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.
25 #include "dynamic-string.h"
31 #include "poll-loop.h"
37 VLOG_DEFINE_THIS_MODULE(cfm);
39 #define CCM_OPCODE 1 /* CFM message opcode meaning CCM. */
43 struct list list_node; /* Node in all_cfms list. */
45 uint32_t seq; /* The sequence number of our last CCM. */
46 uint8_t ccm_interval; /* The CCM transmission interval. */
47 int ccm_interval_ms; /* 'ccm_interval' in milliseconds. */
48 uint8_t maid[CCM_MAID_LEN]; /* The MAID of this CFM. */
50 struct timer tx_timer; /* Send CCM when expired. */
51 struct timer fault_timer; /* Check for faults when expired. */
54 static struct vlog_rate_limit rl = VLOG_RATE_LIMIT_INIT(5, 20);
55 static struct list all_cfms = LIST_INITIALIZER(&all_cfms);
57 static void cfm_unixctl_show(struct unixctl_conn *, const char *args,
61 cfm_generate_maid(struct cfm_internal *cfmi)
63 const char *ovs_md_name = "ovs_md";
64 const char *ovs_ma_name = "ovs_ma";
66 size_t md_len, ma_len;
68 memset(cfmi->maid, 0, CCM_MAID_LEN);
70 md_len = strlen(ovs_md_name);
71 ma_len = strlen(ovs_ma_name);
73 assert(md_len && ma_len && md_len + ma_len + 4 <= CCM_MAID_LEN);
75 cfmi->maid[0] = 4; /* MD name string format. */
76 cfmi->maid[1] = md_len; /* MD name size. */
77 memcpy(&cfmi->maid[2], ovs_md_name, md_len); /* MD name. */
79 ma_p = cfmi->maid + 2 + md_len;
80 ma_p[0] = 2; /* MA name string format. */
81 ma_p[1] = ma_len; /* MA name size. */
82 memcpy(&ma_p[2], ovs_ma_name, ma_len); /* MA name. */
86 ccm_interval_to_ms(uint8_t interval)
89 case 0: NOT_REACHED(); /* Explicitly not supported by 802.1ag. */
90 case 1: return 3; /* Not recommended due to timer resolution. */
91 case 2: return 10; /* Not recommended due to timer resolution. */
96 case 7: return 600000;
97 default: NOT_REACHED(); /* Explicitly not supported by 802.1ag. */
104 cfm_fault_interval(struct cfm_internal *cfmi)
106 /* According to the 802.1ag specification we should assume every other MP
107 * with the same MAID has the same transmission interval that we have. If
108 * an MP has a different interval, cfm_process_heartbeat will register it
109 * as a fault (likely due to a configuration error). Thus we can check all
110 * MPs at once making this quite a bit simpler.
112 * According to the specification we should check when (ccm_interval_ms *
113 * 3.5)ms have passed. */
114 return (cfmi->ccm_interval_ms * 7) / 2;
118 ms_to_ccm_interval(int interval_ms)
122 for (i = 7; i > 0; i--) {
123 if (ccm_interval_to_ms(i) <= interval_ms) {
131 static struct cfm_internal *
132 cfm_to_internal(const struct cfm *cfm)
134 return CONTAINER_OF(cfm, struct cfm_internal, cfm);
138 hash_mpid(uint8_t mpid)
140 return hash_int(mpid, 0);
144 cfm_is_valid_mpid(uint32_t mpid)
146 /* 802.1ag specification requires MPIDs to be within the range [1, 8191] */
147 return mpid >= 1 && mpid <= 8191;
150 static struct remote_mp *
151 lookup_remote_mp(const struct hmap *hmap, uint16_t mpid)
153 struct remote_mp *rmp;
155 HMAP_FOR_EACH_IN_BUCKET (rmp, node, hash_mpid(mpid), hmap) {
156 if (rmp->mpid == mpid) {
167 unixctl_command_register("cfm/show", cfm_unixctl_show, NULL);
170 /* Allocates a 'cfm' object. This object should have its 'mpid', 'maid',
171 * 'eth_src', and 'interval' filled out. cfm_configure() should be called
172 * whenever changes are made to 'cfm', and before cfm_run() is called for the
178 struct cfm_internal *cfmi;
