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 1.2 2005/12/22 15:16:13 corecode 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 void    bstp_initialize_port(struct bridge_softc *, struct bridge_iflist *);
 126 void    bstp_ifupdstatus(struct bridge_softc *, struct bridge_iflist *);
 127 void    bstp_enable_port(struct bridge_softc *, struct bridge_iflist *);
 128 void    bstp_disable_port(struct bridge_softc *, struct bridge_iflist *);
 129 void    bstp_enable_change_detection(struct bridge_iflist *);
 130 void    bstp_disable_change_detection(struct bridge_iflist *);
 131 int     bstp_root_bridge(struct bridge_softc *sc);
 132 int     bstp_supersedes_port_info(struct bridge_softc *,
 133             struct bridge_iflist *, struct bstp_config_unit *);
 134 int     bstp_designated_port(struct bridge_softc *, struct bridge_iflist *);
 135 int     bstp_designated_for_some_port(struct bridge_softc *);
 136 void    bstp_transmit_config(struct bridge_softc *, struct bridge_iflist *);
 137 void    bstp_transmit_tcn(struct bridge_softc *);
 138 void    bstp_received_config_bpdu(struct bridge_softc *,
 139             struct bridge_iflist *, struct bstp_config_unit *);
 140 void    bstp_received_tcn_bpdu(struct bridge_softc *, struct bridge_iflist *,
 141             struct bstp_tcn_unit *);
 142 void    bstp_record_config_information(struct bridge_softc *,
 143             struct bridge_iflist *, struct bstp_config_unit *);
 144 void    bstp_record_config_timeout_values(struct bridge_softc *,
 145             struct bstp_config_unit *);
 146 void    bstp_config_bpdu_generation(struct bridge_softc *);
 147 void    bstp_send_config_bpdu(struct bridge_softc *, struct bridge_iflist *,
 148             struct bstp_config_unit *);
 149 void    bstp_configuration_update(struct bridge_softc *);
 150 void    bstp_root_selection(struct bridge_softc *);
 151 void    bstp_designated_port_selection(struct bridge_softc *);
 152 void    bstp_become_designated_port(struct bridge_softc *,
 153             struct bridge_iflist *);
 154 void    bstp_port_state_selection(struct bridge_softc *);
 155 void    bstp_make_forwarding(struct bridge_softc *, struct bridge_iflist *);
 156 void    bstp_make_blocking(struct bridge_softc *, struct bridge_iflist *);
 157 void    bstp_set_port_state(struct bridge_iflist *, uint8_t);
 158 void    bstp_set_bridge_priority(struct bridge_softc *, uint64_t);
 159 void    bstp_set_port_priority(struct bridge_softc *, struct bridge_iflist *,
 160             uint16_t);
 161 void    bstp_set_path_cost(struct bridge_softc *, struct bridge_iflist *,
 162             uint32_t);
 163 void    bstp_topology_change_detection(struct bridge_softc *);
 164 void    bstp_topology_change_acknowledged(struct bridge_softc *);
 165 void    bstp_acknowledge_topology_change(struct bridge_softc *,
 166             struct bridge_iflist *);
 167
 168 void    bstp_tick(void *);
 169 void    bstp_timer_start(struct bridge_timer *, uint16_t);
 170 void    bstp_timer_stop(struct bridge_timer *);
 171 int     bstp_timer_expired(struct bridge_timer *, uint16_t);
 172
 173 void    bstp_hold_timer_expiry(struct bridge_softc *, struct bridge_iflist *);
 174 void    bstp_message_age_timer_expiry(struct bridge_softc *,
 175             struct bridge_iflist *);
 176 void    bstp_forward_delay_timer_expiry(struct bridge_softc *,
 177             struct bridge_iflist *);
 178 void    bstp_topology_change_timer_expiry(struct bridge_softc *);
 179 void    bstp_tcn_timer_expiry(struct bridge_softc *);
 180 void    bstp_hello_timer_expiry(struct bridge_softc *);
 181
 182 void
 183 bstp_transmit_config(struct bridge_softc *sc, struct bridge_iflist *bif)
 184 {
 185         if (bif->bif_hold_timer.active) {
 186                 bif->bif_config_pending = 1;
 187                 return;
 188         }
 189
 190         bif->bif_config_bpdu.cu_message_type = BSTP_MSGTYPE_CFG;
 191         bif->bif_config_bpdu.cu_rootid = sc->sc_designated_root;
 192         bif->bif_config_bpdu.cu_root_path_cost = sc->sc_root_path_cost;
 193         bif->bif_config_bpdu.cu_bridge_id = sc->sc_bridge_id;
 194         bif->bif_config_bpdu.cu_port_id = bif->bif_port_id;
 195
 196         if (bstp_root_bridge(sc))
 197                 bif->bif_config_bpdu.cu_message_age = 0;
 198         else
 199                 bif->bif_config_bpdu.cu_message_age =
 200                     sc->sc_root_port->bif_message_age_timer.value +
 201                     BSTP_MESSAGE_AGE_INCR;
 202
 203         bif->bif_config_bpdu.cu_max_age = sc->sc_max_age;
 204         bif->bif_config_bpdu.cu_hello_time = sc->sc_hello_time;
 205         bif->bif_config_bpdu.cu_forward_delay = sc->sc_forward_delay;
 206         bif->bif_config_bpdu.cu_topology_change_acknowledgment
 207             = bif->bif_topology_change_acknowledge;
 208         bif->bif_config_bpdu.cu_topology_change = sc->sc_topology_change;
 209
 210         if (bif->bif_config_bpdu.cu_message_age < sc->sc_max_age) {
 211                 bif->bif_topology_change_acknowledge = 0;
