vrrpd: use address cmp for priority tiebreak

Signed-off-by: Quentin Young <qlyoung@cumulusnetworks.com>

diff --git a/vrrpd/vrrp.c b/vrrpd/vrrp.c
index 411c3c7e7b0bfed882143c0b491a85940d124183..2605a84deeb072b79c6327280a18fa640a865ee3 100644 (file)
--- a/vrrpd/vrrp.c
+++ b/vrrpd/vrrp.c
@@ -464,9 +464,25 @@ static void vrrp_send_advertisement(struct vrrp_router *r)
  * However, we have not validated whether the VRID is correct for this virtual
  * router, nor whether the priority is correct (i.e. is not 255 when we are the
  * address owner).
+ *
+ * r
+ *    VRRP Router associated with the socket this advertisement was received on
+ *
+ * src
+ *    Source address of sender
+ *
+ * pkt
+ *    The advertisement they sent
+ *
+ * pktsize
+ *    Size of advertisement
+ *
+ * Returns:
+ *    -1 if advertisement is invalid
+ *     0 otherwise
  */
-static int vrrp_recv_advertisement(struct vrrp_router *r, struct vrrp_pkt *pkt,
-                                   size_t pktsize)
+static int vrrp_recv_advertisement(struct vrrp_router *r, struct ipaddr *src,
+                                  struct vrrp_pkt *pkt, size_t pktsize)
 {
        char dumpbuf[BUFSIZ];
        vrrp_pkt_adver_dump(dumpbuf, sizeof(dumpbuf), pkt);
@@ -500,8 +516,14 @@ static int vrrp_recv_advertisement(struct vrrp_router *r, struct vrrp_pkt *pkt,
                          r->addrs->count);
        }
 
+       int addrcmp;
+       size_t cmpsz = IS_IPADDR_V6(src) ? sizeof(struct in6_addr)
+                                        : sizeof(struct in_addr);
+
        switch (r->fsm.state) {
        case VRRP_STATE_MASTER:
+               addrcmp = memcmp(&src->ip, &r->src.ip, cmpsz);
+
                if (pkt->hdr.priority == 0) {
                        vrrp_send_advertisement(r);
                        THREAD_OFF(r->t_adver_timer);
@@ -509,9 +531,8 @@ static int vrrp_recv_advertisement(struct vrrp_router *r, struct vrrp_pkt *pkt,
                                master, vrrp_adver_timer_expire, r,
                                r->vr->advertisement_interval * 10,
                                &r->t_adver_timer);
-                       /* FIXME: 6.4.3 mandates checking sender IP address */
-               } else if (pkt->hdr.priority > r->priority) {
-                       zlog_err("NOT IMPLEMENTED");
+               } else if (pkt->hdr.priority > r->priority
+                          || ((pkt->hdr.priority == r->priority) && addrcmp > 0)) {
                        THREAD_OFF(r->t_adver_timer);
                        r->master_adver_interval = ntohs(pkt->hdr.v3.adver_int);
                        vrrp_recalculate_timers(r);
@@ -606,7 +627,7 @@ static int vrrp_read(struct thread *thread)
        } else {
                zlog_debug(VRRP_LOGPFX VRRP_LOGPFX_VRID "Packet looks good",
                           r->vr->vrid);
-               vrrp_recv_advertisement(r, pkt, pktsize);
+               vrrp_recv_advertisement(r, &src, pkt, pktsize);
        }
 
        resched = true;