return BGP_ATTR_PARSE_PROCEED;
}
+/*
+ * Check that the nexthop attribute is valid.
+ */
+bgp_attr_parse_ret_t
+bgp_attr_nexthop_valid(struct peer *peer, struct attr *attr)
+{
+ in_addr_t nexthop_h;
+
+ nexthop_h = ntohl(attr->nexthop.s_addr);
+ if ((IPV4_NET0(nexthop_h) || IPV4_NET127(nexthop_h)
+ || IPV4_CLASS_DE(nexthop_h))
+ && !BGP_DEBUG(allow_martians, ALLOW_MARTIANS)) {
+ char buf[INET_ADDRSTRLEN];
+
+ inet_ntop(AF_INET, &attr->nexthop.s_addr, buf,
+ INET_ADDRSTRLEN);
+ flog_err(EC_BGP_ATTR_MARTIAN_NH, "Martian nexthop %s",
+ buf);
+ bgp_notify_send(peer, BGP_NOTIFY_UPDATE_ERR,
+ BGP_NOTIFY_UPDATE_INVAL_NEXT_HOP);
+ return BGP_ATTR_PARSE_ERROR;
+ }
+
+ return BGP_ATTR_PARSE_PROCEED;
+}
+
/* Nexthop attribute. */
static bgp_attr_parse_ret_t bgp_attr_nexthop(struct bgp_attr_parser_args *args)
{
struct attr *const attr = args->attr;
const bgp_size_t length = args->length;
- in_addr_t nexthop_h, nexthop_n;
-
/* Check nexthop attribute length. */
if (length != 4) {
flog_err(EC_BGP_ATTR_LEN,
args->total);
}
- /* According to section 6.3 of RFC4271, syntactically incorrect NEXT_HOP
- attribute must result in a NOTIFICATION message (this is implemented
- below).
- At the same time, semantically incorrect NEXT_HOP is more likely to
- be just
- logged locally (this is implemented somewhere else). The UPDATE
- message
- gets ignored in any of these cases. */
- nexthop_n = stream_get_ipv4(peer->curr);
- nexthop_h = ntohl(nexthop_n);
- if ((IPV4_NET0(nexthop_h) || IPV4_NET127(nexthop_h)
- || IPV4_CLASS_DE(nexthop_h))
- && !BGP_DEBUG(
- allow_martians,
- ALLOW_MARTIANS)) /* loopbacks may be used in testing */
- {
- char buf[INET_ADDRSTRLEN];
- inet_ntop(AF_INET, &nexthop_n, buf, INET_ADDRSTRLEN);
- flog_err(EC_BGP_ATTR_MARTIAN_NH, "Martian nexthop %s", buf);
- return bgp_attr_malformed(
- args, BGP_NOTIFY_UPDATE_INVAL_NEXT_HOP, args->total);
- }
-
- attr->nexthop.s_addr = nexthop_n;
+ attr->nexthop.s_addr = stream_get_ipv4(peer->curr);
attr->flag |= ATTR_FLAG_BIT(BGP_ATTR_NEXT_HOP);
return BGP_ATTR_PARSE_PROCEED;
return BGP_ATTR_PARSE_ERROR;
}
+ /*
+ * RFC4271: If the NEXT_HOP attribute field is syntactically incorrect,
+ * then the Error Subcode MUST be set to Invalid NEXT_HOP Attribute.
+ * This is implemented below and will result in a NOTIFICATION. If the
+ * NEXT_HOP attribute is semantically incorrect, the error SHOULD be
+ * logged, and the route SHOULD be ignored. In this case, a NOTIFICATION
+ * message SHOULD NOT be sent. This is implemented elsewhere.
+ *
+ * RFC4760: An UPDATE message that carries no NLRI, other than the one
+ * encoded in the MP_REACH_NLRI attribute, SHOULD NOT carry the NEXT_HOP
+ * attribute. If such a message contains the NEXT_HOP attribute, the BGP
+ * speaker that receives the message SHOULD ignore this attribute.
+ */
+ if (CHECK_FLAG(attr->flag, ATTR_FLAG_BIT(BGP_ATTR_NEXT_HOP))
+ && !CHECK_FLAG(attr->flag, ATTR_FLAG_BIT(BGP_ATTR_MP_REACH_NLRI))) {
+ if (bgp_attr_nexthop_valid(peer, attr) < 0) {
+ return BGP_ATTR_PARSE_ERROR;
+ }
+ }
+
/* Check all mandatory well-known attributes are present */
if ((ret = bgp_attr_check(peer, attr)) < 0) {
if (as4_path)
stream_putw_at(s, sizep, (stream_get_endp(s) - sizep) - 2);
}
+static int bgp_append_local_as(struct peer *peer, afi_t afi, safi_t safi)
+{
+ if (!BGP_AS_IS_PRIVATE(peer->local_as)
+ || (BGP_AS_IS_PRIVATE(peer->local_as)
+ && !CHECK_FLAG(peer->af_flags[afi][safi],
+ PEER_FLAG_REMOVE_PRIVATE_AS)
+ && !CHECK_FLAG(peer->af_flags[afi][safi],
+ PEER_FLAG_REMOVE_PRIVATE_AS_ALL)
+ && !CHECK_FLAG(peer->af_flags[afi][safi],
+ PEER_FLAG_REMOVE_PRIVATE_AS_REPLACE)
+ && !CHECK_FLAG(peer->af_flags[afi][safi],
+ PEER_FLAG_REMOVE_PRIVATE_AS_ALL_REPLACE)))
+ return 1;
+ return 0;
+}
+
/* Make attribute packet. */
bgp_size_t bgp_packet_attribute(struct bgp *bgp, struct peer *peer,
struct stream *s, struct attr *attr,
/* If replace-as is specified, we only use the
change_local_as when
advertising routes. */
- if (!CHECK_FLAG(
- peer->flags,
- PEER_FLAG_LOCAL_AS_REPLACE_AS)) {
- aspath = aspath_add_seq(aspath,
- peer->local_as);
- }
+ if (!CHECK_FLAG(peer->flags,
+ PEER_FLAG_LOCAL_AS_REPLACE_AS))
+ if (bgp_append_local_as(peer, afi,
+ safi))
+ aspath = aspath_add_seq(
+ aspath, peer->local_as);
aspath = aspath_add_seq(aspath,
peer->change_local_as);
} else {