gvpe/src/vpn.C

/*
    vpn.C -- handle the protocol, encryption, handshaking etc.
    Copyright (C) 2003 Marc Lehmann <pcg@goof.com>
 
    This program is free software; you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
    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 this program; 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 <cstdlib>
#include <cstring>
#include <cstdio>

#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, "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 (1);
        }

      ipv4_ev_watcher.start (ipv4_fd, POLLIN);
    }

  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 (1);
        }

      udpv4_ev_watcher.start (udpv4_fd, POLLIN);
    }

  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 (1);
        }

      icmpv4_ev_watcher.start (icmpv4_fd, POLLIN);
    }
#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 (1);
        }

      if (listen (tcpv4_fd, 5))
        {
          slog (L_ERR, _("can't listen tcpv4 on %s: %s"), (const char *)si, strerror (errno));
          exit (1);
        }

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

  tap = new tap_device ();
  if (!tap) //D this, of course, never catches
    {
      slog (L_ERR, _("cannot create network interface '%s'"), conf.ifname);
      exit (1);
    }
  
  run_script (run_script_cb (this, &vpn::script_if_up), true);

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

  reconnect_all ();

  return 0;
}

// send a vpn packet out to other hosts
bool
vpn::send_vpn_packet (vpn_packet *pkt, const sockinfo &si, int tos)
{
  switch (si.prot)
    {
      case PROT_IPv4:
        return send_ipv4_packet (pkt, si, tos);

      case PROT_UDPv4:
        return send_udpv4_packet (pkt, si, tos);

#if ENABLE_TCP
      case PROT_TCPv4:
        return send_tcpv4_packet (pkt, si, tos);
#endif

#if ENABLE_ICMP
      case PROT_ICMPv4:
        return send_icmpv4_packet (pkt, si, tos);
#endif

      default:
        slog (L_CRIT, _("%s: FATAL: trying to send packet with unsupported protocol"), (const char *)si);
        return false;
    }
}

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 & (POLLIN | POLLERR))
    {
      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, but don't expect it on sends
          // this is slow, but...
          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 if (revents & POLLHUP)
    {
      // this cannot ;) happen on udp sockets
      slog (L_ERR, _("FATAL: POLLHUP on ipv4 fd, terminating."));
      exit (1);
    }
  else
    {
      slog (L_ERR,
              _("FATAL: unknown revents %08x in socket, terminating\n"),
              revents);
      exit (1);
    }
}

#if ENABLE_ICMP
void
vpn::icmpv4_ev (io_watcher &w, short revents)
{
  if (revents & (POLLIN | POLLERR))
    {
      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 if (revents & POLLHUP)
    {
      // this cannot ;) happen on udp sockets
      slog (L_ERR, _("FATAL: POLLHUP on icmpv4 fd, terminating."));
      exit (1);
    }
  else
    {
      slog (L_ERR,
              _("FATAL: unknown revents %08x in socket, terminating\n"),
              revents);
      exit (1);
    }
}
#endif

void
vpn::udpv4_ev (io_watcher &w, short revents)
{
  if (revents & (POLLIN | POLLERR))
    {
      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 if (revents & POLLHUP)
    {
      // this cannot ;) happen on udp sockets
      slog (L_ERR, _("FATAL: POLLHUP on udp v4 fd, terminating."));
      exit (1);
    }
  else
    {
      slog (L_ERR,
              _("FATAL: unknown revents %08x in socket, terminating\n"),
              revents);
      exit (1);
    }
}

void
vpn::tap_ev (io_watcher &w, short revents)
{
  if (revents & POLLIN)
    {
      /* 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, exiting."));
              exit (1);
            }

          if (dst == THISNODE->id)
            {
              slog (L_ERR, _("FATAL: tap packet destined for current node received, exiting."));
              exit (1);
            }

          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 if (revents & (POLLHUP | POLLERR))
    {
      slog (L_ERR, _("FATAL: POLLHUP or POLLERR on network device fd, terminating."));
      exit (1);
    }
  else
    abort ();
}

