]> git.meshlink.io Git - meshlink/blobdiff - src/net.c
Merge branch 'mesh_topology_output' into roles
[meshlink] / src / net.c
index 6979083f1948690d5f468b2ce45d2c43be5d82f8..80e866a0ad461fc49bce1794379044ca97e2e33c 100644 (file)
--- a/src/net.c
+++ b/src/net.c
@@ -1,9 +1,6 @@
 /*
     net.c -- most of the network code
-    Copyright (C) 1998-2005 Ivo Timmermans,
-                  2000-2012 Guus Sliepen <guus@tinc-vpn.org>
-                  2006      Scott Lamb <slamb@slamb.org>
-                 2011      Loïc Grenié <loic.grenie@gmail.com>
+    Copyright (C) 2014 Guus Sliepen <guus@meshlink.io>
 
     This program is free software; you can redistribute it and/or modify
     it under the terms of the GNU General Public License as published by
 
 #include "system.h"
 
-#include <openssl/rand.h>
-
 #include "utils.h"
-#include "avl_tree.h"
 #include "conf.h"
 #include "connection.h"
-#include "device.h"
-#include "event.h"
 #include "graph.h"
 #include "logger.h"
+#include "meshlink_internal.h"
 #include "meta.h"
 #include "net.h"
 #include "netutl.h"
-#include "process.h"
 #include "protocol.h"
-#include "route.h"
-#include "subnet.h"
 #include "xalloc.h"
 
-bool do_purge = false;
-volatile bool running = false;
-#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) {
-       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. */
+#include <assert.h>
 
-       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(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(everyone, 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.
-*/
-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;
+static const int min(int a, int b) {
+       return a < b ? a : b;
 }
 
 /*
   Terminate a connection:
-  - Close the socket
-  - Remove associated edge and tell other connections about it if report = true
+  - Mark it as inactive
+  - Remove the edge representing this connection
+  - Kill it with fire
   - Check if we need to retry making an outgoing connection
-  - Deactivate the host
 */
-void terminate_connection(connection_t *c, bool report) {
-       if(c->status.remove)
-               return;
-
-       ifdebug(CONNECTIONS) logger(LOG_NOTICE, "Closing connection with %s (%s)",
-                          c->name, c->hostname);
+void terminate_connection(meshlink_handle_t *mesh, connection_t *c, bool report) {
+       logger(mesh, MESHLINK_INFO, "Closing connection with %s (%s)", c->name, c->hostname);
 
-       c->status.remove = true;
        c->status.active = false;
 
-       if(c->node)
+       if(c->node && c->node->connection == c)
                c->node->connection = NULL;
 
-       if(c->socket)
-               closesocket(c->socket);
-
        if(c->edge) {
-               if(report && !tunnelserver)
-                       send_del_edge(everyone, c->edge);
+               if(report)
+                       send_del_edge(mesh, mesh->everyone, c->edge);
 
-               edge_del(c->edge);
+               edge_del(mesh, c->edge);
+               c->edge = NULL;
 
                /* Run MST and SSSP algorithms */
 
-               graph();
+               graph(mesh);
 
                /* If the node is not reachable anymore but we remember it had an edge to us, clean it up */
 
                if(report && !c->node->status.reachable) {
                        edge_t *e;
-                       e = lookup_edge(c->node, myself);
+                       e = lookup_edge(c->node, mesh->self);
                        if(e) {
-                               if(!tunnelserver)
-                                       send_del_edge(everyone, e);
-                               edge_del(e);
+                               send_del_edge(mesh, mesh->everyone, e);
+                               edge_del(mesh, e);
                        }
                }
        }
 
+       outgoing_t *outgoing = c->outgoing;
+       connection_del(mesh, c);
+
        /* Check if this was our outgoing connection */
 
-       if(c->outgoing) {
-               retry_outgoing(c->outgoing);
-               c->outgoing = NULL;
-       }
+       if(outgoing)
+               do_outgoing_connection(mesh, outgoing);
 
-       free(c->outbuf);
-       c->outbuf = NULL;
-       c->outbuflen = 0;
-       c->outbufsize = 0;
-       c->outbufstart = 0;
+#ifndef HAVE_MINGW
+       /* Clean up dead proxy processes */
+
+       while(waitpid(-1, NULL, WNOHANG) > 0);
+#endif
 }
 
