lib/rstp.c

   1 /*
   2  * Copyright (c) 2011-2014 M3S, Srl - Italy
   3  *
   4  * Licensed under the Apache License, Version 2.0 (the "License");
   5  * you may not use this file except in compliance with the License.
   6  * You may obtain a copy of the License at:
   7  *
   8  *     http://www.apache.org/licenses/LICENSE-2.0
   9  *
  10  * Unless required by applicable law or agreed to in writing, software
  11  * distributed under the License is distributed on an "AS IS" BASIS,
  12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  13  * See the License for the specific language governing permissions and
  14  * limitations under the License.
  15  */
  16
  17 /*
  18  * Rapid Spanning Tree Protocol (IEEE 802.1D-2004) public interface.
  19  *
  20  * Authors:
  21  *         Martino Fornasa <mf@fornasa.it>
  22  *         Daniele Venturino <daniele.venturino@m3s.it>
  23  *
  24  * References to IEEE 802.1D-2004 standard are enclosed in square brackets.
  25  * E.g. [17.3], [Table 17-1], etc.
  26  *
  27  */
  28
  29 #include <config.h>
  30
  31 #include "rstp.h"
  32 #include "rstp-common.h"
  33 #include "rstp-state-machines.h"
  34 #include <arpa/inet.h>
  35 #include <inttypes.h>
  36 #include <netinet/in.h>
  37 #include <stdlib.h>
  38 #include <sys/types.h>
  39 #include "byte-order.h"
  40 #include "connectivity.h"
  41 #include "ofpbuf.h"
  42 #include "ofproto/ofproto.h"
  43 #include "packets.h"
  44 #include "seq.h"
  45 #include "unixctl.h"
  46 #include "util.h"
  47 #include "vlog.h"
  48
  49 VLOG_DEFINE_THIS_MODULE(rstp);
  50
  51 struct ovs_mutex rstp_mutex = OVS_MUTEX_INITIALIZER;
  52
  53 static struct list all_rstps__ = LIST_INITIALIZER(&all_rstps__);
  54 static struct list *const all_rstps OVS_GUARDED_BY(rstp_mutex) = &all_rstps__;
  55
  56 /* Internal use only. */
  57 static void rstp_set_bridge_address__(struct rstp *, rstp_identifier)
  58     OVS_REQUIRES(rstp_mutex);
  59 static void rstp_set_bridge_priority__(struct rstp *, int new_priority)
  60     OVS_REQUIRES(rstp_mutex);
  61 static void rstp_set_bridge_ageing_time__(struct rstp *, int new_ageing_time)
  62     OVS_REQUIRES(rstp_mutex);
  63 static void rstp_set_bridge_force_protocol_version__(struct rstp *,
  64                                                      enum rstp_force_protocol_version)
  65     OVS_REQUIRES(rstp_mutex);
  66 static void rstp_set_bridge_hello_time__(struct rstp *)
  67     OVS_REQUIRES(rstp_mutex);
  68 static void rstp_set_bridge_max_age__(struct rstp *, int new_max_age)
  69     OVS_REQUIRES(rstp_mutex);
  70 static void rstp_set_bridge_forward_delay__(struct rstp *, int new_forward_delay)
  71     OVS_REQUIRES(rstp_mutex);
  72 static void rstp_set_bridge_transmit_hold_count__(struct rstp *,
  73                                                   int new_transmit_hold_count)
  74     OVS_REQUIRES(rstp_mutex);
  75 static void rstp_set_bridge_migrate_time__(struct rstp *)
  76     OVS_REQUIRES(rstp_mutex);
  77 static void rstp_set_bridge_times__(struct rstp *, int new_forward_delay,
  78                                     int new_hello_time, int new_max_age,
  79                                     int new_message_age)
  80     OVS_REQUIRES(rstp_mutex);
  81
  82 static struct rstp_port *rstp_get_port__(struct rstp *rstp,
  83                                          uint16_t port_number)
  84     OVS_REQUIRES(rstp_mutex);
  85 static void set_port_id__(struct rstp_port *)
  86     OVS_REQUIRES(rstp_mutex);
  87 static void update_port_enabled__(struct rstp_port *)
  88     OVS_REQUIRES(rstp_mutex);
  89 static void set_bridge_priority__(struct rstp *)
  90     OVS_REQUIRES(rstp_mutex);
  91 static void reinitialize_rstp__(struct rstp *)
  92     OVS_REQUIRES(rstp_mutex);
  93 static bool is_port_number_available__(struct rstp *, int, struct rstp_port *)
  94     OVS_REQUIRES(rstp_mutex);
  95 static uint16_t rstp_first_free_number__(struct rstp *, struct rstp_port *)
  96     OVS_REQUIRES(rstp_mutex);
  97 static void rstp_initialize_port_defaults__(struct rstp_port *)
  98     OVS_REQUIRES(rstp_mutex);
  99 static void rstp_port_set_priority__(struct rstp_port *, int priority)
 100     OVS_REQUIRES(rstp_mutex);
 101 static void rstp_port_set_port_number__(struct rstp_port *,
 102                                         uint16_t port_number)
 103     OVS_REQUIRES(rstp_mutex);
 104 static void rstp_port_set_path_cost__(struct rstp_port *, uint32_t path_cost)
 105     OVS_REQUIRES(rstp_mutex);
 106 static void rstp_port_set_administrative_bridge_port__(struct rstp_port *,
 107                                                        uint8_t admin_port_state)
 108     OVS_REQUIRES(rstp_mutex);
 109 static void rstp_port_set_admin_edge__(struct rstp_port *, bool admin_edge)
 110     OVS_REQUIRES(rstp_mutex);
 111 static void rstp_port_set_auto_edge__(struct rstp_port *, bool auto_edge)
 112     OVS_REQUIRES(rstp_mutex);
 113 static void rstp_port_set_mcheck__(struct rstp_port *, bool mcheck)
 114     OVS_REQUIRES(rstp_mutex);
 115 static void reinitialize_port__(struct rstp_port *p)
 116     OVS_REQUIRES(rstp_mutex);
 117
 118 const char *
 119 rstp_state_name(enum rstp_state state)
 120 {
 121     switch (state) {
 122     case RSTP_DISABLED:
 123         return "Disabled";
 124     case RSTP_LEARNING:
 125         return "Learning";
 126     case RSTP_FORWARDING:
 127         return "Forwarding";
 128     case RSTP_DISCARDING:
 129         return "Discarding";
 130     default:
 131         return "Unknown";
 132     }
 133 }
 134
 135 const char *
 136 rstp_port_role_name(enum rstp_port_role role)
 137 {
 138     switch (role) {
