From 5e030fd0652076eb6c3d185d3c2f5b8040da841d Mon Sep 17 00:00:00 2001 From: Dan Walsh Date: Tue, 18 Mar 2014 16:49:16 -0400 Subject: [PATCH] This patch adds SELinux labeling support. 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 (github: rhatdan) --- nsinit/execin.go | 11 ++++++++++- nsinit/init.go | 8 +++++++- nsinit/mount.go | 22 +++++++++++++--------- 3 files changed, 30 insertions(+), 11 deletions(-) diff --git a/nsinit/execin.go b/nsinit/execin.go index f8b893139..9017af06e 100644 --- a/nsinit/execin.go +++ b/nsinit/execin.go @@ -4,6 +4,7 @@ package nsinit import ( "fmt" + "github.com/dotcloud/docker/pkg/label" "github.com/dotcloud/docker/pkg/libcontainer" "github.com/dotcloud/docker/pkg/system" "os" @@ -32,7 +33,11 @@ func (ns *linuxNs) ExecIn(container *libcontainer.Container, nspid int, args []s closeFds() return -1, err } - + processLabel, err := label.GetPidCon(nspid) + if err != nil { + closeFds() + return -1, err + } // foreach namespace fd, use setns to join an existing container's namespaces for _, fd := range fds { if fd > 0 { @@ -80,6 +85,10 @@ dropAndExec: if err := finalizeNamespace(container); err != nil { return -1, err } + err = label.SetProcessLabel(processLabel) + if err != nil { + return -1, err + } if err := system.Execv(args[0], args[0:], container.Env); err != nil { return -1, err } diff --git a/nsinit/init.go b/nsinit/init.go index 117ae875e..5aa5f9f5b 100644 --- a/nsinit/init.go +++ b/nsinit/init.go @@ -4,6 +4,7 @@ package nsinit import ( "fmt" + "github.com/dotcloud/docker/pkg/label" "github.com/dotcloud/docker/pkg/libcontainer" "github.com/dotcloud/docker/pkg/libcontainer/apparmor" "github.com/dotcloud/docker/pkg/libcontainer/capabilities" @@ -12,6 +13,7 @@ import ( "github.com/dotcloud/docker/pkg/system" "github.com/dotcloud/docker/pkg/user" "os" + "runtime" "syscall" ) @@ -57,7 +59,7 @@ func (ns *linuxNs) Init(container *libcontainer.Container, uncleanRootfs, consol return fmt.Errorf("parent death signal %s", err) } ns.logger.Println("setup mount namespace") - if err := setupNewMountNamespace(rootfs, container.Mounts, console, container.ReadonlyFs, container.NoPivotRoot); err != nil { + if err := setupNewMountNamespace(rootfs, container.Mounts, console, container.ReadonlyFs, container.NoPivotRoot, container.Context["mount_label"]); err != nil { return fmt.Errorf("setup mount namespace %s", err) } if err := setupNetwork(container, context); err != nil { @@ -76,6 +78,10 @@ func (ns *linuxNs) Init(container *libcontainer.Container, uncleanRootfs, consol return err } } + runtime.LockOSThread() + if err := label.SetProcessLabel(container.Context["process_label"]); err != nil { + return fmt.Errorf("SetProcessLabel label %s", err) + } ns.logger.Printf("execing %s\n", args[0]) return system.Execv(args[0], args[0:], container.Env) } diff --git a/nsinit/mount.go b/nsinit/mount.go index 61a90125e..796143c68 100644 --- a/nsinit/mount.go +++ b/nsinit/mount.go @@ -4,6 +4,7 @@ package nsinit import ( "fmt" + "github.com/dotcloud/docker/pkg/label" "github.com/dotcloud/docker/pkg/libcontainer" "github.com/dotcloud/docker/pkg/system" "io/ioutil" @@ -20,7 +21,7 @@ const defaultMountFlags = syscall.MS_NOEXEC | syscall.MS_NOSUID | syscall.MS_NOD // // There is no need to unmount the new mounts because as soon as the mount namespace // is no longer in use, the mounts will be removed automatically -func setupNewMountNamespace(rootfs string, bindMounts []libcontainer.Mount, console string, readonly, noPivotRoot bool) error { +func setupNewMountNamespace(rootfs string, bindMounts []libcontainer.Mount, console string, readonly, noPivotRoot