATX_NLINK 0x00000004U       /* Want/got stx_nlink */
+#  define STATX_UID 0x00000008U         /* Want/got stx_uid */
+#  define STATX_GID 0x00000010U         /* Want/got stx_gid */
+#  define STATX_ATIME 0x00000020U       /* Want/got stx_atime */
+#  define STATX_MTIME 0x00000040U       /* Want/got stx_mtime */
+#  define STATX_CTIME 0x00000080U       /* Want/got stx_ctime */
+#  define STATX_INO 0x00000100U         /* Want/got stx_ino */
+#  define STATX_SIZE 0x00000200U        /* Want/got stx_size */
+#  define STATX_BLOCKS 0x00000400U      /* Want/got stx_blocks */
+#  define STATX_BASIC_STATS 0x000007ffU /* The stuff in the normal stat struct */
+#  define STATX_BTIME 0x00000800U       /* Want/got stx_btime */
+#  define STATX_ALL 0x00000fffU         /* All currently supported flags */
+#endif
+
+#endif

fuse_overlayfs_error.h

@@ -0,0 +1,42 @@
+/* fuse-overlayfs: Overlay Filesystem in Userspace
+
+   Copyright (C) 2019 Red Hat Inc.
+
+   This program is free software: you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation; either version 2 of the License, or
+   (at your option) any later version.
+
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with this program.  If not, see <http://www.gnu.org/licenses/>.
+*/
+
+#ifndef FUSE_OVERLAYFS_ERROR_H
+#define FUSE_OVERLAYFS_ERROR_H
+
+#include <config.h>
+
+#ifdef HAVE_ERROR_H
+#  include <error.h>
+#else
+#  define error(status, errno, fmt, ...)                                \
+    do                                                                  \
+      {                                                                 \
+        if (errno == 0)                                                 \
+          fprintf (stderr, "fuse-overlayfs: " fmt "\n", ##__VA_ARGS__); \
+        else                                                            \
+          {                                                             \
+            fprintf (stderr, "fuse-overlayfs: " fmt, ##__VA_ARGS__);    \
+            fprintf (stderr, ": %s\n", strerror (errno));               \
+          }                                                             \
+        if (status)                                                     \
+          exit (status);                                                \
+    } while (0)
+#endif
+
+#endif

lib/Makefile.am

@@ -1,6 +1,6 @@
 ## DO NOT EDIT! GENERATED AUTOMATICALLY!
 ## Process this file with automake to produce Makefile.in.
-# Copyright (C) 2002-2017 Free Software Foundation, Inc.
+# Copyright (C) 2002-2019 Free Software Foundation, Inc.
 #
 # This file is free software; you can redistribute it and/or modify
 # it under the terms of the GNU General Public License as published by
@@ -13,7 +13,7 @@
 # GNU General Public License for more details.
 #
 # You should have received a copy of the GNU General Public License
-# along with this file.  If not, see <http://www.gnu.org/licenses/>.
+# along with this file.  If not, see <https://www.gnu.org/licenses/>.
 #
 # As a special exception to the GNU General Public License,
 # this file may be distributed as part of a program that
@@ -21,9 +21,20 @@
 # the same distribution terms as the rest of that program.
 #
 # Generated by gnulib-tool.
-# Reproduce by: gnulib-tool --import --lib=libgnu --source-base=lib --m4-base=m4 --doc-base=doc --tests-base=tests --aux-dir=. --no-conditional-dependencies --no-libtool --macro-prefix=gl hash
+# Reproduce by:
+# gnulib-tool --import \
+#  --lib=libgnu \
+#  --source-base=lib \
+#  --m4-base=m4 \
+#  --doc-base=doc \
+#  --tests-base=tests \
+#  --aux-dir=. \
+#  --no-conditional-dependencies \
+#  --no-libtool \
+#  --macro-prefix=gl \
+#  hash
 
-AUTOMAKE_OPTIONS = 1.9.6 gnits
+AUTOMAKE_OPTIONS = 1.11 gnits
 
 SUBDIRS =
 noinst_HEADERS =

lib/bitrotate.h

@@ -1,5 +1,5 @@
 /* bitrotate.h - Rotate bits in integers
-   Copyright (C) 2008-2017 Free Software Foundation, Inc.
+   Copyright (C) 2008-2019 Free Software Foundation, Inc.
 
    This program is free software: you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
@@ -12,7 +12,7 @@
    GNU General Public License for more details.
 
    You should have received a copy of the GNU General Public License
-   along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
+   along with this program.  If not, see <https://www.gnu.org/licenses/>.  */
 
 /* Written by Simon Josefsson <simon@josefsson.org>, 2008. */
 
@@ -95,7 +95,8 @@ rotr_sz (size_t x, int n)
 BITROTATE_INLINE uint16_t
 rotl16 (uint16_t x, int n)
 {
-  return ((x << n) | (x >> (16 - n))) & UINT16_MAX;
+  return (((unsigned int) x << n) | ((unsigned int) x >> (16 - n)))
+         & UINT16_MAX;
 }
 
 /* Given an unsigned 16-bit argument X, return the value corresponding
@@ -106,7 +107,8 @@ rotl16 (uint16_t x, int n)
 BITROTATE_INLINE uint16_t
 rotr16 (uint16_t x, int n)
 {
-  return ((x >> n) | (x << (16 - n))) & UINT16_MAX;
+  return (((unsigned int) x >> n) | ((unsigned int) x << (16 - n)))
+         & UINT16_MAX;
 }
 
 /* Given an unsigned 8-bit argument X, return the value corresponding
@@ -117,7 +119,7 @@ rotr16 (uint16_t x, int n)
 BITROTATE_INLINE uint8_t
 rotl8 (uint8_t x, int n)
 {
-  return ((x << n) | (x >> (8 - n))) & UINT8_MAX;
+  return (((unsigned int) x << n) | ((unsigned int) x >> (8 - n))) & UINT8_MAX;
 }
 
 /* Given an unsigned 8-bit argument X, return the value corresponding
@@ -128,7 +130,7 @@ rotl8 (uint8_t x, int n)
 BITROTATE_INLINE uint8_t
 rotr8 (uint8_t x, int n)
 {
-  return ((x >> n) | (x << (8 - n))) & UINT8_MAX;
+  return (((unsigned int) x >> n) | ((unsigned int) x << (8 - n))) & UINT8_MAX;
 }
 
 _GL_INLINE_HEADER_END

lib/hash.c

@@ -1,21 +1,21 @@
 /* hash - hashing table processing.
 
-   Copyright (C) 1998-2004, 2006-2007, 2009-2017 Free Software Foundation, Inc.
+   Copyright (C) 1998-2004, 2006-2007, 2009-2025 Free Software Foundation, Inc.
 
    Written by Jim Meyering, 1992.
 
-   This program is free software: you can redistribute it and/or modify
-   it under the terms of the GNU General Public License as published by
-   the Free Software Foundation; either version 3 of the License, or
-   (at your option) any later version.
+   This file is free software: you can redistribute it and/or modify
+   it under the terms of the GNU Lesser General Public License as
+   published by the Free Software Foundation; either version 2.1 of the
+   License, or (at your option) any later version.
 
-   This program is distributed in the hope that it will be useful,
+   This file is distributed in the hope that it will be useful,
    but WITHOUT ANY WARRANTY; without even the implied warranty of
    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
-   GNU General Public License for more details.
+   GNU Lesser General Public License for more details.
 
-   You should have received a copy of the GNU General Public License
-   along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
+   You should have received a copy of the GNU Lesser General Public License
+   along with this program.  If not, see <https://www.gnu.org/licenses/>.  */
 
 /* A generic hash table package.  */
 
@@ -29,6 +29,7 @@
 #include "bitrotate.h"
 #include "xalloc-oversized.h"
 
+#include <errno.h>
 #include <stdint.h>
 #include <stdio.h>
 #include <stdlib.h>
@@ -138,38 +139,24 @@ static const Hash_tuning default_tuning =
 
 /* Information and lookup.  */
 
-/* The following few functions provide information about the overall hash
-   table organization: the number of entries, number of buckets and maximum
-   length of buckets.  */
-
-/* Return the number of buckets in the hash table.  The table size, the total
-   number of buckets (used plus unused), or the maximum number of slots, are
-   the same quantity.  */
-
 size_t
 hash_get_n_buckets (const Hash_table *table)
 {
   return table->n_buckets;
 }
 
-/* Return the number of slots in use (non-empty buckets).  */
-
 size_t
 hash_get_n_buckets_used (const Hash_table *table)
 {
   return table->n_buckets_used;
 }
 
-/* Return the number of active entries.  */
-
 size_t
 hash_get_n_entries (const Hash_table *table)
 {
   return table->n_entries;
 }
 
-/* Return the length of the longest chain (bucket).  */
-
 size_t
 hash_get_max_bucket_length (const Hash_table *table)
 {
@@ -194,9 +181,6 @@ hash_get_max_bucket_length (const Hash_table *table)
   return max_bucket_length;
 }
 
-/* Do a mild validation of a hash table, by traversing it and checking two
-   statistics.  */
-
 bool
 hash_table_ok (const Hash_table *table)
 {
@@ -254,9 +238,6 @@ safe_hasher (const Hash_table *table, const void *key)
   return table->bucket + n;
 }
 
-/* If ENTRY matches an entry already in the hash table, return the
-   entry from the table.  Otherwise, return NULL.  */
-
 void *
 hash_lookup (const Hash_table *table, const void *entry)
 {
@@ -275,15 +256,6 @@ hash_lookup (const Hash_table *table, const void *entry)
 
 /* Walking.  */
 
-/* The functions in this page traverse the hash table and process the
-   contained entries.  For the traversal to work properly, the hash table
-   should not be resized nor modified while any particular entry is being
-   processed.  In particular, entries should not be added, and an entry
-   may be removed only if there is no shrink threshold and the entry being
-   removed has already been passed to hash_get_next.  */
-
-/* Return the first data in the table, or NULL if the table is empty.  */
-
 void *
 hash_get_first (const Hash_table *table)
 {
@@ -299,10 +271,6 @@ hash_get_first (const Hash_table *table)
       return bucket->data;
 }
 
-/* Return the user data for the entry following ENTRY, where ENTRY has been
-   returned by a previous call to either 'hash_get_first' or 'hash_get_next'.
-   Return NULL if there are no more entries.  */
-
 void *
 hash_get_next (const Hash_table *table, const void *entry)
 {
@@ -328,10 +296,6 @@ hash_get_next (const Hash_table *table, const void *entry)
   return NULL;
 }
 
-/* Fill BUFFER with pointers to active user entries in the hash table, then
-   return the number of pointers copied.  Do not copy more than BUFFER_SIZE
-   pointers.  */
-
 size_t
 hash_get_entries (const Hash_table *table, void **buffer,
                   size_t buffer_size)
@@ -356,14 +320,6 @@ hash_get_entries (const Hash_table *table, void **buffer,
   return counter;
 }
 
-/* Call a PROCESSOR function for each entry of a hash table, and return the
-   number of entries for which the processor function returned success.  A
-   pointer to some PROCESSOR_DATA which will be made available to each call to
-   the processor function.  The PROCESSOR accepts two arguments: the first is
-   the user entry being walked into, the second is the value of PROCESSOR_DATA
-   as received.  The walking continue for as long as the PROCESSOR function
-   returns nonzero.  When it returns zero, the walking is interrupted.  */
-
 size_t
 hash_do_for_each (const Hash_table *table, Hash_processor processor,
                   void *processor_data)
@@ -390,9 +346,6 @@ hash_do_for_each (const Hash_table *table, Hash_processor processor,
 
 /* Allocation and clean-up.  */
 
-/* Return a hash index for a NUL-terminated STRING between 0 and N_BUCKETS-1.
-   This is a convenience routine for constructing other hashing functions.  */
-
 #if USE_DIFF_HASH
 
 /* About hashings, Paul Eggert writes to me (FP), on 1994-01-01: "Please see
@@ -546,50 +499,20 @@ compute_bucket_size (size_t candidate, const Hash_tuning *tuning)
   if (!tuning->is_n_buckets)
     {
       float new_candidate = candidate / tuning->growth_threshold;
-      if (SIZE_MAX <= new_candidate)
-        return 0;
+      if ((float) SIZE_MAX <= new_candidate)
+        goto nomem;
       candidate = new_candidate;
     }
   candidate = next_prime (candidate);
   if (xalloc_oversized (candidate, sizeof (struct hash_entry *)))
-    return 0;
+    goto nomem;
   return candidate;
+
+ nomem:
+  errno = ENOMEM;
+  return 0;
 }
 
-/* Allocate and return a new hash table, or NULL upon failure.  The initial
-   number of buckets is automatically selected so as to _guarantee_ that you
-   may insert at least CANDIDATE different user entries before any growth of
-   the hash table size occurs.  So, if have a reasonably tight a-priori upper
-   bound on the number of entries you intend to insert in the hash table, you
-   may save some table memory and insertion time, by specifying it here.  If
-   the IS_N_BUCKETS field of the TUNING structure is true, the CANDIDATE
-   argument has its meaning changed to the wanted number of buckets.
-
-   TUNING points to a structure of user-supplied values, in case some fine
-   tuning is wanted over the default behavior of the hasher.  If TUNING is
-   NULL, the default tuning parameters are used instead.  If TUNING is
-   provided but the values requested are out of bounds or might cause
-   rounding errors, return NULL.
-
-   The user-supplied HASHER function, when not NULL, accepts two
-   arguments ENTRY and TABLE_SIZE.  It computes, by hashing ENTRY contents, a
-   slot number for that entry which should be in the range 0..TABLE_SIZE-1.
-   This slot number is then returned.
-
-   The user-supplied COMPARATOR function, when not NULL, accepts two
-   arguments pointing to user data, it then returns true for a pair of entries
-   that compare equal, or false otherwise.  This function is internally called
-   on entries which are already known to hash to the same bucket index,
-   but which are distinct pointers.
-
-   The user-supplied DATA_FREER function, when not NULL, may be later called
-   with the user data as an argument, just before the entry containing the
-   data gets freed.  This happens from within 'hash_free' or 'hash_clear'.
-   You should specify this function only if you want these functions to free
-   all of your 'data' data.  This is typically the case when your data is
-   simply an auxiliary struct that you have malloc'd to aggregate several
-   values.  */
-
 Hash_table *
 hash_initialize (size_t candidate, const Hash_tuning *tuning,
                  Hash_hasher hasher, Hash_comparator comparator,
@@ -616,6 +539,7 @@ hash_initialize (size_t candidate, const Hash_tuning *tuning,
          if the user provides invalid tuning options, we silently revert to
          using the defaults, and ignore further request to change the tuning
          options.  */
+      errno = EINVAL;
       goto fail;
     }
 
