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Comparing gvpe/src/connection.C (file contents):
Revision 1.4 by pcg, Wed Apr 2 21:02:25 2003 UTC vs.
Revision 1.35 by pcg, Mon May 10 21:24:48 2004 UTC

1/* 1/*
2 connection.C -- manage a single connection 2 connection.C -- manage a single connection
3 Copyright (C) 2003-2004 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.
… …
16 Foundation, Inc. 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA 17 Foundation, Inc. 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
17*/ 18*/
18 19
19#include "config.h" 20#include "config.h"
20 21
21extern "C" { 22#include <cassert>
22# include "lzf/lzf.h"
23}
24 23
25#include <list> 24#include <list>
26 25
27#include <openssl/rand.h> 26#include <openssl/rand.h>
28#include <openssl/evp.h> 27#include <openssl/evp.h>
… …
35#include "slog.h" 34#include "slog.h"
36#include "device.h" 35#include "device.h"
37#include "vpn.h" 36#include "vpn.h"
38#include "connection.h" 37#include "connection.h"
39 38
39#include "netcompat.h"
40
40#if !HAVE_RAND_PSEUDO_BYTES 41#if !HAVE_RAND_PSEUDO_BYTES
41# define RAND_pseudo_bytes RAND_bytes 42# define RAND_pseudo_bytes RAND_bytes
42#endif 43#endif
43 44
44#define MAGIC "vped\xbd\xc6\xdb\x82" // 8 bytes of magic 45#define MAGIC "vped\xbd\xc6\xdb\x82" // 8 bytes of magic
45 46
47#define ULTRA_FAST 1
48#define HLOG 15
49#include "lzf/lzf.h"
50#include "lzf/lzf_c.c"
51#include "lzf/lzf_d.c"
52
46struct crypto_ctx 53struct crypto_ctx
47{ 54{
48 EVP_CIPHER_CTX cctx; 55 EVP_CIPHER_CTX cctx;
49 HMAC_CTX hctx; 56 HMAC_CTX hctx;
50 57
… …
53}; 60};
54 61
55crypto_ctx::crypto_ctx (const rsachallenge &challenge, int enc) 62crypto_ctx::crypto_ctx (const rsachallenge &challenge, int enc)
56{ 63{
57 EVP_CIPHER_CTX_init (&cctx); 64 EVP_CIPHER_CTX_init (&cctx);
58 EVP_CipherInit_ex (&cctx, CIPHER, 0, &challenge[CHG_CIPHER_KEY], 0, enc); 65 require (EVP_CipherInit_ex (&cctx, CIPHER, 0, &challenge[CHG_CIPHER_KEY], 0, enc));
59 HMAC_CTX_init (&hctx); 66 HMAC_CTX_init (&hctx);
60 HMAC_Init_ex (&hctx, &challenge[CHG_HMAC_KEY], HMAC_KEYLEN, DIGEST, 0); 67 HMAC_Init_ex (&hctx, &challenge[CHG_HMAC_KEY], HMAC_KEYLEN, DIGEST, 0);
61} 68}
62 69
63crypto_ctx::~crypto_ctx () 70crypto_ctx::~crypto_ctx ()
64{ 71{
65 EVP_CIPHER_CTX_cleanup (&cctx); 72 require (EVP_CIPHER_CTX_cleanup (&cctx));
66 HMAC_CTX_cleanup (&hctx); 73 HMAC_CTX_cleanup (&hctx);
67} 74}
68 75
69static void 76static void
70rsa_hash (const rsaid &id, const rsachallenge &chg, rsaresponse &h) 77rsa_hash (const rsaid &id, const rsachallenge &chg, rsaresponse &h)
71{ 78{
72 EVP_MD_CTX ctx; 79 EVP_MD_CTX ctx;
73 80
74 EVP_MD_CTX_init (&ctx); 81 EVP_MD_CTX_init (&ctx);
75 EVP_DigestInit (&ctx, RSA_HASH); 82 require (EVP_DigestInit (&ctx, RSA_HASH));
76 EVP_DigestUpdate(&ctx, &chg, sizeof chg); 83 require (EVP_DigestUpdate(&ctx, &chg, sizeof chg));
77 EVP_DigestUpdate(&ctx, &id, sizeof id); 84 require (EVP_DigestUpdate(&ctx, &id, sizeof id));
78 EVP_DigestFinal (&ctx, (unsigned char *)&h, 0); 85 require (EVP_DigestFinal (&ctx, (unsigned char *)&h, 0));
79 EVP_MD_CTX_cleanup (&ctx); 86 EVP_MD_CTX_cleanup (&ctx);
80} 87}
81 88
82struct rsa_entry { 89struct rsa_entry {
83 tstamp expire; 90 tstamp expire;
… …
131 138
132} rsa_cache; 139} rsa_cache;
133 140
134void rsa_cache::cleaner_cb (time_watcher &w) 141void rsa_cache::cleaner_cb (time_watcher &w)
135{ 142{
136 if (empty ()) 143 if (!empty ())
137 w.at = TSTAMP_CANCEL;
138 else
139 { 144 {
140 w.at = NOW + RSA_TTL; 145 w.start (NOW + RSA_TTL);
141 146
142 for (iterator i = begin (); i != end (); ) 147 for (iterator i = begin (); i != end (); )
143 if (i->expire <= NOW) 148 if (i->expire <= NOW)
144 i = erase (i); 149 i = erase (i);
145 else 150 else
… …
147 } 152 }
148} 153}
149 154
150////////////////////////////////////////////////////////////////////////////// 155//////////////////////////////////////////////////////////////////////////////
151 156
152void pkt_queue::put (tap_packet *p) 157void pkt_queue::put (net_packet *p)
153{ 158{
154 if (queue[i]) 159 if (queue[i])
155 { 160 {
156 delete queue[i]; 161 delete queue[i];
157 j = (j + 1) % QUEUEDEPTH; 162 j = (j + 1) % QUEUEDEPTH;
… …
160 queue[i] = p; 165 queue[i] = p;
161 166
162 i = (i + 1) % QUEUEDEPTH; 167 i = (i + 1) % QUEUEDEPTH;
163} 168}
164 169
165tap_packet *pkt_queue::get () 170net_packet *pkt_queue::get ()
166{ 171{
167 tap_packet *p = queue[j]; 172 net_packet *p = queue[j];
168 173
169 if (p) 174 if (p)
170 { 175 {
171 queue[j] = 0; 176 queue[j] = 0;
172 j = (j + 1) % QUEUEDEPTH; 177 j = (j + 1) % QUEUEDEPTH;
… …
197// only do action once every x seconds per host whole allowing bursts. 202// only do action once every x seconds per host whole allowing bursts.
