/*
net.c -- most of the network code
- Copyright (C) 1998-2005 Ivo Timmermans,
- 2000-2012 Guus Sliepen <guus@tinc-vpn.org>
- 2006 Scott Lamb <slamb@slamb.org>
- 2011 Loïc Grenié <loic.grenie@gmail.com>
+ Copyright (C) 2014 Guus Sliepen <guus@meshlink.io>
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 "system.h"
#include "utils.h"
-#include "splay_tree.h"
#include "conf.h"
#include "connection.h"
-#include "device.h"
#include "graph.h"
#include "logger.h"
+#include "meshlink_internal.h"
#include "meta.h"
#include "net.h"
#include "netutl.h"
-#include "process.h"
#include "protocol.h"
-#include "subnet.h"
#include "xalloc.h"
-int contradicting_add_edge = 0;
-int contradicting_del_edge = 0;
-static int sleeptime = 10;
-
-/* Purge edges and subnets of unreachable nodes. Use carefully. */
-
-void purge(void) {
- splay_node_t *nnode, *nnext, *enode, *enext, *snode, *snext;
- node_t *n;
- edge_t *e;
- subnet_t *s;
-
- logger(DEBUG_PROTOCOL, LOG_DEBUG, "Purging unreachable nodes");
-
- /* Remove all edges and subnets owned by unreachable nodes. */
-
- for(nnode = node_tree->head; nnode; nnode = nnext) {
- nnext = nnode->next;
- n = nnode->data;
-
- if(!n->status.reachable) {
- logger(DEBUG_SCARY_THINGS, LOG_DEBUG, "Purging node %s (%s)", n->name, n->hostname);
-
- for(snode = n->subnet_tree->head; snode; snode = snext) {
- snext = snode->next;
- s = snode->data;
- send_del_subnet(everyone, s);
- if(!strictsubnets)
- subnet_del(n, s);
- }
-
- for(enode = n->edge_tree->head; enode; enode = enext) {
- enext = enode->next;
- e = enode->data;
- if(!tunnelserver)
- send_del_edge(everyone, e);
- edge_del(e);
- }
- }
- }
-
- /* Check if anyone else claims to have an edge to an unreachable node. If not, delete node. */
-
- for(nnode = node_tree->head; nnode; nnode = nnext) {
- nnext = nnode->next;
- n = nnode->data;
-
- if(!n->status.reachable) {
- for(enode = edge_weight_tree->head; enode; enode = enext) {
- enext = enode->next;
- e = enode->data;
-
- if(e->to == n)
- break;
- }
-
- if(!enode && (!strictsubnets || !n->subnet_tree->head))
- /* in strictsubnets mode do not delete nodes with subnets */
- node_del(n);
- }
- }
+static const int min(int a, int b) {
+ return a < b ? a : b;
}
/*
Terminate a connection:
- - Close the socket
- - Remove associated edge and tell other connections about it if report = true
+ - Mark it as inactive
+ - Remove the edge representing this connection
+ - Kill it with fire
- Check if we need to retry making an outgoing connection
- - Deactivate the host
*/
-void terminate_connection(connection_t *c, bool report) {
- logger(DEBUG_CONNECTIONS, LOG_NOTICE, "Closing connection with %s (%s)",
- c->name, c->hostname);
+void terminate_connection(meshlink_handle_t *mesh, connection_t *c, bool report) {
+ logger(mesh, MESHLINK_INFO, "Closing connection with %s (%s)", c->name, c->hostname);
c->status.active = false;
c->node->connection = NULL;
if(c->edge) {
- if(report && !tunnelserver)
- send_del_edge(everyone, c->edge);
+ if(report)
+ send_del_edge(mesh, mesh->everyone, c->edge);
- edge_del(c->edge);
+ edge_del(mesh, c->edge);
c->edge = NULL;
/* Run MST and SSSP algorithms */
- graph();
+ graph(mesh);
/* If the node is not reachable anymore but we remember it had an edge to us, clean it up */
if(report && !c->node->status.reachable) {
edge_t *e;
- e = lookup_edge(c->node, myself);
+ e = lookup_edge(c->node, mesh->self);
if(e) {
- if(!tunnelserver)
- send_del_edge(everyone, e);
- edge_del(e);
+ send_del_edge(mesh, mesh->everyone, e);
+ edge_del(mesh, e);
}
}
}
- free_connection_partially(c);
+ outgoing_t *outgoing = c->outgoing;
+ connection_del(mesh, c);
/* Check if this was our outgoing connection */
- if(c->outgoing) {
- do_outgoing_connection(c);
- } else {
- connection_del(c);
- }
+ if(outgoing)
+ do_outgoing_connection(mesh, outgoing);
+
+#ifndef HAVE_MINGW
+ /* Clean up dead proxy processes */
+
+ while(waitpid(-1, NULL, WNOHANG) > 0);
+#endif
}
/*
end does not reply in time, we consider them dead
and close the connection.
