7c14160baa97395e77c93ed3eef7732eeb471526
[l2tpns.git] / cluster.c
1 // L2TPNS Clustering Stuff
2
3 char const *cvs_id_cluster = "$Id: cluster.c,v 1.4 2004/06/28 02:43:13 fred_nerk Exp $";
4
5 #include <stdio.h>
6 #include <sys/file.h>
7 #include <sys/stat.h>
8 #include <sys/socket.h>
9 #include <netinet/in.h>
10 #include <arpa/inet.h>
11 #include <sys/ioctl.h>
12 #include <net/if.h>
13 #include <string.h>
14 #include <malloc.h>
15 #include <errno.h>
16 #include <stdlib.h>
17 #include <stdarg.h>
18 #include <unistd.h>
19 #include <stdio.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 ipt 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
47 static int hsess, fsess; // Saved copies of the highest used session id, and the first free one.
48
49 #define MAX_HEART_SIZE (8192) // Maximum size of heartbeat packet. Must be less than max IP packet size :)
50 #define MAX_CHANGES (MAX_HEART_SIZE/(sizeof(sessiont) + sizeof(int) ) - 2) // Assumes a session is the biggest type!
51
52 static struct {
53 int type;
54 int id;
55 } cluster_changes[MAX_CHANGES]; // Queue of changed structures that need to go out when next heartbeat.
56
57 static struct {
58 int seq;
59 int size;
60 char data[MAX_HEART_SIZE];
61 } past_hearts[HB_HISTORY_SIZE]; // Ring buffer of heartbeats that we've recently sent out. Needed so
62 // we can re-transmit if needed.
63
64 static struct {
65 u32 peer;
66 time_t basetime;
67 clockt timestamp;
68 int uptodate;
69 } peers[CLUSTER_MAX_SIZE]; // List of all the peers we've heard from.
70 static int num_peers; // Number of peers in list.
71 static int have_peers; // At least one peer
72
73 int rle_decompress(u8 ** src_p, int ssize, u8 *dst, int dsize);
74 int rle_compress(u8 ** src_p, int ssize, u8 *dst, int dsize);
75
76 //
77 // Create a listening socket
78 //
79 // This joins the cluster multi-cast group.
80 //
81 int cluster_init()
82 {
83 struct sockaddr_in addr;
84 struct sockaddr_in interface_addr;
85 struct ip_mreq mreq;
86 struct ifreq ifr;
87 int opt = 0;
88
89 config->cluster_undefined_sessions = MAXSESSION-1;
90 config->cluster_undefined_tunnels = MAXTUNNEL-1;
91
92 if (!config->cluster_address)
93 return 0;
94 if (!*config->cluster_interface)
95 return 0;
96
97 cluster_sockfd = socket(AF_INET, SOCK_DGRAM, UDP);
98
99 memset(&addr, 0, sizeof(addr));
100 addr.sin_family = AF_INET;
101 addr.sin_port = htons(CLUSTERPORT);
102 addr.sin_addr.s_addr = INADDR_ANY;
103 setsockopt(cluster_sockfd, SOL_SOCKET, SO_REUSEADDR, &addr, sizeof(addr));
104
105 if (bind(cluster_sockfd, (void *) &addr, sizeof(addr)) < 0)
106 {
107 log(0, 0, 0, 0, "Failed to bind cluster socket: %s\n", strerror(errno));
108 return -1;
109 }
110
111 strcpy(ifr.ifr_name, config->cluster_interface);
112 if (ioctl(cluster_sockfd, SIOCGIFADDR, &ifr) < 0) {
113 log(0, 0, 0, 0, "Failed to get interface address for (%s): %s\n", config->cluster_interface, strerror(errno));
114 return -1;
115 }
116
117 memcpy(&interface_addr, &ifr.ifr_addr, sizeof(interface_addr) );
118 my_address = interface_addr.sin_addr.s_addr;
119
120 // Join multicast group.
121 mreq.imr_multiaddr.s_addr = config->cluster_address;
122 mreq.imr_interface = interface_addr.sin_addr;
123
124
125 opt = 0; // Turn off multicast loopback.
126 setsockopt(cluster_sockfd, IPPROTO_IP, IP_MULTICAST_LOOP, &opt, sizeof(opt));
127
128 if (setsockopt(cluster_sockfd, IPPROTO_IP, IP_ADD_MEMBERSHIP, &mreq, sizeof(mreq)) < 0) {
129 log(0, 0, 0, 0, "Failed to setsockopt (join mcast group): %s\n", strerror(errno));
130 return -1;
131 }
132
133 if (setsockopt (cluster_sockfd, IPPROTO_IP, IP_MULTICAST_IF, &interface_addr, sizeof(interface_addr)) < 0) {
134 log(0, 0, 0, 0, "Failed to setsockopt (set mcast interface): %s\n", strerror(errno));
135 return -1;
136 }
137
138 config->cluster_last_hb = TIME;
139 config->cluster_seq_number = -1;
140
141 return cluster_sockfd;
142 }
143
144
145 //
146 // Send a chunk of data to the entire cluster (usually via the multicast
147 // address ).
148 //
149
150 int cluster_send_data(void *data, int datalen)
151 {
152 struct sockaddr_in addr = {0};
153
154 if (!cluster_sockfd) return -1;
155 if (!config->cluster_address) return 0;
156
157 addr.sin_addr.s_addr = config->cluster_address;
158 addr.sin_port = htons(CLUSTERPORT);
159 addr.sin_family = AF_INET;
160
161 // log_hex(4, "Cluster send", data, datalen); // VERY big data packets. How about we don't..
162
163 log(5,0,0,0, "Cluster send data: %d bytes\n", datalen);
164
165 if (sendto(cluster_sockfd, data, datalen, MSG_NOSIGNAL, (void *) &addr, sizeof(addr)) < 0)
166 {
167 log(0, 0, 0, 0, "sendto: %s\n", strerror(errno));
168 return -1;
169 }
170
171 return 0;
172 }
173
174 //
175 // Add a chunk of data to a heartbeat packet.
176 // Maintains the format. Assumes that the caller
177 // has passed in a big enough buffer!
178 //
179 static void add_type(char ** p, int type, int more, char * data, int size)
180 {
181 * ( (u32*)(*p) ) = type;
182 *p += sizeof(u32);
183
184 * ( (u32*)(*p) ) = more;
185 *p += sizeof(u32);
186
187 if (data && size > 0) {
188 memcpy(*p, data, size);
189 (*p) += size;
190 }
191 }
192
193 void cluster_uptodate(void)
194 {
195 if (config->cluster_iam_uptodate)
196 return;
197
198 if (config->cluster_undefined_sessions || config->cluster_undefined_tunnels)
199 return;
200
201 config->cluster_iam_uptodate = 1;
202
203 log(0,0,0,0, "Now uptodate with master.\n");
204
205 // If we're not a master, or if we have no slaves
206 // then start taking traffic..
