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. */
51 ccm_interval_to_ms(uint8_t interval)
54 case 0: NOT_REACHED(); /* Explicitly not supported by 802.1ag. */
55 case 1: return 3; /* Not recommended due to timer resolution. */
56 case 2: return 10; /* Not recommended due to timer resolution. */
61 case 7: return 600000;
62 default: NOT_REACHED(); /* Explicitly not supported by 802.1ag. */
69 cfm_fault_interval(struct cfm_internal *cfmi)
71 /* According to the 802.1ag specification we should assume every other MP
72 * with the same MAID has the same transmission interval that we have. If
73 * an MP has a different interval, cfm_process_heartbeat will register it
74 * as a fault (likely due to a configuration error). Thus we can check all
75 * MPs at once making this quite a bit simpler.
77 * According to the specification we should check when (ccm_interval_ms *
78 * 3.5)ms have passed. */
79 return (cfmi->ccm_interval_ms * 7) / 2;
83 ms_to_ccm_interval(int interval_ms)
87 for (i = 7; i > 0; i--) {
88 if (ccm_interval_to_ms(i) <= interval_ms) {
96 static struct cfm_internal *
97 cfm_to_internal(const struct cfm *cfm)
99 return CONTAINER_OF(cfm, struct cfm_internal, cfm);
103 hash_mpid(uint8_t mpid)
105 return hash_int(mpid, 0);
109 cfm_is_valid_mpid(uint32_t mpid)
111 /* 802.1ag specification requires MPIDs to be within the range [1, 8191] */
112 return mpid >= 1 && mpid <= 8191;
115 static struct remote_mp *
116 lookup_remote_mp(const struct hmap *hmap, uint16_t mpid)
118 struct remote_mp *rmp;
120 HMAP_FOR_EACH_IN_BUCKET (rmp, node, hash_mpid(mpid), hmap) {
121 if (rmp->mpid == mpid) {
129 /* Allocates a 'cfm' object. This object should have its 'mpid', 'maid',
130 * 'eth_src', and 'interval' filled out. When changes are made to the 'cfm'
131 * object, cfm_configure should be called before using it. */
136 struct cfm_internal *cfmi;
138 cfmi = xzalloc(sizeof *cfmi);
141 hmap_init(&cfm->remote_mps);
146 cfm_destroy(struct cfm *cfm)
148 struct cfm_internal *cfmi = cfm_to_internal(cfm);
149 struct remote_mp *rmp, *rmp_next;
155 HMAP_FOR_EACH_SAFE (rmp, rmp_next, node, &cfm->remote_mps) {
156 hmap_remove(&cfm->remote_mps, &rmp->node);
160 hmap_destroy(&cfm->remote_mps);
164 /* Should be run periodically to update fault statistics messages. */
166 cfm_run(struct cfm *cfm)
168 struct cfm_internal *cfmi = cfm_to_internal(cfm);
170 if (timer_expired(&cfmi->fault_timer)) {
171 long long int interval = cfm_fault_interval(cfmi);
172 struct remote_mp *rmp;
175 HMAP_FOR_EACH (rmp, node, &cfm->remote_mps) {
176 if (rmp->recv_time < timer_enabled_at(&cfmi->fault_timer, interval)
177 || timer_expired_at(&cfmi->fault_timer, rmp->recv_time)) {
186 timer_set_duration(&cfmi->fault_timer, interval);
190 /* Should be run periodically to check if the CFM module has a CCM message it
193 cfm_should_send_ccm(struct cfm *cfm)
195 struct cfm_internal *cfmi = cfm_to_internal(cfm);
197 return timer_expired(&cfmi->tx_timer);