@@ -645,10 +569,6 @@ hash_initialize (size_t candidate, const Hash_tuning *tuning,
   return NULL;
 }
 
-/* Make all buckets empty, placing any chained entries on the free list.
-   Apply the user-specified function data_freer (if any) to the datas of any
-   affected entries.  */
-
 void
 hash_clear (Hash_table *table)
 {
@@ -687,17 +607,13 @@ hash_clear (Hash_table *table)
   table->n_entries = 0;
 }
 
-/* Reclaim all storage associated with a hash table.  If a data_freer
-   function has been supplied by the user when the hash table was created,
-   this function applies it to the data of each entry before freeing that
-   entry.  */
-
 void
 hash_free (Hash_table *table)
 {
   struct hash_entry *bucket;
   struct hash_entry *cursor;
   struct hash_entry *next;
+  int err = errno;
 
   /* Call the user data_freer function.  */
   if (table->data_freer && table->n_entries)
@@ -740,6 +656,8 @@ hash_free (Hash_table *table)
   /* Free the remainder of the hash table structure.  */
   free (table->bucket);
   free (table);
+
+  errno = err;
 }
 
 /* Insertion and deletion.  */
@@ -853,8 +771,8 @@ hash_find_entry (Hash_table *table, const void *entry,
 /* Internal helper, to move entries from SRC to DST.  Both tables must
    share the same free entry list.  If SAFE, only move overflow
    entries, saving bucket heads for later, so that no allocations will
-   occur.  Return false if the free entry list is exhausted and an
-   allocation fails.  */
+   occur.  Return false (setting errno) if the free entry list is
+   exhausted and an allocation fails.  */
 
 static bool
 transfer_entries (Hash_table *dst, Hash_table *src, bool safe)
@@ -931,14 +849,6 @@ transfer_entries (Hash_table *dst, Hash_table *src, bool safe)
   return true;
 }
 
-/* For an already existing hash table, change the number of buckets through
-   specifying CANDIDATE.  The contents of the hash table are preserved.  The
-   new number of buckets is automatically selected so as to _guarantee_ that
-   the table may receive at least CANDIDATE different user entries, including
-   those already in the table, before any other growth of the hash table size
-   occurs.  If TUNING->IS_N_BUCKETS is true, then CANDIDATE specifies the
-   exact number of buckets desired.  Return true iff the rehash succeeded.  */
-
 bool
 hash_rehash (Hash_table *table, size_t candidate)
 {
@@ -1009,31 +919,17 @@ hash_rehash (Hash_table *table, size_t candidate)
      passes.  Two passes give worse cache performance and takes
      longer, but at this point, we're already out of memory, so slow
      and safe is better than failure.  */
+  int err = errno;
   table->free_entry_list = new_table->free_entry_list;
   if (! (transfer_entries (table, new_table, true)
          && transfer_entries (table, new_table, false)))
     abort ();
   /* table->n_entries already holds its value.  */
   free (new_table->bucket);
+  errno = err;
   return false;
 }
 
-/* Insert ENTRY into hash TABLE if there is not already a matching entry.
-
-   Return -1 upon memory allocation failure.
-   Return 1 if insertion succeeded.
-   Return 0 if there is already a matching entry in the table,
-   and in that case, if MATCHED_ENT is non-NULL, set *MATCHED_ENT
-   to that entry.
-
-   This interface is easier to use than hash_insert when you must
-   distinguish between the latter two cases.  More importantly,
-   hash_insert is unusable for some types of ENTRY values.  When using
-   hash_insert, the only way to distinguish those cases is to compare
-   the return value and ENTRY.  That works only when you can have two
-   different ENTRY values that point to data that compares "equal".  Thus,
-   when the ENTRY value is a simple scalar, you must use
-   hash_insert_if_absent.  ENTRY must not be NULL.  */
 int
 hash_insert_if_absent (Hash_table *table, void const *entry,
                        void const **matched_ent)
@@ -1076,8 +972,11 @@ hash_insert_if_absent (Hash_table *table, void const *entry,
              : (table->n_buckets * tuning->growth_factor
                 * tuning->growth_threshold));
 
-          if (SIZE_MAX <= candidate)
-            return -1;
+          if ((float) SIZE_MAX <= candidate)
+            {
+              errno = ENOMEM;
+              return -1;
+            }
 
           /* If the rehash fails, arrange to return NULL.  */
           if (!hash_rehash (table, candidate))
@@ -1116,12 +1015,6 @@ hash_insert_if_absent (Hash_table *table, void const *entry,
   return 1;
 }
 
-/* If ENTRY matches an entry already in the hash table, return the pointer
-   to the entry from the table.  Otherwise, insert ENTRY and return ENTRY.
-   Return NULL if the storage required for insertion cannot be allocated.
-   This implementation does not support duplicate entries or insertion of
-   NULL.  */
-
 void *
 hash_insert (Hash_table *table, void const *entry)
 {
@@ -1132,12 +1025,8 @@ hash_insert (Hash_table *table, void const *entry)
           : (void *) (err == 0 ? matched_ent : entry));
 }
 
-/* If ENTRY is already in the table, remove it and return the just-deleted
-   data (the user may want to deallocate its storage).  If ENTRY is not in the
-   table, don't modify the table and return NULL.  */
-
 void *
-hash_delete (Hash_table *table, const void *entry)
+hash_remove (Hash_table *table, const void *entry)
 {
   void *data;
   struct hash_entry *bucket;
@@ -1196,6 +1085,12 @@ hash_delete (Hash_table *table, const void *entry)
   return data;
 }
 
+void *
+hash_delete (Hash_table *table, const void *entry)
+{
+  return hash_remove (table, entry);
+}
+
 /* Testing.  */
 
 #if TESTING

lib/hash.h

@@ -1,20 +1,20 @@
 /* hash - hashing table processing.
-   Copyright (C) 1998-1999, 2001, 2003, 2009-2017 Free Software Foundation,
+   Copyright (C) 1998-1999, 2001, 2003, 2009-2025 Free Software Foundation,
    Inc.
    Written by Jim Meyering <meyering@ascend.com>, 1998.
 
-   This program is free software: you can redistribute it and/or modify
-   it under the terms of the GNU General Public License as published by
-   the Free Software Foundation; either version 3 of the License, or
-   (at your option) any later version.
+   This file is free software: you can redistribute it and/or modify
+   it under the terms of the GNU Lesser General Public License as
+   published by the Free Software Foundation; either version 2.1 of the
+   License, or (at your option) any later version.
 
-   This program is distributed in the hope that it will be useful,
+   This file is distributed in the hope that it will be useful,
    but WITHOUT ANY WARRANTY; without even the implied warranty of
    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
-   GNU General Public License for more details.
+   GNU Lesser General Public License for more details.
 
-   You should have received a copy of the GNU General Public License
-   along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
+   You should have received a copy of the GNU Lesser General Public License
+   along with this program.  If not, see <https://www.gnu.org/licenses/>.  */
 
 /* A generic hash table package.  */
 
@@ -27,29 +27,10 @@
 # include <stdio.h>
 # include <stdbool.h>
 
-/* The __attribute__ feature is available in gcc versions 2.5 and later.
-   The warn_unused_result attribute appeared first in gcc-3.4.0.  */
-# if __GNUC__ > 3 || (__GNUC__ == 3 && __GNUC_MINOR__ >= 4)
-#  define _GL_ATTRIBUTE_WUR __attribute__ ((__warn_unused_result__))
-# else
-#  define _GL_ATTRIBUTE_WUR /* empty */
+# ifdef __cplusplus
+extern "C" {
 # endif
 
-# ifndef _GL_ATTRIBUTE_DEPRECATED
-/* The __attribute__((__deprecated__)) feature
-   is available in gcc versions 3.1 and newer.  */
-#  if __GNUC__ < 3 || (__GNUC__ == 3 && __GNUC_MINOR__ < 1)
-#   define _GL_ATTRIBUTE_DEPRECATED /* empty */
-#  else
-#   define _GL_ATTRIBUTE_DEPRECATED __attribute__ ((__deprecated__))
-#  endif
-# endif
-
-typedef size_t (*Hash_hasher) (const void *, size_t);
-typedef bool (*Hash_comparator) (const void *, const void *);
-typedef void (*Hash_data_freer) (void *);
-typedef bool (*Hash_processor) (void *, void *);
-
 struct hash_tuning
   {
     /* This structure is mainly used for 'hash_initialize', see the block
@@ -68,36 +49,234 @@ struct hash_table;
 
 typedef struct hash_table Hash_table;
 
-/* Information and lookup.  */
-size_t hash_get_n_buckets (const Hash_table *) _GL_ATTRIBUTE_PURE;
-size_t hash_get_n_buckets_used (const Hash_table *) _GL_ATTRIBUTE_PURE;
-size_t hash_get_n_entries (const Hash_table *) _GL_ATTRIBUTE_PURE;
-size_t hash_get_max_bucket_length (const Hash_table *) _GL_ATTRIBUTE_PURE;
-bool hash_table_ok (const Hash_table *) _GL_ATTRIBUTE_PURE;
-void hash_print_statistics (const Hash_table *, FILE *);
-void *hash_lookup (const Hash_table *, const void *);
+/*
+ * Information and lookup.
+ */
 
-/* Walking.  */
-void *hash_get_first (const Hash_table *) _GL_ATTRIBUTE_PURE;
-void *hash_get_next (const Hash_table *, const void *);
-size_t hash_get_entries (const Hash_table *, void **, size_t);
-size_t hash_do_for_each (const Hash_table *, Hash_processor, void *);
+/* The following few functions provide information about the overall hash
+   table organization: the number of entries, number of buckets and maximum
+   length of buckets.  */
 
-/* Allocation and clean-up.  */
-size_t hash_string (const char *, size_t) _GL_ATTRIBUTE_PURE;
-void hash_reset_tuning (Hash_tuning *);
-Hash_table *hash_initialize (size_t, const Hash_tuning *,
-                             Hash_hasher, Hash_comparator,
-                             Hash_data_freer) _GL_ATTRIBUTE_WUR;
-void hash_clear (Hash_table *);
-void hash_free (Hash_table *);
+/* Return the number of buckets in the hash table.  The table size, the total
+   number of buckets (used plus unused), or the maximum number of slots, are
+   the same quantity.  */
+extern size_t hash_get_n_buckets (const Hash_table *table)
+       _GL_ATTRIBUTE_PURE;
 
-/* Insertion and deletion.  */
-bool hash_rehash (Hash_table *, size_t) _GL_ATTRIBUTE_WUR;
-void *hash_insert (Hash_table *, const void *) _GL_ATTRIBUTE_WUR;
+/* Return the number of slots in use (non-empty buckets).  */
+extern size_t hash_get_n_buckets_used (const Hash_table *table)
+       _GL_ATTRIBUTE_PURE;
 
