2 * Copyright (c) 2008, 2009, 2010, 2011, 2012, 2013, 2014 Nicira, Inc.
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:
8 * http://www.apache.org/licenses/LICENSE-2.0
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.
17 /* Based on sample implementation in 802.1D-1998. Above copyright and license
18 * applies to all modifications. */
23 #include <sys/types.h>
24 #include <netinet/in.h>
25 #include <arpa/inet.h>
28 #include "byte-order.h"
29 #include "connectivity.h"
37 VLOG_DEFINE_THIS_MODULE(stp);
39 #define STP_PROTOCOL_ID 0x0000
40 #define STP_PROTOCOL_VERSION 0x00
41 #define STP_TYPE_CONFIG 0x00
42 #define STP_TYPE_TCN 0x80
45 struct stp_bpdu_header {
46 ovs_be16 protocol_id; /* STP_PROTOCOL_ID. */
47 uint8_t protocol_version; /* STP_PROTOCOL_VERSION. */
48 uint8_t bpdu_type; /* One of STP_TYPE_*. */
50 BUILD_ASSERT_DECL(sizeof(struct stp_bpdu_header) == 4);
52 enum stp_config_bpdu_flags {
53 STP_CONFIG_TOPOLOGY_CHANGE_ACK = 0x80,
54 STP_CONFIG_TOPOLOGY_CHANGE = 0x01
58 struct stp_config_bpdu {
59 struct stp_bpdu_header header; /* Type STP_TYPE_CONFIG. */
60 uint8_t flags; /* STP_CONFIG_* flags. */
61 ovs_be64 root_id; /* 8.5.1.1: Bridge believed to be root. */
62 ovs_be32 root_path_cost; /* 8.5.1.2: Cost of path to root. */
63 ovs_be64 bridge_id; /* 8.5.1.3: ID of transmitting bridge. */
64 ovs_be16 port_id; /* 8.5.1.4: Port transmitting the BPDU. */
65 ovs_be16 message_age; /* 8.5.1.5: Age of BPDU at tx time. */
66 ovs_be16 max_age; /* 8.5.1.6: Timeout for received data. */
67 ovs_be16 hello_time; /* 8.5.1.7: Time between BPDU generation. */
68 ovs_be16 forward_delay; /* 8.5.1.8: State progression delay. */
70 BUILD_ASSERT_DECL(sizeof(struct stp_config_bpdu) == 35);
74 struct stp_bpdu_header header; /* Type STP_TYPE_TCN. */
76 BUILD_ASSERT_DECL(sizeof(struct stp_tcn_bpdu) == 4);
79 bool active; /* Timer in use? */
80 int value; /* Current value of timer, counting up. */
85 void *aux; /* Auxiliary data the user may retrieve. */
86 int port_id; /* 8.5.5.1: Unique port identifier. */
87 enum stp_state state; /* 8.5.5.2: Current state. */
88 int path_cost; /* 8.5.5.3: Cost of tx/rx on this port. */
89 stp_identifier designated_root; /* 8.5.5.4. */
90 int designated_cost; /* 8.5.5.5: Path cost to root on port. */
91 stp_identifier designated_bridge; /* 8.5.5.6. */
92 int designated_port; /* 8.5.5.7: Port to send config msgs on. */
93 bool topology_change_ack; /* 8.5.5.8: Flag for next config BPDU. */
94 bool config_pending; /* 8.5.5.9: Send BPDU when hold expires? */
95 bool change_detection_enabled; /* 8.5.5.10: Detect topology changes? */
97 struct stp_timer message_age_timer; /* 8.5.6.1: Age of received info. */
98 struct stp_timer forward_delay_timer; /* 8.5.6.2: State change timer. */
99 struct stp_timer hold_timer; /* 8.5.6.3: BPDU rate limit timer. */
101 int tx_count; /* Number of BPDUs transmitted. */
102 int rx_count; /* Number of valid BPDUs received. */
103 int error_count; /* Number of bad BPDUs received. */
109 struct list node; /* Node in all_stps list. */
111 /* Static bridge data. */
112 char *name; /* Human-readable name for log messages. */
113 stp_identifier bridge_id; /* 8.5.3.7: This bridge. */
114 int max_age; /* 8.5.3.4: Time to drop received data. */
115 int hello_time; /* 8.5.3.5: Time between sending BPDUs. */
116 int forward_delay; /* 8.5.3.6: Delay between state changes. */
117 int bridge_max_age; /* 8.5.3.8: max_age when we're root. */
118 int bridge_hello_time; /* 8.5.3.9: hello_time as root. */
119 int bridge_forward_delay; /* 8.5.3.10: forward_delay as root. */
120 int rq_max_age; /* User-requested max age, in ms. */
121 int rq_hello_time; /* User-requested hello time, in ms. */
122 int rq_forward_delay; /* User-requested forward delay, in ms. */
123 int elapsed_remainder; /* Left-over msecs from last stp_tick(). */
125 /* Dynamic bridge data. */
126 stp_identifier designated_root; /* 8.5.3.1: Bridge believed to be root. */
127 unsigned int root_path_cost; /* 8.5.3.2: Cost of path to root. */
128 struct stp_port *root_port; /* 8.5.3.3: Lowest cost port to root. */
129 bool topology_change_detected; /* 8.5.3.11: Detected a topology change? */
130 bool topology_change; /* 8.5.3.12: Received topology change? */
133 struct stp_timer hello_timer; /* 8.5.4.1: Hello timer. */
134 struct stp_timer tcn_timer; /* 8.5.4.2: Topology change timer. */
135 struct stp_timer topology_change_timer; /* 8.5.4.3. */
138 struct stp_port ports[STP_MAX_PORTS];
140 /* Interface to client. */