bool, mountLabel string) error { flag := syscall.MS_PRIVATE if noPivotRoot { flag = syscall.MS_SLAVE @@ -36,7 +37,7 @@ func setupNewMountNamespace(rootfs string, bindMounts []libcontainer.Mount, cons return fmt.Errorf("mounting %s as readonly %s", rootfs, err) } } - if err := mountSystem(rootfs); err != nil { + if err := mountSystem(rootfs, mountLabel); err != nil { return fmt.Errorf("mount system %s", err) } @@ -64,7 +65,7 @@ func setupNewMountNamespace(rootfs string, bindMounts []libcontainer.Mount, cons if err := setupDev(rootfs); err != nil { return err } - if err := setupPtmx(rootfs, console); err != nil { + if err := setupPtmx(rootfs, console, mountLabel); err != nil { return err } if err := system.Chdir(rootfs); err != nil { @@ -196,7 +197,7 @@ func setupDev(rootfs string) error { } // setupConsole ensures that the container has a proper /dev/console setup -func setupConsole(rootfs, console string) error { +func setupConsole(rootfs, console string, mountLabel string) error { oldMask := system.Umask(0000) defer system.Umask(oldMask) @@ -220,6 +221,9 @@ func setupConsole(rootfs, console string) error { if err := system.Mknod(dest, (st.Mode&^07777)|0600, int(st.Rdev)); err != nil { return fmt.Errorf("mknod %s %s", dest, err) } + if err := label.SetFileLabel(console, mountLabel); err != nil { + return fmt.Errorf("SetFileLabel Failed %s %s", dest, err) + } if err := system.Mount(console, dest, "bind", syscall.MS_BIND, ""); err != nil { return fmt.Errorf("bind %s to %s %s", console, dest, err) } @@ -228,7 +232,7 @@ func setupConsole(rootfs, console string) error { // mountSystem sets up linux specific system mounts like sys, proc, shm, and devpts // inside the mount namespace -func mountSystem(rootfs string) error { +func mountSystem(rootfs string, mountLabel string) error { for _, m := range []struct { source string path string @@ -238,8 +242,8 @@ func mountSystem(rootfs string) error { }{ {source: "proc", path: filepath.Join(rootfs, "proc"), device: "proc", flags: defaultMountFlags}, {source: "sysfs", path: filepath.Join(rootfs, "sys"), device: "sysfs", flags: defaultMountFlags}, - {source: "shm", path: filepath.Join(rootfs, "dev", "shm"), device: "tmpfs", flags: defaultMountFlags, data: "mode=1777,size=65536k"}, - {source: "devpts", path: filepath.Join(rootfs, "dev", "pts"), device: "devpts", flags: syscall.MS_NOSUID | syscall.MS_NOEXEC, data: "newinstance,ptmxmode=0666,mode=620,gid=5"}, + {source: "shm", path: filepath.Join(rootfs, "dev", "shm"), device: "tmpfs", flags: defaultMountFlags, data: label.FormatMountLabel("mode=1755,size=65536k", mountLabel)}, + {source: "devpts", path: filepath.Join(rootfs, "dev", "pts"), device: "devpts", flags: syscall.MS_NOSUID | syscall.MS_NOEXEC, data: label.FormatMountLabel("newinstance,ptmxmode=0666,mode=620,gid=5", mountLabel)}, } { if err := os.MkdirAll(m.path, 0755); err != nil && !os.IsExist(err) { return fmt.Errorf("mkdirall %s %s", m.path, err) @@ -253,7 +257,7 @@ func mountSystem(rootfs string) error { // setupPtmx adds a symlink to pts/ptmx for /dev/ptmx and // finishes setting up /dev/console -func setupPtmx(rootfs, console string) error { +func setupPtmx(rootfs, console string, mountLabel string) error { ptmx := filepath.Join(rootfs, "dev/ptmx") if err := os.Remove(ptmx); err != nil && !os.IsNotExist(err) { return err @@ -262,7 +266,7 @@ func setupPtmx(rootfs, console string) error { return fmt.Errorf("symlink dev ptmx %s", err) } if console != "" { - if err := setupConsole(rootfs, console); err != nil { + if err := setupConsole(rootfs, console, mountLabel); err != nil { return err } }