e51ac5a519a82cb88c28d4b04fc8cde802e25b59
[l2tpns.git] / cluster.c
1 // L2TPNS Clustering Stuff
2
3 char const *cvs_id_cluster = "$Id: cluster.c,v 1.32 2005/04/01 08:46:03 bodea Exp $";
4
5 #include <stdio.h>
6 #include <stdlib.h>
7 #include <stdarg.h>
8 #include <unistd.h>
9 #include <inttypes.h>
10 #include <sys/file.h>
11 #include <sys/stat.h>
12 #include <sys/socket.h>
13 #include <netinet/in.h>
14 #include <arpa/inet.h>
15 #include <sys/ioctl.h>
16 #include <net/if.h>
17 #include <string.h>
18 #include <malloc.h>
19 #include <errno.h>
20 #include <libcli.h>
21
22 #include "l2tpns.h"
23 #include "cluster.h"
24 #include "util.h"
25 #include "tbf.h"
26
27 #ifdef BGP
28 #include "bgp.h"
29 #endif
30 /*
31 * All cluster packets have the same format.
32 *
33 * One or more instances of
34 * a 32 bit 'type' id.
35 * a 32 bit 'extra' data dependant on the 'type'.
36 * zero or more bytes of structure data, dependant on the type.
37 *
38 */
39
40 // Module variables.
41 int cluster_sockfd = 0; // The filedescriptor for the cluster communications port.
42
43 in_addr_t my_address = 0; // The network address of my ethernet port.
44 static int walk_session_number = 0; // The next session to send when doing the slow table walk.
45 static int walk_tunnel_number = 0; // The next tunnel to send when doing the slow table walk.
46 int forked = 0; // Sanity check: CLI must not diddle with heartbeat table
47
48 #define MAX_HEART_SIZE (8192) // Maximum size of heartbeat packet. Must be less than max IP packet size :)
49 #define MAX_CHANGES (MAX_HEART_SIZE/(sizeof(sessiont) + sizeof(int) ) - 2) // Assumes a session is the biggest type!
50
51 static struct {
52 int type;
53 int id;
54 } cluster_changes[MAX_CHANGES]; // Queue of changed structures that need to go out when next heartbeat.
55
56 static struct {
57 int seq;
58 int size;
59 char data[MAX_HEART_SIZE];
60 } past_hearts[HB_HISTORY_SIZE]; // Ring buffer of heartbeats that we've recently sent out. Needed so
61 // we can re-transmit if needed.
62
63 static struct {
64 in_addr_t peer;
65 uint32_t basetime;
66 clockt timestamp;
67 int uptodate;
68 } peers[CLUSTER_MAX_SIZE]; // List of all the peers we've heard from.
69 static int num_peers; // Number of peers in list.
70
71 static int rle_decompress(uint8_t **src_p, int ssize, uint8_t *dst, int dsize);
72 static int rle_compress(uint8_t **src_p, int ssize, uint8_t *dst, int dsize);
73
74 //
75 // Create a listening socket
76 //
77 // This joins the cluster multi-cast group.
78 //
79 int cluster_init()
80 {
81 struct sockaddr_in addr;
82 struct sockaddr_in interface_addr;
83 struct ip_mreq mreq;
84 struct ifreq ifr;
85 int opt;
86
87 config->cluster_undefined_sessions = MAXSESSION-1;
88 config->cluster_undefined_tunnels = MAXTUNNEL-1;
89
90 if (!config->cluster_address)
91 return 0;
92 if (!*config->cluster_interface)
93 return 0;
94
95 cluster_sockfd = socket(AF_INET, SOCK_DGRAM, IPPROTO_UDP);
96
97 memset(&addr, 0, sizeof(addr));
98 addr.sin_family = AF_INET;
99 addr.sin_port = htons(CLUSTERPORT);
100 addr.sin_addr.s_addr = INADDR_ANY;
101 setsockopt(cluster_sockfd, SOL_SOCKET, SO_REUSEADDR, &addr, sizeof(addr));
102
103 opt = fcntl(cluster_sockfd, F_GETFL, 0);
104 fcntl(cluster_sockfd, F_SETFL, opt | O_NONBLOCK);
105
106 if (bind(cluster_sockfd, (void *) &addr, sizeof(addr)) < 0)
107 {
108 LOG(0, 0, 0, "Failed to bind cluster socket: %s\n", strerror(errno));
109 return -1;
110 }
111
112 strcpy(ifr.ifr_name, config->cluster_interface);
113 if (ioctl(cluster_sockfd, SIOCGIFADDR, &ifr) < 0)
114 {
115 LOG(0, 0, 0, "Failed to get interface address for (%s): %s\n", config->cluster_interface, strerror(errno));
116 return -1;
117 }
118
119 memcpy(&interface_addr, &ifr.ifr_addr, sizeof(interface_addr));
120 my_address = interface_addr.sin_addr.s_addr;
121
122 // Join multicast group.
123 mreq.imr_multiaddr.s_addr = config->cluster_address;
124 mreq.imr_interface = interface_addr.sin_addr;
125
126
127 opt = 0; // Turn off multicast loopback.
128 setsockopt(cluster_sockfd, IPPROTO_IP, IP_MULTICAST_LOOP, &opt, sizeof(opt));
129
130 if (setsockopt(cluster_sockfd, IPPROTO_IP, IP_ADD_MEMBERSHIP, &mreq, sizeof(mreq)) < 0)
131 {
132 LOG(0, 0, 0, "Failed to setsockopt (join mcast group): %s\n", strerror(errno));
133 return -1;
134 }
135
136 if (setsockopt(cluster_sockfd, IPPROTO_IP, IP_MULTICAST_IF, &interface_addr, sizeof(interface_addr)) < 0)
137 {
138 LOG(0, 0, 0, "Failed to setsockopt (set mcast interface): %s\n", strerror(errno));
139 return -1;
140 }
141
142 config->cluster_last_hb = TIME;
143 config->cluster_seq_number = -1;
144
145 return cluster_sockfd;
146 }
147
148
149 //
150 // Send a chunk of data to the entire cluster (usually via the multicast
151 // address ).
152 //
153
154 static int cluster_send_data(void *data, int datalen)
155 {
156 struct sockaddr_in addr = {0};
157
158 if (!cluster_sockfd) return -1;
159 if (!config->cluster_address) return 0;
160
161 addr.sin_addr.s_addr = config->cluster_address;
162 addr.sin_port = htons(CLUSTERPORT);
163 addr.sin_family = AF_INET;
164
165 LOG(5, 0, 0, "Cluster send data: %d bytes\n", datalen);
166
167 if (sendto(cluster_sockfd, data, datalen, MSG_NOSIGNAL, (void *) &addr, sizeof(addr)) < 0)
168 {
169 LOG(0, 0, 0, "sendto: %s\n", strerror(errno));
170 return -1;
171 }
172
173 return 0;
174 }
175
176 //
177 // Add a chunk of data to a heartbeat packet.
178 // Maintains the format. Assumes that the caller
179 // has passed in a big enough buffer!
