/*
net.c -- most of the network code
- Copyright (C) 1998,99 Ivo Timmermans <zarq@iname.com>
+ 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.
+ 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 <arpa/inet.h>
-#include <errno.h>
-#include <fcntl.h>
-#include <netdb.h>
-#include <netinet/in.h>
-#include <stdio.h>
-#include <stdlib.h>
-#include <string.h>
-#include <sys/signal.h>
-#include <sys/socket.h>
-#include <sys/time.h>
-#include <sys/types.h>
-#include <syslog.h>
-#include <unistd.h>
-
-#include <cipher.h>
-#include <utils.h>
-#include <xalloc.h>
+#include "system.h"
+#include "autoconnect.h"
#include "conf.h"
-#include "encr.h"
+#include "connection.h"
+#include "device.h"
+#include "graph.h"
+#include "logger.h"
+#include "meta.h"
+#include "names.h"
#include "net.h"
#include "netutl.h"
#include "protocol.h"
+#include "subnet.h"
+#include "utils.h"
+#include "xalloc.h"
-int tap_fd = -1;
+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;
-int total_tap_in = 0;
-int total_tap_out = 0;
-int total_socket_in = 0;
-int total_socket_out = 0;
+/* Purge edges and subnets of unreachable nodes. Use carefully. */
-time_t last_ping_time = 0;
+void purge(void) {
+ logger(DEBUG_PROTOCOL, LOG_DEBUG, "Purging unreachable nodes");
-/* The global list of existing connections */
-conn_list_t *conn_list = NULL;
-conn_list_t *myself = NULL;
+ /* Remove all edges and subnets owned by unreachable nodes. */
-/*
- strip off the MAC adresses of an ethernet frame
-*/
-void strip_mac_addresses(vpn_packet_t *p)
-{
- unsigned char tmp[MAXSIZE];
-cp
- memcpy(tmp, p->data, p->len);
- p->len -= 12;
- memcpy(p->data, &tmp[12], p->len);
-cp
-}
+ 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);
-/*
- reassemble MAC addresses
-*/
-void add_mac_addresses(vpn_packet_t *p)
-{
- unsigned char tmp[MAXSIZE];
-cp
- memcpy(&tmp[12], p->data, p->len);
- p->len += 12;
- tmp[0] = tmp[6] = 0xfe;
- tmp[1] = tmp[7] = 0xfd;
- *((ip_t*)(&tmp[2])) = (ip_t)(htonl(myself->vpn_ip));
- *((ip_t*)(&tmp[8])) = *((ip_t*)(&tmp[26]));
- memcpy(p->data, &tmp[0], p->len);
-cp
-}
+ for splay_each(subnet_t, s, n->subnet_tree) {
+ send_del_subnet(everyone, s);
-int xsend(conn_list_t *cl, void *packet)
-{
- int r;
- real_packet_t rp;
-cp
- do_encrypt((vpn_packet_t*)packet, &rp, cl->key);
- rp.from = myself->vpn_ip;
-
- if(debug_lvl > 3)
- syslog(LOG_ERR, "Sent %d bytes to %lx", rp.len, cl->vpn_ip);
-
- if((r = send(cl->socket, (char*)&rp, rp.len, 0)) < 0)
- {
- syslog(LOG_ERR, "Error sending data: %m");
- return -1;
- }
-
- total_socket_out += r;
-cp
- return 0;
-}
+ if(!strictsubnets) {
+ subnet_del(n, s);
+ }
+ }
-int xrecv(conn_list_t *cl, void *packet)
-{
- vpn_packet_t vp;
- int lenin;
-cp
- do_decrypt((real_packet_t*)packet, &vp, cl->key);
- add_mac_addresses(&vp);
-
- if((lenin = write(tap_fd, &vp, vp.len + sizeof(vp.len))) < 0)
- syslog(LOG_ERR, "Can't write to tap device: %m");
- else
- total_tap_out += lenin;
-cp
- return 0;
-}
+ for splay_each(edge_t, e, n->edge_tree) {
+ if(!tunnelserver) {
+ send_del_edge(everyone, e);
+ }
-/*
- add the given packet of size s to the
- queue q, be it the send or receive queue
-*/
-void add_queue(packet_queue_t **q, void *packet, size_t s)
-{
- queue_element_t *e;
-cp
- if(debug_lvl > 3)
- syslog(LOG_DEBUG, "packet to queue: %d", s);
-
- e = xmalloc(sizeof(*e));
- e->packet = xmalloc(s);
- memcpy(e->packet, packet, s);
