]> git.meshlink.io Git - meshlink/blobdiff - src/net.c
Fix a debug message being logged incorrectly.
[meshlink] / src / net.c
index 2c08dcf2460e8e175e4867f3e6a37d1098645a1e..05049cffca96c87039f94b6b5b11e5d4c2b224d8 100644 (file)
--- a/src/net.c
+++ b/src/net.c
@@ -1,7 +1,6 @@
 /*
     net.c -- most of the network code
-    Copyright (C) 1998-2001 Ivo Timmermans <itimmermans@bigfoot.com>,
-                  2000,2001 Guus Sliepen <guus@sliepen.warande.net>
+    Copyright (C) 2014-2017 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
     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
     GNU General Public License for more details.
 
-    You should have received a copy of the GNU General Public License
-    along with this program; if not, write to the Free Software
-    Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
-
-    $Id: net.c,v 1.35.4.110 2001/05/28 08:56:57 guus Exp $
+    You should have received a copy of the GNU General Public License along
+    with this program; if not, write to the Free Software Foundation, Inc.,
+    51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
 */
 
-#include "config.h"
-
-#include <errno.h>
-#include <fcntl.h>
-#include <netdb.h>
-#include <netinet/in.h>
-#ifdef HAVE_LINUX
- #include <netinet/ip.h>
- #include <netinet/tcp.h>
-#endif
-#include <stdio.h>
-#include <stdlib.h>
-#include <string.h>
-#include <sys/signal.h>
-#include <sys/time.h>
-#include <sys/types.h>
-#include <syslog.h>
-#include <unistd.h>
-#include <sys/ioctl.h>
-/* SunOS really wants sys/socket.h BEFORE net/if.h,
-   and FreeBSD wants these lines below the rest. */
-#include <arpa/inet.h>
-#include <sys/socket.h>
-#include <net/if.h>
-
-#ifdef HAVE_OPENSSL_RAND_H
-# include <openssl/rand.h>
-#else
-# include <rand.h>
-#endif
-
-#ifdef HAVE_OPENSSL_EVP_H
-# include <openssl/evp.h>
-#else
-# include <evp.h>
-#endif
-
-#ifdef HAVE_OPENSSL_ERR_H
-# include <openssl/err.h>
-#else
-# include <err.h>
-#endif
-
-#ifdef HAVE_OPENSSL_PEM_H
-# include <openssl/pem.h>
-#else
-# include <pem.h>
-#endif
-
-#ifdef HAVE_TUNTAP
-#include LINUX_IF_TUN_H
-#endif
-
-#include <utils.h>
-#include <xalloc.h>
-#include <avl_tree.h>
-#include <list.h>
+#include "system.h"
 
+#include "utils.h"
 #include "conf.h"
 #include "connection.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 "subnet.h"
-#include "process.h"
-#include "route.h"
+#include "sptps.h"
+#include "xalloc.h"
 
-#include "system.h"
+#include <assert.h>
 
-int tap_fd = -1;
-int taptype = TAP_TYPE_ETHERTAP;
-int total_tap_in = 0;
-int total_tap_out = 0;
-int total_socket_in = 0;
-int total_socket_out = 0;
+#if !defined(min)
+static inline int min(int a, int b) {
+       return a < b ? a : b;
+}
+#endif
 
-config_t *upstreamcfg;
-static int seconds_till_retry;
+static const int default_timeout = 5;
+static const int default_interval = 60;
 
-int keylifetime = 0;
-int keyexpires = 0;
+/*
+  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
+*/
+void terminate_connection(meshlink_handle_t *mesh, connection_t *c, bool report) {
+       logger(mesh, MESHLINK_INFO, "Closing connection with %s", c->name);
 
-char *unknown = NULL;
+       c->status.active = false;
 
-void send_udppacket(connection_t *cl, vpn_packet_t *inpkt)
-{
-  vpn_packet_t outpkt;
-  int outlen, outpad;
-  EVP_CIPHER_CTX ctx;
-  struct sockaddr_in to;
-  socklen_t tolen = sizeof(to);
-  vpn_packet_t *copy;
-cp
-  if(!cl->status.validkey)
-    {
-      if(debug_lvl >= DEBUG_TRAFFIC)
-       syslog(LOG_INFO, _("No valid key known yet for %s (%s), queueing packet"),
-              cl->name, cl->hostname);
-
-      /* Since packet is on the stack of handle_tap_input(),
-         we have to make a copy of it first. */
-
-      copy = xmalloc(sizeof(vpn_packet_t));
-      memcpy(copy, inpkt, sizeof(vpn_packet_t));
-
-      list_insert_tail(cl->queue, copy);
-
-      if(!cl->status.waitingforkey)
-       send_req_key(myself, cl);
-      return;
-    }
-
-  /* Encrypt the packet. */
-
-  RAND_bytes(inpkt->salt, sizeof(inpkt->salt));
-
-  EVP_EncryptInit(&ctx, cl->cipher_pkttype, cl->cipher_pktkey, cl->cipher_pktkey + cl->cipher_pkttype->key_len);
-  EVP_EncryptUpdate(&ctx, outpkt.salt, &outlen, inpkt->salt, inpkt->len + sizeof(inpkt->salt));
-  EVP_EncryptFinal(&ctx, outpkt.salt + outlen, &outpad);
-  outlen += outpad;
-
-  total_socket_out += outlen;
-
-  to.sin_family = AF_INET;
-  to.sin_addr.s_addr = htonl(cl->address);
-  to.sin_port = htons(cl->port);
-
-  if((sendto(myself->socket, (char *) outpkt.salt, outlen, 0, (const struct sockaddr *)&to, tolen)) < 0)
-    {
-      syslog(LOG_ERR, _("Error sending packet to %s (%s): %m"),
-             cl->name, cl->hostname);
-      return;
-    }
-cp
-}
+       if(c->node && c->node->connection == c) {
+               c->node->connection = NULL;
+       }
 
-void receive_packet(connection_t *cl, vpn_packet_t *packet)
-{
-cp
-  if(debug_lvl >= DEBUG_TRAFFIC)
-    syslog(LOG_DEBUG, _("Received packet of %d bytes from %s (%s)"), packet->len, cl->name, cl->hostname);
+       if(c->edge) {
+               if(report) {
+                       send_del_edge(mesh, mesh->everyone, c->edge, 0);
+               }
 
-  route_incoming(cl, packet);
-cp
-}
+               edge_del(mesh, c->edge);
+               c->edge = NULL;
 
-void receive_udppacket(connection_t *cl, vpn_packet_t *inpkt)
-{
-  vpn_packet_t outpkt;
-  int outlen, outpad;
-  EVP_CIPHER_CTX ctx;
-cp
-  /* Decrypt the packet */
-
-  EVP_DecryptInit(&ctx, myself->cipher_pkttype, myself->cipher_pktkey, myself->cipher_pktkey + myself->cipher_pkttype->key_len);
-  EVP_DecryptUpdate(&ctx, outpkt.salt, &outlen, inpkt->salt, inpkt->len);
-  EVP_DecryptFinal(&ctx, outpkt.salt + outlen, &outpad);
-  outlen += outpad;
-  outpkt.len = outlen - sizeof(outpkt.salt);
-
-  receive_packet(cl, &outpkt);
-cp
-}
+               /* Run MST and SSSP algorithms */
 
-void receive_tcppacket(connection_t *cl, char *buffer, int len)
-{
-  vpn_packet_t outpkt;
-cp
-  outpkt.len = len;
-  memcpy(outpkt.data, buffer, len);
+               graph(mesh);
 