180 //
181 static void add_type(char **p, int type, int more, char *data, int size)
182 {
183 *((uint32_t *) (*p)) = type;
184 *p += sizeof(uint32_t);
185
186 *((uint32_t *)(*p)) = more;
187 *p += sizeof(uint32_t);
188
189 if (data && size > 0) {
190 memcpy(*p, data, size);
191 *p += size;
192 }
193 }
194
195 // advertise our presence via BGP or gratuitous ARP
196 static void advertise(void)
197 {
198 #ifdef BGP
199 if (bgp_configured)
200 bgp_enable_routing(1);
201 else
202 #endif /* BGP */
203 if (config->send_garp)
204 send_garp(config->bind_address); // Start taking traffic.
205 }
206
207 static void cluster_uptodate(void)
208 {
209 if (config->cluster_iam_uptodate)
210 return;
211
212 if (config->cluster_undefined_sessions || config->cluster_undefined_tunnels)
213 return;
214
215 config->cluster_iam_uptodate = 1;
216
217 LOG(0, 0, 0, "Now uptodate with master.\n");
218 advertise();
219 }
220
221 //
222 // Send a unicast UDP packet to a peer with 'data' as the
223 // contents.
224 //
225 static int peer_send_data(in_addr_t peer, char *data, int size)
226 {
227 struct sockaddr_in addr = {0};
228
229 if (!cluster_sockfd) return -1;
230 if (!config->cluster_address) return 0;
231
232 if (!peer) // Odd??
233 return -1;
234
235 addr.sin_addr.s_addr = peer;
236 addr.sin_port = htons(CLUSTERPORT);
237 addr.sin_family = AF_INET;
238
239 LOG_HEX(5, "Peer send", data, size);
240
241 if (sendto(cluster_sockfd, data, size, MSG_NOSIGNAL, (void *) &addr, sizeof(addr)) < 0)
242 {
243 LOG(0, 0, 0, "sendto: %s\n", strerror(errno));
244 return -1;
245 }
246
247 return 0;
248 }
249
250 //
251 // Send a structured message to a peer with a single element of type 'type'.
252 //
253 static int peer_send_message(in_addr_t peer, int type, int more, char *data, int size)
254 {
255 char buf[65536]; // Vast overkill.
256 char *p = buf;
257
258 LOG(4, 0, 0, "Sending message to peer (type %d, more %d, size %d)\n", type, more, size);
259 add_type(&p, type, more, data, size);
260
261 return peer_send_data(peer, buf, (p-buf) );
262 }
263
264 //
265 // Forward a state changing packet to the master.
266 //
267 // The master just processes the payload as if it had
268 // received it off the tun device.
269 //
270 int master_forward_packet(char *data, int size, in_addr_t addr, int port)
271 {
272 char buf[65536]; // Vast overkill.
273 char *p = buf;
274
275 if (!config->cluster_master_address) // No election has been held yet. Just skip it.
276 return -1;
277
278 LOG(4, 0, 0, "Forwarding packet from %s to master (size %d)\n", fmtaddr(addr, 0), size);
279
280 STAT(c_forwarded);
281 add_type(&p, C_FORWARD, addr, (char *) &port, sizeof(port));
282 memcpy(p, data, size);
283 p += size;
284
285 return peer_send_data(config->cluster_master_address, buf, (p - buf));
286 }
287
288 //
289 // Forward a throttled packet to the master for handling.
290 //
291 // The master just drops the packet into the appropriate
292 // token bucket queue, and lets normal processing take care
293 // of it.
294 //
295 int master_throttle_packet(int tbfid, char *data, int size)
296 {
297 char buf[65536]; // Vast overkill.
298 char *p = buf;
299
300 if (!config->cluster_master_address) // No election has been held yet. Just skip it.
301 return -1;
302
303 LOG(4, 0, 0, "Throttling packet master (size %d, tbfid %d)\n", size, tbfid);
304
305 add_type(&p, C_THROTTLE, tbfid, data, size);
306
307 return peer_send_data(config->cluster_master_address, buf, (p-buf) );
308
309 }
310
311 //
312 // Forward a walled garden packet to the master for handling.
313 //
314 // The master just writes the packet straight to the tun
315 // device (where is will normally loop through the
316 // firewall rules, and come back in on the tun device)
317 //
318 // (Note that this must be called with the tun header
319 // as the start of the data).
320 int master_garden_packet(sessionidt s, char *data, int size)
321 {
322 char buf[65536]; // Vast overkill.
323 char *p = buf;
324
325 if (!config->cluster_master_address) // No election has been held yet. Just skip it.
326 return -1;
327
328 LOG(4, 0, 0, "Walled garden packet to master (size %d)\n", size);
329
330 add_type(&p, C_GARDEN, s, data, size);
331
332 return peer_send_data(config->cluster_master_address, buf, (p-buf));
333
334 }
335
336 //
337 // Send a chunk of data as a heartbeat..
338 // We save it in the history buffer as we do so.
339 //
340 static void send_heartbeat(int seq, char *data, int size)
341 {
342 int i;
343
344 if (size > sizeof(past_hearts[0].data))
345 {
346 LOG(0, 0, 0, "Tried to heartbeat something larger than the maximum packet!\n");
347 kill(0, SIGTERM);
348 exit(1);
349 }
350 i = seq % HB_HISTORY_SIZE;
351 past_hearts[i].seq = seq;
352 past_hearts[i].size = size;
353 memcpy(&past_hearts[i].data, data, size); // Save it.
354 cluster_send_data(data, size);
355 }
356
357 //
358 // Send an 'i am alive' message to every machine in the cluster.
359 //
360 void cluster_send_ping(time_t basetime)
361 {
362 char buff[100 + sizeof(pingt)];
363 char *p = buff;
364 pingt x;
365
366 if (config->cluster_iam_master && basetime) // We're heartbeating so no need to ping.
367 return;
368
369 LOG(5, 0, 0, "Sending cluster ping...\n");
370
371 x.ver = 1;
372 x.addr = config->bind_address;
373 x.undef = config->cluster_undefined_sessions + config->cluster_undefined_tunnels;
374 x.basetime = basetime;
375
376 add_type(&p, C_PING, basetime, (char *) &x, sizeof(x));
377 cluster_send_data(buff, (p-buff) );
378 }
379
380 //
381 // Walk the session counters looking for non-zero ones to send
382 // to the master. We send up to 600 of them at one time.
383 // We examine a maximum of 3000 sessions.
384 // (50k max session should mean that we normally
385 // examine the entire session table every 25 seconds).
386
387 #define MAX_B_RECS (600)
388 void master_update_counts(void)
389 {
390 int i, c;
391 bytest b[MAX_B_RECS+1];
392
393 if (config->cluster_iam_master) // Only happens on the slaves.
394 return;
395
396 if (!config->cluster_master_address) // If we don't have a master, skip it for a while.
397 return;
398
399 i = MAX_B_RECS * 5; // Examine max 2000 sessions;
400 if (config->cluster_highest_sessionid > i)
401 i = config->cluster_highest_sessionid;
402
403 for ( c = 0; i > 0 ; --i) {
404 // Next session to look at.
405 walk_session_number++;
406 if ( walk_session_number > config->cluster_highest_sessionid)
407 walk_session_number = 1;
408
409 if (!sess_local[walk_session_number].cin && !sess_local[walk_session_number].cout)
410 continue; // Unused. Skip it.
411
412 b[c].sid = walk_session_number;
413 b[c].in = sess_local[walk_session_number].cin;
414 b[c].out = sess_local[walk_session_number].cout;
415
416 if (++c > MAX_B_RECS) // Send a max of 400 elements in a packet.
417 break;
418
419 // Reset counters.
