X-Git-Url: https://www.tinc-vpn.org/git/browse?p=tinc;a=blobdiff_plain;f=src%2Fnet_packet.c;h=43c8ce20204db886b4b7ab2ece7afdd68c9f4b4c;hp=8753bf6511760133efe18455bba73c72513c4676;hb=c0af4c37d2046ffb3e07dd62f266a4fb99ea5614;hpb=aebc97a77f37ec63fbd36721f9b284c975e54270 diff --git a/src/net_packet.c b/src/net_packet.c index 8753bf65..43c8ce20 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) 1998-2003 Ivo Timmermans , - 2000-2003 Guus Sliepen + Copyright (C) 1998-2005 Ivo Timmermans, + 2000-2012 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 @@ -13,11 +15,9 @@ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details. - You should have received a copy of the GNU General Public License - 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 1.1.2.48 2003/12/24 10:48:14 guus Exp $ + You should have received a copy of the GNU General Public License along + with this program; if not, write to the Free Software Foundation, Inc., + 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA. */ #include "system.h" @@ -28,16 +28,21 @@ #include #include +#ifdef HAVE_ZLIB #include -#include +#endif + +#ifdef HAVE_LZO +#include LZO1X_H +#endif #include "avl_tree.h" #include "conf.h" #include "connection.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" @@ -47,154 +52,242 @@ #include "utils.h" #include "xalloc.h" -#ifdef WSAEMSGSIZE -#define EMSGSIZE WSAEMSGSIZE -#endif - int keylifetime = 0; int keyexpires = 0; -EVP_CIPHER_CTX packet_ctx; +#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; +bool localdiscovery = false; + #define MAX_SEQNO 1073741824 -void send_mtu_probe(node_t *n) -{ +/* 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 + + Probes are sent in batches of three, with random sizes between the lower and + upper boundaries for the MTU thus far discovered. + + In case local discovery is enabled, a fourth packet is added to each batch, + which will be broadcast to the local network. +*/ + +void send_mtu_probe(node_t *n) { vpn_packet_t packet; int len, i; + int timeout = 1; - cp(); - n->mtuprobes++; n->mtuevent = NULL; - if(n->mtuprobes >= 10 && !n->minmtu) { - ifdebug(TRAFFIC) logger(LOG_INFO, _("No response to MTU probes from %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; } - 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->mtuprobes > 32) { + if(!n->minmtu) { + n->mtuprobes = 31; + timeout = pinginterval; + goto end; } - len = n->minmtu + 1 + random() % (n->maxmtu - n->minmtu); + 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->mtuprobes < 32 && !n->minmtu) { + ifdebug(TRAFFIC) logger(LOG_INFO, "No response to MTU probes from %s (%s)", n->name, n->hostname); + n->mtuprobes = 31; + } + + 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 + localdiscovery; i++) { + if(n->maxmtu <= n->minmtu) + len = n->maxmtu; + else + 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; + if(i >= 3 && n->mtuprobes <= 10) + packet.priority = -1; + else + packet.priority = 0; - ifdebug(TRAFFIC) logger(LOG_INFO, _("Sending MTU probe length %d to %s (%s)"), len, n->name, n->hostname); + ifdebug(TRAFFIC) logger(LOG_INFO, "Sending MTU probe length %d to %s (%s)", len, n->name, n->hostname); send_udppacket(n, &packet); } - n->mtuevent = xmalloc(sizeof(*n->mtuevent)); +end: + n->mtuevent = new_event(); n->mtuevent->handler = (event_handler_t)send_mtu_probe; n->mtuevent->data = n; - n->mtuevent->time = now + 1; + n->mtuevent->time = now + timeout; event_add(n->mtuevent); } -void mtu_probe_h(node_t *n, vpn_packet_t *packet) { - ifdebug(TRAFFIC) logger(LOG_INFO, _("Got MTU probe length %d from %s (%s)"), packet->len, n->name, n->hostname); +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); + send_udppacket(n, packet); } else { - if(n->minmtu < packet->len) - n->minmtu = packet->len; + 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; } } -static length_t compress_packet(uint8_t *dest, const uint8_t *source, length_t len, int level) -{ - if(level == 10) { +static length_t compress_packet(uint8_t *dest, const uint8_t *source, length_t len, int level) { + 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) { +static length_t uncompress_packet(uint8_t *dest, const uint8_t *source, length_t len, int level) { + 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; } /* VPN packet I/O */ -static void receive_packet(node_t *n, vpn_packet_t *packet) -{ - cp(); - - ifdebug(TRAFFIC) logger(LOG_DEBUG, _("Received