gvpe/src/vpn.C

/*
    vpn.C -- handle the protocol, encryption, handshaking etc.
    Copyright (C) 2003-2005 Marc Lehmann <gvpe@schmorp.de>
 
    This file is part of GVPE.

    GVPE is free software; you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
    the Free Software Foundation; either version 2 of the License, or
    (at your option) any later version.
 
    This program is distributed in the hope that it will be useful,
    but WITHOUT ANY WARRANTY; without even the implied warranty of
    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 gvpe; if not, write to the Free Software
    Foundation, Inc. 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
*/

#include "config.h"

#include <list>

#include <cstdio>
#include <cstring>
#include <cstdlib>

#include <sys/types.h>
#include <sys/socket.h>
#include <sys/wait.h>
#include <errno.h>
#include <time.h>
#include <unistd.h>
#include <fcntl.h>
#include <sys/socket.h>

#include "netcompat.h"

#include "pidfile.h"

#include "connection.h"
#include "util.h"
#include "vpn.h"

vpn network; // THE vpn (bad design...)

/////////////////////////////////////////////////////////////////////////////

const char *vpn::script_if_up ()
{
  // the tunnel device mtu should be the physical mtu - overhead
  // the tricky part is rounding to the cipher key blocksize
  int mtu = conf.mtu - ETH_OVERHEAD - VPE_OVERHEAD - MAX_OVERHEAD;
  mtu += ETH_OVERHEAD - 6 - 6; // now we have the data portion
  mtu -= mtu % EVP_CIPHER_block_size (CIPHER); // round
  mtu -= ETH_OVERHEAD - 6 - 6; // and get interface mtu again

  char *env;
  asprintf (&env, "CONFBASE=%s", confbase); putenv (env);
  asprintf (&env, "NODENAME=%s", THISNODE->nodename); putenv (env);
  asprintf (&env, "NODEID=%d", THISNODE->id); putenv (env);
  asprintf (&env, "IFNAME=%s", tap->interface ()); putenv (env);
  asprintf (&env, "IFTYPE=%s", IFTYPE); putenv (env);
  asprintf (&env, "IFSUBTYPE=%s", IFSUBTYPE); putenv (env);
  asprintf (&env, "MTU=%d", mtu); putenv (env);
  asprintf (&env, "MAC=%02x:%02x:%02x:%02x:%02x:%02x",
            0xfe, 0xfd, 0x80, 0x00, THISNODE->id >> 8,
            THISNODE->id & 0xff);
  putenv (env);

  return ::conf.script_if_up ? ::conf.script_if_up : "if-up";
}

int
vpn::setup ()
{
  ipv4_fd = -1;

  if (THISNODE->protocols & PROT_IPv4 && ::conf.ip_proto)
    {
      ipv4_fd = socket (PF_INET, SOCK_RAW, ::conf.ip_proto);

      if (ipv4_fd < 0)
        return -1;

      fcntl (ipv4_fd, F_SETFL, O_NONBLOCK);

#if defined(SOL_IP) && defined(IP_MTU_DISCOVER)
      // this I really consider a linux bug. I am neither connected
      // nor do I fragment myself. Linux still sets DF and doesn't
      // fragment for me sometimes.
      {
        int oval = IP_PMTUDISC_DONT;
        setsockopt (ipv4_fd, SOL_IP, IP_MTU_DISCOVER, &oval, sizeof oval);
      }
#endif

      sockinfo si (THISNODE, PROT_IPv4);

      if (bind (ipv4_fd, si.sav4 (), si.salenv4 ()))
        {
          slog (L_ERR, _("can't bind ipv4 socket on %s: %s"), (const char *)si, strerror (errno));
          exit (EXIT_FAILURE);
        }

      ipv4_ev_watcher.start (ipv4_fd, EVENT_READ);
    }

  udpv4_fd = -1;

  if (THISNODE->protocols & PROT_UDPv4 && THISNODE->udp_port)
    {
      udpv4_fd = socket (PF_INET, SOCK_DGRAM, IPPROTO_UDP);

      if (udpv4_fd < 0)
        return -1;

      fcntl (udpv4_fd, F_SETFL, O_NONBLOCK);

      // standard daemon practise...
      {
        int oval = 1;
        setsockopt (udpv4_fd, SOL_SOCKET, SO_REUSEADDR, &oval, sizeof oval);
      }

#if defined(SOL_IP) && defined(IP_MTU_DISCOVER)
      // this I really consider a linux bug. I am neither connected
      // nor do I fragment myself. Linux still sets DF and doesn't
      // fragment for me sometimes.
      {
        int oval = IP_PMTUDISC_DONT;
        setsockopt (udpv4_fd, SOL_IP, IP_MTU_DISCOVER, &oval, sizeof oval);
      }
#endif

      sockinfo si (THISNODE, PROT_UDPv4);

      if (bind (udpv4_fd, si.sav4 (), si.salenv4 ()))
        {
          slog (L_ERR, _("can't bind udpv4 on %s: %s"), (const char *)si, strerror (errno));
          exit (EXIT_FAILURE);
        }

      udpv4_ev_watcher.start (udpv4_fd, EVENT_READ);
    }

  icmpv4_fd = -1;

#if ENABLE_ICMP
  if (THISNODE->protocols & PROT_ICMPv4)
    {
      icmpv4_fd = socket (PF_INET, SOCK_RAW, IPPROTO_ICMP);

      if (icmpv4_fd < 0)
        return -1;

      fcntl (icmpv4_fd, F_SETFL, O_NONBLOCK);

#ifdef ICMP_FILTER
      {
        icmp_filter oval;
        oval.data = 0xffffffff;
        if (::conf.icmp_type < 32)
          oval.data &= ~(1 << ::conf.icmp_type);

        setsockopt (icmpv4_fd, SOL_RAW, ICMP_FILTER, &oval, sizeof oval);
      }
#endif

#if defined(SOL_IP) && defined(IP_MTU_DISCOVER)
      // this I really consider a linux bug. I am neither connected
      // nor do I fragment myself. Linux still sets DF and doesn't
      // fragment for me sometimes.
      {
        int oval = IP_PMTUDISC_DONT;
        setsockopt (udpv4_fd, SOL_IP, IP_MTU_DISCOVER, &oval, sizeof oval);
      }
#endif

      sockinfo si (THISNODE, PROT_ICMPv4);

      if (bind (icmpv4_fd, si.sav4 (), si.salenv4 ()))
        {
          slog (L_ERR, _("can't bind icmpv4 on %s: %s"), (const char *)si, strerror (errno));
          exit (EXIT_FAILURE);
        }

      icmpv4_ev_watcher.start (icmpv4_fd, EVENT_READ);
    }
#endif

  tcpv4_fd = -1;

