+
+//
+// Send a structured message to a peer with a single element of type 'type'.
+//
+int peer_send_message(u32 peer, int type, int more, char * data, int size)
+{
+ char buf[65536]; // Vast overkill.
+ char * p = buf;
+
+ log(4,0,0,0, "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 tap device.
+//
+int master_forward_packet(char * data, int size, u32 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(4,0,0,0, "Forwarding packet from %s to master (size %d)\n", inet_toa(addr), 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(4,0,0,0, "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(4,0,0,0, "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(0,0,0,0, "Tried to heartbeat something larger than the maximum packet!\n");
+ kill(0, SIGTERM);
+ }
+ 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(5,0,0,0, "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 100 of them at one time.
+// We examine a maximum of 2000 sessions.
+// (50k max session should mean that we normally
+// examine the entire session table every 25 seconds).
+
+#define MAX_B_RECS (400)
+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_count[walk_session_number].cin && !sess_count[walk_session_number].cout)
+ continue; // Unused. Skip it.
+
+ b[c].sid = walk_session_number;
+ b[c].in = sess_count[walk_session_number].cin;
+ b[c].out = sess_count[walk_session_number].cout;
+
+ if (++c > MAX_B_RECS) // Send a max of 400 elements in a packet.
+ break;
+
+ // Reset counters.
+ sess_count[walk_session_number].cin = sess_count[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(4,0,0,0, "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;
+}
+
+//
+// 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_sid = 0;
+ int last_free = 0;
+ int had_peers = have_peers;
+ clockt t = TIME;
+
+ if (TIME < (config->cluster_last_hb + config->cluster_hb_timeout) )
+ return; // Everything's ok. return.
+
+ if (!config->cluster_iam_master)
+ log(0,0,0,0, "Master timed out! Holding election...\n");
+
+ config->cluster_last_hb = TIME + 1;
+
+ 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.
+
+ have_peers = 1;
+ if (peers[i].basetime < basetime) {
+ log(1,0,0,0, "Expecting %s to become master\n", inet_toa(peers[i].peer) );
+ return; // They'll win the election. Get out of here.
+ }
+
+ if (peers[i].basetime == basetime &&
+ peers[i].peer > my_address) {
+ log(1,0,0,0, "Expecting %s to become master\n", inet_toa(peers[i].peer) );
+ return; // They'll win the election. Wait for them to come up.
+ }
+ }
+
+ if (config->cluster_iam_master) // If we're the master, we've already won
+ {
+#ifdef BGP
+ // master lost all slaves, need to handle traffic ourself
+ if (bgp_configured && had_peers && !have_peers)
+ bgp_enable_routing(1);
+#endif /* BGP */
+ return;
+ }
+
+ // 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(0,0,0,0, "I am declaring myself the master!\n");
+
+#ifdef BGP
+ if (bgp_configured && have_peers)
+ bgp_enable_routing(0); /* stop handling traffic */
+#endif /* BGP */
+
+ 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_sid = 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].tunnel == T_FREE) { // Unused session. Add to free list.
+ session[last_free].next = i;
+ session[i].next = 0;
+ last_free = i;
+ }
+
+ // Reset all the idle timeouts..
+ session[i].last_packet = time_now;
+
+ // Accumulate un-sent byte counters.
+ session[i].cin += sess_count[i].cin;
+ session[i].cout += sess_count[i].cout;
+ session[i].total_cin += sess_count[i].cin;
+ session[i].total_cout += sess_count[i].cout;
+
+ sess_count[i].cin = sess_count[i].cout = 0;
+
+ session[i].radius = 0; // Reset authentication as the radius blocks aren't up to date.
+
+ if (session[i].sid >= high_sid) // This is different to the index into the session table!!!
+ high_sid = session[i].sid+1;
+
+
+ session[i].tbf_in = session[i].tbf_out = 0; // Remove stale pointers from old master.
+ throttle_session(i, session[i].throttle);
+
+// I'm unsure about this. --mo
+// It's potentially a good thing, but it could send a
+// LOT of packets.
