1 | /* |
1 | /* |
2 | vpn.C -- handle the protocol, encryption, handshaking etc. |
2 | vpn.C -- handle the protocol, encryption, handshaking etc. |
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3 | Copyright (C) 2003 Marc Lehmann <pcg@goof.com> |
3 | |
4 | |
4 | This program is free software; you can redistribute it and/or modify |
5 | 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 | 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 | the Free Software Foundation; either version 2 of the License, or |
7 | (at your option) any later version. |
8 | (at your option) any later version. |
… | |
… | |
24 | #include <cstring> |
25 | #include <cstring> |
25 | #include <cstdio> |
26 | #include <cstdio> |
26 | |
27 | |
27 | #include <sys/types.h> |
28 | #include <sys/types.h> |
28 | #include <sys/socket.h> |
29 | #include <sys/socket.h> |
29 | #include <sys/poll.h> |
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30 | #include <sys/wait.h> |
30 | #include <sys/wait.h> |
31 | #include <errno.h> |
31 | #include <errno.h> |
32 | #include <time.h> |
32 | #include <time.h> |
33 | #include <unistd.h> |
33 | #include <unistd.h> |
34 | #include <fcntl.h> |
34 | #include <fcntl.h> |
35 | #include <arpa/inet.h> |
35 | #include <sys/socket.h> |
36 | #include <netinet/in.h> |
36 | |
37 | #include <netinet/ip_icmp.h> |
37 | #include "netcompat.h" |
38 | |
38 | |
39 | #include "pidfile.h" |
39 | #include "pidfile.h" |
40 | |
40 | |
41 | #include "connection.h" |
41 | #include "connection.h" |
42 | #include "util.h" |
42 | #include "util.h" |
43 | #include "vpn.h" |
43 | #include "vpn.h" |
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44 | |
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45 | vpn network; // THE vpn (bad design...) |
44 | |
46 | |
45 | ///////////////////////////////////////////////////////////////////////////// |
47 | ///////////////////////////////////////////////////////////////////////////// |
46 | |
48 | |
47 | const char *vpn::script_if_up () |
49 | const char *vpn::script_if_up () |
48 | { |
50 | { |
… | |
… | |
84 | if (ipv4_fd < 0) |
86 | if (ipv4_fd < 0) |
85 | return -1; |
87 | return -1; |
86 | |
88 | |
87 | fcntl (ipv4_fd, F_SETFL, O_NONBLOCK); |
89 | fcntl (ipv4_fd, F_SETFL, O_NONBLOCK); |
88 | |
90 | |
89 | #ifdef IP_MTU_DISCOVER |
91 | #if defined(SOL_IP) && defined(IP_MTU_DISCOVER) |
90 | // this I really consider a linux bug. I am neither connected |
92 | // this I really consider a linux bug. I am neither connected |
91 | // nor do I fragment myself. Linux still sets DF and doesn't |
93 | // nor do I fragment myself. Linux still sets DF and doesn't |
92 | // fragment for me sometimes. |
94 | // fragment for me sometimes. |
93 | { |
95 | { |
94 | int oval = IP_PMTUDISC_DONT; |
96 | int oval = IP_PMTUDISC_DONT; |
… | |
… | |
122 | { |
124 | { |
123 | int oval = 1; |
125 | int oval = 1; |
124 | setsockopt (udpv4_fd, SOL_SOCKET, SO_REUSEADDR, &oval, sizeof oval); |
126 | setsockopt (udpv4_fd, SOL_SOCKET, SO_REUSEADDR, &oval, sizeof oval); |
125 | } |
127 | } |
126 | |
128 | |
127 | #ifdef IP_MTU_DISCOVER |
129 | #if defined(SOL_IP) && defined(IP_MTU_DISCOVER) |
128 | // this I really consider a linux bug. I am neither connected |
130 | // this I really consider a linux bug. I am neither connected |
129 | // nor do I fragment myself. Linux still sets DF and doesn't |
131 | // nor do I fragment myself. Linux still sets DF and doesn't |
130 | // fragment for me sometimes. |
132 | // fragment for me sometimes. |
131 | { |
133 | { |
132 | int oval = IP_PMTUDISC_DONT; |
134 | int oval = IP_PMTUDISC_DONT; |
… | |
… | |
166 | |
168 | |
167 | setsockopt (icmpv4_fd, SOL_RAW, ICMP_FILTER, &oval, sizeof oval); |
169 | setsockopt (icmpv4_fd, SOL_RAW, ICMP_FILTER, &oval, sizeof oval); |
168 | } |
170 | } |
169 | #endif |
171 | #endif |
170 | |
172 | |
171 | #ifdef IP_MTU_DISCOVER |
173 | #if defined(SOL_IP) && defined(IP_MTU_DISCOVER) |
172 | // this I really consider a linux bug. I am neither connected |
174 | // this I really consider a linux bug. I am neither connected |
173 | // nor do I fragment myself. Linux still sets DF and doesn't |
175 | // nor do I fragment myself. Linux still sets DF and doesn't |
174 | // fragment for me sometimes. |
176 | // fragment for me sometimes. |
175 | { |
177 | { |
176 | int oval = IP_PMTUDISC_DONT; |
178 | int oval = IP_PMTUDISC_DONT; |
… | |
… | |
271 | } |
273 | } |
272 | |
274 | |
273 | bool |
275 | bool |
274 | vpn::send_ipv4_packet (vpn_packet *pkt, const sockinfo &si, int tos) |
276 | vpn::send_ipv4_packet (vpn_packet *pkt, const sockinfo &si, int tos) |
