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"
35 VLOG_DEFINE_THIS_MODULE(cfm);
37 #define CCM_OPCODE 1 /* CFM message opcode meaning CCM. */
41 uint32_t seq; /* The sequence number of our last CCM. */
43 uint8_t ccm_interval; /* The CCM transmission interval. */
44 int ccm_interval_ms; /* 'ccm_interval' in milliseconds. */
46 struct timer tx_timer; /* Send CCM when expired. */
47 struct timer fault_timer; /* Check for faults when expired. */
49 long long x_recv_time;
53 ccm_interval_to_ms(uint8_t interval)
56 case 0: NOT_REACHED(); /* Explicitly not supported by 802.1ag. */
57 case 1: return 3; /* Not recommended due to timer resolution. */
58 case 2: return 10; /* Not recommended due to timer resolution. */
63 case 7: return 600000;
64 default: NOT_REACHED(); /* Explicitly not supported by 802.1ag. */
71 ms_to_ccm_interval(int interval_ms)
75 for (i = 7; i > 0; i--) {
76 if (ccm_interval_to_ms(i) <= interval_ms) {
84 static struct cfm_internal *
85 cfm_to_internal(const struct cfm *cfm)
87 return CONTAINER_OF(cfm, struct cfm_internal, cfm);
91 hash_mpid(uint8_t mpid)
93 return hash_int(mpid, 0);
97 cfm_is_valid_mpid(uint32_t mpid)
99 /* 802.1ag specification requires MPIDs to be within the range [1, 8191] */
100 return mpid >= 1 && mpid <= 8191;
103 static struct remote_mp *
104 lookup_remote_mp(const struct hmap *hmap, uint16_t mpid)
106 struct remote_mp *rmp;
108 HMAP_FOR_EACH_IN_BUCKET (rmp, node, hash_mpid(mpid), hmap) {
109 if (rmp->mpid == mpid) {
117 /* Allocates a 'cfm' object. This object should have its 'mpid', 'maid',
118 * 'eth_src', and 'interval' filled out. When changes are made to the 'cfm'
119 * object, cfm_configure should be called before using it. */
124 struct cfm_internal *cfmi;
126 cfmi = xzalloc(sizeof *cfmi);
128 cfmi->x_recv_time = LLONG_MIN;
130 hmap_init(&cfm->remote_mps);
135 cfm_destroy(struct cfm *cfm)
137 struct cfm_internal *cfmi = cfm_to_internal(cfm);
138 struct remote_mp *rmp, *rmp_next;
144 HMAP_FOR_EACH_SAFE (rmp, rmp_next, node, &cfm->remote_mps) {
145 hmap_remove(&cfm->remote_mps, &rmp->node);
149 hmap_destroy(&cfm->remote_mps);
153 /* Should be run periodically to update fault statistics messages. */
155 cfm_run(struct cfm *cfm)
157 long long now = time_msec();
158 struct cfm_internal *cfmi = cfm_to_internal(cfm);
159 long long fault_interval;
161 /* According to the 802.1ag specification we should assume every other MP
162 * with the same MAID has the same transmission interval that we have. If
163 * an MP has a different interval, cfm_process_heartbeat will register it
164 * as a fault (likely due to a configuration error). Thus we can check all
165 * MPs at once making this quite a bit simpler.
