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  */
  35
  36 /*
  37  * Implementation of the spanning tree protocol as defined in
  38  * ISO/IEC Final DIS 15802-3 (IEEE P802.1D/D17), May 25, 1998.
  39  * (In English: IEEE 802.1D, Draft 17, 1998)
  40  */
  41
  42 #include <sys/param.h>
  43 #include <sys/systm.h>
  44 #include <sys/mbuf.h>
  45 #include <sys/socket.h>
  46 #include <sys/sockio.h>
  47 #include <sys/kernel.h>
  48 #include <sys/callout.h>
  49 #include <sys/proc.h>
  50 #include <sys/lock.h>
  51 #include <sys/thread.h>
  52 #include <sys/thread2.h>
  53 #include <sys/msgport2.h>
  54
  55 #include <net/if.h>
  56 #include <net/if_dl.h>
  57 #include <net/if_types.h>
  58 #include <net/if_llc.h>
  59 #include <net/if_media.h>
  60
  61 #include <netinet/in.h>
  62 #include <netinet/in_systm.h>
  63 #include <netinet/in_var.h>
  64 #include <netinet/if_ether.h>
  65 #include <net/bridge/if_bridgevar.h>
  66
  67 /* BPDU message types */
  68 #define BSTP_MSGTYPE_CFG        0x00            /* Configuration */
  69 #define BSTP_MSGTYPE_TCN        0x80            /* Topology chg notification */
  70
  71 /* BPDU flags */
  72 #define BSTP_FLAG_TC            0x01            /* Topology change */
  73 #define BSTP_FLAG_TCA           0x80            /* Topology change ack */
  74
  75 #define BSTP_MESSAGE_AGE_INCR   (1 * 256)       /* in 256ths of a second */
  76 #define BSTP_TICK_VAL           (1 * 256)       /* in 256ths of a second */
  77
  78 /*
  79  * Because BPDU's do not make nicely aligned structures, two different
  80  * declarations are used: bstp_?bpdu (wire representation, packed) and
  81  * bstp_*_unit (internal, nicely aligned version).
  82  */
  83
  84 /* configuration bridge protocol data unit */
  85 struct bstp_cbpdu {
  86         uint8_t         cbu_dsap;               /* LLC: destination sap */
  87         uint8_t         cbu_ssap;               /* LLC: source sap */
  88         uint8_t         cbu_ctl;                /* LLC: control */
  89         uint16_t        cbu_protoid;            /* protocol id */
  90         uint8_t         cbu_protover;           /* protocol version */
  91         uint8_t         cbu_bpdutype;           /* message type */
  92         uint8_t         cbu_flags;              /* flags (below) */
  93
  94         /* root id */
  95         uint16_t        cbu_rootpri;            /* root priority */
  96         uint8_t cbu_rootaddr[6];        /* root address */
  97
  98         uint32_t        cbu_rootpathcost;       /* root path cost */
  99
 100         /* bridge id */
 101         uint16_t        cbu_bridgepri;          /* bridge priority */
 102         uint8_t         cbu_bridgeaddr[6];      /* bridge address */
 103
 104         uint16_t        cbu_portid;             /* port id */
 105         uint16_t        cbu_messageage;         /* current message age */
 106         uint16_t        cbu_maxage;             /* maximum age */
 107         uint16_t        cbu_hellotime;          /* hello time */
 108         uint16_t        cbu_forwarddelay;       /* forwarding delay */
 109 } __attribute__((__packed__));
 110
 111 /* topology change notification bridge protocol data unit */
 112 struct bstp_tbpdu {
 113         uint8_t         tbu_dsap;               /* LLC: destination sap */
 114         uint8_t         tbu_ssap;               /* LLC: source sap */
 115         uint8_t         tbu_ctl;                /* LLC: control */
 116         uint16_t        tbu_protoid;            /* protocol id */
 117         uint8_t         tbu_protover;           /* protocol version */
 118         uint8_t         tbu_bpdutype;           /* message type */
 119 } __attribute__((__packed__));
 120
 121 const uint8_t bstp_etheraddr[] = { 0x01, 0x80, 0xc2, 0x00, 0x00, 0x00 };
 122
 123 static void     bstp_initialize_port(struct bridge_softc *,
 124                     struct bridge_iflist *);
 125 static void     bstp_ifupdstatus(struct bridge_softc *, struct bridge_iflist *);
 126 static void     bstp_enable_port(struct bridge_softc *, struct bridge_iflist *);
 127 static void     bstp_disable_port(struct bridge_softc *,
 128                     struct bridge_iflist *);
 129 #ifdef notused
 130 static void     bstp_enable_change_detection(struct bridge_iflist *);
 131 static void     bstp_disable_change_detection(struct bridge_iflist *);
 132 #endif /* notused */
 133 static int      bstp_root_bridge(struct bridge_softc *sc);
 134 static void     bstp_transmit_config(struct bridge_softc *,
 135                     struct bridge_iflist *);
 136 static void     bstp_transmit_tcn(struct bridge_softc *);
 137 static void     bstp_received_config_bpdu(struct bridge_softc *,
 138                     struct bridge_iflist *, struct bstp_config_unit *);
 139 static void     bstp_received_tcn_bpdu(struct bridge_softc *,
 140                     struct bridge_iflist *, struct bstp_tcn_unit *);
 141 static void     bstp_record_config_information(struct bridge_softc *,
 142                     struct bridge_iflist *, struct bstp_config_unit *);
 143 static void     bstp_record_config_timeout_values(struct bridge_softc *,
 144                     struct bstp_config_unit *);
 145 static void     bstp_config_bpdu_generation(struct bridge_softc *);
 146 static void     bstp_send_config_bpdu(struct bridge_softc *,
 147                     struct bridge_iflist *, struct bstp_config_unit *);
 148 static void     bstp_configuration_update(struct bridge_softc *);
 149 static void     bstp_port_state_selection(struct bridge_softc *);
 150 static void     bstp_clear_peer_info(struct bridge_softc *,
 151                     struct bridge_iflist *);
 152 static void     bstp_make_forwarding(struct bridge_softc *,
 153                     struct bridge_iflist *);
 154 static void     bstp_make_blocking(struct bridge_softc *,
 155                     struct bridge_iflist *);
 156 static void     bstp_make_l1blocking(struct bridge_softc *sc,
 157                     struct bridge_iflist *bif);
 158 static void     bstp_adjust_bonded_states(struct bridge_softc *sc,
 159                     struct bridge_iflist *obif);
 160 static void     bstp_set_port_state(struct bridge_iflist *, uint8_t);
 161 #ifdef notused
 162 static void     bstp_set_bridge_priority(struct bridge_softc *, uint64_t);
 163 static void     bstp_set_port_priority(struct bridge_softc *,
 164                     struct bridge_iflist *, uint16_t);
 165 static void     bstp_set_path_cost(struct bridge_softc *,
 166                     struct bridge_iflist *, uint32_t);
 167 #endif /* notused */
 168 static void     bstp_topology_change_detection(struct bridge_softc *);
 169 static void     bstp_topology_change_acknowledged(struct bridge_softc *);
 170 static void     bstp_acknowledge_topology_change(struct bridge_softc *,
 171                     struct bridge_iflist *);
 172
 173 static void     bstp_tick(void *);
 174 static void     bstp_timer_start(struct bridge_timer *, uint16_t);
 175 static void     bstp_timer_stop(struct bridge_timer *);
 176 static int      bstp_timer_expired(struct bridge_timer *, uint16_t);
 177
 178 static void     bstp_hold_timer_expiry(struct bridge_softc *,
 179                     struct bridge_iflist *);
 180 static void     bstp_message_age_timer_expiry(struct bridge_softc *,
 181                     struct bridge_iflist *);
 182 static void     bstp_forward_delay_timer_expiry(struct bridge_softc *,
 183                     struct bridge_iflist *);
 184 static void     bstp_topology_change_timer_expiry(struct bridge_softc *);
 185 static void     bstp_tcn_timer_expiry(struct bridge_softc *);
 186 static void     bstp_hello_timer_expiry(struct bridge_softc *);
 187 static int      bstp_addr_cmp(const uint8_t *, const uint8_t *);
 188
 189 /*
 190  * When transmitting a config we tack on our path cost to
 191  * our aggregated path-to-root cost.
