Don't send proxy requests for incoming connections.
[tinc] / src / net.c
index f6b1470..9799fea 100644 (file)
--- a/src/net.c
+++ b/src/net.c
@@ -1,7 +1,9 @@
 /*
     net.c -- most of the network code
     Copyright (C) 1998-2005 Ivo Timmermans,
-                  2000-2006 Guus Sliepen <guus@tinc-vpn.org>
+                  2000-2012 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.
-
-    $Id$
+    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"
 
 bool do_purge = false;
 volatile bool running = false;
+#ifdef HAVE_PSELECT
+bool graph_dump = false;
+#endif
 
 time_t now = 0;
+int contradicting_add_edge = 0;
+int contradicting_del_edge = 0;
+static int sleeptime = 10;
 
 /* Purge edges and subnets of unreachable nodes. Use carefully. */
 
-static void purge(void)
-{
+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"));
+       ifdebug(PROTOCOL) logger(LOG_DEBUG, "Purging unreachable nodes");
 
        /* Remove all edges and subnets owned by unreachable nodes. */
 
@@ -66,22 +69,22 @@ static void purge(void)
                n = nnode->data;
 
                if(!n->status.reachable) {
-                       ifdebug(SCARY_THINGS) logger(LOG_DEBUG, _("Purging node %s (%s)"), n->name,
+                       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);
+                               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(broadcast, e);
+                                       send_del_edge(everyone, e);
                                edge_del(e);
                        }
                }
@@ -102,7 +105,8 @@ static void purge(void)
                                        break;
                        }
 
-                       if(!enode)
+                       if(!enode && (!strictsubnets || !n->subnet_tree->head))
+                               /* in strictsubnets mode do not delete nodes with subnets */
                                node_del(n);
                }
        }
@@ -112,14 +116,11 @@ static void purge(void)
   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)
-{
+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);
 
@@ -149,7 +150,8 @@ static int build_fdset(fd_set *readset, fd_set *writeset)
                        max = listen_socket[i].udp;
        }
 
-       FD_SET(device_fd, readset);
+       if(device_fd >= 0)
+               FD_SET(device_fd, readset);
        if(device_fd > max)
                max = device_fd;
        
@@ -163,14 +165,11 @@ static int build_fdset(fd_set *readset, fd_set *writeset)
   - Check if we need to retry making an outgoing connection
   - Deactivate the host
 */
-void terminate_connection(connection_t *c, bool report)
-{
-       cp();
-
+void terminate_connection(connection_t *c, bool report) {
        if(c->status.remove)
                return;
 
-       ifdebug(CONNECTIONS) logger(LOG_NOTICE, _("Closing connection with %s (%s)"),
+       ifdebug(CONNECTIONS) logger(LOG_NOTICE, "Closing connection with %s (%s)",
                           c->name, c->hostname);
 
        c->status.remove = true;
@@ -184,7 +183,7 @@ void terminate_connection(connection_t *c, bool report)
 
        if(c->edge) {
                if(report && !tunnelserver)
-                       send_del_edge(broadcast, c->edge);
+                       send_del_edge(everyone, c->edge);
 
                edge_del(c->edge);
 
@@ -199,24 +198,20 @@ void terminate_connection(connection_t *c, bool report)
                        e = lookup_edge(c->node, myself);
                        if(e) {
                                if(!tunnelserver)
-                                       send_del_edge(broadcast, e);
+                                       send_del_edge(everyone, e);
                                edge_del(e);
                        }
                }
        }
 
+       free_connection_partially(c);
+
        /* Check if this was our outgoing connection */
 
        if(c->outgoing) {
-               retry_outgoing(c->outgoing);
-               c->outgoing = NULL;
+               c->status.remove = false;
+               do_outgoing_connection(c);      
        }
-
-       free(c->outbuf);
-       c->outbuf = NULL;
-       c->outbuflen = 0;
-       c->outbufsize = 0;
-       c->outbufstart = 0;
 }
 
 /*
@@ -227,35 +222,32 @@ void terminate_connection(connection_t *c, bool report)
   end does not reply in time, we consider them dead
   and close the connection.
 */
-static void check_dead_connections(void)
-{
+static 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 = node->data;
 