198// this implementation ("splay list" ;) is inefficient, 203// this implementation ("splay list" ;) is inefficient,
199// but low on resources. 204// but low on resources.
200struct net_rate_limiter : list<net_rateinfo> 205struct net_rate_limiter : list<net_rateinfo>
201{ 206{
202 static const double ALPHA = 1. - 1. / 90.; // allow bursts 207# define NRL_ALPHA (1. - 1. / 600.) // allow bursts
203 static const double CUTOFF = 20.; // one event every CUTOFF seconds 208# define NRL_CUTOFF 10. // one event every CUTOFF seconds
204 static const double EXPIRE = CUTOFF * 30.; // expire entries after this time 209# define NRL_EXPIRE (NRL_CUTOFF * 30.) // expire entries after this time
210# define NRL_MAXDIF (NRL_CUTOFF * (1. / (1. - NRL_ALPHA))) // maximum diff /count value
205 211
206 bool can (const sockinfo &si) { return can((u32)si.host); } 212 bool can (const sockinfo &si) { return can((u32)si.host); }
207 bool can (u32 host); 213 bool can (u32 host);
208}; 214};
209 215
210net_rate_limiter auth_rate_limiter, reset_rate_limiter; 216net_rate_limiter auth_rate_limiter, reset_rate_limiter;
211 217
… …
214 iterator i; 220 iterator i;
215 221
216 for (i = begin (); i != end (); ) 222 for (i = begin (); i != end (); )
217 if (i->host == host) 223 if (i->host == host)
218 break; 224 break;
219 else if (i->last < NOW - EXPIRE) 225 else if (i->last < NOW - NRL_EXPIRE)
220 i = erase (i); 226 i = erase (i);
221 else 227 else
222 i++; 228 i++;
223 229
224 if (i == end ()) 230 if (i == end ())
225 { 231 {
226 net_rateinfo ri; 232 net_rateinfo ri;
227 233
228 ri.host = host; 234 ri.host = host;
229 ri.pcnt = 1.; 235 ri.pcnt = 1.;
230 ri.diff = CUTOFF * (1. / (1. - ALPHA)); 236 ri.diff = NRL_MAXDIF;
231 ri.last = NOW; 237 ri.last = NOW;
232 238
233 push_front (ri); 239 push_front (ri);
234 240
235 return true; 241 return true;
… …
237 else 243 else
238 { 244 {
239 net_rateinfo ri (*i); 245 net_rateinfo ri (*i);
240 erase (i); 246 erase (i);
241 247
242 ri.pcnt = ri.pcnt * ALPHA; 248 ri.pcnt = ri.pcnt * NRL_ALPHA;
243 ri.diff = ri.diff * ALPHA + (NOW - ri.last); 249 ri.diff = ri.diff * NRL_ALPHA + (NOW - ri.last);
244 250
245 ri.last = NOW; 251 ri.last = NOW;
246 252
253 double dif = ri.diff / ri.pcnt;
254
247 bool send = ri.diff / ri.pcnt > CUTOFF; 255 bool send = dif > NRL_CUTOFF;
248 256
257 if (dif > NRL_MAXDIF)
258 {
259 ri.pcnt = 1.;
260 ri.diff = NRL_MAXDIF;
261 }
249 if (send) 262 else if (send)
250 ri.pcnt++; 263 ri.pcnt++;
251 264
252 push_front (ri); 265 push_front (ri);
253 266
254 return send; 267 return send;
… …
285 hmac_gen (ctx); 298 hmac_gen (ctx);
286 299
287 return !memcmp (hmac, hmac_digest, HMACLENGTH); 300 return !memcmp (hmac, hmac_digest, HMACLENGTH);
288} 301}
289 302
290void vpn_packet::set_hdr (ptype type, unsigned int dst) 303void vpn_packet::set_hdr (ptype type_, unsigned int dst)
291{ 304{
292 this->type = type; 305 type = type_;
293 306
294 int src = THISNODE->id; 307 int src = THISNODE->id;
295 308
296 src1 = src; 309 src1 = src;
297 srcdst = ((src >> 8) << 4) | (dst >> 8); 310 srcdst = ((src >> 8) << 4) | (dst >> 8);
… …
299} 312}
300 313
301#define MAXVPNDATA (MAX_MTU - 6 - 6) 314#define MAXVPNDATA (MAX_MTU - 6 - 6)
302#define DATAHDR (sizeof (u32) + RAND_SIZE) 315#define DATAHDR (sizeof (u32) + RAND_SIZE)
303 316
304struct vpndata_packet:vpn_packet 317struct vpndata_packet : vpn_packet
305 { 318 {
306 u8 data[MAXVPNDATA + DATAHDR]; // seqno 319 u8 data[MAXVPNDATA + DATAHDR]; // seqno
307 320
308 void setup (connection *conn, int dst, u8 *d, u32 len, u32 seqno); 321 void setup (connection *conn, int dst, u8 *d, u32 len, u32 seqno);
309 tap_packet *unpack (connection *conn, u32 &seqno); 322 tap_packet *unpack (connection *conn, u32 &seqno);
… …
322 int outl = 0, outl2; 335 int outl = 0, outl2;
