rstp: Invoke updt_roles_tree__() in max_age and forward_delay setters.
[cascardo/ovs.git] / 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_admin_point_to_point_mac__(struct rstp_port *,
114         enum rstp_admin_point_to_point_mac_state admin_p2p_mac_state)
115     OVS_REQUIRES(rstp_mutex);
116 static void rstp_port_set_mcheck__(struct rstp_port *, bool mcheck)
117     OVS_REQUIRES(rstp_mutex);
118 static void reinitialize_port__(struct rstp_port *p)
119     OVS_REQUIRES(rstp_mutex);
120
121 const char *
122 rstp_state_name(enum rstp_state state)
123 {
124     switch (state) {
125     case RSTP_DISABLED:
126         return "Disabled";
127     case RSTP_LEARNING:
128         return "Learning";
129     case RSTP_FORWARDING:
130         return "Forwarding";
131     case RSTP_DISCARDING:
132         return "Discarding";
133     default:
134         return "Unknown";
135     }
136 }
137
138 const char *
139 rstp_port_role_name(enum rstp_port_role role)
140 {
141     switch (role) {
142     case ROLE_ROOT:
143         return "Root";
144     case ROLE_DESIGNATED:
145         return "Designated";
146     case ROLE_ALTERNATE:
147         return "Alternate";
148     case ROLE_BACKUP:
149         return "Backup";
150     case ROLE_DISABLED:
151         return "Disabled";
152     default:
153         return "Unknown";
154     }
155 }
156
157 /* Caller has to hold a reference to prevent 'rstp' from being deleted
158  * while taking a new reference. */
159 struct rstp *
160 rstp_ref(struct rstp *rstp)
161     OVS_EXCLUDED(rstp_mutex)
162 {
163     if (rstp) {
164         ovs_refcount_ref(&rstp->ref_cnt);
165     }
166     return rstp;
167 }
168
169 /* Frees RSTP struct when reference count reaches zero. */
170 void
171 rstp_unref(struct rstp *rstp)
172     OVS_EXCLUDED(rstp_mutex)
173 {
174     if (rstp && ovs_refcount_unref_relaxed(&rstp->ref_cnt) == 1) {
175         ovs_mutex_lock(&rstp_mutex);
176
177         /* Each RSTP port points back to struct rstp without holding a
178          * reference for that pointer.  This is OK as we never move
179          * ports from one bridge to another, and holders always
180          * release their ports before releasing the bridge.  This
181          * means that there should be not ports at this time. */
182         ovs_assert(hmap_is_empty(&rstp->ports));
183
184         list_remove(&rstp->node);
185         ovs_mutex_unlock(&rstp_mutex);
186         free(rstp->name);
187         free(rstp);
188     }
189 }
190
191 /* Returns the port number.  Mutex is needed to guard against
192  * concurrent reinitialization (which can temporarily clear the
193  * port_number). */
194 int
195 rstp_port_get_number(const struct rstp_port *p)
196     OVS_EXCLUDED(rstp_mutex)
197 {
198     int number;
199
200     ovs_mutex_lock(&rstp_mutex);
201     number = p->port_number;
202     ovs_mutex_unlock(&rstp_mutex);
203
204     return number;
205 }
206
207 static void rstp_unixctl_tcn(struct unixctl_conn *, int argc,
208                              const char *argv[], void *aux);
209
210 /* Decrements the State Machines' timers. */
211 void
212 rstp_tick_timers(struct rstp *rstp)
213     OVS_EXCLUDED(rstp_mutex)
214 {
215     ovs_mutex_lock(&rstp_mutex);
216     decrease_rstp_port_timers__(rstp);
217     ovs_mutex_unlock(&rstp_mutex);
218 }
219
220 /* Processes an incoming BPDU. */
221 void
222 rstp_port_received_bpdu(struct rstp_port *rp, const void *bpdu,
223                         size_t bpdu_size)
224     OVS_EXCLUDED(rstp_mutex)
225 {
226     ovs_mutex_lock(&rstp_mutex);
227     /* Only process packets on ports that have RSTP enabled. */
228     if (rp && rp->rstp_state != RSTP_DISABLED) {
229         process_received_bpdu__(rp, bpdu, bpdu_size);
230     }
231     ovs_mutex_unlock(&rstp_mutex);
232 }
233
234 void
235 rstp_init(void)
236     OVS_EXCLUDED(rstp_mutex)
237 {
238     unixctl_command_register("rstp/tcn", "[bridge]", 0, 1, rstp_unixctl_tcn,
239                              NULL);
240 }
241
242 /* Creates and returns a new RSTP instance that initially has no ports. */
243 struct rstp *
244 rstp_create(const char *name, rstp_identifier bridge_address,
245             void (*send_bpdu)(struct ofpbuf *bpdu, void *port_aux,
246                               void *rstp_aux),
247             void *aux)
248     OVS_EXCLUDED(rstp_mutex)
249 {
250     struct rstp *rstp;
251
252     VLOG_DBG("Creating RSTP instance");
253
254     rstp = xzalloc(sizeof *rstp);
255     rstp->name = xstrdup(name);
256
257     /* Initialize the ports map before calling any setters,
258      * so that the state machines will see an empty ports map. */
259     hmap_init(&rstp->ports);
260
261     ovs_mutex_lock(&rstp_mutex);
262     /* Set bridge address. */
263     rstp_set_bridge_address__(rstp, bridge_address);
264     /* Set default parameters values. */
265     rstp_set_bridge_priority__(rstp, RSTP_DEFAULT_PRIORITY);
266     rstp_set_bridge_ageing_time__(rstp, RSTP_DEFAULT_AGEING_TIME);
267     rstp_set_bridge_force_protocol_version__(rstp, FPV_DEFAULT);
268     rstp_set_bridge_forward_delay__(rstp, RSTP_DEFAULT_BRIDGE_FORWARD_DELAY);
269     rstp_set_bridge_hello_time__(rstp);
270     rstp_set_bridge_max_age__(rstp, RSTP_DEFAULT_BRIDGE_MAX_AGE);
271     rstp_set_bridge_migrate_time__(rstp);
272     rstp_set_bridge_transmit_hold_count__(rstp,
273                                           RSTP_DEFAULT_TRANSMIT_HOLD_COUNT);
274     rstp_set_bridge_times__(rstp, RSTP_DEFAULT_BRIDGE_FORWARD_DELAY,
275                             RSTP_BRIDGE_HELLO_TIME,
276                             RSTP_DEFAULT_BRIDGE_MAX_AGE, 0);
277     rstp->send_bpdu = send_bpdu;
278     rstp->aux = aux;
279     rstp->changes = false;
280     rstp->begin = true;
281
282     ovs_refcount_init(&rstp->ref_cnt);
283
284     list_push_back(all_rstps, &rstp->node);
285     ovs_mutex_unlock(&rstp_mutex);
286
287     VLOG_DBG("RSTP instance creation done");
288     return rstp;
289 }
290
291 /* Called by rstp_set_bridge_address() and rstp_set_bridge_priority(),
292  * it updates the bridge priority vector according to the values passed by
293  * those setters.
