/*
net.c -- most of the network code
- Copyright (C) 1998-2005 Ivo Timmermans,
- 2000-2006 Guus Sliepen <guus@tinc-vpn.org>
+ 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
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., 675 Mass Ave, Cambridge, MA 02139, USA.
-
- $Id$
+ 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 <openssl/rand.h>
-
#include "utils.h"
-#include "avl_tree.h"
#include "conf.h"
#include "connection.h"
-#include "device.h"
-#include "event.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 "route.h"
-#include "subnet.h"
#include "xalloc.h"
-bool do_purge = false;
-volatile bool running = false;
-
-time_t now = 0;
-
-/* Purge edges and subnets of unreachable nodes. Use carefully. */
-
-static void purge(void)
-{
- avl_node_t *nnode, *nnext, *enode, *enext, *snode, *snext;
- node_t *n;
- edge_t *e;
- subnet_t *s;
-
- cp();
-
- ifdebug(PROTOCOL) logger(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) {
- ifdebug(SCARY_THINGS) logger(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;
- if(!tunnelserver)
- send_del_subnet(broadcast, s);
- subnet_del(n, s);
- }
-
- for(enode = n->edge_tree->head; enode; enode = enext) {
- enext = enode->next;
- e = enode->data;
- if(!tunnelserver)
- send_del_edge(broadcast, 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)
- node_del(n);
- }
- }
-}
-
-/*
- put all file descriptors in an fd_set array
- While we're at it, purge stuff that needs to be removed.
-*/
-static int build_fdset(fd_set *readset, fd_set *writeset)
-{
- avl_node_t *node, *next;
- connection_t *c;
- int i, max = 0;
-
- cp();
-
- FD_ZERO(readset);
- FD_ZERO(writeset);
-
- for(node = connection_tree->head; node; node = next) {
- next = node->next;
- c = node->data;
-
- if(c->status.remove) {
- connection_del(c);
- if(!connection_tree->head)
- purge();
- } else {
- FD_SET(c->socket, readset);
- if(c->outbuflen > 0)
- FD_SET(c->socket, writeset);
- if(c->socket > max)
- max = c->socket;
- }
- }
-
- for(i = 0; i < listen_sockets; i++) {
- FD_SET(listen_socket[i].tcp, readset);
- if(listen_socket[i].tcp > max)
- max = listen_socket[i].tcp;
- FD_SET(listen_socket[i].udp, readset);
- if(listen_socket[i].udp > max)
- max = listen_socket[i].udp;
- }
-
- FD_SET(device_fd, readset);
- if(device_fd > max)
- max = device_fd;
-
- return max;
-}
-
/*
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)
-{
- cp();
-
- if(c->status.remove)
- return;
-
- ifdebug(CONNECTIONS) logger(LOG_NOTICE, _("Closing connection with %s (%s)"),
- c->name, c->hostname);
+void terminate_connection(meshlink_handle_t *mesh, connection_t *c, bool report) {
+ logger(DEBUG_CONNECTIONS, LOG_NOTICE, "Closing connection with %s (%s)", c->name, c->hostname);
- c->status.remove = true;
c->status.active = false;
- if(c->node)
+ if(c->node && c->node->connection == c)
c->node->connection = NULL;
- if(c->socket)
- closesocket(c->socket);
-
if(c->edge) {
- if(report && !tunnelserver)
- send_del_edge(broadcast, 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(broadcast, e);
- edge_del(e);
+ send_del_edge(mesh, mesh->everyone, e);
+ edge_del(mesh, e);
}
}
}
+ outgoing_t *outgoing = c->outgoing;
+ connection_del(mesh, c);
+
/* Check if this was our outgoing connection */
- if(c->outgoing) {
- retry_outgoing(c->outgoing);
- c->outgoing = NULL;
- }
+ if(outgoing)
+ do_outgoing_connection(mesh, outgoing);
- free(c->outbuf);
- c->outbuf = NULL;
- c->outbuflen = 0;
- c->outbufsize = 0;
- c->outbufstart = 0;
+#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 check_dead_connections(void)
-{
- avl_node_t *node, *next;
- connection_t *c;
-
- cp();
+static void timeout_handler(event_loop_t *loop, void *data) {
+ meshlink_handle_t *mesh = loop->data;
- for(node = connection_tree->head; node; node = next) {
- next = node->next;
- c = node->data;
-
- 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) {