#if ENABLE_TCP
  if (THISNODE->protocols & PROT_TCPv4 && THISNODE->tcp_port)
    {
      tcpv4_fd = socket (PF_INET, SOCK_STREAM, IPPROTO_TCP);

      if (tcpv4_fd < 0)
        return -1;

      fcntl (tcpv4_fd, F_SETFL, O_NONBLOCK);

      // standard daemon practise...
      {
        int oval = 1;
        setsockopt (tcpv4_fd, SOL_SOCKET, SO_REUSEADDR, &oval, sizeof oval);
      }

      sockinfo si (THISNODE, PROT_TCPv4);

      if (bind (tcpv4_fd, si.sav4 (), si.salenv4 ()))
        {
          slog (L_ERR, _("can't bind tcpv4 on %s: %s"), (const char *)si, strerror (errno));
          exit (EXIT_FAILURE);
        }

      if (listen (tcpv4_fd, 5))
        {
          slog (L_ERR, _("can't listen tcpv4 on %s: %s"), (const char *)si, strerror (errno));
          exit (EXIT_FAILURE);
        }

      tcpv4_ev_watcher.start (tcpv4_fd, EVENT_READ);
    }
#endif

#if ENABLE_DNS
  if (THISNODE->protocols & PROT_DNSv4)
    {
      dns_forwarder.set (::conf.dns_forw_host, ::conf.dns_forw_port, PROT_DNSv4);

      dnsv4_fd = socket (PF_INET, SOCK_DGRAM, IPPROTO_UDP);

      if (dnsv4_fd < 0)
        return -1;

      // standard daemon practise...
      {
        int oval = 1;
        setsockopt (tcpv4_fd, SOL_SOCKET, SO_REUSEADDR, &oval, sizeof oval);
      }

      sockinfo si (THISNODE, PROT_DNSv4);

      if (bind (dnsv4_fd, si.sav4 (), si.salenv4 ()))
        {
          slog (L_ERR, _("can't bind dnsv4 on %s: %s"), (const char *)si, strerror (errno));
          exit (EXIT_FAILURE);
        }

      dnsv4_ev_watcher.start (dnsv4_fd, EVENT_READ);
    }
#endif

  tap = new tap_device ();
  if (!tap) //D this, of course, never catches
    {
      slog (L_ERR, _("cannot create network interface '%s'"), conf.ifname);
      exit (EXIT_FAILURE);
    }
  
  run_script (run_script_cb (this, &vpn::script_if_up), true);

  tap_ev_watcher.start (tap->fd, EVENT_READ);

  reconnect_all ();

  return 0;
}

bool
vpn::send_ipv4_packet (vpn_packet *pkt, const sockinfo &si, int tos)
{
#if defined(SOL_IP) && defined(IP_TOS)
  setsockopt (ipv4_fd, SOL_IP, IP_TOS, &tos, sizeof tos);
#endif
  sendto (ipv4_fd, &((*pkt)[0]), pkt->len, 0, si.sav4 (), si.salenv4 ());

  return true;
}

static u16
ipv4_checksum (u16 *data, unsigned int len)
{
  // use 32 bit accumulator and fold back carry bits at the end
  u32 sum = 0;

  while (len > 1)
    {
      sum += *data++;
      len -= 2;
    }

  // odd byte left?
  if (len)
    sum += *(u8 *)data;

  // add back carry bits
  sum = (sum >> 16) + (sum & 0xffff);   // lo += hi
  sum += (sum >> 16);                   // carry

  return ~sum;
}

#if ENABLE_ICMP
bool
vpn::send_icmpv4_packet (vpn_packet *pkt, const sockinfo &si, int tos)
{
#if defined(SOL_IP) && defined(IP_TOS)
  setsockopt (icmpv4_fd, SOL_IP, IP_TOS, &tos, sizeof tos);
#endif

  pkt->unshift_hdr (4);

  icmp_header *hdr = (icmp_header *)&((*pkt)[0]);
  hdr->type = ::conf.icmp_type;
  hdr->code = 255;
  hdr->checksum = 0;
  hdr->checksum = ipv4_checksum ((u16 *)hdr, pkt->len);

  sendto (icmpv4_fd, &((*pkt)[0]), pkt->len, 0, si.sav4 (), si.salenv4 ());

  return true;
}
#endif

bool
vpn::send_udpv4_packet (vpn_packet *pkt, const sockinfo &si, int tos)
{
#if defined(SOL_IP) && defined(IP_TOS)
  setsockopt (udpv4_fd, SOL_IP, IP_TOS, &tos, sizeof tos);
#endif
  sendto (udpv4_fd, &((*pkt)[0]), pkt->len, 0, si.sav4 (), si.salenv4 ());

  return true;
}

void
vpn::inject_data_packet (tap_packet *pkt, int dst)
{
  if (dst)
    {
      // unicast
      if (dst != THISNODE->id)
        conns[dst - 1]->inject_data_packet (pkt);
    }
  else
    {
      // broadcast, this is ugly, but due to the security policy
      // we have to connect to all hosts...
      for (conns_vector::iterator c = conns.begin (); c != conns.end (); ++c)
        if ((*c)->conf != THISNODE)
          (*c)->inject_data_packet (pkt, true);
  }
}

void
vpn::recv_vpn_packet (vpn_packet *pkt, const sockinfo &rsi)
{
  unsigned int src = pkt->src ();
  unsigned int dst = pkt->dst ();

  slog (L_NOISE, _("<<?/%s received possible vpn packet type %d from %d to %d, length %d"),
        (const char *)rsi, pkt->typ (), pkt->src (), pkt->dst (), pkt->len);

