2 * Copyright (c) 2010, 2011 Nicira Networks.
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.
24 #include "dynamic-string.h"
30 #include "poll-loop.h"
36 VLOG_DEFINE_THIS_MODULE(cfm);
38 #define CCM_OPCODE 1 /* CFM message opcode meaning CCM. */
42 struct list list_node; /* Node in all_cfms list. */
44 uint32_t seq; /* The sequence number of our last CCM. */
45 uint8_t ccm_interval; /* The CCM transmission interval. */
46 int ccm_interval_ms; /* 'ccm_interval' in milliseconds. */
48 struct timer tx_timer; /* Send CCM when expired. */
49 struct timer fault_timer; /* Check for faults when expired. */
52 static struct vlog_rate_limit rl = VLOG_RATE_LIMIT_INIT(5, 20);
53 static struct list all_cfms = LIST_INITIALIZER(&all_cfms);
55 static void cfm_unixctl_show(struct unixctl_conn *, const char *args,
59 ccm_interval_to_ms(uint8_t interval)
62 case 0: NOT_REACHED(); /* Explicitly not supported by 802.1ag. */
63 case 1: return 3; /* Not recommended due to timer resolution. */
64 case 2: return 10; /* Not recommended due to timer resolution. */
69 case 7: return 600000;
70 default: NOT_REACHED(); /* Explicitly not supported by 802.1ag. */
77 cfm_fault_interval(struct cfm_internal *cfmi)
79 /* According to the 802.1ag specification we should assume every other MP
80 * with the same MAID has the same transmission interval that we have. If
81 * an MP has a different interval, cfm_process_heartbeat will register it
82 * as a fault (likely due to a configuration error). Thus we can check all
83 * MPs at once making this quite a bit simpler.
85 * According to the specification we should check when (ccm_interval_ms *
86 * 3.5)ms have passed. */
87 return (cfmi->ccm_interval_ms * 7) / 2;
91 ms_to_ccm_interval(int interval_ms)
95 for (i = 7; i > 0; i--) {
96 if (ccm_interval_to_ms(i) <= interval_ms) {
104 static struct cfm_internal *
105 cfm_to_internal(const struct cfm *cfm)
107 return CONTAINER_OF(cfm, struct cfm_internal, cfm);
111 hash_mpid(uint8_t mpid)
113 return hash_int(mpid, 0);
117 cfm_is_valid_mpid(uint32_t mpid)
119 /* 802.1ag specification requires MPIDs to be within the range [1, 8191] */
120 return mpid >= 1 && mpid <= 8191;
123 static struct remote_mp *
124 lookup_remote_mp(const struct hmap *hmap, uint16_t mpid)
126 struct remote_mp *rmp;
128 HMAP_FOR_EACH_IN_BUCKET (rmp, node, hash_mpid(mpid), hmap) {
129 if (rmp->mpid == mpid) {
140 unixctl_command_register("cfm/show", cfm_unixctl_show, NULL);
143 /* Allocates a 'cfm' object. This object should have its 'mpid', 'maid',
144 * 'eth_src', and 'interval' filled out. cfm_configure() should be called
145 * whenever changes are made to 'cfm', and before cfm_run() is called for the
151 struct cfm_internal *cfmi;
153 cfmi = xzalloc(sizeof *cfmi);
156 hmap_init(&cfm->remote_mps);
157 list_push_back(&all_cfms, &cfmi->list_node);
162 cfm_destroy(struct cfm *cfm)
164 struct cfm_internal *cfmi = cfm_to_internal(cfm);
165 struct remote_mp *rmp, *rmp_next;
171 HMAP_FOR_EACH_SAFE (rmp, rmp_next, node, &cfm->remote_mps) {
172 hmap_remove(&cfm->remote_mps, &rmp->node);
176 hmap_destroy(&cfm->remote_mps);
177 list_remove(&cfmi->list_node);
181 /* Should be run periodically to update fault statistics messages. */
183 cfm_run(struct cfm *cfm)
185 struct cfm_internal *cfmi = cfm_to_internal(cfm);
187 if (timer_expired(&cfmi->fault_timer)) {
188 long long int interval = cfm_fault_interval(cfmi);
189 struct remote_mp *rmp;
