get_mapped_rootid: avoid using (uid_t) -1

Signed-off-by: Serge Hallyn <serge.hallyn@ubuntu.com>

diff --git a/src/lxc/conf.c b/src/lxc/conf.c
index 30d72d4f8333ba031c8506989939226208069ce5..46d3e1945e78ca6a4f52171e17ee519fbe0abc77 100644 (file)
--- a/src/lxc/conf.c
+++ b/src/lxc/conf.c
@@ -3134,7 +3134,8 @@ int lxc_map_ids(struct lxc_list *idmap, pid_t pid)
  * return the host uid to which the container root is mapped, or -1 on
  * error
  */
-static uid_t get_mapped_rootid(struct lxc_conf *conf)
+bool get_mapped_rootid(struct lxc_conf *conf, enum idtype idtype,
+                        unsigned long *val)
 {
        struct lxc_list *it;
        struct id_map *map;
@@ -3145,9 +3146,10 @@ static uid_t get_mapped_rootid(struct lxc_conf *conf)
                        continue;
                if (map->nsid != 0)
                        continue;
-               return (uid_t) map->hostid;
+               *val = map->hostid;
+               return true;
        }
-       return (uid_t)-1;
+       return false;
 }
 
 int mapped_hostid(int id, struct lxc_conf *conf)
@@ -3304,11 +3306,14 @@ int chown_mapped_root(char *path, struct lxc_conf *conf)
 {
        uid_t rootid;
        pid_t pid;
+       unsigned long val;
 
-       if ((rootid = get_mapped_rootid(conf)) <= 0) {
+       if (!get_mapped_rootid(conf, ID_TYPE_UID, &val)) {
                ERROR("No mapping for container root");
                return -1;
        }
+       rootid = (uid_t) val;
+
        if (geteuid() == 0) {
                if (chown(path, rootid, -1) < 0) {
                        ERROR("Error chowning %s", path);