sys/net/bridge/bridgestp.c

   1 /*
   2  * Copyright (c) 2000 Jason L. Wright (jason@thought.net)
   3  * All rights reserved.
   4  *
   5  * Redistribution and use in source and binary forms, with or without
   6  * modification, are permitted provided that the following conditions
   7  * are met:
   8  * 1. Redistributions of source code must retain the above copyright
   9  *    notice, this list of conditions and the following disclaimer.
  10  * 2. Redistributions in binary form must reproduce the above copyright
  11  *    notice, this list of conditions and the following disclaimer in the
  12  *    documentation and/or other materials provided with the distribution.
  13  * 3. All advertising materials mentioning features or use of this software
  14  *    must display the following acknowledgement:
  15  *      This product includes software developed by Jason L. Wright
  16  * 4. The name of the author may not be used to endorse or promote products
  17  *    derived from this software without specific prior written permission.
  18  *
  19  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
  20  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
  21  * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
  22  * DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT,
  23  * INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
  24  * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
  25  * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  26  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
  27  * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
  28  * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
  29  * POSSIBILITY OF SUCH DAMAGE.
  30  *
  31  * $OpenBSD: bridgestp.c,v 1.5 2001/03/22 03:48:29 jason Exp $
  32  * $NetBSD: bridgestp.c,v 1.5 2003/11/28 08:56:48 keihan Exp $
  33  * $FreeBSD: src/sys/net/bridgestp.c,v 1.7 2005/10/11 02:58:32 thompsa Exp $
  34  * $DragonFly: src/sys/net/bridge/bridgestp.c,v 1.5 2008/06/14 07:58:46 sephe Exp $
  35  */
  36
  37 /*
  38  * Implementation of the spanning tree protocol as defined in
  39  * ISO/IEC Final DIS 15802-3 (IEEE P802.1D/D17), May 25, 1998.
  40  * (In English: IEEE 802.1D, Draft 17, 1998)
  41  */
  42
  43 #include <sys/cdefs.h>
  44
  45 #include <sys/param.h>
  46 #include <sys/systm.h>
  47 #include <sys/mbuf.h>
  48 #include <sys/socket.h>
  49 #include <sys/sockio.h>
  50 #include <sys/kernel.h>
  51 #include <sys/callout.h>
  52 #include <sys/proc.h>
  53 #include <sys/lock.h>
  54 #include <sys/thread.h>
  55 #include <sys/thread2.h>
  56
  57 #include <net/if.h>
  58 #include <net/if_dl.h>
  59 #include <net/if_types.h>
  60 #include <net/if_llc.h>
  61 #include <net/if_media.h>
  62
  63 #include <netinet/in.h>
  64 #include <netinet/in_systm.h>
  65 #include <netinet/in_var.h>
  66 #include <netinet/if_ether.h>
  67 #include <net/bridge/if_bridgevar.h>
  68
  69 /* BPDU message types */
  70 #define BSTP_MSGTYPE_CFG        0x00            /* Configuration */
  71 #define BSTP_MSGTYPE_TCN        0x80            /* Topology chg notification */
  72
  73 /* BPDU flags */
  74 #define BSTP_FLAG_TC            0x01            /* Topology change */
  75 #define BSTP_FLAG_TCA           0x80            /* Topology change ack */
  76
  77 #define BSTP_MESSAGE_AGE_INCR   (1 * 256)       /* in 256ths of a second */
  78 #define BSTP_TICK_VAL           (1 * 256)       /* in 256ths of a second */
  79
  80 /*
  81  * Because BPDU's do not make nicely aligned structures, two different
  82  * declarations are used: bstp_?bpdu (wire representation, packed) and
  83  * bstp_*_unit (internal, nicely aligned version).
  84  */
  85
  86 /* configuration bridge protocol data unit */
  87 struct bstp_cbpdu {
  88         uint8_t         cbu_dsap;               /* LLC: destination sap */
  89         uint8_t         cbu_ssap;               /* LLC: source sap */
  90         uint8_t         cbu_ctl;                /* LLC: control */
  91         uint16_t        cbu_protoid;            /* protocol id */
  92         uint8_t         cbu_protover;           /* protocol version */
  93         uint8_t         cbu_bpdutype;           /* message type */
  94         uint8_t         cbu_flags;              /* flags (below) */
  95
  96         /* root id */
  97         uint16_t        cbu_rootpri;            /* root priority */
  98         uint8_t cbu_rootaddr[6];        /* root address */
  99
 100         uint32_t        cbu_rootpathcost;       /* root path cost */
 101
 102         /* bridge id */
 103         uint16_t        cbu_bridgepri;          /* bridge priority */
 104         uint8_t         cbu_bridgeaddr[6];      /* bridge address */
 105
 106         uint16_t        cbu_portid;             /* port id */
 107         uint16_t        cbu_messageage;         /* current message age */
 108         uint16_t        cbu_maxage;             /* maximum age */
 109         uint16_t        cbu_hellotime;          /* hello time */
 110         uint16_t        cbu_forwarddelay;       /* forwarding delay */
 111 } __attribute__((__packed__));
 112
 113 /* topology change notification bridge protocol data unit */
 114 struct bstp_tbpdu {
 115         uint8_t         tbu_dsap;               /* LLC: destination sap */
 116         uint8_t         tbu_ssap;               /* LLC: source sap */
 117         uint8_t         tbu_ctl;                /* LLC: control */
 118         uint16_t        tbu_protoid;            /* protocol id */
 119         uint8_t         tbu_protover;           /* protocol version */
 120         uint8_t         tbu_bpdutype;           /* message type */
 121 } __attribute__((__packed__));
 122
 123 const uint8_t bstp_etheraddr[] = { 0x01, 0x80, 0xc2, 0x00, 0x00, 0x00 };
 124
 125 static void     bstp_initialize_port(struct bridge_softc *,