 /*
@@ -226,387 +98,491 @@ 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) {
-       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) {
+static void timeout_handler(event_loop_t *loop, void *data) {
+       meshlink_handle_t *mesh = loop->data;
+       logger(mesh, MESHLINK_DEBUG, "timeout_handler()");
+
+       for list_each(connection_t, c, mesh->connections) {
+               // Also make sure that if outstanding key requests for the UDP counterpart of a connection has timed out, we restart it.
+               if(c->node) {
+                       if(c->node->status.waitingforkey && c->node->last_req_key + mesh->pingtimeout <= mesh->loop.now.tv_sec)
+                               send_req_key(mesh, c->node);
+               }
+               if(c->last_ping_time + mesh->pingtimeout <= mesh->loop.now.tv_sec) {
                        if(c->status.active) {
                                if(c->status.pinged) {
-                                       ifdebug(CONNECTIONS) logger(LOG_INFO, "%s (%s) didn't respond to PING in %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);
+                                       logger(mesh, MESHLINK_INFO, "%s (%s) didn't respond to PING in %ld seconds", c->name, c->hostname, (long)mesh->loop.now.tv_sec - c->last_ping_time);
+                               } else if(c->last_ping_time + mesh->pinginterval <= mesh->loop.now.tv_sec) {
+                                       send_ping(mesh, c);
                                        continue;
-                               }
-                               ifdebug(CONNECTIONS) logger(LOG_WARNING, "Timeout from %s (%s) during authentication",
-                                                  c->name, c->hostname);
-                               if(c->status.connecting) {
-                                       c->status.connecting = false;
-                                       closesocket(c->socket);
-                                       do_outgoing_connection(c);
                                } else {
-                                       terminate_connection(c, false);
+                                       continue;
                                }
+                       } else {
+                               if(c->status.connecting)
+                                       logger(mesh, MESHLINK_WARNING, "Timeout while connecting to %s (%s)", c->name, c->hostname);
+                               else
+                                       logger(mesh, MESHLINK_WARNING, "Timeout from %s (%s) during authentication", c->name, c->hostname);
                        }
-               }
-
-               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);
-                       }
+                       terminate_connection(mesh, c, c->status.active);
                }
        }
+
+       timeout_set(&mesh->loop, data, &(struct timeval){mesh->pingtimeout, rand() % 100000});
+}
+
+// devclass asc, last_connect_try desc
+static int node_compare_devclass_asc_last_connect_try_desc(const void *a, const void *b)
+{
+       const node_t *na = a, *nb = b;
+
+       if(na->devclass < nb->devclass)
+               { return -1; }
+
+       if(na->devclass > nb->devclass)
+               { return 1; }
+
+       if(na->last_connect_try == nb->last_connect_try)
+               return 0;
+
+       if(nb->last_connect_try == 0 || na->last_connect_try < nb->last_connect_try)
+               return -1;
+
+       if(na->last_connect_try == 0 || na->last_connect_try > nb->last_connect_try)
+               return 1;
+
+       return 0;
+}
+
+// last_connect_try desc
+static int node_compare_last_connect_try_desc(const void *a, const void *b)
+{
+       const node_t *na = a, *nb = b;
+
+       if(na->last_connect_try == nb->last_connect_try)
+               return 0;
+
+       if(nb->last_connect_try == 0 || na->last_connect_try < nb->last_connect_try)
+               return -1;
+
+       if(na->last_connect_try == 0 || na->last_connect_try > nb->last_connect_try)
+               return 1;
+
+       return 0;
+}
+
+// devclass desc
+static int node_compare_devclass_desc(const void *a, const void *b)
+{
+       const node_t *na = a, *nb = b;
+
+       if(na->devclass < nb->devclass)
+               { return -1; }
+
+       if(na->devclass > nb->devclass)
+               { return 1; }
+
+       return 0;
 }
 
