+//
+// This joins the cluster multi-cast group.
+//
+int cluster_init()
+{
+ struct sockaddr_in addr;
+ struct sockaddr_in interface_addr;
+ struct ip_mreq mreq;
+ struct ifreq ifr;
+ int opt;
+
+ config->cluster_undefined_sessions = MAXSESSION-1;
+ config->cluster_undefined_tunnels = MAXTUNNEL-1;
+
+ if (!config->cluster_address)
+ return 0;
+ if (!*config->cluster_interface)
+ return 0;
+
+ cluster_sockfd = socket(AF_INET, SOCK_DGRAM, IPPROTO_UDP);
+
+ memset(&addr, 0, sizeof(addr));
+ addr.sin_family = AF_INET;
+ addr.sin_port = htons(CLUSTERPORT);
+ addr.sin_addr.s_addr = INADDR_ANY;
+ setsockopt(cluster_sockfd, SOL_SOCKET, SO_REUSEADDR, &addr, sizeof(addr));
+
+ opt = fcntl(cluster_sockfd, F_GETFL, 0);
+ fcntl(cluster_sockfd, F_SETFL, opt | O_NONBLOCK);
+
+ if (bind(cluster_sockfd, (void *) &addr, sizeof(addr)) < 0)
+ {
+ LOG(0, 0, 0, "Failed to bind cluster socket: %s\n", strerror(errno));
+ return -1;
+ }
+
+ strcpy(ifr.ifr_name, config->cluster_interface);
+ if (ioctl(cluster_sockfd, SIOCGIFADDR, &ifr) < 0)
+ {
+ LOG(0, 0, 0, "Failed to get interface address for (%s): %s\n", config->cluster_interface, strerror(errno));
+ return -1;
+ }
+
+ memcpy(&interface_addr, &ifr.ifr_addr, sizeof(interface_addr));
+ my_address = interface_addr.sin_addr.s_addr;
+
+ // Join multicast group.
+ mreq.imr_multiaddr.s_addr = config->cluster_address;
+ mreq.imr_interface = interface_addr.sin_addr;
+
+
+ opt = 0; // Turn off multicast loopback.
+ setsockopt(cluster_sockfd, IPPROTO_IP, IP_MULTICAST_LOOP, &opt, sizeof(opt));
+
+ if (setsockopt(cluster_sockfd, IPPROTO_IP, IP_ADD_MEMBERSHIP, &mreq, sizeof(mreq)) < 0)
+ {
+ LOG(0, 0, 0, "Failed to setsockopt (join mcast group): %s\n", strerror(errno));
+ return -1;
+ }
+
+ if (setsockopt(cluster_sockfd, IPPROTO_IP, IP_MULTICAST_IF, &interface_addr, sizeof(interface_addr)) < 0)
+ {
+ LOG(0, 0, 0, "Failed to setsockopt (set mcast interface): %s\n", strerror(errno));
+ return -1;
+ }
+
+ config->cluster_last_hb = TIME;
+ config->cluster_seq_number = -1;
+
+ return cluster_sockfd;
+}
+
+
+//
+// Send a chunk of data to the entire cluster (usually via the multicast
+// address ).
+//
+
+static int cluster_send_data(void *data, int datalen)
+{
+ struct sockaddr_in addr = {0};
+
+ if (!cluster_sockfd) return -1;
+ if (!config->cluster_address) return 0;
+
+ addr.sin_addr.s_addr = config->cluster_address;
+ addr.sin_port = htons(CLUSTERPORT);
+ addr.sin_family = AF_INET;
+
+ LOG(5, 0, 0, "Cluster send data: %d bytes\n", datalen);
+
+ if (sendto(cluster_sockfd, data, datalen, MSG_NOSIGNAL, (void *) &addr, sizeof(addr)) < 0)
+ {
+ LOG(0, 0, 0, "sendto: %s\n", strerror(errno));
+ return -1;
+ }
+
+ return 0;
+}
+
+//
+// Add a chunk of data to a heartbeat packet.
