X-Git-Url: https://tinc-vpn.org/git/browse?a=blobdiff_plain;f=src%2Fnet_packet.c;h=459b24134b1f325a6546ef9b7b6a3e04a557b7de;hb=28b7a53b693f6b4e70218a926e68a36ece54cda1;hp=7bb182db22822c03b66cefd1b842c13234421a84;hpb=914d1be411229c28e6e8e4a0df99afa076a8b448;p=tinc diff --git a/src/net_packet.c b/src/net_packet.c index 7bb182db..459b2413 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, - 2000-2021 Guus Sliepen + 2000-2022 Guus Sliepen 2010 Timothy Redaelli 2010 Brandon Black @@ -55,10 +55,6 @@ #include "route.h" #include "utils.h" -#ifndef MAX -#define MAX(a, b) ((a) > (b) ? (a) : (b)) -#endif - /* The minimum size of a probe is 14 bytes, but since we normally use CBC mode encryption, we can add a few extra random bytes without increasing the resulting packet size. */ @@ -104,6 +100,22 @@ static void try_fix_mtu(node_t *n) { } } +static void reduce_mtu(node_t *n, int mtu) { + if(mtu < MINMTU) { + mtu = MINMTU; + } + + if(n->maxmtu > mtu) { + n->maxmtu = mtu; + } + + if(n->mtu > mtu) { + n->mtu = mtu; + } + + try_fix_mtu(n); +} + static void udp_probe_timeout_handler(void *data) { node_t *n = data; @@ -743,7 +755,7 @@ static void choose_udp_address(const node_t *n, const sockaddr_t **sa, size_t *s So we pick a random edge and a random socket. */ unsigned int i = 0; - unsigned int j = rand() % n->edge_tree.count; + unsigned int j = prng(n->edge_tree.count); edge_t *candidate = NULL; for splay_each(edge_t, e, &n->edge_tree) { @@ -755,7 +767,7 @@ static void choose_udp_address(const node_t *n, const sockaddr_t **sa, size_t *s if(candidate) { *sa = &candidate->address; - *sock = rand() % listen_sockets; + *sock = prng(listen_sockets); } adapt_socket(*sa, sock); @@ -767,7 +779,7 @@ static void choose_local_address(const node_t *n, const sockaddr_t **sa, size_t /* Pick one of the edges from this node at random, then use its local address. */ unsigned int i = 0; - unsigned int j = rand() % n->edge_tree.count; + unsigned int j = prng(n->edge_tree.count); edge_t *candidate = NULL; for splay_each(edge_t, e, &n->edge_tree) { @@ -779,7 +791,7 @@ static void choose_local_address(const node_t *n, const sockaddr_t **sa, size_t if(candidate && candidate->local_address.sa.sa_family) { *sa = &candidate->local_address; - *sock = rand() % listen_sockets; + *sock = prng(listen_sockets); adapt_socket(*sa, sock); } } @@ -927,15 +939,7 @@ static void send_udppacket(node_t *n, vpn_packet_t *origpkt) { if(sendto(listen_socket[sock].udp.fd, (void *)SEQNO(inpkt), inpkt->len, 0, &sa->sa, SALEN(sa->sa)) < 0 && !sockwouldblock(sockerrno)) { if(sockmsgsize(sockerrno)) { - if(n->maxmtu >= origlen) { - n->maxmtu = origlen - 1; - } - - if(n->mtu >= origlen) { - n->mtu = origlen - 1; - } - - try_fix_mtu(n); + reduce_mtu(n, origlen - 1); } else { logger(DEBUG_TRAFFIC, LOG_WARNING, "Error sending packet to %s (%s): %s", n->name, n->hostname, sockstrerror(sockerrno)); } @@ -947,14 +951,15 @@ end: } bool send_sptps_data(node_t *to, node_t *from, int type, const void *data, size_t len) { - node_t *relay = (to->via != myself && (type == PKT_PROBE || (len - SPTPS_DATAGRAM_OVERHEAD) <= to->via->minmtu)) ? to->via : to->nexthop; + size_t origlen = len - SPTPS_DATAGRAM_OVERHEAD; + node_t *relay = (to->via != myself && (type == PKT_PROBE || origlen <= to->via->minmtu)) ? to->via : to->nexthop; bool direct = from == myself && to == relay; bool relay_supported = (relay->options >> 24) >= 4; bool tcponly = (myself->options | relay->options) & OPTION_TCPONLY; /* Send it via TCP if it is a handshake packet, TCPOnly is in use, this is a relay packet that the other node cannot understand, or this packet is larger than the MTU. */ - if(type == SPTPS_HANDSHAKE || tcponly || (!direct && !relay_supported) || (type != PKT_PROBE && (len - SPTPS_DATAGRAM_OVERHEAD) > relay->minmtu)) { + if(type == SPTPS_HANDSHAKE || tcponly || (!direct && !relay_supported) || (type != PKT_PROBE && origlen > relay->minmtu)) { if(type != SPTPS_HANDSHAKE && (to->nexthop->connection->options >> 24) >= 7) { uint8_t buf[len + sizeof(to->id) + sizeof(from->id)]; uint8_t *buf_ptr = buf; @@ -967,8 +972,8 @@ bool