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Comparing gvpe/src/protocol.C (file contents):
Revision 1.5 by pcg, Sat Mar 8 10:48:41 2003 UTC vs.
Revision 1.16 by pcg, Tue Mar 25 18:11:58 2003 UTC

16 Foundation, Inc. 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA 16 Foundation, Inc. 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
17*/ 17*/
18 18
19#include "config.h" 19#include "config.h"
20 20
21#include <list>
22
21#include <cstdlib> 23#include <cstdlib>
22#include <cstring> 24#include <cstring>
23#include <cstdio> 25#include <cstdio>
24 26
25#include <sys/types.h> 27#include <sys/types.h>
60 62
61static const rsachallenge & 63static const rsachallenge &
62challenge_bytes () 64challenge_bytes ()
63{ 65{
64 static rsachallenge challenge; 66 static rsachallenge challenge;
65 static time_t challenge_ttl; // time this challenge needs to be recreated 67 static tstamp challenge_ttl; // time this challenge needs to be recreated
66 68
67 if (now > challenge_ttl) 69 if (NOW > challenge_ttl)
68 { 70 {
69 RAND_bytes ((unsigned char *)&challenge, sizeof (challenge)); 71 RAND_bytes ((unsigned char *)&challenge, sizeof (challenge));
70 challenge_ttl = now + CHALLENGE_TTL; 72 challenge_ttl = NOW + CHALLENGE_TTL;
71 } 73 }
72 74
73 return challenge; 75 return challenge;
76}
77
78// caching of rsa operations really helps slow computers
79struct rsa_entry {
80 tstamp expire;
81 rsachallenge chg;
82 RSA *key; // which key
83 rsaencrdata encr;
84
85 rsa_entry ()
86 {
87 expire = NOW + CHALLENGE_TTL;
88 }
89};
90
91struct rsa_cache : list<rsa_entry>
92{
93 void cleaner_cb (tstamp &ts); time_watcher cleaner;
94
95 const rsaencrdata *public_encrypt (RSA *key, const rsachallenge &chg)
96 {
97 for (iterator i = begin (); i != end (); ++i)
98 {
99 if (i->key == key && !memcmp (&chg, &i->chg, sizeof chg))
100 return &i->encr;
101 }
102
103 if (cleaner.at < NOW)
104 cleaner.start (NOW + CHALLENGE_TTL);
105
106 resize (size () + 1);
107 rsa_entry *e = &(*rbegin ());
108
109 e->key = key;
110 memcpy (&e->chg, &chg, sizeof chg);
111
112 if (0 > RSA_public_encrypt (sizeof chg,
113 (unsigned char *)&chg, (unsigned char *)&e->encr,
114 key, RSA_PKCS1_OAEP_PADDING))
115 fatal ("RSA_public_encrypt error");
116
117 return &e->encr;
118 }
119
120 const rsachallenge *private_decrypt (RSA *key, const rsaencrdata &encr)
121 {
122 for (iterator i = begin (); i != end (); ++i)
123 if (i->key == key && !memcmp (&encr, &i->encr, sizeof encr))
124 return &i->chg;
125
126 if (cleaner.at < NOW)
127 cleaner.start (NOW + CHALLENGE_TTL);
128
129 resize (size () + 1);
130 rsa_entry *e = &(*rbegin ());
131
132 e->key = key;
133 memcpy (&e->encr, &encr, sizeof encr);
134
135 if (0 > RSA_private_decrypt (sizeof encr,
136 (unsigned char *)&encr, (unsigned char *)&e->chg,
137 key, RSA_PKCS1_OAEP_PADDING))
138 {
139 pop_back ();
140 return 0;
141 }
142
143 return &e->chg;
144 }
145
146 rsa_cache ()
147 : cleaner (this, &rsa_cache::cleaner_cb)
148 { }
149
150} rsa_cache;
151
152void rsa_cache::cleaner_cb (tstamp &ts)
153{
154 if (empty ())
155 ts = TSTAMP_CANCEL;
156 else
157 {
158 ts = NOW + 3;
159 for (iterator i = begin (); i != end (); )
160 {
161 if (i->expire >= NOW)
162 i = erase (i);
163 else
164 ++i;
165 }
166 }
74} 167}
75 168
76// run a script. yes, it's a template function. yes, c++ 169// run a script. yes, it's a template function. yes, c++
77// is not a functional language. yes, this suxx. 170// is not a functional language. yes, this suxx.
78template<class owner> 171template<class owner>
112struct crypto_ctx 205struct crypto_ctx
113 { 206 {
114 EVP_CIPHER_CTX cctx; 207 EVP_CIPHER_CTX cctx;
115 HMAC_CTX hctx; 208 HMAC_CTX hctx;
116 209
117 crypto_ctx (rsachallenge &challenge, int enc); 210 crypto_ctx (const rsachallenge &challenge, int enc);
118 ~crypto_ctx (); 211 ~crypto_ctx ();
119 }; 212 };
120 213
121crypto_ctx::crypto_ctx (rsachallenge &challenge, int enc) 214crypto_ctx::crypto_ctx (const rsachallenge &challenge, int enc)
122{ 215{
123 EVP_CIPHER_CTX_init (&cctx); 216 EVP_CIPHER_CTX_init (&cctx);
124 EVP_CipherInit_ex (&cctx, CIPHER, 0, &challenge[CHG_CIPHER_KEY], 0, enc); 217 EVP_CipherInit_ex (&cctx, CIPHER, 0, &challenge[CHG_CIPHER_KEY], 0, enc);
125 HMAC_CTX_init (&hctx); 218 HMAC_CTX_init (&hctx);
126 HMAC_Init_ex (&hctx, &challenge[CHG_HMAC_KEY], HMAC_KEYLEN, DIGEST, 0); 219 HMAC_Init_ex (&hctx, &challenge[CHG_HMAC_KEY], HMAC_KEYLEN, DIGEST, 0);
128 221
129crypto_ctx::~crypto_ctx () 222crypto_ctx::~crypto_ctx ()
130{ 223{
131 EVP_CIPHER_CTX_cleanup (&cctx); 224 EVP_CIPHER_CTX_cleanup (&cctx);
132 HMAC_CTX_cleanup (&hctx); 225 HMAC_CTX_cleanup (&hctx);
226}
227
228//////////////////////////////////////////////////////////////////////////////
229
230void pkt_queue::put (tap_packet *p)
231{
232 if (queue[i])
233 {
234 delete queue[i];
235 j = (j + 1) % QUEUEDEPTH;
236 }
237
238 queue[i] = p;
239
240 i = (i + 1) % QUEUEDEPTH;
241}
242
243tap_packet *pkt_queue::get ()
244{
245 tap_packet *p = queue[j];
246
247 if (p)
248 {
249 queue[j] = 0;
250 j = (j + 1) % QUEUEDEPTH;
251 }
252
253 return p;
254}
255
256pkt_queue::pkt_queue ()
257{
258 memset (queue, 0, sizeof (queue));
259 i = 0;
260 j = 0;
261}
262
263pkt_queue::~pkt_queue ()
264{
265 for (i = QUEUEDEPTH; --i > 0; )
266 delete queue[i];
267}
268
269struct net_rateinfo {
270 u32 host;
271 double pcnt, diff;
272 tstamp last;
273};
274
275// only do action once every x seconds per host whole allowing bursts.
