+/*
+ * Copyright (c) 2010 Nicira Networks.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at:
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include <config.h>
+#include "cfm.h"
+
+#include <stdint.h>
+#include <stdlib.h>
+#include <string.h>
+
+#include "flow.h"
+#include "hash.h"
+#include "hmap.h"
+#include "ofpbuf.h"
+#include "packets.h"
+#include "poll-loop.h"
+#include "timeval.h"
+#include "vlog.h"
+
+VLOG_DEFINE_THIS_MODULE(cfm);
+
+#define CCM_OPCODE 1 /* CFM message opcode meaning CCM. */
+#define DEST_ADDR 0x0180C2000030 /* Destination for MD level 0 CCMs. */
+
+struct cfm_internal {
+ struct cfm cfm;
+ uint32_t seq; /* The sequence number of our last CCM. */
+
+ uint8_t ccm_interval; /* The CCM transmission interval. */
+ int ccm_interval_ms; /* 'ccm_interval' in milliseconds. */
+
+ long long ccm_sent; /* The time we last sent a CCM. */
+ long long fault_check; /* The time we last checked for faults. */
+};
+
+static int
+ccm_interval_to_ms(uint8_t interval)
+{
+ switch (interval) {
+ case 0: NOT_REACHED(); /* Explicitly not supported by 802.1ag. */
+ case 1: return 3; /* Not recommended due to timer resolution. */
+ case 2: return 10; /* Not recommended due to timer resolution. */
+ case 3: return 100;
+ case 4: return 1000;
+ case 5: return 10000;
+ case 6: return 60000;
+ case 7: return 600000;
+ default: NOT_REACHED(); /* Explicitly not supported by 802.1ag. */
+ }
+
+ NOT_REACHED();
+}
+
+static uint8_t
+ms_to_ccm_interval(int interval_ms)
+{
+ uint8_t i;
+
+ for (i = 7; i > 0; i--) {
+ if (ccm_interval_to_ms(i) <= interval_ms) {
+ return i;
+ }
+ }
+
+ return 1;
+}
+
+static struct cfm_internal *
+cfm_to_internal(struct cfm *cfm)
+{
+ return CONTAINER_OF(cfm, struct cfm_internal, cfm);
+}
+
+static uint32_t
+hash_mpid(uint8_t mpid)
+{
+ return hash_int(mpid, 0);
+}
+
+static bool
+cfm_is_valid_mpid(uint32_t mpid)
+{
+ /* 802.1ag specification requires MPIDs to be within the range [1, 8191] */
+ return mpid >= 1 && mpid <= 8191;
+}
+
+static struct remote_mp *
+lookup_remote_mp(const struct hmap *hmap, uint16_t mpid)
+{
+ struct remote_mp *rmp;
+
+ HMAP_FOR_EACH_IN_BUCKET (rmp, node, hash_mpid(mpid), hmap) {
+ if (rmp->mpid == mpid) {
+ return rmp;
+ }
+ }
+
+ return NULL;
+}
+
+static struct ofpbuf *
+compose_ccm(struct cfm_internal *cfmi)
+{
+ struct ccm *ccm;
+ struct ofpbuf *packet;
+ struct eth_header *eth;
+
+ packet = xzalloc(sizeof *packet);
+
+ ofpbuf_init(packet, ETH_HEADER_LEN + CCM_LEN + 2);
+
+ ofpbuf_reserve(packet, 2);
+
+ eth = ofpbuf_put_zeros(packet, ETH_HEADER_LEN);
+ ccm = ofpbuf_put_zeros(packet, CCM_LEN);
+
+ eth_addr_from_uint64(DEST_ADDR, eth->eth_dst);
+ memcpy(eth->eth_src, cfmi->cfm.eth_src, sizeof eth->eth_src);
+ eth->eth_type = htons(ETH_TYPE_CFM);
+