-int hash_insert_if_absent (Hash_table *table, const void *entry,
-                           const void **matched_ent);
-void *hash_delete (Hash_table *, const void *);
+/* Return the number of active entries.  */
+extern size_t hash_get_n_entries (const Hash_table *table)
+       _GL_ATTRIBUTE_PURE;
+
+/* Return the length of the longest chain (bucket).  */
+extern size_t hash_get_max_bucket_length (const Hash_table *table)
+       _GL_ATTRIBUTE_PURE;
+
+/* Do a mild validation of a hash table, by traversing it and checking two
+   statistics.  */
+extern bool hash_table_ok (const Hash_table *table)
+       _GL_ATTRIBUTE_PURE;
+
+extern void hash_print_statistics (const Hash_table *table, FILE *stream);
+
+/* If ENTRY matches an entry already in the hash table, return the
+   entry from the table.  Otherwise, return NULL.  */
+extern void *hash_lookup (const Hash_table *table, const void *entry);
+
+/*
+ * Walking.
+ */
+
+/* The functions in this page traverse the hash table and process the
+   contained entries.  For the traversal to work properly, the hash table
+   should not be resized nor modified while any particular entry is being
+   processed.  In particular, entries should not be added, and an entry
+   may be removed only if there is no shrink threshold and the entry being
+   removed has already been passed to hash_get_next.  */
+
+/* Return the first data in the table, or NULL if the table is empty.  */
+extern void *hash_get_first (const Hash_table *table)
+       _GL_ATTRIBUTE_PURE;
+
+/* Return the user data for the entry following ENTRY, where ENTRY has been
+   returned by a previous call to either 'hash_get_first' or 'hash_get_next'.
+   Return NULL if there are no more entries.  */
+extern void *hash_get_next (const Hash_table *table, const void *entry);
+
+/* Fill BUFFER with pointers to active user entries in the hash table, then
+   return the number of pointers copied.  Do not copy more than BUFFER_SIZE
+   pointers.  */
+extern size_t hash_get_entries (const Hash_table *table, void **buffer,
+                                size_t buffer_size);
+
+typedef bool (*Hash_processor) (void *entry, void *processor_data);
+
+/* Call a PROCESSOR function for each entry of a hash table, and return the
+   number of entries for which the processor function returned success.  A
+   pointer to some PROCESSOR_DATA which will be made available to each call to
+   the processor function.  The PROCESSOR accepts two arguments: the first is
+   the user entry being walked into, the second is the value of PROCESSOR_DATA
+   as received.  The walking continue for as long as the PROCESSOR function
+   returns nonzero.  When it returns zero, the walking is interrupted.  */
+extern size_t hash_do_for_each (const Hash_table *table,
+                                Hash_processor processor, void *processor_data);
+
+/* Return a hash index for a NUL-terminated STRING between 0 and N_BUCKETS-1.
+   This is a convenience routine for constructing other hashing functions.  */
+extern size_t hash_string (const char *string, size_t n_buckets)
+       _GL_ATTRIBUTE_PURE;
+
+/* Return a hash code of ENTRY, in the range 0..TABLE_SIZE-1.
+   This hash code function must have the property that if the comparator of
+   ENTRY1 and ENTRY2 returns true, the hasher returns the same value for ENTRY1
+   and for ENTRY2.
+   The hash code function typically computes an unsigned integer and at the end
+   performs a % TABLE_SIZE modulo operation.  This modulo operation is performed
+   as part of this hash code function, not by the caller, because in some cases
+   the unsigned integer will be a 'size_t', in other cases an 'uintmax_t' or
+   even larger.  */
+typedef size_t (*Hash_hasher) (const void *entry, size_t table_size);
+
+/* Compare two entries, ENTRY1 (being looked up or being inserted) and
+   ENTRY2 (already in the table) for equality.  Return true for equal,
+   false otherwise.  */
+typedef bool (*Hash_comparator) (const void *entry1, const void *entry2);
+
+/* This function is invoked when an ENTRY is removed from the hash table.  */
+typedef void (*Hash_data_freer) (void *entry);
+
+/*
+ * Allocation and clean-up.
+ */
+
+extern void hash_reset_tuning (Hash_tuning *tuning);
+
+/* Reclaim all storage associated with a hash table.  If a data_freer
+   function has been supplied by the user when the hash table was created,
+   this function applies it to the data of each entry before freeing that
+   entry.  This function preserves errno, like 'free'.  */
+extern void hash_free (Hash_table *table);
+
+/* Allocate and return a new hash table, or NULL upon failure.  The initial
+   number of buckets is automatically selected so as to _guarantee_ that you
+   may insert at least CANDIDATE different user entries before any growth of
+   the hash table size occurs.  So, if have a reasonably tight a-priori upper
+   bound on the number of entries you intend to insert in the hash table, you
+   may save some table memory and insertion time, by specifying it here.  If
+   the IS_N_BUCKETS field of the TUNING structure is true, the CANDIDATE
+   argument has its meaning changed to the wanted number of buckets.
+
+   TUNING points to a structure of user-supplied values, in case some fine
+   tuning is wanted over the default behavior of the hasher.  If TUNING is
+   NULL, the default tuning parameters are used instead.  If TUNING is
+   provided but the values requested are out of bounds or might cause
+   rounding errors, return NULL.
+
+   The user-supplied HASHER function, when not NULL, accepts two
+   arguments ENTRY and TABLE_SIZE.  It computes, by hashing ENTRY contents, a
+   slot number for that entry which should be in the range 0..TABLE_SIZE-1.
+   This slot number is then returned.
+
+   The user-supplied COMPARATOR function, when not NULL, accepts two
+   arguments pointing to user data, it then returns true for a pair of entries
+   that compare equal, or false otherwise.  This function is internally called
+   on entries which are already known to hash to the same bucket index,
+   but which are distinct pointers.
+
+   The user-supplied DATA_FREER function, when not NULL, may be later called
+   with the user data as an argument, just before the entry containing the
+   data gets freed.  This happens from within 'hash_free' or 'hash_clear'.
+   You should specify this function only if you want these functions to free
+   all of your 'data' data.  This is typically the case when your data is
+   simply an auxiliary struct that you have malloc'd to aggregate several
+   values.
+
+   Set errno on failure; otherwise errno is unspecified.  */
+_GL_ATTRIBUTE_NODISCARD
+extern Hash_table *hash_initialize (size_t candidate,
+                                    const Hash_tuning *tuning,
+                                    Hash_hasher hasher,
+                                    Hash_comparator comparator,
+                                    Hash_data_freer data_freer)
+  _GL_ATTRIBUTE_MALLOC _GL_ATTRIBUTE_DEALLOC (hash_free, 1);
+
+/* Like hash_initialize, but invokes xalloc_die instead of returning NULL.  */
+/* This function is defined by module 'xhash'.  */
+_GL_ATTRIBUTE_NODISCARD
+extern Hash_table *hash_xinitialize (size_t candidate,
+                                     const Hash_tuning *tuning,
+                                     Hash_hasher hasher,
+                                     Hash_comparator comparator,
+                                     Hash_data_freer data_freer)
+  _GL_ATTRIBUTE_MALLOC _GL_ATTRIBUTE_DEALLOC (hash_free, 1)
+  _GL_ATTRIBUTE_RETURNS_NONNULL;
+
+/* Make all buckets empty, placing any chained entries on the free list.
+   Apply the user-specified function data_freer (if any) to the data of any
+   affected entries.  */
+extern void hash_clear (Hash_table *table);
+
+/*
+ * Insertion and deletion.
+ */
+
+/* For an already existing hash table, change the number of buckets through
+   specifying CANDIDATE.  The contents of the hash table are preserved.  The
+   new number of buckets is automatically selected so as to _guarantee_ that
+   the table may receive at least CANDIDATE different user entries, including
+   those already in the table, before any other growth of the hash table size
+   occurs.  If TUNING->IS_N_BUCKETS is true, then CANDIDATE specifies the
+   exact number of buckets desired.  Return true iff the rehash succeeded,
+   false (setting errno) otherwise.  */
+_GL_ATTRIBUTE_NODISCARD
+extern bool hash_rehash (Hash_table *table, size_t candidate);
+
+/* If ENTRY matches an entry already in the hash table, return the pointer
+   to the entry from the table.  Otherwise, insert ENTRY and return ENTRY.
+   Return NULL (setting errno) if the storage required for insertion
+   cannot be allocated.  This implementation does not support
+   duplicate entries or insertion of NULL.  */
+_GL_ATTRIBUTE_NODISCARD
+extern void *hash_insert (Hash_table *table, const void *entry);
+
+/* Same as hash_insert, but invokes xalloc_die instead of returning NULL.  */
+/* This function is defined by module 'xhash'.  */
+extern void *hash_xinsert (Hash_table *table, const void *entry);
+
+/* Insert ENTRY into hash TABLE if there is not already a matching entry.
+
+   Return -1 (setting errno) upon memory allocation failure.
+   Return 1 if insertion succeeded.
+   Return 0 if there is already a matching entry in the table,
+   and in that case, if MATCHED_ENT is non-NULL, set *MATCHED_ENT
+   to that entry.
+
+   This interface is easier to use than hash_insert when you must
+   distinguish between the latter two cases.  More importantly,
+   hash_insert is unusable for some types of ENTRY values.  When using
+   hash_insert, the only way to distinguish those cases is to compare
+   the return value and ENTRY.  That works only when you can have two
+   different ENTRY values that point to data that compares "equal".  Thus,
+   when the ENTRY value is a simple scalar, you must use
+   hash_insert_if_absent.  ENTRY must not be NULL.  */
+extern int hash_insert_if_absent (Hash_table *table, const void *entry,
+                                  const void **matched_ent);
+
+/* If ENTRY is already in the table, remove it and return the just-deleted
+   data (the user may want to deallocate its storage).  If ENTRY is not in the
+   table, don't modify the table and return NULL.  */
+extern void *hash_remove (Hash_table *table, const void *entry);
+
+/* Same as hash_remove.  This interface is deprecated.
+   FIXME: Remove in 2022.  */
+_GL_ATTRIBUTE_DEPRECATED
+extern void *hash_delete (Hash_table *table, const void *entry);
+
+# ifdef __cplusplus
+}
+# endif
 
 #endif

lib/limits.in.h

@@ -1,6 +1,6 @@
 /* A GNU-like <limits.h>.
 
-   Copyright 2016-2017 Free Software Foundation, Inc.
+   Copyright 2016-2019 Free Software Foundation, Inc.
 
    This program is free software; you can redistribute it and/or
    modify it under the terms of the GNU General Public License
@@ -13,7 +13,7 @@
    GNU General Public License for more details.
 
    You should have received a copy of the GNU General Public License
-   along with this program; if not, see <http://www.gnu.org/licenses/>.  */
+   along with this program; if not, see <https://www.gnu.org/licenses/>.  */
 
 #ifndef _@GUARD_PREFIX@_LIMITS_H
 
@@ -28,15 +28,32 @@
 #ifndef _@GUARD_PREFIX@_LIMITS_H
 #define _@GUARD_PREFIX@_LIMITS_H
 
-/* For HP-UX 11.31.  */
-#if defined LONG_LONG_MIN && !defined LLONG_MIN
-# define LLONG_MIN LONG_LONG_MIN
+#ifndef LLONG_MIN
+# if defined LONG_LONG_MIN /* HP-UX 11.31 */
+#  define LLONG_MIN LONG_LONG_MIN
+# elif defined LONGLONG_MIN /* IRIX 6.5 */
+#  define LLONG_MIN LONGLONG_MIN
+# elif defined __GNUC__
+#  define LLONG_MIN (- __LONG_LONG_MAX__ - 1LL)
+# endif
 #endif
-#if defined LONG_LONG_MAX && !defined LLONG_MAX
-# define LLONG_MAX LONG_LONG_MAX
+#ifndef LLONG_MAX
+# if defined LONG_LONG_MAX /* HP-UX 11.31 */
+#  define LLONG_MAX LONG_LONG_MAX
+# elif defined LONGLONG_MAX /* IRIX 6.5 */
+#  define LLONG_MAX LONGLONG_MAX
+# elif defined __GNUC__
+#  define LLONG_MAX __LONG_LONG_MAX__
+# endif
 #endif
-#if defined ULONG_LONG_MAX && !defined ULLONG_MAX
-# define ULLONG_MAX ULONG_LONG_MAX
+#ifndef ULLONG_MAX
+# if defined ULONG_LONG_MAX /* HP-UX 11.31 */
+#  define ULLONG_MAX ULONG_LONG_MAX
+# elif defined ULONGLONG_MAX /* IRIX 6.5 */
+#  define ULLONG_MAX ULONGLONG_MAX
+# elif defined __GNUC__
+#  define ULLONG_MAX (__LONG_LONG_MAX__ * 2ULL + 1ULL)
+# endif
 #endif
 
 /* The number of usable bits in an unsigned or signed integer type
@@ -53,6 +70,19 @@
 #define _GL_COB8(n) (_GL_COB4 ((n) >> 4) + _GL_COB4 (n))
 #define _GL_COB4(n) (!!((n) & 8) + !!((n) & 4) + !!((n) & 2) + !!((n) & 1))
 
+#ifndef WORD_BIT
+/* Assume 'int' is 32 bits wide.  */
+# define WORD_BIT 32
+#endif
+#ifndef LONG_BIT
+/* Assume 'long' is 32 or 64 bits wide.  */
+# if LONG_MAX == INT_MAX
+#  define LONG_BIT 32
+# else
+#  define LONG_BIT 64
+# endif
+#endif
+
 /* Macros specified by ISO/IEC TS 18661-1:2014.  */
 
 #if (! defined ULLONG_WIDTH                                             \

lib/stdbool.in.h

@@ -1,4 +1,4 @@
-/* Copyright (C) 2001-2003, 2006-2017 Free Software Foundation, Inc.
+/* Copyright (C) 2001-2003, 2006-2019 Free Software Foundation, Inc.
    Written by Bruno Haible <haible@clisp.cons.org>, 2001.
 
    This program is free software; you can redistribute it and/or modify
@@ -12,7 +12,7 @@
    GNU General Public License for more details.
 
    You should have received a copy of the GNU General Public License
-   along with this program; if not, see <http://www.gnu.org/licenses/>.  */
+   along with this program; if not, see <https://www.gnu.org/licenses/>.  */
 
 #ifndef _GL_STDBOOL_H
 #define _GL_STDBOOL_H
@@ -82,9 +82,9 @@ typedef bool _Bool;
    /* If @HAVE__BOOL@:
         Some HP-UX cc and AIX IBM C compiler versions have compiler bugs when
         the built-in _Bool type is used.  See
-          http://gcc.gnu.org/ml/gcc-patches/2003-12/msg02303.html
-          http://lists.gnu.org/archive/html/bug-coreutils/2005-11/msg00161.html
-          http://lists.gnu.org/archive/html/bug-coreutils/2005-10/msg00086.html
+          https://gcc.gnu.org/ml/gcc-patches/2003-12/msg02303.html
+          https://lists.gnu.org/r/bug-coreutils/2005-11/msg00161.html
+          https://lists.gnu.org/r/bug-coreutils/2005-10/msg00086.html
         Similar bugs are likely with other compilers as well; this file
         wouldn't be used if <stdbool.h> was working.
         So we override the _Bool type.

lib/stdint.in.h

@@ -1,4 +1,4 @@
-/* Copyright (C) 2001-2002, 2004-2017 Free Software Foundation, Inc.
+/* Copyright (C) 2001-2002, 2004-2019 Free Software Foundation, Inc.
    Written by Paul Eggert, Bruno Haible, Sam Steingold, Peter Burwood.
    This file is part of gnulib.
 
@@ -13,7 +13,7 @@
    GNU General Public License for more details.
 
    You should have received a copy of the GNU General Public License
-   along with this program; if not, see <http://www.gnu.org/licenses/>.  */
+   along with this program; if not, see <https://www.gnu.org/licenses/>.  */
 
 /*
  * ISO C 99 <stdint.h> for platforms that lack it.

lib/sys_types.in.h

@@ -1,6 +1,6 @@
 /* Provide a more complete sys/types.h.
 
-   Copyright (C) 2011-2017 Free Software Foundation, Inc.
+   Copyright (C) 2011-2019 Free Software Foundation, Inc.
 
    This program is free software; you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
@@ -13,13 +13,24 @@
    GNU General Public License for more details.
 
