2 * Copyright (c) 2008, 2009, 2010, 2011, 2012, 2013 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);
335 ovs_refcount_destroy(&stp->ref_cnt);
340 /* Runs 'stp' given that 'ms' milliseconds have passed. */
342 stp_tick(struct stp *stp, int ms)
347 ovs_mutex_lock(&mutex);
348 /* Convert 'ms' to STP timer ticks. Preserve any leftover milliseconds
349 * from previous stp_tick() calls so that we don't lose STP ticks when we
350 * are called too frequently. */
351 ms = clamp(ms, 0, INT_MAX - 1000) + stp->elapsed_remainder;
352 elapsed = ms_to_timer(ms);
353 stp->elapsed_remainder = ms - timer_to_ms(elapsed);
358 if (stp_timer_expired(&stp->hello_timer, elapsed, stp->hello_time)) {
359 stp_hello_timer_expiry(stp);
361 if (stp_timer_expired(&stp->tcn_timer, elapsed, stp->bridge_hello_time)) {
362 stp_tcn_timer_expiry(stp);
364 if (stp_timer_expired(&stp->topology_change_timer, elapsed,
365 stp->max_age + stp->forward_delay)) {
366 stp_topology_change_timer_expiry(stp);
368 FOR_EACH_ENABLED_PORT (p, stp) {
369 if (stp_timer_expired(&p->message_age_timer, elapsed, stp->max_age)) {
370 stp_message_age_timer_expiry(p);
373 FOR_EACH_ENABLED_PORT (p, stp) {
374 if (stp_timer_expired(&p->forward_delay_timer, elapsed,
375 stp->forward_delay)) {
376 stp_forward_delay_timer_expiry(p);
378 if (stp_timer_expired(&p->hold_timer, elapsed, ms_to_timer(1000))) {
379 stp_hold_timer_expiry(p);
384 ovs_mutex_unlock(&mutex);
388 set_bridge_id(struct stp *stp, stp_identifier new_bridge_id)
391 if (new_bridge_id != stp->bridge_id) {
395 root = stp_is_root_bridge(stp);
396 FOR_EACH_ENABLED_PORT (p, stp) {
397 if (stp_is_designated_port(p)) {
398 p->designated_bridge = new_bridge_id;
401 stp->bridge_id = new_bridge_id;
402 stp_configuration_update(stp);
403 stp_port_state_selection(stp);
404 if (stp_is_root_bridge(stp) && !root) {
405 stp_become_root_bridge(stp);
411 stp_set_bridge_id(struct stp *stp, stp_identifier bridge_id)
413 const uint64_t mac_bits = (UINT64_C(1) << 48) - 1;
414 const uint64_t pri_bits = ~mac_bits;
415 ovs_mutex_lock(&mutex);
416 set_bridge_id(stp, (stp->bridge_id & pri_bits) | (bridge_id & mac_bits));
417 ovs_mutex_unlock(&mutex);
421 stp_set_bridge_priority(struct stp *stp, uint16_t new_priority)
423 const uint64_t mac_bits = (UINT64_C(1) << 48) - 1;
424 ovs_mutex_lock(&mutex);
425 set_bridge_id(stp, ((stp->bridge_id & mac_bits)
426 | ((uint64_t) new_priority << 48)));
427 ovs_mutex_unlock(&mutex);
430 /* Sets the desired hello time for 'stp' to 'ms', in milliseconds. The actual
431 * hello time is clamped to the range of 1 to 10 seconds and subject to the
432 * relationship (bridge_max_age >= 2 * (bridge_hello_time + 1 s)). The bridge
433 * hello time is only used when 'stp' is the root bridge. */
435 stp_set_hello_time(struct stp *stp, int ms)
437 ovs_mutex_lock(&mutex);
438 stp->rq_hello_time = ms;
439 stp_update_bridge_timers(stp);
440 ovs_mutex_unlock(&mutex);
443 /* Sets the desired max age for 'stp' to 'ms', in milliseconds. The actual max
444 * age is clamped to the range of 6 to 40 seconds and subject to the
445 * relationships (2 * (bridge_forward_delay - 1 s) >= bridge_max_age) and
446 * (bridge_max_age >= 2 * (bridge_hello_time + 1 s)). The bridge max age is
447 * only used when 'stp' is the root bridge. */
449 stp_set_max_age(struct stp *stp, int ms)
451 ovs_mutex_lock(&mutex);
452 stp->rq_max_age = ms;
453 stp_update_bridge_timers(stp);
454 ovs_mutex_unlock(&mutex);
457 /* Sets the desired forward delay for 'stp' to 'ms', in milliseconds. The
458 * actual forward delay is clamped to the range of 4 to 30 seconds and subject
459 * to the relationship (2 * (bridge_forward_delay - 1 s) >= bridge_max_age).