*/
-static void timeout_handler(int fd, short events, void *event) {
- splay_node_t *node, *next;
- connection_t *c;
- time_t now = time(NULL);
-
- for(node = connection_tree->head; node; node = next) {
- next = node->next;
- c = node->data;
+static void timeout_handler(event_loop_t *loop, void *data) {
+ meshlink_handle_t *mesh = loop->data;
- if(c->status.control)
- continue;
-
- if(c->last_ping_time + pingtimeout <= now) {
+ for list_each(connection_t, c, mesh->connections) {
+ if(c->last_ping_time + mesh->pingtimeout <= mesh->loop.now.tv_sec) {
if(c->status.active) {
if(c->status.pinged) {
- logger(DEBUG_CONNECTIONS, LOG_INFO, "%s (%s) didn't respond to PING in %ld seconds",
- c->name, c->hostname, (long)now - c->last_ping_time);
- terminate_connection(c, true);
+ logger(mesh, MESHLINK_INFO, "%s (%s) didn't respond to PING in %ld seconds", c->name, c->hostname, (long)mesh->loop.now.tv_sec - c->last_ping_time);
+ } else if(c->last_ping_time + mesh->pinginterval <= mesh->loop.now.tv_sec) {
+ send_ping(mesh, c);
continue;
- } else if(c->last_ping_time + pinginterval <= now) {
- send_ping(c);
- }
- } else {
- if(c->status.connecting) {
- logger(DEBUG_CONNECTIONS, LOG_WARNING, "Timeout while connecting to %s (%s)", c->name, c->hostname);
- c->status.connecting = false;
- closesocket(c->socket);
- do_outgoing_connection(c);
} else {
- logger(DEBUG_CONNECTIONS, LOG_WARNING, "Timeout from %s (%s) during authentication", c->name, c->hostname);
- terminate_connection(c, false);
continue;
}
+ } else {
+ if(c->status.connecting)
+ logger(mesh, MESHLINK_WARNING, "Timeout while connecting to %s (%s)", c->name, c->hostname);
+ else
+ logger(mesh, MESHLINK_WARNING, "Timeout from %s (%s) during authentication", c->name, c->hostname);
}
+ terminate_connection(mesh, c, c->status.active);
}
}
- if(contradicting_del_edge > 100 && contradicting_add_edge > 100) {
- logger(DEBUG_ALWAYS, LOG_WARNING, "Possible node with same Name as us! Sleeping %d seconds.", sleeptime);
- usleep(sleeptime * 1000000LL);
- sleeptime *= 2;
- if(sleeptime < 0)
- sleeptime = 3600;
- } else {
- sleeptime /= 2;
- if(sleeptime < 10)
- sleeptime = 10;
- }
-
- contradicting_add_edge = 0;
- contradicting_del_edge = 0;
-
- event_add(event, &(struct timeval){pingtimeout, 0});
+ timeout_set(&mesh->loop, data, &(struct timeval){mesh->pingtimeout, rand() % 100000});
}
-void handle_meta_connection_data(int fd, short events, void *data) {
- connection_t *c = data;
- int result;
- socklen_t len = sizeof result;
-
- if(c->status.connecting) {
- c->status.connecting = false;
-
- getsockopt(c->socket, SOL_SOCKET, SO_ERROR, &result, &len);
-
- if(!result)
- finish_connecting(c);
- else {
- logger(DEBUG_CONNECTIONS, LOG_DEBUG,
- "Error while connecting to %s (%s): %s",
- c->name, c->hostname, sockstrerror(result));
- closesocket(c->socket);
- do_outgoing_connection(c);
- return;
+/// Utility function to establish connections based on condition check
+/** The function iterates over all nodes, but skips those that do
+ * not pass the condition check.