-               if(c->last_ping_time + pingtimeout < now) {
+               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);
+                                       ifdebug(CONNECTIONS) logger(LOG_INFO, "%s (%s) didn't respond to PING in %ld seconds",
+                                                          c->name, c->hostname, (long)now - c->last_ping_time);
                                        c->status.timeout = true;
                                        terminate_connection(c, true);
-                               } else if(c->last_ping_time + pinginterval < now) {
+                               } 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);
+                                       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"),
+                               ifdebug(CONNECTIONS) logger(LOG_WARNING, "Timeout from %s (%s) during authentication",
                                                   c->name, c->hostname);
                                if(c->status.connecting) {
                                        c->status.connecting = false;
@@ -267,11 +259,11 @@ static void check_dead_connections(void)
                        }
                }
 
-               if(c->outbuflen > 0 && c->last_flushed_time + pingtimeout < now) {
+               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);
+                                               "%s (%s) could not flush for %ld seconds (%d bytes remaining)",
+                                               c->name, c->hostname, (long)now - c->last_flushed_time, c->outbuflen);
                                c->status.timeout = true;
                                terminate_connection(c, true);
                        }
@@ -283,20 +275,30 @@ static void check_dead_connections(void)
   check all connections to see if anything
   happened on their sockets
 */
-static void check_network_activity(fd_set * readset, fd_set * writeset)
-{
+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();
+       static int errors = 0;
 
        /* check input from kernel */
-       if(FD_ISSET(device_fd, readset)) {
-               if(read_packet(&packet))
-                       route(myself, &packet);
+       if(device_fd >= 0 && FD_ISSET(device_fd, readset)) {
+               if(devops.read(&packet)) {
+                       if(packet.len) {
+                               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 */
@@ -309,14 +311,14 @@ static void check_network_activity(fd_set * readset, fd_set * writeset)
                if(FD_ISSET(c->socket, readset)) {
                        if(c->status.connecting) {
                                c->status.connecting = false;
-                               getsockopt(c->socket, SOL_SOCKET, SO_ERROR, &result, &len);
+                               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, strerror(result));
+                                                          "Error while connecting to %s (%s): %s",
+                                                          c->name, c->hostname, sockstrerror(result));
                                        closesocket(c->socket);
                                        do_outgoing_connection(c);
                                        continue;
@@ -339,7 +341,7 @@ static void check_network_activity(fd_set * readset, fd_set * writeset)
 
        for(i = 0; i < listen_sockets; i++) {
                if(FD_ISSET(listen_socket[i].udp, readset))
-                       handle_incoming_vpn_data(listen_socket[i].udp);
+                       handle_incoming_vpn_data(i);
 
                if(FD_ISSET(listen_socket[i].tcp, readset))
                        handle_new_meta_connection(listen_socket[i].tcp);
@@ -349,48 +351,81 @@ static void check_network_activity(fd_set * readset, fd_set * writeset)
 /*
   this is where it all happens...
 */
-int main_loop(void)
-{
+int main_loop(void) {
        fd_set readset, writeset;
+#ifdef HAVE_PSELECT
+       struct timespec tv;
+       sigset_t omask, block_mask;
+       time_t next_event;
+#else
        struct timeval tv;
+#endif
        int r, maxfd;
        time_t last_ping_check, last_config_check, last_graph_dump;
        event_t *event;
 
-       cp();
-
        last_ping_check = now;
        last_config_check = now;
        last_graph_dump = now;
        
        srand(now);
 
+#ifdef HAVE_PSELECT
+       if(lookup_config(config_tree, "GraphDumpFile"))
+               graph_dump = true;
+       /* Block SIGHUP & SIGALRM */
+       sigemptyset(&block_mask);
+       sigaddset(&block_mask, SIGHUP);
+       sigaddset(&block_mask, SIGALRM);
+       sigprocmask(SIG_BLOCK, &block_mask, &omask);
+#endif
+
        running = true;
 
        while(running) {
-               now = time(NULL);
-
-       //      tv.tv_sec = 1 + (rand() & 7);   /* Approx. 5 seconds, randomized to prevent global synchronisation effects */
+#ifdef HAVE_PSELECT
+               next_event = last_ping_check + pingtimeout;
+               if(graph_dump && next_event > last_graph_dump + 60)
+                       next_event = last_graph_dump + 60;
+
+               if((event = peek_next_event()) && next_event > event->time)
+                       next_event = event->time;
+
+               if(next_event <= now)
+                       tv.tv_sec = 0;
+               else
+                       tv.tv_sec = next_event - now;
+               tv.tv_nsec = 0;
+#else
                tv.tv_sec = 1;
                tv.tv_usec = 0;
+#endif
 
                maxfd = build_fdset(&readset, &writeset);
 