-
- if(!*q)
- {
- *q = xmalloc(sizeof(**q));
- (*q)->head = (*q)->tail = NULL;
- }
-
- e->next = NULL; /* We insert at the tail */
-
- if((*q)->tail) /* Do we have a tail? */
- {
- (*q)->tail->next = e;
- e->prev = (*q)->tail;
- }
- else /* No tail -> no head too */
- {
- (*q)->head = e;
- e->prev = NULL;
- }
-
- (*q)->tail = e;
-cp
-}
+ edge_del(e);
+ }
+ }
+ }
-/* Remove a queue element */
-void del_queue(packet_queue_t **q, queue_element_t *e)
-{
-cp
- free(e->packet);
-
- if(e->next) /* There is a successor, so we are not tail */
- {
- if(e->prev) /* There is a predecessor, so we are not head */
- {
- e->next->prev = e->prev;
- e->prev->next = e->next;
- }
- else /* We are head */
- {
- e->next->prev = NULL;
- (*q)->head = e->next;
- }
- }
- else /* We are tail (or all alone!) */
- {
- if(e->prev) /* We are not alone :) */
- {
- e->prev->next = NULL;
- (*q)->tail = e->prev;
- }
- else /* Adieu */
- {
- free(*q);
- *q = NULL;
- }
- }
-
- free(e);
-cp
+ /* 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);
+ }
+ }
+ }
}
-/*
- flush a queue by calling function for
- each packet, and removing it when that
- returned a zero exit code
-*/
-void flush_queue(conn_list_t *cl, packet_queue_t **pq,
- int (*function)(conn_list_t*,void*))
-{
- queue_element_t *p, *next = NULL;
-cp
- for(p = (*pq)->head; p != NULL; )
- {
- next = p->next;
-
- if(!function(cl, p->packet))
- del_queue(pq, p);
-
- p = next;
- }
-
- if(debug_lvl > 3)
- syslog(LOG_DEBUG, "queue flushed");
-cp
-}
+/* 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;
-/*
- flush the send&recv queues
- void because nothing goes wrong here, packets
- remain in the queue if something goes wrong
-*/
-void flush_queues(conn_list_t *cl)
-{
-cp
- if(cl->sq)
- {
- if(debug_lvl > 1)
- syslog(LOG_DEBUG, "Flushing send queue for " IP_ADDR_S,
- IP_ADDR_V(cl->vpn_ip));
- flush_queue(cl, &(cl->sq), xsend);
- }
-
- if(cl->rq)
- {
- if(debug_lvl > 1)
- syslog(LOG_DEBUG, "Flushing receive queue for " IP_ADDR_S,
- IP_ADDR_V(cl->vpn_ip));
- flush_queue(cl, &(cl->rq), xrecv);
- }
-cp
-}
+ if(pits[next_pit] != -1) {
+ closesocket(pits[next_pit]);
+ }
-/*
- send a packet to the given vpn ip.
-*/
-int send_packet(ip_t to, vpn_packet_t *packet)
-{
- conn_list_t *cl;
-cp
- if((cl = lookup_conn(to)) == NULL)
- {
- if(debug_lvl > 2)
- {
- syslog(LOG_NOTICE, "trying to look up " IP_ADDR_S " in connection list failed.",
- IP_ADDR_V(to));
- }
- for(cl = conn_list; cl != NULL && !cl->status.outgoing; cl = cl->next);
- if(!cl)
- { /* No open outgoing connection has been found. */
- if(debug_lvl > 2)
- syslog(LOG_NOTICE, "There is no remote host I can send this packet to.");
- return -1;
- }
- }
-
- if(my_key_expiry <= time(NULL))
- regenerate_keys();
-
- if(!cl->status.dataopen)
- if(setup_vpn_connection(cl) < 0)
- return -1;
-
- if(!cl->status.validkey)
- {
- add_queue(&(cl->sq), packet, packet->len + 2);
- if(!cl->status.waitingforkey)
- send_key_request(cl->vpn_ip); /* Keys should be sent to the host running the tincd */
- return 0;
- }
-
- if(!cl->status.active)
- {
- add_queue(&(cl->sq), packet, packet->len + 2);
- if(debug_lvl > 1)
- syslog(LOG_INFO, IP_ADDR_S " is not ready, queueing packet.", IP_ADDR_V(cl->vpn_ip));
- return 0; /* We don't want to mess up, do we? */
- }
-
- /* can we send it? can we? can we? huh? */
-cp
- return xsend(cl, packet);
-}
+ pits[next_pit++] = fd;
