X-Git-Url: http://git.meshlink.io/?a=blobdiff_plain;f=src%2Fnet_packet.c;h=f7d8640300a6bc5065b572e0828446e9b3cb7c0a;hb=3fba80174dbe29bcfe0d121a2a1d2e61be5ee57b;hp=3243670295d7cb747299488f24f96f20c46117f1;hpb=c11dc8079b60d9f8c5b1c7e8fecd90d0fac5a20c;p=meshlink diff --git a/src/net_packet.c b/src/net_packet.c index 32436702..f7d86403 100644 --- a/src/net_packet.c +++ b/src/net_packet.c @@ -1,7 +1,9 @@ /* net_packet.c -- Handles in- and outgoing VPN packets Copyright (C) 1998-2005 Ivo Timmermans, - 2000-2009 Guus Sliepen + 2000-2011 Guus Sliepen + 2010 Timothy Redaelli + 2010 Brandon Black 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 @@ -26,17 +28,23 @@ #include #include +#ifdef HAVE_ZLIB #include +#endif + +#ifdef HAVE_LZO #include LZO1X_H +#endif -#include "avl_tree.h" +#include "splay_tree.h" +#include "cipher.h" #include "conf.h" #include "connection.h" +#include "crypto.h" +#include "digest.h" #include "device.h" #include "ethernet.h" -#include "event.h" #include "graph.h" -#include "list.h" #include "logger.h" #include "net.h" #include "netutl.h" @@ -46,24 +54,15 @@ #include "utils.h" #include "xalloc.h" -#ifdef HAVE_MINGW -#include -#define EMSGSIZE WSAEMSGSIZE -#define EAGAIN WSATRY_AGAIN -#define EINTR WSAEINTR -#define sockstrerror(x) winerror(x) -#define sockerrno WSAGetLastError() -#else -#define sockstrerror(x) strerror(x) -#define sockerrno errno -#endif - int keylifetime = 0; -int keyexpires = 0; +#ifdef HAVE_LZO static char lzo_wrkmem[LZO1X_999_MEM_COMPRESS > LZO1X_1_MEM_COMPRESS ? LZO1X_999_MEM_COMPRESS : LZO1X_1_MEM_COMPRESS]; +#endif static void send_udppacket(node_t *, vpn_packet_t *); +unsigned replaywin = 16; + #define MAX_SEQNO 1073741824 // mtuprobes == 1..30: initial discovery, send bursts with 1 second interval @@ -71,13 +70,13 @@ static void send_udppacket(node_t *, vpn_packet_t *); // mtuprobes == 32: send 1 burst, sleep pingtimeout second // mtuprobes == 33: no response from other side, restart PMTU discovery process -void send_mtu_probe(node_t *n) { +static void send_mtu_probe_handler(int fd, short events, void *data) { + node_t *n = data; vpn_packet_t packet; int len, i; int timeout = 1; n->mtuprobes++; - n->mtuevent = NULL; if(!n->status.reachable || !n->status.validkey) { ifdebug(TRAFFIC) logger(LOG_INFO, "Trying to send MTU probe to unreachable or rekeying node %s (%s)", n->name, n->hostname); @@ -86,16 +85,21 @@ void send_mtu_probe(node_t *n) { } if(n->mtuprobes > 32) { + if(!n->minmtu) { + n->mtuprobes = 31; + timeout = pinginterval; + goto end; + } + ifdebug(TRAFFIC) logger(LOG_INFO, "%s (%s) did not respond to UDP ping, restarting PMTU discovery", n->name, n->hostname); n->mtuprobes = 1; n->minmtu = 0; n->maxmtu = MTU; } - if(n->mtuprobes >= 10 && !n->minmtu) { + if(n->mtuprobes >= 10 && n->mtuprobes < 32 && !n->minmtu) { ifdebug(TRAFFIC) logger(LOG_INFO, "No response to MTU probes from %s (%s)", n->name, n->hostname); - n->mtuprobes = 0; - return; + n->mtuprobes = 31; } if(n->mtuprobes == 30 || (n->mtuprobes < 30 && n->minmtu >= n->maxmtu)) { @@ -125,7 +129,7 @@ void send_mtu_probe(node_t *n) { len = 64; memset(packet.data, 0, 