gvpe/src/vpn.C

/*
    vpn.C -- handle the protocol, encryption, handshaking etc.
 
    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"

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

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::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 != 0 && 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
            {
              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);
                }
            }
        }

      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:	1.17
Committed:	Wed Oct 15 06:06:41 2003 UTC (20 years, 7 months ago) by pcg
Content type:	text/plain
Branch:	MAIN
Changes since 1.16:	+30 -24 lines
Log Message:	* empty log message *
#	User	Rev	Content
1	pcg	1.1	/*
2			vpn.C -- handle the protocol, encryption, handshaking etc.
3
4			This program is free software; you can redistribute it and/or modify
5			it under the terms of the GNU General Public License as published by
6			the Free Software Foundation; either version 2 of the License, or
7			(at your option) any later version.
8
9			This program is distributed in the hope that it will be useful,
10			but WITHOUT ANY WARRANTY; without even the implied warranty of
11			MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
12			GNU General Public License for more details.
13
14			You should have received a copy of the GNU General Public License
15			along with this program; if not, write to the Free Software
16			Foundation, Inc. 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
17			*/
18
19			#include "config.h"
20
21			#include <list>
22
23			#include <cstdlib>
24			#include <cstring>
25			#include <cstdio>
26
27			#include <sys/types.h>
28			#include <sys/socket.h>
29			#include <sys/wait.h>
30			#include <errno.h>
31			#include <time.h>
32			#include <unistd.h>
33	pcg	1.11	#include <fcntl.h>
34	pcg	1.14	#include <sys/socket.h>
35	pcg	1.15
36			#include "netcompat.h"
37	pcg	1.1
38			#include "pidfile.h"
39
40			#include "connection.h"
41			#include "util.h"
42			#include "vpn.h"
43
44			/////////////////////////////////////////////////////////////////////////////
45
46	pcg	1.2	const char *vpn::script_if_up ()
47	pcg	1.1	{
48			// the tunnel device mtu should be the physical mtu - overhead
49			// the tricky part is rounding to the cipher key blocksize
50			int mtu = conf.mtu - ETH_OVERHEAD - VPE_OVERHEAD - MAX_OVERHEAD;
51			mtu += ETH_OVERHEAD - 6 - 6; // now we have the data portion
52			mtu -= mtu % EVP_CIPHER_block_size (CIPHER); // round
53			mtu -= ETH_OVERHEAD - 6 - 6; // and get interface mtu again
54
55			char *env;
56			asprintf (&env, "CONFBASE=%s", confbase);
57			putenv (env);
58			asprintf (&env, "NODENAME=%s", THISNODE->nodename);
59			putenv (env);
60			asprintf (&env, "NODEID=%d", THISNODE->id);
61			putenv (env);
62			asprintf (&env, "IFNAME=%s", tap->interface ());
63			putenv (env);
64			asprintf (&env, "MTU=%d", mtu);
65			putenv (env);
66			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	1.8	ipv4_ev_watcher.start (ipv4_fd, POLLIN);
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	1.9	udpv4_ev_watcher.start (udpv4_fd, POLLIN);
145			}
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			icmpv4_ev_watcher.start (icmpv4_fd, POLLIN);
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	1.3	tcpv4_ev_watcher.start (tcpv4_fd, POLLIN);
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			tap_ev_watcher.start (tap->fd, POLLIN);
238
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			vpn::recv_vpn_packet (vpn_packet *pkt, const sockinfo &rsi)
341			{
342			unsigned int src = pkt->src ();
343			unsigned int dst = pkt->dst ();
344
345			slog (L_NOISE, _("<<?/%s received possible vpn packet type %d from %d to %d, length %d"),
346			(const char *)rsi, pkt->typ (), pkt->src (), pkt->dst (), pkt->len);
347
348			if (src == 0 \|\| src > conns.size ()
349			\|\| dst > conns.size ()
350			\|\| pkt->typ () >= vpn_packet::PT_MAX)
351			slog (L_WARN, _("(%s): received corrupted packet type %d (src %d, dst %d)"),
352			(const char *)rsi, pkt->typ (), pkt->src (), pkt->dst ());
353	pcg	1.6	else if (dst > conns.size ())
354			slog (L_WARN, _("(%s): received corrupted packet type %d (src %d, dst %d)"),
355			(const char *)rsi, pkt->typ (), pkt->src (), pkt->dst ());
356	pcg	1.1	else
357			{
358			connection *c = conns[src - 1];
359
360	pcg	1.13	if (dst == 0)
361			slog (L_WARN, _("%s(%s): received broadcast (protocol violation)"),
362	pcg	1.1	c->conf->nodename, (const char *)rsi);
363			else if (dst != 0 && dst != THISNODE->id)
364	pcg	1.6	{
365			if (THISNODE->routerprio)
366			// the tos setting gets lost here. who cares.