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

          shutdown_all ();

          remove_pid (pidfilename);

          slog (L_INFO, _("terminating"));

          exit (0);
        }

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

          reconnect_all ();
        }

      events = 0;
    }

  w.at = TSTAMP_CANCEL;
}

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);

      conn->conf = *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
, tap_ev_watcher   (this, &vpn::tap_ev)
{
}

vpn::~vpn ()
{
}

Revision:	1.20
Committed:	Thu Oct 16 14:12:00 2003 UTC (20 years, 7 months ago) by pcg
Content type:	text/plain
Branch:	MAIN
Changes since 1.19:	+2 -0 lines
Log Message:	* empty log message *
#	User	Rev	Content
1	pcg	1.1	/*
2			vpn.C -- handle the protocol, encryption, handshaking etc.
3	pcg	1.19	Copyright (C) 2003 Marc Lehmann <pcg@goof.com>
4	pcg	1.1
5			This program is free software; you can redistribute it and/or modify
6			it under the terms of the GNU General Public License as published by
7			the Free Software Foundation; either version 2 of the License, or
8			(at your option) any later version.
9
10			This program is distributed in the hope that it will be useful,
11			but WITHOUT ANY WARRANTY; without even the implied warranty of
12			MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
13			GNU General Public License for more details.
14
15			You should have received a copy of the GNU General Public License
16			along with this program; if not, write to the Free Software
17			Foundation, Inc. 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
18			*/
19
20			#include "config.h"
21
22			#include <list>
23
24			#include <cstdlib>
25			#include <cstring>
26			#include <cstdio>
27
28			#include <sys/types.h>
29			#include <sys/socket.h>
30			#include <sys/wait.h>
31			#include <errno.h>
32			#include <time.h>
33			#include <unistd.h>
34	pcg	1.11	#include <fcntl.h>
35	pcg	1.14	#include <sys/socket.h>
36	pcg	1.15
37			#include "netcompat.h"
38	pcg	1.1
39			#include "pidfile.h"
40
41			#include "connection.h"
42			#include "util.h"
43			#include "vpn.h"
44
45	pcg	1.20	vpn network; // THE vpn (bad design...)
46
47	pcg	1.1	/////////////////////////////////////////////////////////////////////////////
48
49	pcg	1.2	const char *vpn::script_if_up ()
50	pcg	1.1	{
51			// the tunnel device mtu should be the physical mtu - overhead
52			// the tricky part is rounding to the cipher key blocksize
53			int mtu = conf.mtu - ETH_OVERHEAD - VPE_OVERHEAD - MAX_OVERHEAD;
54			mtu += ETH_OVERHEAD - 6 - 6; // now we have the data portion
55			mtu -= mtu % EVP_CIPHER_block_size (CIPHER); // round
56			mtu -= ETH_OVERHEAD - 6 - 6; // and get interface mtu again
57
58			char *env;
59			asprintf (&env, "CONFBASE=%s", confbase);
60			putenv (env);
61			asprintf (&env, "NODENAME=%s", THISNODE->nodename);
62			putenv (env);
63			asprintf (&env, "NODEID=%d", THISNODE->id);
64			putenv (env);
65			asprintf (&env, "IFNAME=%s", tap->interface ());
