2 protocol_misc.c -- handle the meta-protocol, miscellaneous functions
3 Copyright (C) 1999-2005 Ivo Timmermans,
4 2000-2013 Guus Sliepen <guus@tinc-vpn.org>
6 This program is free software; you can redistribute it and/or modify
7 it under the terms of the GNU General Public License as published by
8 the Free Software Foundation; either version 2 of the License, or
9 (at your option) any later version.
11 This program is distributed in the hope that it will be useful,
12 but WITHOUT ANY WARRANTY; without even the implied warranty of
13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 GNU General Public License for more details.
16 You should have received a copy of the GNU General Public License along
17 with this program; if not, write to the Free Software Foundation, Inc.,
18 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
24 #include "connection.h"
33 int maxoutbufsize = 0;
34 int mtu_info_interval = 5;
35 int udp_info_interval = 5;
37 /* Status and error notification routines */
39 bool send_status(connection_t *c, int statusno, const char *statusstring) {
41 statusstring = "Status";
43 return send_request(c, "%d %d %s", STATUS, statusno, statusstring);
46 bool status_h(connection_t *c, const char *request) {
48 char statusstring[MAX_STRING_SIZE];
50 if(sscanf(request, "%*d %d " MAX_STRING, &statusno, statusstring) != 2) {
51 logger(DEBUG_ALWAYS, LOG_ERR, "Got bad %s from %s (%s)", "STATUS",
52 c->name, c->hostname);
56 logger(DEBUG_STATUS, LOG_NOTICE, "Status message from %s (%s): %d: %s",
57 c->name, c->hostname, statusno, statusstring);
62 bool send_error(connection_t *c, int err, const char *errstring) {
66 return send_request(c, "%d %d %s", ERROR, err, errstring);
69 bool error_h(connection_t *c, const char *request) {
71 char errorstring[MAX_STRING_SIZE];
73 if(sscanf(request, "%*d %d " MAX_STRING, &err, errorstring) != 2) {
74 logger(DEBUG_ALWAYS, LOG_ERR, "Got bad %s from %s (%s)", "ERROR",
75 c->name, c->hostname);
79 logger(DEBUG_ERROR, LOG_NOTICE, "Error message from %s (%s): %d: %s",
80 c->name, c->hostname, err, errorstring);
85 bool send_termreq(connection_t *c) {
86 return send_request(c, "%d", TERMREQ);
89 bool termreq_h(connection_t *c, const char *request) {
93 bool send_ping(connection_t *c) {
94 c->status.pinged = true;
95 c->last_ping_time = now.tv_sec;
97 return send_request(c, "%d", PING);
100 bool ping_h(connection_t *c, const char *request) {
104 bool send_pong(connection_t *c) {
105 return send_request(c, "%d", PONG);
108 bool pong_h(connection_t *c, const char *request) {
109 c->status.pinged = false;
111 /* Succesful connection, reset timeout if this is an outgoing connection. */
114 c->outgoing->timeout = 0;
115 c->outgoing->cfg = NULL;
117 freeaddrinfo(c->outgoing->ai);
118 c->outgoing->ai = NULL;
119 c->outgoing->aip = NULL;
125 /* Sending and receiving packets via TCP */
127 bool send_tcppacket(connection_t *c, const vpn_packet_t *packet) {
128 /* If there already is a lot of data in the outbuf buffer, discard this packet.
129 We use a very simple Random Early Drop algorithm. */
131 if(2.0 * c->outbuf.len / (float)maxoutbufsize - 1 > (float)rand()/(float)RAND_MAX)
134 if(!send_request(c, "%d %hd", PACKET, packet->len))
137 return send_meta(c, (char *)DATA(packet), packet->len);
140 bool tcppacket_h(connection_t *c, const char *request) {
143 if(sscanf(request, "%*d %hd", &len) != 1) {
144 logger(DEBUG_ALWAYS, LOG_ERR, "Got bad %s from %s (%s)", "PACKET", c->name,
149 /* Set reqlen to len, this will tell receive_meta() that a tcppacket is coming. */
156 bool send_sptps_tcppacket(connection_t *c, const char* packet, int len) {
157 /* If there already is a lot of data in the outbuf buffer, discard this packet.
158 We use a very simple Random Early Drop algorithm. */
160 if(2.0 * c->outbuf.len / (float)maxoutbufsize - 1 > (float)rand()/(float)RAND_MAX)
163 if(!send_request(c, "%d %hd", SPTPS_PACKET, len))
166 send_meta_raw(c, packet, len);
170 bool sptps_tcppacket_h(connection_t *c, const char* request) {
173 if(sscanf(request, "%*d %hd", &len) != 1) {
174 logger(DEBUG_ALWAYS, LOG_ERR, "Got bad %s from %s (%s)", "SPTPS_PACKET", c->name,
179 /* Set sptpslen to len, this will tell receive_meta() that a SPTPS packet is coming. */
186 /* Transmitting UDP information */
188 bool send_udp_info(node_t *from, node_t *to) {
189 /* If there's a static relay in the path, there's no point in sending the message
190 farther than the static relay. */
191 to = (to->via == myself) ? to->nexthop : to->via;
193 /* Skip cases where sending UDP info messages doesn't make sense.
194 This is done here in order to avoid repeating the same logic in multiple callsites. */
199 if(!to->status.reachable)
206 struct timeval elapsed;
207 timersub(&now, &to->udp_info_sent, &elapsed);
208 if(elapsed.tv_sec < udp_info_interval)
212 if((myself->options | from->options | to->options) & OPTION_TCPONLY)
215 if((to->nexthop->options >> 24) < 5)
218 char *from_address, *from_port;
219 /* If we're the originator, the address we use is irrelevant
220 because the first intermediate node will ignore it.