367			conns[dst - 1]->inject_vpn_packet (pkt);
368			else
369			slog (L_WARN,
370			_("%s(%s): forwarding request (=> %s), but we are no router"),
371			c->conf->nodename, (const char *)rsi,
372			conns[dst - 1]->conf->nodename);
373			}
374	pcg	1.1	else
375			c->recv_vpn_packet (pkt, rsi);
376			}
377			}
378
379			void
380	pcg	1.9	vpn::ipv4_ev (io_watcher &w, short revents)
381	pcg	1.1	{
382			if (revents & (POLLIN \| POLLERR))
383			{
384			vpn_packet *pkt = new vpn_packet;
385			struct sockaddr_in sa;
386			socklen_t sa_len = sizeof (sa);
387			int len;
388
389	pcg	1.5	len = recvfrom (w.fd, &((pkt)[0]), MAXSIZE, 0, (sockaddr )&sa, &sa_len);
390	pcg	1.1
391	pcg	1.9	sockinfo si(sa, PROT_IPv4);
392	pcg	1.1
393			if (len > 0)
394			{
395			pkt->len = len;
396
397	pcg	1.9	// raw sockets deliver the ipv4, but don't expect it on sends
398			// this is slow, but...
399			pkt->skip_hdr (IP_OVERHEAD);
400
401	pcg	1.1	recv_vpn_packet (pkt, si);
402			}
403			else
404			{
405			// probably ECONNRESET or somesuch
406	pcg	1.9	slog (L_DEBUG, _("%s: %s"), (const char *)si, strerror (errno));
407	pcg	1.1	}
408
409			delete pkt;
410			}
411			else if (revents & POLLHUP)
412			{
413			// this cannot ;) happen on udp sockets
414	pcg	1.9	slog (L_ERR, _("FATAL: POLLHUP on ipv4 fd, terminating."));
415	pcg	1.1	exit (1);
416			}
417			else
418			{
419			slog (L_ERR,
420			_("FATAL: unknown revents %08x in socket, terminating\n"),
421			revents);
422			exit (1);
423			}
424			}
425
426	pcg	1.13	#if ENABLE_ICMP
427	pcg	1.1	void
428	pcg	1.9	vpn::icmpv4_ev (io_watcher &w, short revents)
429	pcg	1.1	{
430			if (revents & (POLLIN \| POLLERR))
431			{
432			vpn_packet *pkt = new vpn_packet;
433			struct sockaddr_in sa;
434			socklen_t sa_len = sizeof (sa);
435			int len;
436
437	pcg	1.5	len = recvfrom (w.fd, &((pkt)[0]), MAXSIZE, 0, (sockaddr )&sa, &sa_len);
438	pcg	1.1
439	pcg	1.9	sockinfo si(sa, PROT_ICMPv4);
440	pcg	1.1
441			if (len > 0)
442			{
443			pkt->len = len;
444
445	pcg	1.14	icmp_header hdr = (icmp_header )&((*pkt)[IP_OVERHEAD]);
446	pcg	1.9
447			if (hdr->type == ::conf.icmp_type
448			&& hdr->code == 255)
449			{
450			// raw sockets deliver the ipv4, but don't expect it on sends
451			// this is slow, but...