207 if (!config->cluster_iam_master || !have_peers)
208 {
209 #ifdef BGP
210 if (bgp_configured)
211 bgp_enable_routing(1);
212 else
213 #endif /* BGP */
214 if (config->send_garp)
215 send_garp(config->bind_address); // Start taking traffic.
216 }
217 }
218
219 //
220 // Send a unicast UDP packet to a peer with 'data' as the
221 // contents.
222 //
223 int peer_send_data(u32 peer, char * data, int size)
224 {
225 struct sockaddr_in addr = {0};
226
227 if (!cluster_sockfd) return -1;
228 if (!config->cluster_address) return 0;
229
230 if (!peer) // Odd??
231 return -1;
232
233 addr.sin_addr.s_addr = peer;
234 addr.sin_port = htons(CLUSTERPORT);
235 addr.sin_family = AF_INET;
236
237 log_hex(5, "Peer send", data, size);
238
239 if (sendto(cluster_sockfd, data, size, MSG_NOSIGNAL, (void *) &addr, sizeof(addr)) < 0)
240 {
241 log(0, 0, 0, 0, "sendto: %s\n", strerror(errno));
242 return -1;
243 }
244
245 return 0;
246 }
247
248 //
249 // Send a structured message to a peer with a single element of type 'type'.
250 //
251 int peer_send_message(u32 peer, int type, int more, char * data, int size)
252 {
253 char buf[65536]; // Vast overkill.
254 char * p = buf;
255
256 log(4,0,0,0, "Sending message to peer (type %d, more %d, size %d)\n", type, more, size);
257 add_type(&p, type, more, data, size);
258
259 return peer_send_data(peer, buf, (p-buf) );
260 }
261
262 //
263 // Forward a state changing packet to the master.
264 //
265 // The master just processes the payload as if it had
266 // received it off the tap device.
267 //
268 int master_forward_packet(char * data, int size, u32 addr, int port)
269 {
270 char buf[65536]; // Vast overkill.
271 char * p = buf;
272
273 if (!config->cluster_master_address) // No election has been held yet. Just skip it.
274 return -1;
275
276 log(4,0,0,0, "Forwarding packet from %s to master (size %d)\n", inet_toa(addr), size);
277
278 STAT(c_forwarded);
279 add_type(&p, C_FORWARD, addr, (char*) &port, sizeof(port) );
280 memcpy(p, data, size);
281 p += size;
282
283 return peer_send_data(config->cluster_master_address, buf, (p-buf) );
284
285 }
286
287 //
288 // Forward a throttled packet to the master for handling.
289 //
290 // The master just drops the packet into the appropriate
291 // token bucket queue, and lets normal processing take care
292 // of it.
293 //
294 int master_throttle_packet(int tbfid, char * data, int size)
295 {
296 char buf[65536]; // Vast overkill.
297 char * p = buf;
298
299 if (!config->cluster_master_address) // No election has been held yet. Just skip it.
300 return -1;
301
302 log(4,0,0,0, "Throttling packet master (size %d, tbfid %d)\n", size, tbfid);
303
304 add_type(&p, C_THROTTLE, tbfid, data, size);
305
306 return peer_send_data(config->cluster_master_address, buf, (p-buf) );
307
308 }
309
310 //
311 // Forward a walled garden packet to the master for handling.
312 //
313 // The master just writes the packet straight to the tun
314 // device (where is will normally loop through the
315 // firewall rules, and come back in on the tun device)
316 //
317 // (Note that this must be called with the tun header
318 // as the start of the data).
319 int master_garden_packet(sessionidt s, char *data, int size)
320 {
321 char buf[65536]; // Vast overkill.
322 char *p = buf;
323
324 if (!config->cluster_master_address) // No election has been held yet. Just skip it.
325 return -1;
326
327 log(4,0,0,0, "Walled garden packet to master (size %d)\n", size);
328
329 add_type(&p, C_GARDEN, s, data, size);
330
331 return peer_send_data(config->cluster_master_address, buf, (p-buf));
332
333 }
334
335 //
336 // Send a chunk of data as a heartbeat..
337 // We save it in the history buffer as we do so.
338 //
339 static void send_heartbeat(int seq, char * data, int size)
340 {
341 int i;
342
343 if (size > sizeof(past_hearts[0].data)) {
344 log(0,0,0,0, "Tried to heartbeat something larger than the maximum packet!\n");
345 kill(0, SIGTERM);
346 }
347 i = seq % HB_HISTORY_SIZE;
348 past_hearts[i].seq = seq;
349 past_hearts[i].size = size;
350 memcpy(&past_hearts[i].data, data, size); // Save it.
351 cluster_send_data(data, size);
352 }
353
354 //
355 // Send an 'i am alive' message to every machine in the cluster.
356 //
357 void cluster_send_ping(time_t basetime)
358 {
359 char buff[100 + sizeof(pingt)];
360 char *p = buff;
361 pingt x;
362
363 if (config->cluster_iam_master && basetime) // We're heartbeating so no need to ping.
364 return;
365
366 log(5,0,0,0, "Sending cluster ping...\n");
367
368 x.ver = 1;
369 x.addr = config->bind_address;
370 x.undef = config->cluster_undefined_sessions + config->cluster_undefined_tunnels;
371 x.basetime = basetime;
372
373 add_type(&p, C_PING, basetime, (char *) &x, sizeof(x));
374 cluster_send_data(buff, (p-buff) );
375 }
376
377 //
378 // Walk the session counters looking for non-zero ones to send
379 // to the master. We send up to 100 of them at one time.
380 // We examine a maximum of 2000 sessions.
381 // (50k max session should mean that we normally
382 // examine the entire session table every 25 seconds).
383
384 #define MAX_B_RECS (400)
385 void master_update_counts(void)
386 {
387 int i, c;
388 bytest b[MAX_B_RECS+1];
389
390 if (config->cluster_iam_master) // Only happens on the slaves.
391 return;
392
393 if (!config->cluster_master_address) // If we don't have a master, skip it for a while.
394 return;
395
396 i = MAX_B_RECS * 5; // Examine max 2000 sessions;
397 if (config->cluster_highest_sessionid > i)
398 i = config->cluster_highest_sessionid;
399
400 for ( c = 0; i > 0 ; --i) {
401 // Next session to look at.