+// if (session[i].throttle)
+// cluster_send_session(s); // Tell the slaves about the new tbf indexes.
+
+ if (session[i].tunnel != T_FREE && i > config->cluster_highest_sessionid)
+ config->cluster_highest_sessionid = i;
+
+ }
+
+ session[last_free].next = 0; // End of chain.
+ last_sid = high_sid; // 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(0,0,0,0, "Warning: Fixed %d uninitialized sessions in becoming master!\n", count);
+
+ config->cluster_undefined_sessions = 0;
+ config->cluster_undefined_tunnels = 0;
+
+ //
+ // FIXME. We need to fix up the tunnel control message
+ // queue here! There's a number of other variables we
+ // should also update.
+ cluster_uptodate();
+}
+
+
+//
+// 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) {
+ session[i].tunnel = 0; // Defined.
+ continue;
+ }
+ if (session[i].tunnel != T_UNDEF)
+ continue;
+ ++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) {
+ tunnel[i].state = TUNNELFREE; // Defined.
+ continue;
+ }
+ if (tunnel[i].state != TUNNELUNDEF)
+ continue;
+ ++config->cluster_undefined_tunnels;
+ }
+
+
+ if (config->cluster_undefined_sessions || config->cluster_undefined_tunnels) {
+ log(2,0,0,0, "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();
+}
+
+int hb_add_type(char **p, int type, int id)
+{
+ switch (type) {
+ case C_CSESSION: { // Compressed C_SESSION.
+ u8 c[sizeof(sessiont) * 2]; // Bigger than worst case.
+ u8 *d = (u8 *) &session[id];
+ u8 *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
+ u8 c[sizeof(tunnelt) * 2]; // Bigger than worst case.
+ u8 *d = (u8 *) &tunnel[id];
+ u8 *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(0,0,0,0, "Found an invalid type in heart queue! (%d)\n", type);
+ kill(0, SIGTERM);
+ }
+ return 0;
+}
+
+//
+// Send a heartbeat, incidently sending out any queued changes..
+//
+void cluster_heartbeat(int highsession, int freesession, int hightunnel)
+{
+ 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;
+
+ hsess = highsession;
+ fsess = freesession;
+ // Fill out the heartbeat header.
+ 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 = highsession;
+ h.freesession = freesession;
+ h.hightunnel = hightunnel;
+ h.size_sess = sizeof(sessiont); // Just in case.
+ h.size_tunn = sizeof(tunnelt);
+
+ 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(0,0,0,0, "FATAL: Overran the heartbeat buffer! This is fatal. Exiting. (size %d)\n", p - buff);
+ kill(0, SIGTERM);
+ }
+
+ //
+ // 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(u32) * 2 + sizeof(sessiont) * 2 ) < (buff + MAX_HEART_SIZE) ) {
+
+ if (!walk_session_number) // session #0 isn't valid.
+ ++walk_session_number;
+
+ if (count >= highsession) // 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)%(highsession+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(u32) * 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(0,0,0,0, "Overran the heartbeat buffer now! This is fatal. Exiting. (size %d)\n", p - buff);
+ kill(0, SIGTERM);
+ }
+
+ log(3,0,0,0, "Sending heartbeat with %d changes (%d x-sess, %d x-tunnels, %d highsess, %d hightun size %d)\n",
+ config->cluster_num_changes, count, tcount, config->cluster_highest_sessionid,
+ config->cluster_highest_tunnelid, (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.
+//
+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(config->cluster_highest_sessionid, fsess, config->cluster_highest_tunnelid);
+
+ return 1;
+}
+
+
+// A particular session has been changed!
+int cluster_send_session(int sid)
+{
+ if (!config->cluster_iam_master) {
+ log(0,0,sid,0, "I'm not a master, but I just tried to change a session!\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(0,0,0,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.