+// Maintains the format. Assumes that the caller
+// has passed in a big enough buffer!
+//
+static void add_type(char **p, int type, int more, char *data, int size)
+{
+ *((uint32_t *) (*p)) = type;
+ *p += sizeof(uint32_t);
+
+ *((uint32_t *)(*p)) = more;
+ *p += sizeof(uint32_t);
+
+ if (data && size > 0) {
+ memcpy(*p, data, size);
+ *p += size;
+ }
+}
+
+// advertise our presence via BGP or gratuitous ARP
+static void advertise_routes(void)
+{
+#ifdef BGP
+ if (bgp_configured)
+ bgp_enable_routing(1);
+ else
+#endif /* BGP */
+ if (config->send_garp)
+ 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)
+ return;
+
+ if (config->cluster_undefined_sessions || config->cluster_undefined_tunnels)
+ return;
+
+ config->cluster_iam_uptodate = 1;
+
+ LOG(0, 0, 0, "Now uptodate with master.\n");
+ advertise_routes();
+}
+
+//
+// Send a unicast UDP packet to a peer with 'data' as the
+// contents.
+//
+static int peer_send_data(in_addr_t peer, char *data, int size)
+{
+ struct sockaddr_in addr = {0};
+
+ if (!cluster_sockfd) return -1;
+ if (!config->cluster_address) return 0;
+
+ if (!peer) // Odd??
+ return -1;
+
+ addr.sin_addr.s_addr = peer;
+ addr.sin_port = htons(CLUSTERPORT);
+ addr.sin_family = AF_INET;
+
+ LOG_HEX(5, "Peer send", data, size);
+
+ if (sendto(cluster_sockfd, data, size, MSG_NOSIGNAL, (void *) &addr, sizeof(addr)) < 0)
+ {
+ LOG(0, 0, 0, "sendto: %s\n", strerror(errno));
+ return -1;
+ }
+
+ return 0;
+}
+
+//
+// Send a structured message to a peer with a single element of type 'type'.
+//
+static int peer_send_message(in_addr_t peer, int type, int more, char *data, int size)
+{
+ char buf[65536]; // Vast overkill.
+ char *p = buf;
+
+ LOG(4, 0, 0, "Sending message to peer (type %d, more %d, size %d)\n", type, more, size);
+ add_type(&p, type, more, data, size);
+
+ return peer_send_data(peer, buf, (p-buf) );
+}
+
+//
+// Forward a state changing packet to the master.
+//
+// The master just processes the payload as if it had
+// received it off the tun device.
+//
+int master_forward_packet(char *data, int size, in_addr_t addr, int port)
+{
+ char buf[65536]; // Vast overkill.
+ char *p = buf;
+
+ if (!config->cluster_master_address) // No election has been held yet. Just skip it.
+ return -1;
+
+ LOG(4, 0, 0, "Forwarding packet from %s to master (size %d)\n", fmtaddr(addr, 0), size);
+
+ STAT(c_forwarded);
+ add_type(&p, C_FORWARD, addr, (char *) &port, sizeof(port));
+ memcpy(p, data, size);
+ p += size;
+
+ return peer_send_data(config->cluster_master_address, buf, (p - buf));
+}
+
+//
+// Forward a throttled packet to the master for handling.
+//
+// The master just drops the packet into the appropriate
+// token bucket queue, and lets normal processing take care
+// of it.
+//
+int master_throttle_packet(int tbfid, char *data, int size)
+{
+ char buf[65536]; // Vast overkill.
+ char *p = buf;
+
+ if (!config->cluster_master_address) // No election has been held yet. Just skip it.
+ return -1;
+
+ LOG(4, 0, 0, "Throttling packet master (size %d, tbfid %d)\n", size, tbfid);
+
+ add_type(&p, C_THROTTLE, tbfid, data, size);
+
+ return peer_send_data(config->cluster_master_address, buf, (p-buf) );
+
+}
+
+//
+// Forward a walled garden packet to the master for handling.
