user: use setresuid32 where available first (on some 32bit platforms:

diff --git a/user.c b/user.c
index 63cc684c5c167110efc1517ae0825759fc150d5a..a992c917e5804912924a8d516e4879ae58b877c6 100644 (file)
--- a/user.c
+++ b/user.c
@@ -40,6 +40,38 @@
 #include "subproc.h"
 #include "util.h"
 
+static bool userSetResGid(gid_t gid)
+{
+       LOG_D("setresgid(%d)", gid);
+#if defined(__NR_setresgid32)
+       if (syscall(__NR_setresgid32, (uintptr_t)gid, (uintptr_t)gid, (uintptr_t)gid) == -1 && errno != ENOSYS) {
+               PLOG_W("setresgid32(%d)", (int)gid);
+               return false;
+       }
+#endif
+       if (syscall(__NR_setresgid, (uintptr_t)gid, (uintptr_t)gid, (uintptr_t)gid) == -1) {
+               PLOG_W("setresgid(%d)", gid);
+               return false;
+       }
+       return true;
+}
+
+static bool userSetResUid(uid_t uid)
+{
+       LOG_D("setresuid(%d)", uid);
+#if defined(__NR_setresuid32)
+       if (syscall(__NR_setresuid32, (uintptr_t)uid, (uintptr_t)uid, (uintptr_t)uid) == -1 && errno != ENOSYS) {
+               PLOG_W("setresuid32(%d)", (int)uid);
+               return false;
+       }
+#endif
+       if (syscall(__NR_setresuid, (uintptr_t)uid, (uintptr_t)uid, (uintptr_t)uid) == -1) {
+               PLOG_W("setresuid(%d)", uid);
+               return false;
+       }
+       return true;
+}
+
 static bool userSetGroups(pid_t pid)
 {
        /*
@@ -279,19 +311,11 @@ bool userInitNsFromChild(struct nsjconf_t* nsjconf)
                return false;
        }
 
-       LOG_D("setresgid(%d, %d, %d)", TAILQ_FIRST(&nsjconf->gids)->inside_id,
-           TAILQ_FIRST(&nsjconf->gids)->inside_id, TAILQ_FIRST(&nsjconf->gids)->inside_id);
-       if (syscall(__NR_setresgid, TAILQ_FIRST(&nsjconf->gids)->inside_id,
-               TAILQ_FIRST(&nsjconf->gids)->inside_id, TAILQ_FIRST(&nsjconf->gids)->inside_id)
-           == -1) {
+       if (!userSetResGid(TAILQ_FIRST(&nsjconf->gids)->inside_id)) {
                PLOG_E("setresgid(%u)", TAILQ_FIRST(&nsjconf->gids)->inside_id);
                return false;
        }
-       LOG_D("setresuid(%d, %d, %d)", TAILQ_FIRST(&nsjconf->uids)->inside_id,
-           TAILQ_FIRST(&nsjconf->uids)->inside_id, TAILQ_FIRST(&nsjconf->uids)->inside_id);
-       if (syscall(__NR_setresuid, TAILQ_FIRST(&nsjconf->uids)->inside_id,
-               TAILQ_FIRST(&nsjconf->uids)->inside_id, TAILQ_FIRST(&nsjconf->uids)->inside_id)
-           == -1) {
+       if (!userSetResUid(TAILQ_FIRST(&nsjconf->uids)->inside_id)) {
                PLOG_E("setresuid(%u)", TAILQ_FIRST(&nsjconf->uids)->inside_id);
                return false;
        }