 212                 bif->bif_config_pending = 0;
 213                 bstp_send_config_bpdu(sc, bif, &bif->bif_config_bpdu);
 214                 bstp_timer_start(&bif->bif_hold_timer, 0);
 215         }
 216 }
 217
 218 void
 219 bstp_send_config_bpdu(struct bridge_softc *sc, struct bridge_iflist *bif,
 220     struct bstp_config_unit *cu)
 221 {
 222         struct ifnet *ifp;
 223         struct mbuf *m;
 224         struct ether_header *eh;
 225         struct bstp_cbpdu bpdu;
 226
 227         ifp = bif->bif_ifp;
 228
 229         if ((ifp->if_flags & IFF_RUNNING) == 0)
 230                 return;
 231
 232         MGETHDR(m, MB_DONTWAIT, MT_DATA);
 233         if (m == NULL)
 234                 return;
 235
 236         eh = mtod(m, struct ether_header *);
 237
 238         m->m_pkthdr.rcvif = ifp;
 239         m->m_pkthdr.len = sizeof(*eh) + sizeof(bpdu);
 240         m->m_len = m->m_pkthdr.len;
 241
 242         bpdu.cbu_ssap = bpdu.cbu_dsap = LLC_8021D_LSAP;
 243         bpdu.cbu_ctl = LLC_UI;
 244         bpdu.cbu_protoid = htons(0);
 245         bpdu.cbu_protover = 0;
 246         bpdu.cbu_bpdutype = cu->cu_message_type;
 247         bpdu.cbu_flags = (cu->cu_topology_change ? BSTP_FLAG_TC : 0) |
 248             (cu->cu_topology_change_acknowledgment ? BSTP_FLAG_TCA : 0);
 249
 250         bpdu.cbu_rootpri = htons(cu->cu_rootid >> 48);
 251         bpdu.cbu_rootaddr[0] = cu->cu_rootid >> 40;
 252         bpdu.cbu_rootaddr[1] = cu->cu_rootid >> 32;
 253         bpdu.cbu_rootaddr[2] = cu->cu_rootid >> 24;
 254         bpdu.cbu_rootaddr[3] = cu->cu_rootid >> 16;
 255         bpdu.cbu_rootaddr[4] = cu->cu_rootid >> 8;
 256         bpdu.cbu_rootaddr[5] = cu->cu_rootid >> 0;
 257
 258         bpdu.cbu_rootpathcost = htonl(cu->cu_root_path_cost);
 259
 260         bpdu.cbu_bridgepri = htons(cu->cu_rootid >> 48);
 261         bpdu.cbu_bridgeaddr[0] = cu->cu_rootid >> 40;
 262         bpdu.cbu_bridgeaddr[1] = cu->cu_rootid >> 32;
 263         bpdu.cbu_bridgeaddr[2] = cu->cu_rootid >> 24;
 264         bpdu.cbu_bridgeaddr[3] = cu->cu_rootid >> 16;
 265         bpdu.cbu_bridgeaddr[4] = cu->cu_rootid >> 8;
 266         bpdu.cbu_bridgeaddr[5] = cu->cu_rootid >> 0;
 267
 268         bpdu.cbu_portid = htons(cu->cu_port_id);
 269         bpdu.cbu_messageage = htons(cu->cu_message_age);
 270         bpdu.cbu_maxage = htons(cu->cu_max_age);
 271         bpdu.cbu_hellotime = htons(cu->cu_hello_time);
 272         bpdu.cbu_forwarddelay = htons(cu->cu_forward_delay);
 273
 274         memcpy(eh->ether_shost, IF_LLADDR(ifp), ETHER_ADDR_LEN);
 275         memcpy(eh->ether_dhost, bstp_etheraddr, ETHER_ADDR_LEN);
 276         eh->ether_type = htons(sizeof(bpdu));
 277
 278         memcpy(mtod(m, caddr_t) + sizeof(*eh), &bpdu, sizeof(bpdu));
 279
 280         bridge_enqueue(sc, ifp, m);
 281 }
 282
 283 int
 284 bstp_root_bridge(struct bridge_softc *sc)
 285 {
 286         return (sc->sc_designated_root == sc->sc_bridge_id);
 287 }
 288
 289 int
 290 bstp_supersedes_port_info(struct bridge_softc *sc, struct bridge_iflist *bif,
 291     struct bstp_config_unit *cu)
 292 {
 293         if (cu->cu_rootid < bif->bif_designated_root)
 294                 return (1);
 295         if (cu->cu_rootid > bif->bif_designated_root)
 296                 return (0);
 297
 298         if (cu->cu_root_path_cost < bif->bif_designated_cost)
 299                 return (1);
 300         if (cu->cu_root_path_cost > bif->bif_designated_cost)
 301                 return (0);
 302
 303         if (cu->cu_bridge_id < bif->bif_designated_bridge)
 304                 return (1);
 305         if (cu->cu_bridge_id > bif->bif_designated_bridge)
 306                 return (0);
 307
 308         if (sc->sc_bridge_id != cu->cu_bridge_id)
 309                 return (1);
 310         if (cu->cu_port_id <= bif->bif_designated_port)
 311                 return (1);
 312         return (0);
 313 }
 314
 315 void
 316 bstp_record_config_information(struct bridge_softc *sc,
 317     struct bridge_iflist *bif, struct bstp_config_unit *cu)
 318 {
 319         bif->bif_designated_root = cu->cu_rootid;
 320         bif->bif_designated_cost = cu->cu_root_path_cost;
 321         bif->bif_designated_bridge = cu->cu_bridge_id;
 322         bif->bif_designated_port = cu->cu_port_id;
 323         bstp_timer_start(&bif->bif_message_age_timer, cu->cu_message_age);
 324 }
 325
 326 void
 327 bstp_record_config_timeout_values(struct bridge_softc *sc,
 328     struct bstp_config_unit *config)
 329 {
 330         sc->sc_max_age = config->cu_max_age;
 331         sc->sc_hello_time = config->cu_hello_time;
 332         sc->sc_forward_delay = config->cu_forward_delay;
 333         sc->sc_topology_change = config->cu_topology_change;
 334 }
 335
 336 void
 337 bstp_config_bpdu_generation(struct bridge_softc *sc)
 338 {
 339         struct bridge_iflist *bif;
 340
 341         LIST_FOREACH(bif, &sc->sc_iflist, bif_next) {
 342                 if ((bif->bif_flags & IFBIF_STP) == 0)
