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/cvs/gvpe/src/vpn.C
Revision: 1.7
Committed: Sun Apr 6 18:12:18 2003 UTC (21 years, 1 month ago) by pcg
Content type: text/plain
Branch: MAIN
Changes since 1.6: +18 -17 lines
Log Message:
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File Contents

# Content
1 /*
2 vpn.C -- handle the protocol, encryption, handshaking etc.
3
4 This program is free software; you can redistribute it and/or modify
5 it under the terms of the GNU General Public License as published by
6 the Free Software Foundation; either version 2 of the License, or
7 (at your option) any later version.
8
9 This program is distributed in the hope that it will be useful,
10 but WITHOUT ANY WARRANTY; without even the implied warranty of
11 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
12 GNU General Public License for more details.
13
14 You should have received a copy of the GNU General Public License
15 along with this program; if not, write to the Free Software
16 Foundation, Inc. 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
17 */
18
19 #include "config.h"
20
21 #include <list>
22
23 #include <cstdlib>
24 #include <cstring>
25 #include <cstdio>
26
27 #include <sys/types.h>
28 #include <sys/socket.h>
29 #include <sys/poll.h>
30 #include <sys/wait.h>
31 #include <netinet/in.h>
32 #include <arpa/inet.h>
33 #include <errno.h>
34 #include <time.h>
35 #include <unistd.h>
36
37 #include "pidfile.h"
38
39 #include "connection.h"
40 #include "util.h"
41 #include "vpn.h"
42
43 /////////////////////////////////////////////////////////////////////////////
44
45 const char *vpn::script_if_up ()
46 {
47 // the tunnel device mtu should be the physical mtu - overhead
48 // the tricky part is rounding to the cipher key blocksize
49 int mtu = conf.mtu - ETH_OVERHEAD - VPE_OVERHEAD - MAX_OVERHEAD;
50 mtu += ETH_OVERHEAD - 6 - 6; // now we have the data portion
51 mtu -= mtu % EVP_CIPHER_block_size (CIPHER); // round
52 mtu -= ETH_OVERHEAD - 6 - 6; // and get interface mtu again
53
54 char *env;
55 asprintf (&env, "CONFBASE=%s", confbase);
56 putenv (env);
57 asprintf (&env, "NODENAME=%s", THISNODE->nodename);
58 putenv (env);
59 asprintf (&env, "NODEID=%d", THISNODE->id);
60 putenv (env);
61 asprintf (&env, "IFNAME=%s", tap->interface ());
62 putenv (env);
63 asprintf (&env, "MTU=%d", mtu);
64 putenv (env);
65 asprintf (&env, "MAC=%02x:%02x:%02x:%02x:%02x:%02x",
66 0xfe, 0xfd, 0x80, 0x00, THISNODE->id >> 8,
67 THISNODE->id & 0xff);
68 putenv (env);
69
70 return ::conf.script_if_up ? ::conf.script_if_up : "if-up";
71 }
72
73 int
74 vpn::setup ()
75 {
76 udpv4_fd = -1;
77
78 if (THISNODE->protocols & PROT_UDPv4)
79 {
80 udpv4_fd = socket (PF_INET, SOCK_DGRAM, IPPROTO_UDP);
81
82 if (udpv4_fd < 0)
83 return -1;
84
85 // standard daemon practise...
86 {
87 int oval = 1;
88 setsockopt (udpv4_fd, SOL_SOCKET, SO_REUSEADDR, &oval, sizeof oval);
89 }
90
91 sockinfo si (THISNODE, PROT_UDPv4);
92
93 if (bind (udpv4_fd, si.sav4 (), si.salenv4 ()))
94 {
95 slog (L_ERR, _("can't bind udpv4 on %s: %s"), (const char *)si, strerror (errno));
96 exit (1);
97 }
98
99 #ifdef IP_MTU_DISCOVER
100 // this I really consider a linux bug. I am neither connected
101 // nor do I fragment myself. Linux still sets DF and doesn't
102 // fragment for me sometimes.
103 {
104 int oval = IP_PMTUDISC_DONT;
105 setsockopt (udpv4_fd, SOL_IP, IP_MTU_DISCOVER, &oval, sizeof oval);
106 }
107 #endif
108
109 udpv4_ev_watcher.start (udpv4_fd, POLLIN);
110 }
111
112 ipv4_fd = -1;
113 if (THISNODE->protocols & PROT_IPv4)
114 {
115 ipv4_fd = socket (PF_INET, SOCK_RAW, ::conf.ip_proto);
116
117 if (ipv4_fd < 0)
118 return -1;
119
120 sockinfo si (THISNODE, PROT_IPv4);
121
122 if (bind (ipv4_fd, si.sav4 (), si.salenv4 ()))
123 {
124 slog (L_ERR, _("can't bind ipv4 socket on %s: %s"), (const char *)si, strerror (errno));
125 exit (1);
126 }
127
128 #ifdef IP_MTU_DISCOVER
129 // this I really consider a linux bug. I am neither connected
130 // nor do I fragment myself. Linux still sets DF and doesn't
131 // fragment for me sometimes.
