gvpe/src/vpn.C

/*
    vpn.C -- handle the protocol, encryption, handshaking etc.
    Copyright (C) 2003-2004 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, "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 (1);
        }

      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 (1);
        }

      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 (1);
        }

      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 (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, 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 (1);
    }
  
  run_script (run_script_cb (this, &vpn::script_if_up), true);

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

  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 & 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, 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
    {
      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 & 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 (1);
    }
}
#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 (1);
    }
}

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, 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
    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;
    }
}

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:	1.22
Committed:	Sat Jan 17 01:18:36 2004 UTC (20 years, 4 months ago) by pcg
Content type:	text/plain
Branch:	MAIN
CVS Tags:	VPE_1_4
Changes since 1.21:	+10 -38 lines
Log Message:	* empty log message *
#	User	Rev	Content
1	pcg	1.1	/*
2			vpn.C -- handle the protocol, encryption, handshaking etc.
3	pcg	1.22	Copyright (C) 2003-2004 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	pcg	1.21	asprintf (&env, "CONFBASE=%s", confbase); putenv (env);
60			asprintf (&env, "NODENAME=%s", THISNODE->nodename); putenv (env);
61			asprintf (&env, "NODEID=%d", THISNODE->id); putenv (env);
62			asprintf (&env, "IFNAME=%s", tap->interface ()); putenv (env);
63			asprintf (&env, "IFTYPE=%s", IFTYPE); putenv (env);
64			asprintf (&env, "IFSUBTYPE=%s", IFSUBTYPE); putenv (env);
65			asprintf (&env, "MTU=%d", mtu); putenv (env);
66	pcg	1.1	asprintf (&env, "MAC=%02x:%02x:%02x:%02x:%02x:%02x",
67			0xfe, 0xfd, 0x80, 0x00, THISNODE->id >> 8,
68			THISNODE->id & 0xff);
69			putenv (env);
70
71			return ::conf.script_if_up ? ::conf.script_if_up : "if-up";
72			}
73
74			int
75			vpn::setup ()
76			{
77	pcg	1.8	ipv4_fd = -1;
78	pcg	1.1
79	pcg	1.8	if (THISNODE->protocols & PROT_IPv4 && ::conf.ip_proto)
80	pcg	1.1	{
81	pcg	1.8	ipv4_fd = socket (PF_INET, SOCK_RAW, ::conf.ip_proto);
82	pcg	1.1
83	pcg	1.8	if (ipv4_fd < 0)
84	pcg	1.1	return -1;
85
86	pcg	1.11	fcntl (ipv4_fd, F_SETFL, O_NONBLOCK);
87
88	pcg	1.14	#if defined(SOL_IP) && defined(IP_MTU_DISCOVER)
89	pcg	1.1	// this I really consider a linux bug. I am neither connected
90			// nor do I fragment myself. Linux still sets DF and doesn't
91			// fragment for me sometimes.
92			{
93			int oval = IP_PMTUDISC_DONT;
94	pcg	1.8	setsockopt (ipv4_fd, SOL_IP, IP_MTU_DISCOVER, &oval, sizeof oval);
95	pcg	1.1	}
96			#endif
97
98	pcg	1.9	sockinfo si (THISNODE, PROT_IPv4);
99
100			if (bind (ipv4_fd, si.sav4 (), si.salenv4 ()))
101			{
102			slog (L_ERR, _("can't bind ipv4 socket on %s: %s"), (const char *)si, strerror (errno));
103			exit (1);
104			}
105
106	pcg	1.22	ipv4_ev_watcher.start (ipv4_fd, EVENT_READ);
107	pcg	1.1	}
108
109	pcg	1.8	udpv4_fd = -1;
110
111			if (THISNODE->protocols & PROT_UDPv4 && THISNODE->udp_port)
112	pcg	1.1	{
113	pcg	1.8	udpv4_fd = socket (PF_INET, SOCK_DGRAM, IPPROTO_UDP);
114	pcg	1.1
115	pcg	1.8	if (udpv4_fd < 0)
116	pcg	1.1	return -1;
117
118	pcg	1.11	fcntl (udpv4_fd, F_SETFL, O_NONBLOCK);
119
120	pcg	1.8	// standard daemon practise...
