/*
net.c -- most of the network code
- Copyright (C) 1998-2002 Ivo Timmermans <ivo@o2w.nl>,
- 2000-2002 Guus Sliepen <guus@sliepen.eu.org>
+ Copyright (C) 1998-2005 Ivo Timmermans,
+ 2000-2021 Guus Sliepen <guus@tinc-vpn.org>
+ 2006 Scott Lamb <slamb@slamb.org>
+ 2011 Loïc Grenié <loic.grenie@gmail.com>
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 1.35.4.182 2002/09/15 14:55:53 guus 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 <stdio.h>
-#include <stdlib.h>
-#include <string.h>
-#include <signal.h>
-#include <sys/time.h>
-#include <sys/types.h>
-#include <syslog.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>
-#ifdef HAVE_NETINET_IN_SYSTM_H
-#include <netinet/in_systm.h>
-#endif
-#include <netinet/in.h>
-#ifdef HAVE_NETINET_IP_H
-#include <netinet/ip.h>
-#endif
-#ifdef HAVE_NETINET_TCP_H
-#include <netinet/tcp.h>
-#endif
-
-#include <openssl/rand.h>
-
-#include <utils.h>
-#include <xalloc.h>
-#include <avl_tree.h>
-#include <list.h>
+#include "system.h"
+#include "autoconnect.h"
+#include "conf_net.h"
#include "conf.h"
#include "connection.h"
+#include "crypto.h"
+#include "graph.h"
+#include "logger.h"
#include "meta.h"
+#include "names.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 "utils.h"
-#include "system.h"
-
-#ifndef HAVE_RAND_PSEUDO_BYTES
-#define RAND_pseudo_bytes RAND_bytes
-#endif
-
-int do_purge = 0;
-int sighup = 0;
-int sigalrm = 0;
-
-time_t now = 0;
+int contradicting_add_edge = 0;
+int contradicting_del_edge = 0;
+static int sleeptime = 10;
+time_t last_config_check = 0;
+static timeout_t pingtimer;
+static timeout_t periodictimer;
+static struct timeval last_periodic_run_time;
/* Purge edges and subnets of unreachable nodes. Use carefully. */
-void purge(void)
-{
- avl_node_t *nnode, *nnext, *enode, *enext, *snode, *snext;
- node_t *n;
- edge_t *e;
- subnet_t *s;
+void purge(void) {
+ logger(DEBUG_PROTOCOL, LOG_DEBUG, "Purging unreachable nodes");
- cp();
+ /* Remove all edges and subnets owned by unreachable nodes. */
- if(debug_lvl >= DEBUG_PROTOCOL)
- syslog(LOG_DEBUG, _("Purging unreachable nodes"));
+ for splay_each(node_t, n, &node_tree) {
+ if(!n->status.reachable) {
+ logger(DEBUG_SCARY_THINGS, LOG_DEBUG, "Purging node %s (%s)", n->name, n->hostname);
- for(nnode = node_tree->head; nnode; nnode = nnext) {
- nnext = nnode->next;
- n = (node_t *) nnode->data;
+ for splay_each(subnet_t, s, &n->subnet_tree) {
+ send_del_subnet(everyone, s);
- 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;
- send_del_subnet(broadcast, s);
- subnet_del(n, s);
+ if(!strictsubnets) {
+ subnet_del(n, s);
+ }
}
- for(enode = n->edge_tree->head; enode; enode = enext) {
- enext = enode->next;
- e = (edge_t *) enode->data;
- send_del_edge(broadcast, e);
+ for splay_each(edge_t, e, &n->edge_tree) {
+ if(!tunnelserver) {
+ send_del_edge(everyone, e);
+ }
+
edge_del(e);
}
+ }
+ }
- node_del(n);
+ /* Check if anyone else claims to have an edge to an unreachable node. If not, delete node. */
+
+ for splay_each(node_t, n, &node_tree) {
+ if(!n->status.reachable) {
+ for splay_each(edge_t, e, &edge_weight_tree)
+ if(e->to == n) {
+ return;
+ }
+
+ if(!autoconnect && (!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);
- if(!connection_tree->head)