460 * The bridge forward delay is only used when 'stp' is the root bridge. */
462 stp_set_forward_delay(struct stp *stp, int ms)
464 ovs_mutex_lock(&mutex);
465 stp->rq_forward_delay = ms;
466 stp_update_bridge_timers(stp);
467 ovs_mutex_unlock(&mutex);
470 /* Returns the name given to 'stp' in the call to stp_create(). */
472 stp_get_name(const struct stp *stp)
476 ovs_mutex_lock(&mutex);
478 ovs_mutex_unlock(&mutex);
482 /* Returns the bridge ID for 'stp'. */
484 stp_get_bridge_id(const struct stp *stp)
486 stp_identifier bridge_id;
488 ovs_mutex_lock(&mutex);
489 bridge_id = stp->bridge_id;
490 ovs_mutex_unlock(&mutex);
494 /* Returns the bridge ID of the bridge currently believed to be the root. */
496 stp_get_designated_root(const struct stp *stp)
498 stp_identifier designated_root;
500 ovs_mutex_lock(&mutex);
501 designated_root = stp->designated_root;
502 ovs_mutex_unlock(&mutex);
503 return designated_root;
506 /* Returns true if 'stp' believes itself to the be root of the spanning tree,
507 * false otherwise. */
509 stp_is_root_bridge(const struct stp *stp)
513 ovs_mutex_lock(&mutex);
514 is_root = stp->bridge_id == stp->designated_root;
515 ovs_mutex_unlock(&mutex);
519 /* Returns the cost of the path from 'stp' to the root of the spanning tree. */
521 stp_get_root_path_cost(const struct stp *stp)
525 ovs_mutex_lock(&mutex);
526 cost = stp->root_path_cost;
527 ovs_mutex_unlock(&mutex);
531 /* Returns the bridge hello time, in ms. The returned value is not necessarily
532 * the value passed to stp_set_hello_time(): it is clamped to the valid range
533 * and quantized to the STP timer resolution. */
535 stp_get_hello_time(const struct stp *stp)
539 ovs_mutex_lock(&mutex);
540 time = timer_to_ms(stp->bridge_hello_time);
541 ovs_mutex_unlock(&mutex);
545 /* Returns the bridge max age, in ms. The returned value is not necessarily
546 * the value passed to stp_set_max_age(): it is clamped to the valid range,
547 * quantized to the STP timer resolution, and adjusted to match the constraints
548 * due to the hello time. */
550 stp_get_max_age(const struct stp *stp)
554 ovs_mutex_lock(&mutex);
555 time = timer_to_ms(stp->bridge_max_age);
556 ovs_mutex_unlock(&mutex);
560 /* Returns the bridge forward delay, in ms. The returned value is not
561 * necessarily the value passed to stp_set_forward_delay(): it is clamped to
562 * the valid range, quantized to the STP timer resolution, and adjusted to
563 * match the constraints due to the forward delay. */
565 stp_get_forward_delay(const struct stp *stp)
569 ovs_mutex_lock(&mutex);
570 time = timer_to_ms(stp->bridge_forward_delay);
571 ovs_mutex_unlock(&mutex);
575 /* Returns true if something has happened to 'stp' which necessitates flushing
576 * the client's MAC learning table. Calling this function resets 'stp' so that
577 * future calls will return false until flushing is required again. */
579 stp_check_and_reset_fdb_flush(struct stp *stp)
583 ovs_mutex_lock(&mutex);
584 needs_flush = stp->fdb_needs_flush;
585 stp->fdb_needs_flush = false;
586 ovs_mutex_unlock(&mutex);
590 /* Returns the port in 'stp' with index 'port_no', which must be between 0 and
593 stp_get_port(struct stp *stp, int port_no)
595 struct stp_port *port;
597 ovs_mutex_lock(&mutex);
598 ovs_assert(port_no >= 0 && port_no < ARRAY_SIZE(stp->ports));
599 port = &stp->ports[port_no];
600 ovs_mutex_unlock(&mutex);
604 /* Returns the port connecting 'stp' to the root bridge, or a null pointer if
605 * there is no such port. */
607 stp_get_root_port(struct stp *stp)
609 struct stp_port *port;
611 ovs_mutex_lock(&mutex);
612 port = stp->root_port;
613 ovs_mutex_unlock(&mutex);
617 /* Finds a port whose state has changed. If successful, stores the port whose
618 * state changed in '*portp' and returns true. If no port has changed, stores
619 * NULL in '*portp' and returns false. */
621 stp_get_changed_port(struct stp *stp, struct stp_port **portp)
623 struct stp_port *end, *p;
624 bool changed = false;
626 ovs_mutex_lock(&mutex);
627 end = &stp->ports[ARRAY_SIZE(stp->ports)];
628 for (p = stp->first_changed_port; p < end; p++) {
629 if (p->state_changed) {
630 p->state_changed = false;
631 stp->first_changed_port = p + 1;
637 stp->first_changed_port = end;
641 ovs_mutex_unlock(&mutex);
645 /* Returns the name for the given 'state' (for use in debugging and log
648 stp_state_name(enum stp_state state)
666 /* Returns true if 'state' is one in which packets received on a port should
667 * be forwarded, false otherwise.
