/*
net.c -- most of the network code
- Copyright (C) 1998-2002 Ivo Timmermans <itimmermans@bigfoot.com>,
- 2000-2002 Guus Sliepen <guus@sliepen.warande.net>
+ Copyright (C) 1998-2005 Ivo Timmermans,
+ 2000-2011 Guus Sliepen <guus@tinc-vpn.org>
+ 2006 Scott Lamb <slamb@slamb.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
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: net.c,v 1.38 2002/04/13 11:07:12 zarq Exp $
+ 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 "config.h"
-
-#include <errno.h>
-#include <fcntl.h>
-#include <netdb.h>
-#include <netinet/in.h>
-#ifdef HAVE_LINUX
- #include <netinet/ip.h>
- #include <netinet/tcp.h>
-#endif
-#include <stdio.h>
-#include <stdlib.h>
-#include <string.h>
-#include <signal.h>
-#include <sys/time.h>
-#include <sys/types.h>
-#include <unistd.h>
-#include <sys/ioctl.h>
-/* SunOS really wants sys/socket.h BEFORE net/if.h,
- and FreeBSD wants these lines below the rest. */
-#include <arpa/inet.h>
-#include <sys/socket.h>
-#include <net/if.h>
+#include "system.h"
#include <openssl/rand.h>
-#include <utils.h>
-#include <xalloc.h>
-#include <avl_tree.h>
-#include <list.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 "meta.h"
#include "net.h"
#include "netutl.h"
#include "process.h"
#include "protocol.h"
-#include "subnet.h"
-#include "graph.h"
-#include "process.h"
#include "route.h"
-#include "device.h"
-#include "event.h"
-#include "logging.h"
-
-#include "system.h"
+#include "subnet.h"
+#include "xalloc.h"
-int do_purge = 0;
-int sighup = 0;
-int sigalrm = 0;
+bool do_purge = false;
+volatile bool running = false;
time_t now = 0;
+int contradicting_add_edge = 0;
+int contradicting_del_edge = 0;
/* Purge edges and subnets of unreachable nodes. Use carefully. */
-void purge(void)
-{
- avl_node_t *nnode, *nnext, *enode, *enext, *snode, *snext, *cnode;
- node_t *n;
- edge_t *e;
- subnet_t *s;
- connection_t *c;
-cp
- if(debug_lvl >= DEBUG_PROTOCOL)
- syslog(LOG_DEBUG, _("Purging unreachable nodes"));
-
- for(nnode = node_tree->head; nnode; nnode = nnext)
- {
- nnext = nnode->next;
- n = (node_t *)nnode->data;
-
- if(!n->status.reachable)
- {
- if(debug_lvl >= DEBUG_SCARY_THINGS)
- syslog(LOG_DEBUG, _("Purging node %s (%s)"), n->name, n->hostname);
-
- for(snode = n->subnet_tree->head; snode; snode = snext)
- {
- snext = snode->next;
- s = (subnet_t *)snode->data;
-
- for(cnode = connection_tree->head; cnode; cnode = cnode->next)
- {
- c = (connection_t *)cnode->data;
- if(c->status.active)
- send_del_subnet(c, s);
- }
-
- subnet_del(n, s);
- }
-
- for(enode = n->edge_tree->head; enode; enode = enext)
- {
- enext = enode->next;
- e = (edge_t *)enode->data;
-
- for(cnode = connection_tree->head; cnode; cnode = cnode->next)
- {
- c = (connection_t *)cnode->data;
- if(c->status.active)
- send_del_edge(c, e);
- }
-
- edge_del(e);
- }
-
- node_del(n);
- }
- }
-cp
+static void purge(void) {
+ avl_node_t *nnode, *nnext, *enode, *enext, *snode, *snext;
+ node_t *n;
+ edge_t *e;
+ subnet_t *s;
+
+ 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;
+ send_del_subnet(broadcast, 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(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 && (!strictsubnets || !n->subnet_tree->head))
+ /* in strictsubnets mode do not delete nodes with subnets */
+ node_del(n);
+ }
+ }
}
/*
put all file descriptors in an fd_set array
While we're at it, purge stuff that needs to be removed.
