X-Git-Url: https://git.librecmc.org/?a=blobdiff_plain;f=util-linux%2Funshare.c;h=875e3f86e3048336e9c8ca6dfdc50b034a6e4734;hb=5b2cc0aaee6985431d9bab1b49ceea7e1fa1d7af;hp=f1a9cdf194c43f4d66d15d55860b890c03272255;hpb=29b33b63d49be88200f794d832450a4c71e85a5e;p=oweals%2Fbusybox.git

diff --git a/util-linux/unshare.c b/util-linux/unshare.c
index f1a9cdf19..875e3f86e 100644
--- a/util-linux/unshare.c
+++ b/util-linux/unshare.c
@@ -6,16 +6,16 @@
  *
  * Licensed under GPLv2 or later, see file LICENSE in this source tree.
  */
-
 //config:config UNSHARE
 //config:	bool "unshare"
 //config:	default y
-//config:	depends on LONG_OPTS && !NOMMU
+//config:	depends on !NOMMU
 //config:	select PLATFORM_LINUX
+//config:	select LONG_OPTS
 //config:	help
 //config:	  Run program with some namespaces unshared from parent.
 
-// depends on LONG_OPTS: it is awkward to exclude code which handles --propagation
+// needs LONG_OPTS: it is awkward to exclude code which handles --propagation
 // and --setgroups based on LONG_OPTS, so instead applet requires LONG_OPTS.
 // depends on !NOMMU: we need fork()
 
@@ -26,21 +26,50 @@
 //usage:#define unshare_trivial_usage
 //usage:       "[OPTIONS] [PROG [ARGS]]"
 //usage:#define unshare_full_usage "\n"
-//usage:     "\n	-m, --mount[=FILE]	Unshare mount namespace"
-//usage:     "\n	-u, --uts[=FILE]	Unshare UTS namespace (hostname etc.)"
-//usage:     "\n	-i, --ipc[=FILE]	Unshare System V IPC namespace"
-//usage:     "\n	-n, --net[=FILE]	Unshare network namespace"
-//usage:     "\n	-p, --pid[=FILE]	Unshare PID namespace"
-//usage:     "\n	-U, --user[=FILE}	Unshare user namespace"
-//usage:     "\n	-f, --fork		Fork before execing PROG"
-//usage:     "\n	-r, --map-root-user	Map current user to root (implies -u)"
+//usage:     "\n	-m,--mount[=FILE]	Unshare mount namespace"
+//usage:     "\n	-u,--uts[=FILE]		Unshare UTS namespace (hostname etc.)"
+//usage:     "\n	-i,--ipc[=FILE]		Unshare System V IPC namespace"
+//usage:     "\n	-n,--net[=FILE]		Unshare network namespace"
+//usage:     "\n	-p,--pid[=FILE]		Unshare PID namespace"
+//usage:     "\n	-U,--user[=FILE]	Unshare user namespace"
+//usage:     "\n	-f,--fork		Fork before execing PROG"
+//usage:     "\n	-r,--map-root-user	Map current user to root (implies -U)"
 //usage:     "\n	--mount-proc[=DIR]	Mount /proc filesystem first (implies -m)"
 //usage:     "\n	--propagation slave|shared|private|unchanged"
 //usage:     "\n				Modify mount propagation in mount namespace"
 //usage:     "\n	--setgroups allow|deny	Control the setgroups syscall in user namespaces"
 
 #include <sched.h>
+#ifndef CLONE_NEWUTS
+# define CLONE_NEWUTS  0x04000000
+#endif
+#ifndef CLONE_NEWIPC
+# define CLONE_NEWIPC  0x08000000
+#endif
+#ifndef CLONE_NEWUSER
+# define CLONE_NEWUSER 0x10000000
+#endif
+#ifndef CLONE_NEWPID
+# define CLONE_NEWPID  0x20000000
+#endif
+#ifndef CLONE_NEWNET
+# define CLONE_NEWNET  0x40000000
+#endif
+
 #include <sys/mount.h>
+#ifndef MS_REC
+# define MS_REC     (1 << 14)
+#endif
+#ifndef MS_PRIVATE
+# define MS_PRIVATE (1 << 18)
+#endif
+#ifndef MS_SLAVE
+# define MS_SLAVE   (1 << 19)
+#endif
+#ifndef MS_SHARED
+# define MS_SHARED  (1 << 20)
+#endif
+
 #include "libbb.h"
 
 static void mount_or_die(const char *source, const char *target,
@@ -57,22 +86,6 @@ static void mount_or_die(const char *source, const char *target,
 	}
 }
 
