X-Git-Url: http://git.sameswireless.fr/l2tpns.git/blobdiff_plain/211cb9427c7f78f59928d7f850721e7d0dfbf271..83699acac624ac96dbc6b387ffeab3e4b85ab4bc:/cluster.c diff --git a/cluster.c b/cluster.c index b4aa1d9..a9e8209 100644 --- a/cluster.c +++ b/cluster.c @@ -1,6 +1,6 @@ // L2TPNS Clustering Stuff -char const *cvs_id_cluster = "$Id: cluster.c,v 1.38 2005-05-24 07:45:13 bodea Exp $"; +char const *cvs_id_cluster = "$Id: cluster.c,v 1.39 2005-05-26 12:17:30 bodea Exp $"; #include #include @@ -193,7 +193,7 @@ static void add_type(char **p, int type, int more, char *data, int size) } // advertise our presence via BGP or gratuitous ARP -static void advertise(void) +static void advertise_routes(void) { #ifdef BGP if (bgp_configured) @@ -204,6 +204,15 @@ static void advertise(void) send_garp(config->bind_address); // Start taking traffic. } +// withdraw our routes (BGP only) +static void withdraw_routes(void) +{ +#ifdef BGP + if (bgp_configured) + bgp_enable_routing(0); +#endif /* BGP */ +} + static void cluster_uptodate(void) { if (config->cluster_iam_uptodate) @@ -215,7 +224,7 @@ static void cluster_uptodate(void) config->cluster_iam_uptodate = 1; LOG(0, 0, 0, "Now uptodate with master.\n"); - advertise(); + advertise_routes(); } // @@ -457,17 +466,22 @@ void cluster_check_slaves(void) continue; // Shutdown peer! Skip them. if (peers[i].uptodate) - have_peers = 1; - - if (!peers[i].uptodate) + have_peers++; + else config->cluster_iam_uptodate = 0; // Start fast heartbeats } -#ifdef BGP - // in a cluster, withdraw/add routes when we get a peer/lose all peers - if (bgp_configured && have_peers != had_peers) - bgp_enable_routing(!have_peers); -#endif /* BGP */ + // in a cluster, withdraw/add routes when we get a peer/lose peers + if (have_peers != had_peers) + { + if (had_peers < config->cluster_master_min_adv && + have_peers >= config->cluster_master_min_adv) + withdraw_routes(); + + else if (had_peers >= config->cluster_master_min_adv && + have_peers < config->cluster_master_min_adv) + advertise_routes(); + } } // @@ -480,20 +494,22 @@ void cluster_check_master(void) int last_free = 0; clockt t = TIME; static int probed = 0; + int have_peers; if (config->cluster_iam_master) return; // Only runs on the slaves... // If the master is late (missed 2 hearbeats by a second and a // hair) it may be that the switch has dropped us from the - // multicast group, try unicasting one probe to the master + // multicast group, try unicasting probes to the master // which will hopefully respond with a unicast heartbeat that // will allow us to limp along until the querier next runs. - if (TIME > (config->cluster_last_hb + 2 * config->cluster_hb_interval + 11)) + if (config->cluster_master_address + && TIME > (config->cluster_last_hb + 2 * config->cluster_hb_interval + 11)) { - if (!probed && config->cluster_master_address) + if (!probed || (TIME > (probed + 2 * config->cluster_hb_interval))) { - probed = 1; + probed = TIME; LOG(1, 0, 0, "Heartbeat from master %.1fs late, probing...\n", 0.1 * (TIME - (config->cluster_last_hb + config->cluster_hb_interval))); @@ -511,7 +527,7 @@ void cluster_check_master(void) LOG(0, 0, 0, "Master timed out! Holding election...\n"); - for (i = 0; i < num_peers; i++) + for (i = have_peers = 0; i < num_peers; i++) { if ((peers[i].timestamp + config->cluster_hb_timeout) < t) continue; // Stale peer! Skip them. @@ -529,6 +545,9 @@ void cluster_check_master(void) LOG(1, 0, 0, "Expecting %s to become master\n", fmtaddr(peers[i].peer, 0)); return; // They'll win the election. Wait for them to come up. } + + if (peers[i].uptodate) + have_peers++; } // Wow. it's been ages since I last heard a heartbeat @@ -540,6 +559,11 @@ void cluster_check_master(void) LOG(0, 0, 0, "I am declaring myself the master!\n"); + if (have_peers < config->cluster_master_min_adv) + advertise_routes(); + else + withdraw_routes(); + if (config->cluster_seq_number == -1) config->cluster_seq_number = 0; @@ -620,9 +644,6 @@ void cluster_check_master(void) config->cluster_undefined_tunnels = 0; config->cluster_iam_uptodate = 1; // assume all peers are up-to-date - if (!num_peers) // lone master - advertise(); - // FIXME. We need to fix up the tunnel control message // queue here! There's a number of other variables we // should also update. @@ -902,6 +923,13 @@ static int cluster_catchup_slave(int seq, in_addr_t slave) int diff; LOG(1, 0, 0, "Slave %s sent LASTSEEN with seq %d\n", fmtaddr(slave, 0), seq); + if (!config->cluster_iam_master) { + LOG(1, 0, 0, "Got LASTSEEN but I'm not a master! Redirecting it to %s.