    You should have received a copy of the GNU General Public License
-   along with this program; if not, see <http://www.gnu.org/licenses/>.  */
+   along with this program; if not, see <https://www.gnu.org/licenses/>.  */
 
 #if __GNUC__ >= 3
 @PRAGMA_SYSTEM_HEADER@
 #endif
 @PRAGMA_COLUMNS@
 
+#if defined _WIN32 && !defined __CYGWIN__ \
+    && (defined __need_off_t || defined __need___off64_t \
+        || defined __need_ssize_t || defined __need_time_t)
+
+/* Special invocation convention inside mingw header files.  */
+
+#@INCLUDE_NEXT@ @NEXT_SYS_TYPES_H@
+
+#else
+/* Normal invocation convention.  */
+
 #ifndef _@GUARD_PREFIX@_SYS_TYPES_H
 
 /* The include_next requires a split double-inclusion guard.  */
@@ -86,10 +97,10 @@ typedef unsigned long long int rpl_ino_t;
 
 /* MSVC 9 defines size_t in <stddef.h>, not in <sys/types.h>.  */
 /* But avoid namespace pollution on glibc systems.  */
-#if ((defined _WIN32 || defined __WIN32__) && ! defined __CYGWIN__) \
-    && ! defined __GLIBC__
+#if (defined _WIN32 && ! defined __CYGWIN__) && ! defined __GLIBC__
 # include <stddef.h>
 #endif
 
 #endif /* _@GUARD_PREFIX@_SYS_TYPES_H */
 #endif /* _@GUARD_PREFIX@_SYS_TYPES_H */
+#endif /* __need_XXX */

lib/xalloc-oversized.h

@@ -1,6 +1,6 @@
 /* xalloc-oversized.h -- memory allocation size checking
 
-   Copyright (C) 1990-2000, 2003-2004, 2006-2017 Free Software Foundation, Inc.
+   Copyright (C) 1990-2000, 2003-2004, 2006-2019 Free Software Foundation, Inc.
 
    This program is free software: you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
@@ -13,7 +13,7 @@
    GNU General Public License for more details.
 
    You should have received a copy of the GNU General Public License
-   along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
+   along with this program.  If not, see <https://www.gnu.org/licenses/>.  */
 
 #ifndef XALLOC_OVERSIZED_H_
 #define XALLOC_OVERSIZED_H_

m4/00gnulib.m4

@@ -1,43 +1,84 @@
-# 00gnulib.m4 serial 3
-dnl Copyright (C) 2009-2017 Free Software Foundation, Inc.
+# 00gnulib.m4
+# serial 9
+dnl Copyright (C) 2009-2025 Free Software Foundation, Inc.
 dnl This file is free software; the Free Software Foundation
 dnl gives unlimited permission to copy and/or distribute it,
 dnl with or without modifications, as long as this notice is preserved.
+dnl This file is offered as-is, without any warranty.
 
 dnl This file must be named something that sorts before all other
-dnl gnulib-provided .m4 files.  It is needed until such time as we can
-dnl assume Autoconf 2.64, with its improved AC_DEFUN_ONCE and
-dnl m4_divert semantics.
+dnl gnulib-provided .m4 files.  It is needed until the clang fix has
+dnl been included in Autoconf.
 
-# Until autoconf 2.63, handling of the diversion stack required m4_init
-# to be called first; but this does not happen with aclocal.  Wrapping
-# the entire execution in another layer of the diversion stack fixes this.
-# Worse, prior to autoconf 2.62, m4_wrap depended on the underlying m4
-# for whether it was FIFO or LIFO; in order to properly balance with
-# m4_init, we need to undo our push just before anything wrapped within
-# the m4_init body.  The way to ensure this is to wrap both sides of
-# m4_init with a one-shot macro that does the pop at the right time.
-m4_ifndef([_m4_divert_diversion],
-[m4_divert_push([KILL])
-m4_define([gl_divert_fixup], [m4_divert_pop()m4_define([$0])])
-m4_define([m4_init],
-  [gl_divert_fixup()]m4_defn([m4_init])[gl_divert_fixup()])])
-
-
-# AC_DEFUN_ONCE([NAME], VALUE)
-# ----------------------------
-# Define NAME to expand to VALUE on the first use (whether by direct
-# expansion, or by AC_REQUIRE), and to nothing on all subsequent uses.
-# Avoid bugs in AC_REQUIRE in Autoconf 2.63 and earlier.  This
-# definition is slower than the version in Autoconf 2.64, because it
-# can only use interfaces that existed since 2.59; but it achieves the
-# same effect.  Quoting is necessary to avoid confusing Automake.
-m4_version_prereq([2.63.263], [],
-[m4_define([AC][_DEFUN_ONCE],
-  [AC][_DEFUN([$1],
-    [AC_REQUIRE([_gl_DEFUN_ONCE([$1])],
-      [m4_indir([_gl_DEFUN_ONCE([$1])])])])]dnl
-[AC][_DEFUN([_gl_DEFUN_ONCE([$1])], [$2])])])
+# The following definitions arrange to use a compiler option
+# -Werror=implicit-function-declaration in AC_CHECK_DECL, when the
+# compiler is clang.  Without it, clang implicitly declares "known"
+# library functions in C mode, but not in C++ mode, which would cause
+# Gnulib to omit a declaration and thus later produce an error in C++
+# mode.  As of clang 9.0, these "known" functions are identified through
+# LIBBUILTIN invocations in the LLVM source file
+# llvm/tools/clang/include/clang/Basic/Builtins.def.
+# It's not possible to AC_REQUIRE the extra tests from AC_CHECK_DECL,
+# because AC_CHECK_DECL, like other Autoconf built-ins, is not supposed
+# to AC_REQUIRE anything: some configure.ac files have their first
+# AC_CHECK_DECL executed conditionally.  Therefore append the extra tests
+# to AC_PROG_CC.
+AC_DEFUN([gl_COMPILER_CLANG],
+[
+dnl AC_REQUIRE([AC_PROG_CC])
+  AC_CACHE_CHECK([whether the compiler is clang],
+    [gl_cv_compiler_clang],
+    [dnl Use _AC_COMPILE_IFELSE instead of AC_EGREP_CPP, to avoid error
+     dnl "circular dependency of AC_LANG_COMPILER(C)" if AC_PROG_CC has
+     dnl not yet been invoked.
+     _AC_COMPILE_IFELSE(
+        [AC_LANG_PROGRAM([[
+           #ifdef __clang__
+           barfbarf
+           #endif
+           ]],[[]])
+        ],
+        [gl_cv_compiler_clang=no],
+        [gl_cv_compiler_clang=yes])
+    ])
+])
+AC_DEFUN([gl_COMPILER_PREPARE_CHECK_DECL],
+[
+dnl AC_REQUIRE([AC_PROG_CC])
+dnl AC_REQUIRE([gl_COMPILER_CLANG])
+  AC_CACHE_CHECK([for compiler option needed when checking for declarations],
+    [gl_cv_compiler_check_decl_option],
+    [if test $gl_cv_compiler_clang = yes; then
+       dnl Test whether the compiler supports the option
+       dnl '-Werror=implicit-function-declaration'.
+       saved_ac_compile="$ac_compile"
+       ac_compile="$ac_compile -Werror=implicit-function-declaration"
+       dnl Use _AC_COMPILE_IFELSE instead of AC_COMPILE_IFELSE, to avoid a
+       dnl warning "AC_COMPILE_IFELSE was called before AC_USE_SYSTEM_EXTENSIONS".
+       _AC_COMPILE_IFELSE([AC_LANG_PROGRAM([[]],[[]])],
+         [gl_cv_compiler_check_decl_option='-Werror=implicit-function-declaration'],
+         [gl_cv_compiler_check_decl_option=none])
+       ac_compile="$saved_ac_compile"
+     else
+       gl_cv_compiler_check_decl_option=none
+     fi
+    ])
+  if test "x$gl_cv_compiler_check_decl_option" != xnone; then
+    ac_compile_for_check_decl="$ac_compile $gl_cv_compiler_check_decl_option"
+  else
+    ac_compile_for_check_decl="$ac_compile"
+  fi
+])
+dnl Redefine _AC_CHECK_DECL_BODY so that it references ac_compile_for_check_decl
+dnl instead of ac_compile.  If, for whatever reason, the override of AC_PROG_CC
+dnl in zzgnulib.m4 is inactive, use the original ac_compile.
+m4_define([_AC_CHECK_DECL_BODY],
+[  ac_saved_ac_compile="$ac_compile"
+  if test -n "$ac_compile_for_check_decl"; then
+    ac_compile="$ac_compile_for_check_decl"
+  fi]
+m4_defn([_AC_CHECK_DECL_BODY])[  ac_compile="$ac_saved_ac_compile"
+])
 
 # gl_00GNULIB
 # -----------

m4/absolute-header.m4

@@ -1,5 +1,5 @@
 # absolute-header.m4 serial 16
-dnl Copyright (C) 2006-2017 Free Software Foundation, Inc.
+dnl Copyright (C) 2006-2019 Free Software Foundation, Inc.
 dnl This file is free software; the Free Software Foundation
 dnl gives unlimited permission to copy and/or distribute it,
 dnl with or without modifications, as long as this notice is preserved.

m4/extern-inline.m4

@@ -1,6 +1,6 @@
 dnl 'extern inline' a la ISO C99.
 
-dnl Copyright 2012-2017 Free Software Foundation, Inc.
+dnl Copyright 2012-2019 Free Software Foundation, Inc.
 dnl This file is free software; the Free Software Foundation
 dnl gives unlimited permission to copy and/or distribute it,
 dnl with or without modifications, as long as this notice is preserved.
@@ -11,7 +11,7 @@ AC_DEFUN([gl_EXTERN_INLINE],
 [/* Please see the Gnulib manual for how to use these macros.
 
    Suppress extern inline with HP-UX cc, as it appears to be broken; see
-   <http://lists.gnu.org/archive/html/bug-texinfo/2013-02/msg00030.html>.
+   <https://lists.gnu.org/r/bug-texinfo/2013-02/msg00030.html>.
 
    Suppress extern inline with Sun C in standards-conformance mode, as it
    mishandles inline functions that call each other.  E.g., for 'inline void f
@@ -25,20 +25,32 @@ AC_DEFUN([gl_EXTERN_INLINE],
    if isdigit is mistakenly implemented via a static inline function,
    a program containing an extern inline function that calls isdigit
    may not work since the C standard prohibits extern inline functions
-   from calling static functions.  This bug is known to occur on:
+   from calling static functions (ISO C 99 section 6.7.4.(3).
+   This bug is known to occur on:
 
      OS X 10.8 and earlier; see:
-     http://lists.gnu.org/archive/html/bug-gnulib/2012-12/msg00023.html
+     https://lists.gnu.org/r/bug-gnulib/2012-12/msg00023.html
 
      DragonFly; see
      http://muscles.dragonflybsd.org/bulk/bleeding-edge-potential/latest-per-pkg/ah-tty-0.3.12.log
 
      FreeBSD; see:
-     http://lists.gnu.org/archive/html/bug-gnulib/2014-07/msg00104.html
+     https://lists.gnu.org/r/bug-gnulib/2014-07/msg00104.html
 
    OS X 10.9 has a macro __header_inline indicating the bug is fixed for C and
-   for clang but remains for g++; see <http://trac.macports.org/ticket/41033>.
-   Assume DragonFly and FreeBSD will be similar.  */
+   for clang but remains for g++; see <https://trac.macports.org/ticket/41033>.
+   Assume DragonFly and FreeBSD will be similar.
+
+   GCC 4.3 and above with -std=c99 or -std=gnu99 implements ISO C99
+   inline semantics, unless -fgnu89-inline is used.  It defines a macro
+   __GNUC_STDC_INLINE__ to indicate this situation or a macro
+   __GNUC_GNU_INLINE__ to indicate the opposite situation.
+   GCC 4.2 with -std=c99 or -std=gnu99 implements the GNU C inline
+   semantics but warns, unless -fgnu89-inline is used:
+     warning: C99 inline functions are not supported; using GNU89
+     warning: to disable this warning use -fgnu89-inline or the gnu_inline function attribute
+   It defines a macro __GNUC_GNU_INLINE__ to indicate this situation.
+ */
 #if (((defined __APPLE__ && defined __MACH__) \
       || defined __DragonFly__ || defined __FreeBSD__) \
      && (defined __header_inline \

m4/gnulib-cache.m4

@@ -1,4 +1,4 @@
-# Copyright (C) 2002-2017 Free Software Foundation, Inc.
+# Copyright (C) 2002-2019 Free Software Foundation, Inc.
 #
 # This file is free software; you can redistribute it and/or modify
 # it under the terms of the GNU General Public License as published by
@@ -11,7 +11,7 @@
 # GNU General Public License for more details.
 #
 # You should have received a copy of the GNU General Public License
-# along with this file.  If not, see <http://www.gnu.org/licenses/>.
+# along with this file.  If not, see <https://www.gnu.org/licenses/>.
 #
 # As a special exception to the GNU General Public License,
 # this file may be distributed as part of a program that
@@ -27,7 +27,17 @@
 
 
 # Specification in the form of a command-line invocation:
-#   gnulib-tool --import --lib=libgnu --source-base=lib --m4-base=m4 --doc-base=doc --tests-base=tests --aux-dir=. --no-conditional-dependencies --no-libtool --macro-prefix=gl hash
+# gnulib-tool --import \
+#  --lib=libgnu \
+#  --source-base=lib \
+#  --m4-base=m4 \
+#  --doc-base=doc \
+#  --tests-base=tests \
+#  --aux-dir=. \
+#  --no-conditional-dependencies \
+#  --no-libtool \
+#  --macro-prefix=gl \
+#  hash
 
 # Specification in the form of a few gnulib-tool.m4 macro invocations:
 gl_LOCAL_DIR([])

m4/gnulib-comp.m4

@@ -1,5 +1,5 @@
 # DO NOT EDIT! GENERATED AUTOMATICALLY!
-# Copyright (C) 2002-2017 Free Software Foundation, Inc.
+# Copyright (C) 2002-2019 Free Software Foundation, Inc.
 #
 # This file is free software; you can redistribute it and/or modify
 # it under the terms of the GNU General Public License as published by
@@ -12,7 +12,7 @@
 # GNU General Public License for more details.
 #
 # You should have received a copy of the GNU General Public License
-# along with this file.  If not, see <http://www.gnu.org/licenses/>.
+# along with this file.  If not, see <https://www.gnu.org/licenses/>.
 #
 # As a special exception to the GNU General Public License,
 # this file may be distributed as part of a program that

m4/gnulib-tool.m4

@@ -1,5 +1,5 @@
 # gnulib-tool.m4 serial 2
-dnl Copyright (C) 2004-2005, 2009-2017 Free Software Foundation, Inc.
+dnl Copyright (C) 2004-2005, 2009-2019 Free Software Foundation, Inc.
 dnl This file is free software; the Free Software Foundation
 dnl gives unlimited permission to copy and/or distribute it,
 dnl with or without modifications, as long as this notice is preserved.

m4/include_next.m4

@@ -1,5 +1,5 @@
 # include_next.m4 serial 24
-dnl Copyright (C) 2006-2017 Free Software Foundation, Inc.
+dnl Copyright (C) 2006-2019 Free Software Foundation, Inc.
 dnl This file is free software; the Free Software Foundation
 dnl gives unlimited permission to copy and/or distribute it,
 dnl with or without modifications, as long as this notice is preserved.

m4/limits-h.m4

@@ -1,6 +1,6 @@
 dnl Check whether limits.h has needed features.
 
