--- /dev/null
+/*
+ autoconnect.c -- automatic connection establishment
+ Copyright (C) 2017 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
+ the Free Software Foundation; either version 2 of the License, or
+ (at your option) any later version.
+
+ This program is distributed in the hope that it will be useful,
+ but WITHOUT ANY WARRANTY; without even the implied warranty of
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ GNU General Public License for more details.
+
+ You should have received a copy of the GNU General Public License along
+ with this program; if not, write to the Free Software Foundation, Inc.,
+ 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+*/
+
+#include "system.h"
+
+#include "connection.h"
+#include "logger.h"
+#include "node.h"
+#include "xalloc.h"
+
+static void make_new_connection() {
+ /* Select a random node we haven't connected to yet. */
+ int count = 0;
+ for splay_each(node_t, n, node_tree) {
+ if(n == myself || n->connection || !(n->status.has_address || n->status.reachable))
+ continue;
+ count++;
+ }
+
+ if(!count)
+ return;
+
+ int r = rand() % count;
+
+ for splay_each(node_t, n, node_tree) {
+ if(n == myself || n->connection || !(n->status.has_address || n->status.reachable))
+ continue;
+
+ if(r--)
+ continue;
+
+ bool found = false;
+
+ for list_each(outgoing_t, outgoing, outgoing_list) {
+ if(!strcmp(outgoing->name, n->name)) {
+ found = true;
+ break;
+ }
+ }
+
+ if(!found) {
+ logger(DEBUG_CONNECTIONS, LOG_INFO, "Autoconnecting to %s", n->name);
+ outgoing_t *outgoing = xzalloc(sizeof *outgoing);
+ outgoing->name = xstrdup(n->name);
+ list_insert_tail(outgoing_list, outgoing);
+ setup_outgoing_connection(outgoing);
+ }
+
+ break;
+ }
+}
+
+static void connect_to_unreachable() {
+ /* Select a random known node. The rationale is that if there are many
+ * reachable nodes, and only a few unreachable nodes, we don't want all
+ * reachable nodes to try to connect to the unreachable ones at the
+ * same time. This way, we back off automatically. Conversely, if there
+ * are only a few reachable nodes, and many unreachable ones, we're
+ * going to try harder to connect to them. */
+
+ int r = rand() % node_tree->count;
+
+ for splay_each(node_t, n, node_tree) {
+ if(r--)
+ continue;
+
+ /* Is it unreachable and do we know an address for it? If not, return. */
+ if(n == myself || n->connection || n->status.reachable || !n->status.has_address)
+ return;
+
+ /* Are we already trying to make an outgoing connection to it? If not, return. */
+ for list_each(outgoing_t, outgoing, outgoing_list)
+ if(!strcmp(outgoing->name, n->name))
+ return;
+
+ logger(DEBUG_CONNECTIONS, LOG_INFO, "Autoconnecting to %s", n->name);
+ outgoing_t *outgoing = xzalloc(sizeof *outgoing);
+ outgoing->name = xstrdup(n->name);
+ list_insert_tail(outgoing_list, outgoing);
+ setup_outgoing_connection(outgoing);
+
+ return;
+ }
+}
+
+static void drop_superfluous_outgoing_connection() {
+ /* Choose a random outgoing connection to a node that has at least one other connection. */
+ int count = 0;
+ for list_each(connection_t, c, connection_list) {
+ if(!c->edge || !c->outgoing || !c->node || c->node->edge_tree->count < 2)
+ continue;
+ count++;
+ }
+
+ if(!count)
+ return;
+
+ int r = rand() % count;
+
+ for list_each(connection_t, c, connection_list) {
+ if(!c->edge || !c->outgoing || !c->node || c->node->edge_tree->count < 2)
+ continue;
+
+ if(r--)
+ continue;
+
+ logger(DEBUG_CONNECTIONS, LOG_INFO, "Autodisconnecting from %s", c->name);
+ list_delete(outgoing_list, c->outgoing);
+ c->outgoing = NULL;
+ terminate_connection(c, c->edge);
+ break;
+ }
+}
+
+static void drop_superfluous_pending_connections() {
+ for list_each(outgoing_t, o, outgoing_list) {
+ /* Only look for connections that are waiting to be retried later. */
+ bool found = false;
+ for list_each(connection_t, c, connection_list) {
+ if(c->outgoing == o) {
+ found = true;
+ break;
+ }
+ }
+
+ if(found)
+ continue;
+
+ logger(DEBUG_CONNECTIONS, LOG_INFO, "Cancelled outgoing connection to %s", o->name);
+ list_delete_node(outgoing_list, node);
+ }
+}
+
+void do_autoconnect() {
+ /* Count number of active connections. */
+ int nc = 0;
+ for list_each(connection_t, c, connection_list) {
+ if(c->edge)
+ nc++;
+ }
+
+ /* Less than 3 connections? Eagerly try to make a new one. */
+ if(nc < 3) {
+ make_new_connection();
+ return;
+ }
+
+ /* More than 3 connections? See if we can get rid of a superfluous one. */
+ if(nc > 3)
+ drop_superfluous_outgoing_connection();
+
+
+ /* Check if there are unreachable nodes that we should try to connect to. */
+ connect_to_unreachable();
+
+ /* Drop pending outgoing connections from the outgoing list. */
+ drop_superfluous_pending_connections();
+}
--- /dev/null
+/*
+ autoconnect.h -- header for autoconnect.c
+ Copyright (C) 2017 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
+ the Free Software Foundation; either version 2 of the License, or
+ (at your option) any later version.
