/*
net_packet.c -- Handles in- and outgoing VPN packets
Copyright (C) 1998-2005 Ivo Timmermans,
- 2000-2021 Guus Sliepen <guus@tinc-vpn.org>
+ 2000-2022 Guus Sliepen <guus@tinc-vpn.org>
2010 Timothy Redaelli <timothy@redaelli.eu>
2010 Brandon Black <blblack@gmail.com>
#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. */
}
}
+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;
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) {
if(candidate) {
*sa = &candidate->address;
- *sock = rand() % listen_sockets;
+ *sock = prng(listen_sockets);
}
adapt_socket(*sa, sock);
/* 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) {
if(candidate && candidate->local_address.sa.sa_family) {
*sa = &candidate->local_address;
- *sock = rand() % listen_sockets;
+ *sock = prng(listen_sockets);
adapt_socket(*sa, sock);
}
}
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));
}
}
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;
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) {
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;
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);
}
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);
}
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;
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;
#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;
}
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;
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;