452			pkt->skip_hdr (ICMP_OVERHEAD);
453
454			recv_vpn_packet (pkt, si);
455			}
456			}
457			else
458			{
459			// probably ECONNRESET or somesuch
460			slog (L_DEBUG, _("%s: %s"), (const char *)si, strerror (errno));
461			}
462
463			delete pkt;
464			}
465			else if (revents & POLLHUP)
466			{
467			// this cannot ;) happen on udp sockets
468			slog (L_ERR, _("FATAL: POLLHUP on icmpv4 fd, terminating."));
469			exit (1);
470			}
471			else
472			{
473			slog (L_ERR,
474			_("FATAL: unknown revents %08x in socket, terminating\n"),
475			revents);
476			exit (1);
477			}
478			}
479	pcg	1.13	#endif
480	pcg	1.9
481			void
482			vpn::udpv4_ev (io_watcher &w, short revents)
483			{
484			if (revents & (POLLIN \| POLLERR))
485			{
486			vpn_packet *pkt = new vpn_packet;
487			struct sockaddr_in sa;
488			socklen_t sa_len = sizeof (sa);
489			int len;
490
491			len = recvfrom (w.fd, &((pkt)[0]), MAXSIZE, 0, (sockaddr )&sa, &sa_len);
492
493			sockinfo si(sa, PROT_UDPv4);
494
495			if (len > 0)
496			{
497			pkt->len = len;
498	pcg	1.1
499			recv_vpn_packet (pkt, si);
500			}
501			else
502			{
503			// probably ECONNRESET or somesuch
504	pcg	1.9	slog (L_DEBUG, _("%s: fd %d, %s"), (const char *)si, w.fd, strerror (errno));
505	pcg	1.1	}
506
507			delete pkt;
508			}
509			else if (revents & POLLHUP)
510			{
511			// this cannot ;) happen on udp sockets
512	pcg	1.9	slog (L_ERR, _("FATAL: POLLHUP on udp v4 fd, terminating."));
513	pcg	1.1	exit (1);
514			}
515			else
516			{
517			slog (L_ERR,
518			_("FATAL: unknown revents %08x in socket, terminating\n"),
519			revents);
520			exit (1);
521			}
522			}
523	pcg	1.2
524			void
525	pcg	1.3	vpn::tap_ev (io_watcher &w, short revents)
526	pcg	1.1	{
527			if (revents & POLLIN)
528			{
529			/* process data */
530			tap_packet *pkt;
531
532			pkt = tap->recv ();
533
534	pcg	1.17	if (!pkt)
535			return;
536	pcg	1.1
537	pcg	1.17	if (pkt->len > 14)
538	pcg	1.1	{
539	pcg	1.17	int dst = mac2id (pkt->dst);
540			int src = mac2id (pkt->src);
541	pcg	1.1
542	pcg	1.17	if (src != THISNODE->id)
543			{
544			slog (L_ERR, _("FATAL: tap packet not originating on current node received, exiting."));
545			exit (1);
546			}
547	pcg	1.1
548	pcg	1.17	if (dst == THISNODE->id)
549	pcg	1.1	{
550	pcg	1.17	slog (L_ERR, _("FATAL: tap packet destined for current node received, exiting."));
551			exit (1);
552	pcg	1.1	}
553	pcg	1.17
554			if (dst > conns.size ())
555			slog (L_ERR, _("tap packet for unknown node %d received, ignoring."), dst);
556	pcg	1.1	else
557			{
558	pcg	1.17	if (dst)
559			{
560			// unicast
561			if (dst != THISNODE->id)
562			conns[dst - 1]->inject_data_packet (pkt);
563			}
564			else
565			{
566			// broadcast, this is ugly, but due to the security policy
567			// we have to connect to all hosts...