  if (src == 0 || src > conns.size ()
      || dst > conns.size ()
      || pkt->typ () >= vpn_packet::PT_MAX)
    slog (L_WARN, _("(%s): received corrupted packet type %d (src %d, dst %d)"),
          (const char *)rsi, pkt->typ (), pkt->src (), pkt->dst ());
  else if (dst > conns.size ())
    slog (L_WARN, _("(%s): received corrupted packet type %d (src %d, dst %d)"),
          (const char *)rsi, pkt->typ (), pkt->src (), pkt->dst ());
  else
    {
      connection *c = conns[src - 1];

      if (dst == 0)
        slog (L_WARN, _("%s(%s): received broadcast (protocol violation)"),
              c->conf->nodename, (const char *)rsi);
      else if (dst != THISNODE->id)
        {
          if (THISNODE->routerprio)
            // the tos setting gets lost here. who cares.
            conns[dst - 1]->inject_vpn_packet (pkt);
          else
            slog (L_WARN,
                  _("%s(%s): forwarding request (=> %s), but we are no router"),
                  c->conf->nodename, (const char *)rsi,
                  conns[dst - 1]->conf->nodename);
        }
      else
        c->recv_vpn_packet (pkt, rsi);
    }
}

void
vpn::ipv4_ev (io_watcher &w, short revents)
{
  if (revents & EVENT_READ)
    {
      vpn_packet *pkt = new vpn_packet;
      struct sockaddr_in sa;
      socklen_t sa_len = sizeof (sa);
      int len;

      len = recvfrom (w.fd, &((*pkt)[0]), MAXSIZE, 0, (sockaddr *)&sa, &sa_len);

      sockinfo si(sa, PROT_IPv4);

      if (len > 0)
        {
          pkt->len = len;

          // raw sockets deliver the ipv4 header, but don't expect it on sends
          pkt->skip_hdr (IP_OVERHEAD);

          recv_vpn_packet (pkt, si);
        }
      else
        {
          // probably ECONNRESET or somesuch
          slog (L_DEBUG, _("%s: %s"), (const char *)si, strerror (errno));
        }

      delete pkt;
    }
  else
    {
      slog (L_ERR,
            _("FATAL: unknown revents %08x in socket, terminating\n"),
            revents);
      exit (EXIT_FAILURE);
    }
}

#if ENABLE_ICMP
void
vpn::icmpv4_ev (io_watcher &w, short revents)
{
  if (revents & EVENT_READ)
    {
      vpn_packet *pkt = new vpn_packet;
      struct sockaddr_in sa;
      socklen_t sa_len = sizeof (sa);
      int len;

      len = recvfrom (w.fd, &((*pkt)[0]), MAXSIZE, 0, (sockaddr *)&sa, &sa_len);

      sockinfo si(sa, PROT_ICMPv4);

      if (len > 0)
        {
          pkt->len = len;

          icmp_header *hdr = (icmp_header *)&((*pkt)[IP_OVERHEAD]);

          if (hdr->type == ::conf.icmp_type
              && hdr->code == 255)
            {
              // raw sockets deliver the ipv4, but don't expect it on sends
              // this is slow, but...
              pkt->skip_hdr (ICMP_OVERHEAD);

              recv_vpn_packet (pkt, si);
            }
        }
      else
        {
          // probably ECONNRESET or somesuch
          slog (L_DEBUG, _("%s: %s"), (const char *)si, strerror (errno));
        }

      delete pkt;
    }
  else
    {
      slog (L_ERR,
              _("FATAL: unknown revents %08x in socket, terminating\n"),
              revents);
      exit (EXIT_FAILURE);
    }
}
#endif

void
vpn::udpv4_ev (io_watcher &w, short revents)
{
  if (revents & EVENT_READ)
    {
      vpn_packet *pkt = new vpn_packet;
      struct sockaddr_in sa;
      socklen_t sa_len = sizeof (sa);
      int len;

      len = recvfrom (w.fd, &((*pkt)[0]), MAXSIZE, 0, (sockaddr *)&sa, &sa_len);

      sockinfo si(sa, PROT_UDPv4);

      if (len > 0)
        {
          pkt->len = len;

          recv_vpn_packet (pkt, si);
        }
      else
        {
          // probably ECONNRESET or somesuch
          slog (L_DEBUG, _("%s: fd %d, %s"), (const char *)si, w.fd, strerror (errno));
        }

      delete pkt;
    }
  else
    {
      slog (L_ERR,
              _("FATAL: unknown revents %08x in socket, terminating\n"),
              revents);
      exit (EXIT_FAILURE);
    }
}

void
vpn::tap_ev (io_watcher &w, short revents)
{
  if (revents & EVENT_READ)
    {
      /* process data */
      tap_packet *pkt;

      pkt = tap->recv ();

      if (!pkt)
        return;

      if (pkt->len > 14)
        {
          int dst = mac2id (pkt->dst);
          int src = mac2id (pkt->src);

          if (src != THISNODE->id)
            {
              slog (L_ERR, _("FATAL: tap packet not originating on current node received (if-up script not working properly?), exiting."));
              exit (EXIT_FAILURE);
            }

          if (dst == THISNODE->id)
            {
              slog (L_ERR, _("FATAL: tap packet destined for current node received, exiting."));
              exit (EXIT_FAILURE);
            }

          if (dst > conns.size ())
            slog (L_ERR, _("tap packet for unknown node %d received, ignoring."), dst);
          else
            inject_data_packet (pkt, dst);
        }

      delete pkt;
    }
  else
    abort ();
}

void
vpn::event_cb (time_watcher &w)
{
  if (events)
    {
      if (events & EVENT_SHUTDOWN)
        {
          slog (L_INFO, _("preparing shutdown..."));

          shutdown_all ();
          remove_pid (conf.pidfilename);
          slog (L_INFO, _("terminating"));
          exit (EXIT_SUCCESS);
        }

      if (events & EVENT_RECONNECT)
        {
          slog (L_INFO, _("forced reconnect"));

          reconnect_all ();
        }

      events = 0;
    }
}

void
vpn::shutdown_all ()
{
  for (conns_vector::iterator c = conns.begin (); c != conns.end (); ++c)
    (*c)->shutdown ();
}

void
vpn::reconnect_all ()
{
  for (conns_vector::iterator c = conns.begin (); c != conns.end (); ++c)
    delete *c;

  conns.clear ();

  connection_init ();

  for (configuration::node_vector::iterator i = conf.nodes.begin ();
       i != conf.nodes.end (); ++i)
    {
      connection *conn = new connection (this, *i);
      conns.push_back (conn);
      conn->establish_connection ();
    }
}