 126                     struct bridge_iflist *);
 127 static void     bstp_ifupdstatus(struct bridge_softc *, struct bridge_iflist *);
 128 static void     bstp_enable_port(struct bridge_softc *, struct bridge_iflist *);
 129 static void     bstp_disable_port(struct bridge_softc *,
 130                     struct bridge_iflist *);
 131 #ifdef notused
 132 static void     bstp_enable_change_detection(struct bridge_iflist *);
 133 static void     bstp_disable_change_detection(struct bridge_iflist *);
 134 #endif /* notused */
 135 static int      bstp_root_bridge(struct bridge_softc *sc);
 136 static int      bstp_supersedes_port_info(struct bridge_softc *,
 137                     struct bridge_iflist *, struct bstp_config_unit *);
 138 static int      bstp_designated_port(struct bridge_softc *,
 139                     struct bridge_iflist *);
 140 static int      bstp_designated_for_some_port(struct bridge_softc *);
 141 static void     bstp_transmit_config(struct bridge_softc *,
 142                     struct bridge_iflist *);
 143 static void     bstp_transmit_tcn(struct bridge_softc *);
 144 static void     bstp_received_config_bpdu(struct bridge_softc *,
 145                     struct bridge_iflist *, struct bstp_config_unit *);
 146 static void     bstp_received_tcn_bpdu(struct bridge_softc *,
 147                     struct bridge_iflist *, struct bstp_tcn_unit *);
 148 static void     bstp_record_config_information(struct bridge_softc *,
 149                     struct bridge_iflist *, struct bstp_config_unit *);
 150 static void     bstp_record_config_timeout_values(struct bridge_softc *,
 151                     struct bstp_config_unit *);
 152 static void     bstp_config_bpdu_generation(struct bridge_softc *);
 153 static void     bstp_send_config_bpdu(struct bridge_softc *,
 154                     struct bridge_iflist *, struct bstp_config_unit *);
 155 static void     bstp_configuration_update(struct bridge_softc *);
 156 static void     bstp_root_selection(struct bridge_softc *);
 157 static void     bstp_designated_port_selection(struct bridge_softc *);
 158 static void     bstp_become_designated_port(struct bridge_softc *,
 159                     struct bridge_iflist *);
 160 static void     bstp_port_state_selection(struct bridge_softc *);
 161 static void     bstp_make_forwarding(struct bridge_softc *,
 162                     struct bridge_iflist *);
 163 static void     bstp_make_blocking(struct bridge_softc *,
 164                     struct bridge_iflist *);
 165 static void     bstp_set_port_state(struct bridge_iflist *, uint8_t);
 166 #ifdef notused
 167 static void     bstp_set_bridge_priority(struct bridge_softc *, uint64_t);
 168 static void     bstp_set_port_priority(struct bridge_softc *,
 169                     struct bridge_iflist *, uint16_t);
 170 static void     bstp_set_path_cost(struct bridge_softc *,
 171                     struct bridge_iflist *, uint32_t);
 172 #endif /* notused */
 173 static void     bstp_topology_change_detection(struct bridge_softc *);
 174 static void     bstp_topology_change_acknowledged(struct bridge_softc *);
 175 static void     bstp_acknowledge_topology_change(struct bridge_softc *,
 176                     struct bridge_iflist *);
 177
 178 static void     bstp_tick(void *);
 179 static void     bstp_timer_start(struct bridge_timer *, uint16_t);
 180 static void     bstp_timer_stop(struct bridge_timer *);
 181 static int      bstp_timer_expired(struct bridge_timer *, uint16_t);
 182
 183 static void     bstp_hold_timer_expiry(struct bridge_softc *,
 184                     struct bridge_iflist *);
 185 static void     bstp_message_age_timer_expiry(struct bridge_softc *,
 186                     struct bridge_iflist *);
 187 static void     bstp_forward_delay_timer_expiry(struct bridge_softc *,
 188                     struct bridge_iflist *);
 189 static void     bstp_topology_change_timer_expiry(struct bridge_softc *);
 190 static void     bstp_tcn_timer_expiry(struct bridge_softc *);
 191 static void     bstp_hello_timer_expiry(struct bridge_softc *);
 192 static int      bstp_addr_cmp(const uint8_t *, const uint8_t *);
 193
 194 static void
 195 bstp_transmit_config(struct bridge_softc *sc, struct bridge_iflist *bif)
 196 {
 197         if (bif->bif_hold_timer.active) {
 198                 bif->bif_config_pending = 1;
 199                 return;
 200         }
 201
 202         bif->bif_config_bpdu.cu_message_type = BSTP_MSGTYPE_CFG;
 203         bif->bif_config_bpdu.cu_rootid = sc->sc_designated_root;
 204         bif->bif_config_bpdu.cu_root_path_cost = sc->sc_root_path_cost;
 205         bif->bif_config_bpdu.cu_bridge_id = sc->sc_bridge_id;
 206         bif->bif_config_bpdu.cu_port_id = bif->bif_port_id;
 207
 208         if (bstp_root_bridge(sc))
 209                 bif->bif_config_bpdu.cu_message_age = 0;
 210         else
 211                 bif->bif_config_bpdu.cu_message_age =
 212                     sc->sc_root_port->bif_message_age_timer.value +
 213                     BSTP_MESSAGE_AGE_INCR;
 214
 215         bif->bif_config_bpdu.cu_max_age = sc->sc_max_age;
 216         bif->bif_config_bpdu.cu_hello_time = sc->sc_hello_time;
 217         bif->bif_config_bpdu.cu_forward_delay = sc->sc_forward_delay;
 218         bif->bif_config_bpdu.cu_topology_change_acknowledgment
 219             = bif->bif_topology_change_acknowledge;
 220         bif->bif_config_bpdu.cu_topology_change = sc->sc_topology_change;
 221
 222         if (bif->bif_config_bpdu.cu_message_age < sc->sc_max_age) {
 223                 bif->bif_topology_change_acknowledge = 0;
 224                 bif->bif_config_pending = 0;
 225                 bstp_send_config_bpdu(sc, bif, &bif->bif_config_bpdu);
 226                 bstp_timer_start(&bif->bif_hold_timer, 0);
 227         }
 228 }
 229
 230 static void