+ *
+ * The condition check function is passed
+ * a pointer to a random number r between 0 and rand_modulo, a pointer to the
+ * current node index i, and the node pointer n. This function should return true
+ * if a connection attempt to the node should be made.
+ *
+ * @param mesh A pointer to the mesh structure
+ * @param rand_modulo Random index is selected between 0 and rand_modulo
+ * @cond_check A function pointer. This function should return true
+ * if a connection attempt to the node should be made
+ */
+static void cond_add_connection(meshlink_handle_t *mesh, int rand_modulo, bool (*cond_check)(int*, int*, node_t*)) {
+ int r = rand() % rand_modulo;
+ int i = 0;
+
+ for splay_each(node_t, n, mesh->nodes) {
+ /* skip nodes that do not pass condition check */
+ if(!(*cond_check)(&i, &r, n))
+ continue;
+
+ /* check if there is already a connection attempt to this node */
+ bool found = false;
+ for list_each(outgoing_t, outgoing, mesh->outgoings) {
+ if(!strcmp(outgoing->name, n->name)) {
+ found = true;
+ break;
+ }
}
- }
- if (!receive_meta(c)) {
- terminate_connection(c, c->status.active);
- return;
+ if(!found) {
+ //TODO: if the node is blacklisted the connection will not happen, but
+ //the user will read this debug message "Autoconnecting to %s" that is misleading
+ logger(mesh, MESHLINK_INFO, "Autoconnecting to %s", n->name);
+ outgoing_t *outgoing = xzalloc(sizeof *outgoing);
+ outgoing->mesh = mesh;
+ outgoing->name = xstrdup(n->name);
+ list_insert_tail(mesh->outgoings, outgoing);
+ setup_outgoing_connection(mesh, outgoing);
+ }
+ break;
}
}
-static void sigterm_handler(int signal, short events, void *data) {
- logger(DEBUG_ALWAYS, LOG_NOTICE, "Got %s signal", strsignal(signal));
- event_loopexit(NULL);
-}
+static bool found_random_node(int *i, int *r, node_t *n) {
+ if((*i)++ != *r)
+ return false;
-static void sighup_handler(int signal, short events, void *data) {
- logger(DEBUG_ALWAYS, LOG_NOTICE, "Got %s signal", strsignal(signal));
- reopenlogger();
- reload_configuration();
+ if(n->connection)
+ return false;
+
+ return true;
}
-static void sigalrm_handler(int signal, short events, void *data) {
- logger(DEBUG_ALWAYS, LOG_NOTICE, "Got %s signal", strsignal(signal));
- retry();
-}
+static bool found_random_unreachable_node(int *i, int *r, node_t *n) {
+ if(n->status.reachable)
+ return false;
+
+ if((*i)++ != *r)
+ return false;
+
+ if(n->connection)
+ return false;
-int reload_configuration(void) {
- connection_t *c;
- splay_node_t *node, *next;
- char *fname;
- struct stat s;
- static time_t last_config_check = 0;
+ return true;
+}
- /* Reread our own configuration file */
+static void periodic_handler(event_loop_t *loop, void *data) {
+ meshlink_handle_t *mesh = loop->data;
- exit_configuration(&config_tree);
- init_configuration(&config_tree);
+ /* Check if there are too many contradicting ADD_EDGE and DEL_EDGE messages.
+ This usually only happens when another node has the same Name as this node.
+ If so, sleep for a short while to prevent a storm of contradicting messages.
