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Comparing gvpe/src/connection.C (file contents):
Revision 1.10 by pcg, Sun Apr 6 18:12:18 2003 UTC vs.
Revision 1.28 by pcg, Tue Jan 27 05:56:35 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.
… …
20 21
21extern "C" { 22extern "C" {
22# include "lzf/lzf.h" 23# include "lzf/lzf.h"
23} 24}
24 25
26#include <cassert>
27
25#include <list> 28#include <list>
26 29
27#include <openssl/rand.h> 30#include <openssl/rand.h>
28#include <openssl/evp.h> 31#include <openssl/evp.h>
29#include <openssl/rsa.h> 32#include <openssl/rsa.h>
… …
34#include "conf.h" 37#include "conf.h"
35#include "slog.h" 38#include "slog.h"
36#include "device.h" 39#include "device.h"
37#include "vpn.h" 40#include "vpn.h"
38#include "connection.h" 41#include "connection.h"
42
43#include "netcompat.h"
39 44
40#if !HAVE_RAND_PSEUDO_BYTES 45#if !HAVE_RAND_PSEUDO_BYTES
41# define RAND_pseudo_bytes RAND_bytes 46# define RAND_pseudo_bytes RAND_bytes
42#endif 47#endif
43 48
… …
131 136
132} rsa_cache; 137} rsa_cache;
133 138
134void rsa_cache::cleaner_cb (time_watcher &w) 139void rsa_cache::cleaner_cb (time_watcher &w)
135{ 140{
136 if (empty ()) 141 if (!empty ())
137 w.at = TSTAMP_CANCEL;
138 else
139 { 142 {
140 w.at = NOW + RSA_TTL; 143 w.start (NOW + RSA_TTL);
141 144
142 for (iterator i = begin (); i != end (); ) 145 for (iterator i = begin (); i != end (); )
143 if (i->expire <= NOW) 146 if (i->expire <= NOW)
144 i = erase (i); 147 i = erase (i);
145 else 148 else
… …
147 } 150 }
148} 151}
149 152
150////////////////////////////////////////////////////////////////////////////// 153//////////////////////////////////////////////////////////////////////////////
151 154
152void pkt_queue::put (tap_packet *p) 155void pkt_queue::put (net_packet *p)
153{ 156{
154 if (queue[i]) 157 if (queue[i])
155 { 158 {
156 delete queue[i]; 159 delete queue[i];
157 j = (j + 1) % QUEUEDEPTH; 160 j = (j + 1) % QUEUEDEPTH;
… …
160 queue[i] = p; 163 queue[i] = p;
161 164
162 i = (i + 1) % QUEUEDEPTH; 165 i = (i + 1) % QUEUEDEPTH;
163} 166}
164 167
165tap_packet *pkt_queue::get () 168net_packet *pkt_queue::get ()
166{ 169{
167 tap_packet *p = queue[j]; 170 net_packet *p = queue[j];
168 171
169 if (p) 172 if (p)
170 { 173 {
171 queue[j] = 0; 174 queue[j] = 0;
172 j = (j + 1) % QUEUEDEPTH; 175 j = (j + 1) % QUEUEDEPTH;
… …
197// only do action once every x seconds per host whole allowing bursts. 200// only do action once every x seconds per host whole allowing bursts.
198// this implementation ("splay list" ;) is inefficient, 201// this implementation ("splay list" ;) is inefficient,
199// but low on resources. 202// but low on resources.