+#ifdef HAVE_MINGW
+               LeaveCriticalSection(&mutex);
+#endif
+#ifdef HAVE_PSELECT
+               r = pselect(maxfd + 1, &readset, &writeset, NULL, &tv, &omask);
+#else
                r = select(maxfd + 1, &readset, &writeset, NULL, &tv);
+#endif
+               now = time(NULL);
+#ifdef HAVE_MINGW
+               EnterCriticalSection(&mutex);
+#endif
 
                if(r < 0) {
-                       if(errno != EINTR && errno != EAGAIN) {
-                               logger(LOG_ERR, _("Error while waiting for input: %s"),
-                                          strerror(errno));
-                               cp_trace();
+                       if(!sockwouldblock(sockerrno)) {
+                               logger(LOG_ERR, "Error while waiting for input: %s", sockstrerror(sockerrno));
                                dump_connections();
                                return 1;
                        }
-
-                       continue;
                }
 
-               check_network_activity(&readset, &writeset);
+               if(r > 0)
+                       check_network_activity(&readset, &writeset);
 
                if(do_purge) {
                        purge();
@@ -399,7 +434,7 @@ int main_loop(void)
 
                /* Let's check if everybody is still alive */
 
-               if(last_ping_check + pingtimeout < now) {
+               if(last_ping_check + pingtimeout <= now) {
                        check_dead_connections();
                        last_ping_check = now;
 
@@ -410,36 +445,70 @@ int main_loop(void)
 
                        /* Should we regenerate our key? */
 
-                       if(keyexpires < now) {
-                               ifdebug(STATUS) logger(LOG_INFO, _("Regenerating symmetric key"));
+                       if(keyexpires <= now) {
+                               avl_node_t *node;
+                               node_t *n;
 
-                               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);
+                               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();
                                keyexpires = now + keylifetime;
                        }
-               }
 
+                       /* Detect ADD_EDGE/DEL_EDGE storms that are caused when
+                        * two tinc daemons with the same name are on the VPN.
+                        * If so, sleep a while. If this happens multiple times
+                        * in a row, sleep longer. */
+
+                       if(contradicting_del_edge > 100 && contradicting_add_edge > 100) {
+                               logger(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;
+                       }
 
-               while((event = get_expired_event())) {
-                       event->handler(event->data);
-                       free_event(event);
+                       contradicting_add_edge = 0;
+                       contradicting_del_edge = 0;
                }
 
                if(sigalrm) {
-                       logger(LOG_INFO, _("Flushing event queue"));
-                       flush_events();
+                       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;
+                       avl_node_t *node, *next;
                        char *fname;
                        struct stat s;
                        
                        sighup = false;
+
+                       reopenlogger();
                        
                        /* Reread our own configuration file */
 
@@ -447,24 +516,41 @@ int main_loop(void)
                        init_configuration(&config_tree);
 
                        if(!read_server_config()) {
-                               logger(LOG_ERR, _("Unable to reread configuration file, exitting."));
+                               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;
                                
-                               if(c->outgoing) {
-                                       free(c->outgoing->name);
-                                       if(c->outgoing->ai)
-                                               freeaddrinfo(c->outgoing->ai);
-                                       free(c->outgoing);
-                                       c->outgoing = NULL;
-                               }
-                               
-                               asprintf(&fname, "%s/hosts/%s", confbase, c->name);
+                               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);
@@ -472,6 +558,36 @@ int main_loop(void)
 
                        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(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);
+                                       }
+                               }
+                       }
+
                        /* Try to make outgoing connections */
                        
                        try_outgoing_connections();
@@ -479,11 +595,16 @@ int main_loop(void)
                
                /* Dump graph if wanted every 60 seconds*/
 
-               if(last_graph_dump + 60 < now) {
+               if(last_graph_dump + 60 <= now) {
                        dump_graph();
                        last_graph_dump = now;
                }
        }
 
+#ifdef HAVE_PSELECT
+       /* Restore SIGHUP & SIGALARM mask */
+       sigprocmask(SIG_SETMASK, &omask, NULL);
+#endif
+
        return 0;
 }