--- gvpe/src/connection.C 2003/04/05 17:54:22 1.7 +++ gvpe/src/connection.C 2004/01/17 01:18:36 1.25 @@ -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 @@ -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; - if (send) + bool send = dif > CUTOFF; + + if (dif > MAXDIF) + { + ri.pcnt = 1.; + ri.diff = MAXDIF; + } + else if (send) ri.pcnt++; push_front (ri); @@ -469,14 +480,26 @@ 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 @@ -548,7 +571,42 @@ ///////////////////////////////////////////////////////////////////////////// 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); @@ -559,13 +617,42 @@ 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) +{ + if (!vpn->send_vpn_packet (pkt, si, tos)) + reset_connection (); +} + void connection::send_ping (const sockinfo &si, u8 pong) { ping_packet *pkt = new ping_packet; pkt->setup (conf->id, pong ? ping_packet::PT_PONG : ping_packet::PT_PING); - vpn->send_vpn_packet (pkt, si, IPTOS_LOWDELAY); + send_vpn_packet (pkt, si, IPTOS_LOWDELAY); delete pkt; } @@ -578,7 +665,7 @@ config_packet *pkt = new config_packet; pkt->setup (vpn_packet::PT_RESET, conf->id); - vpn->send_vpn_packet (pkt, si, IPTOS_MINCOST); + send_vpn_packet (pkt, si, IPTOS_MINCOST); delete pkt; } @@ -590,17 +677,12 @@ auth_req_packet *pkt = new auth_req_packet (conf->id, initiate, THISNODE->protocols); 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"); + rsa_encrypt (conf->rsa_key, chg, pkt->encr); slog (L_TRACE, ">>%d PT_AUTH_REQ [%s]", conf->id, (const char *)si); - vpn->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; } @@ -618,7 +700,7 @@ slog (L_TRACE, ">>%d PT_AUTH_RES [%s]", conf->id, (const char *)si); - vpn->send_vpn_packet (pkt, si, IPTOS_RELIABILITY); // rsa is very very costly + send_vpn_packet (pkt, si, IPTOS_RELIABILITY); // rsa is very very costly delete pkt; } @@ -632,7 +714,7 @@ connect_info_packet *r = new connect_info_packet (conf->id, rid, rsi, rprotocols); r->hmac_set (octx); - vpn->send_vpn_packet (r, si); + send_vpn_packet (r, si); delete r; } @@ -640,33 +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 + && w.at <= NOW) { 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 (); + const sockinfo &dsi = forward_si (si); - if (si.valid () && auth_rate_limiter.can (si)) - { - if (retry_cnt < 4) - send_auth_request (si, true); - else - send_ping (si, 0); - } + 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); } } @@ -690,9 +774,9 @@ last_activity = 0; retry_cnt = 0; - rekey.reset (); - keepalive.reset (); - establish_connection.reset (); + rekey.stop (); + keepalive.stop (); + establish_connection.stop (); } void @@ -707,25 +791,22 @@ 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 - vpn->send_vpn_packet (p, si, tos); + p->setup (this, conf->id, &((*pkt)[6 + 6]), pkt->len - 6 - 6, ++oseqno); // skip 2 macs + send_vpn_packet (p, si, tos); delete p; @@ -734,14 +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 (new vpn_packet (*pkt)); establish_connection (); } @@ -810,32 +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.start (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); } @@ -858,16 +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 an synchronization error"), + conf->nodename, (const char *)rsi); + break; + } else { rsaresponse h; @@ -885,17 +983,7 @@ si = rsi; protocol = rsi.prot; - rekey.start (NOW + ::conf.rekey); - keepalive.start (NOW + ::conf.keepalive); - - // send queued packets - while (tap_packet *p = queue.get ()) - { - send_data_packet (p); - delete p; - } - - connectmode = conf->connectmode; + connection_established (); slog (L_INFO, _("%s(%s): connection established, protocol version %d.%d"), conf->nodename, (const char *)rsi, @@ -931,38 +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 an 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); @@ -987,6 +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; @@ -1006,11 +1091,11 @@ slog (L_TRACE, "<<%d PT_CONNECT_INFO(%d,%s) (%d)", conf->id, p->id, (const char *)p->si, !c->ictx && !c->octx); - //slog (L_ERR, "%d PROTOCL(C%x,T%x,0S%x,S%x,P%x,SP%x)", - // p->id, c->conf->protocols, THISNODE->protocols, p->si.supported_protocols(0), p->si.supported_protocols (c->conf), - // protocol, p->si.prot); - c->send_auth_request (p->si, true); + const sockinfo &dsi = forward_si (p->si); + + if (dsi.valid ()) + c->send_auth_request (dsi, true); } break; @@ -1029,24 +1114,28 @@ 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); slog (L_TRACE, ">>%d PT_CONNECT_REQ(%d)", conf->id, id); p->hmac_set (octx); - vpn->send_vpn_packet (p, si); + send_vpn_packet (p, si); delete p; }