This adds support for RFC9072: Extended Optional Parameters Length for BGP
OPEN Message. I did not add any knobs to force the new format. Seems to
work for me (tested both formats with bgpd). The other ususal suspects
have no support yet so lets see.
--
:wq Claudio
Index: bgpd.8
===================================================================
RCS file: /cvs/src/usr.sbin/bgpd/bgpd.8,v
retrieving revision 1.69
diff -u -p -r1.69 bgpd.8
--- bgpd.8 17 Jun 2021 16:05:25 -0000 1.69
+++ bgpd.8 19 Jul 2021 15:12:41 -0000
@@ -458,6 +458,14 @@ has been started.
.%R RFC 8326
.%T Graceful BGP Session Shutdown
.Re
+.Pp
+.Rs
+.%A E. Chen
+.%A J. Scudder
+.%D July 2021
+.%R RFC 9072
+.%T Extended Optional Parameters Length for BGP OPEN Message
+.Re
.Sh HISTORY
The
.Nm
Index: session.c
===================================================================
RCS file: /cvs/src/usr.sbin/bgpd/session.c,v
retrieving revision 1.422
diff -u -p -r1.422 session.c
--- session.c 24 Jun 2021 09:26:18 -0000 1.422
+++ session.c 19 Jul 2021 15:20:21 -0000
@@ -1413,14 +1413,13 @@ session_open(struct peer *p)
struct bgp_msg *buf;
struct ibuf *opb;
struct msg_open msg;
- u_int16_t len;
- u_int8_t i, op_type, optparamlen = 0;
- int errs = 0;
+ u_int16_t len, optparamlen = 0;
+ u_int8_t i, op_type;
+ int errs = 0, extlen = 0;
int mpcapa = 0;
- if ((opb = ibuf_dynamic(0, UCHAR_MAX - sizeof(op_type) -
- sizeof(optparamlen))) == NULL) {
+ if ((opb = ibuf_dynamic(0, UINT16_MAX - 3)) == NULL) {
bgp_fsm(p, EVNT_CON_FATAL);
return;
}
@@ -1491,9 +1490,18 @@ session_open(struct peer *p)
if (p->capa.ann.enhanced_rr) /* no data */
errs += session_capa_add(opb, CAPA_ENHANCED_RR, 0);
- if (ibuf_size(opb))
- optparamlen = ibuf_size(opb) + sizeof(op_type) +
- sizeof(optparamlen);
+ optparamlen = ibuf_size(opb);
+ if (optparamlen == 0) {
+ /* nothing */
+ } else if (optparamlen + 2 >= 255) {
+ /* RFC9072: 2 byte lenght instead of 1 + 3 byte extra header */
+ optparamlen += sizeof(op_type) + 2 + 3;
+ msg.optparamlen = 255;
+ extlen = 1;
+ } else {
+ optparamlen += sizeof(op_type) + 1;
+ msg.optparamlen = optparamlen;
+ }
len = MSGSIZE_OPEN_MIN + optparamlen;
if (errs || (buf = session_newmsg(OPEN, len)) == NULL) {
@@ -1509,19 +1517,34 @@ session_open(struct peer *p)
else
msg.holdtime = htons(conf->holdtime);
msg.bgpid = conf->bgpid; /* is already in network byte order */
- msg.optparamlen = optparamlen;
errs += ibuf_add(buf->buf, &msg.version, sizeof(msg.version));
errs += ibuf_add(buf->buf, &msg.myas, sizeof(msg.myas));
errs += ibuf_add(buf->buf, &msg.holdtime, sizeof(msg.holdtime));
errs += ibuf_add(buf->buf, &msg.bgpid, sizeof(msg.bgpid));
- errs += ibuf_add(buf->buf, &msg.optparamlen, sizeof(msg.optparamlen));
+ errs += ibuf_add(buf->buf, &msg.optparamlen, 1);
+
+ if (extlen) {
+ /* write RFC9072 extra header */
+ u_int16_t op_extlen = htons(optparamlen - 3);
+ op_type = OPT_PARAM_EXT_LEN;
+ errs += ibuf_add(buf->buf, &op_type, 1);
+ errs += ibuf_add(buf->buf, &op_extlen, 2);
+ }
if (optparamlen) {
op_type = OPT_PARAM_CAPABILITIES;
- optparamlen = ibuf_size(opb);