+//
+// The master just writes the packet straight to the tun
+// device (where is will normally loop through the
+// firewall rules, and come back in on the tun device)
+//
+// (Note that this must be called with the tun header
+// as the start of the data).
+int master_garden_packet(sessionidt s, char *data, int size)
+{
+ char buf[65536]; // Vast overkill.
+ char *p = buf;
+
+ if (!config->cluster_master_address) // No election has been held yet. Just skip it.
+ return -1;
+
+ LOG(4, 0, 0, "Walled garden packet to master (size %d)\n", size);
+
+ add_type(&p, C_GARDEN, s, data, size);
+
+ return peer_send_data(config->cluster_master_address, buf, (p-buf));
+
+}
+
+//
+// Send a chunk of data as a heartbeat..
+// We save it in the history buffer as we do so.
+//
+static void send_heartbeat(int seq, char *data, int size)
+{
+ int i;
+
+ if (size > sizeof(past_hearts[0].data))
+ {
+ LOG(0, 0, 0, "Tried to heartbeat something larger than the maximum packet!\n");
+ kill(0, SIGTERM);
+ exit(1);
+ }
+ i = seq % HB_HISTORY_SIZE;
+ past_hearts[i].seq = seq;
+ past_hearts[i].size = size;
+ memcpy(&past_hearts[i].data, data, size); // Save it.
+ cluster_send_data(data, size);
+}
+
+//
+// Send an 'i am alive' message to every machine in the cluster.
+//
+void cluster_send_ping(time_t basetime)
+{
+ char buff[100 + sizeof(pingt)];
+ char *p = buff;
+ pingt x;
+
+ 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));
+ cluster_send_data(buff, (p-buff) );
+}
+
+//
+// Walk the session counters looking for non-zero ones to send
+// to the master. We send up to 600 of them at one time.
+// We examine a maximum of 3000 sessions.
+// (50k max session should mean that we normally
+// examine the entire session table every 25 seconds).
+
+#define MAX_B_RECS (600)
+void master_update_counts(void)
+{
+ int i, c;
+ bytest b[MAX_B_RECS+1];
+
+ if (config->cluster_iam_master) // Only happens on the slaves.
+ return;
+
+ if (!config->cluster_master_address) // If we don't have a master, skip it for a while.
+ return;
+
+ i = MAX_B_RECS * 5; // Examine max 2000 sessions;
+ if (config->cluster_highest_sessionid > i)
+ i = config->cluster_highest_sessionid;
+
+ for ( c = 0; i > 0 ; --i) {
+ // Next session to look at.
+ walk_session_number++;
+ if ( walk_session_number > config->cluster_highest_sessionid)
+ walk_session_number = 1;
+
+ if (!sess_local[walk_session_number].cin && !sess_local[walk_session_number].cout)
+ continue; // Unused. Skip it.
+
+ b[c].sid = walk_session_number;
+ b[c].in = sess_local[walk_session_number].cin;
+ b[c].out = sess_local[walk_session_number].cout;
+
+ if (++c > MAX_B_RECS) // Send a max of 400 elements in a packet.
+ break;
+
+ // Reset counters.
+ sess_local[walk_session_number].cin = sess_local[walk_session_number].cout = 0;
+ }
+
+ if (!c) // Didn't find any that changes. Get out of here!
+ return;
+
+
+ // Forward the data to the master.
+ LOG(4, 0, 0, "Sending byte counters to master (%d elements)\n", c);
+ peer_send_message(config->cluster_master_address, C_BYTES, c, (char *) &b, sizeof(b[0]) * c);
+ return;
+}
+
+//
+// On the master, check how our slaves are going. If
+// one of them's not up-to-date we'll heartbeat faster.
+// If we don't have any of them, then we need to turn
+// on our own packet handling!
+//
+void cluster_check_slaves(void)
+{
+ int i;
+ static int have_peers = 0;
+ int had_peers = have_peers;
+ clockt t = TIME;
+
+ if (!config->cluster_iam_master)
+ return; // Only runs on the master...