 139     case ROLE_ROOT:
 140         return "Root";
 141     case ROLE_DESIGNATED:
 142         return "Designated";
 143     case ROLE_ALTERNATE:
 144         return "Alternate";
 145     case ROLE_BACKUP:
 146         return "Backup";
 147     case ROLE_DISABLED:
 148         return "Disabled";
 149     default:
 150         return "Unknown";
 151     }
 152 }
 153
 154 /* Caller has to hold a reference to prevent 'rstp' from being deleted
 155  * while taking a new reference. */
 156 struct rstp *
 157 rstp_ref(struct rstp *rstp)
 158     OVS_EXCLUDED(rstp_mutex)
 159 {
 160     if (rstp) {
 161         ovs_refcount_ref(&rstp->ref_cnt);
 162     }
 163     return rstp;
 164 }
 165
 166 /* Frees RSTP struct when reference count reaches zero. */
 167 void
 168 rstp_unref(struct rstp *rstp)
 169     OVS_EXCLUDED(rstp_mutex)
 170 {
 171     if (rstp && ovs_refcount_unref(&rstp->ref_cnt) == 1) {
 172         ovs_mutex_lock(&rstp_mutex);
 173
 174         /* Each RSTP port points back to struct rstp without holding a
 175          * reference for that pointer.  This is OK as we never move
 176          * ports from one bridge to another, and holders always
 177          * release their ports before releasing the bridge.  This
 178          * means that there should be not ports at this time. */
 179         ovs_assert(rstp->ports_count == 0);
 180
 181         list_remove(&rstp->node);
 182         ovs_mutex_unlock(&rstp_mutex);
 183         free(rstp->name);
 184         free(rstp);
 185     }
 186 }
 187
 188 /* Returns the port number.  Mutex is needed to guard against
 189  * concurrent reinitialization (which can temporarily clear the
 190  * port_number). */
 191 int
 192 rstp_port_get_number(const struct rstp_port *p)
 193     OVS_EXCLUDED(rstp_mutex)
 194 {
 195     int number;
 196
 197     ovs_mutex_lock(&rstp_mutex);
 198     number = p->port_number;
 199     ovs_mutex_unlock(&rstp_mutex);
 200
 201     return number;
 202 }
 203
 204 static void rstp_unixctl_tcn(struct unixctl_conn *, int argc,
 205                              const char *argv[], void *aux);
 206
 207 /* Decrements the State Machines' timers. */
 208 void
 209 rstp_tick_timers(struct rstp *rstp)
 210     OVS_EXCLUDED(rstp_mutex)
 211 {
 212     ovs_mutex_lock(&rstp_mutex);
 213     decrease_rstp_port_timers__(rstp);
 214     ovs_mutex_unlock(&rstp_mutex);
 215 }
 216
 217 /* Processes an incoming BPDU. */
 218 void
 219 rstp_port_received_bpdu(struct rstp_port *rp, const void *bpdu,
 220                         size_t bpdu_size)
 221     OVS_EXCLUDED(rstp_mutex)
 222 {
 223     ovs_mutex_lock(&rstp_mutex);
 224     /* Only process packets on ports that have RSTP enabled. */
 225     if (rp && rp->rstp_state != RSTP_DISABLED) {
 226         process_received_bpdu__(rp, bpdu, bpdu_size);
 227     }
 228     ovs_mutex_unlock(&rstp_mutex);
 229 }
 230
 231 void
 232 rstp_init(void)
 233     OVS_EXCLUDED(rstp_mutex)
 234 {
 235     unixctl_command_register("rstp/tcn", "[bridge]", 0, 1, rstp_unixctl_tcn,
 236                              NULL);
 237 }
 238
 239 /* Creates and returns a new RSTP instance that initially has no ports. */
 240 struct rstp *
 241 rstp_create(const char *name, rstp_identifier bridge_address,
 242             void (*send_bpdu)(struct ofpbuf *bpdu, void *port_aux,
 243                               void *rstp_aux),
 244             void *aux)
 245     OVS_EXCLUDED(rstp_mutex)
 246 {
 247     struct rstp *rstp;
 248
 249     VLOG_DBG("Creating RSTP instance");
 250
 251     rstp = xzalloc(sizeof *rstp);
 252     rstp->name = xstrdup(name);
 253
 254     ovs_mutex_lock(&rstp_mutex);
 255     /* Set bridge address. */
 256     rstp_set_bridge_address__(rstp, bridge_address);
 257     /* Set default parameters values. */
 258     rstp_set_bridge_priority__(rstp, RSTP_DEFAULT_PRIORITY);
 259     rstp_set_bridge_ageing_time__(rstp, RSTP_DEFAULT_AGEING_TIME);
 260     rstp_set_bridge_force_protocol_version__(rstp, FPV_DEFAULT);
 261     rstp_set_bridge_forward_delay__(rstp, RSTP_DEFAULT_BRIDGE_FORWARD_DELAY);
 262     rstp_set_bridge_hello_time__(rstp);
 263     rstp_set_bridge_max_age__(rstp, RSTP_DEFAULT_BRIDGE_MAX_AGE);
 264     rstp_set_bridge_migrate_time__(rstp);
 265     rstp_set_bridge_transmit_hold_count__(rstp,
 266                                           RSTP_DEFAULT_TRANSMIT_HOLD_COUNT);
 267     rstp_set_bridge_times__(rstp, RSTP_DEFAULT_BRIDGE_FORWARD_DELAY,
 268                             RSTP_BRIDGE_HELLO_TIME,
 269                             RSTP_DEFAULT_BRIDGE_MAX_AGE, 0);
 270     rstp->send_bpdu = send_bpdu;
 271     rstp->aux = aux;
 272     rstp->changes = false;
 273     rstp->begin = true;
 274
 275     /* Initialize the ports list. */
 276     list_init(&rstp->ports);
 277     ovs_refcount_init(&rstp->ref_cnt);
 278
 279     list_push_back(all_rstps, &rstp->node);
 280     ovs_mutex_unlock(&rstp_mutex);
 281
 282     VLOG_DBG("RSTP instance creation done");
 283     return rstp;
 284 }
 285
 286 /* Called by rstp_set_bridge_address() and rstp_set_bridge_priority(),
 287  * it updates the bridge priority vector according to the values passed by
 288  * those setters.
 289  */
 290 static void
 291 set_bridge_priority__(struct rstp *rstp)
 292     OVS_REQUIRES(rstp_mutex)
 293 {
 294     rstp->bridge_priority.root_bridge_id = rstp->bridge_identifier;
 295     rstp->bridge_priority.designated_bridge_id = rstp->bridge_identifier;
 296     VLOG_DBG("%s: new bridge identifier: "RSTP_ID_FMT"", rstp->name,
 297              RSTP_ID_ARGS(rstp->bridge_identifier));
 298
 299     /* [17.13] When the bridge address changes, recalculates all priority
 300      * vectors.
