utils: make lxc_switch_uid_gid() return bool

src/lxc/attach.c

@@ -854,8 +854,7 @@ static int attach_child_main(struct attach_clone_payload *payload)
 		if (ns_root_uid == LXC_INVALID_UID)
 			goto on_error;
 
-		ret = lxc_switch_uid_gid(ns_root_uid, ns_root_gid);
-		if (ret < 0)
+		if (!lxc_switch_uid_gid(ns_root_uid, ns_root_gid))
 			goto on_error;
 	}
 
@@ -969,8 +968,7 @@ static int attach_child_main(struct attach_clone_payload *payload)
 	if (new_gid == ns_root_gid)
 		new_gid = LXC_INVALID_GID;
 
-	ret = lxc_switch_uid_gid(new_uid, new_gid);
-	if (ret < 0)
+	if (!lxc_switch_uid_gid(new_uid, new_gid))
 		goto on_error;
 
 	/* We're done, so we can now do whatever the user intended us to do. */

src/lxc/cmd/lxc_usernsexec.c

@@ -104,8 +104,7 @@ static int do_child(void *vargv)
 	char **argv = (char **)vargv;
 
 	/* Assume we want to become root */
-	ret = lxc_switch_uid_gid(0, 0);
-	if (ret < 0)
+	if (!lxc_switch_uid_gid(0, 0))
 		return -1;
 
 	if (!lxc_setgroups(0, NULL))

src/lxc/start.c

@@ -1124,8 +1124,7 @@ static int do_start(void *data)
 		if (!handler->conf->root_nsgid_map)
 			nsgid = handler->conf->init_gid;
 
-		ret = lxc_switch_uid_gid(nsuid, nsgid);
-		if (ret < 0)
+		if (!lxc_switch_uid_gid(nsuid, nsgid))
 			goto out_warn_father;
 
 		/* Drop groups only after we switched to a valid gid in the new
@@ -1362,8 +1361,7 @@ static int do_start(void *data)
 	if (new_gid == nsgid)
 		new_gid = LXC_INVALID_GID;
 
-	ret = lxc_switch_uid_gid(new_uid, new_gid);
-	if (ret < 0)
+	if (!lxc_switch_uid_gid(new_uid, new_gid))
 		goto out_warn_father;
 
 	/* If we are in a new user namespace we already dropped all groups when

src/lxc/storage/rsync.c

@@ -50,8 +50,7 @@ int lxc_rsync_exec_wrapper(void *data)
 	int ret;
 	struct rsync_data_char *args = data;
 
-	ret = lxc_switch_uid_gid(0, 0);
-	if (ret < 0)
+	if (!lxc_switch_uid_gid(0, 0))
 		return -1;
 
 	if (!lxc_setgroups(0, NULL))
@@ -116,8 +115,7 @@ int lxc_rsync(struct rsync_data *data)
 		return -1;
 	}
 
-	ret = lxc_switch_uid_gid(0, 0);
-	if (ret < 0)
+	if (!lxc_switch_uid_gid(0, 0))
 		return -1;
 
 	if (!lxc_setgroups(0, NULL))

src/lxc/utils.c

@@ -1351,7 +1351,7 @@ int lxc_preserve_ns(const int pid, const char *ns)
 	return open(path, O_RDONLY | O_CLOEXEC);
 }
 
-int lxc_switch_uid_gid(uid_t uid, gid_t gid)
+bool lxc_switch_uid_gid(uid_t uid, gid_t gid)
 {
 	int ret = 0;
 
@@ -1359,7 +1359,7 @@ int lxc_switch_uid_gid(uid_t uid, gid_t gid)
 		ret = setgid(gid);
 		if (ret < 0) {
 			SYSERROR("Failed to switch to gid %d", gid);
-			return -1;
+			return false;
 		}
 		NOTICE("Switched to gid %d", gid);
 	}
@@ -1368,12 +1368,12 @@ int lxc_switch_uid_gid(uid_t uid, gid_t gid)
 		ret = setuid(uid);
 		if (ret < 0) {
 			SYSERROR("Failed to switch to uid %d", uid);
-			return -1;
+			return false;
 		}
 		NOTICE("Switched to uid %d", uid);
 	}
 
-	return ret;
+	return true;
 }
 
 /* Simple covenience function which enables uniform logging. */

src/lxc/utils.h

@@ -361,7 +361,7 @@ extern bool task_blocks_signal(pid_t pid, int signal);
 /* Switch to a new uid and gid.
  * If LXC_INVALID_{G,U}ID is passed then the set{g,u}id() will not be called.
  */
-extern int lxc_switch_uid_gid(uid_t uid, gid_t gid);
+extern bool lxc_switch_uid_gid(uid_t uid, gid_t gid);
 extern bool lxc_setgroups(int size, gid_t list[]);
 
 /* Find an unused loop device and associate it with source. */