2 * Copyright (c) 2010 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.
29 #include "poll-loop.h"
33 VLOG_DEFINE_THIS_MODULE(cfm);
35 #define CCM_OPCODE 1 /* CFM message opcode meaning CCM. */
36 #define DEST_ADDR UINT64_C(0x0180C2000030) /* MD level 0 CCM destination. */
40 uint32_t seq; /* The sequence number of our last CCM. */
42 uint8_t ccm_interval; /* The CCM transmission interval. */
43 int ccm_interval_ms; /* 'ccm_interval' in milliseconds. */
45 long long ccm_sent; /* The time we last sent a CCM. */
46 long long fault_check; /* The time we last checked for faults. */
50 ccm_interval_to_ms(uint8_t interval)
53 case 0: NOT_REACHED(); /* Explicitly not supported by 802.1ag. */
54 case 1: return 3; /* Not recommended due to timer resolution. */
55 case 2: return 10; /* Not recommended due to timer resolution. */
60 case 7: return 600000;
61 default: NOT_REACHED(); /* Explicitly not supported by 802.1ag. */
68 ms_to_ccm_interval(int interval_ms)
72 for (i = 7; i > 0; i--) {
73 if (ccm_interval_to_ms(i) <= interval_ms) {
81 static struct cfm_internal *
82 cfm_to_internal(struct cfm *cfm)
84 return CONTAINER_OF(cfm, struct cfm_internal, cfm);
88 hash_mpid(uint8_t mpid)
90 return hash_int(mpid, 0);
94 cfm_is_valid_mpid(uint32_t mpid)
96 /* 802.1ag specification requires MPIDs to be within the range [1, 8191] */
97 return mpid >= 1 && mpid <= 8191;
100 static struct remote_mp *
101 lookup_remote_mp(const struct hmap *hmap, uint16_t mpid)
103 struct remote_mp *rmp;
105 HMAP_FOR_EACH_IN_BUCKET (rmp, node, hash_mpid(mpid), hmap) {
106 if (rmp->mpid == mpid) {
114 static struct ofpbuf *
115 compose_ccm(struct cfm_internal *cfmi)
118 struct ofpbuf *packet;
119 struct eth_header *eth;
121 packet = xzalloc(sizeof *packet);
123 ofpbuf_init(packet, ETH_HEADER_LEN + CCM_LEN + 2);
125 ofpbuf_reserve(packet, 2);
127 eth = ofpbuf_put_zeros(packet, ETH_HEADER_LEN);
128 ccm = ofpbuf_put_zeros(packet, CCM_LEN);
130 eth_addr_from_uint64(DEST_ADDR, eth->eth_dst);
131 memcpy(eth->eth_src, cfmi->cfm.eth_src, sizeof eth->eth_src);
132 eth->eth_type = htons(ETH_TYPE_CFM);
134 ccm->mdlevel_version = 0;
135 ccm->opcode = CCM_OPCODE;
136 ccm->tlv_offset = 70;
137 ccm->seq = htonl(++cfmi->seq);
138 ccm->mpid = htons(cfmi->cfm.mpid);
139 ccm->flags = cfmi->ccm_interval;
140 memcpy(ccm->maid, cfmi->cfm.maid, sizeof ccm->maid);
144 /* Allocates a 'cfm' object. This object should have its 'mpid', 'maid',
145 * 'eth_src', and 'interval' filled out. When changes are made to the 'cfm'
146 * object, cfm_configure should be called before using it. */
151 struct cfm_internal *cfmi;
153 cfmi = xzalloc(sizeof *cfmi);
156 hmap_init(&cfm->remote_mps);
157 hmap_init(&cfm->x_remote_mps);
158 hmap_init(&cfm->x_remote_maids);
163 cfm_destroy(struct cfm *cfm)
165 struct remote_mp *rmp, *rmp_next;
166 struct remote_maid *rmaid, *rmaid_next;
172 HMAP_FOR_EACH_SAFE (rmp, rmp_next, node, &cfm->remote_mps) {
173 hmap_remove(&cfm->remote_mps, &rmp->node);
177 HMAP_FOR_EACH_SAFE (rmp, rmp_next, node, &cfm->x_remote_mps) {
178 hmap_remove(&cfm->x_remote_mps, &rmp->node);
182 HMAP_FOR_EACH_SAFE (rmaid, rmaid_next, node, &cfm->x_remote_maids) {
183 hmap_remove(&cfm->x_remote_maids, &rmaid->node);
187 hmap_destroy(&cfm->remote_mps);
188 hmap_destroy(&cfm->x_remote_mps);
189 hmap_destroy(&cfm->x_remote_maids);
190 free(cfm_to_internal(cfm));
193 /* Should be run periodically to update fault statistics and generate CCM
194 * messages. If necessary, returns a packet which the caller is responsible
195 * for sending, un-initing, and deallocating. Otherwise returns NULL. */
197 cfm_run(struct cfm *cfm)
199 long long now = time_msec();
200 struct cfm_internal *cfmi = cfm_to_internal(cfm);
202 /* According to the 802.1ag specification we should assume every other MP
203 * with the same MAID has the same transmission interval that we have. If
204 * an MP has a different interval, cfm_process_heartbeat will register it
205 * as a fault (likely due to a configuration error). Thus we can check all
206 * MPs at once making this quite a bit simpler.