+ ccm->mdlevel_version = 0;
+ ccm->opcode = CCM_OPCODE;
+ ccm->tlv_offset = 70;
+ ccm->seq = htonl(++cfmi->seq);
+ ccm->mpid = htons(cfmi->cfm.mpid);
+ ccm->flags = cfmi->ccm_interval;
+ memcpy(ccm->maid, cfmi->cfm.maid, sizeof ccm->maid);
+ return packet;
+}
+
+/* Allocates a 'cfm' object. This object should have its 'mpid', 'maid',
+ * 'eth_src', and 'interval' filled out. When changes are made to the 'cfm'
+ * object, cfm_configure should be called before using it. */
+struct cfm *
+cfm_create(void)
+{
+ struct cfm *cfm;
+ struct cfm_internal *cfmi;
+
+ cfmi = xzalloc(sizeof *cfmi);
+ cfm = &cfmi->cfm;
+
+ hmap_init(&cfm->remote_mps);
+ hmap_init(&cfm->x_remote_mps);
+ hmap_init(&cfm->x_remote_maids);
+ return cfm;
+}
+
+void
+cfm_destroy(struct cfm *cfm)
+{
+ struct remote_mp *rmp, *rmp_next;
+ struct remote_maid *rmaid, *rmaid_next;
+
+ if (!cfm) {
+ return;
+ }
+
+ HMAP_FOR_EACH_SAFE (rmp, rmp_next, node, &cfm->remote_mps) {
+ hmap_remove(&cfm->remote_mps, &rmp->node);
+ free(rmp);
+ }
+
+ HMAP_FOR_EACH_SAFE (rmp, rmp_next, node, &cfm->x_remote_mps) {
+ hmap_remove(&cfm->x_remote_mps, &rmp->node);
+ free(rmp);
+ }
+
+ HMAP_FOR_EACH_SAFE (rmaid, rmaid_next, node, &cfm->x_remote_maids) {
+ hmap_remove(&cfm->x_remote_maids, &rmaid->node);
+ free(rmaid);
+ }
+
+ hmap_destroy(&cfm->remote_mps);
+ hmap_destroy(&cfm->x_remote_mps);
+ hmap_destroy(&cfm->x_remote_maids);
+ free(cfm_to_internal(cfm));
+}
+
+/* Should be run periodically to update fault statistics and generate CCM
+ * messages. If necessary, returns a packet which the caller is responsible
+ * for sending, un-initing, and deallocating. Otherwise returns NULL. */
+struct ofpbuf *
+cfm_run(struct cfm *cfm)
+{
+ long long now = time_msec();
+ struct cfm_internal *cfmi = cfm_to_internal(cfm);
+
+ /* According to the 802.1ag specification we should assume every other MP
+ * with the same MAID has the same transmission interval that we have. If
+ * an MP has a different interval, cfm_process_heartbeat will register it
+ * as a fault (likely due to a configuration error). Thus we can check all
+ * MPs at once making this quite a bit simpler.
+ *
+ * According to the specification we should check when (ccm_interval_ms *
+ * 3.5)ms have passed. We changed the multiplier to 4 to avoid messy
+ * floating point arithmetic and add a bit of wiggle room. */
+ if (now >= cfmi->fault_check + cfmi->ccm_interval_ms * 4) {
+ bool fault;
+ struct remote_mp *rmp, *rmp_next;
+ struct remote_maid *rmaid, *rmaid_next;
+
+ fault = false;
+
+ HMAP_FOR_EACH (rmp, node, &cfm->remote_mps) {
+ rmp->fault = rmp->fault || cfmi->fault_check > rmp->recv_time;
+ fault = rmp->fault || fault;
+ }
+
+ HMAP_FOR_EACH_SAFE (rmp, rmp_next, node, &cfm->x_remote_mps) {
+ if (cfmi->fault_check > rmp->recv_time) {
