build-sys: Add setns() functions if not in the C library.

[elogind.git] / src / shared / missing.h

diff --git a/src/shared/missing.h b/src/shared/missing.h
index 2661285a227c39fb3d8f181fbbee960aac90ee31..3142306e35c2375382c2539ea81787cb674d4ad9 100644 (file)
--- a/src/shared/missing.h
+++ b/src/shared/missing.h
@@ -28,6 +28,7 @@
 #include <fcntl.h>
 #include <stdlib.h>
 #include <unistd.h>
+#include <errno.h>
 #include <linux/oom.h>
 #include <linux/input.h>
 #include <linux/if_link.h>
@@ -353,3 +354,19 @@ static inline int name_to_handle_at(int fd, const char *name, struct file_handle
 #endif
 
 #endif
+
+#ifndef __NR_setns
+#  if defined(__x86_64__)
+#    define __NR_setns 308
+#  elif defined(__i386__)
+#    define __NR_setns 346
+#  else
+#    error "__NR_setns is not defined"
+#  endif
+#endif
+
+#if !HAVE_DECL_SETNS
+static inline int setns(int fd, int nstype) {
+        return syscall(__NR_setns, fd, nstype);
+}
+#endif