14); - RAND_pseudo_bytes(packet.data + 14, len - 14); + randomize(packet.data + 14, len - 14); packet.len = len; packet.priority = 0; @@ -135,64 +139,92 @@ void send_mtu_probe(node_t *n) { } end: - n->mtuevent = new_event(); - n->mtuevent->handler = (event_handler_t)send_mtu_probe; - n->mtuevent->data = n; - n->mtuevent->time = now + timeout; - event_add(n->mtuevent); + event_add(&n->mtuevent, &(struct timeval){timeout, 0}); } -void mtu_probe_h(node_t *n, vpn_packet_t *packet, length_t len) { +void send_mtu_probe(node_t *n) { + if(!timeout_initialized(&n->mtuevent)) + timeout_set(&n->mtuevent, send_mtu_probe_handler, n); + send_mtu_probe_handler(0, 0, n); +} + +static void mtu_probe_h(node_t *n, vpn_packet_t *packet, length_t len) { ifdebug(TRAFFIC) logger(LOG_INFO, "Got MTU probe length %d from %s (%s)", packet->len, n->name, n->hostname); if(!packet->data[0]) { packet->data[0] = 1; send_udppacket(n, packet); } else { + if(n->mtuprobes > 30) { + if(n->minmtu) + n->mtuprobes = 30; + else + n->mtuprobes = 1; + } + if(len > n->maxmtu) len = n->maxmtu; if(n->minmtu < len) n->minmtu = len; - if(n->mtuprobes > 30) - n->mtuprobes = 30; } } static length_t compress_packet(uint8_t *dest, const uint8_t *source, length_t len, int level) { - if(level == 10) { + if(level == 0) { + memcpy(dest, source, len); + return len; + } else if(level == 10) { +#ifdef HAVE_LZO lzo_uint lzolen = MAXSIZE; lzo1x_1_compress(source, len, dest, &lzolen, lzo_wrkmem); return lzolen; +#else + return -1; +#endif } else if(level < 10) { +#ifdef HAVE_ZLIB unsigned long destlen = MAXSIZE; if(compress2(dest, &destlen, source, len, level) == Z_OK) return destlen; else +#endif return -1; } else { +#ifdef HAVE_LZO lzo_uint lzolen = MAXSIZE; lzo1x_999_compress(source, len, dest, &lzolen, lzo_wrkmem); return lzolen; +#else + return -1; +#endif } return -1; } static length_t uncompress_packet(uint8_t *dest, const uint8_t *source, length_t len, int level) { - if(level > 9) { + if(level == 0) { + memcpy(dest, source, len); + return len; + } else if(level > 9) { +#ifdef HAVE_LZO lzo_uint lzolen = MAXSIZE; if(lzo1x_decompress_safe(source, len, dest, &lzolen, NULL) == LZO_E_OK) return lzolen; else +#endif return -1; - } else { + } +#ifdef HAVE_ZLIB + else { unsigned long destlen = MAXSIZE; if(uncompress(dest, &destlen, source, len) == Z_OK) return destlen; else return -1; } - +#endif + return -1; } @@ -202,18 +234,17 @@ static void receive_packet(node_t *n, vpn_packet_t *packet) { ifdebug(TRAFFIC) logger(LOG_DEBUG, "Received packet of %d bytes from %s (%s)", packet->len, n->name, n->hostname); + n->in_packets++; + n->in_bytes += packet->len; + route(n, packet); } -static bool try_mac(const node_t *n, const vpn_packet_t *inpkt) { - unsigned char hmac[EVP_MAX_MD_SIZE]; - - if(!n->indigest || !n->inmaclength || !n->inkey || inpkt->len < sizeof inpkt->seqno + n->inmaclength) +static bool try_mac(node_t *n, const vpn_packet_t *inpkt) { + if(!digest_active(&n->indigest) || inpkt->len < sizeof inpkt->seqno + digest_length(&n->indigest)) return false; - HMAC(n->indigest, n->inkey, n->inkeylength, (unsigned char *) &inpkt->seqno, inpkt->len - n->inmaclength, (unsigned char *)hmac, NULL); - - return !memcmp(hmac, (char *) &inpkt->seqno + inpkt->len - n->inmaclength, n->inmaclength); + return digest_verify(&n->indigest, &inpkt->seqno, inpkt->len - n->indigest.maclength, (const char *)&inpkt->seqno + inpkt->len - n->indigest.maclength); } static void receive_udppacket(node_t *n, vpn_packet_t *inpkt) { @@ -221,11 +252,9 @@ static void receive_udppacket(node_t *n, vpn_packet_t *inpkt) { vpn_packet_t *pkt[] = { &pkt1, &pkt2, &pkt1, &pkt2 }; int nextpkt = 0; vpn_packet_t *outpkt = pkt[0]; - int outlen, outpad; - unsigned char hmac[EVP_MAX_MD_SIZE]; - int i; + size_t outlen; - if(!n->inkey) { + if(!cipher_active(&n->incipher)) { ifdebug(TRAFFIC) logger(LOG_DEBUG, "Got packet from %s (%s) but he hasn't got our key yet", n->name, n->hostname); return; @@ -233,7 +262,7 @@ static void receive_udppacket(node_t *n, vpn_packet_t *inpkt) { /* Check packet length */ - if(inpkt->len < sizeof(inpkt->seqno) + n->inmaclength) { + if(inpkt->len < sizeof inpkt->seqno + digest_length(&n->indigest)) { ifdebug(TRAFFIC) logger(LOG_DEBUG, "Got too short packet from %s (%s)", n->name, n->hostname); return; @@ -241,66 +270,65 @@ static void receive_udppacket(node_t *n, vpn_packet_t *inpkt) { /* Check the message authentication code */ - if(n->indigest && n->inmaclength) { - inpkt->len -= n->inmaclength; - HMAC(n->indigest, n->inkey, n->inkeylength, - (unsigned char *) &inpkt->seqno, inpkt->len, (unsigned char *)hmac, NULL); - - if(memcmp(hmac, (char *) &inpkt->seqno + inpkt->len, n->inmaclength)) { - ifdebug(TRAFFIC) logger(LOG_DEBUG, "Got unauthenticated packet from %s (%s)", - n->name, n->hostname); + if(digest_active(&n->indigest)) { + inpkt->len -= n->indigest.maclength; + if(!digest_verify(&n->indigest, &inpkt->seqno, inpkt->len, (const char *)&inpkt->seqno + inpkt->len)) { + ifdebug(TRAFFIC) logger(LOG_DEBUG, "Got unauthenticated packet from %s (%s)", n->name, n->hostname); return; } } - /* Decrypt the packet */ - if(n->incipher) { + if(cipher_active(&n->incipher)) { outpkt = pkt[nextpkt++]; + outlen = MAXSIZE; - if(!EVP_DecryptInit_ex(&n->inctx, NULL, NULL, NULL, NULL) - || !EVP_DecryptUpdate(&n->inctx, (unsigned char *) &outpkt->seqno, &outlen, - (unsigned char *) &inpkt->seqno, inpkt->len) - || !EVP_DecryptFinal_ex(&n->inctx, (unsigned char *) &outpkt->seqno + outlen, &outpad)) { - ifdebug(TRAFFIC) logger(LOG_DEBUG, "Error decrypting packet from %s (%s): %s", - n->name, n->hostname, ERR_error_string(ERR_get_error(), NULL)); + if(!cipher_decrypt(&n->incipher, &inpkt->seqno, inpkt->len, &outpkt->seqno, &outlen, true)) { + ifdebug(TRAFFIC) logger(LOG_DEBUG, "Error decrypting packet from %s (%s)", n->name, n->hostname); return; } - outpkt->len = outlen + outpad; + outpkt->len = outlen; inpkt = outpkt; } /* Check the sequence number */ - inpkt->len -= sizeof(inpkt->seqno); + inpkt->len -= sizeof inpkt->seqno; inpkt->seqno = ntohl(inpkt->seqno); - if(inpkt->seqno != n->received_seqno + 1) { - if(inpkt->seqno >= n->received_seqno + sizeof(n->late) * 8) { - logger(LOG_WARNING, "Lost %d packets from %s (%s)", - inpkt->seqno - n->received_seqno - 1, n->name, n->hostname); - - memset(n->late, 0, sizeof(n->late)); - } else if (inpkt->seqno <= n->received_seqno) { - if((n->received_seqno >= sizeof(n->late) * 8 && inpkt->seqno <= n->received_seqno - sizeof(n->late) * 8) || !