bgpd: Regularise BGP NLRI sanity checks a bit

* bgp_route.h: (bgp_nlri_sanity_check) The bulk of the args are equivalent
  to a (struct bgp_nlri), consolidate.
* bgp_route.c: (bgp_nlri_sanity_check) Make this a frontend for all afi/safis.
  Including SAFI_MPLS_LABELED_VPN.
  (bgp_nlri_sanity_check_ip) Regular IP NLRI sanity check based on the
  existing code, and adjusted for (struct bgp_nlri *) arg.
* bgp_attr.c: (bgp_mp_reach_parse) Adjust for passing (struct bgp_nlri *)
  to bgp_nlri_sanity_check.
  Get rid of special-casing to not sanity check VPN.
  (bgp_mp_unreach_parse) Ditto.

* bgp_mplsvpn.c: Use the same VPN parsing code for both the sanity
  check and the actual parse.

  (bgp_nlri_parse_vpn) renamed to bgp_nlri_parse_vpn_body and made
  internal.

  (bgp_nlri_parse_vpn_body) Added (bool) argument to control whether it
  is sanity checking or whether it should update routing state for each
  NLRI.  Send a NOTIFY and reset the session, if there's a parsing
  error, as bgp_nlri_sanity_check_ip does, and as is required by the
  RFC.

  (bgp_nlri_parse_vpn) now a wrapper to call _body with update.

  (bgp_nlri_sanity_check_vpn) wrapper to call parser without
  updating.

* bgp_mplsvpn.h: (bgp_nlri_sanity_check_vpn) export for
  bgp_nlri_sanity_check.

* bgp_packet.c: (bgp_update_receive) Adjust for bgp_nlri_sanity_check
  argument changes.

* test/bgp_mp_attr_test.c: Extend to also test the NLRI parsing functions,
  if the initial MP-attr parsing has succeeded.  Fix the NLRI in the
  VPN cases.  Add further VPN tests.

* tests/bgpd.tests/testbgpmpattr.exp: Add the new test cases.

This commit a joint effort of:

Lou Berger <lberger@labn.net>
Donald Sharp <sharpd@cumulusnetworks.com>
Paul Jakma <paul.jakma@hpe.com> / <paul@jakma.org>

1 files changed, 20 insertions, 6 deletions

diff --git a/bgpd/bgp_route.c b/bgpd/bgp_route.c
index 0dcae61e..c1e5e59b 100644
--- a/bgpd/bgp_route.c
+++ b/bgpd/bgp_route.c
@@ -3322,16 +3322,16 @@ bgp_nlri_parse (struct peer *peer, struct attr *attr, struct bgp_nlri *packet)
   return 0;
 }
 
-/* NLRI encode syntax check routine. */
-int
-bgp_nlri_sanity_check (struct peer *peer, int afi, safi_t safi,
-                       u_char *pnt, bgp_size_t length)
+static int
+bgp_nlri_sanity_check_ip (struct peer *peer, struct bgp_nlri *nlri)
 {
   u_char *end;
   u_char prefixlen;
   int psize;
-
-  end = pnt + length;
+  u_char *pnt = nlri->nlri;
+  afi_t afi = nlri->afi;
+  safi_t safi = nlri->safi;
+  end = pnt + nlri->length;
 
   /* RFC1771 6.3 The NLRI field in the UPDATE message is checked for
      syntactic validity.  If the field is syntactically incorrect,
@@ -3395,6 +3395,20 @@ bgp_nlri_sanity_check (struct peer *peer, int afi, safi_t safi,
   return 0;
 }
 
+int
+bgp_nlri_sanity_check (struct peer *peer, struct bgp_nlri *nlri)
+{
+   switch (nlri->safi)
+     {
+       case SAFI_MPLS_LABELED_VPN:
+         return bgp_nlri_sanity_check_vpn (peer, nlri);
+       case SAFI_UNICAST:
+       case SAFI_MULTICAST:
+         return bgp_nlri_sanity_check_ip (peer, nlri);
+       default: return -1;
+     }
+}
+
 static struct bgp_static *
 bgp_static_new (void)
 {