 343                         continue;
 344                 if (bstp_designated_port(sc, bif) &&
 345                     (bif->bif_state != BSTP_IFSTATE_DISABLED))
 346                         bstp_transmit_config(sc, bif);
 347         }
 348 }
 349
 350 int
 351 bstp_designated_port(struct bridge_softc *sc, struct bridge_iflist *bif)
 352 {
 353         return ((bif->bif_designated_bridge == sc->sc_bridge_id)
 354             && (bif->bif_designated_port == bif->bif_port_id));
 355 }
 356
 357 void
 358 bstp_transmit_tcn(struct bridge_softc *sc)
 359 {
 360         struct bstp_tbpdu bpdu;
 361         struct bridge_iflist *bif = sc->sc_root_port;
 362         struct ifnet *ifp = bif->bif_ifp;
 363         struct ether_header *eh;
 364         struct mbuf *m;
 365
 366         if ((ifp->if_flags & IFF_RUNNING) == 0)
 367                 return;
 368
 369         MGETHDR(m, MB_DONTWAIT, MT_DATA);
 370         if (m == NULL)
 371                 return;
 372
 373         m->m_pkthdr.rcvif = ifp;
 374         m->m_pkthdr.len = sizeof(*eh) + sizeof(bpdu);
 375         m->m_len = m->m_pkthdr.len;
 376
 377         eh = mtod(m, struct ether_header *);
 378
 379         memcpy(eh->ether_shost, IF_LLADDR(ifp), ETHER_ADDR_LEN);
 380         memcpy(eh->ether_dhost, bstp_etheraddr, ETHER_ADDR_LEN);
 381         eh->ether_type = htons(sizeof(bpdu));
 382
 383         bpdu.tbu_ssap = bpdu.tbu_dsap = LLC_8021D_LSAP;
 384         bpdu.tbu_ctl = LLC_UI;
 385         bpdu.tbu_protoid = 0;
 386         bpdu.tbu_protover = 0;
 387         bpdu.tbu_bpdutype = BSTP_MSGTYPE_TCN;
 388
 389         memcpy(mtod(m, caddr_t) + sizeof(*eh), &bpdu, sizeof(bpdu));
 390
 391         bridge_enqueue(sc, ifp, m);
 392 }
 393
 394 void
 395 bstp_configuration_update(struct bridge_softc *sc)
 396 {
 397         bstp_root_selection(sc);
 398         bstp_designated_port_selection(sc);
 399 }
 400
 401 void
 402 bstp_root_selection(struct bridge_softc *sc)
 403 {
 404         struct bridge_iflist *root_port = NULL, *bif;
 405
 406         LIST_FOREACH(bif, &sc->sc_iflist, bif_next) {
 407                 if ((bif->bif_flags & IFBIF_STP) == 0)
 408                         continue;
 409                 if (bstp_designated_port(sc, bif))
 410                         continue;
 411                 if (bif->bif_state == BSTP_IFSTATE_DISABLED)
 412                         continue;
 413                 if (bif->bif_designated_root >= sc->sc_bridge_id)
 414                         continue;
 415                 if (root_port == NULL)
 416                         goto set_port;
 417
 418                 if (bif->bif_designated_root < root_port->bif_designated_root)
 419                         goto set_port;
 420                 if (bif->bif_designated_root > root_port->bif_designated_root)
 421                         continue;
 422
 423                 if ((bif->bif_designated_cost + bif->bif_path_cost) <
 424                     (root_port->bif_designated_cost + root_port->bif_path_cost))
 425                         goto set_port;
 426                 if ((bif->bif_designated_cost + bif->bif_path_cost) >
 427                     (root_port->bif_designated_cost + root_port->bif_path_cost))
 428                         continue;
 429
 430                 if (bif->bif_designated_bridge <
 431                     root_port->bif_designated_bridge)
 432                         goto set_port;
 433                 if (bif->bif_designated_bridge >
 434                     root_port->bif_designated_bridge)
 435                         continue;
 436
 437                 if (bif->bif_designated_port < root_port->bif_designated_port)
 438                         goto set_port;
 439                 if (bif->bif_designated_port > root_port->bif_designated_port)
 440                         continue;
 441
 442                 if (bif->bif_port_id >= root_port->bif_port_id)
 443                         continue;
 444 set_port:
 445                 root_port = bif;
 446         }
 447
 448         sc->sc_root_port = root_port;
 449         if (root_port == NULL) {
 450                 sc->sc_designated_root = sc->sc_bridge_id;
 451                 sc->sc_root_path_cost = 0;
 452         } else {
 453                 sc->sc_designated_root = root_port->bif_designated_root;
 454                 sc->sc_root_path_cost = root_port->bif_designated_cost +
 455                     root_port->bif_path_cost;
 456         }
 457 }
 458
 459 void
 460 bstp_designated_port_selection(struct bridge_softc *sc)
 461 {
 462         struct bridge_iflist *bif;
 463
 464         LIST_FOREACH(bif, &sc->sc_iflist, bif_next) {
 465                 if ((bif->bif_flags & IFBIF_STP) == 0)
 466                         continue;
 467                 if (bstp_designated_port(sc, bif))
 468                         goto designated;
 469                 if (bif->bif_designated_root != sc->sc_designated_root)
 470                         goto designated;
 471
 472                 if (sc->sc_root_path_cost < bif->bif_designated_cost)