141 bool fdb_needs_flush; /* MAC learning tables needs flushing. */
142 struct stp_port *first_changed_port;
143 void (*send_bpdu)(struct ofpbuf *bpdu, int port_no, void *aux);
146 struct ovs_refcount ref_cnt;
149 static struct ovs_mutex mutex;
150 static struct list all_stps__ = LIST_INITIALIZER(&all_stps__);
151 static struct list *const all_stps OVS_GUARDED_BY(mutex) = &all_stps__;
153 #define FOR_EACH_ENABLED_PORT(PORT, STP) \
154 for ((PORT) = stp_next_enabled_port((STP), (STP)->ports); \
156 (PORT) = stp_next_enabled_port((STP), (PORT) + 1))
157 static struct stp_port *
158 stp_next_enabled_port(const struct stp *stp, const struct stp_port *port)
161 for (; port < &stp->ports[ARRAY_SIZE(stp->ports)]; port++) {
162 if (port->state != STP_DISABLED) {
163 return CONST_CAST(struct stp_port *, port);
169 #define MESSAGE_AGE_INCREMENT 1
171 static void stp_transmit_config(struct stp_port *) OVS_REQUIRES(mutex);
172 static bool stp_supersedes_port_info(const struct stp_port *,
173 const struct stp_config_bpdu *)
175 static void stp_record_config_information(struct stp_port *,
176 const struct stp_config_bpdu *)
178 static void stp_record_config_timeout_values(struct stp *,
179 const struct stp_config_bpdu *)
181 static bool stp_is_designated_port(const struct stp_port *)
183 static void stp_config_bpdu_generation(struct stp *) OVS_REQUIRES(mutex);
184 static void stp_transmit_tcn(struct stp *) OVS_REQUIRES(mutex);
185 static void stp_configuration_update(struct stp *) OVS_REQUIRES(mutex);
186 static bool stp_supersedes_root(const struct stp_port *root,
187 const struct stp_port *) OVS_REQUIRES(mutex);
188 static void stp_root_selection(struct stp *) OVS_REQUIRES(mutex);
189 static void stp_designated_port_selection(struct stp *) OVS_REQUIRES(mutex);
190 static void stp_become_designated_port(struct stp_port *)
192 static void stp_port_state_selection(struct stp *) OVS_REQUIRES(mutex);
193 static void stp_make_forwarding(struct stp_port *) OVS_REQUIRES(mutex);
194 static void stp_make_blocking(struct stp_port *) OVS_REQUIRES(mutex);
195 static void stp_set_port_state(struct stp_port *, enum stp_state)
197 static void stp_topology_change_detection(struct stp *) OVS_REQUIRES(mutex);
198 static void stp_topology_change_acknowledged(struct stp *)
200 static void stp_acknowledge_topology_change(struct stp_port *)
202 static void stp_received_config_bpdu(struct stp *, struct stp_port *,
203 const struct stp_config_bpdu *)
205 static void stp_received_tcn_bpdu(struct stp *, struct stp_port *)
207 static void stp_hello_timer_expiry(struct stp *) OVS_REQUIRES(mutex);
208 static void stp_message_age_timer_expiry(struct stp_port *)
210 static bool stp_is_designated_for_some_port(const struct stp *)
212 static void stp_forward_delay_timer_expiry(struct stp_port *)
214 static void stp_tcn_timer_expiry(struct stp *) OVS_REQUIRES(mutex);
215 static void stp_topology_change_timer_expiry(struct stp *)
217 static void stp_hold_timer_expiry(struct stp_port *) OVS_REQUIRES(mutex);
218 static void stp_initialize_port(struct stp_port *, enum stp_state)
220 static void stp_become_root_bridge(struct stp *) OVS_REQUIRES(mutex);
221 static void stp_update_bridge_timers(struct stp *) OVS_REQUIRES(mutex);
223 static int clamp(int x, int min, int max);
224 static int ms_to_timer(int ms);
225 static int timer_to_ms(int timer);
226 static void stp_start_timer(struct stp_timer *, int value);
227 static void stp_stop_timer(struct stp_timer *);
228 static bool stp_timer_expired(struct stp_timer *, int elapsed, int timeout);
230 static void stp_send_bpdu(struct stp_port *, const void *, size_t)
232 static void stp_unixctl_tcn(struct unixctl_conn *, int argc,
233 const char *argv[], void *aux);
238 unixctl_command_register("stp/tcn", "[bridge]", 0, 1, stp_unixctl_tcn,
242 /* Creates and returns a new STP instance that initially has no ports enabled.
244 * 'bridge_id' should be a 48-bit MAC address as returned by
245 * eth_addr_to_uint64(). 'bridge_id' may also have a priority value in its top
246 * 16 bits; if those bits are set to 0, STP_DEFAULT_BRIDGE_PRIORITY is used.
247 * (This priority may be changed with stp_set_bridge_priority().)
249 * When the bridge needs to send out a BPDU, it calls 'send_bpdu'. This
250 * callback may be called from stp_tick() or stp_received_bpdu(). The
251 * arguments to 'send_bpdu' are an STP BPDU encapsulated in 'bpdu',
252 * the spanning tree port number 'port_no' that should transmit the
253 * packet, and auxiliary data to be passed to the callback in 'aux'.