-dnl Copyright 2016-2017 Free Software Foundation, Inc.
+dnl Copyright 2016-2019 Free Software Foundation, Inc.
 dnl This file is free software; the Free Software Foundation
 dnl gives unlimited permission to copy and/or distribute it,
 dnl with or without modifications, as long as this notice is preserved.
@@ -11,14 +11,18 @@ AC_DEFUN_ONCE([gl_LIMITS_H],
 [
   gl_CHECK_NEXT_HEADERS([limits.h])
 
-  AC_CACHE_CHECK([whether limits.h has ULLONG_WIDTH etc.],
+  AC_CACHE_CHECK([whether limits.h has LLONG_MAX, WORD_BIT, ULLONG_WIDTH etc.],
     [gl_cv_header_limits_width],
     [AC_COMPILE_IFELSE(
-       [AC_LANG_PROGRAM([[#ifndef __STDC_WANT_IEC_60559_BFP_EXT__
-                           #define __STDC_WANT_IEC_60559_BFP_EXT__ 1
-                          #endif
-                          #include <limits.h>
-                          int ullw = ULLONG_WIDTH;]])],
+       [AC_LANG_PROGRAM(
+          [[#ifndef __STDC_WANT_IEC_60559_BFP_EXT__
+             #define __STDC_WANT_IEC_60559_BFP_EXT__ 1
+            #endif
+            #include <limits.h>
+            long long llm = LLONG_MAX;
+            int wb = WORD_BIT;
+            int ullw = ULLONG_WIDTH;
+          ]])],
        [gl_cv_header_limits_width=yes],
        [gl_cv_header_limits_width=no])])
   if test "$gl_cv_header_limits_width" = yes; then
@@ -29,3 +33,11 @@ AC_DEFUN_ONCE([gl_LIMITS_H],
   AC_SUBST([LIMITS_H])
   AM_CONDITIONAL([GL_GENERATE_LIMITS_H], [test -n "$LIMITS_H"])
 ])
+
+dnl Unconditionally enables the replacement of <limits.h>.
+AC_DEFUN([gl_REPLACE_LIMITS_H],
+[
+  AC_REQUIRE([gl_LIMITS_H])
+  LIMITS_H='limits.h'
+  AM_CONDITIONAL([GL_GENERATE_LIMITS_H], [test -n "$LIMITS_H"])
+])

m4/longlong.m4

@@ -1,14 +1,15 @@
-# longlong.m4 serial 17
-dnl Copyright (C) 1999-2007, 2009-2017 Free Software Foundation, Inc.
+# longlong.m4 serial 18
+dnl Copyright (C) 1999-2007, 2009-2019 Free Software Foundation, Inc.
 dnl This file is free software; the Free Software Foundation
 dnl gives unlimited permission to copy and/or distribute it,
 dnl with or without modifications, as long as this notice is preserved.
 
 dnl From Paul Eggert.
 
+AC_PREREQ([2.62])
+
 # Define HAVE_LONG_LONG_INT if 'long long int' works.
-# This fixes a bug in Autoconf 2.61, and can be faster
-# than what's in Autoconf 2.62 through 2.68.
+# This can be faster than what's in Autoconf 2.62 through 2.68.
 
 # Note: If the type 'long long int' exists but is only 32 bits large
 # (as on some very old compilers), HAVE_LONG_LONG_INT will not be
@@ -56,8 +57,7 @@ AC_DEFUN([AC_TYPE_LONG_LONG_INT],
 ])
 
 # Define HAVE_UNSIGNED_LONG_LONG_INT if 'unsigned long long int' works.
-# This fixes a bug in Autoconf 2.61, and can be faster
-# than what's in Autoconf 2.62 through 2.68.
+# This can be faster than what's in Autoconf 2.62 through 2.68.
 
 # Note: If the type 'unsigned long long int' exists but is only 32 bits
 # large (as on some very old compilers), AC_TYPE_UNSIGNED_LONG_LONG_INT

m4/multiarch.m4

@@ -1,5 +1,5 @@
 # multiarch.m4 serial 7
-dnl Copyright (C) 2008-2017 Free Software Foundation, Inc.
+dnl Copyright (C) 2008-2019 Free Software Foundation, Inc.
 dnl This file is free software; the Free Software Foundation
 dnl gives unlimited permission to copy and/or distribute it,
 dnl with or without modifications, as long as this notice is preserved.

m4/off_t.m4

@@ -1,5 +1,5 @@
 # off_t.m4 serial 1
-dnl Copyright (C) 2012-2017 Free Software Foundation, Inc.
+dnl Copyright (C) 2012-2019 Free Software Foundation, Inc.
 dnl This file is free software; the Free Software Foundation
 dnl gives unlimited permission to copy and/or distribute it,
 dnl with or without modifications, as long as this notice is preserved.

m4/ssize_t.m4

@@ -1,5 +1,5 @@
 # ssize_t.m4 serial 5 (gettext-0.18.2)
-dnl Copyright (C) 2001-2003, 2006, 2010-2017 Free Software Foundation, Inc.
+dnl Copyright (C) 2001-2003, 2006, 2010-2019 Free Software Foundation, Inc.
 dnl This file is free software; the Free Software Foundation
 dnl gives unlimited permission to copy and/or distribute it,
 dnl with or without modifications, as long as this notice is preserved.

m4/stdbool.m4

@@ -1,6 +1,6 @@
 # Check for stdbool.h that conforms to C99.
 
-dnl Copyright (C) 2002-2006, 2009-2017 Free Software Foundation, Inc.
+dnl Copyright (C) 2002-2006, 2009-2019 Free Software Foundation, Inc.
 dnl This file is free software; the Free Software Foundation
 dnl gives unlimited permission to copy and/or distribute it,
 dnl with or without modifications, as long as this notice is preserved.
@@ -87,8 +87,8 @@ AC_DEFUN([AC_CHECK_HEADER_STDBOOL],
              char o[sizeof n == m * sizeof n[0] ? 1 : -1];
              char p[-1 - (Bool) 0 < 0 && -1 - (bool) 0 < 0 ? 1 : -1];
              /* Catch a bug in an HP-UX C compiler.  See
-                http://gcc.gnu.org/ml/gcc-patches/2003-12/msg02303.html
-                http://lists.gnu.org/archive/html/bug-coreutils/2005-11/msg00161.html
+                https://gcc.gnu.org/ml/gcc-patches/2003-12/msg02303.html
+                https://lists.gnu.org/r/bug-coreutils/2005-11/msg00161.html
               */
              Bool q = true;
              Bool *pq = &q;

m4/stdint.m4

@@ -1,5 +1,5 @@
-# stdint.m4 serial 50
-dnl Copyright (C) 2001-2017 Free Software Foundation, Inc.
+# stdint.m4 serial 53
+dnl Copyright (C) 2001-2019 Free Software Foundation, Inc.
 dnl This file is free software; the Free Software Foundation
 dnl gives unlimited permission to copy and/or distribute it,
 dnl with or without modifications, as long as this notice is preserved.
@@ -7,9 +7,12 @@ dnl with or without modifications, as long as this notice is preserved.
 dnl From Paul Eggert and Bruno Haible.
 dnl Test whether <stdint.h> is supported or must be substituted.
 
+AC_PREREQ([2.61])
+
 AC_DEFUN_ONCE([gl_STDINT_H],
 [
   AC_PREREQ([2.59])dnl
+  AC_REQUIRE([AC_CANONICAL_HOST]) dnl for cross-compiles
 
   AC_REQUIRE([gl_LIMITS_H])
   AC_REQUIRE([gt_TYPE_WINT_T])
@@ -288,8 +291,12 @@ static const char *macro_values[] =
 ]])],
               [gl_cv_header_working_stdint_h=yes],
               [],
-              [dnl When cross-compiling, assume it works.
-               gl_cv_header_working_stdint_h=yes
+              [case "$host_os" in
+                         # Guess yes on native Windows.
+                 mingw*) gl_cv_header_working_stdint_h="guessing yes" ;;
+                         # In general, assume it works.
+                 *)      gl_cv_header_working_stdint_h="guessing yes" ;;
+               esac
               ])
          ])
       ])
@@ -299,15 +306,16 @@ static const char *macro_values[] =
   HAVE_SYS_BITYPES_H=0
   HAVE_SYS_INTTYPES_H=0
   STDINT_H=stdint.h
-  if test "$gl_cv_header_working_stdint_h" = yes; then
-    HAVE_C99_STDINT_H=1
-    dnl Now see whether the system <stdint.h> works without
-    dnl __STDC_CONSTANT_MACROS/__STDC_LIMIT_MACROS defined.
-    AC_CACHE_CHECK([whether stdint.h predates C++11],
-      [gl_cv_header_stdint_predates_cxx11_h],
-      [gl_cv_header_stdint_predates_cxx11_h=yes
-       AC_COMPILE_IFELSE([
-         AC_LANG_PROGRAM([[
+  case "$gl_cv_header_working_stdint_h" in
+    *yes)
+      HAVE_C99_STDINT_H=1
+      dnl Now see whether the system <stdint.h> works without
+      dnl __STDC_CONSTANT_MACROS/__STDC_LIMIT_MACROS defined.
+      AC_CACHE_CHECK([whether stdint.h predates C++11],
+        [gl_cv_header_stdint_predates_cxx11_h],
+        [gl_cv_header_stdint_predates_cxx11_h=yes
+         AC_COMPILE_IFELSE([
+           AC_LANG_PROGRAM([[
 #define _GL_JUST_INCLUDE_SYSTEM_STDINT_H 1 /* work if build isn't clean */
 #include <stdint.h>
 ]
@@ -315,49 +323,50 @@ gl_STDINT_INCLUDES
 [
 intmax_t im = INTMAX_MAX;
 int32_t i32 = INT32_C (0x7fffffff);
-         ]])],
-         [gl_cv_header_stdint_predates_cxx11_h=no])])
+           ]])],
+           [gl_cv_header_stdint_predates_cxx11_h=no])])
 
-    if test "$gl_cv_header_stdint_predates_cxx11_h" = yes; then
-      AC_DEFINE([__STDC_CONSTANT_MACROS], [1],
-                [Define to 1 if the system <stdint.h> predates C++11.])
-      AC_DEFINE([__STDC_LIMIT_MACROS], [1],
-                [Define to 1 if the system <stdint.h> predates C++11.])
-    fi
-    AC_CACHE_CHECK([whether stdint.h has UINTMAX_WIDTH etc.],
-      [gl_cv_header_stdint_width],
-      [gl_cv_header_stdint_width=no
-       AC_COMPILE_IFELSE(
-         [AC_LANG_PROGRAM([[
-            /* Work if build is not clean.  */
-            #define _GL_JUST_INCLUDE_SYSTEM_STDINT_H 1
-            #ifndef __STDC_WANT_IEC_60559_BFP_EXT__
-             #define __STDC_WANT_IEC_60559_BFP_EXT__ 1
-            #endif
-            #include <stdint.h>
-            ]gl_STDINT_INCLUDES[
-            int iw = UINTMAX_WIDTH;
-            ]])],
-         [gl_cv_header_stdint_width=yes])])
-    if test "$gl_cv_header_stdint_width" = yes; then
-      STDINT_H=
-    fi
-  else
-    dnl Check for <sys/inttypes.h>, and for
-    dnl <sys/bitypes.h> (used in Linux libc4 >= 4.6.7 and libc5).
-    AC_CHECK_HEADERS([sys/inttypes.h sys/bitypes.h])
-    if test $ac_cv_header_sys_inttypes_h = yes; then
-      HAVE_SYS_INTTYPES_H=1
-    fi
-    if test $ac_cv_header_sys_bitypes_h = yes; then
-      HAVE_SYS_BITYPES_H=1
-    fi
-    gl_STDINT_TYPE_PROPERTIES
-  fi
+      if test "$gl_cv_header_stdint_predates_cxx11_h" = yes; then
+        AC_DEFINE([__STDC_CONSTANT_MACROS], [1],
+                  [Define to 1 if the system <stdint.h> predates C++11.])
+        AC_DEFINE([__STDC_LIMIT_MACROS], [1],
+                  [Define to 1 if the system <stdint.h> predates C++11.])
+      fi
+      AC_CACHE_CHECK([whether stdint.h has UINTMAX_WIDTH etc.],
+        [gl_cv_header_stdint_width],
+        [gl_cv_header_stdint_width=no
+         AC_COMPILE_IFELSE(
+           [AC_LANG_PROGRAM([[
+              /* Work if build is not clean.  */
+              #define _GL_JUST_INCLUDE_SYSTEM_STDINT_H 1
+              #ifndef __STDC_WANT_IEC_60559_BFP_EXT__
+               #define __STDC_WANT_IEC_60559_BFP_EXT__ 1
+              #endif
+              #include <stdint.h>
+              ]gl_STDINT_INCLUDES[
+              int iw = UINTMAX_WIDTH;
+              ]])],
+           [gl_cv_header_stdint_width=yes])])
+      if test "$gl_cv_header_stdint_width" = yes; then
+        STDINT_H=
+      fi
+      ;;
+    *)
+      dnl Check for <sys/inttypes.h>, and for
+      dnl <sys/bitypes.h> (used in Linux libc4 >= 4.6.7 and libc5).
+      AC_CHECK_HEADERS([sys/inttypes.h sys/bitypes.h])
+      if test $ac_cv_header_sys_inttypes_h = yes; then
+        HAVE_SYS_INTTYPES_H=1
+      fi
+      if test $ac_cv_header_sys_bitypes_h = yes; then
+        HAVE_SYS_BITYPES_H=1
+      fi
+      gl_STDINT_TYPE_PROPERTIES
+      ;;
+  esac
 
   dnl The substitute stdint.h needs the substitute limit.h's _GL_INTEGER_WIDTH.
-  LIMITS_H=limits.h
-  AM_CONDITIONAL([GL_GENERATE_LIMITS_H], [test -n "$LIMITS_H"])
+  gl_REPLACE_LIMITS_H
 