 473                         goto designated;
 474                 if (sc->sc_root_path_cost > bif->bif_designated_cost)
 475                         continue;
 476
 477                 if (sc->sc_bridge_id < bif->bif_designated_bridge)
 478                         goto designated;
 479                 if (sc->sc_bridge_id > bif->bif_designated_bridge)
 480                         continue;
 481
 482                 if (bif->bif_port_id > bif->bif_designated_port)
 483                         continue;
 484 designated:
 485                 bstp_become_designated_port(sc, bif);
 486         }
 487 }
 488
 489 void
 490 bstp_become_designated_port(struct bridge_softc *sc, struct bridge_iflist *bif)
 491 {
 492         bif->bif_designated_root = sc->sc_designated_root;
 493         bif->bif_designated_cost = sc->sc_root_path_cost;
 494         bif->bif_designated_bridge = sc->sc_bridge_id;
 495         bif->bif_designated_port = bif->bif_port_id;
 496 }
 497
 498 void
 499 bstp_port_state_selection(struct bridge_softc *sc)
 500 {
 501         struct bridge_iflist *bif;
 502
 503         LIST_FOREACH(bif, &sc->sc_iflist, bif_next) {
 504                 if ((bif->bif_flags & IFBIF_STP) == 0)
 505                         continue;
 506                 if (bif == sc->sc_root_port) {
 507                         bif->bif_config_pending = 0;
 508                         bif->bif_topology_change_acknowledge = 0;
 509                         bstp_make_forwarding(sc, bif);
 510                 } else if (bstp_designated_port(sc, bif)) {
 511                         bstp_timer_stop(&bif->bif_message_age_timer);
 512                         bstp_make_forwarding(sc, bif);
 513                 } else {
 514                         bif->bif_config_pending = 0;
 515                         bif->bif_topology_change_acknowledge = 0;
 516                         bstp_make_blocking(sc, bif);
 517                 }
 518         }
 519 }
 520
 521 void
 522 bstp_make_forwarding(struct bridge_softc *sc, struct bridge_iflist *bif)
 523 {
 524         if (bif->bif_state == BSTP_IFSTATE_BLOCKING) {
 525                 bstp_set_port_state(bif, BSTP_IFSTATE_LISTENING);
 526                 bstp_timer_start(&bif->bif_forward_delay_timer, 0);
 527         }
 528 }
 529
 530 void
 531 bstp_make_blocking(struct bridge_softc *sc, struct bridge_iflist *bif)
 532 {
 533         if ((bif->bif_state != BSTP_IFSTATE_DISABLED) &&
 534             (bif->bif_state != BSTP_IFSTATE_BLOCKING)) {
 535                 if ((bif->bif_state == BSTP_IFSTATE_FORWARDING) ||
 536                     (bif->bif_state == BSTP_IFSTATE_LEARNING)) {
 537                         if (bif->bif_change_detection_enabled) {
 538                                 bstp_topology_change_detection(sc);
 539                         }
 540                 }
 541                 bstp_set_port_state(bif, BSTP_IFSTATE_BLOCKING);
 542                 bridge_rtdelete(sc, bif->bif_ifp, IFBF_FLUSHDYN);
 543                 bstp_timer_stop(&bif->bif_forward_delay_timer);
 544         }
 545 }
 546
 547 void
 548 bstp_set_port_state(struct bridge_iflist *bif, uint8_t state)
 549 {
 550         bif->bif_state = state;
 551 }
 552
 553 void
 554 bstp_topology_change_detection(struct bridge_softc *sc)
 555 {
 556         if (bstp_root_bridge(sc)) {
 557                 sc->sc_topology_change = 1;
 558                 bstp_timer_start(&sc->sc_topology_change_timer, 0);
 559         } else if (!sc->sc_topology_change_detected) {
 560                 bstp_transmit_tcn(sc);
 561                 bstp_timer_start(&sc->sc_tcn_timer, 0);
 562         }
 563         sc->sc_topology_change_detected = 1;
 564 }
 565
 566 void
 567 bstp_topology_change_acknowledged(struct bridge_softc *sc)
 568 {
 569         sc->sc_topology_change_detected = 0;
 570         bstp_timer_stop(&sc->sc_tcn_timer);
 571 }
 572
 573 void
 574 bstp_acknowledge_topology_change(struct bridge_softc *sc,
 575     struct bridge_iflist *bif)
 576 {
 577         bif->bif_topology_change_acknowledge = 1;
 578         bstp_transmit_config(sc, bif);
 579 }
 580
 581 struct mbuf *
 582 bstp_input(struct ifnet *ifp, struct mbuf *m)
 583 {
 584         struct bridge_softc *sc = ifp->if_bridge;
 585         struct bridge_iflist *bif = NULL;
 586         struct ether_header *eh;
 587         struct bstp_tbpdu tpdu;
 588         struct bstp_cbpdu cpdu;
 589         struct bstp_config_unit cu;
 590         struct bstp_tcn_unit tu;
 591         uint16_t len;
 592
 593         eh = mtod(m, struct ether_header *);
 594
 595         LIST_FOREACH(bif, &sc->sc_iflist, bif_next) {
 596                 if ((bif->bif_flags & IFBIF_STP) == 0)
 597                         continue;
 598                 if (bif->bif_ifp == ifp)
 599                         break;
 600         }
 601         if (bif == NULL)
 602                 goto out;
 603
 604         len = ntohs(eh->ether_type);
 605         if (len < sizeof(tpdu))
 606                 goto out;
 607
 608         m_adj(m, ETHER_HDR_LEN);