256 stp_create(const char *name, stp_identifier bridge_id,
257 void (*send_bpdu)(struct ofpbuf *bpdu, int port_no, void *aux),
260 static struct ovsthread_once once = OVSTHREAD_ONCE_INITIALIZER;
264 if (ovsthread_once_start(&once)) {
265 /* We need a recursive mutex because stp_send_bpdu() could loop back
266 * into the stp module through a patch port. This happens
267 * intentionally as part of the unit tests. Ideally we'd ditch
268 * the call back function, but for now this is what we have. */
269 ovs_mutex_init_recursive(&mutex);
270 ovsthread_once_done(&once);
273 ovs_mutex_lock(&mutex);
274 stp = xzalloc(sizeof *stp);
275 stp->name = xstrdup(name);
276 stp->bridge_id = bridge_id;
277 if (!(stp->bridge_id >> 48)) {
278 stp->bridge_id |= (uint64_t) STP_DEFAULT_BRIDGE_PRIORITY << 48;
281 stp->rq_max_age = STP_DEFAULT_MAX_AGE;
282 stp->rq_hello_time = STP_DEFAULT_HELLO_TIME;
283 stp->rq_forward_delay = STP_DEFAULT_FWD_DELAY;
284 stp_update_bridge_timers(stp);
285 stp->max_age = stp->bridge_max_age;
286 stp->hello_time = stp->bridge_hello_time;
287 stp->forward_delay = stp->bridge_forward_delay;
289 stp->designated_root = stp->bridge_id;
290 stp->root_path_cost = 0;
291 stp->root_port = NULL;
292 stp->topology_change_detected = false;
293 stp->topology_change = false;
295 stp_stop_timer(&stp->tcn_timer);
296 stp_stop_timer(&stp->topology_change_timer);
297 stp_start_timer(&stp->hello_timer, 0);
299 stp->send_bpdu = send_bpdu;
302 stp->first_changed_port = &stp->ports[ARRAY_SIZE(stp->ports)];
303 for (p = stp->ports; p < &stp->ports[ARRAY_SIZE(stp->ports)]; p++) {
305 p->port_id = (stp_port_no(p) + 1) | (STP_DEFAULT_PORT_PRIORITY << 8);
306 p->path_cost = 19; /* Recommended default for 100 Mb/s link. */
307 stp_initialize_port(p, STP_DISABLED);
309 ovs_refcount_init(&stp->ref_cnt);
311 list_push_back(all_stps, &stp->node);
312 ovs_mutex_unlock(&mutex);
317 stp_ref(const struct stp *stp_)
319 struct stp *stp = CONST_CAST(struct stp *, stp_);
321 ovs_refcount_ref(&stp->ref_cnt);
326 /* Destroys 'stp'. */
328 stp_unref(struct stp *stp)
330 if (stp && ovs_refcount_unref(&stp->ref_cnt) == 1) {
331 ovs_mutex_lock(&mutex);
332 list_remove(&stp->node);
333 ovs_mutex_unlock(&mutex);
339 /* Runs 'stp' given that 'ms' milliseconds have passed. */
341 stp_tick(struct stp *stp, int ms)
346 ovs_mutex_lock(&mutex);
347 /* Convert 'ms' to STP timer ticks. Preserve any leftover milliseconds
348 * from previous stp_tick() calls so that we don't lose STP ticks when we
349 * are called too frequently. */
350 ms = clamp(ms, 0, INT_MAX - 1000) + stp->elapsed_remainder;
351 elapsed = ms_to_timer(ms);
352 stp->elapsed_remainder = ms - timer_to_ms(elapsed);
357 if (stp_timer_expired(&stp->hello_timer, elapsed, stp->hello_time)) {
358 stp_hello_timer_expiry(stp);
360 if (stp_timer_expired(&stp->tcn_timer, elapsed, stp->bridge_hello_time)) {
361 stp_tcn_timer_expiry(stp);
363 if (stp_timer_expired(&stp->topology_change_timer, elapsed,
364 stp->max_age + stp->forward_delay)) {
365 stp_topology_change_timer_expiry(stp);
367 FOR_EACH_ENABLED_PORT (p, stp) {
368 if (stp_timer_expired(&p->message_age_timer, elapsed, stp->max_age)) {
369 stp_message_age_timer_expiry(p);
372 FOR_EACH_ENABLED_PORT (p, stp) {
373 if (stp_timer_expired(&p->forward_delay_timer, elapsed,
374 stp->forward_delay)) {
375 stp_forward_delay_timer_expiry(p);
377 if (stp_timer_expired(&p->hold_timer, elapsed, ms_to_timer(1000))) {
378 stp_hold_timer_expiry(p);
383 ovs_mutex_unlock(&mutex);
387 set_bridge_id(struct stp *stp, stp_identifier new_bridge_id)
390 if (new_bridge_id != stp->bridge_id) {
394 root = stp_is_root_bridge(stp);
395 FOR_EACH_ENABLED_PORT (p, stp) {
396 if (stp_is_designated_port(p)) {
397 p->designated_bridge = new_bridge_id;
400 stp->bridge_id = new_bridge_id;
401 stp_configuration_update(stp);
402 stp_port_state_selection(stp);
403 if (stp_is_root_bridge(stp) && !root) {
404 stp_become_root_bridge(stp);
410 stp_set_bridge_id(struct stp *stp, stp_identifier bridge_id)
412 const uint64_t mac_bits = (UINT64_C(1) << 48) - 1;
413 const uint64_t pri_bits = ~mac_bits;
414 ovs_mutex_lock(&mutex);
415 set_bridge_id(stp, (stp->bridge_id & pri_bits) | (bridge_id & mac_bits));
416 ovs_mutex_unlock(&mutex);
420 stp_set_bridge_priority(struct stp *stp, uint16_t new_priority)
422 const uint64_t mac_bits = (UINT64_C(1) << 48) - 1;
423 ovs_mutex_lock(&mutex);
424 set_bridge_id(stp, ((stp->bridge_id & mac_bits)
425 | ((uint64_t) new_priority << 48)));
426 ovs_mutex_unlock(&mutex);
429 /* Sets the desired hello time for 'stp' to 'ms', in milliseconds. The actual
430 * hello time is clamped to the range of 1 to 10 seconds and subject to the
431 * relationship (bridge_max_age >= 2 * (bridge_hello_time + 1 s)). The bridge
432 * hello time is only used when 'stp' is the root bridge. */
434 stp_set_hello_time(struct stp *stp, int ms)
436 ovs_mutex_lock(&mutex);
437 stp->rq_hello_time = ms;
438 stp_update_bridge_timers(stp);
439 ovs_mutex_unlock(&mutex);
442 /* Sets the desired max age for 'stp' to 'ms', in milliseconds. The actual max
443 * age is clamped to the range of 6 to 40 seconds and subject to the
444 * relationships (2 * (bridge_forward_delay - 1 s) >= bridge_max_age) and
445 * (bridge_max_age >= 2 * (bridge_hello_time + 1 s)). The bridge max age is
446 * only used when 'stp' is the root bridge. */
448 stp_set_max_age(struct stp *stp, int ms)
450 ovs_mutex_lock(&mutex);
451 stp->rq_max_age = ms;
452 stp_update_bridge_timers(stp);
453 ovs_mutex_unlock(&mutex);
456 /* Sets the desired forward delay for 'stp' to 'ms', in milliseconds. The
457 * actual forward delay is clamped to the range of 4 to 30 seconds and subject
458 * to the relationship (2 * (bridge_forward_delay - 1 s) >= bridge_max_age).