669 * Returns true if 'state' is STP_DISABLED, since presumably in that case the
670 * port should still work, just not have STP applied to it. */
672 stp_forward_in_state(enum stp_state state)
674 return (state & (STP_DISABLED | STP_FORWARDING)) != 0;
677 /* Returns true if 'state' is one in which MAC learning should be done on
678 * packets received on a port, false otherwise.
680 * Returns true if 'state' is STP_DISABLED, since presumably in that case the
681 * port should still work, just not have STP applied to it. */
683 stp_learn_in_state(enum stp_state state)
685 return (state & (STP_DISABLED | STP_LEARNING | STP_FORWARDING)) != 0;
688 /* Returns the name for the given 'role' (for use in debugging and log
691 stp_role_name(enum stp_role role)
696 case STP_ROLE_DESIGNATED:
698 case STP_ROLE_ALTERNATE:
700 case STP_ROLE_DISABLED:
707 /* Notifies the STP entity that bridge protocol data unit 'bpdu', which is
708 * 'bpdu_size' bytes in length, was received on port 'p'.
710 * This function may call the 'send_bpdu' function provided to stp_create(). */
712 stp_received_bpdu(struct stp_port *p, const void *bpdu, size_t bpdu_size)
714 struct stp *stp = p->stp;
715 const struct stp_bpdu_header *header;
717 ovs_mutex_lock(&mutex);
718 if (p->state == STP_DISABLED) {
722 if (bpdu_size < sizeof(struct stp_bpdu_header)) {
723 VLOG_WARN("%s: received runt %"PRIuSIZE"-byte BPDU", stp->name, bpdu_size);
729 if (header->protocol_id != htons(STP_PROTOCOL_ID)) {
730 VLOG_WARN("%s: received BPDU with unexpected protocol ID %"PRIu16,
731 stp->name, ntohs(header->protocol_id));
735 if (header->protocol_version != STP_PROTOCOL_VERSION) {
736 VLOG_DBG("%s: received BPDU with unexpected protocol version %"PRIu8,
737 stp->name, header->protocol_version);
740 switch (header->bpdu_type) {
741 case STP_TYPE_CONFIG:
742 if (bpdu_size < sizeof(struct stp_config_bpdu)) {
743 VLOG_WARN("%s: received config BPDU with invalid size %"PRIuSIZE,
744 stp->name, bpdu_size);
748 stp_received_config_bpdu(stp, p, bpdu);
752 if (bpdu_size != sizeof(struct stp_tcn_bpdu)) {
753 VLOG_WARN("%s: received TCN BPDU with invalid size %"PRIuSIZE,
754 stp->name, bpdu_size);
758 stp_received_tcn_bpdu(stp, p);
762 VLOG_WARN("%s: received BPDU of unexpected type %"PRIu8,
763 stp->name, header->bpdu_type);
770 ovs_mutex_unlock(&mutex);
773 /* Returns the STP entity in which 'p' is nested. */
775 stp_port_get_stp(struct stp_port *p)
779 ovs_mutex_lock(&mutex);
781 ovs_mutex_unlock(&mutex);
785 /* Sets the 'aux' member of 'p'.
