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Comparing gvpe/src/connection.C (file contents):
Revision 1.5 by pcg, Wed Apr 2 21:43:44 2003 UTC vs.
Revision 1.31 by pcg, Sun Feb 8 07:24:25 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 static const double ALPHA = 1. - 1. / 600.; // allow bursts
203 static const double CUTOFF = 20.; // one event every CUTOFF seconds 208 static const double CUTOFF = 10.; // one event every CUTOFF seconds
204 static const double EXPIRE = CUTOFF * 30.; // expire entries after this time 209 static const double EXPIRE = CUTOFF * 30.; // expire entries after this time
210 static const double MAXDIF = CUTOFF * (1. / (1. - 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
… …
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 = 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;
… …
242 ri.pcnt = ri.pcnt * ALPHA; 248 ri.pcnt = ri.pcnt * ALPHA;
243 ri.diff = ri.diff * ALPHA + (NOW - ri.last); 249 ri.diff = ri.diff * 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 > CUTOFF;
248 256
257 if (dif > MAXDIF)
258 {
259 ri.pcnt = 1.;
260 ri.diff = 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;
451}; 461};
462
463#define FEATURES ((ENABLE_COMPRESSION ? FEATURE_COMPRESSION : 0) \
464 | (ENABLE_ROHC ? FEATURE_ROHC : 0))
452 465
453void config_packet::setup (ptype type, int dst) 466void config_packet::setup (ptype type, int dst)
454{ 467{
455 prot_major = PROTOCOL_MAJOR; 468 prot_major = PROTOCOL_MAJOR;
456 prot_minor = PROTOCOL_MINOR; 469 prot_minor = PROTOCOL_MINOR;
457 randsize = RAND_SIZE; 470 randsize = RAND_SIZE;
458 hmaclen = HMACLENGTH; 471 hmaclen = HMACLENGTH;
459 flags = curflags (); 472 flags = ENABLE_COMPRESSION ? 0x81 : 0x80;
460 challengelen = sizeof (rsachallenge); 473 challengelen = sizeof (rsachallenge);
474 features = FEATURES;
461 475
462 cipher_nid = htonl (EVP_CIPHER_nid (CIPHER)); 476 cipher_nid = htonl (EVP_CIPHER_nid (CIPHER));
463 digest_nid = htonl (EVP_MD_type (RSA_HASH)); 477 digest_nid = htonl (EVP_MD_type (RSA_HASH));
464 hmac_nid = htonl (EVP_MD_type (DIGEST)); 478 hmac_nid = htonl (EVP_MD_type (DIGEST));
465 479
… …
467 set_hdr (type, dst); 481 set_hdr (type, dst);
468} 482}
469 483
470bool config_packet::chk_config () const 484bool config_packet::chk_config () const
471{ 485{
472 return prot_major == PROTOCOL_MAJOR 486 if (prot_major != PROTOCOL_MAJOR)
473 && randsize == RAND_SIZE 487 slog (L_WARN, _("major version mismatch (remote %d <=> local %d)"), prot_major, PROTOCOL_MAJOR);
474 && hmaclen == HMACLENGTH 488 else if (randsize != RAND_SIZE)
475 && flags == curflags () 489 slog (L_WARN, _("rand size mismatch (remote %d <=> local %d)"), randsize, RAND_SIZE);
490 else if (hmaclen != HMACLENGTH)
491 slog (L_WARN, _("hmac length mismatch (remote %d <=> local %d)"), hmaclen, HMACLENGTH);
492#if 0 // this implementation should handle all flag settings
493 else if (flags != curflags ())
494 slog (L_WARN, _("flag mismatch (remote %x <=> local %x)"), flags, curflags ());
495#endif
476 && challengelen == sizeof (rsachallenge) 496 else if (challengelen != sizeof (rsachallenge))
497 slog (L_WARN, _("challenge length mismatch (remote %d <=> local %d)"), challengelen, sizeof (rsachallenge));