192 HMAP_FOR_EACH (rmp, node, &cfm->remote_mps) {
193 rmp->fault = !rmp->recv;
198 VLOG_DBG("No CCM from RMP %"PRIu16" in the last %lldms",
199 rmp->mpid, interval);
204 VLOG_DBG("All RMPs received CCMs in the last %lldms", interval);
207 timer_set_duration(&cfmi->fault_timer, interval);
211 /* Should be run periodically to check if the CFM module has a CCM message it
214 cfm_should_send_ccm(struct cfm *cfm)
216 struct cfm_internal *cfmi = cfm_to_internal(cfm);
218 return timer_expired(&cfmi->tx_timer);
221 /* Composes a CCM message into 'ccm'. Messages generated with this function
222 * should be sent whenever cfm_should_send_ccm() indicates. */
224 cfm_compose_ccm(struct cfm *cfm, struct ccm *ccm)
226 struct cfm_internal *cfmi = cfm_to_internal(cfm);
228 timer_set_duration(&cfmi->tx_timer, cfmi->ccm_interval_ms);
230 ccm->mdlevel_version = 0;
231 ccm->opcode = CCM_OPCODE;
232 ccm->tlv_offset = 70;
233 ccm->seq = htonl(++cfmi->seq);
234 ccm->mpid = htons(cfmi->cfm.mpid);
235 ccm->flags = cfmi->ccm_interval;
236 memcpy(ccm->maid, cfmi->cfm.maid, sizeof ccm->maid);
240 cfm_wait(struct cfm *cfm)
242 struct cfm_internal *cfmi = cfm_to_internal(cfm);
244 timer_wait(&cfmi->tx_timer);
245 timer_wait(&cfmi->fault_timer);
248 /* Should be called whenever a client of the cfm library changes the internals
249 * of 'cfm'. Returns true if 'cfm' is valid. */
251 cfm_configure(struct cfm *cfm)
253 struct cfm_internal *cfmi = cfm_to_internal(cfm);
256 if (!cfm_is_valid_mpid(cfm->mpid) || !cfm->interval) {
260 interval = ms_to_ccm_interval(cfm->interval);
262 if (interval != cfmi->ccm_interval) {
263 cfmi->ccm_interval = interval;
264 cfmi->ccm_interval_ms = ccm_interval_to_ms(interval);
266 timer_set_expired(&cfmi->tx_timer);
267 timer_set_duration(&cfmi->fault_timer, cfm_fault_interval(cfmi));
273 /* Given an array of MPIDs, updates the 'remote_mps' map of 'cfm' to reflect
274 * it. Invalid MPIDs are skipped. */
276 cfm_update_remote_mps(struct cfm *cfm, const uint16_t *mpids, size_t n_mpids)
279 struct hmap new_rmps;
280 struct remote_mp *rmp, *rmp_next;
282 hmap_init(&new_rmps);
284 for (i = 0; i < n_mpids; i++) {
285 uint16_t mpid = mpids[i];
287 if (!cfm_is_valid_mpid(mpid)
288 || lookup_remote_mp(&new_rmps, mpid)) {
292 if ((rmp = lookup_remote_mp(&cfm->remote_mps, mpid))) {
293 hmap_remove(&cfm->remote_mps, &rmp->node);
295 rmp = xzalloc(sizeof *rmp);
299 hmap_insert(&new_rmps, &rmp->node, hash_mpid(mpid));
302 hmap_swap(&new_rmps, &cfm->remote_mps);
304 HMAP_FOR_EACH_SAFE (rmp, rmp_next, node, &new_rmps) {
305 hmap_remove(&new_rmps, &rmp->node);
309 hmap_destroy(&new_rmps);
312 /* Finds a 'remote_mp' with 'mpid' in 'cfm'. If no such 'remote_mp' exists
314 const struct remote_mp *
315 cfm_get_remote_mp(const struct cfm *cfm, uint16_t mpid)
317 return lookup_remote_mp(&cfm->remote_mps, mpid);
320 /* Generates 'maid' from 'md_name' and 'ma_name'. A NULL parameter indicates
321 * the default should be used. Returns false if unsuccessful. */
323 cfm_generate_maid(const char *md_name, const char *ma_name,
324 uint8_t maid[CCM_MAID_LEN])
327 size_t md_len, ma_len;
337 memset(maid, 0, CCM_MAID_LEN);
339 md_len = strlen(md_name);
340 ma_len = strlen(ma_name);
342 if (!md_len || !ma_len || md_len + ma_len + 4 > CCM_MAID_LEN) {
346 maid[0] = 4; /* MD name string format. */
347 maid[1] = md_len; /* MD name size. */
348 memcpy(&maid[2], md_name, md_len); /* MD name. */