-  receive_packet(cl, &outpkt);
-cp
-}
+               /* If the node is not reachable anymore but we remember it had an edge to us, clean it up */
 
-void accept_packet(vpn_packet_t *packet)
-{
-cp
-  if(debug_lvl >= DEBUG_TRAFFIC)
-    syslog(LOG_DEBUG, _("Writing packet of %d bytes to tap device"),
-           packet->len);
-
-  if(taptype == TAP_TYPE_TUNTAP)
-    {
-      if(write(tap_fd, packet->data, packet->len) < 0)
-        syslog(LOG_ERR, _("Can't write to tun/tap device: %m"));
-      else
-        total_tap_out += packet->len;
-    }
-  else /* ethertap */
-    {
-      if(write(tap_fd, packet->data - 2, packet->len + 2) < 0)
-        syslog(LOG_ERR, _("Can't write to ethertap device: %m"));
-      else
-        total_tap_out += packet->len;
-    }
-cp
-}
+               if(report && c->node && !c->node->status.reachable) {
+                       edge_t *e;
+                       e = lookup_edge(c->node, mesh->self);
 
-/*
-  send a packet to the given vpn ip.
-*/
-void send_packet(connection_t *cl, vpn_packet_t *packet)
-{
-cp
-  if(debug_lvl >= DEBUG_TRAFFIC)
-    syslog(LOG_ERR, _("Sending packet of %d bytes to %s (%s)"),
-           packet->len, cl->name, cl->hostname);
-
-  if(cl == myself)
-    {
-      if(debug_lvl >= DEBUG_TRAFFIC)
-        {
-          syslog(LOG_NOTICE, _("Packet is looping back to us!"));
-        }
-
-      return;
-    }
-
-  if(!cl->status.active)
-    {
-      if(debug_lvl >= DEBUG_TRAFFIC)
-       syslog(LOG_INFO, _("%s (%s) is not active, dropping packet"),
-              cl->name, cl->hostname);
-
-      return;
-    }
-
-  /* Check if it has to go via TCP or UDP... */
-cp
-  if((cl->options | myself->options) & OPTION_TCPONLY)
-    {
-      if(send_tcppacket(cl, packet))
-        terminate_connection(cl);
-    }
-  else
-    send_udppacket(cl, packet);
-}
+                       if(e) {
+                               send_del_edge(mesh, mesh->everyone, e, 0);
+                               edge_del(mesh, e);
+                       }
+               }
+       }
 
-void flush_queue(connection_t *cl)
-{
-  list_node_t *node, *next;
-cp
-  if(debug_lvl >= DEBUG_TRAFFIC)
-    syslog(LOG_INFO, _("Flushing queue for %s (%s)"), cl->name, cl->hostname);
-
-  for(node = cl->queue->head; node; node = next)
-    {
-      next = node->next;
-      send_udppacket(cl, (vpn_packet_t *)node->data);
-      list_delete_node(cl->queue, node);
-    }
-cp
-}
+       outgoing_t *outgoing = c->outgoing;
+       connection_del(mesh, c);
 
-/*
-  open the local ethertap device
-*/
-int setup_tap_fd(void)
-{
-  int nfd;
-  const char *tapfname;
-  config_t const *cfg;
-#ifdef HAVE_LINUX
-# ifdef HAVE_TUNTAP
-  struct ifreq ifr;
-# endif
-#endif
+       /* Check if this was our outgoing connection */
+
+       if(outgoing) {
+               do_outgoing_connection(mesh, outgoing);
+       }
+
+#ifndef HAVE_MINGW
+       /* Clean up dead proxy processes */
+
+       while(waitpid(-1, NULL, WNOHANG) > 0);
 
-cp
-  if((cfg = get_config_val(config, config_tapdevice)))
-    tapfname = cfg->data.ptr;
-  else
-   {
-#ifdef HAVE_LINUX
-# ifdef HAVE_TUNTAP
-      tapfname = "/dev/net/tun";
-# else
-      tapfname = "/dev/tap0";
-# endif
-#endif
-#ifdef HAVE_FREEBSD
-      tapfname = "/dev/tap0";
-#endif
-#ifdef HAVE_SOLARIS
-      tapfname = "/dev/tun";
-#endif
-   }
-cp
-  if((nfd = open(tapfname, O_RDWR | O_NONBLOCK)) < 0)
-    {
-      syslog(LOG_ERR, _("Could not open %s: %m"), tapfname);
-      return -1;
-    }
-cp
-  tap_fd = nfd;
-
-  taptype = TAP_TYPE_ETHERTAP;
-
-  /* Set default MAC address for ethertap devices */
-
-  mymac.type = SUBNET_MAC;
-  mymac.net.mac.address.x[0] = 0xfe;
-  mymac.net.mac.address.x[1] = 0xfd;
-  mymac.net.mac.address.x[2] = 0x00;
-  mymac.net.mac.address.x[3] = 0x00;
-  mymac.net.mac.address.x[4] = 0x00;
-  mymac.net.mac.address.x[5] = 0x00;
-
-#ifdef HAVE_LINUX
- #ifdef HAVE_TUNTAP
-  /* Ok now check if this is an old ethertap or a new tun/tap thingie */
-  memset(&ifr, 0, sizeof(ifr));
-cp
-  ifr.ifr_flags = IFF_TAP | IFF_NO_PI;
-  if (netname)
-    strncpy(ifr.ifr_name, netname, IFNAMSIZ);
-cp
-  if (!ioctl(tap_fd, TUNSETIFF, (void *) &ifr))
-  {
-    syslog(LOG_INFO, _("%s is a new style tun/tap device"), tapfname);
-    taptype = TAP_TYPE_TUNTAP;
-  }
- #endif
-#endif
-#ifdef HAVE_FREEBSD
- taptype = TAP_TYPE_TUNTAP;
 #endif
-cp
-  return 0;
 }
 
 /*
-  set up the socket that we listen on for incoming
-  (tcp) connections
+  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 setup_listen_meta_socket(int port)
-{
-  int nfd, flags;
-  struct sockaddr_in a;
-  int option;
-  config_t const *cfg;
-cp
-  if((nfd = socket(AF_INET, SOCK_STREAM, IPPROTO_TCP)) < 0)
-    {
-      syslog(LOG_ERR, _("Creating metasocket failed: %m"));
-      return -1;
-    }
-
-  flags = fcntl(nfd, F_GETFL);
-  if(fcntl(nfd, F_SETFL, flags | O_NONBLOCK) < 0)
-    {
-      close(nfd);
-      syslog(LOG_ERR, _("System call `%s' failed: %m"),
-            "fcntl");
-      return -1;
-    }
-
-  /* Optimize TCP settings */
-
-  option = 1;
-  setsockopt(nfd, SOL_SOCKET, SO_REUSEADDR, &option, sizeof(option));
-  setsockopt(nfd, SOL_SOCKET, SO_KEEPALIVE, &option, sizeof(option));
-#ifdef HAVE_LINUX
-  setsockopt(nfd, SOL_TCP, TCP_NODELAY, &option, sizeof(option));
-
-  option = IPTOS_LOWDELAY;
-  setsockopt(nfd, SOL_IP, IP_TOS, &option, sizeof(option));
-
-  if((cfg = get_config_val(config, config_interface)))
-    {
-      if(setsockopt(nfd, SOL_SOCKET, SO_BINDTODEVICE, cfg->data.ptr, strlen(cfg->data.ptr)))
-        {
-          close(nfd);
-          syslog(LOG_ERR, _("Unable to bind listen socket to interface %s: %m"), cfg->data.ptr);
-          return -1;
-        }
-    }
-#endif
+static void timeout_handler(event_loop_t *loop, void *data) {
+       assert(data);
+
+       meshlink_handle_t *mesh = loop->data;
+       logger(mesh, MESHLINK_DEBUG, "timeout_handler()");
+
+       for list_each(connection_t, c, mesh->connections) {
+               int pingtimeout = c->node ? mesh->dev_class_traits[c->node->devclass].pingtimeout : default_timeout;
+               int pinginterval = c->node ? mesh->dev_class_traits[c->node->devclass].pinginterval : default_interval;
+
+               if(c->outgoing && c->outgoing->timeout < 5) {
+                       pingtimeout = 1;
+               }
+
+               // 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 + pingtimeout <= mesh->loop.now.tv_sec) {
+                               send_req_key(mesh, c->node);
+                       }
+               }
+
+               if(c->last_ping_time + pingtimeout <= mesh->loop.now.tv_sec) {
+                       if(c->status.active) {
+                               if(c->status.pinged) {
+                                       logger(mesh, MESHLINK_INFO, "%s didn't respond to PING in %ld seconds", c->name, (long)mesh->loop.now.tv_sec - c->last_ping_time);
+                               } else if(c->last_ping_time + pinginterval <= mesh->loop.now.tv_sec) {
+                                       send_ping(mesh, c);
+                                       continue;
+                               } else {
+                                       continue;
+                               }
+                       } else {
+                               if(c->status.connecting) {
+                                       logger(mesh, MESHLINK_WARNING, "Timeout while connecting to %s", c->name);
+                               } else {
+                                       logger(mesh, MESHLINK_WARNING, "Timeout from %s during authentication", c->name);
+                               }
+                       }
+
+                       terminate_connection(mesh, c, c->status.active);
+               }
+       }
 