66			putenv (env);
67			asprintf (&env, "MTU=%d", mtu);
68			putenv (env);
69			asprintf (&env, "MAC=%02x:%02x:%02x:%02x:%02x:%02x",
70			0xfe, 0xfd, 0x80, 0x00, THISNODE->id >> 8,
71			THISNODE->id & 0xff);
72			putenv (env);
73
74			return ::conf.script_if_up ? ::conf.script_if_up : "if-up";
75			}
76
77			int
78			vpn::setup ()
79			{
80	pcg	1.8	ipv4_fd = -1;
81	pcg	1.1
82	pcg	1.8	if (THISNODE->protocols & PROT_IPv4 && ::conf.ip_proto)
83	pcg	1.1	{
84	pcg	1.8	ipv4_fd = socket (PF_INET, SOCK_RAW, ::conf.ip_proto);
85	pcg	1.1
86	pcg	1.8	if (ipv4_fd < 0)
87	pcg	1.1	return -1;
88
89	pcg	1.11	fcntl (ipv4_fd, F_SETFL, O_NONBLOCK);
90
91	pcg	1.14	#if defined(SOL_IP) && defined(IP_MTU_DISCOVER)
92	pcg	1.1	// this I really consider a linux bug. I am neither connected
93			// nor do I fragment myself. Linux still sets DF and doesn't
94			// fragment for me sometimes.
95			{
96			int oval = IP_PMTUDISC_DONT;
97	pcg	1.8	setsockopt (ipv4_fd, SOL_IP, IP_MTU_DISCOVER, &oval, sizeof oval);
98	pcg	1.1	}
99			#endif
100
101	pcg	1.9	sockinfo si (THISNODE, PROT_IPv4);
102
103			if (bind (ipv4_fd, si.sav4 (), si.salenv4 ()))
104			{
105			slog (L_ERR, _("can't bind ipv4 socket on %s: %s"), (const char *)si, strerror (errno));
106			exit (1);
107			}
108
109	pcg	1.8	ipv4_ev_watcher.start (ipv4_fd, POLLIN);
110	pcg	1.1	}
111
112	pcg	1.8	udpv4_fd = -1;
113
114			if (THISNODE->protocols & PROT_UDPv4 && THISNODE->udp_port)
115	pcg	1.1	{
116	pcg	1.8	udpv4_fd = socket (PF_INET, SOCK_DGRAM, IPPROTO_UDP);
117	pcg	1.1
118	pcg	1.8	if (udpv4_fd < 0)
119	pcg	1.1	return -1;
120
121	pcg	1.11	fcntl (udpv4_fd, F_SETFL, O_NONBLOCK);
122
123	pcg	1.8	// standard daemon practise...
124			{
125			int oval = 1;
126			setsockopt (udpv4_fd, SOL_SOCKET, SO_REUSEADDR, &oval, sizeof oval);
127			}
128
129	pcg	1.14	#if defined(SOL_IP) && defined(IP_MTU_DISCOVER)
130	pcg	1.9	// this I really consider a linux bug. I am neither connected
131			// nor do I fragment myself. Linux still sets DF and doesn't
132			// fragment for me sometimes.
133			{
134			int oval = IP_PMTUDISC_DONT;
135			setsockopt (udpv4_fd, SOL_IP, IP_MTU_DISCOVER, &oval, sizeof oval);
136			}
137			#endif
138
139	pcg	1.8	sockinfo si (THISNODE, PROT_UDPv4);
140	pcg	1.2
141	pcg	1.8	if (bind (udpv4_fd, si.sav4 (), si.salenv4 ()))
142	pcg	1.1	{
143	pcg	1.8	slog (L_ERR, _("can't bind udpv4 on %s: %s"), (const char *)si, strerror (errno));
144	pcg	1.1	exit (1);
145			}
146
147	pcg	1.9	udpv4_ev_watcher.start (udpv4_fd, POLLIN);
148			}
149
150			icmpv4_fd = -1;
151
152			#if ENABLE_ICMP
153			if (THISNODE->protocols & PROT_ICMPv4)
154			{
155			icmpv4_fd = socket (PF_INET, SOCK_RAW, IPPROTO_ICMP);
156
157			if (icmpv4_fd < 0)
158			return -1;
159
160	pcg	1.11	fcntl (icmpv4_fd, F_SETFL, O_NONBLOCK);
161
162	pcg	1.9	#ifdef ICMP_FILTER
163			{
164			icmp_filter oval;
165			oval.data = 0xffffffff;
166			if (::conf.icmp_type < 32)
167			oval.data &= ~(1 << ::conf.icmp_type);
168
169			setsockopt (icmpv4_fd, SOL_RAW, ICMP_FILTER, &oval, sizeof oval);