 609
 610         if (m->m_pkthdr.len > len)
 611                 m_adj(m, len - m->m_pkthdr.len);
 612         if (m->m_len < sizeof(tpdu) &&
 613             (m = m_pullup(m, sizeof(tpdu))) == NULL)
 614                 goto out;
 615
 616         memcpy(&tpdu, mtod(m, caddr_t), sizeof(tpdu));
 617
 618         if (tpdu.tbu_dsap != LLC_8021D_LSAP ||
 619             tpdu.tbu_ssap != LLC_8021D_LSAP ||
 620             tpdu.tbu_ctl != LLC_UI)
 621                 goto out;
 622         if (tpdu.tbu_protoid != 0 || tpdu.tbu_protover != 0)
 623                 goto out;
 624
 625         switch (tpdu.tbu_bpdutype) {
 626         case BSTP_MSGTYPE_TCN:
 627                 tu.tu_message_type = tpdu.tbu_bpdutype;
 628                 bstp_received_tcn_bpdu(sc, bif, &tu);
 629                 break;
 630         case BSTP_MSGTYPE_CFG:
 631                 if (m->m_len < sizeof(cpdu) &&
 632                     (m = m_pullup(m, sizeof(cpdu))) == NULL)
 633                         goto out;
 634                 memcpy(&cpdu, mtod(m, caddr_t), sizeof(cpdu));
 635
 636                 cu.cu_rootid =
 637                     (((uint64_t)ntohs(cpdu.cbu_rootpri)) << 48) |
 638                     (((uint64_t)cpdu.cbu_rootaddr[0]) << 40) |
 639                     (((uint64_t)cpdu.cbu_rootaddr[1]) << 32) |
 640                     (((uint64_t)cpdu.cbu_rootaddr[2]) << 24) |
 641                     (((uint64_t)cpdu.cbu_rootaddr[3]) << 16) |
 642                     (((uint64_t)cpdu.cbu_rootaddr[4]) << 8) |
 643                     (((uint64_t)cpdu.cbu_rootaddr[5]) << 0);
 644
 645                 cu.cu_bridge_id =
 646                     (((uint64_t)ntohs(cpdu.cbu_bridgepri)) << 48) |
 647                     (((uint64_t)cpdu.cbu_bridgeaddr[0]) << 40) |
 648                     (((uint64_t)cpdu.cbu_bridgeaddr[1]) << 32) |
 649                     (((uint64_t)cpdu.cbu_bridgeaddr[2]) << 24) |
 650                     (((uint64_t)cpdu.cbu_bridgeaddr[3]) << 16) |
 651                     (((uint64_t)cpdu.cbu_bridgeaddr[4]) << 8) |
 652                     (((uint64_t)cpdu.cbu_bridgeaddr[5]) << 0);
 653
 654                 cu.cu_root_path_cost = ntohl(cpdu.cbu_rootpathcost);
 655                 cu.cu_message_age = ntohs(cpdu.cbu_messageage);
 656                 cu.cu_max_age = ntohs(cpdu.cbu_maxage);
 657                 cu.cu_hello_time = ntohs(cpdu.cbu_hellotime);
 658                 cu.cu_forward_delay = ntohs(cpdu.cbu_forwarddelay);
 659                 cu.cu_port_id = ntohs(cpdu.cbu_portid);
 660                 cu.cu_message_type = cpdu.cbu_bpdutype;
 661                 cu.cu_topology_change_acknowledgment =
 662                     (cpdu.cbu_flags & BSTP_FLAG_TCA) ? 1 : 0;
 663                 cu.cu_topology_change =
 664                     (cpdu.cbu_flags & BSTP_FLAG_TC) ? 1 : 0;
 665                 bstp_received_config_bpdu(sc, bif, &cu);
 666                 break;
 667         default:
 668                 goto out;
 669         }
 670
 671  out:
 672         if (m)
 673                 m_freem(m);
 674         return (NULL);
 675 }
 676
 677 void
 678 bstp_received_config_bpdu(struct bridge_softc *sc, struct bridge_iflist *bif,
 679     struct bstp_config_unit *cu)
 680 {
 681         int root;
 682
 683         root = bstp_root_bridge(sc);
 684
 685         if (bif->bif_state != BSTP_IFSTATE_DISABLED) {
 686                 if (bstp_supersedes_port_info(sc, bif, cu)) {
 687                         bstp_record_config_information(sc, bif, cu);
 688                         bstp_configuration_update(sc);
 689                         bstp_port_state_selection(sc);
 690
 691                         if ((bstp_root_bridge(sc) == 0) && root) {
 692                                 bstp_timer_stop(&sc->sc_hello_timer);
 693
 694                                 if (sc->sc_topology_change_detected) {
 695                                         bstp_timer_stop(
 696                                             &sc->sc_topology_change_timer);
 697                                         bstp_transmit_tcn(sc);
 698                                         bstp_timer_start(&sc->sc_tcn_timer, 0);
 699                                 }
 700                         }
 701
 702                         if (bif == sc->sc_root_port) {
 703                                 bstp_record_config_timeout_values(sc, cu);
 704                                 bstp_config_bpdu_generation(sc);
 705
 706                                 if (cu->cu_topology_change_acknowledgment)
 707                                         bstp_topology_change_acknowledged(sc);
 708                         }
 709                 } else if (bstp_designated_port(sc, bif))
 710                         bstp_transmit_config(sc, bif);
 711         }
 712 }
 713
 714 void
 715 bstp_received_tcn_bpdu(struct bridge_softc *sc, struct bridge_iflist *bif,
 716     struct bstp_tcn_unit *tcn)
 717 {
 718         if (bif->bif_state != BSTP_IFSTATE_DISABLED &&
 719             bstp_designated_port(sc, bif)) {