 231 bstp_send_config_bpdu(struct bridge_softc *sc, struct bridge_iflist *bif,
 232     struct bstp_config_unit *cu)
 233 {
 234         struct ifnet *ifp;
 235         struct mbuf *m;
 236         struct ether_header *eh;
 237         struct bstp_cbpdu bpdu;
 238
 239         ifp = bif->bif_ifp;
 240
 241         if ((ifp->if_flags & IFF_RUNNING) == 0)
 242                 return;
 243
 244         MGETHDR(m, MB_DONTWAIT, MT_DATA);
 245         if (m == NULL)
 246                 return;
 247
 248         eh = mtod(m, struct ether_header *);
 249
 250         m->m_pkthdr.rcvif = ifp;
 251         m->m_pkthdr.len = sizeof(*eh) + sizeof(bpdu);
 252         m->m_len = m->m_pkthdr.len;
 253
 254         bpdu.cbu_ssap = bpdu.cbu_dsap = LLC_8021D_LSAP;
 255         bpdu.cbu_ctl = LLC_UI;
 256         bpdu.cbu_protoid = htons(0);
 257         bpdu.cbu_protover = 0;
 258         bpdu.cbu_bpdutype = cu->cu_message_type;
 259         bpdu.cbu_flags = (cu->cu_topology_change ? BSTP_FLAG_TC : 0) |
 260             (cu->cu_topology_change_acknowledgment ? BSTP_FLAG_TCA : 0);
 261
 262         bpdu.cbu_rootpri = htons(cu->cu_rootid >> 48);
 263         bpdu.cbu_rootaddr[0] = cu->cu_rootid >> 40;
 264         bpdu.cbu_rootaddr[1] = cu->cu_rootid >> 32;
 265         bpdu.cbu_rootaddr[2] = cu->cu_rootid >> 24;
 266         bpdu.cbu_rootaddr[3] = cu->cu_rootid >> 16;
 267         bpdu.cbu_rootaddr[4] = cu->cu_rootid >> 8;
 268         bpdu.cbu_rootaddr[5] = cu->cu_rootid >> 0;
 269
 270         bpdu.cbu_rootpathcost = htonl(cu->cu_root_path_cost);
 271
 272         bpdu.cbu_bridgepri = htons(cu->cu_bridge_id >> 48);
 273         bpdu.cbu_bridgeaddr[0] = cu->cu_bridge_id >> 40;
 274         bpdu.cbu_bridgeaddr[1] = cu->cu_bridge_id >> 32;
 275         bpdu.cbu_bridgeaddr[2] = cu->cu_bridge_id >> 24;
 276         bpdu.cbu_bridgeaddr[3] = cu->cu_bridge_id >> 16;
 277         bpdu.cbu_bridgeaddr[4] = cu->cu_bridge_id >> 8;
 278         bpdu.cbu_bridgeaddr[5] = cu->cu_bridge_id >> 0;
 279
 280         bpdu.cbu_portid = htons(cu->cu_port_id);
 281         bpdu.cbu_messageage = htons(cu->cu_message_age);
 282         bpdu.cbu_maxage = htons(cu->cu_max_age);
 283         bpdu.cbu_hellotime = htons(cu->cu_hello_time);
 284         bpdu.cbu_forwarddelay = htons(cu->cu_forward_delay);
 285
 286         memcpy(eh->ether_shost, IF_LLADDR(ifp), ETHER_ADDR_LEN);
 287         memcpy(eh->ether_dhost, bstp_etheraddr, ETHER_ADDR_LEN);
 288         eh->ether_type = htons(sizeof(bpdu));
 289
 290         memcpy(mtod(m, caddr_t) + sizeof(*eh), &bpdu, sizeof(bpdu));
 291
 292         bridge_enqueue(ifp, m);
 293 }
 294
 295 static int
 296 bstp_root_bridge(struct bridge_softc *sc)
 297 {
 298         return (sc->sc_designated_root == sc->sc_bridge_id);
 299 }
 300
 301 static int
 302 bstp_supersedes_port_info(struct bridge_softc *sc, struct bridge_iflist *bif,
 303     struct bstp_config_unit *cu)
 304 {
 305         if (cu->cu_rootid < bif->bif_designated_root)
 306                 return (1);
 307         if (cu->cu_rootid > bif->bif_designated_root)
 308                 return (0);
 309
 310         if (cu->cu_root_path_cost < bif->bif_designated_cost)
 311                 return (1);
 312         if (cu->cu_root_path_cost > bif->bif_designated_cost)
 313                 return (0);
 314
 315         if (cu->cu_bridge_id < bif->bif_designated_bridge)
 316                 return (1);
 317         if (cu->cu_bridge_id > bif->bif_designated_bridge)
 318                 return (0);
 319
 320         if (sc->sc_bridge_id != cu->cu_bridge_id)
 321                 return (1);
 322         if (cu->cu_port_id <= bif->bif_designated_port)
 323                 return (1);
 324         return (0);
 325 }
 326
 327 static void
 328 bstp_record_config_information(struct bridge_softc *sc,
 329     struct bridge_iflist *bif, struct bstp_config_unit *cu)
 330 {
 331         bif->bif_designated_root = cu->cu_rootid;
 332         bif->bif_designated_cost = cu->cu_root_path_cost;
 333         bif->bif_designated_bridge = cu->cu_bridge_id;
 334         bif->bif_designated_port = cu->cu_port_id;
 335         bstp_timer_start(&bif->bif_message_age_timer, cu->cu_message_age);
 336 }
 337
 338 static void
 339 bstp_record_config_timeout_values(struct bridge_softc *sc,
 340     struct bstp_config_unit *config)
 341 {
 342         sc->sc_max_age = config->cu_max_age;
 343         sc->sc_hello_time = config->cu_hello_time;
 344         sc->sc_forward_delay = config->cu_forward_delay;
 345         sc->sc_topology_change = config->cu_topology_change;
 346 }
 347
 348 static void
 349 bstp_config_bpdu_generation(struct bridge_softc *sc)
 350 {
 351         struct bridge_iflist *bif;
 352
 353         LIST_FOREACH(bif, &sc->sc_iflist, bif_next) {
 354                 if ((bif->bif_flags & IFBIF_STP) == 0)
 355                         continue;
 356                 if (bstp_designated_port(sc, bif) &&
 357                     (bif->bif_state != BSTP_IFSTATE_DISABLED))
 358                         bstp_transmit_config(sc, bif);
 359         }
 360 }
 361
 362 static int
 363 bstp_designated_port(struct bridge_softc *sc, struct bridge_iflist *bif)
 364 {
 365         return ((bif->bif_designated_bridge == sc->sc_bridge_id)
 366             && (bif->bif_designated_port == bif->bif_port_id));
 367 }
 368
 369 static void
 370 bstp_transmit_tcn(struct bridge_softc *sc)
 371 {
 372         struct bstp_tbpdu bpdu;
 373         struct bridge_iflist *bif = sc->sc_root_port;
 374         struct ifnet *ifp = bif->bif_ifp;
 375         struct ether_header *eh;
 376         struct mbuf *m;
 377
 378         if ((ifp->if_flags & IFF_RUNNING) == 0)
 379                 return;
 380
 381         MGETHDR(m, MB_DONTWAIT, MT_DATA);
 382         if (m == NULL)
 383                 return;
 384
 385         m->m_pkthdr.rcvif = ifp;
 386         m->m_pkthdr.len = sizeof(*eh) + sizeof(bpdu);
