lxc-usernsexec: allow to select which {g,u}id to switch to

Signed-off-by: Christian Brauner (Microsoft) <christian.brauner@ubuntu.com>

diff --git a/src/lxc/cmd/lxc_usernsexec.c b/src/lxc/cmd/lxc_usernsexec.c
index 96a1182a3037d949815b107b7a277aa84fd202c8..b17faa38c79bdc539bb0d37958e2a3ac717db354 100644 (file)
--- a/src/lxc/cmd/lxc_usernsexec.c
+++ b/src/lxc/cmd/lxc_usernsexec.c
@@ -32,6 +32,9 @@
 #include "utils.h"
 
 __hidden extern int lxc_log_fd;
+/* Assume we want to become root */
+static uid_t uid = 0;
+static gid_t gid = 0;
 
 static void usage(const char *name)
 {
@@ -90,8 +93,7 @@ static int do_child(void *vargv)
        if (!lxc_drop_groups() && errno != EPERM)
                return -1;
 
-       /* Assume we want to become root */
-       if (!lxc_switch_uid_gid(0, 0))
+       if (!lxc_switch_uid_gid(uid, gid))
                return -1;
 
        ret = unshare(CLONE_NEWNS);
@@ -328,7 +330,7 @@ int main(int argc, char *argv[])
                }
        }
 
-       while ((c = getopt(argc, argv, "m:hs")) != EOF) {
+       while ((c = getopt(argc, argv, "m:hsu:g:")) != EOF) {
                switch (c) {
                case 'm':
                        ret = parse_map(optarg);
@@ -343,6 +345,14 @@ int main(int argc, char *argv[])
                case 's':
                        map_self = true;
                        break;
+               case 'u':
+                       if (lxc_safe_uint(optarg, &uid) < 0)
+                               return -1;
+                       break;
+               case 'g':
+                       if (lxc_safe_uint(optarg, &gid) < 0)
+                               return -1;
+                       break;
                default:
                        usage(argv[0]);
                        _exit(EXIT_FAILURE);