276// this implementation ("splay list" ;) is inefficient,
277// but low on resources.
278struct net_rate_limiter : private list<net_rateinfo>
279{
280 static const double ALPHA = 1. - 1. / 90.; // allow bursts
281 static const double CUTOFF = 20.; // one event every CUTOFF seconds
282 static const double EXPIRE = CUTOFF * 30.; // expire entries after this time
283
284 bool can (u32 host);
285 bool can (SOCKADDR *sa) { return can((u32)sa->sin_addr.s_addr); }
286 bool can (sockinfo &si) { return can((u32)si.host); }
287};
288
289net_rate_limiter auth_rate_limiter, reset_rate_limiter;
290
291bool net_rate_limiter::can (u32 host)
292{
293 iterator i;
294
295 for (i = begin (); i != end (); )
296 if (i->host == host)
297 break;
298 else if (i->last < NOW - EXPIRE)
299 i = erase (i);
300 else
301 i++;
302
303 if (i == end ())
304 {
305 net_rateinfo ri;
306
307 ri.host = host;
308 ri.pcnt = 1.;
309 ri.diff = CUTOFF * (1. / (1. - ALPHA));
310 ri.last = NOW;
311
312 push_front (ri);
313
314 return true;
315 }
316 else
317 {
318 net_rateinfo ri (*i);
319 erase (i);
320
321 ri.pcnt = ri.pcnt * ALPHA;
322 ri.diff = ri.diff * ALPHA + (NOW - ri.last);
323
324 ri.last = NOW;
325
326 bool send = ri.diff / ri.pcnt > CUTOFF;
327
328 if (send)
329 ri.pcnt++;
330
331 //printf ("RATE %d %f,%f = %f > %f\n", !!send, ri.pcnt, ri.diff, ri.diff / ri.pcnt, CUTOFF);
332
333 push_front (ri);
334
335 return send;
336 }
133} 337}
134 338
135///////////////////////////////////////////////////////////////////////////// 339/////////////////////////////////////////////////////////////////////////////
136 340
137static void next_wakeup (time_t next) 341static void next_wakeup (time_t next)
200 404
201 unsigned int src () 405 unsigned int src ()
202 { 406 {
203 return src1 | ((srcdst >> 4) << 8); 407 return src1 | ((srcdst >> 4) << 8);
204 } 408 }
409
205 unsigned int dst () 410 unsigned int dst ()
206 { 411 {
207 return dst1 | ((srcdst & 0xf) << 8); 412 return dst1 | ((srcdst & 0xf) << 8);
208 } 413 }
414
209 ptype typ () 415 ptype typ ()
210 { 416 {
211 return (ptype) type; 417 return (ptype) type;
212 } 418 }
213 }; 419 };
252 u32 cl; 458 u32 cl;
253 459
254 cl = lzf_compress (d, l, cdata + 2, (l - 2) & ~7); 460 cl = lzf_compress (d, l, cdata + 2, (l - 2) & ~7);
255 if (cl) 461 if (cl)
256 { 462 {
257 //printf ("compressed packet, %d => %d\n", l, cl);//D
258 type = PT_DATA_COMPRESSED; 463 type = PT_DATA_COMPRESSED;
259 d = cdata; 464 d = cdata;
260 l = cl + 2; 465 l = cl + 2;
261 466
262 d[0] = cl >> 8; 467 d[0] = cl >> 8;
264 } 469 }
265#endif 470#endif
266 471
267 EVP_EncryptInit_ex (cctx, 0, 0, 0, 0); 472 EVP_EncryptInit_ex (cctx, 0, 0, 0, 0);
268 473
474 struct {
269#if RAND_SIZE 475#if RAND_SIZE
270 struct {
271 u8 rnd[RAND_SIZE]; 476 u8 rnd[RAND_SIZE];
477#endif
272 u32 seqno; 478 u32 seqno;
273 } datahdr; 479 } datahdr;
274 480
275 datahdr.seqno = seqno; 481 datahdr.seqno = ntohl (seqno);
482#if RAND_SIZE
276 RAND_pseudo_bytes ((unsigned char *) datahdr.rnd, RAND_SIZE); 483 RAND_pseudo_bytes ((unsigned char *) datahdr.rnd, RAND_SIZE);
484#endif
277 485
278 EVP_EncryptUpdate (cctx, 486 EVP_EncryptUpdate (cctx,
279 (unsigned char *) data + outl, &outl2, 487 (unsigned char *) data + outl, &outl2,
280 (unsigned char *) &datahdr, DATAHDR); 488 (unsigned char *) &datahdr, DATAHDR);
281 outl += outl2; 489 outl += outl2;
282#else
283 EVP_EncryptUpdate (cctx,
284 (unsigned char *) data + outl, &outl2,
285 (unsigned char *) &seqno, DATAHDR);
286 outl += outl2;
287#endif
288 490
289 EVP_EncryptUpdate (cctx, 491 EVP_EncryptUpdate (cctx,
290 (unsigned char *) data + outl, &outl2, 492 (unsigned char *) data + outl, &outl2,
291 (unsigned char *) d, l); 493 (unsigned char *) d, l);
292 outl += outl2; 494 outl += outl2;
328 outl += outl2; 530 outl += outl2;
329 531
330 EVP_DecryptFinal_ex (cctx, (unsigned char *)d + outl, &outl2); 532 EVP_DecryptFinal_ex (cctx, (unsigned char *)d + outl, &outl2);
331 outl += outl2; 533 outl += outl2;
332 534
333 seqno = *(u32 *)(d + RAND_SIZE); 535 seqno = ntohl (*(u32 *)(d + RAND_SIZE));
334 536
335 id2mac (dst () ? dst() : THISNODE->id, p->dst); 537 id2mac (dst () ? dst() : THISNODE->id, p->dst);
336 id2mac (src (), p->src); 538 id2mac (src (), p->src);
337 539
338#if ENABLE_COMPRESSION 540#if ENABLE_COMPRESSION
339 if (type == PT_DATA_COMPRESSED) 541 if (type == PT_DATA_COMPRESSED)
340 { 542 {