-  memset(&a, 0, sizeof(a));
-  a.sin_family = AF_INET;
-  a.sin_port = htons(port);
-
-  if((cfg = get_config_val(config, config_interfaceip)))
-    a.sin_addr.s_addr = htonl(cfg->data.ip->address);
-  else
-    a.sin_addr.s_addr = htonl(INADDR_ANY);
-
-  if(bind(nfd, (struct sockaddr *)&a, sizeof(struct sockaddr)))
-    {
-      close(nfd);
-      syslog(LOG_ERR, _("Can't bind to port %hd/tcp: %m"), port);
-      return -1;
-    }
-
-  if(listen(nfd, 3))
-    {
-      close(nfd);
-      syslog(LOG_ERR, _("System call `%s' failed: %m"),
-            "listen");
-      return -1;
-    }
-cp
-  return nfd;
+       timeout_set(&mesh->loop, data, &(struct timespec) {
+               1, prng(mesh, TIMER_FUDGE)
+       });
 }
 
-/*
-  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)
-    {
-      close(nfd);
-      syslog(LOG_ERR, _("Creating socket failed: %m"));
-      return -1;
-    }
-
-  setsockopt(nfd, SOL_SOCKET, SO_REUSEADDR, &one, sizeof(one));
-
-  flags = fcntl(nfd, F_GETFL);
-  if(fcntl(nfd, F_SETFL, flags | O_NONBLOCK) < 0)
-    {
-      close(nfd);
-      syslog(LOG_ERR, _("System call `%s' failed: %m"),
-            "fcntl");
-      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)))
-    {
-      close(nfd);
-      syslog(LOG_ERR, _("Can't bind to port %hd/udp: %m"), port);
-      return -1;
-    }
-cp
-  return nfd;
-}
+// devclass asc, last_successfull_connection desc
+static int node_compare_devclass_asc_lsc_desc(const void *a, const void *b) {
+       const node_t *na = a, *nb = b;
 
-/*
-  setup an outgoing meta (tcp) socket
-*/
-int setup_outgoing_meta_socket(connection_t *cl)
-{
-  int flags;
-  struct sockaddr_in a;
-  config_t const *cfg;
-  int option;
-cp
-  if(debug_lvl >= DEBUG_CONNECTIONS)
-    syslog(LOG_INFO, _("Trying to connect to %s"), cl->hostname);
-
-  if((cfg = get_config_val(cl->config, config_port)) == 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 for %s port %d failed: %m"),
-             cl->hostname, cl->port);
-      return -1;
-    }
-
-  /* Bind first to get a fix on our source port */
-
-  a.sin_family = AF_INET;
-  a.sin_port = htons(0);
-  a.sin_addr.s_addr = htonl(INADDR_ANY);
-
-  if(bind(cl->meta_socket, (struct sockaddr *)&a, sizeof(struct sockaddr)))
-    {
-      close(cl->meta_socket);
-      syslog(LOG_ERR, _("System call `%s' failed: %m"), "bind");
-      return -1;
-    }
-
-  /* Optimize TCP settings */
-
-  option = 1;
-  setsockopt(cl->meta_socket, SOL_SOCKET, SO_KEEPALIVE, &option, sizeof(option));
-#ifdef HAVE_LINUX
-  setsockopt(cl->meta_socket, SOL_TCP, TCP_NODELAY, &option, sizeof(option));
-
-  option = IPTOS_LOWDELAY;
-  setsockopt(cl->meta_socket, SOL_IP, IP_TOS, &option, sizeof(option));
-#endif
-  /* Connect */
-
-  a.sin_family = AF_INET;
-  a.sin_port = htons(cl->port);
-  a.sin_addr.s_addr = htonl(cl->address);
-
-  if(connect(cl->meta_socket, (struct sockaddr *)&a, sizeof(a)) == -1)
-    {
-      close(cl->meta_socket);
-      syslog(LOG_ERR, _("%s port %hd: %m"), cl->hostname, cl->port);
-      return -1;
-    }
-
-  flags = fcntl(cl->meta_socket, F_GETFL);
-  if(fcntl(cl->meta_socket, F_SETFL, flags | O_NONBLOCK) < 0)
-    {
-      close(cl->meta_socket);
-      syslog(LOG_ERR, _("fcntl for %s port %d: %m"),
-             cl->hostname, cl->port);
-      return -1;
-    }
-
-  if(debug_lvl >= DEBUG_CONNECTIONS)
-    syslog(LOG_INFO, _("Connected to %s port %hd"),
-         cl->hostname, cl->port);
-
-  cl->status.meta = 1;
-cp
-  return 0;
-}
+       if(na->devclass < nb->devclass) {
+               return -1;
+       }
 
-/*
-  Setup an outgoing meta connection.
-*/
-int setup_outgoing_connection(char *name)
-{
-  connection_t *ncn;
-  struct hostent *h;
-  config_t const *cfg;
-cp
-  if(check_id(name))
-    {
-      syslog(LOG_ERR, _("Invalid name for outgoing connection"));
-      return -1;
-    }
-
-  ncn = new_connection();
-  asprintf(&ncn->name, "%s", name);
-
-  if(read_host_config(ncn))
-    {
-      syslog(LOG_ERR, _("Error reading host configuration file for %s"), ncn->name);
-      free_connection(ncn);
-      return -1;
-    }
-
-  if(!(cfg = get_config_val(ncn->config, config_address)))
-    {
-      syslog(LOG_ERR, _("No address specified for %s"), ncn->name);
-      free_connection(ncn);
-      return -1;
-    }
-
-  if(!(h = gethostbyname(cfg->data.ptr)))
-    {
-      syslog(LOG_ERR, _("Error looking up `%s': %m"), cfg->data.ptr);
-      free_connection(ncn);
-      return -1;
-    }
-
-  ncn->address = ntohl(*((ipv4_t*)(h->h_addr_list[0])));
-  ncn->hostname = hostlookup(htonl(ncn->address));
-
-  if(setup_outgoing_meta_socket(ncn) < 0)
-    {
-      syslog(LOG_ERR, _("Could not set up a meta connection to %s"),
-             ncn->hostname);
-      free_connection(ncn);
-      return -1;
-    }
-
-  ncn->status.outgoing = 1;
-  ncn->buffer = xmalloc(MAXBUFSIZE);
-  ncn->buflen = 0;
-  ncn->last_ping_time = time(NULL);
-
-  connection_add(ncn);
-
-  send_id(ncn);
-cp
-  return 0;
-}
+       if(na->devclass > nb->devclass) {
+               return 1;
+       }
 