+
 /*
-  check all connections to see if anything
-  happened on their sockets
-*/
-static void check_network_activity(fd_set * readset, fd_set * writeset) {
-       connection_t *c;
-       avl_node_t *node;
-       int result, i;
-       socklen_t len = sizeof(result);
-       vpn_packet_t packet;
-       static int errors = 0;
-
-       /* check input from kernel */
-       if(device_fd >= 0 && FD_ISSET(device_fd, readset)) {
-               if(devops.read(&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;
-                       }
-               }
+
+
+autoconnect()
+{
+       timeout = 5
+
+       // find the best one for initial connect
+
+       if cur < min
+               newcon =
+                       first from nodes
+                               where dclass <= my.dclass and !connection and (timestamp - last_retry) > retry_timeout
+                               order by dclass asc, last_connection desc
+               if newcon
+                       timeout = 0
+                       goto connect
+
+
+       // find better nodes to connect to: in case we have less than min connections within [BACKBONE, i] and there are nodes which we are not connected to within the range
+
+       if min <= cur < max
+               j = 0
+               for i = BACKBONE to my.dclass
+                       j += count(from connections where node.dclass = i)
+                       if j < min
+                               newcon =
+                                       first from nodes
+                                               where dclass = i and !connection and (timestamp - last_retry) > retry_timeout
+                                               order by last_connection desc
+                               if newcon
+                                       goto connect
+                       else
+                               break
+
+
+       // heal partitions
+
+       if min <= cur < max
+               newcon =
+                       first from nodes
+                               where dclass <= my.dclass and !reachable and (timestamp - last_retry) > retry_timeout
+                               order by dclass asc, last_connection desc
+               if newcon
+                       goto connect
+
+
+       // connect
+
+connect:
+       if newcon
+               connect newcon
+
+
+       // disconnect outgoing connections in case we have more than min connections within [BACKBONE, i] and there are nodes which we are connected to within the range [i, PORTABLE]
+
+       if min < cur <= max
+               j = 0
+               for i = BACKBONE to my.dclass
+                       j += count(from connections where node.dclass = i)
+                       if min < j
+                               delcon =
+                                       first from nodes
+                                               where dclass >= i and outgoing_connection
+                                               order by dclass desc
+                               if disconnect
+                                       goto disconnect
+                               else
+                                       break
+
+
+       // disconnect connections in case we have more than enough connections
+
+       if max < cur
+               delcon =
+                       first from nodes
+                               where outgoing_connection
+                               order by dclass desc
+               goto disconnect
+
+       // disconnect
+
+disconnect
+       if delcon
+               disconnect delcon
+
+
+       // next iteration
+       next (timeout, autoconnect)
+
+}
+
+
+ */
+
+
+static void periodic_handler(event_loop_t *loop, void *data) {
+       meshlink_handle_t *mesh = loop->data;
+
+       /* Check if there are too many contradicting ADD_EDGE and DEL_EDGE messages.
+          This usually only happens when another node has the same Name as this node.
+          If so, sleep for a short while to prevent a storm of contradicting messages.
+       */
+
+       if(mesh->contradicting_del_edge > 100 && mesh->contradicting_add_edge > 100) {
+               logger(mesh, MESHLINK_WARNING, "Possible node with same Name as us! Sleeping %d seconds.", mesh->sleeptime);
+               usleep(mesh->sleeptime * 1000000LL);
+               mesh->sleeptime *= 2;
+               if(mesh->sleeptime < 0)
+                       mesh->sleeptime = 3600;
+       } else {
+               mesh->sleeptime /= 2;
+               if(mesh->sleeptime < 10)
+                       mesh->sleeptime = 10;
        }
 
-       /* 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;
-                               }
-                       }
+       mesh->contradicting_add_edge = 0;
+       mesh->contradicting_del_edge = 0;
 
-                       if(!receive_meta(c)) {
-                               terminate_connection(c, c->status.active);
-                               continue;
-                       }
-               }
+       int timeout = 5;
+
+       /* Check if we need to make or break connections. */
+
+       if(mesh->nodes->count > 1) {
+
+               logger(mesh, MESHLINK_INFO, "--- autoconnect begin ---");
+
+
+               int retry_timeout = min(mesh->nodes->count * 5, 60);
+
+               // connect disconnect nodes
+
+               node_t* connect_to = NULL;
+               node_t* disconnect_from = NULL;
 
-               if(FD_ISSET(c->socket, writeset)) {
-                       if(!flush_meta(c)) {
-                               terminate_connection(c, c->status.active);
-                               continue;
+
+               // get cur_connects
+
+               int cur_connects = 0;
+
+               for list_each(connection_t, c, mesh->connections)
+               {
+                       if(!c->status.remove_unused)
+                       {
+                               cur_connects += 1;
                        }
                }
-       }
 