+//
+int cluster_catchup_slave(int seq, u32 slave)
+{
+ int s;
+ int diff;
+
+ log(1,0,0,0, "Slave %s sent LASTSEEN with seq %d\n", inet_toa(slave), seq);
+
+ 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(0,0,0,0, "A slaved 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.
+ }
+
+ // 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(0,0,0,0, "Tried to re-send heartbeat for %s but %d doesn't match %d! (%d,%d)\n",
+ inet_toa(slave), 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.
+//
+int cluster_add_peer(u32 peer, time_t basetime, pingt *p)
+{
+ int i;
+ u32 clusterid;
+
+ clusterid = p->addr;
+ if (clusterid != config->bind_address)
+ {
+ // Is this for us?
+ log(4,0,0,0, "Skipping ping from %s (different cluster)\n", inet_toa(peer));
+ return 0;
+ }
+
+ // Is this the master shutting down??
+ if (peer == config->cluster_master_address && !basetime) {
+ config->cluster_master_address = 0;
+ config->cluster_last_hb = 0; // Force an election.
+ cluster_check_master();
+ 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;
+ break;
+ }
+
+ if (i >= num_peers)
+ {
+ log(4,0,0,0, "Adding %s as a peer\n", inet_toa(peer));
+
+ // Not found. Is there a stale slot to re-use?
+ for (i = 0; i < num_peers ; ++i)
+ {
+ if (peers[i].peer != peer)
+ continue;
+ if ((peers[i].timestamp + config->cluster_hb_timeout * 10) < TIME) // Stale.
+ break;
+ }
+
+ if (i >= CLUSTER_MAX_SIZE)
+ {
+ // Too many peers!!
+ log(0,0,0,0, "Tried to add %s as a peer, but I already have %d of them!\n", inet_toa(peer), i);
+ return -1;
+ }
+
+ peers[i].peer = peer;
+ peers[i].basetime = basetime;
+ peers[i].timestamp = TIME;
+ if (i == num_peers)
+ ++num_peers;
+
+ log(1,0,0,0, "Added %s as a new peer. Now %d peers\n", inet_toa(peer), num_peers);
+ }
+
+#ifdef BGP
+ /* drop routes if we've now got a peer */
+ if (bgp_configured && config->cluster_iam_master && !have_peers)
+ bgp_enable_routing(0);
+#endif /* BGP */
+
+ have_peers = 1;
+
+ return 1;
+}
+
+/* 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.
+//
+int cluster_handle_bytes(char * data, int size)
+{
+ bytest * b;
+
+ b = (bytest*) data;
+
+ log(3,0,0,0, "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(0,0,0,0, "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;
+ session[b->sid].last_packet = time_now; // Reset idle timer!
+
+ size -= sizeof(*b);
+ ++b;
+ }
+
+ if (size != 0)
+ log(0,0,0,0, "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 , u8 * p)
+{
+ if (more >= MAXSESSION) {
+ log(0,0,0,0, "DANGER: Received a heartbeat session id > MAXSESSION!\n");
+ return -1;
+ }
+
+ if (session[more].tunnel == T_UNDEF) {
+ if (config->cluster_iam_uptodate) { // Sanity.
+ log(0,0,0,0, "I thought I was uptodate but I just found an undefined session!\n");
+ } else {
+ --config->cluster_undefined_sessions;
+ }
+ }
+
+ load_session(more, (sessiont*) p); // Copy session into session table..
+
+ log(5,0,more,0, "Received session update (%d undef)\n", config->cluster_undefined_sessions);
+
+ if (!config->cluster_iam_uptodate)
+ cluster_uptodate(); // Check to see if we're up to date.
+ return 0;
+}
+
+static int cluster_recv_tunnel(int more, u8 *p)
+{
+ if (more >= MAXTUNNEL) {
+ log(0,0,0,0, "DANGER: Received a tunnel session id > MAXTUNNEL!\n");
+ return -1;
+ }
+
+ if (tunnel[more].state == TUNNELUNDEF) {
+ if (config->cluster_iam_uptodate) { // Sanity.