-int read_rsa_public_key(connection_t *cl)
-{
-  config_t const *cfg;
-  FILE *fp;
-  char *fname;
-  void *result;
-cp
-  if(!cl->rsa_key)
-    cl->rsa_key = RSA_new();
-
-  /* First, check for simple PublicKey statement */
-
-  if((cfg = get_config_val(cl->config, config_publickey)))
-    {
-      BN_hex2bn(&cl->rsa_key->n, cfg->data.ptr);
-      BN_hex2bn(&cl->rsa_key->e, "FFFF");
-      return 0;
-    }
-
-  /* Else, check for PublicKeyFile statement and read it */
-
-  if((cfg = get_config_val(cl->config, config_publickeyfile)))
-    {
-      if(is_safe_path(cfg->data.ptr))
-        {
-          if((fp = fopen(cfg->data.ptr, "r")) == NULL)
-            {
-              syslog(LOG_ERR, _("Error reading RSA public key file `%s': %m"),
-                    cfg->data.ptr);
-              return -1;
-            }
-          result = PEM_read_RSAPublicKey(fp, &cl->rsa_key, NULL, NULL);
-          fclose(fp);
-          if(!result)
-            {
-              syslog(LOG_ERR, _("Reading RSA public key file `%s' failed: %m"),
-                    cfg->data.ptr);
-              return -1;
-            }
-          return 0;
-        }
-      else
-        return -1;
-    }
-
-  /* Else, check if a harnessed public key is in the config file */
-
-  asprintf(&fname, "%s/hosts/%s", confbase, cl->name);
-  if((fp = fopen(fname, "r")))
-    {
-      result = PEM_read_RSAPublicKey(fp, &cl->rsa_key, NULL, NULL);
-      fclose(fp);
-      free(fname);
-      if(result)
-        return 0;
-    }
-
-  free(fname);
-
-  /* Nothing worked. */
-
-  syslog(LOG_ERR, _("No public key for %s specified!"), cl->name);
-cp
-  return -1;
-}
+       if(na->last_successfull_connection == nb->last_successfull_connection) {
+               return 0;
+       }
 
-int read_rsa_private_key(void)
-{
-  config_t const *cfg;
-  FILE *fp;
-  void *result;
-cp
-  if(!myself->rsa_key)
-    myself->rsa_key = RSA_new();
-
-  if((cfg = get_config_val(config, config_privatekey)))
-    {
-      BN_hex2bn(&myself->rsa_key->d, cfg->data.ptr);
-      BN_hex2bn(&myself->rsa_key->e, "FFFF");
-    }
-  else if((cfg = get_config_val(config, config_privatekeyfile)))
-    {
-      if((fp = fopen(cfg->data.ptr, "r")) == NULL)
-        {
-          syslog(LOG_ERR, _("Error reading RSA private key file `%s': %m"),
-                cfg->data.ptr);
-          return -1;
-        }
-      result = PEM_read_RSAPrivateKey(fp, &myself->rsa_key, NULL, NULL);
-      fclose(fp);
-      if(!result)
-        {
-          syslog(LOG_ERR, _("Reading RSA private key file `%s' failed: %m"),
-                cfg->data.ptr);
-          return -1;
-        }
-    }
-  else
-    {
-      syslog(LOG_ERR, _("No private key for tinc daemon specified!"));
-      return -1;
-    }
-cp
-  return 0;
-}
+       if(na->last_successfull_connection == 0 || na->last_successfull_connection > nb->last_successfull_connection) {
+               return -1;
+       }
 
-/*
-  Configure connection_t myself and set up the local sockets (listen only)
-*/
-int setup_myself(void)
-{
-  config_t const *cfg;
-  config_t *next;
-  subnet_t *net;
-cp
-  myself = new_connection();
-
-  asprintf(&myself->hostname, "MYSELF");
-  myself->options = 0;
-  myself->protocol_version = PROT_CURRENT;
-
-  if(!(cfg = get_config_val(config, config_name))) /* Not acceptable */
-    {
-      syslog(LOG_ERR, _("Name for tinc daemon required!"));
-      return -1;
-    }
-  else
-    asprintf(&myself->name, "%s", (char*)cfg->data.val);
-
-  if(check_id(myself->name))
-    {
-      syslog(LOG_ERR, _("Invalid name for myself!"));
-      return -1;
-    }
-cp
-  if(read_rsa_private_key())
-    return -1;
-
-  if(read_host_config(myself))
-    {
-      syslog(LOG_ERR, _("Cannot open host configuration file for myself!"));
-      return -1;
-    }
-
-  if(read_rsa_public_key(myself))
-    return -1;
-cp
+       if(nb->last_successfull_connection == 0 || na->last_successfull_connection < nb->last_successfull_connection) {
+               return 1;
+       }
 
-/*
-  if(RSA_check_key(myself->rsa_key) != 1)
-    {
-      syslog(LOG_ERR, _("Invalid public/private keypair!"));
-      return -1;
-    }
-*/
-  if(!(cfg = get_config_val(myself->config, config_port)))
-    myself->port = 655;
-  else
-    myself->port = cfg->data.val;
-
-  if((cfg = get_config_val(myself->config, config_indirectdata)))
-    if(cfg->data.val == stupid_true)
-      myself->options |= OPTION_INDIRECT;
-
-  if((cfg = get_config_val(myself->config, config_tcponly)))
-    if(cfg->data.val == stupid_true)
-      myself->options |= OPTION_TCPONLY;
-
-/* Read in all the subnets specified in the host configuration file */
-
-  for(next = myself->config; (cfg = get_config_val(next, config_subnet)); next = cfg->next)
-    {
-      net = new_subnet();
-      net->type = SUBNET_IPV4;
-      net->net.ipv4.address = cfg->data.ip->address;
-      net->net.ipv4.mask = cfg->data.ip->mask;
-
-      /* Teach newbies what subnets are... */
-
-      if((net->net.ipv4.address & net->net.ipv4.mask) != net->net.ipv4.address)
-        {
-          syslog(LOG_ERR, _("Network address and subnet mask do not match!"));
-          return -1;
-        }
-
-      subnet_add(myself, net);
-    }
-
-  if((myself->meta_socket = setup_listen_meta_socket(myself->port)) < 0)
-    {
-      syslog(LOG_ERR, _("Unable to set up a listening TCP socket!"));
-      return -1;
-    }
-
-  if((myself->socket = setup_vpn_in_socket(myself->port)) < 0)
-    {
-      syslog(LOG_ERR, _("Unable to set up a listening UDP socket!"));
-      return -1;
-    }
-cp
-  /* Generate packet encryption key */
-
-  myself->cipher_pkttype = EVP_bf_cbc();
-
-  myself->cipher_pktkeylength = myself->cipher_pkttype->key_len + myself->cipher_pkttype->iv_len;
-
-  myself->cipher_pktkey = (char *)xmalloc(myself->cipher_pktkeylength);
-  RAND_pseudo_bytes(myself->cipher_pktkey, myself->cipher_pktkeylength);
-
-  if(!(cfg = get_config_val(config, config_keyexpire)))
-    keylifetime = 3600;
-  else
-    keylifetime = cfg->data.val;
-
-  keyexpires = time(NULL) + keylifetime;
-cp
-  /* Check some options */
-
-  if((cfg = get_config_val(config, config_indirectdata)))
-    {
-      if(cfg->data.val == stupid_true)
-        myself->options |= OPTION_INDIRECT;
-    }
-
-  if((cfg = get_config_val(config, config_tcponly)))
-    {
-      if(cfg->data.val == stupid_true)
-        myself->options |= OPTION_TCPONLY;
-    }
-
-  if(myself->options & OPTION_TCPONLY)
-    myself->options |= OPTION_INDIRECT;
-
-  /* Activate ourselves */
-
-  myself->status.active = 1;
-
-  syslog(LOG_NOTICE, _("Ready: listening on port %hd"), myself->port);
-cp
-  return 0;
-}
+       if(na < nb) {
+               return -1;
+       }
 