402 walk_session_number++;
403 if ( walk_session_number > config->cluster_highest_sessionid)
404 walk_session_number = 1;
405
406 if (!sess_count[walk_session_number].cin && !sess_count[walk_session_number].cout)
407 continue; // Unused. Skip it.
408
409 b[c].sid = walk_session_number;
410 b[c].in = sess_count[walk_session_number].cin;
411 b[c].out = sess_count[walk_session_number].cout;
412
413 if (++c > MAX_B_RECS) // Send a max of 400 elements in a packet.
414 break;
415
416 // Reset counters.
417 sess_count[walk_session_number].cin = sess_count[walk_session_number].cout = 0;
418 }
419
420 if (!c) // Didn't find any that changes. Get out of here!
421 return;
422
423
424 // Forward the data to the master.
425 log(4,0,0,0, "Sending byte counters to master (%d elements)\n", c);
426 peer_send_message(config->cluster_master_address, C_BYTES, c, (char*) &b, sizeof(b[0]) * c);
427 return;
428 }
429
430 //
431 // Check that we have a master. If it's been too
432 // long since we heard from a master then hold an election.
433 //
434 void cluster_check_master(void)
435 {
436 int i, count, tcount, high_sid = 0;
437 int last_free = 0;
438 int had_peers = have_peers;
439 clockt t = TIME;
440
441 if (TIME < (config->cluster_last_hb + config->cluster_hb_timeout) )
442 return; // Everything's ok. return.
443
444 if (!config->cluster_iam_master)
445 log(0,0,0,0, "Master timed out! Holding election...\n");
446
447 config->cluster_last_hb = TIME + 1;
448
449 for (i = have_peers = 0; i < num_peers ; ++i) {
450 if ((peers[i].timestamp + config->cluster_hb_timeout) < t)
451 continue; // Stale peer! Skip them.
452
453 if (!peers[i].basetime)
454 continue; // Shutdown peer! Skip them.
455
456 have_peers = 1;
457 if (peers[i].basetime < basetime) {
458 log(1,0,0,0, "Expecting %s to become master\n", inet_toa(peers[i].peer) );
459 return; // They'll win the election. Get out of here.
460 }
461
462 if (peers[i].basetime == basetime &&
463 peers[i].peer > my_address) {
464 log(1,0,0,0, "Expecting %s to become master\n", inet_toa(peers[i].peer) );
465 return; // They'll win the election. Wait for them to come up.
466 }
467 }
468
469 if (config->cluster_iam_master) // If we're the master, we've already won
470 {
471 #ifdef BGP
472 // master lost all slaves, need to handle traffic ourself
473 if (bgp_configured && had_peers && !have_peers)
474 bgp_enable_routing(1);
475 #endif /* BGP */
476 return;
477 }
478
479 // Wow. it's been ages since I last heard a heartbeat
480 // and I'm better than an of my peers so it's time
481 // to become a master!!!
482
483 config->cluster_iam_master = 1;
484 config->cluster_master_address = 0;
485
486 log(0,0,0,0, "I am declaring myself the master!\n");
487
488 #ifdef BGP
489 if (bgp_configured && have_peers)
490 bgp_enable_routing(0); /* stop handling traffic */
491 #endif /* BGP */
492
493 if (config->cluster_seq_number == -1)
494 config->cluster_seq_number = 0;
495
496 //
497 // Go through and mark all the tunnels as defined.
498 // Count the highest used tunnel number as well.
499 //
500 config->cluster_highest_tunnelid = 0;
501 for (i = 0, tcount = 0; i < MAXTUNNEL; ++i) {
502 if (tunnel[i].state == TUNNELUNDEF)
503 tunnel[i].state = TUNNELFREE;
504
505 if (tunnel[i].state != TUNNELFREE && i > config->cluster_highest_tunnelid)
506 config->cluster_highest_tunnelid = i;
507 }
508
509 //
510 // Go through and mark all the sessions as being defined.
511 // reset the idle timeouts.
512 // add temporary byte counters to permanent ones.
513 // Re-string the free list.
514 // Find the ID of the highest session.
515 last_free = 0;
516 high_sid = 0;
517 config->cluster_highest_sessionid = 0;
518 for (i = 0, count = 0; i < MAXSESSION; ++i) {
519 if (session[i].tunnel == T_UNDEF) {
520 session[i].tunnel = T_FREE;
521 ++count;
522 }
523
524 if (session[i].tunnel == T_FREE) { // Unused session. Add to free list.
525 session[last_free].next = i;
526 session[i].next = 0;
527 last_free = i;
528 }
529
530 // Reset all the idle timeouts..
531 session[i].last_packet = time_now;
532
533 // Accumulate un-sent byte counters.
534 session[i].cin += sess_count[i].cin;
535 session[i].cout += sess_count[i].cout;
536 session[i].total_cin += sess_count[i].cin;
537 session[i].total_cout += sess_count[i].cout;
538
539 sess_count[i].cin = sess_count[i].cout = 0;
540
541 session[i].radius = 0; // Reset authentication as the radius blocks aren't up to date.
542
543 if (session[i].sid >= high_sid) // This is different to the index into the session table!!!
544 high_sid = session[i].sid+1;
545
546
547 session[i].tbf_in = session[i].tbf_out = 0; // Remove stale pointers from old master.
548 throttle_session(i, session[i].throttle);
549
550 // I'm unsure about this. --mo
551 // It's potentially a good thing, but it could send a
552 // LOT of packets.
553 // if (session[i].throttle)
554 // cluster_send_session(s); // Tell the slaves about the new tbf indexes.
555
556 if (session[i].tunnel != T_FREE && i > config->cluster_highest_sessionid)
557 config->cluster_highest_sessionid = i;
558
559 }
560
561 session[last_free].next = 0; // End of chain.
562 last_sid = high_sid; // Keep track of the highest used session ID.
563
564 become_master();
565
566 rebuild_address_pool();
567
568 // If we're not the very first master, this is a big issue!
569 if(count>0)
570 log(0,0,0,0, "Warning: Fixed %d uninitialized sessions in becoming master!\n", count);
571
572 config->cluster_undefined_sessions = 0;
573 config->cluster_undefined_tunnels = 0;
574
575 //
576 // FIXME. We need to fix up the tunnel control message
577 // queue here! There's a number of other variables we
578 // should also update.
579 cluster_uptodate();
580 }
581
582
583 //
584 // Check that our session table is validly matching what the
585 // master has in mind.
