mirror of https://github.com/kubernetes/kops.git
87 lines
2.8 KiB
Go
87 lines
2.8 KiB
Go
package configs
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import (
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"errors"
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"fmt"
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"math"
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)
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var (
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errNoUIDMap = errors.New("User namespaces enabled, but no uid mappings found.")
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errNoUserMap = errors.New("User namespaces enabled, but no user mapping found.")
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errNoGIDMap = errors.New("User namespaces enabled, but no gid mappings found.")
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errNoGroupMap = errors.New("User namespaces enabled, but no group mapping found.")
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)
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// HostUID gets the translated uid for the process on host which could be
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// different when user namespaces are enabled.
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func (c Config) HostUID(containerId int) (int, error) {
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if c.Namespaces.Contains(NEWUSER) {
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if c.UidMappings == nil {
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return -1, errNoUIDMap
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}
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id, found := c.hostIDFromMapping(int64(containerId), c.UidMappings)
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if !found {
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return -1, errNoUserMap
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}
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// If we are a 32-bit binary running on a 64-bit system, it's possible
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// the mapped user is too large to store in an int, which means we
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// cannot do the mapping. We can't just return an int64, because
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// os.Setuid() takes an int.
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if id > math.MaxInt {
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return -1, fmt.Errorf("mapping for uid %d (host id %d) is larger than native integer size (%d)", containerId, id, math.MaxInt)
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}
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return int(id), nil
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}
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// Return unchanged id.
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return containerId, nil
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}
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// HostRootUID gets the root uid for the process on host which could be non-zero
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// when user namespaces are enabled.
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func (c Config) HostRootUID() (int, error) {
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return c.HostUID(0)
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}
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// HostGID gets the translated gid for the process on host which could be
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// different when user namespaces are enabled.
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func (c Config) HostGID(containerId int) (int, error) {
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if c.Namespaces.Contains(NEWUSER) {
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if c.GidMappings == nil {
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return -1, errNoGIDMap
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}
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id, found := c.hostIDFromMapping(int64(containerId), c.GidMappings)
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if !found {
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return -1, errNoGroupMap
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}
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// If we are a 32-bit binary running on a 64-bit system, it's possible
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// the mapped user is too large to store in an int, which means we
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// cannot do the mapping. We can't just return an int64, because
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// os.Setgid() takes an int.
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if id > math.MaxInt {
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return -1, fmt.Errorf("mapping for gid %d (host id %d) is larger than native integer size (%d)", containerId, id, math.MaxInt)
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}
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return int(id), nil
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}
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// Return unchanged id.
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return containerId, nil
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}
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// HostRootGID gets the root gid for the process on host which could be non-zero
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// when user namespaces are enabled.
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func (c Config) HostRootGID() (int, error) {
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return c.HostGID(0)
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}
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// Utility function that gets a host ID for a container ID from user namespace map
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// if that ID is present in the map.
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func (c Config) hostIDFromMapping(containerID int64, uMap []IDMap) (int64, bool) {
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for _, m := range uMap {
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if (containerID >= m.ContainerID) && (containerID <= (m.ContainerID + m.Size - 1)) {
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hostID := m.HostID + (containerID - m.ContainerID)
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return hostID, true
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}
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}
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return -1, false
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}
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