send_sptps_data(node_t *to, node_t *from, int type, const void *data, size_ return send_sptps_tcppacket(to->nexthop->connection, buf, sizeof(buf)); } - char buf[len * 4 / 3 + 5]; - b64encode(data, buf, len); + char buf[B64_SIZE(len)]; + b64encode_tinc(data, buf, len); /* If this is a handshake packet, use ANS_KEY instead of REQ_KEY, for two reasons: - We don't want intermediate nodes to switch to UDP to relay these packets; @@ -987,8 +992,8 @@ bool send_sptps_data(node_t *to, node_t *from, int type, const void *data, size_ overhead += sizeof(to->id) + sizeof(from->id); } - uint8_t buf[len + overhead]; - uint8_t *buf_ptr = buf; + char buf[len + overhead]; + char *buf_ptr = buf; if(relay_supported) { if(direct) { @@ -1025,18 +1030,7 @@ bool send_sptps_data(node_t *to, node_t *from, int type, const void *data, size_ if(sendto(listen_socket[sock].udp.fd, buf, buf_ptr - buf, 0, &sa->sa, SALEN(sa->sa)) < 0 && !sockwouldblock(sockerrno)) { if(sockmsgsize(sockerrno)) { - // Compensate for SPTPS overhead - len -= SPTPS_DATAGRAM_OVERHEAD; - - if(relay->maxmtu >= len) { - relay->maxmtu = len - 1; - } - - if(relay->mtu >= len) { - relay->mtu = len - 1; - } - - try_fix_mtu(relay); + reduce_mtu(relay, (int)origlen - 1); } else { logger(DEBUG_TRAFFIC, LOG_WARNING, "Error sending UDP SPTPS packet to %s (%s): %s", relay->name, relay->hostname, sockstrerror(sockerrno)); return false; @@ -1171,7 +1165,7 @@ static void send_udp_probe_packet(node_t *n, size_t len) { vpn_packet_t packet; if(len > sizeof(packet.data)) { - logger(DEBUG_TRAFFIC, LOG_INFO, "Truncating probe length %zu to %s (%s)", len, n->name, n->hostname); + logger(DEBUG_TRAFFIC, LOG_INFO, "Truncating probe length %lu to %s (%s)", (unsigned long)len, n->name, n->hostname); len = sizeof(packet.data); } @@ -1181,7 +1175,7 @@ static void send_udp_probe_packet(node_t *n, size_t len) { packet.len = len; packet.priority = 0; - logger(DEBUG_TRAFFIC, LOG_INFO, "Sending UDP probe length %zu to %s (%s)", len, n->name, n->hostname); + logger(DEBUG_TRAFFIC, LOG_INFO, "Sending UDP probe length %lu to %s (%s)", (unsigned long)len, n->name, n->hostname); send_udppacket(n, &packet); } @@ -1267,7 +1261,7 @@ static length_t choose_initial_maxmtu(node_t *n) { int ip_mtu; socklen_t ip_mtu_len = sizeof(ip_mtu); - if(getsockopt(sock, IPPROTO_IP, IP_MTU, &ip_mtu, &ip_mtu_len)) { + if(getsockopt(sock, IPPROTO_IP, IP_MTU, (void *)&ip_mtu, &ip_mtu_len)) { logger(DEBUG_TRAFFIC, LOG_ERR, "getsockopt(IP_MTU) on %s (%s) failed: %s", n->name, n->hostname, sockstrerror(sockerrno)); close(sock); return MTU; @@ -1275,6 +1269,11 @@ static length_t choose_initial_maxmtu(node_t *n) { close(sock); + if(ip_mtu < MINMTU) { + logger(DEBUG_TRAFFIC, LOG_ERR, "getsockopt(IP_MTU) on %s (%s) returned absurdly small value: %d", n->name, n->hostname, ip_mtu); + return MTU; + } + /* getsockopt(IP_MTU) returns the MTU of the physical interface. We need to remove various overheads to get to the tinc MTU. */ length_t mtu = ip_mtu; @@ -1311,11 +1310,6 @@ static length_t choose_initial_maxmtu(node_t *n) { #endif } - if(mtu < 512) { - logger(DEBUG_TRAFFIC, LOG_ERR, "getsockopt(IP_MTU) on %s (%s) returned absurdly small value: %d", n->name, n->hostname, ip_mtu); - return MTU; - } - if(mtu > MTU) { return MTU; } @@ -1416,7 +1410,7 @@ static void try_mtu(node_t *n) { const float multiplier = (n->maxmtu == MTU) ? 0.97f : 1.0f; const float cycle_position = (float) probes_per_cycle - (float)(n->mtuprobes % probes_per_cycle) - 1.0f; - const length_t minmtu = MAX(n->minmtu, 512); + const length_t minmtu = MAX(n->minmtu, MINMTU); const float interval = (float)(n->maxmtu - minmtu); length_t offset = 0; @@ -1430,7 +1424,7 @@ static void try_mtu(node_t *n) { on the precise MTU as we are approaching it. The last probe of the cycle is always 1 byte in size - this is to make sure we'll get at least one reply per cycle so that we can make progress. */ - offset = (length_t) powf(interval, multiplier * cycle_position / ((float) probes_per_cycle - 1.0f)); + offset = lrintf(powf(interval, multiplier * cycle_position / (float)(probes_per_cycle - 1))); } length_t maxmtu = n->maxmtu;