323 ptype type = PT_DATA_UNCOMPRESSED; 336 ptype type = PT_DATA_UNCOMPRESSED;
324 337
325#if ENABLE_COMPRESSION 338#if ENABLE_COMPRESSION
326 u8 cdata[MAX_MTU]; 339 u8 cdata[MAX_MTU];
327 u32 cl;
328 340
341 if (conn->features & ENABLE_COMPRESSION)
342 {
329 cl = lzf_compress (d, l, cdata + 2, (l - 2) & ~7); 343 u32 cl = lzf_compress (d, l, cdata + 2, (l - 2) & ~7);
344
330 if (cl) 345 if (cl)
331 { 346 {
332 type = PT_DATA_COMPRESSED; 347 type = PT_DATA_COMPRESSED;
333 d = cdata; 348 d = cdata;
334 l = cl + 2; 349 l = cl + 2;
335 350
336 d[0] = cl >> 8; 351 d[0] = cl >> 8;
337 d[1] = cl; 352 d[1] = cl;
353 }
338 } 354 }
339#endif 355#endif
340 356
341 EVP_EncryptInit_ex (cctx, 0, 0, 0, 0); 357 require (EVP_EncryptInit_ex (cctx, 0, 0, 0, 0));
342 358
343 struct { 359 struct {
344#if RAND_SIZE 360#if RAND_SIZE
345 u8 rnd[RAND_SIZE]; 361 u8 rnd[RAND_SIZE];
346#endif 362#endif
… …
350 datahdr.seqno = ntohl (seqno); 366 datahdr.seqno = ntohl (seqno);
351#if RAND_SIZE 367#if RAND_SIZE
352 RAND_pseudo_bytes ((unsigned char *) datahdr.rnd, RAND_SIZE); 368 RAND_pseudo_bytes ((unsigned char *) datahdr.rnd, RAND_SIZE);
353#endif 369#endif
354 370
355 EVP_EncryptUpdate (cctx, 371 require (EVP_EncryptUpdate (cctx,
356 (unsigned char *) data + outl, &outl2, 372 (unsigned char *) data + outl, &outl2,
357 (unsigned char *) &datahdr, DATAHDR); 373 (unsigned char *) &datahdr, DATAHDR));
358 outl += outl2; 374 outl += outl2;
359 375
360 EVP_EncryptUpdate (cctx, 376 require (EVP_EncryptUpdate (cctx,
361 (unsigned char *) data + outl, &outl2, 377 (unsigned char *) data + outl, &outl2,
362 (unsigned char *) d, l); 378 (unsigned char *) d, l));
363 outl += outl2; 379 outl += outl2;
364 380
365 EVP_EncryptFinal_ex (cctx, (unsigned char *) data + outl, &outl2); 381 require (EVP_EncryptFinal_ex (cctx, (unsigned char *) data + outl, &outl2));
366 outl += outl2; 382 outl += outl2;
367 383
368 len = outl + data_hdr_size (); 384 len = outl + data_hdr_size ();
369 385
370 set_hdr (type, dst); 386 set_hdr (type, dst);
… …
379 int outl = 0, outl2; 395 int outl = 0, outl2;
380 tap_packet *p = new tap_packet; 396 tap_packet *p = new tap_packet;
381 u8 *d; 397 u8 *d;
382 u32 l = len - data_hdr_size (); 398 u32 l = len - data_hdr_size ();
383 399
384 EVP_DecryptInit_ex (cctx, 0, 0, 0, 0); 400 require (EVP_DecryptInit_ex (cctx, 0, 0, 0, 0));
385 401
386#if ENABLE_COMPRESSION 402#if ENABLE_COMPRESSION
387 u8 cdata[MAX_MTU]; 403 u8 cdata[MAX_MTU];
388 404
389 if (type == PT_DATA_COMPRESSED) 405 if (type == PT_DATA_COMPRESSED)
… …
391 else 407 else
392#endif 408#endif
393 d = &(*p)[6 + 6 - DATAHDR]; 409 d = &(*p)[6 + 6 - DATAHDR];
394 410
395 /* this overwrites part of the src mac, but we fix that later */ 411 /* this overwrites part of the src mac, but we fix that later */
396 EVP_DecryptUpdate (cctx, 412 require (EVP_DecryptUpdate (cctx,
397 d, &outl2, 413 d, &outl2,
398 (unsigned char *)&data, len - data_hdr_size ()); 414 (unsigned char *)&data, len - data_hdr_size ()));
399 outl += outl2; 415 outl += outl2;
400 416
401 EVP_DecryptFinal_ex (cctx, (unsigned char *)d + outl, &outl2); 417 require (EVP_DecryptFinal_ex (cctx, (unsigned char *)d + outl, &outl2));
402 outl += outl2; 418 outl += outl2;
403 419
404 seqno = ntohl (*(u32 *)(d + RAND_SIZE)); 420 seqno = ntohl (*(u32 *)(d + RAND_SIZE));
405 421
406 id2mac (dst () ? dst() : THISNODE->id, p->dst); 422 id2mac (dst () ? dst() : THISNODE->id, p->dst);
… …
435{ 451{
436 // actually, hmaclen cannot be checked because the hmac 452 // actually, hmaclen cannot be checked because the hmac
437 // field comes before this data, so peers with other 453 // field comes before this data, so peers with other
438 // hmacs simply will not work. 454 // hmacs simply will not work.