-int send_broadcast(conn_list_t *cl, vpn_packet_t *packet)
-{
- conn_list_t *p;
-cp
- for(p = cl; p != NULL; p = p->next)
- if(send_packet(p->real_ip, packet) < 0)
- {
- syslog(LOG_ERR, "Could not send a broadcast packet to %08lx (%08lx): %m",
- p->vpn_ip, p->real_ip);
- break; /* FIXME: should retry later, and send a ping over the metaconnection. */
- }
-cp
- return 0;
+ if(next_pit >= sizeof pits / sizeof pits[0]) {
+ next_pit = 0;
+ }
}
/*
- open the local ethertap device
+ Terminate a connection:
+ - Mark it as inactive
+ - Remove the edge representing this connection
+ - Kill it with fire
+ - Check if we need to retry making an outgoing connection
*/
-int setup_tap_fd(void)
-{
- int nfd;
- const char *tapfname;
- config_t const *cfg;
-cp
- if((cfg = get_config_val(tapdevice)) == NULL)
- tapfname = "/dev/tap0";
- else
- tapfname = cfg->data.ptr;
-
- if((nfd = open(tapfname, O_RDWR | O_NONBLOCK)) < 0)
- {
- syslog(LOG_ERR, "Could not open %s: %m", tapfname);
- return -1;
- }
-
- tap_fd = nfd;
-cp
- return 0;
-}
+void terminate_connection(connection_t *c, bool report) {
+ logger(DEBUG_CONNECTIONS, LOG_NOTICE, "Closing connection with %s (%s)", c->name, c->hostname);
-/*
- set up the socket that we listen on for incoming
- (tcp) connections
-*/
-int setup_listen_meta_socket(int port)
-{
- int nfd, flags;
- struct sockaddr_in a;
- const int one = 1;
-cp
- if((nfd = socket(AF_INET, SOCK_STREAM, IPPROTO_TCP)) < 0)
- {
- syslog(LOG_ERR, "Creating metasocket failed: %m");
- return -1;
- }
-
- if(setsockopt(nfd, SOL_SOCKET, SO_REUSEADDR, &one, sizeof(one)))
- {
- syslog(LOG_ERR, "setsockopt: %m");
- return -1;
- }
-
- flags = fcntl(nfd, F_GETFL);
- if(fcntl(nfd, F_SETFL, flags | O_NONBLOCK) < 0)
- {
- syslog(LOG_ERR, "fcntl: %m");
- return -1;
- }
-
- memset(&a, 0, sizeof(a));
- a.sin_family = AF_INET;
- a.sin_port = htons(port);
- a.sin_addr.s_addr = htonl(INADDR_ANY);
-
- if(bind(nfd, (struct sockaddr *)&a, sizeof(struct sockaddr)))
- {
- syslog(LOG_ERR, "Can't bind to port %hd/tcp: %m", port);
- return -1;
- }
-
- if(listen(nfd, 3))
- {
- syslog(LOG_ERR, "listen: %m");
- return -1;
- }
-cp
- return nfd;
-}
+ if(c->node) {
+ if(c->node->connection == c) {
+ c->node->connection = NULL;
+ }
-/*
- setup the socket for incoming encrypted
- data (the udp part)
-*/
-int setup_vpn_in_socket(int port)
-{
- int nfd, flags;
- struct sockaddr_in a;
- const int one = 1;
-cp
- if((nfd = socket(AF_INET, SOCK_DGRAM, IPPROTO_UDP)) < 0)
- {
- syslog(LOG_ERR, "Creating socket failed: %m");
- return -1;
- }
-
- if(setsockopt(nfd, SOL_SOCKET, SO_REUSEADDR, &one, sizeof(one)))
- {
- syslog(LOG_ERR, "setsockopt: %m");
- return -1;
- }
-
- flags = fcntl(nfd, F_GETFL);
- if(fcntl(nfd, F_SETFL, flags | O_NONBLOCK) < 0)
- {
- syslog(LOG_ERR, "fcntl: %m");
- return -1;
- }
-
- memset(&a, 0, sizeof(a));
- a.sin_family = AF_INET;
- a.sin_port = htons(port);
- a.sin_addr.s_addr = htonl(INADDR_ANY);
-
- if(bind(nfd, (struct sockaddr *)&a, sizeof(struct sockaddr)))
- {
- syslog(LOG_ERR, "Can't bind to port %hd/udp: %m", port);
- return -1;
- }
-cp
- return nfd;
-}
+ if(c->edge) {
+ if(report && !tunnelserver) {
+ send_del_edge(everyone, c->edge);
+ }
-/*
- setup an outgoing meta (tcp) socket
-*/
-int setup_outgoing_meta_socket(conn_list_t *cl)
-{
- int flags;
- struct sockaddr_in a;
- config_t const *cfg;
-cp
- if((cfg = get_config_val(upstreamport)) == NULL)
