Zebra does not check flags when updating static routes

[qlyoung]

Before installing a new static route Zebra checks to see if an equivalent route already exists and deletes it before installing the new route.

zebra_static.c

394   /* Do nothing if there is a same static route.  */
395   for (si = rn->info; si; si = si->next)
396     {
397       if (type == si->type
398           && (! gate ||
399               ((afi == AFI_IP && IPV4_ADDR_SAME (gate, &si->addr.ipv4)) ||
400                (afi == AFI_IP6 && IPV6_ADDR_SAME (gate, &si->addr.ipv6))))
401           && (! ifindex || ifindex == si->ifindex))
402         {
403           if ((distance == si->distance) && (tag == si->tag) &&
404               !memcmp (&si->snh_label, snh_label, sizeof (struct static_nh_label)))
405             {
406               route_unlock_node (rn);
407               return 0;
408             }
409           else
410             update = si;
411         }
412     }

This fails to check the route flags, which results in behavior like this:

cumulus# conf t
cumulus(config)# ip route 1.2.3.4/24 reject
cumulus(config)# do show ip route static
Codes: K - kernel route, C - connected, S - static, R - RIP,
       O - OSPF, I - IS-IS, B - BGP, P - PIM, T - Table, v - VNC,
       V - VPN,
       > - selected route, * - FIB route

S>* 1.2.3.0/24 [1/0] is directly connected, Null0, rej
cumulus(config)# ip route 1.2.3.4/24 blackhole
cumulus(config)# do show ip route static
Codes: K - kernel route, C - connected, S - static, R - RIP,
       O - OSPF, I - IS-IS, B - BGP, P - PIM, T - Table, v - VNC,
       V - VPN,
       > - selected route, * - FIB route

S>* 1.2.3.0/24 [1/0] is directly connected, Null0, rej
cumulus(config)#

The route flags are still set to reject. Correct behavior:

cumulus# conf t
cumulus(config)# ip route
  A.B.C.D    IP destination prefix
  A.B.C.D/M  IP destination prefix (e.g. 10.0.0.0/8)
cumulus(config)# ip route 1.2.3.4/24 reject
cumulus(config)# do show ip route static
Codes: K - kernel route, C - connected, S - static, R - RIP,
       O - OSPF, I - IS-IS, B - BGP, P - PIM, T - Table, v - VNC,
       V - VPN,
       > - selected route, * - FIB route

S>* 1.2.3.0/24 [1/0] is directly connected, Null0, rej
cumulus(config)# ip route 1.2.3.4/24 blackhole
cumulus(config)# do show ip route static
Codes: K - kernel route, C - connected, S - static, R - RIP,
       O - OSPF, I - IS-IS, B - BGP, P - PIM, T - Table, v - VNC,
       V - VPN,
       > - selected route, * - FIB route

S>* 1.2.3.0/24 [1/0] is directly connected, Null0, bh
cumulus(config)#

The route has been changed to a blackhole route.