/*
protocol_misc.c -- handle the meta-protocol, miscellaneous functions
Copyright (C) 1999-2005 Ivo Timmermans,
- 2000-2012 Guus Sliepen <guus@tinc-vpn.org>
+ 2000-2013 Guus Sliepen <guus@tinc-vpn.org>
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
#include "netutl.h"
#include "protocol.h"
#include "utils.h"
+#include "xalloc.h"
int maxoutbufsize = 0;
+int mtu_info_interval = 5;
+int udp_info_interval = 5;
/* Status and error notification routines */
bool send_ping(connection_t *c) {
c->status.pinged = true;
- c->last_ping_time = time(NULL);
+ c->last_ping_time = now.tv_sec;
return send_request(c, "%d", PING);
}
if(!send_request(c, "%d %hd", PACKET, packet->len))
return false;
- return send_meta(c, (char *)packet->data, packet->len);
+ return send_meta(c, (char *)DATA(packet), packet->len);
}
bool tcppacket_h(connection_t *c, const char *request) {
return true;
}
+
+/* Transmitting UDP information */
+
+bool send_udp_info(node_t *from, node_t *to) {
+ /* If there's a static relay in the path, there's no point in sending the message
+ farther than the static relay. */
+ to = (to->via == myself) ? to->nexthop : to->via;
+
+ /* Skip cases where sending UDP info messages doesn't make sense.
+ This is done here in order to avoid repeating the same logic in multiple callsites. */
+
+ if(to == myself)
+ return true;
+
+ if(!to->status.reachable)
+ return true;
+
+ if(from == myself) {
+ if(to->connection)
+ return true;
+
+ struct timeval elapsed;
+ timersub(&now, &to->udp_info_sent, &elapsed);
+ if(elapsed.tv_sec < udp_info_interval)
+ return true;
+ }
+
+ if((myself->options | from->options | to->options) & OPTION_TCPONLY)
+ return true;
+
+ if((to->nexthop->options >> 24) < 5)
+ return true;
+
+ char *from_address, *from_port;
+ /* If we're the originator, the address we use is irrelevant
+ because the first intermediate node will ignore it.
+ We use our local address as it somewhat makes sense
+ and it's simpler than introducing an encoding for "null" addresses anyway. */
+ sockaddr2str((from != myself) ? &from->address : &to->nexthop->connection->edge->local_address, &from_address, &from_port);
+
+ bool x = send_request(to->nexthop->connection, "%d %s %s %s %s", UDP_INFO, from->name, to->name, from_address, from_port);
+
+ free(from_address);
+ free(from_port);
+
+ if(from == myself)
+ to->udp_info_sent = now;
+
+ return x;
+}
+
+bool udp_info_h(connection_t *c, const char* request) {
+ char from_name[MAX_STRING_SIZE];
+ char to_name[MAX_STRING_SIZE];
+ char from_address[MAX_STRING_SIZE];
+ char from_port[MAX_STRING_SIZE];
+
+ if(sscanf(request, "%*d "MAX_STRING" "MAX_STRING" "MAX_STRING" "MAX_STRING, from_name, to_name, from_address, from_port) != 4) {
+ logger(DEBUG_ALWAYS, LOG_ERR, "Got bad %s from %s (%s)", "UDP_INFO", c->name, c->hostname);
+ return false;
+ }
+
+ if(!check_id(from_name) || !check_id(to_name)) {
+ logger(DEBUG_ALWAYS, LOG_ERR, "Got bad %s from %s (%s): %s", "UDP_INFO", c->name, c->hostname, "invalid name");
+ return false;
+ }
+
+ node_t *from = lookup_node(from_name);
+ if(!from) {
+ logger(DEBUG_ALWAYS, LOG_ERR, "Got %s from %s (%s) origin %s which does not exist in our connection list", "UDP_INFO", c->name, c->hostname, from_name);
+ return true;
+ }
+
+ if(from != from->via) {
+ /* Not supposed to happen, as it means the message wandered past a static relay */
+ logger(DEBUG_PROTOCOL, LOG_WARNING, "Got UDP info message from %s (%s) which we can't reach directly", from->name, from->hostname);
+ return true;
+ }
+
+ /* If we have a direct edge to "from", we are in a better position
+ to guess its address than it is itself. */
+ if(!from->connection && !from->status.udp_confirmed) {
+ sockaddr_t from_addr = str2sockaddr(from_address, from_port);
+ if(sockaddrcmp(&from_addr, &from->address))
+ update_node_udp(from, &from_addr);
+ }
+
+ node_t *to = lookup_node(to_name);
+ if(!to) {
+ logger(DEBUG_ALWAYS, LOG_ERR, "Got %s from %s (%s) destination %s which does not exist in our connection list", "UDP_INFO", c->name, c->hostname, to_name);
+ return true;
+ }
+
+ /* Send our own data (which could be what we just received) up the chain. */
+
+ return send_udp_info(from, to);
+}
+
+/* Transmitting MTU information */
+
+bool send_mtu_info(node_t *from, node_t *to, int mtu) {
+ /* Skip cases where sending MTU info messages doesn't make sense.