- ifdebug(CONNECTIONS) logger(LOG_INFO, _("%s (%s) didn't respond to PING in %d seconds"),
- c->name, c->hostname, now - c->last_ping_time);
- c->status.timeout = true;
- terminate_connection(c, true);
- } else if(c->last_ping_time + pinginterval < now) {
- send_ping(c);
- }
- } else {
- if(c->status.remove) {
- logger(LOG_WARNING, _("Old connection_t for %s (%s) status %04x still lingering, deleting..."),
- c->name, c->hostname, c->status.value);
- connection_del(c);
+ logger(DEBUG_CONNECTIONS, LOG_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;
- }
- ifdebug(CONNECTIONS) logger(LOG_WARNING, _("Timeout from %s (%s) during authentication"),
- c->name, c->hostname);
- if(c->status.connecting) {
- c->status.connecting = false;
- closesocket(c->socket);
- do_outgoing_connection(c);
} else {
- terminate_connection(c, false);
- }
- }
- }
-
- if(c->outbuflen > 0 && c->last_flushed_time + pingtimeout < now) {
- if(c->status.active) {
- ifdebug(CONNECTIONS) logger(LOG_INFO,
- _("%s (%s) could not flush for %d seconds (%d bytes remaining)"),
- c->name, c->hostname, now - c->last_flushed_time, c->outbuflen);
- c->status.timeout = true;
- terminate_connection(c, true);
- }
- }
- }
-}
-
-/*
- check all connections to see if anything
- happened on their sockets
-*/
-static void check_network_activity(fd_set * readset, fd_set * writeset)
-{
- connection_t *c;
- avl_node_t *node;
- int result, i;
- socklen_t len = sizeof(result);
- vpn_packet_t packet;
-
- cp();
-
- /* check input from kernel */
- if(FD_ISSET(device_fd, readset)) {
- if(read_packet(&packet))
- route(myself, &packet);
- }
-
- /* check meta connections */
- for(node = connection_tree->head; node; node = node->next) {
- c = node->data;
-
- if(c->status.remove)
- continue;
-
- if(FD_ISSET(c->socket, readset)) {
- if(c->status.connecting) {
- c->status.connecting = false;
- getsockopt(c->socket, SOL_SOCKET, SO_ERROR, &result, &len);
-
- if(!result)
- finish_connecting(c);
- else {
- ifdebug(CONNECTIONS) logger(LOG_DEBUG,
- _("Error while connecting to %s (%s): %s"),
- c->name, c->hostname, strerror(result));
- closesocket(c->socket);
- do_outgoing_connection(c);
continue;
}
+ } else {
+ if(c->status.connecting)
+ logger(DEBUG_CONNECTIONS, LOG_WARNING, "Timeout while connecting to %s (%s)", c->name, c->hostname);
+ else
+ logger(DEBUG_CONNECTIONS, LOG_WARNING, "Timeout from %s (%s) during authentication", c->name, c->hostname);
}
-
- if(!receive_meta(c)) {
- terminate_connection(c, c->status.active);
- continue;
- }
- }
-
- if(FD_ISSET(c->socket, writeset)) {
- if(!flush_meta(c)) {
- terminate_connection(c, c->status.active);
- continue;
- }
+ terminate_connection(mesh, c, c->status.active);
}
}
- for(i = 0; i < listen_sockets; i++) {
- if(FD_ISSET(listen_socket[i].udp, readset))
- handle_incoming_vpn_data(listen_socket[i].udp);
-
- if(FD_ISSET(listen_socket[i].tcp, readset))
- handle_new_meta_connection(listen_socket[i].tcp);
- }
+ timeout_set(&mesh->loop, data, &(struct timeval){mesh->pingtimeout, rand() % 100000});
}
-/*
- this is where it all happens...
-*/
-int main_loop(void)
-{
- fd_set readset, writeset;
- struct timeval tv;
- int r, maxfd;
- time_t last_ping_check, last_config_check;
- event_t *event;
+static void periodic_handler(event_loop_t *loop, void *data) {
+ meshlink_handle_t *mesh = loop->data;
+
+ /* 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(mesh->contradicting_del_edge > 100 && mesh->contradicting_add_edge > 100) {
+ logger(DEBUG_ALWAYS, LOG_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;
+ }
- cp();
+ mesh->contradicting_add_edge = 0;
+ mesh->contradicting_del_edge = 0;
- last_ping_check = now;
- last_config_check = now;
- srand(now);
+ /* If AutoConnect is set, check if we need to make or break connections. */
- running = true;
+ 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++;
+ }
- while(running) {
- now = time(NULL);
+ 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.