341 u32 cl = (d[DATAHDR] << 8) | d[DATAHDR + 1]; 543 u32 cl = (d[DATAHDR] << 8) | d[DATAHDR + 1];
342 p->len = lzf_decompress (d + DATAHDR + 2, cl, &(*p)[6 + 6], MAX_MTU) + 6 + 6; 544 p->len = lzf_decompress (d + DATAHDR + 2, cl, &(*p)[6 + 6], MAX_MTU) + 6 + 6;
343 //printf ("decompressxed %d(%d) => %d\n", cl, len - data_hdr_size (), p->len);//D
344 } 545 }
345 else 546 else
346 p->len = outl + (6 + 6 - DATAHDR); 547 p->len = outl + (6 + 6 - DATAHDR);
347#endif 548#endif
348 549
369 u32 digest_nid; 570 u32 digest_nid;
370 571
371 const u8 curflags () const 572 const u8 curflags () const
372 { 573 {
373 return 0x80 574 return 0x80
374 | (ENABLE_COMPRESSION ? 0x01 : 0x00) 575 | (ENABLE_COMPRESSION ? 0x01 : 0x00);
375 | (ENABLE_TRUST ? 0x02 : 0x00);
376 } 576 }
377 577
378 void setup (ptype type, int dst) 578 void setup (ptype type, int dst)
379 { 579 {
380 prot_major = PROTOCOL_MAJOR; 580 prot_major = PROTOCOL_MAJOR;
481connection::send_ping (SOCKADDR *dsa, u8 pong) 681connection::send_ping (SOCKADDR *dsa, u8 pong)
482{ 682{
483 ping_packet *pkt = new ping_packet; 683 ping_packet *pkt = new ping_packet;
484 684
485 pkt->setup (conf->id, pong ? ping_packet::PT_PONG : ping_packet::PT_PING); 685 pkt->setup (conf->id, pong ? ping_packet::PT_PONG : ping_packet::PT_PING);
486 vpn->send_vpn_packet (pkt, dsa); 686 vpn->send_vpn_packet (pkt, dsa, IPTOS_LOWDELAY);
487 687
488 delete pkt; 688 delete pkt;
489} 689}
490 690
491void 691void
492connection::send_reset (SOCKADDR *dsa) 692connection::send_reset (SOCKADDR *dsa)
493{ 693{
494 static net_rate_limiter limiter(1); 694 if (reset_rate_limiter.can (dsa) && connectmode != conf_node::C_DISABLED)
495
496 if (limiter.can (dsa))
497 { 695 {
498 config_packet *pkt = new config_packet; 696 config_packet *pkt = new config_packet;
499 697
500 pkt->setup (vpn_packet::PT_RESET, conf->id); 698 pkt->setup (vpn_packet::PT_RESET, conf->id);
501 vpn->send_vpn_packet (pkt, dsa); 699 vpn->send_vpn_packet (pkt, dsa, IPTOS_MINCOST);
502 700
503 delete pkt; 701 delete pkt;
504 } 702 }
505} 703}
506 704
507static rsachallenge * 705static rsachallenge *
508gen_challenge (SOCKADDR *sa) 706gen_challenge (u32 seqrand, SOCKADDR *sa)
509{ 707{
510 static rsachallenge k; 708 static rsachallenge k;
511 709
512 memcpy (&k, &challenge_bytes (), sizeof (k)); 710 memcpy (&k, &challenge_bytes (), sizeof (k));
513 RAND_bytes ((unsigned char *)&k[CHG_SEQNO], sizeof (u32)); 711 *(u32 *)&k[CHG_SEQNO] ^= seqrand;
514 xor_sa (k, sa); 712 xor_sa (k, sa);
515 713
516 return &k; 714 return &k;
517} 715}
518 716
519void 717void
520connection::send_auth (auth_subtype subtype, SOCKADDR *sa, rsachallenge *k) 718connection::send_auth (auth_subtype subtype, SOCKADDR *sa, const rsachallenge *k)
521{ 719{
522 static net_rate_limiter limiter(2);
523
524 if (subtype != AUTH_INIT || limiter.can (sa)) 720 if (subtype == AUTH_REPLY || auth_rate_limiter.can (sa))
525 { 721 {
722 if (!k)
723 k = gen_challenge (seqrand, sa);
724
526 auth_packet *pkt = new auth_packet (conf->id, subtype); 725 auth_packet *pkt = new auth_packet (conf->id, subtype);
527 726
528 //printf ("send auth_packet subtype %d\n", subtype);//D 727 memcpy (pkt->challenge, rsa_cache.public_encrypt (conf->rsa_key, *k), sizeof (rsaencrdata));
529
530 if (!k)
531 k = gen_challenge (sa);
532
533#if ENABLE_TRUST
534 if (0 > RSA_public_encrypt (sizeof (*k),
535 (unsigned char *)k, (unsigned char *)&pkt->challenge,
536 conf->rsa_key, RSA_PKCS1_OAEP_PADDING))
537 fatal ("RSA_public_encrypt error");
538#else
539# error untrusted mode not yet implemented: programemr does not know how to
540 rsaencrdata enc;
541
542 if (0 > RSA_private_encrypt (sizeof (*k),
543 (unsigned char *)k, (unsigned char *)&enc,
544 ::conf.rsa_key, RSA_PKCS1_OAEP_PADDING))
545 fatal ("RSA_private_encrypt error");
546
547 if (0 > RSA_public_encrypt (sizeof (enc),
548 (unsigned char *)enc, (unsigned char *)&pkt->challenge,
549 conf->rsa_key, RSA_NO_PADDING))
550 fatal ("RSA_public_encrypt error");
551#endif
552 728
553 slog (L_TRACE, ">>%d PT_AUTH(%d) [%s]", conf->id, subtype, (const char *)sockinfo (sa)); 729 slog (L_TRACE, ">>%d PT_AUTH(%d) [%s]", conf->id, subtype, (const char *)sockinfo (sa));
554 730
555 vpn->send_vpn_packet (pkt, sa); 731 vpn->send_vpn_packet (pkt, sa, IPTOS_RELIABILITY);
556 732
557 delete pkt; 733 delete pkt;
558 } 734 }
559} 735}
560 736
561void 737void
