X-Git-Url: https://www.tinc-vpn.org/git/browse?a=blobdiff_plain;f=src%2Fprotocol_misc.c;h=050e30a0e3908f7bdaafeb8869689a49bf783b16;hb=ba0a3bcb2d565eec26aed30eef902d3482877cf9;hp=28571ef30082806599b20ab45595a1c5b845d395;hpb=4c85542894f7fca823b119b05e07179deb24229a;p=tinc

diff --git a/src/protocol_misc.c b/src/protocol_misc.c
index 28571ef3..050e30a0 100644
--- a/src/protocol_misc.c
+++ b/src/protocol_misc.c
@@ -1,7 +1,7 @@
 /*
     protocol_misc.c -- handle the meta-protocol, miscellaneous functions
     Copyright (C) 1999-2005 Ivo Timmermans,
-                  2000-2009 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
@@ -20,6 +20,7 @@
 
 #include "system.h"
 
+#include "address_cache.h"
 #include "conf.h"
 #include "connection.h"
 #include "logger.h"
@@ -28,122 +29,342 @@
 #include "netutl.h"
 #include "protocol.h"
 #include "utils.h"
+#include "xalloc.h"
+
+#ifndef MIN
+#define MIN(x, y) (((x)<(y))?(x):(y))
+#endif
 
 int maxoutbufsize = 0;
+int mtu_info_interval = 5;
+int udp_info_interval = 5;
+
+bool send_termreq(connection_t *c) {
+	return send_request(c, "%d", TERMREQ);
+}
 
-/* Status and error notification routines */
+bool termreq_h(connection_t *c, const char *request) {
+	(void)c;
+	(void)request;
+	return false;
+}
+
+bool send_ping(connection_t *c) {
+	c->status.pinged = true;
+	c->last_ping_time = now.tv_sec;
 
-bool send_status(connection_t *c, int statusno, const char *statusstring) {
-	if(!statusstring)
-		statusstring = "Status";
+	return send_request(c, "%d", PING);
+}
 
-	return send_request(c, "%d %d %s", STATUS, statusno, statusstring);
+bool ping_h(connection_t *c, const char *request) {
+	(void)request;
+	return send_pong(c);
 }
 
-bool status_h(connection_t *c) {
-	int statusno;
-	char statusstring[MAX_STRING_SIZE];
+bool send_pong(connection_t *c) {
+	return send_request(c, "%d", PONG);
+}
 
-	if(sscanf(c->buffer, "%*d %d " MAX_STRING, &statusno, statusstring) != 2) {
-		logger(LOG_ERR, "Got bad %s from %s (%s)", "STATUS",
-			   c->name, c->hostname);
-		return false;
-	}
+bool pong_h(connection_t *c, const char *request) {
+	(void)request;
+	c->status.pinged = false;
 
-	ifdebug(STATUS) logger(LOG_NOTICE, "Status message from %s (%s): %d: %s",
-			   c->name, c->hostname, statusno, statusstring);
+	/* Successful connection, reset timeout if this is an outgoing connection. */
+
+	if(c->outgoing && c->outgoing->timeout) {
+		c->outgoing->timeout = 0;
+		reset_address_cache(c->outgoing->node->address_cache, &c->address);
+	}
 
 	return true;
 }
 
-bool send_error(connection_t *c, int err, const char *errstring) {
-	if(!errstring)
-		errstring = "Error";
+/* Sending and receiving packets via TCP */
+
+bool send_tcppacket(connection_t *c, const vpn_packet_t *packet) {
+	/* If there already is a lot of data in the outbuf buffer, discard this packet.
+	   We use a very simple Random Early Drop algorithm. */
+
+	if(2.0 * c->outbuf.len / (float)maxoutbufsize - 1 > (float)rand() / (float)RAND_MAX) {
+		return true;
+	}
+
+	if(!send_request(c, "%d %d", PACKET, packet->len)) {
+		return false;
+	}
 
-	return send_request(c, "%d %d %s", ERROR, err, errstring);
+	return send_meta(c, (char *)DATA(packet), packet->len);
 }
 
-bool error_h(connection_t *c) {
-	int err;
-	char errorstring[MAX_STRING_SIZE];
+bool tcppacket_h(connection_t *c, const char *request) {
+	short int len;
 