294  */
295 static void
296 set_bridge_priority__(struct rstp *rstp)
297     OVS_REQUIRES(rstp_mutex)
298 {
299     struct rstp_port *p;
300
301     rstp->bridge_priority.root_bridge_id = rstp->bridge_identifier;
302     rstp->bridge_priority.designated_bridge_id = rstp->bridge_identifier;
303     VLOG_DBG("%s: new bridge identifier: "RSTP_ID_FMT"", rstp->name,
304              RSTP_ID_ARGS(rstp->bridge_identifier));
305
306     /* [17.13] When the bridge address changes, recalculates all priority
307      * vectors.
308      */
309     HMAP_FOR_EACH (p, node, &rstp->ports) {
310         p->selected = false;
311         p->reselect = true;
312     }
313     rstp->changes = true;
314     updt_roles_tree__(rstp);
315 }
316
317 /* Sets the bridge address. */
318 static void
319 rstp_set_bridge_address__(struct rstp *rstp, rstp_identifier bridge_address)
320     OVS_REQUIRES(rstp_mutex)
321 {
322     VLOG_DBG("%s: set bridge address to: "RSTP_ID_FMT"", rstp->name,
323              RSTP_ID_ARGS(bridge_address));
324
325     rstp->address = bridge_address;
326     rstp->bridge_identifier = bridge_address;
327     set_bridge_priority__(rstp);
328 }
329
330 /* Sets the bridge address. */
331 void
332 rstp_set_bridge_address(struct rstp *rstp, rstp_identifier bridge_address)
333     OVS_EXCLUDED(rstp_mutex)
334 {
335     ovs_mutex_lock(&rstp_mutex);
336     rstp_set_bridge_address__(rstp, bridge_address);
337     ovs_mutex_unlock(&rstp_mutex);
338 }
339
340 const char *
341 rstp_get_name(const struct rstp *rstp)
342     OVS_EXCLUDED(rstp_mutex)
343 {
344     char *name;
345
346     ovs_mutex_lock(&rstp_mutex);
347     name = rstp->name;
348     ovs_mutex_unlock(&rstp_mutex);
349     return name;
350 }
351
352 rstp_identifier
353 rstp_get_bridge_id(const struct rstp *rstp)
354     OVS_EXCLUDED(rstp_mutex)
355 {
356     rstp_identifier bridge_id;
357
358     ovs_mutex_lock(&rstp_mutex);
359     bridge_id = rstp->bridge_identifier;
360     ovs_mutex_unlock(&rstp_mutex);
361
362     return bridge_id;
363 }
364
365 /* Sets the bridge priority. */
366 static void
367 rstp_set_bridge_priority__(struct rstp *rstp, int new_priority)
368     OVS_REQUIRES(rstp_mutex)
369 {
370     new_priority = ROUND_DOWN(new_priority, RSTP_PRIORITY_STEP);
371
372     if (new_priority >= RSTP_MIN_PRIORITY
373         && new_priority <= RSTP_MAX_PRIORITY) {
374         VLOG_DBG("%s: set bridge priority to %d", rstp->name, new_priority);
375
376         rstp->priority = new_priority;
377         rstp->bridge_identifier &= 0x0000ffffffffffffULL;
378         rstp->bridge_identifier |= (uint64_t)new_priority << 48;
379         set_bridge_priority__(rstp);
380     }
381 }
382
383 void
384 rstp_set_bridge_priority(struct rstp *rstp, int new_priority)
385     OVS_EXCLUDED(rstp_mutex)
386 {
387     ovs_mutex_lock(&rstp_mutex);
388     rstp_set_bridge_priority__(rstp, new_priority);
389     ovs_mutex_unlock(&rstp_mutex);
390 }
391
392 /* Sets the bridge ageing time. */
393 static void
394 rstp_set_bridge_ageing_time__(struct rstp *rstp, int new_ageing_time)
395     OVS_REQUIRES(rstp_mutex)
396 {
397     if (new_ageing_time >= RSTP_MIN_AGEING_TIME
398         && new_ageing_time <= RSTP_MAX_AGEING_TIME) {
399         VLOG_DBG("%s: set ageing time to %d", rstp->name, new_ageing_time);
400
401         rstp->ageing_time = new_ageing_time;
402     }
403 }
404
405 void
406 rstp_set_bridge_ageing_time(struct rstp *rstp, int new_ageing_time)
407     OVS_EXCLUDED(rstp_mutex)
408 {
409     ovs_mutex_lock(&rstp_mutex);
410     rstp_set_bridge_ageing_time__(rstp, new_ageing_time);
411     ovs_mutex_unlock(&rstp_mutex);
412 }
413
414 /* Reinitializes RSTP when switching from RSTP mode to STP mode
415  * or vice versa.
