- Update the unshare application to support the pid and user namespaces.
- Update the man page for the new options
- Fix typo in the man page where UTS was spelled UTC.
- Remove the vestigal support for running a suid unshare.
After unsharing a user namespace setuid(getuid()) won't work because
no uid or gid mappings have been specified yet. So it is just easier not
to have any support for running suid.
Signed-off-by: "Eric W. Biederman" <ebiederm@xxxxxxxxxxxx>
---
This is on top of unshare with Neil's unshare patch reverted.
sys-utils/unshare.1 | 19 +++++++++++++++----
sys-utils/unshare.c | 27 ++++++++++++++++++---------
2 files changed, 33 insertions(+), 13 deletions(-)
diff --git a/sys-utils/unshare.1 b/sys-utils/unshare.1
index 1325e34..8cdc6e5 100644
--- a/sys-utils/unshare.1
+++ b/sys-utils/unshare.1
@@ -1,7 +1,7 @@
.\" Process this file with
.\" groff -man -Tascii lscpu.1
.\"
-.TH UNSHARE 1 "October 2008" "util-linux" "User Commands"
+.TH UNSHARE 1 "January 2013" "util-linux" "User Commands"
.SH NAME
unshare \- run program with some namespaces unshared from parent
.SH SYNOPSIS
@@ -31,6 +31,13 @@ process will have independent IPv4 and IPv6 stacks, IP routing tables, firewall
rules, the \fI/proc/net\fP and \fI/sys/class/net\fP directory trees, sockets
etc. (\fBCLONE_NEWNET\fP flag).
.TP
+.BR "pid namespace"
+children will have a distinct set of pid to process mappings than their parent.
+(\fBCLONE_NEWPID\fP flag).
+.TP
+.BR "user namespace"
+process will have distinct set of uids, gids and capabilities. (\fBCLONE_NEWUSER\fP flag).
+.TP
See the \fBclone\fR(2) for exact semantics of the flags.
.SH OPTIONS
.TP
@@ -41,16 +48,20 @@ Print a help message,
Unshare the mount namespace,
.TP
.BR \-u , " \-\-uts"
-Unshare the UTC namespace,
+Unshare the UTS namespace,
.TP
.BR \-i , " \-\-ipc"
Unshare the IPC namespace,
.TP
.BR \-n , " \-\-net"
Unshare the network namespace.
+.TP
+.BR \-p , " \-\-pid"
+Unshare the pid namespace.
+.TP
+.BR \-U , " \-\-user"
+Unshare the user namespace.
.SH NOTES
-The unshare command drops potential privileges before executing the
-target program. This allows to setuid unshare.
.SH SEE ALSO
.BR unshare (2),
.BR clone (2)
diff --git a/sys-utils/unshare.c b/sys-utils/unshare.c
index 9de997b..00cc2cf 100644
--- a/sys-utils/unshare.c
+++ b/sys-utils/unshare.c
@@ -41,6 +41,12 @@
#ifndef CLONE_NEWNET
# define CLONE_NEWNET 0x40000000
#endif
+#ifndef CLONE_NEWUSER
+# define CLONE_NEWUSER 0x10000000
+#endif
+#ifndef CLONE_NEWPID
+# define CLONE_NEWPID 0x20000000
+#endif
#ifndef HAVE_UNSHARE
# include <sys/syscall.h>
@@ -63,7 +69,9 @@ static void usage(int status)
fputs(_(" -m, --mount unshare mounts namespace\n"
" -u, --uts unshare UTS namespace (hostname etc)\n"
" -i, --ipc unshare System V IPC namespace\n"
- " -n, --net unshare network namespace\n"), out);
+ " -n, --net unshare network namespace\n"
+ " -p, --pid unshare pid namespace\n"
+ " -U, --user unshare user namespace\n"), out);
fputs(USAGE_SEPARATOR, out);
fputs(USAGE_HELP, out);
@@ -82,6 +90,8 @@ int main(int argc, char *argv[])
{ "uts", no_argument, 0, 'u' },
{ "ipc", no_argument, 0, 'i' },
{ "net", no_argument, 0, 'n' },
+ { "pid", no_argument, 0, 'p' },
+ { "user", no_argument, 0, 'U' },
{ NULL, 0, 0, 0 }
};
@@ -94,7 +104,7 @@ int main(int argc, char *argv[])
textdomain(PACKAGE);
atexit(close_stdout);
- while((c = getopt_long(argc, argv, "hVmuin", longopts, NULL)) != -1) {
+ while((c = getopt_long(argc, argv, "hVmuinpU", longopts, NULL)) != -1) {
switch(c) {
case 'h':
usage(EXIT_SUCCESS);
@@ -113,6 +123,12 @@ int main(int argc, char *argv[])
case 'n':
unshare_flags |= CLONE_NEWNET;
break;
+ case 'p':
+ unshare_flags |= CLONE_NEWPID;
+ break;
+ case 'U':
+ unshare_flags |= CLONE_NEWUSER;
+ break;
default:
usage(EXIT_FAILURE);
}
@@ -124,13 +140,6 @@ int main(int argc, char *argv[])
if(-1 == unshare(unshare_flags))
err(EXIT_FAILURE, _("unshare failed"));
- /* drop potential root euid/egid if we had been setuid'd */
- if (setgid(getgid()) < 0)
- err(EXIT_FAILURE, _("cannot set group id"));
-
- if (setuid(getuid()) < 0)
- err(EXIT_FAILURE, _("cannot set user id"));
-
execvp(argv[optind], argv + optind);
err(EXIT_FAILURE, _("exec %s failed"), argv[optind]);
--
1.7.5.4
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