170			}
171			#endif
172
173	pcg	1.14	#if defined(SOL_IP) && defined(IP_MTU_DISCOVER)
174	pcg	1.1	// this I really consider a linux bug. I am neither connected
175			// nor do I fragment myself. Linux still sets DF and doesn't
176			// fragment for me sometimes.
177			{
178			int oval = IP_PMTUDISC_DONT;
179	pcg	1.8	setsockopt (udpv4_fd, SOL_IP, IP_MTU_DISCOVER, &oval, sizeof oval);
180	pcg	1.1	}
181			#endif
182
183	pcg	1.9	sockinfo si (THISNODE, PROT_ICMPv4);
184
185			if (bind (icmpv4_fd, si.sav4 (), si.salenv4 ()))
186			{
187			slog (L_ERR, _("can't bind icmpv4 on %s: %s"), (const char *)si, strerror (errno));
188			exit (1);
189			}
190
191			icmpv4_ev_watcher.start (icmpv4_fd, POLLIN);
192	pcg	1.1	}
193	pcg	1.9	#endif
194	pcg	1.1
195	pcg	1.8	tcpv4_fd = -1;
196
197	pcg	1.2	#if ENABLE_TCP
198	pcg	1.8	if (THISNODE->protocols & PROT_TCPv4 && THISNODE->tcp_port)
199	pcg	1.2	{
200			tcpv4_fd = socket (PF_INET, SOCK_STREAM, IPPROTO_TCP);
201
202			if (tcpv4_fd < 0)
203			return -1;
204
205	pcg	1.11	fcntl (tcpv4_fd, F_SETFL, O_NONBLOCK);
206
207	pcg	1.3	// standard daemon practise...
208			{
209			int oval = 1;
210			setsockopt (tcpv4_fd, SOL_SOCKET, SO_REUSEADDR, &oval, sizeof oval);
211			}
212
213	pcg	1.2	sockinfo si (THISNODE, PROT_TCPv4);
214
215			if (bind (tcpv4_fd, si.sav4 (), si.salenv4 ()))
216			{
217			slog (L_ERR, _("can't bind tcpv4 on %s: %s"), (const char *)si, strerror (errno));
218			exit (1);
219			}
220
221			if (listen (tcpv4_fd, 5))
222			{
223			slog (L_ERR, _("can't listen tcpv4 on %s: %s"), (const char *)si, strerror (errno));
224			exit (1);
225			}
226
227	pcg	1.3	tcpv4_ev_watcher.start (tcpv4_fd, POLLIN);
228	pcg	1.2	}
229			#endif
230
231	pcg	1.1	tap = new tap_device ();
232			if (!tap) //D this, of course, never catches
233			{
234			slog (L_ERR, _("cannot create network interface '%s'"), conf.ifname);
235			exit (1);
236			}
237
238			run_script (run_script_cb (this, &vpn::script_if_up), true);
239
240			tap_ev_watcher.start (tap->fd, POLLIN);
241
242			reconnect_all ();
243
244			return 0;
245			}
246
247	pcg	1.5	// send a vpn packet out to other hosts
248	pcg	1.7	bool
249	pcg	1.5	vpn::send_vpn_packet (vpn_packet *pkt, const sockinfo &si, int tos)
250			{
251			switch (si.prot)
252			{
253			case PROT_IPv4:
254	pcg	1.7	return send_ipv4_packet (pkt, si, tos);
255	pcg	1.5
256			case PROT_UDPv4:
257	pcg	1.7	return send_udpv4_packet (pkt, si, tos);
258	pcg	1.5
259			#if ENABLE_TCP
260			case PROT_TCPv4:
261	pcg	1.7	return send_tcpv4_packet (pkt, si, tos);
262	pcg	1.5	#endif
263
264	pcg	1.9	#if ENABLE_ICMP
265			case PROT_ICMPv4:
266			return send_icmpv4_packet (pkt, si, tos);
267			#endif
268
269	pcg	1.5	default:
270			slog (L_CRIT, _("%s: FATAL: trying to send packet with unsupported protocol"), (const char *)si);
271	pcg	1.7	return false;
272	pcg	1.5	}
273			}
274
275	pcg	1.7	bool
276	pcg	1.1	vpn::send_ipv4_packet (vpn_packet *pkt, const sockinfo &si, int tos)
277			{
278	pcg	1.14	#if defined(SOL_IP) && defined(IP_TOS)
