Dear OpenBSD developers, This patch adds support for the "BGP Administrative Shutdown Communication" to bgpd(8) and bgpctl(8).
The draft-ietf-idr-shutdown (https://tools.ietf.org/html/draft-ietf-idr-shutdown) document specifies a mechanism to transmit a short freeform message across the wire as part of an Administrative Shutdown Cease NOTIFICATION message. This message serves to inform the neighbor why the BGP session was shut down. This is useful to communicate for instance a ticket reference, contact person or other information to the neighbor. Example usage: [job@kiera ~]$ bgpctl show Neighbor AS MsgRcvd MsgSent OutQ Up/Down State/PrfRcvd 165.254.255.24 15562 70684 60 0 00:21:16 33653 [job@kiera ~]$ bgpctl neighbor 165.254.255.24 down "goodbye, we are upgrading to openbsd 6.1" request processed [job@kiera ~]$ bgpctl show Neighbor AS MsgRcvd MsgSent OutQ Up/Down State/PrfRcvd 165.254.255.24 15562 70708 62 0 00:00:08 Idle [job@kiera ~]$ bgpctl show neighbor 165.254.255.24 | grep reason BGP state = Idle, marked down with shutdown reason "goodbye, we are upgrading to openbsd 6.1", down for 00:00:17 On the neighbor's side you'll see the following in syslog: Jan 8 19:28:54 shutdown bgpd[50719]: neighbor 165.254.255.26: received notification: Cease, administratively down Jan 8 19:28:54 shutdown bgpd[50719]: neighbor 165.254.255.26: received shutdown reason: "goodbye, we are upgrading to openbsd 6.1" and this is also visible through bgpctl(8): [job@shutdown~]$ bgpctl show neighbor 165.254.255.26 | grep reason Last received shutdown reason: "goodbye, we are upgrading to openbsd 6.1" This work has been tested against pmacct and exabgp which also support draft-ietf-idr-shutdown. The BGP Administrative Shutdown Communication feature for OpenBGPD was developed by Peter van Dijk <peter.van.d...@powerdns.com> and Job Snijders <j...@ntt.net>. Kind regards, Job Index: usr.sbin/bgpctl/bgpctl.8 =================================================================== RCS file: /cvs/src/usr.sbin/bgpctl/bgpctl.8,v retrieving revision 1.69 diff -u -p -r1.69 bgpctl.8 --- usr.sbin/bgpctl/bgpctl.8 25 May 2016 14:15:59 -0000 1.69 +++ usr.sbin/bgpctl/bgpctl.8 8 Jan 2017 17:45:24 -0000 @@ -104,8 +104,14 @@ Destroy a previously cloned peer. The peer must be down before calling this function. .Ar peer may be the neighbor's address or description. -.It Cm neighbor Ar peer Cm down -Take the BGP session to the specified neighbor down. +.It Cm neighbor Ar peer Cm down Op Ar reason +Take the BGP session to the specified neighbor down. If a +.Ar reason +is provided, the +.Ar reason +is send as Administrative Shutdown Communication to the neighbor. The +.Ar reason +cannot exceed 128 octets. .Ar peer may be the neighbor's address or description. .It Cm neighbor Ar peer Cm refresh Index: usr.sbin/bgpctl/bgpctl.c =================================================================== RCS file: /cvs/src/usr.sbin/bgpctl/bgpctl.c,v retrieving revision 1.188 diff -u -p -r1.188 bgpctl.c --- usr.sbin/bgpctl/bgpctl.c 3 Jun 2016 17:36:37 -0000 1.188 +++ usr.sbin/bgpctl/bgpctl.c 8 Jan 2017 17:45:24 -0000 @@ -159,6 +159,7 @@ main(int argc, char *argv[]) memcpy(&neighbor.addr, &res->peeraddr, sizeof(neighbor.addr)); strlcpy(neighbor.descr, res->peerdesc, sizeof(neighbor.descr)); + strlcpy(neighbor.shutcomm, res->shutcomm, sizeof(neighbor.shutcomm)); if ((fd = socket(AF_UNIX, SOCK_STREAM, 0)) == -1) err(1, "control_init: socket"); @@ -702,6 +703,13 @@ show_neighbor_msg(struct imsg *imsg, enu inet_ntoa(ina)); printf("%s\n", print_auth_method(p->auth.method)); printf(" BGP state = %s", statenames[p->state]); + if (p->conf.down) { + printf(", marked down"); + if (*(p->conf.shutcomm)) { + printf(" with shutdown reason \"%s\"", + log_shutcomm(p->conf.shutcomm)); + } + } if (p->stats.last_updown != 0) printf(", %s for %s", p->state == STATE_ESTABLISHED ? "up" : "down", @@ -736,6 +744,10 @@ show_neighbor_msg(struct imsg *imsg, enu break; print_neighbor_msgstats(p); printf("\n"); + if (*(p->stats.last_shutcomm)) { + printf(" Last received shutdown reason: \"%s\"\n", + log_shutcomm(p->stats.last_shutcomm)); + } if (p->state == STATE_IDLE) { static const char *errstr; Index: usr.sbin/bgpctl/parser.c =================================================================== RCS file: /cvs/src/usr.sbin/bgpctl/parser.c,v retrieving revision 1.73 diff -u -p -r1.73 parser.c --- usr.sbin/bgpctl/parser.c 11 Oct 2015 19:53:57 -0000 1.73 +++ usr.sbin/bgpctl/parser.c 8 Jan 2017 17:45:24 -0000 @@ -43,6 +43,7 @@ enum token_type { PREFIX, PEERDESC, RIBNAME, + SHUTDOWN_COMMUNICATION, COMMUNITY, LOCALPREF, MED, @@ -239,9 +240,15 @@ static const struct token t_neighbor[] = { ENDTOKEN, "", NONE, NULL} }; +static const struct token t_neighbor_modifiers_shutcomm[] = { + { NOTOKEN, "", NONE, NULL}, + { SHUTDOWN_COMMUNICATION, "", NONE, NULL}, + { ENDTOKEN, "", NONE, NULL} +}; + static const struct token t_neighbor_modifiers[] = { { KEYWORD, "up", NEIGHBOR_UP, NULL}, - { KEYWORD, "down", NEIGHBOR_DOWN, NULL}, + { KEYWORD, "down", NEIGHBOR_DOWN, t_neighbor_modifiers_shutcomm}, { KEYWORD, "clear", NEIGHBOR_CLEAR, NULL}, { KEYWORD, "refresh", NEIGHBOR_RREFRESH, NULL}, { KEYWORD, "destroy", NEIGHBOR_DESTROY, NULL}, @@ -549,6 +556,16 @@ match_token(int *argc, char **argv[], co t = &table[i]; } break; + case SHUTDOWN_COMMUNICATION: + if (!match && word != NULL && wordlen > 0) { + if (strlcpy(res.shutcomm, word, + sizeof(res.shutcomm)) >= + sizeof(res.shutcomm)) + errx(1, "shutdown reason too long"); + match++; + t = &table[i]; + } + break; case COMMUNITY: if (word != NULL && wordlen > 0 && parse_community(word, &res)) { @@ -664,6 +681,9 @@ show_valid_args(const struct token table break; case RIBNAME: fprintf(stderr, " <rib name>\n"); + break; + case SHUTDOWN_COMMUNICATION: + fprintf(stderr, " <shutdown reason>\n"); break; case COMMUNITY: fprintf(stderr, " <community>\n"); Index: usr.sbin/bgpctl/parser.h =================================================================== RCS file: /cvs/src/usr.sbin/bgpctl/parser.h,v retrieving revision 1.27 diff -u -p -r1.27 parser.h --- usr.sbin/bgpctl/parser.h 17 Apr 2015 07:51:09 -0000 1.27 +++ usr.sbin/bgpctl/parser.h 8 Jan 2017 17:45:24 -0000 @@ -65,6 +65,7 @@ struct parse_result { struct filter_community community; char peerdesc[PEER_DESCR_LEN]; char rib[PEER_DESCR_LEN]; + char shutcomm[SHUT_COMM_LEN]; char *irr_outdir; int flags; u_int rtableid; Index: usr.sbin/bgpd/bgpd.8 =================================================================== RCS file: /cvs/src/usr.sbin/bgpd/bgpd.8,v retrieving revision 1.48 diff -u -p -r1.48 bgpd.8 --- usr.sbin/bgpd/bgpd.8 14 Aug 2013 06:32:36 -0000 1.48 +++ usr.sbin/bgpd/bgpd.8 8 Jan 2017 17:45:24 -0000 @@ -238,6 +238,26 @@ control socket .Re .Pp .Rs +.%A J. Snijders +.%A J. Heitz +.%A K. Patel +.%A I. Bagdonas +.%A A. Simpson +.%D January 2017 +.%R draft-ietf-idr-large-community +.%T Large BGP Communities Attribute +.Re +.Pp +.Rs +.%A J. Snijders +.%A J. Heitz +.%A J. Scudder +.%D January 2017 +.%R draft-ietf-idr-shutdown +.%T BGP Administrative Shutdown Communication +.Re +.Pp +.Rs .%A A. Heffernan .%D August 1998 .