Add a new type, C_MASTER which is issued by a slave upon receiving a

LASTSEEN message from another slave.  Indicates the current master address.

diff --git a/Changes b/Changes
index 56cf0e9..15070db 100644 (file)
--- a/Changes
+++ b/Changes
@@ -6,13 +6,13 @@
   + 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 peers (TODO: pre-emptively
-    drop routes if the master is late and we are the best candidate).
+  + Drop BGP as soon as we become master with 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 a ping, indicating that it's not the master.
-  
+    master) sends back new message type, C_MASTER which indicates the
+    address of the current master.
+
 * Mon May 16 2005 Brendan O'Dea <bod@optusnet.com.au> 2.0.20
 - Add handling of "throttle=N" RADIUS attributes.
 - Fix RADIUS indexing (should have 16K entries with 64 sockets).

diff --git a/cluster.c b/cluster.c
index 29322fc..48c2059 100644 (file)
--- a/cluster.c
+++ b/cluster.c
@@ -1,6 +1,6 @@
 // L2TPNS Clustering Stuff
 
-char const *cvs_id_cluster = "$Id: cluster.c,v 1.26.2.8 2005/05/22 12:02:41 bodea Exp $";
+char const *cvs_id_cluster = "$Id: cluster.c,v 1.26.2.9 2005/05/23 12:48:17 bodea Exp $";
 
 #include <stdio.h>
 #include <stdlib.h>
@@ -354,9 +354,9 @@ static void send_heartbeat(int seq, char *data, int size)
 }
 
 //
-// Send an 'i am alive' message to every machine in the cluster, or to a single peer
+// Send an 'i am alive' message to every machine in the cluster.
 //
-static void send_ping(time_t basetime, in_addr_t peer)
+void cluster_send_ping(time_t basetime)
 {
        char buff[100 + sizeof(pingt)];
        char *p = buff;
@@ -365,29 +365,15 @@ static void send_ping(time_t basetime, in_addr_t peer)
        if (config->cluster_iam_master && basetime)             // We're heartbeating so no need to ping.
                return;
 
+       LOG(5, 0, 0, "Sending cluster ping...\n");
+
        x.ver = 1;
        x.addr = config->bind_address;
        x.undef = config->cluster_undefined_sessions + config->cluster_undefined_tunnels;
        x.basetime = basetime;
 
        add_type(&p, C_PING, basetime, (char *) &x, sizeof(x));
-
-       if (peer)
-               peer_send_data(peer, buff, (p-buff));
-       else
-               cluster_send_data(buff, (p-buff) );
-}
-
-void cluster_send_ping(time_t basetime)
-{
-       LOG(5, 0, 0, "Sending cluster ping...\n");
-       send_ping(0, basetime);
-}
-
-static void peer_send_ping(in_addr_t peer, time_t basetime)
-{
-       LOG(5, 0, 0, "Sending unicast ping to %s...\n", fmtaddr(peer, 0));
-       send_ping(peer, basetime);
+       cluster_send_data(buff, (p-buff) );
 }
 
 //
@@ -917,9 +903,10 @@ static int cluster_catchup_slave(int seq, in_addr_t slave)
 
        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! Sending a PING.\n");
-                       // Send a ping to the slave so they know we're no longer a master
-               peer_send_ping(slave, basetime);
+               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;
        }
 
@@ -1034,6 +1021,20 @@ 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
@@ -1408,10 +1409,13 @@ 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.
@@ -1452,6 +1456,11 @@ 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 bd776f4..3482c9c 100644 (file)
--- a/cluster.h
+++ b/cluster.h
@@ -1,5 +1,5 @@
 // L2TPNS Clustering Stuff
-// $Id: cluster.h,v 1.9 2004/12/16 08:49:53 bodea Exp $
+// $Id: cluster.h,v 1.9.2.1 2005/05/23 12:48:18 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             4       // Protocol version number..
 #define HB_MAX_SEQ             (1<<30) // Maximum sequence number. (MUST BE A POWER OF 2!)