 301      */
 302     if (rstp->ports_count > 0) {
 303         struct rstp_port *p;
 304
 305         LIST_FOR_EACH (p, node, &rstp->ports) {
 306             p->selected = false;
 307             p->reselect = true;
 308         }
 309     }
 310     rstp->changes = true;
 311     updt_roles_tree__(rstp);
 312 }
 313
 314 /* Sets the bridge address. */
 315 static void
 316 rstp_set_bridge_address__(struct rstp *rstp, rstp_identifier bridge_address)
 317     OVS_REQUIRES(rstp_mutex)
 318 {
 319     VLOG_DBG("%s: set bridge address to: "RSTP_ID_FMT"", rstp->name,
 320              RSTP_ID_ARGS(bridge_address));
 321
 322     rstp->address = bridge_address;
 323     rstp->bridge_identifier = bridge_address;
 324     set_bridge_priority__(rstp);
 325 }
 326
 327 /* Sets the bridge address. */
 328 void
 329 rstp_set_bridge_address(struct rstp *rstp, rstp_identifier bridge_address)
 330     OVS_EXCLUDED(rstp_mutex)
 331 {
 332     ovs_mutex_lock(&rstp_mutex);
 333     rstp_set_bridge_address__(rstp, bridge_address);
 334     ovs_mutex_unlock(&rstp_mutex);
 335 }
 336
 337 const char *
 338 rstp_get_name(const struct rstp *rstp)
 339     OVS_EXCLUDED(rstp_mutex)
 340 {
 341     char *name;
 342
 343     ovs_mutex_lock(&rstp_mutex);
 344     name = rstp->name;
 345     ovs_mutex_unlock(&rstp_mutex);
 346     return name;
 347 }
 348
 349 rstp_identifier
 350 rstp_get_bridge_id(const struct rstp *rstp)
 351     OVS_EXCLUDED(rstp_mutex)
 352 {
 353     rstp_identifier bridge_id;
 354
 355     ovs_mutex_lock(&rstp_mutex);
 356     bridge_id = rstp->bridge_identifier;
 357     ovs_mutex_unlock(&rstp_mutex);
 358
 359     return bridge_id;
 360 }
 361
 362 /* Sets the bridge priority. */
 363 static void
 364 rstp_set_bridge_priority__(struct rstp *rstp, int new_priority)
 365     OVS_REQUIRES(rstp_mutex)
 366 {
 367     new_priority = ROUND_DOWN(new_priority, RSTP_PRIORITY_STEP);
 368
 369     if (new_priority >= RSTP_MIN_PRIORITY
 370         && new_priority <= RSTP_MAX_PRIORITY) {
 371         VLOG_DBG("%s: set bridge priority to %d", rstp->name, new_priority);
 372
 373         rstp->priority = new_priority;
 374         rstp->bridge_identifier &= 0x0000ffffffffffffULL;
 375         rstp->bridge_identifier |= (uint64_t)new_priority << 48;
 376         set_bridge_priority__(rstp);
 377     }
 378 }
 379
 380 void
 381 rstp_set_bridge_priority(struct rstp *rstp, int new_priority)
 382     OVS_EXCLUDED(rstp_mutex)
 383 {
 384     ovs_mutex_lock(&rstp_mutex);
 385     rstp_set_bridge_priority__(rstp, new_priority);
 386     ovs_mutex_unlock(&rstp_mutex);
 387 }
 388
 389 /* Sets the bridge ageing time. */
 390 static void
 391 rstp_set_bridge_ageing_time__(struct rstp *rstp, int new_ageing_time)
 392     OVS_REQUIRES(rstp_mutex)
 393 {
 394     if (new_ageing_time >= RSTP_MIN_AGEING_TIME
 395         && new_ageing_time <= RSTP_MAX_AGEING_TIME) {
 396         VLOG_DBG("%s: set ageing time to %d", rstp->name, new_ageing_time);
 397
 398         rstp->ageing_time = new_ageing_time;
 399     }
 400 }
 401
 402 void
 403 rstp_set_bridge_ageing_time(struct rstp *rstp, int new_ageing_time)
 404     OVS_EXCLUDED(rstp_mutex)
 405 {
 406     ovs_mutex_lock(&rstp_mutex);
 407     rstp_set_bridge_ageing_time__(rstp, new_ageing_time);
 408     ovs_mutex_unlock(&rstp_mutex);
 409 }
 410
 411 /* Reinitializes RSTP when switching from RSTP mode to STP mode
 412  * or vice versa.
 413  */
 414 static void
 415 reinitialize_rstp__(struct rstp *rstp)
 416     OVS_REQUIRES(rstp_mutex)
 417 {
 418     struct rstp temp;
 419     static struct list ports;
 420
 421     /* Copy rstp in temp */
 422     temp = *rstp;
 423     ports = rstp->ports;
 424
 425     /* stop and clear rstp */
 426     memset(rstp, 0, sizeof(struct rstp));
 427
 428     /* Initialize rstp. */
 429     rstp->name = temp.name;
 430     /* Set bridge address. */
 431     rstp_set_bridge_address__(rstp, temp.address);
 432     /* Set default parameters values. */
 433     rstp_set_bridge_priority__(rstp, RSTP_DEFAULT_PRIORITY);
 434     rstp_set_bridge_ageing_time__(rstp, RSTP_DEFAULT_AGEING_TIME);
 435     rstp_set_bridge_forward_delay__(rstp, RSTP_DEFAULT_BRIDGE_FORWARD_DELAY);
 436     rstp_set_bridge_hello_time__(rstp);
 437     rstp_set_bridge_max_age__(rstp, RSTP_DEFAULT_BRIDGE_MAX_AGE);
 438     rstp_set_bridge_migrate_time__(rstp);
 439     rstp_set_bridge_transmit_hold_count__(rstp,
 440                                           RSTP_DEFAULT_TRANSMIT_HOLD_COUNT);
 441     rstp_set_bridge_times__(rstp, RSTP_DEFAULT_BRIDGE_FORWARD_DELAY,
 442                             RSTP_BRIDGE_HELLO_TIME,
 443                             RSTP_DEFAULT_BRIDGE_MAX_AGE, 0);
 444
 445     rstp->send_bpdu = temp.send_bpdu;
 446     rstp->aux = temp.aux;
 447     rstp->node = temp.node;
 448     rstp->changes = false;
 449     rstp->begin = true;
 450     rstp->ports = ports;
 451     rstp->ports_count = temp.ports_count;
 452
 453     if (rstp->ports_count > 0) {
 454         struct rstp_port *p;
 455
 456         LIST_FOR_EACH (p, node, &rstp->ports) {
 457             reinitialize_port__(p);
 458         }
 459     }
 460     rstp->ref_cnt = temp.ref_cnt;
 461 }
 462
 463 /* Sets the force protocol version parameter. */
 464 static void
 465 rstp_set_bridge_force_protocol_version__(struct rstp *rstp,
 466                 enum rstp_force_protocol_version new_force_protocol_version)
 467     OVS_REQUIRES(rstp_mutex)
 468 {
 469     if (new_force_protocol_version != rstp->force_protocol_version &&
 470             (new_force_protocol_version == FPV_STP_COMPATIBILITY ||
 471              new_force_protocol_version == FPV_DEFAULT)) {
 472         VLOG_DBG("%s: set bridge Force Protocol Version to %d", rstp->name,
 473                  new_force_protocol_version);
 474
 475         /* [17.13] The Spanning Tree Protocol Entity shall be reinitialized,
 476          * as specified by the assertion of BEGIN (17.18.1) in the state
 477          * machine specification.