%R RFC 2385 Index: usr.sbin/bgpd/bgpd.conf.5 =================================================================== RCS file: /cvs/src/usr.sbin/bgpd/bgpd.conf.5,v retrieving revision 1.144 diff -u -p -r1.144 bgpd.conf.5 --- usr.sbin/bgpd/bgpd.conf.5 28 Jun 2016 16:59:14 -0000 1.144 +++ usr.sbin/bgpd/bgpd.conf.5 8 Jan 2017 17:45:24 -0000 @@ -722,9 +722,17 @@ The description is used when logging nei reports, for specifying neighbors, etc., but has no further meaning to .Xr bgpd 8 . .Pp -.It Ic down +.It Ic down Op Ar reason Do not start the session when bgpd comes up but stay in .Em IDLE . +If the session is cleared at runtime, after a +.Ic down +.Ar reason +was configured at runtime, the +.Ar reason +is sent as Administrative Shutdown Communication. The +.Ar reason +cannot exceed 128 octets. .Pp .It Xo .Ic dump Index: usr.sbin/bgpd/bgpd.h =================================================================== RCS file: /cvs/src/usr.sbin/bgpd/bgpd.h,v retrieving revision 1.294 diff -u -p -r1.294 bgpd.h --- usr.sbin/bgpd/bgpd.h 6 Jun 2016 15:59:10 -0000 1.294 +++ usr.sbin/bgpd/bgpd.h 8 Jan 2017 17:45:24 -0000 @@ -38,6 +38,7 @@ #define CONFFILE "/etc/bgpd.conf" #define BGPD_USER "_bgpd" #define PEER_DESCR_LEN 32 +#define SHUT_COMM_LEN 129 #define PFTABLE_LEN 32 #define TCP_MD5_KEY_LEN 80 #define IPSEC_ENC_KEY_LEN 32 @@ -296,6 +297,7 @@ struct peer_config { struct capabilities capabilities; char group[PEER_DESCR_LEN]; char descr[PEER_DESCR_LEN]; + char shutcomm[SHUT_COMM_LEN]; char rib[PEER_DESCR_LEN]; char if_depend[IFNAMSIZ]; char demote_group[IFNAMSIZ]; @@ -579,6 +581,7 @@ struct ctl_show_nexthop { struct ctl_neighbor { struct bgpd_addr addr; char descr[PEER_DESCR_LEN]; + char shutcomm[SHUT_COMM_LEN]; int show_timers; }; @@ -1060,6 +1063,7 @@ const char *log_sockaddr(struct sockaddr const char *log_as(u_int32_t); const char *log_rd(u_int64_t); const char *log_ext_subtype(u_int8_t); +const char *log_shutcomm(const char *); int aspath_snprint(char *, size_t, void *, u_int16_t); int aspath_asprint(char **, void *, u_int16_t); size_t aspath_strlen(void *, u_int16_t); Index: usr.sbin/bgpd/control.c =================================================================== RCS file: /cvs/src/usr.sbin/bgpd/control.c,v retrieving revision 1.82 diff -u -p -r1.82 control.c --- usr.sbin/bgpd/control.c 5 Dec 2015 18:28:04 -0000 1.82 +++ usr.sbin/bgpd/control.c 8 Jan 2017 17:45:24 -0000 @@ -337,9 +337,15 @@ control_dispatch_msg(struct pollfd *pfd, switch (imsg.hdr.type) { case IMSG_CTL_NEIGHBOR_UP: bgp_fsm(p, EVNT_START); + p->conf.down = 0; + p->conf.shutcomm[0] = '\0'; control_result(c, CTL_RES_OK); break; case IMSG_CTL_NEIGHBOR_DOWN: + p->conf.down = 1; + strlcpy(p->conf.shutcomm, + neighbor->shutcomm, + sizeof(neighbor->shutcomm)); session_stop(p, ERR_CEASE_ADMIN_DOWN); control_result(c, CTL_RES_OK); break; Index: usr.sbin/bgpd/parse.y =================================================================== RCS file: /cvs/src/usr.sbin/bgpd/parse.y,v retrieving revision 1.288 diff -u -p -r1.288 parse.y --- usr.sbin/bgpd/parse.y 21 Jun 2016 21:35:24 -0000 1.288 +++ usr.sbin/bgpd/parse.y 8 Jan 2017 17:45:24 -0000 @@ -1029,8 +1029,19 @@ peeropts : REMOTEAS as4number { | PASSIVE { curpeer->conf.passive = 1; } - | DOWN { + | DOWN { curpeer->conf.down = 1; + } + | DOWN STRING { + curpeer->conf.down = 1; + if (strlcpy(curpeer->conf.shutcomm, $2, + sizeof(curpeer->conf.shutcomm)) >= + sizeof(curpeer->conf.shutcomm)) { + yyerror("shutdown reason too long"); + free($2); + YYERROR; + } + free($2); } | RIB STRING { if (!find_rib($2)) { Index: usr.sbin/bgpd/session.c =================================================================== RCS file: /cvs/src/usr.sbin/bgpd/session.c,v retrieving