+
+ config->cluster_iam_uptodate = 1; // cleared in loop below
+
+ for (i = have_peers = 0; i < num_peers; i++)
+ {
+ if ((peers[i].timestamp + config->cluster_hb_timeout) < t)
+ continue; // Stale peer! Skip them.
+
+ if (!peers[i].basetime)
+ continue; // Shutdown peer! Skip them.
+
+ if (peers[i].uptodate)
+ have_peers++;
+ else
+ config->cluster_iam_uptodate = 0; // Start fast heartbeats
+ }
+
+ // 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();
+ }
+}
+
+//
+// Check that we have a master. If it's been too
+// long since we heard from a master then hold an election.
+//
+void cluster_check_master(void)
+{
+ int i, count, tcount, high_unique_id = 0;
+ 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 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 (config->cluster_master_address
+ && TIME > (config->cluster_last_hb + 2 * config->cluster_hb_interval + 11))
+ {
+ if (!probed || (TIME > (probed + 2 * config->cluster_hb_interval)))
+ {
+ probed = TIME;
+ LOG(1, 0, 0, "Heartbeat from master %.1fs late, probing...\n",
+ 0.1 * (TIME - (config->cluster_last_hb + config->cluster_hb_interval)));
+
+ peer_send_message(config->cluster_master_address,
+ C_LASTSEEN, config->cluster_seq_number, NULL, 0);
+ }
+ } else { // We got a recent heartbeat; reset the probe flag.
+ probed = 0;
+ }
+
+ if (TIME < (config->cluster_last_hb + config->cluster_hb_timeout))
+ return; // Everything's ok!
+
+ config->cluster_last_hb = TIME + 1; // Just the one election thanks.
+
+ LOG(0, 0, 0, "Master timed out! Holding election...\n");
+
+ for (i = have_peers = 0; i < num_peers; i++)
+ {
+ if ((peers[i].timestamp + config->cluster_hb_timeout) < t)
+ continue; // Stale peer! Skip them.
+
+ if (!peers[i].basetime)
+ continue; // Shutdown peer! Skip them.
+
+ if (peers[i].basetime < basetime) {
+ LOG(1, 0, 0, "Expecting %s to become master\n", fmtaddr(peers[i].peer, 0));
+ return; // They'll win the election. Get out of here.
+ }
+
+ if (peers[i].basetime == basetime &&
+ peers[i].peer > my_address) {
+ 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
+ // and I'm better than an of my peers so it's time
+ // to become a master!!!
+
+ config->cluster_iam_master = 1;
+ config->cluster_master_address = 0;
+
+ 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;
+
+ //
+ // Go through and mark all the tunnels as defined.
+ // Count the highest used tunnel number as well.
+ //
+ config->cluster_highest_tunnelid = 0;
+ for (i = 0, tcount = 0; i < MAXTUNNEL; ++i) {
+ if (tunnel[i].state == TUNNELUNDEF)
+ tunnel[i].state = TUNNELFREE;
+
+ if (tunnel[i].state != TUNNELFREE && i > config->cluster_highest_tunnelid)
+ config->cluster_highest_tunnelid = i;
+ }
+
+ //
+ // Go through and mark all the sessions as being defined.
+ // reset the idle timeouts.
+ // add temporary byte counters to permanent ones.
+ // Re-string the free list.
+ // Find the ID of the highest session.
+ last_free = 0;
+ high_unique_id = 0;
+ config->cluster_highest_sessionid = 0;
+ for (i = 0, count = 0; i < MAXSESSION; ++i) {
+ if (session[i].tunnel == T_UNDEF) {
+ session[i].tunnel = T_FREE;
+ ++count;
+ }
+
+ if (!session[i].opened) { // Unused session. Add to free list.
+ memset(&session[i], 0, sizeof(session[i]));
+ session[i].tunnel = T_FREE;
+ session[last_free].next = i;
+ session[i].next = 0;
+ last_free = i;
+ continue;
+ }
+
+ // Reset idle timeouts..
+ session[i].last_packet = time_now;
+
+ // Reset die relative to our uptime rather than the old master's
+ if (session[i].die) session[i].die = TIME;
+
+ // Accumulate un-sent byte counters.