+ */
- if(!read_server_config()) {
- logger(DEBUG_ALWAYS, LOG_ERR, "Unable to reread configuration file, exitting.");
- event_loopexit(NULL);
- return EINVAL;
+ if(mesh->contradicting_del_edge > 100 && mesh->contradicting_add_edge > 100) {
+ logger(mesh, MESHLINK_WARNING, "Possible node with same Name as us! Sleeping %d seconds.", mesh->sleeptime);
+ usleep(mesh->sleeptime * 1000000LL);
+ mesh->sleeptime *= 2;
+ if(mesh->sleeptime < 0)
+ mesh->sleeptime = 3600;
+ } else {
+ mesh->sleeptime /= 2;
+ if(mesh->sleeptime < 10)
+ mesh->sleeptime = 10;
}
- /* Close connections to hosts that have a changed or deleted host config file */
-
- for(node = connection_tree->head; node; node = next) {
- c = node->data;
- next = node->next;
+ mesh->contradicting_add_edge = 0;
+ mesh->contradicting_del_edge = 0;
- if(c->status.control)
- continue;
-
- if(c->outgoing) {
- free(c->outgoing->name);
- if(c->outgoing->ai)
- freeaddrinfo(c->outgoing->ai);
- free(c->outgoing);
- c->outgoing = NULL;
+ int timeout = 5;
+
+ /* If AutoConnect is set, check if we need to make or break connections. */
+
+ if(autoconnect && mesh->nodes->count > 1) {
+ /* Count number of active connections */
+ int nc = 0;
+ for list_each(connection_t, c, mesh->connections) {
+ if(c->status.active)
+ nc++;
}
-
- xasprintf(&fname, "%s/hosts/%s", confbase, c->name);
- if(stat(fname, &s) || s.st_mtime > last_config_check)
- terminate_connection(c, c->status.active);
- free(fname);
- }
- last_config_check = time(NULL);
+ /* Count number of unreachable nodes */
+ int num_unreachable = 0;
+ for splay_each(node_t, n, mesh->nodes) {
+ if(!n->status.reachable)
+ num_unreachable++;
+ }
- /* If StrictSubnet is set, expire deleted Subnets and read new ones in */
+ if(nc < autoconnect) {
+ /* 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.
+ */
+ cond_add_connection(mesh, mesh->nodes->count, &found_random_node);
+ } else if(num_unreachable > 0) {
+ /* Min number of connections established. Now try
+ to connect to some unreachable nodes to attempt
+ to heal possible partitions.
+ */
+ cond_add_connection(mesh, num_unreachable, &found_random_unreachable_node);
+ }
+
+ if(nc > autoconnect) {
+ /* 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, mesh->connections) {
+ if(!c->status.active)
+ continue;
- if(strictsubnets) {
- subnet_t *subnet;
+ if(i++ != r)
+ continue;
+ if(!c->outgoing || !c->node || c->node->edge_tree->count < 2)
+ break;
- for(node = subnet_tree->head; node; node = node->next) {
- subnet = node->data;
- subnet->expires = 1;
+ logger(mesh, MESHLINK_INFO, "Autodisconnecting from %s", c->name);
+ list_delete(mesh->outgoings, c->outgoing);
+ c->outgoing = NULL;
+ terminate_connection(mesh, c, c->status.active);
+ break;
+ }
}
- load_all_subnets();
-
- for(node = subnet_tree->head; node; node = next) {
- next = node->next;
- subnet = node->data;
- if(subnet->expires == 1) {
- send_del_subnet(everyone, subnet);
- if(subnet->owner->status.reachable)
- subnet_update(subnet->owner, subnet, false);
- subnet_del(subnet->owner, subnet);
- } else if(subnet->expires == -1) {
- subnet->expires = 0;
- } else {
- send_add_subnet(everyone, subnet);
- if(subnet->owner->status.reachable)
- subnet_update(subnet->owner, subnet, true);
+ if(nc >= autoconnect) {
+ /* If we have enough active connections,
+ remove any pending outgoing connections.
+ Do not remove pending connections to unreachable
+ nodes.
+ */
+ node_t *o_node = NULL;
+ for list_each(outgoing_t, o, mesh->outgoings) {
+ o_node = lookup_node(mesh, o->name);
+ /* o_node is NULL if it is not part of the graph yet */
+ if(!o_node || !o_node->status.reachable)
+ continue;
+
+ bool found = false;
+ for list_each(connection_t, c, mesh->connections) {
+ if(c->outgoing == o) {
+ found = true;
+ break;
+ }
+ }
+ if(!found) {
+ logger(mesh, MESHLINK_INFO, "Cancelled outgoing connection to %s", o->name);
+ /* The node variable is leaked in from using the list_each macro.