connection *vpn::find_router ()
{
  u32 prio = 1;
  connection *router = 0;

  for (conns_vector::iterator i = conns.begin (); i != conns.end (); ++i)
    {
      connection *c = *i;

      if (c->conf->routerprio > prio
          && c->connectmode == conf_node::C_ALWAYS // so we don't drop the connection if in use
          && c->ictx && c->octx
          && c->conf != THISNODE)                  // redundant, since ictx==octx==0 always on thisnode
        {
          prio = c->conf->routerprio;
          router = c;
        }
    }

  return router;
}

void vpn::send_connect_request (int id)
{
  connection *c = find_router ();

  if (c)
    c->send_connect_request (id);
  else
    // no router found, aggressively connect to all routers
    for (conns_vector::iterator i = conns.begin (); i != conns.end (); ++i)
      if ((*i)->conf->routerprio && (*i)->conf != THISNODE)
        (*i)->establish_connection ();
}

void
connection::dump_status ()
{
  slog (L_NOTICE, _("node %s (id %d)"), conf->nodename, conf->id);
  slog (L_NOTICE, _("  connectmode %d (%d) / sockaddr %s / minor %d"),
        connectmode, conf->connectmode, (const char *)si, (int)prot_minor);
  slog (L_NOTICE, _("  ictx/octx %08lx/%08lx / oseqno %d / retry_cnt %d"),
        (long)ictx, (long)octx, (int)oseqno, (int)retry_cnt);
  slog (L_NOTICE, _("  establish_conn %ld / rekey %ld / keepalive %ld"),
        (long)(establish_connection.at), (long)(rekey.at), (long)(keepalive.at));
}

void
vpn::dump_status ()
{
  slog (L_NOTICE, _("BEGIN status dump (%ld)"), (long)NOW);

  for (conns_vector::iterator c = conns.begin (); c != conns.end (); ++c)
    (*c)->dump_status ();

  slog (L_NOTICE, _("END status dump"));
}

vpn::vpn (void)
: event            (this, &vpn::event_cb)
, udpv4_ev_watcher (this, &vpn::udpv4_ev)
, ipv4_ev_watcher  (this, &vpn::ipv4_ev)
#if ENABLE_TCP
, tcpv4_ev_watcher (this, &vpn::tcpv4_ev)
#endif
#if ENABLE_ICMP
, icmpv4_ev_watcher(this, &vpn::icmpv4_ev)
#endif
#if ENABLE_DNS
, dnsv4_ev_watcher (this, &vpn::dnsv4_ev)
#endif
, tap_ev_watcher   (this, &vpn::tap_ev)
{
}