562connection::establish_connection () 738connection::establish_connection_cb (tstamp &ts)
563{ 739{
564 if (!ictx && conf != THISNODE && connectmode != conf_node::C_NEVER) 740 if (ictx || conf == THISNODE || connectmode == conf_node::C_NEVER)
741 ts = TSTAMP_CANCEL;
742 else if (ts <= NOW)
565 { 743 {
566 if (now >= next_retry) 744 double retry_int = double (retry_cnt & 3 ? (retry_cnt & 3) : 1 << (retry_cnt >> 2)) * 0.25;
567 {
568 int retry_int = retry_cnt & 3 ? (retry_cnt & 3) : 1 << (retry_cnt >> 2);
569 745
570 if (retry_cnt < (17 << 2) | 3) 746 if (retry_int < 3600 * 8)
571 retry_cnt++; 747 retry_cnt++;
572 748
573 if (connectmode == conf_node::C_ONDEMAND 749 ts = NOW + retry_int;
574 && retry_int > ::conf.keepalive)
575 retry_int = ::conf.keepalive;
576 750
577 next_retry = now + retry_int;
578 next_wakeup (next_retry);
579
580 if (conf->hostname) 751 if (conf->hostname)
581 { 752 {
582 reset_dstaddr (); 753 reset_dstaddr ();
583 if (sa.sin_addr.s_addr) 754 if (sa.sin_addr.s_addr)
584 if (retry_cnt < 4) 755 if (retry_cnt < 4)
585 send_auth (AUTH_INIT, &sa); 756 send_auth (AUTH_INIT, &sa);
586 else 757 else if (auth_rate_limiter.can (&sa))
587 send_ping (&sa, 0); 758 send_ping (&sa, 0);
588 } 759 }
589 else 760 else
590 vpn->connect_request (conf->id); 761 vpn->connect_request (conf->id);
591 }
592 } 762 }
593} 763}
594 764
595void 765void
596connection::reset_connection () 766connection::reset_connection ()
601 771
602 if (::conf.script_node_down) 772 if (::conf.script_node_down)
603 run_script (this, &connection::script_node_down, false); 773 run_script (this, &connection::script_node_down, false);
604 } 774 }
605 775
606 delete ictx; 776 delete ictx; ictx = 0;
607 ictx = 0; 777 delete octx; octx = 0;
608 778
609 delete octx; 779 RAND_bytes ((unsigned char *)&seqrand, sizeof (u32));
610 octx = 0;
611 780
612 sa.sin_port = 0; 781 sa.sin_port = 0;
613 sa.sin_addr.s_addr = 0; 782 sa.sin_addr.s_addr = 0;
614 783
615 next_retry = 0;
616 next_rekey = 0;
617 last_activity = 0; 784 last_activity = 0;
785
786 rekey.reset ();
787 keepalive.reset ();
788 establish_connection.reset ();
618} 789}
619 790
620void 791void
621connection::shutdown () 792connection::shutdown ()
622{ 793{
625 796
626 reset_connection (); 797 reset_connection ();
627} 798}
628 799
629void 800void
630connection::rekey () 801connection::rekey_cb (tstamp &ts)
631{ 802{
803 ts = TSTAMP_CANCEL;
804
632 reset_connection (); 805 reset_connection ();
633 establish_connection (); 806 establish_connection ();
634} 807}
635 808
636void 809void
637connection::send_data_packet (tap_packet * pkt, bool broadcast) 810connection::send_data_packet (tap_packet * pkt, bool broadcast)
638{ 811{
639 vpndata_packet *p = new vpndata_packet; 812 vpndata_packet *p = new vpndata_packet;
813 int tos = 0;
814
815 if (conf->inherit_tos
816 && (*pkt)[12] == 0x08 && (*pkt)[13] == 0x00 // IP
817 && ((*pkt)[14] & 0xf0) == 0x40) // IPv4
818 tos = (*pkt)[15] & IPTOS_TOS_MASK;
640 819
641 p->setup (this, broadcast ? 0 : conf->id, &((*pkt)[6 + 6]), pkt->len - 6 - 6, ++oseqno); // skip 2 macs 820 p->setup (this, broadcast ? 0 : conf->id, &((*pkt)[6 + 6]), pkt->len - 6 - 6, ++oseqno); // skip 2 macs
642 vpn->send_vpn_packet (p, &sa); 821 vpn->send_vpn_packet (p, &sa, tos);
643 822
644 delete p; 823 delete p;
645 824
646 if (oseqno > MAX_SEQNO) 825 if (oseqno > MAX_SEQNO)
647 rekey (); 826 rekey ();
662} 841}
663 842
664void 843void
665connection::recv_vpn_packet (vpn_packet *pkt, SOCKADDR *ssa) 844connection::recv_vpn_packet (vpn_packet *pkt, SOCKADDR *ssa)
666{ 845{
667 last_activity = now; 846 last_activity = NOW;
668 847
669 slog (L_NOISE, "<<%d received packet type %d from %d to %d", 848 slog (L_NOISE, "<<%d received packet type %d from %d to %d",
670 conf->id, pkt->typ (), pkt->src (), pkt->dst ()); 849 conf->id, pkt->typ (), pkt->src (), pkt->dst ());
671 850
672 switch (pkt->typ ()) 851 switch (pkt->typ ())
673 { 852 {
674 case vpn_packet::PT_PING: 853 case vpn_packet::PT_PING:
675 send_ping (ssa, 1); // pong
676 break;
677
678 case vpn_packet::PT_PONG:
679 // we send pings instead of auth packets after some retries, 854 // we send pings instead of auth packets after some retries,
680 // so reset the retry counter and establish a conenction 855 // so reset the retry counter and establish a conenction
681 // when we receive a pong. 856 // when we receive a pong.
