X-Git-Url: https://tinc-vpn.org/git/browse?p=tinc;a=blobdiff_plain;f=src%2Fnet_packet.c;h=aca84683e5aaa5a500758803bdcaf90ba435ac8e;hp=79d3b18ab095e519c4e89d1be4431165b523c5b6;hb=b5ccce296848aab72d574ca3de14af5fdf3efa4d;hpb=1401faf608e1c8af0d0754e545b0ec79d2bd5d93 diff --git a/src/net_packet.c b/src/net_packet.c index 79d3b18a..aca84683 100644 --- a/src/net_packet.c +++ b/src/net_packet.c @@ -1,7 +1,7 @@ /* net_packet.c -- Handles in- and outgoing VPN packets - Copyright (C) 1998-2002 Ivo Timmermans , - 2000-2002 Guus Sliepen + Copyright (C) 1998-2005 Ivo Timmermans, + 2000-2009 Guus Sliepen 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 @@ -17,76 +17,109 @@ along with this program; if not, write to the Free Software Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. - $Id: net_packet.c,v 1.1.2.32 2003/07/06 23:16:28 guus Exp $ + $Id$ */ -#include "config.h" - -#include -#include -#include -#include -#include -#include -#include -#include -#include -#include -#include -#include -/* SunOS really wants sys/socket.h BEFORE net/if.h, - and FreeBSD wants these lines below the rest. */ -#include -#include -#include -#ifdef HAVE_NETINET_IN_SYSTM_H -#include -#endif -#ifdef HAVE_NETINET_IP_H -#include -#endif -#ifdef HAVE_NETINET_TCP_H -#include -#endif +#include "system.h" #include +#include #include #include #include #include -#include - -#include -#include -#include -#include +#include LZO1X_H +#include "avl_tree.h" #include "conf.h" #include "connection.h" -#include "meta.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" -#include "process.h" #include "protocol.h" -#include "subnet.h" -#include "graph.h" #include "process.h" #include "route.h" -#include "device.h" -#include "event.h" -#include "logger.h" +#include "utils.h" +#include "xalloc.h" -#include "system.h" +#ifdef WSAEMSGSIZE +#define EMSGSIZE WSAEMSGSIZE +#endif int keylifetime = 0; int keyexpires = 0; -EVP_CIPHER_CTX packet_ctx; static char lzo_wrkmem[LZO1X_999_MEM_COMPRESS > LZO1X_1_MEM_COMPRESS ? LZO1X_999_MEM_COMPRESS : LZO1X_1_MEM_COMPRESS]; +static void send_udppacket(node_t *, vpn_packet_t *); #define MAX_SEQNO 1073741824 +void send_mtu_probe(node_t *n) +{ + vpn_packet_t packet; + int len, i; + + cp(); + + n->mtuprobes++; + n->mtuevent = NULL; + + if(!n->status.reachable) { + logger(LOG_DEBUG, _("Trying to send MTU probe to unreachable node %s (%s)"), n->name, n->hostname); + return; + } + + if(n->mtuprobes >= 10 && !n->minmtu) { + ifdebug(TRAFFIC) logger(LOG_INFO, _("No response to MTU probes from %s (%s)"), n->name, n->hostname); + return; + } + + 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; + } + + len = n->minmtu + 1 + rand() % (n->maxmtu - n->minmtu); + if(len < 64) + len = 64; + + memset(packet.data, 0, 14); + RAND_pseudo_bytes(packet.data + 14, len - 14); + packet.len = len; + packet.priority = 0; + + ifdebug(TRAFFIC) logger(LOG_INFO, _("Sending MTU probe length %d to %s (%s)"), len, n->name, n->hostname); + + send_udppacket(n, &packet); + } + + n->mtuevent = new_event(); + n->mtuevent->handler = (event_handler_t)send_mtu_probe; + n->mtuevent->data = n; + n->mtuevent->time = now + 1; + event_add(n->mtuevent); +} + +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_packet(n, packet); + } else { + if(n->minmtu < len) + n->minmtu = len; + } +} + static length_t compress_packet(uint8_t *dest, const uint8_t *source, length_t len, int level) { if(level == 10) { @@ -133,10 +166,22 @@ static void receive_packet(node_t *n, vpn_packet_t *packet) { cp(); - logger(DEBUG_TRAFFIC, LOG_DEBUG, _("Received packet of %d bytes from %s (%s)"), + ifdebug(TRAFFIC) logger(LOG_DEBUG, _("Received packet of %d bytes from %s (%s)"), packet->len, n->name, n->hostname); - route_incoming(n, packet); + 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) + 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); } static void receive_udppacket(node_t *n, vpn_packet_t *inpkt) @@ -146,20 +191,34 @@ static void receive_udppacket(node_t *n, vpn_packet_t *inpkt) int nextpkt = 0; vpn_packet_t *outpkt = pkt[0]; int outlen, outpad; - char hmac[EVP_MAX_MD_SIZE]; + unsigned char hmac[EVP_MAX_MD_SIZE]; int i; cp(); + if(!n->inkey) { + ifdebug(TRAFFIC) logger(LOG_DEBUG, _("Got packet from %s (%s) but he hasn't got our key yet"), + n->name, n->hostname); + return; + } + + /* Check packet length */ + + if(inpkt->len < sizeof(inpkt->seqno) + n->inmaclength) { + ifdebug(TRAFFIC) logger(LOG_DEBUG, _("Got too short packet from %s (%s)"), + n->name, n->hostname); + return; + } + /* Check the message authentication code */ - if(myself->digest && myself->maclength) { - inpkt->len -= myself->maclength; - HMAC(myself->digest, myself->key, myself->keylength, - (char *) &inpkt->seqno, inpkt->len, hmac, NULL); + 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, myself->maclength)) { - logger(DEBUG_TRAFFIC, LOG_DEBUG, _("Got unauthenticated packet from %s (%s)"), + 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); return; } @@ -167,15 +226,17 @@ static void receive_udppacket(node_t *n, vpn_packet_t *inpkt) /* Decrypt the packet */ - if(myself->cipher) { + if(n->incipher) { outpkt = pkt[nextpkt++]; -// EVP_DecryptInit_ex(&packet_ctx, myself->cipher, NULL, myself->key, -// myself->key + myself->cipher->key_len); - EVP_DecryptInit_ex(&packet_ctx, NULL, NULL, NULL, NULL); - EVP_DecryptUpdate(&packet_ctx, (char *) &outpkt->seqno, &outlen, - (char *) &inpkt->seqno, inpkt->len); - EVP_DecryptFinal_ex(&packet_ctx, (char *) &outpkt->seqno + outlen, &outpad); + 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)); + return; + } outpkt->len = outlen + outpad; inpkt = outpkt; @@ -188,41 +249,57 @@ static void receive_udppacket(node_t *n, vpn_packet_t *inpkt) if(inpkt->seqno != n->received_seqno + 1) { if(inpkt->seqno >= n->received_seqno + sizeof(n->late) * 8) { - logger(DEBUG_ALWAYS, LOG_WARNING, _("Lost %d packets from %s (%s)"), + 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(inpkt->seqno <= n->received_seqno - sizeof(n->late) * 8 || !(n->late[(inpkt->seqno / 8) % sizeof(n->late)] & (1 << inpkt->seqno % 8))) { - logger(DEBUG_ALWAYS, LOG_WARNING, _("Got late or replayed packet from %s (%s), seqno %d, last received %d"), + 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); - } else - for(i = n->received_seqno + 1; i < inpkt->seqno; i++) - n->late[(inpkt->seqno / 8) % sizeof(n->late)] |= 1 << i % 8; + return; + } + } else { + for(i = n->received_seqno + 1; i < inpkt->seqno; i++) + n->late[(i / 8) % sizeof(n->late)] |= 1 << i % 