459 * The bridge forward delay is only used when 'stp' is the root bridge. */
461 stp_set_forward_delay(struct stp *stp, int ms)
463 ovs_mutex_lock(&mutex);
464 stp->rq_forward_delay = ms;
465 stp_update_bridge_timers(stp);
466 ovs_mutex_unlock(&mutex);
469 /* Returns the name given to 'stp' in the call to stp_create(). */
471 stp_get_name(const struct stp *stp)
475 ovs_mutex_lock(&mutex);
477 ovs_mutex_unlock(&mutex);
481 /* Returns the bridge ID for 'stp'. */
483 stp_get_bridge_id(const struct stp *stp)
485 stp_identifier bridge_id;
487 ovs_mutex_lock(&mutex);
488 bridge_id = stp->bridge_id;
489 ovs_mutex_unlock(&mutex);
493 /* Returns the bridge ID of the bridge currently believed to be the root. */
495 stp_get_designated_root(const struct stp *stp)
497 stp_identifier designated_root;
499 ovs_mutex_lock(&mutex);
500 designated_root = stp->designated_root;
501 ovs_mutex_unlock(&mutex);
502 return designated_root;
505 /* Returns true if 'stp' believes itself to the be root of the spanning tree,
506 * false otherwise. */
508 stp_is_root_bridge(const struct stp *stp)
512 ovs_mutex_lock(&mutex);
513 is_root = stp->bridge_id == stp->designated_root;
514 ovs_mutex_unlock(&mutex);
518 /* Returns the cost of the path from 'stp' to the root of the spanning tree. */
520 stp_get_root_path_cost(const struct stp *stp)
524 ovs_mutex_lock(&mutex);
525 cost = stp->root_path_cost;
526 ovs_mutex_unlock(&mutex);
530 /* Returns the bridge hello time, in ms. The returned value is not necessarily
531 * the value passed to stp_set_hello_time(): it is clamped to the valid range
532 * and quantized to the STP timer resolution. */
534 stp_get_hello_time(const struct stp *stp)
538 ovs_mutex_lock(&mutex);
539 time = timer_to_ms(stp->bridge_hello_time);
540 ovs_mutex_unlock(&mutex);
544 /* Returns the bridge max age, in ms. The returned value is not necessarily
545 * the value passed to stp_set_max_age(): it is clamped to the valid range,
546 * quantized to the STP timer resolution, and adjusted to match the constraints
547 * due to the hello time. */
549 stp_get_max_age(const struct stp *stp)
553 ovs_mutex_lock(&mutex);
554 time = timer_to_ms(stp->bridge_max_age);
555 ovs_mutex_unlock(&mutex);
559 /* Returns the bridge forward delay, in ms. The returned value is not
560 * necessarily the value passed to stp_set_forward_delay(): it is clamped to
561 * the valid range, quantized to the STP timer resolution, and adjusted to
562 * match the constraints due to the forward delay. */
564 stp_get_forward_delay(const struct stp *stp)
568 ovs_mutex_lock(&mutex);
569 time = timer_to_ms(stp->bridge_forward_delay);
570 ovs_mutex_unlock(&mutex);
574 /* Returns true if something has happened to 'stp' which necessitates flushing
575 * the client's MAC learning table. Calling this function resets 'stp' so that
576 * future calls will return false until flushing is required again. */
578 stp_check_and_reset_fdb_flush(struct stp *stp)
582 ovs_mutex_lock(&mutex);
583 needs_flush = stp->fdb_needs_flush;
584 stp->fdb_needs_flush = false;
585 ovs_mutex_unlock(&mutex);
589 /* Returns the port in 'stp' with index 'port_no', which must be between 0 and
592 stp_get_port(struct stp *stp, int port_no)
594 struct stp_port *port;
596 ovs_mutex_lock(&mutex);
597 ovs_assert(port_no >= 0 && port_no < ARRAY_SIZE(stp->ports));
598 port = &stp->ports[port_no];
599 ovs_mutex_unlock(&mutex);
603 /* Returns the port connecting 'stp' to the root bridge, or a null pointer if
604 * there is no such port. */
606 stp_get_root_port(struct stp *stp)
608 struct stp_port *port;
610 ovs_mutex_lock(&mutex);
611 port = stp->root_port;
612 ovs_mutex_unlock(&mutex);
616 /* Finds a port whose state has changed. If successful, stores the port whose
617 * state changed in '*portp' and returns true. If no port has changed, stores
618 * NULL in '*portp' and returns false. */
620 stp_get_changed_port(struct stp *stp, struct stp_port **portp)
622 struct stp_port *end, *p;
623 bool changed = false;
625 ovs_mutex_lock(&mutex);
626 end = &stp->ports[ARRAY_SIZE(stp->ports)];
627 for (p = stp->first_changed_port; p < end; p++) {
628 if (p->state_changed) {
629 p->state_changed = false;
630 stp->first_changed_port = p + 1;
636 stp->first_changed_port = end;
640 ovs_mutex_unlock(&mutex);
644 /* Returns the name for the given 'state' (for use in debugging and log
647 stp_state_name(enum stp_state state)
665 /* Returns true if 'state' is one in which packets received on a port should
666 * be forwarded, false otherwise.
668 * Returns true if 'state' is STP_DISABLED, since presumably in that case the
669 * port should still work, just not have STP applied to it. */
671 stp_forward_in_state(enum stp_state state)
673 return (state & (STP_DISABLED | STP_FORWARDING)) != 0;
676 /* Returns true if 'state' is one in which MAC learning should be done on
677 * packets received on a port, false otherwise.
679 * Returns true if 'state' is STP_DISABLED, since presumably in that case the
680 * port should still work, just not have STP applied to it. */
682 stp_learn_in_state(enum stp_state state)
684 return (state & (STP_DISABLED | STP_LEARNING | STP_FORWARDING)) != 0;
687 /* Returns the name for the given 'role' (for use in debugging and log
690 stp_role_name(enum stp_role role)
695 case STP_ROLE_DESIGNATED:
697 case STP_ROLE_ALTERNATE:
699 case STP_ROLE_DISABLED:
706 /* Notifies the STP entity that bridge protocol data unit 'bpdu', which is
707 * 'bpdu_size' bytes in length, was received on port 'p'.