787 * The 'aux' member will be reset to NULL when stp_port_disable() is
788 * called or stp_port_enable() is called when the port is in a Disabled
791 stp_port_set_aux(struct stp_port *p, void *aux)
793 ovs_mutex_lock(&mutex);
795 ovs_mutex_unlock(&mutex);
798 /* Returns the 'aux' member of 'p'. */
800 stp_port_get_aux(struct stp_port *p)
804 ovs_mutex_lock(&mutex);
806 ovs_mutex_unlock(&mutex);
810 /* Returns the index of port 'p' within its bridge. */
812 stp_port_no(const struct stp_port *p)
817 ovs_mutex_lock(&mutex);
819 ovs_assert(p >= stp->ports && p < &stp->ports[ARRAY_SIZE(stp->ports)]);
820 index = p - p->stp->ports;
821 ovs_mutex_unlock(&mutex);
825 /* Returns the port ID for 'p'. */
827 stp_port_get_id(const struct stp_port *p)
831 ovs_mutex_lock(&mutex);
832 port_id = p->port_id;
833 ovs_mutex_unlock(&mutex);
837 /* Returns the state of port 'p'. */
839 stp_port_get_state(const struct stp_port *p)
841 enum stp_state state;
843 ovs_mutex_lock(&mutex);
845 ovs_mutex_unlock(&mutex);
849 /* Returns the role of port 'p'. */
851 stp_port_get_role(const struct stp_port *p)
853 struct stp_port *root_port;
856 ovs_mutex_lock(&mutex);
857 root_port = p->stp->root_port;
858 if (root_port && root_port->port_id == p->port_id) {
859 role = STP_ROLE_ROOT;
860 } else if (stp_is_designated_port(p)) {
861 role = STP_ROLE_DESIGNATED;
862 } else if (p->state == STP_DISABLED) {
863 role = STP_ROLE_DISABLED;
865 role = STP_ROLE_ALTERNATE;
867 ovs_mutex_unlock(&mutex);
871 /* Retrieves BPDU transmit and receive counts for 'p'. */
873 stp_port_get_counts(const struct stp_port *p,
874 int *tx_count, int *rx_count, int *error_count)
876 ovs_mutex_lock(&mutex);
877 *tx_count = p->tx_count;
878 *rx_count = p->rx_count;
879 *error_count = p->error_count;
880 ovs_mutex_unlock(&mutex);
883 /* Disables STP on port 'p'. */
885 stp_port_disable(struct stp_port *p)
889 ovs_mutex_lock(&mutex);
891 if (p->state != STP_DISABLED) {
892 bool root = stp_is_root_bridge(stp);
893 stp_become_designated_port(p);
894 stp_set_port_state(p, STP_DISABLED);
895 p->topology_change_ack = false;
896 p->config_pending = false;
897 stp_stop_timer(&p->message_age_timer);
898 stp_stop_timer(&p->forward_delay_timer);
899 stp_configuration_update(stp);
900 stp_port_state_selection(stp);
901 if (stp_is_root_bridge(stp) && !root) {
902 stp_become_root_bridge(stp);
906 ovs_mutex_unlock(&mutex);
909 /* Enables STP on port 'p'. The port will initially be in "blocking" state. */
911 stp_port_enable(struct stp_port *p)
913 ovs_mutex_lock(&mutex);
914 if (p->state == STP_DISABLED) {
915 stp_initialize_port(p, STP_BLOCKING);
916 stp_port_state_selection(p->stp);
918 ovs_mutex_unlock(&mutex);
921 /* Sets the priority of port 'p' to 'new_priority'. Lower numerical values
922 * are interpreted as higher priorities. */
924 stp_port_set_priority(struct stp_port *p, uint8_t new_priority)
926 uint16_t new_port_id;
928 ovs_mutex_lock(&mutex);
929 new_port_id = (p->port_id & 0xff) | (new_priority << 8);
930 if (p->port_id != new_port_id) {
931 struct stp *stp = p->stp;
932 if (stp_is_designated_port(p)) {
933 p->designated_port = new_port_id;
935 p->port_id = new_port_id;
936 if (stp->bridge_id == p->designated_bridge
937 && p->port_id < p->designated_port) {
938 stp_become_designated_port(p);
939 stp_port_state_selection(stp);
942 ovs_mutex_unlock(&mutex);
945 /* Convert 'speed' (measured in Mb/s) into the path cost. */
947 stp_convert_speed_to_cost(unsigned int speed)
951 ovs_mutex_lock(&mutex);
952 ret = speed >= 10000 ? 2 /* 10 Gb/s. */
953 : speed >= 1000 ? 4 /* 1 Gb/s. */
954 : speed >= 100 ? 19 /* 100 Mb/s. */
955 : speed >= 16 ? 62 /* 16 Mb/s. */
956 : speed >= 10 ? 100 /* 10 Mb/s. */
957 : speed >= 4 ? 250 /* 4 Mb/s. */
958 : 19; /* 100 Mb/s (guess). */
959 ovs_mutex_unlock(&mutex);