 478          */
 479         reinitialize_rstp__(rstp);
 480         rstp->force_protocol_version = new_force_protocol_version;
 481         if (rstp->force_protocol_version < 2) {
 482             rstp->stp_version = true;
 483             rstp->rstp_version = false;
 484         } else {
 485             rstp->stp_version = false;
 486             rstp->rstp_version = true;
 487         }
 488         rstp->changes = true;
 489         move_rstp__(rstp);
 490     }
 491 }
 492
 493 void
 494 rstp_set_bridge_force_protocol_version(struct rstp *rstp,
 495                 enum rstp_force_protocol_version new_force_protocol_version)
 496     OVS_EXCLUDED(rstp_mutex)
 497 {
 498     ovs_mutex_lock(&rstp_mutex);
 499     rstp_set_bridge_force_protocol_version__(rstp, new_force_protocol_version);
 500     ovs_mutex_unlock(&rstp_mutex);
 501 }
 502
 503 /* Sets the bridge Hello Time parameter. */
 504 static void
 505 rstp_set_bridge_hello_time__(struct rstp *rstp)
 506     OVS_REQUIRES(rstp_mutex)
 507 {
 508     VLOG_DBG("%s: set RSTP Hello Time to %d", rstp->name,
 509              RSTP_BRIDGE_HELLO_TIME);
 510     /* 2 is the only acceptable value. */
 511     rstp->bridge_hello_time = RSTP_BRIDGE_HELLO_TIME;
 512 }
 513
 514 /* Sets the bridge max age parameter. */
 515 static void
 516 rstp_set_bridge_max_age__(struct rstp *rstp, int new_max_age)
 517     OVS_REQUIRES(rstp_mutex)
 518 {
 519     if (new_max_age >= RSTP_MIN_BRIDGE_MAX_AGE &&
 520         new_max_age <= RSTP_MAX_BRIDGE_MAX_AGE) {
 521         /* [17.13] */
 522         if ((2 * (rstp->bridge_forward_delay - 1) >= new_max_age)
 523             && (new_max_age >= 2 * rstp->bridge_hello_time)) {
 524             VLOG_DBG("%s: set RSTP bridge Max Age to %d", rstp->name,
 525                      new_max_age);
 526
 527             rstp->bridge_max_age = new_max_age;
 528             rstp->bridge_times.max_age = new_max_age;
 529         }
 530     }
 531 }
 532
 533 void
 534 rstp_set_bridge_max_age(struct rstp *rstp, int new_max_age)
 535     OVS_EXCLUDED(rstp_mutex)
 536 {
 537     ovs_mutex_lock(&rstp_mutex);
 538     rstp_set_bridge_max_age__(rstp, new_max_age);
 539     ovs_mutex_unlock(&rstp_mutex);
 540 }
 541
 542 /* Sets the bridge forward delay parameter. */
 543 static void
 544 rstp_set_bridge_forward_delay__(struct rstp *rstp, int new_forward_delay)
 545     OVS_REQUIRES(rstp_mutex)
 546 {
 547     if (new_forward_delay >= RSTP_MIN_BRIDGE_FORWARD_DELAY
 548         && new_forward_delay <= RSTP_MAX_BRIDGE_FORWARD_DELAY) {
 549         if (2 * (new_forward_delay - 1) >= rstp->bridge_max_age) {
 550             VLOG_DBG("%s: set RSTP Forward Delay to %d", rstp->name,
 551                      new_forward_delay);
 552             rstp->bridge_forward_delay = new_forward_delay;
 553             rstp->bridge_times.forward_delay = new_forward_delay;
 554         }
 555     }
 556 }
 557
 558 void
 559 rstp_set_bridge_forward_delay(struct rstp *rstp, int new_forward_delay)
 560     OVS_EXCLUDED(rstp_mutex)
 561 {
 562     ovs_mutex_lock(&rstp_mutex);
 563     rstp_set_bridge_forward_delay__(rstp, new_forward_delay);
 564     ovs_mutex_unlock(&rstp_mutex);
 565 }
 566
 567 /* Sets the bridge transmit hold count parameter. */
 568 static void
 569 rstp_set_bridge_transmit_hold_count__(struct rstp *rstp,
 570                                       int new_transmit_hold_count)
 571     OVS_REQUIRES(rstp_mutex)
 572 {
 573     struct rstp_port *p;
 574
 575     if (new_transmit_hold_count >= RSTP_MIN_TRANSMIT_HOLD_COUNT
 576         && new_transmit_hold_count <= RSTP_MAX_TRANSMIT_HOLD_COUNT) {
 577         VLOG_DBG("%s: set RSTP Transmit Hold Count to %d", rstp->name,
 578                  new_transmit_hold_count);
 579         /* Resetting txCount on all ports [17.13]. */
 580
 581         rstp->transmit_hold_count = new_transmit_hold_count;
 582         if (rstp->ports_count > 0) {
 583             LIST_FOR_EACH (p, node, &rstp->ports) {
 584                 p->tx_count = 0;
 585             }
 586         }
 587     }
 588 }
 589
 590 void
 591 rstp_set_bridge_transmit_hold_count(struct rstp *rstp,
 592                                     int new_transmit_hold_count)
 593     OVS_EXCLUDED(rstp_mutex)
 594 {
 595     ovs_mutex_lock(&rstp_mutex);
 596     rstp_set_bridge_transmit_hold_count__(rstp, new_transmit_hold_count);
 597     ovs_mutex_unlock(&rstp_mutex);
 598 }
 599
 600 /* Sets the bridge migrate time parameter. */
 601 static void
 602 rstp_set_bridge_migrate_time__(struct rstp *rstp)
 603     OVS_REQUIRES(rstp_mutex)
 604 {
 605     VLOG_DBG("%s: set RSTP Migrate Time to %d", rstp->name,
 606              RSTP_MIGRATE_TIME);
 607     /* 3 is the only acceptable value */
 608     rstp->migrate_time = RSTP_MIGRATE_TIME;
 609 }
 610
 611 /* Sets the bridge times. */
 612 static void
 613 rstp_set_bridge_times__(struct rstp *rstp, int new_forward_delay,
 614                         int new_hello_time, int new_max_age,
 615                         int new_message_age)
 616     OVS_REQUIRES(rstp_mutex)
 617 {
 618     VLOG_DBG("%s: set RSTP times to (%d, %d, %d, %d)", rstp->name,
 619              new_forward_delay, new_hello_time, new_max_age, new_message_age);
 620     if (new_forward_delay >= RSTP_MIN_BRIDGE_FORWARD_DELAY
 621         && new_forward_delay <= RSTP_MAX_BRIDGE_FORWARD_DELAY) {
 622         rstp->bridge_times.forward_delay = new_forward_delay;
 623     }
 624     if (new_hello_time == RSTP_BRIDGE_HELLO_TIME) {
 625         rstp->bridge_times.hello_time = new_hello_time;
 626     }
 627     if (new_max_age >= RSTP_MIN_BRIDGE_MAX_AGE
 628         && new_max_age <= RSTP_MAX_BRIDGE_MAX_AGE) {
 629         rstp->bridge_times.max_age = new_max_age;
 630     }
 631     rstp->bridge_times.message_age = new_message_age;
 632 }
 633
 634 /* Sets the port id, it is called by rstp_port_set_port_number__() or
 635  * rstp_port_set_priority__().