+ */
+ int r = rand() % mesh->nodes->count;
+ int i = 0;
+
+ for splay_each(node_t, n, mesh->nodes) {
+ if(i++ != r)
+ continue;
- // tv.tv_sec = 1 + (rand() & 7); /* Approx. 5 seconds, randomized to prevent global synchronisation effects */
- tv.tv_sec = 1;
- tv.tv_usec = 0;
+ if(n->connection)
+ break;
- maxfd = build_fdset(&readset, &writeset);
+ bool found = false;
- r = select(maxfd + 1, &readset, &writeset, NULL, &tv);
+ for list_each(outgoing_t, outgoing, mesh->outgoings) {
+ if(!strcmp(outgoing->name, n->name)) {
+ found = true;
+ break;
+ }
+ }
- if(r < 0) {
- if(errno != EINTR && errno != EAGAIN) {
- logger(LOG_ERR, _("Error while waiting for input: %s"),
- strerror(errno));
- cp_trace();
- dump_connections();
- return 1;
+ 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(mesh->outgoings, outgoing);
+ setup_outgoing_connection(mesh, outgoing);
+ }
+ break;
}
+ } else 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;
- continue;
- }
+ if(i++ != r)
+ continue;
- check_network_activity(&readset, &writeset);
+ if(!c->outgoing || !c->node || c->node->edge_tree->count < 2)
+ break;
- if(do_purge) {
- purge();
- do_purge = false;
+ logger(DEBUG_CONNECTIONS, LOG_INFO, "Autodisconnecting from %s", c->name);
+ list_delete(mesh->outgoings, c->outgoing);
+ c->outgoing = NULL;
+ terminate_connection(mesh, c, c->status.active);
+ break;
+ }
}
- /* Let's check if everybody is still alive */
-
- if(last_ping_check + pingtimeout < now) {
- check_dead_connections();
- last_ping_check = now;
-
- if(routing_mode == RMODE_SWITCH)
- age_subnets();
-
- age_past_requests();
-
- /* Should we regenerate our key? */
-
- if(keyexpires < now) {
- ifdebug(STATUS) logger(LOG_INFO, _("Regenerating symmetric key"));
-
- RAND_pseudo_bytes((unsigned char *)myself->key, myself->keylength);
- if(myself->cipher)
- EVP_DecryptInit_ex(&packet_ctx, myself->cipher, NULL, (unsigned char *)myself->key, (unsigned char *)myself->key + myself->cipher->key_len);
- send_key_changed(broadcast, myself);
- keyexpires = now + keylifetime;
+ if(nc >= autoconnect) {
+ /* If we have enough active connections,
+ remove any pending outgoing connections.
+ */
+ for list_each(outgoing_t, o, mesh->outgoings) {
+ bool found = false;
+ for list_each(connection_t, c, mesh->connections) {
+ if(c->outgoing == o) {
+ found = true;
+ break;
+ }
+ }
+ if(!found) {
+ logger(DEBUG_CONNECTIONS, LOG_INFO, "Cancelled outgoing connection to %s", o->name);
+ list_delete_node(mesh->outgoings, node);
+ }
}
}
+ }
+ timeout_set(&mesh->loop, data, &(struct timeval){5, rand() % 100000});
+}
- while((event = get_expired_event())) {
- event->handler(event->data);
- free(event);
- }
-
- if(sigalrm) {
- logger(LOG_INFO, _("Flushing event queue"));
+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;
+ }
+}
- while(event_tree->head) {
- event = event_tree->head->data;
- event->handler(event->data);
- event_del(event);
- }
- sigalrm = false;
- }
+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});
+ }
- if(sighup) {
- connection_t *c;
- avl_node_t *node;
- char *fname;
- struct stat s;
-
- sighup = false;
-
- /* Reread our own configuration file */
-
- exit_configuration(&config_tree);
- init_configuration(&config_tree);
-
- if(!read_server_config()) {
- logger(LOG_ERR, _("Unable to reread configuration file, exitting."));
- return 1;
- }
+ /* 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;
+ }
- /* Close connections to hosts that have a changed or deleted host config file */
-
- for(node = connection_tree->head; node; node = node->next) {
- c = node->data;
-
- if(c->outgoing) {
- free(c->outgoing->name);
- freeaddrinfo(c->outgoing->ai);
- free(c->outgoing);
- c->outgoing = NULL;
- }
-
- asprintf(&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);
- }
+ /* Kick the ping timeout handler */
+ timeout_set(&mesh->loop, &mesh->pingtimer, &(struct timeval){0, 0});
+}
- last_config_check = now;
+/*
+ this is where it all happens...
+*/
+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){mesh->pingtimeout, rand() % 100000});
- /* Try to make outgoing connections */
-
- try_outgoing_connections();
- }
+ if(!event_loop_run(&mesh->loop)) {
+ logger(DEBUG_ALWAYS, LOG_ERR, "Error while waiting for input: %s", strerror(errno));
+ return 1;
}
+ timeout_del(&mesh->loop, &mesh->periodictimer);
+ timeout_del(&mesh->loop, &mesh->pingtimer);
+
return 0;
}