586 //
587 // In particular, if we have too many sessions marked 'undefined'
588 // we fix it up here, and we ensure that the 'first free session'
589 // pointer is valid.
590 //
591 static void cluster_check_sessions(int highsession, int freesession_ptr, int hightunnel)
592 {
593 int i;
594
595 sessionfree = freesession_ptr; // Keep the freesession ptr valid.
596
597 if (config->cluster_iam_uptodate)
598 return;
599
600 if (highsession > config->cluster_undefined_sessions && hightunnel > config->cluster_undefined_tunnels)
601 return;
602
603 // Clear out defined sessions, counting the number of
604 // undefs remaining.
605 config->cluster_undefined_sessions = 0;
606 for (i = 1 ; i < MAXSESSION; ++i) {
607 if (i > highsession) {
608 session[i].tunnel = 0; // Defined.
609 continue;
610 }
611 if (session[i].tunnel != T_UNDEF)
612 continue;
613 ++config->cluster_undefined_sessions;
614 }
615
616 // Clear out defined tunnels, counting the number of
617 // undefs remaining.
618 config->cluster_undefined_tunnels = 0;
619 for (i = 1 ; i < MAXTUNNEL; ++i) {
620 if (i > hightunnel) {
621 tunnel[i].state = TUNNELFREE; // Defined.
622 continue;
623 }
624 if (tunnel[i].state != TUNNELUNDEF)
625 continue;
626 ++config->cluster_undefined_tunnels;
627 }
628
629
630 if (config->cluster_undefined_sessions || config->cluster_undefined_tunnels) {
631 log(2,0,0,0, "Cleared undefined sessions/tunnels. %d sess (high %d), %d tunn (high %d)\n",
632 config->cluster_undefined_sessions, highsession, config->cluster_undefined_tunnels, hightunnel);
633 return;
634 }
635
636 // Are we up to date?
637
638 if (!config->cluster_iam_uptodate)
639 cluster_uptodate();
640 }
641
642 int hb_add_type(char **p, int type, int id)
643 {
644 switch (type) {
645 case C_CSESSION: { // Compressed C_SESSION.
646 u8 c[sizeof(sessiont) * 2]; // Bigger than worst case.
647 u8 *d = (u8 *) &session[id];
648 u8 *orig = d;
649 int size;
650
651 size = rle_compress( &d, sizeof(sessiont), c, sizeof(c) );
652
653 // Did we compress the full structure, and is the size actually
654 // reduced??
655 if ( (d - orig) == sizeof(sessiont) && size < sizeof(sessiont) ) {
656 add_type(p, C_CSESSION, id, (char*) c, size);
657 break;
658 }
659 // Failed to compress : Fall through.
660 }
661 case C_SESSION: add_type(p, C_SESSION, id,
662 (char*) &session[id], sizeof(sessiont));
663 break;
664
665 case C_CTUNNEL: { // Compressed C_TUNNEL
666 u8 c[sizeof(tunnelt) * 2]; // Bigger than worst case.
667 u8 *d = (u8 *) &tunnel[id];
668 u8 *orig = d;
669 int size;
670
671 size = rle_compress( &d, sizeof(tunnelt), c, sizeof(c) );
672
673 // Did we compress the full structure, and is the size actually
674 // reduced??
675 if ( (d - orig) == sizeof(tunnelt) && size < sizeof(tunnelt) ) {
676 add_type(p, C_CTUNNEL, id, c, size);
677 break;
678 }
679 // Failed to compress : Fall through.
680 }
681 case C_TUNNEL: add_type(p, C_TUNNEL, id,
682 (char*) &tunnel[id], sizeof(tunnelt));
683 break;
684 default:
685 log(0,0,0,0, "Found an invalid type in heart queue! (%d)\n", type);
686 kill(0, SIGTERM);
687 }
688 return 0;
689 }
690
691 //
692 // Send a heartbeat, incidently sending out any queued changes..
693 //
694 void cluster_heartbeat(int highsession, int freesession, int hightunnel)
695 {
696 int i, count = 0, tcount = 0;
697 char buff[MAX_HEART_SIZE + sizeof(heartt) + sizeof(int) ];
698 heartt h;
699 char * p = buff;
700
701 if (!config->cluster_iam_master) // Only the master does this.
702 return;
703
704 hsess = highsession;
705 fsess = freesession;
706 // Fill out the heartbeat header.
707 h.version = HB_VERSION;
708 h.seq = config->cluster_seq_number;
709 h.basetime = basetime;
710 h.clusterid = config->bind_address; // Will this do??
711 h.basetime = basetime;
712 h.highsession = highsession;
713 h.freesession = freesession;
714 h.hightunnel = hightunnel;
715 h.size_sess = sizeof(sessiont); // Just in case.
716 h.size_tunn = sizeof(tunnelt);
717
718 add_type(&p, C_HEARTBEAT, HB_VERSION, (char*) &h, sizeof(h) );
719
720 for (i = 0; i < config->cluster_num_changes; ++i) {
721 hb_add_type(&p, cluster_changes[i].type, cluster_changes[i].id);
722 }
723
724 if (p > (buff + sizeof(buff))) { // Did we somehow manage to overun the buffer?
725 log(0,0,0,0, "FATAL: Overran the heartbeat buffer! This is fatal. Exiting. (size %d)\n", p - buff);
726 kill(0, SIGTERM);
727 }
728
729 //
730 // Fill out the packet with sessions from the session table...
731 // (not forgetting to leave space so we can get some tunnels in too )
732 while ( (p + sizeof(u32) * 2 + sizeof(sessiont) * 2 ) < (buff + MAX_HEART_SIZE) ) {
733
734 if (!walk_session_number) // session #0 isn't valid.
735 ++walk_session_number;
736
737 if (count >= highsession) // If we're a small cluster, don't go wild.
738 break;
739
740 hb_add_type(&p, C_CSESSION, walk_session_number);
741 walk_session_number = (1+walk_session_number)%(highsession+1); // +1 avoids divide by zero.
742
743 ++count; // Count the number of extra sessions we're sending.
744 }
745
746 //
747 // Fill out the packet with tunnels from the tunnel table...
748 // This effectively means we walk the tunnel table more quickly
749 // than the session table. This is good because stuffing up a
750 // tunnel is a much bigger deal than stuffing up a session.
751 //
752 while ( (p + sizeof(u32) * 2 + sizeof(tunnelt) ) < (buff + MAX_HEART_SIZE) ) {
753
754 if (!walk_tunnel_number) // tunnel #0 isn't valid.