 192  */
 193 static void
 194 bstp_transmit_config(struct bridge_softc *sc, struct bridge_iflist *bif)
 195 {
 196         if (bif->bif_hold_timer.active) {
 197                 bif->bif_config_pending = 1;
 198                 return;
 199         }
 200
 201         bif->bif_config_bpdu.cu_message_type = BSTP_MSGTYPE_CFG;
 202         bif->bif_config_bpdu.cu_rootid = sc->sc_designated_root;
 203         bif->bif_config_bpdu.cu_root_path_cost = sc->sc_designated_cost +
 204                                                  bif->bif_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 if (sc->sc_root_port) {
 211                 bif->bif_config_bpdu.cu_message_age =
 212                         sc->sc_root_port->bif_message_age_timer.value +
 213                         BSTP_MESSAGE_AGE_INCR;
 214         } else {
 215                 bif->bif_config_bpdu.cu_message_age = BSTP_MESSAGE_AGE_INCR;
 216         }
 217
 218         bif->bif_config_bpdu.cu_max_age = sc->sc_max_age;
 219         bif->bif_config_bpdu.cu_hello_time = sc->sc_hello_time;
 220         bif->bif_config_bpdu.cu_forward_delay = sc->sc_forward_delay;
 221         bif->bif_config_bpdu.cu_topology_change_acknowledgment
 222             = bif->bif_topology_change_acknowledge;
 223         bif->bif_config_bpdu.cu_topology_change = sc->sc_topology_change;
 224
 225         if (bif->bif_config_bpdu.cu_message_age < sc->sc_max_age ||
 226             (sc->sc_ifp->if_flags & IFF_LINK1)) {
 227                 bif->bif_topology_change_acknowledge = 0;
 228                 bif->bif_config_pending = 0;
 229                 bstp_send_config_bpdu(sc, bif, &bif->bif_config_bpdu);
 230                 bstp_timer_start(&bif->bif_hold_timer, 0);
 231         }
 232 }
 233
 234 static void
 235 bstp_send_config_bpdu(struct bridge_softc *sc, struct bridge_iflist *bif,
 236                       struct bstp_config_unit *cu)
 237 {
 238         struct ifnet *ifp;
 239         struct mbuf *m;
 240         struct ether_header *eh;
 241         struct bstp_cbpdu bpdu;
 242
 243         ifp = bif->bif_ifp;
 244
 245         if ((ifp->if_flags & IFF_RUNNING) == 0)
 246                 return;
 247
 248         MGETHDR(m, MB_DONTWAIT, MT_DATA);
 249         if (m == NULL)
 250                 return;
 251
 252         eh = mtod(m, struct ether_header *);
 253
 254         m->m_pkthdr.rcvif = ifp;
 255         m->m_pkthdr.len = sizeof(*eh) + sizeof(bpdu);
 256         m->m_len = m->m_pkthdr.len;
 257
 258         bpdu.cbu_ssap = bpdu.cbu_dsap = LLC_8021D_LSAP;
 259         bpdu.cbu_ctl = LLC_UI;
 260         bpdu.cbu_protoid = htons(0);
 261         bpdu.cbu_protover = 0;
 262         bpdu.cbu_bpdutype = cu->cu_message_type;
 263         bpdu.cbu_flags = (cu->cu_topology_change ? BSTP_FLAG_TC : 0) |
 264             (cu->cu_topology_change_acknowledgment ? BSTP_FLAG_TCA : 0);
 265
 266         bpdu.cbu_rootpri = htons(cu->cu_rootid >> 48);
 267         bpdu.cbu_rootaddr[0] = cu->cu_rootid >> 40;
 268         bpdu.cbu_rootaddr[1] = cu->cu_rootid >> 32;
 269         bpdu.cbu_rootaddr[2] = cu->cu_rootid >> 24;
 270         bpdu.cbu_rootaddr[3] = cu->cu_rootid >> 16;
 271         bpdu.cbu_rootaddr[4] = cu->cu_rootid >> 8;
 272         bpdu.cbu_rootaddr[5] = cu->cu_rootid >> 0;
 273
 274         bpdu.cbu_rootpathcost = htonl(cu->cu_root_path_cost);
 275
 276         bpdu.cbu_bridgepri = htons(cu->cu_bridge_id >> 48);
 277         bpdu.cbu_bridgeaddr[0] = cu->cu_bridge_id >> 40;
 278         bpdu.cbu_bridgeaddr[1] = cu->cu_bridge_id >> 32;
 279         bpdu.cbu_bridgeaddr[2] = cu->cu_bridge_id >> 24;
 280         bpdu.cbu_bridgeaddr[3] = cu->cu_bridge_id >> 16;
 281         bpdu.cbu_bridgeaddr[4] = cu->cu_bridge_id >> 8;
 282         bpdu.cbu_bridgeaddr[5] = cu->cu_bridge_id >> 0;
 283
 284         bpdu.cbu_portid = htons(cu->cu_port_id);
 285         bpdu.cbu_messageage = htons(cu->cu_message_age);
 286         bpdu.cbu_maxage = htons(cu->cu_max_age);
 287         bpdu.cbu_hellotime = htons(cu->cu_hello_time);
 288         bpdu.cbu_forwarddelay = htons(cu->cu_forward_delay);
 289
 290         /*
 291          * Packets sent from the bridge always use the bridge MAC
 292          * as the source.
 293          */
 294         memcpy(eh->ether_shost, IF_LLADDR(sc->sc_ifp), ETHER_ADDR_LEN);
 295         memcpy(eh->ether_dhost, bstp_etheraddr, ETHER_ADDR_LEN);
 296         eh->ether_type = htons(sizeof(bpdu));
 297
 298         memcpy(mtod(m, caddr_t) + sizeof(*eh), &bpdu, sizeof(bpdu));
 299
 300         bridge_enqueue(ifp, m);
 301 }
 302
 303 static int
 304 bstp_root_bridge(struct bridge_softc *sc)
 305 {
 306         return (sc->sc_designated_root == sc->sc_bridge_id);
 307 }
 308
 309 /*
 310  * Returns TRUE if the recorded information from our peer has a shorter
 311  * graph distance than our current best.
 312  */
 313 int
 314 bstp_supersedes_port_info(struct bridge_softc *sc, struct bridge_iflist *bif)
 315 {
 316         if (bif->bif_peer_root < sc->sc_designated_root)
 317                 return (1);
 318         if (bif->bif_peer_root > sc->sc_designated_root)
 319                 return (0);
 320
 321         /*
 322          * Both bif_peer_cost and sc_designated_cost have NOT added in
 323          * bif->bif_path_cost, so we can optimize it out.
 324          */
 325         if (bif->bif_peer_cost < sc->sc_designated_cost)
 326                 return (1);
 327         if (bif->bif_peer_cost > sc->sc_designated_cost)
 328                 return (0);
 329
 330         if (bif->bif_peer_bridge < sc->sc_designated_bridge)
 331                 return (1);
 332         if (bif->bif_peer_bridge > sc->sc_designated_bridge)
 333                 return (0);
 334
 335         /* bridge_id or bridge+port collision w/peer returns TRUE */
 336         if (bif->bif_peer_bridge != sc->sc_bridge_id)
 337                 return (1);
 338         if (bif->bif_peer_port <= sc->sc_designated_port)
 339                 return (1);
 340         return (0);
 341 }
 342
 343 /*
 344  * The shorter graph distance represented by cu (most of which is also
 345  * already stored in our bif_peer_* fields) becomes the designated info.
 346  *
 347  * NOTE: sc_designated_cost does not include bif_path_cost, it is added
 348  *       in later on a port-by-port basis as needed.