   AC_SUBST([HAVE_C99_STDINT_H])
   AC_SUBST([HAVE_SYS_BITYPES_H])
@@ -533,9 +542,3 @@ AC_DEFUN([gl_STDINT_TYPE_PROPERTIES],
     BITSIZEOF_WINT_T=32
   fi
 ])
-
-dnl Autoconf >= 2.61 has AC_COMPUTE_INT built-in.
-dnl Remove this when we can assume autoconf >= 2.61.
-m4_ifdef([AC_COMPUTE_INT], [], [
-  AC_DEFUN([AC_COMPUTE_INT], [_AC_COMPUTE_INT([$2],[$1],[$3],[$4])])
-])

m4/sys_types_h.m4

@@ -1,5 +1,5 @@
-# sys_types_h.m4 serial 8
-dnl Copyright (C) 2011-2017 Free Software Foundation, Inc.
+# sys_types_h.m4 serial 9
+dnl Copyright (C) 2011-2019 Free Software Foundation, Inc.
 dnl This file is free software; the Free Software Foundation
 dnl gives unlimited permission to copy and/or distribute it,
 dnl with or without modifications, as long as this notice is preserved.
@@ -35,12 +35,12 @@ AC_DEFUN([gl_SYS_TYPES_H_DEFAULTS],
 ])
 
 # This works around a buggy version in autoconf <= 2.69.
-# See <https://lists.gnu.org/archive/html/autoconf/2016-08/msg00014.html>
+# See <https://lists.gnu.org/r/autoconf/2016-08/msg00014.html>
 
 m4_version_prereq([2.70], [], [
 
 # This is taken from the following Autoconf patch:
-# http://git.sv.gnu.org/cgit/autoconf.git/commit/?id=e17a30e98
+# https://git.savannah.gnu.org/cgit/autoconf.git/commit/?id=e17a30e987d7ee695fb4294a82d987ec3dc9b974
 
 m4_undefine([AC_HEADER_MAJOR])
 AC_DEFUN([AC_HEADER_MAJOR],

m4/wint_t.m4

@@ -1,5 +1,5 @@
 # wint_t.m4 serial 7
-dnl Copyright (C) 2003, 2007-2017 Free Software Foundation, Inc.
+dnl Copyright (C) 2003, 2007-2019 Free Software Foundation, Inc.
 dnl This file is free software; the Free Software Foundation
 dnl gives unlimited permission to copy and/or distribute it,
 dnl with or without modifications, as long as this notice is preserved.

m4/zzgnulib.m4

@@ -0,0 +1,25 @@
+# zzgnulib.m4
+# serial 1
+dnl Copyright (C) 2020-2025 Free Software Foundation, Inc.
+dnl This file is free software; the Free Software Foundation
+dnl gives unlimited permission to copy and/or distribute it,
+dnl with or without modifications, as long as this notice is preserved.
+dnl This file is offered as-is, without any warranty.
+
+dnl This file must be named something that sorts after all other
+dnl package- or gnulib-provided .m4 files - at least for those packages
+dnl that redefine AC_PROG_CC.
+
+dnl Redefine AC_PROG_CC so that it ends with invocations of gl_COMPILER_CLANG
+dnl and gl_COMPILER_PREPARE_CHECK_DECL.
+m4_define([AC_PROG_CC],
+  m4_defn([AC_PROG_CC])[
+gl_COMPILER_CLANG
+gl_COMPILER_PREPARE_CHECK_DECL
+])
+
+# gl_ZZGNULIB
+# -----------
+# Witness macro that this file has been included.  Needed to force
+# Automake to include this file after all other gnulib .m4 files.
+AC_DEFUN([gl_ZZGNULIB])

plugin-manager.c

@@ -0,0 +1,127 @@
+/* fuse-overlayfs: Overlay Filesystem in Userspace
+
+   Copyright (C) 2019 Red Hat Inc.
+
+   This program is free software: you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation; either version 2 of the License, or
+   (at your option) any later version.
+
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with this program.  If not, see <http://www.gnu.org/licenses/>.
+*/
+#define _GNU_SOURCE
+#define _FILE_OFFSET_BITS 64
+
+#include <config.h>
+#include <plugin.h>
+#include <stdlib.h>
+#include <fuse_overlayfs_error.h>
+#include <errno.h>
+#include <string.h>
+
+struct ovl_plugin_context *
+load_plugins (const char *plugins)
+{
+  char *saveptr = NULL, *it;
+  cleanup_free char *buf = NULL;
+  struct ovl_plugin_context *ctx;
+
+  ctx = calloc (1, sizeof (*ctx));
+  if (ctx == NULL)
+    error (EXIT_FAILURE, errno, "cannot allocate context");
+
+  buf = strdup (plugins);
+  if (buf == NULL)
+    error (EXIT_FAILURE, errno, "cannot allocate memory");
+
+  for (it = strtok_r (buf, ":", &saveptr); it; it = strtok_r (NULL, ":", &saveptr))
+    plugin_load_one (ctx, it);
+
+  return ctx;
+}
+
+void
+plugin_load_one (struct ovl_plugin_context *context, const char *path)
+{
+  plugin_name name;
+  struct ovl_plugin *p;
+  plugin_version version;
+  void *handle = dlopen (path, RTLD_NOW | RTLD_LOCAL);
+  if (! handle)
+    error (EXIT_FAILURE, 0, "cannot load plugin %s: %s", path, dlerror ());
+
+  p = calloc (1, sizeof (*p));
+  if (p == NULL)
+    error (EXIT_FAILURE, errno, "cannot load plugin %s", path);
+  p->next = context->plugins;
+
+  version = dlsym (handle, "plugin_version");
+  if (version == NULL)
+    error (EXIT_FAILURE, 0, "cannot find symbol `plugin_version` in plugin %s", path);
+
+  if (version () != 1)
+    error (EXIT_FAILURE, 0, "invalid plugin version for %s", path);
+
+  p->handle = handle;
+  name = dlsym (handle, "plugin_name");
+  if (name == NULL)
+    error (EXIT_FAILURE, 0, "cannot find symbol `plugin_name` in plugin %s", path);
+
+  p->name = name ();
+
+  if (plugin_find (context, p->name))
+    error (EXIT_FAILURE, 0, "plugin %s added twice", p->name);
+
+  p->load = dlsym (handle, "plugin_load");
+  if (p->load == NULL)
+    error (EXIT_FAILURE, 0, "cannot find symbol `plugin_load` in plugin %s", path);
+
+  p->release = dlsym (handle, "plugin_release");
+  if (p->release == NULL)
+    error (EXIT_FAILURE, 0, "cannot find symbol `plugin_release` in plugin %s", path);
+
+  context->plugins = p;
+}
+
+struct ovl_plugin *
+plugin_find (struct ovl_plugin_context *context, const char *name)
+{
+  struct ovl_plugin *it;
+
+  for (it = context->plugins; it; it = it->next)
+    {
+      if (strcmp (name, it->name) == 0)
+        return it;
+    }
+  return NULL;
+}
+
+int
+plugin_free_all (struct ovl_plugin_context *context)
+{
+  struct ovl_plugin *it, *next;
+
+  it = context->plugins;
+  while (it)
+    {
+      next = it->next;
+
+      it->release ();
+
+      /* Skip dlclose (it->handle) as it causes plugins written in Go to crash.  */
+
+      free (it);
+
+      it = next;
+    }
+
+  free (context);
+
+  return 0;
+}

plugin-manager.h

@@ -0,0 +1,44 @@
+/* fuse-overlayfs: Overlay Filesystem in Userspace
+
+   Copyright (C) 2019 Red Hat Inc.
+
+   This program is free software: you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation; either version 2 of the License, or
+   (at your option) any later version.
+
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with this program.  If not, see <http://www.gnu.org/licenses/>.
+*/
+
+#ifndef PLUGIN_MANAGER_H
+#define PLUGIN_MANAGER_H
+#include <config.h>
+
+#include <dlfcn.h>
+
+struct ovl_plugin_context
+{
+  struct ovl_plugin *plugins;
+};
+
+void plugin_load_one (struct ovl_plugin_context *context, const char *path);
+int plugin_free_all (struct ovl_plugin_context *context);
+struct ovl_plugin *plugin_find (struct ovl_plugin_context *context, const char *name);
+struct ovl_plugin_context *load_plugins (const char *plugins);
+
+#endif
+
+/* taken from glibc unistd.h and fixes musl */
+#ifndef TEMP_FAILURE_RETRY
+#define TEMP_FAILURE_RETRY(expression) \
+  (__extension__ ({ long int __result;                                                     \
+       do __result = (long int) (expression);                                 \
+       while (__result == -1L && errno == EINTR);                             \
+       __result; }))
+#endif

plugin.h

@@ -0,0 +1,41 @@
+/* fuse-overlayfs: Overlay Filesystem in Userspace
+
+   Copyright (C) 2019 Red Hat Inc.
+
+   This program is free software: you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation; either version 2 of the License, or
+   (at your option) any later version.
+
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with this program.  If not, see <http://www.gnu.org/licenses/>.
+*/
+
+#ifndef PLUGIN_H
+#define PLUGIN_H
+#include <config.h>
+
+#include <utils.h>
+#include <fuse-overlayfs.h>
+
+typedef struct data_source *(*plugin_load_data_source) (const char *opaque, const char *path);
+typedef int (*plugin_release) ();
+typedef const char *(*plugin_name) ();
+typedef int (*plugin_version) ();
+
+struct ovl_plugin
+{
+  struct ovl_plugin *next;
+  const char *name;
+  void *handle;
+
+  plugin_load_data_source load;
+  plugin_release release;
+};
+
+#endif

rpm/fuse-overlayfs.spec.template

@@ -3,7 +3,7 @@ Name: fuse-overlayfs
 Version: #VERSION#
 Release: 1%{?dist}
 Source0: %{url}/archive/%{name}-%{version}.tar.gz
-License: GPLv3+
+License: GPLv2+
 URL: https://github.com/giuseppe/fuse-overlayfs
 
 # We always run autogen.sh
@@ -14,20 +14,42 @@ BuildRequires: fuse3-devel
 Requires: fuse3
 
 %description
-fuse-overlayfs is a FUSE overlayfs implementation.
+%{summary}.
+
+%package devel
+Summary: %{summary}
+BuildArch: noarch
+
+%description devel
+%{summary}
+
+This package contains library source intended for
+building other packages which use import path with
+%{import_path} prefix.
 