 387         m->m_len = m->m_pkthdr.len;
 388
 389         eh = mtod(m, struct ether_header *);
 390
 391         memcpy(eh->ether_shost, IF_LLADDR(ifp), ETHER_ADDR_LEN);
 392         memcpy(eh->ether_dhost, bstp_etheraddr, ETHER_ADDR_LEN);
 393         eh->ether_type = htons(sizeof(bpdu));
 394
 395         bpdu.tbu_ssap = bpdu.tbu_dsap = LLC_8021D_LSAP;
 396         bpdu.tbu_ctl = LLC_UI;
 397         bpdu.tbu_protoid = 0;
 398         bpdu.tbu_protover = 0;
 399         bpdu.tbu_bpdutype = BSTP_MSGTYPE_TCN;
 400
 401         memcpy(mtod(m, caddr_t) + sizeof(*eh), &bpdu, sizeof(bpdu));
 402
 403         bridge_enqueue(ifp, m);
 404 }
 405
 406 static void
 407 bstp_configuration_update(struct bridge_softc *sc)
 408 {
 409         bstp_root_selection(sc);
 410         bstp_designated_port_selection(sc);
 411 }
 412
 413 static void
 414 bstp_root_selection(struct bridge_softc *sc)
 415 {
 416         struct bridge_iflist *root_port = NULL, *bif;
 417
 418         LIST_FOREACH(bif, &sc->sc_iflist, bif_next) {
 419                 if ((bif->bif_flags & IFBIF_STP) == 0)
 420                         continue;
 421                 if (bstp_designated_port(sc, bif))
 422                         continue;
 423                 if (bif->bif_state == BSTP_IFSTATE_DISABLED)
 424                         continue;
 425                 if (bif->bif_designated_root >= sc->sc_bridge_id)
 426                         continue;
 427                 if (root_port == NULL)
 428                         goto set_port;
 429
 430                 if (bif->bif_designated_root < root_port->bif_designated_root)
 431                         goto set_port;
 432                 if (bif->bif_designated_root > root_port->bif_designated_root)
 433                         continue;
 434
 435                 if ((bif->bif_designated_cost + bif->bif_path_cost) <
 436                     (root_port->bif_designated_cost + root_port->bif_path_cost))
 437                         goto set_port;
 438                 if ((bif->bif_designated_cost + bif->bif_path_cost) >
 439                     (root_port->bif_designated_cost + root_port->bif_path_cost))
 440                         continue;
 441
 442                 if (bif->bif_designated_bridge <
 443                     root_port->bif_designated_bridge)
 444                         goto set_port;
 445                 if (bif->bif_designated_bridge >
 446                     root_port->bif_designated_bridge)
 447                         continue;
 448
 449                 if (bif->bif_designated_port < root_port->bif_designated_port)
 450                         goto set_port;
 451                 if (bif->bif_designated_port > root_port->bif_designated_port)
 452                         continue;
 453
 454                 if (bif->bif_port_id >= root_port->bif_port_id)
 455                         continue;
 456 set_port:
 457                 root_port = bif;
 458         }
 459
 460         sc->sc_root_port = root_port;
 461         if (root_port == NULL) {
 462                 sc->sc_designated_root = sc->sc_bridge_id;
 463                 sc->sc_root_path_cost = 0;
 464         } else {
 465                 sc->sc_designated_root = root_port->bif_designated_root;
 466                 sc->sc_root_path_cost = root_port->bif_designated_cost +
 467                     root_port->bif_path_cost;
 468         }
 469 }
 470
 471 static void
 472 bstp_designated_port_selection(struct bridge_softc *sc)
 473 {
 474         struct bridge_iflist *bif;
 475
 476         LIST_FOREACH(bif, &sc->sc_iflist, bif_next) {
 477                 if ((bif->bif_flags & IFBIF_STP) == 0)
 478                         continue;
 479                 if (bstp_designated_port(sc, bif))
 480                         goto designated;
 481                 if (bif->bif_designated_root != sc->sc_designated_root)
 482                         goto designated;
 483
 484                 if (sc->sc_root_path_cost < bif->bif_designated_cost)
 485                         goto designated;
 486                 if (sc->sc_root_path_cost > bif->bif_designated_cost)
 487                         continue;
 488
 489                 if (sc->sc_bridge_id < bif->bif_designated_bridge)
 490                         goto designated;
 491                 if (sc->sc_bridge_id > bif->bif_designated_bridge)
 492                         continue;
 493
 494                 if (bif->bif_port_id > bif->bif_designated_port)
 495                         continue;
 496 designated:
 497                 bstp_become_designated_port(sc, bif);
 498         }
 499 }
 500
 501 static void
 502 bstp_become_designated_port(struct bridge_softc *sc, struct bridge_iflist *bif)
 503 {
 504         bif->bif_designated_root = sc->sc_designated_root;
 505         bif->bif_designated_cost = sc->sc_root_path_cost;
 506         bif->bif_designated_bridge = sc->sc_bridge_id;
 507         bif->bif_designated_port = bif->bif_port_id;
 508 }
 509
 510 static void
 511 bstp_port_state_selection(struct bridge_softc *sc)
 512 {
 513         struct bridge_iflist *bif;
 514
 515         LIST_FOREACH(bif, &sc->sc_iflist, bif_next) {
 516                 if ((bif->bif_flags & IFBIF_STP) == 0)
 517                         continue;
 518                 if (bif == sc->sc_root_port) {
 519                         bif->bif_config_pending = 0;
 520                         bif->bif_topology_change_acknowledge = 0;
 521                         bstp_make_forwarding(sc, bif);
 522                 } else if (bstp_designated_port(sc, bif)) {
 523                         bstp_timer_stop(&bif->bif_message_age_timer);
 524                         bstp_make_forwarding(sc, bif);
 525                 } else {
 526                         bif->bif_config_pending = 0;
 527                         bif->bif_topology_change_acknowledge = 0;