121			{
122			int oval = 1;
123			setsockopt (udpv4_fd, SOL_SOCKET, SO_REUSEADDR, &oval, sizeof oval);
124			}
125
126	pcg	1.14	#if defined(SOL_IP) && defined(IP_MTU_DISCOVER)
127	pcg	1.9	// this I really consider a linux bug. I am neither connected
128			// nor do I fragment myself. Linux still sets DF and doesn't
129			// fragment for me sometimes.
130			{
131			int oval = IP_PMTUDISC_DONT;
132			setsockopt (udpv4_fd, SOL_IP, IP_MTU_DISCOVER, &oval, sizeof oval);
133			}
134			#endif
135
136	pcg	1.8	sockinfo si (THISNODE, PROT_UDPv4);
137	pcg	1.2
138	pcg	1.8	if (bind (udpv4_fd, si.sav4 (), si.salenv4 ()))
139	pcg	1.1	{
140	pcg	1.8	slog (L_ERR, _("can't bind udpv4 on %s: %s"), (const char *)si, strerror (errno));
141	pcg	1.1	exit (1);
142			}
143
144	pcg	1.22	udpv4_ev_watcher.start (udpv4_fd, EVENT_READ);
145	pcg	1.9	}
146
147			icmpv4_fd = -1;
148
149			#if ENABLE_ICMP
150			if (THISNODE->protocols & PROT_ICMPv4)
151			{
152			icmpv4_fd = socket (PF_INET, SOCK_RAW, IPPROTO_ICMP);
153
154			if (icmpv4_fd < 0)
155			return -1;
156
157	pcg	1.11	fcntl (icmpv4_fd, F_SETFL, O_NONBLOCK);
158
159	pcg	1.9	#ifdef ICMP_FILTER
160			{
161			icmp_filter oval;
162			oval.data = 0xffffffff;
163			if (::conf.icmp_type < 32)
164			oval.data &= ~(1 << ::conf.icmp_type);
165
166			setsockopt (icmpv4_fd, SOL_RAW, ICMP_FILTER, &oval, sizeof oval);
167			}
168			#endif
169
170	pcg	1.14	#if defined(SOL_IP) && defined(IP_MTU_DISCOVER)
171	pcg	1.1	// this I really consider a linux bug. I am neither connected
172			// nor do I fragment myself. Linux still sets DF and doesn't
173			// fragment for me sometimes.
174			{
175			int oval = IP_PMTUDISC_DONT;
176	pcg	1.8	setsockopt (udpv4_fd, SOL_IP, IP_MTU_DISCOVER, &oval, sizeof oval);
177	pcg	1.1	}
178			#endif
179
180	pcg	1.9	sockinfo si (THISNODE, PROT_ICMPv4);
181
182			if (bind (icmpv4_fd, si.sav4 (), si.salenv4 ()))
183			{
184			slog (L_ERR, _("can't bind icmpv4 on %s: %s"), (const char *)si, strerror (errno));
185			exit (1);
186			}
187
188	pcg	1.22	icmpv4_ev_watcher.start (icmpv4_fd, EVENT_READ);
189	pcg	1.1	}
190	pcg	1.9	#endif
191	pcg	1.1
192	pcg	1.8	tcpv4_fd = -1;
193
194	pcg	1.2	#if ENABLE_TCP
195	pcg	1.8	if (THISNODE->protocols & PROT_TCPv4 && THISNODE->tcp_port)
196	pcg	1.2	{
197			tcpv4_fd = socket (PF_INET, SOCK_STREAM, IPPROTO_TCP);
198
199			if (tcpv4_fd < 0)
200			return -1;
201
202	pcg	1.11	fcntl (tcpv4_fd, F_SETFL, O_NONBLOCK);
203
204	pcg	1.3	// standard daemon practise...