477 && cipher_nid == htonl (EVP_CIPHER_nid (CIPHER)) 498 else if (cipher_nid != htonl (EVP_CIPHER_nid (CIPHER)))
499 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)) 500 else if (digest_nid != htonl (EVP_MD_type (RSA_HASH)))
501 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)); 502 else if (hmac_nid != htonl (EVP_MD_type (DIGEST)))
503 slog (L_WARN, _("hmac mismatch (remote %x <=> local %x)"), ntohl (hmac_nid), EVP_MD_type (DIGEST));
504 else
505 return true;
506
507 return false;
480} 508}
481 509
482struct auth_req_packet : config_packet 510struct auth_req_packet : config_packet
483{ 511{
484 char magic[8]; 512 char magic[8];
485 u8 initiate; // false if this is just an automatic reply 513 u8 initiate; // false if this is just an automatic reply
486 u8 protocols; // supported protocols (will get patches on forward) 514 u8 protocols; // supported protocols (will be patched on forward)
487 u8 pad2, pad3; 515 u8 pad2, pad3;
488 rsaid id; 516 rsaid id;
489 rsaencrdata encr; 517 rsaencrdata encr;
490 518
491 auth_req_packet (int dst, bool initiate_, u8 protocols_) 519 auth_req_packet (int dst, bool initiate_, u8 protocols_)
… …
546}; 574};
547 575
548///////////////////////////////////////////////////////////////////////////// 576/////////////////////////////////////////////////////////////////////////////
549 577
550void 578void
579connection::connection_established ()
580{
581 if (ictx && octx)
582 {
583 connectmode = conf->connectmode;
584
585 rekey.start (NOW + ::conf.rekey);
586 keepalive.start (NOW + ::conf.keepalive);
587
588 // send queued packets
589 if (ictx && octx)
590 {
591 while (tap_packet *p = (tap_packet *)data_queue.get ())
592 {
593 send_data_packet (p);
594 delete p;
595 }
596
597 while (vpn_packet *p = (vpn_packet *)vpn_queue.get ())
598 {
599 send_vpn_packet (p, si, IPTOS_RELIABILITY);
600 delete p;
601 }
602 }
603 }
604 else
605 {
606 retry_cnt = 0;
607 establish_connection.start (NOW + 5);
608 keepalive.stop ();
609 rekey.stop ();
610 }
611}
612
613void
551connection::reset_dstaddr () 614connection::reset_si ()
552{ 615{
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); 616 protocol = best_protocol (THISNODE->protocols & conf->protocols);
587 617
588 // mask out protocols we cannot establish 618 // mask out protocols we cannot establish
589 if (!conf->udp_port) protocol &= ~PROT_UDPv4; 619 if (!conf->udp_port) protocol &= ~PROT_UDPv4;
590 if (!conf->tcp_port) protocol &= ~PROT_TCPv4; 620 if (!conf->tcp_port) protocol &= ~PROT_TCPv4;
591 621
592 if (protocol) 622 si.set (conf, protocol);
623}
624
625// ensure sockinfo is valid, forward if necessary
626const sockinfo &
627connection::forward_si (const sockinfo &si) const
628{
629 if (!si.valid ())
630 {
631 connection *r = vpn->find_router ();
632
633 if (r)
634 {
635 slog (L_DEBUG, _("%s: no common protocol, trying indirectly through %s"),
636 conf->nodename, r->conf->nodename);
637 return r->si;
638 }
639 else
640 slog (L_DEBUG, _("%s: node unreachable, no common protocol"),
641 conf->nodename);
593 { 642 }
594 rsachallenge chg;
595 643
596 rsa_cache.gen (pkt->id, chg); 644 return si;
645}
597 646
598 if (0 > RSA_public_encrypt (sizeof chg, 647void