+ log(0,0,0,0, "I thought I was uptodate but I just found an undefined tunnel!\n");
+ } else {
+ --config->cluster_undefined_tunnels;
+ }
+ }
+
+ memcpy(&tunnel[more], p, sizeof(tunnel[more]) );
+
+ //
+ // Clear tunnel control messages. These are dynamically allocated.
+ // If we get unlucky, this may cause the tunnel to drop!
+ //
+ tunnel[more].controls = tunnel[more].controle = NULL;
+ tunnel[more].controlc = 0;
+
+ log(5,0,0,more, "Received tunnel update\n");
+
+ if (!config->cluster_iam_uptodate)
+ cluster_uptodate(); // Check to see if we're up to date.
+
+ return 0;
+}
+
+
+//
+// Process a version one heartbeat..
+//
+static int cluster_process_heartbeat_v2(u8 * data, int size, int more, u8 * p, u32 addr)
+{
+ heartt * h;
+ int s = size - (p-data);
+ int i, type;
+
+ if (more != HB_VERSION) {
+ log(0,0,0,0, "Received a heartbeat version that I don't understand!\n");
+ return -1; // Ignore it??
+ }
+ // Ok. It's a heartbeat packet from a cluster master!
+ if (s < sizeof(*h))
+ goto shortpacket;
+
+
+ h = (heartt*) p;
+ p += sizeof(*h);
+ s -= sizeof(*h);
+
+ if (h->clusterid != config->bind_address)
+ return -1; // It's not part of our cluster.
+
+ if (config->cluster_iam_master) { // Sanity...
+ // Note that this MUST match the election process above!
+
+ log(0,0,0,0, "I just got a packet claiming to be from a master but _I_ am the master!\n");
+ if (!h->basetime) {
+ log(0,0,0,0, "Heartbeat from addr %s with zero basetime!\n", inet_toa(htonl(addr)) );
+ return -1; // Skip it.
+ }
+ if (basetime > h->basetime) {
+ log(0,0,0,0, "They're (%s) an older master than me so I'm gone!\n", inet_toa(htonl(addr)));
+ kill(0, SIGTERM);
+ }
+ if (basetime == h->basetime && my_address < addr) { // Tie breaker.
+ log(0,0,0,0, "They're a higher IP address than me, so I'm gone!\n");
+ kill(0, SIGTERM);
+ }
+ return -1; // Skip it.
+ }
+
+ if (config->cluster_seq_number == -1) // Don't have one. Just align to the master...
+ config->cluster_seq_number = h->seq;
+
+ config->cluster_last_hb = TIME; // Reset to ensure that we don't become master!!
+
+ if (config->cluster_seq_number != h->seq) { // Out of sequence heartbeat!
+ log(1,0,0,0, "HB: Got seq# %d but was expecting %d. asking for resend.\n", h->seq, config->cluster_seq_number);
+
+ peer_send_message(addr, C_LASTSEEN, config->cluster_seq_number, NULL, 0);
+
+ config->cluster_last_hb = TIME; // Reset to ensure that we don't become master!!
+
+ // Just drop the packet. The master will resend it as part of the catchup.
+
+ return 0;
+ }
+ // Save the packet in our buffer.
+ // This is needed in case we become the master.
+ config->cluster_seq_number = (h->seq+1)%HB_MAX_SEQ;
+ i = h->seq % HB_HISTORY_SIZE;
+ past_hearts[i].seq = h->seq;
+ past_hearts[i].size = size;
+ memcpy(&past_hearts[i].data, data, size); // Save it.
+
+
+ // Check that we don't have too many undefined sessions, and
+ // that the free session pointer is correct.
+ cluster_check_sessions(h->highsession, h->freesession, h->hightunnel);
+
+ // Ok. process the packet...
+ while ( s > 0) {
+
+ type = * ((u32*) p);
+ p += sizeof(u32);
+ s -= sizeof(u32);
+
+ more = * ((u32*) p);
+ p += sizeof(u32);
+ s -= sizeof(u32);
+
+ switch (type) {
+ case C_CSESSION: { // Compressed session structure.
