Put the RFC9234 open policy handing in its own function

While there fix a spelling mistake and remove an extra check for new == NULL
and old == NULL. The caller make this check already.
OK tb@

diff --git a/usr.sbin/bgpd/rde_update.c b/usr.sbin/bgpd/rde_update.c
index 335884a..9332136 100644 (file)
--- a/usr.sbin/bgpd/rde_update.c
+++ b/usr.sbin/bgpd/rde_update.c
@@ -1,4 +1,4 @@
-/*     $OpenBSD: rde_update.c,v 1.142 2022/07/08 10:01:52 claudio Exp $ */
+/*     $OpenBSD: rde_update.c,v 1.143 2022/07/11 16:55:21 claudio Exp $ */
 
 /*
  * Copyright (c) 2004 Claudio Jeker <claudio@openbsd.org>
@@ -96,6 +96,44 @@ up_test_update(struct rde_peer *peer, struct prefix *p)
        return (1);
 }
 
+/* RFC9234 open policy handling */
+static int
+up_enforce_open_policy(struct rde_peer *peer, struct filterstate *state)
+{
+       uint8_t role;
+
+       if (!peer_has_open_policy(peer, &role))
+               return 0;
+
+       /*
+        * do not propagate (consider it filtered) if OTC is present and
+        * neighbor role is peer, provider or rs.
+        */
+       if (role == CAPA_ROLE_PEER || role == CAPA_ROLE_PROVIDER ||
+           role == CAPA_ROLE_RS)
+               if (state->aspath.flags & F_ATTR_OTC)
+                       return (1);
+
+       /*
+        * add OTC attribute if not present for peers, customers and rs-clients.
+        */
+       if (role == CAPA_ROLE_PEER || role == CAPA_ROLE_CUSTOMER ||
+           role == CAPA_ROLE_RS_CLIENT)
+               if ((state->aspath.flags & F_ATTR_OTC) == 0) {
+                       uint32_t tmp;
+
+                       tmp = htonl(peer->conf.local_as);
+                       if (attr_optadd(&state->aspath,
+                           ATTR_OPTIONAL|ATTR_TRANSITIVE, ATTR_OTC,
+                           &tmp, sizeof(tmp)) == -1)
+                               log_peer_warnx(&peer->conf,
+                                   "failed to add OTC attribute");
+                       state->aspath.flags |= F_ATTR_OTC;
+               }
+
+       return 0;
+}
+
 void
 up_generate_updates(struct filter_head *rules, struct rde_peer *peer,
     struct prefix *new, struct prefix *old)
@@ -104,12 +142,9 @@ up_generate_updates(struct filter_head *rules, struct rde_peer *peer,
        struct bgpd_addr        addr;
        struct prefix           *p;
        int                     need_withdraw;
-       uint8_t                 prefixlen, role;
+       uint8_t                 prefixlen;
 
        if (new == NULL) {
-               if (old == NULL)
-                       /* no prefix to update or withdraw */
-                       return;
                pt_getaddr(old->pt, &addr);
                prefixlen = old->pt->prefixlen;
        } else {
@@ -123,7 +158,7 @@ up_generate_updates(struct filter_head *rules, struct rde_peer *peer,
                need_withdraw = 0;
                /*
                 * up_test_update() needs to run before the output filters
-                * else the well known communities wont work properly.
+                * else the well known communities won't work properly.
                 * The output filters would not be able to add well known
                 * communities.
                 */
@@ -156,43 +191,14 @@ up_generate_updates(struct filter_head *rules, struct rde_peer *peer,
                        break;
                }
 
-               /* RFC9234 open policy handling */
-               if (peer_has_open_policy(peer, &role)) {
-                       /*
-                        * do not propagate (consider it filtered) if
-                        * OTC is present and neighbor role is peer,
-                        * provider or rs.
-                        */
-                       if ((role == CAPA_ROLE_PEER ||
-                           role == CAPA_ROLE_PROVIDER ||
-                           role == CAPA_ROLE_RS) &&
-                           state.aspath.flags & F_ATTR_OTC) {
-                               rde_filterstate_clean(&state);
-                               if (peer->flags & PEERFLAG_EVALUATE_ALL) {
-                                       new = TAILQ_NEXT(new, entry.list.rib);
-                                       if (new != NULL && prefix_eligible(new))
-                                               continue;
-                               }
-                               break;
-                       }
-                       /*
-                        * add OTC attribute if not present for peers,
-                        * customers and rs-clients.
-                        */
-                       if ((role == CAPA_ROLE_PEER ||
-                           role == CAPA_ROLE_CUSTOMER ||
-                           role == CAPA_ROLE_RS_CLIENT) &&
-                           (state.aspath.flags & F_ATTR_OTC) == 0) {
-                               uint32_t tmp;
-
-                               tmp = htonl(peer->conf.local_as);
-                               if (attr_optadd(&state.aspath,
-                                   ATTR_OPTIONAL|ATTR_TRANSITIVE, ATTR_OTC,
-                                   &tmp, sizeof(tmp)) == -1)
-                                       log_peer_warnx(&peer->conf,
-                                           "failed to add OTC attribute");
-                               state.aspath.flags |= F_ATTR_OTC;
+               if (up_enforce_open_policy(peer, &state)) {
+                       rde_filterstate_clean(&state);
+                       if (peer->flags & PEERFLAG_EVALUATE_ALL) {
+                               new = TAILQ_NEXT(new, entry.list.rib);
+                               if (new != NULL && prefix_eligible(new))
+                                       continue;
                        }
+                       break;
                }
 
                /* check if this was actually a withdraw */