 636  */
 637 static void
 638 set_port_id__(struct rstp_port *p)
 639     OVS_REQUIRES(rstp_mutex)
 640 {
 641     struct rstp *rstp;
 642
 643     rstp = p->rstp;
 644     /* [9.2.7] Port identifier. */
 645     p->port_id = p->port_number | (p->priority << 8);
 646     VLOG_DBG("%s: new RSTP port id "RSTP_PORT_ID_FMT"", rstp->name,
 647              p->port_id);
 648 }
 649
 650 /* Sets the port priority. */
 651 static void
 652 rstp_port_set_priority__(struct rstp_port *port, int priority)
 653     OVS_REQUIRES(rstp_mutex)
 654 {
 655     if (priority >= RSTP_MIN_PORT_PRIORITY
 656         && priority <= RSTP_MAX_PORT_PRIORITY) {
 657         VLOG_DBG("%s, port %u: set RSTP port priority to %d", port->rstp->name,
 658                  port->port_number, priority);
 659
 660         priority -= priority % RSTP_STEP_PORT_PRIORITY;
 661         port->priority = priority;
 662         set_port_id__(port);
 663         port->selected = false;
 664         port->reselect = true;
 665     }
 666 }
 667
 668 /* Checks if a port number is available. */
 669 static bool
 670 is_port_number_available__(struct rstp *rstp, int n, struct rstp_port *port)
 671     OVS_REQUIRES(rstp_mutex)
 672 {
 673     if (n >= 1 && n <= RSTP_MAX_PORTS) {
 674         struct rstp_port *p = rstp_get_port__(rstp, n);
 675
 676         return p == NULL || p == port;
 677     }
 678     return false;
 679 }
 680
 681 static uint16_t
 682 rstp_first_free_number__(struct rstp *rstp, struct rstp_port *rstp_port)
 683     OVS_REQUIRES(rstp_mutex)
 684 {
 685     int free_number = 1;
 686
 687     while (free_number <= RSTP_MAX_PORTS) {
 688         if (is_port_number_available__(rstp, free_number, rstp_port)) {
 689             return free_number;
 690         }
 691         free_number++;
 692     }
 693     VLOG_DBG("%s, No free port number available.", rstp->name);
 694     return 0;
 695 }
 696
 697 /* Sets the port number. */
 698 static void
 699 rstp_port_set_port_number__(struct rstp_port *port, uint16_t port_number)
 700     OVS_REQUIRES(rstp_mutex)
 701 {
 702     /* If new_port_number is available, use it, otherwise use the first free
 703      * available port number. */
 704     port->port_number =
 705         is_port_number_available__(port->rstp, port_number, port)
 706         ? port_number
 707         : rstp_first_free_number__(port->rstp, port);
 708
 709     set_port_id__(port);
 710     /* [17.13] is not clear. I suppose that a port number change
 711      * should trigger reselection like a port priority change. */
 712     port->selected = false;
 713     port->reselect = true;
 714
 715     VLOG_DBG("%s: set new RSTP port number %d", port->rstp->name,
 716              port->port_number);
 717 }
 718
 719 /* Converts the link speed to a port path cost [Table 17-3]. */
 720 uint32_t
 721 rstp_convert_speed_to_cost(unsigned int speed)
 722 {
 723     uint32_t value;
 724
 725     value = speed >= 10000000 ? 2 /* 10 Tb/s. */
 726           : speed >= 1000000 ? 20 /* 1 Tb/s. */
 727           : speed >= 100000 ? 200 /* 100 Gb/s. */
 728           : speed >= 10000 ? 2000 /* 10 Gb/s. */
 729           : speed >= 1000 ? 20000 /* 1 Gb/s. */
 730           : speed >= 100 ? 200000 /* 100 Mb/s. */
 731           : speed >= 10 ? 2000000 /* 10 Mb/s. */
 732           : speed >= 1 ? 20000000 /* 1 Mb/s. */
 733           : RSTP_DEFAULT_PORT_PATH_COST; /* 100 Mb/s. */
 734
 735     return value;
 736 }
 737
 738 /* Sets the port path cost. */
 739 static void
 740 rstp_port_set_path_cost__(struct rstp_port *port, uint32_t path_cost)
 741     OVS_REQUIRES(rstp_mutex)
 742 {
 743     if (path_cost >= RSTP_MIN_PORT_PATH_COST
 744         && path_cost <= RSTP_MAX_PORT_PATH_COST) {
 745         VLOG_DBG("%s, port %u, set RSTP port path cost to %d",
 746                  port->rstp->name, port->port_number, path_cost);
 747
 748         port->port_path_cost = path_cost;
 749         port->selected = false;
 750         port->reselect = true;
 751     }
 752 }
 753
 754 /* Gets the root path cost. */
 755 uint32_t
 756 rstp_get_root_path_cost(const struct rstp *rstp)
 757     OVS_EXCLUDED(rstp_mutex)
 758 {
 759     uint32_t cost;
 760
 761     ovs_mutex_lock(&rstp_mutex);
 762     cost = rstp->root_priority.root_path_cost;
 763     ovs_mutex_unlock(&rstp_mutex);
 764     return cost;
 765 }
 766
 767 /* Returns true if something has happened to 'rstp' which necessitates
 768  * flushing the client's MAC learning table.
 769  */
 770 bool
 771 rstp_check_and_reset_fdb_flush(struct rstp *rstp)
 772     OVS_EXCLUDED(rstp_mutex)
 773 {
 774     bool needs_flush;
 775     struct rstp_port *p;
 776
 777     needs_flush = false;
 778
 779     ovs_mutex_lock(&rstp_mutex);
 780     if (rstp->ports_count > 0){
 781         LIST_FOR_EACH (p, node, &rstp->ports) {
 782             if (p->fdb_flush) {
 783                 needs_flush = true;
 784                 /* fdb_flush should be reset by the filtering database
 785                  * once the entries are removed if rstp_version is TRUE, and
 786                  * immediately if stp_version is TRUE.*/
 787                 p->fdb_flush = false;
 788             }
 789         }
 790     }
 791     ovs_mutex_unlock(&rstp_mutex);
 792     return needs_flush;
 793 }
 794
 795 /* Finds a port whose state has changed, and returns the aux pointer set for
 796  * the port.  A NULL pointer is returned when no changed port is found.  On
 797  * return '*portp' contains the pointer to the rstp port that changed, or NULL
 798  * if no changed port can be found.
 799  *
 800  * If '*portp' is passed as non-NULL, it must be the value set by the last
 801  * invocation of this function.
 802  *
 803  * This function may only be called by the thread that creates and deletes
 804  * ports.  Otherwise this function is not thread safe, as the returned
 805  * '*portp' could become stale before it is used in the next invocation. */
 806 void *
 807 rstp_get_next_changed_port_aux(struct rstp *rstp, struct rstp_port **portp)
 808 {
 809     void *aux = NULL;
 810
 811     ovs_mutex_lock(&rstp_mutex);
 812     if (*portp == NULL) {
 813         struct rstp_port *p;
 814
 815         LIST_FOR_EACH (p, node, &rstp->ports) {
 816             if (p->state_changed) {
 817                 p->state_changed = false;
 818                 aux = p->aux;
 819                 *portp = p;
 820                 goto out;
 821             }
 822         }
 823     } else { /* continue */
 824         struct rstp_port *p = *portp;
 825
 826         LIST_FOR_EACH_CONTINUE (p, node, &rstp->ports) {
 827             if (p->state_changed) {
 828                 p->state_changed = false;
 829                 aux = p->aux;
 830                 *portp = p;
 831                 goto out;
 832             }
 833         }
 834     }
 835     /* No changed port found. */
 836     *portp = NULL;
 837 out:
 838     ovs_mutex_unlock(&rstp_mutex);
 839     return aux;
 840 }
 841
 842 /* Returns the port in 'rstp' with number 'port_number'.