755 ++walk_tunnel_number;
756
757 if (tcount >= config->cluster_highest_tunnelid)
758 break;
759
760 hb_add_type(&p, C_CTUNNEL, walk_tunnel_number);
761 walk_tunnel_number = (1+walk_tunnel_number)%(config->cluster_highest_tunnelid+1); // +1 avoids divide by zero.
762
763 ++tcount;
764 }
765
766 //
767 // Did we do something wrong?
768 if (p > (buff + sizeof(buff))) { // Did we somehow manage to overun the buffer?
769 log(0,0,0,0, "Overran the heartbeat buffer now! This is fatal. Exiting. (size %d)\n", p - buff);
770 kill(0, SIGTERM);
771 }
772
773 log(3,0,0,0, "Sending heartbeat with %d changes (%d x-sess, %d x-tunnels, %d highsess, %d hightun size %d)\n",
774 config->cluster_num_changes, count, tcount, config->cluster_highest_sessionid,
775 config->cluster_highest_tunnelid, (p-buff));
776
777 config->cluster_num_changes = 0;
778
779 send_heartbeat(h.seq, buff, (p-buff) ); // Send out the heartbeat to the cluster, keeping a copy of it.
780
781 config->cluster_seq_number = (config->cluster_seq_number+1)%HB_MAX_SEQ; // Next seq number to use.
782 }
783
784 //
785 // A structure of type 'type' has changed; Add it to the queue to send.
786 //
787 int type_changed(int type, int id)
788 {
789 int i;
790
791 for (i = 0 ; i < config->cluster_num_changes ; ++i)
792 if ( cluster_changes[i].id == id &&
793 cluster_changes[i].type == type)
794 return 0; // Already marked for change.
795
796 cluster_changes[i].type = type;
797 cluster_changes[i].id = id;
798 ++config->cluster_num_changes;
799
800 if (config->cluster_num_changes > MAX_CHANGES)
801 cluster_heartbeat(config->cluster_highest_sessionid, fsess, config->cluster_highest_tunnelid);
802
803 return 1;
804 }
805
806
807 // A particular session has been changed!
808 int cluster_send_session(int sid)
809 {
810 if (!config->cluster_iam_master) {
811 log(0,0,sid,0, "I'm not a master, but I just tried to change a session!\n");
812 return -1;
813 }
814
815 return type_changed(C_CSESSION, sid);
816 }
817
818 // A particular tunnel has been changed!
819 int cluster_send_tunnel(int tid)
820 {
821 if (!config->cluster_iam_master) {
822 log(0,0,0,tid, "I'm not a master, but I just tried to change a tunnel!\n");
823 return -1;
824 }
825
826 return type_changed(C_CTUNNEL, tid);
827 }
828
829
830 //
831 // We're a master, and a slave has just told us that it's
832 // missed a packet. We'll resend it every packet since
833 // the last one it's seen.
834 //
835 int cluster_catchup_slave(int seq, u32 slave)
836 {
837 int s;
838 int diff;
839
840 log(1,0,0,0, "Slave %s sent LASTSEEN with seq %d\n", inet_toa(slave), seq);
841
842 diff = config->cluster_seq_number - seq; // How many packet do we need to send?
843 if (diff < 0)
844 diff += HB_MAX_SEQ;
845
846 if (diff >= HB_HISTORY_SIZE) { // Ouch. We don't have the packet to send it!
847 log(0,0,0,0, "A slaved asked for message %d when our seq number is %d. Killing it.\n",
848 seq, config->cluster_seq_number);
849 return peer_send_message(slave, C_KILL, seq, NULL, 0);// Kill the slave. Nothing else to do.
850 }
851
852 // Now resend every packet that it missed, in order.
853 while (seq != config->cluster_seq_number) {
854 s = seq%HB_HISTORY_SIZE;
855 if (seq != past_hearts[s].seq) {
856 log(0,0,0,0, "Tried to re-send heartbeat for %s but %d doesn't match %d! (%d,%d)\n",
857 inet_toa(slave), seq, past_hearts[s].seq, s, config->cluster_seq_number);
858 return -1; // What to do here!?
859 }
860 peer_send_data(slave, past_hearts[s].data, past_hearts[s].size);
861 seq = (seq+1)%HB_MAX_SEQ; // Increment to next seq number.
862 }
863 return 0; // All good!
864 }
865
866 //
867 // We've heard from another peer! Add it to the list
868 // that we select from at election time.
869 //
870 int cluster_add_peer(u32 peer, time_t basetime, pingt *p)
871 {
872 int i;
873 u32 clusterid;
874
875 clusterid = p->addr;
876 if (clusterid != config->bind_address)
877 {
878 // Is this for us?
879 log(4,0,0,0, "Skipping ping from %s (different cluster)\n", inet_toa(peer));
880 return 0;
881 }
882
883 // Is this the master shutting down??
884 if (peer == config->cluster_master_address && !basetime) {
885 config->cluster_master_address = 0;
886 config->cluster_last_hb = 0; // Force an election.
887 cluster_check_master();
888 return 0;
889 }
890
891 for (i = 0; i < num_peers ; ++i)
892 {
893 if (peers[i].peer != peer)
894 continue;
895
896 // This peer already exists. Just update the timestamp.
897 peers[i].basetime = basetime;
898 peers[i].timestamp = TIME;
899 break;
900 }
901
902 if (i >= num_peers)
903 {
904 log(4,0,0,0, "Adding %s as a peer\n", inet_toa(peer));
905
906 // Not found. Is there a stale slot to re-use?
907 for (i = 0; i < num_peers ; ++i)
908 {
909 if (peers[i].peer != peer)
910 continue;
911 if ((peers[i].timestamp + config->cluster_hb_timeout * 10) < TIME) // Stale.
912 break;
913 }
914
915 if (i >= CLUSTER_MAX_SIZE)
916 {
917 // Too many peers!!
918 log(0,0,0,0, "Tried to add %s as a peer, but I already have %d of them!\n", inet_toa(peer), i);
919 return -1;
920 }
921
922 peers[i].peer = peer;
923 peers[i].basetime = basetime;
924 peers[i].timestamp = TIME;
925 if (i == num_peers)
926 ++num_peers;
927
928 log(1,0,0,0, "Added %s as a new peer. Now %d peers\n", inet_toa(peer), num_peers);
929 }
930
931 #ifdef BGP
932 /* drop routes if we've now got a peer */
933 if (bgp_configured && config->cluster_iam_master && !have_peers)
934 bgp_enable_routing(0);
935 #endif /* BGP */
936
937 have_peers = 1;
938
939 return 1;
940 }
941
942 /* Handle the slave updating the byte counters for the master. */
943 //
944 // Note that we don't mark the session as dirty; We rely on
945 // the slow table walk to propogate this back out to the slaves.
