x/sys/unix: Add support for the setns system call.
This system call is used to reassociate the current thread with a Linux
namespace (e.g. a network namespace or a mount namespace). This system
call is key to interacting with the primitives enabling Linux containers.
The users of this system call will most likely want to wrap their calls
with a pair of LockOSThread / UnlockOSThread calls. Here is an example
that is a reasonably close approximation of the `ns_exec' program given
as an example in `man 2 setns':
package main
import (
"log"
"os"
"os/exec"
"runtime"
"golang.org/x/sys/unix"
)
func main() {
if len(os.Args) < 3 {
log.Fatalf("%s /proc/PID/ns/FILE cmd args...", os.Args[0])
}
fd, err := unix.Open(os.Args[1], unix.O_RDONLY, 0)
if err != nil {
log.Fatalf("open: %s", err)
}
runtime.LockOSThread()
defer runtime.UnlockOSThread()
if err = unix.Setns(fd, 0); err != nil {
log.Fatalf("setns: %s", err)
}
cmd := exec.Command(os.Args[2], os.Args[3:]...)
cmd.Stdin = os.Stdin
cmd.Stdout = os.Stdout
cmd.Stderr = os.Stderr
err = cmd.Run()
if err != nil {
log.Fatalf("exec: %s", err)
}
}
Fixes golang/go#5968.
Change-Id: I78dc54667cfaef4f9e99a08d48f6e423686f1b22
Reviewed-on: https://go-review.googlesource.com/20054
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
diff --git a/unix/syscall_linux.go b/unix/syscall_linux.go
index 9f6727c..3df5f9c 100644
--- a/unix/syscall_linux.go
+++ b/unix/syscall_linux.go
@@ -895,6 +895,7 @@
//sysnb Setpgid(pid int, pgid int) (err error)
//sysnb Setsid() (pid int, err error)
//sysnb Settimeofday(tv *Timeval) (err error)
+//sys Setns(fd int, nstype int) (err error)
// issue 1435.
// On linux Setuid and Setgid only affects the current thread, not the process.
diff --git a/unix/zsyscall_linux_386.go b/unix/zsyscall_linux_386.go
index af464ca..106cd59 100644
--- a/unix/zsyscall_linux_386.go
+++ b/unix/zsyscall_linux_386.go
@@ -922,6 +922,16 @@
// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
+func Setns(fd int, nstype int) (err error) {
+ _, _, e1 := Syscall(SYS_SETNS, uintptr(fd), uintptr(nstype), 0)
+ if e1 != 0 {
+ err = errnoErr(e1)
+ }
+ return
+}
+
+// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
+
func Setpriority(which int, who int, prio int) (err error) {
_, _, e1 := Syscall(SYS_SETPRIORITY, uintptr(which), uintptr(who), uintptr(prio))
if e1 != 0 {
diff --git a/unix/zsyscall_linux_amd64.go b/unix/zsyscall_linux_amd64.go
index 350aaaa..c1bae65 100644
--- a/unix/zsyscall_linux_amd64.go
+++ b/unix/zsyscall_linux_amd64.go
@@ -922,6 +922,16 @@
// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
+func Setns(fd int, nstype int) (err error) {
+ _, _, e1 := Syscall(SYS_SETNS, uintptr(fd), uintptr(nstype), 0)
+ if e1 != 0 {
+ err = errnoErr(e1)
+ }
+ return
+}
+
+// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
+
func Setpriority(which int, who int, prio int) (err error) {
_, _, e1 := Syscall(SYS_SETPRIORITY, uintptr(which), uintptr(who), uintptr(prio))
if e1 != 0 {
diff --git a/unix/zsyscall_linux_arm.go b/unix/zsyscall_linux_arm.go
index 5782e49..3383f97 100644
--- a/unix/zsyscall_linux_arm.go
+++ b/unix/zsyscall_linux_arm.go
@@ -922,6 +922,16 @@
// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
+func Setns(fd int, nstype int) (err error) {
+ _, _, e1 := Syscall(SYS_SETNS, uintptr(fd), uintptr(nstype), 0)
+ if e1 != 0 {
+ err = errnoErr(e1)
+ }
+ return
+}
+
+// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
+
func Setpriority(which int, who int, prio int) (err error) {
_, _, e1 := Syscall(SYS_SETPRIORITY, uintptr(which), uintptr(who), uintptr(prio))
if e1 != 0 {
diff --git a/unix/zsyscall_linux_arm64.go b/unix/zsyscall_linux_arm64.go
index 1ee44a2..8c5cd13 100644
--- a/unix/zsyscall_linux_arm64.go
+++ b/unix/zsyscall_linux_arm64.go
@@ -922,6 +922,16 @@
// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
+func Setns(fd int, nstype int) (err error) {
+ _, _, e1 := Syscall(SYS_SETNS, uintptr(fd), uintptr(nstype), 0)
+ if e1 != 0 {
+ err = errnoErr(e1)
+ }
+ return
+}
+
+// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
+
func Setpriority(which int, who int, prio int) (err error) {
_, _, e1 := Syscall(SYS_SETPRIORITY, uintptr(which), uintptr(who), uintptr(prio))
if e1 != 0 {
diff --git a/unix/zsyscall_linux_mips64.go b/unix/zsyscall_linux_mips64.go
index 8488755..7eac55b 100644
--- a/unix/zsyscall_linux_mips64.go
+++ b/unix/zsyscall_linux_mips64.go
@@ -922,6 +922,16 @@
// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
+func Setns(fd int, nstype int) (err error) {
+ _, _, e1 := Syscall(SYS_SETNS, uintptr(fd), uintptr(nstype), 0)
+ if e1 != 0 {
+ err = errnoErr(e1)
+ }
+ return
+}
+
+// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
+
func Setpriority(which int, who int, prio int) (err error) {
_, _, e1 := Syscall(SYS_SETPRIORITY, uintptr(which), uintptr(who), uintptr(prio))
if e1 != 0 {
diff --git a/unix/zsyscall_linux_mips64le.go b/unix/zsyscall_linux_mips64le.go
index d6535ac..e8b61a6 100644
--- a/unix/zsyscall_linux_mips64le.go
+++ b/unix/zsyscall_linux_mips64le.go
@@ -922,6 +922,16 @@
// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
+func Setns(fd int, nstype int) (err error) {
+ _, _, e1 := Syscall(SYS_SETNS, uintptr(fd), uintptr(nstype), 0)
+ if e1 != 0 {
+ err = errnoErr(e1)
+ }
+ return
+}
+
+// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
+
func Setpriority(which int, who int, prio int) (err error) {
_, _, e1 := Syscall(SYS_SETPRIORITY, uintptr(which), uintptr(who), uintptr(prio))
if e1 != 0 {
diff --git a/unix/zsyscall_linux_ppc64.go b/unix/zsyscall_linux_ppc64.go
index 5758068..f8eaae9 100644
--- a/unix/zsyscall_linux_ppc64.go
+++ b/unix/zsyscall_linux_ppc64.go
@@ -922,6 +922,16 @@
// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
+func Setns(fd int, nstype int) (err error) {
+ _, _, e1 := Syscall(SYS_SETNS, uintptr(fd), uintptr(nstype), 0)
+ if e1 != 0 {
+ err = errnoErr(e1)
+ }
+ return
+}
+
+// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
+
func Setpriority(which int, who int, prio int) (err error) {
_, _, e1 := Syscall(SYS_SETPRIORITY, uintptr(which), uintptr(who), uintptr(prio))
if e1 != 0 {
diff --git a/unix/zsyscall_linux_ppc64le.go b/unix/zsyscall_linux_ppc64le.go
index fbe422b..22d444f 100644
--- a/unix/zsyscall_linux_ppc64le.go
+++ b/unix/zsyscall_linux_ppc64le.go
@@ -922,6 +922,16 @@
// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
+func Setns(fd int, nstype int) (err error) {
+ _, _, e1 := Syscall(SYS_SETNS, uintptr(fd), uintptr(nstype), 0)
+ if e1 != 0 {
+ err = errnoErr(e1)
+ }
+ return
+}
+
+// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
+
func Setpriority(which int, who int, prio int) (err error) {
_, _, e1 := Syscall(SYS_SETPRIORITY, uintptr(which), uintptr(who), uintptr(prio))
if e1 != 0 {