599 (unsigned char *)&chg, (unsigned char *)&pkt->encr, 648connection::send_vpn_packet (vpn_packet *pkt, const sockinfo &si, int tos)
600 conf->rsa_key, RSA_PKCS1_OAEP_PADDING)) 649{
601 fatal ("RSA_public_encrypt error"); 650 if (!vpn->send_vpn_packet (pkt, si, tos))
651 reset_connection ();
652}
602 653
603 slog (L_TRACE, ">>%d PT_AUTH_REQ [%s]", conf->id, (const char *)si); 654void
655connection::send_ping (const sockinfo &si, u8 pong)
656{
657 ping_packet *pkt = new ping_packet;
604 658
605 send_vpn_packet (pkt, si, IPTOS_RELIABILITY); // rsa is very very costly 659 pkt->setup (conf->id, pong ? ping_packet::PT_PONG : ping_packet::PT_PING);
660 send_vpn_packet (pkt, si, IPTOS_LOWDELAY);
661
662 delete pkt;
663}
664
665void
666connection::send_reset (const sockinfo &si)
667{
668 if (reset_rate_limiter.can (si) && connectmode != conf_node::C_DISABLED)
669 {
670 config_packet *pkt = new config_packet;
671
672 pkt->setup (vpn_packet::PT_RESET, conf->id);
673 send_vpn_packet (pkt, si, IPTOS_MINCOST);
606 674
607 delete pkt; 675 delete pkt;
608 } 676 }
609 else 677}
610 ; // silently fail 678
679void
680connection::send_auth_request (const sockinfo &si, bool initiate)
681{
682 auth_req_packet *pkt = new auth_req_packet (conf->id, initiate, THISNODE->protocols);
683
684 rsachallenge chg;
685 rsa_cache.gen (pkt->id, chg);
686 rsa_encrypt (conf->rsa_key, chg, pkt->encr);
687
688 slog (L_TRACE, ">>%d PT_AUTH_REQ [%s]", conf->id, (const char *)si);
689
690 send_vpn_packet (pkt, si, IPTOS_RELIABILITY | IPTOS_LOWDELAY); // rsa is very very costly
691
692 delete pkt;
611} 693}
612 694
613void 695void
614connection::send_auth_response (const sockinfo &si, const rsaid &id, const rsachallenge &chg) 696connection::send_auth_response (const sockinfo &si, const rsaid &id, const rsachallenge &chg)
615{ 697{
… …
643} 725}
644 726
645void 727void
646connection::establish_connection_cb (time_watcher &w) 728connection::establish_connection_cb (time_watcher &w)
647{ 729{
648 if (ictx || conf == THISNODE 730 if (!ictx
731 && conf != THISNODE
649 || connectmode == conf_node::C_NEVER 732 && connectmode != conf_node::C_NEVER
650 || connectmode == conf_node::C_DISABLED) 733 && connectmode != conf_node::C_DISABLED
651 w.at = TSTAMP_CANCEL; 734 && NOW > w.at)
652 else if (w.at <= NOW)
653 { 735 {
654 double retry_int = double (retry_cnt & 3 ? (retry_cnt & 3) : 1 << (retry_cnt >> 2)) * 0.6; 736 double retry_int = double (retry_cnt & 3 ? (retry_cnt & 3) : 1 << (retry_cnt >> 2)) * 0.6;
655 737
656 if (retry_int < 3600 * 8) 738 if (retry_int < 3600 * 8)
657 retry_cnt++; 739 retry_cnt++;
658 740
659 w.at = NOW + retry_int; 741 w.start (NOW + retry_int);
660 742
661 if (conf->hostname) 743 reset_si ();
744
745 if (si.prot && !si.host)
746 vpn->send_connect_request (conf->id);
747 else
662 { 748 {
663 reset_dstaddr (); 749 const sockinfo &dsi = forward_si (si);
750
664 if (si.host && auth_rate_limiter.can (si)) 751 if (dsi.valid () && auth_rate_limiter.can (dsi))
665 { 752 {
666 if (retry_cnt < 4) 753 if (retry_cnt < 4)
667 send_auth_request (si, true); 754 send_auth_request (dsi, true);
668 else 755 else
669 send_ping (si, 0); 756 send_ping (dsi, 0);
670 } 757 }
671 } 758 }
672 else
673 vpn->connect_request (conf->id);