- cl->port = 655;
- else
- cl->port = cfg->data.val;
-
- cl->meta_socket = socket(AF_INET, SOCK_STREAM, IPPROTO_TCP);
- if(cl->meta_socket == -1)
- {
- syslog(LOG_ERR, "Creating socket failed: %m");
- return -1;
- }
-
- a.sin_family = AF_INET;
- a.sin_port = htons(cl->port);
- a.sin_addr.s_addr = htonl(cl->real_ip);
-
- if(connect(cl->meta_socket, (struct sockaddr *)&a, sizeof(a)) == -1)
- {
- syslog(LOG_ERR, IP_ADDR_S ":%d: %m", IP_ADDR_V(cl->real_ip), cl->port);
- return -1;
- }
-
- flags = fcntl(cl->meta_socket, F_GETFL);
- if(fcntl(cl->meta_socket, F_SETFL, flags | O_NONBLOCK) < 0)
- {
- syslog(LOG_ERR, "fcntl: %m");
- return -1;
- }
-
- cl->hostname = hostlookup(htonl(cl->real_ip));
-
- syslog(LOG_INFO, "Connected to %s:%hd" , cl->hostname, cl->port);
-cp
- return 0;
-}
+ edge_del(c->edge);
+ c->edge = NULL;
-/*
- setup an outgoing connection. It's not
- necessary to also open an udp socket as
- well, because the other host will initiate
- an authentication sequence during which
- we will do just that.
-*/
-int setup_outgoing_connection(ip_t ip)
-{
- conn_list_t *ncn;
-cp
- ncn = new_conn_list();
- ncn->real_ip = ip;
-
- if(setup_outgoing_meta_socket(ncn) < 0)
- {
- syslog(LOG_ERR, "Could not set up a meta connection.");
- free_conn_element(ncn);
- return -1;
- }
-
- ncn->status.meta = 1;
- ncn->status.outgoing = 1;
- ncn->next = conn_list;
- conn_list = ncn;
-cp
- return 0;
-}
+ /* Run MST and SSSP algorithms */
-/*
- set up the local sockets (listen only)
-*/
-int setup_myself(void)
-{
- config_t const *cfg;
-cp
- myself = new_conn_list();
-
- if(!(cfg = get_config_val(myvpnip)))
- {
- syslog(LOG_ERR, "No value for my VPN IP given");
- return -1;
- }
-
- myself->vpn_ip = cfg->data.ip->ip;
- myself->vpn_mask = cfg->data.ip->mask;
-
- if(!(cfg = get_config_val(listenport)))
- myself->port = 655;
- else
- myself->port = cfg->data.val;
-
- if((myself->meta_socket = setup_listen_meta_socket(myself->port)) < 0)
- {
- syslog(LOG_ERR, "Unable to set up a listening socket");
- return -1;
- }
-
- if((myself->socket = setup_vpn_in_socket(myself->port)) < 0)
- {
- syslog(LOG_ERR, "Unable to set up an incoming vpn data socket");
- close(myself->meta_socket);
- return -1;
- }
-
- myself->status.active = 1;
-
- syslog(LOG_NOTICE, "Ready: listening on port %d.", myself->port);
-cp
- return 0;
-}
+ graph();
-/*
- setup all initial network connections
-*/
-int setup_network_connections(void)
-{
- config_t const *cfg;
-cp
- if((cfg = get_config_val(pingtimeout)) == NULL)
- timeout = 10;
- else
- timeout = cfg->data.val;
-
- if(setup_tap_fd() < 0)
- return -1;
-
- if(setup_myself() < 0)
- return -1;
-
- if((cfg = get_config_val(upstreamip)) == NULL)
- /* No upstream IP given, we're listen only. */
- return 0;
-
- if(setup_outgoing_connection(cfg->data.ip->ip))
- return -1;
-cp
- return 0;
-}
+ /* If the node is not reachable anymore but we remember it had an edge to us, clean it up */
-RETSIGTYPE
-sigalrm_handler(int a)
-{
- config_t const *cfg;
- static int seconds_till_retry;
-cp
- cfg = get_config_val(upstreamip);
-
- if(!setup_outgoing_connection(cfg->data.ip->ip))
- {
- signal(SIGALRM, SIG_IGN);
- seconds_till_retry = 5;
- }
- else
- {
- signal(SIGALRM, sigalrm_handler);
- seconds_till_retry += 5;
- alarm(seconds_till_retry);
- syslog(LOG_ERR, "Still failed to connect to other. Will retry in %d seconds.",
- seconds_till_retry);