132 {
133 int oval = IP_PMTUDISC_DONT;
134 setsockopt (ipv4_fd, SOL_IP, IP_MTU_DISCOVER, &oval, sizeof oval);
135 }
136 #endif
137
138 ipv4_ev_watcher.start (ipv4_fd, POLLIN);
139 }
140
141 #if ENABLE_TCP
142 if (THISNODE->protocols & PROT_TCPv4)
143 {
144 tcpv4_fd = socket (PF_INET, SOCK_STREAM, IPPROTO_TCP);
145
146 if (tcpv4_fd < 0)
147 return -1;
148
149 // standard daemon practise...
150 {
151 int oval = 1;
152 setsockopt (tcpv4_fd, SOL_SOCKET, SO_REUSEADDR, &oval, sizeof oval);
153 }
154
155 sockinfo si (THISNODE, PROT_TCPv4);
156
157 if (bind (tcpv4_fd, si.sav4 (), si.salenv4 ()))
158 {
159 slog (L_ERR, _("can't bind tcpv4 on %s: %s"), (const char *)si, strerror (errno));
160 exit (1);
161 }
162
163 if (listen (tcpv4_fd, 5))
164 {
165 slog (L_ERR, _("can't listen tcpv4 on %s: %s"), (const char *)si, strerror (errno));
166 exit (1);
167 }
168
169 tcpv4_ev_watcher.start (tcpv4_fd, POLLIN);
170 }
171 #endif
172
173 tap = new tap_device ();
174 if (!tap) //D this, of course, never catches
175 {
176 slog (L_ERR, _("cannot create network interface '%s'"), conf.ifname);
177 exit (1);
178 }
179
180 run_script (run_script_cb (this, &vpn::script_if_up), true);
181
182 tap_ev_watcher.start (tap->fd, POLLIN);
183
184 reconnect_all ();
185
186 return 0;
187 }
188
189 // send a vpn packet out to other hosts
190 bool
191 vpn::send_vpn_packet (vpn_packet *pkt, const sockinfo &si, int tos)
192 {
193 switch (si.prot)
194 {
195 case PROT_IPv4:
196 return send_ipv4_packet (pkt, si, tos);
197
198 case PROT_UDPv4:
199 return send_udpv4_packet (pkt, si, tos);
200
201 #if ENABLE_TCP
202 case PROT_TCPv4:
203 return send_tcpv4_packet (pkt, si, tos);
204 #endif
205
206 default:
207 slog (L_CRIT, _("%s: FATAL: trying to send packet with unsupported protocol"), (const char *)si);
208 return false;
209 }
210 }
211
212 bool
213 vpn::send_ipv4_packet (vpn_packet *pkt, const sockinfo &si, int tos)
214 {
215 setsockopt (ipv4_fd, SOL_IP, IP_TOS, &tos, sizeof tos);
216 sendto (ipv4_fd, &((*pkt)[0]), pkt->len, 0, si.sav4 (), si.salenv4 ());
217
218 return true;
219 }
220
221 bool
222 vpn::send_udpv4_packet (vpn_packet *pkt, const sockinfo &si, int tos)
223 {
224 setsockopt (udpv4_fd, SOL_IP, IP_TOS, &tos, sizeof tos);
225 sendto (udpv4_fd, &((*pkt)[0]), pkt->len, 0, si.sav4 (), si.salenv4 ());
226
227 return true;
228 }
229
230 void
231 vpn::recv_vpn_packet (vpn_packet *pkt, const sockinfo &rsi)
232 {
233 unsigned int src = pkt->src ();
234 unsigned int dst = pkt->dst ();
235
236 slog (L_NOISE, _("<<?/%s received possible vpn packet type %d from %d to %d, length %d"),
237 (const char *)rsi, pkt->typ (), pkt->src (), pkt->dst (), pkt->len);
238
239 if (src == 0 || src > conns.size ()
240 || dst > conns.size ()
241 || pkt->typ () >= vpn_packet::PT_MAX)
242 slog (L_WARN, _("(%s): received corrupted packet type %d (src %d, dst %d)"),
243 (const char *)rsi, pkt->typ (), pkt->src (), pkt->dst ());
244 else if (dst > conns.size ())
245 slog (L_WARN, _("(%s): received corrupted packet type %d (src %d, dst %d)"),
246 (const char *)rsi, pkt->typ (), pkt->src (), pkt->dst ());
247 else
248 {
249 connection *c = conns[src - 1];
250
251 if (dst == 0 && !THISNODE->routerprio)
252 slog (L_WARN, _("%s(%s): received broadcast, but we are no router"),
253 c->conf->nodename, (const char *)rsi);
254 else if (dst != 0 && dst != THISNODE->id)
255 {
256 if (THISNODE->routerprio)
257 // the tos setting gets lost here. who cares.