420 sess_local[walk_session_number].cin = sess_local[walk_session_number].cout = 0;
421 }
422
423 if (!c) // Didn't find any that changes. Get out of here!
424 return;
425
426
427 // Forward the data to the master.
428 LOG(4, 0, 0, "Sending byte counters to master (%d elements)\n", c);
429 peer_send_message(config->cluster_master_address, C_BYTES, c, (char *) &b, sizeof(b[0]) * c);
430 return;
431 }
432
433 //
434 // On the master, check how our slaves are going. If
435 // one of them's not up-to-date we'll heartbeat faster.
436 // If we don't have any of them, then we need to turn
437 // on our own packet handling!
438 //
439 void cluster_check_slaves(void)
440 {
441 int i;
442 static int have_peers = 0;
443 int had_peers = have_peers;
444 clockt t = TIME;
445
446 if (!config->cluster_iam_master)
447 return; // Only runs on the master...
448
449 config->cluster_iam_uptodate = 1; // cleared in loop below
450
451 for (i = have_peers = 0; i < num_peers; i++)
452 {
453 if ((peers[i].timestamp + config->cluster_hb_timeout) < t)
454 continue; // Stale peer! Skip them.
455
456 if (!peers[i].basetime)
457 continue; // Shutdown peer! Skip them.
458
459 if (peers[i].uptodate)
460 have_peers = 1;
461
462 if (!peers[i].uptodate)
463 config->cluster_iam_uptodate = 0; // Start fast heartbeats
464 }
465
466 #ifdef BGP
467 // in a cluster, withdraw/add routes when we get a peer/lose all peers
468 if (bgp_configured && have_peers != had_peers)
469 bgp_enable_routing(!have_peers);
470 #endif /* BGP */
471 }
472
473 //
474 // Check that we have a master. If it's been too
475 // long since we heard from a master then hold an election.
476 //
477 void cluster_check_master(void)
478 {
479 int i, count, tcount, high_unique_id = 0;
480 int last_free = 0;
481 clockt t = TIME;
482 static int probed = 0;
483
484 if (config->cluster_iam_master)
485 return; // Only runs on the slaves...
486
487 // If the master is late (missed 2 hearbeats by a second and a
488 // hair) it may be that the switch has dropped us from the
489 // multicast group, try unicasting one probe to the master
490 // which will hopefully respond with a unicast heartbeat that
491 // will allow us to limp along until the querier next runs.
492 if (TIME > (config->cluster_last_hb + 2 * config->cluster_hb_interval + 11))
493 {
494 if (!probed && config->cluster_master_address)
495 {
496 probed = 1;
497 LOG(1, 0, 0, "Heartbeat from master %.1fs late, probing...\n",
498 0.1 * (TIME - (config->cluster_last_hb + config->cluster_hb_interval)));
499
500 peer_send_message(config->cluster_master_address,
501 C_LASTSEEN, config->cluster_seq_number, NULL, 0);
502 }
503 } else { // We got a recent heartbeat; reset the probe flag.
504 probed = 0;
505 }
506
507 if (TIME < (config->cluster_last_hb + config->cluster_hb_timeout))
508 return; // Everything's ok!
509
510 config->cluster_last_hb = TIME + 1; // Just the one election thanks.
511
512 LOG(0, 0, 0, "Master timed out! Holding election...\n");
513
514 for (i = 0; i < num_peers; i++)
515 {
516 if ((peers[i].timestamp + config->cluster_hb_timeout) < t)
517 continue; // Stale peer! Skip them.
518
519 if (!peers[i].basetime)
520 continue; // Shutdown peer! Skip them.
521
522 if (peers[i].basetime < basetime) {
523 LOG(1, 0, 0, "Expecting %s to become master\n", fmtaddr(peers[i].peer, 0));
524 return; // They'll win the election. Get out of here.
525 }
526
527 if (peers[i].basetime == basetime &&
528 peers[i].peer > my_address) {
529 LOG(1, 0, 0, "Expecting %s to become master\n", fmtaddr(peers[i].peer, 0));
530 return; // They'll win the election. Wait for them to come up.
531 }
532 }
533
534 // Wow. it's been ages since I last heard a heartbeat
535 // and I'm better than an of my peers so it's time
536 // to become a master!!!
537
538 config->cluster_iam_master = 1;
539 config->cluster_master_address = 0;
540
541 LOG(0, 0, 0, "I am declaring myself the master!\n");
542
543 if (config->cluster_seq_number == -1)
544 config->cluster_seq_number = 0;
545
546 //
547 // Go through and mark all the tunnels as defined.
548 // Count the highest used tunnel number as well.
549 //
550 config->cluster_highest_tunnelid = 0;
551 for (i = 0, tcount = 0; i < MAXTUNNEL; ++i) {
552 if (tunnel[i].state == TUNNELUNDEF)
553 tunnel[i].state = TUNNELFREE;
554
555 if (tunnel[i].state != TUNNELFREE && i > config->cluster_highest_tunnelid)
556 config->cluster_highest_tunnelid = i;
557 }
558
559 //
560 // Go through and mark all the sessions as being defined.
561 // reset the idle timeouts.
562 // add temporary byte counters to permanent ones.
563 // Re-string the free list.
564 // Find the ID of the highest session.
565 last_free = 0;
566 high_unique_id = 0;
567 config->cluster_highest_sessionid = 0;
568 for (i = 0, count = 0; i < MAXSESSION; ++i) {
569 if (session[i].tunnel == T_UNDEF) {
570 session[i].tunnel = T_FREE;
571 ++count;
572 }
573
574 if (!session[i].opened) { // Unused session. Add to free list.
575 memset(&session[i], 0, sizeof(session[i]));
576 session[i].tunnel = T_FREE;
577 session[last_free].next = i;
578 session[i].next = 0;
579 last_free = i;
580 continue;
581 }
582
583 // Reset idle timeouts..
584 session[i].last_packet = time_now;
585
586 // Reset die relative to our uptime rather than the old master's
587 if (session[i].die) session[i].die = TIME;
588
589 // Accumulate un-sent byte counters.
590 session[i].cin += sess_local[i].cin;
591 session[i].cout += sess_local[i].cout;
592 session[i].total_cin += sess_local[i].cin;
593 session[i].total_cout += sess_local[i].cout;
594
595 sess_local[i].cin = sess_local[i].cout = 0;
596
597 session[i].radius = 0; // Reset authentication as the radius blocks aren't up to date.
598
599 if (session[i].unique_id >= high_unique_id) // This is different to the index into the session table!!!
600 high_unique_id = session[i].unique_id+1;
601
602 session[i].tbf_in = session[i].tbf_out = 0; // Remove stale pointers from old master.
603 throttle_session(i, session[i].throttle_in, session[i].throttle_out);
604
605 config->cluster_highest_sessionid = i;
606 }
607
608 session[last_free].next = 0; // End of chain.
609 last_id = high_unique_id; // Keep track of the highest used session ID.
610
611 become_master();
612
613 rebuild_address_pool();
614
615 // If we're not the very first master, this is a big issue!
616 if(count>0)
617 LOG(0, 0, 0, "Warning: Fixed %d uninitialized sessions in becoming master!\n", count);
618
619 config->cluster_undefined_sessions = 0;
620 config->cluster_undefined_tunnels = 0;
621 config->cluster_iam_uptodate = 1; // assume all peers are up-to-date
622
623 if (!num_peers) // lone master
624 advertise();
625
626 // FIXME. We need to fix up the tunnel control message
627 // queue here! There's a number of other variables we
628 // should also update.