416  */
417 static void
418 reinitialize_rstp__(struct rstp *rstp)
419     OVS_REQUIRES(rstp_mutex)
420 {
421     struct rstp temp;
422     static struct hmap ports;
423     struct rstp_port *p;
424
425     /* Copy rstp in temp */
426     temp = *rstp;
427     ports = rstp->ports;
428
429     /* stop and clear rstp */
430     memset(rstp, 0, sizeof(struct rstp));
431
432     /* Initialize rstp. */
433     rstp->name = temp.name;
434
435     /* Initialize the ports hmap before calling any setters,
436      * so that the state machines will see an empty ports list. */
437     hmap_init(&rstp->ports);
438
439     /* Set bridge address. */
440     rstp_set_bridge_address__(rstp, temp.address);
441     /* Set default parameters values. */
442     rstp_set_bridge_priority__(rstp, RSTP_DEFAULT_PRIORITY);
443     rstp_set_bridge_ageing_time__(rstp, RSTP_DEFAULT_AGEING_TIME);
444     rstp_set_bridge_forward_delay__(rstp, RSTP_DEFAULT_BRIDGE_FORWARD_DELAY);
445     rstp_set_bridge_hello_time__(rstp);
446     rstp_set_bridge_max_age__(rstp, RSTP_DEFAULT_BRIDGE_MAX_AGE);
447     rstp_set_bridge_migrate_time__(rstp);
448     rstp_set_bridge_transmit_hold_count__(rstp,
449                                           RSTP_DEFAULT_TRANSMIT_HOLD_COUNT);
450     rstp_set_bridge_times__(rstp, RSTP_DEFAULT_BRIDGE_FORWARD_DELAY,
451                             RSTP_BRIDGE_HELLO_TIME,
452                             RSTP_DEFAULT_BRIDGE_MAX_AGE, 0);
453
454     rstp->send_bpdu = temp.send_bpdu;
455     rstp->aux = temp.aux;
456     rstp->node = temp.node;
457     rstp->changes = false;
458     rstp->begin = true;
459
460     /* Restore ports. */
461     rstp->ports = ports;
462
463     HMAP_FOR_EACH (p, node, &rstp->ports) {
464         reinitialize_port__(p);
465     }
466
467     rstp->ref_cnt = temp.ref_cnt;
468 }
469
470 /* Sets the force protocol version parameter. */
471 static void
472 rstp_set_bridge_force_protocol_version__(struct rstp *rstp,
473                 enum rstp_force_protocol_version new_force_protocol_version)
474     OVS_REQUIRES(rstp_mutex)
475 {
476     if (new_force_protocol_version != rstp->force_protocol_version &&
477             (new_force_protocol_version == FPV_STP_COMPATIBILITY ||
478              new_force_protocol_version == FPV_DEFAULT)) {
479         VLOG_DBG("%s: set bridge Force Protocol Version to %d", rstp->name,
480                  new_force_protocol_version);
481
482         /* [17.13] The Spanning Tree Protocol Entity shall be reinitialized,
483          * as specified by the assertion of BEGIN (17.18.1) in the state
484          * machine specification.
485          */
486         reinitialize_rstp__(rstp);
487         rstp->force_protocol_version = new_force_protocol_version;
488         if (rstp->force_protocol_version < 2) {
489             rstp->stp_version = true;
490             rstp->rstp_version = false;
491         } else {
492             rstp->stp_version = false;
493             rstp->rstp_version = true;
494         }
495         rstp->changes = true;
496         move_rstp__(rstp);
497     }
498 }
499
500 void
501 rstp_set_bridge_force_protocol_version(struct rstp *rstp,
502                 enum rstp_force_protocol_version new_force_protocol_version)
503     OVS_EXCLUDED(rstp_mutex)
504 {
505     ovs_mutex_lock(&rstp_mutex);
506     rstp_set_bridge_force_protocol_version__(rstp, new_force_protocol_version);
507     ovs_mutex_unlock(&rstp_mutex);
508 }
509
510 /* Sets the bridge Hello Time parameter. */
511 static void
512 rstp_set_bridge_hello_time__(struct rstp *rstp)
513     OVS_REQUIRES(rstp_mutex)
514 {
515     VLOG_DBG("%s: set RSTP Hello Time to %d", rstp->name,
516              RSTP_BRIDGE_HELLO_TIME);
517     /* 2 is the only acceptable value. */
518     rstp->bridge_hello_time = RSTP_BRIDGE_HELLO_TIME;
519 }
520
521 /* Sets the bridge max age parameter. */
522 static void
523 rstp_set_bridge_max_age__(struct rstp *rstp, int new_max_age)
524     OVS_REQUIRES(rstp_mutex)
525 {
526     if (rstp->bridge_max_age != new_max_age
527         && new_max_age >= RSTP_MIN_BRIDGE_MAX_AGE
528         && new_max_age <= RSTP_MAX_BRIDGE_MAX_AGE) {
529         /* [17.13] */
530         if ((2 * (rstp->bridge_forward_delay - 1) >= new_max_age)
531             && (new_max_age >= 2 * rstp->bridge_hello_time)) {
532             VLOG_DBG("%s: set RSTP bridge Max Age to %d", rstp->name,
533                      new_max_age);
534
535             rstp->bridge_max_age = new_max_age;
536             rstp->bridge_times.max_age = new_max_age;
537             rstp->changes = true;
538             updt_roles_tree__(rstp);
539         }
540     }
541 }
542
543 void
544 rstp_set_bridge_max_age(struct rstp *rstp, int new_max_age)
545     OVS_EXCLUDED(rstp_mutex)
546 {
547     ovs_mutex_lock(&rstp_mutex);
548     rstp_set_bridge_max_age__(rstp, new_max_age);
549     ovs_mutex_unlock(&rstp_mutex);
550 }
551
552 /* Sets the bridge forward delay parameter. */
553 static void
554 rstp_set_bridge_forward_delay__(struct rstp *rstp, int new_forward_delay)
555     OVS_REQUIRES(rstp_mutex)
556 {
557     if (rstp->bridge_forward_delay != new_forward_delay
558             && new_forward_delay >= RSTP_MIN_BRIDGE_FORWARD_DELAY
559             && new_forward_delay <= RSTP_MAX_BRIDGE_FORWARD_DELAY) {
560         if (2 * (new_forward_delay - 1) >= rstp->bridge_max_age) {
561             VLOG_DBG("%s: set RSTP Forward Delay to %d", rstp->name,
562                      new_forward_delay);
563             rstp->bridge_forward_delay = new_forward_delay;
564             rstp->bridge_times.forward_delay = new_forward_delay;
565             rstp->changes = true;
566             updt_roles_tree__(rstp);
567         }
568     }
569 }
570
571 void
572 rstp_set_bridge_forward_delay(struct rstp *rstp, int new_forward_delay)
573     OVS_EXCLUDED(rstp_mutex)
574 {
575     ovs_mutex_lock(&rstp_mutex);
576     rstp_set_bridge_forward_delay__(rstp, new_forward_delay);
577     ovs_mutex_unlock(&rstp_mutex);
578 }
579
580 /* Sets the bridge transmit hold count parameter. */
581 static void
582 rstp_set_bridge_transmit_hold_count__(struct rstp *rstp,
583                                       int new_transmit_hold_count)
584     OVS_REQUIRES(rstp_mutex)
585 {
586     if (new_transmit_hold_count >= RSTP_MIN_TRANSMIT_HOLD_COUNT
587         && new_transmit_hold_count <= RSTP_MAX_TRANSMIT_HOLD_COUNT) {
588         struct rstp_port *p;
589
590         VLOG_DBG("%s: set RSTP Transmit Hold Count to %d", rstp->name,
