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 |
void |
191 |
vpn::send_vpn_packet (vpn_packet *pkt, const sockinfo &si, int tos) |
192 |
{ |
193 |
switch (si.prot) |
194 |
{ |
195 |
case PROT_IPv4: |
196 |
send_ipv4_packet (pkt, si, tos); |
197 |
break; |
198 |
|
199 |
case PROT_UDPv4: |
200 |
send_udpv4_packet (pkt, si, tos); |
201 |
break; |
202 |
|
203 |
#if ENABLE_TCP |
204 |
case PROT_TCPv4: |
205 |
send_tcpv4_packet (pkt, si, tos); |
206 |
break; |
207 |
#endif |
208 |
|
209 |
default: |
210 |
slog (L_CRIT, _("%s: FATAL: trying to send packet with unsupported protocol"), (const char *)si); |
211 |
abort (); |
212 |
} |
213 |
} |
214 |
|
215 |
void |
216 |
vpn::send_ipv4_packet (vpn_packet *pkt, const sockinfo &si, int tos) |
217 |
{ |
218 |
setsockopt (ipv4_fd, SOL_IP, IP_TOS, &tos, sizeof tos); |
219 |
sendto (ipv4_fd, &((*pkt)[0]), pkt->len, 0, si.sav4 (), si.salenv4 ()); |
220 |
} |
221 |
|
222 |
void |
223 |
vpn::send_udpv4_packet (vpn_packet *pkt, const sockinfo &si, int tos) |
224 |
{ |
225 |
setsockopt (udpv4_fd, SOL_IP, IP_TOS, &tos, sizeof tos); |
226 |
sendto (udpv4_fd, &((*pkt)[0]), pkt->len, 0, si.sav4 (), si.salenv4 ()); |
227 |
} |
228 |
|
229 |
void |
230 |
vpn::recv_vpn_packet (vpn_packet *pkt, const sockinfo &rsi) |
231 |
{ |
232 |
unsigned int src = pkt->src (); |
233 |
unsigned int dst = pkt->dst (); |
234 |
|
235 |
slog (L_NOISE, _("<<?/%s received possible vpn packet type %d from %d to %d, length %d"), |
236 |
(const char *)rsi, pkt->typ (), pkt->src (), pkt->dst (), pkt->len); |
237 |
|
238 |
if (src == 0 || src > conns.size () |
239 |
|| dst > conns.size () |
240 |
|| pkt->typ () >= vpn_packet::PT_MAX) |
241 |
slog (L_WARN, _("(%s): received corrupted packet type %d (src %d, dst %d)"), |
242 |
(const char *)rsi, pkt->typ (), pkt->src (), pkt->dst ()); |
243 |
else if (dst > conns.size ()) |
244 |
slog (L_WARN, _("(%s): received corrupted packet type %d (src %d, dst %d)"), |
245 |
(const char *)rsi, pkt->typ (), pkt->src (), pkt->dst ()); |
246 |
else |
247 |
{ |
248 |
connection *c = conns[src - 1]; |
249 |
|
250 |
if (dst == 0 && !THISNODE->routerprio) |
251 |
slog (L_WARN, _("%s(%s): received broadcast, but we are no router"), |
252 |
c->conf->nodename, (const char *)rsi); |
253 |
else if (dst != 0 && dst != THISNODE->id) |
254 |
{ |
255 |
if (THISNODE->routerprio) |
256 |
// the tos setting gets lost here. who cares. |
257 |
conns[dst - 1]->inject_vpn_packet (pkt); |
258 |
else |
259 |
slog (L_WARN, |
260 |
_("%s(%s): forwarding request (=> %s), but we are no router"), |
261 |
c->conf->nodename, (const char *)rsi, |
262 |
conns[dst - 1]->conf->nodename); |
263 |
} |
264 |
else |
265 |
c->recv_vpn_packet (pkt, rsi); |
266 |
} |
267 |
} |
268 |
|
269 |
void |
270 |
vpn::udpv4_ev (io_watcher &w, short revents) |
271 |
{ |
272 |
if (revents & (POLLIN | POLLERR)) |
273 |
{ |
274 |
vpn_packet *pkt = new vpn_packet; |
275 |
struct sockaddr_in sa; |
276 |
socklen_t sa_len = sizeof (sa); |
277 |
int len; |
278 |
|
279 |
len = recvfrom (w.fd, &((*pkt)[0]), MAXSIZE, 0, (sockaddr *)&sa, &sa_len); |
280 |
|
281 |
sockinfo si(sa, PROT_UDPv4); |
282 |
|
283 |
if (len > 0) |
284 |
{ |
285 |
pkt->len = len; |
286 |
|
287 |
recv_vpn_packet (pkt, si); |
288 |
} |
289 |
else |
290 |
{ |
291 |
// probably ECONNRESET or somesuch |
292 |
slog (L_DEBUG, _("%s: fd %d, %s"), (const char *)si, w.fd, strerror (errno)); |
293 |