200struct net_rate_limiter : list<net_rateinfo> 203struct net_rate_limiter : list<net_rateinfo>
201{ 204{
202 static const double ALPHA = 1. - 1. / 180.; // allow bursts 205 static const double ALPHA = 1. - 1. / 600.; // allow bursts
203 static const double CUTOFF = 10.; // one event every CUTOFF seconds 206 static const double CUTOFF = 10.; // one event every CUTOFF seconds
204 static const double EXPIRE = CUTOFF * 30.; // expire entries after this time 207 static const double EXPIRE = CUTOFF * 30.; // expire entries after this time
205 static const double MAXDIF = CUTOFF * (1. / (1. - ALPHA)); // maximum diff /count value 208 static const double MAXDIF = CUTOFF * (1. / (1. - ALPHA)); // maximum diff /count value
206 209
207 bool can (const sockinfo &si) { return can((u32)si.host); } 210 bool can (const sockinfo &si) { return can((u32)si.host); }
208 bool can (u32 host); 211 bool can (u32 host);
209}; 212};
210 213
211net_rate_limiter auth_rate_limiter, reset_rate_limiter; 214net_rate_limiter auth_rate_limiter, reset_rate_limiter;
212 215
… …
307} 310}
308 311
309#define MAXVPNDATA (MAX_MTU - 6 - 6) 312#define MAXVPNDATA (MAX_MTU - 6 - 6)
310#define DATAHDR (sizeof (u32) + RAND_SIZE) 313#define DATAHDR (sizeof (u32) + RAND_SIZE)
311 314
312struct vpndata_packet:vpn_packet 315struct vpndata_packet : vpn_packet
313 { 316 {
314 u8 data[MAXVPNDATA + DATAHDR]; // seqno 317 u8 data[MAXVPNDATA + DATAHDR]; // seqno
315 318
316 void setup (connection *conn, int dst, u8 *d, u32 len, u32 seqno); 319 void setup (connection *conn, int dst, u8 *d, u32 len, u32 seqno);
317 tap_packet *unpack (connection *conn, u32 &seqno); 320 tap_packet *unpack (connection *conn, u32 &seqno);
… …
475 set_hdr (type, dst); 478 set_hdr (type, dst);
476} 479}
477 480
478bool config_packet::chk_config () const 481bool config_packet::chk_config () const
479{ 482{
480 return prot_major == PROTOCOL_MAJOR 483 if (prot_major != PROTOCOL_MAJOR)
481 && randsize == RAND_SIZE 484 slog (L_WARN, _("major version mismatch (remote %d <=> local %d)"), prot_major, PROTOCOL_MAJOR);
482 && hmaclen == HMACLENGTH 485 else if (randsize != RAND_SIZE)
483 && flags == curflags () 486 slog (L_WARN, _("rand size mismatch (remote %d <=> local %d)"), randsize, RAND_SIZE);
487 else if (hmaclen != HMACLENGTH)
488 slog (L_WARN, _("hmac length mismatch (remote %d <=> local %d)"), hmaclen, HMACLENGTH);
489 else if (flags != curflags ())
490 slog (L_WARN, _("flag mismatch (remote %x <=> local %x)"), flags, curflags ());
484 && challengelen == sizeof (rsachallenge) 491 else if (challengelen != sizeof (rsachallenge))
492 slog (L_WARN, _("challenge length mismatch (remote %d <=> local %d)"), challengelen, sizeof (rsachallenge));
485 && cipher_nid == htonl (EVP_CIPHER_nid (CIPHER)) 493 else if (cipher_nid != htonl (EVP_CIPHER_nid (CIPHER)))
494 slog (L_WARN, _("cipher mismatch (remote %x <=> local %x)"), ntohl (cipher_nid), EVP_CIPHER_nid (CIPHER));
486 && digest_nid == htonl (EVP_MD_type (RSA_HASH)) 495 else if (digest_nid != htonl (EVP_MD_type (RSA_HASH)))
496 slog (L_WARN, _("digest mismatch (remote %x <=> local %x)"), ntohl (digest_nid), EVP_MD_type (RSA_HASH));