 528                         bstp_make_blocking(sc, bif);
 529                 }
 530         }
 531 }
 532
 533 static void
 534 bstp_make_forwarding(struct bridge_softc *sc, struct bridge_iflist *bif)
 535 {
 536         if (bif->bif_state == BSTP_IFSTATE_BLOCKING) {
 537                 bstp_set_port_state(bif, BSTP_IFSTATE_LISTENING);
 538                 bstp_timer_start(&bif->bif_forward_delay_timer, 0);
 539         }
 540 }
 541
 542 static void
 543 bstp_make_blocking(struct bridge_softc *sc, struct bridge_iflist *bif)
 544 {
 545         if ((bif->bif_state != BSTP_IFSTATE_DISABLED) &&
 546             (bif->bif_state != BSTP_IFSTATE_BLOCKING)) {
 547                 if ((bif->bif_state == BSTP_IFSTATE_FORWARDING) ||
 548                     (bif->bif_state == BSTP_IFSTATE_LEARNING)) {
 549                         if (bif->bif_change_detection_enabled) {
 550                                 bstp_topology_change_detection(sc);
 551                         }
 552                 }
 553                 bstp_set_port_state(bif, BSTP_IFSTATE_BLOCKING);
 554                 bridge_rtdelete(sc, bif->bif_ifp, IFBF_FLUSHDYN);
 555                 bstp_timer_stop(&bif->bif_forward_delay_timer);
 556         }
 557 }
 558
 559 static void
 560 bstp_set_port_state(struct bridge_iflist *bif, uint8_t state)
 561 {
 562         bif->bif_state = state;
 563 }
 564
 565 static void
 566 bstp_topology_change_detection(struct bridge_softc *sc)
 567 {
 568         if (bstp_root_bridge(sc)) {
 569                 sc->sc_topology_change = 1;
 570                 bstp_timer_start(&sc->sc_topology_change_timer, 0);
 571         } else if (!sc->sc_topology_change_detected) {
 572                 bstp_transmit_tcn(sc);
 573                 bstp_timer_start(&sc->sc_tcn_timer, 0);
 574         }
 575         sc->sc_topology_change_detected = 1;
 576 }
 577
 578 static void
 579 bstp_topology_change_acknowledged(struct bridge_softc *sc)
 580 {
 581         sc->sc_topology_change_detected = 0;
 582         bstp_timer_stop(&sc->sc_tcn_timer);
 583 }
 584
 585 static void
 586 bstp_acknowledge_topology_change(struct bridge_softc *sc,
 587     struct bridge_iflist *bif)
 588 {
 589         bif->bif_topology_change_acknowledge = 1;
 590         bstp_transmit_config(sc, bif);
 591 }
 592
 593 struct mbuf *
 594 bstp_input(struct bridge_softc *sc, struct bridge_iflist *bif, struct mbuf *m)
 595 {
 596         struct ether_header *eh;
 597         struct bstp_tbpdu tpdu;
 598         struct bstp_cbpdu cpdu;
 599         struct bstp_config_unit cu;
 600         struct bstp_tcn_unit tu;
 601         uint16_t len;
 602
 603         if ((bif->bif_flags & IFBIF_STP) == 0)
 604                 goto out;
 605
 606         eh = mtod(m, struct ether_header *);
 607
 608         len = ntohs(eh->ether_type);
 609         if (len < sizeof(tpdu))
 610                 goto out;
 611
 612         m_adj(m, ETHER_HDR_LEN);
 613
 614         if (m->m_pkthdr.len > len)
 615                 m_adj(m, len - m->m_pkthdr.len);
 616         if (m->m_len < sizeof(tpdu) &&
 617             (m = m_pullup(m, sizeof(tpdu))) == NULL)
 618                 goto out;
 619
 620         memcpy(&tpdu, mtod(m, caddr_t), sizeof(tpdu));
 621
 622         if (tpdu.tbu_dsap != LLC_8021D_LSAP ||
 623             tpdu.tbu_ssap != LLC_8021D_LSAP ||
 624             tpdu.tbu_ctl != LLC_UI)
 625                 goto out;
 626         if (tpdu.tbu_protoid != 0 || tpdu.tbu_protover != 0)
 627                 goto out;
 628
 629         switch (tpdu.tbu_bpdutype) {
 630         case BSTP_MSGTYPE_TCN:
 631                 tu.tu_message_type = tpdu.tbu_bpdutype;
 632                 bstp_received_tcn_bpdu(sc, bif, &tu);
 633                 break;
 634         case BSTP_MSGTYPE_CFG:
 635                 if (m->m_len < sizeof(cpdu) &&
 636                     (m = m_pullup(m, sizeof(cpdu))) == NULL)
 637                         goto out;
 638                 memcpy(&cpdu, mtod(m, caddr_t), sizeof(cpdu));
 639
 640                 cu.cu_rootid =
 641                     (((uint64_t)ntohs(cpdu.cbu_rootpri)) << 48) |
 642                     (((uint64_t)cpdu.cbu_rootaddr[0]) << 40) |
 643                     (((uint64_t)cpdu.cbu_rootaddr[1]) << 32) |
 644                     (((uint64_t)cpdu.cbu_rootaddr[2]) << 24) |
 645                     (((uint64_t)cpdu.cbu_rootaddr[3]) << 16) |
 646                     (((uint64_t)cpdu.cbu_rootaddr[4]) << 8) |
 647                     (((uint64_t)cpdu.cbu_rootaddr[5]) << 0);
 648
 649                 cu.cu_bridge_id =
 650                     (((uint64_t)ntohs(cpdu.cbu_bridgepri)) << 48) |
 651                     (((uint64_t)cpdu.cbu_bridgeaddr[0]) << 40) |
 652                     (((uint64_t)cpdu.cbu_bridgeaddr[1]) << 32) |
 653                     (((uint64_t)cpdu.cbu_bridgeaddr[2]) << 24) |
 654                     (((uint64_t)cpdu.cbu_bridgeaddr[3]) << 16) |
 655                     (((uint64_t)cpdu.cbu_bridgeaddr[4]) << 8) |
 656                     (((uint64_t)cpdu.cbu_bridgeaddr[5]) << 0);
 657
 658                 cu.cu_root_path_cost = ntohl(cpdu.cbu_rootpathcost);
 659                 cu.cu_message_age = ntohs(cpdu.cbu_messageage);
 660                 cu.cu_max_age = ntohs(cpdu.cbu_maxage);
 661                 cu.cu_hello_time = ntohs(cpdu.cbu_hellotime);
 662                 cu.cu_forward_delay = ntohs(cpdu.cbu_forwarddelay);
 663                 cu.cu_port_id = ntohs(cpdu.cbu_portid);
 664                 cu.cu_message_type = cpdu.cbu_bpdutype;
 665                 cu.cu_topology_change_acknowledgment =
 666                     (cpdu.cbu_flags & BSTP_FLAG_TCA) ? 1 : 0;
 667                 cu.cu_topology_change =
 668                     (cpdu.cbu_flags & BSTP_FLAG_TC) ? 1 : 0;
 669                 bstp_received_config_bpdu(sc, bif, &cu);
 670                 break;
 671         default:
 672                 goto out;
 673         }
 674
 675 out:
 676         if (m)
 677                 m_freem(m);
 678         return (NULL);
 679 }
 680
 681 static void
 682 bstp_received_config_bpdu(struct bridge_softc *sc, struct bridge_iflist *bif,
 683     struct bstp_config_unit *cu)
 684 {
 685         int root;
 686
 687         root = bstp_root_bridge(sc);
 688
 689         if (bif->bif_state != BSTP_IFSTATE_DISABLED) {
 690                 if (bstp_supersedes_port_info(sc, bif, cu)) {
 691                         bstp_record_config_information(sc, bif, cu);
 692                         bstp_configuration_update(sc);
 693                         bstp_port_state_selection(sc);
 694
 695                         if ((bstp_root_bridge(sc) == 0) && root) {
 696                                 bstp_timer_stop(&sc->sc_hello_timer);
 697
 698                                 if (sc->sc_topology_change_detected) {
 699                                         bstp_timer_stop(
 700                                             &sc->sc_topology_change_timer);
 701                                         bstp_transmit_tcn(sc);
 702                                         bstp_timer_start(&sc->sc_tcn_timer, 0);
 703                                 }
 704                         }
 705
 706                         if (bif == sc->sc_root_port) {
 707                                 bstp_record_config_timeout_values(sc, cu);
 708                                 bstp_config_bpdu_generation(sc);
 709
 710                                 if (cu->cu_topology_change_acknowledgment)
 711                                         bstp_topology_change_acknowledged(sc);
 712                         }
 713                 } else if (bstp_designated_port(sc, bif))
 714                         bstp_transmit_config(sc, bif);
 715         }
 716 }
 717
 718 static void
 719 bstp_received_tcn_bpdu(struct bridge_softc *sc, struct bridge_iflist *bif,
 720     struct bstp_tcn_unit *tcn)
 721 {
 722         if (bif->bif_state != BSTP_IFSTATE_DISABLED &&
 723             bstp_designated_port(sc, bif)) {
 724                 bstp_topology_change_detection(sc);
 725                 bstp_acknowledge_topology_change(sc, bif);
 726         }
 727 }
 728
 729 static void
 730 bstp_hello_timer_expiry(struct bridge_softc *sc)
 731 {
 732         bstp_config_bpdu_generation(sc);
 733         bstp_timer_start(&sc->sc_hello_timer, 0);
 734 }
 735
 736 static void
 737 bstp_message_age_timer_expiry(struct bridge_softc *sc,
 738     struct bridge_iflist *bif)
 739 {
 740         int root;
 741
 742         root = bstp_root_bridge(sc);
 743         bstp_become_designated_port(sc, bif);
 744         bstp_configuration_update(sc);
 745         bstp_port_state_selection(sc);
 746
 747         if ((bstp_root_bridge(sc)) && (root == 0)) {
 748                 sc->sc_max_age = sc->sc_bridge_max_age;
 749                 sc->sc_hello_time = sc->sc_bridge_hello_time;
 750                 sc->sc_forward_delay = sc->sc_bridge_forward_delay;
 751
 752                 bstp_topology_change_detection(sc);
 753                 bstp_timer_stop(&sc->sc_tcn_timer);
 754                 bstp_config_bpdu_generation(sc);
 755                 bstp_timer_start(&sc->sc_hello_timer, 0);
 756         }
 757 }
 758
 759 static void
 760 bstp_forward_delay_timer_expiry(struct bridge_softc *sc,
 761     struct bridge_iflist *bif)
 762 {
 763         if (bif->bif_state == BSTP_IFSTATE_LISTENING) {
 764                 bstp_set_port_state(bif, BSTP_IFSTATE_LEARNING);
 765                 bstp_timer_start(&bif->bif_forward_delay_timer, 0);
 766         } else if (bif->bif_state == BSTP_IFSTATE_LEARNING) {
 767                 bstp_set_port_state(bif, BSTP_IFSTATE_FORWARDING);
 768                 if (bstp_designated_for_some_port(sc) &&
 769                     bif->bif_change_detection_enabled)
 770                         bstp_topology_change_detection(sc);
 771         }
 772 }
 773
 774 static int
 775 bstp_designated_for_some_port(struct bridge_softc *sc)
 776 {
 777
 778         struct bridge_iflist *bif;
 779
 780         LIST_FOREACH(bif, &sc->sc_iflist, bif_next) {
 781                 if ((bif->bif_flags & IFBIF_STP) == 0)
 782                         continue;
 783                 if (bif->bif_designated_bridge == sc->sc_bridge_id)
 784                         return (1);
 785         }
 786         return (0);
 787 }
 788
 789 static void
 790 bstp_tcn_timer_expiry(struct bridge_softc *sc)
 791 {
 792         bstp_transmit_tcn(sc);
 793         bstp_timer_start(&sc->sc_tcn_timer, 0);
 794 }
 795
 796 static void
 797 bstp_topology_change_timer_expiry(struct bridge_softc *sc)
 798 {
 799         sc->sc_topology_change_detected = 0;
 800         sc->sc_topology_change = 0;
 801 }
 802
 803 static void
 804 bstp_hold_timer_expiry(struct bridge_softc *sc, struct bridge_iflist *bif)
 805 {
 806         if (bif->bif_config_pending)
 807                 bstp_transmit_config(sc, bif);
 808 }
 809
 810 static int
 811 bstp_addr_cmp(const uint8_t *a, const uint8_t *b)
 812 {
 813         int i, d;
 814
 815         for (i = 0, d = 0; i < ETHER_ADDR_LEN && d == 0; i++) {
 816                 d = ((int)a[i]) - ((int)b[i]);
 817         }
 818
 819         return (d);
 820 }
 821
 822 void
 823 bstp_initialization(struct bridge_softc *sc)
 824 {
 825         struct bridge_iflist *bif, *mif;
 826         u_char *e_addr;
 827
 828         mif = NULL;
 829         LIST_FOREACH(bif, &sc->sc_iflist, bif_next) {
 830                 if ((bif->bif_flags & IFBIF_STP) == 0)
 831                         continue;
 832                 if (bif->bif_ifp->if_type != IFT_ETHER)
 833                         continue;
 834                 bif->bif_port_id = (bif->bif_priority << 8) |
 835                     (bif->bif_ifp->if_index & 0xff);
 836
 837                 if (mif == NULL) {