- }
-cp
-}
+ if(report && !c->node->status.reachable) {
+ edge_t *e;
+ e = lookup_edge(c->node, myself);
-/*
- close all open network connections
-*/
-void close_network_connections(void)
-{
- conn_list_t *p;
-cp
- for(p = conn_list; p != NULL; p = p->next)
- {
- if(p->status.dataopen)
- {
- shutdown(p->socket, 0); /* No more receptions */
- close(p->socket);
+ if(e) {
+ if(!tunnelserver) {
+ send_del_edge(everyone, e);
+ }
+
+ edge_del(e);
+ }
+ }
+ }
}
- if(p->status.meta)
- {
- send_termreq(p);
- shutdown(p->meta_socket, 0); /* No more receptions */
- close(p->meta_socket);
- }
- }
-
- if(myself)
- if(myself->status.active)
- {
- close(myself->meta_socket);
- close(myself->socket);
- }
-
- close(tap_fd);
- destroy_conn_list();
-
- syslog(LOG_NOTICE, "Terminating.");
-cp
- return;
-}
-/*
- create a data (udp) socket
-*/
-int setup_vpn_connection(conn_list_t *cl)
-{
- int nfd, flags;
- struct sockaddr_in a;
-cp
- if(debug_lvl > 1)
- syslog(LOG_DEBUG, "Opening UDP socket to " IP_ADDR_S, IP_ADDR_V(cl->real_ip));
-
- nfd = socket(AF_INET, SOCK_DGRAM, IPPROTO_UDP);
- if(nfd == -1)
- {
- syslog(LOG_ERR, "Creating data socket failed: %m");
- return -1;
- }
-
- a.sin_family = AF_INET;
- a.sin_port = htons(cl->port);
- a.sin_addr.s_addr = htonl(cl->real_ip);
-
- if(connect(nfd, (struct sockaddr *)&a, sizeof(a)) == -1)
- {
- syslog(LOG_ERR, "Create connection to %08lx:%d failed: %m", ntohs(cl->real_ip),
- cl->port);
- return -1;
- }
-
- flags = fcntl(nfd, F_GETFL);
- if(fcntl(nfd, F_SETFL, flags | O_NONBLOCK) < 0)
- {
- syslog(LOG_ERR, "This is a bug: %s:%d: %d:%m", __FILE__, __LINE__, nfd);
- return -1;
- }
-
- cl->socket = nfd;
- cl->status.dataopen = 1;
-cp
- return 0;
-}
+ outgoing_t *outgoing = c->outgoing;
+ connection_del(c);
-/*
- handle an incoming tcp connect call and open
- a connection to it.
-*/
-conn_list_t *create_new_connection(int sfd)
-{
- conn_list_t *p;
- struct sockaddr_in ci;
- int len = sizeof(ci);
-cp
- p = new_conn_list();
-
- if(getpeername(sfd, &ci, &len) < 0)
- {
- syslog(LOG_ERR, "Error: getpeername: %m");
- return NULL;
- }
-
- p->hostname = hostlookup(ci.sin_addr.s_addr);
- p->real_ip = ntohl(ci.sin_addr.s_addr);
- p->meta_socket = sfd;
- p->status.meta = 1;
-
- syslog(LOG_NOTICE, "Connection from %s:%d", p->hostname, htons(ci.sin_port));
-
- if(send_basic_info(p) < 0)
- {
- free(p);
- return NULL;
- }
-cp
- return p;
-}
+ /* Check if this was our outgoing connection */
-/*
- put all file descriptors in an fd_set array
-*/
-void build_fdset(fd_set *fs)
-{
- conn_list_t *p;
-cp
- FD_ZERO(fs);
-
- for(p = conn_list; p != NULL; p = p->next)
- {
- if(p->status.meta)
- FD_SET(p->meta_socket, fs);
- if(p->status.dataopen)
- FD_SET(p->socket, fs);
- }
-
- FD_SET(myself->meta_socket, fs);
- FD_SET(myself->socket, fs);
- FD_SET(tap_fd, fs);
-cp
+ if(outgoing) {
+ do_outgoing_connection(outgoing);
+ }
+
+#ifndef HAVE_MINGW
+ /* Clean up dead proxy processes */
+
+ while(waitpid(-1, NULL, WNOHANG) > 0);
+
+#endif
}
/*
- receive incoming data from the listening
- udp socket and write it to the ethertap
- device after being decrypted
+ Check if the other end is active.
+ If we have sent packets, but didn't receive any,
+ then possibly the other end is dead. We send a
+ PING request over the meta connection. If the other
+ end does not reply in time, we consider them dead
+ and close the connection.