- purge();
- } else
- FD_SET(c->socket, fs);
- }
+/* Put a misbehaving connection in the tarpit */
+void tarpit(int fd) {
+ static int pits[10] = {-1, -1, -1, -1, -1, -1, -1, -1, -1, -1};
+ static unsigned int next_pit = 0;
- for(i = 0; i < listen_sockets; i++) {
- FD_SET(listen_socket[i].tcp, fs);
- FD_SET(listen_socket[i].udp, fs);
+ if(pits[next_pit] != -1) {
+ closesocket(pits[next_pit]);
}
- FD_SET(device_fd, fs);
+ pits[next_pit++] = fd;
+
+ if(next_pit >= sizeof pits / sizeof pits[0]) {
+ next_pit = 0;
+ }
}
/*
Terminate a connection:
- - Close the socket
- - Remove associated edge and tell other connections about it if report = 1
+ - 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, int report)
-{
- cp();
+void terminate_connection(connection_t *c, bool report) {
+ logger(DEBUG_CONNECTIONS, LOG_NOTICE, "Closing connection with %s (%s)", c->name, c->hostname);
- if(c->status.remove)
- return;
+ if(c->node) {
+ if(c->node->connection == c) {
+ c->node->connection = NULL;
+ }
- if(debug_lvl >= DEBUG_CONNECTIONS)
- syslog(LOG_NOTICE, _("Closing connection with %s (%s)"),
- c->name, c->hostname);
+ if(c->edge) {
+ if(report && !tunnelserver) {
+ send_del_edge(everyone, c->edge);
+ }
- c->status.remove = 1;
- c->status.active = 0;
+ edge_del(c->edge);
+ c->edge = NULL;
- if(c->node)
- c->node->connection = NULL;
+ /* Run MST and SSSP algorithms */
- if(c->socket)
- close(c->socket);
+ graph();
- if(c->edge) {
- if(report)
- send_del_edge(broadcast, c->edge);
+ /* If the node is not reachable anymore but we remember it had an edge to us, clean it up */
- edge_del(c->edge);
+ if(report && !c->node->status.reachable) {
+ edge_t *e;
+ e = lookup_edge(c->node, myself);
- /* Run MST and SSSP algorithms */
+ if(e) {
+ if(!tunnelserver) {
+ send_del_edge(everyone, e);
+ }
- graph();
+ edge_del(e);
+ }
+ }
+ }
}
+ outgoing_t *outgoing = c->outgoing;
+ connection_del(c);
+
/* Check if this was our outgoing connection */
- if(c->outgoing) {
- retry_outgoing(c->outgoing);
- c->outgoing = NULL;
+ if(outgoing) {
+ do_outgoing_connection(outgoing);
}
+
+#ifndef HAVE_WINDOWS
+ /* 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.
*/
-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);
- }
+static void timeout_handler(void *data) {
+
+ bool close_all_connections = false;
+
+ /*
+ timeout_handler will start after 30 seconds from start of tincd
+ hold information about the elapsed time since last time the handler
+ has been run
+ */
+ long sleep_time = now.tv_sec - last_periodic_run_time.tv_sec;
+
+ /*
+ It seems that finding sane default value is harder than expected
+ Since we send every second a UDP packet to make holepunching work
+ And default UDP state expire on firewalls is between 15-30 seconds
+ we drop all connections after 60 Seconds - UDPDiscoveryTimeout=30
+ by default
+ */
+ if(sleep_time > 2 * udp_discovery_timeout) {
+ logger(DEBUG_ALWAYS, LOG_ERR, "Awaking from dead after %ld seconds of sleep", sleep_time);
+ /*
+ Do not send any packets to tinc after we wake up.
+ The other node probably closed our connection but we still
+ are holding context information to them. This may happen on
+ laptops or any other hardware which can be suspended for some time.