629 }
630
631
632 //
633 // Check that our session table is validly matching what the
634 // master has in mind.
635 //
636 // In particular, if we have too many sessions marked 'undefined'
637 // we fix it up here, and we ensure that the 'first free session'
638 // pointer is valid.
639 //
640 static void cluster_check_sessions(int highsession, int freesession_ptr, int hightunnel)
641 {
642 int i;
643
644 sessionfree = freesession_ptr; // Keep the freesession ptr valid.
645
646 if (config->cluster_iam_uptodate)
647 return;
648
649 if (highsession > config->cluster_undefined_sessions && hightunnel > config->cluster_undefined_tunnels)
650 return;
651
652 // Clear out defined sessions, counting the number of
653 // undefs remaining.
654 config->cluster_undefined_sessions = 0;
655 for (i = 1 ; i < MAXSESSION; ++i) {
656 if (i > highsession) {
657 if (session[i].tunnel == T_UNDEF) session[i].tunnel = T_FREE; // Defined.
658 continue;
659 }
660 if (session[i].tunnel != T_UNDEF)
661 continue;
662
663 if (session[i].tunnel == T_UNDEF)
664 ++config->cluster_undefined_sessions;
665 }
666
667 // Clear out defined tunnels, counting the number of
668 // undefs remaining.
669 config->cluster_undefined_tunnels = 0;
670 for (i = 1 ; i < MAXTUNNEL; ++i) {
671 if (i > hightunnel) {
672 if (tunnel[i].state == TUNNELUNDEF) tunnel[i].state = TUNNELFREE; // Defined.
673 continue;
674 }
675
676 if (tunnel[i].state == TUNNELUNDEF)
677 ++config->cluster_undefined_tunnels;
678 }
679
680
681 if (config->cluster_undefined_sessions || config->cluster_undefined_tunnels) {
682 LOG(2, 0, 0, "Cleared undefined sessions/tunnels. %d sess (high %d), %d tunn (high %d)\n",
683 config->cluster_undefined_sessions, highsession, config->cluster_undefined_tunnels, hightunnel);
684 return;
685 }
686
687 // Are we up to date?
688
689 if (!config->cluster_iam_uptodate)
690 cluster_uptodate();
691 }
692
693 static int hb_add_type(char **p, int type, int id)
694 {
695 switch (type) {
696 case C_CSESSION: { // Compressed C_SESSION.
697 uint8_t c[sizeof(sessiont) * 2]; // Bigger than worst case.
698 uint8_t *d = (uint8_t *) &session[id];
699 uint8_t *orig = d;
700 int size;
701
702 size = rle_compress( &d, sizeof(sessiont), c, sizeof(c) );
703
704 // Did we compress the full structure, and is the size actually
705 // reduced??
706 if ( (d - orig) == sizeof(sessiont) && size < sizeof(sessiont) ) {
707 add_type(p, C_CSESSION, id, (char *) c, size);
708 break;
709 }
710 // Failed to compress : Fall through.
711 }
712 case C_SESSION: add_type(p, C_SESSION, id,
713 (char *) &session[id], sizeof(sessiont));
714 break;
715
716 case C_CTUNNEL: { // Compressed C_TUNNEL
717 uint8_t c[sizeof(tunnelt) * 2]; // Bigger than worst case.
718 uint8_t *d = (uint8_t *) &tunnel[id];
719 uint8_t *orig = d;
720 int size;
721
722 size = rle_compress( &d, sizeof(tunnelt), c, sizeof(c) );
723
724 // Did we compress the full structure, and is the size actually
725 // reduced??
726 if ( (d - orig) == sizeof(tunnelt) && size < sizeof(tunnelt) ) {
727 add_type(p, C_CTUNNEL, id, c, size);
728 break;
729 }
730 // Failed to compress : Fall through.
731 }
732 case C_TUNNEL: add_type(p, C_TUNNEL, id,
733 (char *) &tunnel[id], sizeof(tunnelt));
734 break;
735 default:
736 LOG(0, 0, 0, "Found an invalid type in heart queue! (%d)\n", type);
737 kill(0, SIGTERM);
738 exit(1);
739 }
740 return 0;
741 }
742
743 //
744 // Send a heartbeat, incidently sending out any queued changes..
745 //
746 void cluster_heartbeat()
747 {
748 int i, count = 0, tcount = 0;
749 char buff[MAX_HEART_SIZE + sizeof(heartt) + sizeof(int) ];
750 heartt h;
751 char *p = buff;
752
753 if (!config->cluster_iam_master) // Only the master does this.
754 return;
755
756 config->cluster_table_version += config->cluster_num_changes;
757
758 // Fill out the heartbeat header.
759 memset(&h, 0, sizeof(h));
760
761 h.version = HB_VERSION;
762 h.seq = config->cluster_seq_number;
763 h.basetime = basetime;
764 h.clusterid = config->bind_address; // Will this do??
765 h.basetime = basetime;
766 h.highsession = config->cluster_highest_sessionid;
767 h.freesession = sessionfree;
768 h.hightunnel = config->cluster_highest_tunnelid;
769 h.size_sess = sizeof(sessiont); // Just in case.
770 h.size_tunn = sizeof(tunnelt);
771 h.interval = config->cluster_hb_interval;
772 h.timeout = config->cluster_hb_timeout;
773 h.table_version = config->cluster_table_version;
774
775 add_type(&p, C_HEARTBEAT, HB_VERSION, (char *) &h, sizeof(h));
776
777 for (i = 0; i < config->cluster_num_changes; ++i) {
778 hb_add_type(&p, cluster_changes[i].type, cluster_changes[i].id);
779 }
780
781 if (p > (buff + sizeof(buff))) { // Did we somehow manage to overun the buffer?
782 LOG(0, 0, 0, "FATAL: Overran the heartbeat buffer! This is fatal. Exiting. (size %d)\n", (int) (p - buff));
783 kill(0, SIGTERM);
784 exit(1);
785 }
786
787 //
788 // Fill out the packet with sessions from the session table...
789 // (not forgetting to leave space so we can get some tunnels in too )
790 while ( (p + sizeof(uint32_t) * 2 + sizeof(sessiont) * 2 ) < (buff + MAX_HEART_SIZE) ) {
791
792 if (!walk_session_number) // session #0 isn't valid.
793 ++walk_session_number;
794
795 if (count >= config->cluster_highest_sessionid) // If we're a small cluster, don't go wild.
796 break;
797
798 hb_add_type(&p, C_CSESSION, walk_session_number);
799 walk_session_number = (1+walk_session_number)%(config->cluster_highest_sessionid+1); // +1 avoids divide by zero.
800
801 ++count; // Count the number of extra sessions we're sending.
802 }
803
804 //
805 // Fill out the packet with tunnels from the tunnel table...
806 // This effectively means we walk the tunnel table more quickly
807 // than the session table. This is good because stuffing up a
808 // tunnel is a much bigger deal than stuffing up a session.
809 //
810 while ( (p + sizeof(uint32_t) * 2 + sizeof(tunnelt) ) < (buff + MAX_HEART_SIZE) ) {
811
812 if (!walk_tunnel_number) // tunnel #0 isn't valid.