 838                         mif = bif;
 839                         continue;
 840                 }
 841                 if (bstp_addr_cmp(IF_LLADDR(bif->bif_ifp),
 842                     IF_LLADDR(mif->bif_ifp)) < 0) {
 843                         mif = bif;
 844                         continue;
 845                 }
 846         }
 847         if (mif == NULL) {
 848                 bstp_stop(sc);
 849                 return;
 850         }
 851
 852         e_addr = IF_LLADDR(mif->bif_ifp);
 853         sc->sc_bridge_id =
 854             (((uint64_t)sc->sc_bridge_priority) << 48) |
 855             (((uint64_t)e_addr[0]) << 40) |
 856             (((uint64_t)e_addr[1]) << 32) |
 857             (((uint64_t)e_addr[2]) << 24) |
 858             (((uint64_t)e_addr[3]) << 16) |
 859             (((uint64_t)e_addr[4]) << 8) |
 860             (((uint64_t)e_addr[5]));
 861
 862         sc->sc_designated_root = sc->sc_bridge_id;
 863         sc->sc_root_path_cost = 0;
 864         sc->sc_root_port = NULL;
 865
 866         sc->sc_max_age = sc->sc_bridge_max_age;
 867         sc->sc_hello_time = sc->sc_bridge_hello_time;
 868         sc->sc_forward_delay = sc->sc_bridge_forward_delay;
 869         sc->sc_topology_change_detected = 0;
 870         sc->sc_topology_change = 0;
 871         bstp_timer_stop(&sc->sc_tcn_timer);
 872         bstp_timer_stop(&sc->sc_topology_change_timer);
 873
 874         if (callout_pending(&sc->sc_bstpcallout) == 0)
 875                 callout_reset(&sc->sc_bstpcallout, hz,
 876                     bstp_tick, sc);
 877
 878         LIST_FOREACH(bif, &sc->sc_iflist, bif_next) {
 879                 if (bif->bif_flags & IFBIF_STP)
 880                         bstp_ifupdstatus(sc, bif);
 881                 else
 882                         bstp_disable_port(sc, bif);
 883         }
 884
 885         bstp_port_state_selection(sc);
 886         bstp_config_bpdu_generation(sc);
 887         bstp_timer_start(&sc->sc_hello_timer, 0);
 888 }
 889
 890 void
 891 bstp_stop(struct bridge_softc *sc)
 892 {
 893         struct bridge_iflist *bif;
 894
 895         LIST_FOREACH(bif, &sc->sc_iflist, bif_next) {
 896                 bstp_set_port_state(bif, BSTP_IFSTATE_DISABLED);
 897                 bstp_timer_stop(&bif->bif_hold_timer);
 898                 bstp_timer_stop(&bif->bif_message_age_timer);
 899                 bstp_timer_stop(&bif->bif_forward_delay_timer);
 900         }
 901
 902         callout_stop(&sc->sc_bstpcallout);
 903
 904         bstp_timer_stop(&sc->sc_topology_change_timer);
 905         bstp_timer_stop(&sc->sc_tcn_timer);
 906         bstp_timer_stop(&sc->sc_hello_timer);
 907
 908 }
 909
 910 static void
 911 bstp_initialize_port(struct bridge_softc *sc, struct bridge_iflist *bif)
 912 {
 913         bstp_become_designated_port(sc, bif);
 914         bstp_set_port_state(bif, BSTP_IFSTATE_BLOCKING);
 915         bif->bif_topology_change_acknowledge = 0;
 916         bif->bif_config_pending = 0;
 917         bif->bif_change_detection_enabled = 1;
 918         bstp_timer_stop(&bif->bif_message_age_timer);
 919         bstp_timer_stop(&bif->bif_forward_delay_timer);
 920         bstp_timer_stop(&bif->bif_hold_timer);
 921 }
 922
 923 static void
 924 bstp_enable_port(struct bridge_softc *sc, struct bridge_iflist *bif)
 925 {
 926         bstp_initialize_port(sc, bif);
 927         bstp_port_state_selection(sc);
 928 }
 929
 930 static void
 931 bstp_disable_port(struct bridge_softc *sc, struct bridge_iflist *bif)
 932 {
 933         int root;
 934
 935         root = bstp_root_bridge(sc);
 936         bstp_become_designated_port(sc, bif);
 937         bstp_set_port_state(bif, BSTP_IFSTATE_DISABLED);
 938         bif->bif_topology_change_acknowledge = 0;
 939         bif->bif_config_pending = 0;
 940         bstp_timer_stop(&bif->bif_message_age_timer);
 941         bstp_timer_stop(&bif->bif_forward_delay_timer);
 942         bstp_configuration_update(sc);
 943         bstp_port_state_selection(sc);
 944         bridge_rtdelete(sc, bif->bif_ifp, IFBF_FLUSHDYN);
 945
 946         if (bstp_root_bridge(sc) && (root == 0)) {
 947                 sc->sc_max_age = sc->sc_bridge_max_age;
 948                 sc->sc_hello_time = sc->sc_bridge_hello_time;
 949                 sc->sc_forward_delay = sc->sc_bridge_forward_delay;
 950
 951                 bstp_topology_change_detection(sc);
 952                 bstp_timer_stop(&sc->sc_tcn_timer);
 953                 bstp_config_bpdu_generation(sc);
 954                 bstp_timer_start(&sc->sc_hello_timer, 0);
 955         }
 956 }
 957
 958 #ifdef notused
 959 static void
 960 bstp_set_bridge_priority(struct bridge_softc *sc, uint64_t new_bridge_id)
 961 {
 962         struct bridge_iflist *bif;
 963         int root;
 964
 965         root = bstp_root_bridge(sc);
 966
 967         LIST_FOREACH(bif, &sc->sc_iflist, bif_next) {
 968                 if ((bif->bif_flags & IFBIF_STP) == 0)
 969                         continue;
 970                 if (bstp_designated_port(sc, bif))
 971                         bif->bif_designated_bridge = new_bridge_id;
 972         }
 973
 974         sc->sc_bridge_id = new_bridge_id;
 975
 976         bstp_configuration_update(sc);
 977         bstp_port_state_selection(sc);
 978
 979         if (bstp_root_bridge(sc) && (root == 0)) {
 980                 sc->sc_max_age = sc->sc_bridge_max_age;
 981                 sc->sc_hello_time = sc->sc_bridge_hello_time;
 982                 sc->sc_forward_delay = sc->sc_bridge_forward_delay;
 983
 984                 bstp_topology_change_detection(sc);
 985                 bstp_timer_stop(&sc->sc_tcn_timer);
 986                 bstp_config_bpdu_generation(sc);
 987                 bstp_timer_start(&sc->sc_hello_timer, 0);
 988         }
 989 }
 990
 991 static void