 843  *
 844  * XXX: May only be called while concurrent deletion of ports is excluded. */
 845 static struct rstp_port *
 846 rstp_get_port__(struct rstp *rstp, uint16_t port_number)
 847     OVS_REQUIRES(rstp_mutex)
 848 {
 849     struct rstp_port *port;
 850
 851     ovs_assert(rstp && port_number > 0 && port_number <= RSTP_MAX_PORTS);
 852
 853     if (rstp->ports_count > 0) {
 854         LIST_FOR_EACH (port, node, &rstp->ports) {
 855             if (port->port_number == port_number) {
 856                 return port;
 857             }
 858         }
 859     }
 860     return NULL;
 861 }
 862
 863 struct rstp_port *
 864 rstp_get_port(struct rstp *rstp, uint16_t port_number)
 865     OVS_EXCLUDED(rstp_mutex)
 866 {
 867     struct rstp_port *p;
 868
 869     ovs_mutex_lock(&rstp_mutex);
 870     p = rstp_get_port__(rstp, port_number);
 871     ovs_mutex_unlock(&rstp_mutex);
 872     return p;
 873 }
 874
 875 void *
 876 rstp_get_port_aux(struct rstp *rstp, uint16_t port_number)
 877     OVS_EXCLUDED(rstp_mutex)
 878 {
 879     struct rstp_port *p;
 880     void *aux;
 881
 882     ovs_mutex_lock(&rstp_mutex);
 883     p = rstp_get_port__(rstp, port_number);
 884     aux = p->aux;
 885     ovs_mutex_unlock(&rstp_mutex);
 886     return aux;
 887 }
 888
 889 /* Updates the port_enabled parameter. */
 890 static void
 891 update_port_enabled__(struct rstp_port *p)
 892     OVS_REQUIRES(rstp_mutex)
 893 {
 894     if (p->mac_operational && p->is_administrative_bridge_port
 895         == RSTP_ADMIN_BRIDGE_PORT_STATE_ENABLED) {
 896         p->port_enabled = true;
 897     } else {
 898         p->port_enabled = false;
 899     }
 900 }
 901
 902 /* Sets the port MAC_Operational parameter [6.4.2]. */
 903 void
 904 rstp_port_set_mac_operational(struct rstp_port *p, bool new_mac_operational)
 905     OVS_EXCLUDED(rstp_mutex)
 906 {
 907     struct rstp *rstp;
 908
 909     ovs_mutex_lock(&rstp_mutex);
 910     rstp = p->rstp;
 911     if (p->mac_operational != new_mac_operational) {
 912         p->mac_operational = new_mac_operational;
 913         update_port_enabled__(p);
 914         rstp->changes = true;
 915         move_rstp__(rstp);
 916     }
 917     ovs_mutex_unlock(&rstp_mutex);
 918 }
 919
 920 /* Sets the port Administrative Bridge Port parameter. */
 921 static void
 922 rstp_port_set_administrative_bridge_port__(struct rstp_port *p,
 923                                            uint8_t admin_port_state)
 924     OVS_REQUIRES(rstp_mutex)
 925 {
 926     if (admin_port_state == RSTP_ADMIN_BRIDGE_PORT_STATE_DISABLED
 927         || admin_port_state == RSTP_ADMIN_BRIDGE_PORT_STATE_ENABLED) {
 928
 929         p->is_administrative_bridge_port = admin_port_state;
 930         update_port_enabled__(p);
 931     }
 932 }
 933
 934 /* Sets the port oper_point_to_point_mac parameter. */
 935 static void
 936 rstp_port_set_oper_point_to_point_mac__(struct rstp_port *p,
 937                                         uint8_t new_oper_p2p_mac)
 938     OVS_REQUIRES(rstp_mutex)
 939 {
 940     if (new_oper_p2p_mac == RSTP_OPER_P2P_MAC_STATE_DISABLED
 941         || new_oper_p2p_mac == RSTP_OPER_P2P_MAC_STATE_ENABLED) {
 942
 943         p->oper_point_to_point_mac = new_oper_p2p_mac;
 944         update_port_enabled__(p);
 945     }
 946 }
 947
 948 /* Initializes a port with the defaults values for its parameters. */
 949 static void
 950 rstp_initialize_port_defaults__(struct rstp_port *p)
 951     OVS_REQUIRES(rstp_mutex)
 952 {
 953     rstp_port_set_administrative_bridge_port__(p,
 954                                          RSTP_ADMIN_BRIDGE_PORT_STATE_ENABLED);
 955     rstp_port_set_oper_point_to_point_mac__(p, 1);
 956     rstp_port_set_path_cost__(p, RSTP_DEFAULT_PORT_PATH_COST);
 957     rstp_port_set_admin_edge__(p, false);
 958     rstp_port_set_auto_edge__(p, true);
 959     rstp_port_set_mcheck__(p, false);
 960
 961     /* Initialize state machines. */
 962     p->port_receive_sm_state = PORT_RECEIVE_SM_INIT;
 963     p->port_protocol_migration_sm_state = PORT_PROTOCOL_MIGRATION_SM_INIT;
 964     p->bridge_detection_sm_state = BRIDGE_DETECTION_SM_INIT;
 965     p->port_transmit_sm_state = PORT_TRANSMIT_SM_INIT;
 966     p->port_information_sm_state = PORT_INFORMATION_SM_INIT;
 967     p->port_role_transition_sm_state = PORT_ROLE_TRANSITION_SM_INIT;
 968     p->port_state_transition_sm_state = PORT_STATE_TRANSITION_SM_INIT;
 969     p->topology_change_sm_state = TOPOLOGY_CHANGE_SM_INIT;
 970     p->uptime = 0;
 971
 972 }
 973
 974 static void
 975 reinitialize_port__(struct rstp_port *p)
 976     OVS_REQUIRES(rstp_mutex)
 977 {
 978     struct rstp_port temp_port;
 979     struct rstp *rstp;
 980
 981     rstp = p->rstp;
 982     temp_port = *p;
 983     memset(p, 0, sizeof(struct rstp_port));
 984
 985     p->ref_cnt = temp_port.ref_cnt;
 986     p->rstp = rstp;
 987     p->node = temp_port.node;
 988     p->aux = temp_port.aux;
 989     p->port_number = temp_port.port_number;
 990     p->port_priority = temp_port.port_priority;
 991     p->port_id = temp_port.port_id;
 992     p->rstp_state = RSTP_DISCARDING;
 993
 994     rstp_initialize_port_defaults__(p);
 995
 996     VLOG_DBG("%s: RSTP port "RSTP_PORT_ID_FMT" reinitialized.", rstp->name,
 997              p->port_id);
 998 }
 999
1000 void
1001 reinitialize_port(struct rstp_port *p)
1002     OVS_EXCLUDED(rstp_mutex)
1003 {
1004     ovs_mutex_lock(&rstp_mutex);
1005     reinitialize_port__(p);
1006     ovs_mutex_unlock(&rstp_mutex);
1007 }
1008
1009 /* Sets the port state. */
1010 void
1011 rstp_port_set_state__(struct rstp_port *p, enum rstp_state state)
1012     OVS_REQUIRES(rstp_mutex)
1013 {
1014     struct rstp *rstp;
1015
1016     rstp = p->rstp;
1017     VLOG_DBG("%s, port %u: set RSTP port state %s -> %s", rstp->name,
1018              p->port_number,