*/
-int handle_incoming_vpn_data(conn_list_t *cl)
-{
- real_packet_t rp;
- int lenin;
- int x, l = sizeof(x);
- conn_list_t *f;
-cp
- if(getsockopt(cl->socket, SOL_SOCKET, SO_ERROR, &x, &l) < 0)
- {
- syslog(LOG_ERR, "This is a bug: %s:%d: %d:%m", __FILE__, __LINE__, cl->socket);
- return -1;
- }
- if(x)
- {
- syslog(LOG_ERR, "Incoming data socket error: %s", sys_errlist[x]);
- return -1;
- }
-
- rp.len = -1;
- lenin = recvfrom(cl->socket, &rp, MTU, 0, NULL, NULL);
- if(lenin <= 0)
- {
- syslog(LOG_ERR, "Receiving data failed: %m");
- return -1;
- }
- total_socket_in += lenin;
- if(rp.len >= 0)
- {
- f = lookup_conn(rp.from);
- if(debug_lvl > 3)
- syslog(LOG_DEBUG, "packet from " IP_ADDR_S " (len %d)",
- IP_ADDR_V(rp.from), rp.len);
- if(!f)
- {
- syslog(LOG_ERR, "Got packet from unknown source " IP_ADDR_S,
- IP_ADDR_V(rp.from));
- return -1;
+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;
}
- if(f->status.validkey)
- xrecv(f, &rp);
- else
- {
- add_queue(&(f->rq), &rp, rp.len);
- if(!cl->status.waitingforkey)
- send_key_request(rp.from);
+ 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 {
+ 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);
+ }
}
- if(my_key_expiry <= time(NULL))
- regenerate_keys();
- }
-cp
- return 0;
+ timeout_set(data, &(struct timeval) {
+ 1, rand() % 100000
+ });
}
-/*
- terminate a connection and notify the other
- end before closing the sockets
-*/
-void terminate_connection(conn_list_t *cl)
-{
-cp
- if(cl->status.remove)
- return;
-
- if(debug_lvl > 0)
- syslog(LOG_NOTICE, "Closing connection with %s.", cl->hostname);
-
- if(cl->status.timeout)
- send_timeout(cl);
- else if(!cl->status.termreq)
- send_termreq(cl);
-
- close(cl->socket);
- if(cl->status.meta)
- close(cl->meta_socket);
-
- if(cl->status.outgoing)
- {
- alarm(5);
- signal(SIGALRM, sigalrm_handler);
- syslog(LOG_NOTICE, "Try to re-establish outgoing connection in 5 seconds.");
- }
-
- cl->status.remove = 1;
-cp
-}
+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);
+ nanosleep(&(struct timespec) {
+ sleeptime, 0
+ }, NULL);
+ sleeptime *= 2;
+
+ if(sleeptime < 0) {
+ sleeptime = 3600;
+ }
+ } else {
+ sleeptime /= 2;
+
+ if(sleeptime < 10) {
+ sleeptime = 10;
+ }
+ }
-/*
- send out a ping request to all active
- connections
-*/
-int send_broadcast_ping(void)
-{
- conn_list_t *p;
-cp
- for(p = conn_list; p != NULL; p = p->next)
- {
- if(p->status.remove)
- continue;
- if(p->status.active && p->status.meta)
- {
- if(send_ping(p))
- terminate_connection(p);
- else
- {
- p->status.pinged = 1;
- p->status.got_pong = 0;
- }
+ contradicting_add_edge = 0;
+ contradicting_del_edge = 0;
+
+ /* If AutoConnect is set, check if we need to make or break connections. */
+
+ if(autoconnect && node_tree->count > 1) {
+ do_autoconnect();
}
- }
- last_ping_time = time(NULL);
-cp
- return 0;
+ timeout_set(data, &(struct timeval) {
+ 5, rand() % 100000
+ });
}
-/*
- end all connections that did not respond
- to the ping probe in time
-*/
-int check_dead_connections(void)
-{
- conn_list_t *p;
-cp
- for(p = conn_list; p != NULL; p = p->next)
- {
- if(p->status.remove)
- continue;
- if(p->status.active && p->status.meta && p->status.pinged && !p->status.got_pong)
- {
- syslog(LOG_INFO, "%s (" IP_ADDR_S ") didn't respond to ping",
- p->hostname, IP_ADDR_V(p->vpn_ip));
- p->status.timeout = 1;
- terminate_connection(p);
+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;
}
- }
-cp
- return 0;
}
-/*
- accept a new tcp connect and create a
- new connection
-*/