275 | { |
277 | { |
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278 | #if defined(SOL_IP) && defined(IP_TOS) |
276 | setsockopt (ipv4_fd, SOL_IP, IP_TOS, &tos, sizeof tos); |
279 | setsockopt (ipv4_fd, SOL_IP, IP_TOS, &tos, sizeof tos); |
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280 | #endif |
277 | sendto (ipv4_fd, &((*pkt)[0]), pkt->len, 0, si.sav4 (), si.salenv4 ()); |
281 | sendto (ipv4_fd, &((*pkt)[0]), pkt->len, 0, si.sav4 (), si.salenv4 ()); |
278 | |
282 | |
279 | return true; |
283 | return true; |
280 | } |
284 | } |
281 | |
285 | |
… | |
… | |
300 | sum += (sum >> 16); // carry |
304 | sum += (sum >> 16); // carry |
301 | |
305 | |
302 | return ~sum; |
306 | return ~sum; |
303 | } |
307 | } |
304 | |
308 | |
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309 | #if ENABLE_ICMP |
305 | bool |
310 | bool |
306 | vpn::send_icmpv4_packet (vpn_packet *pkt, const sockinfo &si, int tos) |
311 | vpn::send_icmpv4_packet (vpn_packet *pkt, const sockinfo &si, int tos) |
307 | { |
312 | { |
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313 | #if defined(SOL_IP) && defined(IP_TOS) |
308 | setsockopt (icmpv4_fd, SOL_IP, IP_TOS, &tos, sizeof tos); |
314 | setsockopt (icmpv4_fd, SOL_IP, IP_TOS, &tos, sizeof tos); |
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315 | #endif |
309 | |
316 | |
310 | pkt->unshift_hdr (4); |
317 | pkt->unshift_hdr (4); |
311 | |
318 | |
312 | icmphdr *hdr = (icmphdr *)&((*pkt)[0]); |
319 | icmp_header *hdr = (icmp_header *)&((*pkt)[0]); |
313 | hdr->type = ::conf.icmp_type; |
320 | hdr->type = ::conf.icmp_type; |
314 | hdr->code = 255; |
321 | hdr->code = 255; |
315 | hdr->checksum = 0; |
322 | hdr->checksum = 0; |
316 | hdr->checksum = ipv4_checksum ((u16 *)hdr, pkt->len); |
323 | hdr->checksum = ipv4_checksum ((u16 *)hdr, pkt->len); |
317 | |
324 | |
318 | sendto (icmpv4_fd, &((*pkt)[0]), pkt->len, 0, si.sav4 (), si.salenv4 ()); |
325 | sendto (icmpv4_fd, &((*pkt)[0]), pkt->len, 0, si.sav4 (), si.salenv4 ()); |
319 | |
326 | |
320 | return true; |
327 | return true; |
321 | } |
328 | } |
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329 | #endif |
322 | |
330 | |
323 | bool |
331 | bool |
324 | vpn::send_udpv4_packet (vpn_packet *pkt, const sockinfo &si, int tos) |
332 | vpn::send_udpv4_packet (vpn_packet *pkt, const sockinfo &si, int tos) |
325 | { |
333 | { |
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334 | #if defined(SOL_IP) && defined(IP_TOS) |
326 | setsockopt (udpv4_fd, SOL_IP, IP_TOS, &tos, sizeof tos); |
335 | setsockopt (udpv4_fd, SOL_IP, IP_TOS, &tos, sizeof tos); |
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336 | #endif |
327 | sendto (udpv4_fd, &((*pkt)[0]), pkt->len, 0, si.sav4 (), si.salenv4 ()); |
337 | sendto (udpv4_fd, &((*pkt)[0]), pkt->len, 0, si.sav4 (), si.salenv4 ()); |
328 | |
338 | |
329 | return true; |
339 | return true; |
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340 | } |
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341 | |
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342 | void |
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343 | vpn::inject_data_packet (tap_packet *pkt, int dst) |
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344 | { |
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345 | if (dst) |
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346 | { |
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347 | // unicast |
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348 | if (dst != THISNODE->id) |
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349 | conns[dst - 1]->inject_data_packet (pkt); |
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350 | } |
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351 | else |
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352 | { |
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353 | // broadcast, this is ugly, but due to the security policy |
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354 | // we have to connect to all hosts... |
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355 | for (conns_vector::iterator c = conns.begin (); c != conns.end (); ++c) |
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356 | if ((*c)->conf != THISNODE) |
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357 | (*c)->inject_data_packet (pkt, true); |
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358 | } |
330 | } |
359 | } |
331 | |
360 | |
332 | void |
361 | void |
333 | vpn::recv_vpn_packet (vpn_packet *pkt, const sockinfo &rsi) |