963 /* Sets the path cost of port 'p' to 'path_cost'. Lower values are generally
964 * used to indicate faster links. Use stp_port_set_speed() to automatically
965 * generate a default path cost from a link speed. */
967 stp_port_set_path_cost(struct stp_port *p, uint16_t path_cost)
969 ovs_mutex_lock(&mutex);
970 if (p->path_cost != path_cost) {
971 struct stp *stp = p->stp;
972 p->path_cost = path_cost;
973 stp_configuration_update(stp);
974 stp_port_state_selection(stp);
976 ovs_mutex_unlock(&mutex);
979 /* Sets the path cost of port 'p' based on 'speed' (measured in Mb/s). */
981 stp_port_set_speed(struct stp_port *p, unsigned int speed)
983 stp_port_set_path_cost(p, stp_convert_speed_to_cost(speed));
986 /* Enables topology change detection on port 'p'. */
988 stp_port_enable_change_detection(struct stp_port *p)
990 p->change_detection_enabled = true;
993 /* Disables topology change detection on port 'p'. */
995 stp_port_disable_change_detection(struct stp_port *p)
997 p->change_detection_enabled = false;
1001 stp_transmit_config(struct stp_port *p) OVS_REQUIRES(mutex)
1003 struct stp *stp = p->stp;
1004 bool root = stp_is_root_bridge(stp);
1005 if (!root && !stp->root_port) {
1008 if (p->hold_timer.active) {
1009 p->config_pending = true;
1011 struct stp_config_bpdu config;
1012 memset(&config, 0, sizeof config);
1013 config.header.protocol_id = htons(STP_PROTOCOL_ID);
1014 config.header.protocol_version = STP_PROTOCOL_VERSION;
1015 config.header.bpdu_type = STP_TYPE_CONFIG;
1017 if (p->topology_change_ack) {
1018 config.flags |= STP_CONFIG_TOPOLOGY_CHANGE_ACK;
1020 if (stp->topology_change) {
1021 config.flags |= STP_CONFIG_TOPOLOGY_CHANGE;
1023 config.root_id = htonll(stp->designated_root);
1024 config.root_path_cost = htonl(stp->root_path_cost);
1025 config.bridge_id = htonll(stp->bridge_id);
1026 config.port_id = htons(p->port_id);
1028 config.message_age = htons(0);
1030 config.message_age = htons(stp->root_port->message_age_timer.value
1031 + MESSAGE_AGE_INCREMENT);
1033 config.max_age = htons(stp->max_age);
1034 config.hello_time = htons(stp->hello_time);
1035 config.forward_delay = htons(stp->forward_delay);
1036 if (ntohs(config.message_age) < stp->max_age) {
1037 p->topology_change_ack = false;
1038 p->config_pending = false;
1039 stp_send_bpdu(p, &config, sizeof config);
1040 stp_start_timer(&p->hold_timer, 0);
1046 stp_supersedes_port_info(const struct stp_port *p,
1047 const struct stp_config_bpdu *config)
1050 if (ntohll(config->root_id) != p->designated_root) {
1051 return ntohll(config->root_id) < p->designated_root;
1052 } else if (ntohl(config->root_path_cost) != p->designated_cost) {
1053 return ntohl(config->root_path_cost) < p->designated_cost;
1054 } else if (ntohll(config->bridge_id) != p->designated_bridge) {
1055 return ntohll(config->bridge_id) < p->designated_bridge;
1057 return (ntohll(config->bridge_id) != p->stp->bridge_id
1058 || ntohs(config->port_id) <= p->designated_port);
1063 stp_record_config_information(struct stp_port *p,
1064 const struct stp_config_bpdu *config)
1067 p->designated_root = ntohll(config->root_id);
1068 p->designated_cost = ntohl(config->root_path_cost);
1069 p->designated_bridge = ntohll(config->bridge_id);
1070 p->designated_port = ntohs(config->port_id);
1071 stp_start_timer(&p->message_age_timer, ntohs(config->message_age));
1075 stp_record_config_timeout_values(struct stp *stp,
1076 const struct stp_config_bpdu *config)
1079 stp->max_age = ntohs(config->max_age);
1080 stp->hello_time = ntohs(config->hello_time);
1081 stp->forward_delay = ntohs(config->forward_delay);
1082 stp->topology_change = config->flags & STP_CONFIG_TOPOLOGY_CHANGE;
1086 stp_is_designated_port(const struct stp_port *p) OVS_REQUIRES(mutex)
1088 return (p->designated_bridge == p->stp->bridge_id
1089 && p->designated_port == p->port_id);