487 && hmac_nid == htonl (EVP_MD_type (DIGEST)); 497 else if (hmac_nid != htonl (EVP_MD_type (DIGEST)))
498 slog (L_WARN, _("hmac mismatch (remote %x <=> local %x)"), ntohl (hmac_nid), EVP_MD_type (DIGEST));
499 else
500 return true;
501
502 return false;
488} 503}
489 504
490struct auth_req_packet : config_packet 505struct auth_req_packet : config_packet
491{ 506{
492 char magic[8]; 507 char magic[8];
493 u8 initiate; // false if this is just an automatic reply 508 u8 initiate; // false if this is just an automatic reply
494 u8 protocols; // supported protocols (will get patches on forward) 509 u8 protocols; // supported protocols (will be patched on forward)
495 u8 pad2, pad3; 510 u8 pad2, pad3;
496 rsaid id; 511 rsaid id;
497 rsaencrdata encr; 512 rsaencrdata encr;
498 513
499 auth_req_packet (int dst, bool initiate_, u8 protocols_) 514 auth_req_packet (int dst, bool initiate_, u8 protocols_)
… …
565 rekey.start (NOW + ::conf.rekey); 580 rekey.start (NOW + ::conf.rekey);
566 keepalive.start (NOW + ::conf.keepalive); 581 keepalive.start (NOW + ::conf.keepalive);
567 582
568 // send queued packets 583 // send queued packets
569 if (ictx && octx) 584 if (ictx && octx)
585 {
570 while (tap_packet *p = queue.get ()) 586 while (tap_packet *p = (tap_packet *)data_queue.get ())
571 { 587 {
572 send_data_packet (p); 588 send_data_packet (p);
573 delete p; 589 delete p;
574 } 590 }
591
592 while (vpn_packet *p = (vpn_packet *)vpn_queue.get ())
593 {
594 send_vpn_packet (p, si, IPTOS_RELIABILITY);
595 delete p;
596 }
597 }
575 } 598 }
576 else 599 else
577 { 600 {
578 retry_cnt = 0; 601 retry_cnt = 0;
579 establish_connection.start (NOW + 5); 602 establish_connection.start (NOW + 5);
580 keepalive.reset (); 603 keepalive.stop ();
581 rekey.reset (); 604 rekey.stop ();
582 } 605 }
583} 606}
584 607
585void 608void
586connection::reset_si () 609connection::reset_si ()
… …
652connection::send_auth_request (const sockinfo &si, bool initiate) 675connection::send_auth_request (const sockinfo &si, bool initiate)
653{ 676{
654 auth_req_packet *pkt = new auth_req_packet (conf->id, initiate, THISNODE->protocols); 677 auth_req_packet *pkt = new auth_req_packet (conf->id, initiate, THISNODE->protocols);
655 678
656 rsachallenge chg; 679 rsachallenge chg;
657
658 rsa_cache.gen (pkt->id, chg); 680 rsa_cache.gen (pkt->id, chg);
659 681 rsa_encrypt (conf->rsa_key, chg, pkt->encr);
660 if (0 > RSA_public_encrypt (sizeof chg,
661 (unsigned char *)&chg, (unsigned char *)&pkt->encr,
662 conf->rsa_key, RSA_PKCS1_OAEP_PADDING))
663 fatal ("RSA_public_encrypt error");
664 682
665 slog (L_TRACE, ">>%d PT_AUTH_REQ [%s]", conf->id, (const char *)si); 683 slog (L_TRACE, ">>%d PT_AUTH_REQ [%s]", conf->id, (const char *)si);
666 684
667 send_vpn_packet (pkt, si, IPTOS_RELIABILITY | IPTOS_LOWDELAY); // rsa is very very costly 685 send_vpn_packet (pkt, si, IPTOS_RELIABILITY | IPTOS_LOWDELAY); // rsa is very very costly
668 686
… …
702} 720}
703 721
704void 722void
705connection::establish_connection_cb (time_watcher &w) 723connection::establish_connection_cb (time_watcher &w)
706{ 724{
707 if (ictx || conf == THISNODE 725 if (!ictx
726 && conf != THISNODE