439 u8 prot_major, prot_minor, randsize, hmaclen; 455 u8 prot_major, prot_minor, randsize, hmaclen;
440 u8 flags, challengelen, pad2, pad3; 456 u8 flags, challengelen, features, pad3;
441 u32 cipher_nid, digest_nid, hmac_nid; 457 u32 cipher_nid, digest_nid, hmac_nid;
442
443 const u8 curflags () const
444 {
445 return 0x80
446 | (ENABLE_COMPRESSION ? 0x01 : 0x00);
447 }
448 458
449 void setup (ptype type, int dst); 459 void setup (ptype type, int dst);
450 bool chk_config () const; 460 bool chk_config () const;
461
462 static u8 get_features ()
463 {
464 u8 f = 0;
465#if ENABLE_COMPRESSION
466 f |= FEATURE_COMPRESSION;
467#endif
468#if ENABLE_ROHC
469 f |= FEATURE_ROHC;
470#endif
471 return f;
472 }
451}; 473};
452 474
453void config_packet::setup (ptype type, int dst) 475void config_packet::setup (ptype type, int dst)
454{ 476{
455 prot_major = PROTOCOL_MAJOR; 477 prot_major = PROTOCOL_MAJOR;
456 prot_minor = PROTOCOL_MINOR; 478 prot_minor = PROTOCOL_MINOR;
457 randsize = RAND_SIZE; 479 randsize = RAND_SIZE;
458 hmaclen = HMACLENGTH; 480 hmaclen = HMACLENGTH;
459 flags = curflags (); 481 flags = ENABLE_COMPRESSION ? 0x81 : 0x80;
460 challengelen = sizeof (rsachallenge); 482 challengelen = sizeof (rsachallenge);
483 features = get_features ();
461 484
462 cipher_nid = htonl (EVP_CIPHER_nid (CIPHER)); 485 cipher_nid = htonl (EVP_CIPHER_nid (CIPHER));
463 digest_nid = htonl (EVP_MD_type (RSA_HASH)); 486 digest_nid = htonl (EVP_MD_type (RSA_HASH));
464 hmac_nid = htonl (EVP_MD_type (DIGEST)); 487 hmac_nid = htonl (EVP_MD_type (DIGEST));
465 488
… …
467 set_hdr (type, dst); 490 set_hdr (type, dst);
468} 491}
469 492
470bool config_packet::chk_config () const 493bool config_packet::chk_config () const
471{ 494{
472 return prot_major == PROTOCOL_MAJOR 495 if (prot_major != PROTOCOL_MAJOR)
473 && randsize == RAND_SIZE 496 slog (L_WARN, _("major version mismatch (remote %d <=> local %d)"), prot_major, PROTOCOL_MAJOR);
474 && hmaclen == HMACLENGTH 497 else if (randsize != RAND_SIZE)
475 && flags == curflags () 498 slog (L_WARN, _("rand size mismatch (remote %d <=> local %d)"), randsize, RAND_SIZE);
499 else if (hmaclen != HMACLENGTH)
500 slog (L_WARN, _("hmac length mismatch (remote %d <=> local %d)"), hmaclen, HMACLENGTH);
501#if 0 // this implementation should handle all flag settings
502 else if (flags != curflags ())
503 slog (L_WARN, _("flag mismatch (remote %x <=> local %x)"), flags, curflags ());
504#endif
476 && challengelen == sizeof (rsachallenge) 505 else if (challengelen != sizeof (rsachallenge))
506 slog (L_WARN, _("challenge length mismatch (remote %d <=> local %d)"), challengelen, sizeof (rsachallenge));
477 && cipher_nid == htonl (EVP_CIPHER_nid (CIPHER)) 507 else if (cipher_nid != htonl (EVP_CIPHER_nid (CIPHER)))
508 slog (L_WARN, _("cipher mismatch (remote %x <=> local %x)"), ntohl (cipher_nid), EVP_CIPHER_nid (CIPHER));
478 && digest_nid == htonl (EVP_MD_type (RSA_HASH)) 509 else if (digest_nid != htonl (EVP_MD_type (RSA_HASH)))
510 slog (L_WARN, _("digest mismatch (remote %x <=> local %x)"), ntohl (digest_nid), EVP_MD_type (RSA_HASH));
479 && hmac_nid == htonl (EVP_MD_type (DIGEST)); 511 else if (hmac_nid != htonl (EVP_MD_type (DIGEST)))
512 slog (L_WARN, _("hmac mismatch (remote %x <=> local %x)"), ntohl (hmac_nid), EVP_MD_type (DIGEST));
513 else
514 return true;
515
516 return false;
480} 517}
481 518
482struct auth_req_packet : config_packet 519struct auth_req_packet : config_packet
483{ 520{
484 char magic[8]; 521 char magic[8];
485 u8 initiate; // false if this is just an automatic reply 522 u8 initiate; // false if this is just an automatic reply
486 u8 protocols; // supported protocols (will get patches on forward) 523 u8 protocols; // supported protocols (will be patched on forward)
487 u8 pad2, pad3; 524 u8 pad2, pad3;
488 rsaid id; 525 rsaid id;
489 rsaencrdata encr; 526 rsaencrdata encr;
490 527
491 auth_req_packet (int dst, bool initiate_, u8 protocols_) 528 auth_req_packet (int dst, bool initiate_, u8 protocols_)
… …
546}; 583};
547 584
548///////////////////////////////////////////////////////////////////////////// 585/////////////////////////////////////////////////////////////////////////////
549 586
550void 587void
588connection::connection_established ()
589{
590 if (ictx && octx)
591 {
592 connectmode = conf->connectmode;
593
594 rekey.start (NOW + ::conf.rekey);
595 keepalive.start (NOW + ::conf.keepalive);
596
597 // send queued packets
598 if (ictx && octx)
599 {
600 while (tap_packet *p = (tap_packet *)data_queue.get ())
601 {
602 send_data_packet (p);
603 delete p;
604 }
605
606 while (vpn_packet *p = (vpn_packet *)vpn_queue.get ())
607 {
608 send_vpn_packet (p, si, IPTOS_RELIABILITY);
609 delete p;
610 }
611 }
612 }
613 else
614 {
615 retry_cnt = 0;
616 establish_connection.start (NOW + 5);
617 keepalive.stop ();
618 rekey.stop ();
619 }
620}
621
622void
551connection::reset_dstaddr () 623connection::reset_si ()
552{ 624{
553 si.set (conf);
554}
555
556void
557connection::send_ping (const sockinfo &si, u8 pong)
558{
559 ping_packet *pkt = new ping_packet;
560
561 pkt->setup (conf->id, pong ? ping_packet::PT_PONG : ping_packet::PT_PING);
562 send_vpn_packet (pkt, si, IPTOS_LOWDELAY);
563
564 delete pkt;
565}
566
567void
568connection::send_reset (const sockinfo &si)
569{
570 if (reset_rate_limiter.can (si) && connectmode != conf_node::C_DISABLED)
571 {
572 config_packet *pkt = new config_packet;
573
574 pkt->setup (vpn_packet::PT_RESET, conf->id);
575 send_vpn_packet (pkt, si, IPTOS_MINCOST);
576
577 delete pkt;
578 }
579}
580
581void
582connection::send_auth_request (const sockinfo &si, bool initiate)