revision 1.351 diff -u -p -r1.351 session.c --- usr.sbin/bgpd/session.c 25 Jul 2016 14:29:28 -0000 1.351 +++ usr.sbin/bgpd/session.c 8 Jan 2017 17:45:24 -0000 @@ -552,6 +552,9 @@ session_main(int debug, int verbose) while ((p = peers) != NULL) { peers = p->next; + strlcpy(p->conf.shutcomm, + "bgpd shutting down", + sizeof(p->conf.shutcomm)); session_stop(p, ERR_CEASE_ADMIN_DOWN); pfkey_remove(p); free(p); @@ -2206,6 +2209,7 @@ parse_notification(struct peer *peer) u_int8_t subcode; u_int8_t capa_code; u_int8_t capa_len; + u_int8_t shutcomm_len; u_int8_t i; /* just log */ @@ -2300,6 +2304,31 @@ parse_notification(struct peer *peer) return (1); } + if (errcode == ERR_CEASE && subcode == ERR_CEASE_ADMIN_DOWN) { + if (datalen >= sizeof(shutcomm_len)) { + memcpy(&shutcomm_len, p, sizeof(shutcomm_len)); + p += sizeof(shutcomm_len); + datalen -= sizeof(shutcomm_len); + if(datalen < shutcomm_len) { + log_peer_warnx(&peer->conf, + "received truncated shutdown reason"); + return (0); + } + if (shutcomm_len > (SHUT_COMM_LEN-1)) { + log_peer_warnx(&peer->conf, + "received overly long shutdown reason"); + return (0); + } + memcpy(peer->stats.last_shutcomm, p, shutcomm_len); + peer->stats.last_shutcomm[shutcomm_len] = '\0'; + log_peer_warnx(&peer->conf, + "received shutdown reason: \"%s\"", + log_shutcomm(peer->stats.last_shutcomm)); + p+=shutcomm_len; + datalen-=shutcomm_len; + } + } + return (0); } @@ -3180,11 +3209,29 @@ session_demote(struct peer *p, int level void session_stop(struct peer *peer, u_int8_t subcode) { + char data[SHUT_COMM_LEN]; + uint8_t datalen; + uint8_t shutcomm_len; + char *communication; + + datalen=0; + + communication = peer->conf.shutcomm; + + if (subcode == ERR_CEASE_ADMIN_DOWN && communication && + *communication) { + shutcomm_len=strlen(communication); + if(shutcomm_len < SHUT_COMM_LEN) { + data[0] = shutcomm_len; + datalen = shutcomm_len + sizeof(data[0]); + memcpy(data + 1, communication, shutcomm_len); + } + } switch (peer->state) { case STATE_OPENSENT: case STATE_OPENCONFIRM: case STATE_ESTABLISHED: - session_notification(peer, ERR_CEASE, subcode, NULL, 0); + session_notification(peer, ERR_CEASE, subcode, data, datalen); break; default: /* session not open, no need to send notification */ Index: usr.sbin/bgpd/session.h =================================================================== RCS file: /cvs/src/usr.sbin/bgpd/session.h,v retrieving revision 1.121 diff -u -p -r1.121 session.h --- usr.sbin/bgpd/session.h 25 Oct 2015 18:49:01 -0000 1.121 +++ usr.sbin/bgpd/session.h 8 Jan 2017 17:45:24 -0000 @@ -168,6 +168,7 @@ struct peer_stats { u_int32_t prefix_cnt; u_int8_t last_sent_errcode; u_int8_t last_sent_suberr; + char last_shutcomm[SHUT_COMM_LEN]; }; enum Timer { Index: usr.sbin/bgpd/util.c =================================================================== RCS file: /cvs/src/usr.sbin/bgpd/util.c,v retrieving revision 1.21 diff -u -p -r1.21 util.c --- usr.sbin/bgpd/util.c 3 Jun 2016 17:36:37 -0000 1.21 +++ usr.sbin/bgpd/util.c 8 Jan 2017 17:45:24 -0000 @@ -24,6 +24,7 @@ #include <stdlib.h> #include <stdio.h> #include <string.h> +#include <vis.h> #include "bgpd.h" #include "rde.h" @@ -156,6 +157,24 @@ log_ext_subtype(u_int8_t subtype) snprintf(etype, sizeof(etype), "[%u]", subtype); return (etype); } +} + +const char * +log_shutcomm(const char *communication) { + static char buf[(SHUT_COMM_LEN - 1) * 4 + 1]; + const char *p; + char *q; + + p = communication; + for (q = buf; *p && q < &buf[sizeof(buf) - 1]; p++) { + if (*p == '\n') + *q++ = ' '; + else + q = vis(q, *p, 0, 0); + } + *q = '\0'; + + return buf; } const char *