8; } } - n->received_seqno = inpkt->seqno; - n->late[(n->received_seqno / 8) % sizeof(n->late)] &= ~(1 << n->received_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; /* Decompress the packet */ - if(myself->compression) { + length_t origlen = inpkt->len; + + if(n->incompression) { outpkt = pkt[nextpkt++]; - if((outpkt->len = uncompress_packet(outpkt->data, inpkt->data, inpkt->len, myself->compression)) < 0) { - logger(DEBUG_ALWAYS, LOG_ERR, _("Error while uncompressing packet from %s (%s)"), - n->name, n->hostname); + if((outpkt->len = uncompress_packet(outpkt->data, inpkt->data, inpkt->len, n->incompression)) < 0) { + ifdebug(TRAFFIC) logger(LOG_ERR, _("Error while uncompressing packet from %s (%s)"), + n->name, n->hostname); return; } inpkt = outpkt; + + origlen -= MTU/64 + 20; } - receive_packet(n, inpkt); + inpkt->priority = 0; + + if(n->connection) + n->connection->last_ping_time = now; + + if(!inpkt->data[12] && !inpkt->data[13]) + mtu_probe_h(n, inpkt, origlen); + else + receive_packet(n, inpkt); } void receive_tcppacket(connection_t *c, char *buffer, int len) @@ -232,47 +309,58 @@ void receive_tcppacket(connection_t *c, char *buffer, int len) cp(); outpkt.len = len; + if(c->options & OPTION_TCPONLY) + outpkt.priority = 0; + else + outpkt.priority = -1; memcpy(outpkt.data, buffer, len); receive_packet(c->node, &outpkt); } -static void send_udppacket(node_t *n, vpn_packet_t *inpkt) +static void send_udppacket(node_t *n, vpn_packet_t *origpkt) { vpn_packet_t pkt1, pkt2; vpn_packet_t *pkt[] = { &pkt1, &pkt2, &pkt1, &pkt2 }; + vpn_packet_t *inpkt = origpkt; int nextpkt = 0; vpn_packet_t *outpkt; int origlen; int outlen, outpad; - vpn_packet_t *copy; static int priority = 0; int origpriority; int sock; cp(); + if(!n->status.reachable) { + ifdebug(TRAFFIC) logger(LOG_INFO, _("Trying to send UDP packet to unreachable node %s (%s)"), n->name, n->hostname); + return; + } + /* Make sure we have a valid key */ if(!n->status.validkey) { - logger(DEBUG_TRAFFIC, LOG_INFO, - _("No valid key known yet for %s (%s), queueing packet"), + ifdebug(TRAFFIC) logger(LOG_INFO, + _("No valid key known yet for %s (%s), forwarding via TCP"), n->name, n->hostname); - /* Since packet is on the stack of handle_tap_input(), we have to make a copy of it first. */ + if(!n->status.waitingforkey) + send_req_key(n); - copy = xmalloc(sizeof(vpn_packet_t)); - memcpy(copy, inpkt, sizeof(vpn_packet_t)); + n->status.waitingforkey = true; - list_insert_tail(n->queue, copy); + send_tcppacket(n->nexthop->connection, origpkt); - if(n->queue->count > MAXQUEUELENGTH) - list_delete_head(n->queue); + return; + } - if(!n->status.waitingforkey) - send_req_key(n->nexthop->connection, myself, n); + 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); - n->status.waitingforkey = 1; + send_tcppacket(n->nexthop->connection, origpkt); return; } @@ -282,11 +370,11 @@ static void send_udppacket(node_t *n, vpn_packet_t *inpkt) /* Compress the packet */ - if(n->compression) { + if(n->outcompression) { outpkt = pkt[nextpkt++]; - if((outpkt->len = compress_packet(outpkt->data, inpkt->data, inpkt->len, n->compression)) < 0) { - logger(DEBUG_ALWAYS, LOG_ERR, _("Error while compressing packet to %s (%s)"), + if((outpkt->len = compress_packet(outpkt->data, inpkt->data, inpkt->len, n->outcompression)) < 0) { + ifdebug(TRAFFIC) logger(LOG_ERR, _("Error while compressing packet to %s (%s)"), n->name, n->hostname); return; } @@ -301,14 +389,17 @@ static void send_udppacket(node_t *n, vpn_packet_t *inpkt) /* Encrypt the packet */ - if(n->cipher) { + if(n->outcipher) { outpkt = pkt[nextpkt++]; -// EVP_EncryptInit_ex(&packet_ctx, n->cipher, NULL, n->key, n->key + n->cipher->key_len); - EVP_EncryptInit_ex(&n->packet_ctx, NULL, NULL, NULL, NULL); - EVP_EncryptUpdate(&n->packet_ctx, (char *) &outpkt->seqno, &outlen, - (char *) &inpkt->seqno, inpkt->len); - EVP_EncryptFinal_ex(&n->packet_ctx, (char *) &outpkt->seqno + outlen, &outpad); + 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)); + goto end; + } outpkt->len = outlen + outpad; inpkt = outpkt; @@ -316,10 +407,10 @@ static void send_udppacket(node_t *n, vpn_packet_t *inpkt) /* Add the message authentication code */ - if(n->digest && n->maclength) { - HMAC(n->digest, n->key, n->keylength, (char *) &inpkt->seqno, - inpkt->len, (char *) &inpkt->seqno + inpkt->len, &outlen); - inpkt->len += n->maclength; + 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; } /* Determine which socket we have to use */ @@ -337,97 +428,120 @@ static void send_udppacket(node_t *n, vpn_packet_t *inpkt) if(priorityinheritance && origpriority != priority && listen_socket[sock].sa.sa.sa_family == AF_INET) { priority = origpriority; - logger(DEBUG_TRAFFIC, LOG_DEBUG, _("Setting outgoing packet priority to %d"), priority); + 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 */ - logger(DEBUG_ALWAYS, LOG_ERR, _("System call `%s' failed: %s"), "setsockopt", - strerror(errno)); + 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) { - logger(DEBUG_ALWAYS, LOG_ERR, _("Error sending packet to %s (%s): %s"), n->name, - n->hostname, strerror(errno)); - return; + if(errno == EMSGSIZE) { + 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)); } - inpkt->len = origlen; +end: + origpkt->len = origlen; } /* send a packet to the given vpn ip. */ -void send_packet(node_t *n, vpn_packet_t *packet) +void send_packet(const node_t *n, vpn_packet_t *packet) { node_t *via; cp(); - logger(DEBUG_TRAFFIC, LOG_ERR, _("Sending packet of %d bytes to %s (%s)"), - packet->len, n->name, n->hostname); - if(n == myself) { - logger(DEBUG_TRAFFIC, LOG_NOTICE, _("Packet is looping back to us!")); + if(overwrite_mac) + memcpy(packet->data, mymac.x, ETH_ALEN); + write_packet(packet); return; } + ifdebug(TRAFFIC) logger(LOG_ERR, _("Sending packet of %d bytes to %s (%s)"), + packet->len, n->name, n->hostname); + if(!n->status.reachable) { - logger(DEBUG_TRAFFIC, LOG_INFO, _("Node %s (%s) is not reachable"), + ifdebug(TRAFFIC) logger(LOG_INFO, _("Node %s (%s) is not reachable"), n->name, n->hostname); return; } - via = (n->via == myself) ? n->nexthop : n->via; + via = (packet->priority == -1 || n->via == myself) ? n->nexthop : n->via; if(via != n) - logger(DEBUG_TRAFFIC, LOG_ERR, _("Sending packet to %s via %s (%s)"), + ifdebug(TRAFFIC) logger(LOG_INFO, _("Sending packet to %s via %s (%s)"), n->name, via->name, n->via->hostname); - if((myself->options | via->options) & OPTION_TCPONLY) { - if(send_tcppacket(via->connection, packet)) - terminate_connection(via->connection, 