208 * According to the specification we should check when (ccm_interval_ms *
209 * 3.5)ms have passed. We changed the multiplier to 4 to avoid messy
210 * floating point arithmetic and add a bit of wiggle room. */
211 if (now >= cfmi->fault_check + cfmi->ccm_interval_ms * 4) {
213 struct remote_mp *rmp, *rmp_next;
214 struct remote_maid *rmaid, *rmaid_next;
218 HMAP_FOR_EACH (rmp, node, &cfm->remote_mps) {
219 rmp->fault = rmp->fault || cfmi->fault_check > rmp->recv_time;
220 fault = rmp->fault || fault;
223 HMAP_FOR_EACH_SAFE (rmp, rmp_next, node, &cfm->x_remote_mps) {
224 if (cfmi->fault_check > rmp->recv_time) {
225 hmap_remove(&cfm->x_remote_mps, &rmp->node);
230 HMAP_FOR_EACH_SAFE (rmaid, rmaid_next, node, &cfm->x_remote_maids) {
231 if (cfmi->fault_check > rmaid->recv_time) {
232 hmap_remove(&cfm->x_remote_maids, &rmaid->node);
237 fault = (fault || !hmap_is_empty(&cfm->x_remote_mps)
238 || !hmap_is_empty(&cfm->x_remote_maids));
241 cfmi->fault_check = now;
244 if (now >= cfmi->ccm_sent + cfmi->ccm_interval_ms) {
245 cfmi->ccm_sent = now;
246 return compose_ccm(cfmi);
253 cfm_wait(struct cfm *cfm)
256 struct cfm_internal *cfmi = cfm_to_internal(cfm);
258 wait = MIN(cfmi->ccm_sent + cfmi->ccm_interval_ms,
259 cfmi->fault_check + cfmi->ccm_interval_ms * 4);
260 poll_timer_wait_until(wait);
263 /* Should be called whenever a client of the cfm library changes the internals
264 * of 'cfm'. Returns true if 'cfm' is valid. */
266 cfm_configure(struct cfm *cfm)
268 struct cfm_internal *cfmi;
270 if (!cfm_is_valid_mpid(cfm->mpid) || !cfm->interval) {
274 cfmi = cfm_to_internal(cfm);
275 cfmi->ccm_interval = ms_to_ccm_interval(cfm->interval);
276 cfmi->ccm_interval_ms = ccm_interval_to_ms(cfmi->ccm_interval);
278 /* Force a resend and check in case anything changed. */
280 cfmi->fault_check = 0;
284 /* Given an array of MPIDs, updates the 'remote_mps' map of 'cfm' to reflect
285 * it. Invalid MPIDs are skipped. */
287 cfm_update_remote_mps(struct cfm *cfm, const uint16_t *mpids, size_t n_mpids)
290 struct hmap new_rmps;
291 struct remote_mp *rmp, *rmp_next;
293 hmap_init(&new_rmps);
295 for (i = 0; i < n_mpids; i++) {
296 uint16_t mpid = mpids[i];
298 if (!cfm_is_valid_mpid(mpid)
299 || lookup_remote_mp(&new_rmps, mpid)) {
303 if ((rmp = lookup_remote_mp(&cfm->remote_mps, mpid))) {
304 hmap_remove(&cfm->remote_mps, &rmp->node);
305 } else if ((rmp = lookup_remote_mp(&cfm->x_remote_mps, mpid))) {
306 hmap_remove(&cfm->x_remote_mps, &rmp->node);
308 rmp = xzalloc(sizeof *rmp);
312 hmap_insert(&new_rmps, &rmp->node, hash_mpid(mpid));
315 hmap_swap(&new_rmps, &cfm->remote_mps);
317 HMAP_FOR_EACH_SAFE (rmp, rmp_next, node, &new_rmps) {
318 hmap_remove(&new_rmps, &rmp->node);
322 hmap_destroy(&new_rmps);
325 /* Finds a 'remote_mp' with 'mpid' in 'cfm'. If no such 'remote_mp' exists