709 * This function may call the 'send_bpdu' function provided to stp_create(). */
711 stp_received_bpdu(struct stp_port *p, const void *bpdu, size_t bpdu_size)
713 struct stp *stp = p->stp;
714 const struct stp_bpdu_header *header;
716 ovs_mutex_lock(&mutex);
717 if (p->state == STP_DISABLED) {
721 if (bpdu_size < sizeof(struct stp_bpdu_header)) {
722 VLOG_WARN("%s: received runt %"PRIuSIZE"-byte BPDU", stp->name, bpdu_size);
728 if (header->protocol_id != htons(STP_PROTOCOL_ID)) {
729 VLOG_WARN("%s: received BPDU with unexpected protocol ID %"PRIu16,
730 stp->name, ntohs(header->protocol_id));
734 if (header->protocol_version != STP_PROTOCOL_VERSION) {
735 VLOG_DBG("%s: received BPDU with unexpected protocol version %"PRIu8,
736 stp->name, header->protocol_version);
739 switch (header->bpdu_type) {
740 case STP_TYPE_CONFIG:
741 if (bpdu_size < sizeof(struct stp_config_bpdu)) {
742 VLOG_WARN("%s: received config BPDU with invalid size %"PRIuSIZE,
743 stp->name, bpdu_size);
747 stp_received_config_bpdu(stp, p, bpdu);
751 if (bpdu_size != sizeof(struct stp_tcn_bpdu)) {
752 VLOG_WARN("%s: received TCN BPDU with invalid size %"PRIuSIZE,
753 stp->name, bpdu_size);
757 stp_received_tcn_bpdu(stp, p);
761 VLOG_WARN("%s: received BPDU of unexpected type %"PRIu8,
762 stp->name, header->bpdu_type);
769 ovs_mutex_unlock(&mutex);
772 /* Returns the STP entity in which 'p' is nested. */
774 stp_port_get_stp(struct stp_port *p)
778 ovs_mutex_lock(&mutex);
780 ovs_mutex_unlock(&mutex);
784 /* Sets the 'aux' member of 'p'.
786 * The 'aux' member will be reset to NULL when stp_port_disable() is
787 * called or stp_port_enable() is called when the port is in a Disabled
790 stp_port_set_aux(struct stp_port *p, void *aux)
792 ovs_mutex_lock(&mutex);
794 ovs_mutex_unlock(&mutex);
797 /* Returns the 'aux' member of 'p'. */
799 stp_port_get_aux(struct stp_port *p)
803 ovs_mutex_lock(&mutex);
805 ovs_mutex_unlock(&mutex);
809 /* Returns the index of port 'p' within its bridge. */
811 stp_port_no(const struct stp_port *p)
816 ovs_mutex_lock(&mutex);
818 ovs_assert(p >= stp->ports && p < &stp->ports[ARRAY_SIZE(stp->ports)]);
819 index = p - p->stp->ports;
820 ovs_mutex_unlock(&mutex);
824 /* Returns the port ID for 'p'. */
826 stp_port_get_id(const struct stp_port *p)
830 ovs_mutex_lock(&mutex);
831 port_id = p->port_id;
832 ovs_mutex_unlock(&mutex);
836 /* Returns the state of port 'p'. */
838 stp_port_get_state(const struct stp_port *p)
840 enum stp_state state;
842 ovs_mutex_lock(&mutex);
844 ovs_mutex_unlock(&mutex);
848 /* Returns the role of port 'p'. */
850 stp_port_get_role(const struct stp_port *p)
852 struct stp_port *root_port;
855 ovs_mutex_lock(&mutex);
856 root_port = p->stp->root_port;
857 if (root_port && root_port->port_id == p->port_id) {
858 role = STP_ROLE_ROOT;
859 } else if (stp_is_designated_port(p)) {
860 role = STP_ROLE_DESIGNATED;
861 } else if (p->state == STP_DISABLED) {
862 role = STP_ROLE_DISABLED;
864 role = STP_ROLE_ALTERNATE;
866 ovs_mutex_unlock(&mutex);
870 /* Retrieves BPDU transmit and receive counts for 'p'. */
872 stp_port_get_counts(const struct stp_port *p,
873 int *tx_count, int *rx_count, int *error_count)
875 ovs_mutex_lock(&mutex);
876 *tx_count = p->tx_count;
877 *rx_count = p->rx_count;
878 *error_count = p->error_count;
879 ovs_mutex_unlock(&mutex);
882 /* Disables STP on port 'p'. */
884 stp_port_disable(struct stp_port *p)
888 ovs_mutex_lock(&mutex);
890 if (p->state != STP_DISABLED) {
891 bool root = stp_is_root_bridge(stp);
892 stp_become_designated_port(p);
893 stp_set_port_state(p, STP_DISABLED);
894 p->topology_change_ack = false;
895 p->config_pending = false;
896 stp_stop_timer(&p->message_age_timer);
897 stp_stop_timer(&p->forward_delay_timer);
898 stp_configuration_update(stp);
899 stp_port_state_selection(stp);
900 if (stp_is_root_bridge(stp) && !root) {
901 stp_become_root_bridge(stp);
905 ovs_mutex_unlock(&mutex);
908 /* Enables STP on port 'p'. The port will initially be in "blocking" state. */
910 stp_port_enable(struct stp_port *p)
912 ovs_mutex_lock(&mutex);
913 if (p->state == STP_DISABLED) {
914 stp_initialize_port(p, STP_BLOCKING);
915 stp_port_state_selection(p->stp);
917 ovs_mutex_unlock(&mutex);
920 /* Sets the priority of port 'p' to 'new_priority'. Lower numerical values
921 * are interpreted as higher priorities. */
923 stp_port_set_priority(struct stp_port *p, uint8_t new_priority)
925 uint16_t new_port_id;
927 ovs_mutex_lock(&mutex);
928 new_port_id = (p->port_id & 0xff) | (new_priority << 8);
929 if (p->port_id != new_port_id) {
930 struct stp *stp = p->stp;
931 if (stp_is_designated_port(p)) {
932 p->designated_port = new_port_id;
934 p->port_id = new_port_id;
935 if (stp->bridge_id == p->designated_bridge
936 && p->port_id < p->designated_port) {
937 stp_become_designated_port(p);
938 stp_port_state_selection(stp);
941 ovs_mutex_unlock(&mutex);
944 /* Convert 'speed' (measured in Mb/s) into the path cost. */
946 stp_convert_speed_to_cost(unsigned int speed)
950 ovs_mutex_lock(&mutex);
951 ret = speed >= 10000 ? 2 /* 10 Gb/s. */
952 : speed >= 1000 ? 4 /* 1 Gb/s. */
953 : speed >= 100 ? 19 /* 100 Mb/s. */