946 //
947 int cluster_handle_bytes(char * data, int size)
948 {
949 bytest * b;
950
951 b = (bytest*) data;
952
953 log(3,0,0,0, "Got byte counter update (size %d)\n", size);
954
955 /* Loop around, adding the byte
956 counts to each of the sessions. */
957
958 while (size >= sizeof(*b) ) {
959 if (b->sid > MAXSESSION) {
960 log(0,0,0,0, "Got C_BYTES with session #%d!\n", b->sid);
961 return -1; /* Abort processing */
962 }
963
964 session[b->sid].total_cin += b->in;
965 session[b->sid].total_cout += b->out;
966
967 session[b->sid].cin += b->in;
968 session[b->sid].cout += b->out;
969 session[b->sid].last_packet = time_now; // Reset idle timer!
970
971 size -= sizeof(*b);
972 ++b;
973 }
974
975 if (size != 0)
976 log(0,0,0,0, "Got C_BYTES with %d bytes of trailing junk!\n", size);
977
978 return size;
979 }
980
981 //
982 // Handle receiving a session structure in a heartbeat packet.
983 //
984 static int cluster_recv_session(int more , u8 * p)
985 {
986 if (more >= MAXSESSION) {
987 log(0,0,0,0, "DANGER: Received a heartbeat session id > MAXSESSION!\n");
988 return -1;
989 }
990
991 if (session[more].tunnel == T_UNDEF) {
992 if (config->cluster_iam_uptodate) { // Sanity.
993 log(0,0,0,0, "I thought I was uptodate but I just found an undefined session!\n");
994 } else {
995 --config->cluster_undefined_sessions;
996 }
997 }
998
999 load_session(more, (sessiont*) p); // Copy session into session table..
1000
1001 log(5,0,more,0, "Received session update (%d undef)\n", config->cluster_undefined_sessions);
1002
1003 if (!config->cluster_iam_uptodate)
1004 cluster_uptodate(); // Check to see if we're up to date.
1005 return 0;
1006 }
1007
1008 static int cluster_recv_tunnel(int more, u8 *p)
1009 {
1010 if (more >= MAXTUNNEL) {
1011 log(0,0,0,0, "DANGER: Received a tunnel session id > MAXTUNNEL!\n");
1012 return -1;
1013 }
1014
1015 if (tunnel[more].state == TUNNELUNDEF) {
1016 if (config->cluster_iam_uptodate) { // Sanity.
1017 log(0,0,0,0, "I thought I was uptodate but I just found an undefined tunnel!\n");
1018 } else {
1019 --config->cluster_undefined_tunnels;
1020 }
1021 }
1022
1023 memcpy(&tunnel[more], p, sizeof(tunnel[more]) );
1024
1025 //
1026 // Clear tunnel control messages. These are dynamically allocated.
1027 // If we get unlucky, this may cause the tunnel to drop!
1028 //
1029 tunnel[more].controls = tunnel[more].controle = NULL;
1030 tunnel[more].controlc = 0;
1031
1032 log(5,0,0,more, "Received tunnel update\n");
1033
1034 if (!config->cluster_iam_uptodate)
1035 cluster_uptodate(); // Check to see if we're up to date.
1036
1037 return 0;
1038 }
1039
1040
1041 //
1042 // Process a version one heartbeat..
1043 //
1044 static int cluster_process_heartbeat_v2(u8 * data, int size, int more, u8 * p, u32 addr)
1045 {
1046 heartt * h;
1047 int s = size - (p-data);
1048 int i, type;
1049
1050 if (more != HB_VERSION) {
1051 log(0,0,0,0, "Received a heartbeat version that I don't understand!\n");
1052 return -1; // Ignore it??
1053 }
1054 // Ok. It's a heartbeat packet from a cluster master!
1055 if (s < sizeof(*h))
1056 goto shortpacket;
1057
1058
1059 h = (heartt*) p;
1060 p += sizeof(*h);
1061 s -= sizeof(*h);
1062
1063 if (h->clusterid != config->bind_address)
1064 return -1; // It's not part of our cluster.
1065
1066 if (config->cluster_iam_master) { // Sanity...
1067 // Note that this MUST match the election process above!
1068
1069 log(0,0,0,0, "I just got a packet claiming to be from a master but _I_ am the master!\n");
1070 if (!h->basetime) {
1071 log(0,0,0,0, "Heartbeat from addr %s with zero basetime!\n", inet_toa(htonl(addr)) );
1072 return -1; // Skip it.
1073 }
1074 if (basetime > h->basetime) {
1075 log(0,0,0,0, "They're (%s) an older master than me so I'm gone!\n", inet_toa(htonl(addr)));
1076 kill(0, SIGTERM);
1077 }
1078 if (basetime == h->basetime && my_address < addr) { // Tie breaker.
1079 log(0,0,0,0, "They're a higher IP address than me, so I'm gone!\n");
1080 kill(0, SIGTERM);
1081 }
1082 return -1; // Skip it.
1083 }
1084
1085 if (config->cluster_seq_number == -1) // Don't have one. Just align to the master...
1086 config->cluster_seq_number = h->seq;
1087
1088 config->cluster_last_hb = TIME; // Reset to ensure that we don't become master!!
1089
1090 if (config->cluster_seq_number != h->seq) { // Out of sequence heartbeat!
1091 log(1,0,0,0, "HB: Got seq# %d but was expecting %d. asking for resend.\n", h->seq, config->cluster_seq_number);
1092
1093 peer_send_message(addr, C_LASTSEEN, config->cluster_seq_number, NULL, 0);
1094
1095 config->cluster_last_hb = TIME; // Reset to ensure that we don't become master!!
1096
1097 // Just drop the packet. The master will resend it as part of the catchup.
1098
1099 return 0;
1100 }
1101 // Save the packet in our buffer.
1102 // This is needed in case we become the master.
1103 config->cluster_seq_number = (h->seq+1)%HB_MAX_SEQ;
1104 i = h->seq % HB_HISTORY_SIZE;
1105 past_hearts[i].seq = h->seq;
1106 past_hearts[i].size = size;
1107 memcpy(&past_hearts[i].data, data, size); // Save it.
1108
1109
1110 // Check that we don't have too many undefined sessions, and
1111 // that the free session pointer is correct.
1112 cluster_check_sessions(h->highsession, h->freesession, h->hightunnel);
1113
1114 // Ok. process the packet...