362 | vpn::recv_vpn_packet (vpn_packet *pkt, const sockinfo &rsi) |
334 | { |
363 | { |
… | |
… | |
348 | (const char *)rsi, pkt->typ (), pkt->src (), pkt->dst ()); |
377 | (const char *)rsi, pkt->typ (), pkt->src (), pkt->dst ()); |
349 | else |
378 | else |
350 | { |
379 | { |
351 | connection *c = conns[src - 1]; |
380 | connection *c = conns[src - 1]; |
352 | |
381 | |
353 | if (dst == 0 && !THISNODE->routerprio) |
382 | if (dst == 0) |
354 | slog (L_WARN, _("%s(%s): received broadcast, but we are no router"), |
383 | slog (L_WARN, _("%s(%s): received broadcast (protocol violation)"), |
355 | c->conf->nodename, (const char *)rsi); |
384 | c->conf->nodename, (const char *)rsi); |
356 | else if (dst != 0 && dst != THISNODE->id) |
385 | else if (dst != THISNODE->id) |
357 | { |
386 | { |
358 | if (THISNODE->routerprio) |
387 | if (THISNODE->routerprio) |
359 | // the tos setting gets lost here. who cares. |
388 | // the tos setting gets lost here. who cares. |
360 | conns[dst - 1]->inject_vpn_packet (pkt); |
389 | conns[dst - 1]->inject_vpn_packet (pkt); |
361 | else |
390 | else |
… | |
… | |
414 | revents); |
443 | revents); |
415 | exit (1); |
444 | exit (1); |
416 | } |
445 | } |
417 | } |
446 | } |
418 | |
447 | |
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448 | #if ENABLE_ICMP |
419 | void |
449 | void |
420 | vpn::icmpv4_ev (io_watcher &w, short revents) |
450 | vpn::icmpv4_ev (io_watcher &w, short revents) |
421 | { |
451 | { |
422 | if (revents & (POLLIN | POLLERR)) |
452 | if (revents & (POLLIN | POLLERR)) |
423 | { |
453 | { |
… | |
… | |
432 | |
462 | |
433 | if (len > 0) |
463 | if (len > 0) |
434 | { |
464 | { |
435 | pkt->len = len; |
465 | pkt->len = len; |
436 | |
466 | |
437 | icmphdr *hdr = (icmphdr *)&((*pkt)[IP_OVERHEAD]); |
467 | icmp_header *hdr = (icmp_header *)&((*pkt)[IP_OVERHEAD]); |
438 | |
468 | |
439 | if (hdr->type == ::conf.icmp_type |
469 | if (hdr->type == ::conf.icmp_type |
440 | && hdr->code == 255) |
470 | && hdr->code == 255) |
441 | { |
471 | { |
442 | // raw sockets deliver the ipv4, but don't expect it on sends |
472 | // raw sockets deliver the ipv4, but don't expect it on sends |
… | |
… | |
466 | _("FATAL: unknown revents %08x in socket, terminating\n"), |
496 | _("FATAL: unknown revents %08x in socket, terminating\n"), |
467 | revents); |
497 | revents); |
468 | exit (1); |
498 | exit (1); |
469 | } |
499 | } |
470 | } |
500 | } |
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501 | #endif |
471 | |
502 | |
472 | void |
503 | void |
473 | vpn::udpv4_ev (io_watcher &w, short revents) |
504 | vpn::udpv4_ev (io_watcher &w, short revents) |
474 | { |
505 | { |
475 | if (revents & (POLLIN | POLLERR)) |
506 | if (revents & (POLLIN | POLLERR)) |
… | |
… | |
520 | /* process data */ |
551 | /* process data */ |
521 | tap_packet *pkt; |
552 | tap_packet *pkt; |
522 | |
553 | |
523 | pkt = tap->recv (); |
554 | pkt = tap->recv (); |
524 | |
555 | |
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556 | if (!pkt) |
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557 | return; |
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558 | |
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559 | if (pkt->len > 14) |
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560 | { |
525 | int dst = mac2id (pkt->dst); |
561 | int dst = mac2id (pkt->dst); |
526 | int src = mac2id (pkt->src); |
562 | int src = mac2id (pkt->src); |
527 | |
563 | |
528 | if (src != THISNODE->id) |
564 | if (src != THISNODE->id) |
529 | { |
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530 | slog (L_ERR, _("FATAL: tap packet not originating on current node received, terminating.")); |
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531 | exit (1); |
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532 | } |
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533 | |
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534 | if (dst == THISNODE->id) |
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535 | { |
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536 | slog (L_ERR, _("FATAL: tap packet destined for current node received, terminating.")); |
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537 | exit (1); |
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538 | } |
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539 | |
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540 | if (dst > conns.size ()) |
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541 | slog (L_ERR, _("tap packet for unknown node %d received, ignoring."), dst); |
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542 | else |