+ u8 c [ sizeof(sessiont) + 2];
+ int size;
+ u8 * orig_p = p;
+
+ size = rle_decompress((u8 **) &p, s, c, sizeof(c) );
+ s -= (p - orig_p);
+
+ if (size != sizeof(sessiont) ) { // Ouch! Very very bad!
+ log(0,0,0,0, "DANGER: Received a CSESSION that didn't decompress correctly!\n");
+ // Now what? Should exit! No-longer up to date!
+ break;
+ }
+
+ cluster_recv_session(more, c);
+ break;
+ }
+ case C_SESSION:
+ if ( s < sizeof(session[more]))
+ goto shortpacket;
+
+ cluster_recv_session(more, p);
+
+ p += sizeof(session[more]);
+ s -= sizeof(session[more]);
+ break;
+
+ case C_CTUNNEL: { // Compressed tunnel structure.
+ u8 c [ sizeof(tunnelt) + 2];
+ int size;
+ u8 * orig_p = p;
+
+ size = rle_decompress( (u8 **) &p, s, c, sizeof(c) );
+ s -= (p - orig_p);
+
+ if (size != sizeof(tunnelt) ) { // Ouch! Very very bad!
+ log(0,0,0,0, "DANGER: Received a CSESSION that didn't decompress correctly!\n");
+ // Now what? Should exit! No-longer up to date!
+ break;
+ }
+
+ cluster_recv_tunnel(more, c);
+ break;
+
+ }
+ case C_TUNNEL:
+ if ( s < sizeof(tunnel[more]))
+ goto shortpacket;
+
+ cluster_recv_tunnel(more, p);
+
+ p += sizeof(tunnel[more]);
+ s -= sizeof(tunnel[more]);
+ break;
+ default:
+ log(0,0,0,0, "DANGER: I received a heartbeat element where I didn't understand the type! (%d)\n", type);
+ return -1; // can't process any more of the packet!!
+ }
+ }
+ if (config->cluster_master_address != addr)
+ {
+ char *str;
+ str = strdup(inet_toa(config->cluster_master_address));
+ log(0,0,0,0, "My master just changed from %s to %s!\n", str, inet_toa(addr));
+ if (str) free(str);
+ }
+
+ config->cluster_master_address = addr;
+ config->cluster_last_hb = TIME; // Successfully received a heartbeat!
+ return 0;
+
+shortpacket:
+ log(0,0,0,0, "I got an incomplete heartbeat packet! This means I'm probably out of sync!!\n");
+ return -1;
+}
+
+//
+// We got a packet on the cluster port!
+// Handle pings, lastseens, and heartbeats!
+//
+int processcluster(char * data, int size, u32 addr)
+{
+ int type, more;
+ char * p = data;
+ int s = size;
+
+ if (addr == my_address)
+ return -1; // Ignore it. Something looped back the multicast!
+
+ log(5,0,0,0, "Process cluster: %d bytes from %s\n", size, inet_toa(addr));
+
+ if (s <= 0) // Any data there??
+ return -1;
+
+ if (s < 8)
+ goto shortpacket;
+
+ type = * ((u32*) p);
+ p += sizeof(u32);
+ s -= sizeof(u32);
+
+ more = * ((u32*) p);
+ p += sizeof(u32);
+ s -= sizeof(u32);
+
+ switch (type) {
+ case C_PING: // Update the peers table.
+ return cluster_add_peer(addr, more, (pingt*)p);
+
+ 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.
+ struct sockaddr_in a;
+ a.sin_addr.s_addr = more;
+
+ a.sin_port = * (int*) p;
+ s -= sizeof(int);
+ p += sizeof(int);
+
+ if (!config->cluster_iam_master) { // huh?