682 if (!ictx && !octx) 857 if (!ictx && !octx)
683 { 858 {
684 retry_cnt = 0; 859 retry_cnt = 0;
685 next_retry = 0; 860 establish_connection.at = 0;
686 establish_connection (); 861 establish_connection ();
687 } 862 }
863 else
864 send_ping (ssa, 1); // pong
688 865
866 break;
867
868 case vpn_packet::PT_PONG:
689 break; 869 break;
690 870
691 case vpn_packet::PT_RESET: 871 case vpn_packet::PT_RESET:
692 { 872 {
693 reset_connection (); 873 reset_connection ();
694 874
695 config_packet *p = (config_packet *) pkt; 875 config_packet *p = (config_packet *) pkt;
696 if (p->chk_config ()) 876 if (!p->chk_config ())
877 {
878 slog (L_WARN, _("protocol mismatch, disabling node '%s'"), conf->nodename);
879 connectmode = conf_node::C_DISABLED;
880 }
697 if (connectmode == conf_node::C_ALWAYS) 881 else if (connectmode == conf_node::C_ALWAYS)
698 establish_connection (); 882 establish_connection ();
699
700 //D slog the protocol mismatch?
701 } 883 }
702 break; 884 break;
703 885
704 case vpn_packet::PT_AUTH: 886 case vpn_packet::PT_AUTH:
705 { 887 {
715 PROTOCOL_MINOR, conf->nodename, p->prot_minor); 897 PROTOCOL_MINOR, conf->nodename, p->prot_minor);
716 898
717 if (p->subtype == AUTH_INIT) 899 if (p->subtype == AUTH_INIT)
718 send_auth (AUTH_INITREPLY, ssa); 900 send_auth (AUTH_INITREPLY, ssa);
719 901
720 rsachallenge k; 902 const rsachallenge *k = rsa_cache.private_decrypt (::conf.rsa_key, p->challenge);
721 903
722#if ENABLE_TRUST
723 if (0 > RSA_private_decrypt (sizeof (rsaencrdata),
724 (unsigned char *)&p->challenge, (unsigned char *)&k,
725 ::conf.rsa_key, RSA_PKCS1_OAEP_PADDING))
726 // continued below
727#else
728 rsaencrdata j;
729 904 if (!k)
730 if (0 > RSA_private_decrypt (sizeof (rsaencrdata),
731 (unsigned char *)&p->challenge, (unsigned char *)&j,
732 ::conf.rsa_key, RSA_NO_PADDING))
733 fatal ("RSA_private_decrypt error");
734
735 if (0 > RSA_public_decrypt (sizeof (k),
736 (unsigned char *)&j, (unsigned char *)&k,
737 conf->rsa_key, RSA_PKCS1_OAEP_PADDING))
738 // continued below
739#endif
740 { 905 {
741 slog (L_ERR, _("challenge from %s (%s) illegal or corrupted"), 906 slog (L_ERR, _("challenge from %s (%s) illegal or corrupted"),
742 conf->nodename, (const char *)sockinfo (ssa)); 907 conf->nodename, (const char *)sockinfo (ssa));
908 send_reset (ssa);
743 break; 909 break;
744 } 910 }
745 911
746 retry_cnt = 0; 912 retry_cnt = 0;
747 next_retry = now + 8; 913 establish_connection.set (NOW + 8); //? ;)
914 keepalive.reset ();
915 rekey.reset ();
748 916
749 switch (p->subtype) 917 switch (p->subtype)
750 { 918 {
751 case AUTH_INIT: 919 case AUTH_INIT:
752 case AUTH_INITREPLY: 920 case AUTH_INITREPLY:
753 delete ictx; 921 delete ictx;
754 ictx = 0; 922 ictx = 0;
755 923
756 delete octx; 924 delete octx;
757 925
758 octx = new crypto_ctx (k, 1); 926 octx = new crypto_ctx (*k, 1);
759 oseqno = *(u32 *)&k[CHG_SEQNO] & 0x7fffffff; 927 oseqno = ntohl (*(u32 *)&k[CHG_SEQNO]) & 0x7fffffff;
760 928
761 send_auth (AUTH_REPLY, ssa, &k); 929 send_auth (AUTH_REPLY, ssa, k);
762 break; 930 break;
763 931
764 case AUTH_REPLY: 932 case AUTH_REPLY:
765 933
766 if (!memcmp ((u8 *)gen_challenge (ssa) + sizeof (u32), (u8 *)&k + sizeof (u32), 934 if (!memcmp ((u8 *)gen_challenge (seqrand, ssa), (u8 *)k, sizeof (rsachallenge)))
767 sizeof (rsachallenge) - sizeof (u32)))
768 { 935 {
769 delete ictx; 936 delete ictx;
770 937
771 ictx = new crypto_ctx (k, 0); 938 ictx = new crypto_ctx (*k, 0);
772 iseqno = *(u32 *)&k[CHG_SEQNO] & 0x7fffffff; // at least 2**31 sequence numbers are valid 939 iseqno.reset (ntohl (*(u32 *)&k[CHG_SEQNO]) & 0x7fffffff); // at least 2**31 sequence numbers are valid
773 ismask = 0xffffffff; // initially, all lower sequence numbers are invalid
774 940
775 sa = *ssa; 941 sa = *ssa;
776 942
777 next_rekey = now + ::conf.rekey; 943 rekey.set (NOW + ::conf.rekey);
778 next_wakeup (next_rekey); 944 keepalive.set (NOW + ::conf.keepalive);
779 945
780 // send queued packets 946 // send queued packets
781 while (tap_packet *p = queue.get ()) 947 while (tap_packet *p = queue.get ())
782 { 948 {
783 send_data_packet (p); 949 send_data_packet (p);
828 else 994 else
829 { 995 {
830 u32 seqno; 996 u32 seqno;
831 tap_packet *d = p->unpack (this, seqno); 997 tap_packet *d = p->unpack (this, seqno);
832 998
833 if (seqno <= iseqno - 32) 999 if (iseqno.recv_ok (seqno))
834 slog (L_ERR, _("received duplicate or outdated packet (received %08lx, expected %08lx)\n"
835 "possible replay attack, or just massive packet reordering"), seqno, iseqno + 1);//D
836 else if (seqno > iseqno + 32)
837 slog (L_ERR, _("received duplicate or out-of-sync packet (received %08lx, expected %08lx)\n"