*/
-void build_fdset(fd_set *fs)
-{
- avl_node_t *node, *next;
- connection_t *c;
- int i;
-cp
- FD_ZERO(fs);
-
- for(node = connection_tree->head; node; node = next)
- {
- next = node->next;
- c = (connection_t *)node->data;
-
- if(c->status.remove)
- connection_del(c);
- else
- FD_SET(c->socket, fs);
- }
-
- if(!connection_tree->head)
- purge();
-
- for(i = 0; i < listen_sockets; i++)
- {
- FD_SET(listen_socket[i].tcp, fs);
- FD_SET(listen_socket[i].udp, fs);
- }
-
- FD_SET(device_fd, fs);
-cp
+static int build_fdset(fd_set *readset, fd_set *writeset) {
+ avl_node_t *node, *next;
+ connection_t *c;
+ int i, max = 0;
+
+ 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;
+ }
+
+ if(device_fd >= 0)
+ 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 = 1
+ - Remove associated edge and tell other connections about it if report = true
- Check if we need to retry making an outgoing connection
- Deactivate the host
*/
-void terminate_connection(connection_t *c, int report)
-{
- avl_node_t *node;
- connection_t *other;
-cp
- if(c->status.remove)
- return;
-
- if(debug_lvl >= DEBUG_CONNECTIONS)
- syslog(LOG_NOTICE, _("Closing connection with %s (%s)"),
- c->name, c->hostname);
-
- c->status.remove = 1;
- c->status.active = 0;
-
- if(c->node)
- c->node->connection = NULL;
-
- if(c->socket)
- close(c->socket);
-
- if(c->edge)
- {
- if(report)
- {
- for(node = connection_tree->head; node; node = node->next)
- {
- other = (connection_t *)node->data;
- if(other->status.active && other != c)
- send_del_edge(other, c->edge);
- }
- }
-
- edge_del(c->edge);
-
- /* Run MST and SSSP algorithms */
-
- graph();
- }
-
- /* Check if this was our outgoing connection */
-
- if(c->outgoing)
- {
- retry_outgoing(c->outgoing);
- c->outgoing = NULL;
- }
-cp
+void terminate_connection(connection_t *c, bool report) {
+ if(c->status.remove)
+ return;
+
+ ifdebug(CONNECTIONS) logger(LOG_NOTICE, "Closing connection with %s (%s)",
+ c->name, c->hostname);
+
+ c->status.remove = true;
+ c->status.active = false;
+
+ if(c->node)
+ c->node->connection = NULL;
+
+ if(c->socket)
+ closesocket(c->socket);
+
+ if(c->edge) {
+ if(report && !tunnelserver)
+ send_del_edge(broadcast, c->edge);
+
+ edge_del(c->edge);
+
+ /* Run MST and SSSP algorithms */
+
+ graph();
+
+ /* 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);
+ if(e) {
+ if(!tunnelserver)
+ send_del_edge(broadcast, e);
+ edge_del(e);
+ }
+ }
+ }
+
+ /* Check if this was our outgoing connection */
+
+ if(c->outgoing) {
+ retry_outgoing(c->outgoing);
+ c->outgoing = NULL;
+ }
+
+ free(c->outbuf);
+ c->outbuf = NULL;
+ c->outbuflen = 0;
+ c->outbufsize = 0;
+ c->outbufstart = 0;
}
/*
end does not reply in time, we consider them dead
and close the connection.
*/
-void check_dead_connections(void)
-{
- avl_node_t *node, *next;
- connection_t *c;
-cp
- for(node = connection_tree->head; node; node = next)
- {
- next = node->next;
- c = (connection_t *)node->data;
- if(c->last_ping_time + pingtimeout < now)
- {
- if(c->status.active)
- {
- if(c->status.pinged)
- {
- if(debug_lvl >= DEBUG_PROTOCOL)
- syslog(LOG_INFO, _("%s (%s) didn't respond to PING"),
- c->name, c->hostname);
- c->status.timeout = 1;
- terminate_connection(c, 1);
- }
- else
- {
- send_ping(c);
- }
- }
- else
- {
- if(debug_lvl >= DEBUG_CONNECTIONS)
- syslog(LOG_WARNING, _("Timeout from %s (%s) during authentication"),
- c->name, c->hostname);
- terminate_connection(c, 0);
- }
- }
- }
-cp
+static void check_dead_connections(void) {
+ avl_node_t *node, *next;
+ connection_t *c;
+
+ for(node = connection_tree->head; node; node = next) {
+ next = node->next;
+ c = node->data;
+
+ if(c->last_ping_time + pingtimeout < now) {
+ if(c->status.active) {
+ if(c->status.pinged) {
+ ifdebug(CONNECTIONS) logger(LOG_INFO, "%s (%s) didn't respond to PING in %ld 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, bitfield_to_int(&c->status, sizeof c->status));