167 * According to the specification we should check when (ccm_interval_ms *
168 * 3.5)ms have passed. */
169 fault_interval = (cfmi->ccm_interval_ms * 7) / 2;
170 if (timer_expired(&cfmi->fault_timer)) {
172 struct remote_mp *rmp;
174 fault = now < cfmi->x_recv_time + fault_interval;
176 HMAP_FOR_EACH (rmp, node, &cfm->remote_mps) {
177 if (timer_expired_at(&cfmi->fault_timer, rmp->recv_time)) {
187 timer_set_duration(&cfmi->fault_timer, fault_interval);
191 /* Should be run periodically to check if the CFM module has a CCM message it
194 cfm_should_send_ccm(struct cfm *cfm)
196 struct cfm_internal *cfmi = cfm_to_internal(cfm);
198 return timer_expired(&cfmi->tx_timer);
201 /* Composes a CCM message into 'ccm'. Messages generated with this function
202 * should be sent whenever cfm_should_send_ccm() indicates. */
204 cfm_compose_ccm(struct cfm *cfm, struct ccm *ccm)
206 struct cfm_internal *cfmi = cfm_to_internal(cfm);
208 timer_set_duration(&cfmi->tx_timer, cfmi->ccm_interval_ms);
210 ccm->mdlevel_version = 0;
211 ccm->opcode = CCM_OPCODE;
212 ccm->tlv_offset = 70;
213 ccm->seq = htonl(++cfmi->seq);
214 ccm->mpid = htons(cfmi->cfm.mpid);
215 ccm->flags = cfmi->ccm_interval;
216 memcpy(ccm->maid, cfmi->cfm.maid, sizeof ccm->maid);
220 cfm_wait(struct cfm *cfm)
222 struct cfm_internal *cfmi = cfm_to_internal(cfm);
224 timer_wait(&cfmi->tx_timer);
225 timer_wait(&cfmi->fault_timer);
228 /* Should be called whenever a client of the cfm library changes the internals
229 * of 'cfm'. Returns true if 'cfm' is valid. */
231 cfm_configure(struct cfm *cfm)
233 struct cfm_internal *cfmi;
235 if (!cfm_is_valid_mpid(cfm->mpid) || !cfm->interval) {
239 cfmi = cfm_to_internal(cfm);
240 cfmi->ccm_interval = ms_to_ccm_interval(cfm->interval);
241 cfmi->ccm_interval_ms = ccm_interval_to_ms(cfmi->ccm_interval);
243 /* Force a resend and check in case anything changed. */
244 timer_set_expired(&cfmi->tx_timer);
245 timer_set_expired(&cfmi->fault_timer);
249 /* Given an array of MPIDs, updates the 'remote_mps' map of 'cfm' to reflect
250 * it. Invalid MPIDs are skipped. */
252 cfm_update_remote_mps(struct cfm *cfm, const uint16_t *mpids, size_t n_mpids)
255 struct hmap new_rmps;
256 struct remote_mp *rmp, *rmp_next;
258 hmap_init(&new_rmps);
260 for (i = 0; i < n_mpids; i++) {
261 uint16_t mpid = mpids[i];
263 if (!cfm_is_valid_mpid(mpid)
264 || lookup_remote_mp(&new_rmps, mpid)) {
268 if ((rmp = lookup_remote_mp(&cfm->remote_mps, mpid))) {
269 hmap_remove(&cfm->remote_mps, &rmp->node);
271 rmp = xzalloc(sizeof *rmp);
275 hmap_insert(&new_rmps, &rmp->node, hash_mpid(mpid));
278 hmap_swap(&new_rmps, &cfm->remote_mps);
280 HMAP_FOR_EACH_SAFE (rmp, rmp_next, node, &new_rmps) {
281 hmap_remove(&new_rmps, &rmp->node);
285 hmap_destroy(&new_rmps);
288 /* Finds a 'remote_mp' with 'mpid' in 'cfm'. If no such 'remote_mp' exists
290 const struct remote_mp *
291 cfm_get_remote_mp(const struct cfm *cfm, uint16_t mpid)
293 return lookup_remote_mp(&cfm->remote_mps, mpid);
296 /* Generates 'maid' from 'md_name' and 'ma_name'. A NULL parameter indicates
297 * the default should be used. Returns false if unsuccessful. */