591                  new_transmit_hold_count);
592         /* Resetting txCount on all ports [17.13]. */
593
594         rstp->transmit_hold_count = new_transmit_hold_count;
595         HMAP_FOR_EACH (p, node, &rstp->ports) {
596             p->tx_count = 0;
597         }
598     }
599 }
600
601 void
602 rstp_set_bridge_transmit_hold_count(struct rstp *rstp,
603                                     int new_transmit_hold_count)
604     OVS_EXCLUDED(rstp_mutex)
605 {
606     ovs_mutex_lock(&rstp_mutex);
607     rstp_set_bridge_transmit_hold_count__(rstp, new_transmit_hold_count);
608     ovs_mutex_unlock(&rstp_mutex);
609 }
610
611 /* Sets the bridge migrate time parameter. */
612 static void
613 rstp_set_bridge_migrate_time__(struct rstp *rstp)
614     OVS_REQUIRES(rstp_mutex)
615 {
616     VLOG_DBG("%s: set RSTP Migrate Time to %d", rstp->name,
617              RSTP_MIGRATE_TIME);
618     /* 3 is the only acceptable value */
619     rstp->migrate_time = RSTP_MIGRATE_TIME;
620 }
621
622 /* Sets the bridge times. */
623 static void
624 rstp_set_bridge_times__(struct rstp *rstp, int new_forward_delay,
625                         int new_hello_time, int new_max_age,
626                         int new_message_age)
627     OVS_REQUIRES(rstp_mutex)
628 {
629     VLOG_DBG("%s: set RSTP times to (%d, %d, %d, %d)", rstp->name,
630              new_forward_delay, new_hello_time, new_max_age, new_message_age);
631     if (new_forward_delay >= RSTP_MIN_BRIDGE_FORWARD_DELAY
632         && new_forward_delay <= RSTP_MAX_BRIDGE_FORWARD_DELAY) {
633         rstp->bridge_times.forward_delay = new_forward_delay;
634     }
635     if (new_hello_time == RSTP_BRIDGE_HELLO_TIME) {
636         rstp->bridge_times.hello_time = new_hello_time;
637     }
638     if (new_max_age >= RSTP_MIN_BRIDGE_MAX_AGE
639         && new_max_age <= RSTP_MAX_BRIDGE_MAX_AGE) {
640         rstp->bridge_times.max_age = new_max_age;
641     }
642     rstp->bridge_times.message_age = new_message_age;
643 }
644
645 /* Sets the port id, it is called by rstp_port_set_port_number__() or
646  * rstp_port_set_priority__().
647  */
648 static void
649 set_port_id__(struct rstp_port *p)
650     OVS_REQUIRES(rstp_mutex)
651 {
652     struct rstp *rstp;
653
654     rstp = p->rstp;
655     /* [9.2.7] Port identifier. */
656     p->port_id = p->port_number | (p->priority << 8);
657     VLOG_DBG("%s: new RSTP port id "RSTP_PORT_ID_FMT"", rstp->name,
658              p->port_id);
659 }
660
661 /* Sets the port priority. */
662 static void
663 rstp_port_set_priority__(struct rstp_port *port, int priority)
664     OVS_REQUIRES(rstp_mutex)
665 {
666     if (priority >= RSTP_MIN_PORT_PRIORITY
667         && priority <= RSTP_MAX_PORT_PRIORITY) {
668         VLOG_DBG("%s, port %u: set RSTP port priority to %d", port->rstp->name,
669                  port->port_number, priority);
670
671         priority -= priority % RSTP_STEP_PORT_PRIORITY;
672         port->priority = priority;
673         set_port_id__(port);
674         port->selected = false;
675         port->reselect = true;
676     }
677 }
678
679 /* Checks if a port number is available. */
680 static bool
681 is_port_number_available__(struct rstp *rstp, int n, struct rstp_port *port)
682     OVS_REQUIRES(rstp_mutex)
683 {
684     if (n >= 1 && n <= RSTP_MAX_PORTS) {
685         struct rstp_port *p = rstp_get_port__(rstp, n);
686
687         return p == NULL || p == port;
688     }
689     return false;
690 }
691
692 static uint16_t
693 rstp_first_free_number__(struct rstp *rstp, struct rstp_port *rstp_port)
694     OVS_REQUIRES(rstp_mutex)
695 {
696     int free_number = 1;
697
698     while (free_number <= RSTP_MAX_PORTS) {
699         if (is_port_number_available__(rstp, free_number, rstp_port)) {
700             return free_number;
701         }
702         free_number++;
703     }
704     VLOG_DBG("%s, No free port number available.", rstp->name);
705     return 0;
706 }
707
708 /* Sets the port number. */
709 static void
710 rstp_port_set_port_number__(struct rstp_port *port, uint16_t port_number)
711     OVS_REQUIRES(rstp_mutex)
712 {
713     /* If new_port_number is available, use it, otherwise use the first free
714      * available port number. */
715     port->port_number =
716         is_port_number_available__(port->rstp, port_number, port)
717         ? port_number
718         : rstp_first_free_number__(port->rstp, port);
719
720     set_port_id__(port);
721     /* [17.13] is not clear. I suppose that a port number change
722      * should trigger reselection like a port priority change. */
723     port->selected = false;
724     port->reselect = true;
725
726     VLOG_DBG("%s: set new RSTP port number %d", port->rstp->name,
727              port->port_number);
728 }
729
730 /* Converts the link speed to a port path cost [Table 17-3]. */
731 uint32_t
732 rstp_convert_speed_to_cost(unsigned int speed)
733 {
734     uint32_t value;
735
736     value = speed >= 10000000 ? 2 /* 10 Tb/s. */
737           : speed >= 1000000 ? 20 /* 1 Tb/s. */
738           : speed >= 100000 ? 200 /* 100 Gb/s. */
739           : speed >= 10000 ? 2000 /* 10 Gb/s. */
740           : speed >= 1000 ? 20000 /* 1 Gb/s. */
741           : speed >= 100 ? 200000 /* 100 Mb/s. */
742           : speed >= 10 ? 2000000 /* 10 Mb/s. */
743           : speed >= 1 ? 20000000 /* 1 Mb/s. */
744           : RSTP_DEFAULT_PORT_PATH_COST; /* 100 Mb/s. */
745
746     return value;
747 }
748
749 /* Sets the port path cost. */
750 static void
751 rstp_port_set_path_cost__(struct rstp_port *port, uint32_t path_cost)
752     OVS_REQUIRES(rstp_mutex)
753 {
754     if (path_cost >= RSTP_MIN_PORT_PATH_COST
755         && path_cost <= RSTP_MAX_PORT_PATH_COST) {
756         VLOG_DBG("%s, port %u, set RSTP port path cost to %d",
757                  port->rstp->name, port->port_number, path_cost);
758
759         port->port_path_cost = path_cost;
760         port->selected = false;
761         port->reselect = true;
762     }
763 }
764
765 /* Gets the root path cost. */
766 uint32_t
767 rstp_get_root_path_cost(const struct rstp *rstp)
768     OVS_EXCLUDED(rstp_mutex)
769 {
770     uint32_t cost;
771
772     ovs_mutex_lock(&rstp_mutex);
773     cost = rstp->root_priority.root_path_cost;
774     ovs_mutex_unlock(&rstp_mutex);
775     return cost;
776 }
777
778 /* Returns true if something has happened to 'rstp' which necessitates
779  * flushing the client's MAC learning table.