-RETSIGTYPE
-sigalrm_handler(int a)
-{
-  config_t const *cfg;
-cp
-  cfg = get_config_val(upstreamcfg, config_connectto);
-
-  if(!cfg)
-    {
-      if(upstreamcfg == config)
-      {
-        /* No upstream IP given, we're listen only. */
-        signal(SIGALRM, SIG_IGN);
-        return;
-      }
-    }
-  else
-    {
-      /* We previously tried all the ConnectTo lines. Now wrap back to the first. */
-      cfg = get_config_val(config, config_connectto);
-    }
-    
-  while(cfg)
-    {
-      upstreamcfg = cfg->next;
-      if(!setup_outgoing_connection(cfg->data.ptr))   /* function returns 0 when there are no problems */
-        {
-          signal(SIGALRM, SIG_IGN);
-          return;
-        }
-      cfg = get_config_val(upstreamcfg, config_connectto); /* Or else we try the next ConnectTo line */
-    }
-
-  signal(SIGALRM, sigalrm_handler);
-  upstreamcfg = config;
-  seconds_till_retry += 5;
-  if(seconds_till_retry > MAXTIMEOUT)    /* Don't wait more than MAXTIMEOUT seconds. */
-    seconds_till_retry = MAXTIMEOUT;
-  syslog(LOG_ERR, _("Still failed to connect to other, will retry in %d seconds"),
-        seconds_till_retry);
-  alarm(seconds_till_retry);
-cp
-}
+       if(na > nb) {
+               return 1;
+       }
 
-/*
-  setup all initial network connections
-*/
-int setup_network_connections(void)
-{
-  config_t const *cfg;
-cp
-  init_connections();
-  init_subnets();
-
-  if((cfg = get_config_val(config, config_pingtimeout)) == NULL)
-    timeout = 60;
-  else
-    {
-      timeout = cfg->data.val;
-      if(timeout < 1)
-        {
-          timeout = 86400;
-        }
-     }
-
-  if(setup_tap_fd() < 0)
-    return -1;
-
-  /* Run tinc-up script to further initialize the tap interface */
-  execute_script("tinc-up");
-
-  if(setup_myself() < 0)
-    return -1;
-
-  if(!(cfg = get_config_val(config, config_connectto)))
-    /* No upstream IP given, we're listen only. */
-    return 0;
-
-  while(cfg)
-    {
-      upstreamcfg = cfg->next;
-      if(!setup_outgoing_connection(cfg->data.ptr))   /* function returns 0 when there are no problems */
-        return 0;
-      cfg = get_config_val(upstreamcfg, config_connectto); /* Or else we try the next ConnectTo line */
-    }
-
-  if(do_detach)
-    {
-      signal(SIGALRM, sigalrm_handler);
-      upstreamcfg = config;
-      seconds_till_retry = MAXTIMEOUT;
-      syslog(LOG_NOTICE, _("Trying to re-establish outgoing connection in %d seconds"), seconds_till_retry);
-      alarm(seconds_till_retry);
-    }
-  else
-    return -1;
-
-cp
-  return 0;
+       return 0;
 }
 
-/*
-  close all open network connections
-*/
-void close_network_connections(void)
-{
-  avl_node_t *node;
-  connection_t *p;
-cp
-  for(node = connection_tree->head; node; node = node->next)
-    {
-      p = (connection_t *)node->data;
-      p->status.outgoing = 0;
-      p->status.active = 0;
-      terminate_connection(p);
-    }
-
-  if(myself)
-    if(myself->status.active)
-      {
-       close(myself->meta_socket);
-        free_connection(myself);
-        myself = NULL;
-      }
-
-  close(tap_fd);
-
-  /* Execute tinc-down script right after shutting down the interface */
-  execute_script("tinc-down");
-
-  destroy_connection_tree();
-cp
-  return;
-}
+// last_successfull_connection desc
+static int node_compare_lsc_desc(const void *a, const void *b) {
+       const node_t *na = a, *nb = b;
 
-/*
-  handle an incoming tcp connect call and open
-  a connection to it.
-*/
-connection_t *create_new_connection(int sfd)
-{
-  connection_t *p;
-  struct sockaddr_in ci;
-  int len = sizeof(ci);
-cp
-  p = new_connection();
-
-  if(getpeername(sfd, (struct sockaddr *) &ci, (socklen_t *) &len) < 0)
-    {
-      syslog(LOG_ERR, _("System call `%s' failed: %m"),
-            "getpeername");
-      close(sfd);
-      return NULL;
-    }
-
-  p->name = unknown;
-  p->address = ntohl(ci.sin_addr.s_addr);
-  p->hostname = hostlookup(ci.sin_addr.s_addr);
-  p->port = htons(ci.sin_port);                                /* This one will be overwritten later */
-  p->meta_socket = sfd;
-  p->status.meta = 1;
-  p->buffer = xmalloc(MAXBUFSIZE);
-  p->buflen = 0;
-  p->last_ping_time = time(NULL);
-
-  if(debug_lvl >= DEBUG_CONNECTIONS)
-    syslog(LOG_NOTICE, _("Connection from %s port %d"),
-         p->hostname, htons(ci.sin_port));
-
-  p->allow_request = ID;
-cp
-  return p;
-}
+       if(na->last_successfull_connection == nb->last_successfull_connection) {
+               return 0;
+       }
 
-/*
-  put all file descriptors in an fd_set array
-*/
-void build_fdset(fd_set *fs)
-{
-  avl_node_t *node;
-  connection_t *p;
-cp
-  FD_ZERO(fs);
-
-  FD_SET(myself->socket, fs);
-
-  for(node = connection_tree->head; node; node = node->next)
-    {
-      p = (connection_t *)node->data;
-      if(p->status.meta)
-        FD_SET(p->meta_socket, fs);
-    }
-
-  FD_SET(myself->meta_socket, fs);
-  FD_SET(tap_fd, fs);
-cp
-}
+       if(na->last_successfull_connection == 0 || na->last_successfull_connection > nb->last_successfull_connection) {
+               return -1;
+       }
 
