fixup! ipv6/nib: fix lifetime handling in RIO handling

RIOT-OS · Feb 6, 2024 · c4de18a · c4de18a
1 parent 59e3fa6
commit c4de18a
Showing 1 changed file with 11 additions and 8 deletions.
diff --git a/sys/net/gnrc/network_layer/ipv6/nib/nib_ft.c b/sys/net/gnrc/network_layer/ipv6/nib/nib_ft.c
@@ -42,16 +42,19 @@ int gnrc_ipv6_nib_ft_add(const ipv6_addr_t *dst, unsigned dst_len,
     bool is_default_route = ((dst == NULL) || (dst_len == 0) ||
                              ipv6_addr_is_unspecified(dst));
 
-    if (ltime < UINT32_MAX) {
-        /* UINT32_MAX means infinite lifetime.
+    uint32_t ltime_ms = 0;
+    if (ltime > 0 && ltime < UINT32_MAX) {
+        /* 0 or UINT32_MAX mean infinite lifetime.
          * The valid lifetime is given in seconds, but our timers work in
          * milliseconds, so we have to scale down to the smallest possible
-         * value (UINT32_MAX - 1). This is however alright since we ask for
+         * value (UINT32_MAX ms). This is however alright since we ask for
          * a new router advertisement before this timeout expires */
-        ltime = (ltime > (UINT32_MAX / MS_PER_SEC)) ? (UINT32_MAX - 1) : ltime;
+        ltime_ms = ltime * MS_PER_SEC;
+        if (ltime_ms / MS_PER_SEC != ltime) {
+            /* If there was an overflow take the maximum */
+            ltime_ms = UINT32_MAX;
+        }
     }
-    uint32_t ltime_ms = ltime * MS_PER_SEC;
-
     if ((iface == 0) || ((is_default_route) && (next_hop == NULL))) {
         return -EINVAL;
     }
@@ -65,7 +68,7 @@ int gnrc_ipv6_nib_ft_add(const ipv6_addr_t *dst, unsigned dst_len,
         }
         else {
             _prime_def_router = ptr;
-            if (ltime > 0) {
+            if (ltime_ms > 0) {
                 _evtimer_add(ptr, GNRC_IPV6_NIB_RTR_TIMEOUT,
                              &ptr->rtr_timeout, ltime_ms);
             }
@@ -80,7 +83,7 @@ int gnrc_ipv6_nib_ft_add(const ipv6_addr_t *dst, unsigned dst_len,
         if (ptr == NULL) {
             res = -ENOMEM;
         }
-        else if (ltime > 0) {
+        else if (ltime_ms > 0) {
             _evtimer_add(ptr, GNRC_IPV6_NIB_ROUTE_TIMEOUT,
                          &ptr->route_timeout, ltime_ms);
         }