 %prep
 %autosetup -n %{name}-%{version}
 
 %build
-env NOCONFIGURE=1 ./autogen.sh
-%configure --disable-silent-rules
-
-%make_build
+./autogen.sh
+./configure --prefix=%{_usr} --libdir=%{_libdir}
+%{__make}
 
 %install
-%make_install INSTALL="install -p"
+make DESTDIR=%{buildroot} install
+install -d %{buildroot}%{_usr}/lib/modules-load.d
+echo fuse > %{buildroot}%{_usr}/lib/modules-load.d/fuse-overlayfs.conf
+
+%post
+modprobe fuse > /dev/null 2>&1 || :
+
+%check
+
+#define license tag if not already defined
+%{!?_licensedir:%global license %doc}
 
 %files
 %license COPYING
 %{_bindir}/%{name}
+%{_mandir}/man1/*
+%{_usr}/lib/modules-load.d/fuse-overlayfs.conf

tests/alpine.sh

@@ -0,0 +1,11 @@
+#!/bin/sh
+
+cd "$(dirname "$0")"
+
+set -ex
+
+docker build -t fuse-overlayfs:alpine -f ../Containerfile.alpine ..
+
+docker run --privileged --rm --entrypoint /unlink.sh -w /tmp \
+	-e EXPECT_UMOUNT_STATUS=1 \
+	-v "$(pwd)/unlink.sh:/unlink.sh" fuse-overlayfs:alpine

tests/fedora-installs.sh

@@ -2,27 +2,274 @@
 
 set -xeuo pipefail
 
-mkdir lower upper workdir merged
+mkdir lower:1 upper:2 workdir:3 merged
 
-fuse-overlayfs -o lowerdir=lower,upperdir=upper,workdir=workdir,suid,dev merged
+fuse-overlayfs -o 'sync=0,lowerdir=lower\\:1,upperdir=upper\\:2,workdir=workdir\\:3,suid,dev' merged
 
-docker run --rm -ti -v merged:/merged fedora dnf --installroot /merged --releasever 30 install -y glibc-common gedit
+docker run --rm -v $(pwd)/merged:/merged fedora dnf --use-host-config --installroot /merged --releasever 41 install -y glibc-common gedit
 
 umount merged
 
 # Make sure workdir is empty, and move the upper layer down
-rm -rf workdir lower
-mv upper lower
+rm -rf lower:1 workdir:3
+mv upper:2 lower
 mkdir upper workdir
 
-fuse-overlayfs -o lowerdir=lower,upperdir=upper,workdir=workdir,suid,dev merged
+gcc -static -o suid-test $(dirname $0)/suid-test.c
+
+fuse-overlayfs -o sync=0,threaded=1,lowerdir=lower,upperdir=upper,workdir=workdir,suid,dev merged
+SUID_TEST=$(pwd)/suid-test
+(cd merged; $SUID_TEST)
+
+# Test the number of hard links for populated directories is > 2
+test $(stat -c %h merged/etc) -gt 2
+ls merged/usr
+test $(stat -c %h merged/usr) -gt 2
+
+stat -c %A upper/suid | grep s
+stat -c %a upper/nosuid | grep -v s
 
 # Install some big packages
-docker run --rm -ti -v merged:/merged fedora dnf --installroot /merged --releasever 30 install -y emacs texlive
+docker run --rm -v $(pwd)/merged:/merged fedora dnf --use-host-config --installroot /merged --releasever 41 install -y emacs texlive
 
-docker run --rm -ti -v merged:/merged fedora sh -c 'rm /merged/usr/share/glib-2.0/schemas/gschemas.compiled; glib-compile-schemas /merged/usr/share/glib-2.0/schemas/'
+docker run --rm -v $(pwd)/merged:/merged fedora sh -c 'rm /merged/usr/share/glib-2.0/schemas/gschemas.compiled; glib-compile-schemas /merged/usr/share/glib-2.0/schemas/'
 
 umount merged
-fuse-overlayfs -o lowerdir=lower,upperdir=upper,workdir=workdir,suid,dev merged
+fuse-overlayfs -o sync=0,lowerdir=lower,upperdir=upper,workdir=workdir,suid,dev merged
 
-docker run --rm -ti -v merged:/merged fedora sh -c 'rm -rf /merged/usr/share/glib-2.0/'
+docker run --rm -v $(pwd)/merged:/merged fedora sh -c 'rm -rf /merged/usr/share/glib-2.0/'
+
+tar -c --to-stdout $(pwd)/merged > /dev/null
+
+umount merged
+rm -rf workdir lower upper
+mkdir upper workdir lower
+
+# fast_ino_check
+fuse-overlayfs -o fast_ino_check=1,sync=0,lowerdir=lower,upperdir=upper,workdir=workdir,suid,dev merged
+
+docker run --rm -v $(pwd)/merged:/merged fedora dnf --use-host-config --installroot /merged --releasever 41 install -y glibc-common gedit
+
+mkdir merged/a-directory
+
+python -c 'import socket; socket.socket(socket.AF_UNIX, socket.SOCK_DGRAM).bind("merged/unix-socket")'
+
+setfattr -n user.foo -v bar merged/a-directory
+getfattr -d merged/a-directory | grep bar
+getfattr --only-values -n user.foo merged/a-directory | grep bar
+getfattr --only-values -n user.foo upper/a-directory | grep bar
+
+umount merged
+
+touch lower/file-lower-layer
+
+# set a "big" xattr
+setfattr -n user.big-xattr -v "$(seq 1000 | tr -d '\n')" lower/file-lower-layer
+
+# no upper layer
+fuse-overlayfs -o lowerdir=lower merged
+
+tar -c --to-stdout $(pwd)/merged > /dev/null
+
+set +o pipefail
+
+touch merged/a 2>&1 | grep Read-only
+touch merged/file-lower-layer 2>&1 | grep Read-only
+touch merged/usr 2>&1 | grep Read-only
+mkdir merged/abcd12345 2>&1 | grep Read-only
+ln merged/file-lower-layer merged/file-lower-layer-link 2>&1 | grep Read-only
+ln -s merged/file-lower-layer merged/a-symlink 2>&1 | grep Read-only
+
+umount merged
+
+# https://github.com/containers/fuse-overlayfs/issues/136
+rm -rf lower1 lower2 lower3 lower upper workdir merged
+mkdir lower1 lower2 lower3 upper workdir merged
+
+mkdir -p lower1/dir1/dir2
+touch lower1/dir1/dir2/foo
+touch lower2/.wh.dir1
+mkdir -p lower3/dir1/dir2
+
+fuse-overlayfs -o lowerdir=lower3:lower2:lower1,upperdir=upper,workdir=workdir merged
+
+test \! -e merged/dir1/dir2/foo
+
+umount merged
+
+# https://github.com/containers/fuse-overlayfs/issues/138
+rm -rf lower1 lower2 lower3 lower upper workdir merged
+mkdir lower1 lower2 lower3 upper workdir merged
+
+mkdir -p lower1/dir1/dir2
+touch lower1/dir1/dir2/foo
+mkdir -p lower3/dir1/dir2
+touch lower3/dir1/dir2/.wh..wh..opq
+
+fuse-overlayfs -o lowerdir=lower3:lower2:lower1,upperdir=upper,workdir=workdir merged
+
+test \! -e merged/dir1/dir2/foo
+
+umount merged
+
+# https://github.com/containers/fuse-overlayfs/issues/143
+rm -rf lower upper workdir merged
+mkdir lower upper workdir merged
+touch lower/deps.txt
+ln -s src/deps.txt upper/
+
+fuse-overlayfs -o lowerdir=lower,upperdir=upper,workdir=workdir merged
+
+test \! -e merged/dir1/dir2/foo
+
+touch -h merged/deps.txt
+
+
+# https://github.com/containers/fuse-overlayfs/issues/151
+
+umount merged
+
+rm -rf lower upper workdir merged
+mkdir lower upper workdir merged
+mkdir lower/a lower/b
+touch lower/.wh.test lower/a/test lower/b/test
+
+fuse-overlayfs -o lowerdir=lower,upperdir=upper,workdir=workdir merged
+
+test -e merged/a/test
+
+ls -l merged/b
+
+test -e merged/b/test
+
+#### Correct number of directory nlink
+
+umount merged
+
+rm -rf lower upper workdir merged
+mkdir lower upper workdir merged
+mkdir lower/a lower/a/1 lower/a/2 lower/a/3
+
+fuse-overlayfs -o lowerdir=lower,upperdir=upper,workdir=workdir merged
+
+test $(stat -c %h merged/a) = 5
+
+mkdir merged/a/4
+
+test $(stat -c %h merged/a) = 6
+
+rm -rf merged/a/4
+
+test $(stat -c %h merged/a) = 5
+
+rm -rf merged/a/3
+
+test $(stat -c %h merged/a) = 4
+
+# symlink mtime
+
+touch merged/afile
+ln -s afile merged/alink
+touch -h -d "2020-01-02 12:13:14" merged/alink
+stat --format "%y" merged/alink | grep "12:13:14"
+stat --format "%x" merged/alink | grep "12:13:14"
+
+# file mtime
+touch -h -d "2020-01-02 11:12:13" merged/afile
+stat --format "%y" merged/afile | grep "11:12:13"
+stat --format "%x" merged/afile | grep "11:12:13"
+
+# dir mtime
+mkdir merged/adir
+touch -h -d "2020-01-02 10:11:12" merged/adir
+stat --format "%y" merged/adir | grep "10:11:12"
+stat --format "%x" merged/adir | grep "10:11:12"
+
+upper_max_filename_len=$(stat -f -c %l upper)
+merged_max_filename_len=$(stat -f -c %l merged)
+
+test $merged_max_filename_len -lt $upper_max_filename_len
+
+if touch merged/$(printf %${upper_max_filename_len}s | tr ' ' A}); then
+    exit 1
+fi
+
+touch merged/$(printf %${merged_max_filename_len}s | tr ' ' A})
+
+# If a file is removed but referenced, we must still be able to access it.
+echo 12345 | tee merged/toremove
+exec 3<> merged/toremove
+sleep 90 &
+exec 3>&-
+sleep_pid=$!
+rm merged/toremove
+grep 12345 /proc/$sleep_pid/fd/3
+
+touch merged/a merged/b
+chmod 6 merged/a
+mv merged/a merged/x
+mv merged/b merged/a
+
+# https://github.com/containers/fuse-overlayfs/issues/279
+umount -l merged
+
+rm -rf lower upper workdir merged
+mkdir lower upper workdir merged
+mkdir lower/test
+touch lower/test/a.txt
+
+fuse-overlayfs -o lowerdir=lower,upperdir=upper,workdir=workdir merged
+
+(cd merged/test; touch a.txt; mv a.txt a2.txt; touch a3.txt; ln -s a3.txt a.txt)
+
+if test -e upperdir/test/.wh.a.txt; then
+   echo "whiteout file still exists" >&2
+   exit 1
+fi
+
+# https://github.com/containers/fuse-overlayfs/issues/306
+umount -l merged
+
+rm -rf lower upper workdir merged
+mkdir lower upper workdir merged
+
+mkdir -p lower/a/b
+fuse-overlayfs -o lowerdir=lower,upperdir=upper,workdir=workdir merged
+
+rm -rf merged/a
+mkdir -p merged/a/b
+rm -rf merged/a/b
+test \! -e upper/a/b
+
+mknod merged/dev-foo c 10 175
+attr -l merged/dev-foo
+
+# https://github.com/containers/fuse-overlayfs/issues/337
+umount -l merged
+
+rm -rf lower upper workdir merged
+mkdir lower upper workdir merged
+
+mkdir upper/foo
+ln -s not/existing lower/foo
+
+fuse-overlayfs -o lowerdir=lower,upperdir=upper,workdir=workdir merged
+
+stat merged/foo
+
+umount merged
+
+# https://github.com/containers/fuse-overlayfs/issues/444
+
+rm -rf lower upper workdir merged
+mkdir lower upper workdir merged
+
+mkdir -p lower/base/test/test1
+touch lower/base/test/test1/test1-file
+
+fuse-overlayfs -o lowerdir=lower,upperdir=upper,workdir=workdir merged
+
+mv merged/base/test/test1 merged/base/test/tmp
+cp -r merged/base/test/tmp merged/base/test/test1
+
+umount merged

tests/suid-test.c

@@ -0,0 +1,30 @@
+#define _GNU_SOURCE
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <unistd.h>
+#include <fcntl.h>
+#include <sys/stat.h>
+
+int
+main ()
+{
+  int fd;
+
+  unlink ("suid");
+  unlink ("nosuid");
+
+  fd = open ("suid", O_WRONLY | O_CREAT | O_EXCL);
+  write (fd, "1", 1);
+  fchown (fd, 0, 0);
+  fchmod (fd, S_ISUID | 0755);
+  close (fd);
+
+  fd = open ("nosuid", O_WRONLY | O_CREAT | O_EXCL);
+  write (fd, "1", 1);
+  fchown (fd, 0, 0);
+  fchmod (fd, S_ISUID | 0755);
+  write (fd, "2", 1);
+  close (fd);
+  return 0;
+}

tests/unlink.sh

@@ -1,13 +1,29 @@
 #!/bin/sh
 
+set -ex
+
+rm -rf unlink-test
+mkdir unlink-test
+
+cd unlink-test
+
 mkdir lower upper workdir merged
 
 touch lower/a
 
 fuse-overlayfs -o lowerdir=lower,upperdir=upper,workdir=workdir,suid,dev merged
 
-unlink lower/a
+unlink merged/a
 
-test \! -e lower/a
+test \! -e merged/a
 
-umount merged
+echo hello > merged/foo
+ln merged/foo merged/foo2
+rm merged/foo
+grep hello merged/foo2
+ln merged/foo2 merged/foo
+echo world >> merged/foo2
+grep hello merged/foo
+grep world merged/foo
+
+umount merged || [ $? -eq "${EXPECT_UMOUNT_STATUS:-0}" ]

tests/unpriv.sh

@@ -0,0 +1,55 @@
+#!/bin/sh
+
+set -ex
+
+test $(id -u) -gt 0
+
+rm -rf unpriv-test
+mkdir unpriv-test
+
+cd unpriv-test
+
+mkdir lower upper workdir merged
+
+touch lower/a lower/b
+chmod 444 lower/a lower/b
+
+fuse-overlayfs -o lowerdir=lower,upperdir=upper,workdir=workdir merged
+
+rm -f merged/a
+chmod 406 merged/b
+
+test \! -e merged/a
+test $(stat --printf=%a merged/b) -eq 406
+test $(stat --printf=%a upper/b) -eq 406
+if [ ${FUSE_OVERLAYFS_DISABLE_OVL_WHITEOUT:-0} -eq 1 ]; then
+    test -e upper/.wh.a
+else
+    test -c upper/a
+fi
+
+fusermount -u merged || [ $? -eq "${EXPECT_UMOUNT_STATUS:-0}" ]
+
+# xattr_permissions=2
+rm -rf lower upper workdir merged
+mkdir lower upper workdir merged
+
+touch upper/file
+unshare -r setcap cap_net_admin+ep upper/file
+
+fuse-overlayfs -o lowerdir=lower,upperdir=upper,workdir=workdir,xattr_permissions=2 merged
+
+# Ensure the security xattr namespace is isolated.
+test "$(unshare -r getcap merged/file)" = ''
+unshare -r setcap cap_net_admin+ep merged/file
+test "$(unshare -r getcap merged/file)" = 'merged/file cap_net_admin=ep'
+
+# Ensure UID is preserved with chgrp.
+podman unshare chgrp 1 merged/file
+test $(podman unshare stat -c %u:%g merged/file) = 0:1
+
+# Ensure UID and GID are preserved with chmod.
+chmod 600 merged/file
+test $(podman unshare stat -c %u:%g merged/file) = 0:1
+
+fusermount -u merged || [ $? -eq "${EXPECT_UMOUNT_STATUS:-0}" ]