205			{
206			int oval = 1;
207			setsockopt (tcpv4_fd, SOL_SOCKET, SO_REUSEADDR, &oval, sizeof oval);
208			}
209
210	pcg	1.2	sockinfo si (THISNODE, PROT_TCPv4);
211
212			if (bind (tcpv4_fd, si.sav4 (), si.salenv4 ()))
213			{
214			slog (L_ERR, _("can't bind tcpv4 on %s: %s"), (const char *)si, strerror (errno));
215			exit (1);
216			}
217
218			if (listen (tcpv4_fd, 5))
219			{
220			slog (L_ERR, _("can't listen tcpv4 on %s: %s"), (const char *)si, strerror (errno));
221			exit (1);
222			}
223
224	pcg	1.22	tcpv4_ev_watcher.start (tcpv4_fd, EVENT_READ);
225	pcg	1.2	}
226			#endif
227
228	pcg	1.1	tap = new tap_device ();
229			if (!tap) //D this, of course, never catches
230			{
231			slog (L_ERR, _("cannot create network interface '%s'"), conf.ifname);
232			exit (1);
233			}
234
235			run_script (run_script_cb (this, &vpn::script_if_up), true);
236
237	pcg	1.22	tap_ev_watcher.start (tap->fd, EVENT_READ);
238	pcg	1.1
239			reconnect_all ();
240
241			return 0;
242			}
243
244	pcg	1.5	// send a vpn packet out to other hosts
245	pcg	1.7	bool
246	pcg	1.5	vpn::send_vpn_packet (vpn_packet *pkt, const sockinfo &si, int tos)
247			{
248			switch (si.prot)
249			{
250			case PROT_IPv4:
251	pcg	1.7	return send_ipv4_packet (pkt, si, tos);
252	pcg	1.5
253			case PROT_UDPv4:
254	pcg	1.7	return send_udpv4_packet (pkt, si, tos);
255	pcg	1.5
256			#if ENABLE_TCP
257			case PROT_TCPv4:
258	pcg	1.7	return send_tcpv4_packet (pkt, si, tos);
259	pcg	1.5	#endif
260
261	pcg	1.9	#if ENABLE_ICMP
262			case PROT_ICMPv4:
263			return send_icmpv4_packet (pkt, si, tos);
264			#endif
265
266	pcg	1.5	default:
267			slog (L_CRIT, _("%s: FATAL: trying to send packet with unsupported protocol"), (const char *)si);
268	pcg	1.7	return false;
269	pcg	1.5	}
270			}
271
272	pcg	1.7	bool
273	pcg	1.1	vpn::send_ipv4_packet (vpn_packet *pkt, const sockinfo &si, int tos)
274			{
275	pcg	1.14	#if defined(SOL_IP) && defined(IP_TOS)
276	pcg	1.1	setsockopt (ipv4_fd, SOL_IP, IP_TOS, &tos, sizeof tos);
277	pcg	1.14	#endif
278	pcg	1.1	sendto (ipv4_fd, &((*pkt)[0]), pkt->len, 0, si.sav4 (), si.salenv4 ());
279	pcg	1.7
280			return true;
281	pcg	1.1	}
282
283	pcg	1.9	static u16
284			ipv4_checksum (u16 *data, unsigned int len)
285			{
286			// use 32 bit accumulator and fold back carry bits at the end
287			u32 sum = 0;
288
289			while (len > 1)
290			{
291			sum += *data++;
292			len -= 2;
293			}
294
295			// odd byte left?
296			if (len)
297			sum += (u8 )data;
298
299			// add back carry bits
300			sum = (sum >> 16) + (sum & 0xffff); // lo += hi
301			sum += (sum >> 16); // carry
302
303			return ~sum;
304			}
305
306	pcg	1.13	#if ENABLE_ICMP
307	pcg	1.9	bool
308			vpn::send_icmpv4_packet (vpn_packet *pkt, const sockinfo &si, int tos)
309			{
310	pcg	1.14	#if defined(SOL_IP) && defined(IP_TOS)
311	pcg	1.9	setsockopt (icmpv4_fd, SOL_IP, IP_TOS, &tos, sizeof tos);
312	pcg	1.14	#endif
313	pcg	1.9
314			pkt->unshift_hdr (4);
315
316	pcg	1.14	icmp_header hdr = (icmp_header )&((*pkt)[0]);
317	pcg	1.9	hdr->type = ::conf.icmp_type;
318			hdr->code = 255;
319			hdr->checksum = 0;
320			hdr->checksum = ipv4_checksum ((u16 *)hdr, pkt->len);
321
322			sendto (icmpv4_fd, &((*pkt)[0]), pkt->len, 0, si.sav4 (), si.salenv4 ());
323
324			return true;
325			}
326	pcg	1.13	#endif
327	pcg	1.9
328	pcg	1.7	bool
329	pcg	1.1	vpn::send_udpv4_packet (vpn_packet *pkt, const sockinfo &si, int tos)
330			{
331	pcg	1.14	#if defined(SOL_IP) && defined(IP_TOS)
332	pcg	1.1	setsockopt (udpv4_fd, SOL_IP, IP_TOS, &tos, sizeof tos);
333	pcg	1.14	#endif
334	pcg	1.1	sendto (udpv4_fd, &((*pkt)[0]), pkt->len, 0, si.sav4 (), si.salenv4 ());
335	pcg	1.7
336			return true;
337	pcg	1.1	}
338
339			void
340	pcg	1.18	vpn::inject_data_packet (tap_packet *pkt, int dst)
341			{
342			if (dst)
343			{
344			// unicast
345			if (dst != THISNODE->id)
346			conns[dst - 1]->inject_data_packet (pkt);
347			}
348			else
349			{
350			// broadcast, this is ugly, but due to the security policy
351			// we have to connect to all hosts...