200 /* Composes a CCM message into 'ccm'. Messages generated with this function
201 * should be sent whenever cfm_should_send_ccm() indicates. */
203 cfm_compose_ccm(struct cfm *cfm, struct ccm *ccm)
205 struct cfm_internal *cfmi = cfm_to_internal(cfm);
207 timer_set_duration(&cfmi->tx_timer, cfmi->ccm_interval_ms);
209 ccm->mdlevel_version = 0;
210 ccm->opcode = CCM_OPCODE;
211 ccm->tlv_offset = 70;
212 ccm->seq = htonl(++cfmi->seq);
213 ccm->mpid = htons(cfmi->cfm.mpid);
214 ccm->flags = cfmi->ccm_interval;
215 memcpy(ccm->maid, cfmi->cfm.maid, sizeof ccm->maid);
219 cfm_wait(struct cfm *cfm)
221 struct cfm_internal *cfmi = cfm_to_internal(cfm);
223 timer_wait(&cfmi->tx_timer);
224 timer_wait(&cfmi->fault_timer);
227 /* Should be called whenever a client of the cfm library changes the internals
228 * of 'cfm'. Returns true if 'cfm' is valid. */
230 cfm_configure(struct cfm *cfm)
232 struct cfm_internal *cfmi = cfm_to_internal(cfm);
235 if (!cfm_is_valid_mpid(cfm->mpid) || !cfm->interval) {
239 interval = ms_to_ccm_interval(cfm->interval);
241 if (interval != cfmi->ccm_interval) {
242 cfmi->ccm_interval = interval;
243 cfmi->ccm_interval_ms = ccm_interval_to_ms(interval);
245 timer_set_expired(&cfmi->tx_timer);
246 timer_set_duration(&cfmi->fault_timer, cfm_fault_interval(cfmi));
252 /* Given an array of MPIDs, updates the 'remote_mps' map of 'cfm' to reflect
253 * it. Invalid MPIDs are skipped. */
255 cfm_update_remote_mps(struct cfm *cfm, const uint16_t *mpids, size_t n_mpids)
258 struct hmap new_rmps;
259 struct remote_mp *rmp, *rmp_next;
261 hmap_init(&new_rmps);
263 for (i = 0; i < n_mpids; i++) {
264 uint16_t mpid = mpids[i];
266 if (!cfm_is_valid_mpid(mpid)
267 || lookup_remote_mp(&new_rmps, mpid)) {
271 if ((rmp = lookup_remote_mp(&cfm->remote_mps, mpid))) {
272 hmap_remove(&cfm->remote_mps, &rmp->node);
274 rmp = xzalloc(sizeof *rmp);
278 hmap_insert(&new_rmps, &rmp->node, hash_mpid(mpid));
281 hmap_swap(&new_rmps, &cfm->remote_mps);
283 HMAP_FOR_EACH_SAFE (rmp, rmp_next, node, &new_rmps) {
284 hmap_remove(&new_rmps, &rmp->node);
288 hmap_destroy(&new_rmps);
291 /* Finds a 'remote_mp' with 'mpid' in 'cfm'. If no such 'remote_mp' exists
293 const struct remote_mp *
294 cfm_get_remote_mp(const struct cfm *cfm, uint16_t mpid)
296 return lookup_remote_mp(&cfm->remote_mps, mpid);
299 /* Generates 'maid' from 'md_name' and 'ma_name'. A NULL parameter indicates
300 * the default should be used. Returns false if unsuccessful. */
302 cfm_generate_maid(const char *md_name, const char *ma_name,
303 uint8_t maid[CCM_MAID_LEN])
306 size_t md_len, ma_len;
316 memset(maid, 0, CCM_MAID_LEN);
318 md_len = strlen(md_name);
319 ma_len = strlen(ma_name);
321 if (!md_len || !ma_len || md_len + ma_len + 4 > CCM_MAID_LEN) {
325 maid[0] = 4; /* MD name string format. */
326 maid[1] = md_len; /* MD name size. */
327 memcpy(&maid[2], md_name, md_len); /* MD name. */
329 ma_p = maid + 2 + md_len;
330 ma_p[0] = 2; /* MA name string format. */