838 "possible replay attack, or just massive packet loss"), seqno, iseqno + 1);//D
839 else
840 { 1000 {
841 if (seqno > iseqno)
842 {
843 ismask <<= seqno - iseqno;
844 iseqno = seqno;
845 }
846
847 u32 mask = 1 << (iseqno - seqno);
848
849 //printf ("received seqno %08lx, iseqno %08lx, mask %08lx is %08lx\n", seqno, iseqno, mask, ismask);
850 if (ismask & mask)
851 slog (L_ERR, _("received duplicate packet (received %08lx, expected %08lx)\n"
852 "possible replay attack, or just packet duplication"), seqno, iseqno + 1);//D
853 else
854 {
855 ismask |= mask;
856
857 vpn->tap->send (d); 1001 vpn->tap->send (d);
858 1002
859 if (p->dst () == 0) // re-broadcast 1003 if (p->dst () == 0) // re-broadcast
860 for (vpn::conns_vector::iterator i = vpn->conns.begin (); i != vpn->conns.end (); ++i) 1004 for (vpn::conns_vector::iterator i = vpn->conns.begin (); i != vpn->conns.end (); ++i)
861 { 1005 {
862 connection *c = *i; 1006 connection *c = *i;
863 1007
864 if (c->conf != THISNODE && c->conf != conf) 1008 if (c->conf != THISNODE && c->conf != conf)
865 c->inject_data_packet (d); 1009 c->inject_data_packet (d);
866 }
867
868 delete d;
869
870 break;
871 } 1010 }
1011
1012 delete d;
1013
1014 break;
872 } 1015 }
873 } 1016 }
874 } 1017 }
875 else 1018 else
876 slog (L_ERR, _("received data packet from unknown source %s"), (const char *)sockinfo (ssa));//D 1019 slog (L_ERR, _("received data packet from unknown source %s"), (const char *)sockinfo (ssa));//D
947 send_reset (ssa); 1090 send_reset (ssa);
948 break; 1091 break;
949 } 1092 }
950} 1093}
951 1094
952void connection::timer () 1095void connection::keepalive_cb (tstamp &ts)
953{ 1096{
954 if (conf != THISNODE) 1097 if (NOW >= last_activity + ::conf.keepalive + 30)
955 { 1098 {
956 if (now >= next_retry && connectmode == conf_node::C_ALWAYS) 1099 reset_connection ();
957 establish_connection (); 1100 establish_connection ();
958 1101 }
959 if (ictx && octx)
960 {
961 if (now >= next_rekey)
962 rekey ();
963 else if (now >= last_activity + ::conf.keepalive + 30)
964 {
965 reset_connection ();
966 establish_connection ();
967 }
968 else if (now >= last_activity + ::conf.keepalive) 1102 else if (NOW < last_activity + ::conf.keepalive)
1103 ts = last_activity + ::conf.keepalive;
969 if (conf->connectmode != conf_node::C_ONDEMAND 1104 else if (conf->connectmode != conf_node::C_ONDEMAND
970 || THISNODE->connectmode != conf_node::C_ONDEMAND) 1105 || THISNODE->connectmode != conf_node::C_ONDEMAND)
1106 {
971 send_ping (&sa); 1107 send_ping (&sa);
972 else 1108 ts = NOW + 5;
1109 }
1110 else
973 reset_connection (); 1111 reset_connection ();
974 1112
975 }
976 }
977} 1113}
978 1114
979void connection::connect_request (int id) 1115void connection::connect_request (int id)
980{ 1116{
981 connect_req_packet *p = new connect_req_packet (conf->id, id); 1117 connect_req_packet *p = new connect_req_packet (conf->id, id);
1018 putenv ("STATE=down"); 1154 putenv ("STATE=down");
1019 1155
1020 return ::conf.script_node_up ? ::conf.script_node_down : "node-down"; 1156 return ::conf.script_node_up ? ::conf.script_node_down : "node-down";
1021} 1157}
1022 1158
1159connection::connection(struct vpn *vpn_)
1160: vpn(vpn_)
1161, rekey (this, &connection::rekey_cb)
1162, keepalive (this, &connection::keepalive_cb)
1163, establish_connection (this, &connection::establish_connection_cb)
1164{
1165 octx = ictx = 0;
1166 retry_cnt = 0;
1167
1168 connectmode = conf_node::C_ALWAYS; // initial setting
1169 reset_connection ();
1170}
1171
1172connection::~connection ()
1173{
1174 shutdown ();
1175}
1176
1023///////////////////////////////////////////////////////////////////////////// 1177/////////////////////////////////////////////////////////////////////////////
1024
1025vpn::vpn (void)
1026{}
1027 1178
1028const char *vpn::script_if_up () 1179const char *vpn::script_if_up ()
1029{ 1180{
1030 // the tunnel device mtu should be the physical mtu - overhead 1181 // the tunnel device mtu should be the physical mtu - overhead
1031 // the tricky part is rounding to the cipher key blocksize 1182 // the tricky part is rounding to the cipher key blocksize
1082 { 1233 {
1083 int oval = 1; 1234 int oval = 1;
1084 setsockopt (socket_fd, SOL_SOCKET, SO_REUSEADDR, &oval, sizeof oval); 1235 setsockopt (socket_fd, SOL_SOCKET, SO_REUSEADDR, &oval, sizeof oval);
1085 } 1236 }
1086 1237
1238 udp_ev_watcher.start (socket_fd, POLLIN);
1239
1087 tap = new tap_device (); 1240 tap = new tap_device ();
1088 if (!tap) //D this, of course, never catches 1241 if (!tap) //D this, of course, never catches
1089 { 1242 {
1090 slog (L_ERR, _("cannot create network interface '%s'"), conf.ifname); 1243 slog (L_ERR, _("cannot create network interface '%s'"), conf.ifname);
