--- gvpe/src/connection.C 2003/08/08 07:52:26 1.13 +++ gvpe/src/connection.C 2005/03/02 05:49:31 1.41 @@ -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 @@ -18,9 +19,7 @@ #include "config.h" -extern "C" { -# include "lzf/lzf.h" -} +#include #include @@ -37,12 +36,20 @@ #include "vpn.h" #include "connection.h" +#include "netcompat.h" + #if !HAVE_RAND_PSEUDO_BYTES # define RAND_pseudo_bytes RAND_bytes #endif #define MAGIC "vped\xbd\xc6\xdb\x82" // 8 bytes of magic +#define ULTRA_FAST 1 +#define HLOG 15 +#include "lzf/lzf.h" +#include "lzf/lzf_c.c" +#include "lzf/lzf_d.c" + struct crypto_ctx { EVP_CIPHER_CTX cctx; @@ -55,14 +62,14 @@ 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 +79,10 @@ 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 +140,9 @@ 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) @@ -199,12 +204,12 @@ // but low on resources. struct net_rate_limiter : list { - static const double ALPHA = 1. - 1. / 180.; // 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 +# define NRL_ALPHA (1. - 1. / 600.) // allow bursts +# define NRL_CUTOFF 10. // one event every CUTOFF seconds +# define NRL_EXPIRE (NRL_CUTOFF * 30.) // expire entries after this time +# define NRL_MAXDIF (NRL_CUTOFF * (1. / (1. - NRL_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); }; @@ -217,7 +222,7 @@ for (i = begin (); i != end (); ) if (i->host == host) break; - else if (i->last < NOW - EXPIRE) + else if (i->last < NOW - NRL_EXPIRE) i = erase (i); else i++; @@ -228,7 +233,7 @@ ri.host = host; ri.pcnt = 1.; - ri.diff = MAXDIF; + ri.diff = NRL_MAXDIF; ri.last = NOW; push_front (ri); @@ -240,19 +245,19 @@ net_rateinfo ri (*i); erase (i); - ri.pcnt = ri.pcnt * ALPHA; - ri.diff = ri.diff * ALPHA + (NOW - ri.last); + ri.pcnt = ri.pcnt * NRL_ALPHA; + ri.diff = ri.diff * NRL_ALPHA + (NOW - ri.last); ri.last = NOW; double dif = ri.diff / ri.pcnt; - bool send = dif > CUTOFF; + bool send = dif > NRL_CUTOFF; - if (dif > MAXDIF) + if (dif > NRL_MAXDIF) { ri.pcnt = 1.; - ri.diff = MAXDIF; + ri.diff = NRL_MAXDIF; } else if (send) ri.pcnt++; @@ -309,7 +314,7 @@ #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 @@ -332,21 +337,24 @@ #if ENABLE_COMPRESSION u8 cdata[MAX_MTU]; - u32 cl; - cl = lzf_compress (d, l, cdata + 2, (l - 2) & ~7); - if (cl) + if (conn->features & ENABLE_COMPRESSION) { - type = PT_DATA_COMPRESSED; - d = cdata; - l = cl + 2; + u32 cl = lzf_compress (d, l, cdata + 2, (l - 2) & ~7); - d[0] = cl >> 8; - d[1] = cl; + if (cl) + { + type = PT_DATA_COMPRESSED; + d = cdata; + l = cl + 2; + + d[0] = cl >> 8; + d[1] = cl; + } } #endif - EVP_EncryptInit_ex (cctx, 0, 0, 0, 0); + require (EVP_EncryptInit_ex (cctx, 0, 0, 0, 0)); struct { #if RAND_SIZE @@ -360,17 +368,17 @@ 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 (); @@ -389,7 +397,7 @@ 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]; @@ -401,12 +409,12 @@ 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)); @@ -445,17 +453,23 @@ // field comes before this data, so peers with other // hmacs simply will not work. u8 prot_major, prot_minor, randsize, hmaclen; - u8 flags, challengelen, pad2, pad3; + u8 flags, challengelen, features, pad3; u32 cipher_nid, digest_nid, hmac_nid; - const u8 curflags () const - { - return 0x80 - | (ENABLE_COMPRESSION ? 