errs += ibuf_add(buf->buf, &op_type, sizeof(op_type));
- errs += ibuf_add(buf->buf, &optparamlen, sizeof(optparamlen));
+
+ optparamlen = ibuf_size(opb);
+ if (extlen) {
+ /* RFC9072: 2-byte extended length */
+ u_int16_t op_extlen = htons(optparamlen);
+ errs += ibuf_add(buf->buf, &op_extlen, 2);
+ } else {
+ u_int8_t op_len = optparamlen;
+ errs += ibuf_add(buf->buf, &op_len, 1);
+ }
errs += ibuf_add(buf->buf, opb->buf, ibuf_size(opb));
}
@@ -2042,8 +2065,8 @@ parse_open(struct peer *peer)
u_int16_t short_as, msglen;
u_int16_t holdtime, oholdtime, myholdtime;
u_int32_t as, bgpid;
- u_int8_t optparamlen, plen;
- u_int8_t op_type, op_len;
+ u_int16_t optparamlen, extlen, plen, op_len;
+ u_int8_t op_type;
p = peer->rbuf->rptr;
p += MSGSIZE_HEADER_MARKER;
@@ -2116,41 +2139,56 @@ parse_open(struct peer *peer)
}
peer->remote_bgpid = bgpid;
- memcpy(&optparamlen, p, sizeof(optparamlen));
- p += sizeof(optparamlen);
+ extlen = 0;
+ optparamlen = *p++;
- if (optparamlen != msglen - MSGSIZE_OPEN_MIN) {
+ if (optparamlen == 0) {
+ if (msglen != MSGSIZE_OPEN_MIN) {
+bad_len:
log_peer_warnx(&peer->conf,
"corrupt OPEN message received: length mismatch");
session_notification(peer, ERR_OPEN, 0, NULL, 0);
change_state(peer, STATE_IDLE, EVNT_RCVD_OPEN);
return (-1);
+ }
+ } else {
+ if (msglen < MSGSIZE_OPEN_MIN + 1)
+ goto bad_len;
+
+ op_type = *p;
+ if (op_type == OPT_PARAM_EXT_LEN) {
+ p++;
+ memcpy(&optparamlen, p, sizeof(optparamlen));
+ optparamlen = ntohs(optparamlen);
+ p += sizeof(optparamlen);
+ extlen = 1;
+ }
+
+ /* RFC9020 encoding has 3 extra bytes */
+ if (optparamlen + 3 * extlen != msglen - MSGSIZE_OPEN_MIN)
+ goto bad_len;
}
plen = optparamlen;
while (plen > 0) {
- if (plen < 2) {
- log_peer_warnx(&peer->conf,
- "corrupt OPEN message received, len wrong");
- session_notification(peer, ERR_OPEN, 0, NULL, 0);
- change_state(peer, STATE_IDLE, EVNT_RCVD_OPEN);
- return (-1);
- }
+ if (plen < 2 + extlen)
+ goto bad_len;
+
memcpy(&op_type, p, sizeof(op_type));
p += sizeof(op_type);
plen -= sizeof(op_type);
- memcpy(&op_len, p, sizeof(op_len));
- p += sizeof(op_len);
- plen -= sizeof(op_len);
+ if (!extlen) {
+ op_len = *p++;
+ plen--;
+ } else {
+ memcpy(&op_len, p, sizeof(op_len));
+ op_len = ntohs(op_len);
+ p += sizeof(op_len);
+ plen -= sizeof(op_len);
+ }
if (op_len > 0) {
- if (plen < op_len) {
- log_peer_warnx(&peer->conf,
- "corrupt OPEN message received, len wrong");
- session_notification(peer, ERR_OPEN, 0,
- NULL, 0);
- change_state(peer, STATE_IDLE, EVNT_RCVD_OPEN);
- return (-1);
- }
+ if (plen < op_len)
+ goto bad_len;
op_val = p;
p += op_len;
plen -= op_len;
Index: session.h
===================================================================
RCS file: /cvs/src/usr.sbin/bgpd/session.h,v
retrieving revision 1.151
diff -u -p -r1.151 session.h
--- session.h 27 May 2021 08:27:48 -0000 1.151
+++ session.h 19 Jul 2021 09:10:40 -0000
@@ -103,7 +103,8 @@ enum suberr_fsm {
enum opt_params {
OPT_PARAM_NONE,
OPT_PARAM_AUTH,
- OPT_PARAM_CAPABILITIES
+ OPT_PARAM_CAPABILITIES,
+ OPT_PARAM_EXT_LEN=255,
};
enum capa_codes {
