bgpd: bugfix vpn-vrf leak: consider route changed if labels change

vpn-vrf leak code was not triggering a BGP update or an announce to zebra
if a route's labels changed. This changeset corrects that problem.

Signed-off-by: G. Paul Ziemba <paulz@labn.net>

diff --git a/bgpd/bgp_mplsvpn.c b/bgpd/bgp_mplsvpn.c
index 13a283a058c33ef514debd577d75c50ebe633054..6d8f4d93c4476832bbf5fcc0e2f7e30087e57acf 100644 (file)
--- a/bgpd/bgp_mplsvpn.c
+++ b/bgpd/bgp_mplsvpn.c
@@ -331,6 +331,57 @@ static int ecom_intersect(struct ecommunity *e1, struct ecommunity *e2)
        return 0;
 }
 
+static bool labels_same(struct bgp_info *bi, mpls_label_t *label, uint32_t n)
+{
+       uint32_t i;
+
+       if (!bi->extra) {
+               if (!n)
+                       return true;
+               else
+                       return false;
+       }
+
+       if (n != bi->extra->num_labels)
+               return false;
+
+       for (i = 0; i < n; ++i) {
+               if (label[i] != bi->extra->label[i])
+                       return false;
+       }
+       return true;
+}
+
+/*
+ * make encoded route labels match specified encoded label set
+ */
+static void setlabels(
+       struct bgp_info *bi,
+       mpls_label_t *label,            /* array of labels */
+       uint32_t num_labels)
+{
+       if (num_labels)
+               assert(label);
+       assert(num_labels <= BGP_MAX_LABELS);
+
+       if (!num_labels) {
+               if (bi->extra)
+                       bi->extra->num_labels = 0;
+               return;
+       }
+
+       struct bgp_info_extra *extra = bgp_info_extra_get(bi);
+       uint32_t i;
+
+       for (i = 0; i < num_labels; ++i) {
+               extra->label[i] = label[i];
+               if (!bgp_is_valid_label(&label[i])) {
+                       bgp_set_valid_label(&extra->label[i]);
+               }
+       }
+       extra->num_labels = num_labels;
+}
+
 /*
  * returns pointer to new bgp_info upon success
  */
@@ -343,7 +394,7 @@ leak_update(
        safi_t          safi,
        struct bgp_info *source_bi,
        mpls_label_t    *label,
-       int             num_labels,
+       uint32_t        num_labels,
        void            *parent,
        struct bgp      *bgp_orig,
        struct prefix   *nexthop_orig,
@@ -371,7 +422,10 @@ leak_update(
        }
 
        if (bi) {
+               bool labelssame = labels_same(bi, label, num_labels);
+
                if (attrhash_cmp(bi->attr, new_attr)
+                   && labelssame
                    && !CHECK_FLAG(bi->flags, BGP_INFO_REMOVED)) {
 
                        bgp_attr_unintern(&new_attr);
@@ -395,6 +449,12 @@ leak_update(
                bi->attr = new_attr;
                bi->uptime = bgp_clock();
 
+               /*
+                * rewrite labels
+                */
+               if (!labelssame)
+                       setlabels(bi, label, num_labels);
+
                if (nexthop_self_flag)
                        bgp_info_set_flag(bn, bi, BGP_INFO_ANNC_NH_SELF);
 
@@ -442,23 +502,10 @@ leak_update(
        if (nexthop_self_flag)
                bgp_info_set_flag(bn, new, BGP_INFO_ANNC_NH_SELF);
 
+       if (num_labels)
+               setlabels(new, label, num_labels);
+
        bgp_info_extra_get(new);
-       if (label) {
-               int i;
-
-               for (i = 0; i < num_labels; ++i) {
-                       new->extra->label[i] = label[i];
-                       if (!bgp_is_valid_label(&label[i])) {
-                               if (debug) {
-                                       zlog_debug(
-                                               "%s: %s: marking label %d valid",
-                                               __func__, buf_prefix, i);
-                               }
-                               bgp_set_valid_label(&new->extra->label[i]);
-                       }
-               }
-               new->extra->num_labels = num_labels;
-       }
        new->extra->parent = parent;
 
        if (bgp_orig)
@@ -889,7 +936,7 @@ static void vpn_leak_to_vrf_update_onevrf(struct bgp *bgp_vrf,       /* to */
        const char *debugmsg;
        struct prefix nexthop_orig;
        mpls_label_t *pLabels = NULL;
-       int num_labels = 0;
+       uint32_t num_labels = 0;
        int nexthop_self_flag = 1;
 
        int debug = BGP_DEBUG(vpn, VPN_LEAK_TO_VRF);