279	pcg	1.1	setsockopt (ipv4_fd, SOL_IP, IP_TOS, &tos, sizeof tos);
280	pcg	1.14	#endif
281	pcg	1.1	sendto (ipv4_fd, &((*pkt)[0]), pkt->len, 0, si.sav4 (), si.salenv4 ());
282	pcg	1.7
283			return true;
284	pcg	1.1	}
285
286	pcg	1.9	static u16
287			ipv4_checksum (u16 *data, unsigned int len)
288			{
289			// use 32 bit accumulator and fold back carry bits at the end
290			u32 sum = 0;
291
292			while (len > 1)
293			{
294			sum += *data++;
295			len -= 2;
296			}
297
298			// odd byte left?
299			if (len)
300			sum += (u8 )data;
301
302			// add back carry bits
303			sum = (sum >> 16) + (sum & 0xffff); // lo += hi
304			sum += (sum >> 16); // carry
305
306			return ~sum;
307			}
308
309	pcg	1.13	#if ENABLE_ICMP
310	pcg	1.9	bool
311			vpn::send_icmpv4_packet (vpn_packet *pkt, const sockinfo &si, int tos)
312			{
313	pcg	1.14	#if defined(SOL_IP) && defined(IP_TOS)
314	pcg	1.9	setsockopt (icmpv4_fd, SOL_IP, IP_TOS, &tos, sizeof tos);
315	pcg	1.14	#endif
316	pcg	1.9
317			pkt->unshift_hdr (4);
318
319	pcg	1.14	icmp_header hdr = (icmp_header )&((*pkt)[0]);
320	pcg	1.9	hdr->type = ::conf.icmp_type;
321			hdr->code = 255;
322			hdr->checksum = 0;
323			hdr->checksum = ipv4_checksum ((u16 *)hdr, pkt->len);
324
325			sendto (icmpv4_fd, &((*pkt)[0]), pkt->len, 0, si.sav4 (), si.salenv4 ());
326
327			return true;
328			}
329	pcg	1.13	#endif
330	pcg	1.9
331	pcg	1.7	bool
332	pcg	1.1	vpn::send_udpv4_packet (vpn_packet *pkt, const sockinfo &si, int tos)
333			{
334	pcg	1.14	#if defined(SOL_IP) && defined(IP_TOS)
335	pcg	1.1	setsockopt (udpv4_fd, SOL_IP, IP_TOS, &tos, sizeof tos);
336	pcg	1.14	#endif
337	pcg	1.1	sendto (udpv4_fd, &((*pkt)[0]), pkt->len, 0, si.sav4 (), si.salenv4 ());
338	pcg	1.7
339			return true;
340	pcg	1.1	}
341
342			void
343	pcg	1.18	vpn::inject_data_packet (tap_packet *pkt, int dst)
344			{
345			if (dst)
346			{
347			// unicast
348			if (dst != THISNODE->id)
349			conns[dst - 1]->inject_data_packet (pkt);
350			}
351			else
352			{
353			// broadcast, this is ugly, but due to the security policy
354			// we have to connect to all hosts...
355			for (conns_vector::iterator c = conns.begin (); c != conns.end (); ++c)
356			if ((*c)->conf != THISNODE)
357			(*c)->inject_data_packet (pkt, true);
358			}
359			}
360
361			void
362	pcg	1.1	vpn::recv_vpn_packet (vpn_packet *pkt, const sockinfo &rsi)
363			{
364			unsigned int src = pkt->src ();
365			unsigned int dst = pkt->dst ();
366
367			slog (L_NOISE, _("<<?/%s received possible vpn packet type %d from %d to %d, length %d"),
368			(const char *)rsi, pkt->typ (), pkt->src (), pkt->dst (), pkt->len);
369
370			if (src == 0 \|\| src > conns.size ()
371			\|\| dst > conns.size ()
372			\|\| pkt->typ () >= vpn_packet::PT_MAX)
373			slog (L_WARN, _("(%s): received corrupted packet type %d (src %d, dst %d)"),
374			(const char *)rsi, pkt->typ (), pkt->src (), pkt->dst ());
375	pcg	1.6	else if (dst > conns.size ())
376			slog (L_WARN, _("(%s): received corrupted packet type %d (src %d, dst %d)"),