1019              rstp_state_name(p->rstp_state), rstp_state_name(state));
1020
1021     if (state != p->rstp_state && !p->state_changed) {
1022         p->state_changed = true;
1023         seq_change(connectivity_seq_get());
1024     }
1025     p->rstp_state = state;
1026 }
1027
1028 void
1029 rstp_port_set_state(struct rstp_port *p, enum rstp_state state)
1030     OVS_EXCLUDED(rstp_mutex)
1031 {
1032     ovs_mutex_lock(&rstp_mutex);
1033     rstp_port_set_state__(p, state);
1034     ovs_mutex_unlock(&rstp_mutex);
1035 }
1036
1037 /* Adds a RSTP port. */
1038 struct rstp_port *
1039 rstp_add_port(struct rstp *rstp)
1040     OVS_EXCLUDED(rstp_mutex)
1041 {
1042     struct rstp_port *p = xzalloc(sizeof *p);
1043
1044     ovs_refcount_init(&p->ref_cnt);
1045
1046     ovs_mutex_lock(&rstp_mutex);
1047     p->rstp = rstp;
1048     rstp_port_set_priority__(p, RSTP_DEFAULT_PORT_PRIORITY);
1049     rstp_port_set_port_number__(p, 0);
1050     p->aux = NULL;
1051     rstp_initialize_port_defaults__(p);
1052     VLOG_DBG("%s: RSTP port "RSTP_PORT_ID_FMT" initialized.", rstp->name,
1053              p->port_id);
1054
1055     rstp_port_set_state__(p, RSTP_DISCARDING);
1056     list_push_back(&rstp->ports, &p->node);
1057     rstp->ports_count++;
1058     rstp->changes = true;
1059     move_rstp__(rstp);
1060     VLOG_DBG("%s: added port "RSTP_PORT_ID_FMT"", rstp->name, p->port_id);
1061     ovs_mutex_unlock(&rstp_mutex);
1062     return p;
1063 }
1064
1065 /* Caller has to hold a reference to prevent 'rstp_port' from being deleted
1066  * while taking a new reference. */
1067 struct rstp_port *
1068 rstp_port_ref(const struct rstp_port *rp_)
1069     OVS_EXCLUDED(rstp_mutex)
1070 {
1071     struct rstp_port *rp = CONST_CAST(struct rstp_port *, rp_);
1072
1073     if (rp) {
1074         ovs_refcount_ref(&rp->ref_cnt);
1075     }
1076     return rp;
1077 }
1078
1079 /* Frees RSTP struct.  This can be caller by any thread. */
1080 void
1081 rstp_port_unref(struct rstp_port *rp)
1082     OVS_EXCLUDED(rstp_mutex)
1083 {
1084     if (rp && ovs_refcount_unref(&rp->ref_cnt) == 1) {
1085         struct rstp *rstp;
1086
1087         ovs_mutex_lock(&rstp_mutex);
1088         rstp = rp->rstp;
1089         rstp_port_set_state__(rp, RSTP_DISABLED);
1090         list_remove(&rp->node);
1091         rstp->ports_count--;
1092         VLOG_DBG("%s: removed port "RSTP_PORT_ID_FMT"", rstp->name, rp->port_id);
1093         ovs_mutex_unlock(&rstp_mutex);
1094         free(rp);
1095     }
1096 }
1097
1098 /* Sets the port Admin Edge parameter. */
1099 static void
1100 rstp_port_set_admin_edge__(struct rstp_port *port, bool admin_edge)
1101      OVS_REQUIRES(rstp_mutex)
1102 {
1103     if (port->admin_edge != admin_edge) {
1104         VLOG_DBG("%s, port %u: set RSTP Admin Edge to %d", port->rstp->name,
1105                  port->port_number, admin_edge);
1106
1107         port->admin_edge = admin_edge;
1108     }
1109 }
1110
1111 /* Sets the port Auto Edge parameter. */
1112 static void
1113 rstp_port_set_auto_edge__(struct rstp_port *port, bool auto_edge)
1114     OVS_REQUIRES(rstp_mutex)
1115 {
1116     if (port->auto_edge != auto_edge) {
1117         VLOG_DBG("%s, port %u: set RSTP Auto Edge to %d", port->rstp->name,
1118                  port->port_number, auto_edge);
1119
1120         port->auto_edge = auto_edge;
1121     }
1122 }
1123
1124 /* Sets the port mcheck parameter.
1125  * [17.19.13] May be set by management to force the Port Protocol Migration
1126  * state machine to transmit RST BPDUs for a MigrateTime (17.13.9) period, to
1127  * test whether all STP Bridges (17.4) on the attached LAN have been removed
1128  * and the Port can continue to transmit RSTP BPDUs. Setting mcheck has no
1129  * effect if stpVersion (17.20.12) is TRUE, i.e., the Bridge is operating in
1130  * STP Compatibility mode.
1131  */
1132 static void
1133 rstp_port_set_mcheck__(struct rstp_port *port, bool mcheck)
1134     OVS_REQUIRES(rstp_mutex)
1135 {
1136     if (mcheck == true && port->rstp->force_protocol_version >= 2) {
1137         port->mcheck = true;
1138
1139         VLOG_DBG("%s, port %u: set RSTP mcheck to %d", port->rstp->name,
1140                  port->port_number, mcheck);
1141     }
1142 }
1143
1144 /* Returns the designated bridge id. */
1145 rstp_identifier
1146 rstp_get_designated_id(const struct rstp *rstp)
1147     OVS_EXCLUDED(rstp_mutex)
1148 {
1149     rstp_identifier designated_id;
1150
1151     ovs_mutex_lock(&rstp_mutex);
1152     designated_id = rstp->root_priority.designated_bridge_id;
1153     ovs_mutex_unlock(&rstp_mutex);
1154
1155     return designated_id;
1156 }
1157
1158 /* Returns the root bridge id. */
1159 rstp_identifier
1160 rstp_get_root_id(const struct rstp *rstp)
1161     OVS_EXCLUDED(rstp_mutex)
1162 {
1163     rstp_identifier root_id;
1164
1165     ovs_mutex_lock(&rstp_mutex);
1166     root_id = rstp->root_priority.root_bridge_id;
1167     ovs_mutex_unlock(&rstp_mutex);
1168
1169     return root_id;
1170 }
1171
1172 /* Returns the designated port id. */
1173 uint16_t
1174 rstp_get_designated_port_id(const struct rstp *rstp)
1175     OVS_EXCLUDED(rstp_mutex)
1176 {
1177     uint16_t designated_port_id;
1178
1179     ovs_mutex_lock(&rstp_mutex);
1180     designated_port_id = rstp->root_priority.designated_port_id;
1181     ovs_mutex_unlock(&rstp_mutex);
1182
1183     return designated_port_id;
1184 }
1185
1186 /* Return the bridge port id. */
1187 uint16_t
1188 rstp_get_bridge_port_id(const struct rstp *rstp)
1189     OVS_EXCLUDED(rstp_mutex)
1190 {
1191     uint16_t bridge_port_id;
1192
1193     ovs_mutex_lock(&rstp_mutex);
1194     bridge_port_id = rstp->root_priority.bridge_port_id;
1195     ovs_mutex_unlock(&rstp_mutex);
1196
1197     return bridge_port_id;
1198 }
1199
1200 /* Returns true if the bridge believes to the be root of the spanning tree,
1201  * false otherwise.