 720                 bstp_topology_change_detection(sc);
 721                 bstp_acknowledge_topology_change(sc, bif);
 722         }
 723 }
 724
 725 void
 726 bstp_hello_timer_expiry(struct bridge_softc *sc)
 727 {
 728         bstp_config_bpdu_generation(sc);
 729         bstp_timer_start(&sc->sc_hello_timer, 0);
 730 }
 731
 732 void
 733 bstp_message_age_timer_expiry(struct bridge_softc *sc,
 734     struct bridge_iflist *bif)
 735 {
 736         int root;
 737
 738         root = bstp_root_bridge(sc);
 739         bstp_become_designated_port(sc, bif);
 740         bstp_configuration_update(sc);
 741         bstp_port_state_selection(sc);
 742
 743         if ((bstp_root_bridge(sc)) && (root == 0)) {
 744                 sc->sc_max_age = sc->sc_bridge_max_age;
 745                 sc->sc_hello_time = sc->sc_bridge_hello_time;
 746                 sc->sc_forward_delay = sc->sc_bridge_forward_delay;
 747
 748                 bstp_topology_change_detection(sc);
 749                 bstp_timer_stop(&sc->sc_tcn_timer);
 750                 bstp_config_bpdu_generation(sc);
 751                 bstp_timer_start(&sc->sc_hello_timer, 0);
 752         }
 753 }
 754
 755 void
 756 bstp_forward_delay_timer_expiry(struct bridge_softc *sc,
 757     struct bridge_iflist *bif)
 758 {
 759         if (bif->bif_state == BSTP_IFSTATE_LISTENING) {
 760                 bstp_set_port_state(bif, BSTP_IFSTATE_LEARNING);
 761                 bstp_timer_start(&bif->bif_forward_delay_timer, 0);
 762         } else if (bif->bif_state == BSTP_IFSTATE_LEARNING) {
 763                 bstp_set_port_state(bif, BSTP_IFSTATE_FORWARDING);
 764                 if (bstp_designated_for_some_port(sc) &&
 765                     bif->bif_change_detection_enabled)
 766                         bstp_topology_change_detection(sc);
 767         }
 768 }
 769
 770 int
 771 bstp_designated_for_some_port(struct bridge_softc *sc)
 772 {
 773
 774         struct bridge_iflist *bif;
 775
 776         LIST_FOREACH(bif, &sc->sc_iflist, bif_next) {
 777                 if ((bif->bif_flags & IFBIF_STP) == 0)
 778                         continue;
 779                 if (bif->bif_designated_bridge == sc->sc_bridge_id)
 780                         return (1);
 781         }
 782         return (0);
 783 }
 784
 785 void
 786 bstp_tcn_timer_expiry(struct bridge_softc *sc)
 787 {
 788         bstp_transmit_tcn(sc);
 789         bstp_timer_start(&sc->sc_tcn_timer, 0);
 790 }
 791
 792 void
 793 bstp_topology_change_timer_expiry(struct bridge_softc *sc)
 794 {
 795         sc->sc_topology_change_detected = 0;
 796         sc->sc_topology_change = 0;
 797 }
 798
 799 void
 800 bstp_hold_timer_expiry(struct bridge_softc *sc, struct bridge_iflist *bif)
 801 {
 802         if (bif->bif_config_pending)
 803                 bstp_transmit_config(sc, bif);
 804 }
 805
 806 void
 807 bstp_initialization(struct bridge_softc *sc)
 808 {
 809         struct bridge_iflist *bif, *mif;
 810
 811         mif = NULL;
 812         LIST_FOREACH(bif, &sc->sc_iflist, bif_next) {
 813                 if ((bif->bif_flags & IFBIF_STP) == 0)
 814                         continue;
 815                 if (bif->bif_ifp->if_type != IFT_ETHER)
 816                         continue;
 817                 bif->bif_port_id = (bif->bif_priority << 8) |
 818                     (bif->bif_ifp->if_index & 0xff);
 819
 820                 if (mif == NULL) {
 821                         mif = bif;
 822                         continue;
 823                 }
 824                 if (memcmp(IF_LLADDR(bif->bif_ifp),
 825                     IF_LLADDR(mif->bif_ifp), ETHER_ADDR_LEN) < 0) {
 826                         mif = bif;
 827                         continue;
 828                 }
 829         }
 830         if (mif == NULL) {
 831                 bstp_stop(sc);
 832                 return;
 833         }
 834
 835         sc->sc_bridge_id =
 836             (((uint64_t)sc->sc_bridge_priority) << 48) |
 837             (((uint64_t)IF_LLADDR(mif->bif_ifp)[0]) << 40) |
 838             (((uint64_t)IF_LLADDR(mif->bif_ifp)[1]) << 32) |
 839             (IF_LLADDR(mif->bif_ifp)[2] << 24) |
 840             (IF_LLADDR(mif->bif_ifp)[3] << 16) |
 841             (IF_LLADDR(mif->bif_ifp)[4] << 8) |
 842             (IF_LLADDR(mif->bif_ifp)[5]);
 843
 844         sc->sc_designated_root = sc->sc_bridge_id;
 845         sc->sc_root_path_cost = 0;
 846         sc->sc_root_port = NULL;
 847
 848         sc->sc_max_age = sc->sc_bridge_max_age;
 849         sc->sc_hello_time = sc->sc_bridge_hello_time;
 850         sc->sc_forward_delay = sc->sc_bridge_forward_delay;
 851         sc->sc_topology_change_detected = 0;
 852         sc->sc_topology_change = 0;
 853         bstp_timer_stop(&sc->sc_tcn_timer);
 854         bstp_timer_stop(&sc->sc_topology_change_timer);
 855
 856         if (callout_pending(&sc->sc_bstpcallout) == 0)
 857                 callout_reset(&sc->sc_bstpcallout, hz,
 858                     bstp_tick, sc);