-int handle_new_meta_connection(conn_list_t *cl)
-{
- conn_list_t *ncn;
- struct sockaddr client;
- int nfd, len = sizeof(client);
-cp
- if((nfd = accept(cl->meta_socket, &client, &len)) < 0)
- {
- syslog(LOG_ERR, "Accepting a new connection failed: %m");
- return -1;
- }
-
- if((ncn = create_new_connection(nfd)) == NULL)
- {
- shutdown(nfd, 2);
- close(nfd);
- syslog(LOG_NOTICE, "Closed attempted connection.");
- return 0;
- }
-
- ncn->status.meta = 1;
- ncn->next = conn_list;
- conn_list = ncn;
-cp
- return 0;
+#ifndef HAVE_MINGW
+static void sigterm_handler(void *data) {
+ logger(DEBUG_ALWAYS, LOG_NOTICE, "Got %s signal", strsignal(((signal_t *)data)->signum));
+ event_exit();
}
-/*
- dispatch any incoming meta requests
-*/
-int handle_incoming_meta_data(conn_list_t *cl)
-{
- int x, l = sizeof(x);
- unsigned char tmp[1600];
- int request;
- int lenin = 0;
-cp
- if(getsockopt(cl->meta_socket, SOL_SOCKET, SO_ERROR, &x, &l) < 0)
- {
- syslog(LOG_ERR, "This is a bug: %s:%d: %d:%m", __FILE__, __LINE__, cl->meta_socket);
- return -1;
- }
- if(x)
- {
- syslog(LOG_ERR, "Metadata socket error: %s", sys_errlist[x]);
- return -1;
- }
-
- if(read(cl->meta_socket, &tmp, 1) <= 0)
- {
- syslog(LOG_ERR, "Receive failed: %m");
- return -1;
- }
-
- request = (int)(tmp[0]);
-
- if(debug_lvl > 3)
- syslog(LOG_DEBUG, "got request %d", request);
-
- if(request_handlers[request] == NULL)
- syslog(LOG_ERR, "Unknown request %d.", request);
- else
- if(request_handlers[request](cl) < 0)
- return -1;
-cp
- return 0;
+static void sighup_handler(void *data) {
+ logger(DEBUG_ALWAYS, LOG_NOTICE, "Got %s signal", strsignal(((signal_t *)data)->signum));
+ reopenlogger();
+
+ if(reload_configuration()) {
+ exit(1);
+ }
}
-/*
- check all connections to see if anything
- happened on their sockets
-*/
-void check_network_activity(fd_set *f)
-{
- conn_list_t *p;
- int x, l = sizeof(x);
-cp
- for(p = conn_list; p != NULL; p = p->next)
- {
- if(p->status.remove)
- continue;
-
- if(p->status.dataopen)
- if(FD_ISSET(p->socket, f))
- {
- /*
- The only thing that can happen to get us here is apparently an
- error on this outgoing(!) UDP socket that isn't immediate (i.e.
- something that will not trigger an error directly on send()).
- I've once got here when it said `No route to host'.
- */
- getsockopt(p->socket, SOL_SOCKET, SO_ERROR, &x, &l);
- syslog(LOG_ERR, "Outgoing data socket error: %s", sys_errlist[x]);
- terminate_connection(p);
- return;
- }
-
- if(p->status.meta)
- if(FD_ISSET(p->meta_socket, f))
- if(handle_incoming_meta_data(p) < 0)
- {
- terminate_connection(p);
- return;
- }
- }
-
- if(FD_ISSET(myself->socket, f))
- handle_incoming_vpn_data(myself);
-
- if(FD_ISSET(myself->meta_socket, f))
- handle_new_meta_connection(myself);
-cp
+static void sigalrm_handler(void *data) {
+ logger(DEBUG_ALWAYS, LOG_NOTICE, "Got %s signal", strsignal(((signal_t *)data)->signum));
+ retry();
}
+#endif
-/*
- read, encrypt and send data that is
- available through the ethertap device
-*/
-void handle_tap_input(void)
-{
- vpn_packet_t vp;
- ip_t from, to;
- int ether_type, lenin;
-cp
- memset(&vp, 0, sizeof(vp));
- if((lenin = read(tap_fd, &vp, MTU)) <= 0)
- {
- syslog(LOG_ERR, "Error while reading from tapdevice: %m");
- return;
- }
-
- total_tap_in += lenin;
-
- ether_type = ntohs(*((unsigned short*)(&vp.data[12])));
- if(ether_type != 0x0800)
- {
- if(debug_lvl > 0)
- syslog(LOG_INFO, "Non-IP ethernet frame %04x from " MAC_ADDR_S,
- ether_type, MAC_ADDR_V(vp.data[6]));
- return;
- }
-
- if(lenin < 32)
- {