780  */
781 bool
782 rstp_check_and_reset_fdb_flush(struct rstp *rstp)
783     OVS_EXCLUDED(rstp_mutex)
784 {
785     bool needs_flush;
786     struct rstp_port *p;
787
788     needs_flush = false;
789
790     ovs_mutex_lock(&rstp_mutex);
791     HMAP_FOR_EACH (p, node, &rstp->ports) {
792         if (p->fdb_flush) {
793             needs_flush = true;
794             /* fdb_flush should be reset by the filtering database
795              * once the entries are removed if rstp_version is TRUE, and
796              * immediately if stp_version is TRUE.*/
797             p->fdb_flush = false;
798         }
799     }
800     ovs_mutex_unlock(&rstp_mutex);
801     return needs_flush;
802 }
803
804 /* Finds a port whose state has changed, and returns the aux pointer set for
805  * the port.  A NULL pointer is returned when no changed port is found.  On
806  * return '*portp' contains the pointer to the rstp port that changed, or NULL
807  * if no changed port can be found.
808  *
809  * If '*portp' is passed as non-NULL, it must be the value set by the last
810  * invocation of this function.
811  *
812  * This function may only be called by the thread that creates and deletes
813  * ports.  Otherwise this function is not thread safe, as the returned
814  * '*portp' could become stale before it is used in the next invocation. */
815 void *
816 rstp_get_next_changed_port_aux(struct rstp *rstp, struct rstp_port **portp)
817 {
818     void *aux = NULL;
819
820     ovs_mutex_lock(&rstp_mutex);
821     if (*portp == NULL) {
822         struct rstp_port *p;
823
824         HMAP_FOR_EACH (p, node, &rstp->ports) {
825             if (p->state_changed) {
826                 p->state_changed = false;
827                 aux = p->aux;
828                 *portp = p;
829                 goto out;
830             }
831         }
832     } else { /* continue */
833         struct rstp_port *p = *portp;
834
835         HMAP_FOR_EACH_CONTINUE (p, node, &rstp->ports) {
836             if (p->state_changed) {
837                 p->state_changed = false;
838                 aux = p->aux;
839                 *portp = p;
840                 goto out;
841             }
842         }
843     }
844     /* No changed port found. */
845     *portp = NULL;
846 out:
847     ovs_mutex_unlock(&rstp_mutex);
848     return aux;
849 }
850
851 /* Returns the port in 'rstp' with number 'port_number'.
852  *
853  * XXX: May only be called while concurrent deletion of ports is excluded. */
854 static struct rstp_port *
855 rstp_get_port__(struct rstp *rstp, uint16_t port_number)
856     OVS_REQUIRES(rstp_mutex)
857 {
858     struct rstp_port *port;
859
860     ovs_assert(rstp && port_number > 0 && port_number <= RSTP_MAX_PORTS);
861
862     HMAP_FOR_EACH_WITH_HASH (port, node, hash_int(port_number, 0),
863                              &rstp->ports) {
864         if (port->port_number == port_number) {
865             return port;
866         }
867     }
868     return NULL;
869 }
870
871 struct rstp_port *
872 rstp_get_port(struct rstp *rstp, uint16_t port_number)
873     OVS_EXCLUDED(rstp_mutex)
874 {
875     struct rstp_port *p;
876
877     ovs_mutex_lock(&rstp_mutex);
878     p = rstp_get_port__(rstp, port_number);
879     ovs_mutex_unlock(&rstp_mutex);
880     return p;
881 }
882
883 void *
884 rstp_get_port_aux(struct rstp *rstp, uint16_t port_number)
885     OVS_EXCLUDED(rstp_mutex)
886 {
887     struct rstp_port *p;
888     void *aux;
889
890     ovs_mutex_lock(&rstp_mutex);
891     p = rstp_get_port__(rstp, port_number);
892     aux = p->aux;
893     ovs_mutex_unlock(&rstp_mutex);
894     return aux;
895 }
896
897 /* Updates the port_enabled parameter. */
898 static void
899 update_port_enabled__(struct rstp_port *p)
900     OVS_REQUIRES(rstp_mutex)
901 {
902     if (p->mac_operational && p->is_administrative_bridge_port
903         == RSTP_ADMIN_BRIDGE_PORT_STATE_ENABLED) {
904         p->port_enabled = true;
905     } else {
906         p->port_enabled = false;
907     }
908 }
909
910 /* Sets the port MAC_Operational parameter [6.4.2]. */
911 void
912 rstp_port_set_mac_operational(struct rstp_port *p, bool new_mac_operational)
913     OVS_EXCLUDED(rstp_mutex)
914 {
915     struct rstp *rstp;
916
917     ovs_mutex_lock(&rstp_mutex);
918     rstp = p->rstp;
919     if (p->mac_operational != new_mac_operational) {
920         p->mac_operational = new_mac_operational;
921         update_port_enabled__(p);
922         rstp->changes = true;
923         move_rstp__(rstp);
924     }
925     ovs_mutex_unlock(&rstp_mutex);
926 }
927
928 /* Sets the port Administrative Bridge Port parameter. */
929 static void
930 rstp_port_set_administrative_bridge_port__(struct rstp_port *p,
931                                            uint8_t admin_port_state)
932     OVS_REQUIRES(rstp_mutex)
933 {
934     VLOG_DBG("%s, port %u: set RSTP port admin-port-state to %d",
935              p->rstp->name, p->port_number, admin_port_state);
936
937     if (admin_port_state == RSTP_ADMIN_BRIDGE_PORT_STATE_DISABLED
938         || admin_port_state == RSTP_ADMIN_BRIDGE_PORT_STATE_ENABLED) {
939
940         p->is_administrative_bridge_port = admin_port_state;
941         update_port_enabled__(p);
942     }
943 }
944
945 /* Sets the port oper_point_to_point_mac parameter. */
946 static void
947 rstp_port_set_oper_point_to_point_mac__(struct rstp_port *p,