+ session[i].cin += sess_local[i].cin;
+ session[i].cout += sess_local[i].cout;
+ session[i].total_cin += sess_local[i].cin;
+ session[i].total_cout += sess_local[i].cout;
+
+ sess_local[i].cin = sess_local[i].cout = 0;
+
+ sess_local[i].radius = 0; // Reset authentication as the radius blocks aren't up to date.
+
+ if (session[i].unique_id >= high_unique_id) // This is different to the index into the session table!!!
+ high_unique_id = session[i].unique_id+1;
+
+ session[i].tbf_in = session[i].tbf_out = 0; // Remove stale pointers from old master.
+ throttle_session(i, session[i].throttle_in, session[i].throttle_out);
+
+ config->cluster_highest_sessionid = i;
+ }
+
+ session[last_free].next = 0; // End of chain.
+ last_id = high_unique_id; // Keep track of the highest used session ID.
+
+ become_master();
+
+ rebuild_address_pool();
+
+ // If we're not the very first master, this is a big issue!
+ if(count>0)
+ LOG(0, 0, 0, "Warning: Fixed %d uninitialized sessions in becoming master!\n", count);
+
+ config->cluster_undefined_sessions = 0;
+ config->cluster_undefined_tunnels = 0;
+ config->cluster_iam_uptodate = 1; // assume all peers are up-to-date
+
+ // FIXME. We need to fix up the tunnel control message
+ // queue here! There's a number of other variables we
+ // should also update.
+}
+
+
+//
+// Check that our session table is validly matching what the
+// master has in mind.
+//
+// In particular, if we have too many sessions marked 'undefined'
+// we fix it up here, and we ensure that the 'first free session'
+// pointer is valid.
+//
+static void cluster_check_sessions(int highsession, int freesession_ptr, int hightunnel)
+{
+ int i;
+
+ sessionfree = freesession_ptr; // Keep the freesession ptr valid.
+
+ if (config->cluster_iam_uptodate)
+ return;
+
+ if (highsession > config->cluster_undefined_sessions && hightunnel > config->cluster_undefined_tunnels)
+ return;
+
+ // Clear out defined sessions, counting the number of
+ // undefs remaining.
+ config->cluster_undefined_sessions = 0;
+ for (i = 1 ; i < MAXSESSION; ++i) {
+ if (i > highsession) {
+ if (session[i].tunnel == T_UNDEF) session[i].tunnel = T_FREE; // Defined.
+ continue;
+ }
+
+ if (session[i].tunnel == T_UNDEF)
+ ++config->cluster_undefined_sessions;
+ }
+
+ // Clear out defined tunnels, counting the number of
+ // undefs remaining.
+ config->cluster_undefined_tunnels = 0;
+ for (i = 1 ; i < MAXTUNNEL; ++i) {
+ if (i > hightunnel) {
+ if (tunnel[i].state == TUNNELUNDEF) tunnel[i].state = TUNNELFREE; // Defined.
+ continue;
+ }
+
+ if (tunnel[i].state == TUNNELUNDEF)
+ ++config->cluster_undefined_tunnels;
+ }
+
+
+ if (config->cluster_undefined_sessions || config->cluster_undefined_tunnels) {
+ LOG(2, 0, 0, "Cleared undefined sessions/tunnels. %d sess (high %d), %d tunn (high %d)\n",
+ config->cluster_undefined_sessions, highsession, config->cluster_undefined_tunnels, hightunnel);
+ return;
+ }
+
+ // Are we up to date?
+
+ if (!config->cluster_iam_uptodate)
+ cluster_uptodate();
+}
+
+static int hb_add_type(char **p, int type, int id)
+{
+ switch (type) {
+ case C_CSESSION: { // Compressed C_SESSION.
+ uint8_t c[sizeof(sessiont) * 2]; // Bigger than worst case.
+ uint8_t *d = (uint8_t *) &session[id];
+ uint8_t *orig = d;
+ int size;
+
+ size = rle_compress( &d, sizeof(sessiont), c, sizeof(c) );
+
+ // Did we compress the full structure, and is the size actually
+ // reduced??