583{
584 auth_req_packet *pkt = new auth_req_packet (conf->id, initiate, THISNODE->protocols);
585
586 protocol = best_protocol (THISNODE->protocols & conf->protocols); 625 protocol = best_protocol (THISNODE->protocols & conf->protocols);
587 626
588 // mask out protocols we cannot establish 627 // mask out protocols we cannot establish
589 if (!conf->udp_port) protocol &= ~PROT_UDPv4; 628 if (!conf->udp_port) protocol &= ~PROT_UDPv4;
590 if (!conf->tcp_port) protocol &= ~PROT_TCPv4; 629 if (!conf->tcp_port) protocol &= ~PROT_TCPv4;
591 630
592 if (protocol) 631 si.set (conf, protocol);
632}
633
634// ensure sockinfo is valid, forward if necessary
635const sockinfo &
636connection::forward_si (const sockinfo &si) const
637{
638 if (!si.valid ())
639 {
640 connection *r = vpn->find_router ();
641
642 if (r)
643 {
644 slog (L_DEBUG, _("%s: no common protocol, trying indirectly through %s"),
645 conf->nodename, r->conf->nodename);
646 return r->si;
647 }
648 else
649 slog (L_DEBUG, _("%s: node unreachable, no common protocol"),
650 conf->nodename);
593 { 651 }
594 rsachallenge chg;
595 652
596 rsa_cache.gen (pkt->id, chg); 653 return si;
654}
597 655
598 if (0 > RSA_public_encrypt (sizeof chg, 656void
599 (unsigned char *)&chg, (unsigned char *)&pkt->encr, 657connection::send_vpn_packet (vpn_packet *pkt, const sockinfo &si, int tos)
600 conf->rsa_key, RSA_PKCS1_OAEP_PADDING)) 658{
601 fatal ("RSA_public_encrypt error"); 659 if (!vpn->send_vpn_packet (pkt, si, tos))
660 reset_connection ();
661}
602 662
603 slog (L_TRACE, ">>%d PT_AUTH_REQ [%s]", conf->id, (const char *)si); 663void
664connection::send_ping (const sockinfo &si, u8 pong)
665{
666 ping_packet *pkt = new ping_packet;
604 667
605 send_vpn_packet (pkt, si, IPTOS_RELIABILITY); // rsa is very very costly 668 pkt->setup (conf->id, pong ? ping_packet::PT_PONG : ping_packet::PT_PING);
669 send_vpn_packet (pkt, si, IPTOS_LOWDELAY);
670
671 delete pkt;
672}
673
674void
675connection::send_reset (const sockinfo &si)
676{
677 if (reset_rate_limiter.can (si) && connectmode != conf_node::C_DISABLED)
678 {
679 config_packet *pkt = new config_packet;
680
681 pkt->setup (vpn_packet::PT_RESET, conf->id);
682 send_vpn_packet (pkt, si, IPTOS_MINCOST);
606 683
607 delete pkt; 684 delete pkt;
608 } 685 }
609 else 686}
610 ; // silently fail 687
688void
689connection::send_auth_request (const sockinfo &si, bool initiate)
690{
691 auth_req_packet *pkt = new auth_req_packet (conf->id, initiate, THISNODE->protocols);
692
693 rsachallenge chg;
694 rsa_cache.gen (pkt->id, chg);
695 rsa_encrypt (conf->rsa_key, chg, pkt->encr);
696
697 slog (L_TRACE, ">>%d PT_AUTH_REQ [%s]", conf->id, (const char *)si);
698
699 send_vpn_packet (pkt, si, IPTOS_RELIABILITY | IPTOS_LOWDELAY); // rsa is very very costly
700
701 delete pkt;
611} 702}
612 703
613void 704void
614connection::send_auth_response (const sockinfo &si, const rsaid &id, const rsachallenge &chg) 705connection::send_auth_response (const sockinfo &si, const rsaid &id, const rsachallenge &chg)
615{ 706{
… …
643} 734}
644 735
645void 736void
646connection::establish_connection_cb (time_watcher &w) 737connection::establish_connection_cb (time_watcher &w)
647{ 738{
648 if (ictx || conf == THISNODE 739 if (!ictx
740 && conf != THISNODE
649 || connectmode == conf_node::C_NEVER 741 && connectmode != conf_node::C_NEVER
650 || connectmode == conf_node::C_DISABLED) 742 && connectmode != conf_node::C_DISABLED
651 w.at = TSTAMP_CANCEL; 743 && NOW > w.at)
652 else if (w.at <= NOW)
653 { 744 {
654 double retry_int = double (retry_cnt & 3 ? (retry_cnt & 3) : 1 << (retry_cnt >> 2)) * 0.6; 745 double retry_int = double (retry_cnt & 3 ? (retry_cnt & 3) : 1 << (retry_cnt >> 2)) * 0.6;
655 746
656 if (retry_int < 3600 * 8) 747 if (retry_int < 3600 * 8)
657 retry_cnt++; 748 retry_cnt++;
658 749
659 w.at = NOW + retry_int; 750 w.start (NOW + retry_int);
660 751
661 if (conf->hostname) 752 reset_si ();
753
754 if (si.prot && !si.host)
755 vpn->send_connect_request (conf->id);
756 else
662 { 757 {
663 reset_dstaddr (); 758 const sockinfo &dsi = forward_si (si);
759
664 if (si.host && auth_rate_limiter.can (si)) 760 if (dsi.valid () && auth_rate_limiter.can (dsi))
665 { 761 {
666 if (retry_cnt < 4) 762 if (retry_cnt < 4)
667 send_auth_request (si, true); 763 send_auth_request (dsi, true);
668 else 764 else
669 send_ping (si, 0); 765 send_ping (dsi, 0);
670 } 766 }
671 } 767 }
672 else
673 vpn->connect_request (conf->id);
674 } 768 }
675} 769}
676 770
677void 771void
678connection::reset_connection () 772connection::reset_connection ()
… …
692 si.host= 0; 786 si.host= 0;
693 787
694 last_activity = 0; 788 last_activity = 0;
695 retry_cnt = 0; 789 retry_cnt = 0;
696 790
697 rekey.reset (); 791 rekey.stop ();
698 keepalive.reset (); 792 keepalive.stop ();
699 establish_connection.reset (); 793 establish_connection.stop ();
700} 794}
701 795
702void 796void
703connection::shutdown () 797connection::shutdown ()
704{ 798{
… …
709} 803}
710 804
711void 805void
712connection::rekey_cb (time_watcher &w) 806connection::rekey_cb (time_watcher &w)
713{ 807{
714 w.at = TSTAMP_CANCEL;
715
716 reset_connection (); 808 reset_connection ();
717 establish_connection (); 809 establish_connection ();
718} 810}
719 811
720void 812void
721connection::send_data_packet (tap_packet *pkt, bool broadcast) 813connection::send_data_packet (tap_packet *pkt)
722{ 814{
723 vpndata_packet *p = new vpndata_packet; 815 vpndata_packet *p = new vpndata_packet;
724 int tos = 0; 816 int tos = 0;
725 817
726 if (conf->inherit_tos 818 // I am not hilarious about peeking into packets, but so be it.