-       for(i = 0; i < listen_sockets; i++) {
-               if(FD_ISSET(listen_socket[i].udp, readset))
-                       handle_incoming_vpn_data(i);
+               logger(mesh, MESHLINK_INFO, "* cur_connects = %d", cur_connects);
 
-               if(FD_ISSET(listen_socket[i].tcp, readset))
-                       handle_new_meta_connection(listen_socket[i].tcp);
-       }
-}
 
-/*
-  this is where it all happens...
-*/
-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;
-
-       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
+               // get min_connects and max_connects
 
-       running = true;
-
-       while(running) {
-#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
+               assert(mesh->devclass >= 0 && mesh->devclass <= _DEV_CLASS_MAX);
 
-               maxfd = build_fdset(&readset, &writeset);
+               int min_connects = dev_class_traits[mesh->devclass].min_connects;
+               int max_connects = dev_class_traits[mesh->devclass].max_connects;
 
-#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
+               logger(mesh, MESHLINK_INFO, "* min_connects = %d", min_connects);
+               logger(mesh, MESHLINK_INFO, "* max_connects = %d", max_connects);
+
+
+               // find the best one for initial connect
+
+               if(cur_connects < min_connects)
+               {
+                       splay_tree_t *nodes = splay_alloc_tree(node_compare_devclass_asc_last_connect_try_desc, NULL);
 
-               if(r < 0) {
-                       if(!sockwouldblock(sockerrno)) {
-                               logger(LOG_ERR, "Error while waiting for input: %s", sockstrerror(sockerrno));
-                               dump_connections();
-                               return 1;
+                       for splay_each(node_t, n, mesh->nodes)
+                       {
+                               if(n->devclass <= mesh->devclass && !n->connection && (n->last_connect_try == 0 || (time(NULL) - n->last_connect_try) > retry_timeout))
+                                       { splay_insert(nodes, n); }
                        }
-               }
 
-               if(r > 0)
-                       check_network_activity(&readset, &writeset);
+                       if(nodes->head)
+                       {
+                               logger(mesh, MESHLINK_INFO, "* found best one for initial connect");
+
+                               //timeout = 0;
+                               connect_to = (node_t*)nodes->head->data;
+                       }
 
-               if(do_purge) {
-                       purge();
-                       do_purge = false;
+                       splay_free_tree(nodes);
                }
 
-               /* Let's check if everybody is still alive */
 
-               if(last_ping_check + pingtimeout <= now) {
-                       check_dead_connections();
-                       last_ping_check = now;
+               // find better nodes to connect to
 
-                       if(routing_mode == RMODE_SWITCH)
-                               age_subnets();
+               if(!connect_to && min_connects <= cur_connects && cur_connects < max_connects)
+               {
+                       unsigned int connects = 0;
 
-                       age_past_requests();
+                       for(int devclass = 0; devclass <= mesh->devclass; ++devclass)
+                       {
+                               for list_each(connection_t, c, mesh->connections)
+                               {
+                                       if(!c->status.remove_unused && c->node && c->node->devclass == devclass)
+                                               { connects += 1; }
+                               }
 
-                       /* Should we regenerate our key? */
+                               if( connects < min_connects )
+                               {
+                                       splay_tree_t *nodes = splay_alloc_tree(node_compare_last_connect_try_desc, NULL);
 
-                       if(keyexpires <= now) {
-                               avl_node_t *node;
-                               node_t *n;
+                                       for splay_each(node_t, n, mesh->nodes)
+                                       {
+                                               if(n->devclass == devclass && !n->connection && (n->last_connect_try == 0 || (time(NULL) - n->last_connect_try) > retry_timeout))
+                                                       { splay_insert(nodes, n); }
+                                       }
 
-                               ifdebug(STATUS) logger(LOG_INFO, "Expiring symmetric keys");
+                                       if(nodes->head)
+                                       {
+                                               logger(mesh, MESHLINK_INFO, "* found better node");
+                                               connect_to = (node_t*)nodes->head->data;
 
-                               for(node = node_tree->head; node; node = node->next) {
-                                       n = node->data;
-                                       if(n->inkey) {
-                                               free(n->inkey);
-                                               n->inkey = NULL;
+                                               splay_free_tree(nodes);
+                                               break;
                                        }
+
+                                       splay_free_tree(nodes);
                                }
+                               else
+                                       { break; }
+                       }
+               }
+
 