1093 stp_config_bpdu_generation(struct stp *stp) OVS_REQUIRES(mutex)
1097 FOR_EACH_ENABLED_PORT (p, stp) {
1098 if (stp_is_designated_port(p)) {
1099 stp_transmit_config(p);
1105 stp_transmit_tcn(struct stp *stp) OVS_REQUIRES(mutex)
1107 struct stp_port *p = stp->root_port;
1108 struct stp_tcn_bpdu tcn_bpdu;
1112 tcn_bpdu.header.protocol_id = htons(STP_PROTOCOL_ID);
1113 tcn_bpdu.header.protocol_version = STP_PROTOCOL_VERSION;
1114 tcn_bpdu.header.bpdu_type = STP_TYPE_TCN;
1115 stp_send_bpdu(p, &tcn_bpdu, sizeof tcn_bpdu);
1119 stp_configuration_update(struct stp *stp) OVS_REQUIRES(mutex)
1121 stp_root_selection(stp);
1122 stp_designated_port_selection(stp);
1123 seq_change(connectivity_seq_get());
1127 stp_supersedes_root(const struct stp_port *root, const struct stp_port *p)
1130 int p_cost = p->designated_cost + p->path_cost;
1131 int root_cost = root->designated_cost + root->path_cost;
1133 if (p->designated_root != root->designated_root) {
1134 return p->designated_root < root->designated_root;
1135 } else if (p_cost != root_cost) {
1136 return p_cost < root_cost;
1137 } else if (p->designated_bridge != root->designated_bridge) {
1138 return p->designated_bridge < root->designated_bridge;
1139 } else if (p->designated_port != root->designated_port) {
1140 return p->designated_port < root->designated_port;
1142 return p->port_id < root->port_id;
1147 stp_root_selection(struct stp *stp) OVS_REQUIRES(mutex)
1149 struct stp_port *p, *root;
1152 FOR_EACH_ENABLED_PORT (p, stp) {
1153 if (stp_is_designated_port(p)
1154 || p->designated_root >= stp->bridge_id) {
1157 if (root && !stp_supersedes_root(root, p)) {
1162 stp->root_port = root;
1164 stp->designated_root = stp->bridge_id;
1165 stp->root_path_cost = 0;
1167 stp->designated_root = root->designated_root;
1168 stp->root_path_cost = root->designated_cost + root->path_cost;
1173 stp_designated_port_selection(struct stp *stp) OVS_REQUIRES(mutex)
1177 FOR_EACH_ENABLED_PORT (p, stp) {
1178 if (stp_is_designated_port(p)
1179 || p->designated_root != stp->designated_root
1180 || stp->root_path_cost < p->designated_cost
1181 || (stp->root_path_cost == p->designated_cost
1182 && (stp->bridge_id < p->designated_bridge
1183 || (stp->bridge_id == p->designated_bridge
1184 && p->port_id <= p->designated_port))))
1186 stp_become_designated_port(p);
1192 stp_become_designated_port(struct stp_port *p) OVS_REQUIRES(mutex)
1194 struct stp *stp = p->stp;
1195 p->designated_root = stp->designated_root;
1196 p->designated_cost = stp->root_path_cost;
1197 p->designated_bridge = stp->bridge_id;
1198 p->designated_port = p->port_id;
1202 stp_port_state_selection(struct stp *stp) OVS_REQUIRES(mutex)
1206 FOR_EACH_ENABLED_PORT (p, stp) {
1207 if (p == stp->root_port) {
1208 p->config_pending = false;
1209 p->topology_change_ack = false;
1210 stp_make_forwarding(p);
1211 } else if (stp_is_designated_port(p)) {
1212 stp_stop_timer(&p->message_age_timer);
1213 stp_make_forwarding(p);
1215 p->config_pending = false;
1216 p->topology_change_ack = false;
1217 stp_make_blocking(p);
1223 stp_make_forwarding(struct stp_port *p) OVS_REQUIRES(mutex)
1225 if (p->state == STP_BLOCKING) {
1226 stp_set_port_state(p, STP_LISTENING);
1227 stp_start_timer(&p->forward_delay_timer, 0);
1232 stp_make_blocking(struct stp_port *p) OVS_REQUIRES(mutex)
1234 if (!(p->state & (STP_DISABLED | STP_BLOCKING))) {
1235 if (p->state & (STP_FORWARDING | STP_LEARNING)) {
1236 if (p->change_detection_enabled) {
1237 stp_topology_change_detection(p->stp);
1240 stp_set_port_state(p, STP_BLOCKING);
1241 stp_stop_timer(&p->forward_delay_timer);
1246 stp_set_port_state(struct stp_port *p, enum stp_state state)
1249 if (state != p->state && !p->state_changed) {
1250 p->state_changed = true;
1251 if (p < p->stp->first_changed_port) {
1252 p->stp->first_changed_port = p;