377			(const char *)rsi, pkt->typ (), pkt->src (), pkt->dst ());
378	pcg	1.1	else
379			{
380			connection *c = conns[src - 1];
381
382	pcg	1.13	if (dst == 0)
383			slog (L_WARN, _("%s(%s): received broadcast (protocol violation)"),
384	pcg	1.1	c->conf->nodename, (const char *)rsi);
385	pcg	1.18	else if (dst != THISNODE->id)
386	pcg	1.6	{
387			if (THISNODE->routerprio)
388			// the tos setting gets lost here. who cares.
389			conns[dst - 1]->inject_vpn_packet (pkt);
390			else
391			slog (L_WARN,
392			_("%s(%s): forwarding request (=> %s), but we are no router"),
393			c->conf->nodename, (const char *)rsi,
394			conns[dst - 1]->conf->nodename);
395			}
396	pcg	1.1	else
397			c->recv_vpn_packet (pkt, rsi);
398			}
399			}
400
401			void
402	pcg	1.9	vpn::ipv4_ev (io_watcher &w, short revents)
403	pcg	1.1	{
404			if (revents & (POLLIN \| POLLERR))
405			{
406			vpn_packet *pkt = new vpn_packet;
407			struct sockaddr_in sa;
408			socklen_t sa_len = sizeof (sa);
409			int len;
410
411	pcg	1.5	len = recvfrom (w.fd, &((pkt)[0]), MAXSIZE, 0, (sockaddr )&sa, &sa_len);
412	pcg	1.1
413	pcg	1.9	sockinfo si(sa, PROT_IPv4);
414	pcg	1.1
415			if (len > 0)
416			{
417			pkt->len = len;
418
419	pcg	1.9	// raw sockets deliver the ipv4, but don't expect it on sends
420			// this is slow, but...
421			pkt->skip_hdr (IP_OVERHEAD);
422
423	pcg	1.1	recv_vpn_packet (pkt, si);
424			}
425			else
426			{
427			// probably ECONNRESET or somesuch
428	pcg	1.9	slog (L_DEBUG, _("%s: %s"), (const char *)si, strerror (errno));
429	pcg	1.1	}
430
431			delete pkt;
432			}
433			else if (revents & POLLHUP)
434			{
435			// this cannot ;) happen on udp sockets
436	pcg	1.9	slog (L_ERR, _("FATAL: POLLHUP on ipv4 fd, terminating."));
437	pcg	1.1	exit (1);
438			}
439			else
440			{
441			slog (L_ERR,
442			_("FATAL: unknown revents %08x in socket, terminating\n"),
443			revents);
444			exit (1);
445			}
446			}
447
448	pcg	1.13	#if ENABLE_ICMP
449	pcg	1.1	void
450	pcg	1.9	vpn::icmpv4_ev (io_watcher &w, short revents)
451	pcg	1.1	{
452			if (revents & (POLLIN \| POLLERR))
453			{
454			vpn_packet *pkt = new vpn_packet;
455			struct sockaddr_in sa;
456			socklen_t sa_len = sizeof (sa);
457			int len;
458
459	pcg	1.5	len = recvfrom (w.fd, &((pkt)[0]), MAXSIZE, 0, (sockaddr )&sa, &sa_len);
460	pcg	1.1
461	pcg	1.9	sockinfo si(sa, PROT_ICMPv4);
462	pcg	1.1
463			if (len > 0)
464			{
465			pkt->len = len;
466
467	pcg	1.14	icmp_header hdr = (icmp_header )&((*pkt)[IP_OVERHEAD]);
468	pcg	1.9
469			if (hdr->type == ::conf.icmp_type
470			&& hdr->code == 255)
471			{
472			// raw sockets deliver the ipv4, but don't expect it on sends
473			// this is slow, but...
474			pkt->skip_hdr (ICMP_OVERHEAD);
475
476			recv_vpn_packet (pkt, si);
477			}
478			}
479			else
480			{
481			// probably ECONNRESET or somesuch
482			slog (L_DEBUG, _("%s: %s"), (const char *)si, strerror (errno));
483			}
484
485			delete pkt;
486			}
487			else if (revents & POLLHUP)
488			{
489			// this cannot ;) happen on udp sockets
