mirror of https://github.com/k3s-io/k3s
38 lines
848 B
Go
38 lines
848 B
Go
package userns
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import (
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"sync"
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"github.com/opencontainers/runc/libcontainer/user"
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)
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var (
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inUserNS bool
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nsOnce sync.Once
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)
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// runningInUserNS detects whether we are currently running in a user namespace.
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// Originally copied from github.com/lxc/lxd/shared/util.go
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func runningInUserNS() bool {
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nsOnce.Do(func() {
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uidmap, err := user.CurrentProcessUIDMap()
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if err != nil {
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// This kernel-provided file only exists if user namespaces are supported
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return
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}
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inUserNS = uidMapInUserNS(uidmap)
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})
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return inUserNS
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}
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func uidMapInUserNS(uidmap []user.IDMap) bool {
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/*
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* We assume we are in the initial user namespace if we have a full
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* range - 4294967295 uids starting at uid 0.
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*/
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if len(uidmap) == 1 && uidmap[0].ID == 0 && uidmap[0].ParentID == 0 && uidmap[0].Count == 4294967295 {
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return false
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}
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return true
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}
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