+ if ( (d - orig) == sizeof(sessiont) && size < sizeof(sessiont) ) {
+ add_type(p, C_CSESSION, id, (char *) c, size);
+ break;
+ }
+ // Failed to compress : Fall through.
+ }
+ case C_SESSION: add_type(p, C_SESSION, id,
+ (char *) &session[id], sizeof(sessiont));
+ break;
+
+ case C_CTUNNEL: { // Compressed C_TUNNEL
+ uint8_t c[sizeof(tunnelt) * 2]; // Bigger than worst case.
+ uint8_t *d = (uint8_t *) &tunnel[id];
+ uint8_t *orig = d;
+ int size;
+
+ size = rle_compress( &d, sizeof(tunnelt), c, sizeof(c) );
+
+ // Did we compress the full structure, and is the size actually
+ // reduced??
+ if ( (d - orig) == sizeof(tunnelt) && size < sizeof(tunnelt) ) {
+ add_type(p, C_CTUNNEL, id, c, size);
+ break;
+ }
+ // Failed to compress : Fall through.
+ }
+ case C_TUNNEL: add_type(p, C_TUNNEL, id,
+ (char *) &tunnel[id], sizeof(tunnelt));
+ break;
+ default:
+ LOG(0, 0, 0, "Found an invalid type in heart queue! (%d)\n", type);
+ kill(0, SIGTERM);
+ exit(1);
+ }
+ return 0;
+}
+
+//
+// Send a heartbeat, incidently sending out any queued changes..
+//
+void cluster_heartbeat()
+{
+ int i, count = 0, tcount = 0;
+ char buff[MAX_HEART_SIZE + sizeof(heartt) + sizeof(int) ];
+ heartt h;
+ char *p = buff;
+
+ if (!config->cluster_iam_master) // Only the master does this.
+ return;
+
+ config->cluster_table_version += config->cluster_num_changes;
+
+ // Fill out the heartbeat header.
+ memset(&h, 0, sizeof(h));
+
+ h.version = HB_VERSION;
+ h.seq = config->cluster_seq_number;
+ h.basetime = basetime;
+ h.clusterid = config->bind_address; // Will this do??
+ h.basetime = basetime;
+ h.highsession = config->cluster_highest_sessionid;
+ h.freesession = sessionfree;
+ h.hightunnel = config->cluster_highest_tunnelid;
+ h.size_sess = sizeof(sessiont); // Just in case.
+ h.size_tunn = sizeof(tunnelt);
+ h.interval = config->cluster_hb_interval;
+ h.timeout = config->cluster_hb_timeout;
+ h.table_version = config->cluster_table_version;
+
+ add_type(&p, C_HEARTBEAT, HB_VERSION, (char *) &h, sizeof(h));
+
+ for (i = 0; i < config->cluster_num_changes; ++i) {
+ hb_add_type(&p, cluster_changes[i].type, cluster_changes[i].id);
+ }
+
+ if (p > (buff + sizeof(buff))) { // Did we somehow manage to overun the buffer?
+ LOG(0, 0, 0, "FATAL: Overran the heartbeat buffer! This is fatal. Exiting. (size %d)\n", (int) (p - buff));
+ kill(0, SIGTERM);
+ exit(1);
+ }
+
+ //
+ // Fill out the packet with sessions from the session table...
+ // (not forgetting to leave space so we can get some tunnels in too )
+ while ( (p + sizeof(uint32_t) * 2 + sizeof(sessiont) * 2 ) < (buff + MAX_HEART_SIZE) ) {
+
+ if (!walk_session_number) // session #0 isn't valid.
+ ++walk_session_number;
+
+ if (count >= config->cluster_highest_sessionid) // If we're a small cluster, don't go wild.
+ break;
+
+ hb_add_type(&p, C_CSESSION, walk_session_number);
+ walk_session_number = (1+walk_session_number)%(config->cluster_highest_sessionid+1); // +1 avoids divide by zero.