+ hmap_remove(&cfm->x_remote_mps, &rmp->node);
+ free(rmp);
+ }
+ }
+
+ HMAP_FOR_EACH_SAFE (rmaid, rmaid_next, node, &cfm->x_remote_maids) {
+ if (cfmi->fault_check > rmaid->recv_time) {
+ hmap_remove(&cfm->x_remote_maids, &rmaid->node);
+ free(rmaid);
+ }
+ }
+
+ fault = (fault || !hmap_is_empty(&cfm->x_remote_mps)
+ || !hmap_is_empty(&cfm->x_remote_maids));
+
+ cfm->fault = fault;
+ cfmi->fault_check = now;
+ }
+
+ if (now >= cfmi->ccm_sent + cfmi->ccm_interval_ms) {
+ cfmi->ccm_sent = now;
+ return compose_ccm(cfmi);
+ }
+
+ return NULL;
+}
+
+void
+cfm_wait(struct cfm *cfm)
+{
+ long long wait;
+ struct cfm_internal *cfmi = cfm_to_internal(cfm);
+
+ wait = MIN(cfmi->ccm_sent + cfmi->ccm_interval_ms,
+ cfmi->fault_check + cfmi->ccm_interval_ms * 4);
+ poll_timer_wait_until(wait);
+}
+
+/* Should be called whenever a client of the cfm library changes the internals
+ * of 'cfm'. Returns true if 'cfm' is valid. */
+bool
+cfm_configure(struct cfm *cfm)
+{
+ struct cfm_internal *cfmi;
+
+ if (!cfm_is_valid_mpid(cfm->mpid) || !cfm->interval) {
+ return false;
+ }
+
+ cfmi = cfm_to_internal(cfm);
+ cfmi->ccm_interval = ms_to_ccm_interval(cfm->interval);
+ cfmi->ccm_interval_ms = ccm_interval_to_ms(cfmi->ccm_interval);
+
+ /* Force a resend and check in case anything changed. */
+ cfmi->ccm_sent = 0;
+ cfmi->fault_check = 0;
+ return true;
+}
+
+/* Given an array of MPIDs, updates the 'remote_mps' map of 'cfm' to reflect
+ * it. Invalid MPIDs are skipped. */
+void
+cfm_update_remote_mps(struct cfm *cfm, const uint16_t *mpids, size_t n_mpids)
+{
+ size_t i;
+ struct hmap new_rmps;
+ struct remote_mp *rmp, *rmp_next;
+
+ hmap_init(&new_rmps);
+
+ for (i = 0; i < n_mpids; i++) {
+ uint16_t mpid = mpids[i];
+
+ if (!cfm_is_valid_mpid(mpid)
+ || lookup_remote_mp(&new_rmps, mpid)) {
+ continue;
+ }
+
+ if ((rmp = lookup_remote_mp(&cfm->remote_mps, mpid))) {
+ hmap_remove(&cfm->remote_mps, &rmp->node);
+ } else if ((rmp = lookup_remote_mp(&cfm->x_remote_mps, mpid))) {
+ hmap_remove(&cfm->x_remote_mps, &rmp->node);
+ } else {
+ rmp = xzalloc(sizeof *rmp);
+ rmp->mpid = mpid;
+ }
+
+ hmap_insert(&new_rmps, &rmp->node, hash_mpid(mpid));
+ }
+
+ hmap_swap(&new_rmps, &cfm->remote_mps);
+
+ HMAP_FOR_EACH_SAFE (rmp, rmp_next, node, &new_rmps) {
+ hmap_remove(&new_rmps, &rmp->node);
+ free(rmp);
+ }
+
+ hmap_destroy(&new_rmps);
+}
+
+/* Finds a 'remote_mp' with 'mpid' in 'cfm'. If no such 'remote_mp' exists
+ * returns NULL. */
+const struct remote_mp *
+cfm_get_remote_mp(const struct cfm *cfm, uint16_t mpid)
+{
+ return lookup_remote_mp(&cfm->remote_mps, mpid);
+}
+
+/* Generates 'maid' from 'md_name' and 'ma_name'. A NULL parameter indicates
+ * the default should be used. Returns false if unsuccessful. */