258 conns[dst - 1]->inject_vpn_packet (pkt);
259 else
260 slog (L_WARN,
261 _("%s(%s): forwarding request (=> %s), but we are no router"),
262 c->conf->nodename, (const char *)rsi,
263 conns[dst - 1]->conf->nodename);
264 }
265 else
266 c->recv_vpn_packet (pkt, rsi);
267 }
268 }
269
270 void
271 vpn::udpv4_ev (io_watcher &w, short revents)
272 {
273 if (revents & (POLLIN | POLLERR))
274 {
275 vpn_packet *pkt = new vpn_packet;
276 struct sockaddr_in sa;
277 socklen_t sa_len = sizeof (sa);
278 int len;
279
280 len = recvfrom (w.fd, &((*pkt)[0]), MAXSIZE, 0, (sockaddr *)&sa, &sa_len);
281
282 sockinfo si(sa, PROT_UDPv4);
283
284 if (len > 0)
285 {
286 pkt->len = len;
287
288 recv_vpn_packet (pkt, si);
289 }
290 else
291 {
292 // probably ECONNRESET or somesuch
293 slog (L_DEBUG, _("%s: fd %d, %s"), (const char *)si, w.fd, strerror (errno));
294 }
295
296 delete pkt;
297 }
298 else if (revents & POLLHUP)
299 {
300 // this cannot ;) happen on udp sockets
301 slog (L_ERR, _("FATAL: POLLHUP on udp v4 fd, terminating."));
302 exit (1);
303 }
304 else
305 {
306 slog (L_ERR,
307 _("FATAL: unknown revents %08x in socket, terminating\n"),
308 revents);
309 exit (1);
310 }
311 }
312
313 void
314 vpn::ipv4_ev (io_watcher &w, short revents)
315 {
316 if (revents & (POLLIN | POLLERR))
317 {
318 vpn_packet *pkt = new vpn_packet;
319 struct sockaddr_in sa;
320 socklen_t sa_len = sizeof (sa);
321 int len;
322
323 len = recvfrom (w.fd, &((*pkt)[0]), MAXSIZE, 0, (sockaddr *)&sa, &sa_len);
324
325 sockinfo si(sa, PROT_IPv4);
326
327 if (len > 0)
328 {
329 pkt->len = len;
330
331 // raw sockets deliver the ipv4, but don't expect it on sends
332 // this is slow, but...
333 pkt->skip_hdr (IP_OVERHEAD);
334
335 recv_vpn_packet (pkt, si);
336 }
337 else
338 {
339 // probably ECONNRESET or somesuch
340 slog (L_DEBUG, _("%s: %s"), (const char *)si, strerror (errno));
341 }
342
343 delete pkt;
344 }
345 else if (revents & POLLHUP)
346 {
347 // this cannot ;) happen on udp sockets
348 slog (L_ERR, _("FATAL: POLLHUP on ipv4 fd, terminating."));
349 exit (1);
350 }
351 else
352 {
353 slog (L_ERR,
354 _("FATAL: unknown revents %08x in socket, terminating\n"),
355 revents);
356 exit (1);
357 }
358 }
359
360 void
361 vpn::tap_ev (io_watcher &w, short revents)
362 {
363 if (revents & POLLIN)
364 {
365 /* process data */
366 tap_packet *pkt;
367
368 pkt = tap->recv ();
369
370 int dst = mac2id (pkt->dst);
371 int src = mac2id (pkt->src);
372
373 if (src != THISNODE->id)
374 {
375 slog (L_ERR, _("FATAL: tap packet not originating on current node received, terminating."));
376 exit (1);
377 }
378
379 if (dst == THISNODE->id)
380 {
381 slog (L_ERR, _("FATAL: tap packet destined for current node received, terminating."));
382 exit (1);
383 }
384
385 if (dst > conns.size ())
386 slog (L_ERR, _("tap packet for unknown node %d received, ignoring."), dst);
387 else
388 {
389 if (dst)
390 {
391 // unicast
392 if (dst != THISNODE->id)
393 conns[dst - 1]->inject_data_packet (pkt);
394 }
395 else
396 {
397 // broadcast, first check router, then self, then english
398 connection *router = find_router ();
399
400 if (router)
401 router->inject_data_packet (pkt, true);
402 else
403 for (conns_vector::iterator c = conns.begin (); c != conns.end (); ++c)