674 } 759 }
675} 760}
676 761
677void 762void
678connection::reset_connection () 763connection::reset_connection ()
… …
692 si.host= 0; 777 si.host= 0;
693 778
694 last_activity = 0; 779 last_activity = 0;
695 retry_cnt = 0; 780 retry_cnt = 0;
696 781
697 rekey.reset (); 782 rekey.stop ();
698 keepalive.reset (); 783 keepalive.stop ();
699 establish_connection.reset (); 784 establish_connection.stop ();
700} 785}
701 786
702void 787void
703connection::shutdown () 788connection::shutdown ()
704{ 789{
… …
709} 794}
710 795
711void 796void
712connection::rekey_cb (time_watcher &w) 797connection::rekey_cb (time_watcher &w)
713{ 798{
714 w.at = TSTAMP_CANCEL;
715
716 reset_connection (); 799 reset_connection ();
717 establish_connection (); 800 establish_connection ();
718} 801}
719 802
720void 803void
721connection::send_data_packet (tap_packet *pkt, bool broadcast) 804connection::send_data_packet (tap_packet *pkt)
722{ 805{
723 vpndata_packet *p = new vpndata_packet; 806 vpndata_packet *p = new vpndata_packet;
724 int tos = 0; 807 int tos = 0;
725 808
726 if (conf->inherit_tos 809 // I am not hilarious about peeking into packets, but so be it.
727 && (*pkt)[12] == 0x08 && (*pkt)[13] == 0x00 // IP 810 if (conf->inherit_tos && pkt->is_ipv4 ())
728 && ((*pkt)[14] & 0xf0) == 0x40) // IPv4
729 tos = (*pkt)[15] & IPTOS_TOS_MASK; 811 tos = (*pkt)[15] & IPTOS_TOS_MASK;
730 812
731 p->setup (this, broadcast ? 0 : conf->id, &((*pkt)[6 + 6]), pkt->len - 6 - 6, ++oseqno); // skip 2 macs 813 p->setup (this, conf->id, &((*pkt)[6 + 6]), pkt->len - 6 - 6, ++oseqno); // skip 2 macs
732 send_vpn_packet (p, si, tos); 814 send_vpn_packet (p, si, tos);
733 815
734 delete p; 816 delete p;
735 817
736 if (oseqno > MAX_SEQNO) 818 if (oseqno > MAX_SEQNO)
737 rekey (); 819 rekey ();
738} 820}
739 821
740void 822void
741connection::inject_data_packet (tap_packet *pkt, bool broadcast) 823connection::inject_data_packet (tap_packet *pkt, bool broadcast/*TODO DDD*/)
742{ 824{
743 if (ictx && octx) 825 if (ictx && octx)
744 send_data_packet (pkt, broadcast); 826 send_data_packet (pkt);
745 else 827 else
746 { 828 {
747 if (!broadcast)//DDDD 829 if (!broadcast)//DDDD
748 queue.put (new tap_packet (*pkt)); 830 data_queue.put (new tap_packet (*pkt));
831
832 establish_connection ();
833 }
834}
835
836void connection::inject_vpn_packet (vpn_packet *pkt, int tos)
837{
838 if (ictx && octx)
839 send_vpn_packet (pkt, si, tos);
840 else
841 {
842 vpn_queue.put ((vpn_packet *)new data_packet (*(data_packet *)pkt));
749 843
750 establish_connection (); 844 establish_connection ();
751 } 845 }
752} 846}
753 847
… …
812 if (p->initiate) 906 if (p->initiate)
813 send_auth_request (rsi, false); 907 send_auth_request (rsi, false);
814 908
815 rsachallenge k; 909 rsachallenge k;
816 910
817 if (0 > RSA_private_decrypt (sizeof (p->encr), 911 if (!rsa_decrypt (::conf.rsa_key, p->encr, k))
818 (unsigned char *)&p->encr, (unsigned char *)&k, 912 {
819 ::conf.rsa_key, RSA_PKCS1_OAEP_PADDING))
820 slog (L_ERR, _("%s(%s): challenge illegal or corrupted"), 913 slog (L_ERR, _("%s(%s): challenge illegal or corrupted (%s). mismatched key or config file?"),