708 || connectmode == conf_node::C_NEVER 727 && connectmode != conf_node::C_NEVER
709 || connectmode == conf_node::C_DISABLED) 728 && connectmode != conf_node::C_DISABLED
710 w.at = TSTAMP_CANCEL; 729 && NOW > w.at)
711 else if (w.at <= NOW)
712 { 730 {
713 double retry_int = double (retry_cnt & 3 ? (retry_cnt & 3) : 1 << (retry_cnt >> 2)) * 0.6; 731 double retry_int = double (retry_cnt & 3 ? (retry_cnt & 3) : 1 << (retry_cnt >> 2)) * 0.6;
714 732
715 if (retry_int < 3600 * 8) 733 if (retry_int < 3600 * 8)
716 retry_cnt++; 734 retry_cnt++;
717 735
718 w.at = NOW + retry_int; 736 w.start (NOW + retry_int);
719 737
720 reset_si (); 738 reset_si ();
721 739
722 if (si.prot && !si.host) 740 if (si.prot && !si.host)
723 vpn->send_connect_request (conf->id); 741 vpn->send_connect_request (conf->id);
… …
754 si.host= 0; 772 si.host= 0;
755 773
756 last_activity = 0; 774 last_activity = 0;
757 retry_cnt = 0; 775 retry_cnt = 0;
758 776
759 rekey.reset (); 777 rekey.stop ();
760 keepalive.reset (); 778 keepalive.stop ();
761 establish_connection.reset (); 779 establish_connection.stop ();
762} 780}
763 781
764void 782void
765connection::shutdown () 783connection::shutdown ()
766{ 784{
… …
771} 789}
772 790
773void 791void
774connection::rekey_cb (time_watcher &w) 792connection::rekey_cb (time_watcher &w)
775{ 793{
776 w.at = TSTAMP_CANCEL;
777
778 reset_connection (); 794 reset_connection ();
779 establish_connection (); 795 establish_connection ();
780} 796}
781 797
782void 798void
783connection::send_data_packet (tap_packet *pkt, bool broadcast) 799connection::send_data_packet (tap_packet *pkt)
784{ 800{
785 vpndata_packet *p = new vpndata_packet; 801 vpndata_packet *p = new vpndata_packet;
786 int tos = 0; 802 int tos = 0;
787 803
788 if (conf->inherit_tos 804 // I am not hilarious about peeking into packets, but so be it.
789 && (*pkt)[12] == 0x08 && (*pkt)[13] == 0x00 // IP 805 if (conf->inherit_tos && pkt->is_ipv4 ())
790 && ((*pkt)[14] & 0xf0) == 0x40) // IPv4
791 tos = (*pkt)[15] & IPTOS_TOS_MASK; 806 tos = (*pkt)[15] & IPTOS_TOS_MASK;
792 807
793 p->setup (this, broadcast ? 0 : conf->id, &((*pkt)[6 + 6]), pkt->len - 6 - 6, ++oseqno); // skip 2 macs 808 p->setup (this, conf->id, &((*pkt)[6 + 6]), pkt->len - 6 - 6, ++oseqno); // skip 2 macs
794 send_vpn_packet (p, si, tos); 809 send_vpn_packet (p, si, tos);
795 810
796 delete p; 811 delete p;
797 812
798 if (oseqno > MAX_SEQNO) 813 if (oseqno > MAX_SEQNO)
799 rekey (); 814 rekey ();
800} 815}
801 816
802void 817void
803connection::inject_data_packet (tap_packet *pkt, bool broadcast) 818connection::inject_data_packet (tap_packet *pkt, bool broadcast/*TODO DDD*/)
804{ 819{
805 if (ictx && octx) 820 if (ictx && octx)
806 send_data_packet (pkt, broadcast); 821 send_data_packet (pkt);
807 else 822 else
808 { 823 {
809 if (!broadcast)//DDDD 824 if (!broadcast)//DDDD
810 queue.put (new tap_packet (*pkt)); 825 data_queue.put (new tap_packet (*pkt));
811 826
812 establish_connection (); 827 establish_connection ();
813 } 828 }
814} 829}
815 830
816void connection::inject_vpn_packet (vpn_packet *pkt, int tos) 831void connection::inject_vpn_packet (vpn_packet *pkt, int tos)