813 ++walk_tunnel_number;
814
815 if (tcount >= config->cluster_highest_tunnelid)
816 break;
817
818 hb_add_type(&p, C_CTUNNEL, walk_tunnel_number);
819 walk_tunnel_number = (1+walk_tunnel_number)%(config->cluster_highest_tunnelid+1); // +1 avoids divide by zero.
820
821 ++tcount;
822 }
823
824 //
825 // Did we do something wrong?
826 if (p > (buff + sizeof(buff))) { // Did we somehow manage to overun the buffer?
827 LOG(0, 0, 0, "Overran the heartbeat buffer now! This is fatal. Exiting. (size %d)\n", (int) (p - buff));
828 kill(0, SIGTERM);
829 exit(1);
830 }
831
832 LOG(3, 0, 0, "Sending v%d heartbeat #%d, change #%" PRIu64 " with %d changes "
833 "(%d x-sess, %d x-tunnels, %d highsess, %d hightun, size %d)\n",
834 HB_VERSION, h.seq, h.table_version, config->cluster_num_changes,
835 count, tcount, config->cluster_highest_sessionid,
836 config->cluster_highest_tunnelid, (int) (p - buff));
837
838 config->cluster_num_changes = 0;
839
840 send_heartbeat(h.seq, buff, (p-buff) ); // Send out the heartbeat to the cluster, keeping a copy of it.
841
842 config->cluster_seq_number = (config->cluster_seq_number+1)%HB_MAX_SEQ; // Next seq number to use.
843 }
844
845 //
846 // A structure of type 'type' has changed; Add it to the queue to send.
847 //
848 static int type_changed(int type, int id)
849 {
850 int i;
851
852 for (i = 0 ; i < config->cluster_num_changes ; ++i)
853 if ( cluster_changes[i].id == id &&
854 cluster_changes[i].type == type)
855 return 0; // Already marked for change.
856
857 cluster_changes[i].type = type;
858 cluster_changes[i].id = id;
859 ++config->cluster_num_changes;
860
861 if (config->cluster_num_changes > MAX_CHANGES)
862 cluster_heartbeat(); // flush now
863
864 return 1;
865 }
866
867
868 // A particular session has been changed!
869 int cluster_send_session(int sid)
870 {
871 if (!config->cluster_iam_master) {
872 LOG(0, sid, 0, "I'm not a master, but I just tried to change a session!\n");
873 return -1;
874 }
875
876 if (forked) {
877 LOG(0, sid, 0, "cluster_send_session called from child process!\n");
878 return -1;
879 }
880
881 return type_changed(C_CSESSION, sid);
882 }
883
884 // A particular tunnel has been changed!
885 int cluster_send_tunnel(int tid)
886 {
887 if (!config->cluster_iam_master) {
888 LOG(0, 0, tid, "I'm not a master, but I just tried to change a tunnel!\n");
889 return -1;
890 }
891
892 return type_changed(C_CTUNNEL, tid);
893 }
894
895
896 //
897 // We're a master, and a slave has just told us that it's
898 // missed a packet. We'll resend it every packet since
899 // the last one it's seen.
900 //
901 static int cluster_catchup_slave(int seq, in_addr_t slave)
902 {
903 int s;
904 int diff;
905
906 LOG(1, 0, 0, "Slave %s sent LASTSEEN with seq %d\n", fmtaddr(slave, 0), seq);
907
908 diff = config->cluster_seq_number - seq; // How many packet do we need to send?
909 if (diff < 0)
910 diff += HB_MAX_SEQ;
911
912 if (diff >= HB_HISTORY_SIZE) { // Ouch. We don't have the packet to send it!
913 LOG(0, 0, 0, "A slave asked for message %d when our seq number is %d. Killing it.\n",
914 seq, config->cluster_seq_number);
915 return peer_send_message(slave, C_KILL, seq, NULL, 0);// Kill the slave. Nothing else to do.
916 }
917
918 // Now resend every packet that it missed, in order.
919 while (seq != config->cluster_seq_number) {
920 s = seq%HB_HISTORY_SIZE;
921 if (seq != past_hearts[s].seq) {
922 LOG(0, 0, 0, "Tried to re-send heartbeat for %s but %d doesn't match %d! (%d,%d)\n",
923 fmtaddr(slave, 0), seq, past_hearts[s].seq, s, config->cluster_seq_number);
924 return -1; // What to do here!?
925 }
926 peer_send_data(slave, past_hearts[s].data, past_hearts[s].size);
927 seq = (seq+1)%HB_MAX_SEQ; // Increment to next seq number.
928 }
929 return 0; // All good!
930 }
931
932 //
933 // We've heard from another peer! Add it to the list
934 // that we select from at election time.
935 //
936 static int cluster_add_peer(in_addr_t peer, time_t basetime, pingt *pp, int size)
937 {
938 int i;
939 in_addr_t clusterid;
940 pingt p;
941
942 // Allow for backward compatability.
943 // Just the ping packet into a new structure to allow
944 // for the possibility that we might have received
945 // more or fewer elements than we were expecting.
946 if (size > sizeof(p))
947 size = sizeof(p);
948
949 memset( (void *) &p, 0, sizeof(p) );
950 memcpy( (void *) &p, (void *) pp, size);
951
952 clusterid = p.addr;
953 if (clusterid != config->bind_address)
954 {
955 // Is this for us?
956 LOG(4, 0, 0, "Skipping ping from %s (different cluster)\n", fmtaddr(peer, 0));
957 return 0;
958 }
959
960 for (i = 0; i < num_peers ; ++i)
961 {
962 if (peers[i].peer != peer)
963 continue;
964
965 // This peer already exists. Just update the timestamp.
966 peers[i].basetime = basetime;
967 peers[i].timestamp = TIME;
968 peers[i].uptodate = !p.undef;
969 break;
970 }
971
972 // Is this the master shutting down??
973 if (peer == config->cluster_master_address && !basetime) {
974 LOG(3, 0, 0, "Master %s shutting down...\n", fmtaddr(config->cluster_master_address, 0));
975 config->cluster_master_address = 0;
976 config->cluster_last_hb = 0; // Force an election.
977 cluster_check_master();
978 return 0;
979 }
980
981 if (i >= num_peers)
982 {
983 LOG(4, 0, 0, "Adding %s as a peer\n", fmtaddr(peer, 0));
984
985 // Not found. Is there a stale slot to re-use?
986 for (i = 0; i < num_peers ; ++i)
987 {
988 if (!peers[i].basetime) // Shutdown
989 break;
990
991 if ((peers[i].timestamp + config->cluster_hb_timeout * 10) < TIME) // Stale.
992 break;
993 }
994
995 if (i >= CLUSTER_MAX_SIZE)
996 {
997 // Too many peers!!
998 LOG(0, 0, 0, "Tried to add %s as a peer, but I already have %d of them!\n", fmtaddr(peer, 0), i);
999 return -1;
1000 }
1001
1002 peers[i].peer = peer;
1003 peers[i].basetime = basetime;
1004 peers[i].timestamp = TIME;
1005 peers[i].uptodate = !p.undef;
1006 if (i == num_peers)
1007 ++num_peers;
1008
1009 LOG(1, 0, 0, "Added %s as a new peer. Now %d peers\n", fmtaddr(peer, 0), num_peers);
1010 }
1011
1012 return 1;
1013 }
1014
1015 /* Handle the slave updating the byte counters for the master. */
1016 //
1017 // Note that we don't mark the session as dirty; We rely on
1018 // the slow table walk to propogate this back out to the slaves.