299 cfm_generate_maid(const char *md_name, const char *ma_name,
300 uint8_t maid[CCM_MAID_LEN])
303 size_t md_len, ma_len;
313 memset(maid, 0, CCM_MAID_LEN);
315 md_len = strlen(md_name);
316 ma_len = strlen(ma_name);
318 if (!md_len || !ma_len || md_len + ma_len + 4 > CCM_MAID_LEN) {
322 maid[0] = 4; /* MD name string format. */
323 maid[1] = md_len; /* MD name size. */
324 memcpy(&maid[2], md_name, md_len); /* MD name. */
326 ma_p = maid + 2 + md_len;
327 ma_p[0] = 2; /* MA name string format. */
328 ma_p[1] = ma_len; /* MA name size. */
329 memcpy(&ma_p[2], ma_name, ma_len); /* MA name. */
333 /* Returns true if the CFM library should process packets from 'flow'. */
335 cfm_should_process_flow(const struct flow *flow)
337 return (ntohs(flow->dl_type) == ETH_TYPE_CFM
338 && eth_addr_equals(flow->dl_dst, eth_addr_ccm));
341 /* Updates internal statistics relevant to packet 'p'. Should be called on
342 * every packet whose flow returned true when passed to
343 * cfm_should_process_flow. */
345 cfm_process_heartbeat(struct cfm *cfm, const struct ofpbuf *p)
349 uint8_t ccm_interval;
350 struct remote_mp *rmp;
351 struct eth_header *eth;
353 struct cfm_internal *cfmi = cfm_to_internal(cfm);
354 static struct vlog_rate_limit rl = VLOG_RATE_LIMIT_INIT(5, 20);
357 ccm = ofpbuf_at(p, (uint8_t *)p->l3 - (uint8_t *)p->data, CCM_LEN);
360 VLOG_INFO_RL(&rl, "Received an un-parseable 802.1ag CCM heartbeat.");
364 if (ccm->opcode != CCM_OPCODE) {
365 VLOG_INFO_RL(&rl, "Received an unsupported 802.1ag message. "
366 "(opcode %u)", ccm->opcode);
370 if (memcmp(ccm->maid, cfm->maid, sizeof ccm->maid)) {
371 cfmi->x_recv_time = time_msec();
373 VLOG_WARN_RL(&rl, "Received unexpected remote MAID from MAC "
374 ETH_ADDR_FMT, ETH_ADDR_ARGS(eth->eth_src));
376 ccm_mpid = ntohs(ccm->mpid);
377 ccm_interval = ccm->flags & 0x7;
379 rmp = lookup_remote_mp(&cfm->remote_mps, ccm_mpid);
382 rmp->recv_time = time_msec();
383 rmp->fault = ccm_interval != cfmi->ccm_interval;
384 cfm->fault = rmp->fault || cfm->fault;
386 cfmi->x_recv_time = time_msec();
388 VLOG_WARN_RL(&rl, "Received unexpected remote MPID %d from MAC "
389 ETH_ADDR_FMT, ccm_mpid, ETH_ADDR_ARGS(eth->eth_src));
395 cfm_dump_ds(const struct cfm *cfm, struct ds *ds)
397 const struct cfm_internal *cfmi = cfm_to_internal(cfm);
398 long long int now = time_msec();
399 struct remote_mp *rmp;
401 ds_put_format(ds, "MPID %"PRIu16": %s\n", cfm->mpid,
402 cfm->fault ? "fault" : "");
404 ds_put_format(ds, "\tinterval: %dms\n", cfmi->ccm_interval_ms);
405 ds_put_format(ds, "\tnext CCM tx: %lldms\n",
406 timer_msecs_until_expired(&cfmi->tx_timer));
407 ds_put_format(ds, "\tnext fault check: %lldms\n",
408 timer_msecs_until_expired(&cfmi->fault_timer));
410 if (cfmi->x_recv_time != LLONG_MIN) {
411 ds_put_format(ds, "\ttime since bad CCM rx: %lldms\n",
412 now - cfmi->x_recv_time);
415 ds_put_cstr(ds, "\n");
416 HMAP_FOR_EACH (rmp, node, &cfm->remote_mps) {
417 ds_put_format(ds, "Remote MPID %"PRIu16": %s\n", rmp->mpid,
418 rmp->fault ? "fault" : "");
419 ds_put_format(ds, "\ttime since CCM rx: %lldms\n",
420 time_msec() - rmp->recv_time);