568			for (conns_vector::iterator c = conns.begin (); c != conns.end (); ++c)
569			if ((*c)->conf != THISNODE)
570			(*c)->inject_data_packet (pkt);
571			}
572	pcg	1.1	}
573			}
574
575			delete pkt;
576			}
577			else if (revents & (POLLHUP \| POLLERR))
578			{
579			slog (L_ERR, _("FATAL: POLLHUP or POLLERR on network device fd, terminating."));
580			exit (1);
581			}
582			else
583			abort ();
584			}
585
586			void
587	pcg	1.3	vpn::event_cb (time_watcher &w)
588	pcg	1.1	{
589			if (events)
590			{
591			if (events & EVENT_SHUTDOWN)
592			{
593			slog (L_INFO, _("preparing shutdown..."));
594
595			shutdown_all ();
596
597			remove_pid (pidfilename);
598
599			slog (L_INFO, _("terminating"));
600
601			exit (0);
602			}
603
604			if (events & EVENT_RECONNECT)
605			{
606			slog (L_INFO, _("forced reconnect"));
607
608			reconnect_all ();
609			}
610
611			events = 0;
612			}
613
614	pcg	1.3	w.at = TSTAMP_CANCEL;
615	pcg	1.1	}
616
617			void
618			vpn::shutdown_all ()
619			{
620			for (conns_vector::iterator c = conns.begin (); c != conns.end (); ++c)
621			(*c)->shutdown ();
622			}
623
624			void
625			vpn::reconnect_all ()
626			{
627			for (conns_vector::iterator c = conns.begin (); c != conns.end (); ++c)
628			delete *c;
629
630			conns.clear ();
631
632			connection_init ();
633
634			for (configuration::node_vector::iterator i = conf.nodes.begin ();
635			i != conf.nodes.end (); ++i)
636			{
637			connection *conn = new connection (this);
638
639			conn->conf = *i;
640			conns.push_back (conn);
641
642			conn->establish_connection ();
643			}
644			}
645
646			connection *vpn::find_router ()
647			{
648	pcg	1.12	u32 prio = 1;
649	pcg	1.1	connection *router = 0;
650
651			for (conns_vector::iterator i = conns.begin (); i != conns.end (); ++i)
652			{
653			connection c = i;
654
655	pcg	1.13	if (c->conf->routerprio > prio
656	pcg	1.11	&& c->connectmode == conf_node::C_ALWAYS // so we don't drop the connection if in use
657			&& c->ictx && c->octx
658	pcg	1.13	&& c->conf != THISNODE) // redundant, since ictx==octx==0 always on thisnode
659	pcg	1.1	{
660			prio = c->conf->routerprio;
661			router = c;
662			}
663			}
664
665			return router;
666			}
667
668	pcg	1.7	void vpn::send_connect_request (int id)
669	pcg	1.1	{
670			connection *c = find_router ();
671
672			if (c)
673	pcg	1.7	c->send_connect_request (id);
674			else
675			// no router found, aggressively connect to all routers
676			for (conns_vector::iterator i = conns.begin (); i != conns.end (); ++i)
677	pcg	1.13	if ((i)->conf->routerprio && (i)->conf != THISNODE)
678	pcg	1.7	(*i)->establish_connection ();
679	pcg	1.1	}
680
681			void
682			connection::dump_status ()
683			{
684			slog (L_NOTICE, _("node %s (id %d)"), conf->nodename, conf->id);
685			slog (L_NOTICE, _(" connectmode %d (%d) / sockaddr %s / minor %d"),
686			connectmode, conf->connectmode, (const char *)si, (int)prot_minor);
687			slog (L_NOTICE, _(" ictx/octx %08lx/%08lx / oseqno %d / retry_cnt %d"),
688			(long)ictx, (long)octx, (int)oseqno, (int)retry_cnt);
689			slog (L_NOTICE, _(" establish_conn %ld / rekey %ld / keepalive %ld"),
690			(long)(establish_connection.at), (long)(rekey.at), (long)(keepalive.at));
691			}
692
693			void
694			vpn::dump_status ()
695			{
696			slog (L_NOTICE, _("BEGIN status dump (%ld)"), (long)NOW);
697
698			for (conns_vector::iterator c = conns.begin (); c != conns.end (); ++c)
699			(*c)->dump_status ();
700
701			slog (L_NOTICE, _("END status dump"));
702			}
703
704			vpn::vpn (void)
705	pcg	1.9	: event (this, &vpn::event_cb)
706			, udpv4_ev_watcher (this, &vpn::udpv4_ev)
707			, ipv4_ev_watcher (this, &vpn::ipv4_ev)
708	pcg	1.2	#if ENABLE_TCP
709	pcg	1.9	, tcpv4_ev_watcher (this, &vpn::tcpv4_ev)
710			#endif
711			#if ENABLE_ICMP
712			, icmpv4_ev_watcher(this, &vpn::icmpv4_ev)
713	pcg	1.2	#endif
714	pcg	1.9	, tap_ev_watcher (this, &vpn::tap_ev)
715	pcg	1.1	{
716			}
717
718			vpn::~vpn ()
719			{
720			}
721