-// TODO: move to libbb
-static int wait_for_exitstatus(pid_t pid)
-{
-	int exit_status, n;
-
-	n = safe_waitpid(pid, &exit_status, 0);
-	if (n < 0)
-		bb_perror_msg_and_die("waitpid");
-	return exit_status;
-}
-
-/*
- * Longest possible path to a procfs file used in unshare. Must be able to
- * contain the '/proc/' string, the '/ns/user' string which is the longest
- * namespace name and a 32-bit integer representing the process ID.
- */
 #define PATH_PROC_SETGROUPS	"/proc/self/setgroups"
 #define PATH_PROC_UIDMAP	"/proc/self/uid_map"
 #define PATH_PROC_GIDMAP	"/proc/self/gid_map"
@@ -90,7 +103,7 @@ enum {
 	OPT_mount	= 1 << 0,
 	OPT_uts		= 1 << 1,
 	OPT_ipc		= 1 << 2,
-	OPT_network	= 1 << 3,
+	OPT_net		= 1 << 3,
 	OPT_pid		= 1 << 4,
 	OPT_user	= 1 << 5, /* OPT_user, NS_USR_POS, and ns_list[] index must match! */
 	OPT_fork	= 1 << 6,
@@ -124,12 +137,12 @@ static const struct namespace_descr ns_list[] = {
  * we are forced to use "fake" letters for them.
  * '+': stop at first non-option.
  */
-static const char opt_str[] = "+muinpU""fr""\xfd::""\xfe:""\xff:";
+static const char opt_str[] ALIGN1 = "+muinpU""fr""\xfd::""\xfe:""\xff:";
 static const char unshare_longopts[] ALIGN1 =
 	"mount\0"		Optional_argument	"\xf0"
 	"uts\0"			Optional_argument	"\xf1"
 	"ipc\0"			Optional_argument	"\xf2"
-	"network\0"		Optional_argument	"\xf3"
+	"net\0"			Optional_argument	"\xf3"
 	"pid\0"			Optional_argument	"\xf4"
 	"user\0"		Optional_argument	"\xf5"
 	"fork\0"		No_argument		"f"
@@ -297,7 +310,7 @@ int unshare_main(int argc UNUSED_PARAM, char **argv)
 
 	if (fdp.wr >= 0) {
 		close(fdp.wr); /* Release child */
-		/*close(fdp.rd);*/
+		close(fdp.rd); /* should close fd, to not confuse exec'ed PROG */
 	}
 
 	if (need_mount) {
@@ -323,14 +336,7 @@ int unshare_main(int argc UNUSED_PARAM, char **argv)
 	 * that'll become PID 1 in this new namespace.
 	 */
 	if (opts & OPT_fork) {
-		pid_t pid = xfork();
-		if (pid > 0) {
-			/* Parent */
-			int exit_status = wait_for_exitstatus(pid);
-			if (WIFSIGNALED(exit_status))
-				kill_myself_with_sig(WTERMSIG(exit_status));
-			return WEXITSTATUS(exit_status);
-		}
+		xvfork_parent_waits_and_exits();
 		/* Child continues */
 	}
 
@@ -370,11 +376,5 @@ int unshare_main(int argc UNUSED_PARAM, char **argv)
 		mount_or_die("proc", proc_mnt_target, "proc", MS_NOSUID | MS_NOEXEC | MS_NODEV);
 	}
 
-	if (argv[0]) {
-		BB_EXECVP_or_die(argv);
-	}
-	/* unshare from util-linux 2.27.1, despite not documenting it,
-	 * runs a login shell (argv0="-sh") if no PROG is given
-	 */
-	run_shell(getenv("SHELL"), /*login:*/ 1, NULL, NULL);
+	exec_prog_or_SHELL(argv);
 }