 349  */
 350 static void
 351 bstp_record_config_information(struct bridge_softc *sc,
 352                                struct bridge_iflist *bif,
 353                                struct bstp_config_unit *cu)
 354 {
 355         sc->sc_designated_root = bif->bif_peer_root;
 356         sc->sc_designated_cost = bif->bif_peer_cost;
 357         sc->sc_designated_bridge = bif->bif_peer_bridge;
 358         sc->sc_designated_port = bif->bif_peer_port;
 359         bstp_timer_start(&bif->bif_message_age_timer, cu->cu_message_age);
 360 }
 361
 362 static void
 363 bstp_record_config_timeout_values(struct bridge_softc *sc,
 364                                   struct bstp_config_unit *config)
 365 {
 366         sc->sc_max_age = config->cu_max_age;
 367         sc->sc_hello_time = config->cu_hello_time;
 368         sc->sc_forward_delay = config->cu_forward_delay;
 369         sc->sc_topology_change = config->cu_topology_change;
 370 }
 371
 372 static void
 373 bstp_config_bpdu_generation(struct bridge_softc *sc)
 374 {
 375         struct bridge_iflist *bif, *nbif;
 376
 377         TAILQ_FOREACH_MUTABLE(bif, &sc->sc_iflists[mycpuid], bif_next, nbif) {
 378                 if ((bif->bif_flags & IFBIF_STP) == 0)
 379                         continue;
 380                 if (bif->bif_state != BSTP_IFSTATE_DISABLED &&
 381                     ((sc->sc_ifp->if_flags & IFF_LINK1) ||
 382                      (bif->bif_flags & IFBIF_DESIGNATED))) {
 383                         bstp_transmit_config(sc, bif);
 384                 }
 385
 386                 if (nbif != NULL && !nbif->bif_onlist) {
 387                         KKASSERT(bif->bif_onlist);
 388                         nbif = TAILQ_NEXT(bif, bif_next);
 389                 }
 390         }
 391 }
 392
 393 static void
 394 bstp_transmit_tcn(struct bridge_softc *sc)
 395 {
 396         struct bstp_tbpdu bpdu;
 397         struct ifnet *ifp;
 398         struct ether_header *eh;
 399         struct mbuf *m;
 400
 401         if (sc->sc_root_port == NULL)   /* all iterfaces disabled */
 402                 return;
 403
 404         ifp = sc->sc_root_port->bif_ifp;
 405         if ((ifp->if_flags & IFF_RUNNING) == 0)
 406                 return;
 407
 408         MGETHDR(m, MB_DONTWAIT, MT_DATA);
 409         if (m == NULL)
 410                 return;
 411
 412         m->m_pkthdr.rcvif = ifp;
 413         m->m_pkthdr.len = sizeof(*eh) + sizeof(bpdu);
 414         m->m_len = m->m_pkthdr.len;
 415
 416         eh = mtod(m, struct ether_header *);
 417
 418         /*
 419          * Packets sent from the bridge always use the bridge MAC
 420          * as the source.
 421          */
 422         memcpy(eh->ether_shost, IF_LLADDR(sc->sc_ifp), ETHER_ADDR_LEN);
 423         memcpy(eh->ether_dhost, bstp_etheraddr, ETHER_ADDR_LEN);
 424         eh->ether_type = htons(sizeof(bpdu));
 425
 426         bpdu.tbu_ssap = bpdu.tbu_dsap = LLC_8021D_LSAP;
 427         bpdu.tbu_ctl = LLC_UI;
 428         bpdu.tbu_protoid = 0;
 429         bpdu.tbu_protover = 0;
 430         bpdu.tbu_bpdutype = BSTP_MSGTYPE_TCN;
 431
 432         memcpy(mtod(m, caddr_t) + sizeof(*eh), &bpdu, sizeof(bpdu));
 433
 434         bridge_enqueue(ifp, m);
 435 }
 436
 437 /*
 438  * Recalculate sc->sc_designated* and sc->sc_root_port (if our bridge
 439  * is calculated to be the root bridge).  We do this by initializing
 440  * the designated variables to point at us and then scan our peers.
 441  * Any uninitialized peers will have a max-value root.
 442  *
 443  * Clear IFBIF_DESIGNATED on any ports which no longer match the criteria
 444  * required to be a designated port.  Only aged out ports and the root
 445  * port can be designated.
 446  *
 447  * If we win we do a second scan to determine which port on our bridge
 448  * is the best.
 449  */
 450 static void
 451 bstp_configuration_update(struct bridge_softc *sc)
 452 {
 453         uint64_t        designated_root = sc->sc_bridge_id;
 454         uint64_t        designated_bridge = sc->sc_bridge_id;
 455         uint32_t        designated_cost = 0xFFFFFFFFU;
 456         uint16_t        designated_port = 65535;
 457         struct bridge_iflist *root_port = NULL;
 458         struct bridge_iflist *bif;
 459
 460         /*
 461          * Resolve information from our peers.  Aged peers will have
 462          * a maxed bif_peer_root and not come under consideration.
 463          */
 464         TAILQ_FOREACH(bif, &sc->sc_iflists[mycpuid], bif_next) {
 465                 if ((bif->bif_flags & IFBIF_STP) == 0)
 466                         continue;
 467                 if (bif->bif_state == BSTP_IFSTATE_DISABLED ||
 468                     bif->bif_state == BSTP_IFSTATE_L1BLOCKING) {
 469                         continue;
 470                 }
 471
 472                 if (bif->bif_peer_root > designated_root)
 473                         continue;
 474                 if (bif->bif_peer_root < designated_root)
 475                         goto set_port;
 476
 477                 /*
 478                  * NOTE: The designated_cost temporary variable already added
 479                  *       in the path code of the related root port.
 480                  */
 481                 if (bif->bif_peer_cost + bif->bif_path_cost > designated_cost)
 482                         continue;
 483                 if (bif->bif_peer_cost + bif->bif_path_cost < designated_cost)
 484                         goto set_port;
 485
 486                 if (bif->bif_peer_bridge > designated_bridge)
 487                         continue;
 488                 if (bif->bif_peer_bridge < designated_bridge)
 489                         goto set_port;
 490
 491                 if (bif->bif_peer_port > designated_port)
 492                         continue;
 493                 if (bif->bif_peer_port < designated_port)
 494                         goto set_port;
 495
 496                 /*
 497                  * Same root, path cost, bridge, and port.  Set the root
 498                  * only if we do not already have it.
 499                  */
 500                 if (root_port)
 501                         continue;
 502
 503                 /*
 504                  * New root port (from peers)
 505                  *
 506                  * NOTE: Temporarily add bif_path_cost into the designated
 507                  *       cost to reduce complexity in the loop, it will be
 508                  *       subtracted out when we are done.
 509                  */
 510 set_port:
 511                 designated_root = bif->bif_peer_root;
 512                 designated_cost = bif->bif_peer_cost + bif->bif_path_cost;
 513                 designated_bridge = bif->bif_peer_bridge;
 514                 designated_port = bif->bif_peer_port;
 515                 root_port = bif;
 516         }
 517
 518         /*
 519          * root_port will be NULL at the start here if all of our
 520          * peers are aged or are not as good a root as our bridge would
 521          * be.  It can also be NULL due to all related links being
 522          * disabled.
 523          *
 524          * If the root winds up being our bridge scan again against local
 525          * information.  Unconditionally update IFBIF_DESIGNATED.
 526          */
 527         TAILQ_FOREACH(bif, &sc->sc_iflists[mycpuid], bif_next) {
 528                 bif->bif_flags &= ~(IFBIF_DESIGNATED | IFBIF_ROOT);
 529                 if ((bif->bif_flags & IFBIF_STP) == 0)
 530                         continue;
 531                 if (bif->bif_state == BSTP_IFSTATE_DISABLED ||
 532                     bif->bif_state == BSTP_IFSTATE_L1BLOCKING) {
 533                         continue;
 534                 }
 535
 536                 /*
 537                  * Set DESIGNATED for an aged or unknown peer.