+ This is done here in order to avoid repeating the same logic in multiple callsites. */
+
+ if(to == myself)
+ return true;
+
+ if(!to->status.reachable)
+ return true;
+
+ if(from == myself) {
+ if(to->connection)
+ return true;
+
+ struct timeval elapsed;
+ timersub(&now, &to->mtu_info_sent, &elapsed);
+ if(elapsed.tv_sec < mtu_info_interval)
+ return true;
+ }
+
+ if((to->nexthop->options >> 24) < 6)
+ return true;
+
+ /* We will send the passed-in MTU value, unless we believe ours is better. */
+
+ node_t *via = (from->via == myself) ? from->nexthop : from->via;
+ if(from->minmtu == from->maxmtu && from->via == myself) {
+ /* We have a direct measurement. Override the value entirely.
+ Note that we only do that if we are sitting as a static relay in the path;
+ otherwise, we can't guarantee packets will flow through us, and increasing
+ MTU could therefore end up being too optimistic. */
+ mtu = from->minmtu;
+ } else if(via->minmtu == via->maxmtu) {
+ /* Static relay. Ensure packets will make it through the entire relay path. */
+ mtu = MIN(mtu, via->minmtu);
+ } else if(via->nexthop->minmtu == via->nexthop->maxmtu) {
+ /* Dynamic relay. Ensure packets will make it through the entire relay path. */
+ mtu = MIN(mtu, via->nexthop->minmtu);
+ }
+
+ if(from == myself)
+ to->mtu_info_sent = now;
+
+ /* If none of the conditions above match in the steady state, it means we're using TCP,
+ so the MTU is irrelevant. That said, it is still important to honor the MTU that was passed in,
+ because other parts of the relay path might be able to use UDP, which means they care about the MTU. */
+
+ return send_request(to->nexthop->connection, "%d %s %s %d", MTU_INFO, from->name, to->name, mtu);
+}
+
+bool mtu_info_h(connection_t *c, const char* request) {
+ char from_name[MAX_STRING_SIZE];
+ char to_name[MAX_STRING_SIZE];
+ int mtu;
+
+ if(sscanf(request, "%*d "MAX_STRING" "MAX_STRING" %d", from_name, to_name, &mtu) != 3) {
+ logger(DEBUG_ALWAYS, LOG_ERR, "Got bad %s from %s (%s)", "MTU_INFO", c->name, c->hostname);
+ return false;
+ }
+
+ if(mtu < 512) {
+ logger(DEBUG_ALWAYS, LOG_ERR, "Got bad %s from %s (%s): %s", "MTU_INFO", c->name, c->hostname, "invalid MTU");
+ return false;
+ }
+
+ mtu = MIN(mtu, MTU);
+
+ if(!check_id(from_name) || !check_id(to_name)) {
+ logger(DEBUG_ALWAYS, LOG_ERR, "Got bad %s from %s (%s): %s", "MTU_INFO", c->name, c->hostname, "invalid name");
+ return false;
+ }
+
+ node_t *from = lookup_node(from_name);
+ if(!from) {
+ logger(DEBUG_ALWAYS, LOG_ERR, "Got %s from %s (%s) origin %s which does not exist in our connection list", "MTU_INFO", c->name, c->hostname, from_name);
+ return true;
+ }
+
+ /* If we don't know the current MTU for that node, use the one we received.
+ Even if we're about to make our own measurements, the value we got from downstream nodes should be pretty close
+ so it's a good idea to use it in the mean time. */
+ if(from->mtu != mtu && from->minmtu != from->maxmtu) {
+ logger(DEBUG_TRAFFIC, LOG_INFO, "Using provisional MTU %d for node %s (%s)", mtu, from->name, from->hostname);
+ from->mtu = mtu;
+ }
+
+ node_t *to = lookup_node(to_name);
+ if(!to) {
+ logger(DEBUG_ALWAYS, LOG_ERR, "Got %s from %s (%s) destination %s which does not exist in our connection list", "MTU_INFO", c->name, c->hostname, to_name);
+ return true;
+ }
+
+ /* Continue passing the MTU value (or a better one if we have it) up the chain. */
+
+ return send_mtu_info(from, to, mtu);
+}