mirror of https://github.com/docker/docs.git
60 lines
1.3 KiB
Go
60 lines
1.3 KiB
Go
// +build linux
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package daemon
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import (
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"fmt"
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"io/ioutil"
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"os"
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"strconv"
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"strings"
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)
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const (
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rootKeyFile = "/proc/sys/kernel/keys/root_maxkeys"
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rootBytesFile = "/proc/sys/kernel/keys/root_maxbytes"
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rootKeyLimit = 1000000
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// it is standard configuration to allocate 25 bytes per key
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rootKeyByteMultiplier = 25
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)
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// ModifyRootKeyLimit checks to see if the root key limit is set to
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// at least 1000000 and changes it to that limit along with the maxbytes
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// allocated to the keys at a 25 to 1 multiplier.
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func ModifyRootKeyLimit() error {
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value, err := readRootKeyLimit(rootKeyFile)
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if err != nil {
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return err
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}
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if value < rootKeyLimit {
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return setRootKeyLimit(rootKeyLimit)
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}
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return nil
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}
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func setRootKeyLimit(limit int) error {
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keys, err := os.OpenFile(rootKeyFile, os.O_WRONLY, 0)
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if err != nil {
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return err
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}
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defer keys.Close()
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if _, err := fmt.Fprintf(keys, "%d", limit); err != nil {
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return err
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}
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bytes, err := os.OpenFile(rootBytesFile, os.O_WRONLY, 0)
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if err != nil {
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return err
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}
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defer bytes.Close()
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_, err = fmt.Fprintf(bytes, "%d", limit*rootKeyByteMultiplier)
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return err
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}
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func readRootKeyLimit(path string) (int, error) {
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data, err := ioutil.ReadFile(path)
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if err != nil {
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return -1, err
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}
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return strconv.Atoi(strings.Trim(string(data), "\n"))
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}
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