packet of %d bytes from %s (%s)"), +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); route(n, packet); } -static void receive_udppacket(node_t *n, vpn_packet_t *inpkt) -{ +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) { vpn_packet_t pkt1, pkt2; vpn_packet_t *pkt[] = { &pkt1, &pkt2, &pkt1, &pkt2 }; 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) + myself->maclength) { - ifdebug(TRAFFIC) logger(LOG_DEBUG, _("Got too short packet from %s (%s)"), + 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)) { - ifdebug(TRAFFIC) logger(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; } @@ -202,14 +295,14 @@ static void receive_udppacket(node_t *n, vpn_packet_t *inpkt) /* Decrypt the packet */ - if(myself->cipher) { + if(n->incipher) { outpkt = pkt[nextpkt++]; - if(!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)) { - ifdebug(TRAFFIC) logger(LOG_DEBUG, _("Error decrypting packet from %s (%s): %s"), + 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; } @@ -223,98 +316,122 @@ 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(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 + 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[(inpkt->seqno / 8) % sizeof(n->late)] |= 1 << i % 8; + n->late[(i / 8) % replaywin] |= 1 << i % 8; + } } + + n->farfuture = 0; + n->late[(inpkt->seqno / 8) % replaywin] &= ~(1 << inpkt->seqno % 8); } - - n->received_seqno = inpkt->seqno; - n->late[(n->received_seqno / 8) % sizeof(n->late)] &= ~(1 << n->received_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) { - ifdebug(TRAFFIC) logger(LOG_ERR, _("Error while uncompressing packet from %s (%s)"), + 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; } - if(n->connection) - n->connection->last_ping_time = now; + inpkt->priority = 0; if(!inpkt->data[12] && !inpkt->data[13]) - mtu_probe_h(n, inpkt); + mtu_probe_h(n, inpkt, origlen); else 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; - 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; +#if defined(SOL_IP) && defined(IP_TOS) static int priority = 0; +#endif 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) { ifdebug(TRAFFIC) logger(LOG_INFO, - _("No valid key known yet for %s (%s), queueing packet"), + "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. */ - - *(copy = xmalloc(sizeof(*copy))) = *inpkt; + if(n->last_req_key + 10 <= now) { + send_req_key(n); + n->last_req_key = now; + } - 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 %s", + n->name, n->hostname, n != n->nexthop ? n->nexthop->name : "TCP"); - n->status.waitingforkey = true; + if(n != n->nexthop) + send_packet(n->nexthop, origpkt); + else + send_tcppacket(n->nexthop->connection, origpkt); return; } @@ -324,11 +441,11 @@ 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) { - ifdebug(TRAFFIC) logger(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; } @@ -343,14 +460,14 @@ static void send_udppacket(node_t *n, vpn_packet_t *inpkt) /* Encrypt the packet */ - if(n->cipher) { + if(n->outcipher) { outpkt = pkt[nextpkt++]; - if(!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)) { - ifdebug(TRAFFIC) logger(LOG_ERR, _("Error while encrypting packet to %s (%s): %s"), + 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; } @@ -361,77 +478,101 @@ 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 */ - 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 */ + struct sockaddr *sa; + socklen_t sl; + int sock; + + /* Overloaded use of priority field: -1 means local broadcast */ + + if(origpriority == -1 && n->prevedge) { + struct sockaddr_in in; + in.sin_family = AF_INET; + in.sin_addr.s_addr = -1; + in.sin_port = n->prevedge->address.in.sin_port; + sa = (struct sockaddr *)∈ + sl = sizeof in; + sock = 0; + } else { + if(origpriority == -1) + origpriority = 0; + + sa = &(n->address.sa); + sl = SALEN(n->address.sa); + sock = n->sock; + } + #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 */ - logger(LOG_ERR, _("System call `%s' failed: %s"), "setsockopt", strerror(errno)); + ifdebug(TRAFFIC) logger(LOG_DEBUG, "Setting outgoing packet priority to %d", priority); + 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(errno == EMSGSIZE) { + if(sendto(listen_socket[sock].udp, (char *) &inpkt->seqno, inpkt->len, 0, sa, sl) < 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)); + ifdebug(TRAFFIC) logger(LOG_WARNING, "Error sending