+ connection_del(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 %ld 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
*/
-void check_network_activity(fd_set *f)
-{
- connection_t *c;
- avl_node_t *node;
- int result, i;
- int len = sizeof(result);
- vpn_packet_t packet;
-cp
- if(FD_ISSET(device_fd, f))
- {
- if(!read_packet(&packet))
- route_outgoing(&packet);
- }
-
- for(node = connection_tree->head; node; node = node->next)
- {
- c = (connection_t *)node->data;
-
- if(c->status.remove)
- continue;
-
- if(FD_ISSET(c->socket, f))
- {
- if(c->status.connecting)
- {
- c->status.connecting = 0;
- getsockopt(c->socket, SOL_SOCKET, SO_ERROR, &result, &len);
- if(!result)
- finish_connecting(c);
- else
- {
- if(debug_lvl >= DEBUG_CONNECTIONS)
- syslog(LOG_DEBUG, _("Error while connecting to %s (%s): %s"), c->name, c->hostname, strerror(result));
- close(c->socket);
- do_outgoing_connection(c);
- continue;
- }
- }
- if(receive_meta(c) < 0)
- {
- terminate_connection(c, c->status.active);
- continue;
- }
- }
- }
-
- for(i = 0; i < listen_sockets; i++)
- {
- if(FD_ISSET(listen_socket[i].udp, f))
- handle_incoming_vpn_data(listen_socket[i].udp);
- if(FD_ISSET(listen_socket[i].tcp, f))
- handle_new_meta_connection(listen_socket[i].tcp);
- }
-cp
+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;
+ static int errors = 0;
+
+ /* check input from kernel */
+ if(device_fd >= 0 && FD_ISSET(device_fd, readset)) {
+ if(read_packet(&packet)) {
+ errors = 0;
+ packet.priority = 0;
+ route(myself, &packet);
+ } else {
+ usleep(errors * 50000);
+ errors++;
+ if(errors > 10) {
+ logger(LOG_ERR, "Too many errors from %s, exiting!", device);
+ running = false;
+ }
+ }
+ }
+
+ /* 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, (void *)&result, &len);
+
+ if(!result)
+ finish_connecting(c);
+ else {
+ ifdebug(CONNECTIONS) logger(LOG_DEBUG,
+ "Error while connecting to %s (%s): %s",
+ c->name, c->hostname, sockstrerror(result));
+ closesocket(c->socket);
+ do_outgoing_connection(c);
+ continue;
+ }
+ }
+
+ 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;
+ }
+ }
+ }
+
+ 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);
+ }
}
/*
this is where it all happens...
*/
-void main_loop(void)
-{
- fd_set fset;
- struct timeval tv;
- int r;
- time_t last_ping_check;
- event_t *event;
-cp
- last_ping_check = now;
-
- srand(now);
-
- for(;;)
- {
- now = time(NULL);
-
- tv.tv_sec = 1 + (rand() & 7); /* Approx. 5 seconds, randomized to prevent global synchronisation effects */
- tv.tv_usec = 0;
-
- build_fdset(&fset);
-
- if((r = select(FD_SETSIZE, &fset, NULL, NULL, &tv)) < 0)
- {
- if(errno != EINTR && errno != EAGAIN)
- {
- syslog(LOG_ERR, _("Error while waiting for input: %s"), strerror(errno));
- cp_trace();
- dump_connections();
- return;
- }
-
- continue;
- }
-
- check_network_activity(&fset);
-
- if(do_purge)
- {
- purge();
- do_purge = 0;
- }
-
- /* 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_mac();
-
- age_past_requests();
-
- /* Should we regenerate our key? */
-
- if(keyexpires < now)
- {
- if(debug_lvl >= DEBUG_STATUS)
- syslog(LOG_INFO, _("Regenerating symmetric key"));
-
- RAND_pseudo_bytes(myself->key, myself->keylength);
- send_key_changed(myself->connection, myself);
- keyexpires = now + keylifetime;
- }
- }
-
-
- while((event = get_expired_event()))
- {
- event->handler(event->data);
- free(event);
- }
-
- if(sigalrm)
- {
- syslog(LOG_INFO, _("Flushing event queue"));
-
- while(event_tree->head)
- {
- event = (event_t *)event_tree->head->data;
- event->handler(event->data);
- event_del(event);
- }
- sigalrm = 0;
- }
-
- if(sighup)
- {
- sighup = 0;
- close_network_connections();
- exit_configuration(&config_tree);
-
- syslog(LOG_INFO, _("Rereading configuration file and restarting in 5 seconds..."));
- sleep(5);
-