1254 seq_change(connectivity_seq_get());
1260 stp_topology_change_detection(struct stp *stp) OVS_REQUIRES(mutex)
1262 static struct vlog_rate_limit rl = VLOG_RATE_LIMIT_INIT(1, 5);
1264 if (stp_is_root_bridge(stp)) {
1265 stp->topology_change = true;
1266 stp_start_timer(&stp->topology_change_timer, 0);
1267 } else if (!stp->topology_change_detected) {
1268 stp_transmit_tcn(stp);
1269 stp_start_timer(&stp->tcn_timer, 0);
1271 stp->fdb_needs_flush = true;
1272 stp->topology_change_detected = true;
1273 seq_change(connectivity_seq_get());
1274 VLOG_INFO_RL(&rl, "%s: detected topology change.", stp->name);
1278 stp_topology_change_acknowledged(struct stp *stp) OVS_REQUIRES(mutex)
1280 stp->topology_change_detected = false;
1281 stp_stop_timer(&stp->tcn_timer);
1285 stp_acknowledge_topology_change(struct stp_port *p) OVS_REQUIRES(mutex)
1287 p->topology_change_ack = true;
1288 stp_transmit_config(p);
1292 stp_received_config_bpdu(struct stp *stp, struct stp_port *p,
1293 const struct stp_config_bpdu *config)
1296 if (ntohs(config->message_age) >= ntohs(config->max_age)) {
1297 VLOG_WARN("%s: received config BPDU with message age (%u) greater "
1298 "than max age (%u)",
1300 ntohs(config->message_age), ntohs(config->max_age));
1303 if (p->state != STP_DISABLED) {
1304 bool root = stp_is_root_bridge(stp);
1305 if (stp_supersedes_port_info(p, config)) {
1306 stp_record_config_information(p, config);
1307 stp_configuration_update(stp);
1308 stp_port_state_selection(stp);
1309 if (!stp_is_root_bridge(stp) && root) {
1310 stp_stop_timer(&stp->hello_timer);
1311 if (stp->topology_change_detected) {
1312 stp_stop_timer(&stp->topology_change_timer);
1313 stp_transmit_tcn(stp);
1314 stp_start_timer(&stp->tcn_timer, 0);
1317 if (p == stp->root_port) {
1318 stp_record_config_timeout_values(stp, config);
1319 stp_config_bpdu_generation(stp);
1320 if (config->flags & STP_CONFIG_TOPOLOGY_CHANGE_ACK) {
1321 stp_topology_change_acknowledged(stp);
1323 if (config->flags & STP_CONFIG_TOPOLOGY_CHANGE) {
1324 stp->fdb_needs_flush = true;
1327 } else if (stp_is_designated_port(p)) {
1328 stp_transmit_config(p);
1334 stp_received_tcn_bpdu(struct stp *stp, struct stp_port *p)
1337 if (p->state != STP_DISABLED) {
1338 if (stp_is_designated_port(p)) {
1339 stp_topology_change_detection(stp);
1340 stp_acknowledge_topology_change(p);
1346 stp_hello_timer_expiry(struct stp *stp) OVS_REQUIRES(mutex)
1348 stp_config_bpdu_generation(stp);
1349 stp_start_timer(&stp->hello_timer, 0);
1353 stp_message_age_timer_expiry(struct stp_port *p) OVS_REQUIRES(mutex)
1355 struct stp *stp = p->stp;
1356 bool root = stp_is_root_bridge(stp);
1357 stp_become_designated_port(p);
1358 stp_configuration_update(stp);
1359 stp_port_state_selection(stp);
1360 if (stp_is_root_bridge(stp) && !root) {
1361 stp->max_age = stp->bridge_max_age;
1362 stp->hello_time = stp->bridge_hello_time;
1363 stp->forward_delay = stp->bridge_forward_delay;
1364 stp_topology_change_detection(stp);
1365 stp_stop_timer(&stp->tcn_timer);
1366 stp_config_bpdu_generation(stp);
1367 stp_start_timer(&stp->hello_timer, 0);
1372 stp_is_designated_for_some_port(const struct stp *stp) OVS_REQUIRES(mutex)
1374 const struct stp_port *p;
1376 FOR_EACH_ENABLED_PORT (p, stp) {
1377 if (p->designated_bridge == stp->bridge_id) {
1385 stp_forward_delay_timer_expiry(struct stp_port *p) OVS_REQUIRES(mutex)
1387 if (p->state == STP_LISTENING) {
1388 stp_set_port_state(p, STP_LEARNING);
1389 stp_start_timer(&p->forward_delay_timer, 0);
1390 } else if (p->state == STP_LEARNING) {
1391 stp_set_port_state(p, STP_FORWARDING);
1392 if (stp_is_designated_for_some_port(p->stp)) {
1393 if (p->change_detection_enabled) {
1394 stp_topology_change_detection(p->stp);
1401 stp_tcn_timer_expiry(struct stp *stp) OVS_REQUIRES(mutex)
1403 stp_transmit_tcn(stp);