180 cfmi = xzalloc(sizeof *cfmi);
183 hmap_init(&cfm->remote_mps);
184 cfm_generate_maid(cfmi);
185 list_push_back(&all_cfms, &cfmi->list_node);
190 cfm_destroy(struct cfm *cfm)
192 struct cfm_internal *cfmi = cfm_to_internal(cfm);
193 struct remote_mp *rmp, *rmp_next;
199 HMAP_FOR_EACH_SAFE (rmp, rmp_next, node, &cfm->remote_mps) {
200 hmap_remove(&cfm->remote_mps, &rmp->node);
204 hmap_destroy(&cfm->remote_mps);
205 list_remove(&cfmi->list_node);
209 /* Should be run periodically to update fault statistics messages. */
211 cfm_run(struct cfm *cfm)
213 struct cfm_internal *cfmi = cfm_to_internal(cfm);
215 if (timer_expired(&cfmi->fault_timer)) {
216 long long int interval = cfm_fault_interval(cfmi);
217 struct remote_mp *rmp;
220 HMAP_FOR_EACH (rmp, node, &cfm->remote_mps) {
221 rmp->fault = !rmp->recv;
226 VLOG_DBG("No CCM from RMP %"PRIu16" in the last %lldms",
227 rmp->mpid, interval);
232 VLOG_DBG("All RMPs received CCMs in the last %lldms", interval);
235 timer_set_duration(&cfmi->fault_timer, interval);
239 /* Should be run periodically to check if the CFM module has a CCM message it
242 cfm_should_send_ccm(struct cfm *cfm)
244 struct cfm_internal *cfmi = cfm_to_internal(cfm);
246 return timer_expired(&cfmi->tx_timer);
249 /* Composes a CCM message into 'ccm'. Messages generated with this function
250 * should be sent whenever cfm_should_send_ccm() indicates. */
252 cfm_compose_ccm(struct cfm *cfm, struct ccm *ccm)
254 struct cfm_internal *cfmi = cfm_to_internal(cfm);
256 timer_set_duration(&cfmi->tx_timer, cfmi->ccm_interval_ms);
258 ccm->mdlevel_version = 0;
259 ccm->opcode = CCM_OPCODE;
260 ccm->tlv_offset = 70;
261 ccm->seq = htonl(++cfmi->seq);
262 ccm->mpid = htons(cfmi->cfm.mpid);
263 ccm->flags = cfmi->ccm_interval;
264 memcpy(ccm->maid, cfmi->maid, sizeof ccm->maid);
268 cfm_wait(struct cfm *cfm)
270 struct cfm_internal *cfmi = cfm_to_internal(cfm);
272 timer_wait(&cfmi->tx_timer);
273 timer_wait(&cfmi->fault_timer);
276 /* Should be called whenever a client of the cfm library changes the internals
277 * of 'cfm'. Returns true if 'cfm' is valid. */
279 cfm_configure(struct cfm *cfm)
281 struct cfm_internal *cfmi = cfm_to_internal(cfm);
284 if (!cfm_is_valid_mpid(cfm->mpid) || !cfm->interval) {
288 interval = ms_to_ccm_interval(cfm->interval);
290 if (interval != cfmi->ccm_interval) {
291 cfmi->ccm_interval = interval;
292 cfmi->ccm_interval_ms = ccm_interval_to_ms(interval);
294 timer_set_expired(&cfmi->tx_timer);
295 timer_set_duration(&cfmi->fault_timer, cfm_fault_interval(cfmi));
301 /* Given an array of MPIDs, updates the 'remote_mps' map of 'cfm' to reflect
302 * it. Invalid MPIDs are skipped. */
304 cfm_update_remote_mps(struct cfm *cfm, const uint16_t *mpids, size_t n_mpids)
307 struct hmap new_rmps;
308 struct remote_mp *rmp, *rmp_next;
310 hmap_init(&new_rmps);
312 for (i = 0; i < n_mpids; i++) {
313 uint16_t mpid = mpids[i];
315 if (!cfm_is_valid_mpid(mpid)
316 || lookup_remote_mp(&new_rmps, mpid)) {
320 if ((rmp = lookup_remote_mp(&cfm->remote_mps, mpid))) {
321 hmap_remove(&cfm->remote_mps, &rmp->node);
323 rmp = xzalloc(sizeof *rmp);
327 hmap_insert(&new_rmps, &rmp->node, hash_mpid(mpid));
330 hmap_swap(&new_rmps, &cfm->remote_mps);
332 HMAP_FOR_EACH_SAFE (rmp, rmp_next, node, &new_rmps) {
333 hmap_remove(&new_rmps, &rmp->node);
337 hmap_destroy(&new_rmps);
340 /* Finds a 'remote_mp' with 'mpid' in 'cfm'. If no such 'remote_mp' exists