352			for (conns_vector::iterator c = conns.begin (); c != conns.end (); ++c)
353			if ((*c)->conf != THISNODE)
354			(*c)->inject_data_packet (pkt, true);
355			}
356			}
357
358			void
359	pcg	1.1	vpn::recv_vpn_packet (vpn_packet *pkt, const sockinfo &rsi)
360			{
361			unsigned int src = pkt->src ();
362			unsigned int dst = pkt->dst ();
363
364			slog (L_NOISE, _("<<?/%s received possible vpn packet type %d from %d to %d, length %d"),
365			(const char *)rsi, pkt->typ (), pkt->src (), pkt->dst (), pkt->len);
366
367			if (src == 0 \|\| src > conns.size ()
368			\|\| dst > conns.size ()
369			\|\| pkt->typ () >= vpn_packet::PT_MAX)
370			slog (L_WARN, _("(%s): received corrupted packet type %d (src %d, dst %d)"),
371			(const char *)rsi, pkt->typ (), pkt->src (), pkt->dst ());
372	pcg	1.6	else if (dst > conns.size ())
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	1.1	else
376			{
377			connection *c = conns[src - 1];
378
379	pcg	1.13	if (dst == 0)
380			slog (L_WARN, _("%s(%s): received broadcast (protocol violation)"),
381	pcg	1.1	c->conf->nodename, (const char *)rsi);
382	pcg	1.18	else if (dst != THISNODE->id)
383	pcg	1.6	{
384			if (THISNODE->routerprio)
385			// the tos setting gets lost here. who cares.
386			conns[dst - 1]->inject_vpn_packet (pkt);
387			else
388			slog (L_WARN,
389			_("%s(%s): forwarding request (=> %s), but we are no router"),
390			c->conf->nodename, (const char *)rsi,
391			conns[dst - 1]->conf->nodename);
392			}
393	pcg	1.1	else
394			c->recv_vpn_packet (pkt, rsi);
395			}
396			}
397
398			void
399	pcg	1.9	vpn::ipv4_ev (io_watcher &w, short revents)
400	pcg	1.1	{
401	pcg	1.22	if (revents & EVENT_READ)
402	pcg	1.1	{
403			vpn_packet *pkt = new vpn_packet;
404			struct sockaddr_in sa;
405			socklen_t sa_len = sizeof (sa);
406			int len;
407
408	pcg	1.5	len = recvfrom (w.fd, &((pkt)[0]), MAXSIZE, 0, (sockaddr )&sa, &sa_len);
409	pcg	1.1
410	pcg	1.9	sockinfo si(sa, PROT_IPv4);
411	pcg	1.1
412			if (len > 0)
413			{
414			pkt->len = len;
415
416	pcg	1.9	// raw sockets deliver the ipv4, but don't expect it on sends
417			// this is slow, but...