+ Sending any data to node that wasn't expecting it will produce
+ annoying and misleading errors on the other side about failed signature
+ verification and or about missing sptps context
+ */
+ close_all_connections = true;
+ }
+
+ last_periodic_run_time = now;
+
+ for list_each(connection_t, c, &connection_list) {
+ // control connections (eg. tinc ctl) do not have any timeout
+ if(c->status.control) {
+ continue;
+ }
+
+ if(close_all_connections) {
+ logger(DEBUG_ALWAYS, LOG_ERR, "Forcing connection close after sleep time %s (%s)", c->name, c->hostname);
+ terminate_connection(c, c->edge);
+ continue;
+ }
+
+ // Bail out early if we haven't reached the ping timeout for this node yet
+ if(c->last_ping_time + pingtimeout > now.tv_sec) {
+ continue;
+ }
+
+ // timeout during connection establishing
+ if(!c->edge) {
+ if(c->status.connecting) {
+ logger(DEBUG_CONNECTIONS, LOG_WARNING, "Timeout while connecting to %s (%s)", c->name, c->hostname);
} else {
- if(c->status.remove) {
- syslog(LOG_WARNING, _("Old connection_t for %s (%s) status %04x still lingering, deleting..."),
- c->name, c->hostname, c->status);
- connection_del(c);
- continue;
- }
- if(debug_lvl >= DEBUG_CONNECTIONS)
- syslog(LOG_WARNING, _("Timeout from %s (%s) during authentication"),
- c->name, c->hostname);
- terminate_connection(c, 0);
+ logger(DEBUG_CONNECTIONS, LOG_WARNING, "Timeout from %s (%s) during authentication", c->name, c->hostname);
+ c->status.tarpit = true;
}
+
+ terminate_connection(c, c->edge);
+ continue;
+ }
+
+ // helps in UDP holepunching
+ try_tx(c->node, false);
+
+ // timeout during ping
+ 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.tv_sec - c->last_ping_time));
+ terminate_connection(c, c->edge);
+ continue;
+ }
+
+ // check whether we need to send a new ping
+ if(c->last_ping_time + pinginterval <= now.tv_sec) {
+ send_ping(c);
}
}
+
+ timeout_set(data, &(struct timeval) {
+ 1, jitter()
+ });
}
-/*
- 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);
+static void periodic_handler(void *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(contradicting_del_edge > 100 && contradicting_add_edge > 100) {
+ logger(DEBUG_ALWAYS, LOG_WARNING, "Possible node with same Name as us! Sleeping %d seconds.", sleeptime);
+ sleep_millis(sleeptime * 1000);
+ sleeptime *= 2;
+
+ if(sleeptime < 0) {
+ sleeptime = 3600;
+ }
+ } else {
+ sleeptime /= 2;
+
+ if(sleeptime < 10) {
+ sleeptime = 10;
+ }
}
- for(node = connection_tree->head; node; node = node->next) {
- c = (connection_t *) node->data;
+ contradicting_add_edge = 0;
+ contradicting_del_edge = 0;
- if(c->status.remove)
- continue;
+ /* If AutoConnect is set, check if we need to make or break connections. */
- 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(autoconnect && node_tree.count > 1) {
+ do_autoconnect();
+ }
- if(receive_meta(c) < 0) {
- terminate_connection(c, c->status.active);
- continue;
- }
+ timeout_set(data, &(struct timeval) {
+ 5, jitter()
+ });
+}
+
+void handle_meta_connection_data(connection_t *c) {
+ if(!receive_meta(c)) {
+ if(!c->status.control) {
+ c->status.tarpit = true;
}
+
+ terminate_connection(c, c->edge);
+ return;
}
+}
+
+#ifndef HAVE_WINDOWS
+static void sigterm_handler(void *data) {
+ logger(DEBUG_ALWAYS, LOG_NOTICE, "Got %s signal", strsignal(((signal_t *)data)->signum));
+ event_exit();
+}
- for(i = 0; i < listen_sockets; i++) {