727 && (*pkt)[12] == 0x08 && (*pkt)[13] == 0x00 // IP 819 if (conf->inherit_tos && pkt->is_ipv4 ())
728 && ((*pkt)[14] & 0xf0) == 0x40) // IPv4
729 tos = (*pkt)[15] & IPTOS_TOS_MASK; 820 tos = (*pkt)[15] & IPTOS_TOS_MASK;
730 821
731 p->setup (this, broadcast ? 0 : conf->id, &((*pkt)[6 + 6]), pkt->len - 6 - 6, ++oseqno); // skip 2 macs 822 p->setup (this, conf->id, &((*pkt)[6 + 6]), pkt->len - 6 - 6, ++oseqno); // skip 2 macs
732 send_vpn_packet (p, si, tos); 823 send_vpn_packet (p, si, tos);
733 824
734 delete p; 825 delete p;
735 826
736 if (oseqno > MAX_SEQNO) 827 if (oseqno > MAX_SEQNO)
737 rekey (); 828 rekey ();
738} 829}
739 830
740void 831void
741connection::inject_data_packet (tap_packet *pkt, bool broadcast) 832connection::inject_data_packet (tap_packet *pkt, bool broadcast/*TODO DDD*/)
742{ 833{
743 if (ictx && octx) 834 if (ictx && octx)
744 send_data_packet (pkt, broadcast); 835 send_data_packet (pkt);
745 else 836 else
746 { 837 {
747 if (!broadcast)//DDDD 838 if (!broadcast)//DDDD
748 queue.put (new tap_packet (*pkt)); 839 data_queue.put (new tap_packet (*pkt));
840
841 establish_connection ();
842 }
843}
844
845void connection::inject_vpn_packet (vpn_packet *pkt, int tos)
846{
847 if (ictx && octx)
848 send_vpn_packet (pkt, si, tos);
849 else
850 {
851 vpn_queue.put ((vpn_packet *)new data_packet (*(data_packet *)pkt));
749 852
750 establish_connection (); 853 establish_connection ();
751 } 854 }
752} 855}
753 856
… …
812 if (p->initiate) 915 if (p->initiate)
813 send_auth_request (rsi, false); 916 send_auth_request (rsi, false);
814 917
815 rsachallenge k; 918 rsachallenge k;
816 919
817 if (0 > RSA_private_decrypt (sizeof (p->encr), 920 if (!rsa_decrypt (::conf.rsa_key, p->encr, k))
818 (unsigned char *)&p->encr, (unsigned char *)&k, 921 {
819 ::conf.rsa_key, RSA_PKCS1_OAEP_PADDING))
820 slog (L_ERR, _("%s(%s): challenge illegal or corrupted"), 922 slog (L_ERR, _("%s(%s): challenge illegal or corrupted (%s). mismatched key or config file?"),
821 conf->nodename, (const char *)rsi); 923 conf->nodename, (const char *)rsi, ERR_error_string (ERR_get_error (), 0));
924 break;
925 }
822 else 926 else
823 { 927 {
824 retry_cnt = 0;
825 establish_connection.set (NOW + 8); //? ;)
826 keepalive.reset ();
827 rekey.reset ();
828
829 delete ictx;
830 ictx = 0;
831
832 delete octx; 928 delete octx;
833 929
834 octx = new crypto_ctx (k, 1); 930 octx = new crypto_ctx (k, 1);
835 oseqno = ntohl (*(u32 *)&k[CHG_SEQNO]) & 0x7fffffff; 931 oseqno = ntohl (*(u32 *)&k[CHG_SEQNO]) & 0x7fffffff;
836 932
933 // compatibility code, remove when no longer required
934 if (p->flags & 1) p->features |= FEATURE_COMPRESSION;
935
837 conf->protocols = p->protocols; 936 conf->protocols = p->protocols;
937 features = p->features & config_packet::get_features ();
938
838 send_auth_response (rsi, p->id, k); 939 send_auth_response (rsi, p->id, k);
940
941 connection_established ();
839 942
840 break; 943 break;
841 } 944 }
842 } 945 }
946 else
947 slog (L_WARN, _("%s(%s): protocol mismatch"),
948 conf->nodename, (const char *)rsi);
843 949
844 send_reset (rsi); 950 send_reset (rsi);
845 } 951 }
846 952
847 break; 953 break;
… …
860 PROTOCOL_MINOR, conf->nodename, p->prot_minor); 966 PROTOCOL_MINOR, conf->nodename, p->prot_minor);
861 967
862 rsachallenge chg; 968 rsachallenge chg;
863 969
864 if (!rsa_cache.find (p->id, chg)) 970 if (!rsa_cache.find (p->id, chg))
971 {
865 slog (L_ERR, _("%s(%s): unrequested auth response"), 972 slog (L_ERR, _("%s(%s): unrequested auth response ignored"),
866 conf->nodename, (const char *)rsi); 973 conf->nodename, (const char *)rsi);
974 break;
975 }
867 else 976 else
868 { 977 {
869 crypto_ctx *cctx = new crypto_ctx (chg, 0); 978 crypto_ctx *cctx = new crypto_ctx (chg, 0);
870 979
871 if (!p->hmac_chk (cctx)) 980 if (!p->hmac_chk (cctx))
981 {
872 slog (L_ERR, _("%s(%s): hmac authentication error on auth response, received invalid packet\n" 982 slog (L_ERR, _("%s(%s): hmac authentication error on auth response, received invalid packet\n"
873 "could be an attack, or just corruption or an synchronization error"), 983 "could be an attack, or just corruption or a synchronization error"),
874 conf->nodename, (const char *)rsi); 984 conf->nodename, (const char *)rsi);
985 break;
986 }
875 else 987 else
