X-Git-Url: https://www.tinc-vpn.org/git/browse?a=blobdiff_plain;f=src%2Fnet_packet.c;h=7be466201eae816acca0d52ab3fd6ddcff545f92;hb=886a6f61a1f4cc48a77b42d10f34f9126377d904;hp=e430b6c96a5efcd948f53bb019d71fff1f9b82c2;hpb=7ea85043ac1fb2096baea44f6b0af27ac0d0b2cf;p=tinc diff --git a/src/net_packet.c b/src/net_packet.c index e430b6c9..7be46620 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 + 2000-2010 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 @@ -20,8 +22,19 @@ #include "system.h" +#include +#include +#include +#include +#include + +#ifdef HAVE_ZLIB #include +#endif + +#ifdef HAVE_LZO #include LZO1X_H +#endif #include "splay_tree.h" #include "cipher.h" @@ -42,43 +55,73 @@ #include "utils.h" #include "xalloc.h" -#ifdef WSAEMSGSIZE -#define EMSGSIZE WSAEMSGSIZE -#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 +// mtuprobes == 31: sleep pinginterval seconds +// mtuprobes == 32: send 1 burst, sleep pingtimeout second +// mtuprobes == 33: no response from other side, restart PMTU discovery process + 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++; - if(!n->status.reachable) { - logger(LOG_DEBUG, "Trying to send MTU probe to unreachable node %s (%s)", n->name, n->hostname); + 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); + n->mtuprobes = 0; return; } + if(n->mtuprobes > 32) { + 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) { ifdebug(TRAFFIC) logger(LOG_INFO, "No response to MTU probes from %s (%s)", n->name, n->hostname); + n->mtuprobes = 0; return; } + if(n->mtuprobes == 30 || (n->mtuprobes < 30 && n->minmtu >= n->maxmtu)) { + if(n->minmtu > n->maxmtu) + n->minmtu = n->maxmtu; + else + n->maxmtu = n->minmtu; + n->mtu = n->minmtu; + ifdebug(TRAFFIC) logger(LOG_INFO, "Fixing MTU of %s (%s) to %d after %d probes", n->name, n->hostname, n->mtu, n->mtuprobes); + n->mtuprobes = 31; + } + + if(n->mtuprobes == 31) { + timeout = pinginterval; + goto end; + } else if(n->mtuprobes == 32) { + timeout = pingtimeout; + } + for(i = 0; i < 3; i++) { - if(n->mtuprobes >= 30 || n->minmtu >= n->maxmtu) { - n->mtu = n->minmtu; - ifdebug(TRAFFIC) logger(LOG_INFO, "Fixing MTU of %s (%s) to %d after %d probes", n->name, n->hostname, n->mtu, n->mtuprobes); - return; - } + if(n->maxmtu <= n->minmtu) + len = n->maxmtu; + else + len = n->minmtu + 1 + rand() % (n->maxmtu - n->minmtu); - len = n->minmtu + 1 + rand() % (n->maxmtu - n->minmtu); if(len < 64) len = 64; @@ -92,7 +135,8 @@ static void send_mtu_probe_handler(int fd, short events, void *data) { send_udppacket(n, &packet); } - event_add(&n->mtuevent, &(struct timeval){1, 0}); +end: + event_add(&n->mtuevent, &(struct timeval){timeout, 0}); } void send_mtu_probe(node_t *n) { @@ -106,48 +150,73 @@ void mtu_probe_h(node_t *n, vpn_packet_t *packet, length_t len) { if(!packet->data[0]) { packet->data[0] = 1; - send_packet(n, packet); + send_udppacket(n, packet); } else { + 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; } @@ -164,7 +233,7 @@ 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; - return digest_verify(&n->indigest, &inpkt->seqno, inpkt->len, (const char *)&inpkt->seqno + inpkt->len); + 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) { @@ -191,11 +260,13 @@ static void receive_udppacket(node_t *n, vpn_packet_t *inpkt) { /* Check the message authentication code */ - if(digest_active(&n->indigest) && !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; + 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(cipher_active(&n->incipher)) { @@ -216,25 +287,32 @@ static void receive_udppacket(node_t *n, vpn_packet_t *inpkt) { 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(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; @@ -289,7 +367,9 @@ static void send_udppacket(node_t *n, vpn_packet_t *origpkt) { vpn_packet_t *outpkt; int origlen; size_t outlen; +#if defined(SOL_IP) && defined(IP_TOS) static int priority = 0; +#endif int origpriority; int sock; @@ -301,14 +381,16 @@ 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); @@ -317,10 +399,13 @@ static void send_udppacket(node_t *n, vpn_packet_t *origpkt) { if(n->options & OPTION_PMTU_DISCOVERY && inpkt->len > n->minmtu && (inpkt->data[12] | inpkt->data[13])) { ifdebug(TRAFFIC) logger(LOG_INFO, - "Packet for %s (%s) larger than minimum MTU, forwarding via TCP", - n->name, n->hostname); + "Packet for %s (%s) larger than minimum MTU, forwarding via %s", + n->name, n->hostname, n != n->nexthop ? n->nexthop->name : "TCP"); - send_tcppacket(n->nexthop->connection, origpkt); + if(n != n->nexthop) + send_packet(n->nexthop, origpkt); + else + send_tcppacket(n->nexthop->connection, origpkt); return; } @@ -390,14 +475,14 @@ static void send_udppacket(node_t *n, vpn_packet_t *origpkt) { } #endif - if((sendto(listen_socket[sock].udp, (char *) &inpkt->seqno, inpkt->len, 0, &(n->address.sa), SALEN(n->address.sa))) < 0) { - if(errno == EMSGSIZE) { + if(sendto(listen_socket[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) n->mtu = origlen - 1; } else - logger(LOG_ERR, "Error sending packet to %s (%s): %s", n->name, n->hostname, strerror(errno)); + logger(LOG_ERR, "Error sending packet to %s (%s): %s", n->name, n->hostname, sockstrerror(sockerrno)); } end: @@ -467,26 +552,28 @@ 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) { splay_node_t *node; - edge_t *e; - node_t *n = NULL; + node_t *n, *found = NULL; + 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(sockaddrcmp_noport(from, &e->address)) - continue; + if(last_hard_try == now) + return NULL; + else + last_hard_try = now; - if(!n) - n = e->to; + for(node = node_tree->head; node; node = node->next) { + n = node->data; - if(!try_mac(e->to, pkt)) + if(n == myself || !n->status.reachable || !digest_active(&n->indigest)) continue; - n = e->to; - break; + if(try_mac(n, pkt)) { + found = n; + break; + } } - return n; + return found; } void handle_incoming_vpn_data(int sock, short events, void *data) { @@ -495,15 +582,18 @@ void handle_incoming_vpn_data(int sock, short events, void *data) { sockaddr_t 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(errno != EAGAIN && errno != EINTR) - logger(LOG_ERR, "Receiving packet failed: %s", strerror(errno)); + 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);