948                                         uint8_t new_oper_p2p_mac)
949     OVS_REQUIRES(rstp_mutex)
950 {
951     if (new_oper_p2p_mac == RSTP_OPER_P2P_MAC_STATE_DISABLED
952         || new_oper_p2p_mac == RSTP_OPER_P2P_MAC_STATE_ENABLED) {
953
954         p->oper_point_to_point_mac = new_oper_p2p_mac;
955         update_port_enabled__(p);
956     }
957 }
958
959 /* Initializes a port with the defaults values for its parameters. */
960 static void
961 rstp_initialize_port_defaults__(struct rstp_port *p)
962     OVS_REQUIRES(rstp_mutex)
963 {
964     rstp_port_set_administrative_bridge_port__(p,
965                                          RSTP_ADMIN_BRIDGE_PORT_STATE_ENABLED);
966     rstp_port_set_oper_point_to_point_mac__(p,
967                                          RSTP_OPER_P2P_MAC_STATE_ENABLED);
968     rstp_port_set_path_cost__(p, RSTP_DEFAULT_PORT_PATH_COST);
969     rstp_port_set_admin_edge__(p, false);
970     rstp_port_set_auto_edge__(p, true);
971     rstp_port_set_mcheck__(p, false);
972
973     /* Initialize state machines. */
974     p->port_receive_sm_state = PORT_RECEIVE_SM_INIT;
975     p->port_protocol_migration_sm_state = PORT_PROTOCOL_MIGRATION_SM_INIT;
976     p->bridge_detection_sm_state = BRIDGE_DETECTION_SM_INIT;
977     p->port_transmit_sm_state = PORT_TRANSMIT_SM_INIT;
978     p->port_information_sm_state = PORT_INFORMATION_SM_INIT;
979     p->port_role_transition_sm_state = PORT_ROLE_TRANSITION_SM_INIT;
980     p->port_state_transition_sm_state = PORT_STATE_TRANSITION_SM_INIT;
981     p->topology_change_sm_state = TOPOLOGY_CHANGE_SM_INIT;
982     p->uptime = 0;
983
984 }
985
986 static void
987 reinitialize_port__(struct rstp_port *p)
988     OVS_REQUIRES(rstp_mutex)
989 {
990     struct rstp_port temp_port;
991     struct rstp *rstp;
992
993     rstp = p->rstp;
994     temp_port = *p;
995     memset(p, 0, sizeof(struct rstp_port));
996
997     p->ref_cnt = temp_port.ref_cnt;
998     p->rstp = rstp;
999     p->node = temp_port.node;
1000     p->aux = temp_port.aux;
1001     p->port_number = temp_port.port_number;
1002     p->port_priority = temp_port.port_priority;
1003     p->port_id = temp_port.port_id;
1004     p->rstp_state = RSTP_DISCARDING;
1005
1006     rstp_initialize_port_defaults__(p);
1007
1008     VLOG_DBG("%s: RSTP port "RSTP_PORT_ID_FMT" reinitialized.", rstp->name,
1009              p->port_id);
1010 }
1011
1012 void
1013 reinitialize_port(struct rstp_port *p)
1014     OVS_EXCLUDED(rstp_mutex)
1015 {
1016     ovs_mutex_lock(&rstp_mutex);
1017     reinitialize_port__(p);
1018     ovs_mutex_unlock(&rstp_mutex);
1019 }
1020
1021 /* Sets the port state. */
1022 void
1023 rstp_port_set_state__(struct rstp_port *p, enum rstp_state state)
1024     OVS_REQUIRES(rstp_mutex)
1025 {
1026     struct rstp *rstp;
1027
1028     rstp = p->rstp;
1029     VLOG_DBG("%s, port %u: set RSTP port state %s -> %s", rstp->name,
1030              p->port_number,
1031              rstp_state_name(p->rstp_state), rstp_state_name(state));
1032
1033     if (state != p->rstp_state && !p->state_changed) {
1034         p->state_changed = true;
1035         seq_change(connectivity_seq_get());
1036     }
1037     p->rstp_state = state;
1038 }
1039
1040 void
1041 rstp_port_set_state(struct rstp_port *p, enum rstp_state state)
1042     OVS_EXCLUDED(rstp_mutex)
1043 {
1044     ovs_mutex_lock(&rstp_mutex);
1045     rstp_port_set_state__(p, state);
1046     ovs_mutex_unlock(&rstp_mutex);
1047 }
1048
1049 /* Adds a RSTP port. */
1050 struct rstp_port *
1051 rstp_add_port(struct rstp *rstp)
1052     OVS_EXCLUDED(rstp_mutex)
1053 {
1054     struct rstp_port *p = xzalloc(sizeof *p);
1055
1056     ovs_refcount_init(&p->ref_cnt);
1057
1058     ovs_mutex_lock(&rstp_mutex);
1059     p->rstp = rstp;
1060     rstp_port_set_priority__(p, RSTP_DEFAULT_PORT_PRIORITY);
1061     rstp_port_set_port_number__(p, 0);
1062     p->aux = NULL;
1063     rstp_initialize_port_defaults__(p);
1064     VLOG_DBG("%s: RSTP port "RSTP_PORT_ID_FMT" initialized.", rstp->name,
1065              p->port_id);
1066
1067     rstp_port_set_state__(p, RSTP_DISCARDING);
1068     hmap_insert(&rstp->ports, &p->node, hash_int(p->port_number, 0));
1069     rstp->changes = true;
1070     move_rstp__(rstp);
1071     VLOG_DBG("%s: added port "RSTP_PORT_ID_FMT"", rstp->name, p->port_id);
1072     ovs_mutex_unlock(&rstp_mutex);
1073     return p;
1074 }
1075
1076 /* Caller has to hold a reference to prevent 'rstp_port' from being deleted
1077  * while taking a new reference. */
1078 struct rstp_port *
1079 rstp_port_ref(const struct rstp_port *rp_)
1080     OVS_EXCLUDED(rstp_mutex)
1081 {
1082     struct rstp_port *rp = CONST_CAST(struct rstp_port *, rp_);
1083
1084     if (rp) {
1085         ovs_refcount_ref(&rp->ref_cnt);
1086     }
1087     return rp;
1088 }
1089
1090 /* Frees RSTP struct.  This can be caller by any thread. */
1091 void
1092 rstp_port_unref(struct rstp_port *rp)
1093     OVS_EXCLUDED(rstp_mutex)
1094 {
1095     if (rp && ovs_refcount_unref_relaxed(&rp->ref_cnt) == 1) {
1096         struct rstp *rstp;
1097
1098         ovs_mutex_lock(&rstp_mutex);
1099         rstp = rp->rstp;
1100         rstp_port_set_state__(rp, RSTP_DISABLED);
1101         hmap_remove(&rstp->ports, &rp->node);
1102         VLOG_DBG("%s: removed port "RSTP_PORT_ID_FMT"", rstp->name,