+bool
+cfm_generate_maid(const char *md_name, const char *ma_name,
+ uint8_t maid[CCM_MAID_LEN])
+{
+ uint8_t *ma_p;
+ size_t md_len, ma_len;
+
+ if (!md_name) {
+ md_name = "ovs";
+ }
+
+ if (!ma_name) {
+ ma_name = "ovs";
+ }
+
+ memset(maid, 0, CCM_MAID_LEN);
+
+ md_len = strlen(md_name);
+ ma_len = strlen(ma_name);
+
+ if (!md_len || !ma_len || md_len + ma_len + 4 > CCM_MAID_LEN) {
+ return false;
+ }
+
+ maid[0] = 4; /* MD name string format. */
+ maid[1] = md_len; /* MD name size. */
+ memcpy(&maid[2], md_name, md_len); /* MD name. */
+
+ ma_p = maid + 2 + md_len;
+ ma_p[0] = 2; /* MA name string format. */
+ ma_p[1] = ma_len; /* MA name size. */
+ memcpy(&ma_p[2], ma_name, ma_len); /* MA name. */
+ return true;
+}
+
+/* Returns true if the CFM library should process packets from 'flow'. */
+bool
+cfm_should_process_flow(const struct flow *flow)
+{
+ return (ntohs(flow->dl_type) == ETH_TYPE_CFM
+ && eth_addr_to_uint64(flow->dl_dst) == DEST_ADDR);
+}
+
+/* Updates internal statistics relevant to packet 'p'. Should be called on
+ * every packet whose flow returned true when passed to
+ * cfm_should_process_flow. */
+void
+cfm_process_heartbeat(struct cfm *cfm, const struct ofpbuf *p)
+{
+ struct ccm *ccm;
+ uint16_t ccm_mpid;
+ uint32_t ccm_seq;
+ uint8_t ccm_interval;
+ struct remote_mp *rmp;
+
+ struct cfm_internal *cfmi = cfm_to_internal(cfm);
+ static struct vlog_rate_limit rl = VLOG_RATE_LIMIT_INIT(5, 20);
+
+ ccm = ofpbuf_at(p, (uint8_t *)p->l3 - (uint8_t *)p->data, CCM_LEN);
+
+ if (!ccm) {
+ VLOG_INFO_RL(&rl, "Received an un-parseable 802.1ag CCM heartbeat.");
+ return;
+ }
+
+ if (ccm->opcode != CCM_OPCODE) {
+ VLOG_INFO_RL(&rl, "Received an unsupported 802.1ag message. "
+ "(opcode %u)", ccm->opcode);
+ return;
+ }
+
+ if (memcmp(ccm->maid, cfm->maid, sizeof ccm->maid)) {
+ uint32_t hash;
+ struct remote_maid *rmaid;
+
+ hash = hash_bytes(ccm->maid, sizeof ccm->maid, 0);
+
+ HMAP_FOR_EACH_IN_BUCKET (rmaid, node, hash, &cfm->x_remote_maids) {
+ if (memcmp(rmaid->maid, ccm->maid, sizeof rmaid->maid) == 0) {
+ rmaid->recv_time = time_msec();
+ return;
+ }
+ }
+
+ rmaid = xzalloc(sizeof *rmaid);
+ rmaid->recv_time = time_msec();
+ memcpy(rmaid->maid, ccm->maid, sizeof rmaid->maid);
+ hmap_insert(&cfm->x_remote_maids, &rmaid->node, hash);
+ return;
+ }
+
+ ccm_mpid = ntohs(ccm->mpid);
+ ccm_seq = ntohl(ccm->seq);
+ ccm_interval = ccm->flags & 0x7;
+
+ rmp = lookup_remote_mp(&cfm->remote_mps, ccm_mpid);
+
+ if (!rmp) {
+ rmp = lookup_remote_mp(&cfm->x_remote_mps, ccm_mpid);
+ }
+
+ if (!rmp) {
+ rmp = xzalloc(sizeof *rmp);
+ rmp->mpid = ccm_mpid;
+ hmap_insert(&cfm->x_remote_mps, &rmp->node, hash_mpid(ccm_mpid));
+ }
+
+ rmp->recv_time = time_msec();
+ rmp->fault = ccm_interval != cfmi->ccm_interval;
+}