821 conf->nodename, (const char *)rsi); 914 conf->nodename, (const char *)rsi, ERR_error_string (ERR_get_error (), 0));
915 break;
916 }
822 else 917 else
823 { 918 {
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; 919 delete octx;
833 920
834 octx = new crypto_ctx (k, 1); 921 octx = new crypto_ctx (k, 1);
835 oseqno = ntohl (*(u32 *)&k[CHG_SEQNO]) & 0x7fffffff; 922 oseqno = ntohl (*(u32 *)&k[CHG_SEQNO]) & 0x7fffffff;
836 923
924 // compatibility code, remove when no longer required
925 if (p->flags & 1) p->features |= FEATURE_COMPRESSION;
926
837 conf->protocols = p->protocols; 927 conf->protocols = p->protocols;
928 features = p->features & FEATURES;
929
838 send_auth_response (rsi, p->id, k); 930 send_auth_response (rsi, p->id, k);
931
932 connection_established ();
839 933
840 break; 934 break;
841 } 935 }
842 } 936 }
937 else
938 slog (L_WARN, _("%s(%s): protocol mismatch"),
939 conf->nodename, (const char *)rsi);
843 940
844 send_reset (rsi); 941 send_reset (rsi);
845 } 942 }
846 943
847 break; 944 break;
… …
860 PROTOCOL_MINOR, conf->nodename, p->prot_minor); 957 PROTOCOL_MINOR, conf->nodename, p->prot_minor);
861 958
862 rsachallenge chg; 959 rsachallenge chg;
863 960
864 if (!rsa_cache.find (p->id, chg)) 961 if (!rsa_cache.find (p->id, chg))
962 {
865 slog (L_ERR, _("%s(%s): unrequested auth response"), 963 slog (L_ERR, _("%s(%s): unrequested auth response ignored"),
866 conf->nodename, (const char *)rsi); 964 conf->nodename, (const char *)rsi);
965 break;
966 }
867 else 967 else
868 { 968 {
869 crypto_ctx *cctx = new crypto_ctx (chg, 0); 969 crypto_ctx *cctx = new crypto_ctx (chg, 0);
870 970
871 if (!p->hmac_chk (cctx)) 971 if (!p->hmac_chk (cctx))
972 {
872 slog (L_ERR, _("%s(%s): hmac authentication error on auth response, received invalid packet\n" 973 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"), 974 "could be an attack, or just corruption or a synchronization error"),
874 conf->nodename, (const char *)rsi); 975 conf->nodename, (const char *)rsi);
976 break;
977 }
875 else 978 else
876 { 979 {
877 rsaresponse h; 980 rsaresponse h;
878 981
879 rsa_hash (p->id, chg, h); 982 rsa_hash (p->id, chg, h);
… …
885 delete ictx; ictx = cctx; 988 delete ictx; ictx = cctx;
886 989
887 iseqno.reset (ntohl (*(u32 *)&chg[CHG_SEQNO]) & 0x7fffffff); // at least 2**31 sequence numbers are valid 990 iseqno.reset (ntohl (*(u32 *)&chg[CHG_SEQNO]) & 0x7fffffff); // at least 2**31 sequence numbers are valid
888 991
889 si = rsi; 992 si = rsi;
993 protocol = rsi.prot;
890 994
891 rekey.set (NOW + ::conf.rekey); 995 connection_established ();
892 keepalive.set (NOW + ::conf.keepalive);
893 996
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"), 997 slog (L_INFO, _("%s(%s): connection established, protocol version %d.%d"),
904 conf->nodename, (const char *)rsi, 998 conf->nodename, (const char *)rsi,
905 strprotocol (protocol),
906 p->prot_major, p->prot_minor); 999 p->prot_major, p->prot_minor);
907 1000
908 if (::conf.script_node_up) 1001 if (::conf.script_node_up)
909 run_script (run_script_cb (this, &connection::script_node_up), false); 1002 run_script (run_script_cb (this, &connection::script_node_up), false);
910 1003
… …
933 1026
934 if (ictx && octx) 1027 if (ictx && octx)
935 { 1028 {