- init_configuration(&config_tree);
-
- if(read_server_config())
- {
- syslog(LOG_ERR, _("Unable to reread configuration file, exitting."));
- exit(1);
- }
-
- if(setup_network_connections())
- return;
-
- continue;
- }
- }
-cp
+int main_loop(void) {
+ fd_set readset, writeset;
+ struct timeval tv;
+ int r, maxfd;
+ time_t last_ping_check, last_config_check, last_graph_dump;
+ event_t *event;
+
+ last_ping_check = now;
+ last_config_check = now;
+ last_graph_dump = now;
+
+ srand(now);
+
+ running = true;
+
+ while(running) {
+ now = time(NULL);
+
+ // tv.tv_sec = 1 + (rand() & 7); /* Approx. 5 seconds, randomized to prevent global synchronisation effects */
+ tv.tv_sec = 1;
+ tv.tv_usec = 0;
+
+ maxfd = build_fdset(&readset, &writeset);
+
+#ifdef HAVE_MINGW
+ LeaveCriticalSection(&mutex);
+#endif
+ r = select(maxfd + 1, &readset, &writeset, NULL, &tv);
+#ifdef HAVE_MINGW
+ EnterCriticalSection(&mutex);
+#endif
+
+ if(r < 0) {
+ if(!sockwouldblock(sockerrno)) {
+ logger(LOG_ERR, "Error while waiting for input: %s", sockstrerror(sockerrno));
+ dump_connections();
+ return 1;
+ }
+ }
+
+ if(r > 0)
+ check_network_activity(&readset, &writeset);
+
+ if(do_purge) {
+ purge();
+ do_purge = false;
+ }
+
+ /* 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) {
+ avl_node_t *node;
+ node_t *n;
+
+ ifdebug(STATUS) logger(LOG_INFO, "Expiring symmetric keys");
+
+ for(node = node_tree->head; node; node = node->next) {
+ n = node->data;
+ if(n->inkey) {
+ free(n->inkey);
+ n->inkey = NULL;
+ }
+ }
+
+ send_key_changed(broadcast, myself);
+ keyexpires = now + keylifetime;
+ }
+
+ if(contradicting_del_edge > 10 && contradicting_add_edge > 10) {
+ logger(LOG_WARNING, "Possible node with same Name as us!");
+
+ if(rand() % 3 == 0) {
+ logger(LOG_ERR, "Shutting down, check configuration of all nodes for duplicate Names!");
+ running = false;
+ break;
+ }
+
+ contradicting_add_edge = 0;
+ contradicting_del_edge = 0;
+ }
+ }
+
+ if(sigalrm) {
+ avl_node_t *node;
+ logger(LOG_INFO, "Flushing event queue");
+ expire_events();
+ for(node = connection_tree->head; node; node = node->next) {
+ connection_t *c = node->data;
+ send_ping(c);
+ }
+ sigalrm = false;
+ }
+
+ while((event = get_expired_event())) {
+ event->handler(event->data);
+ free_event(event);
+ }
+
+ if(sighup) {
+ connection_t *c;
+ avl_node_t *node, *next;
+ 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;
+ }
+
+ /* Cancel non-active outgoing connections */
+
+ for(node = connection_tree->head; node; node = next) {
+ next = node->next;
+ c = node->data;
+
+ c->outgoing = NULL;
+
+ if(c->status.connecting) {
+ terminate_connection(c, false);
+ connection_del(c);
+ }
+ }
+
+ /* Wipe list of outgoing connections */
+
+ for(list_node_t *node = outgoing_list->head; node; node = node->next) {
+ outgoing_t *outgoing = node->data;
+
+ if(outgoing->event)
+ event_del(outgoing->event);
+ }
+
+ list_delete_list(outgoing_list);
+
+ /* 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;
+
+ 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 = now;
+
+ /* If StrictSubnet is set, expire deleted Subnets and read new ones in */
+
+ if(strictsubnets) {
+ subnet_t *subnet;
+
+ for(node = subnet_tree->head; node; node = node->next) {
+ subnet = node->data;
+ subnet->expires = 1;
+ }
+
+ load_all_subnets();
+
+ for(node = subnet_tree->head; node; node = next) {
+ next = node->next;
+ subnet = node->data;
+ if(subnet->expires == 1) {
+ send_del_subnet(broadcast, 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(broadcast, subnet);
+ if(subnet->owner->status.reachable)
+ subnet_update(subnet->owner, subnet, true);
+ }
+ }
+ }
+
+ /* Try to make outgoing connections */
+
+ try_outgoing_connections();
+ }
+
+ /* Dump graph if wanted every 60 seconds*/
+
+ if(last_graph_dump + 60 < now) {
+ dump_graph();
+ last_graph_dump = now;
+ }
+ }
+
+ return 0;
}