+ log(0,0,0,0, "I'm not the master, but I got a C_FORWARD from %s?\n", inet_toa(addr));
+ return -1;
+ }
+
+ log(4,0,0,0, "Got a forwarded packet... (%s:%d)\n", inet_toa(more), a.sin_port);
+ STAT(recv_forward);
+ processudp(p, s, &a);
+ return 0;
+ }
+ case C_THROTTLE: { // Receive a forwarded packet from a slave.
+ if (!config->cluster_iam_master) {
+ log(0,0,0,0, "I'm not the master, but I got a C_THROTTLE from %s?\n", inet_toa(addr));
+ return -1;
+ }
+
+ tbf_queue_packet(more, p, s); // The TBF id tells wether it goes in or out.
+ return 0;
+ }
+ case C_GARDEN:
+ // Receive a walled garden packet from a slave.
+ if (!config->cluster_iam_master) {
+ log(0,0,0,0, "I'm not the master, but I got a C_GARDEN from %s?\n", inet_toa(addr));
+ return -1;
+ }
+
+ tun_write(p, s);
+ return 0;
+
+ case C_BYTES:
+ return cluster_handle_bytes(p, s);
+
+ case C_KILL: // The master asked us to die!? (usually because we're too out of date).
+ if (config->cluster_iam_master) {
+ log(0,0,0,0, "_I_ am master, but I received a C_KILL from %s! (Seq# %d)\n", inet_toa(addr), more);
+ return -1;
+ }
+ if (more != config->cluster_seq_number) {
+ log(0,0,0,0, "The master asked us to die but the seq number didn't match!?\n");
+ return -1;
+ }
+
+ if (addr != config->cluster_master_address) {
+ log(0,0,0,0, "Received a C_KILL from %s which doesn't match config->cluster_master_address (%x)\n",
+ inet_toa(addr), config->cluster_master_address);
+ // We can only warn about it. The master might really have switched!
+ }
+
+ log(0,0,0,0, "Received a valid C_KILL: I'm going to die now.\n");
+ kill(0, SIGTERM);
+ exit(0); // Lets be paranoid;
+ return -1; // Just signalling the compiler.
+
+ case C_HEARTBEAT:
+ log(4,0,0,0, "Got a heartbeat from %s\n", inet_toa(addr));
+
+ return cluster_process_heartbeat_v2(data, size, more, p, addr);
+
+ default:
+ log(0,0,0,0, "Strange type packet received on cluster socket (%d)\n", type);
+ return -1;
+ }
+ return 0;
+shortpacket:
+ log(0,0,0,0, "I got an cluster heartbeat packet! This means I'm probably out of sync!!\n");
+ return -1;
+}
+
+//====================================================================================================
+
+int cmd_show_cluster(struct cli_def *cli, char *command, char **argv, int argc)
+{
+ int i;
+
+ if (CLI_HELP_REQUESTED)
+ return CLI_HELP_NO_ARGS;
+
+ cli_print(cli, "Cluster status : %s", config->cluster_iam_master ? "Master" : "Slave" );
+ cli_print(cli, "My address : %s", inet_toa(my_address));
+ cli_print(cli, "VIP address : %s", inet_toa(config->bind_address));
+ cli_print(cli, "Multicast address: %s", inet_toa(config->cluster_address));
+ cli_print(cli, "Multicast i'face : %s", config->cluster_interface);
+
+ if (!config->cluster_iam_master) {
+ cli_print(cli, "My master : %s (last heartbeat %.1f seconds old)",
+ config->cluster_master_address ? inet_toa(config->cluster_master_address) : "Not defined",
+ 0.1 * (TIME - config->cluster_last_hb));
+ cli_print(cli, "Uptodate : %s", config->cluster_iam_uptodate ? "Yes" : "No");
+ cli_print(cli, "Next sequence number expected: %d", config->cluster_seq_number);
+ cli_print(cli, "%d sessions undefined of %d", config->cluster_undefined_sessions, config->cluster_highest_sessionid);
+ cli_print(cli, "%d tunnels undefined of %d", config->cluster_undefined_tunnels, config->cluster_highest_tunnelid);
+ } else {
+ cli_print(cli, "Next heartbeat # : %d", config->cluster_seq_number);
+ cli_print(cli, "Highest session : %d", config->cluster_highest_sessionid);
+ cli_print(cli, "Highest tunnel : %d", config->cluster_highest_tunnelid);
+ cli_print(cli, "%d changes queued for sending", config->cluster_num_changes);
+ }
+ cli_print(cli, "%d peers.", num_peers);
+
+ if (num_peers)
+ cli_print(cli, "%20s %10s %8s", "Address", "Basetime", "Age");
+ for (i = 0; i < num_peers; ++i) {
+ cli_print(cli, "%20s %10d %8d", inet_toa(peers[i].peer),
+ peers[i].basetime, TIME - peers[i].timestamp);
+ }
+ return CLI_OK;
+}
+
+//
+// Simple run-length-encoding compression.
