/usr/share/gocode/src/github.com/opencontainers/runc/libcontainer/standard_init_linux.go is in golang-github-opencontainers-runc-dev 1.0.0~rc4+dfsg1-6.
This file is owned by root:root, with mode 0o644.
The actual contents of the file can be viewed below.
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 | // +build linux
package libcontainer
import (
"fmt"
"os"
"os/exec"
"syscall" //only for Exec
"github.com/opencontainers/runc/libcontainer/apparmor"
"github.com/opencontainers/runc/libcontainer/configs"
"github.com/opencontainers/runc/libcontainer/keys"
"github.com/opencontainers/runc/libcontainer/seccomp"
"github.com/opencontainers/runc/libcontainer/system"
"github.com/opencontainers/selinux/go-selinux/label"
"golang.org/x/sys/unix"
)
type linuxStandardInit struct {
pipe *os.File
consoleSocket *os.File
parentPid int
stateDirFD int
config *initConfig
}
func (l *linuxStandardInit) getSessionRingParams() (string, uint32, uint32) {
var newperms uint32
if l.config.Config.Namespaces.Contains(configs.NEWUSER) {
// with user ns we need 'other' search permissions
newperms = 0x8
} else {
// without user ns we need 'UID' search permissions
newperms = 0x80000
}
// create a unique per session container name that we can
// join in setns; however, other containers can also join it
return fmt.Sprintf("_ses.%s", l.config.ContainerId), 0xffffffff, newperms
}
func (l *linuxStandardInit) Init() error {
if !l.config.Config.NoNewKeyring {
ringname, keepperms, newperms := l.getSessionRingParams()
// do not inherit the parent's session keyring
sessKeyId, err := keys.JoinSessionKeyring(ringname)
if err != nil {
return err
}
// make session keyring searcheable
if err := keys.ModKeyringPerm(sessKeyId, keepperms, newperms); err != nil {
return err
}
}
if err := setupNetwork(l.config); err != nil {
return err
}
if err := setupRoute(l.config.Config); err != nil {
return err
}
label.Init()
// prepareRootfs() can be executed only for a new mount namespace.
if l.config.Config.Namespaces.Contains(configs.NEWNS) {
if err := prepareRootfs(l.pipe, l.config.Config); err != nil {
return err
}
}
// Set up the console. This has to be done *before* we finalize the rootfs,
// but *after* we've given the user the chance to set up all of the mounts
// they wanted.
if l.config.CreateConsole {
if err := setupConsole(l.consoleSocket, l.config, true); err != nil {
return err
}
if err := system.Setctty(); err != nil {
return err
}
}
// Finish the rootfs setup.
if l.config.Config.Namespaces.Contains(configs.NEWNS) {
if err := finalizeRootfs(l.config.Config); err != nil {
return err
}
}
if hostname := l.config.Config.Hostname; hostname != "" {
if err := unix.Sethostname([]byte(hostname)); err != nil {
return err
}
}
if err := apparmor.ApplyProfile(l.config.AppArmorProfile); err != nil {
return err
}
if err := label.SetProcessLabel(l.config.ProcessLabel); err != nil {
return err
}
for key, value := range l.config.Config.Sysctl {
if err := writeSystemProperty(key, value); err != nil {
return err
}
}
for _, path := range l.config.Config.ReadonlyPaths {
if err := readonlyPath(path); err != nil {
return err
}
}
for _, path := range l.config.Config.MaskPaths {
if err := maskPath(path); err != nil {
return err
}
}
pdeath, err := system.GetParentDeathSignal()
if err != nil {
return err
}
if l.config.NoNewPrivileges {
if err := unix.Prctl(unix.PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0); err != nil {
return err
}
}
// Tell our parent that we're ready to Execv. This must be done before the
// Seccomp rules have been applied, because we need to be able to read and
// write to a socket.
if err := syncParentReady(l.pipe); err != nil {
return err
}
// Without NoNewPrivileges seccomp is a privileged operation, so we need to
// do this before dropping capabilities; otherwise do it as late as possible
// just before execve so as few syscalls take place after it as possible.
if l.config.Config.Seccomp != nil && !l.config.NoNewPrivileges {
if err := seccomp.InitSeccomp(l.config.Config.Seccomp); err != nil {
return err
}
}
if err := finalizeNamespace(l.config); err != nil {
return err
}
// finalizeNamespace can change user/group which clears the parent death
// signal, so we restore it here.
if err := pdeath.Restore(); err != nil {
return err
}
// compare the parent from the initial start of the init process and make sure that it did not change.
// if the parent changes that means it died and we were reparented to something else so we should
// just kill ourself and not cause problems for someone else.
if unix.Getppid() != l.parentPid {
return unix.Kill(unix.Getpid(), unix.SIGKILL)
}
// check for the arg before waiting to make sure it exists and it is returned
// as a create time error.
name, err := exec.LookPath(l.config.Args[0])
if err != nil {
return err
}
// close the pipe to signal that we have completed our init.
l.pipe.Close()
// wait for the fifo to be opened on the other side before
// exec'ing the users process.
fd, err := unix.Openat(l.stateDirFD, execFifoFilename, os.O_WRONLY|unix.O_CLOEXEC, 0)
if err != nil {
return newSystemErrorWithCause(err, "openat exec fifo")
}
if _, err := unix.Write(fd, []byte("0")); err != nil {
return newSystemErrorWithCause(err, "write 0 exec fifo")
}
if l.config.Config.Seccomp != nil && l.config.NoNewPrivileges {
if err := seccomp.InitSeccomp(l.config.Config.Seccomp); err != nil {
return newSystemErrorWithCause(err, "init seccomp")
}
}
// close the statedir fd before exec because the kernel resets dumpable in the wrong order
// https://github.com/torvalds/linux/blob/v4.9/fs/exec.c#L1290-L1318
unix.Close(l.stateDirFD)
if err := syscall.Exec(name, l.config.Args[0:], os.Environ()); err != nil {
return newSystemErrorWithCause(err, "exec user process")
}
return nil
}
|