-/*
-  receive incoming data from the listening
-  udp socket and write it to the ethertap
-  device after being decrypted
-*/
-void handle_incoming_vpn_data(void)
-{
-  vpn_packet_t pkt;
-  int x, l = sizeof(x);
-  struct sockaddr_in from;
-  socklen_t fromlen = sizeof(from);
-  connection_t *cl;
-cp
-  if(getsockopt(myself->socket, SOL_SOCKET, SO_ERROR, &x, &l) < 0)
-    {
-      syslog(LOG_ERR, _("This is a bug: %s:%d: %d:%m"),
-            __FILE__, __LINE__, myself->socket);
-      return;
-    }
-  if(x)
-    {
-      syslog(LOG_ERR, _("Incoming data socket error: %s"), strerror(x));
-      return;
-    }
-
-  if((pkt.len = recvfrom(myself->socket, (char *) pkt.salt, MTU, 0, (struct sockaddr *)&from, &fromlen)) <= 0)
-    {
-      syslog(LOG_ERR, _("Receiving packet failed: %m"));
-      return;
-    }
-
-  cl = lookup_connection(ntohl(from.sin_addr.s_addr), ntohs(from.sin_port));
-
-  if(!cl)
-    {
-      syslog(LOG_WARNING, _("Received UDP packets on port %hd from unknown source %x:%hd"), myself->port, ntohl(from.sin_addr.s_addr), ntohs(from.sin_port));
-      return;
-    }
-
-  cl->last_ping_time = time(NULL);
-
-  receive_udppacket(cl, &pkt);
-cp
+       if(nb->last_successfull_connection == 0 || na->last_successfull_connection < nb->last_successfull_connection) {
+               return 1;
+       }
+
+       if(na < nb) {
+               return -1;
+       }
+
+       if(na > nb) {
+               return 1;
+       }
+
+       return 0;
 }
 
-/*
-  terminate a connection and notify the other
-  end before closing the sockets
-*/
-void terminate_connection(connection_t *cl)
-{
-  connection_t *p;
-  subnet_t *subnet;
-  avl_node_t *node, *next;
-cp
-  if(cl->status.remove)
-    return;
-
-  if(debug_lvl >= DEBUG_CONNECTIONS)
-    syslog(LOG_NOTICE, _("Closing connection with %s (%s)"),
-           cl->name, cl->hostname);
-
-  cl->status.remove = 1;
-
-  if(cl->socket)
-    close(cl->socket);
-  if(cl->status.meta)
-    close(cl->meta_socket);
-
-  if(cl->status.meta)
-    {
-
-      /* Find all connections that were lost because they were behind cl
-         (the connection that was dropped). */
-
-        for(node = connection_tree->head; node; node = node->next)
-          {
-            p = (connection_t *)node->data;
-            if(p->nexthop == cl && p != cl)
-              terminate_connection(p);
-          }
-
-      /* Inform others of termination if it was still active */
-
-      if(cl->status.active)
-        for(node = connection_tree->head; node; node = node->next)
-          {
-            p = (connection_t *)node->data;
-            if(p->status.meta && p->status.active && p != cl)
-              send_del_host(p, cl);    /* Sounds like recursion, but p does not have a meta connection :) */
-          }
-    }
-
-  /* Remove the associated subnets */
-
-  for(node = cl->subnet_tree->head; node; node = next)
-    {
-      next = node->next;
-      subnet = (subnet_t *)node->data;
-      subnet_del(subnet);
-    }
-
-  /* Check if this was our outgoing connection */
-
-  if(cl->status.outgoing)
-    {
-      cl->status.outgoing = 0;
-      signal(SIGALRM, sigalrm_handler);
-      seconds_till_retry = 5;
-      alarm(seconds_till_retry);
-      syslog(LOG_NOTICE, _("Trying to re-establish outgoing connection in 5 seconds"));
-    }
-
-  /* Deactivate */
-
-  cl->status.active = 0;
-cp
+// 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;
+       }
+
+       if(na < nb) {
+               return -1;
+       }
+
+       if(na > nb) {
+               return 1;
+       }
+
+       return 0;
 }
 
+
 /*
-  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.
-*/
-void check_dead_connections(void)
+
+autoconnect()
 {
-  time_t now;
-  avl_node_t *node;
-  connection_t *cl;
-cp
-  now = time(NULL);
-
-  for(node = connection_tree->head; node; node = node->next)
-    {
-      cl = (connection_t *)node->data;
-      if(cl->status.active && cl->status.meta)
-        {
-          if(cl->last_ping_time + timeout < now)
-            {
-              if(cl->status.pinged)
-                {
-                  if(debug_lvl >= DEBUG_PROTOCOL)
-                   syslog(LOG_INFO, _("%s (%s) didn't respond to PING"),
-                          cl->name, cl->hostname);
-                 cl->status.timeout = 1;
-                 terminate_connection(cl);
-                }
-              else
-                {
-                  send_ping(cl);
-                }
-            }
-        }
-    }
-cp
+        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)
+
 }
 