vpn::~vpn ()
{
}

Revision:	1.30
Committed:	Fri Mar 4 20:26:50 2005 UTC (19 years, 2 months ago) by pcg
Content type:	text/plain
Branch:	MAIN
Changes since 1.29:	+4 -5 lines
Log Message:	* empty log message *
#	User	Rev	Content
1	pcg	1.1	/*
2			vpn.C -- handle the protocol, encryption, handshaking etc.
3	pcg	1.28	Copyright (C) 2003-2005 Marc Lehmann <gvpe@schmorp.de>
4	pcg	1.1
5	pcg	1.28	This file is part of GVPE.
6
7			GVPE is free software; you can redistribute it and/or modify
8	pcg	1.1	it under the terms of the GNU General Public License as published by
9			the Free Software Foundation; either version 2 of the License, or
10			(at your option) any later version.
11
12			This program is distributed in the hope that it will be useful,
13			but WITHOUT ANY WARRANTY; without even the implied warranty of
14			MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15			GNU General Public License for more details.
16
17			You should have received a copy of the GNU General Public License
18	pcg	1.28	along with gvpe; if not, write to the Free Software
19	pcg	1.1	Foundation, Inc. 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
20			*/
21
22			#include "config.h"
23
24			#include <list>
25
26	pcg	1.23	#include <cstdio>
27			#include <cstring>
28	pcg	1.1	#include <cstdlib>
29
30			#include <sys/types.h>
31			#include <sys/socket.h>
32			#include <sys/wait.h>
33			#include <errno.h>
34			#include <time.h>
35			#include <unistd.h>
36	pcg	1.11	#include <fcntl.h>
37	pcg	1.14	#include <sys/socket.h>
38	pcg	1.15
39			#include "netcompat.h"
40	pcg	1.1
41			#include "pidfile.h"
42
43			#include "connection.h"
44			#include "util.h"
45			#include "vpn.h"
46
47	pcg	1.20	vpn network; // THE vpn (bad design...)
48
49	pcg	1.1	/////////////////////////////////////////////////////////////////////////////
50
51	pcg	1.2	const char *vpn::script_if_up ()
52	pcg	1.1	{
53			// the tunnel device mtu should be the physical mtu - overhead
54			// the tricky part is rounding to the cipher key blocksize
55			int mtu = conf.mtu - ETH_OVERHEAD - VPE_OVERHEAD - MAX_OVERHEAD;
56			mtu += ETH_OVERHEAD - 6 - 6; // now we have the data portion
57			mtu -= mtu % EVP_CIPHER_block_size (CIPHER); // round
58			mtu -= ETH_OVERHEAD - 6 - 6; // and get interface mtu again
59
60			char *env;
61	pcg	1.21	asprintf (&env, "CONFBASE=%s", confbase); putenv (env);
62			asprintf (&env, "NODENAME=%s", THISNODE->nodename); putenv (env);
63			asprintf (&env, "NODEID=%d", THISNODE->id); putenv (env);
64			asprintf (&env, "IFNAME=%s", tap->interface ()); putenv (env);
65			asprintf (&env, "IFTYPE=%s", IFTYPE); putenv (env);
66			asprintf (&env, "IFSUBTYPE=%s", IFSUBTYPE); putenv (env);
67			asprintf (&env, "MTU=%d", mtu); putenv (env);
68	pcg	1.1	asprintf (&env, "MAC=%02x:%02x:%02x:%02x:%02x:%02x",
69			0xfe, 0xfd, 0x80, 0x00, THISNODE->id >> 8,
70			THISNODE->id & 0xff);
71			putenv (env);
72
73			return ::conf.script_if_up ? ::conf.script_if_up : "if-up";
74			}
75
76			int
77			vpn::setup ()
78			{
79	pcg	1.8	ipv4_fd = -1;
80	pcg	1.1
81	pcg	1.8	if (THISNODE->protocols & PROT_IPv4 && ::conf.ip_proto)
82	pcg	1.1	{
83	pcg	1.8	ipv4_fd = socket (PF_INET, SOCK_RAW, ::conf.ip_proto);
84	pcg	1.1
85	pcg	1.8	if (ipv4_fd < 0)
86	pcg	1.1	return -1;
87
88	pcg	1.11	fcntl (ipv4_fd, F_SETFL, O_NONBLOCK);
89
90	pcg	1.14	#if defined(SOL_IP) && defined(IP_MTU_DISCOVER)
91	pcg	1.1	// this I really consider a linux bug. I am neither connected
92			// nor do I fragment myself. Linux still sets DF and doesn't
93			// fragment for me sometimes.
94			{
95			int oval = IP_PMTUDISC_DONT;
96	pcg	1.8	setsockopt (ipv4_fd, SOL_IP, IP_MTU_DISCOVER, &oval, sizeof oval);
97	pcg	1.1	}
98			#endif
99
100	pcg	1.9	sockinfo si (THISNODE, PROT_IPv4);
101
102			if (bind (ipv4_fd, si.sav4 (), si.salenv4 ()))
103			{
104			slog (L_ERR, _("can't bind ipv4 socket on %s: %s"), (const char *)si, strerror (errno));
105	pcg	1.23	exit (EXIT_FAILURE);
106	pcg	1.9	}
107
108	pcg	1.22	ipv4_ev_watcher.start (ipv4_fd, EVENT_READ);
109	pcg	1.1	}
110
111	pcg	1.8	udpv4_fd = -1;
112
113			if (THISNODE->protocols & PROT_UDPv4 && THISNODE->udp_port)
114	pcg	1.1	{
115	pcg	1.8	udpv4_fd = socket (PF_INET, SOCK_DGRAM, IPPROTO_UDP);
116	pcg	1.1
117	pcg	1.8	if (udpv4_fd < 0)
118	pcg	1.1	return -1;
119
120	pcg	1.11	fcntl (udpv4_fd, F_SETFL, O_NONBLOCK);
121
122	pcg	1.8	// standard daemon practise...
123			{
124			int oval = 1;
125			setsockopt (udpv4_fd, SOL_SOCKET, SO_REUSEADDR, &oval, sizeof oval);
126			}
127
128	pcg	1.14	#if defined(SOL_IP) && defined(IP_MTU_DISCOVER)
129	pcg	1.9	// this I really consider a linux bug. I am neither connected
130			// nor do I fragment myself. Linux still sets DF and doesn't
131			// fragment for me sometimes.
132			{
133			int oval = IP_PMTUDISC_DONT;
134			setsockopt (udpv4_fd, SOL_IP, IP_MTU_DISCOVER, &oval, sizeof oval);
135			}
136			#endif
137
138	pcg	1.8	sockinfo si (THISNODE, PROT_UDPv4);
139	pcg	1.2
140	pcg	1.8	if (bind (udpv4_fd, si.sav4 (), si.salenv4 ()))
141	pcg	1.1	{
142	pcg	1.8	slog (L_ERR, _("can't bind udpv4 on %s: %s"), (const char *)si, strerror (errno));