 859
 860         LIST_FOREACH(bif, &sc->sc_iflist, bif_next) {
 861                 if (bif->bif_flags & IFBIF_STP)
 862                         bstp_ifupdstatus(sc, bif);
 863                 else
 864                         bstp_disable_port(sc, bif);
 865         }
 866
 867         bstp_port_state_selection(sc);
 868         bstp_config_bpdu_generation(sc);
 869         bstp_timer_start(&sc->sc_hello_timer, 0);
 870 }
 871
 872 void
 873 bstp_stop(struct bridge_softc *sc)
 874 {
 875         struct bridge_iflist *bif;
 876
 877         LIST_FOREACH(bif, &sc->sc_iflist, bif_next) {
 878                 bstp_set_port_state(bif, BSTP_IFSTATE_DISABLED);
 879                 bstp_timer_stop(&bif->bif_hold_timer);
 880                 bstp_timer_stop(&bif->bif_message_age_timer);
 881                 bstp_timer_stop(&bif->bif_forward_delay_timer);
 882         }
 883
 884         callout_stop(&sc->sc_bstpcallout);
 885
 886         bstp_timer_stop(&sc->sc_topology_change_timer);
 887         bstp_timer_stop(&sc->sc_tcn_timer);
 888         bstp_timer_stop(&sc->sc_hello_timer);
 889
 890 }
 891
 892 void
 893 bstp_initialize_port(struct bridge_softc *sc, struct bridge_iflist *bif)
 894 {
 895         bstp_become_designated_port(sc, bif);
 896         bstp_set_port_state(bif, BSTP_IFSTATE_BLOCKING);
 897         bif->bif_topology_change_acknowledge = 0;
 898         bif->bif_config_pending = 0;
 899         bif->bif_change_detection_enabled = 1;
 900         bstp_timer_stop(&bif->bif_message_age_timer);
 901         bstp_timer_stop(&bif->bif_forward_delay_timer);
 902         bstp_timer_stop(&bif->bif_hold_timer);
 903 }
 904
 905 void
 906 bstp_enable_port(struct bridge_softc *sc, struct bridge_iflist *bif)
 907 {
 908         bstp_initialize_port(sc, bif);
 909         bstp_port_state_selection(sc);
 910 }
 911
 912 void
 913 bstp_disable_port(struct bridge_softc *sc, struct bridge_iflist *bif)
 914 {
 915         int root;
 916
 917         root = bstp_root_bridge(sc);
 918         bstp_become_designated_port(sc, bif);
 919         bstp_set_port_state(bif, BSTP_IFSTATE_DISABLED);
 920         bif->bif_topology_change_acknowledge = 0;
 921         bif->bif_config_pending = 0;
 922         bstp_timer_stop(&bif->bif_message_age_timer);
 923         bstp_timer_stop(&bif->bif_forward_delay_timer);
 924         bstp_configuration_update(sc);
 925         bstp_port_state_selection(sc);
 926         bridge_rtdelete(sc, bif->bif_ifp, IFBF_FLUSHDYN);
 927
 928         if (bstp_root_bridge(sc) && (root == 0)) {
 929                 sc->sc_max_age = sc->sc_bridge_max_age;
 930                 sc->sc_hello_time = sc->sc_bridge_hello_time;
 931                 sc->sc_forward_delay = sc->sc_bridge_forward_delay;
 932
 933                 bstp_topology_change_detection(sc);
 934                 bstp_timer_stop(&sc->sc_tcn_timer);
 935                 bstp_config_bpdu_generation(sc);
 936                 bstp_timer_start(&sc->sc_hello_timer, 0);
 937         }
 938 }
 939
 940 void
 941 bstp_set_bridge_priority(struct bridge_softc *sc, uint64_t new_bridge_id)
 942 {
 943         struct bridge_iflist *bif;
 944         int root;
 945
 946         root = bstp_root_bridge(sc);
 947
 948         LIST_FOREACH(bif, &sc->sc_iflist, bif_next) {
 949                 if ((bif->bif_flags & IFBIF_STP) == 0)
 950                         continue;
 951                 if (bstp_designated_port(sc, bif))
 952                         bif->bif_designated_bridge = new_bridge_id;
 953         }
 954
 955         sc->sc_bridge_id = new_bridge_id;
 956
 957         bstp_configuration_update(sc);
 958         bstp_port_state_selection(sc);
 959
 960         if (bstp_root_bridge(sc) && (root == 0)) {
 961                 sc->sc_max_age = sc->sc_bridge_max_age;
 962                 sc->sc_hello_time = sc->sc_bridge_hello_time;
 963                 sc->sc_forward_delay = sc->sc_bridge_forward_delay;
 964
 965                 bstp_topology_change_detection(sc);
 966                 bstp_timer_stop(&sc->sc_tcn_timer);
 967                 bstp_config_bpdu_generation(sc);
 968                 bstp_timer_start(&sc->sc_hello_timer, 0);
 969         }
 970 }
 971
 972 void
 973 bstp_set_port_priority(struct bridge_softc *sc, struct bridge_iflist *bif,
 974     uint16_t new_port_id)
 975 {
 976         if (bstp_designated_port(sc, bif))
 977                 bif->bif_designated_port = new_port_id;
 978
 979         bif->bif_port_id = new_port_id;
 980
 981         if ((sc->sc_bridge_id == bif->bif_designated_bridge) &&
 982             (bif->bif_port_id < bif->bif_designated_port)) {
 983                 bstp_become_designated_port(sc, bif);
 984                 bstp_port_state_selection(sc);
 985         }
 986 }
 987
 988 void
 989 bstp_set_path_cost(struct bridge_softc *sc, struct bridge_iflist *bif,
 990     uint32_t path_cost)
 991 {
 992         bif->bif_path_cost = path_cost;
 993         bstp_configuration_update(sc);
 994         bstp_port_state_selection(sc);
 995 }
 996
 997 void