1019 //
1020 static int cluster_handle_bytes(char *data, int size)
1021 {
1022 bytest *b;
1023
1024 b = (bytest *) data;
1025
1026 LOG(3, 0, 0, "Got byte counter update (size %d)\n", size);
1027
1028 /* Loop around, adding the byte
1029 counts to each of the sessions. */
1030
1031 while (size >= sizeof(*b) ) {
1032 if (b->sid > MAXSESSION) {
1033 LOG(0, 0, 0, "Got C_BYTES with session #%d!\n", b->sid);
1034 return -1; /* Abort processing */
1035 }
1036
1037 session[b->sid].total_cin += b->in;
1038 session[b->sid].total_cout += b->out;
1039
1040 session[b->sid].cin += b->in;
1041 session[b->sid].cout += b->out;
1042 session[b->sid].last_packet = time_now; // Reset idle timer!
1043
1044 size -= sizeof(*b);
1045 ++b;
1046 }
1047
1048 if (size != 0)
1049 LOG(0, 0, 0, "Got C_BYTES with %d bytes of trailing junk!\n", size);
1050
1051 return size;
1052 }
1053
1054 //
1055 // Handle receiving a session structure in a heartbeat packet.
1056 //
1057 static int cluster_recv_session(int more, uint8_t *p)
1058 {
1059 if (more >= MAXSESSION) {
1060 LOG(0, 0, 0, "DANGER: Received a heartbeat session id > MAXSESSION!\n");
1061 return -1;
1062 }
1063
1064 if (session[more].tunnel == T_UNDEF) {
1065 if (config->cluster_iam_uptodate) { // Sanity.
1066 LOG(0, 0, 0, "I thought I was uptodate but I just found an undefined session!\n");
1067 } else {
1068 --config->cluster_undefined_sessions;
1069 }
1070 }
1071
1072 load_session(more, (sessiont *) p); // Copy session into session table..
1073
1074 LOG(5, more, 0, "Received session update (%d undef)\n", config->cluster_undefined_sessions);
1075
1076 if (!config->cluster_iam_uptodate)
1077 cluster_uptodate(); // Check to see if we're up to date.
1078
1079 return 0;
1080 }
1081
1082 static int cluster_recv_tunnel(int more, uint8_t *p)
1083 {
1084 if (more >= MAXTUNNEL) {
1085 LOG(0, 0, 0, "DANGER: Received a tunnel session id > MAXTUNNEL!\n");
1086 return -1;
1087 }
1088
1089 if (tunnel[more].state == TUNNELUNDEF) {
1090 if (config->cluster_iam_uptodate) { // Sanity.
1091 LOG(0, 0, 0, "I thought I was uptodate but I just found an undefined tunnel!\n");
1092 } else {
1093 --config->cluster_undefined_tunnels;
1094 }
1095 }
1096
1097 memcpy(&tunnel[more], p, sizeof(tunnel[more]) );
1098
1099 //
1100 // Clear tunnel control messages. These are dynamically allocated.
1101 // If we get unlucky, this may cause the tunnel to drop!
1102 //
1103 tunnel[more].controls = tunnel[more].controle = NULL;
1104 tunnel[more].controlc = 0;
1105
1106 LOG(5, 0, more, "Received tunnel update\n");
1107
1108 if (!config->cluster_iam_uptodate)
1109 cluster_uptodate(); // Check to see if we're up to date.
1110
1111 return 0;
1112 }
1113
1114
1115 //
1116 // Process a heartbeat..
1117 //
1118 // v3: added interval, timeout
1119 // v4: added table_version
1120 static int cluster_process_heartbeat(uint8_t *data, int size, int more, uint8_t *p, in_addr_t addr)
1121 {
1122 heartt *h;
1123 int s = size - (p-data);
1124 int i, type;
1125
1126 #if HB_VERSION != 4
1127 # error "need to update cluster_process_heartbeat()"
1128 #endif
1129
1130 // we handle versions 3 through 4
1131 if (more < 3 || more > HB_VERSION) {
1132 LOG(0, 0, 0, "Received a heartbeat version that I don't support (%d)!\n", more);
1133 return -1; // Ignore it??
1134 }
1135
1136 // Ok. It's a heartbeat packet from a cluster master!
1137 if (s < sizeof(*h))
1138 goto shortpacket;
1139
1140 h = (heartt *) p;
1141 p += sizeof(*h);
1142 s -= sizeof(*h);
1143
1144 if (h->clusterid != config->bind_address)
1145 return -1; // It's not part of our cluster.
1146
1147 if (config->cluster_iam_master) { // Sanity...
1148 // Note that this MUST match the election process above!
1149
1150 LOG(0, 0, 0, "I just got a heartbeat from master %s, but _I_ am the master!\n", fmtaddr(addr, 0));
1151 if (!h->basetime) {
1152 LOG(0, 0, 0, "Heartbeat with zero basetime! Ignoring\n");
1153 return -1; // Skip it.
1154 }
1155
1156 if (more >= 4) {
1157 if (h->table_version > config->cluster_table_version) {
1158 LOG(0, 0, 0, "They've seen more state changes (%" PRIu64 " vs my %" PRIu64 ") so I'm gone!\n",
1159 h->table_version, config->cluster_table_version);
1160
1161 kill(0, SIGTERM);
1162 exit(1);
1163 }
1164 if (h->table_version < config->cluster_table_version)
1165 return -1;
1166 }
1167
1168 if (basetime > h->basetime) {
1169 LOG(0, 0, 0, "They're an older master than me so I'm gone!\n");
1170 kill(0, SIGTERM);
1171 exit(1);
1172 }
1173
1174 if (basetime < h->basetime)
1175 return -1;
1176
1177 if (my_address < addr) { // Tie breaker.
1178 LOG(0, 0, 0, "They're a higher IP address than me, so I'm gone!\n");
1179 kill(0, SIGTERM);
1180 exit(1);
1181 }
1182
1183 return -1; // Skip it.
1184 }
1185
1186 if (config->cluster_seq_number == -1) // Don't have one. Just align to the master...
1187 config->cluster_seq_number = h->seq;
1188
1189 config->cluster_last_hb = TIME; // Reset to ensure that we don't become master!!
1190
1191 if (config->cluster_seq_number != h->seq) { // Out of sequence heartbeat!
1192 static int lastseen_seq = 0;
1193 static time_t lastseen_time = 0;
1194
1195 // limit to once per second for a particular seq#
1196 int ask = (config->cluster_seq_number != lastseen_seq || time_now != lastseen_time);
1197
1198 LOG(1, 0, 0, "HB: Got seq# %d but was expecting %d. %s.\n",
1199 h->seq, config->cluster_seq_number,
1200 ask ? "Asking for resend" : "Ignoring");
1201
1202 if (ask)
1203 {
1204 lastseen_seq = config->cluster_seq_number;
1205 lastseen_time = time_now;
1206 peer_send_message(addr, C_LASTSEEN, config->cluster_seq_number, NULL, 0);
1207 }
1208
1209 config->cluster_last_hb = TIME; // Reset to ensure that we don't become master!!
1210
1211 // Just drop the packet. The master will resend it as part of the catchup.
1212
1213 return 0;
1214 }
1215 // Save the packet in our buffer.
1216 // This is needed in case we become the master.