954 : speed >= 16 ? 62 /* 16 Mb/s. */
955 : speed >= 10 ? 100 /* 10 Mb/s. */
956 : speed >= 4 ? 250 /* 4 Mb/s. */
957 : 19; /* 100 Mb/s (guess). */
958 ovs_mutex_unlock(&mutex);
962 /* Sets the path cost of port 'p' to 'path_cost'. Lower values are generally
963 * used to indicate faster links. Use stp_port_set_speed() to automatically
964 * generate a default path cost from a link speed. */
966 stp_port_set_path_cost(struct stp_port *p, uint16_t path_cost)
968 ovs_mutex_lock(&mutex);
969 if (p->path_cost != path_cost) {
970 struct stp *stp = p->stp;
971 p->path_cost = path_cost;
972 stp_configuration_update(stp);
973 stp_port_state_selection(stp);
975 ovs_mutex_unlock(&mutex);
978 /* Sets the path cost of port 'p' based on 'speed' (measured in Mb/s). */
980 stp_port_set_speed(struct stp_port *p, unsigned int speed)
982 stp_port_set_path_cost(p, stp_convert_speed_to_cost(speed));
985 /* Enables topology change detection on port 'p'. */
987 stp_port_enable_change_detection(struct stp_port *p)
989 p->change_detection_enabled = true;
992 /* Disables topology change detection on port 'p'. */
994 stp_port_disable_change_detection(struct stp_port *p)
996 p->change_detection_enabled = false;
1000 stp_transmit_config(struct stp_port *p) OVS_REQUIRES(mutex)
1002 struct stp *stp = p->stp;
1003 bool root = stp_is_root_bridge(stp);
1004 if (!root && !stp->root_port) {
1007 if (p->hold_timer.active) {
1008 p->config_pending = true;
1010 struct stp_config_bpdu config;
1011 memset(&config, 0, sizeof config);
1012 config.header.protocol_id = htons(STP_PROTOCOL_ID);
1013 config.header.protocol_version = STP_PROTOCOL_VERSION;
1014 config.header.bpdu_type = STP_TYPE_CONFIG;
1016 if (p->topology_change_ack) {
1017 config.flags |= STP_CONFIG_TOPOLOGY_CHANGE_ACK;
1019 if (stp->topology_change) {
1020 config.flags |= STP_CONFIG_TOPOLOGY_CHANGE;
1022 config.root_id = htonll(stp->designated_root);
1023 config.root_path_cost = htonl(stp->root_path_cost);
1024 config.bridge_id = htonll(stp->bridge_id);
1025 config.port_id = htons(p->port_id);
1027 config.message_age = htons(0);
1029 config.message_age = htons(stp->root_port->message_age_timer.value
1030 + MESSAGE_AGE_INCREMENT);
1032 config.max_age = htons(stp->max_age);
1033 config.hello_time = htons(stp->hello_time);
1034 config.forward_delay = htons(stp->forward_delay);
1035 if (ntohs(config.message_age) < stp->max_age) {
1036 p->topology_change_ack = false;
1037 p->config_pending = false;
1038 stp_send_bpdu(p, &config, sizeof config);
1039 stp_start_timer(&p->hold_timer, 0);
1045 stp_supersedes_port_info(const struct stp_port *p,
1046 const struct stp_config_bpdu *config)
1049 if (ntohll(config->root_id) != p->designated_root) {
1050 return ntohll(config->root_id) < p->designated_root;
1051 } else if (ntohl(config->root_path_cost) != p->designated_cost) {
1052 return ntohl(config->root_path_cost) < p->designated_cost;
1053 } else if (ntohll(config->bridge_id) != p->designated_bridge) {
1054 return ntohll(config->bridge_id) < p->designated_bridge;
1056 return (ntohll(config->bridge_id) != p->stp->bridge_id
1057 || ntohs(config->port_id) <= p->designated_port);
1062 stp_record_config_information(struct stp_port *p,
1063 const struct stp_config_bpdu *config)
1066 p->designated_root = ntohll(config->root_id);
1067 p->designated_cost = ntohl(config->root_path_cost);
1068 p->designated_bridge = ntohll(config->bridge_id);
1069 p->designated_port = ntohs(config->port_id);
1070 stp_start_timer(&p->message_age_timer, ntohs(config->message_age));
1074 stp_record_config_timeout_values(struct stp *stp,
1075 const struct stp_config_bpdu *config)
1078 stp->max_age = ntohs(config->max_age);
1079 stp->hello_time = ntohs(config->hello_time);
1080 stp->forward_delay = ntohs(config->forward_delay);
1081 stp->topology_change = config->flags & STP_CONFIG_TOPOLOGY_CHANGE;
1085 stp_is_designated_port(const struct stp_port *p) OVS_REQUIRES(mutex)
1087 return (p->designated_bridge == p->stp->bridge_id
1088 && p->designated_port == p->port_id);
1092 stp_config_bpdu_generation(struct stp *stp) OVS_REQUIRES(mutex)
1096 FOR_EACH_ENABLED_PORT (p, stp) {
1097 if (stp_is_designated_port(p)) {
1098 stp_transmit_config(p);
1104 stp_transmit_tcn(struct stp *stp) OVS_REQUIRES(mutex)
1106 struct stp_port *p = stp->root_port;
1107 struct stp_tcn_bpdu tcn_bpdu;
1111 tcn_bpdu.header.protocol_id = htons(STP_PROTOCOL_ID);
1112 tcn_bpdu.header.protocol_version = STP_PROTOCOL_VERSION;
1113 tcn_bpdu.header.bpdu_type = STP_TYPE_TCN;
1114 stp_send_bpdu(p, &tcn_bpdu, sizeof tcn_bpdu);
1118 stp_configuration_update(struct stp *stp) OVS_REQUIRES(mutex)
1120 stp_root_selection(stp);
1121 stp_designated_port_selection(stp);
1122 seq_change(connectivity_seq_get());
1126 stp_supersedes_root(const struct stp_port *root, const struct stp_port *p)
1129 int p_cost = p->designated_cost + p->path_cost;
1130 int root_cost = root->designated_cost + root->path_cost;
1132 if (p->designated_root != root->designated_root) {
1133 return p->designated_root < root->designated_root;
1134 } else if (p_cost != root_cost) {
1135 return p_cost < root_cost;
1136 } else if (p->designated_bridge != root->designated_bridge) {
