udev: avoid magic constants in kernel-cmdline parsers

Lets recognize the fact that startswith() returns a pointer to the tail on
success. Use it instead of hard-coding string-lengths as magic constants.

diff --git a/src/udev/udevd.c b/src/udev/udevd.c
index 193702cd288303f4142e67fabc132990ff084082..65d086e9eea742c7accd3bd08c46883bbbc4a892 100644 (file)
--- a/src/udev/udevd.c
+++ b/src/udev/udevd.c
@@ -967,7 +967,7 @@ static void kernel_cmdline_options(struct udev *udev) {
                 return;
 
         FOREACH_WORD_QUOTED(word, l, line, state) {
-                char *s, *opt;
+                char *s, *opt, *value;
 
                 s = strndup(word, l);
                 if (!s)
@@ -979,24 +979,24 @@ static void kernel_cmdline_options(struct udev *udev) {
                 else
                         opt = s;
 
-                if (startswith(opt, "udev.log-priority=")) {
+                if ((value = startswith(opt, "udev.log-priority="))) {
                         int prio;
 
-                        prio = util_log_priority(opt + 18);
+                        prio = util_log_priority(value);
                         log_set_max_level(prio);
                         udev_set_log_priority(udev, prio);
-                } else if (startswith(opt, "udev.children-max=")) {
-                        r = safe_atoi(opt + 18, &arg_children_max);
+                } else if ((value = startswith(opt, "udev.children-max="))) {
+                        r = safe_atoi(value, &arg_children_max);
                         if (r < 0)
-                                log_warning("Invalid udev.children-max ignored: %s", opt + 18);
-                } else if (startswith(opt, "udev.exec-delay=")) {
-                        r = safe_atoi(opt + 16, &arg_exec_delay);
+                                log_warning("Invalid udev.children-max ignored: %s", value);
+                } else if ((value = startswith(opt, "udev.exec-delay="))) {
+                        r = safe_atoi(value, &arg_exec_delay);
                         if (r < 0)
-                                log_warning("Invalid udev.exec-delay ignored: %s", opt + 16);
-                } else if (startswith(opt, "udev.event-timeout=")) {
-                        r = safe_atou64(opt + 19, &arg_event_timeout_usec);
+                                log_warning("Invalid udev.exec-delay ignored: %s", value);
+                } else if ((value = startswith(opt, "udev.event-timeout="))) {
+                        r = safe_atou64(value, &arg_event_timeout_usec);
                         if (r < 0) {
-                                log_warning("Invalid udev.event-timeout ignored: %s", opt + 19);
+                                log_warning("Invalid udev.event-timeout ignored: %s", value);
                                 break;
                         }
                         arg_event_timeout_usec *= USEC_PER_SEC;