1217 config->cluster_seq_number = (h->seq+1)%HB_MAX_SEQ;
1218 i = h->seq % HB_HISTORY_SIZE;
1219 past_hearts[i].seq = h->seq;
1220 past_hearts[i].size = size;
1221 memcpy(&past_hearts[i].data, data, size); // Save it.
1222
1223
1224 // Check that we don't have too many undefined sessions, and
1225 // that the free session pointer is correct.
1226 cluster_check_sessions(h->highsession, h->freesession, h->hightunnel);
1227
1228 if (h->interval != config->cluster_hb_interval)
1229 {
1230 LOG(2, 0, 0, "Master set ping/heartbeat interval to %u (was %u)\n",
1231 h->interval, config->cluster_hb_interval);
1232
1233 config->cluster_hb_interval = h->interval;
1234 }
1235
1236 if (h->timeout != config->cluster_hb_timeout)
1237 {
1238 LOG(2, 0, 0, "Master set heartbeat timeout to %u (was %u)\n",
1239 h->timeout, config->cluster_hb_timeout);
1240
1241 config->cluster_hb_timeout = h->timeout;
1242 }
1243
1244 // Ok. process the packet...
1245 while ( s > 0) {
1246
1247 type = *((uint32_t *) p);
1248 p += sizeof(uint32_t);
1249 s -= sizeof(uint32_t);
1250
1251 more = *((uint32_t *) p);
1252 p += sizeof(uint32_t);
1253 s -= sizeof(uint32_t);
1254
1255 switch (type) {
1256 case C_CSESSION: { // Compressed session structure.
1257 uint8_t c[ sizeof(sessiont) + 2];
1258 int size;
1259 uint8_t *orig_p = p;
1260
1261 size = rle_decompress((uint8_t **) &p, s, c, sizeof(c) );
1262 s -= (p - orig_p);
1263
1264 if (size != sizeof(sessiont) ) { // Ouch! Very very bad!
1265 LOG(0, 0, 0, "DANGER: Received a CSESSION that didn't decompress correctly!\n");
1266 // Now what? Should exit! No-longer up to date!
1267 break;
1268 }
1269
1270 cluster_recv_session(more, c);
1271 break;
1272 }
1273 case C_SESSION:
1274 if ( s < sizeof(session[more]))
1275 goto shortpacket;
1276
1277 cluster_recv_session(more, p);
1278
1279 p += sizeof(session[more]);
1280 s -= sizeof(session[more]);
1281 break;
1282
1283 case C_CTUNNEL: { // Compressed tunnel structure.
1284 uint8_t c[ sizeof(tunnelt) + 2];
1285 int size;
1286 uint8_t *orig_p = p;
1287
1288 size = rle_decompress((uint8_t **) &p, s, c, sizeof(c));
1289 s -= (p - orig_p);
1290
1291 if (size != sizeof(tunnelt) ) { // Ouch! Very very bad!
1292 LOG(0, 0, 0, "DANGER: Received a CSESSION that didn't decompress correctly!\n");
1293 // Now what? Should exit! No-longer up to date!
1294 break;
1295 }
1296
1297 cluster_recv_tunnel(more, c);
1298 break;
1299
1300 }
1301 case C_TUNNEL:
1302 if ( s < sizeof(tunnel[more]))
1303 goto shortpacket;
1304
1305 cluster_recv_tunnel(more, p);
1306
1307 p += sizeof(tunnel[more]);
1308 s -= sizeof(tunnel[more]);
1309 break;
1310 default:
1311 LOG(0, 0, 0, "DANGER: I received a heartbeat element where I didn't understand the type! (%d)\n", type);
1312 return -1; // can't process any more of the packet!!
1313 }
1314 }
1315
1316 if (config->cluster_master_address != addr)
1317 {
1318 LOG(0, 0, 0, "My master just changed from %s to %s!\n",
1319 fmtaddr(config->cluster_master_address, 0), fmtaddr(addr, 1));
1320
1321 config->cluster_master_address = addr;
1322 }
1323
1324 config->cluster_last_hb = TIME; // Successfully received a heartbeat!
1325 config->cluster_table_version = h->table_version;
1326 return 0;
1327
1328 shortpacket:
1329 LOG(0, 0, 0, "I got an incomplete heartbeat packet! This means I'm probably out of sync!!\n");
1330 return -1;
1331 }
1332
1333 //
1334 // We got a packet on the cluster port!
1335 // Handle pings, lastseens, and heartbeats!
1336 //
1337 int processcluster(char *data, int size, in_addr_t addr)
1338 {
1339 int type, more;
1340 char *p = data;
1341 int s = size;
1342
1343 if (addr == my_address)
1344 return -1; // Ignore it. Something looped back the multicast!
1345
1346 LOG(5, 0, 0, "Process cluster: %d bytes from %s\n", size, fmtaddr(addr, 0));
1347
1348 if (s <= 0) // Any data there??
1349 return -1;
1350
1351 if (s < 8)
1352 goto shortpacket;
1353
1354 type = *((uint32_t *) p);
1355 p += sizeof(uint32_t);
1356 s -= sizeof(uint32_t);
1357
1358 more = *((uint32_t *) p);
1359 p += sizeof(uint32_t);
1360 s -= sizeof(uint32_t);
1361
1362 switch (type) {
1363 case C_PING: // Update the peers table.
1364 return cluster_add_peer(addr, more, (pingt *) p, s);
1365
1366 case C_LASTSEEN: // Catch up a slave (slave missed a packet).
1367 return cluster_catchup_slave(more, addr);
1368
1369 case C_FORWARD: { // Forwarded control packet. pass off to processudp.
1370 struct sockaddr_in a;
1371 a.sin_addr.s_addr = more;
1372
1373 a.sin_port = *(int *) p;
1374 s -= sizeof(int);
1375 p += sizeof(int);
1376
1377 if (!config->cluster_iam_master) { // huh?
1378 LOG(0, 0, 0, "I'm not the master, but I got a C_FORWARD from %s?\n", fmtaddr(addr, 0));
1379 return -1;
1380 }
1381
1382 LOG(4, 0, 0, "Got a forwarded packet... (%s:%d)\n", fmtaddr(more, 0), a.sin_port);
1383 STAT(recv_forward);
1384 processudp(p, s, &a);
1385 return 0;
1386 }
1387 case C_THROTTLE: { // Receive a forwarded packet from a slave.
1388 if (!config->cluster_iam_master) {
1389 LOG(0, 0, 0, "I'm not the master, but I got a C_THROTTLE from %s?\n", fmtaddr(addr, 0));
1390 return -1;
1391 }
1392
1393 tbf_queue_packet(more, p, s); // The TBF id tells wether it goes in or out.
1394 return 0;
1395 }
1396 case C_GARDEN:
1397 // Receive a walled garden packet from a slave.
1398 if (!config->cluster_iam_master) {
1399 LOG(0, 0, 0, "I'm not the master, but I got a C_GARDEN from %s?\n", fmtaddr(addr, 0));
1400 return -1;
1401 }
1402
1403 tun_write(p, s);
1404 return 0;
1405
1406 case C_BYTES:
1407 return cluster_handle_bytes(p, s);
1408
1409 case C_KILL: // The master asked us to die!? (usually because we're too out of date).