1137 return p->designated_bridge < root->designated_bridge;
1138 } else if (p->designated_port != root->designated_port) {
1139 return p->designated_port < root->designated_port;
1141 return p->port_id < root->port_id;
1146 stp_root_selection(struct stp *stp) OVS_REQUIRES(mutex)
1148 struct stp_port *p, *root;
1151 FOR_EACH_ENABLED_PORT (p, stp) {
1152 if (stp_is_designated_port(p)
1153 || p->designated_root >= stp->bridge_id) {
1156 if (root && !stp_supersedes_root(root, p)) {
1161 stp->root_port = root;
1163 stp->designated_root = stp->bridge_id;
1164 stp->root_path_cost = 0;
1166 stp->designated_root = root->designated_root;
1167 stp->root_path_cost = root->designated_cost + root->path_cost;
1172 stp_designated_port_selection(struct stp *stp) OVS_REQUIRES(mutex)
1176 FOR_EACH_ENABLED_PORT (p, stp) {
1177 if (stp_is_designated_port(p)
1178 || p->designated_root != stp->designated_root
1179 || stp->root_path_cost < p->designated_cost
1180 || (stp->root_path_cost == p->designated_cost
1181 && (stp->bridge_id < p->designated_bridge
1182 || (stp->bridge_id == p->designated_bridge
1183 && p->port_id <= p->designated_port))))
1185 stp_become_designated_port(p);
1191 stp_become_designated_port(struct stp_port *p) OVS_REQUIRES(mutex)
1193 struct stp *stp = p->stp;
1194 p->designated_root = stp->designated_root;
1195 p->designated_cost = stp->root_path_cost;
1196 p->designated_bridge = stp->bridge_id;
1197 p->designated_port = p->port_id;
1201 stp_port_state_selection(struct stp *stp) OVS_REQUIRES(mutex)
1205 FOR_EACH_ENABLED_PORT (p, stp) {
1206 if (p == stp->root_port) {
1207 p->config_pending = false;
1208 p->topology_change_ack = false;
1209 stp_make_forwarding(p);
1210 } else if (stp_is_designated_port(p)) {
1211 stp_stop_timer(&p->message_age_timer);
1212 stp_make_forwarding(p);
1214 p->config_pending = false;
1215 p->topology_change_ack = false;
1216 stp_make_blocking(p);
1222 stp_make_forwarding(struct stp_port *p) OVS_REQUIRES(mutex)
1224 if (p->state == STP_BLOCKING) {
1225 stp_set_port_state(p, STP_LISTENING);
1226 stp_start_timer(&p->forward_delay_timer, 0);
1231 stp_make_blocking(struct stp_port *p) OVS_REQUIRES(mutex)
1233 if (!(p->state & (STP_DISABLED | STP_BLOCKING))) {
1234 if (p->state & (STP_FORWARDING | STP_LEARNING)) {
1235 if (p->change_detection_enabled) {
1236 stp_topology_change_detection(p->stp);
1239 stp_set_port_state(p, STP_BLOCKING);
1240 stp_stop_timer(&p->forward_delay_timer);
1245 stp_set_port_state(struct stp_port *p, enum stp_state state)
1248 if (state != p->state && !p->state_changed) {
1249 p->state_changed = true;
1250 if (p < p->stp->first_changed_port) {
1251 p->stp->first_changed_port = p;
1253 seq_change(connectivity_seq_get());
1259 stp_topology_change_detection(struct stp *stp) OVS_REQUIRES(mutex)
1261 static struct vlog_rate_limit rl = VLOG_RATE_LIMIT_INIT(1, 5);
1263 if (stp_is_root_bridge(stp)) {
1264 stp->topology_change = true;
1265 stp_start_timer(&stp->topology_change_timer, 0);
1266 } else if (!stp->topology_change_detected) {
1267 stp_transmit_tcn(stp);
1268 stp_start_timer(&stp->tcn_timer, 0);
1270 stp->fdb_needs_flush = true;
1271 stp->topology_change_detected = true;
1272 seq_change(connectivity_seq_get());
1273 VLOG_INFO_RL(&rl, "%s: detected topology change.", stp->name);
1277 stp_topology_change_acknowledged(struct stp *stp) OVS_REQUIRES(mutex)
1279 stp->topology_change_detected = false;
1280 stp_stop_timer(&stp->tcn_timer);
1284 stp_acknowledge_topology_change(struct stp_port *p) OVS_REQUIRES(mutex)
1286 p->topology_change_ack = true;
1287 stp_transmit_config(p);
1291 stp_received_config_bpdu(struct stp *stp, struct stp_port *p,
1292 const struct stp_config_bpdu *config)
1295 if (ntohs(config->message_age) >= ntohs(config->max_age)) {
1296 VLOG_WARN("%s: received config BPDU with message age (%u) greater "
1297 "than max age (%u)",
1299 ntohs(config->message_age), ntohs(config->max_age));
1302 if (p->state != STP_DISABLED) {
1303 bool root = stp_is_root_bridge(stp);
1304 if (stp_supersedes_port_info(p, config)) {
1305 stp_record_config_information(p, config);
1306 stp_configuration_update(stp);
1307 stp_port_state_selection(stp);
1308 if (!stp_is_root_bridge(stp) && root) {
1309 stp_stop_timer(&stp->hello_timer);
1310 if (stp->topology_change_detected) {
1311 stp_stop_timer(&stp->topology_change_timer);
1312 stp_transmit_tcn(stp);
1313 stp_start_timer(&stp->tcn_timer, 0);
1316 if (p == stp->root_port) {
1317 stp_record_config_timeout_values(stp, config);
1318 stp_config_bpdu_generation(stp);
1319 if (config->flags & STP_CONFIG_TOPOLOGY_CHANGE_ACK) {
1320 stp_topology_change_acknowledged(stp);
1322 if (config->flags & STP_CONFIG_TOPOLOGY_CHANGE) {
1323 stp->fdb_needs_flush = true;
1326 } else if (stp_is_designated_port(p)) {
1327 stp_transmit_config(p);
1333 stp_received_tcn_bpdu(struct stp *stp, struct stp_port *p)
1336 if (p->state != STP_DISABLED) {
1337 if (stp_is_designated_port(p)) {
1338 stp_topology_change_detection(stp);
1339 stp_acknowledge_topology_change(p);
1345 stp_hello_timer_expiry(struct stp *stp) OVS_REQUIRES(mutex)
1347 stp_config_bpdu_generation(stp);
1348 stp_start_timer(&stp->hello_timer, 0);