1202  */
1203 bool
1204 rstp_is_root_bridge(const struct rstp *rstp)
1205     OVS_EXCLUDED(rstp_mutex)
1206 {
1207     bool is_root;
1208
1209     ovs_mutex_lock(&rstp_mutex);
1210     is_root = rstp->bridge_identifier ==
1211                 rstp->root_priority.designated_bridge_id;
1212     ovs_mutex_unlock(&rstp_mutex);
1213
1214     return is_root;
1215 }
1216
1217 /* Returns the bridge ID of the bridge currently believed to be the root. */
1218 rstp_identifier
1219 rstp_get_designated_root(const struct rstp *rstp)
1220     OVS_EXCLUDED(rstp_mutex)
1221 {
1222     rstp_identifier designated_root;
1223
1224     ovs_mutex_lock(&rstp_mutex);
1225     designated_root = rstp->root_priority.designated_bridge_id;
1226     ovs_mutex_unlock(&rstp_mutex);
1227
1228     return designated_root;
1229 }
1230
1231 /* Returns the port connecting 'rstp' to the root bridge, or a null pointer if
1232  * there is no such port.
1233  */
1234 struct rstp_port *
1235 rstp_get_root_port(struct rstp *rstp)
1236     OVS_EXCLUDED(rstp_mutex)
1237 {
1238     struct rstp_port *p;
1239
1240     ovs_mutex_lock(&rstp_mutex);
1241     if (rstp->ports_count > 0){
1242         LIST_FOR_EACH (p, node, &rstp->ports) {
1243             if (p->port_id == rstp->root_port_id) {
1244                 ovs_mutex_unlock(&rstp_mutex);
1245                 return p;
1246             }
1247         }
1248     }
1249     ovs_mutex_unlock(&rstp_mutex);
1250     return NULL;
1251 }
1252
1253 /* Returns the state of port 'p'. */
1254 enum rstp_state
1255 rstp_port_get_state(const struct rstp_port *p)
1256 {
1257     enum rstp_state state;
1258
1259     ovs_mutex_lock(&rstp_mutex);
1260     state = p->rstp_state;
1261     ovs_mutex_unlock(&rstp_mutex);
1262
1263     return state;
1264 }
1265
1266 /* Retrieves port status. */
1267 void
1268 rstp_port_get_status(const struct rstp_port *p, uint16_t *id,
1269                      enum rstp_state *state, enum rstp_port_role *role,
1270                      int *tx_count, int *rx_count, int *error_count,
1271                      int *uptime)
1272     OVS_EXCLUDED(rstp_mutex)
1273 {
1274     ovs_mutex_lock(&rstp_mutex);
1275     *id = p->port_id;
1276     *state = p->rstp_state;
1277     *role = p->role;
1278
1279     *tx_count = p->tx_count;
1280     *rx_count = p->rx_rstp_bpdu_cnt;
1281     *error_count = p->error_count;
1282     *uptime = p->uptime;
1283     ovs_mutex_unlock(&rstp_mutex);
1284 }
1285
1286 void
1287 rstp_port_set(struct rstp_port *port, uint16_t port_num, int priority,
1288               uint32_t path_cost, bool is_admin_edge, bool is_auto_edge,
1289               bool do_mcheck, void *aux)
1290     OVS_EXCLUDED(rstp_mutex)
1291 {
1292     ovs_mutex_lock(&rstp_mutex);
1293     port->aux = aux;
1294     rstp_port_set_priority__(port, priority);
1295     rstp_port_set_port_number__(port, port_num);
1296     rstp_port_set_path_cost__(port, path_cost);
1297     rstp_port_set_admin_edge__(port, is_admin_edge);
1298     rstp_port_set_auto_edge__(port, is_auto_edge);
1299     rstp_port_set_mcheck__(port, do_mcheck);
1300     ovs_mutex_unlock(&rstp_mutex);
1301 }
1302
1303 /* Individual setters only used by test-rstp.c. */
1304 void
1305 rstp_port_set_priority(struct rstp_port *port, int priority)
1306     OVS_EXCLUDED(rstp_mutex)
1307 {
1308     ovs_mutex_lock(&rstp_mutex);
1309     rstp_port_set_priority__(port, priority);
1310     ovs_mutex_unlock(&rstp_mutex);
1311 }
1312
1313 void
1314 rstp_port_set_path_cost(struct rstp_port *port, uint32_t path_cost)
1315     OVS_EXCLUDED(rstp_mutex)
1316 {
1317     ovs_mutex_lock(&rstp_mutex);
1318     rstp_port_set_path_cost__(port, path_cost);
1319     ovs_mutex_unlock(&rstp_mutex);
1320 }
1321
1322 void
1323 rstp_port_set_aux(struct rstp_port *port, void *aux)
1324     OVS_EXCLUDED(rstp_mutex)
1325 {
1326     ovs_mutex_lock(&rstp_mutex);
1327     port->aux = aux;
1328     ovs_mutex_unlock(&rstp_mutex);
1329 }
1330
1331 /* Unixctl. */
1332 static struct rstp *
1333 rstp_find(const char *name)
1334     OVS_REQUIRES(rstp_mutex)
1335 {
1336     struct rstp *rstp;
1337
1338     LIST_FOR_EACH (rstp, node, all_rstps) {
1339         if (!strcmp(rstp->name, name)) {
1340             return rstp;
1341         }
1342     }
1343     return NULL;
1344 }
1345
1346 static void
1347 rstp_unixctl_tcn(struct unixctl_conn *conn, int argc,
1348                  const char *argv[], void *aux OVS_UNUSED)
1349     OVS_EXCLUDED(rstp_mutex)
1350 {
1351     ovs_mutex_lock(&rstp_mutex);
1352     if (argc > 1) {
1353         struct rstp *rstp = rstp_find(argv[1]);
1354         if (!rstp) {
1355             unixctl_command_reply_error(conn, "No such RSTP object");
1356             goto out;
1357         }
1358         rstp->changes = true;
1359         move_rstp__(rstp);
1360     } else {
1361         struct rstp *rstp;
1362         LIST_FOR_EACH (rstp, node, all_rstps) {
1363             rstp->changes = true;
1364             move_rstp__(rstp);
1365         }
1366     }
1367     unixctl_command_reply(conn, "OK");
1368
1369 out:
1370     ovs_mutex_unlock(&rstp_mutex);
1371 }