bgpd: Allow bgp static routes to use /32's

If you are including a network statement of a /32
then the current bgp martian checks will match the /32
together.

Problem:
!
router bgp 3235
 neighbor 192.168.161.2 remote-as external
 neighbor 192.168.161.131 remote-as external
 !
 address-family ipv4 unicast
  network 10.10.3.11/32
  network 192.168.161.0/24
  no neighbor 192.168.161.2 activate
  neighbor 192.168.161.2 route-map BLUE in
 exit-address-family
!
eva# show bgp ipv4 uni
BGP table version is 1, local router ID is 10.10.3.11, vrf id 0
Default local pref 100, local AS 3235
Status codes:  s suppressed, d damped, h history, * valid, > best, = multipath,
               i internal, r RIB-failure, S Stale, R Removed
Nexthop codes: @NNN nexthop's vrf id, < announce-nh-self
Origin codes:  i - IGP, e - EGP, ? - incomplete
   Network          Next Hop            Metric LocPrf Weight Path
   10.10.3.11/32    0.0.0.0(eva)             0         32768 i
*> 192.168.161.0/24 0.0.0.0(eva)             0         32768 i
Displayed  2 routes and 2 total paths
eva# show bgp import-check-table
Current BGP import check cache:
 192.168.161.0 valid [IGP metric 0], #paths 1
  if enp39s0
  Last update: Fri Sep 25 08:00:42 2020
 10.10.3.11 valid [IGP metric 0], #paths 1
  if lo
  Last update: Fri Sep 25 08:00:42 2020
eva# show bgp ipv4 uni summ
BGP router identifier 10.10.3.11, local AS number 3235 vrf-id 0
BGP table version 1
RIB entries 3, using 576 bytes of memory
Peers 1, using 21 KiB of memory
Neighbor                 V         AS   MsgRcvd   MsgSent   TblVer  InQ OutQ  Up/Down State/PfxRcd   PfxSnt
janelle(192.168.161.131) 4      60000        69        70        0    0    0 00:03:21            0        1
Total number of neighbors 1

When we are deciding that a nexthop is valid there is not much point in checking
that a static route has a martian nexthop or not, since we self derived it already.

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

diff --git a/bgpd/bgp_route.c b/bgpd/bgp_route.c
index 96fbcad0280f3ff113a673ded0cc0977854fd7fe..2c15143ee46fd1f757623a46dc4b2229a1939e66 100644 (file)
--- a/bgpd/bgp_route.c
+++ b/bgpd/bgp_route.c
@@ -3243,14 +3243,20 @@ bool bgp_update_martian_nexthop(struct bgp *bgp, afi_t afi, safi_t safi,
                (type == ZEBRA_ROUTE_BGP && stype == BGP_ROUTE_STATIC) ? true
                                                                       : false;
 
-       /* Only validated for unicast and multicast currently. */
-       /* Also valid for EVPN where the nexthop is an IP address. */
-       if (safi != SAFI_UNICAST && safi != SAFI_MULTICAST && safi != SAFI_EVPN)
+       /*
+        * Only validated for unicast and multicast currently.
+        * Also valid for EVPN where the nexthop is an IP address.
+        * If we are a bgp static route being checked then there is
+        * no need to check to see if the nexthop is martian as
+        * that it should be ok.
+        */
+       if (is_bgp_static_route ||
+           (safi != SAFI_UNICAST && safi != SAFI_MULTICAST && safi != SAFI_EVPN))
                return false;
 
        /* If NEXT_HOP is present, validate it. */
        if (attr->flag & ATTR_FLAG_BIT(BGP_ATTR_NEXT_HOP)) {
-               if ((attr->nexthop.s_addr == INADDR_ANY && !is_bgp_static_route)
+               if (attr->nexthop.s_addr == INADDR_ANY
                    || IPV4_CLASS_DE(ntohl(attr->nexthop.s_addr))
                    || bgp_nexthop_self(bgp, afi, type, stype, attr, rn))
                        return true;
@@ -3269,8 +3275,7 @@ bool bgp_update_martian_nexthop(struct bgp *bgp, afi_t afi, safi_t safi,
                switch (attr->mp_nexthop_len) {
                case BGP_ATTR_NHLEN_IPV4:
                case BGP_ATTR_NHLEN_VPNV4:
-                       ret = ((attr->mp_nexthop_global_in.s_addr == INADDR_ANY
-                               && !is_bgp_static_route)
+                       ret = (attr->mp_nexthop_global_in.s_addr == INADDR_ANY
                               || IPV4_CLASS_DE(
                                       ntohl(attr->mp_nexthop_global_in.s_addr))
                               || bgp_nexthop_self(bgp, afi, type, stype, attr,
@@ -3279,9 +3284,8 @@ bool bgp_update_martian_nexthop(struct bgp *bgp, afi_t afi, safi_t safi,
 
                case BGP_ATTR_NHLEN_IPV6_GLOBAL:
                case BGP_ATTR_NHLEN_VPNV6_GLOBAL:
-                       ret = ((IN6_IS_ADDR_UNSPECIFIED(
+                       ret = (IN6_IS_ADDR_UNSPECIFIED(
                                        &attr->mp_nexthop_global)
-                               && !is_bgp_static_route)
                               || IN6_IS_ADDR_LOOPBACK(&attr->mp_nexthop_global)
                               || IN6_IS_ADDR_MULTICAST(
                                       &attr->mp_nexthop_global)