1103                  rp->port_id);
1104         ovs_mutex_unlock(&rstp_mutex);
1105         free(rp);
1106     }
1107 }
1108
1109 /* Sets the port Admin Edge parameter. */
1110 static void
1111 rstp_port_set_admin_edge__(struct rstp_port *port, bool admin_edge)
1112      OVS_REQUIRES(rstp_mutex)
1113 {
1114     if (port->admin_edge != admin_edge) {
1115         VLOG_DBG("%s, port %u: set RSTP Admin Edge to %d", port->rstp->name,
1116                  port->port_number, admin_edge);
1117
1118         port->admin_edge = admin_edge;
1119     }
1120 }
1121
1122 /* Sets the port Auto Edge parameter. */
1123 static void
1124 rstp_port_set_auto_edge__(struct rstp_port *port, bool auto_edge)
1125     OVS_REQUIRES(rstp_mutex)
1126 {
1127     if (port->auto_edge != auto_edge) {
1128         VLOG_DBG("%s, port %u: set RSTP Auto Edge to %d", port->rstp->name,
1129                  port->port_number, auto_edge);
1130
1131         port->auto_edge = auto_edge;
1132     }
1133 }
1134
1135 /* Sets the port admin_point_to_point_mac parameter. */
1136 static void rstp_port_set_admin_point_to_point_mac__(struct rstp_port *port,
1137         enum rstp_admin_point_to_point_mac_state admin_p2p_mac_state)
1138     OVS_REQUIRES(rstp_mutex)
1139 {
1140     VLOG_DBG("%s, port %u: set RSTP port admin-point-to-point-mac to %d",
1141             port->rstp->name, port->port_number, admin_p2p_mac_state);
1142
1143     if (admin_p2p_mac_state == RSTP_ADMIN_P2P_MAC_FORCE_TRUE) {
1144         port->admin_point_to_point_mac = admin_p2p_mac_state;
1145         rstp_port_set_oper_point_to_point_mac__(port,
1146                 RSTP_OPER_P2P_MAC_STATE_ENABLED);
1147     } else if (admin_p2p_mac_state == RSTP_ADMIN_P2P_MAC_FORCE_FALSE) {
1148         port->admin_point_to_point_mac = admin_p2p_mac_state;
1149         rstp_port_set_oper_point_to_point_mac__(port,
1150                 RSTP_OPER_P2P_MAC_STATE_DISABLED);
1151     } else if (admin_p2p_mac_state == RSTP_ADMIN_P2P_MAC_AUTO) {
1152         /* If adminPointToPointMAC is set to Auto, then the value of
1153          * operPointToPointMAC is determined in accordance with the
1154          * specific procedures defined for the MAC entity concerned, as
1155          * defined in 6.5. If these procedures determine that the MAC
1156          * entity is connected to a point-to-point LAN, then
1157          * operPointToPointMAC is set TRUE; otherwise it is set FALSE.
1158          * In the absence of a specific definition of how to determine
1159          * whether the MAC is connected to a point-to-point LAN or not,
1160          * the value of operPointToPointMAC shall be FALSE. */
1161         port->admin_point_to_point_mac = admin_p2p_mac_state;
1162         rstp_port_set_oper_point_to_point_mac__(
1163             port, RSTP_OPER_P2P_MAC_STATE_DISABLED);
1164     }
1165 }
1166
1167 /* Sets the port mcheck parameter.
1168  * [17.19.13] May be set by management to force the Port Protocol Migration
1169  * state machine to transmit RST BPDUs for a MigrateTime (17.13.9) period, to
1170  * test whether all STP Bridges (17.4) on the attached LAN have been removed
1171  * and the Port can continue to transmit RSTP BPDUs. Setting mcheck has no
1172  * effect if stpVersion (17.20.12) is TRUE, i.e., the Bridge is operating in
1173  * STP Compatibility mode.
1174  */
1175 static void
1176 rstp_port_set_mcheck__(struct rstp_port *port, bool mcheck)
1177     OVS_REQUIRES(rstp_mutex)
1178 {
1179     if (mcheck == true && port->rstp->force_protocol_version >= 2) {
1180         port->mcheck = true;
1181
1182         VLOG_DBG("%s, port %u: set RSTP mcheck to %d", port->rstp->name,
1183                  port->port_number, mcheck);
1184     }
1185 }
1186
1187 /* Returns the designated bridge id. */
1188 rstp_identifier
1189 rstp_get_designated_id(const struct rstp *rstp)
1190     OVS_EXCLUDED(rstp_mutex)
1191 {
1192     rstp_identifier designated_id;
1193
1194     ovs_mutex_lock(&rstp_mutex);
1195     designated_id = rstp->root_priority.designated_bridge_id;
1196     ovs_mutex_unlock(&rstp_mutex);
1197
1198     return designated_id;
1199 }
1200
1201 /* Returns the root bridge id. */
1202 rstp_identifier
1203 rstp_get_root_id(const struct rstp *rstp)
1204     OVS_EXCLUDED(rstp_mutex)
1205 {
1206     rstp_identifier root_id;
1207
1208     ovs_mutex_lock(&rstp_mutex);
1209     root_id = rstp->root_priority.root_bridge_id;
1210     ovs_mutex_unlock(&rstp_mutex);
1211
1212     return root_id;
1213 }
1214
1215 /* Returns the designated port id. */
1216 uint16_t
1217 rstp_get_designated_port_id(const struct rstp *rstp)
1218     OVS_EXCLUDED(rstp_mutex)
1219 {
1220     uint16_t designated_port_id;
1221
1222     ovs_mutex_lock(&rstp_mutex);
1223     designated_port_id = rstp->root_priority.designated_port_id;
1224     ovs_mutex_unlock(&rstp_mutex);
1225
1226     return designated_port_id;
1227 }
1228
1229 /* Return the bridge port id. */
1230 uint16_t
1231 rstp_get_bridge_port_id(const struct rstp *rstp)
1232     OVS_EXCLUDED(rstp_mutex)
1233 {
1234     uint16_t bridge_port_id;
1235
1236     ovs_mutex_lock(&rstp_mutex);
1237     bridge_port_id = rstp->root_priority.bridge_port_id;
1238     ovs_mutex_unlock(&rstp_mutex);
1239
1240     return bridge_port_id;
1241 }
1242
1243 /* Returns true if the bridge believes to the be root of the spanning tree,
1244  * false otherwise.