 538                  */
 539                 if (bif->bif_peer_bridge == 0xFFFFFFFFFFFFFFFFLLU)
 540                         bif->bif_flags |= IFBIF_DESIGNATED;
 541                 if (designated_root != sc->sc_bridge_id)
 542                         continue;
 543
 544                 /*
 545                  * This is only reached if our bridge is the root bridge,
 546                  * select the root port (IFBIF_DESIGNATED is set at the
 547                  * end).
 548                  *
 549                  * We do NOT use peer info here.
 550                  */
 551                 if (bif->bif_path_cost > designated_cost)
 552                         continue;
 553                 if (bif->bif_path_cost < designated_cost)
 554                         goto set_port2;
 555
 556                 if (bif->bif_port_id > designated_port)
 557                         continue;
 558                 if (bif->bif_port_id < designated_port)
 559                         goto set_port2;
 560                 /* degenerate case (possible peer collision w/our key */
 561
 562                 /*
 563                  * New port
 564                  */
 565 set_port2:
 566                 designated_cost = bif->bif_path_cost;
 567                 designated_bridge = sc->sc_bridge_id;
 568                 designated_port = bif->bif_port_id;
 569                 root_port = bif;
 570         }
 571
 572         /*
 573          * Update aggregate information.  The selected root port always
 574          * becomes a designated port (along with aged ports).  This can
 575          * either be the port whos peer is closest to the root or it
 576          * can be one of our ports if our bridge is the root.
 577          *
 578          * The root cost we record in sc_designated_root does not include
 579          * bif_path_cost of the root port, since we may transmit this
 580          * out of any port we will add the cost back in later on on
 581          * a per-port basis.
 582          *
 583          * root_port can be NULL here (if all links are disabled)
 584          */
 585         if (root_port) {
 586                 sc->sc_designated_root = designated_root;
 587                 sc->sc_designated_cost = designated_cost -
 588                                          root_port->bif_path_cost;
 589                 sc->sc_designated_bridge = designated_bridge;
 590                 sc->sc_designated_port = designated_port;
 591                 root_port->bif_flags |= IFBIF_DESIGNATED | IFBIF_ROOT;
 592         } else {
 593                 sc->sc_designated_root = designated_root;
 594                 sc->sc_designated_cost = designated_cost;
 595                 sc->sc_designated_bridge = designated_bridge;
 596                 sc->sc_designated_port = designated_port;
 597         }
 598         sc->sc_root_port = root_port;
 599 }
 600
 601 /*
 602  * Calculate the desired state for each interface link on our bridge.
 603  *
 604  * The best port will match against sc->sc_root_port (whether we are root
 605  * or whether that port is the closest to the root).  We push this port
 606  * towards a FORWARDING state.
 607  *
 608  * Next come designated ports, either aged ports or ports with no peer info
 609  * (yet), or the peer who is closest to the root. We push this port towards
 610  * a FORWARDING state as well.
 611  *
 612  * Any remaining ports are pushed towards a BLOCKING state.  Both sides of
 613  * the port (us and our peer) should wind up placing the two ends in this
 614  * state or bad things happen.
 615  */
 616 static void
 617 bstp_port_state_selection(struct bridge_softc *sc)
 618 {
 619         struct bridge_iflist *bif, *nbif;
 620
 621         TAILQ_FOREACH_MUTABLE(bif, &sc->sc_iflists[mycpuid], bif_next, nbif) {
 622                 if ((bif->bif_flags & IFBIF_STP) == 0)
 623                         continue;
 624                 if (sc->sc_root_port &&
 625                     bif->bif_info == sc->sc_root_port->bif_info) {
 626                         bif->bif_config_pending = 0;
 627                         bif->bif_topology_change_acknowledge = 0;
 628                         bstp_make_forwarding(sc, bif);
 629                 } else if (bif->bif_flags & IFBIF_DESIGNATED) {
 630                         bstp_timer_stop(&bif->bif_message_age_timer);
 631                         bstp_make_forwarding(sc, bif);
 632                 } else {
 633                         bif->bif_config_pending = 0;
 634                         bif->bif_topology_change_acknowledge = 0;
 635                         bstp_make_blocking(sc, bif);
 636                 }
 637
 638                 if (nbif != NULL && !nbif->bif_onlist) {
 639                         KKASSERT(bif->bif_onlist);
 640                         nbif = TAILQ_NEXT(bif, bif_next);
 641                 }
 642         }
 643 }
 644
 645 /*
 646  * Clear peer info, effectively makes the port looked aged out.
 647  * It becomes a designated go-to port.
 648  */
 649 static void
 650 bstp_clear_peer_info(struct bridge_softc *sc, struct bridge_iflist *bif)
 651 {
 652         bif->bif_peer_root = 0xFFFFFFFFFFFFFFFFLLU;
 653         bif->bif_peer_cost = 0xFFFFFFFFU;
 654         bif->bif_peer_bridge = 0xFFFFFFFFFFFFFFFFLLU;
 655         bif->bif_peer_port = 0xFFFFU;
 656
 657         if (bif->bif_state != BSTP_IFSTATE_DISABLED &&
 658             bif->bif_state != BSTP_IFSTATE_L1BLOCKING) {
 659                 bif->bif_flags |= IFBIF_DESIGNATED;
 660         }
 661 }
 662
 663 static void
 664 bstp_make_forwarding(struct bridge_softc *sc, struct bridge_iflist *bif)
 665 {
 666         if (bif->bif_state == BSTP_IFSTATE_BLOCKING ||
 667             bif->bif_state == BSTP_IFSTATE_BONDED) {
 668                 bstp_set_port_state(bif, BSTP_IFSTATE_LISTENING);
 669                 bstp_timer_start(&bif->bif_forward_delay_timer, 0);
 670         }
 671 }
 672
 673 static void
 674 bstp_make_blocking(struct bridge_softc *sc, struct bridge_iflist *bif)
 675 {
 676         if (bif->bif_state != BSTP_IFSTATE_DISABLED &&
 677             bif->bif_state != BSTP_IFSTATE_BLOCKING &&
 678             bif->bif_state != BSTP_IFSTATE_BONDED &&
 679             bif->bif_state != BSTP_IFSTATE_L1BLOCKING) {
 680                 if ((bif->bif_state == BSTP_IFSTATE_FORWARDING) ||
 681                     (bif->bif_state == BSTP_IFSTATE_LEARNING)) {
 682                         if (bif->bif_change_detection_enabled) {
 683                                 bstp_topology_change_detection(sc);
 684                         }
 685                 }
 686                 bstp_set_port_state(bif, BSTP_IFSTATE_BLOCKING);
 687                 bridge_rtdelete(sc, bif->bif_ifp, IFBF_FLUSHDYN);
 688                 bstp_timer_stop(&bif->bif_forward_delay_timer);
 689                 if (sc->sc_ifp->if_flags & IFF_LINK2)
 690                         bstp_adjust_bonded_states(sc, bif);
 691         }
 692 }
 693
 694 static void
 695 bstp_make_l1blocking(struct bridge_softc *sc, struct bridge_iflist *bif)
 696 {
 697         int was_forwarding = (bif->bif_state == BSTP_IFSTATE_FORWARDING);
 698
 699         switch(bif->bif_state) {
 700         case BSTP_IFSTATE_LISTENING:
 701         case BSTP_IFSTATE_LEARNING:
 702         case BSTP_IFSTATE_FORWARDING:
 703         case BSTP_IFSTATE_BLOCKING:
 704         case BSTP_IFSTATE_BONDED:
 705                 bstp_set_port_state(bif, BSTP_IFSTATE_L1BLOCKING);
 706                 bridge_rtdelete(sc, bif->bif_ifp, IFBF_FLUSHDYN);
 707                 bstp_timer_stop(&bif->bif_forward_delay_timer);
 708                 bstp_timer_stop(&bif->bif_link1_timer);
 709                 if (bif->bif_flags & IFBIF_DESIGNATED) {
 710                         bif->bif_flags &= ~IFBIF_DESIGNATED;
 711                         bstp_configuration_update(sc);
 712                         bstp_port_state_selection(sc);
 713                 }
 714                 if (was_forwarding && (sc->sc_ifp->if_flags & IFF_LINK2))
 715                         bstp_adjust_bonded_states(sc, bif);
 716                 break;
 717         default:
 718                 break;
 719         }
 720 }
 721
 722 /*
 723  * Member (bif) changes to or from a FORWARDING state.  All members in the
 724  * same bonding group which are in a BLOCKING or BONDED state must be set
 725  * to either BLOCKING or BONDED based on whether any members in the bonding
 726  * group remain in the FORWARDING state.
