handle numerical owner/group string in lookup_user/group()

1 files changed, 32 insertions, 25 deletions

diff --git a/udev/udev-util.c b/udev/udev-util.c
index 76d7270f66..2620d9a994 100644
--- a/udev/udev-util.c
+++ b/udev/udev-util.c
@@ -126,48 +126,55 @@ int util_unlink_secure(struct udev *udev, const char *filename)
 
 uid_t util_lookup_user(struct udev *udev, const char *user)
 {
+	char *endptr;
 	int buflen = sysconf(_SC_GETPW_R_SIZE_MAX);
 	char buf[buflen];
 	struct passwd pwbuf;
 	struct passwd *pw;
-	uid_t uid = 0;
+	uid_t uid;
 
 	if (strcmp(user, "root") == 0)
 		return 0;
-	errno = 0;
-	getpwnam_r(user, &pwbuf, buf, buflen, &pw);
-	if (pw == NULL) {
+		uid = strtoul(user, &endptr, 10);
+		if (endptr[0] == '\0')
+			return uid;
+
+		errno = 0;
+		getpwnam_r(user, &pwbuf, buf, buflen, &pw);
+		if (pw != NULL)
+			return pw->pw_uid;
 		if (errno == 0 || errno == ENOENT || errno == ESRCH)
 			err(udev, "specified user '%s' unknown\n", user);
 		else
 			err(udev, "error resolving user '%s': %m\n", user);
-	} else
-		uid = pw->pw_uid;
-
-	return uid;
-}
+		return 0;
+	}
 
-extern gid_t util_lookup_group(struct udev *udev, const char *group)
-{
-	int buflen = sysconf(_SC_GETGR_R_SIZE_MAX);
-	char buf[buflen];
-	struct group grbuf;
-	struct group *gr;
-	gid_t gid = 0;
+	extern gid_t util_lookup_group(struct udev *udev, const char *group)
+	{
+		char *endptr;
+		int buflen = sysconf(_SC_GETGR_R_SIZE_MAX);
+		char buf[buflen];
+		struct group grbuf;
+		struct group *gr;
+		gid_t gid = 0;
 
-	if (strcmp(group, "root") == 0)
-		return 0;
-	errno = 0;
-	getgrnam_r(group, &grbuf, buf, buflen, &gr);
-	if (gr == NULL) {
+		if (strcmp(group, "root") == 0)
+			return 0;
+		gid = strtoul(group, &endptr, 10);
+		if (endptr[0] == '\0')
+			return gid;
+
+		errno = 0;
+		getgrnam_r(group, &grbuf, buf, buflen, &gr);
+		if (gr != NULL)
+			return gr->gr_gid;
 		if (errno == 0 || errno == ENOENT || errno == ESRCH)
 			err(udev, "specified group '%s' unknown\n", group);
 		else
 			err(udev, "error resolving group '%s': %m\n", group);
-	} else
-		gid = gr->gr_gid;
-	return gid;
-}
+		return 0;
+	}
 
 /* handle "[<SUBSYSTEM>/<KERNEL>]<attribute>" format */
 int util_resolve_subsys_kernel(struct udev *udev, const char *string,