143	pcg	1.23	exit (EXIT_FAILURE);
144	pcg	1.1	}
145
146	pcg	1.22	udpv4_ev_watcher.start (udpv4_fd, EVENT_READ);
147	pcg	1.9	}
148
149			icmpv4_fd = -1;
150
151			#if ENABLE_ICMP
152			if (THISNODE->protocols & PROT_ICMPv4)
153			{
154			icmpv4_fd = socket (PF_INET, SOCK_RAW, IPPROTO_ICMP);
155
156			if (icmpv4_fd < 0)
157			return -1;
158
159	pcg	1.11	fcntl (icmpv4_fd, F_SETFL, O_NONBLOCK);
160
161	pcg	1.9	#ifdef ICMP_FILTER
162			{
163			icmp_filter oval;
164			oval.data = 0xffffffff;
165			if (::conf.icmp_type < 32)
166			oval.data &= ~(1 << ::conf.icmp_type);
167
168			setsockopt (icmpv4_fd, SOL_RAW, ICMP_FILTER, &oval, sizeof oval);
169			}
170			#endif
171
172	pcg	1.14	#if defined(SOL_IP) && defined(IP_MTU_DISCOVER)
173	pcg	1.1	// this I really consider a linux bug. I am neither connected
174			// nor do I fragment myself. Linux still sets DF and doesn't
175			// fragment for me sometimes.
176			{
177			int oval = IP_PMTUDISC_DONT;
178	pcg	1.8	setsockopt (udpv4_fd, SOL_IP, IP_MTU_DISCOVER, &oval, sizeof oval);
179	pcg	1.1	}
180			#endif
181
182	pcg	1.9	sockinfo si (THISNODE, PROT_ICMPv4);
183
184			if (bind (icmpv4_fd, si.sav4 (), si.salenv4 ()))
185			{
186			slog (L_ERR, _("can't bind icmpv4 on %s: %s"), (const char *)si, strerror (errno));
187	pcg	1.23	exit (EXIT_FAILURE);
188	pcg	1.9	}
189
190	pcg	1.22	icmpv4_ev_watcher.start (icmpv4_fd, EVENT_READ);
191	pcg	1.1	}
192	pcg	1.9	#endif
193	pcg	1.1
194	pcg	1.8	tcpv4_fd = -1;
195
196	pcg	1.2	#if ENABLE_TCP
197	pcg	1.8	if (THISNODE->protocols & PROT_TCPv4 && THISNODE->tcp_port)
198	pcg	1.2	{
199			tcpv4_fd = socket (PF_INET, SOCK_STREAM, IPPROTO_TCP);
200
201			if (tcpv4_fd < 0)
202			return -1;
203
204	pcg	1.11	fcntl (tcpv4_fd, F_SETFL, O_NONBLOCK);
205
206	pcg	1.3	// standard daemon practise...
207			{
208			int oval = 1;
209			setsockopt (tcpv4_fd, SOL_SOCKET, SO_REUSEADDR, &oval, sizeof oval);
210			}
211
212	pcg	1.2	sockinfo si (THISNODE, PROT_TCPv4);
213
214			if (bind (tcpv4_fd, si.sav4 (), si.salenv4 ()))
215			{
216			slog (L_ERR, _("can't bind tcpv4 on %s: %s"), (const char *)si, strerror (errno));
217	pcg	1.23	exit (EXIT_FAILURE);
218	pcg	1.2	}
219
220			if (listen (tcpv4_fd, 5))
221			{
222			slog (L_ERR, _("can't listen tcpv4 on %s: %s"), (const char *)si, strerror (errno));
223	pcg	1.23	exit (EXIT_FAILURE);
224	pcg	1.2	}
225
226	pcg	1.22	tcpv4_ev_watcher.start (tcpv4_fd, EVENT_READ);
227	pcg	1.2	}
228			#endif
229
230	pcg	1.24	#if ENABLE_DNS
231			if (THISNODE->protocols & PROT_DNSv4)
232			{
233	pcg	1.29	dns_forwarder.set (::conf.dns_forw_host, ::conf.dns_forw_port, PROT_DNSv4);
234
235	pcg	1.24	dnsv4_fd = socket (PF_INET, SOCK_DGRAM, IPPROTO_UDP);
236
237			if (dnsv4_fd < 0)
238			return -1;
239
240			// standard daemon practise...
241			{
242			int oval = 1;
243			setsockopt (tcpv4_fd, SOL_SOCKET, SO_REUSEADDR, &oval, sizeof oval);
244			}
245
246			sockinfo si (THISNODE, PROT_DNSv4);
247
248			if (bind (dnsv4_fd, si.sav4 (), si.salenv4 ()))
249			{
250			slog (L_ERR, _("can't bind dnsv4 on %s: %s"), (const char *)si, strerror (errno));
251			exit (EXIT_FAILURE);
252			}
253
254			dnsv4_ev_watcher.start (dnsv4_fd, EVENT_READ);
255			}
256			#endif
257
258	pcg	1.1	tap = new tap_device ();
259			if (!tap) //D this, of course, never catches
260			{
261			slog (L_ERR, _("cannot create network interface '%s'"), conf.ifname);
262	pcg	1.23	exit (EXIT_FAILURE);
263	pcg	1.1	}
264
265			run_script (run_script_cb (this, &vpn::script_if_up), true);
266
267	pcg	1.22	tap_ev_watcher.start (tap->fd, EVENT_READ);
268	pcg	1.1
269			reconnect_all ();
270
271			return 0;
272			}
273
274	pcg	1.7	bool
275	pcg	1.1	vpn::send_ipv4_packet (vpn_packet *pkt, const sockinfo &si, int tos)
276			{
277	pcg	1.14	#if defined(SOL_IP) && defined(IP_TOS)
278	pcg	1.1	setsockopt (ipv4_fd, SOL_IP, IP_TOS, &tos, sizeof tos);
279	pcg	1.14	#endif
280	pcg	1.1	sendto (ipv4_fd, &((*pkt)[0]), pkt->len, 0, si.sav4 (), si.salenv4 ());
281	pcg	1.7
282			return true;
283	pcg	1.1	}
284
285	pcg	1.9	static u16
286			ipv4_checksum (u16 *data, unsigned int len)
287			{
288			// use 32 bit accumulator and fold back carry bits at the end
289			u32 sum = 0;
290
291			while (len > 1)
292			{
293			sum += *data++;
294			len -= 2;
295			}
296
297			// odd byte left?
298			if (len)
299			sum += (u8 )data;
300
301			// add back carry bits
302			sum = (sum >> 16) + (sum & 0xffff); // lo += hi
303			sum += (sum >> 16); // carry
304
305			return ~sum;
306			}
307
308	pcg	1.13	#if ENABLE_ICMP
309	pcg	1.9	bool
310			vpn::send_icmpv4_packet (vpn_packet *pkt, const sockinfo &si, int tos)
311			{
312	pcg	1.14	#if defined(SOL_IP) && defined(IP_TOS)
313	pcg	1.9	setsockopt (icmpv4_fd, SOL_IP, IP_TOS, &tos, sizeof tos);
314	pcg	1.14	#endif
315	pcg	1.9
316			pkt->unshift_hdr (4);
317
318	pcg	1.14	icmp_header hdr = (icmp_header )&((*pkt)[0]);
319	pcg	1.9	hdr->type = ::conf.icmp_type;
320			hdr->code = 255;
321			hdr->checksum = 0;
322			hdr->checksum = ipv4_checksum ((u16 *)hdr, pkt->len);
323
324			sendto (icmpv4_fd, &((*pkt)[0]), pkt->len, 0, si.sav4 (), si.salenv4 ());
325
326			return true;
327			}