1352 stp_message_age_timer_expiry(struct stp_port *p) OVS_REQUIRES(mutex)
1354 struct stp *stp = p->stp;
1355 bool root = stp_is_root_bridge(stp);
1356 stp_become_designated_port(p);
1357 stp_configuration_update(stp);
1358 stp_port_state_selection(stp);
1359 if (stp_is_root_bridge(stp) && !root) {
1360 stp->max_age = stp->bridge_max_age;
1361 stp->hello_time = stp->bridge_hello_time;
1362 stp->forward_delay = stp->bridge_forward_delay;
1363 stp_topology_change_detection(stp);
1364 stp_stop_timer(&stp->tcn_timer);
1365 stp_config_bpdu_generation(stp);
1366 stp_start_timer(&stp->hello_timer, 0);
1371 stp_is_designated_for_some_port(const struct stp *stp) OVS_REQUIRES(mutex)
1373 const struct stp_port *p;
1375 FOR_EACH_ENABLED_PORT (p, stp) {
1376 if (p->designated_bridge == stp->bridge_id) {
1384 stp_forward_delay_timer_expiry(struct stp_port *p) OVS_REQUIRES(mutex)
1386 if (p->state == STP_LISTENING) {
1387 stp_set_port_state(p, STP_LEARNING);
1388 stp_start_timer(&p->forward_delay_timer, 0);
1389 } else if (p->state == STP_LEARNING) {
1390 stp_set_port_state(p, STP_FORWARDING);
1391 if (stp_is_designated_for_some_port(p->stp)) {
1392 if (p->change_detection_enabled) {
1393 stp_topology_change_detection(p->stp);
1400 stp_tcn_timer_expiry(struct stp *stp) OVS_REQUIRES(mutex)
1402 stp_transmit_tcn(stp);
1403 stp_start_timer(&stp->tcn_timer, 0);
1407 stp_topology_change_timer_expiry(struct stp *stp) OVS_REQUIRES(mutex)
1409 stp->topology_change_detected = false;
1410 stp->topology_change = false;
1414 stp_hold_timer_expiry(struct stp_port *p) OVS_REQUIRES(mutex)
1416 if (p->config_pending) {
1417 stp_transmit_config(p);
1422 stp_initialize_port(struct stp_port *p, enum stp_state state)
1425 ovs_assert(state & (STP_DISABLED | STP_BLOCKING));
1426 stp_become_designated_port(p);
1427 stp_set_port_state(p, state);
1428 p->topology_change_ack = false;
1429 p->config_pending = false;
1430 p->change_detection_enabled = true;
1432 stp_stop_timer(&p->message_age_timer);
1433 stp_stop_timer(&p->forward_delay_timer);
1434 stp_stop_timer(&p->hold_timer);
1435 p->tx_count = p->rx_count = p->error_count = 0;
1439 stp_become_root_bridge(struct stp *stp) OVS_REQUIRES(mutex)
1441 stp->max_age = stp->bridge_max_age;
1442 stp->hello_time = stp->bridge_hello_time;
1443 stp->forward_delay = stp->bridge_forward_delay;
1444 stp_topology_change_detection(stp);
1445 stp_stop_timer(&stp->tcn_timer);
1446 stp_config_bpdu_generation(stp);
1447 stp_start_timer(&stp->hello_timer, 0);
1451 stp_start_timer(struct stp_timer *timer, int value) OVS_REQUIRES(mutex)
1453 timer->value = value;
1454 timer->active = true;
1458 stp_stop_timer(struct stp_timer *timer) OVS_REQUIRES(mutex)
1460 timer->active = false;
1464 stp_timer_expired(struct stp_timer *timer, int elapsed, int timeout)
1467 if (timer->active) {
1468 timer->value += elapsed;
1469 if (timer->value >= timeout) {
1470 timer->active = false;
1477 /* Returns the number of whole STP timer ticks in 'ms' milliseconds. There
1478 * are 256 STP timer ticks per second. */
1482 return ms * 0x100 / 1000;
1485 /* Returns the number of whole milliseconds in 'timer' STP timer ticks. There
1486 * are 256 STP timer ticks per second. */
1488 timer_to_ms(int timer)
1490 return timer * 1000 / 0x100;
1494 clamp(int x, int min, int max)
1496 return x < min ? min : x > max ? max : x;
1500 stp_update_bridge_timers(struct stp *stp) OVS_REQUIRES(mutex)
1504 ht = clamp(stp->rq_hello_time, 1000, 10000);
1505 ma = clamp(stp->rq_max_age, MAX(2 * (ht + 1000), 6000), 40000);
1506 fd = clamp(stp->rq_forward_delay, ma / 2 + 1000, 30000);
1508 stp->bridge_hello_time = ms_to_timer(ht);
1509 stp->bridge_max_age = ms_to_timer(ma);
1510 stp->bridge_forward_delay = ms_to_timer(fd);
1512 if (stp_is_root_bridge(stp)) {
1513 stp->max_age = stp->bridge_max_age;
1514 stp->hello_time = stp->bridge_hello_time;
1515 stp->forward_delay = stp->bridge_forward_delay;
1520 stp_send_bpdu(struct stp_port *p, const void *bpdu, size_t bpdu_size)
1523 struct eth_header *eth;
1524 struct llc_header *llc;
1528 pkt = ofpbuf_new(ETH_HEADER_LEN + LLC_HEADER_LEN + bpdu_size);
1529 pkt->l2 = eth = ofpbuf_put_zeros(pkt, sizeof *eth);
1530 llc = ofpbuf_put_zeros(pkt, sizeof *llc);
1531 pkt->l3 = ofpbuf_put(pkt, bpdu, bpdu_size);
1534 memcpy(eth->eth_dst, eth_addr_stp, ETH_ADDR_LEN);
1535 /* p->stp->send_bpdu() must fill in source address. */
1536 eth->eth_type = htons(pkt->size - ETH_HEADER_LEN);
1539 llc->llc_dsap = STP_LLC_DSAP;
1540 llc->llc_ssap = STP_LLC_SSAP;
1541 llc->llc_cntl = STP_LLC_CNTL;
1543 p->stp->send_bpdu(pkt, stp_port_no(p), p->stp->aux);
1550 stp_find(const char *name) OVS_REQUIRES(mutex)
1554 LIST_FOR_EACH (stp, node, all_stps) {
1555 if (!strcmp(stp->name, name)) {
1563 stp_unixctl_tcn(struct unixctl_conn *conn, int argc,
1564 const char *argv[], void *aux OVS_UNUSED)
1566 ovs_mutex_lock(&mutex);
1568 struct stp *stp = stp_find(argv[1]);
1571 unixctl_command_reply_error(conn, "no such stp object");
1574 stp_topology_change_detection(stp);
1578 LIST_FOR_EACH (stp, node, all_stps) {
1579 stp_topology_change_detection(stp);
1583 unixctl_command_reply(conn, "OK");
1586 ovs_mutex_unlock(&mutex);