utils.c

@@ -0,0 +1,387 @@
+/* fuse-overlayfs: Overlay Filesystem in Userspace
+
+   Copyright (C) 2019 Red Hat Inc.
+
+   This program is free software: you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation; either version 2 of the License, or
+   (at your option) any later version.
+
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with this program.  If not, see <http://www.gnu.org/licenses/>.
+*/
+
+#define _GNU_SOURCE
+#define _FILE_OFFSET_BITS 64
+
+#include <config.h>
+#include "utils.h"
+#include <errno.h>
+#include <fcntl.h>
+#include <string.h>
+#include <sys/sysmacros.h>
+#include <sys/syscall.h>
+#include <stdint.h>
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <sys/xattr.h>
+
+#ifndef TEMP_FAILURE_RETRY
+#  define TEMP_FAILURE_RETRY(expression) \
+    (__extension__ ({ long int __result;                                                     \
+       do __result = (long int) (expression);                                 \
+       while (__result == -1L && errno == EINTR);                             \
+       __result; }))
+#endif
+
+#ifndef RESOLVE_IN_ROOT
+#  define RESOLVE_IN_ROOT 0x10
+#endif
+#ifndef __NR_openat2
+#  define __NR_openat2 437
+#endif
+
+/* uClibc and uClibc-ng don't provide O_TMPFILE */
+#ifndef O_TMPFILE
+#  define O_TMPFILE (020000000 | O_DIRECTORY)
+#endif
+
+/* List of all valid flags for the open/openat flags argument: */
+#define VALID_OPEN_FLAGS \
+  (O_RDONLY | O_WRONLY | O_RDWR | O_CREAT | O_EXCL | O_NOCTTY | O_TRUNC | O_APPEND | O_NDELAY | O_NONBLOCK | O_NDELAY | O_SYNC | O_DSYNC | FASYNC | O_DIRECT | O_LARGEFILE | O_DIRECTORY | O_NOFOLLOW | O_NOATIME | O_CLOEXEC | O_PATH | O_TMPFILE)
+
+static int
+syscall_openat2 (int dirfd, const char *path, uint64_t flags, uint64_t mode, uint64_t resolve)
+{
+  struct openat2_open_how
+  {
+    uint64_t flags;
+    uint64_t mode;
+    uint64_t resolve;
+  } how = {
+    .flags = flags & VALID_OPEN_FLAGS,
+    .mode = (flags & O_CREAT) ? (mode & 07777) : 0,
+    .resolve = resolve,
+  };
+
+  return (int) syscall (__NR_openat2, dirfd, path, &how, sizeof (how), 0);
+}
+
+int
+safe_openat (int dirfd, const char *pathname, int flags, mode_t mode)
+{
+  static bool openat2_supported = true;
+
+  if (openat2_supported)
+    {
+      int ret;
+
+      ret = syscall_openat2 (dirfd, pathname, flags, mode, RESOLVE_IN_ROOT);
+      if (ret < 0)
+        {
+          if (errno == ENOSYS)
+            openat2_supported = false;
+          if (errno == ENOSYS || errno == EINVAL)
+            goto fallback;
+        }
+      return ret;
+    }
+fallback:
+  return openat (dirfd, pathname, flags, mode);
+}
+
+int
+file_exists_at (int dirfd, const char *pathname)
+{
+  int ret = faccessat (dirfd, pathname, F_OK, AT_SYMLINK_NOFOLLOW | AT_EACCESS);
+  if (ret < 0 && errno == EINVAL)
+    {
+      struct stat buf;
+      return fstatat (dirfd, pathname, &buf, AT_SYMLINK_NOFOLLOW);
+    }
+  return ret;
+}
+
+#ifdef HAVE_STATX
+void
+copy_statx_to_stat_time (struct statx_timestamp *stx, struct timespec *st)
+{
+  st->tv_sec = stx->tv_sec;
+  st->tv_nsec = stx->tv_nsec;
+}
+
+void
+statx_to_stat (struct statx *stx, struct stat *st)
+{
+  st->st_dev = makedev (stx->stx_dev_major, stx->stx_dev_minor);
+  st->st_ino = stx->stx_ino;
+  st->st_mode = stx->stx_mode;
+  st->st_nlink = stx->stx_nlink;
+  st->st_uid = stx->stx_uid;
+  st->st_gid = stx->stx_gid;
+  st->st_rdev = makedev (stx->stx_rdev_major, stx->stx_rdev_minor);
+  st->st_size = stx->stx_size;
+  st->st_blksize = stx->stx_blksize;
+  st->st_blocks = stx->stx_blocks;
+  copy_statx_to_stat_time (&stx->stx_atime, &st->st_atim);
+  copy_statx_to_stat_time (&stx->stx_ctime, &st->st_ctim);
+  copy_statx_to_stat_time (&stx->stx_mtime, &st->st_mtim);
+}
+#endif
+
+int
+strconcat3 (char *dest, size_t size, const char *s1, const char *s2, const char *s3)
+{
+  size_t t;
+  char *current = dest;
+
+  size--;
+
+  if (s1)
+    {
+      t = strlen (s1);
+      if (t > size)
+        t = size;
+
+      memcpy (current, s1, t);
+      current += t;
+
+      size -= t;
+    }
+  if (s2)
+    {
+      t = strlen (s2);
+      if (t > size)
+        t = size;
+
+      memcpy (current, s2, t);
+      current += t;
+
+      size -= t;
+    }
+  if (s3)
+    {
+      t = strlen (s3);
+      if (t > size)
+        t = size;
+
+      memcpy (current, s3, t);
+      current += t;
+    }
+  *current = '\0';
+
+  return current - dest;
+}
+
+void
+cleanup_freep (void *p)
+{
+  void **pp = (void **) p;
+  free (*pp);
+}
+
+void
+cleanup_filep (FILE **f)
+{
+  FILE *file = *f;
+  if (file)
+    (void) fclose (file);
+}
+
+void
+cleanup_closep (void *p)
+{
+  int *pp = p;
+  if (*pp >= 0)
+    TEMP_FAILURE_RETRY (close (*pp));
+}
+
+void
+cleanup_dirp (DIR **p)
+{
+  DIR *dir = *p;
+  if (dir)
+    closedir (dir);
+}
+
+int
+open_fd_or_get_path (struct ovl_layer *l, const char *path, char *out, int *fd, int flags)
+{
+  out[0] = '\0';
+
+  *fd = l->ds->openat (l, path, O_NONBLOCK | O_NOFOLLOW | flags, 0);
+  if (*fd < 0 && (errno == ELOOP || errno == EISDIR || errno == ENXIO))
+    {
+      strconcat3 (out, PATH_MAX, l->path, "/", path);
+      return 0;
+    }
+
+  return *fd;
+}
+
+int
+read_device (const char *s, dev_t *dev)
+{
+  unsigned int major, minor;
+  int ret;
+
+  while (*s == '-')
+    s++;
+
+  ret = sscanf (s, "%u-%u", &major, &minor);
+  if (ret != 2)
+    {
+      errno = EINVAL;
+      return -1;
+    }
+
+  *dev = makedev (major, minor);
+
+  return 0;
+}
+
+int
+override_mode (struct ovl_layer *l, int fd, const char *abs_path, const char *path, struct stat *st)
+{
+  int ret;
+  uid_t uid;
+  gid_t gid;
+  mode_t mode = 0;
+  char buf[64];
+  cleanup_close int cleanup_fd = -1;
+  const char *xattr_name;
+  cleanup_free char *type = NULL;
+
+  switch (st->st_mode & S_IFMT)
+    {
+    case S_IFDIR:
+    case S_IFREG:
+      break;
+
+    default:
+      return 0;
+    }
+
+  switch (l->stat_override_mode)
+    {
+    case STAT_OVERRIDE_NONE:
+      return 0;
+
+    case STAT_OVERRIDE_USER:
+      xattr_name = XATTR_OVERRIDE_STAT;
+      break;
+
+    case STAT_OVERRIDE_PRIVILEGED:
+      xattr_name = XATTR_PRIVILEGED_OVERRIDE_STAT;
+      break;
+
+    case STAT_OVERRIDE_CONTAINERS:
+      xattr_name = XATTR_OVERRIDE_CONTAINERS_STAT;
+      break;
+
+    default:
+      errno = EINVAL;
+      return -1;
+    }
+
+  if (fd >= 0)
+    {
+      ret = fgetxattr (fd, xattr_name, buf, sizeof (buf) - 1);
+    }
+  else if (abs_path)
+    {
+      ret = lgetxattr (abs_path, xattr_name, buf, sizeof (buf) - 1);
+    }
+  else
+    {
+      char full_path[PATH_MAX];
+
+      full_path[0] = '\0';
+      ret = open_fd_or_get_path (l, path, full_path, &cleanup_fd, O_RDONLY);
+      if (ret < 0)
+        return ret;
+      fd = cleanup_fd;
+
+      if (fd >= 0)
+        ret = fgetxattr (fd, xattr_name, buf, sizeof (buf) - 1);
+      else
+        ret = lgetxattr (full_path, xattr_name, buf, sizeof (buf) - 1);
+    }
+
+  if (ret < 0)
+    return errno == ENODATA ? 0 : ret;
+
+  buf[ret] = '\0';
+
+  ret = sscanf (buf, "%d:%d:%o:%ms", &uid, &gid, &mode, &type);
+  if (ret == 4)
+    {
+      if (has_prefix (type, "dir"))
+        mode |= S_IFDIR;
+      else if (has_prefix (type, "file"))
+        mode |= S_IFREG;
+      else if (has_prefix (type, "symlink"))
+        mode |= S_IFLNK;
+      else if (has_prefix (type, "pipe"))
+        mode |= S_IFIFO;
+      else if (has_prefix (type, "socket"))
+        mode |= S_IFSOCK;
+      else if (has_prefix (type, "block"))
+        {
+          mode |= S_IFBLK;
+          ret = read_device (type + strlen ("block"), &st->st_rdev);
+          if (ret < 0)
+            return ret;
+        }
+      else if (has_prefix (type, "char"))
+        {
+          mode |= S_IFCHR;
+          ret = read_device (type + strlen ("char"), &st->st_rdev);
+          if (ret < 0)
+            return ret;
+        }
+      else
+        {
+          errno = EINVAL;
+          return -1;
+        }
+    }
+  else if (ret == 3)
+    {
+      /* If a type is not specified, keep the original one.  */
+      mode |= (st->st_mode & S_IFMT);
+    }
+  else
+    {
+      errno = EINVAL;
+      return -1;
+    }
+
+  st->st_uid = uid;
+  st->st_gid = gid;
+  st->st_mode = mode;
+
+  return 0;
+}
+
+bool
+has_prefix (const char *str, const char *pref)
+{
+  while (1)
+    {
+      if (*pref == '\0')
+        return true;
+      if (*str == '\0')
+        return false;
+      if (*pref != *str)
+        return false;
+      str++;
+      pref++;
+    }
+  return false;
+}

utils.h

@@ -4,7 +4,7 @@
 
    This program is free software: you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
-   the Free Software Foundation; either version 3 of the License, or
+   the Free Software Foundation; either version 2 of the License, or
    (at your option) any later version.
 
    This program is distributed in the hope that it will be useful,
@@ -16,42 +16,52 @@
    along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */
 #ifndef UTILS_H
-# define UTILS_H
+#define UTILS_H
 
-void
-cleanup_freep (void *p)
-{
-  void **pp = (void **) p;
-  free (*pp);
-}
+#ifndef _GNU_SOURCE
+#  define _GNU_SOURCE
+#endif
 
-void
-cleanup_filep (FILE **f)
-{
-  FILE *file = *f;
-  if (file)
-    (void) fclose (file);
-}
+#include <config.h>
+#include <dirent.h>
+#include <fcntl.h>
+#include <limits.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <sys/types.h>
+#include <unistd.h>
+#include "fuse-overlayfs.h"
 
-void
-cleanup_closep (void *p)
-{
-  int *pp = p;
-  if (*pp >= 0)
-    close (*pp);
-}
+#define XATTR_OVERRIDE_STAT "user.fuseoverlayfs.override_stat"
+#define XATTR_PRIVILEGED_OVERRIDE_STAT "security.fuseoverlayfs.override_stat"
+#define XATTR_OVERRIDE_CONTAINERS_STAT "user.containers.override_stat"
 
-void
-cleanup_dirp (DIR **p)
-{
-  DIR *dir = *p;
-  if (dir)
-    closedir (dir);
-}
+void cleanup_freep (void *p);
+void cleanup_filep (FILE **f);
+void cleanup_closep (void *p);
+void cleanup_dirp (DIR **p);
 
-# define cleanup_file __attribute__((cleanup (cleanup_filep)))
-# define cleanup_free __attribute__((cleanup (cleanup_freep)))
-# define cleanup_close __attribute__((cleanup (cleanup_closep)))
-# define cleanup_dir __attribute__((cleanup (cleanup_dirp)))
+int file_exists_at (int dirfd, const char *pathname);
+
+int strconcat3 (char *dest, size_t size, const char *s1, const char *s2, const char *s3);
+int open_fd_or_get_path (struct ovl_layer *l, const char *path, char *out, int *fd, int flags);
+
+#define cleanup_file __attribute__ ((cleanup (cleanup_filep)))
+#define cleanup_free __attribute__ ((cleanup (cleanup_freep)))
+#define cleanup_close __attribute__ ((cleanup (cleanup_closep)))
+#define cleanup_dir __attribute__ ((cleanup (cleanup_dirp)))
+
+#define LIKELY(x) __builtin_expect ((x), 1)
+#define UNLIKELY(x) __builtin_expect ((x), 0)
+
+#ifdef HAVE_STATX
+void statx_to_stat (struct statx *stx, struct stat *st);
+#endif
+
+int safe_openat (int dirfd, const char *pathname, int flags, mode_t mode);
+
+int override_mode (struct ovl_layer *l, int fd, const char *abs_path, const char *path, struct stat *st);
+
+bool has_prefix (const char *str, const char *pref);
 
 #endif