} |
294 |
|
295 |
delete pkt; |
296 |
} |
297 |
else if (revents & POLLHUP) |
298 |
{ |
299 |
// this cannot ;) happen on udp sockets |
300 |
slog (L_ERR, _("FATAL: POLLHUP on udp v4 fd, terminating.")); |
301 |
exit (1); |
302 |
} |
303 |
else |
304 |
{ |
305 |
slog (L_ERR, |
306 |
_("FATAL: unknown revents %08x in socket, terminating\n"), |
307 |
revents); |
308 |
exit (1); |
309 |
} |
310 |
} |
311 |
|
312 |
void |
313 |
vpn::ipv4_ev (io_watcher &w, short revents) |
314 |
{ |
315 |
if (revents & (POLLIN | POLLERR)) |
316 |
{ |
317 |
vpn_packet *pkt = new vpn_packet; |
318 |
struct sockaddr_in sa; |
319 |
socklen_t sa_len = sizeof (sa); |
320 |
int len; |
321 |
|
322 |
len = recvfrom (w.fd, &((*pkt)[0]), MAXSIZE, 0, (sockaddr *)&sa, &sa_len); |
323 |
|
324 |
sockinfo si(sa, PROT_IPv4); |
325 |
|
326 |
if (len > 0) |
327 |
{ |
328 |
pkt->len = len; |
329 |
|
330 |
// raw sockets deliver the ipv4, but don't expect it on sends |
331 |
// this is slow, but... |
332 |
pkt->skip_hdr (IP_OVERHEAD); |
333 |
|
334 |
recv_vpn_packet (pkt, si); |
335 |
} |
336 |
else |
337 |
{ |
338 |
// probably ECONNRESET or somesuch |
339 |
slog (L_DEBUG, _("%s: %s"), (const char *)si, strerror (errno)); |
340 |
} |
341 |
|
342 |
delete pkt; |
343 |
} |
344 |
else if (revents & POLLHUP) |
345 |
{ |
346 |
// this cannot ;) happen on udp sockets |
347 |
slog (L_ERR, _("FATAL: POLLHUP on ipv4 fd, terminating.")); |
348 |
exit (1); |
349 |
} |
350 |
else |
351 |
{ |
352 |
slog (L_ERR, |
353 |
_("FATAL: unknown revents %08x in socket, terminating\n"), |
354 |
revents); |
355 |
exit (1); |
356 |
} |
357 |
} |
358 |
|
359 |
void |
360 |
vpn::tap_ev (io_watcher &w, short revents) |
361 |
{ |
362 |
if (revents & POLLIN) |
363 |
{ |
364 |
/* process data */ |
365 |
tap_packet *pkt; |
366 |
|
367 |
pkt = tap->recv (); |
368 |
|
369 |
int dst = mac2id (pkt->dst); |
370 |
int src = mac2id (pkt->src); |
371 |
|
372 |
if (src != THISNODE->id) |
373 |
{ |
374 |
slog (L_ERR, _("FATAL: tap packet not originating on current node received, terminating.")); |
375 |
exit (1); |
376 |
} |
377 |
|
378 |
if (dst == THISNODE->id) |
379 |
{ |
380 |
slog (L_ERR, _("FATAL: tap packet destined for current node received, terminating.")); |
381 |
exit (1); |
382 |
} |
383 |
|
384 |
if (dst > conns.size ()) |
385 |
slog (L_ERR, _("tap packet for unknown node %d received, ignoring."), dst); |
386 |
else |
387 |
{ |
388 |
if (dst) |
389 |
{ |
390 |
// unicast |
391 |
if (dst != THISNODE->id) |
392 |
conns[dst - 1]->inject_data_packet (pkt); |
393 |
} |
394 |
else |
395 |
{ |
396 |
// broadcast, first check router, then self, then english |
397 |
connection *router = find_router (); |
398 |
|
399 |
if (router) |
400 |
router->inject_data_packet (pkt, true); |
401 |
else |
402 |
for (conns_vector::iterator c = conns.begin (); c != conns.end (); ++c) |
403 |
if ((*c)->conf != THISNODE) |
404 |
(*c)->inject_data_packet (pkt); |
405 |
} |
406 |
} |
407 |
|
408 |
delete pkt; |
409 |
} |
410 |
else if (revents & (POLLHUP | POLLERR)) |
411 |
{ |
412 |
slog (L_ERR, _("FATAL: POLLHUP or POLLERR on network device fd, terminating.")); |
413 |
exit (1); |
414 |
} |
415 |
else |
416 |
abort (); |
417 |
} |
418 |
|
419 |
void |
420 |
vpn::event_cb (time_watcher &w) |
421 |
{ |
422 |
if (events) |
423 |
{ |
424 |
if (events & EVENT_SHUTDOWN) |
425 |
{ |
426 |
slog (L_INFO, _("preparing shutdown...")); |