 992 bstp_set_port_priority(struct bridge_softc *sc, struct bridge_iflist *bif,
 993     uint16_t new_port_id)
 994 {
 995         if (bstp_designated_port(sc, bif))
 996                 bif->bif_designated_port = new_port_id;
 997
 998         bif->bif_port_id = new_port_id;
 999
1000         if ((sc->sc_bridge_id == bif->bif_designated_bridge) &&
1001             (bif->bif_port_id < bif->bif_designated_port)) {
1002                 bstp_become_designated_port(sc, bif);
1003                 bstp_port_state_selection(sc);
1004         }
1005 }
1006
1007 static void
1008 bstp_set_path_cost(struct bridge_softc *sc, struct bridge_iflist *bif,
1009     uint32_t path_cost)
1010 {
1011         bif->bif_path_cost = path_cost;
1012         bstp_configuration_update(sc);
1013         bstp_port_state_selection(sc);
1014 }
1015
1016 static void
1017 bstp_enable_change_detection(struct bridge_iflist *bif)
1018 {
1019         bif->bif_change_detection_enabled = 1;
1020 }
1021
1022 static void
1023 bstp_disable_change_detection(struct bridge_iflist *bif)
1024 {
1025         bif->bif_change_detection_enabled = 0;
1026 }
1027 #endif /* notused */
1028
1029 void
1030 bstp_linkstate(struct ifnet *ifp, int state)
1031 {
1032         struct bridge_softc *sc;
1033         struct bridge_iflist *bif;
1034
1035         sc = ifp->if_bridge;
1036         lwkt_serialize_enter(sc->sc_ifp->if_serializer);
1037
1038         LIST_FOREACH(bif, &sc->sc_iflist, bif_next) {
1039                 if ((bif->bif_flags & IFBIF_STP) == 0)
1040                         continue;
1041
1042                 if (bif->bif_ifp == ifp) {
1043                         bstp_ifupdstatus(sc, bif);
1044                         break;
1045                 }
1046         }
1047         lwkt_serialize_exit(sc->sc_ifp->if_serializer);
1048 }
1049
1050 static void
1051 bstp_ifupdstatus(struct bridge_softc *sc, struct bridge_iflist *bif)
1052 {
1053         struct ifnet *ifp = bif->bif_ifp;
1054         struct ifmediareq ifmr;
1055         int error = 0;
1056
1057         bzero((char *)&ifmr, sizeof(ifmr));
1058         lwkt_serialize_enter(ifp->if_serializer);
1059         error = (*ifp->if_ioctl)(ifp, SIOCGIFMEDIA, (caddr_t)&ifmr, NULL);
1060         lwkt_serialize_exit(ifp->if_serializer);
1061
1062         if ((error == 0) && (ifp->if_flags & IFF_UP)) {
1063                 if (ifmr.ifm_status & IFM_ACTIVE) {
1064                         if (bif->bif_state == BSTP_IFSTATE_DISABLED)
1065                                 bstp_enable_port(sc, bif);
1066
1067                 } else {
1068                         if (bif->bif_state != BSTP_IFSTATE_DISABLED)
1069                                 bstp_disable_port(sc, bif);
1070                 }
1071                 return;
1072         }
1073
1074         if (bif->bif_state != BSTP_IFSTATE_DISABLED)
1075                 bstp_disable_port(sc, bif);
1076 }
1077
1078 static void
1079 bstp_tick(void *arg)
1080 {
1081         struct bridge_softc *sc = arg;
1082         struct bridge_iflist *bif;
1083
1084         lwkt_serialize_enter(sc->sc_ifp->if_serializer);
1085
1086         LIST_FOREACH(bif, &sc->sc_iflist, bif_next) {
1087                 if ((bif->bif_flags & IFBIF_STP) == 0)
1088                         continue;
1089                 /*
1090                  * XXX This can cause a lag in "link does away"
1091                  * XXX and "spanning tree gets updated".  We need
1092                  * XXX come sort of callback from the link state
1093                  * XXX update code to kick spanning tree.
1094                  * XXX --thorpej@NetBSD.org
1095                  */
1096                 bstp_ifupdstatus(sc, bif);
1097         }
1098
1099         if (bstp_timer_expired(&sc->sc_hello_timer, sc->sc_hello_time))
1100                 bstp_hello_timer_expiry(sc);
1101
1102         if (bstp_timer_expired(&sc->sc_tcn_timer, sc->sc_bridge_hello_time))
1103                 bstp_tcn_timer_expiry(sc);
1104
1105         if (bstp_timer_expired(&sc->sc_topology_change_timer,
1106             sc->sc_topology_change_time))
1107                 bstp_topology_change_timer_expiry(sc);
1108
1109         LIST_FOREACH(bif, &sc->sc_iflist, bif_next) {
1110                 if ((bif->bif_flags & IFBIF_STP) == 0)
1111                         continue;
1112                 if (bstp_timer_expired(&bif->bif_message_age_timer,
1113                     sc->sc_max_age))
1114                         bstp_message_age_timer_expiry(sc, bif);
1115         }
1116
1117         LIST_FOREACH(bif, &sc->sc_iflist, bif_next) {
1118                 if ((bif->bif_flags & IFBIF_STP) == 0)
1119                         continue;
1120                 if (bstp_timer_expired(&bif->bif_forward_delay_timer,
1121                     sc->sc_forward_delay))
1122                         bstp_forward_delay_timer_expiry(sc, bif);
1123
1124                 if (bstp_timer_expired(&bif->bif_hold_timer,
1125                     sc->sc_hold_time))
1126                         bstp_hold_timer_expiry(sc, bif);
1127         }
1128
1129         if (sc->sc_ifp->if_flags & IFF_RUNNING)
1130                 callout_reset(&sc->sc_bstpcallout, hz, bstp_tick, sc);
1131
1132         lwkt_serialize_exit(sc->sc_ifp->if_serializer);
1133 }
1134
1135 static void
1136 bstp_timer_start(struct bridge_timer *t, uint16_t v)
1137 {
1138         t->value = v;
1139         t->active = 1;
1140 }
1141
1142 static void
1143 bstp_timer_stop(struct bridge_timer *t)
1144 {
1145         t->value = 0;
1146         t->active = 0;
1147 }
1148
1149 static int
1150 bstp_timer_expired(struct bridge_timer *t, uint16_t v)
1151 {
1152         if (t->active == 0)
1153                 return (0);
1154         t->value += BSTP_TICK_VAL;
1155         if (t->value >= v) {
1156                 bstp_timer_stop(t);
1157                 return (1);
1158         }
1159         return (0);
1160
1161 }