+// Format is
+// 1 byte < 128 = count of non-zero bytes following. // Not legal to be zero.
+// n non-zero bytes;
+// or
+// 1 byte > 128 = (count - 128) run of zero bytes. //
+// repeat.
+// count == 0 indicates end of compressed stream.
+//
+// Compress from 'src' into 'dst'. return number of bytes
+// used from 'dst'.
+// Updates *src_p to indicate 1 past last bytes used.
+//
+// We could get an extra byte in the zero runs by storing (count-1)
+// but I'm playing it safe.
+//
+// Worst case is a 50% expansion in space required (trying to
+// compress { 0x00, 0x01 } * N )
+int rle_compress(u8 ** src_p, int ssize, u8 *dst, int dsize)
+{
+ int count;
+ int orig_dsize = dsize;
+ u8 * x,*src;
+ src = *src_p;
+
+ while (ssize > 0 && dsize > 2) {
+ count = 0;
+ x = dst++; --dsize; // Reserve space for count byte..
+
+ if (*src) { // Copy a run of non-zero bytes.
+ while (*src && count < 127 && ssize > 0 && dsize > 1) { // Count number of non-zero bytes.
+ *dst++ = *src++;
+ --dsize; --ssize;
+ ++count;
+ }
+ *x = count; // Store number of non-zero bytes. Guarenteed to be non-zero!
+
+ } else { // Compress a run of zero bytes.
+ while (*src == 0 && count < 127 && ssize > 0) {
+ ++src;
+ --ssize;
+ ++count;
+ }
+ *x = count | 0x80 ;
+ }
+ }
+
+ *dst++ = 0x0; // Add Stop byte.
+ --dsize;
+
+ *src_p = src;
+ return (orig_dsize - dsize);
+}
+
+//
+// Decompress the buffer into **p.
+// 'psize' is the size of the decompression buffer available.
+//
+// Returns the number of bytes decompressed.
+//
+// Decompresses from '*src_p' into 'dst'.
+// Return the number of dst bytes used.
+// Updates the 'src_p' pointer to point to the
+// first un-used byte.
+int rle_decompress(u8 ** src_p, int ssize, u8 *dst, int dsize)
+{
+ int count;
+ int orig_dsize = dsize;
+ char * src = *src_p;
+
+ while (ssize >0 && dsize > 0) { // While there's more to decompress, and there's room in the decompress buffer...
+ count = *src++; --ssize; // get the count byte from the source.
+ if (count == 0x0) // End marker reached? If so, finish.
+ break;
+
+ if (count & 0x80) { // Decompress a run of zeros
+ for (count &= 0x7f ; count > 0 && dsize > 0; --count) {
+ *dst++ = 0x0;
+ --dsize;
+ }
+ } else { // Copy run of non-zero bytes.
+ for ( ; count > 0 && ssize && dsize; --count) { // Copy non-zero bytes across.
+ *dst++ = *src++;
+ --ssize; --dsize;
+ }
+ }
+ }
+ *src_p = src;
+ return (orig_dsize - dsize);
+}
projects / l2tpns.git / blobdiff