\n", + fmtaddr(config->cluster_master_address, 0)); + + peer_send_message(slave, C_MASTER, config->cluster_master_address, NULL, 0); + return 0; + } diff = config->cluster_seq_number - seq; // How many packet do we need to send? if (diff < 0) @@ -913,9 +941,11 @@ static int cluster_catchup_slave(int seq, in_addr_t slave) return peer_send_message(slave, C_KILL, seq, NULL, 0);// Kill the slave. Nothing else to do. } + LOG(1, 0, 0, "Sending %d catchup packets to slave %s\n", diff, fmtaddr(slave, 0) ); + // Now resend every packet that it missed, in order. while (seq != config->cluster_seq_number) { - s = seq%HB_HISTORY_SIZE; + s = seq % HB_HISTORY_SIZE; if (seq != past_hearts[s].seq) { LOG(0, 0, 0, "Tried to re-send heartbeat for %s but %d doesn't match %d! (%d,%d)\n", fmtaddr(slave, 0), seq, past_hearts[s].seq, s, config->cluster_seq_number); @@ -968,8 +998,10 @@ static int cluster_add_peer(in_addr_t peer, time_t basetime, pingt *pp, int size } // Is this the master shutting down?? - if (peer == config->cluster_master_address && !basetime) { - LOG(3, 0, 0, "Master %s shutting down...\n", fmtaddr(config->cluster_master_address, 0)); + if (peer == config->cluster_master_address) { + LOG(3, 0, 0, "Master %s %s\n", fmtaddr(config->cluster_master_address, 0), + basetime ? "has restarted!" : "shutting down..."); + config->cluster_master_address = 0; config->cluster_last_hb = 0; // Force an election. cluster_check_master(); @@ -1010,6 +1042,20 @@ static int cluster_add_peer(in_addr_t peer, time_t basetime, pingt *pp, int size return 1; } +// A slave responds with C_MASTER when it gets a message which should have gone to a master. +static int cluster_set_master(in_addr_t peer, in_addr_t master) +{ + if (config->cluster_iam_master) // Sanity... + return 0; + + LOG(3, 0, 0, "Peer %s set the master to %s...\n", fmtaddr(peer, 0), + fmtaddr(master, 1)); + + config->cluster_master_address = master; + cluster_check_master(); + return 0; +} + /* Handle the slave updating the byte counters for the master. */ // // Note that we don't mark the session as dirty; We rely on @@ -1283,9 +1329,33 @@ static int cluster_process_heartbeat(uint8_t *data, int size, int more, uint8_t exit(1); } + // + // Send it a unicast heartbeat to see give it a chance to die. + // NOTE: It's actually safe to do seq-number - 1 without checking + // for wrap around. + // + cluster_catchup_slave(config->cluster_seq_number - 1, addr); + return -1; // Skip it. } + // + // Try and guard against a stray master appearing. + // + // Ignore heartbeats received from another master before the + // timeout (less a smidgen) for the old master has elapsed. + // + // Note that after a clean failover, the cluster_master_address + // is cleared, so this doesn't run. + // + if (config->cluster_master_address && addr != config->cluster_master_address + && (config->cluster_last_hb + config->cluster_hb_timeout - 11) > TIME) { + LOG(0, 0, 0, "Ignoring stray heartbeat from %s, current master %s has not yet timed out (last heartbeat %.1f seconds ago).\n", + fmtaddr(addr, 0), fmtaddr(config->cluster_master_address, 1), + 0.1 * (TIME - config->cluster_last_hb)); + return -1; // ignore + } + if (config->cluster_seq_number == -1) // Don't have one. Just align to the master... config->cluster_seq_number = h->seq; @@ -1487,10 +1557,13 @@ int processcluster(char *data, int size, in_addr_t addr) s -= sizeof(uint32_t); switch (type) { - case C_PING: // Update the peers table. + case C_PING: // Update the peers table. return cluster_add_peer(addr, more, (pingt *) p, s); - case C_LASTSEEN: // Catch up a slave (slave missed a packet). + case C_MASTER: // Our master is wrong + return cluster_set_master(addr, more); + + case C_LASTSEEN: // Catch up a slave (slave missed a packet). return cluster_catchup_slave(more, addr); case C_FORWARD: { // Forwarded control packet. pass off to processudp. @@ -1531,6 +1604,11 @@ int processcluster(char *data, int size, in_addr_t addr) return 0; case C_BYTES: + if (!config->cluster_iam_master) { + LOG(0, 0, 0, "I'm not the master, but I got a C_BYTES from %s?\n", fmtaddr(addr, 0)); + return -1; + } + return cluster_handle_bytes(p, s); case C_KILL: // The master asked us to die!? (usually because we're too out of date).