327 const struct remote_mp *
328 cfm_get_remote_mp(const struct cfm *cfm, uint16_t mpid)
330 return lookup_remote_mp(&cfm->remote_mps, mpid);
333 /* Generates 'maid' from 'md_name' and 'ma_name'. A NULL parameter indicates
334 * the default should be used. Returns false if unsuccessful. */
336 cfm_generate_maid(const char *md_name, const char *ma_name,
337 uint8_t maid[CCM_MAID_LEN])
340 size_t md_len, ma_len;
350 memset(maid, 0, CCM_MAID_LEN);
352 md_len = strlen(md_name);
353 ma_len = strlen(ma_name);
355 if (!md_len || !ma_len || md_len + ma_len + 4 > CCM_MAID_LEN) {
359 maid[0] = 4; /* MD name string format. */
360 maid[1] = md_len; /* MD name size. */
361 memcpy(&maid[2], md_name, md_len); /* MD name. */
363 ma_p = maid + 2 + md_len;
364 ma_p[0] = 2; /* MA name string format. */
365 ma_p[1] = ma_len; /* MA name size. */
366 memcpy(&ma_p[2], ma_name, ma_len); /* MA name. */
370 /* Returns true if the CFM library should process packets from 'flow'. */
372 cfm_should_process_flow(const struct flow *flow)
374 return (ntohs(flow->dl_type) == ETH_TYPE_CFM
375 && eth_addr_to_uint64(flow->dl_dst) == DEST_ADDR);
378 /* Updates internal statistics relevant to packet 'p'. Should be called on
379 * every packet whose flow returned true when passed to
380 * cfm_should_process_flow. */
382 cfm_process_heartbeat(struct cfm *cfm, const struct ofpbuf *p)
387 uint8_t ccm_interval;
388 struct remote_mp *rmp;
390 struct cfm_internal *cfmi = cfm_to_internal(cfm);
391 static struct vlog_rate_limit rl = VLOG_RATE_LIMIT_INIT(5, 20);
393 ccm = ofpbuf_at(p, (uint8_t *)p->l3 - (uint8_t *)p->data, CCM_LEN);
396 VLOG_INFO_RL(&rl, "Received an un-parseable 802.1ag CCM heartbeat.");
400 if (ccm->opcode != CCM_OPCODE) {
401 VLOG_INFO_RL(&rl, "Received an unsupported 802.1ag message. "
402 "(opcode %u)", ccm->opcode);
406 if (memcmp(ccm->maid, cfm->maid, sizeof ccm->maid)) {
408 struct remote_maid *rmaid;
410 hash = hash_bytes(ccm->maid, sizeof ccm->maid, 0);
412 HMAP_FOR_EACH_IN_BUCKET (rmaid, node, hash, &cfm->x_remote_maids) {
413 if (memcmp(rmaid->maid, ccm->maid, sizeof rmaid->maid) == 0) {
414 rmaid->recv_time = time_msec();
419 rmaid = xzalloc(sizeof *rmaid);
420 rmaid->recv_time = time_msec();
421 memcpy(rmaid->maid, ccm->maid, sizeof rmaid->maid);
422 hmap_insert(&cfm->x_remote_maids, &rmaid->node, hash);
426 ccm_mpid = ntohs(ccm->mpid);
427 ccm_seq = ntohl(ccm->seq);
428 ccm_interval = ccm->flags & 0x7;
430 rmp = lookup_remote_mp(&cfm->remote_mps, ccm_mpid);
433 rmp = lookup_remote_mp(&cfm->x_remote_mps, ccm_mpid);
437 rmp = xzalloc(sizeof *rmp);
438 rmp->mpid = ccm_mpid;
439 hmap_insert(&cfm->x_remote_mps, &rmp->node, hash_mpid(ccm_mpid));
442 rmp->recv_time = time_msec();
443 rmp->fault = ccm_interval != cfmi->ccm_interval;