1115 while ( s > 0) {
1116
1117 type = * ((u32*) p);
1118 p += sizeof(u32);
1119 s -= sizeof(u32);
1120
1121 more = * ((u32*) p);
1122 p += sizeof(u32);
1123 s -= sizeof(u32);
1124
1125 switch (type) {
1126 case C_CSESSION: { // Compressed session structure.
1127 u8 c [ sizeof(sessiont) + 2];
1128 int size;
1129 u8 * orig_p = p;
1130
1131 size = rle_decompress((u8 **) &p, s, c, sizeof(c) );
1132 s -= (p - orig_p);
1133
1134 if (size != sizeof(sessiont) ) { // Ouch! Very very bad!
1135 log(0,0,0,0, "DANGER: Received a CSESSION that didn't decompress correctly!\n");
1136 // Now what? Should exit! No-longer up to date!
1137 break;
1138 }
1139
1140 cluster_recv_session(more, c);
1141 break;
1142 }
1143 case C_SESSION:
1144 if ( s < sizeof(session[more]))
1145 goto shortpacket;
1146
1147 cluster_recv_session(more, p);
1148
1149 p += sizeof(session[more]);
1150 s -= sizeof(session[more]);
1151 break;
1152
1153 case C_CTUNNEL: { // Compressed tunnel structure.
1154 u8 c [ sizeof(tunnelt) + 2];
1155 int size;
1156 u8 * orig_p = p;
1157
1158 size = rle_decompress( (u8 **) &p, s, c, sizeof(c) );
1159 s -= (p - orig_p);
1160
1161 if (size != sizeof(tunnelt) ) { // Ouch! Very very bad!
1162 log(0,0,0,0, "DANGER: Received a CSESSION that didn't decompress correctly!\n");
1163 // Now what? Should exit! No-longer up to date!
1164 break;
1165 }
1166
1167 cluster_recv_tunnel(more, c);
1168 break;
1169
1170 }
1171 case C_TUNNEL:
1172 if ( s < sizeof(tunnel[more]))
1173 goto shortpacket;
1174
1175 cluster_recv_tunnel(more, p);
1176
1177 p += sizeof(tunnel[more]);
1178 s -= sizeof(tunnel[more]);
1179 break;
1180 default:
1181 log(0,0,0,0, "DANGER: I received a heartbeat element where I didn't understand the type! (%d)\n", type);
1182 return -1; // can't process any more of the packet!!
1183 }
1184 }
1185 if (config->cluster_master_address != addr)
1186 {
1187 char *str;
1188 str = strdup(inet_toa(config->cluster_master_address));
1189 log(0,0,0,0, "My master just changed from %s to %s!\n", str, inet_toa(addr));
1190 if (str) free(str);
1191 }
1192
1193 config->cluster_master_address = addr;
1194 config->cluster_last_hb = TIME; // Successfully received a heartbeat!
1195 return 0;
1196
1197 shortpacket:
1198 log(0,0,0,0, "I got an incomplete heartbeat packet! This means I'm probably out of sync!!\n");
1199 return -1;
1200 }
1201
1202 //
1203 // We got a packet on the cluster port!
1204 // Handle pings, lastseens, and heartbeats!
1205 //
1206 int processcluster(char * data, int size, u32 addr)
1207 {
1208 int type, more;
1209 char * p = data;
1210 int s = size;
1211
1212 if (addr == my_address)
1213 return -1; // Ignore it. Something looped back the multicast!
1214
1215 log(5,0,0,0, "Process cluster: %d bytes from %s\n", size, inet_toa(addr));
1216
1217 if (s <= 0) // Any data there??
1218 return -1;
1219
1220 if (s < 8)
1221 goto shortpacket;
1222
1223 type = * ((u32*) p);
1224 p += sizeof(u32);
1225 s -= sizeof(u32);
1226
1227 more = * ((u32*) p);
1228 p += sizeof(u32);
1229 s -= sizeof(u32);
1230
1231 switch (type) {
1232 case C_PING: // Update the peers table.
1233 return cluster_add_peer(addr, more, (pingt*)p);
1234
1235 case C_LASTSEEN: // Catch up a slave (slave missed a packet).
1236 return cluster_catchup_slave(more, addr);
1237
1238 case C_FORWARD: { // Forwarded control packet. pass off to processudp.
1239 struct sockaddr_in a;
1240 a.sin_addr.s_addr = more;
1241
1242 a.sin_port = * (int*) p;
1243 s -= sizeof(int);
1244 p += sizeof(int);
1245
1246 if (!config->cluster_iam_master) { // huh?
1247 log(0,0,0,0, "I'm not the master, but I got a C_FORWARD from %s?\n", inet_toa(addr));
1248 return -1;
1249 }
1250
1251 log(4,0,0,0, "Got a forwarded packet... (%s:%d)\n", inet_toa(more), a.sin_port);
1252 STAT(recv_forward);
1253 processudp(p, s, &a);
1254 return 0;
1255 }
1256 case C_THROTTLE: { // Receive a forwarded packet from a slave.
1257 if (!config->cluster_iam_master) {
1258 log(0,0,0,0, "I'm not the master, but I got a C_THROTTLE from %s?\n", inet_toa(addr));
1259 return -1;
1260 }
1261
1262 tbf_queue_packet(more, p, s); // The TBF id tells wether it goes in or out.
1263 return 0;
1264 }
1265 case C_GARDEN:
1266 // Receive a walled garden packet from a slave.
1267 if (!config->cluster_iam_master) {
1268 log(0,0,0,0, "I'm not the master, but I got a C_GARDEN from %s?\n", inet_toa(addr));
1269 return -1;
1270 }
1271
1272 tun_write(p, s);
1273 return 0;
1274
1275 case C_BYTES:
1276 return cluster_handle_bytes(p, s);
1277
1278 case C_KILL: // The master asked us to die!? (usually because we're too out of date).
1279 if (config->cluster_iam_master) {
1280 log(0,0,0,0, "_I_ am master, but I received a C_KILL from %s! (Seq# %d)\n", inet_toa(addr), more);
1281 return -1;
1282 }
1283 if (more != config->cluster_seq_number) {
1284 log(0,0,0,0, "The master asked us to die but the seq number didn't match!?\n");
1285 return -1;
1286 }
1287
1288 if (addr != config->cluster_master_address) {
1289 log(0,0,0,0, "Received a C_KILL from %s which doesn't match config->cluster_master_address (%x)\n",
1290 inet_toa(addr), config->cluster_master_address);
1291 // We can only warn about it. The master might really have switched!