418			pkt->skip_hdr (IP_OVERHEAD);
419
420	pcg	1.1	recv_vpn_packet (pkt, si);
421			}
422			else
423			{
424			// probably ECONNRESET or somesuch
425	pcg	1.9	slog (L_DEBUG, _("%s: %s"), (const char *)si, strerror (errno));
426	pcg	1.1	}
427
428			delete pkt;
429			}
430			else
431			{
432			slog (L_ERR,
433			_("FATAL: unknown revents %08x in socket, terminating\n"),
434			revents);
435			exit (1);
436			}
437			}
438
439	pcg	1.13	#if ENABLE_ICMP
440	pcg	1.1	void
441	pcg	1.9	vpn::icmpv4_ev (io_watcher &w, short revents)
442	pcg	1.1	{
443	pcg	1.22	if (revents & EVENT_READ)
444	pcg	1.1	{
445			vpn_packet *pkt = new vpn_packet;
446			struct sockaddr_in sa;
447			socklen_t sa_len = sizeof (sa);
448			int len;
449
450	pcg	1.5	len = recvfrom (w.fd, &((pkt)[0]), MAXSIZE, 0, (sockaddr )&sa, &sa_len);
451	pcg	1.1
452	pcg	1.9	sockinfo si(sa, PROT_ICMPv4);
453	pcg	1.1
454			if (len > 0)
455			{
456			pkt->len = len;
457
458	pcg	1.14	icmp_header hdr = (icmp_header )&((*pkt)[IP_OVERHEAD]);
459	pcg	1.9
460			if (hdr->type == ::conf.icmp_type
461			&& hdr->code == 255)
462			{
463			// raw sockets deliver the ipv4, but don't expect it on sends
464			// this is slow, but...
465			pkt->skip_hdr (ICMP_OVERHEAD);
466
467			recv_vpn_packet (pkt, si);
468			}
469			}
470			else
471			{
472			// probably ECONNRESET or somesuch
473			slog (L_DEBUG, _("%s: %s"), (const char *)si, strerror (errno));
474			}
475
476			delete pkt;
477			}
478			else
479			{
480			slog (L_ERR,
481			_("FATAL: unknown revents %08x in socket, terminating\n"),
482			revents);
483			exit (1);
484			}
485			}
486	pcg	1.13	#endif
487	pcg	1.9
488			void
489			vpn::udpv4_ev (io_watcher &w, short revents)
490			{
491	pcg	1.22	if (revents & EVENT_READ)
492	pcg	1.9	{
493			vpn_packet *pkt = new vpn_packet;
494			struct sockaddr_in sa;
495			socklen_t sa_len = sizeof (sa);
496			int len;
497
498			len = recvfrom (w.fd, &((pkt)[0]), MAXSIZE, 0, (sockaddr )&sa, &sa_len);
499
500			sockinfo si(sa, PROT_UDPv4);
501
502			if (len > 0)
503			{
504			pkt->len = len;
505	pcg	1.1
506			recv_vpn_packet (pkt, si);
507			}
508			else
509			{
510			// probably ECONNRESET or somesuch
511	pcg	1.9	slog (L_DEBUG, _("%s: fd %d, %s"), (const char *)si, w.fd, strerror (errno));
512	pcg	1.1	}
513
514			delete pkt;
515			}
516			else
517			{
518			slog (L_ERR,
519			_("FATAL: unknown revents %08x in socket, terminating\n"),
520			revents);
521			exit (1);
522			}
523			}
524	pcg	1.2
525			void
526	pcg	1.3	vpn::tap_ev (io_watcher &w, short revents)
527	pcg	1.1	{
528	pcg	1.22	if (revents & EVENT_READ)
529	pcg	1.1	{
530			/* process data */
531			tap_packet *pkt;
532
533			pkt = tap->recv ();
534
535	pcg	1.17	if (!pkt)
536			return;
537	pcg	1.1
538	pcg	1.17	if (pkt->len > 14)
539	pcg	1.1	{
540	pcg	1.17	int dst = mac2id (pkt->dst);
541			int src = mac2id (pkt->src);
542	pcg	1.1
543	pcg	1.17	if (src != THISNODE->id)
544			{
545			slog (L_ERR, _("FATAL: tap packet not originating on current node received, exiting."));
546			exit (1);
547			}
548	pcg	1.1
549	pcg	1.17	if (dst == THISNODE->id)
550	pcg	1.1	{
551	pcg	1.17	slog (L_ERR, _("FATAL: tap packet destined for current node received, exiting."));
552			exit (1);
553	pcg	1.1	}
554	pcg	1.17
555			if (dst > conns.size ())
556			slog (L_ERR, _("tap packet for unknown node %d received, ignoring."), dst);
557	pcg	1.1	else
558	pcg	1.18	inject_data_packet (pkt, dst);
559	pcg	1.1	}
560
561			delete pkt;
562			}
563			else
564			abort ();
565			}
566
567			void