(n->late[(inpkt->seqno / 8) % sizeof(n->late)] & (1 << inpkt->seqno % 8))) { - logger(LOG_WARNING, "Got late or replayed packet from %s (%s), seqno %d, last received %d", - n->name, n->hostname, inpkt->seqno, n->received_seqno); - return; + if(replaywin) { + if(inpkt->seqno != n->received_seqno + 1) { + if(inpkt->seqno >= n->received_seqno + replaywin * 8) { + if(n->farfuture++ < replaywin >> 2) { + logger(LOG_WARNING, "Packet from %s (%s) is %d seqs in the future, dropped (%u)", + n->name, n->hostname, inpkt->seqno - n->received_seqno - 1, n->farfuture); + return; + } + logger(LOG_WARNING, "Lost %d packets from %s (%s)", + inpkt->seqno - n->received_seqno - 1, n->name, n->hostname); + memset(n->late, 0, replaywin); + } else if (inpkt->seqno <= n->received_seqno) { + if((n->received_seqno >= replaywin * 8 && inpkt->seqno <= n->received_seqno - replaywin * 8) || !(n->late[(inpkt->seqno / 8) % replaywin] & (1 << inpkt->seqno % 8))) { + logger(LOG_WARNING, "Got late or replayed packet from %s (%s), seqno %d, last received %d", + n->name, n->hostname, inpkt->seqno, n->received_seqno); + return; + } + } else { + for(int i = n->received_seqno + 1; i < inpkt->seqno; i++) + n->late[(i / 8) % replaywin] |= 1 << i % 8; } - } else { - for(i = n->received_seqno + 1; i < inpkt->seqno; i++) - n->late[(i / 8) % sizeof(n->late)] |= 1 << i % 8; } + + n->farfuture = 0; + n->late[(inpkt->seqno / 8) % replaywin] &= ~(1 << inpkt->seqno % 8); } - - n->late[(inpkt->seqno / 8) % sizeof(n->late)] &= ~(1 << inpkt->seqno % 8); if(inpkt->seqno > n->received_seqno) n->received_seqno = inpkt->seqno; if(n->received_seqno > MAX_SEQNO) - keyexpires = 0; + regenerate_key(); /* Decompress the packet */ @@ -328,7 +356,7 @@ static void receive_udppacket(node_t *n, vpn_packet_t *inpkt) { receive_packet(n, inpkt); } -void receive_tcppacket(connection_t *c, char *buffer, int len) { +void receive_tcppacket(connection_t *c, const char *buffer, int len) { vpn_packet_t outpkt; outpkt.len = len; @@ -347,11 +375,12 @@ static void send_udppacket(node_t *n, vpn_packet_t *origpkt) { vpn_packet_t *inpkt = origpkt; int nextpkt = 0; vpn_packet_t *outpkt; - int origlen; - int outlen, outpad; + int origlen = origpkt->len; + size_t outlen; +#if defined(SOL_IP) && defined(IP_TOS) static int priority = 0; - int origpriority; - int sock; + int origpriority = origpkt->priority; +#endif if(!n->status.reachable) { ifdebug(TRAFFIC) logger(LOG_INFO, "Trying to send UDP packet to unreachable node %s (%s)", n->name, n->hostname); @@ -361,14 +390,16 @@ static void send_udppacket(node_t *n, vpn_packet_t *origpkt) { /* Make sure we have a valid key */ if(!n->status.validkey) { + time_t now = time(NULL); + ifdebug(TRAFFIC) logger(LOG_INFO, "No valid key known yet for %s (%s), forwarding via TCP", n->name, n->hostname); - if(!n->status.waitingforkey) + if(n->last_req_key + 10 <= now) { send_req_key(n); - - n->status.waitingforkey = true; + n->last_req_key = now; + } send_tcppacket(n->nexthop->connection, origpkt); @@ -388,9 +419,6 @@ static void send_udppacket(node_t *n, vpn_packet_t *origpkt) { return; } - origlen = inpkt->len; - origpriority = inpkt->priority; - /* Compress the packet */ if(n->outcompression) { @@ -408,57 +436,55 @@ static void send_udppacket(node_t *n, vpn_packet_t *origpkt) { /* Add sequence number */ inpkt->seqno = htonl(++(n->sent_seqno)); - inpkt->len += sizeof(inpkt->seqno); + inpkt->len += sizeof inpkt->seqno; /* Encrypt the packet */ - if(n->outcipher) { + if(cipher_active(&n->outcipher)) { outpkt = pkt[nextpkt++]; + outlen = MAXSIZE; - if(!EVP_EncryptInit_ex(&n->outctx, NULL, NULL, NULL, NULL) - || !EVP_EncryptUpdate(&n->outctx, (unsigned char *) &outpkt->seqno, &outlen, - (unsigned char *) &inpkt->seqno, inpkt->len) - || !EVP_EncryptFinal_ex(&n->outctx, (unsigned char *) &outpkt->seqno + outlen, &outpad)) { - ifdebug(TRAFFIC) logger(LOG_ERR, "Error while encrypting packet to %s (%s): %s", - n->name, n->hostname, ERR_error_string(ERR_get_error(), NULL)); + if(!cipher_encrypt(&n->outcipher, &inpkt->seqno, inpkt->len, &outpkt->seqno, &outlen, true)) { + ifdebug(TRAFFIC) logger(LOG_ERR, "Error while encrypting packet to %s (%s)", n->name, n->hostname); goto end; } - outpkt->len = outlen + outpad; + outpkt->len = outlen; inpkt = outpkt; } /* Add the message authentication code */ - if(n->outdigest && n->outmaclength) { - HMAC(n->outdigest, n->outkey, n->outkeylength, (unsigned char *) &inpkt->seqno, - inpkt->len, (unsigned char *) &inpkt->seqno + inpkt->len, NULL); - inpkt->len += n->outmaclength; + if(digest_active(&n->outdigest)) { + digest_create(&n->outdigest, &inpkt->seqno, inpkt->len, (char *)&inpkt->seqno + inpkt->len); + inpkt->len += digest_length(&n->outdigest); } /* Determine which socket we have to use */ - for(sock = 0; sock < listen_sockets; sock++) - if(n->address.sa.sa_family == listen_socket[sock].sa.sa.sa_family) - break; - - if(sock >= listen_sockets) - sock = 0; /* If none is available, just use the first and hope for the best. */ + if(n->address.sa.sa_family != listen_socket[n->sock].sa.sa.sa_family) { + for(int sock = 0; sock < listen_sockets; sock++) { + if(n->address.sa.sa_family == listen_socket[sock].sa.sa.sa_family) { + n->sock = sock; + break; + } + } + } /* Send the packet */ #if defined(SOL_IP) && defined(IP_TOS) if(priorityinheritance && origpriority != priority - && listen_socket[sock].sa.sa.sa_family == AF_INET) { + && listen_socket[n->sock].sa.sa.sa_family == AF_INET) { priority = origpriority; ifdebug(TRAFFIC) logger(LOG_DEBUG, "Setting outgoing packet priority to %d", priority); - if(setsockopt(listen_socket[sock].udp, SOL_IP, IP_TOS, &priority, sizeof(priority))) /* SO_PRIORITY doesn't seem to work */ + if(setsockopt(listen_socket[n->sock].udp, SOL_IP, IP_TOS, &priority, sizeof(priority))) /* SO_PRIORITY doesn't seem to work */ logger(LOG_ERR, "System call `%s' failed: %s", "setsockopt", strerror(errno)); } #endif - if((sendto(listen_socket[sock].udp, (char *) &inpkt->seqno, inpkt->len, 0, &(n->address.sa), SALEN(n->address.sa))) < 