876 { 988 {
877 rsaresponse h; 989 rsaresponse h;
878 990
879 rsa_hash (p->id, chg, h); 991 rsa_hash (p->id, chg, h);
… …
885 delete ictx; ictx = cctx; 997 delete ictx; ictx = cctx;
886 998
887 iseqno.reset (ntohl (*(u32 *)&chg[CHG_SEQNO]) & 0x7fffffff); // at least 2**31 sequence numbers are valid 999 iseqno.reset (ntohl (*(u32 *)&chg[CHG_SEQNO]) & 0x7fffffff); // at least 2**31 sequence numbers are valid
888 1000
889 si = rsi; 1001 si = rsi;
1002 protocol = rsi.prot;
890 1003
891 rekey.set (NOW + ::conf.rekey); 1004 connection_established ();
892 keepalive.set (NOW + ::conf.keepalive);
893 1005
894 // send queued packets
895 while (tap_packet *p = queue.get ())
896 {
897 send_data_packet (p);
898 delete p;
899 }
900
901 connectmode = conf->connectmode;
902
903 slog (L_INFO, _("%s(%s): %s connection established, protocol version %d.%d"), 1006 slog (L_INFO, _("%s(%s): connection established, protocol version %d.%d"),
904 conf->nodename, (const char *)rsi, 1007 conf->nodename, (const char *)rsi,
905 strprotocol (protocol),
906 p->prot_major, p->prot_minor); 1008 p->prot_major, p->prot_minor);
907 1009
908 if (::conf.script_node_up) 1010 if (::conf.script_node_up)
909 run_script (run_script_cb (this, &connection::script_node_up), false); 1011 run_script (run_script_cb (this, &connection::script_node_up), false);
910 1012
… …
933 1035
934 if (ictx && octx) 1036 if (ictx && octx)
935 { 1037 {
936 vpndata_packet *p = (vpndata_packet *)pkt; 1038 vpndata_packet *p = (vpndata_packet *)pkt;
937 1039
938 if (rsi == si) 1040 if (!p->hmac_chk (ictx))
1041 slog (L_ERR, _("%s(%s): hmac authentication error, received invalid packet\n"
1042 "could be an attack, or just corruption or a synchronization error"),
1043 conf->nodename, (const char *)rsi);
1044 else
939 { 1045 {
940 if (!p->hmac_chk (ictx))
941 slog (L_ERR, _("%s(%s): hmac authentication error, received invalid packet\n"
942 "could be an attack, or just corruption or an synchronization error"),
943 conf->nodename, (const char *)rsi);
944 else 1046 u32 seqno;
1047 tap_packet *d = p->unpack (this, seqno);
1048
1049 if (iseqno.recv_ok (seqno))
945 { 1050 {
946 u32 seqno; 1051 vpn->tap->send (d);
947 tap_packet *d = p->unpack (this, seqno);
948 1052
949 if (iseqno.recv_ok (seqno)) 1053 if (si != rsi)
950 { 1054 {
951 vpn->tap->send (d); 1055 // fast re-sync on connection changes, useful especially for tcp/ip
952
953 if (p->dst () == 0) // re-broadcast
954 for (vpn::conns_vector::iterator i = vpn->conns.begin (); i != vpn->conns.end (); ++i)
955 {
956 connection *c = *i;
957
958 if (c->conf != THISNODE && c->conf != conf)
959 c->inject_data_packet (d);
960 }
961
962 delete d;
963
964 break; 1056 si = rsi;
1057
1058 slog (L_INFO, _("%s(%s): socket address changed to %s"),
1059 conf->nodename, (const char *)si, (const char *)rsi);
965 } 1060 }
966 } 1061 }
1062
1063 delete d;
1064 break;
967 } 1065 }
968 else
969 slog (L_ERR, _("received data packet from unknown source %s"), (const char *)rsi);
970 } 1066 }
971 1067
972 send_reset (rsi); 1068 send_reset (rsi);
973 break; 1069 break;
974 1070
… …
976 if (ictx && octx && rsi == si && pkt->hmac_chk (ictx)) 1072 if (ictx && octx && rsi == si && pkt->hmac_chk (ictx))
977 { 1073 {
978 connect_req_packet *p = (connect_req_packet *) pkt; 1074 connect_req_packet *p = (connect_req_packet *) pkt;
979 1075
980 assert (p->id > 0 && p->id <= vpn->conns.size ()); // hmac-auth does not mean we accept anything 1076 assert (p->id > 0 && p->id <= vpn->conns.size ()); // hmac-auth does not mean we accept anything
1077 connection *c = vpn->conns[p->id - 1];
981 conf->protocols = p->protocols; 1078 conf->protocols = p->protocols;
982 connection *c = vpn->conns[p->id - 1];
983 1079
984 slog (L_TRACE, "<<%d PT_CONNECT_REQ(%d) [%d]\n", 1080 slog (L_TRACE, "<<%d PT_CONNECT_REQ(%d) [%d]\n",
985 conf->id, p->id, c->ictx && c->octx); 1081 conf->id, p->id, c->ictx && c->octx);
986 1082
987 if (c->ictx && c->octx) 1083 if (c->ictx && c->octx)
… …
989 // send connect_info packets to both sides, in case one is 1085 // send connect_info packets to both sides, in case one is
990 // behind a nat firewall (or both ;) 1086 // behind a nat firewall (or both ;)
991 c->send_connect_info (conf->id, si, conf->protocols); 1087 c->send_connect_info (conf->id, si, conf->protocols);