- if(FD_ISSET(listen_socket[i].udp, f))
- handle_incoming_vpn_data(listen_socket[i].udp);
+static void sighup_handler(void *data) {
+ logger(DEBUG_ALWAYS, LOG_NOTICE, "Got %s signal", strsignal(((signal_t *)data)->signum));
+ reopenlogger();
- if(FD_ISSET(listen_socket[i].tcp, f))
- handle_new_meta_connection(listen_socket[i].tcp);
+ if(reload_configuration()) {
+ exit(1);
}
}
-/*
- 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;
+static void sigalrm_handler(void *data) {
+ logger(DEBUG_ALWAYS, LOG_NOTICE, "Got %s signal", strsignal(((signal_t *)data)->signum));
+ retry();
+}
+#endif
- cp();
+int reload_configuration(void) {
+ char fname[PATH_MAX];
- last_ping_check = now;
- srand(now);
+ /* Reread our own configuration file */
- for(;;) {
- now = time(NULL);
+ splay_empty_tree(&config_tree);
- tv.tv_sec = 1 + (rand() & 7); /* Approx. 5 seconds, randomized to prevent global synchronisation effects */
- tv.tv_usec = 0;
+ if(!read_server_config(&config_tree)) {
+ logger(DEBUG_ALWAYS, LOG_ERR, "Unable to reread configuration file.");
+ return EINVAL;
+ }
- build_fdset(&fset);
+ read_config_options(&config_tree, NULL);
- r = select(FD_SETSIZE, &fset, NULL, NULL, &tv);
+ snprintf(fname, sizeof(fname), "%s" SLASH "hosts" SLASH "%s", confbase, myself->name);
+ read_config_file(&config_tree, fname, true);
- if(r < 0) {
- if(errno != EINTR && errno != EAGAIN) {
- syslog(LOG_ERR, _("Error while waiting for input: %s"),
- strerror(errno));
- cp_trace();
- dump_connections();
- return;
- }
+ /* Parse some options that are allowed to be changed while tinc is running */
- continue;
- }
+ setup_myself_reloadable();
- check_network_activity(&fset);
+ /* If StrictSubnet is set, expire deleted Subnets and read new ones in */
- if(do_purge) {
- purge();
- do_purge = 0;
- }
+ if(strictsubnets) {
+ for splay_each(subnet_t, subnet, &subnet_tree)
+ if(subnet->owner) {
+ subnet->expires = 1;
+ }
+ }
- /* Let's check if everybody is still alive */
+ for splay_each(node_t, n, &node_tree) {
+ n->status.has_address = false;
+ }
- if(last_ping_check + pingtimeout < now) {
- check_dead_connections();
- last_ping_check = now;
+ load_all_nodes();
- if(routing_mode == RMODE_SWITCH)
- age_mac();
+ if(strictsubnets) {
+ for splay_each(subnet_t, subnet, &subnet_tree) {
+ if(!subnet->owner) {
+ continue;
+ }
- age_past_requests();
+ if(subnet->expires == 1) {
+ send_del_subnet(everyone, subnet);
- /* Should we regenerate our key? */
+ if(subnet->owner->status.reachable) {
+ subnet_update(subnet->owner, subnet, false);
+ }
- if(keyexpires < now) {
- if(debug_lvl >= DEBUG_STATUS)
- syslog(LOG_INFO, _("Regenerating symmetric key"));
+ subnet_del(subnet->owner, subnet);
+ } else if(subnet->expires == -1) {
+ subnet->expires = 0;
+ } else {
+ send_add_subnet(everyone, subnet);
- RAND_pseudo_bytes(myself->key, myself->keylength);
- send_key_changed(broadcast, myself);
- keyexpires = now + keylifetime;
+ if(subnet->owner->status.reachable) {
+ subnet_update(subnet->owner, subnet, true);
+ }
}
}
+ } else { /* Only read our own subnets back in */
+ for splay_each(subnet_t, subnet, &myself->subnet_tree)
+ if(!subnet->expires) {
+ subnet->expires = 1;
+ }
+ config_t *cfg = lookup_config(&config_tree, "Subnet");
- while((event = get_expired_event())) {
- event->handler(event->data);
- free(event);
- }
+ while(cfg) {
+ subnet_t *subnet, *s2;
- if(sigalrm) {