0x01 : 0x00); - } - void setup (ptype type, int dst); bool chk_config () const; + + static u8 get_features () + { + u8 f = 0; +#if ENABLE_COMPRESSION + f |= FEATURE_COMPRESSION; +#endif +#if ENABLE_ROHC + f |= FEATURE_ROHC; +#endif + return f; + } }; void config_packet::setup (ptype type, int dst) @@ -464,8 +478,9 @@ prot_minor = PROTOCOL_MINOR; randsize = RAND_SIZE; hmaclen = HMACLENGTH; - flags = curflags (); + flags = ENABLE_COMPRESSION ? 0x81 : 0x80; challengelen = sizeof (rsachallenge); + features = get_features (); cipher_nid = htonl (EVP_CIPHER_nid (CIPHER)); digest_nid = htonl (EVP_MD_type (RSA_HASH)); @@ -477,21 +492,35 @@ 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); +#if 0 // this implementation should handle all flag settings + else if (flags != curflags ()) + slog (L_WARN, _("flag mismatch (remote %x <=> local %x)"), flags, curflags ()); +#endif + 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; @@ -562,7 +591,9 @@ { connectmode = conf->connectmode; - rekey.start (NOW + ::conf.rekey); + // make sure rekeying timeouts are slightly asymmetric + rekey.start (NOW + ::conf.rekey + + (conf->id > THISNODE->id ? 10 : 0)); keepalive.start (NOW + ::conf.keepalive); // send queued packets @@ -585,8 +616,8 @@ { retry_cnt = 0; establish_connection.start (NOW + 5); - keepalive.reset (); - rekey.reset (); + keepalive.stop (); + rekey.stop (); } } @@ -598,6 +629,7 @@ // mask out protocols we cannot establish if (!conf->udp_port) protocol &= ~PROT_UDPv4; if (!conf->tcp_port) protocol &= ~PROT_TCPv4; + if (!conf->dns_port) protocol &= ~PROT_DNSv4; si.set (conf, protocol); } @@ -627,7 +659,33 @@ void connection::send_vpn_packet (vpn_packet *pkt, const sockinfo &si, int tos) { - if (!vpn->send_vpn_packet (pkt, si, tos)) + bool ok; + + switch (si.prot) + { + case PROT_IPv4: + ok = vpn->send_ipv4_packet (pkt, si, tos); break; + case PROT_UDPv4: + ok = vpn->send_udpv4_packet (pkt, si, tos); break; +#if ENABLE_TCP + case PROT_TCPv4: + ok = vpn->send_tcpv4_packet (pkt, si, tos); break; +#endif +#if ENABLE_ICMP + case PROT_ICMPv4: + ok = vpn->send_icmpv4_packet (pkt, si, tos); break; +#endif +#if ENABLE_DNS + case PROT_DNSv4: + ok = send_dnsv4_packet (pkt, si, tos); break; +#endif + + default: + slog (L_CRIT, _("%s: FATAL: trying to send packet with unsupported protocol"), (const char *)si); + ok = false; + } + + if (!ok) reset_connection (); } @@ -662,13 +720,8 @@ 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); @@ -712,18 +765,20 @@ 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) + if (retry_int < conf->max_retry) retry_cnt++; + else + retry_int = conf->max_retry; - w.at = NOW + retry_int; + w.start (NOW + retry_int); reset_si (); @@ -759,14 +814,14 @@ delete ictx; ictx = 0; delete octx; octx = 0; - si.host= 0; + si.host = 0; last_activity = 0; retry_cnt = 0; - rekey.reset (); - keepalive.reset (); - establish_connection.reset (); + rekey.stop (); + keepalive.stop (); + establish_connection.stop (); } void @@ -781,25 +836,21 @@ 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; // I am not hilarious about peeking into packets, but so be it. - if (conf->inherit_tos - && (*pkt)[12] == 0x08 && (*pkt)[13] == 0x00 // IP - && ((*pkt)[14] & 0xf0) == 0x40) // IPv4 + 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; @@ -809,10 +860,10 @@ } 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 @@ -828,7 +879,7 @@ send_vpn_packet (pkt, si, tos); else { - vpn_queue.put (new vpn_packet (*pkt)); + vpn_queue.put ((vpn_packet *)new data_packet (*(data_packet *)pkt)); establish_connection (); } @@ -897,11 +948,12 @@ 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 { delete octx; @@ -909,7 +961,11 @@ octx = new crypto_ctx (k, 1); oseqno = ntohl (*(u32 *)&k[CHG_SEQNO]) & 0x7fffffff; + // compatibility code, remove when no longer required + if (p->flags & 1) p->features |= FEATURE_COMPRESSION; + conf->protocols = p->protocols; + features = p->features & config_packet::get_features (); send_auth_response (rsi, p->id, k); @@ -918,6 +974,9 @@ break; } } + else + slog (L_WARN, _("%s(%s): protocol mismatch"), + conf->nodename, (const char *)rsi); send_reset (rsi); } @@ -941,7 +1000,7 @@ if (!rsa_cache.find (p->id, chg)) { - slog (L_ERR, _("%s(%s): unrequested auth response"), + slog (L_ERR, _("%s(%s): unrequested auth response ignored"), conf->nodename, (const char *)rsi); break; } @@ -950,9 +1009,12 @@ 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; @@ -1008,7 +1070,7 @@ 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"), + "could be an attack, or just corruption or a synchronization error"), conf->nodename, (const char *)rsi); else { @@ -1019,28 +1081,18 @@ { 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; - - if (c->conf != THISNODE && c->conf != conf) - c->inject_data_packet (d); - } - if (si != rsi) { - // fast re-sync on conneciton changes, useful especially for tcp/ip + // fast re-sync on connection changes, useful especially for tcp/ip si = rsi; slog (L_INFO, _("%s(%s): socket address changed to %s"), conf->nodename, (const char *)si, (const char *)rsi); } - - delete d; - - break; } + + delete d; + break; } } @@ -1075,23 +1127,24 @@ case vpn_packet::PT_CONNECT_INFO: if (ictx && octx && rsi == si && pkt->hmac_chk (ictx)) { - connect_info_packet *p = (connect_info_packet *) pkt; + 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 - - connection *c = vpn->conns[p->id - 1]; + if (p->id > 0 && p->id <= vpn->conns.size ()) // hmac-auth does not mean we accept anything + { + 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); + 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); + slog (L_TRACE, "<<%d PT_CONNECT_INFO(%d,%s) (%d)", + conf->id, p->id, (const char *)p->si, !c->ictx && !c->octx); - const sockinfo &dsi = forward_si (p->si); + const sockinfo &dsi = forward_si (p->si); - if (dsi.valid ()) - c->send_auth_request (dsi, true); + if (dsi.valid ()) + c->send_auth_request (dsi, true); + } } break; @@ -1110,17 +1163,17 @@ 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.at = last_activity + ::conf.keepalive + 10; + w.start (last_activity + ::conf.keepalive + 10); else reset_connection (); } @@ -1165,15 +1218,23 @@ return ::conf.script_node_up ? ::conf.script_node_down : "node-down"; } -connection::connection(struct vpn *vpn_) -: vpn(vpn_) +connection::connection (struct vpn *vpn, conf_node *conf) +: vpn(vpn), conf(conf) , rekey (this, &connection::rekey_cb) , keepalive (this, &connection::keepalive_cb) , establish_connection (this, &connection::establish_connection_cb) +#if ENABLE_DNS +, dnsv4_tw (this, &connection::dnsv4_cb) +, dns_rcvdq (0), dns_snddq (0) +, dns_rcvseq (0), dns_sndseq (0) +#endif { octx = ictx = 0; retry_cnt = 0; + if (!conf->protocols) // make sure some protocol is enabled + conf->protocols = PROT_UDPv4; + connectmode = conf_node::C_ALWAYS; // initial setting reset_connection (); }