 727  *
 728  * Going between the BLOCKING and BONDED states does not require a
 729  * configuration update.
 730  */
 731 static void
 732 bstp_adjust_bonded_states(struct bridge_softc *sc, struct bridge_iflist *obif)
 733 {
 734         struct bridge_iflist *bif;
 735         int state = BSTP_IFSTATE_BLOCKING;
 736
 737         TAILQ_FOREACH(bif, &sc->sc_iflists[mycpuid], bif_next) {
 738                 if ((bif->bif_flags & IFBIF_STP) == 0)
 739                         continue;
 740                 if (bif->bif_state != BSTP_IFSTATE_FORWARDING)
 741                         continue;
 742                 if (memcmp(IF_LLADDR(bif->bif_ifp), IF_LLADDR(obif->bif_ifp),
 743                            ETHER_ADDR_LEN) != 0) {
 744                         continue;
 745                 }
 746                 state = BSTP_IFSTATE_BONDED;
 747                 break;
 748         }
 749         TAILQ_FOREACH(bif, &sc->sc_iflists[mycpuid], bif_next) {
 750                 if ((bif->bif_flags & IFBIF_STP) == 0)
 751                         continue;
 752                 if (bif->bif_state != BSTP_IFSTATE_BLOCKING &&
 753                     bif->bif_state != BSTP_IFSTATE_BONDED) {
 754                         continue;
 755                 }
 756                 if (memcmp(IF_LLADDR(bif->bif_ifp), IF_LLADDR(obif->bif_ifp),
 757                            ETHER_ADDR_LEN) != 0) {
 758                         continue;
 759                 }
 760                 if (bif->bif_bond_weight == 0)
 761                         bif->bif_state = BSTP_IFSTATE_BLOCKING;
 762                 else
 763                         bif->bif_state = state;
 764         }
 765 }
 766
 767 static void
 768 bstp_set_port_state(struct bridge_iflist *bif, uint8_t state)
 769 {
 770         bif->bif_state = state;
 771 }
 772
 773 static void
 774 bstp_topology_change_detection(struct bridge_softc *sc)
 775 {
 776         if (bstp_root_bridge(sc)) {
 777                 sc->sc_topology_change = 1;
 778                 bstp_timer_start(&sc->sc_topology_change_timer, 0);
 779         } else if (!sc->sc_topology_change_detected) {
 780                 bstp_transmit_tcn(sc);
 781                 bstp_timer_start(&sc->sc_tcn_timer, 0);
 782         }
 783         sc->sc_topology_change_detected = 1;
 784 }
 785
 786 static void
 787 bstp_topology_change_acknowledged(struct bridge_softc *sc)
 788 {
 789         sc->sc_topology_change_detected = 0;
 790         bstp_timer_stop(&sc->sc_tcn_timer);
 791 }
 792
 793 static void
 794 bstp_acknowledge_topology_change(struct bridge_softc *sc,
 795                                  struct bridge_iflist *bif)
 796 {
 797         bif->bif_topology_change_acknowledge = 1;
 798         bstp_transmit_config(sc, bif);
 799 }
 800
 801 void
 802 bstp_input(struct bridge_softc *sc, struct bridge_iflist *bif, struct mbuf *m)
 803 {
 804         struct ether_header *eh;
 805         struct bstp_tbpdu tpdu;
 806         struct bstp_cbpdu cpdu;
 807         struct bstp_config_unit cu;
 808         struct bstp_tcn_unit tu;
 809         uint16_t len;
 810
 811         if ((bif->bif_flags & IFBIF_STP) == 0)
 812                 goto out;
 813
 814         /*
 815          * The L1BLOCKING (ping pong failover) test needs to reset the
 816          * timer if LINK1 is active.
 817          */
 818         if (bif->bif_state == BSTP_IFSTATE_L1BLOCKING) {
 819                 bstp_set_port_state(bif, BSTP_IFSTATE_BLOCKING);
 820                 if (sc->sc_ifp->if_flags & IFF_LINK1)
 821                         bstp_timer_start(&bif->bif_link1_timer, 0);
 822                 bstp_make_forwarding(sc, bif);
 823         } else if (sc->sc_ifp->if_flags & IFF_LINK1) {
 824                 bstp_timer_start(&bif->bif_link1_timer, 0);
 825         }
 826
 827         eh = mtod(m, struct ether_header *);
 828
 829         len = ntohs(eh->ether_type);
 830         if (len < sizeof(tpdu))
 831                 goto out;
 832
 833         m_adj(m, ETHER_HDR_LEN);
 834
 835         if (m->m_pkthdr.len > len)
 836                 m_adj(m, len - m->m_pkthdr.len);
 837         if (m->m_len < sizeof(tpdu) &&
 838             (m = m_pullup(m, sizeof(tpdu))) == NULL)
 839                 goto out;
 840
 841         memcpy(&tpdu, mtod(m, caddr_t), sizeof(tpdu));
 842
 843         if (tpdu.tbu_dsap != LLC_8021D_LSAP ||
 844             tpdu.tbu_ssap != LLC_8021D_LSAP ||
 845             tpdu.tbu_ctl != LLC_UI)
 846                 goto out;
 847         if (tpdu.tbu_protoid != 0 || tpdu.tbu_protover != 0)
 848                 goto out;
 849
 850         switch (tpdu.tbu_bpdutype) {
 851         case BSTP_MSGTYPE_TCN:
 852                 tu.tu_message_type = tpdu.tbu_bpdutype;
 853                 bstp_received_tcn_bpdu(sc, bif, &tu);
 854                 break;
 855         case BSTP_MSGTYPE_CFG:
 856                 if (m->m_len < sizeof(cpdu) &&
 857                     (m = m_pullup(m, sizeof(cpdu))) == NULL)
 858                         goto out;
 859                 memcpy(&cpdu, mtod(m, caddr_t), sizeof(cpdu));
 860
 861                 cu.cu_rootid =
 862                     (((uint64_t)ntohs(cpdu.cbu_rootpri)) << 48) |
 863                     (((uint64_t)cpdu.cbu_rootaddr[0]) << 40) |
 864                     (((uint64_t)cpdu.cbu_rootaddr[1]) << 32) |
 865                     (((uint64_t)cpdu.cbu_rootaddr[2]) << 24) |
 866                     (((uint64_t)cpdu.cbu_rootaddr[3]) << 16) |
 867                     (((uint64_t)cpdu.cbu_rootaddr[4]) << 8) |
 868                     (((uint64_t)cpdu.cbu_rootaddr[5]) << 0);
 869
 870                 cu.cu_bridge_id =
 871                     (((uint64_t)ntohs(cpdu.cbu_bridgepri)) << 48) |
 872                     (((uint64_t)cpdu.cbu_bridgeaddr[0]) << 40) |
 873                     (((uint64_t)cpdu.cbu_bridgeaddr[1]) << 32) |
 874                     (((uint64_t)cpdu.cbu_bridgeaddr[2]) << 24) |
 875                     (((uint64_t)cpdu.cbu_bridgeaddr[3]) << 16) |
 876                     (((uint64_t)cpdu.cbu_bridgeaddr[4]) << 8) |
 877                     (((uint64_t)cpdu.cbu_bridgeaddr[5]) << 0);
 878
 879                 cu.cu_root_path_cost = ntohl(cpdu.cbu_rootpathcost);
 880                 cu.cu_message_age = ntohs(cpdu.cbu_messageage);
 881                 cu.cu_max_age = ntohs(cpdu.cbu_maxage);
 882                 cu.cu_hello_time = ntohs(cpdu.cbu_hellotime);
 883                 cu.cu_forward_delay = ntohs(cpdu.cbu_forwarddelay);
 884                 cu.cu_port_id = ntohs(cpdu.cbu_portid);
 885                 cu.cu_message_type = cpdu.cbu_bpdutype;
 886                 cu.cu_topology_change_acknowledgment =
 887                     (cpdu.cbu_flags & BSTP_FLAG_TCA) ? 1 : 0;
 888                 cu.cu_topology_change =
 889                     (cpdu.cbu_flags & BSTP_FLAG_TC) ? 1 : 0;
 890                 bstp_received_config_bpdu(sc, bif, &cu);
 891                 break;
 892         default:
 893                 goto out;
 894         }
 895 out:
 896         if (m)
 897                 m_freem(m);
 898 }
 899
 900 static void
 901 bstp_received_config_bpdu(struct bridge_softc *sc, struct bridge_iflist *bif,
 902                           struct bstp_config_unit *cu)
 903 {
 904         int iamroot;
 905
 906         iamroot = bstp_root_bridge(sc);
 907
 908         if (bif->bif_state != BSTP_IFSTATE_DISABLED) {
 909                 /*
 910                  * Record information from peer.  The peer_cost field
 911                  * does not include the local bif->bif_path_cost, it will
 912                  * be added in as needed (since it can be modified manually
 913                  * this way we don't have to worry about fixups).