- syslog(LOG_INFO, _("Flushing event queue"));
+ if(get_config_subnet(cfg, &subnet)) {
+ if((s2 = lookup_subnet(myself, subnet))) {
+ if(s2->expires == 1) {
+ s2->expires = 0;
+ }
- while(event_tree->head) {
- event = (event_t *) event_tree->head->data;
- event->handler(event->data);
- event_del(event);
+ free_subnet(subnet);
+ } else {
+ subnet_add(myself, subnet);
+ send_add_subnet(everyone, subnet);
+ subnet_update(myself, subnet, true);
+ }
}
- sigalrm = 0;
- }
- if(sighup) {
- sighup = 0;
- close_network_connections();
- exit_configuration(&config_tree);
+ cfg = lookup_config_next(&config_tree, cfg);
+ }
- syslog(LOG_INFO, _("Rereading configuration file and restarting in 5 seconds..."));
- sleep(5);
+ for splay_each(subnet_t, subnet, &myself->subnet_tree) {
+ if(subnet->expires == 1) {
+ send_del_subnet(everyone, subnet);
+ subnet_update(myself, subnet, false);
+ subnet_del(myself, subnet);
+ }
+ }
+ }
- init_configuration(&config_tree);
+ /* Try to make outgoing connections */
- if(read_server_config()) {
- syslog(LOG_ERR,
- _("Unable to reread configuration file, exitting."));
- exit(1);
- }
+ try_outgoing_connections();
- if(setup_network_connections())
- return;
+ /* Close connections to hosts that have a changed or deleted host config file */
+ for list_each(connection_t, c, &connection_list) {
+ if(c->status.control) {
continue;
}
+
+ snprintf(fname, sizeof(fname), "%s" SLASH "hosts" SLASH "%s", confbase, c->name);
+ struct stat s;
+
+ if(stat(fname, &s) || s.st_mtime > last_config_check) {
+ logger(DEBUG_CONNECTIONS, LOG_INFO, "Host config file of %s has been changed", c->name);
+ terminate_connection(c, c->edge);
+ }
}
+
+ last_config_check = now.tv_sec;
+
+ return 0;
+}
+
+void retry(void) {
+ /* Reset the reconnection timers for all outgoing connections */
+ for list_each(outgoing_t, outgoing, &outgoing_list) {
+ outgoing->timeout = 0;
+
+ if(outgoing->ev.cb)
+ timeout_set(&outgoing->ev, &(struct timeval) {
+ 0, 0
+ });
+ }
+
+ /* Check for outgoing connections that are in progress, and reset their ping timers */
+ for list_each(connection_t, c, &connection_list) {
+ if(c->outgoing && !c->node) {
+ c->last_ping_time = 0;
+ }
+ }
+
+ /* Kick the ping timeout handler */
+ timeout_set(&pingtimer, &(struct timeval) {
+ 0, 0
+ });
+}
+
+/*
+ this is where it all happens...
+*/
+int main_loop(void) {
+ last_periodic_run_time = now;
+ timeout_add(&pingtimer, timeout_handler, &pingtimer, &(struct timeval) {
+ pingtimeout, jitter()
+ });
+ timeout_add(&periodictimer, periodic_handler, &periodictimer, &(struct timeval) {
+ 0, 0
+ });
+
+#ifndef HAVE_WINDOWS
+ signal_t sighup = {0};
+ signal_t sigterm = {0};
+ signal_t sigquit = {0};
+ signal_t sigint = {0};
+ signal_t sigalrm = {0};
+
+ signal_add(&sighup, sighup_handler, &sighup, SIGHUP);
+ signal_add(&sigterm, sigterm_handler, &sigterm, SIGTERM);
+ signal_add(&sigquit, sigterm_handler, &sigquit, SIGQUIT);
+ signal_add(&sigint, sigterm_handler, &sigint, SIGINT);
+ signal_add(&sigalrm, sigalrm_handler, &sigalrm, SIGALRM);
+#endif
+
+ if(!event_loop()) {
+ logger(DEBUG_ALWAYS, LOG_ERR, "Error while waiting for input: %s", sockstrerror(sockerrno));
+ return 1;
+ }
+
+#ifndef HAVE_WINDOWS
+ signal_del(&sighup);
+ signal_del(&sigterm);
+ signal_del(&sigquit);
+ signal_del(&sigint);
+ signal_del(&sigalrm);
+#endif
+
+ timeout_del(&periodictimer);
+ timeout_del(&pingtimer);
+
+ return 0;
}