-                               send_key_changed();
-                               keyexpires = now + keylifetime;
+               // heal partitions
+
+               if(!connect_to && min_connects <= cur_connects && cur_connects < max_connects)
+               {
+                       splay_tree_t *nodes = splay_alloc_tree(node_compare_devclass_asc_last_connect_try_desc, NULL);
+
+                       for splay_each(node_t, n, mesh->nodes)
+                       {
+                               if(n->devclass <= mesh->devclass && !n->status.reachable && (n->last_connect_try == 0 || (time(NULL) - n->last_connect_try) > retry_timeout))
+                                       { splay_insert(nodes, n); }
                        }
 
-                       /* 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;
+                       if(nodes->head)
+                       {
+                               logger(mesh, MESHLINK_INFO, "* try to heal partition");
+                               connect_to = (node_t*)nodes->head->data;
                        }
 
-                       contradicting_add_edge = 0;
-                       contradicting_del_edge = 0;
+                       splay_free_tree(nodes);
                }
 
-               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);
+
+               // perform connect
+
+               if(connect_to && !connect_to->connection)
+               {
+                       /* check if there is already a connection attempt to this node */
+                       bool found = false;
+                       for list_each(outgoing_t, outgoing, mesh->outgoings) {
+                               if(!strcmp(outgoing->name, connect_to->name)) {
+                                       found = true;
+                                       break;
+                               }
                        }
-                       sigalrm = false;
-               }
 
-               while((event = get_expired_event())) {
-                       event->handler(event->data);
-                       free_event(event);
+                       if(!found)
+                       {
+                               logger(mesh, MESHLINK_INFO, "Autoconnecting to %s", connect_to->name);
+                               outgoing_t *outgoing = xzalloc(sizeof(outgoing_t));
+                               outgoing->mesh = mesh;
+                               outgoing->name = xstrdup(connect_to->name);
+                               list_insert_tail(mesh->outgoings, outgoing);
+                               setup_outgoing_connection(mesh, outgoing);      
+                       }
                }
 
-               if(sighup) {
-                       connection_t *c;
-                       avl_node_t *node, *next;
-                       char *fname;
-                       struct stat s;
-                       
-                       sighup = false;
 
-                       reopenlogger();
-                       
-                       /* Reread our own configuration file */
+               // disconnect suboptimal outgoing connections
 
-                       exit_configuration(&config_tree);
-                       init_configuration(&config_tree);
+               if(min_connects < cur_connects && cur_connects <= max_connects)
+               {
+                       unsigned int connects = 0;
 
-                       if(!read_server_config()) {
-                               logger(LOG_ERR, "Unable to reread configuration file, exitting.");
-                               return 1;
-                       }
+                       for(int devclass = 0; devclass <= mesh->devclass; ++devclass)
+                       {
+                               for list_each(connection_t, c, mesh->connections)
+                               {
+                                       if(!c->status.remove_unused && c->node && c->node->devclass == devclass)
+                                               { connects += 1; }
+                               }
 
-                       /* Cancel non-active outgoing connections */
+                               if( min_connects < connects )
+                               {
+                                       splay_tree_t *nodes = splay_alloc_tree(node_compare_devclass_desc, NULL);
 
-                       for(node = connection_tree->head; node; node = next) {
-                               next = node->next;
-                               c = node->data;
+                                       for list_each(connection_t, c, mesh->connections)
+                                       {
+                                               if(!c->status.remove_unused && c->outgoing && c->node && c->node->devclass >= devclass)
+                                                       { splay_insert(nodes, c->node); }
+                                       }
 
-                               c->outgoing = NULL;
+                                       if(nodes->head)
+                                       {
+                                               logger(mesh, MESHLINK_INFO, "* disconnect suboptimal outgoing connection");
+                                               disconnect_from = (node_t*)nodes->head->data;
+                                       }
 
-                               if(c->status.connecting) {
-                                       terminate_connection(c, false);
-                                       connection_del(c);
+                                       splay_free_tree(nodes);
+                                       break;
                                }
                        }
+               }
 
-                       /* Wipe list of outgoing connections */
 
-                       for(list_node_t *node = outgoing_list->head; node; node = node->next) {
-                               outgoing_t *outgoing = node->data;
+               // disconnect connections (too many connections)
 
