From ca4801db5521d0dc9f7c7f854f62f27c55420558 Mon Sep 17 00:00:00 2001 From: bodea Date: Thu, 26 May 2005 12:17:30 +0000 Subject: [PATCH] merge cluster fixes from release_2_0 branch --- Changes | 18 +++++- Docs/manual.html | 5 ++ Docs/startup-config.5 | 6 +- cluster.c | 126 ++++++++++++++++++++++++++++++++++-------- cluster.h | 5 +- l2tpns.c | 4 +- l2tpns.h | 9 ++- l2tpns.spec | 2 +- 8 files changed, 143 insertions(+), 32 deletions(-) diff --git a/Changes b/Changes index 09b32a3..72e1d6f 100644 --- a/Changes +++ b/Changes @@ -1,4 +1,4 @@ -* Mon May 16 2005 Brendan O'Dea 2.1.0 +* Thu May 26 2005 Brendan O'Dea 2.1.0 - Add IPv6 support from Jonathan McDowell. - Add CHAP support from Jordan Hrycaj. - Add interim accounting support from Vladislav Bjelic. @@ -61,6 +61,22 @@ - Add sessionctl plugin to provide drop/kill via nsctl. - Add handling of "throttle=N" RADIUS attributes. - Fix RADIUS indexing (should have 16K entries with 64 sockets). +- Cluster changes from Michael, intended to prevent a stray master + from trashing a cluster: + + Ignore heartbeats from peers claiming to be the master before the + timeout on the old master has expired. + + A master receiving a stray heartbeat sends a unicast HB back, which + should cause the rogue to die due to the tie-breaker code. + + Keep probing the master for late heartbeats. + + Drop BGP as soon as we become master with the minumum required peers. + + Any PING seen from a master forces an election (rather than just + where basetime is zero). + + A slave which receives a LASTSEEN message (presumably a restarted + master) sends back new message type, C_MASTER which indicates the + address of the current master. +- New config option: cluster_master_min_adv which determines the minimum + number of up to date slaves required before the master will drop + routes. * Fri Dec 17 2004 Brendan O'Dea 2.0.13 - Better cluster master collision resolution: keep a counter of state diff --git a/Docs/manual.html b/Docs/manual.html index 3d1adf9..e4cc1a5 100644 --- a/Docs/manual.html +++ b/Docs/manual.html @@ -324,6 +324,11 @@ Cluster heartbeat timeout in tenths of a second. A new master will be elected when this interval has been passed without seeing a heartbeat from the master. + +
  • cluster_master_min_adv (int)
    +Determines the minumum number of up to date slaves required before the +master will drop routes (default: 1). +

    • BGP routing configuration is entered by the command: diff --git a/Docs/startup-config.5 b/Docs/startup-config.5 index 2d4d174..71d5981 100644 --- a/Docs/startup-config.5 +++ b/Docs/startup-config.5 @@ -2,7 +2,7 @@ .de Id .ds Dt \\$4 \\$5 .. -.Id $Id: startup-config.5,v 1.7 2005/05/10 11:59:25 bodea Exp $ +.Id $Id: startup-config.5,v 1.8 2005/05/26 12:17:31 bodea Exp $ .TH STARTUP-CONFIG 5 "\*(Dt" L2TPNS "File Formats and Conventions" .SH NAME startup\-config \- configuration file for l2tpns @@ -189,6 +189,10 @@ Cluster heartbeat timeout in tenths of a second. A new master will be elected when this interval has been passed without seeing a heartbeat from the master. .TP +.B cluster_master_min_adv +Determines the minumum number of up to date slaves required before the +master will drop routes (default: 1). +.TP .B ipv6_prefix Enable negotiation of IPv6. This forms the the first 64 bits of the client allocated address. The remaining 64 come from the allocated diff --git a/cluster.c b/cluster.c index 2524c7a..c529fea 