2b01982d1f
docker will run the process(es) within the container with an SELinux label and will label all of the content within the container with mount label. Any temporary file systems created within the container need to be mounted with the same mount label. The user can override the process label by specifying -Z With a string of space separated options. -Z "user=unconfined_u role=unconfined_r type=unconfined_t level=s0" Would cause the process label to run with unconfined_u:unconfined_r:unconfined_t:s0" By default the processes will run execute within the container as svirt_lxc_net_t. All of the content in the container as svirt_sandbox_file_t. The process mcs level is based of the PID of the docker process that is creating the container. If you run the container in --priv mode, the labeling will be disabled. Docker-DCO-1.1-Signed-off-by: Dan Walsh <dwalsh@redhat.com> (github: rhatdan)
108 lines
2.7 KiB
Go
108 lines
2.7 KiB
Go
// +build linux
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package nsinit
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import (
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"fmt"
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"github.com/dotcloud/docker/pkg/label"
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"github.com/dotcloud/docker/pkg/libcontainer"
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"github.com/dotcloud/docker/pkg/system"
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"os"
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"path/filepath"
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"strconv"
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"syscall"
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)
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// ExecIn uses an existing pid and joins the pid's namespaces with the new command.
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func (ns *linuxNs) ExecIn(container *libcontainer.Container, nspid int, args []string) (int, error) {
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for _, nsv := range container.Namespaces {
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// skip the PID namespace on unshare because it it not supported
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if nsv.Key != "NEWPID" {
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if err := system.Unshare(nsv.Value); err != nil {
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return -1, err
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}
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}
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}
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fds, err := ns.getNsFds(nspid, container)
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closeFds := func() {
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for _, f := range fds {
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system.Closefd(f)
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}
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}
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if err != nil {
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closeFds()
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return -1, err
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}
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processLabel, err := label.GetPidCon(nspid)
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if err != nil {
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closeFds()
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return -1, err
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}
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// foreach namespace fd, use setns to join an existing container's namespaces
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for _, fd := range fds {
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if fd > 0 {
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ns.logger.Printf("setns on %d\n", fd)
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if err := system.Setns(fd, 0); err != nil {
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closeFds()
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return -1, fmt.Errorf("setns %s", err)
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}
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}
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system.Closefd(fd)
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}
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// if the container has a new pid and mount namespace we need to
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// remount proc and sys to pick up the changes
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if container.Namespaces.Contains("NEWNS") && container.Namespaces.Contains("NEWPID") {
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ns.logger.Println("forking to remount /proc and /sys")
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pid, err := system.Fork()
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if err != nil {
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return -1, err
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}
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if pid == 0 {
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// TODO: make all raw syscalls to be fork safe
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if err := system.Unshare(syscall.CLONE_NEWNS); err != nil {
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return -1, err
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}
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if err := remountProc(); err != nil {
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return -1, fmt.Errorf("remount proc %s", err)
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}
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if err := remountSys(); err != nil {
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return -1, fmt.Errorf("remount sys %s", err)
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}
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goto dropAndExec
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}
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proc, err := os.FindProcess(pid)
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if err != nil {
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return -1, err
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}
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state, err := proc.Wait()
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if err != nil {
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return -1, err
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}
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os.Exit(state.Sys().(syscall.WaitStatus).ExitStatus())
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}
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dropAndExec:
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if err := finalizeNamespace(container); err != nil {
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return -1, err
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}
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err = label.SetProcessLabel(processLabel)
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if err != nil {
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return -1, err
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}
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if err := system.Execv(args[0], args[0:], container.Env); err != nil {
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return -1, err
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}
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panic("unreachable")
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}
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func (ns *linuxNs) getNsFds(pid int, container *libcontainer.Container) ([]uintptr, error) {
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fds := make([]uintptr, len(container.Namespaces))
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for i, ns := range container.Namespaces {
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f, err := os.OpenFile(filepath.Join("/proc/", strconv.Itoa(pid), "ns", ns.File), os.O_RDONLY, 0)
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if err != nil {
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return fds, err
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}
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fds[i] = f.Fd()
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}
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return fds, nil
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}
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