1); + if(packet->priority == -1 || ((myself->options | via->options) & OPTION_TCPONLY)) { + if(!send_tcppacket(via->connection, packet)) + terminate_connection(via->connection, true); } else send_udppacket(via, packet); } /* Broadcast a packet using the minimum spanning tree */ -void broadcast_packet(node_t *from, vpn_packet_t *packet) +void broadcast_packet(const node_t *from, vpn_packet_t *packet) { avl_node_t *node; connection_t *c; cp(); - logger(DEBUG_TRAFFIC, LOG_INFO, _("Broadcasting packet of %d bytes from %s (%s)"), + ifdebug(TRAFFIC) logger(LOG_INFO, _("Broadcasting packet of %d bytes from %s (%s)"), packet->len, from->name, from->hostname); + if(from != myself) { + send_packet(myself, packet); + + // In TunnelServer mode, do not forward broadcast packets. + // The MST might not be valid and create loops. + if(tunnelserver) + return; + } + for(node = connection_tree->head; node; node = node->next) { - c = (connection_t *) node->data; + c = node->data; if(c->status.active && c->status.mst && c != from->nexthop->connection) send_packet(c->node, packet); } } -void flush_queue(node_t *n) -{ - list_node_t *node, *next; +static node_t *try_harder(const sockaddr_t *from, const vpn_packet_t *pkt) { + avl_node_t *node; + edge_t *e; + node_t *n = NULL; - cp(); + for(node = edge_weight_tree->head; node; node = node->next) { + e = node->data; + + if(sockaddrcmp_noport(from, &e->address)) + continue; - logger(DEBUG_TRAFFIC, LOG_INFO, _("Flushing queue for %s (%s)"), n->name, n->hostname); + if(!n) + n = e->to; - for(node = n->queue->head; node; node = next) { - next = node->next; - send_udppacket(n, (vpn_packet_t *) node->data); - list_delete_node(n->queue, node); + if(!try_mac(e->to, pkt)) + continue; + + n = e->to; + break; } + + return n; } void handle_incoming_vpn_data(int sock) { vpn_packet_t pkt; - int x, l = sizeof(x); char *hostname; sockaddr_t from; socklen_t fromlen = sizeof(from); @@ -435,22 +549,11 @@ void handle_incoming_vpn_data(int sock) cp(); - if(getsockopt(sock, SOL_SOCKET, SO_ERROR, &x, &l) < 0) { - logger(DEBUG_ALWAYS, LOG_ERR, _("This is a bug: %s:%d: %d:%s"), - __FILE__, __LINE__, sock, strerror(errno)); - cp_trace(); - exit(1); - } - - if(x) { - logger(DEBUG_ALWAYS, LOG_ERR, _("Incoming data socket error: %s"), strerror(x)); - return; - } - pkt.len = recvfrom(sock, (char *) &pkt.seqno, MAXSIZE, 0, &from.sa, &fromlen); - if(pkt.len <= 0) { - logger(DEBUG_ALWAYS, LOG_ERR, _("Receiving packet failed: %s"), strerror(errno)); + if(pkt.len < 0) { + if(errno != EAGAIN && errno != EINTR) + logger(LOG_ERR, _("Receiving packet failed: %s"), strerror(errno)); return; } @@ -459,15 +562,18 @@ void handle_incoming_vpn_data(int sock) n = lookup_node_udp(&from); if(!n) { - hostname = sockaddr2hostname(&from); - logger(DEBUG_ALWAYS, LOG_WARNING, _("Received UDP packet from unknown source %s"), - hostname); - free(hostname); - return; + n = try_harder(&from, &pkt); + if(n) + update_node_udp(n, &from); + else ifdebug(PROTOCOL) { + hostname = sockaddr2hostname(&from); + logger(LOG_WARNING, _("Received UDP packet from unknown source %s"), hostname); + free(hostname); + return; + } + else + return; } - if(n->connection) - n->connection->last_ping_time = now; - receive_udppacket(n, &pkt); }