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). diff --git a/cluster.h b/cluster.h index 9c3c562..63fbc77 100644 --- a/cluster.h +++ b/cluster.h @@ -1,5 +1,5 @@ // L2TPNS Clustering Stuff -// $Id: cluster.h,v 1.10 2005/05/08 08:00:50 bodea Exp $ +// $Id: cluster.h,v 1.11 2005/05/26 12:17:30 bodea Exp $ #ifndef __CLUSTER_H__ #define __CLUSTER_H__ @@ -14,11 +14,12 @@ #define C_LASTSEEN 7 // Tell master the last heartbeat that I handled. #define C_KILL 8 // Tell a slave to die. #define C_FORWARD 9 // Forwarded packet.. -#define C_BYTES 10 // Update byte counters. +#define C_BYTES 10 // Update byte counters. #define C_THROTTLE 11 // A packet for the master to throttle. (The TBF tells direction). #define C_CSESSION 12 // Compressed session structure. #define C_CTUNNEL 13 // Compressed tunnel structure. #define C_GARDEN 14 // Gardened packet +#define C_MASTER 15 // Tell a slave the address of the master. #define HB_VERSION 5 // Protocol version number.. #define HB_MAX_SEQ (1<<30) // Maximum sequence number. (MUST BE A POWER OF 2!) diff --git a/l2tpns.c b/l2tpns.c index e0e3cf2..a592ff6 100644 --- a/l2tpns.c +++ b/l2tpns.c @@ -4,7 +4,7 @@ // Copyright (c) 2002 FireBrick (Andrews & Arnold Ltd / Watchfront Ltd) - GPL licenced // vim: sw=8 ts=8 -char const *cvs_id_l2tpns = "$Id: l2tpns.c,v 1.104 2005/05/16 04:51:16 bodea Exp $"; +char const *cvs_id_l2tpns = "$Id: l2tpns.c,v 1.105 2005/05/26 12:17:30 bodea Exp $"; #include #include @@ -131,6 +131,7 @@ config_descriptt config_values[] = { CONFIG("cluster_interface", cluster_interface, STRING), CONFIG("cluster_hb_interval", cluster_hb_interval, INT), CONFIG("cluster_hb_timeout", cluster_hb_timeout, INT), + CONFIG("cluster_master_min_adv", cluster_master_min_adv, INT), CONFIG("ipv6_prefix", ipv6_prefix, IPv6), { NULL, 0, 0, 0 }, }; @@ -3199,6 +3200,7 @@ static void initdata(int optdebug, char *optconfig) config->debug = optdebug; config->num_tbfs = MAXTBFS; config->rl_rate = 28; // 28kbps + config->cluster_master_min_adv = 1; strcpy(config->random_device, RANDOMDEVICE); log_stream = stderr; diff --git a/l2tpns.h b/l2tpns.h index f527c61..8ac0a7f 100644 --- a/l2tpns.h +++ b/l2tpns.h @@ -1,5 +1,5 @@ // L2TPNS Global Stuff -// $Id: l2tpns.h,v 1.72 2005/05/20 01:32:14 bodea Exp $ +// $Id: l2tpns.h,v 1.73 2005/05/26 12:17:30 bodea Exp $ #ifndef __L2TPNS_H__ #define __L2TPNS_H__ @@ -474,7 +474,8 @@ typedef struct char old_plugins[64][MAXPLUGINS]; int next_tbf; // Next HTB id available to use - int scheduler_fifo; // If the system has multiple CPUs, use FIFO scheduling policy for this process. + int scheduler_fifo; // If the system has multiple CPUs, use FIFO scheduling + // policy for this process. int lock_pages; // Lock pages into memory. int icmp_rate; // Max number of ICMP unreachable per second to send int max_packets; // DoS prevention: per session limit of packets/0.1s @@ -501,6 +502,10 @@ typedef struct struct in6_addr ipv6_prefix; // Our IPv6 network pool. + + int cluster_master_min_adv; // Master advertises routes while the number of up to date + // slaves is less than this value. + #ifdef BGP #define BGP_NUM_PEERS 2 uint16_t as_number; diff --git a/l2tpns.spec b/l2tpns.spec index 1472f03..2c18f82 100644 --- a/l2tpns.spec +++ b/l2tpns.spec @@ -43,5 +43,5 @@ rm -rf %{buildroot} %attr(644,root,root) /usr/share/man/man[58]/* %changelog -* Mon May 16 2005 Brendan O'Dea 2.1.0-1 +* Thu May 26 2005 Brendan O'Dea 2.1.0-1 - 2.1.0 release, see /usr/share/doc/l2tpns-2.1.0/Changes -- 2.20.1