221 We use our local address as it somewhat makes sense
222 and it's simpler than introducing an encoding for "null" addresses anyway. */
223 sockaddr2str((from != myself) ? &from->address : &to->nexthop->connection->edge->local_address, &from_address, &from_port);
225 bool x = send_request(to->nexthop->connection, "%d %s %s %s %s", UDP_INFO, from->name, to->name, from_address, from_port);
231 to->udp_info_sent = now;
236 bool udp_info_h(connection_t *c, const char* request) {
237 char from_name[MAX_STRING_SIZE];
238 char to_name[MAX_STRING_SIZE];
239 char from_address[MAX_STRING_SIZE];
240 char from_port[MAX_STRING_SIZE];
242 if(sscanf(request, "%*d "MAX_STRING" "MAX_STRING" "MAX_STRING" "MAX_STRING, from_name, to_name, from_address, from_port) != 4) {
243 logger(DEBUG_ALWAYS, LOG_ERR, "Got bad %s from %s (%s)", "UDP_INFO", c->name, c->hostname);
247 if(!check_id(from_name) || !check_id(to_name)) {
248 logger(DEBUG_ALWAYS, LOG_ERR, "Got bad %s from %s (%s): %s", "UDP_INFO", c->name, c->hostname, "invalid name");
252 node_t *from = lookup_node(from_name);
254 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);
258 if(from != from->via) {
259 /* Not supposed to happen, as it means the message wandered past a static relay */
260 logger(DEBUG_PROTOCOL, LOG_WARNING, "Got UDP info message from %s (%s) which we can't reach directly", from->name, from->hostname);
264 /* If we have a direct edge to "from", we are in a better position
265 to guess its address than it is itself. */
266 if(!from->connection && !from->status.udp_confirmed) {
267 sockaddr_t from_addr = str2sockaddr(from_address, from_port);
268 if(sockaddrcmp(&from_addr, &from->address))
269 update_node_udp(from, &from_addr);
272 node_t *to = lookup_node(to_name);
274 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);
278 /* Send our own data (which could be what we just received) up the chain. */
280 return send_udp_info(from, to);
283 /* Transmitting MTU information */
285 bool send_mtu_info(node_t *from, node_t *to, int mtu) {
286 /* Skip cases where sending MTU info messages doesn't make sense.
287 This is done here in order to avoid repeating the same logic in multiple callsites. */
292 if(!to->status.reachable)
299 struct timeval elapsed;
300 timersub(&now, &to->mtu_info_sent, &elapsed);
301 if(elapsed.tv_sec < mtu_info_interval)
305 if((to->nexthop->options >> 24) < 6)
308 /* We will send the passed-in MTU value, unless we believe ours is better. */
310 node_t *via = (from->via == myself) ? from->nexthop : from->via;
311 if(from->minmtu == from->maxmtu && from->via == myself) {
312 /* We have a direct measurement. Override the value entirely.
313 Note that we only do that if we are sitting as a static relay in the path;
314 otherwise, we can't guarantee packets will flow through us, and increasing
315 MTU could therefore end up being too optimistic. */
317 } else if(via->minmtu == via->maxmtu) {
318 /* Static relay. Ensure packets will make it through the entire relay path. */
319 mtu = MIN(mtu, via->minmtu);
320 } else if(via->nexthop->minmtu == via->nexthop->maxmtu) {
321 /* Dynamic relay. Ensure packets will make it through the entire relay path. */
322 mtu = MIN(mtu, via->nexthop->minmtu);
326 to->mtu_info_sent = now;
328 /* If none of the conditions above match in the steady state, it means we're using TCP,
329 so the MTU is irrelevant. That said, it is still important to honor the MTU that was passed in,
330 because other parts of the relay path might be able to use UDP, which means they care about the MTU. */
332 return send_request(to->nexthop->connection, "%d %s %s %d", MTU_INFO, from->name, to->name, mtu);
335 bool mtu_info_h(connection_t *c, const char* request) {
336 char from_name[MAX_STRING_SIZE];
337 char to_name[MAX_STRING_SIZE];
340 if(sscanf(request, "%*d "MAX_STRING" "MAX_STRING" %d", from_name, to_name, &mtu) != 3) {
341 logger(DEBUG_ALWAYS, LOG_ERR, "Got bad %s from %s (%s)", "MTU_INFO", c->name, c->hostname);
346 logger(DEBUG_ALWAYS, LOG_ERR, "Got bad %s from %s (%s): %s", "MTU_INFO", c->name, c->hostname, "invalid MTU");
352 if(!check_id(from_name) || !check_id(to_name)) {
353 logger(DEBUG_ALWAYS, LOG_ERR, "Got bad %s from %s (%s): %s", "MTU_INFO", c->name, c->hostname, "invalid name");
357 node_t *from = lookup_node(from_name);
359 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);
363 /* If we don't know the current MTU for that node, use the one we received.
364 Even if we're about to make our own measurements, the value we got from downstream nodes should be pretty close
365 so it's a good idea to use it in the mean time. */
366 if(from->mtu != mtu && from->minmtu != from->maxmtu) {
367 logger(DEBUG_TRAFFIC, LOG_INFO, "Using provisional MTU %d for node %s (%s)", mtu, from->name, from->hostname);
371 node_t *to = lookup_node(to_name);
373 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);
377 /* Continue passing the MTU value (or a better one if we have it) up the chain. */
379 return send_mtu_info(from, to, mtu);