-                               if(outgoing->event)
-                                       event_del(outgoing->event);
-                       }
+               if(!disconnect_from && max_connects < cur_connects)
+               {
+                       splay_tree_t *nodes = splay_alloc_tree(node_compare_devclass_desc, NULL);
 
-                       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);
+                       for list_each(connection_t, c, mesh->connections)
+                       {
+                               if(!c->status.remove_unused && c->node)
+                                       { splay_insert(nodes, c->node); }
                        }
 
-                       last_config_check = now;
+                       if(nodes->head)
+                       {
+                               logger(mesh, MESHLINK_INFO, "* disconnect connection (too many connections");
 
-                       /* If StrictSubnet is set, expire deleted Subnets and read new ones in */
+                               //timeout = 0;
+                               disconnect_from = (node_t*)nodes->head->data;
+                       }
 
-                       if(strictsubnets) {
-                               subnet_t *subnet;
+                       splay_free_tree(nodes);
+               }
 
-                               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);
-                                       }
-                               }
-                       }
+               // perform disconnect
 
-                       /* Try to make outgoing connections */
-                       
-                       try_outgoing_connections();
+               if(disconnect_from && disconnect_from->connection)
+               {
+                       logger(mesh, MESHLINK_INFO, "Autodisconnecting from %s", disconnect_from->connection->name);
+                       list_delete(mesh->outgoings, disconnect_from->connection->outgoing);
+                       disconnect_from->connection->outgoing = NULL;
+                       terminate_connection(mesh, disconnect_from->connection, disconnect_from->connection->status.active);
                }
-               
-               /* Dump graph if wanted every 60 seconds*/
 
-               if(last_graph_dump + 60 <= now) {
-                       dump_graph();
-                       last_graph_dump = now;
-               }
+
+               // done!
+
+               logger(mesh, MESHLINK_INFO, "--- autoconnect end ---");
        }
 
-#ifdef HAVE_PSELECT
-       /* Restore SIGHUP & SIGALARM mask */
-       sigprocmask(SIG_SETMASK, &omask, NULL);
-#endif
+       timeout_set(&mesh->loop, data, &(struct timeval){timeout, rand() % 100000});
+}
+
+void handle_meta_connection_data(meshlink_handle_t *mesh, connection_t *c) {
+       if (!receive_meta(mesh, c)) {
+               terminate_connection(mesh, c, c->status.active);
+               return;
+       }
+}
+
+void retry(meshlink_handle_t *mesh) {
+       /* Reset the reconnection timers for all outgoing connections */
+       for list_each(outgoing_t, outgoing, mesh->outgoings) {
+               outgoing->timeout = 0;
+               if(outgoing->ev.cb)
+                       timeout_set(&mesh->loop, &outgoing->ev, &(struct timeval){0, 0});
+       }
+
+       /* Check for outgoing connections that are in progress, and reset their ping timers */
+       for list_each(connection_t, c, mesh->connections) {
+               if(c->outgoing && !c->node)
+                       c->last_ping_time = 0;
+       }
+
+       /* Kick the ping timeout handler */
+       timeout_set(&mesh->loop, &mesh->pingtimer, &(struct timeval){0, 0});
+}
+
+/*
+  this is where it all happens...
+*/
+int main_loop(meshlink_handle_t *mesh) {
+       timeout_add(&mesh->loop, &mesh->pingtimer, timeout_handler, &mesh->pingtimer, &(struct timeval){mesh->pingtimeout, rand() % 100000});
+       timeout_add(&mesh->loop, &mesh->periodictimer, periodic_handler, &mesh->periodictimer, &(struct timeval){0, 0});
+
+       //Add signal handler
+       mesh->datafromapp.signum = 0;
+       signal_add(&(mesh->loop),&(mesh->datafromapp), (signal_cb_t)meshlink_send_from_queue,mesh, mesh->datafromapp.signum);
+
+       if(!event_loop_run(&(mesh->loop), &(mesh->mesh_mutex))) {
+               logger(mesh, MESHLINK_ERROR, "Error while waiting for input: %s", strerror(errno));
+               return 1;
+       }
+
+       timeout_del(&mesh->loop, &mesh->periodictimer);
+       timeout_del(&mesh->loop, &mesh->pingtimer);
 
        return 0;
 }