350 ma_p = maid + 2 + md_len;
351 ma_p[0] = 2; /* MA name string format. */
352 ma_p[1] = ma_len; /* MA name size. */
353 memcpy(&ma_p[2], ma_name, ma_len); /* MA name. */
357 /* Returns true if the CFM library should process packets from 'flow'. */
359 cfm_should_process_flow(const struct flow *flow)
361 return (ntohs(flow->dl_type) == ETH_TYPE_CFM
362 && eth_addr_equals(flow->dl_dst, eth_addr_ccm));
365 /* Updates internal statistics relevant to packet 'p'. Should be called on
366 * every packet whose flow returned true when passed to
367 * cfm_should_process_flow. */
369 cfm_process_heartbeat(struct cfm *cfm, const struct ofpbuf *p)
373 uint8_t ccm_interval;
374 struct remote_mp *rmp;
375 struct eth_header *eth;
376 struct cfm_internal *cfmi = cfm_to_internal(cfm);
379 ccm = ofpbuf_at(p, (uint8_t *)p->l3 - (uint8_t *)p->data, CCM_LEN);
382 VLOG_INFO_RL(&rl, "Received an un-parseable 802.1ag CCM heartbeat.");
386 if (ccm->opcode != CCM_OPCODE) {
387 VLOG_INFO_RL(&rl, "Received an unsupported 802.1ag message. "
388 "(opcode %u)", ccm->opcode);
392 /* According to the 802.1ag specification, reception of a CCM with an
393 * incorrect ccm_interval, unexpected MAID, or unexpected MPID should
394 * trigger a fault. We ignore this requirement for several reasons.
396 * Faults can cause a controller or Open vSwitch to make potentially
397 * expensive changes to the network topology. It seems prudent to trigger
398 * them judiciously, especially when CFM is used to check slave status of
399 * bonds. Furthermore, faults can be maliciously triggered by crafting
401 if (memcmp(ccm->maid, cfm->maid, sizeof ccm->maid)) {
402 VLOG_WARN_RL(&rl, "Received unexpected remote MAID from MAC "
403 ETH_ADDR_FMT, ETH_ADDR_ARGS(eth->eth_src));
405 ccm_mpid = ntohs(ccm->mpid);
406 ccm_interval = ccm->flags & 0x7;
408 rmp = lookup_remote_mp(&cfm->remote_mps, ccm_mpid);
413 if (ccm_interval != cfmi->ccm_interval) {
414 VLOG_WARN_RL(&rl, "received a CCM with an invalid interval"
415 " (%"PRIu8") from RMP %"PRIu16, ccm_interval,
419 VLOG_WARN_RL(&rl, "Received unexpected remote MPID %d from MAC "
420 ETH_ADDR_FMT, ccm_mpid, ETH_ADDR_ARGS(eth->eth_src));
423 VLOG_DBG("Received CCM (mpid %"PRIu16") (interval %"PRIu8")", ccm_mpid,
428 static struct cfm_internal *
429 cfm_find(const char *name)
431 struct cfm_internal *cfmi;
433 LIST_FOR_EACH (cfmi, list_node, &all_cfms) {
434 if (cfmi->cfm.name && !strcmp(cfmi->cfm.name, name)) {
442 cfm_unixctl_show(struct unixctl_conn *conn,
443 const char *args, void *aux OVS_UNUSED)
445 struct ds ds = DS_EMPTY_INITIALIZER;
446 const struct cfm_internal *cfmi;
447 struct remote_mp *rmp;
449 cfmi = cfm_find(args);
451 unixctl_command_reply(conn, 501, "no such CFM object");
455 ds_put_format(&ds, "MPID %"PRIu16": %s\n", cfmi->cfm.mpid,
456 cfmi->cfm.fault ? "fault" : "");
458 ds_put_format(&ds, "\tinterval: %dms\n", cfmi->ccm_interval_ms);
459 ds_put_format(&ds, "\tnext CCM tx: %lldms\n",
460 timer_msecs_until_expired(&cfmi->tx_timer));
461 ds_put_format(&ds, "\tnext fault check: %lldms\n",
462 timer_msecs_until_expired(&cfmi->fault_timer));
464 ds_put_cstr(&ds, "\n");
465 HMAP_FOR_EACH (rmp, node, &cfmi->cfm.remote_mps) {
466 ds_put_format(&ds, "Remote MPID %"PRIu16": %s\n", rmp->mpid,
467 rmp->fault ? "fault" : "");
468 ds_put_format(&ds, "\trecv since check: %s",
469 rmp->recv ? "true" : "false");
472 unixctl_command_reply(conn, 200, ds_cstr(&ds));