427 |
|
428 |
shutdown_all (); |
429 |
|
430 |
remove_pid (pidfilename); |
431 |
|
432 |
slog (L_INFO, _("terminating")); |
433 |
|
434 |
exit (0); |
435 |
} |
436 |
|
437 |
if (events & EVENT_RECONNECT) |
438 |
{ |
439 |
slog (L_INFO, _("forced reconnect")); |
440 |
|
441 |
reconnect_all (); |
442 |
} |
443 |
|
444 |
events = 0; |
445 |
} |
446 |
|
447 |
w.at = TSTAMP_CANCEL; |
448 |
} |
449 |
|
450 |
void |
451 |
vpn::shutdown_all () |
452 |
{ |
453 |
for (conns_vector::iterator c = conns.begin (); c != conns.end (); ++c) |
454 |
(*c)->shutdown (); |
455 |
} |
456 |
|
457 |
void |
458 |
vpn::reconnect_all () |
459 |
{ |
460 |
for (conns_vector::iterator c = conns.begin (); c != conns.end (); ++c) |
461 |
delete *c; |
462 |
|
463 |
conns.clear (); |
464 |
|
465 |
connection_init (); |
466 |
|
467 |
for (configuration::node_vector::iterator i = conf.nodes.begin (); |
468 |
i != conf.nodes.end (); ++i) |
469 |
{ |
470 |
connection *conn = new connection (this); |
471 |
|
472 |
conn->conf = *i; |
473 |
conns.push_back (conn); |
474 |
|
475 |
conn->establish_connection (); |
476 |
} |
477 |
} |
478 |
|
479 |
connection *vpn::find_router () |
480 |
{ |
481 |
u32 prio = 0; |
482 |
connection *router = 0; |
483 |
|
484 |
for (conns_vector::iterator i = conns.begin (); i != conns.end (); ++i) |
485 |
{ |
486 |
connection *c = *i; |
487 |
|
488 |
if (c->conf->routerprio > prio |
489 |
&& c->connectmode == conf_node::C_ALWAYS |
490 |
&& c->conf != THISNODE |
491 |
&& c->ictx && c->octx) |
492 |
{ |
493 |
prio = c->conf->routerprio; |
494 |
router = c; |
495 |
} |
496 |
} |
497 |
|
498 |
return router; |
499 |
} |
500 |
|
501 |
void vpn::connect_request (int id) |
502 |
{ |
503 |
connection *c = find_router (); |
504 |
|
505 |
if (c) |
506 |
c->connect_request (id); |
507 |
//else // does not work, because all others must connect to the same router |
508 |
// // no router found, aggressively connect to all routers |
509 |
// for (conns_vector::iterator i = conns.begin (); i != conns.end (); ++i) |
510 |
// if ((*i)->conf->routerprio) |
511 |
// (*i)->establish_connection (); |
512 |
} |
513 |
|
514 |
void |
515 |
connection::dump_status () |
516 |
{ |
517 |
slog (L_NOTICE, _("node %s (id %d)"), conf->nodename, conf->id); |
518 |
slog (L_NOTICE, _(" connectmode %d (%d) / sockaddr %s / minor %d"), |
519 |
connectmode, conf->connectmode, (const char *)si, (int)prot_minor); |
520 |
slog (L_NOTICE, _(" ictx/octx %08lx/%08lx / oseqno %d / retry_cnt %d"), |
521 |
(long)ictx, (long)octx, (int)oseqno, (int)retry_cnt); |
522 |
slog (L_NOTICE, _(" establish_conn %ld / rekey %ld / keepalive %ld"), |
523 |
(long)(establish_connection.at), (long)(rekey.at), (long)(keepalive.at)); |
524 |
} |
525 |
|
526 |
void |
527 |
vpn::dump_status () |
528 |
{ |
529 |
slog (L_NOTICE, _("BEGIN status dump (%ld)"), (long)NOW); |
530 |
|
531 |
for (conns_vector::iterator c = conns.begin (); c != conns.end (); ++c) |
532 |
(*c)->dump_status (); |
533 |
|
534 |
slog (L_NOTICE, _("END status dump")); |
535 |
} |
536 |
|
537 |
vpn::vpn (void) |
538 |
: event(this, &vpn::event_cb) |
539 |
, udpv4_ev_watcher(this, &vpn::udpv4_ev) |
540 |
, ipv4_ev_watcher (this, &vpn::ipv4_ev) |
541 |
, tap_ev_watcher (this, &vpn::tap_ev) |
542 |
#if ENABLE_TCP |
543 |
, tcpv4_ev_watcher(this, &vpn::tcpv4_ev) |
544 |
#endif |
545 |
{ |
546 |
} |
547 |
|
548 |
vpn::~vpn () |
549 |
{ |
550 |
} |
551 |
|