1404 stp_start_timer(&stp->tcn_timer, 0);
1408 stp_topology_change_timer_expiry(struct stp *stp) OVS_REQUIRES(mutex)
1410 stp->topology_change_detected = false;
1411 stp->topology_change = false;
1415 stp_hold_timer_expiry(struct stp_port *p) OVS_REQUIRES(mutex)
1417 if (p->config_pending) {
1418 stp_transmit_config(p);
1423 stp_initialize_port(struct stp_port *p, enum stp_state state)
1426 ovs_assert(state & (STP_DISABLED | STP_BLOCKING));
1427 stp_become_designated_port(p);
1428 stp_set_port_state(p, state);
1429 p->topology_change_ack = false;
1430 p->config_pending = false;
1431 p->change_detection_enabled = true;
1433 stp_stop_timer(&p->message_age_timer);
1434 stp_stop_timer(&p->forward_delay_timer);
1435 stp_stop_timer(&p->hold_timer);
1436 p->tx_count = p->rx_count = p->error_count = 0;
1440 stp_become_root_bridge(struct stp *stp) OVS_REQUIRES(mutex)
1442 stp->max_age = stp->bridge_max_age;
1443 stp->hello_time = stp->bridge_hello_time;
1444 stp->forward_delay = stp->bridge_forward_delay;
1445 stp_topology_change_detection(stp);
1446 stp_stop_timer(&stp->tcn_timer);
1447 stp_config_bpdu_generation(stp);
1448 stp_start_timer(&stp->hello_timer, 0);
1452 stp_start_timer(struct stp_timer *timer, int value) OVS_REQUIRES(mutex)
1454 timer->value = value;
1455 timer->active = true;
1459 stp_stop_timer(struct stp_timer *timer) OVS_REQUIRES(mutex)
1461 timer->active = false;
1465 stp_timer_expired(struct stp_timer *timer, int elapsed, int timeout)
1468 if (timer->active) {
1469 timer->value += elapsed;
1470 if (timer->value >= timeout) {
1471 timer->active = false;
1478 /* Returns the number of whole STP timer ticks in 'ms' milliseconds. There
1479 * are 256 STP timer ticks per second. */
1483 return ms * 0x100 / 1000;
1486 /* Returns the number of whole milliseconds in 'timer' STP timer ticks. There
1487 * are 256 STP timer ticks per second. */
1489 timer_to_ms(int timer)
1491 return timer * 1000 / 0x100;
1495 clamp(int x, int min, int max)
1497 return x < min ? min : x > max ? max : x;
1501 stp_update_bridge_timers(struct stp *stp) OVS_REQUIRES(mutex)
1505 ht = clamp(stp->rq_hello_time, 1000, 10000);
1506 ma = clamp(stp->rq_max_age, MAX(2 * (ht + 1000), 6000), 40000);
1507 fd = clamp(stp->rq_forward_delay, ma / 2 + 1000, 30000);
1509 stp->bridge_hello_time = ms_to_timer(ht);
1510 stp->bridge_max_age = ms_to_timer(ma);
1511 stp->bridge_forward_delay = ms_to_timer(fd);
1513 if (stp_is_root_bridge(stp)) {
1514 stp->max_age = stp->bridge_max_age;
1515 stp->hello_time = stp->bridge_hello_time;
1516 stp->forward_delay = stp->bridge_forward_delay;
1521 stp_send_bpdu(struct stp_port *p, const void *bpdu, size_t bpdu_size)
1524 struct eth_header *eth;
1525 struct llc_header *llc;
1529 pkt = ofpbuf_new(ETH_HEADER_LEN + LLC_HEADER_LEN + bpdu_size);
1530 pkt->l2 = eth = ofpbuf_put_zeros(pkt, sizeof *eth);
1531 llc = ofpbuf_put_zeros(pkt, sizeof *llc);
1532 pkt->l3 = ofpbuf_put(pkt, bpdu, bpdu_size);
1535 memcpy(eth->eth_dst, eth_addr_stp, ETH_ADDR_LEN);
1536 /* p->stp->send_bpdu() must fill in source address. */
1537 eth->eth_type = htons(pkt->size - ETH_HEADER_LEN);
1540 llc->llc_dsap = STP_LLC_DSAP;
1541 llc->llc_ssap = STP_LLC_SSAP;
1542 llc->llc_cntl = STP_LLC_CNTL;
1544 p->stp->send_bpdu(pkt, stp_port_no(p), p->stp->aux);
1551 stp_find(const char *name) OVS_REQUIRES(mutex)
1555 LIST_FOR_EACH (stp, node, all_stps) {
1556 if (!strcmp(stp->name, name)) {
1564 stp_unixctl_tcn(struct unixctl_conn *conn, int argc,
1565 const char *argv[], void *aux OVS_UNUSED)
1567 ovs_mutex_lock(&mutex);
1569 struct stp *stp = stp_find(argv[1]);
1572 unixctl_command_reply_error(conn, "no such stp object");
1575 stp_topology_change_detection(stp);
1579 LIST_FOR_EACH (stp, node, all_stps) {
1580 stp_topology_change_detection(stp);
1584 unixctl_command_reply(conn, "OK");
1587 ovs_mutex_unlock(&mutex);