-/*
-  accept a new tcp connect and create a
-  new connection
 */
-int handle_new_meta_connection()
-{
-  connection_t *ncn;
-  struct sockaddr client;
-  int nfd, len = sizeof(client);
-cp
-  if((nfd = accept(myself->meta_socket, &client, &len)) < 0)
-    {
-      syslog(LOG_ERR, _("Accepting a new connection failed: %m"));
-      return -1;
-    }
-
-  if(!(ncn = create_new_connection(nfd)))
-    {
-      shutdown(nfd, 2);
-      close(nfd);
-      syslog(LOG_NOTICE, _("Closed attempted connection"));
-      return 0;
-    }
-
-  connection_add(ncn);
-
-  send_id(ncn);
-cp
-  return 0;
+
+
+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);
+               struct timespec ts = {mesh->sleeptime, 0};
+               clock_nanosleep(CLOCK_MONOTONIC, 0, &ts, NULL);
+               mesh->sleeptime *= 2;
+
+               if(mesh->sleeptime < 0) {
+                       mesh->sleeptime = 3600;
+               }
+       } else {
+               mesh->sleeptime /= 2;
+
+               if(mesh->sleeptime < 10) {
+                       mesh->sleeptime = 10;
+               }
+       }
+
+       mesh->contradicting_add_edge = 0;
+       mesh->contradicting_del_edge = 0;
+
+       int timeout = default_timeout;
+
+       /* Check if we need to make or break connections. */
+
+       if(mesh->nodes->count > 1) {
+
+               logger(mesh, MESHLINK_DEBUG, "--- autoconnect begin ---");
+
+               int retry_timeout = min(mesh->nodes->count * default_timeout, 60);
+
+               logger(mesh, MESHLINK_DEBUG, "* devclass = %d", mesh->devclass);
+               logger(mesh, MESHLINK_DEBUG, "* nodes = %d", mesh->nodes->count);
+               logger(mesh, MESHLINK_DEBUG, "* retry_timeout = %d", retry_timeout);
+
+
+               // connect disconnect nodes
+
+               node_t *connect_to = NULL;
+               node_t *disconnect_from = NULL;
+
+
+               // get cur_connects
+
+               unsigned int cur_connects = 0;
+
+               for list_each(connection_t, c, mesh->connections) {
+                       if(c->status.active) {
+                               cur_connects += 1;
+                       }
+               }
+
+               logger(mesh, MESHLINK_DEBUG, "* cur_connects = %d", cur_connects);
+               logger(mesh, MESHLINK_DEBUG, "* outgoings = %d", mesh->outgoings->count);
+
+               // get min_connects and max_connects
+
+               unsigned int min_connects = mesh->dev_class_traits[mesh->devclass].min_connects;
+               unsigned int max_connects = mesh->dev_class_traits[mesh->devclass].max_connects;
+
+               logger(mesh, MESHLINK_DEBUG, "* min_connects = %d", min_connects);
+               logger(mesh, MESHLINK_DEBUG, "* 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_lsc_desc, NULL);
+
+                       for splay_each(node_t, n, mesh->nodes) {
+                               logger(mesh, MESHLINK_DEBUG, "* %s->devclass = %d", n->name, n->devclass);
+
+                               if(n != mesh->self && n->devclass <= mesh->devclass && !n->connection && !n->status.blacklisted && (n->last_connect_try == 0 || (mesh->loop.now.tv_sec - n->last_connect_try) > retry_timeout)) {
+                                       splay_insert(nodes, n);
+                               }
+                       }
+
+                       if(nodes->head) {
+                               //timeout = 0;
+                               connect_to = (node_t *)nodes->head->data;
+
+                               logger(mesh, MESHLINK_DEBUG, "* found best one for initial connect: %s", connect_to->name);
+                       } else {
+                               logger(mesh, MESHLINK_DEBUG, "* could not find node for initial connect");
+                       }
+
+                       splay_delete_tree(nodes);
+               }
+
+
+               // find better nodes to connect to
+
+               if(!connect_to && min_connects <= cur_connects && cur_connects < max_connects) {
+                       unsigned int connects = 0;
+
+                       for(dev_class_t devclass = 0; devclass <= mesh->devclass; ++devclass) {
+                               for list_each(connection_t, c, mesh->connections) {
+                                       if(c->status.active && c->node && c->node->devclass == devclass) {
+                                               connects += 1;
+                                       }
+                               }
+
+                               if(connects < min_connects) {
+                                       splay_tree_t *nodes = splay_alloc_tree(node_compare_lsc_desc, NULL);
+
+                                       for splay_each(node_t, n, mesh->nodes) {
+                                               if(n != mesh->self && n->devclass == devclass && !n->connection && !n->status.blacklisted && (n->last_connect_try == 0 || (mesh->loop.now.tv_sec - n->last_connect_try) > retry_timeout)) {
+                                                       splay_insert(nodes, n);
+                                               }
+                                       }
+
+                                       if(nodes->head) {
+                                               logger(mesh, MESHLINK_DEBUG, "* found better node");
+                                               connect_to = (node_t *)nodes->head->data;
+
+                                               splay_delete_tree(nodes);
+                                               break;
+                                       }
+
+                                       splay_delete_tree(nodes);
+                               } else {
+                                       break;
+                               }
+                       }
+
+                       if(!connect_to) {
+                               logger(mesh, MESHLINK_DEBUG, "* could not find better nodes");
+                       }
+               }
+
+
+               // heal partitions
+
+               if(!connect_to && min_connects <= cur_connects && cur_connects < max_connects) {
+                       splay_tree_t *nodes = splay_alloc_tree(node_compare_devclass_asc_lsc_desc, NULL);
+
+                       for splay_each(node_t, n, mesh->nodes) {
+                               if(n != mesh->self && n->devclass <= mesh->devclass && !n->status.reachable && !n->status.blacklisted && (n->last_connect_try == 0 || (mesh->loop.now.tv_sec - n->last_connect_try) > retry_timeout)) {
+                                       splay_insert(nodes, n);
+                               }
+                       }
+
+                       if(nodes->head) {
+                               logger(mesh, MESHLINK_DEBUG, "* try to heal partition");
+                               connect_to = (node_t *)nodes->head->data;
+                       } else {
+                               logger(mesh, MESHLINK_DEBUG, "* could not find nodes for partition healing");
+                       }
+
+                       splay_delete_tree(nodes);
+               }
+
+
+               // perform connect
+
+               if(connect_to && !connect_to->connection) {
+                       connect_to->last_connect_try = mesh->loop.now.tv_sec;
+                       logger(mesh, MESHLINK_DEBUG, "Autoconnect trying to connect to %s", connect_to->name);
+
+                       /* check if there is already a connection attempt to this node */
+                       bool skip = false;
+
+                       for list_each(outgoing_t, outgoing, mesh->outgoings) {
+                               if(outgoing->node == connect_to) {
+                                       logger(mesh, MESHLINK_DEBUG, "* skip autoconnect since it is an outgoing connection already");
+                                       skip = true;
+                                       break;
+                               }
+                       }
+
+                       if(!connect_to->status.reachable && !node_read_public_key(mesh, connect_to)) {
+                               logger(mesh, MESHLINK_DEBUG, "* skip autoconnect since we don't know this node's public key");
+                               skip = true;
+                       }
+
+                       if(!skip) {
+                               logger(mesh, MESHLINK_DEBUG, "Autoconnecting to %s", connect_to->name);
+                               outgoing_t *outgoing = xzalloc(sizeof(outgoing_t));
+                               outgoing->node = connect_to;
+                               list_insert_tail(mesh->outgoings, outgoing);
+                               setup_outgoing_connection(mesh, outgoing);
+                       }
+               }
+
+
+               // disconnect suboptimal outgoing connections
+
+               if(min_connects < cur_connects /*&& cur_connects <= max_connects*/) {
+                       unsigned int connects = 0;
+
+                       for(dev_class_t devclass = 0; devclass <= mesh->devclass; ++devclass) {
+                               for list_each(connection_t, c, mesh->connections) {
+                                       if(c->status.active && c->node && c->node->devclass == devclass) {
+                                               connects += 1;
+                                       }
+                               }
+
+                               if(min_connects < connects) {
+                                       splay_tree_t *nodes = splay_alloc_tree(node_compare_devclass_desc, NULL);
+
+                                       for list_each(connection_t, c, mesh->connections) {
+                                               if(c->outgoing && c->node && c->node->devclass >= devclass) {
+                                                       splay_insert(nodes, c->node);
+                                               }
+                                       }
+
+                                       if(nodes->head) {
+                                               logger(mesh, MESHLINK_DEBUG, "* disconnect suboptimal outgoing connection");
+                                               disconnect_from = (node_t *)nodes->head->data;
+                                       }
+
+                                       splay_delete_tree(nodes);
+                                       break;
+                               }
+                       }
+
+                       if(!disconnect_from) {
+                               logger(mesh, MESHLINK_DEBUG, "* no suboptimal outgoing connections");
+                       }
+               }
+
+
+               // disconnect connections (too many connections)
+
+               if(!disconnect_from && max_connects < cur_connects) {
+                       splay_tree_t *nodes = splay_alloc_tree(node_compare_devclass_desc, NULL);
+
+                       for list_each(connection_t, c, mesh->connections) {
+                               if(c->status.active && c->node) {
+                                       splay_insert(nodes, c->node);
+                               }
+                       }
+
+                       if(nodes->head) {
+                               logger(mesh, MESHLINK_DEBUG, "* disconnect connection (too many connections)");
+
+                               //timeout = 0;
+                               disconnect_from = (node_t *)nodes->head->data;
+                       } else {
+                               logger(mesh, MESHLINK_DEBUG, "* no node we want to disconnect, even though we have too many connections");
+                       }
+
+                       splay_delete_tree(nodes);
+               }
+
+
+               // perform disconnect
+
+               if(disconnect_from && disconnect_from->connection) {
+                       logger(mesh, MESHLINK_DEBUG, "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);
+               }
+
+               // reduce timeout if we don't have enough connections + outgoings
+               if(cur_connects + mesh->outgoings->count < 3) {
+                       timeout = 1;
+               }
+
+               // done!
+
+               logger(mesh, MESHLINK_DEBUG, "--- autoconnect end ---");
+       }
+
+       for splay_each(node_t, n, mesh->nodes) {
+               if(n->status.dirty) {
+                       if(!node_write_config(mesh, n)) {
+                               logger(mesh, MESHLINK_DEBUG, "Could not update %s", n->name);
+                       }
+
+                       n->status.dirty = false;
+               }
+
+               if(n->status.validkey && n->last_req_key + 3600 < mesh->loop.now.tv_sec) {
+                       logger(mesh, MESHLINK_DEBUG, "SPTPS key renewal for node %s", n->name);
+
+                       if(!sptps_force_kex(&n->sptps)) {
+                               logger(mesh, MESHLINK_ERROR, "SPTPS key renewal for node %s failed", n->name);
+                               n->status.validkey = false;
+                               sptps_stop(&n->sptps);
+                               n->status.waitingforkey = false;
+                               n->last_req_key = 0;
+                       } else {
+                               n->last_req_key = mesh->loop.now.tv_sec;
+                       }
+               }
+       }
+
+       timeout_set(&mesh->loop, data, &(struct timespec) {
+               timeout, prng(mesh, TIMER_FUDGE)
+       });
 }
 