331 ma_p[1] = ma_len; /* MA name size. */
332 memcpy(&ma_p[2], ma_name, ma_len); /* MA name. */
336 /* Returns true if the CFM library should process packets from 'flow'. */
338 cfm_should_process_flow(const struct flow *flow)
340 return (ntohs(flow->dl_type) == ETH_TYPE_CFM
341 && eth_addr_equals(flow->dl_dst, eth_addr_ccm));
344 /* Updates internal statistics relevant to packet 'p'. Should be called on
345 * every packet whose flow returned true when passed to
346 * cfm_should_process_flow. */
348 cfm_process_heartbeat(struct cfm *cfm, const struct ofpbuf *p)
352 uint8_t ccm_interval;
353 struct remote_mp *rmp;
354 struct eth_header *eth;
356 struct cfm_internal *cfmi = cfm_to_internal(cfm);
357 static struct vlog_rate_limit rl = VLOG_RATE_LIMIT_INIT(5, 20);
360 ccm = ofpbuf_at(p, (uint8_t *)p->l3 - (uint8_t *)p->data, CCM_LEN);
363 VLOG_INFO_RL(&rl, "Received an un-parseable 802.1ag CCM heartbeat.");
367 if (ccm->opcode != CCM_OPCODE) {
368 VLOG_INFO_RL(&rl, "Received an unsupported 802.1ag message. "
369 "(opcode %u)", ccm->opcode);
373 /* According to the 802.1ag specification, reception of a CCM with an
374 * incorrect ccm_interval, unexpected MAID, or unexpected MPID should
375 * trigger a fault. We ignore this requirement for several reasons.
377 * Faults can cause a controller or Open vSwitch to make potentially
378 * expensive changes to the network topology. It seems prudent to trigger
379 * them judiciously, especially when CFM is used to check slave status of
380 * bonds. Furthermore, faults can be maliciously triggered by crafting
382 if (memcmp(ccm->maid, cfm->maid, sizeof ccm->maid)) {
383 VLOG_WARN_RL(&rl, "Received unexpected remote MAID from MAC "
384 ETH_ADDR_FMT, ETH_ADDR_ARGS(eth->eth_src));
386 ccm_mpid = ntohs(ccm->mpid);
387 ccm_interval = ccm->flags & 0x7;
389 rmp = lookup_remote_mp(&cfm->remote_mps, ccm_mpid);
392 rmp->recv_time = time_msec();
394 if (ccm_interval != cfmi->ccm_interval) {
395 VLOG_WARN_RL(&rl, "received a CCM with an invalid interval"
396 " (%"PRIu8") from RMP %"PRIu16, ccm_interval,
400 VLOG_WARN_RL(&rl, "Received unexpected remote MPID %d from MAC "
401 ETH_ADDR_FMT, ccm_mpid, ETH_ADDR_ARGS(eth->eth_src));
407 cfm_dump_ds(const struct cfm *cfm, struct ds *ds)
409 const struct cfm_internal *cfmi = cfm_to_internal(cfm);
410 struct remote_mp *rmp;
412 ds_put_format(ds, "MPID %"PRIu16": %s\n", cfm->mpid,
413 cfm->fault ? "fault" : "");
415 ds_put_format(ds, "\tinterval: %dms\n", cfmi->ccm_interval_ms);
416 ds_put_format(ds, "\tnext CCM tx: %lldms\n",
417 timer_msecs_until_expired(&cfmi->tx_timer));
418 ds_put_format(ds, "\tnext fault check: %lldms\n",
419 timer_msecs_until_expired(&cfmi->fault_timer));
421 ds_put_cstr(ds, "\n");
422 HMAP_FOR_EACH (rmp, node, &cfm->remote_mps) {
423 ds_put_format(ds, "Remote MPID %"PRIu16": %s\n", rmp->mpid,
424 rmp->fault ? "fault" : "");
425 ds_put_format(ds, "\ttime since CCM rx: %lldms\n",
426 time_msec() - rmp->recv_time);