X-Git-Url: https://www.tinc-vpn.org/git/browse?p=tinc;a=blobdiff_plain;f=src%2Fnet_packet.c;h=054679e9aa0c75bca437e96443336a21d7ee53e4;hp=054a66feb2f5a4a12420227b329364aa08655f14;hb=724d79e88051b9c50704424c1cda2cedcf87dba0;hpb=242c4e2ca67d0b5c78dfe6e68a5ddcd27be1de99 diff --git a/src/net_packet.c b/src/net_packet.c index 054a66fe..054679e9 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 + 2000-2013 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 @@ -26,8 +28,13 @@ #include #include +#ifdef HAVE_ZLIB #include +#endif + +#ifdef HAVE_LZO #include LZO1X_H +#endif #include "avl_tree.h" #include "conf.h" @@ -36,7 +43,6 @@ #include "ethernet.h" #include "event.h" #include "graph.h" -#include "list.h" #include "logger.h" #include "net.h" #include "netutl.h" @@ -46,22 +52,34 @@ #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; +bool localdiscovery = false; + #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 +/* 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 at least three, with random sizes between the + lower and upper boundaries for the MTU thus far discovered. + + After the initial discovery, a fourth packet is added to each batch with a + size larger than the currently known PMTU, to test if the PMTU has increased. + + In case local discovery is enabled, another 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; @@ -78,16 +96,21 @@ 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)) { @@ -107,11 +130,16 @@ void send_mtu_probe(node_t *n) { timeout = pingtimeout; } - for(i = 0; i < 3; i++) { - if(n->maxmtu <= n->minmtu) + for(i = 0; i < 4 + localdiscovery; i++) { + if(i == 0) { + if(n->mtuprobes < 30 || n->maxmtu + 8 >= MTU) + continue; + len = n->maxmtu + 8; + } else if(n->maxmtu <= n->minmtu) { len = n->maxmtu; - else + } else { len = n->minmtu + 1 + rand() % (n->maxmtu - n->minmtu); + } if(len < 64) len = 64; @@ -119,7 +147,10 @@ void send_mtu_probe(node_t *n) { memset(packet.data, 0, 14); RAND_pseudo_bytes(packet.data + 14, len - 14); packet.len = len; - packet.priority = 0; + if(i >= 4 && 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); @@ -141,50 +172,83 @@ void mtu_probe_h(node_t *n, vpn_packet_t *packet, length_t len) { packet->data[0] = 1; send_udppacket(n, packet); } else { + if(n->mtuprobes > 30) { + if (len == n->maxmtu + 8) { + ifdebug(TRAFFIC) logger(LOG_INFO, "Increase in PMTU to %s (%s) detected, restarting PMTU discovery", n->name, n->hostname); + n->maxmtu = MTU; + n->mtuprobes = 10; + return; + } + + 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; } @@ -268,25 +332,32 @@ 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; @@ -320,9 +391,12 @@ 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; + if(len > sizeof outpkt.data) + return; + outpkt.len = len; if(c->options & OPTION_TCPONLY) outpkt.priority = 0; @@ -341,9 +415,10 @@ static void send_udppacket(node_t *n, vpn_packet_t *origpkt) { vpn_packet_t *outpkt; int origlen; int outlen, outpad; +#if defined(SOL_IP) && defined(IP_TOS) static int priority = 0; +#endif int origpriority; - int sock; if(!n->status.reachable) { ifdebug(TRAFFIC) logger(LOG_INFO, "Trying to send UDP packet to unreachable node %s (%s)", n->name, n->hostname); @@ -357,10 +432,10 @@ static void send_udppacket(node_t *n, vpn_packet_t *origpkt) { "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); @@ -430,33 +505,68 @@ static void send_udppacket(node_t *n, vpn_packet_t *origpkt) { /* 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; + sockaddr_t broadcast; + + /* Overloaded use of priority field: -1 means local broadcast */ + + if(origpriority == -1 && n->prevedge) { + sock = rand() % listen_sockets; + memset(&broadcast, 0, sizeof broadcast); + if(listen_socket[sock].sa.sa.sa_family == AF_INET6) { + broadcast.in6.sin6_family = AF_INET6; + broadcast.in6.sin6_addr.s6_addr[0x0] = 0xff; + broadcast.in6.sin6_addr.s6_addr[0x1] = 0x02; + broadcast.in6.sin6_addr.s6_addr[0xf] = 0x01; + broadcast.in6.sin6_port = n->prevedge->address.in.sin_port; + broadcast.in6.sin6_scope_id = listen_socket[sock].sa.in6.sin6_scope_id; + } else { + broadcast.in.sin_family = AF_INET; + broadcast.in.sin_addr.s_addr = -1; + broadcast.in.sin_port = n->prevedge->address.in.sin_port; + } + sa = &broadcast.sa; + sl = SALEN(broadcast.sa); + } 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 */ + 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: @@ -472,7 +582,7 @@ void send_packet(const node_t *n, vpn_packet_t *packet) { if(n == myself) { if(overwrite_mac) memcpy(packet->data, mymac.x, ETH_ALEN); - write_packet(packet); + devops.write(packet); return; } @@ -503,24 +613,50 @@ void send_packet(const node_t *n, 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; + + // Always give ourself a copy of the packet. + 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 || broadcast_mode == BMODE_NONE) + return; 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); + 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; - // In TunnelServer mode, do not forward broadcast packets. - // The MST might not be valid and create loops. - if(tunnelserver) - return; - } + if(c->status.active && c->status.mst && c != from->nexthop->connection) + send_packet(c->node, packet); + } + break; - for(node = connection_tree->head; node; node = node->next) { - c = node->data; + // 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; - if(c->status.active && c->status.mst && c != from->nexthop->connection) - send_packet(c->node, packet); + 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(n, packet); + } + break; + + default: + break; } } @@ -528,20 +664,21 @@ 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; 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; @@ -549,6 +686,10 @@ static node_t *try_harder(const sockaddr_t *from, const vpn_packet_t *pkt) { break; } + if(hard) + last_hard_try = now; + + last_hard_try = now; return n; } @@ -559,11 +700,11 @@ void handle_incoming_vpn_data(int sock) { socklen_t fromlen = sizeof(from); node_t *n; - 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) { - if(errno != EAGAIN && errno != EINTR) - logger(LOG_ERR, "Receiving packet failed: %s", strerror(errno)); + if(!sockwouldblock(sockerrno)) + logger(LOG_ERR, "Receiving packet failed: %s", sockstrerror(sockerrno)); return; } @@ -585,5 +726,7 @@ void handle_incoming_vpn_data(int sock) { return; } + n->sock = sock; + receive_udppacket(n, &pkt); }