 914                  */
 915                 bif->bif_peer_root = cu->cu_rootid;
 916                 bif->bif_peer_cost = cu->cu_root_path_cost;
 917                 bif->bif_peer_bridge = cu->cu_bridge_id;
 918                 bif->bif_peer_port = cu->cu_port_id;
 919
 920                 if (bstp_supersedes_port_info(sc, bif)) {
 921                         bstp_record_config_information(sc, bif, cu);
 922                         bstp_configuration_update(sc);
 923                         bstp_port_state_selection(sc);
 924
 925                         /*
 926                          * If our bridge loses its root status (?)
 927                          *
 928                          * Hello's (unsolicited CFG packets) are generated
 929                          * every hello period of LINK1 is set, otherwise
 930                          * we are no longer the root bridge and must stop
 931                          * generating unsolicited CFG packets.
 932                          */
 933                         if (iamroot && bstp_root_bridge(sc) == 0) {
 934                                 if ((sc->sc_ifp->if_flags & IFF_LINK1) == 0)
 935                                         bstp_timer_stop(&sc->sc_hello_timer);
 936
 937                                 if (sc->sc_topology_change_detected) {
 938                                         bstp_timer_stop(
 939                                             &sc->sc_topology_change_timer);
 940                                         bstp_transmit_tcn(sc);
 941                                         bstp_timer_start(&sc->sc_tcn_timer, 0);
 942                                 }
 943                         }
 944
 945                         if (sc->sc_root_port &&
 946                             bif->bif_info == sc->sc_root_port->bif_info) {
 947                                 bstp_record_config_timeout_values(sc, cu);
 948                                 bstp_config_bpdu_generation(sc);
 949
 950                                 if (cu->cu_topology_change_acknowledgment)
 951                                         bstp_topology_change_acknowledged(sc);
 952                         }
 953                 } else if (bif->bif_flags & IFBIF_DESIGNATED) {
 954                         /*
 955                          * Update designated ports (aged out peers or
 956                          * the port closest to the root) at a faster pace.
 957                          *
 958                          * Clear our designated flag if we aren't marked
 959                          * as the root port.
 960                          */
 961                         bstp_transmit_config(sc, bif);
 962                         if ((bif->bif_flags & IFBIF_ROOT) == 0) {
 963                                 bif->bif_flags &= ~IFBIF_DESIGNATED;
 964                                 bstp_configuration_update(sc);
 965                                 bstp_port_state_selection(sc);
 966                         }
 967                 }
 968         }
 969 }
 970
 971 static void
 972 bstp_received_tcn_bpdu(struct bridge_softc *sc, struct bridge_iflist *bif,
 973                        struct bstp_tcn_unit *tcn)
 974 {
 975         if (bif->bif_state != BSTP_IFSTATE_DISABLED &&
 976             (bif->bif_flags & IFBIF_DESIGNATED)) {
 977                 bstp_topology_change_detection(sc);
 978                 bstp_acknowledge_topology_change(sc, bif);
 979         }
 980 }
 981
 982 /*
 983  * link1 forces continuous hello's (the bridge interface must be cycled
 984  * to start them up), so keep the timer hot if that is the case, otherwise
 985  * only send HELLO's if we are the root.
 986  */
 987 static void
 988 bstp_hello_timer_expiry(struct bridge_softc *sc)
 989 {
 990         bstp_config_bpdu_generation(sc);
 991
 992         if ((sc->sc_ifp->if_flags & IFF_LINK1) || bstp_root_bridge(sc))
 993                 bstp_timer_start(&sc->sc_hello_timer, 0);
 994 }
 995
 996 static void
 997 bstp_message_age_timer_expiry(struct bridge_softc *sc,
 998                               struct bridge_iflist *bif)
 999 {
1000         int iamroot;
1001
1002         iamroot = bstp_root_bridge(sc);
1003         bstp_clear_peer_info(sc, bif);
1004         bstp_configuration_update(sc);
1005         bstp_port_state_selection(sc);
1006
1007         /*
1008          * If we've become the root and were not the root before
1009          * we have some cleanup to do.  This also occurs if we
1010          * wind up being completely isolated.
1011          */
1012         if (iamroot == 0 && bstp_root_bridge(sc)) {
1013                 sc->sc_max_age = sc->sc_bridge_max_age;
1014                 sc->sc_hello_time = sc->sc_bridge_hello_time;
1015                 sc->sc_forward_delay = sc->sc_bridge_forward_delay;
1016
1017                 bstp_topology_change_detection(sc);
1018                 bstp_timer_stop(&sc->sc_tcn_timer);
1019                 bstp_config_bpdu_generation(sc);
1020                 bstp_timer_start(&sc->sc_hello_timer, 0);
1021         }
1022 }
1023
1024 static void
1025 bstp_forward_delay_timer_expiry(struct bridge_softc *sc,
1026                                 struct bridge_iflist *bif)
1027 {
1028         if (bif->bif_state == BSTP_IFSTATE_LISTENING) {
1029                 bstp_set_port_state(bif, BSTP_IFSTATE_LEARNING);
1030                 bstp_timer_start(&bif->bif_forward_delay_timer, 0);
1031         } else if (bif->bif_state == BSTP_IFSTATE_LEARNING) {
1032                 bstp_set_port_state(bif, BSTP_IFSTATE_FORWARDING);
1033                 if (sc->sc_designated_bridge == sc->sc_bridge_id &&
1034                     bif->bif_change_detection_enabled) {
1035                         bstp_topology_change_detection(sc);
1036                 }
1037                 if (sc->sc_ifp->if_flags & IFF_LINK2)
1038                         bstp_adjust_bonded_states(sc, bif);
1039         }
1040 }
1041
1042 static void
1043 bstp_tcn_timer_expiry(struct bridge_softc *sc)
1044 {
1045         bstp_transmit_tcn(sc);
1046         bstp_timer_start(&sc->sc_tcn_timer, 0);
1047 }
1048
1049 static void
1050 bstp_topology_change_timer_expiry(struct bridge_softc *sc)
1051 {
1052         sc->sc_topology_change_detected = 0;
1053         sc->sc_topology_change = 0;
1054 }
1055
1056 static void
1057 bstp_hold_timer_expiry(struct bridge_softc *sc, struct bridge_iflist *bif)
1058 {
1059         if (bif->bif_config_pending)
1060                 bstp_transmit_config(sc, bif);
1061 }
1062
1063 /*
1064  * If no traffic received directly on this port for the specified
1065  * period with link1 set we go into a special blocking mode to
1066  * fail-over traffic to another port.