+
+ ++count; // Count the number of extra sessions we're sending.
+ }
+
+ //
+ // Fill out the packet with tunnels from the tunnel table...
+ // This effectively means we walk the tunnel table more quickly
+ // than the session table. This is good because stuffing up a
+ // tunnel is a much bigger deal than stuffing up a session.
+ //
+ while ( (p + sizeof(uint32_t) * 2 + sizeof(tunnelt) ) < (buff + MAX_HEART_SIZE) ) {
+
+ if (!walk_tunnel_number) // tunnel #0 isn't valid.
+ ++walk_tunnel_number;
+
+ if (tcount >= config->cluster_highest_tunnelid)
+ break;
+
+ hb_add_type(&p, C_CTUNNEL, walk_tunnel_number);
+ walk_tunnel_number = (1+walk_tunnel_number)%(config->cluster_highest_tunnelid+1); // +1 avoids divide by zero.
+
+ ++tcount;
+ }
+
+ //
+ // Did we do something wrong?
+ if (p > (buff + sizeof(buff))) { // Did we somehow manage to overun the buffer?
+ LOG(0, 0, 0, "Overran the heartbeat buffer now! This is fatal. Exiting. (size %d)\n", (int) (p - buff));
+ kill(0, SIGTERM);
+ exit(1);
+ }
+
+ LOG(3, 0, 0, "Sending v%d heartbeat #%d, change #%" PRIu64 " with %d changes "
+ "(%d x-sess, %d x-tunnels, %d highsess, %d hightun, size %d)\n",
+ HB_VERSION, h.seq, h.table_version, config->cluster_num_changes,
+ count, tcount, config->cluster_highest_sessionid,
+ config->cluster_highest_tunnelid, (int) (p - buff));
+
+ config->cluster_num_changes = 0;
+
+ send_heartbeat(h.seq, buff, (p-buff) ); // Send out the heartbeat to the cluster, keeping a copy of it.
+
+ config->cluster_seq_number = (config->cluster_seq_number+1)%HB_MAX_SEQ; // Next seq number to use.
+}
+
+//
+// A structure of type 'type' has changed; Add it to the queue to send.
+//
+static int type_changed(int type, int id)
+{
+ int i;
+
+ for (i = 0 ; i < config->cluster_num_changes ; ++i)
+ if ( cluster_changes[i].id == id &&
+ cluster_changes[i].type == type)
+ return 0; // Already marked for change.
+
+ cluster_changes[i].type = type;
+ cluster_changes[i].id = id;
+ ++config->cluster_num_changes;
+
+ if (config->cluster_num_changes > MAX_CHANGES)
+ cluster_heartbeat(); // flush now
+
+ return 1;
+}
+
+
+// A particular session has been changed!
+int cluster_send_session(int sid)
+{
+ if (!config->cluster_iam_master) {
+ LOG(0, sid, 0, "I'm not a master, but I just tried to change a session!\n");
+ return -1;
+ }
+
+ if (forked) {
+ LOG(0, sid, 0, "cluster_send_session called from child process!\n");
+ return -1;
+ }
+
+ return type_changed(C_CSESSION, sid);
+}
+
+// A particular tunnel has been changed!
+int cluster_send_tunnel(int tid)
+{
+ if (!config->cluster_iam_master) {
+ LOG(0, 0, tid, "I'm not a master, but I just tried to change a tunnel!\n");
+ return -1;
+ }
+
+ return type_changed(C_CTUNNEL, tid);
+}
+
+
+//
+// We're a master, and a slave has just told us that it's
+// missed a packet. We'll resend it every packet since
+// the last one it's seen.
+//
+static int cluster_catchup_slave(int seq, in_addr_t slave)
+{
+ int s;
+ 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)
+ diff += HB_MAX_SEQ;
+
+ if (diff >= HB_HISTORY_SIZE) { // Ouch. We don't have the packet to send it!
+ LOG(0, 0, 0, "A slave asked for message %d when our seq number is %d. Killing it.\n",
+ seq, config->cluster_seq_number);
+ 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;
+ 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);
+ return -1; // What to do here!?