936 vpndata_packet *p = (vpndata_packet *)pkt; 1029 vpndata_packet *p = (vpndata_packet *)pkt;
937 1030
938 if (rsi == si) 1031 if (!p->hmac_chk (ictx))
1032 slog (L_ERR, _("%s(%s): hmac authentication error, received invalid packet\n"
1033 "could be an attack, or just corruption or a synchronization error"),
1034 conf->nodename, (const char *)rsi);
1035 else
939 { 1036 {
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 1037 u32 seqno;
1038 tap_packet *d = p->unpack (this, seqno);
1039
1040 if (iseqno.recv_ok (seqno))
945 { 1041 {
946 u32 seqno; 1042 vpn->tap->send (d);
947 tap_packet *d = p->unpack (this, seqno);
948 1043
949 if (iseqno.recv_ok (seqno)) 1044 if (si != rsi)
950 { 1045 {
951 vpn->tap->send (d); 1046 // 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; 1047 si = rsi;
1048
1049 slog (L_INFO, _("%s(%s): socket address changed to %s"),
1050 conf->nodename, (const char *)si, (const char *)rsi);
965 } 1051 }
1052
1053 delete d;
1054
1055 break;
966 } 1056 }
967 } 1057 }
968 else
969 slog (L_ERR, _("received data packet from unknown source %s"), (const char *)rsi);
970 } 1058 }
971 1059
972 send_reset (rsi); 1060 send_reset (rsi);
973 break; 1061 break;
974 1062
… …
976 if (ictx && octx && rsi == si && pkt->hmac_chk (ictx)) 1064 if (ictx && octx && rsi == si && pkt->hmac_chk (ictx))
977 { 1065 {
978 connect_req_packet *p = (connect_req_packet *) pkt; 1066 connect_req_packet *p = (connect_req_packet *) pkt;
979 1067
980 assert (p->id > 0 && p->id <= vpn->conns.size ()); // hmac-auth does not mean we accept anything 1068 assert (p->id > 0 && p->id <= vpn->conns.size ()); // hmac-auth does not mean we accept anything
1069 connection *c = vpn->conns[p->id - 1];
981 conf->protocols = p->protocols; 1070 conf->protocols = p->protocols;
982 connection *c = vpn->conns[p->id - 1];
983 1071
984 slog (L_TRACE, "<<%d PT_CONNECT_REQ(%d) [%d]\n", 1072 slog (L_TRACE, "<<%d PT_CONNECT_REQ(%d) [%d]\n",
985 conf->id, p->id, c->ictx && c->octx); 1073 conf->id, p->id, c->ictx && c->octx);
986 1074
987 if (c->ictx && c->octx) 1075 if (c->ictx && c->octx)
… …
989 // send connect_info packets to both sides, in case one is 1077 // send connect_info packets to both sides, in case one is
990 // behind a nat firewall (or both ;) 1078 // behind a nat firewall (or both ;)
991 c->send_connect_info (conf->id, si, conf->protocols); 1079 c->send_connect_info (conf->id, si, conf->protocols);
992 send_connect_info (c->conf->id, c->si, c->conf->protocols); 1080 send_connect_info (c->conf->id, c->si, c->conf->protocols);
993 } 1081 }
1082 else
1083 c->establish_connection ();
994 } 1084 }
995 1085
996 break; 1086 break;
997 1087
998 case vpn_packet::PT_CONNECT_INFO: 1088 case vpn_packet::PT_CONNECT_INFO:
999 if (ictx && octx && rsi == si && pkt->hmac_chk (ictx)) 1089 if (ictx && octx && rsi == si && pkt->hmac_chk (ictx))
1000 { 1090 {
1001 connect_info_packet *p = (connect_info_packet *) pkt; 1091 connect_info_packet *p = (connect_info_packet *) pkt;
1002 1092
1003 assert (p->id > 0 && p->id <= vpn->conns.size ()); // hmac-auth does not mean we accept anything 1093 assert (p->id > 0 && p->id <= vpn->conns.size ()); // hmac-auth does not mean we accept anything
1004 conf->protocols = p->protocols; 1094