1292 }
1293
1294 log(0,0,0,0, "Received a valid C_KILL: I'm going to die now.\n");
1295 kill(0, SIGTERM);
1296 exit(0); // Lets be paranoid;
1297 return -1; // Just signalling the compiler.
1298
1299 case C_HEARTBEAT:
1300 log(4,0,0,0, "Got a heartbeat from %s\n", inet_toa(addr));
1301
1302 return cluster_process_heartbeat_v2(data, size, more, p, addr);
1303
1304 default:
1305 log(0,0,0,0, "Strange type packet received on cluster socket (%d)\n", type);
1306 return -1;
1307 }
1308 return 0;
1309 shortpacket:
1310 log(0,0,0,0, "I got an cluster heartbeat packet! This means I'm probably out of sync!!\n");
1311 return -1;
1312 }
1313
1314 //====================================================================================================
1315
1316 int cmd_show_cluster(struct cli_def *cli, char *command, char **argv, int argc)
1317 {
1318 int i;
1319
1320 if (CLI_HELP_REQUESTED)
1321 return CLI_HELP_NO_ARGS;
1322
1323 cli_print(cli, "Cluster status : %s", config->cluster_iam_master ? "Master" : "Slave" );
1324 cli_print(cli, "My address : %s", inet_toa(my_address));
1325 cli_print(cli, "VIP address : %s", inet_toa(config->bind_address));
1326 cli_print(cli, "Multicast address: %s", inet_toa(config->cluster_address));
1327 cli_print(cli, "Multicast i'face : %s", config->cluster_interface);
1328
1329 if (!config->cluster_iam_master) {
1330 cli_print(cli, "My master : %s (last heartbeat %.1f seconds old)",
1331 config->cluster_master_address ? inet_toa(config->cluster_master_address) : "Not defined",
1332 0.1 * (TIME - config->cluster_last_hb));
1333 cli_print(cli, "Uptodate : %s", config->cluster_iam_uptodate ? "Yes" : "No");
1334 cli_print(cli, "Next sequence number expected: %d", config->cluster_seq_number);
1335 cli_print(cli, "%d sessions undefined of %d", config->cluster_undefined_sessions, config->cluster_highest_sessionid);
1336 cli_print(cli, "%d tunnels undefined of %d", config->cluster_undefined_tunnels, config->cluster_highest_tunnelid);
1337 } else {
1338 cli_print(cli, "Next heartbeat # : %d", config->cluster_seq_number);
1339 cli_print(cli, "Highest session : %d", config->cluster_highest_sessionid);
1340 cli_print(cli, "Highest tunnel : %d", config->cluster_highest_tunnelid);
1341 cli_print(cli, "%d changes queued for sending", config->cluster_num_changes);
1342 }
1343 cli_print(cli, "%d peers.", num_peers);
1344
1345 if (num_peers)
1346 cli_print(cli, "%20s %10s %8s", "Address", "Basetime", "Age");
1347 for (i = 0; i < num_peers; ++i) {
1348 cli_print(cli, "%20s %10d %8d", inet_toa(peers[i].peer),
1349 peers[i].basetime, TIME - peers[i].timestamp);
1350 }
1351 return CLI_OK;
1352 }
1353
1354 //
1355 // Simple run-length-encoding compression.
1356 // Format is
1357 // 1 byte < 128 = count of non-zero bytes following. // Not legal to be zero.
1358 // n non-zero bytes;
1359 // or
1360 // 1 byte > 128 = (count - 128) run of zero bytes. //
1361 // repeat.
1362 // count == 0 indicates end of compressed stream.
1363 //
1364 // Compress from 'src' into 'dst'. return number of bytes
1365 // used from 'dst'.
1366 // Updates *src_p to indicate 1 past last bytes used.
1367 //
1368 // We could get an extra byte in the zero runs by storing (count-1)
1369 // but I'm playing it safe.
1370 //
1371 // Worst case is a 50% expansion in space required (trying to
1372 // compress { 0x00, 0x01 } * N )
1373 int rle_compress(u8 ** src_p, int ssize, u8 *dst, int dsize)
1374 {
1375 int count;
1376 int orig_dsize = dsize;
1377 u8 * x,*src;
1378 src = *src_p;
1379
1380 while (ssize > 0 && dsize > 2) {
1381 count = 0;
1382 x = dst++; --dsize; // Reserve space for count byte..
1383
1384 if (*src) { // Copy a run of non-zero bytes.
1385 while (*src && count < 127 && ssize > 0 && dsize > 1) { // Count number of non-zero bytes.
1386 *dst++ = *src++;
1387 --dsize; --ssize;
1388 ++count;
1389 }
1390 *x = count; // Store number of non-zero bytes. Guarenteed to be non-zero!
1391
1392 } else { // Compress a run of zero bytes.
1393 while (*src == 0 && count < 127 && ssize > 0) {
1394 ++src;
1395 --ssize;
1396 ++count;
1397 }
1398 *x = count | 0x80 ;
1399 }
1400 }
1401
1402 *dst++ = 0x0; // Add Stop byte.
1403 --dsize;
1404
1405 *src_p = src;
1406 return (orig_dsize - dsize);
1407 }
1408
1409 //
1410 // Decompress the buffer into **p.
1411 // 'psize' is the size of the decompression buffer available.
1412 //
1413 // Returns the number of bytes decompressed.
1414 //
1415 // Decompresses from '*src_p' into 'dst'.
1416 // Return the number of dst bytes used.
1417 // Updates the 'src_p' pointer to point to the
1418 // first un-used byte.
1419 int rle_decompress(u8 ** src_p, int ssize, u8 *dst, int dsize)
1420 {
1421 int count;
1422 int orig_dsize = dsize;
1423 char * src = *src_p;
1424
1425 while (ssize >0 && dsize > 0) { // While there's more to decompress, and there's room in the decompress buffer...
1426 count = *src++; --ssize; // get the count byte from the source.
1427 if (count == 0x0) // End marker reached? If so, finish.
1428 break;
1429
1430 if (count & 0x80) { // Decompress a run of zeros
1431 for (count &= 0x7f ; count > 0 && dsize > 0; --count) {
1432 *dst++ = 0x0;
1433 --dsize;
1434 }
1435 } else { // Copy run of non-zero bytes.
1436 for ( ; count > 0 && ssize && dsize; --count) { // Copy non-zero bytes across.
1437 *dst++ = *src++;
1438 --ssize; --dsize;
1439 }
1440 }
1441 }
1442 *src_p = src;
1443 return (orig_dsize - dsize);
1444 }