992 send_connect_info (c->conf->id, c->si, c->conf->protocols); 1088 send_connect_info (c->conf->id, c->si, c->conf->protocols);
993 } 1089 }
1090 else
1091 c->establish_connection ();
994 } 1092 }
995 1093
996 break; 1094 break;
997 1095
998 case vpn_packet::PT_CONNECT_INFO: 1096 case vpn_packet::PT_CONNECT_INFO:
999 if (ictx && octx && rsi == si && pkt->hmac_chk (ictx)) 1097 if (ictx && octx && rsi == si && pkt->hmac_chk (ictx))
1000 { 1098 {
1001 connect_info_packet *p = (connect_info_packet *) pkt; 1099 connect_info_packet *p = (connect_info_packet *) pkt;
1002 1100
1003 assert (p->id > 0 && p->id <= vpn->conns.size ()); // hmac-auth does not mean we accept anything 1101 assert (p->id > 0 && p->id <= vpn->conns.size ()); // hmac-auth does not mean we accept anything
1004 conf->protocols = p->protocols; 1102
1005 connection *c = vpn->conns[p->id - 1]; 1103 connection *c = vpn->conns[p->id - 1];
1104
1105 c->conf->protocols = p->protocols;
1106 protocol = best_protocol (c->conf->protocols & THISNODE->protocols & p->si.supported_protocols (c->conf));
1107 p->si.upgrade_protocol (protocol, c->conf);
1006 1108
1007 slog (L_TRACE, "<<%d PT_CONNECT_INFO(%d,%s) (%d)", 1109 slog (L_TRACE, "<<%d PT_CONNECT_INFO(%d,%s) (%d)",
1008 conf->id, p->id, (const char *)p->si, !c->ictx && !c->octx); 1110 conf->id, p->id, (const char *)p->si, !c->ictx && !c->octx);
1009 1111
1112 const sockinfo &dsi = forward_si (p->si);
1113
1114 if (dsi.valid ())
1010 c->send_auth_request (p->si, true); 1115 c->send_auth_request (dsi, true);
1011 } 1116 }
1012 1117
1013 break; 1118 break;
1014 1119
1015 default: 1120 default:
… …
1024 { 1129 {
1025 reset_connection (); 1130 reset_connection ();
1026 establish_connection (); 1131 establish_connection ();
1027 } 1132 }
1028 else if (NOW < last_activity + ::conf.keepalive) 1133 else if (NOW < last_activity + ::conf.keepalive)
1029 w.at = last_activity + ::conf.keepalive; 1134 w.start (last_activity + ::conf.keepalive);
1030 else if (conf->connectmode != conf_node::C_ONDEMAND 1135 else if (conf->connectmode != conf_node::C_ONDEMAND
1031 || THISNODE->connectmode != conf_node::C_ONDEMAND) 1136 || THISNODE->connectmode != conf_node::C_ONDEMAND)
1032 { 1137 {
1033 send_ping (si); 1138 send_ping (si);
1034 w.at = NOW + 5; 1139 w.start (NOW + 5);
1035 } 1140 }
1141 else if (NOW < last_activity + ::conf.keepalive + 10)
1142 // hold ondemand connections implicitly a few seconds longer
1143 // should delete octx, though, or something like that ;)
1144 w.start (last_activity + ::conf.keepalive + 10);
1036 else 1145 else
1037 reset_connection (); 1146 reset_connection ();
1038} 1147}
1039 1148
1040void connection::connect_request (int id) 1149void connection::send_connect_request (int id)
1041{ 1150{
1042 connect_req_packet *p = new connect_req_packet (conf->id, id, conf->protocols); 1151 connect_req_packet *p = new connect_req_packet (conf->id, id, conf->protocols);
1043 1152
1044 slog (L_TRACE, ">>%d PT_CONNECT_REQ(%d)", conf->id, id); 1153 slog (L_TRACE, ">>%d PT_CONNECT_REQ(%d)", conf->id, id);
1045 p->hmac_set (octx); 1154 p->hmac_set (octx);
… …
1075 putenv ("STATE=down"); 1184 putenv ("STATE=down");
1076 1185
1077 return ::conf.script_node_up ? ::conf.script_node_down : "node-down"; 1186 return ::conf.script_node_up ? ::conf.script_node_down : "node-down";
1078} 1187}
1079 1188
1080// send a vpn packet out to other hosts
1081void
1082connection::send_vpn_packet (vpn_packet *pkt, const sockinfo &si, int tos)
1083{
1084 switch (protocol)
1085 {
1086 case PROT_IPv4:
1087 vpn->send_ipv4_packet (pkt, si, tos);
1088 break;
1089
1090 case PROT_UDPv4:
1091 vpn->send_udpv4_packet (pkt, si, tos);
1092 break;
1093
1094 case PROT_TCPv4:
1095 vpn->send_tcpv4_packet (pkt, si, tos);
1096 break;
1097 }
1098}
1099
1100connection::connection(struct vpn *vpn_) 1189connection::connection(struct vpn *vpn_)
1101: vpn(vpn_) 1190: vpn(vpn_)
1102, rekey (this, &connection::rekey_cb) 1191, rekey (this, &connection::rekey_cb)
1103, keepalive (this, &connection::keepalive_cb) 1192, keepalive (this, &connection::keepalive_cb)
1104, establish_connection (this, &connection::establish_connection_cb) 1193, establish_connection (this, &connection::establish_connection_cb)

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