--- gvpe/src/connection.C 2003/04/02 21:02:25 1.4 +++ gvpe/src/connection.C 2004/01/29 18:55:10 1.29 @@ -1,5 +1,6 @@ /* connection.C -- manage a single connection + Copyright (C) 2003-2004 Marc Lehmann This program is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by @@ -22,6 +23,8 @@ # include "lzf/lzf.h" } +#include + #include #include @@ -37,6 +40,8 @@ #include "vpn.h" #include "connection.h" +#include "netcompat.h" + #if !HAVE_RAND_PSEUDO_BYTES # define RAND_pseudo_bytes RAND_bytes #endif @@ -55,14 +60,14 @@ crypto_ctx::crypto_ctx (const rsachallenge &challenge, int enc) { EVP_CIPHER_CTX_init (&cctx); - EVP_CipherInit_ex (&cctx, CIPHER, 0, &challenge[CHG_CIPHER_KEY], 0, enc); + require (EVP_CipherInit_ex (&cctx, CIPHER, 0, &challenge[CHG_CIPHER_KEY], 0, enc)); HMAC_CTX_init (&hctx); HMAC_Init_ex (&hctx, &challenge[CHG_HMAC_KEY], HMAC_KEYLEN, DIGEST, 0); } crypto_ctx::~crypto_ctx () { - EVP_CIPHER_CTX_cleanup (&cctx); + require (EVP_CIPHER_CTX_cleanup (&cctx)); HMAC_CTX_cleanup (&hctx); } @@ -72,10 +77,10 @@ EVP_MD_CTX ctx; EVP_MD_CTX_init (&ctx); - EVP_DigestInit (&ctx, RSA_HASH); - EVP_DigestUpdate(&ctx, &chg, sizeof chg); - EVP_DigestUpdate(&ctx, &id, sizeof id); - EVP_DigestFinal (&ctx, (unsigned char *)&h, 0); + require (EVP_DigestInit (&ctx, RSA_HASH)); + require (EVP_DigestUpdate(&ctx, &chg, sizeof chg)); + require (EVP_DigestUpdate(&ctx, &id, sizeof id)); + require (EVP_DigestFinal (&ctx, (unsigned char *)&h, 0)); EVP_MD_CTX_cleanup (&ctx); } @@ -133,11 +138,9 @@ void rsa_cache::cleaner_cb (time_watcher &w) { - if (empty ()) - w.at = TSTAMP_CANCEL; - else + if (!empty ()) { - w.at = NOW + RSA_TTL; + w.start (NOW + RSA_TTL); for (iterator i = begin (); i != end (); ) if (i->expire <= NOW) @@ -149,7 +152,7 @@ ////////////////////////////////////////////////////////////////////////////// -void pkt_queue::put (tap_packet *p) +void pkt_queue::put (net_packet *p) { if (queue[i]) { @@ -162,9 +165,9 @@ i = (i + 1) % QUEUEDEPTH; } -tap_packet *pkt_queue::get () +net_packet *pkt_queue::get () { - tap_packet *p = queue[j]; + net_packet *p = queue[j]; if (p) { @@ -199,11 +202,12 @@ // but low on resources. struct net_rate_limiter : list { - static const double ALPHA = 1. - 1. / 90.; // allow bursts - static const double CUTOFF = 20.; // one event every CUTOFF seconds - static const double EXPIRE = CUTOFF * 30.; // expire entries after this time + static const double ALPHA = 1. - 1. / 600.; // allow bursts + static const double CUTOFF = 10.; // one event every CUTOFF seconds + static const double EXPIRE = CUTOFF * 30.; // expire entries after this time + static const double MAXDIF = CUTOFF * (1. / (1. - ALPHA)); // maximum diff /count value - bool can (const sockinfo &si) { return can((u32)si.host); } + bool can (const sockinfo &si) { return can((u32)si.host); } bool can (u32 host); }; @@ -227,7 +231,7 @@ ri.host = host; ri.pcnt = 1.; - ri.diff = CUTOFF * (1. / (1. - ALPHA)); + ri.diff = MAXDIF; ri.last = NOW; push_front (ri); @@ -244,9 +248,16 @@ ri.last = NOW; - bool send = ri.diff / ri.pcnt > CUTOFF; + double dif = ri.diff / ri.pcnt; + + bool send = dif > CUTOFF; - if (send) + if (dif > MAXDIF) + { + ri.pcnt = 1.; + ri.diff = MAXDIF; + } + else if (send) ri.pcnt++; push_front (ri); @@ -287,9 +298,9 @@ return !memcmp (hmac, hmac_digest, HMACLENGTH); } -void vpn_packet::set_hdr (ptype type, unsigned int dst) +void vpn_packet::set_hdr (ptype type_, unsigned int dst) { - this->type = type; + type = type_; int src = THISNODE->id; @@ -301,7 +312,7 @@ #define MAXVPNDATA (MAX_MTU - 6 - 6) #define DATAHDR (sizeof (u32) + RAND_SIZE) -struct vpndata_packet:vpn_packet +struct vpndata_packet : vpn_packet { u8 data[MAXVPNDATA + DATAHDR]; // seqno @@ -338,7 +349,7 @@ } #endif - EVP_EncryptInit_ex (cctx, 0, 0, 0, 0); + require (EVP_EncryptInit_ex (cctx, 0, 0, 0, 0)); struct { #if RAND_SIZE @@ -352,17 +363,17 @@ RAND_pseudo_bytes ((unsigned char *) datahdr.rnd, RAND_SIZE); #endif - EVP_EncryptUpdate (cctx, + require (EVP_EncryptUpdate (cctx, (unsigned char *) data + outl, &outl2, - (unsigned char *) &datahdr, DATAHDR); + (unsigned char *) &datahdr, DATAHDR)); outl += outl2; - EVP_EncryptUpdate (cctx, + require (EVP_EncryptUpdate (cctx, (unsigned char *) data + outl, &outl2, - (unsigned char *) d, l); + (unsigned char *) d, l)); outl += outl2; - EVP_EncryptFinal_ex (cctx, (unsigned char *) data + outl, &outl2); + require (EVP_EncryptFinal_ex (cctx, (unsigned char *) data + outl, &outl2)); outl += outl2; len = outl + data_hdr_size (); @@ -381,7 +392,7 @@ u8 *d; u32 l = len - data_hdr_size (); - EVP_DecryptInit_ex (cctx, 0, 0, 0, 0); + require (EVP_DecryptInit_ex (cctx, 0, 0, 0, 0)); #if ENABLE_COMPRESSION u8 cdata[MAX_MTU]; @@ -393,12 +404,12 @@ d = &(*p)[6 + 6 - DATAHDR]; /* this overwrites part of the src mac, but we fix that later */ - EVP_DecryptUpdate (cctx, + require (EVP_DecryptUpdate (cctx, d, &outl2, - (unsigned char *)&data, len - data_hdr_size ()); + (unsigned char *)&data, len - data_hdr_size ())); outl += outl2; - EVP_DecryptFinal_ex (cctx, (unsigned char *)d + outl, &outl2); + require (EVP_DecryptFinal_ex (cctx, (unsigned char *)d + outl, &outl2)); outl += outl2; seqno = ntohl (*(u32 *)(d + RAND_SIZE)); @@ -469,21 +480,33 @@ bool config_packet::chk_config () const { - return prot_major == PROTOCOL_MAJOR - && randsize == RAND_SIZE - && hmaclen == HMACLENGTH - && flags == curflags () - && challengelen == sizeof (rsachallenge) - && cipher_nid == htonl (EVP_CIPHER_nid (CIPHER)) - && digest_nid == htonl (EVP_MD_type (RSA_HASH)) - && hmac_nid == htonl (EVP_MD_type (DIGEST)); + if (prot_major != PROTOCOL_MAJOR) + slog (L_WARN, _("major version mismatch (remote %d <=> local %d)"), prot_major, PROTOCOL_MAJOR); + else if (randsize != RAND_SIZE) + slog (L_WARN, _("rand size mismatch (remote %d <=> local %d)"), randsize, RAND_SIZE); + else if (hmaclen != HMACLENGTH) + slog (L_WARN, _("hmac length mismatch (remote %d <=> local %d)"), hmaclen, HMACLENGTH); + else if (flags != curflags ()) + slog (L_WARN, _("flag mismatch (remote %x <=> local %x)"), flags, curflags ()); + else if (challengelen != sizeof (rsachallenge)) + slog (L_WARN, _("challenge length mismatch (remote %d <=> local %d)"), challengelen, sizeof (rsachallenge)); + else if (cipher_nid != htonl (EVP_CIPHER_nid (CIPHER))) + slog (L_WARN, _("cipher mismatch (remote %x <=> local %x)"), ntohl (cipher_nid), EVP_CIPHER_nid (CIPHER)); + else if (digest_nid != htonl (EVP_MD_type (RSA_HASH))) + slog (L_WARN, _("digest mismatch (remote %x <=> local %x)"), ntohl (digest_nid), EVP_MD_type (RSA_HASH)); + else if (hmac_nid != htonl (EVP_MD_type (DIGEST))) + slog (L_WARN, _("hmac mismatch (remote %x <=> local %x)"), ntohl (hmac_nid), EVP_MD_type (DIGEST)); + else + return true; + + return false; } struct auth_req_packet : config_packet { char magic[8]; u8 initiate; // false if this is just an automatic reply - u8 protocols; // supported protocols (will get patches on forward) + u8 protocols; // supported protocols (will be patched on forward) u8 pad2, pad3; rsaid id; rsaencrdata encr; @@ -548,9 +571,79 @@ ///////////////////////////////////////////////////////////////////////////// void -connection::reset_dstaddr () +connection::connection_established () +{ + if (ictx && octx) + { + connectmode = conf->connectmode; + + rekey.start (NOW + ::conf.rekey); + keepalive.start (NOW + ::conf.keepalive); + + // send queued packets + if (ictx && octx) + { + while (tap_packet *p = (tap_packet *)data_queue.get ()) + { + send_data_packet (p); + delete p; + } + + while (vpn_packet *p = (vpn_packet *)vpn_queue.get ()) + { + send_vpn_packet (p, si, IPTOS_RELIABILITY); + delete p; + } + } + } + else + { + retry_cnt = 0; + establish_connection.start (NOW + 5); + keepalive.stop (); + rekey.stop (); + } +} + +void +connection::reset_si () +{ + protocol = best_protocol (THISNODE->protocols & conf->protocols); + + // mask out protocols we cannot establish + if (!conf->udp_port) protocol &= ~PROT_UDPv4; + if (!conf->tcp_port) protocol &= ~PROT_TCPv4; + + si.set (conf, protocol); +} + +// ensure sockinfo is valid, forward if necessary +const sockinfo & +connection::forward_si (const sockinfo &si) const +{ + if (!si.valid ()) + { + connection *r = vpn->find_router (); + + if (r) + { + slog (L_DEBUG, _("%s: no common protocol, trying indirectly through %s"), + conf->nodename, r->conf->nodename); + return r->si; + } + else + slog (L_DEBUG, _("%s: node unreachable, no common protocol"), + conf->nodename); + } + + return si; +} + +void +connection::send_vpn_packet (vpn_packet *pkt, const sockinfo &si, int tos) { - si.set (conf); + if (!vpn->send_vpn_packet (pkt, si, tos)) + reset_connection (); } void @@ -583,31 +676,15 @@ { auth_req_packet *pkt = new auth_req_packet (conf->id, initiate, THISNODE->protocols); - protocol = best_protocol (THISNODE->protocols & conf->protocols); - - // mask out protocols we cannot establish - if (!conf->udp_port) protocol &= ~PROT_UDPv4; - if (!conf->tcp_port) protocol &= ~PROT_TCPv4; - - if (protocol) - { - rsachallenge chg; - - rsa_cache.gen (pkt->id, chg); - - if (0 > RSA_public_encrypt (sizeof chg, - (unsigned char *)&chg, (unsigned char *)&pkt->encr, - conf->rsa_key, RSA_PKCS1_OAEP_PADDING)) - fatal ("RSA_public_encrypt error"); + rsachallenge chg; + rsa_cache.gen (pkt->id, chg); + rsa_encrypt (conf->rsa_key, chg, pkt->encr); - slog (L_TRACE, ">>%d PT_AUTH_REQ [%s]", conf->id, (const char *)si); + slog (L_TRACE, ">>%d