1091 exit (1); 1244 exit (1);
1092 } 1245 }
1093 1246
1094 run_script (this, &vpn::script_if_up, true); 1247 run_script (this, &vpn::script_if_up, true);
1095 1248
1249 vpn_ev_watcher.start (tap->fd, POLLIN);
1250
1251 reconnect_all ();
1252
1096 return 0; 1253 return 0;
1097} 1254}
1098 1255
1099void 1256void
1100vpn::send_vpn_packet (vpn_packet *pkt, SOCKADDR *sa) 1257vpn::send_vpn_packet (vpn_packet *pkt, SOCKADDR *sa, int tos)
1101{ 1258{
1259 setsockopt (socket_fd, SOL_IP, IP_TOS, &tos, sizeof tos);
1102 sendto (socket_fd, &((*pkt)[0]), pkt->len, 0, (sockaddr *)sa, sizeof (*sa)); 1260 sendto (socket_fd, &((*pkt)[0]), pkt->len, 0, (sockaddr *)sa, sizeof (*sa));
1103} 1261}
1104 1262
1105void 1263void
1106vpn::shutdown_all () 1264vpn::shutdown_all ()
1163 // if ((*i)->conf->routerprio) 1321 // if ((*i)->conf->routerprio)
1164 // (*i)->establish_connection (); 1322 // (*i)->establish_connection ();
1165} 1323}
1166 1324
1167void 1325void
1168vpn::main_loop () 1326vpn::udp_ev (short revents)
1169{ 1327{
1170 struct pollfd pollfd[2]; 1328 if (revents & (POLLIN | POLLERR))
1171
1172 pollfd[0].fd = tap->fd;
1173 pollfd[0].events = POLLIN;
1174 pollfd[1].fd = socket_fd;
1175 pollfd[1].events = POLLIN;
1176
1177 events = 0;
1178 now = time (0);
1179 next_timecheck = now + 1;
1180
1181 reconnect_all ();
1182
1183 for (;;)
1184 { 1329 {
1185 int npoll = poll (pollfd, 2, (next_timecheck - now) * 1000); 1330 vpn_packet *pkt = new vpn_packet;
1186 1331 struct sockaddr_in sa;
1187 now = time (0); 1332 socklen_t sa_len = sizeof (sa);
1333 int len;
1188 1334
1335 len = recvfrom (socket_fd, &((*pkt)[0]), MAXSIZE, 0, (sockaddr *)&sa, &sa_len);
1336
1189 if (npoll > 0) 1337 if (len > 0)
1338 {
1339 pkt->len = len;
1340
1341 unsigned int src = pkt->src ();
1342 unsigned int dst = pkt->dst ();
1343
1344 slog (L_NOISE, _("<<?/%s received possible vpn packet type %d from %d to %d, length %d"),
1345 (const char *)sockinfo (sa), pkt->typ (), pkt->src (), pkt->dst (), pkt->len);
1346
1347 if (dst > conns.size () || pkt->typ () >= vpn_packet::PT_MAX)
1348 slog (L_WARN, _("<<? received CORRUPTED packet type %d from %d to %d"),
1349 pkt->typ (), pkt->src (), pkt->dst ());
1350 else if (dst == 0 && !THISNODE->routerprio)
1351 slog (L_WARN, _("<<%d received broadcast, but we are no router"), dst);
1352 else if (dst != 0 && dst != THISNODE->id)
1353 slog (L_WARN,
1354 _("received frame for node %d ('%s') from %s, but this is node %d ('%s')"),
1355 dst, conns[dst - 1]->conf->nodename,
1356 (const char *)sockinfo (sa),
1357 THISNODE->id, THISNODE->nodename);
1358 else if (src == 0 || src > conns.size ())
1359 slog (L_WARN, _("received frame from unknown node %d (%s)"), src, (const char *)sockinfo (sa));
1360 else
1361 conns[src - 1]->recv_vpn_packet (pkt, &sa);
1190 { 1362 }
1191 if (pollfd[1].revents) 1363 else
1364 {
1365 // probably ECONNRESET or somesuch
1366 slog (L_DEBUG, _("%s: %s"), (const char *)sockinfo(sa), strerror (errno));
1367 }
1368
1369 delete pkt;
1370 }
1371 else if (revents & POLLHUP)
1372 {
1373 // this cannot ;) happen on udp sockets
1374 slog (L_ERR, _("FATAL: POLLHUP on socket fd, terminating."));
1375 exit (1);
1376 }
1377 else
1378 {
1379 slog (L_ERR,
1380 _("FATAL: unknown revents %08x in socket, terminating\n"),
1381 revents);
1382 exit (1);
1383 }
1384}
1385
1386void
1387vpn::vpn_ev (short revents)
1388{
1389 if (revents & POLLIN)
1390 {
1391 /* process data */
1392 tap_packet *pkt;
1393
1394 pkt = tap->recv ();
1395
1396 int dst = mac2id (pkt->dst);
1397 int src = mac2id (pkt->src);
1398
1399 if (src != THISNODE->id)
1400 {
1401 slog (L_ERR, _("FATAL: tap packet not originating on current node received, terminating."));
1402 exit (1);
1403 }
1404
1405 if (dst == THISNODE->id)
1406 {
1407 slog (L_ERR, _("FATAL: tap packet destined for current node received, terminating."));
1408 exit (1);
1409 }
1410
1411 if (dst > conns.size ())
1412 slog (L_ERR, _("tap packet for unknown node %d received, ignoring."), dst);
1413 else
1414 {
1415 if (dst)
1192 { 1416 {
1193 if (pollfd[1].revents & (POLLIN | POLLERR)) 1417 // unicast
1194 {
1195 vpn_packet *pkt = new vpn_packet;
1196 struct sockaddr_in sa;
1197 socklen_t sa_len = sizeof (sa);
1198 int len;
1199
1200 len = recvfrom (socket_fd, &((*pkt)[0]), MAXSIZE, 0, (sockaddr *)&sa, &sa_len);
1201
1202 if (len > 0)
1203 {
1204 pkt->len = len;
1205
1206 unsigned int src = pkt->src ();
1207 unsigned int dst = pkt->dst ();
1208
1209 slog (L_NOISE, _("<<?/%s received possible vpn packet type %d from %d to %d, length %d"),
1210 (const char *)sockinfo (sa), pkt->typ (), pkt->src (), pkt->dst (), pkt->len);
1211
1212 if (dst > conns.size () || pkt->typ () >= vpn_packet::PT_MAX)