+ }
+ peer_send_data(slave, past_hearts[s].data, past_hearts[s].size);
+ seq = (seq+1)%HB_MAX_SEQ; // Increment to next seq number.
+ }
+ return 0; // All good!
+}
+
+//
+// We've heard from another peer! Add it to the list
+// that we select from at election time.
+//
+static int cluster_add_peer(in_addr_t peer, time_t basetime, pingt *pp, int size)
+{
+ int i;
+ in_addr_t clusterid;
+ pingt p;
+
+ // Allow for backward compatability.
+ // Just the ping packet into a new structure to allow
+ // for the possibility that we might have received
+ // more or fewer elements than we were expecting.
+ if (size > sizeof(p))
+ size = sizeof(p);
+
+ memset( (void *) &p, 0, sizeof(p) );
+ memcpy( (void *) &p, (void *) pp, size);
+
+ clusterid = p.addr;
+ if (clusterid != config->bind_address)
+ {
+ // Is this for us?
+ LOG(4, 0, 0, "Skipping ping from %s (different cluster)\n", fmtaddr(peer, 0));
+ return 0;
+ }
+
+ for (i = 0; i < num_peers ; ++i)
+ {
+ if (peers[i].peer != peer)
+ continue;
+
+ // This peer already exists. Just update the timestamp.
+ peers[i].basetime = basetime;
+ peers[i].timestamp = TIME;
+ peers[i].uptodate = !p.undef;
+ break;
+ }
+
+ // Is this the master shutting down??
+ 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();
+ return 0;
+ }
+
+ if (i >= num_peers)
+ {
+ LOG(4, 0, 0, "Adding %s as a peer\n", fmtaddr(peer, 0));
+
+ // Not found. Is there a stale slot to re-use?
+ for (i = 0; i < num_peers ; ++i)
+ {
+ if (!peers[i].basetime) // Shutdown
+ break;
+
+ if ((peers[i].timestamp + config->cluster_hb_timeout * 10) < TIME) // Stale.
+ break;
+ }
+
+ if (i >= CLUSTER_MAX_SIZE)
+ {
+ // Too many peers!!
+ LOG(0, 0, 0, "Tried to add %s as a peer, but I already have %d of them!\n", fmtaddr(peer, 0), i);
+ return -1;
+ }
+
+ peers[i].peer = peer;
+ peers[i].basetime = basetime;
+ peers[i].timestamp = TIME;
+ peers[i].uptodate = !p.undef;
+ if (i == num_peers)
+ ++num_peers;
+
+ LOG(1, 0, 0, "Added %s as a new peer. Now %d peers\n", fmtaddr(peer, 0), num_peers);
+ }
+
+ 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
+// the slow table walk to propogate this back out to the slaves.
+//
+static int cluster_handle_bytes(char *data, int size)
+{
+ bytest *b;
+
+ b = (bytest *) data;
+
+ LOG(3, 0, 0, "Got byte counter update (size %d)\n", size);
+
+ /* Loop around, adding the byte
+ counts to each of the sessions. */
+
+ while (size >= sizeof(*b) ) {
+ if (b->sid > MAXSESSION) {
+ LOG(0, 0, 0, "Got C_BYTES with session #%d!\n", b->sid);
+ return -1; /* Abort processing */
+ }
+
+ session[b->sid].total_cin += b->in;
+ session[b->sid].total_cout += b->out;
+
+ session[b->sid].cin += b->in;
+ session[b->sid].cout += b->out;
+
+ if (b->in)
+ session[b->sid].last_packet = time_now; // Reset idle timer!
+
+ size -= sizeof(*b);
+ ++b;
+ }
+
+ if (size != 0)
+ LOG(0, 0, 0, "Got C_BYTES with %d bytes of trailing junk!\n", size);
+
+ return size;
+}
+
+//
+// Handle receiving a session structure in a heartbeat packet.
+//
+static int cluster_recv_session(int more, uint8_t *p)