1067  */
1068 static void
1069 bstp_link1_timer_expiry(struct bridge_softc *sc, struct bridge_iflist *bif)
1070 {
1071         if (sc->sc_ifp->if_flags & IFF_LINK1)
1072                 bstp_make_l1blocking(sc, bif);
1073 }
1074
1075 static int
1076 bstp_addr_cmp(const uint8_t *a, const uint8_t *b)
1077 {
1078         int i, d;
1079
1080         for (i = 0, d = 0; i < ETHER_ADDR_LEN && d == 0; i++) {
1081                 d = ((int)a[i]) - ((int)b[i]);
1082         }
1083
1084         return (d);
1085 }
1086
1087 void
1088 bstp_initialization(struct bridge_softc *sc)
1089 {
1090         struct bridge_iflist *bif, *mif, *nbif;
1091         u_char *e_addr;
1092
1093         KKASSERT(&curthread->td_msgport == BRIDGE_CFGPORT);
1094
1095         /*
1096          * Figure out our bridge ID, use the lowest-valued MAC.
1097          * Include the bridge's own random MAC in the calculation.
1098          */
1099         mif = NULL;
1100
1101         TAILQ_FOREACH(bif, &sc->sc_iflists[mycpuid], bif_next) {
1102                 if ((bif->bif_flags & IFBIF_STP) == 0)
1103                         continue;
1104                 if (bif->bif_ifp->if_type != IFT_ETHER)
1105                         continue;
1106                 if (mif == NULL) {
1107                         mif = bif;
1108                         continue;
1109                 }
1110
1111                 bif->bif_port_id = (bif->bif_priority << 8) |
1112                                    (bif->bif_ifp->if_index & 0xff);
1113                 if (bstp_addr_cmp(IF_LLADDR(bif->bif_ifp),
1114                                   IF_LLADDR(mif->bif_ifp)) < 0) {
1115                         mif = bif;
1116                         continue;
1117                 }
1118         }
1119         if (mif == NULL) {
1120                 bstp_stop(sc);
1121                 return;
1122         }
1123
1124         if (bstp_addr_cmp(IF_LLADDR(sc->sc_ifp), IF_LLADDR(mif->bif_ifp)) < 0)
1125                 e_addr = IF_LLADDR(sc->sc_ifp);
1126         else
1127                 e_addr = IF_LLADDR(mif->bif_ifp);
1128
1129         sc->sc_bridge_id =
1130             (((uint64_t)sc->sc_bridge_priority) << 48) |
1131             (((uint64_t)e_addr[0]) << 40) |
1132             (((uint64_t)e_addr[1]) << 32) |
1133             (((uint64_t)e_addr[2]) << 24) |
1134             (((uint64_t)e_addr[3]) << 16) |
1135             (((uint64_t)e_addr[4]) << 8) |
1136             (((uint64_t)e_addr[5]));
1137
1138         /*
1139          * Remainder of setup.
1140          */
1141
1142         sc->sc_designated_root = sc->sc_bridge_id;
1143         sc->sc_designated_cost = 0;
1144         sc->sc_root_port = NULL;
1145
1146         sc->sc_max_age = sc->sc_bridge_max_age;
1147         sc->sc_hello_time = sc->sc_bridge_hello_time;
1148         sc->sc_forward_delay = sc->sc_bridge_forward_delay;
1149         sc->sc_topology_change_detected = 0;
1150         sc->sc_topology_change = 0;
1151         bstp_timer_stop(&sc->sc_tcn_timer);
1152         bstp_timer_stop(&sc->sc_topology_change_timer);
1153
1154         if (callout_pending(&sc->sc_bstpcallout) == 0)
1155                 callout_reset(&sc->sc_bstpcallout, hz,
1156                     bstp_tick, sc);
1157
1158         TAILQ_FOREACH_MUTABLE(bif, &sc->sc_iflists[mycpuid], bif_next, nbif) {
1159                 if (sc->sc_ifp->if_flags & IFF_LINK1)
1160                         bstp_timer_start(&bif->bif_link1_timer, 0);
1161                 if (bif->bif_flags & IFBIF_STP)
1162                         bstp_ifupdstatus(sc, bif);
1163                 else
1164                         bstp_disable_port(sc, bif);
1165
1166                 if (nbif != NULL && !nbif->bif_onlist) {
1167                         KKASSERT(bif->bif_onlist);
1168                         nbif = TAILQ_NEXT(bif, bif_next);
1169                 }
1170         }
1171
1172         bstp_port_state_selection(sc);
1173         bstp_config_bpdu_generation(sc);
1174         bstp_timer_start(&sc->sc_hello_timer, 0);
1175 }
1176
1177 void
1178 bstp_stop(struct bridge_softc *sc)
1179 {
1180         struct bridge_iflist *bif;
1181         struct lwkt_msg *lmsg;
1182
1183         KKASSERT(&curthread->td_msgport == BRIDGE_CFGPORT);
1184
1185         TAILQ_FOREACH(bif, &sc->sc_iflists[mycpuid], bif_next) {
1186                 bstp_set_port_state(bif, BSTP_IFSTATE_DISABLED);
1187                 bstp_timer_stop(&bif->bif_hold_timer);
1188                 bstp_timer_stop(&bif->bif_message_age_timer);
1189                 bstp_timer_stop(&bif->bif_forward_delay_timer);
1190                 bstp_timer_stop(&bif->bif_link1_timer);
1191         }
1192
1193         callout_stop(&sc->sc_bstpcallout);
1194
1195         bstp_timer_stop(&sc->sc_topology_change_timer);
1196         bstp_timer_stop(&sc->sc_tcn_timer);
1197         bstp_timer_stop(&sc->sc_hello_timer);
1198
1199         crit_enter();
1200         lmsg = &sc->sc_bstptimemsg.lmsg;
1201         if ((lmsg->ms_flags & MSGF_DONE) == 0) {
1202                 /* Pending to be processed; drop it */
1203                 lwkt_dropmsg(lmsg);
1204         }
1205         crit_exit();
1206 }
1207
1208 static void
1209 bstp_initialize_port(struct bridge_softc *sc, struct bridge_iflist *bif)
1210 {
1211         int needs_adjust = (bif->bif_state == BSTP_IFSTATE_FORWARDING ||
1212                             bif->bif_state == BSTP_IFSTATE_BLOCKING ||
1213                             bif->bif_state == BSTP_IFSTATE_BONDED);
1214
1215         bstp_set_port_state(bif, BSTP_IFSTATE_BLOCKING);
1216         bstp_clear_peer_info(sc, bif);
1217         bif->bif_topology_change_acknowledge = 0;
1218         bif->bif_config_pending = 0;
1219         bif->bif_change_detection_enabled = 1;
1220         bstp_timer_stop(&bif->bif_message_age_timer);
1221         bstp_timer_stop(&bif->bif_forward_delay_timer);
1222         bstp_timer_stop(&bif->bif_hold_timer);
1223         bstp_timer_stop(&bif->bif_link1_timer);
1224         if (needs_adjust && (sc->sc_ifp->if_flags & IFF_LINK2))
1225                 bstp_adjust_bonded_states(sc, bif);
1226 }
1227
1228 static void
1229 bstp_enable_port(struct bridge_softc *sc, struct bridge_iflist *bif)
1230 {
1231         bstp_initialize_port(sc, bif);
1232         if (sc->sc_ifp->if_flags & IFF_LINK1)
1233                 bstp_timer_start(&bif->bif_link1_timer, 0);
1234         bstp_port_state_selection(sc);
1235 }
1236
1237 static void
1238 bstp_disable_port(struct bridge_softc *sc, struct bridge_iflist *bif)
1239 {
1240         int was_forwarding = (bif->bif_state == BSTP_IFSTATE_FORWARDING);
1241         int iamroot;
1242
1243         iamroot = bstp_root_bridge(sc);
1244
1245         bstp_clear_peer_info(sc, bif);
1246         bstp_set_port_state(bif, BSTP_IFSTATE_DISABLED);
1247         bif->bif_topology_change_acknowledge = 0;
1248         bif->bif_config_pending = 0;
1249         bstp_timer_stop(&bif->bif_message_age_timer);
1250         bstp_timer_stop(&bif->bif_forward_delay_timer);
1251         bstp_timer_stop(&bif->bif_link1_timer);
1252         bstp_configuration_update(sc);
1253         bstp_port_state_selection(sc);
1254         bridge_rtdelete(sc, bif->bif_ifp, IFBF_FLUSHDYN);
1255         if (was_forwarding && (sc->sc_ifp->if_flags & IFF_LINK2))
1256                 bstp_adjust_bonded_states(sc, bif);
1257
1258         if (iamroot == 0 && bstp_root_bridge(sc)) {
1259                 sc->sc_max_age = sc->sc_bridge_max_age;
1260                 sc->sc_hello_time = sc->sc_bridge_hello_time;
1261                 sc->sc_forward_delay = sc->sc_bridge_forward_delay;
1262
1263                 bstp_topology_change_detection(sc);
1264                 bstp_timer_stop(&sc->sc_tcn_timer);
1265                 bstp_config_bpdu_generation(sc);
1266                 bstp_timer_start(&sc->sc_hello_timer, 0);
1267         }
1268 }
1269
1270 void
1271 bstp_linkstate(struct ifnet *ifp, int state)
1272 {
1273         struct bridge_softc *sc;
1274         struct bridge_iflist *bif;
1275
1276         sc = ifp->if_bridge;
1277         ifnet_serialize_all(sc->sc_ifp);
1278
1279         /*
1280          * bstp_ifupdstatus() may block, but it is the last
1281          * operation of the member iface iteration, so we
1282          * don't need to use LIST_FOREACH_MUTABLE()+bif_onlist
1283          * check here.