1005 connection *c = vpn->conns[p->id - 1]; 1095 connection *c = vpn->conns[p->id - 1];
1096
1097 c->conf->protocols = p->protocols;
1098 protocol = best_protocol (c->conf->protocols & THISNODE->protocols & p->si.supported_protocols (c->conf));
1099 p->si.upgrade_protocol (protocol, c->conf);
1006 1100
1007 slog (L_TRACE, "<<%d PT_CONNECT_INFO(%d,%s) (%d)", 1101 slog (L_TRACE, "<<%d PT_CONNECT_INFO(%d,%s) (%d)",
1008 conf->id, p->id, (const char *)p->si, !c->ictx && !c->octx); 1102 conf->id, p->id, (const char *)p->si, !c->ictx && !c->octx);
1009 1103
1104 const sockinfo &dsi = forward_si (p->si);
1105
1106 if (dsi.valid ())
1010 c->send_auth_request (p->si, true); 1107 c->send_auth_request (dsi, true);
1011 } 1108 }
1012 1109
1013 break; 1110 break;
1014 1111
1015 default: 1112 default:
… …
1024 { 1121 {
1025 reset_connection (); 1122 reset_connection ();
1026 establish_connection (); 1123 establish_connection ();
1027 } 1124 }
1028 else if (NOW < last_activity + ::conf.keepalive) 1125 else if (NOW < last_activity + ::conf.keepalive)
1029 w.at = last_activity + ::conf.keepalive; 1126 w.start (last_activity + ::conf.keepalive);
1030 else if (conf->connectmode != conf_node::C_ONDEMAND 1127 else if (conf->connectmode != conf_node::C_ONDEMAND
1031 || THISNODE->connectmode != conf_node::C_ONDEMAND) 1128 || THISNODE->connectmode != conf_node::C_ONDEMAND)
1032 { 1129 {
1033 send_ping (si); 1130 send_ping (si);
1034 w.at = NOW + 5; 1131 w.start (NOW + 5);
1035 } 1132 }
1133 else if (NOW < last_activity + ::conf.keepalive + 10)
1134 // hold ondemand connections implicitly a few seconds longer
1135 // should delete octx, though, or something like that ;)
1136 w.start (last_activity + ::conf.keepalive + 10);
1036 else 1137 else
1037 reset_connection (); 1138 reset_connection ();
1038} 1139}
1039 1140
1040void connection::connect_request (int id) 1141void connection::send_connect_request (int id)
1041{ 1142{
1042 connect_req_packet *p = new connect_req_packet (conf->id, id, conf->protocols); 1143 connect_req_packet *p = new connect_req_packet (conf->id, id, conf->protocols);
1043 1144
1044 slog (L_TRACE, ">>%d PT_CONNECT_REQ(%d)", conf->id, id); 1145 slog (L_TRACE, ">>%d PT_CONNECT_REQ(%d)", conf->id, id);
1045 p->hmac_set (octx); 1146 p->hmac_set (octx);
… …
1075 putenv ("STATE=down"); 1176 putenv ("STATE=down");
1076 1177
1077 return ::conf.script_node_up ? ::conf.script_node_down : "node-down"; 1178 return ::conf.script_node_up ? ::conf.script_node_down : "node-down";
1078} 1179}
1079 1180
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#if ENABLE_TCP
1095 case PROT_TCPv4:
1096 vpn->send_tcpv4_packet (pkt, si, tos);
1097 break;
1098#endif
1099 }
1100}
1101
1102connection::connection(struct vpn *vpn_) 1181connection::connection(struct vpn *vpn_)
1103: vpn(vpn_) 1182: vpn(vpn_)
1104, rekey (this, &connection::rekey_cb) 1183, rekey (this, &connection::rekey_cb)
1105, keepalive (this, &connection::keepalive_cb) 1184, keepalive (this, &connection::keepalive_cb)
1106, establish_connection (this, &connection::establish_connection_cb) 1185, establish_connection (this, &connection::establish_connection_cb)

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