1245  */
1246 bool
1247 rstp_is_root_bridge(const struct rstp *rstp)
1248     OVS_EXCLUDED(rstp_mutex)
1249 {
1250     bool is_root;
1251
1252     ovs_mutex_lock(&rstp_mutex);
1253     is_root = rstp->bridge_identifier ==
1254                 rstp->root_priority.designated_bridge_id;
1255     ovs_mutex_unlock(&rstp_mutex);
1256
1257     return is_root;
1258 }
1259
1260 /* Returns the bridge ID of the bridge currently believed to be the root. */
1261 rstp_identifier
1262 rstp_get_designated_root(const struct rstp *rstp)
1263     OVS_EXCLUDED(rstp_mutex)
1264 {
1265     rstp_identifier designated_root;
1266
1267     ovs_mutex_lock(&rstp_mutex);
1268     designated_root = rstp->root_priority.designated_bridge_id;
1269     ovs_mutex_unlock(&rstp_mutex);
1270
1271     return designated_root;
1272 }
1273
1274 /* Returns the port connecting 'rstp' to the root bridge, or a null pointer if
1275  * there is no such port.
1276  */
1277 struct rstp_port *
1278 rstp_get_root_port(struct rstp *rstp)
1279     OVS_EXCLUDED(rstp_mutex)
1280 {
1281     struct rstp_port *p;
1282
1283     ovs_mutex_lock(&rstp_mutex);
1284     HMAP_FOR_EACH (p, node, &rstp->ports) {
1285         if (p->port_id == rstp->root_port_id) {
1286             ovs_mutex_unlock(&rstp_mutex);
1287             return p;
1288         }
1289     }
1290     ovs_mutex_unlock(&rstp_mutex);
1291     return NULL;
1292 }
1293
1294 /* Returns the state of port 'p'. */
1295 enum rstp_state
1296 rstp_port_get_state(const struct rstp_port *p)
1297 {
1298     enum rstp_state state;
1299
1300     ovs_mutex_lock(&rstp_mutex);
1301     state = p->rstp_state;
1302     ovs_mutex_unlock(&rstp_mutex);
1303
1304     return state;
1305 }
1306
1307 /* Retrieves port status. */
1308 void
1309 rstp_port_get_status(const struct rstp_port *p, uint16_t *id,
1310                      enum rstp_state *state, enum rstp_port_role *role,
1311                      rstp_identifier *designated_bridge_id,
1312                      uint16_t *designated_port_id,
1313                      uint32_t *designated_path_cost, int *tx_count,
1314                      int *rx_count, int *error_count, int *uptime)
1315     OVS_EXCLUDED(rstp_mutex)
1316 {
1317     ovs_mutex_lock(&rstp_mutex);
1318     *id = p->port_id;
1319     *state = p->rstp_state;
1320     *role = p->role;
1321
1322     *designated_bridge_id = p->port_priority.designated_bridge_id;
1323     *designated_port_id = p->port_priority.designated_port_id;
1324     *designated_path_cost = p->port_priority.root_path_cost;
1325
1326     *tx_count = p->tx_count;
1327     *rx_count = p->rx_rstp_bpdu_cnt;
1328     *error_count = p->error_count;
1329     *uptime = p->uptime;
1330     ovs_mutex_unlock(&rstp_mutex);
1331 }
1332
1333 void
1334 rstp_port_set(struct rstp_port *port, uint16_t port_num, int priority,
1335               uint32_t path_cost, bool is_admin_edge, bool is_auto_edge,
1336               enum rstp_admin_point_to_point_mac_state admin_p2p_mac_state,
1337               bool admin_port_state, bool do_mcheck, void *aux)
1338     OVS_EXCLUDED(rstp_mutex)
1339 {
1340     ovs_mutex_lock(&rstp_mutex);
1341     port->aux = aux;
1342     rstp_port_set_priority__(port, priority);
1343     rstp_port_set_port_number__(port, port_num);
1344     rstp_port_set_path_cost__(port, path_cost);
1345     rstp_port_set_admin_edge__(port, is_admin_edge);
1346     rstp_port_set_auto_edge__(port, is_auto_edge);
1347     rstp_port_set_admin_point_to_point_mac__(port, admin_p2p_mac_state);
1348     rstp_port_set_administrative_bridge_port__(port, admin_port_state);
1349     rstp_port_set_mcheck__(port, do_mcheck);
1350     ovs_mutex_unlock(&rstp_mutex);
1351 }
1352
1353 /* Individual setters only used by test-rstp.c. */
1354 void
1355 rstp_port_set_priority(struct rstp_port *port, int priority)
1356     OVS_EXCLUDED(rstp_mutex)
1357 {
1358     ovs_mutex_lock(&rstp_mutex);
1359     rstp_port_set_priority__(port, priority);
1360     ovs_mutex_unlock(&rstp_mutex);
1361 }
1362
1363 void
1364 rstp_port_set_path_cost(struct rstp_port *port, uint32_t path_cost)
1365     OVS_EXCLUDED(rstp_mutex)
1366 {
1367     ovs_mutex_lock(&rstp_mutex);
1368     rstp_port_set_path_cost__(port, path_cost);
1369     ovs_mutex_unlock(&rstp_mutex);
1370 }
1371
1372 void
1373 rstp_port_set_aux(struct rstp_port *port, void *aux)
1374     OVS_EXCLUDED(rstp_mutex)
1375 {
1376     ovs_mutex_lock(&rstp_mutex);
1377     port->aux = aux;
1378     ovs_mutex_unlock(&rstp_mutex);
1379 }
1380
1381 /* Unixctl. */
1382 static struct rstp *
1383 rstp_find(const char *name)
1384     OVS_REQUIRES(rstp_mutex)
1385 {
1386     struct rstp *rstp;
1387
1388     LIST_FOR_EACH (rstp, node, all_rstps) {
1389         if (!strcmp(rstp->name, name)) {
1390             return rstp;
1391         }
1392     }
1393     return NULL;
1394 }
1395
1396 static void
1397 rstp_unixctl_tcn(struct unixctl_conn *conn, int argc,
1398                  const char *argv[], void *aux OVS_UNUSED)
1399     OVS_EXCLUDED(rstp_mutex)
1400 {
1401     ovs_mutex_lock(&rstp_mutex);
1402     if (argc > 1) {
1403         struct rstp *rstp = rstp_find(argv[1]);
1404         if (!rstp) {
1405             unixctl_command_reply_error(conn, "No such RSTP object");
1406             goto out;
1407         }
1408         rstp->changes = true;
1409         move_rstp__(rstp);
1410     } else {
1411         struct rstp *rstp;
1412         LIST_FOR_EACH (rstp, node, all_rstps) {
1413             rstp->changes = true;
1414             move_rstp__(rstp);
1415         }
1416     }
1417     unixctl_command_reply(conn, "OK");
1418
1419 out:
1420     ovs_mutex_unlock(&rstp_mutex);
1421 }