404 if ((*c)->conf != THISNODE)
405 (*c)->inject_data_packet (pkt);
406 }
407 }
408
409 delete pkt;
410 }
411 else if (revents & (POLLHUP | POLLERR))
412 {
413 slog (L_ERR, _("FATAL: POLLHUP or POLLERR on network device fd, terminating."));
414 exit (1);
415 }
416 else
417 abort ();
418 }
419
420 void
421 vpn::event_cb (time_watcher &w)
422 {
423 if (events)
424 {
425 if (events & EVENT_SHUTDOWN)
426 {
427 slog (L_INFO, _("preparing shutdown..."));
428
429 shutdown_all ();
430
431 remove_pid (pidfilename);
432
433 slog (L_INFO, _("terminating"));
434
435 exit (0);
436 }
437
438 if (events & EVENT_RECONNECT)
439 {
440 slog (L_INFO, _("forced reconnect"));
441
442 reconnect_all ();
443 }
444
445 events = 0;
446 }
447
448 w.at = TSTAMP_CANCEL;
449 }
450
451 void
452 vpn::shutdown_all ()
453 {
454 for (conns_vector::iterator c = conns.begin (); c != conns.end (); ++c)
455 (*c)->shutdown ();
456 }
457
458 void
459 vpn::reconnect_all ()
460 {
461 for (conns_vector::iterator c = conns.begin (); c != conns.end (); ++c)
462 delete *c;
463
464 conns.clear ();
465
466 connection_init ();
467
468 for (configuration::node_vector::iterator i = conf.nodes.begin ();
469 i != conf.nodes.end (); ++i)
470 {
471 connection *conn = new connection (this);
472
473 conn->conf = *i;
474 conns.push_back (conn);
475
476 conn->establish_connection ();
477 }
478 }
479
480 connection *vpn::find_router ()
481 {
482 u32 prio = 0;
483 connection *router = 0;
484
485 for (conns_vector::iterator i = conns.begin (); i != conns.end (); ++i)
486 {
487 connection *c = *i;
488
489 if (c->conf->routerprio > prio
490 && c->connectmode == conf_node::C_ALWAYS
491 && c->conf != THISNODE
492 && c->ictx && c->octx)
493 {
494 prio = c->conf->routerprio;
495 router = c;
496 }
497 }
498
499 return router;
500 }
501
502 void vpn::send_connect_request (int id)
503 {
504 connection *c = find_router ();
505
506 if (c)
507 c->send_connect_request (id);
508 else
509 // no router found, aggressively connect to all routers
510 for (conns_vector::iterator i = conns.begin (); i != conns.end (); ++i)
511 if ((*i)->conf->routerprio)
512 (*i)->establish_connection ();
513 }
514
515 void
516 connection::dump_status ()
517 {
518 slog (L_NOTICE, _("node %s (id %d)"), conf->nodename, conf->id);
519 slog (L_NOTICE, _(" connectmode %d (%d) / sockaddr %s / minor %d"),
520 connectmode, conf->connectmode, (const char *)si, (int)prot_minor);
521 slog (L_NOTICE, _(" ictx/octx %08lx/%08lx / oseqno %d / retry_cnt %d"),
522 (long)ictx, (long)octx, (int)oseqno, (int)retry_cnt);
523 slog (L_NOTICE, _(" establish_conn %ld / rekey %ld / keepalive %ld"),
524 (long)(establish_connection.at), (long)(rekey.at), (long)(keepalive.at));
525 }
526
527 void
528 vpn::dump_status ()
529 {
530 slog (L_NOTICE, _("BEGIN status dump (%ld)"), (long)NOW);
531
532 for (conns_vector::iterator c = conns.begin (); c != conns.end (); ++c)
533 (*c)->dump_status ();
534
535 slog (L_NOTICE, _("END status dump"));
536 }
537
538 vpn::vpn (void)
539 : event(this, &vpn::event_cb)
540 , udpv4_ev_watcher(this, &vpn::udpv4_ev)
541 , ipv4_ev_watcher (this, &vpn::ipv4_ev)
542 , tap_ev_watcher (this, &vpn::tap_ev)
543 #if ENABLE_TCP
544 , tcpv4_ev_watcher(this, &vpn::tcpv4_ev)
545 #endif
546 {
547 }
548
549 vpn::~vpn ()
550 {
551 }
552