817{ 832{
818 if (ictx && octx) 833 if (ictx && octx)
819 send_vpn_packet (pkt, si, tos); 834 send_vpn_packet (pkt, si, tos);
820 else 835 else
836 {
837 vpn_queue.put ((vpn_packet *)new data_packet (*(data_packet *)pkt));
838
821 establish_connection (); 839 establish_connection ();
840 }
822} 841}
823 842
824void 843void
825connection::recv_vpn_packet (vpn_packet *pkt, const sockinfo &rsi) 844connection::recv_vpn_packet (vpn_packet *pkt, const sockinfo &rsi)
826{ 845{
… …
882 if (p->initiate) 901 if (p->initiate)
883 send_auth_request (rsi, false); 902 send_auth_request (rsi, false);
884 903
885 rsachallenge k; 904 rsachallenge k;
886 905
887 if (0 > RSA_private_decrypt (sizeof (p->encr), 906 if (!rsa_decrypt (::conf.rsa_key, p->encr, k))
888 (unsigned char *)&p->encr, (unsigned char *)&k, 907 {
889 ::conf.rsa_key, RSA_PKCS1_OAEP_PADDING))
890 slog (L_ERR, _("%s(%s): challenge illegal or corrupted"), 908 slog (L_ERR, _("%s(%s): challenge illegal or corrupted (%s). mismatched key or config file?"),
891 conf->nodename, (const char *)rsi); 909 conf->nodename, (const char *)rsi, ERR_error_string (ERR_get_error (), 0));
910 break;
911 }
892 else 912 else
893 { 913 {
894 delete octx; 914 delete octx;
895 915
896 octx = new crypto_ctx (k, 1); 916 octx = new crypto_ctx (k, 1);
… …
903 connection_established (); 923 connection_established ();
904 924
905 break; 925 break;
906 } 926 }
907 } 927 }
928 else
929 slog (L_WARN, _("%s(%s): protocol mismatch"),
930 conf->nodename, (const char *)rsi);
908 931
909 send_reset (rsi); 932 send_reset (rsi);
910 } 933 }
911 934
912 break; 935 break;
… …
925 PROTOCOL_MINOR, conf->nodename, p->prot_minor); 948 PROTOCOL_MINOR, conf->nodename, p->prot_minor);
926 949
927 rsachallenge chg; 950 rsachallenge chg;
928 951
929 if (!rsa_cache.find (p->id, chg)) 952 if (!rsa_cache.find (p->id, chg))
953 {
930 slog (L_ERR, _("%s(%s): unrequested auth response"), 954 slog (L_ERR, _("%s(%s): unrequested auth response ignored"),
931 conf->nodename, (const char *)rsi); 955 conf->nodename, (const char *)rsi);
956 break;
957 }
932 else 958 else
933 { 959 {
934 crypto_ctx *cctx = new crypto_ctx (chg, 0); 960 crypto_ctx *cctx = new crypto_ctx (chg, 0);
935 961
936 if (!p->hmac_chk (cctx)) 962 if (!p->hmac_chk (cctx))
963 {
937 slog (L_ERR, _("%s(%s): hmac authentication error on auth response, received invalid packet\n" 964 slog (L_ERR, _("%s(%s): hmac authentication error on auth response, received invalid packet\n"
938 "could be an attack, or just corruption or an synchronization error"), 965 "could be an attack, or just corruption or a synchronization error"),
939 conf->nodename, (const char *)rsi); 966 conf->nodename, (const char *)rsi);
967 break;
968 }
940 else 969 else
941 { 970 {
942 rsaresponse h; 971 rsaresponse h;
943 972
944 rsa_hash (p->id, chg, h); 973 rsa_hash (p->id, chg, h);
… …
990 { 1019 {
991 vpndata_packet *p = (vpndata_packet *)pkt; 1020 vpndata_packet *p = (vpndata_packet *)pkt;
992 1021
993 if (!p->hmac_chk (ictx)) 1022 if (!p->hmac_chk (ictx))
994 slog (L_ERR, _("%s(%s): hmac authentication error, received invalid packet\n" 1023 slog (L_ERR, _("%s(%s): hmac authentication error, received invalid packet\n"