+
+ This program is distributed in the hope that it will be useful,
+ but WITHOUT ANY WARRANTY; without even the implied warranty of
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ GNU General Public License for more details.
+
+ You should have received a copy of the GNU General Public License along
+ with this program; if not, write to the Free Software Foundation, Inc.,
+ 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+*/
+
+#ifndef __TINC_AUTOCONNECT_H__
+#define __TINC_AUTOCONNECT_H__
+
+extern void do_autoconnect(void);
+
+#endif
#include "system.h"
-#include "utils.h"
+#include "autoconnect.h"
#include "conf.h"
#include "connection.h"
#include "device.h"
#include "netutl.h"
#include "protocol.h"
#include "subnet.h"
+#include "utils.h"
#include "xalloc.h"
int contradicting_add_edge = 0;
/* If AutoConnect is set, check if we need to make or break connections. */
- if(autoconnect && node_tree->count > 1) {
- /* Count number of active connections */
- int nc = 0;
- for list_each(connection_t, c, connection_list) {
- if(c->edge)
- nc++;
- }
-
- if(nc < 3) {
- /* Not enough active connections, try to add one.
- Choose a random node, if we don't have a connection to it,
- and we are not already trying to make one, create an
- outgoing connection to this node.
- */
- int count = 0;
- for splay_each(node_t, n, node_tree) {
- if(n == myself || n->connection || !(n->status.has_address || n->status.reachable))
- continue;
- count++;
- }
-
- if(!count)
- goto end;
-
- int r = rand() % count;
-
- for splay_each(node_t, n, node_tree) {
- if(n == myself || n->connection || !(n->status.has_address || n->status.reachable))
- continue;
-
- if(r--)
- continue;
-
- bool found = false;
-
- for list_each(outgoing_t, outgoing, outgoing_list) {
- if(!strcmp(outgoing->name, n->name)) {
- found = true;
- break;
- }
- }
-
- if(!found) {
- logger(DEBUG_CONNECTIONS, LOG_INFO, "Autoconnecting to %s", n->name);
- outgoing_t *outgoing = xzalloc(sizeof *outgoing);
- outgoing->name = xstrdup(n->name);
- list_insert_tail(outgoing_list, outgoing);
- setup_outgoing_connection(outgoing);
- }
-
- break;
- }
- } else if(nc > 3) {
- /* Too many active connections, try to remove one.
- Choose a random outgoing connection to a node
- that has at least one other connection.
- */
- int r = rand() % nc;
- int i = 0;
-
- for list_each(connection_t, c, connection_list) {
- if(!c->edge)
- continue;
-
- if(i++ != r)
- continue;
-
- if(!c->outgoing || !c->node || c->node->edge_tree->count < 2)
- break;
-
- logger(DEBUG_CONNECTIONS, LOG_INFO, "Autodisconnecting from %s", c->name);
- list_delete(outgoing_list, c->outgoing);
- c->outgoing = NULL;
- terminate_connection(c, c->edge);
- break;
- }
- }
-
- if(nc >= 3) {
- /* If we have enough active connections,
- remove any pending outgoing connections.
- */
- for list_each(outgoing_t, o, outgoing_list) {
- bool found = false;
- for list_each(connection_t, c, connection_list) {
- if(c->outgoing == o) {
- found = true;
- break;
- }
- }
- if(!found) {
- logger(DEBUG_CONNECTIONS, LOG_INFO, "Cancelled outgoing connection to %s", o->name);
- list_delete_node(outgoing_list, node);
- }
- }
- }
- }
+ if(autoconnect && node_tree->count > 1)
+ do_autoconnect();
-end:
timeout_set(data, &(struct timeval){5, rand() % 100000});
}
projects / tinc / commitdiff