PT_AUTH_REQ [%s]", conf->id, (const char *)si); - send_vpn_packet (pkt, si, IPTOS_RELIABILITY); // rsa is very very costly + send_vpn_packet (pkt, si, IPTOS_RELIABILITY | IPTOS_LOWDELAY); // rsa is very very costly - delete pkt; - } - else - ; // silently fail + delete pkt; } void @@ -645,32 +722,35 @@ void connection::establish_connection_cb (time_watcher &w) { - if (ictx || conf == THISNODE - || connectmode == conf_node::C_NEVER - || connectmode == conf_node::C_DISABLED) - w.at = TSTAMP_CANCEL; - else if (w.at <= NOW) + if (!ictx + && conf != THISNODE + && connectmode != conf_node::C_NEVER + && connectmode != conf_node::C_DISABLED + && NOW > w.at) { double retry_int = double (retry_cnt & 3 ? (retry_cnt & 3) : 1 << (retry_cnt >> 2)) * 0.6; if (retry_int < 3600 * 8) retry_cnt++; - w.at = NOW + retry_int; + w.start (NOW + retry_int); + + reset_si (); - if (conf->hostname) + if (si.prot && !si.host) + vpn->send_connect_request (conf->id); + else { - reset_dstaddr (); - if (si.host && auth_rate_limiter.can (si)) - { - if (retry_cnt < 4) - send_auth_request (si, true); - else - send_ping (si, 0); - } + const sockinfo &dsi = forward_si (si); + + if (dsi.valid () && auth_rate_limiter.can (dsi)) + { + if (retry_cnt < 4) + send_auth_request (dsi, true); + else + send_ping (dsi, 0); + } } - else - vpn->connect_request (conf->id); } } @@ -694,9 +774,9 @@ last_activity = 0; retry_cnt = 0; - rekey.reset (); - keepalive.reset (); - establish_connection.reset (); + rekey.stop (); + keepalive.stop (); + establish_connection.stop (); } void @@ -711,24 +791,21 @@ void connection::rekey_cb (time_watcher &w) { - w.at = TSTAMP_CANCEL; - reset_connection (); establish_connection (); } void -connection::send_data_packet (tap_packet *pkt, bool broadcast) +connection::send_data_packet (tap_packet *pkt) { vpndata_packet *p = new vpndata_packet; int tos = 0; - if (conf->inherit_tos - && (*pkt)[12] == 0x08 && (*pkt)[13] == 0x00 // IP - && ((*pkt)[14] & 0xf0) == 0x40) // IPv4 + // I am not hilarious about peeking into packets, but so be it. + if (conf->inherit_tos && pkt->is_ipv4 ()) tos = (*pkt)[15] & IPTOS_TOS_MASK; - p->setup (this, broadcast ? 0 : conf->id, &((*pkt)[6 + 6]), pkt->len - 6 - 6, ++oseqno); // skip 2 macs + p->setup (this, conf->id, &((*pkt)[6 + 6]), pkt->len - 6 - 6, ++oseqno); // skip 2 macs send_vpn_packet (p, si, tos); delete p; @@ -738,14 +815,26 @@ } void -connection::inject_data_packet (tap_packet *pkt, bool broadcast) +connection::inject_data_packet (tap_packet *pkt, bool broadcast/*TODO DDD*/) { if (ictx && octx) - send_data_packet (pkt, broadcast); + send_data_packet (pkt); else { if (!broadcast)//DDDD - queue.put (new tap_packet (*pkt)); + data_queue.put (new tap_packet (*pkt)); + + establish_connection (); + } +} + +void connection::inject_vpn_packet (vpn_packet *pkt, int tos) +{ + if (ictx && octx) + send_vpn_packet (pkt, si, tos); + else + { + vpn_queue.put ((vpn_packet *)new data_packet (*(data_packet *)pkt)); establish_connection (); } @@ -814,32 +903,31 @@ rsachallenge k; - if (0 > RSA_private_decrypt (sizeof (p->encr), - (unsigned char *)&p->encr, (unsigned char *)&k, - ::conf.rsa_key, RSA_PKCS1_OAEP_PADDING)) - slog (L_ERR, _("%s(%s): challenge illegal or corrupted"), - conf->nodename, (const char *)rsi); + if (!rsa_decrypt (::conf.rsa_key, p->encr, k)) + { + slog (L_ERR, _("%s(%s): challenge illegal or corrupted (%s). mismatched key or config file?"), + conf->nodename, (const char *)rsi, ERR_error_string (ERR_get_error (), 0)); + break; + } else { - retry_cnt = 0; - establish_connection.set (NOW + 8); //? ;) - keepalive.reset (); - rekey.reset (); - - delete ictx; - ictx = 0; - delete octx; octx = new crypto_ctx (k, 1); oseqno = ntohl (*(u32 *)&k[CHG_SEQNO]) & 0x7fffffff; conf->protocols = p->protocols; + send_auth_response (rsi, p->id, k); + connection_established (); + break; } } + else + slog (L_WARN, _("%s(%s): protocol mismatch"), + conf->nodename, (const char *)rsi); send_reset (rsi); } @@ -862,16 +950,22 @@ rsachallenge chg; if (!rsa_cache.find (p->id, chg)) - slog (L_ERR, _("%s(%s): unrequested auth response"), - conf->nodename, (const char *)rsi); + { + slog (L_ERR, _("%s(%s): unrequested auth response ignored"), + conf->nodename, (const char *)rsi); + break; + } else { crypto_ctx *cctx = new crypto_ctx (chg, 0); if (!p->hmac_chk (cctx)) - slog (L_ERR, _("%s(%s): hmac authentication error on auth response, received invalid packet\n" - "could be an attack, or just corruption or an synchronization error"), - conf->nodename, (const char *)rsi); + { + slog (L_ERR, _("%s(%s): hmac authentication error on auth response, received invalid packet\n" + "could be an attack, or just corruption or a synchronization error"), + conf->nodename, (const char *)rsi); + break; + } else { rsaresponse h; @@ -887,22 +981,12 @@ iseqno.reset (ntohl (*(u32 *)&chg[CHG_SEQNO]) & 0x7fffffff); // at least 2**31 sequence numbers are valid si = rsi; + protocol = rsi.prot; - rekey.set (NOW + ::conf.rekey); - keepalive.set (NOW + ::conf.keepalive); + connection_established (); - // send queued packets - while (tap_packet *p = queue.get ()) - { - send_data_packet (p); - delete p; - } - - connectmode = conf->connectmode; - - slog (L_INFO, _("%s(%s): %s connection established, protocol version %d.%d"), + slog (L_INFO, _("%s(%s): connection established, protocol version %d.%d"), conf->nodename, (const char *)rsi, - strprotocol (protocol), p->prot_major, p->prot_minor); if (::conf.script_node_up) @@ -935,38 +1019,33 @@ { vpndata_packet *p = (vpndata_packet *)pkt; - if (rsi == si) + if (!p->hmac_chk (ictx)) + slog (L_ERR, _("%s(%s): hmac authentication error, received invalid packet\n" + "could be an attack, or just corruption or a synchronization error"), + conf->nodename, (const char *)rsi); + else { - if (!p->hmac_chk (ictx)) - slog (L_ERR, _("%s(%s): hmac authentication error, received invalid packet\n" - "could be an attack, or just corruption or an synchronization error"), - conf->nodename, (const char *)rsi); - else + u32 seqno; + tap_packet *d = p->unpack (this, seqno); + + if (iseqno.recv_ok (seqno)) { - u32 seqno; - tap_packet *d = p->unpack (this, seqno); + vpn->tap->send (d); - if (iseqno.recv_ok (seqno)) + if (si != rsi) { - vpn->tap->send (d); - - if (p->dst () == 0) // re-broadcast - for (vpn::conns_vector::iterator i = vpn->conns.begin (); i != vpn->conns.end (); ++i) - { - connection *c = *i; + // fast re-sync on connection changes, useful especially for tcp/ip + si = rsi; - if (c->conf != THISNODE && c->conf != conf) - c->inject_data_packet (d); - } + slog (L_INFO, _("%s(%s): socket address changed to %s"), + conf->nodename, (const char *)si, (const char *)rsi); + } - delete d; + delete d; - break; - } + break; } } - else - slog (L_ERR, _("received data packet from unknown source %s"), (const char *)rsi); } send_reset (rsi); @@ -978,8 +1057,8 @@ connect_req_packet *p = (connect_req_packet *) pkt; assert (p->id > 0 && p->id <= vpn->conns.size ()); // hmac-auth does not mean we accept anything - conf->protocols = p->protocols; connection *c = vpn->conns[p->id - 1]; + conf->protocols = p->protocols; slog (L_TRACE, "<<%d PT_CONNECT_REQ(%d) [%d]\n", conf->id, p->id, c->ictx && c->octx); @@ -991,6 +1070,8 @@ c->send_connect_info (conf->id, si, conf->protocols); send_connect_info (c->conf->id, c->si, c->conf->protocols); } + else + c->establish_connection (); } break; @@ -1001,13 +1082,20 @@ connect_info_packet *p = (connect_info_packet *) pkt; assert (p->id > 0 && p->id <= vpn->conns.size ()); // hmac-auth does not mean we accept anything - conf->protocols = p->protocols; + connection *c = vpn->conns[p->id - 1]; + c->conf->protocols = p->protocols; + protocol = best_protocol (c->conf->protocols & THISNODE->protocols & p->si.supported_protocols (c->conf)); + p->si.upgrade_protocol (protocol, c->conf); + slog (L_TRACE, "<<%d PT_CONNECT_INFO(%d,%s) (%d)", conf->id, p->id, (const char *)p->si, !c->ictx && !c->octx); - c->send_auth_request (p->si, true); + const sockinfo &dsi = forward_si (p->si); + + if (dsi.valid ()) + c->send_auth_request (dsi, true); } break; @@ -1026,18 +1114,22 @@ establish_connection (); } else if (NOW < last_activity + ::conf.keepalive) - w.at = last_activity + ::conf.keepalive; + w.start (last_activity + ::conf.keepalive); else if (conf->connectmode != conf_node::C_ONDEMAND || THISNODE->connectmode != conf_node::C_ONDEMAND) { send_ping (si); - w.at = NOW + 5; + w.start (NOW + 5); } + else if (NOW < last_activity + ::conf.keepalive + 10) + // hold ondemand connections implicitly a few seconds longer + // should delete octx, though, or something like that ;) + w.start (last_activity + ::conf.keepalive + 10); else reset_connection (); } -void connection::connect_request (int id) +void connection::send_connect_request (int id) { connect_req_packet *p = new connect_req_packet (conf->id, id, conf->protocols); @@ -1077,26 +1169,6 @@ return ::conf.script_node_up ? ::conf.script_node_down : "node-down"; } -// send a vpn packet out to other hosts -void -connection::send_vpn_packet (vpn_packet *pkt, const sockinfo &si, int tos) -{ - switch (protocol) - { - case PROT_IPv4: - vpn->send_ipv4_packet (pkt, si, tos); - break; - - case PROT_UDPv4: - vpn->send_udpv4_packet (pkt, si, tos); - break; - - case PROT_TCPv4: - vpn->send_tcpv4_packet (pkt, si, tos); - break; - } -} - connection::connection(struct vpn *vpn_) : vpn(vpn_) , rekey (this, &connection::rekey_cb)