1284          */
1285         TAILQ_FOREACH(bif, &sc->sc_iflists[mycpuid], bif_next) {
1286                 if ((bif->bif_flags & IFBIF_STP) == 0)
1287                         continue;
1288
1289                 if (bif->bif_ifp == ifp) {
1290                         bstp_ifupdstatus(sc, bif);
1291                         break;
1292                 }
1293         }
1294         ifnet_deserialize_all(sc->sc_ifp);
1295 }
1296
1297 static void
1298 bstp_ifupdstatus(struct bridge_softc *sc, struct bridge_iflist *bif)
1299 {
1300         struct ifnet *ifp = bif->bif_ifp;
1301         struct ifmediareq ifmr;
1302         int error = 0;
1303
1304         bzero((char *)&ifmr, sizeof(ifmr));
1305         ifnet_serialize_all(ifp);
1306         error = (*ifp->if_ioctl)(ifp, SIOCGIFMEDIA, (caddr_t)&ifmr, NULL);
1307         ifnet_deserialize_all(ifp);
1308
1309         if ((error == 0) && (ifp->if_flags & IFF_UP)) {
1310                 if (ifmr.ifm_status & IFM_ACTIVE) {
1311                         if (bif->bif_state == BSTP_IFSTATE_DISABLED)
1312                                 bstp_enable_port(sc, bif);
1313
1314                 } else {
1315                         if (bif->bif_state != BSTP_IFSTATE_DISABLED)
1316                                 bstp_disable_port(sc, bif);
1317                 }
1318                 return;
1319         }
1320
1321         if (bif->bif_state != BSTP_IFSTATE_DISABLED)
1322                 bstp_disable_port(sc, bif);
1323 }
1324
1325 static void
1326 bstp_tick(void *arg)
1327 {
1328         struct bridge_softc *sc = arg;
1329         struct lwkt_msg *lmsg;
1330
1331         KKASSERT(mycpuid == BRIDGE_CFGCPU);
1332
1333         crit_enter();
1334
1335         if (callout_pending(&sc->sc_bstpcallout) ||
1336             !callout_active(&sc->sc_bstpcallout)) {
1337                 crit_exit();
1338                 return;
1339         }
1340         callout_deactivate(&sc->sc_bstpcallout);
1341
1342         lmsg = &sc->sc_bstptimemsg.lmsg;
1343         KKASSERT(lmsg->ms_flags & MSGF_DONE);
1344         lwkt_sendmsg(BRIDGE_CFGPORT, lmsg);
1345
1346         crit_exit();
1347 }
1348
1349 void
1350 bstp_tick_handler(netmsg_t msg)
1351 {
1352         struct bridge_softc *sc = msg->lmsg.u.ms_resultp;
1353         struct bridge_iflist *bif;
1354
1355         KKASSERT(&curthread->td_msgport == BRIDGE_CFGPORT);
1356         crit_enter();
1357         /* Reply ASAP */
1358         lwkt_replymsg(&msg->lmsg, 0);
1359         crit_exit();
1360
1361         ifnet_serialize_all(sc->sc_ifp);
1362
1363         /*
1364          * NOTE:
1365          * We don't need to worry that member iface is ripped
1366          * from the per-cpu list during the blocking operation
1367          * in the loop body, since deletion is serialized by
1368          * BRIDGE_CFGPORT
1369          */
1370
1371         TAILQ_FOREACH(bif, &sc->sc_iflists[mycpuid], bif_next) {
1372                 if ((bif->bif_flags & IFBIF_STP) == 0)
1373                         continue;
1374                 /*
1375                  * XXX This can cause a lag in "link does away"
1376                  * XXX and "spanning tree gets updated".  We need
1377                  * XXX come sort of callback from the link state
1378                  * XXX update code to kick spanning tree.
1379                  * XXX --thorpej@NetBSD.org
1380                  */
1381                 bstp_ifupdstatus(sc, bif);
1382         }
1383
1384         if (bstp_timer_expired(&sc->sc_hello_timer, sc->sc_hello_time))
1385                 bstp_hello_timer_expiry(sc);
1386
1387         if (bstp_timer_expired(&sc->sc_tcn_timer, sc->sc_bridge_hello_time))
1388                 bstp_tcn_timer_expiry(sc);
1389
1390         if (bstp_timer_expired(&sc->sc_topology_change_timer,
1391             sc->sc_topology_change_time))
1392                 bstp_topology_change_timer_expiry(sc);
1393
1394         TAILQ_FOREACH(bif, &sc->sc_iflists[mycpuid], bif_next) {
1395                 if ((bif->bif_flags & IFBIF_STP) == 0)
1396                         continue;
1397                 if (bstp_timer_expired(&bif->bif_message_age_timer,
1398                     sc->sc_max_age))
1399                         bstp_message_age_timer_expiry(sc, bif);
1400         }
1401
1402         TAILQ_FOREACH(bif, &sc->sc_iflists[mycpuid], bif_next) {
1403                 if ((bif->bif_flags & IFBIF_STP) == 0)
1404                         continue;
1405                 if (bstp_timer_expired(&bif->bif_forward_delay_timer,
1406                     sc->sc_forward_delay))
1407                         bstp_forward_delay_timer_expiry(sc, bif);
1408
1409                 if (bstp_timer_expired(&bif->bif_hold_timer,
1410                     sc->sc_hold_time))
1411                         bstp_hold_timer_expiry(sc, bif);
1412
1413                 if (bstp_timer_expired(&bif->bif_link1_timer,
1414                     sc->sc_hello_time * 10))
1415                         bstp_link1_timer_expiry(sc, bif);
1416         }
1417
1418         if (sc->sc_ifp->if_flags & IFF_RUNNING)
1419                 callout_reset(&sc->sc_bstpcallout, hz, bstp_tick, sc);
1420
1421         ifnet_deserialize_all(sc->sc_ifp);
1422 }
1423
1424 static void
1425 bstp_timer_start(struct bridge_timer *t, uint16_t v)
1426 {
1427         t->value = v;
1428         t->active = 1;
1429 }
1430
1431 static void
1432 bstp_timer_stop(struct bridge_timer *t)
1433 {
1434         t->value = 0;
1435         t->active = 0;
1436 }
1437
1438 static int
1439 bstp_timer_expired(struct bridge_timer *t, uint16_t v)
1440 {
1441         if (t->active == 0)
1442                 return (0);
1443         t->value += BSTP_TICK_VAL;
1444         if (t->value >= v) {
1445                 bstp_timer_stop(t);
1446                 return (1);
1447         }
1448         return (0);
1449
1450 }