- if(debug_lvl > 0)
- syslog(LOG_INFO, "Dropping short packet");
- return;
- }
-
- from = ntohl(*((unsigned long*)(&vp.data[26])));
- to = ntohl(*((unsigned long*)(&vp.data[30])));
-
- if(debug_lvl > 3)
- syslog(LOG_DEBUG, "An IP packet (%04x) for " IP_ADDR_S " from " IP_ADDR_S,
- ether_type, IP_ADDR_V(to), IP_ADDR_V(from));
- if(debug_lvl > 4)
- syslog(LOG_DEBUG, MAC_ADDR_S " to " MAC_ADDR_S,
- MAC_ADDR_V(vp.data[0]), MAC_ADDR_V(vp.data[6]));
-
- vp.len = (length_t)lenin - 2;
-
- strip_mac_addresses(&vp);
-
- send_packet(to, &vp);
-cp
+int reload_configuration(void) {
+ char fname[PATH_MAX];
+
+ /* Reread our own configuration file */
+
+ exit_configuration(&config_tree);
+ init_configuration(&config_tree);
+
+ if(!read_server_config()) {
+ logger(DEBUG_ALWAYS, LOG_ERR, "Unable to reread configuration file.");
+ return EINVAL;
+ }
+
+ read_config_options(config_tree, NULL);
+
+ snprintf(fname, sizeof(fname), "%s" SLASH "hosts" SLASH "%s", confbase, myself->name);
+ read_config_file(config_tree, fname, true);
+
+ /* Parse some options that are allowed to be changed while tinc is running */
+
+ setup_myself_reloadable();
+
+ /* If StrictSubnet is set, expire deleted Subnets and read new ones in */
+
+ if(strictsubnets) {
+ for splay_each(subnet_t, subnet, subnet_tree)
+ if(subnet->owner) {
+ subnet->expires = 1;
+ }
+ }
+
+ for splay_each(node_t, n, node_tree) {
+ n->status.has_address = false;
+ }
+
+ load_all_nodes();
+
+ if(strictsubnets) {
+ for splay_each(subnet_t, subnet, subnet_tree) {
+ if(!subnet->owner) {
+ continue;
+ }
+
+ 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);
+ }
+ }
+ }
+ } 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(cfg) {
+ subnet_t *subnet, *s2;
+
+ if(get_config_subnet(cfg, &subnet)) {
+ if((s2 = lookup_subnet(myself, subnet))) {
+ if(s2->expires == 1) {
+ s2->expires = 0;
+ }
+
+ free_subnet(subnet);
+ } else {
+ subnet_add(myself, subnet);
+ send_add_subnet(everyone, subnet);
+ subnet_update(myself, subnet, true);
+ }
+ }
+
+ cfg = lookup_config_next(config_tree, cfg);
+ }
+
+ 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);
+ }
+ }
+ }
+
+ /* Try to make outgoing connections */
+
+ try_outgoing_connections();
+
+ /* 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...
*/
-void main_loop(void)
-{
- fd_set fset;
- struct timeval tv;
- int r;
-cp
- last_ping_time = time(NULL);
-
- for(;;)
- {
- tv.tv_sec = timeout;
- tv.tv_usec = 0;
-
- prune_conn_list();
- build_fdset(&fset);
-
- if((r = select(FD_SETSIZE, &fset, NULL, NULL, &tv)) < 0)
- {
- if(errno == EINTR) /* because of alarm */
- continue;
- syslog(LOG_ERR, "Error while waiting for input: %m");
- return;
- }
-
- if(r == 0 || last_ping_time + timeout < time(NULL))
- /* Timeout... hm... something might be wrong. */
- {
- check_dead_connections();
- send_broadcast_ping();
- continue;
+int main_loop(void) {
+ last_periodic_run_time = now;
+ timeout_add(&pingtimer, timeout_handler, &pingtimer, &(struct timeval) {
+ pingtimeout, rand() % 100000
+ });
+ timeout_add(&periodictimer, periodic_handler, &periodictimer, &(struct timeval) {
+ 0, 0
+ });
+
+#ifndef HAVE_MINGW
+ 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;
}
- check_network_activity(&fset);
+#ifndef HAVE_MINGW
+ signal_del(&sighup);
+ signal_del(&sigterm);
+ signal_del(&sigquit);
+ signal_del(&sigint);
+ signal_del(&sigalrm);
+#endif
+
+ timeout_del(&periodictimer);
+ timeout_del(&pingtimer);
- /* local tap data */
- if(FD_ISSET(tap_fd, &fset))
- handle_tap_input();
- }
-cp
+ return 0;
}