1410 if (config->cluster_iam_master) {
1411 LOG(0, 0, 0, "_I_ am master, but I received a C_KILL from %s! (Seq# %d)\n", fmtaddr(addr, 0), more);
1412 return -1;
1413 }
1414 if (more != config->cluster_seq_number) {
1415 LOG(0, 0, 0, "The master asked us to die but the seq number didn't match!?\n");
1416 return -1;
1417 }
1418
1419 if (addr != config->cluster_master_address) {
1420 LOG(0, 0, 0, "Received a C_KILL from %s which doesn't match config->cluster_master_address (%s)\n",
1421 fmtaddr(addr, 0), fmtaddr(config->cluster_master_address, 1));
1422 // We can only warn about it. The master might really have switched!
1423 }
1424
1425 LOG(0, 0, 0, "Received a valid C_KILL: I'm going to die now.\n");
1426 kill(0, SIGTERM);
1427 exit(0); // Lets be paranoid;
1428 return -1; // Just signalling the compiler.
1429
1430 case C_HEARTBEAT:
1431 LOG(4, 0, 0, "Got a heartbeat from %s\n", fmtaddr(addr, 0));
1432 return cluster_process_heartbeat(data, size, more, p, addr);
1433
1434 default:
1435 LOG(0, 0, 0, "Strange type packet received on cluster socket (%d)\n", type);
1436 return -1;
1437 }
1438 return 0;
1439
1440 shortpacket:
1441 LOG(0, 0, 0, "I got a _short_ cluster heartbeat packet! This means I'm probably out of sync!!\n");
1442 return -1;
1443 }
1444
1445 //====================================================================================================
1446
1447 int cmd_show_cluster(struct cli_def *cli, char *command, char **argv, int argc)
1448 {
1449 int i;
1450
1451 if (CLI_HELP_REQUESTED)
1452 return CLI_HELP_NO_ARGS;
1453
1454 cli_print(cli, "Cluster status : %s", config->cluster_iam_master ? "Master" : "Slave" );
1455 cli_print(cli, "My address : %s", fmtaddr(my_address, 0));
1456 cli_print(cli, "VIP address : %s", fmtaddr(config->bind_address, 0));
1457 cli_print(cli, "Multicast address: %s", fmtaddr(config->cluster_address, 0));
1458 cli_print(cli, "Multicast i'face : %s", config->cluster_interface);
1459
1460 if (!config->cluster_iam_master) {
1461 cli_print(cli, "My master : %s (last heartbeat %.1f seconds old)",
1462 config->cluster_master_address
1463 ? fmtaddr(config->cluster_master_address, 0)
1464 : "Not defined",
1465 0.1 * (TIME - config->cluster_last_hb));
1466 cli_print(cli, "Uptodate : %s", config->cluster_iam_uptodate ? "Yes" : "No");
1467 cli_print(cli, "Table version # : %" PRIu64, config->cluster_table_version);
1468 cli_print(cli, "Next sequence number expected: %d", config->cluster_seq_number);
1469 cli_print(cli, "%d sessions undefined of %d", config->cluster_undefined_sessions, config->cluster_highest_sessionid);
1470 cli_print(cli, "%d tunnels undefined of %d", config->cluster_undefined_tunnels, config->cluster_highest_tunnelid);
1471 } else {
1472 cli_print(cli, "Table version # : %" PRIu64, config->cluster_table_version);
1473 cli_print(cli, "Next heartbeat # : %d", config->cluster_seq_number);
1474 cli_print(cli, "Highest session : %d", config->cluster_highest_sessionid);
1475 cli_print(cli, "Highest tunnel : %d", config->cluster_highest_tunnelid);
1476 cli_print(cli, "%d changes queued for sending", config->cluster_num_changes);
1477 }
1478 cli_print(cli, "%d peers.", num_peers);
1479
1480 if (num_peers)
1481 cli_print(cli, "%20s %10s %8s", "Address", "Basetime", "Age");
1482 for (i = 0; i < num_peers; ++i) {
1483 cli_print(cli, "%20s %10u %8d", fmtaddr(peers[i].peer, 0),
1484 peers[i].basetime, TIME - peers[i].timestamp);
1485 }
1486 return CLI_OK;
1487 }
1488
1489 //
1490 // Simple run-length-encoding compression.
1491 // Format is
1492 // 1 byte < 128 = count of non-zero bytes following. // Not legal to be zero.
1493 // n non-zero bytes;
1494 // or
1495 // 1 byte > 128 = (count - 128) run of zero bytes. //
1496 // repeat.
1497 // count == 0 indicates end of compressed stream.
1498 //
1499 // Compress from 'src' into 'dst'. return number of bytes
1500 // used from 'dst'.
1501 // Updates *src_p to indicate 1 past last bytes used.
1502 //
1503 // We could get an extra byte in the zero runs by storing (count-1)
1504 // but I'm playing it safe.
1505 //
1506 // Worst case is a 50% expansion in space required (trying to
1507 // compress { 0x00, 0x01 } * N )
1508 static int rle_compress(uint8_t **src_p, int ssize, uint8_t *dst, int dsize)
1509 {
1510 int count;
1511 int orig_dsize = dsize;
1512 uint8_t *x, *src;
1513 src = *src_p;
1514
1515 while (ssize > 0 && dsize > 2) {
1516 count = 0;
1517 x = dst++; --dsize; // Reserve space for count byte..
1518
1519 if (*src) { // Copy a run of non-zero bytes.
1520 while (*src && count < 127 && ssize > 0 && dsize > 1) { // Count number of non-zero bytes.
1521 *dst++ = *src++;
1522 --dsize; --ssize;
1523 ++count;
1524 }
1525 *x = count; // Store number of non-zero bytes. Guarenteed to be non-zero!
1526
1527 } else { // Compress a run of zero bytes.
1528 while (*src == 0 && count < 127 && ssize > 0) {
1529 ++src;
1530 --ssize;
1531 ++count;
1532 }
1533 *x = count | 0x80 ;
1534 }
1535 }
1536
1537 *dst++ = 0x0; // Add Stop byte.
1538 --dsize;
1539
1540 *src_p = src;
1541 return (orig_dsize - dsize);
1542 }
1543
1544 //
1545 // Decompress the buffer into **p.
1546 // 'psize' is the size of the decompression buffer available.
1547 //
1548 // Returns the number of bytes decompressed.
1549 //
1550 // Decompresses from '*src_p' into 'dst'.
1551 // Return the number of dst bytes used.
1552 // Updates the 'src_p' pointer to point to the
1553 // first un-used byte.
1554 static int rle_decompress(uint8_t **src_p, int ssize, uint8_t *dst, int dsize)
1555 {
1556 int count;
1557 int orig_dsize = dsize;
1558 char *src = *src_p;
1559
1560 while (ssize >0 && dsize > 0) { // While there's more to decompress, and there's room in the decompress buffer...
1561 count = *src++; --ssize; // get the count byte from the source.
1562 if (count == 0x0) // End marker reached? If so, finish.
1563 break;
1564
1565 if (count & 0x80) { // Decompress a run of zeros
1566 for (count &= 0x7f ; count > 0 && dsize > 0; --count) {
1567 *dst++ = 0x0;
1568 --dsize;
1569 }
1570 } else { // Copy run of non-zero bytes.
1571 for ( ; count > 0 && ssize && dsize; --count) { // Copy non-zero bytes across.
1572 *dst++ = *src++;
1573 --ssize; --dsize;
1574 }
1575 }
1576 }
1577 *src_p = src;
1578 return (orig_dsize - dsize);
1579 }