+ The o variable could be used, but using node directly
+ is more efficient.
+ */
+ list_delete_node(mesh->outgoings, node);
+ }
}
}
+
+ if (nc + mesh->outgoings->count < min(autoconnect, mesh->nodes->count - 1))
+ timeout = 0;
}
- /* Try to make outgoing connections */
-
- try_outgoing_connections();
+ timeout_set(&mesh->loop, data, &(struct timeval){timeout, rand() % 100000});
+}
- return 0;
+void handle_meta_connection_data(meshlink_handle_t *mesh, connection_t *c) {
+ if (!receive_meta(mesh, c)) {
+ terminate_connection(mesh, c, c->status.active);
+ return;
+ }
}
-void retry(void) {
- connection_t *c;
- splay_node_t *node;
+void retry(meshlink_handle_t *mesh) {
+ /* Reset the reconnection timers for all outgoing connections */
+ for list_each(outgoing_t, outgoing, mesh->outgoings) {
+ outgoing->timeout = 0;
+ if(outgoing->ev.cb)
+ timeout_set(&mesh->loop, &outgoing->ev, &(struct timeval){0, 0});
+ }
- for(node = connection_tree->head; node; node = node->next) {
- c = node->data;
-
- if(c->outgoing && !c->node) {
- if(timeout_initialized(&c->outgoing->ev))
- event_del(&c->outgoing->ev);
- if(c->status.connecting)
- close(c->socket);
- c->outgoing->timeout = 0;
- do_outgoing_connection(c);
- }
+ /* Check for outgoing connections that are in progress, and reset their ping timers */
+ for list_each(connection_t, c, mesh->connections) {
+ if(c->outgoing && !c->node)
+ c->last_ping_time = 0;
}
+
+ /* Kick the ping timeout handler */
+ timeout_set(&mesh->loop, &mesh->pingtimer, &(struct timeval){0, 0});
}
/*
this is where it all happens...
*/
-int main_loop(void) {
- struct event timeout_event;
-
- timeout_set(&timeout_event, timeout_handler, &timeout_event);
- event_add(&timeout_event, &(struct timeval){pingtimeout, 0});
+int main_loop(meshlink_handle_t *mesh) {
+ timeout_add(&mesh->loop, &mesh->pingtimer, timeout_handler, &mesh->pingtimer, &(struct timeval){mesh->pingtimeout, rand() % 100000});
+ timeout_add(&mesh->loop, &mesh->periodictimer, periodic_handler, &mesh->periodictimer, &(struct timeval){0, 0});
-#ifndef HAVE_MINGW
- struct event sighup_event;
- struct event sigterm_event;
- struct event sigquit_event;
- struct event sigalrm_event;
-
- signal_set(&sighup_event, SIGHUP, sighup_handler, NULL);
- signal_add(&sighup_event, NULL);
- signal_set(&sigterm_event, SIGTERM, sigterm_handler, NULL);
- signal_add(&sigterm_event, NULL);
- signal_set(&sigquit_event, SIGQUIT, sigterm_handler, NULL);
- signal_add(&sigquit_event, NULL);
- signal_set(&sigalrm_event, SIGALRM, sigalrm_handler, NULL);
- signal_add(&sigalrm_event, NULL);
-#endif
+ //Add signal handler
+ mesh->datafromapp.signum = 0;
+ signal_add(&(mesh->loop),&(mesh->datafromapp), (signal_cb_t)meshlink_send_from_queue,mesh, mesh->datafromapp.signum);
- if(event_loop(0) < 0) {
- logger(DEBUG_ALWAYS, LOG_ERR, "Error while waiting for input: %s", strerror(errno));
+ if(!event_loop_run(&mesh->loop)) {
+ logger(mesh, MESHLINK_ERROR, "Error while waiting for input: %s", strerror(errno));
return 1;
}
-#ifndef HAVE_MINGW
- signal_del(&sighup_event);
- signal_del(&sigterm_event);
- signal_del(&sigquit_event);
- signal_del(&sigalrm_event);
-#endif
-
- event_del(&timeout_event);
+ timeout_del(&mesh->loop, &mesh->periodictimer);
+ timeout_del(&mesh->loop, &mesh->pingtimer);
return 0;
}
projects / meshlink / blobdiff