X-Git-Url: https://git.librecmc.org/?p=oweals%2Ftinc.git;a=blobdiff_plain;f=src%2Fnet_packet.c;h=18eaf34bf16a2279680382a8bcdce34c0114ffd3;hp=7a473ab2f0c2dc814e008827a3697727e7e5c1ba;hb=2f68561a5fce59e5329c9f5e33ed9d4455661ca7;hpb=7ad1369857935e6e823690cd3779f49d98a3c460 diff --git a/src/net_packet.c b/src/net_packet.c index 7a473ab..18eaf34 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) 1998-2005 Ivo Timmermans, - 2000-2012 Guus Sliepen + 2000-2016 Guus Sliepen 2010 Timothy Redaelli 2010 Brandon Black @@ -70,11 +70,15 @@ bool localdiscovery = false; 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. + Probes are sent in batches of at least 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, + 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) { @@ -126,19 +130,24 @@ void send_mtu_probe(node_t *n) { timeout = pingtimeout; } - for(i = 0; i < 3 + localdiscovery; 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; memset(packet.data, 0, 14); - RAND_pseudo_bytes(packet.data + 14, len - 14); + RAND_bytes(packet.data + 14, len - 14); packet.len = len; - if(i >= 3 && n->mtuprobes <= 10) + if(i >= 4 && n->mtuprobes <= 10) packet.priority = -1; else packet.priority = 0; @@ -164,6 +173,13 @@ void mtu_probe_h(node_t *n, vpn_packet_t *packet, length_t len) { 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 @@ -253,14 +269,14 @@ static bool try_mac(const node_t *n, const vpn_packet_t *inpkt) { 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 !memcmp_constant_time(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]; + vpn_packet_t *outpkt; int outlen, outpad; unsigned char hmac[EVP_MAX_MD_SIZE]; int i; @@ -286,7 +302,7 @@ static void receive_udppacket(node_t *n, vpn_packet_t *inpkt) { 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)) { + if(memcmp_constant_time(hmac, (char *) &inpkt->seqno + inpkt->len, n->inmaclength)) { ifdebug(TRAFFIC) logger(LOG_DEBUG, "Got unauthenticated packet from %s (%s)", n->name, n->hostname); return; @@ -298,10 +314,10 @@ static void receive_udppacket(node_t *n, vpn_packet_t *inpkt) { if(n->incipher) { outpkt = pkt[nextpkt++]; - if(!EVP_DecryptInit_ex(&n->inctx, NULL, NULL, NULL, NULL) - || !EVP_DecryptUpdate(&n->inctx, (unsigned char *) &outpkt->seqno, &outlen, + 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)) { + || !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; @@ -320,16 +336,16 @@ static void receive_udppacket(node_t *n, vpn_packet_t *inpkt) { 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)", + ifdebug(TRAFFIC) 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)", + ifdebug(TRAFFIC) 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", + ifdebug(TRAFFIC) 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; } @@ -378,6 +394,9 @@ static void receive_udppacket(node_t *n, vpn_packet_t *inpkt) { 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; @@ -396,9 +415,6 @@ 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; if(!n->status.reachable) { @@ -463,10 +479,10 @@ static void send_udppacket(node_t *n, vpn_packet_t *origpkt) { if(n->outcipher) { outpkt = pkt[nextpkt++]; - if(!EVP_EncryptInit_ex(&n->outctx, NULL, NULL, NULL, NULL) - || !EVP_EncryptUpdate(&n->outctx, (unsigned char *) &outpkt->seqno, &outlen, + 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)) { + || !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; @@ -505,12 +521,22 @@ static void send_udppacket(node_t *n, vpn_packet_t *origpkt) { /* Overloaded use of priority field: -1 means local broadcast */ if(origpriority == -1 && n->prevedge) { - broadcast.in.sin_family = AF_INET; - broadcast.in.sin_addr.s_addr = -1; - broadcast.in.sin_port = n->prevedge->address.in.sin_port; + 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 = sizeof broadcast.in; - sock = 0; + sl = SALEN(broadcast.sa); } else { if(origpriority == -1) origpriority = 0; @@ -520,15 +546,27 @@ static void send_udppacket(node_t *n, vpn_packet_t *origpkt) { sock = n->sock; } + if(priorityinheritance && origpriority != listen_socket[n->sock].priority) { + listen_socket[n->sock].priority = origpriority; + switch(listen_socket[n->sock].sa.sa.sa_family) { #if defined(SOL_IP) && defined(IP_TOS) - if(priorityinheritance && origpriority != priority - && 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[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)); - } + case AF_INET: + ifdebug(TRAFFIC) logger(LOG_DEBUG, "Setting IPv4 outgoing packet priority to %d", origpriority); + if(setsockopt(listen_socket[n->sock].udp, SOL_IP, IP_TOS, (void *)&origpriority, sizeof(origpriority))) /* SO_PRIORITY doesn't seem to work */ + logger(LOG_ERR, "System call `%s' failed: %s", "setsockopt", strerror(errno)); + break; +#endif +#if defined(IPPROTO_IPV6) && defined(IPV6_TCLASS) + case AF_INET6: + ifdebug(TRAFFIC) logger(LOG_DEBUG, "Setting IPv6 outgoing packet priority to %d", origpriority); + if(setsockopt(listen_socket[n->sock].udp, IPPROTO_IPV6, IPV6_TCLASS, (void *)&origpriority, sizeof(origpriority))) + logger(LOG_ERR, "System call `%s' failed: %s", "setsockopt", strerror(errno)); + break; #endif + default: + break; + } + } if(sendto(listen_socket[sock].udp, (char *) &inpkt->seqno, inpkt->len, 0, sa, sl) < 0 && !sockwouldblock(sockerrno)) { if(sockmsgsize(sockerrno)) { @@ -621,7 +659,7 @@ void broadcast_packet(const node_t *from, vpn_packet_t *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)) + if(n->status.reachable && n != myself && ((n->via == myself && n->nexthop == n) || n->via == n)) send_packet(n, packet); } break; @@ -635,7 +673,6 @@ 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) { @@ -644,11 +681,8 @@ static node_t *try_harder(const sockaddr_t *from, const vpn_packet_t *pkt) { if(e->to == myself) continue; - if(sockaddrcmp_noport(from, &e->address)) { - if(last_hard_try == now) - continue; - hard = true; - } + if(last_hard_try == now && sockaddrcmp_noport(from, &e->address)) + continue; if(!try_mac(e->to, pkt)) continue; @@ -657,9 +691,6 @@ 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; }