 998 bstp_enable_change_detection(struct bridge_iflist *bif)
 999 {
1000         bif->bif_change_detection_enabled = 1;
1001 }
1002
1003 void
1004 bstp_disable_change_detection(struct bridge_iflist *bif)
1005 {
1006         bif->bif_change_detection_enabled = 0;
1007 }
1008
1009 void
1010 bstp_linkstate(struct ifnet *ifp, int state)
1011 {
1012         struct bridge_softc *sc;
1013         struct bridge_iflist *bif;
1014
1015         sc = ifp->if_bridge;
1016         lwkt_serialize_enter(sc->sc_ifp->if_serializer);
1017
1018         LIST_FOREACH(bif, &sc->sc_iflist, bif_next) {
1019                 if ((bif->bif_flags & IFBIF_STP) == 0)
1020                         continue;
1021
1022                 if (bif->bif_ifp == ifp) {
1023                         bstp_ifupdstatus(sc, bif);
1024                         break;
1025                 }
1026         }
1027         lwkt_serialize_exit(sc->sc_ifp->if_serializer);
1028 }
1029
1030 void
1031 bstp_ifupdstatus(struct bridge_softc *sc, struct bridge_iflist *bif)
1032 {
1033         struct ifnet *ifp = bif->bif_ifp;
1034         struct ifmediareq ifmr;
1035         int error = 0;
1036
1037         bzero((char *)&ifmr, sizeof(ifmr));
1038         lwkt_serialize_enter(ifp->if_serializer);
1039         error = (*ifp->if_ioctl)(ifp, SIOCGIFMEDIA, (caddr_t)&ifmr, curthread->td_proc->p_ucred);
1040         lwkt_serialize_exit(ifp->if_serializer);
1041
1042         if ((error == 0) && (ifp->if_flags & IFF_UP)) {
1043                 if (ifmr.ifm_status & IFM_ACTIVE) {
1044                         if (bif->bif_state == BSTP_IFSTATE_DISABLED)
1045                                 bstp_enable_port(sc, bif);
1046
1047                 } else {
1048                         if (bif->bif_state != BSTP_IFSTATE_DISABLED)
1049                                 bstp_disable_port(sc, bif);
1050                 }
1051                 return;
1052         }
1053
1054         if (bif->bif_state != BSTP_IFSTATE_DISABLED)
1055                 bstp_disable_port(sc, bif);
1056 }
1057
1058 void
1059 bstp_tick(void *arg)
1060 {
1061         struct bridge_softc *sc = arg;
1062         struct bridge_iflist *bif;
1063
1064         lwkt_serialize_enter(sc->sc_ifp->if_serializer);
1065
1066 #if 0
1067         LIST_FOREACH(bif, &sc->sc_iflist, bif_next) {
1068                 if ((bif->bif_flags & IFBIF_STP) == 0)
1069                         continue;
1070                 /*
1071                  * XXX This can cause a lag in "link does away"
1072                  * XXX and "spanning tree gets updated".  We need
1073                  * XXX come sort of callback from the link state
1074                  * XXX update code to kick spanning tree.
1075                  * XXX --thorpej@NetBSD.org
1076                  */
1077                 bstp_ifupdstatus(sc, bif);
1078         }
1079 #endif
1080
1081         if (bstp_timer_expired(&sc->sc_hello_timer, sc->sc_hello_time))
1082                 bstp_hello_timer_expiry(sc);
1083
1084         if (bstp_timer_expired(&sc->sc_tcn_timer, sc->sc_bridge_hello_time))
1085                 bstp_tcn_timer_expiry(sc);
1086
1087         if (bstp_timer_expired(&sc->sc_topology_change_timer,
1088             sc->sc_topology_change_time))
1089                 bstp_topology_change_timer_expiry(sc);
1090
1091         LIST_FOREACH(bif, &sc->sc_iflist, bif_next) {
1092                 if ((bif->bif_flags & IFBIF_STP) == 0)
1093                         continue;
1094                 if (bstp_timer_expired(&bif->bif_message_age_timer,
1095                     sc->sc_max_age))
1096                         bstp_message_age_timer_expiry(sc, bif);
1097         }
1098
1099         LIST_FOREACH(bif, &sc->sc_iflist, bif_next) {
1100                 if ((bif->bif_flags & IFBIF_STP) == 0)
1101                         continue;
1102                 if (bstp_timer_expired(&bif->bif_forward_delay_timer,
1103                     sc->sc_forward_delay))
1104                         bstp_forward_delay_timer_expiry(sc, bif);
1105
1106                 if (bstp_timer_expired(&bif->bif_hold_timer,
1107                     sc->sc_hold_time))
1108                         bstp_hold_timer_expiry(sc, bif);
1109         }
1110
1111         if (sc->sc_ifp->if_flags & IFF_RUNNING)
1112                 callout_reset(&sc->sc_bstpcallout, hz, bstp_tick, sc);
1113
1114         lwkt_serialize_exit(sc->sc_ifp->if_serializer);
1115 }
1116
1117 void
1118 bstp_timer_start(struct bridge_timer *t, uint16_t v)
1119 {
1120         t->value = v;
1121         t->active = 1;
1122 }
1123
1124 void
1125 bstp_timer_stop(struct bridge_timer *t)
1126 {
1127         t->value = 0;
1128         t->active = 0;
1129 }
1130
1131 int
1132 bstp_timer_expired(struct bridge_timer *t, uint16_t v)
1133 {
1134         if (t->active == 0)
1135                 return (0);
1136         t->value += BSTP_TICK_VAL;
1137         if (t->value >= v) {
1138                 bstp_timer_stop(t);
1139                 return (1);
1140         }
1141         return (0);
1142
1143 }