Enfroce proper encoding of ASPA announce/withdraw PDU.

An announce PDU requires at least one provider ASnum while a withdraw
must not include any provider ASnums. The first is mandated by the ASPA
profile and the 2nd by the 8210bis draft.

Further cleanup some leftovers from the old per-AFI split of ASPA.
OK tb@

diff --git a/usr.sbin/bgpd/rtr_proto.c b/usr.sbin/bgpd/rtr_proto.c
index b990335..acec237 100644 (file)
--- a/usr.sbin/bgpd/rtr_proto.c
+++ b/usr.sbin/bgpd/rtr_proto.c
@@ -1,4 +1,4 @@
-/*     $OpenBSD: rtr_proto.c,v 1.39 2024/08/20 11:59:39 claudio Exp $ */
+/*     $OpenBSD: rtr_proto.c,v 1.40 2024/09/10 08:41:13 claudio Exp $ */
 
 /*
  * Copyright (c) 2020 Claudio Jeker <claudio@openbsd.org>
@@ -110,8 +110,6 @@ struct rtr_routerkey {
        /* followed by Subject Public Key Info */
 } __packed;
 
-#define FLAG_AFI_V6    0x1
-#define FLAG_AFI_MASK  FLAG_AFI_V6
 struct rtr_aspa {
        struct rtr_header       hdr;
        uint32_t                cas;
@@ -191,7 +189,6 @@ struct rtr_session {
        char                            descr[PEER_DESCR_LEN];
        struct roa_tree                 roa_set;
        struct aspa_tree                aspa;
-       struct aspa_tree                aspa_oldv6;
        struct ibuf_read                r;
        struct msgbuf                   w;
        struct timer_head               timers;
@@ -277,7 +274,6 @@ rtr_reset_cache(struct rtr_session *rs)
        timer_stop(&rs->timers, Timer_Rtr_Expire);
        free_roatree(&rs->roa_set);
        free_aspatree(&rs->aspa);
-       free_aspatree(&rs->aspa_oldv6);
 }
 
 static struct ibuf *
@@ -761,6 +757,17 @@ rtr_parse_aspa(struct rtr_session *rs, struct ibuf *pdu)
        flags = rtr_aspa.hdr.flags;
        cnt = ibuf_size(pdu) / sizeof(uint32_t);
 
+       if ((flags & FLAG_ANNOUNCE) && cnt == 0) {
+               rtr_send_error(rs, pdu, CORRUPT_DATA, "%s: "
+                   "announce with empty SPAS", log_rtr_type(ASPA));
+               return -1;
+       }
+       if ((flags & FLAG_ANNOUNCE) == 0 && cnt != 0) {
+               rtr_send_error(rs, pdu, CORRUPT_DATA, "%s: "
+                   "withdraw with non-empty SPAS", log_rtr_type(ASPA));
+               return -1;
+       }
+
        if (rs->state != RTR_STATE_EXCHANGE) {
                rtr_send_error(rs, pdu, CORRUPT_DATA, "%s: out of context",
                    log_rtr_type(ASPA));
@@ -1398,7 +1405,6 @@ rtr_new(uint32_t id, struct rtr_config_msg *conf)
 
        RB_INIT(&rs->roa_set);
        RB_INIT(&rs->aspa);
-       RB_INIT(&rs->aspa_oldv6);
        TAILQ_INIT(&rs->timers);
        msgbuf_init(&rs->w);
 
@@ -1518,8 +1524,6 @@ rtr_aspa_merge(struct aspa_tree *at)
        TAILQ_FOREACH(rs, &rtrs, entry) {
                RB_FOREACH(aspa, aspa_tree, &rs->aspa)
                        rtr_aspa_insert(at, aspa);
-               RB_FOREACH(aspa, aspa_tree, &rs->aspa_oldv6)
-                       rtr_aspa_insert(at, aspa);
        }
 }