bgpd: Allow bgp to understand the different nexthop types

When BGP is being redistributed prefixes, allow it to
understand the nexthop type.

This fixes the issue where a blackhole route was being interpreted
to having a nexthop of 1.0.0.0( ruh-roh!!! ).  This broke
downstream neighbors as that they would receive a 1.0.0.0 nexthop,
which is bad, very very bad.

This commit sets us up for the future where we can match
a route-map against a nexthop type.  In that bgp is
now at least nominally paying attention to the type.

Signed-off-by: Donald Sharp <sharpd@cumulusnetworks.com>

diff --git a/bgpd/bgp_route.c b/bgpd/bgp_route.c
index 4ee1aafbe9f375f7b27e8d1de80280ba7449ea2a..e0ae2a96119fea87f32f6d3fdcf8061362bffe55 100644 (file)
--- a/bgpd/bgp_route.c
+++ b/bgpd/bgp_route.c
@@ -6148,8 +6148,9 @@ DEFUN (no_ipv6_aggregate_address,
 
 /* Redistribute route treatment. */
 void bgp_redistribute_add(struct bgp *bgp, struct prefix *p,
-                         const union g_addr *nexthop, unsigned int ifindex,
-                         u_int32_t metric, u_char type, u_short instance,
+                         const union g_addr *nexthop, ifindex_t ifindex,
+                         enum nexthop_types_t nhtype, uint32_t metric,
+                         u_char type, u_short instance,
                          route_tag_t tag)
 {
        struct bgp_info *new;
@@ -6164,15 +6165,31 @@ void bgp_redistribute_add(struct bgp *bgp, struct prefix *p,
 
        /* Make default attribute. */
        bgp_attr_default_set(&attr, BGP_ORIGIN_INCOMPLETE);
-       if (nexthop) {
+
+       switch(nhtype) {
+       case NEXTHOP_TYPE_IFINDEX:
+               break;
+       case NEXTHOP_TYPE_IPV4:
+       case NEXTHOP_TYPE_IPV4_IFINDEX:
+               attr.nexthop = nexthop->ipv4;
+               break;
+       case NEXTHOP_TYPE_IPV6:
+       case NEXTHOP_TYPE_IPV6_IFINDEX:
+               attr.mp_nexthop_global = nexthop->ipv6;
+               attr.mp_nexthop_len = BGP_ATTR_NHLEN_IPV6_GLOBAL;
+               break;
+       case NEXTHOP_TYPE_BLACKHOLE:
                switch (p->family) {
                case AF_INET:
-                       attr.nexthop = nexthop->ipv4;
+                       attr.nexthop.s_addr = INADDR_ANY;
                        break;
                case AF_INET6:
-                       attr.mp_nexthop_global = nexthop->ipv6;
+                       memset(&attr.mp_nexthop_global, 0,
+                              sizeof(attr.mp_nexthop_global));
                        attr.mp_nexthop_len = BGP_ATTR_NHLEN_IPV6_GLOBAL;
+                       break;
                }
+               break;
        }
        attr.nh_ifindex = ifindex;
 

diff --git a/bgpd/bgp_route.h b/bgpd/bgp_route.h
index 6fbeed896318236c5d1474111bd8ae2f05185de8..085de3fabb0eb64f6e275ff325e2206cc3b84ba7 100644 (file)
--- a/bgpd/bgp_route.h
+++ b/bgpd/bgp_route.h
@@ -328,9 +328,11 @@ extern int bgp_nlri_parse_ip(struct peer *, struct attr *, struct bgp_nlri *);
 
 extern int bgp_maximum_prefix_overflow(struct peer *, afi_t, safi_t, int);
 
-extern void bgp_redistribute_add(struct bgp *, struct prefix *,
-                                const union g_addr *, unsigned int ifindex,
-                                u_int32_t, u_char, u_short, route_tag_t);
+extern void bgp_redistribute_add(struct bgp *bgp, struct prefix *p,
+                                const union g_addr *nexthop, ifindex_t ifindex,
+                                enum nexthop_types_t nhtype, uint32_t metric,
+                                u_char type, u_short instance,
+                                route_tag_t tag);
 extern void bgp_redistribute_delete(struct bgp *, struct prefix *, u_char,
                                    u_short);
 extern void bgp_redistribute_withdraw(struct bgp *, afi_t, int, u_short);

diff --git a/bgpd/bgp_zebra.c b/bgpd/bgp_zebra.c
index bec70502263c8df1b94f1ce7be3fa336f449aaac..b6bf008bae292eb1c1ea74d06087ff26ab5baf93 100644 (file)
--- a/bgpd/bgp_zebra.c
+++ b/bgpd/bgp_zebra.c
@@ -524,9 +524,10 @@ static int bgp_interface_vrf_update(int command, struct zclient *zclient,
 static int zebra_read_route(int command, struct zclient *zclient,
                            zebra_size_t length, vrf_id_t vrf_id)
 {
+       enum nexthop_types_t nhtype;
        struct zapi_route api;
        union g_addr nexthop;
-       unsigned int ifindex;
+       ifindex_t ifindex;
        int add, i;
        struct bgp *bgp;
 
@@ -548,6 +549,7 @@ static int zebra_read_route(int command, struct zclient *zclient,
 
        nexthop = api.nexthops[0].gate;
        ifindex = api.nexthops[0].ifindex;
+       nhtype = api.nexthops[0].type;
 
        add = (command == ZEBRA_REDISTRIBUTE_ROUTE_ADD);
        if (add) {
@@ -568,8 +570,8 @@ static int zebra_read_route(int command, struct zclient *zclient,
 
                /* Now perform the add/update. */
                bgp_redistribute_add(bgp, &api.prefix, &nexthop, ifindex,
-                                    api.metric, api.type, api.instance,
-                                    api.tag);
+                                    nhtype, api.metric, api.type,
+                                    api.instance, api.tag);
        } else {
                bgp_redistribute_delete(bgp, &api.prefix, api.type,
                                        api.instance);