490			slog (L_ERR, _("FATAL: POLLHUP on icmpv4 fd, terminating."));
491			exit (1);
492			}
493			else
494			{
495			slog (L_ERR,
496			_("FATAL: unknown revents %08x in socket, terminating\n"),
497			revents);
498			exit (1);
499			}
500			}
501	pcg	1.13	#endif
502	pcg	1.9
503			void
504			vpn::udpv4_ev (io_watcher &w, short revents)
505			{
506			if (revents & (POLLIN \| POLLERR))
507			{
508			vpn_packet *pkt = new vpn_packet;
509			struct sockaddr_in sa;
510			socklen_t sa_len = sizeof (sa);
511			int len;
512
513			len = recvfrom (w.fd, &((pkt)[0]), MAXSIZE, 0, (sockaddr )&sa, &sa_len);
514
515			sockinfo si(sa, PROT_UDPv4);
516
517			if (len > 0)
518			{
519			pkt->len = len;
520	pcg	1.1
521			recv_vpn_packet (pkt, si);
522			}
523			else
524			{
525			// probably ECONNRESET or somesuch
526	pcg	1.9	slog (L_DEBUG, _("%s: fd %d, %s"), (const char *)si, w.fd, strerror (errno));
527	pcg	1.1	}
528
529			delete pkt;
530			}
531			else if (revents & POLLHUP)
532			{
533			// this cannot ;) happen on udp sockets
534	pcg	1.9	slog (L_ERR, _("FATAL: POLLHUP on udp v4 fd, terminating."));
535	pcg	1.1	exit (1);
536			}
537			else
538			{
539			slog (L_ERR,
540			_("FATAL: unknown revents %08x in socket, terminating\n"),
541			revents);
542			exit (1);
543			}
544			}
545	pcg	1.2
546			void
547	pcg	1.3	vpn::tap_ev (io_watcher &w, short revents)
548	pcg	1.1	{
549			if (revents & POLLIN)
550			{
551			/* process data */
552			tap_packet *pkt;
553
554			pkt = tap->recv ();
555
556	pcg	1.17	if (!pkt)
557			return;
558	pcg	1.1
559	pcg	1.17	if (pkt->len > 14)
560	pcg	1.1	{
561	pcg	1.17	int dst = mac2id (pkt->dst);
562			int src = mac2id (pkt->src);
563	pcg	1.1
564	pcg	1.17	if (src != THISNODE->id)
565			{
566			slog (L_ERR, _("FATAL: tap packet not originating on current node received, exiting."));
567			exit (1);
568			}
569	pcg	1.1
570	pcg	1.17	if (dst == THISNODE->id)
571	pcg	1.1	{
572	pcg	1.17	slog (L_ERR, _("FATAL: tap packet destined for current node received, exiting."));
573			exit (1);
574	pcg	1.1	}
575	pcg	1.17
576			if (dst > conns.size ())
577			slog (L_ERR, _("tap packet for unknown node %d received, ignoring."), dst);
578	pcg	1.1	else
579	pcg	1.18	inject_data_packet (pkt, dst);
580	pcg	1.1	}
581
582			delete pkt;
583			}
584			else if (revents & (POLLHUP \| POLLERR))
585			{
586			slog (L_ERR, _("FATAL: POLLHUP or POLLERR on network device fd, terminating."));
587			exit (1);
588			}
589			else
590			abort ();
591			}
592
593			void
594	pcg	1.3	vpn::event_cb (time_watcher &w)
595	pcg	1.1	{
596			if (events)
597			{
598			if (events & EVENT_SHUTDOWN)
599			{
600			slog (L_INFO, _("preparing shutdown..."));
601
602			shutdown_all ();
603
604			remove_pid (pidfilename);
605
606			slog (L_INFO, _("terminating"));
607
608			exit (0);
609			}
610
611			if (events & EVENT_RECONNECT)
612			{
613			slog (L_INFO, _("forced reconnect"));
614
615			reconnect_all ();
616			}
617
618			events = 0;
619			}
620
621	pcg	1.3	w.at = TSTAMP_CANCEL;
622	pcg	1.1	}
623