328	pcg	1.13	#endif
329	pcg	1.9
330	pcg	1.7	bool
331	pcg	1.1	vpn::send_udpv4_packet (vpn_packet *pkt, const sockinfo &si, int tos)
332			{
333	pcg	1.14	#if defined(SOL_IP) && defined(IP_TOS)
334	pcg	1.1	setsockopt (udpv4_fd, SOL_IP, IP_TOS, &tos, sizeof tos);
335	pcg	1.14	#endif
336	pcg	1.1	sendto (udpv4_fd, &((*pkt)[0]), pkt->len, 0, si.sav4 (), si.salenv4 ());
337	pcg	1.7
338			return true;
339	pcg	1.1	}
340
341			void
342	pcg	1.18	vpn::inject_data_packet (tap_packet *pkt, int dst)
343			{
344			if (dst)
345			{
346			// unicast
347			if (dst != THISNODE->id)
348			conns[dst - 1]->inject_data_packet (pkt);
349			}
350			else
351			{
352			// broadcast, this is ugly, but due to the security policy
353			// we have to connect to all hosts...
354			for (conns_vector::iterator c = conns.begin (); c != conns.end (); ++c)
355			if ((*c)->conf != THISNODE)
356			(*c)->inject_data_packet (pkt, true);
357			}
358			}
359
360			void
361	pcg	1.1	vpn::recv_vpn_packet (vpn_packet *pkt, const sockinfo &rsi)
362			{
363			unsigned int src = pkt->src ();
364			unsigned int dst = pkt->dst ();
365
366			slog (L_NOISE, _("<<?/%s received possible vpn packet type %d from %d to %d, length %d"),
367			(const char *)rsi, pkt->typ (), pkt->src (), pkt->dst (), pkt->len);
368
369			if (src == 0 \|\| src > conns.size ()
370			\|\| dst > conns.size ()
371			\|\| pkt->typ () >= vpn_packet::PT_MAX)
372			slog (L_WARN, _("(%s): received corrupted packet type %d (src %d, dst %d)"),
373			(const char *)rsi, pkt->typ (), pkt->src (), pkt->dst ());
374	pcg	1.6	else if (dst > conns.size ())
375			slog (L_WARN, _("(%s): received corrupted packet type %d (src %d, dst %d)"),
376			(const char *)rsi, pkt->typ (), pkt->src (), pkt->dst ());
377	pcg	1.1	else
378			{
379			connection *c = conns[src - 1];
380
381	pcg	1.13	if (dst == 0)
382			slog (L_WARN, _("%s(%s): received broadcast (protocol violation)"),
383	pcg	1.1	c->conf->nodename, (const char *)rsi);
384	pcg	1.18	else if (dst != THISNODE->id)
385	pcg	1.6	{
386			if (THISNODE->routerprio)
387			// the tos setting gets lost here. who cares.
388			conns[dst - 1]->inject_vpn_packet (pkt);
389			else
390			slog (L_WARN,
391			_("%s(%s): forwarding request (=> %s), but we are no router"),
392			c->conf->nodename, (const char *)rsi,
393			conns[dst - 1]->conf->nodename);
394			}
395	pcg	1.1	else
396			c->recv_vpn_packet (pkt, rsi);
397			}
398			}
399
400			void
401	pcg	1.9	vpn::ipv4_ev (io_watcher &w, short revents)
402	pcg	1.1	{
403	pcg	1.22	if (revents & EVENT_READ)
404	pcg	1.1	{
405			vpn_packet *pkt = new vpn_packet;
406			struct sockaddr_in sa;
407			socklen_t sa_len = sizeof (sa);
408			int len;
409
410	pcg	1.5	len = recvfrom (w.fd, &((pkt)[0]), MAXSIZE, 0, (sockaddr )&sa, &sa_len);
411	pcg	1.1
412	pcg	1.9	sockinfo si(sa, PROT_IPv4);
413	pcg	1.1
414			if (len > 0)
415			{
416			pkt->len = len;
417
418	pcg	1.30	// raw sockets deliver the ipv4 header, but don't expect it on sends
419	pcg	1.9	pkt->skip_hdr (IP_OVERHEAD);
420
421	pcg	1.1	recv_vpn_packet (pkt, si);
422			}
423			else
424			{
425			// probably ECONNRESET or somesuch
426	pcg	1.9	slog (L_DEBUG, _("%s: %s"), (const char *)si, strerror (errno));
427	pcg	1.1	}
428
429			delete pkt;
430			}
431			else
432			{
433			slog (L_ERR,
434	pcg	1.30	_("FATAL: unknown revents %08x in socket, terminating\n"),
435			revents);
436	pcg	1.23	exit (EXIT_FAILURE);
437	pcg	1.1	}
438			}
439
440	pcg	1.13	#if ENABLE_ICMP
441	pcg	1.1	void
442	pcg	1.9	vpn::icmpv4_ev (io_watcher &w, short revents)
443	pcg	1.1	{
444	pcg	1.22	if (revents & EVENT_READ)
445	pcg	1.1	{
446			vpn_packet *pkt = new vpn_packet;
447			struct sockaddr_in sa;
448			socklen_t sa_len = sizeof (sa);
449			int len;
450
451	pcg	1.5	len = recvfrom (w.fd, &((pkt)[0]), MAXSIZE, 0, (sockaddr )&sa, &sa_len);
452	pcg	1.1
453	pcg	1.9	sockinfo si(sa, PROT_ICMPv4);
454	pcg	1.1
455			if (len > 0)
456			{
457			pkt->len = len;
458
459	pcg	1.14	icmp_header hdr = (icmp_header )&((*pkt)[IP_OVERHEAD]);
460	pcg	1.9
461			if (hdr->type == ::conf.icmp_type
462			&& hdr->code == 255)
463			{
464			// raw sockets deliver the ipv4, but don't expect it on sends
465			// this is slow, but...
466			pkt->skip_hdr (ICMP_OVERHEAD);
467
468			recv_vpn_packet (pkt, si);
469			}
470			}
471			else
472			{
473			// probably ECONNRESET or somesuch
474			slog (L_DEBUG, _("%s: %s"), (const char *)si, strerror (errno));
475			}
476
477			delete pkt;
478			}
479			else
480			{
481			slog (L_ERR,
482			_("FATAL: unknown revents %08x in socket, terminating\n"),
483			revents);
484	pcg	1.23	exit (EXIT_FAILURE);
485	pcg	1.9	}
486			}
487	pcg	1.13	#endif
488	pcg	1.9
489			void
490			vpn::udpv4_ev (io_watcher &w, short revents)
491			{
492	pcg	1.22	if (revents & EVENT_READ)
493	pcg	1.9	{
494			vpn_packet *pkt = new vpn_packet;
495			struct sockaddr_in sa;
496			socklen_t sa_len = sizeof (sa);
497			int len;
498
499			len = recvfrom (w.fd, &((pkt)[0]), MAXSIZE, 0, (sockaddr )&sa, &sa_len);
500
501			sockinfo si(sa, PROT_UDPv4);
502
503			if (len > 0)
504			{
505			pkt->len = len;
506	pcg	1.1
507			recv_vpn_packet (pkt, si);
508			}