0) { - if(sockerrno == EMSGSIZE) { + if(sendto(listen_socket[n->sock].udp, (char *) &inpkt->seqno, inpkt->len, 0, &(n->address.sa), SALEN(n->address.sa)) < 0 && !sockwouldblock(sockerrno)) { + if(sockmsgsize(sockerrno)) { if(n->maxmtu >= origlen) n->maxmtu = origlen - 1; if(n->mtu >= origlen) @@ -474,13 +500,15 @@ end: /* send a packet to the given vpn ip. */ -void send_packet(const node_t *n, vpn_packet_t *packet) { +void send_packet(node_t *n, vpn_packet_t *packet) { node_t *via; if(n == myself) { if(overwrite_mac) memcpy(packet->data, mymac.x, ETH_ALEN); - write_packet(packet); + n->out_packets++; + n->out_bytes += packet->len; + devops.write(packet); return; } @@ -493,6 +521,9 @@ void send_packet(const node_t *n, vpn_packet_t *packet) { return; } + n->out_packets++; + n->out_bytes += packet->len; + via = (packet->priority == -1 || n->via == myself) ? n->nexthop : n->via; if(via != n) @@ -509,7 +540,7 @@ void send_packet(const node_t *n, vpn_packet_t *packet) { /* Broadcast a packet using the minimum spanning tree */ void broadcast_packet(const node_t *from, vpn_packet_t *packet) { - avl_node_t *node; + splay_node_t *node; connection_t *c; ifdebug(TRAFFIC) logger(LOG_INFO, "Broadcasting packet of %d bytes from %s (%s)", @@ -533,23 +564,25 @@ void broadcast_packet(const node_t *from, vpn_packet_t *packet) { } static node_t *try_harder(const sockaddr_t *from, const vpn_packet_t *pkt) { - avl_node_t *node; + splay_node_t *node; edge_t *e; node_t *n = NULL; + bool hard = false; static time_t last_hard_try = 0; + time_t now = time(NULL); for(node = edge_weight_tree->head; node; node = node->next) { e = node->data; + if(e->to == myself) + continue; + if(sockaddrcmp_noport(from, &e->address)) { if(last_hard_try == now) continue; - last_hard_try = now; + hard = true; } - if(!n) - n = e->to; - if(!try_mac(e->to, pkt)) continue; @@ -557,24 +590,30 @@ static node_t *try_harder(const sockaddr_t *from, const vpn_packet_t *pkt) { break; } + if(hard) + last_hard_try = now; + return n; } -void handle_incoming_vpn_data(int sock) { +void handle_incoming_vpn_data(int sock, short events, void *data) { vpn_packet_t pkt; char *hostname; sockaddr_t from; - socklen_t fromlen = sizeof(from); + socklen_t fromlen = sizeof from; node_t *n; + int len; - pkt.len = recvfrom(sock, (char *) &pkt.seqno, MAXSIZE, 0, &from.sa, &fromlen); + len = recvfrom(sock, (char *) &pkt.seqno, MAXSIZE, 0, &from.sa, &fromlen); - if(pkt.len < 0) { - if(sockerrno != EAGAIN && sockerrno != EINTR) + if(len <= 0 || len > MAXSIZE) { + if(!sockwouldblock(sockerrno)) logger(LOG_ERR, "Receiving packet failed: %s", sockstrerror(sockerrno)); return; } + pkt.len = len; + sockaddrunmap(&from); /* Some braindead IPv6 implementations do stupid things. */ n = lookup_node_udp(&from); @@ -593,5 +632,19 @@ void handle_incoming_vpn_data(int sock) { return; } + n->sock = (intptr_t)data; + receive_udppacket(n, &pkt); } + +void handle_device_data(int sock, short events, void *data) { + vpn_packet_t packet; + + packet.priority = 0; + + if(devops.read(&packet)) { + myself->in_packets++; + myself->in_bytes += packet.len; + route(myself, &packet); + } +}