packet to %s (%s): %s", n->name, n->hostname, sockstrerror(sockerrno)); } end: - inpkt->len = origlen; + origpkt->len = origlen; } /* send a packet to the given vpn ip. */ -void send_packet(const node_t *n, vpn_packet_t *packet) -{ +void send_packet(const node_t *n, vpn_packet_t *packet) { node_t *via; - cp(); - if(n == myself) { - write_packet(packet); + if(overwrite_mac) + memcpy(packet->data, mymac.x, ETH_ALEN); + devops.write(packet); return; } - ifdebug(TRAFFIC) logger(LOG_ERR, _("Sending packet of %d bytes to %s (%s)"), + ifdebug(TRAFFIC) logger(LOG_ERR, "Sending packet of %d bytes to %s (%s)", packet->len, n->name, n->hostname); if(!n->status.reachable) { - ifdebug(TRAFFIC) logger(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) - ifdebug(TRAFFIC) logger(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(packet->priority == -1 || ((myself->options | via->options) & OPTION_TCPONLY)) { if(!send_tcppacket(via->connection, packet)) terminate_connection(via->connection, true); } else @@ -440,53 +581,101 @@ 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) -{ +void broadcast_packet(const node_t *from, vpn_packet_t *packet) { avl_node_t *node; connection_t *c; + node_t *n; - cp(); + // Always give ourself a copy of the packet. + if(from != myself) + send_packet(myself, packet); - ifdebug(TRAFFIC) logger(LOG_INFO, _("Broadcasting packet of %d bytes from %s (%s)"), + // In TunnelServer mode, do not forward broadcast packets. + // The MST might not be valid and create loops. + if(tunnelserver || broadcast_mode == BMODE_NONE) + return; + + ifdebug(TRAFFIC) logger(LOG_INFO, "Broadcasting packet of %d bytes from %s (%s)", packet->len, from->name, from->hostname); - for(node = connection_tree->head; node; node = node->next) { - c = node->data; + switch(broadcast_mode) { + // In MST mode, broadcast packets travel via the Minimum Spanning Tree. + // This guarantees all nodes receive the broadcast packet, and + // usually distributes the sending of broadcast packets over all nodes. + case BMODE_MST: + for(node = connection_tree->head; node; node = node->next) { + c = node->data; + + if(c->status.active && c->status.mst && c != from->nexthop->connection) + send_packet(c->node, packet); + } + break; - if(c->status.active && c->status.mst && c != from->nexthop->connection) - send_packet(c->node, packet); + // In direct mode, we send copies to each node we know of. + // However, this only reaches nodes that can be reached in a single hop. + // We don't have enough information to forward broadcast packets in this case. + case BMODE_DIRECT: + if(from != myself) + break; + + for(node = node_udp_tree->head; node; node = node->next) { + n = node->data; + + if(n->status.reachable && ((n->via == myself && n->nexthop == n) || n->via == n)) + send_packet(c->node, packet); + } + break; + + default: + break; } } -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; + bool hard = false; + static time_t last_hard_try = 0; - cp(); + for(node = edge_weight_tree->head; node; node = node->next) { + e = node->data; - ifdebug(TRAFFIC) logger(LOG_INFO, _("Flushing queue for %s (%s)"), n->name, n->hostname); + if(e->to == myself) + continue; - for(node = n->queue->head; node; node = next) { - next = node->next; - send_udppacket(n, node->data); - list_delete_node(n->queue, node); + if(sockaddrcmp_noport(from, &e->address)) { + if(last_hard_try == now) + continue; + hard = true; + } + + if(!try_mac(e->to, pkt)) + continue; + + n = e->to; + break; } + + if(hard) + last_hard_try = now; + + last_hard_try = now; + return n; } -void handle_incoming_vpn_data(int sock) -{ +void handle_incoming_vpn_data(int sock) { vpn_packet_t pkt; char *hostname; sockaddr_t from; socklen_t fromlen = sizeof(from); node_t *n; - cp(); - - pkt.len = recvfrom(sock, (char *) &pkt.seqno, MAXSIZE, 0, &from.sa, &fromlen); + pkt.len = recvfrom(listen_socket[sock].udp, (char *) &pkt.seqno, MAXSIZE, 0, &from.sa, &fromlen); if(pkt.len < 0) { - logger(LOG_ERR, _("Receiving packet failed: %s"), strerror(errno)); + if(!sockwouldblock(sockerrno)) + logger(LOG_ERR, "Receiving packet failed: %s", sockstrerror(sockerrno)); return; } @@ -495,12 +684,20 @@ void handle_incoming_vpn_data(int sock) n = lookup_node_udp(&from); if(!n) { - hostname = sockaddr2hostname(&from); - logger(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; } + n->sock = sock; + receive_udppacket(n, &pkt); }