624			void
625			vpn::shutdown_all ()
626			{
627			for (conns_vector::iterator c = conns.begin (); c != conns.end (); ++c)
628			(*c)->shutdown ();
629			}
630
631			void
632			vpn::reconnect_all ()
633			{
634			for (conns_vector::iterator c = conns.begin (); c != conns.end (); ++c)
635			delete *c;
636
637			conns.clear ();
638
639			connection_init ();
640
641			for (configuration::node_vector::iterator i = conf.nodes.begin ();
642			i != conf.nodes.end (); ++i)
643			{
644			connection *conn = new connection (this);
645
646			conn->conf = *i;
647			conns.push_back (conn);
648
649			conn->establish_connection ();
650			}
651			}
652
653			connection *vpn::find_router ()
654			{
655	pcg	1.12	u32 prio = 1;
656	pcg	1.1	connection *router = 0;
657
658			for (conns_vector::iterator i = conns.begin (); i != conns.end (); ++i)
659			{
660			connection c = i;
661
662	pcg	1.13	if (c->conf->routerprio > prio
663	pcg	1.11	&& c->connectmode == conf_node::C_ALWAYS // so we don't drop the connection if in use
664			&& c->ictx && c->octx
665	pcg	1.13	&& c->conf != THISNODE) // redundant, since ictx==octx==0 always on thisnode
666	pcg	1.1	{
667			prio = c->conf->routerprio;
668			router = c;
669			}
670			}
671
672			return router;
673			}
674
675	pcg	1.7	void vpn::send_connect_request (int id)
676	pcg	1.1	{
677			connection *c = find_router ();
678
679			if (c)
680	pcg	1.7	c->send_connect_request (id);
681			else
682			// no router found, aggressively connect to all routers
683			for (conns_vector::iterator i = conns.begin (); i != conns.end (); ++i)
684	pcg	1.13	if ((i)->conf->routerprio && (i)->conf != THISNODE)
685	pcg	1.7	(*i)->establish_connection ();
686	pcg	1.1	}
687
688			void
689			connection::dump_status ()
690			{
691			slog (L_NOTICE, _("node %s (id %d)"), conf->nodename, conf->id);
692			slog (L_NOTICE, _(" connectmode %d (%d) / sockaddr %s / minor %d"),
693			connectmode, conf->connectmode, (const char *)si, (int)prot_minor);
694			slog (L_NOTICE, _(" ictx/octx %08lx/%08lx / oseqno %d / retry_cnt %d"),
695			(long)ictx, (long)octx, (int)oseqno, (int)retry_cnt);
696			slog (L_NOTICE, _(" establish_conn %ld / rekey %ld / keepalive %ld"),
697			(long)(establish_connection.at), (long)(rekey.at), (long)(keepalive.at));
698			}
699
700			void
701			vpn::dump_status ()
702			{
703			slog (L_NOTICE, _("BEGIN status dump (%ld)"), (long)NOW);
704
705			for (conns_vector::iterator c = conns.begin (); c != conns.end (); ++c)
706			(*c)->dump_status ();
707
708			slog (L_NOTICE, _("END status dump"));
709			}
710
711			vpn::vpn (void)
712	pcg	1.9	: event (this, &vpn::event_cb)
713			, udpv4_ev_watcher (this, &vpn::udpv4_ev)
714			, ipv4_ev_watcher (this, &vpn::ipv4_ev)
715	pcg	1.2	#if ENABLE_TCP
716	pcg	1.9	, tcpv4_ev_watcher (this, &vpn::tcpv4_ev)
717			#endif
718			#if ENABLE_ICMP
719			, icmpv4_ev_watcher(this, &vpn::icmpv4_ev)
720	pcg	1.2	#endif
721	pcg	1.9	, tap_ev_watcher (this, &vpn::tap_ev)
722	pcg	1.1	{
723			}
724
725			vpn::~vpn ()
726			{
727			}
728