568	pcg	1.3	vpn::event_cb (time_watcher &w)
569	pcg	1.1	{
570			if (events)
571			{
572			if (events & EVENT_SHUTDOWN)
573			{
574			slog (L_INFO, _("preparing shutdown..."));
575
576			shutdown_all ();
577			remove_pid (pidfilename);
578			slog (L_INFO, _("terminating"));
579			exit (0);
580			}
581
582			if (events & EVENT_RECONNECT)
583			{
584			slog (L_INFO, _("forced reconnect"));
585
586			reconnect_all ();
587			}
588
589			events = 0;
590			}
591			}
592
593			void
594			vpn::shutdown_all ()
595			{
596			for (conns_vector::iterator c = conns.begin (); c != conns.end (); ++c)
597			(*c)->shutdown ();
598			}
599
600			void
601			vpn::reconnect_all ()
602			{
603			for (conns_vector::iterator c = conns.begin (); c != conns.end (); ++c)
604			delete *c;
605
606			conns.clear ();
607
608			connection_init ();
609
610			for (configuration::node_vector::iterator i = conf.nodes.begin ();
611			i != conf.nodes.end (); ++i)
612			{
613			connection *conn = new connection (this);
614
615			conn->conf = *i;
616			conns.push_back (conn);
617
618			conn->establish_connection ();
619			}
620			}
621
622			connection *vpn::find_router ()
623			{
624	pcg	1.12	u32 prio = 1;
625	pcg	1.1	connection *router = 0;
626
627			for (conns_vector::iterator i = conns.begin (); i != conns.end (); ++i)
628			{
629			connection c = i;
630
631	pcg	1.13	if (c->conf->routerprio > prio
632	pcg	1.11	&& c->connectmode == conf_node::C_ALWAYS // so we don't drop the connection if in use
633			&& c->ictx && c->octx
634	pcg	1.13	&& c->conf != THISNODE) // redundant, since ictx==octx==0 always on thisnode
635	pcg	1.1	{
636			prio = c->conf->routerprio;
637			router = c;
638			}
639			}
640
641			return router;
642			}
643
644	pcg	1.7	void vpn::send_connect_request (int id)
645	pcg	1.1	{
646			connection *c = find_router ();
647
648			if (c)
649	pcg	1.7	c->send_connect_request (id);
650			else
651			// no router found, aggressively connect to all routers
652			for (conns_vector::iterator i = conns.begin (); i != conns.end (); ++i)
653	pcg	1.13	if ((i)->conf->routerprio && (i)->conf != THISNODE)
654	pcg	1.7	(*i)->establish_connection ();
655	pcg	1.1	}
656
657			void
658			connection::dump_status ()
659			{
660			slog (L_NOTICE, _("node %s (id %d)"), conf->nodename, conf->id);
661			slog (L_NOTICE, _(" connectmode %d (%d) / sockaddr %s / minor %d"),
662			connectmode, conf->connectmode, (const char *)si, (int)prot_minor);
663			slog (L_NOTICE, _(" ictx/octx %08lx/%08lx / oseqno %d / retry_cnt %d"),
664			(long)ictx, (long)octx, (int)oseqno, (int)retry_cnt);
665			slog (L_NOTICE, _(" establish_conn %ld / rekey %ld / keepalive %ld"),
666			(long)(establish_connection.at), (long)(rekey.at), (long)(keepalive.at));
667			}
668
669			void
670			vpn::dump_status ()
671			{
672			slog (L_NOTICE, _("BEGIN status dump (%ld)"), (long)NOW);
673
674			for (conns_vector::iterator c = conns.begin (); c != conns.end (); ++c)
675			(*c)->dump_status ();
676
677			slog (L_NOTICE, _("END status dump"));
678			}
679
680			vpn::vpn (void)
681	pcg	1.9	: event (this, &vpn::event_cb)
682			, udpv4_ev_watcher (this, &vpn::udpv4_ev)
683			, ipv4_ev_watcher (this, &vpn::ipv4_ev)
684	pcg	1.2	#if ENABLE_TCP
685	pcg	1.9	, tcpv4_ev_watcher (this, &vpn::tcpv4_ev)
686			#endif
687			#if ENABLE_ICMP
688			, icmpv4_ev_watcher(this, &vpn::icmpv4_ev)
689	pcg	1.2	#endif
690	pcg	1.9	, tap_ev_watcher (this, &vpn::tap_ev)
691	pcg	1.1	{
692			}
693
694			vpn::~vpn ()
695			{
696			}
697