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543 | { |
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544 | if (dst) |
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545 | { |
565 | { |
546 | // unicast |
566 | slog (L_ERR, _("FATAL: tap packet not originating on current node received, exiting.")); |
547 | if (dst != THISNODE->id) |
567 | exit (1); |
548 | conns[dst - 1]->inject_data_packet (pkt); |
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549 | } |
568 | } |
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569 | |
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570 | if (dst == THISNODE->id) |
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571 | { |
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572 | slog (L_ERR, _("FATAL: tap packet destined for current node received, exiting.")); |
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573 | exit (1); |
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574 | } |
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575 | |
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576 | if (dst > conns.size ()) |
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577 | slog (L_ERR, _("tap packet for unknown node %d received, ignoring."), dst); |
550 | else |
578 | else |
551 | { |
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552 | // broadcast, first check router, then self, then english |
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553 | connection *router = find_router (); |
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554 | |
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555 | if (router) |
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556 | router->inject_data_packet (pkt, true); |
579 | inject_data_packet (pkt, dst); |
557 | else |
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558 | for (conns_vector::iterator c = conns.begin (); c != conns.end (); ++c) |
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559 | if ((*c)->conf != THISNODE) |
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560 | (*c)->inject_data_packet (pkt); |
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561 | } |
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562 | } |
580 | } |
563 | |
581 | |
564 | delete pkt; |
582 | delete pkt; |
565 | } |
583 | } |
566 | else if (revents & (POLLHUP | POLLERR)) |
584 | else if (revents & (POLLHUP | POLLERR)) |
… | |
… | |
632 | } |
650 | } |
633 | } |
651 | } |
634 | |
652 | |
635 | connection *vpn::find_router () |
653 | connection *vpn::find_router () |
636 | { |
654 | { |
637 | u32 prio = 0; |
655 | u32 prio = 1; |
638 | connection *router = 0; |
656 | connection *router = 0; |
639 | |
657 | |
640 | for (conns_vector::iterator i = conns.begin (); i != conns.end (); ++i) |
658 | for (conns_vector::iterator i = conns.begin (); i != conns.end (); ++i) |
641 | { |
659 | { |
642 | connection *c = *i; |
660 | connection *c = *i; |
643 | |
661 | |
644 | if (c->conf->routerprio > prio |
662 | if (c->conf->routerprio > prio |
645 | && c->connectmode == conf_node::C_ALWAYS // so we don't drop the connection if in use |
663 | && c->connectmode == conf_node::C_ALWAYS // so we don't drop the connection if in use |
646 | && c->ictx && c->octx |
664 | && c->ictx && c->octx |
647 | && c->conf != THISNODE // redundant, since ictx==octx==0 always on thisnode |
665 | && c->conf != THISNODE) // redundant, since ictx==octx==0 always on thisnode |
648 | && (!THISNODE->routerprio |
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649 | || c->conf->routerprio <= THISNODE->routerprio)) |
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650 | { |
666 | { |
651 | prio = c->conf->routerprio; |
667 | prio = c->conf->routerprio; |
652 | router = c; |
668 | router = c; |
653 | } |
669 | } |
654 | } |
670 | } |
… | |
… | |
663 | if (c) |
679 | if (c) |
664 | c->send_connect_request (id); |
680 | c->send_connect_request (id); |
665 | else |
681 | else |
666 | // no router found, aggressively connect to all routers |
682 | // no router found, aggressively connect to all routers |
667 | for (conns_vector::iterator i = conns.begin (); i != conns.end (); ++i) |
683 | for (conns_vector::iterator i = conns.begin (); i != conns.end (); ++i) |
668 | if ((*i)->conf->routerprio) |
684 | if ((*i)->conf->routerprio && (*i)->conf != THISNODE) |
669 | (*i)->establish_connection (); |
685 | (*i)->establish_connection (); |
670 | } |
686 | } |
671 | |
687 | |
672 | void |
688 | void |
673 | connection::dump_status () |
689 | connection::dump_status () |