995 "could be an attack, or just corruption or an synchronization error"), 1024 "could be an attack, or just corruption or a synchronization error"),
996 conf->nodename, (const char *)rsi); 1025 conf->nodename, (const char *)rsi);
997 else 1026 else
998 { 1027 {
999 u32 seqno; 1028 u32 seqno;
1000 tap_packet *d = p->unpack (this, seqno); 1029 tap_packet *d = p->unpack (this, seqno);
1001 1030
1002 if (iseqno.recv_ok (seqno)) 1031 if (iseqno.recv_ok (seqno))
1003 { 1032 {
1004 vpn->tap->send (d); 1033 vpn->tap->send (d);
1005 1034
1006 if (p->dst () == 0) // re-broadcast
1007 for (vpn::conns_vector::iterator i = vpn->conns.begin (); i != vpn->conns.end (); ++i)
1008 {
1009 connection *c = *i;
1010
1011 if (c->conf != THISNODE && c->conf != conf)
1012 c->inject_data_packet (d);
1013 }
1014
1015 if (si != rsi) 1035 if (si != rsi)
1016 { 1036 {
1017 // fast re-sync on conneciton changes, useful especially for tcp/ip 1037 // fast re-sync on connection changes, useful especially for tcp/ip
1018 si = rsi; 1038 si = rsi;
1019 1039
1020 slog (L_INFO, _("%s(%s): socket address changed to %s"), 1040 slog (L_INFO, _("%s(%s): socket address changed to %s"),
1021 conf->nodename, (const char *)si, (const char *)rsi); 1041 conf->nodename, (const char *)si, (const char *)rsi);
1022 } 1042 }
… …
1048 // send connect_info packets to both sides, in case one is 1068 // send connect_info packets to both sides, in case one is
1049 // behind a nat firewall (or both ;) 1069 // behind a nat firewall (or both ;)
1050 c->send_connect_info (conf->id, si, conf->protocols); 1070 c->send_connect_info (conf->id, si, conf->protocols);
1051 send_connect_info (c->conf->id, c->si, c->conf->protocols); 1071 send_connect_info (c->conf->id, c->si, c->conf->protocols);
1052 } 1072 }
1073 else
1074 c->establish_connection ();
1053 } 1075 }
1054 1076
1055 break; 1077 break;
1056 1078
1057 case vpn_packet::PT_CONNECT_INFO: 1079 case vpn_packet::PT_CONNECT_INFO:
… …
1090 { 1112 {
1091 reset_connection (); 1113 reset_connection ();
1092 establish_connection (); 1114 establish_connection ();
1093 } 1115 }
1094 else if (NOW < last_activity + ::conf.keepalive) 1116 else if (NOW < last_activity + ::conf.keepalive)
1095 w.at = last_activity + ::conf.keepalive; 1117 w.start (last_activity + ::conf.keepalive);
1096 else if (conf->connectmode != conf_node::C_ONDEMAND 1118 else if (conf->connectmode != conf_node::C_ONDEMAND
1097 || THISNODE->connectmode != conf_node::C_ONDEMAND) 1119 || THISNODE->connectmode != conf_node::C_ONDEMAND)
1098 { 1120 {
1099 send_ping (si); 1121 send_ping (si);
1100 w.at = NOW + 5; 1122 w.start (NOW + 5);
1101 } 1123 }
1124 else if (NOW < last_activity + ::conf.keepalive + 10)
1125 // hold ondemand connections implicitly a few seconds longer
1126 // should delete octx, though, or something like that ;)
1127 w.start (last_activity + ::conf.keepalive + 10);
1102 else 1128 else
1103 reset_connection (); 1129 reset_connection ();
1104} 1130}
1105 1131
1106void connection::send_connect_request (int id) 1132void connection::send_connect_request (int id)

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