-/*
-  check all connections to see if anything
-  happened on their sockets
-*/
-void check_network_activity(fd_set *f)
-{
-  connection_t *p;
-  avl_node_t *node;
-cp
-  if(FD_ISSET(myself->socket, f))
-    handle_incoming_vpn_data();
-
-  for(node = connection_tree->head; node; node = node->next)
-    {
-      p = (connection_t *)node->data;
-
-      if(p->status.remove)
-       return;
-
-      if(p->status.meta)
-       if(FD_ISSET(p->meta_socket, f))
-         if(receive_meta(p) < 0)
-           {
-             terminate_connection(p);
-             return;
-           }
-    }
-
-  if(FD_ISSET(myself->meta_socket, f))
-    handle_new_meta_connection();
-cp
+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;
+       }
 }
 
-/*
-  read, encrypt and send data that is
-  available through the ethertap device
-*/
-void handle_tap_input(void)
-{
-  vpn_packet_t vp;
-  int lenin;
-cp
-  if(taptype == TAP_TYPE_TUNTAP)
-    {
-      if((lenin = read(tap_fd, vp.data, MTU)) <= 0)
-        {
-          syslog(LOG_ERR, _("Error while reading from tun/tap device: %m"));
-          return;
-        }
-      vp.len = lenin;
-    }
-  else                 /* ethertap */
-    {
-      if((lenin = read(tap_fd, vp.data - 2, MTU)) <= 0)
-        {
-          syslog(LOG_ERR, _("Error while reading from ethertap device: %m"));
-          return;
-        }
-      vp.len = lenin - 2;
-    }
-
-  total_tap_in += vp.len;
-
-  if(lenin < 32)
-    {
-      if(debug_lvl >= DEBUG_TRAFFIC)
-       syslog(LOG_WARNING, _("Received short packet from tap device"));
-      return;
-    }
-
-  if(debug_lvl >= DEBUG_TRAFFIC)
-    {
-      syslog(LOG_DEBUG, _("Read packet of length %d from tap device"), vp.len);
-    }
-
-  route_outgoing(&vp);
-cp
+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 timespec) {
+                               0, 0
+                       });
+               }
+       }
+
+       /* For active connections, check if their addresses are still valid.
+        * If yes, reset their ping timers, otherwise terminate them. */
+       for list_each(connection_t, c, mesh->connections) {
+               if(!c->status.active) {
+                       continue;
+               }
+
+               if(!c->status.pinged) {
+                       c->last_ping_time = 0;
+               }
+
+               sockaddr_t sa;
+               socklen_t salen = sizeof(sa);
+
+               if(getsockname(c->socket, &sa.sa, &salen)) {
+                       continue;
+               }
+
+               switch(sa.sa.sa_family) {
+               case AF_INET:
+                       sa.in.sin_port = 0;
+                       break;
+
+               case AF_INET6:
+                       sa.in6.sin6_port = 0;
+                       break;
+
+               default:
+                       continue;
+               }
+
+               int sock = socket(sa.sa.sa_family, SOCK_STREAM, IPPROTO_TCP);
+
+               if(sock != -1) {
+                       continue;
+               }
+
+               if(bind(sock, &sa.sa, salen) && errno == EADDRNOTAVAIL) {
+                       logger(mesh, MESHLINK_DEBUG, "Local address for connection to %s no longer valid, terminating", c->name);
+                       terminate_connection(mesh, c, c->status.active);
+               }
+
+               closesocket(sock);
+       }
+
+       /* Kick the ping timeout handler */
+       timeout_set(&mesh->loop, &mesh->pingtimer, &(struct timespec) {
+               0, 0
+       });
 }
 
 /*
   this is where it all happens...
 */
-void main_loop(void)
-{
-  fd_set fset;
-  struct timeval tv;
-  int r;
-  time_t last_ping_check;
-  int t;
-cp
-  last_ping_check = time(NULL);
-
-  for(;;)
-    {
-      tv.tv_sec = timeout;
-      tv.tv_usec = 0;
-
-      prune_connection_tree();
-      build_fdset(&fset);
-
-      if((r = select(FD_SETSIZE, &fset, NULL, NULL, &tv)) < 0)
-        {
-         if(errno != EINTR) /* because of alarm */
-            {
-              syslog(LOG_ERR, _("Error while waiting for input: %m"));
-              return;
-            }
-        }
-
-      if(sighup)
-        {
-          syslog(LOG_INFO, _("Rereading configuration file and restarting in 5 seconds"));
-          sighup = 0;
-          close_network_connections();
-          clear_config(&config);
-
-          if(read_server_config())
-            {
-              syslog(LOG_ERR, _("Unable to reread configuration file, exiting"));
-              exit(1);
-            }
-
-          sleep(5);
-
-          if(setup_network_connections())
-            return;
-
-          continue;
-        }
-
-      t = time(NULL);
-
-      /* Let's check if everybody is still alive */
-
-      if(last_ping_check + timeout < t)
-       {
-         check_dead_connections();
-          last_ping_check = time(NULL);
-
-          /* Should we regenerate our key? */
-
-          if(keyexpires < t)
-            {
-              if(debug_lvl >= DEBUG_STATUS)
-                syslog(LOG_INFO, _("Regenerating symmetric key"));
-
-              RAND_bytes(myself->cipher_pktkey, myself->cipher_pktkeylength);
-              send_key_changed(myself, NULL);
-              keyexpires = time(NULL) + keylifetime;
-            }
+void main_loop(meshlink_handle_t *mesh) {
+       timeout_add(&mesh->loop, &mesh->pingtimer, timeout_handler, &mesh->pingtimer, &(struct timespec) {
+               1, prng(mesh, TIMER_FUDGE)
+       });
+       timeout_add(&mesh->loop, &mesh->periodictimer, periodic_handler, &mesh->periodictimer, &(struct timespec) {
+               0, 0
+       });
+
+       //Add signal handler
+       mesh->datafromapp.signum = 0;
+       signal_add(&mesh->loop, &mesh->datafromapp, meshlink_send_from_queue, mesh, mesh->datafromapp.signum);
+
+       if(!event_loop_run(&mesh->loop, &mesh->mutex)) {
+               logger(mesh, MESHLINK_ERROR, "Error while waiting for input: %s", strerror(errno));
+               call_error_cb(mesh, MESHLINK_ENETWORK);
        }
 
-      if(r > 0)
-        {
-          check_network_activity(&fset);
-
-          /* local tap data */
-          if(FD_ISSET(tap_fd, &fset))
-           handle_tap_input();
-        }
-    }
-cp
+       signal_del(&mesh->loop, &mesh->datafromapp);
+       timeout_del(&mesh->loop, &mesh->periodictimer);
+       timeout_del(&mesh->loop, &mesh->pingtimer);
 }