509			else
510			{
511			// probably ECONNRESET or somesuch
512	pcg	1.9	slog (L_DEBUG, _("%s: fd %d, %s"), (const char *)si, w.fd, strerror (errno));
513	pcg	1.1	}
514
515			delete pkt;
516			}
517			else
518			{
519			slog (L_ERR,
520			_("FATAL: unknown revents %08x in socket, terminating\n"),
521			revents);
522	pcg	1.23	exit (EXIT_FAILURE);
523	pcg	1.1	}
524			}
525	pcg	1.2
526			void
527	pcg	1.3	vpn::tap_ev (io_watcher &w, short revents)
528	pcg	1.1	{
529	pcg	1.22	if (revents & EVENT_READ)
530	pcg	1.1	{
531			/* process data */
532			tap_packet *pkt;
533
534			pkt = tap->recv ();
535
536	pcg	1.17	if (!pkt)
537			return;
538	pcg	1.1
539	pcg	1.17	if (pkt->len > 14)
540	pcg	1.1	{
541	pcg	1.17	int dst = mac2id (pkt->dst);
542			int src = mac2id (pkt->src);
543	pcg	1.1
544	pcg	1.17	if (src != THISNODE->id)
545			{
546	pcg	1.30	slog (L_ERR, _("FATAL: tap packet not originating on current node received (if-up script not working properly?), exiting."));
547	pcg	1.23	exit (EXIT_FAILURE);
548	pcg	1.17	}
549	pcg	1.1
550	pcg	1.17	if (dst == THISNODE->id)
551	pcg	1.1	{
552	pcg	1.17	slog (L_ERR, _("FATAL: tap packet destined for current node received, exiting."));
553	pcg	1.23	exit (EXIT_FAILURE);
554	pcg	1.1	}
555	pcg	1.17
556			if (dst > conns.size ())
557			slog (L_ERR, _("tap packet for unknown node %d received, ignoring."), dst);
558	pcg	1.1	else
559	pcg	1.18	inject_data_packet (pkt, dst);
560	pcg	1.1	}
561
562			delete pkt;
563			}
564			else
565			abort ();
566			}
567
568			void
569	pcg	1.3	vpn::event_cb (time_watcher &w)
570	pcg	1.1	{
571			if (events)
572			{
573			if (events & EVENT_SHUTDOWN)
574			{
575			slog (L_INFO, _("preparing shutdown..."));
576
577			shutdown_all ();
578	pcg	1.24	remove_pid (conf.pidfilename);
579	pcg	1.1	slog (L_INFO, _("terminating"));
580	pcg	1.23	exit (EXIT_SUCCESS);
581	pcg	1.1	}
582
583			if (events & EVENT_RECONNECT)
584			{
585			slog (L_INFO, _("forced reconnect"));
586
587			reconnect_all ();
588			}
589
590			events = 0;
591			}
592			}
593
594			void
595			vpn::shutdown_all ()
596			{
597			for (conns_vector::iterator c = conns.begin (); c != conns.end (); ++c)
598			(*c)->shutdown ();
599			}
600
601			void
602			vpn::reconnect_all ()
603			{
604			for (conns_vector::iterator c = conns.begin (); c != conns.end (); ++c)
605			delete *c;
606
607			conns.clear ();
608
609			connection_init ();
610
611			for (configuration::node_vector::iterator i = conf.nodes.begin ();
612			i != conf.nodes.end (); ++i)
613			{
614	pcg	1.27	connection conn = new connection (this, i);
615	pcg	1.1	conns.push_back (conn);
616			conn->establish_connection ();
617			}
618			}
619
620			connection *vpn::find_router ()
621			{
622	pcg	1.26	u32 prio = 1;
623	pcg	1.1	connection *router = 0;
624
625			for (conns_vector::iterator i = conns.begin (); i != conns.end (); ++i)
626			{
627			connection c = i;
628
629	pcg	1.13	if (c->conf->routerprio > prio
630	pcg	1.11	&& c->connectmode == conf_node::C_ALWAYS // so we don't drop the connection if in use
631			&& c->ictx && c->octx
632	pcg	1.13	&& c->conf != THISNODE) // redundant, since ictx==octx==0 always on thisnode
633	pcg	1.1	{
634			prio = c->conf->routerprio;
635			router = c;
636			}
637			}
638
639			return router;
640			}
641
642	pcg	1.7	void vpn::send_connect_request (int id)
643	pcg	1.1	{
644			connection *c = find_router ();
645
646			if (c)
647	pcg	1.7	c->send_connect_request (id);
648			else
649			// no router found, aggressively connect to all routers
650			for (conns_vector::iterator i = conns.begin (); i != conns.end (); ++i)
651	pcg	1.13	if ((i)->conf->routerprio && (i)->conf != THISNODE)
652	pcg	1.7	(*i)->establish_connection ();
653	pcg	1.1	}
654
655			void
656			connection::dump_status ()
657			{
658			slog (L_NOTICE, _("node %s (id %d)"), conf->nodename, conf->id);
659			slog (L_NOTICE, _(" connectmode %d (%d) / sockaddr %s / minor %d"),
660			connectmode, conf->connectmode, (const char *)si, (int)prot_minor);
661			slog (L_NOTICE, _(" ictx/octx %08lx/%08lx / oseqno %d / retry_cnt %d"),
662			(long)ictx, (long)octx, (int)oseqno, (int)retry_cnt);
663			slog (L_NOTICE, _(" establish_conn %ld / rekey %ld / keepalive %ld"),
664			(long)(establish_connection.at), (long)(rekey.at), (long)(keepalive.at));
665			}
666
667			void
668			vpn::dump_status ()
669			{
670			slog (L_NOTICE, _("BEGIN status dump (%ld)"), (long)NOW);
671
672			for (conns_vector::iterator c = conns.begin (); c != conns.end (); ++c)
673			(*c)->dump_status ();
674
675			slog (L_NOTICE, _("END status dump"));
676			}
677
678			vpn::vpn (void)
679	pcg	1.9	: event (this, &vpn::event_cb)
680			, udpv4_ev_watcher (this, &vpn::udpv4_ev)
681			, ipv4_ev_watcher (this, &vpn::ipv4_ev)
682	pcg	1.2	#if ENABLE_TCP
683	pcg	1.9	, tcpv4_ev_watcher (this, &vpn::tcpv4_ev)
684			#endif
685			#if ENABLE_ICMP
686			, icmpv4_ev_watcher(this, &vpn::icmpv4_ev)
687	pcg	1.24	#endif
688			#if ENABLE_DNS
689			, dnsv4_ev_watcher (this, &vpn::dnsv4_ev)
690	pcg	1.2	#endif
691	pcg	1.9	, tap_ev_watcher (this, &vpn::tap_ev)
692	pcg	1.1	{
693			}
694
695			vpn::~vpn ()
696			{
697			}
698