342 const struct remote_mp *
343 cfm_get_remote_mp(const struct cfm *cfm, uint16_t mpid)
345 return lookup_remote_mp(&cfm->remote_mps, mpid);
348 /* Returns true if the CFM library should process packets from 'flow'. */
350 cfm_should_process_flow(const struct flow *flow)
352 return (ntohs(flow->dl_type) == ETH_TYPE_CFM
353 && eth_addr_equals(flow->dl_dst, eth_addr_ccm));
356 /* Updates internal statistics relevant to packet 'p'. Should be called on
357 * every packet whose flow returned true when passed to
358 * cfm_should_process_flow. */
360 cfm_process_heartbeat(struct cfm *cfm, const struct ofpbuf *p)
364 uint8_t ccm_interval;
365 struct remote_mp *rmp;
366 struct eth_header *eth;
367 struct cfm_internal *cfmi = cfm_to_internal(cfm);
370 ccm = ofpbuf_at(p, (uint8_t *)p->l3 - (uint8_t *)p->data, CCM_LEN);
373 VLOG_INFO_RL(&rl, "Received an un-parseable 802.1ag CCM heartbeat.");
377 if (ccm->opcode != CCM_OPCODE) {
378 VLOG_INFO_RL(&rl, "Received an unsupported 802.1ag message. "
379 "(opcode %u)", ccm->opcode);
383 /* According to the 802.1ag specification, reception of a CCM with an
384 * incorrect ccm_interval, unexpected MAID, or unexpected MPID should
385 * trigger a fault. We ignore this requirement for several reasons.
387 * Faults can cause a controller or Open vSwitch to make potentially
388 * expensive changes to the network topology. It seems prudent to trigger
389 * them judiciously, especially when CFM is used to check slave status of
390 * bonds. Furthermore, faults can be maliciously triggered by crafting
392 if (memcmp(ccm->maid, cfmi->maid, sizeof ccm->maid)) {
393 VLOG_WARN_RL(&rl, "Received unexpected remote MAID from MAC "
394 ETH_ADDR_FMT, ETH_ADDR_ARGS(eth->eth_src));
396 ccm_mpid = ntohs(ccm->mpid);
397 ccm_interval = ccm->flags & 0x7;
399 rmp = lookup_remote_mp(&cfm->remote_mps, ccm_mpid);
404 if (ccm_interval != cfmi->ccm_interval) {
405 VLOG_WARN_RL(&rl, "received a CCM with an invalid interval"
406 " (%"PRIu8") from RMP %"PRIu16, ccm_interval,
410 VLOG_WARN_RL(&rl, "Received unexpected remote MPID %d from MAC "
411 ETH_ADDR_FMT, ccm_mpid, ETH_ADDR_ARGS(eth->eth_src));
414 VLOG_DBG("Received CCM (mpid %"PRIu16") (interval %"PRIu8")", ccm_mpid,
419 static struct cfm_internal *
420 cfm_find(const char *name)
422 struct cfm_internal *cfmi;
424 LIST_FOR_EACH (cfmi, list_node, &all_cfms) {
425 if (cfmi->cfm.name && !strcmp(cfmi->cfm.name, name)) {
433 cfm_unixctl_show(struct unixctl_conn *conn,
434 const char *args, void *aux OVS_UNUSED)
436 struct ds ds = DS_EMPTY_INITIALIZER;
437 const struct cfm_internal *cfmi;
438 struct remote_mp *rmp;
440 cfmi = cfm_find(args);
442 unixctl_command_reply(conn, 501, "no such CFM object");
446 ds_put_format(&ds, "MPID %"PRIu16": %s\n", cfmi->cfm.mpid,
447 cfmi->cfm.fault ? "fault" : "");
449 ds_put_format(&ds, "\tinterval: %dms\n", cfmi->ccm_interval_ms);
450 ds_put_format(&ds, "\tnext CCM tx: %lldms\n",
451 timer_msecs_until_expired(&cfmi->tx_timer));
452 ds_put_format(&ds, "\tnext fault check: %lldms\n",
453 timer_msecs_until_expired(&cfmi->fault_timer));
455 ds_put_cstr(&ds, "\n");
456 HMAP_FOR_EACH (rmp, node, &cfmi->cfm.remote_mps) {
457 ds_put_format(&ds, "Remote MPID %"PRIu16": %s\n", rmp->mpid,
458 rmp->fault ? "fault" : "");
459 ds_put_format(&ds, "\trecv since check: %s",
460 rmp->recv ? "true" : "false");
463 unixctl_command_reply(conn, 200, ds_cstr(&ds));