-	if(sscanf(c->buffer, "%*d %d " MAX_STRING, &err, errorstring) != 2) {
-		logger(LOG_ERR, "Got bad %s from %s (%s)", "ERROR",
-			   c->name, c->hostname);
+	if(sscanf(request, "%*d %hd", &len) != 1) {
+		logger(DEBUG_ALWAYS, LOG_ERR, "Got bad %s from %s (%s)", "PACKET", c->name,
+		       c->hostname);
 		return false;
 	}
 
-	ifdebug(ERROR) logger(LOG_NOTICE, "Error message from %s (%s): %d: %s",
-			   c->name, c->hostname, err, errorstring);
+	/* Set reqlen to len, this will tell receive_meta() that a tcppacket is coming. */
 
-	terminate_connection(c, c->status.active);
+	c->tcplen = len;
 
 	return true;
 }
 
-bool send_termreq(connection_t *c) {
-	return send_request(c, "%d", TERMREQ);
-}
+bool send_sptps_tcppacket(connection_t *c, const char *packet, int len) {
+	/* If there already is a lot of data in the outbuf buffer, discard this packet.
+	   We use a very simple Random Early Drop algorithm. */
 
-bool termreq_h(connection_t *c) {
-	terminate_connection(c, c->status.active);
+	if(2.0 * c->outbuf.len / (float)maxoutbufsize - 1 > (float)rand() / (float)RAND_MAX) {
+		return true;
+	}
 
+	if(!send_request(c, "%d %d", SPTPS_PACKET, len)) {
+		return false;
+	}
+
+	send_meta_raw(c, packet, len);
 	return true;
 }
 
-bool send_ping(connection_t *c) {
-	c->status.pinged = true;
-	c->last_ping_time = now;
+bool sptps_tcppacket_h(connection_t *c, const char *request) {
+	short int len;
 
-	return send_request(c, "%d", PING);
-}
+	if(sscanf(request, "%*d %hd", &len) != 1) {
+		logger(DEBUG_ALWAYS, LOG_ERR, "Got bad %s from %s (%s)", "SPTPS_PACKET", c->name,
+		       c->hostname);
+		return false;
+	}
 
-bool ping_h(connection_t *c) {
-	return send_pong(c);
+	/* Set sptpslen to len, this will tell receive_meta() that a SPTPS packet is coming. */
+
+	c->sptpslen = len;
+
+	return true;
 }
 
-bool send_pong(connection_t *c) {
-	return send_request(c, "%d", PONG);
+/* 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;
+
+	if(to == NULL) {
+		logger(DEBUG_ALWAYS, LOG_ERR, "Something went wrong when selecting relay - possible fake UDP_INFO");
+		return false;
+	}
+
+	/* 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 pong_h(connection_t *c) {
-	c->status.pinged = false;
+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];
 
-	/* Succesful connection, reset timeout if this is an outgoing connection. */
+	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(c->outgoing)
-		c->outgoing->timeout = 0;
+	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;
+	}
 
-	return true;
+	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);
 }
 
-/* Sending and receiving packets via TCP */
+/* Transmitting MTU information */
 
-bool send_tcppacket(connection_t *c, vpn_packet_t *packet) {
-	/* If there already is a lot of data in the outbuf buffer, discard this packet.
-           We use a very simple Random Early Drop algorithm. */
+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(2.0 * c->outbuflen / (float)maxoutbufsize - 1 > (float)rand()/(float)RAND_MAX)
+	if(!to->status.reachable) {
 		return true;
+	}
 
-	if(!send_request(c, "%d %hd", PACKET, packet->len))
-		return false;
+	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;
+	}
 
-	return send_meta(c, (char *)packet->data, packet->len);
+	/* 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 tcppacket_h(connection_t *c) {
-	short int len;
+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(c->buffer, "%*d %hd", &len) != 1) {
-		logger(LOG_ERR, "Got bad %s from %s (%s)", "PACKET", c->name,
-			   c->hostname);
+	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;
 	}
 
-	/* Set reqlen to len, this will tell receive_meta() that a tcppacket is coming. */
+	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;
+	}
 
-	c->tcplen = len;
+	mtu = MIN(mtu, MTU);
 
-	return true;
+	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);
 }