1213 slog (L_WARN, _("<<? received CORRUPTED packet type %d from %d to %d"),
1214 pkt->typ (), pkt->src (), pkt->dst ());
1215 else if (dst == 0 && !THISNODE->routerprio)
1216 slog (L_WARN, _("<<%d received broadcast, but we are no router"), dst);
1217 else if (dst != 0 && dst != THISNODE->id) 1418 if (dst != THISNODE->id)
1218 slog (L_WARN,
1219 _("received frame for node %d ('%s') from %s, but this is node %d ('%s')"),
1220 dst, conns[dst - 1]->conf->nodename,
1221 (const char *)sockinfo (sa),
1222 THISNODE->id, THISNODE->nodename);
1223 else if (src == 0 || src > conns.size ())
1224 slog (L_WARN, _("received frame from unknown node %d (%s)"), src, (const char *)sockinfo (sa));
1225 else
1226 conns[src - 1]->recv_vpn_packet (pkt, &sa); 1419 conns[dst - 1]->inject_data_packet (pkt);
1227 }
1228 else
1229 {
1230 // probably ECONNRESET or somesuch
1231 slog (L_DEBUG, _("%s: %s"), (const char *)sockinfo(sa), strerror (errno));
1232 }
1233
1234 delete pkt;
1235 } 1420 }
1236 else if (pollfd[1].revents & POLLHUP) 1421 else
1237 { 1422 {
1238 // this cannot ;) happen on udp sockets 1423 // broadcast, first check router, then self, then english
1239 slog (L_ERR, _("FATAL: POLLHUP on socket fd, terminating.")); 1424 connection *router = find_router ();
1240 exit (1); 1425
1241 } 1426 if (router)
1427 router->inject_data_packet (pkt, true);
1242 else 1428 else
1243 { 1429 for (conns_vector::iterator c = conns.begin (); c != conns.end (); ++c)
1244 slog (L_ERR, 1430 if ((*c)->conf != THISNODE)
1245 _("FATAL: unknown revents %08x in socket, terminating\n"), 1431 (*c)->inject_data_packet (pkt);
1246 pollfd[1].revents);
1247 exit (1);
1248 }
1249 } 1432 }
1433 }
1250 1434
1251 // I use else here to give vpn_packets absolute priority 1435 delete pkt;
1252 else if (pollfd[0].revents) 1436 }
1253 {
1254 if (pollfd[0].revents & POLLIN)
1255 {
1256 /* process data */
1257 tap_packet *pkt;
1258
1259 pkt = tap->recv ();
1260
1261 int dst = mac2id (pkt->dst);
1262 int src = mac2id (pkt->src);
1263
1264 if (src != THISNODE->id)
1265 {
1266 slog (L_ERR, _("FATAL: tap packet not originating on current node received, terminating."));
1267 exit (1);
1268 }
1269
1270 if (dst == THISNODE->id)
1271 {
1272 slog (L_ERR, _("FATAL: tap packet destined for current node received, terminating."));
1273 exit (1);
1274 }
1275
1276 if (dst > conns.size ())
1277 slog (L_ERR, _("tap packet for unknown node %d received, ignoring."), dst);
1278 else
1279 {
1280 if (dst)
1281 {
1282 // unicast
1283 if (dst != THISNODE->id)
1284 conns[dst - 1]->inject_data_packet (pkt);
1285 }
1286 else
1287 {
1288 // broadcast, first check router, then self, then english
1289 connection *router = find_router ();
1290
1291 if (router)
1292 router->inject_data_packet (pkt, true);
1293 else
1294 for (conns_vector::iterator c = conns.begin (); c != conns.end (); ++c)
1295 if ((*c)->conf != THISNODE)
1296 (*c)->inject_data_packet (pkt);
1297 }
1298 }
1299
1300 delete pkt;
1301 }
1302 else if (pollfd[0].revents & (POLLHUP | POLLERR)) 1437 else if (revents & (POLLHUP | POLLERR))
1303 { 1438 {
1304 slog (L_ERR, _("FATAL: POLLHUP or POLLERR on network device fd, terminating.")); 1439 slog (L_ERR, _("FATAL: POLLHUP or POLLERR on network device fd, terminating."));
1305 exit (1); 1440 exit (1);
1306 } 1441 }
1307 else 1442 else
1308 abort (); 1443 abort ();
1309 } 1444}
1310 }
1311 1445
1446void
1447vpn::event_cb (tstamp &ts)
1448{
1312 if (events) 1449 if (events)
1313 { 1450 {
1314 if (events & EVENT_SHUTDOWN) 1451 if (events & EVENT_SHUTDOWN)
1315 { 1452 {
1316 shutdown_all (); 1453 shutdown_all ();
1317 1454
1318 remove_pid (pidfilename); 1455 remove_pid (pidfilename);
1319 1456
1320 slog (L_INFO, _("vped terminating")); 1457 slog (L_INFO, _("vped terminating"));
1321 1458
1322 exit (0); 1459 exit (0);
1323 } 1460 }
1324 1461
1325 if (events & EVENT_RECONNECT) 1462 if (events & EVENT_RECONNECT)
1326 reconnect_all (); 1463 reconnect_all ();
1327 1464
1328 events = 0; 1465 events = 0;
1329 }
1330
1331 // very very very dumb and crude and inefficient timer handling, or maybe not?
1332 if (now >= next_timecheck)
1333 {
1334 next_timecheck = now + TIMER_GRANULARITY;
1335
1336 for (conns_vector::iterator c = conns.begin ();
1337 c != conns.end (); ++c)
1338 (*c)->timer ();
1339 }
1340 } 1466 }
1467
1468 ts = TSTAMP_CANCEL;
1469}
1470
1471#include <sys/time.h>//D
1472vpn::vpn (void)
1473: udp_ev_watcher (this, &vpn::udp_ev)
1474, vpn_ev_watcher (this, &vpn::vpn_ev)
1475, event (this, &vpn::event_cb)
1476{
1341} 1477}
1342 1478
1343vpn::~vpn () 1479vpn::~vpn ()
1344{} 1480{
1481}
1345 1482

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