gvpe/src/device-linux.C

/*
    device-linux.C -- Interaction with Linux tun/tap device
    Copyright (C) 2003-2005 Marc Lehmann <gvpe@schmorp.de>
 
    This file is part of GVPE.

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

#include "config.h"

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

#include <errno.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <net/if.h>
#include <unistd.h>
#include <sys/ioctl.h>

#include <net/if.h>

#ifdef LINUX_IF_TUN_H
# include LINUX_IF_TUN_H
#else
#include <linux/if_tun.h>
#endif
#define DEFAULT_DEVICE "/dev/net/tun"

#include "gettext.h"

#include "conf.h"

#if TEST_ETHEREMU
# define IF_istun
# include "ether_emu.C"
#endif

const char *
tap_device::info ()
{
  return _("Linux tun/tap device");
}

tap_device::tap_device ()
{
  struct ifreq ifr;

  device = DEFAULT_DEVICE;

  fd = open (device, O_RDWR);

  if (fd < 0)
    {
      slog (L_ERR, _("could not open device %s: %s"), device, strerror (errno));
      exit (EXIT_FAILURE);
    }

  memset (&ifr, 0, sizeof (ifr));
#if TEST_ETHEREMU
  ifr.ifr_flags = IFF_TUN | IFF_NO_PI;
#else
  ifr.ifr_flags = IFF_TAP | IFF_NO_PI;
#endif

  if (conf.ifname)
    strncpy (ifr.ifr_name, conf.ifname, IFNAMSIZ);
  else
    ifr.ifr_name[0] = 0;

  if (!ioctl (fd, TUNSETIFF, &ifr))
    {
      strncpy (ifrname, ifr.ifr_name, IFNAMSIZ);
      ifrname [IFNAMSIZ] = 0;
    }
  else
    {
      slog (L_CRIT, _("unable to configure tun/tap interface: %s"), strerror (errno));
      exit (EXIT_FAILURE);
    }

  if (ioctl (fd, TUNSETPERSIST, conf.ifpersist ? 1 : 0))
    slog (L_WARN, _("cannot set persistency mode for device %s: %s"), ifrname, strerror (errno));

  slog (L_DEBUG, _("%s is a %s"), device, info ());
}

tap_device::~tap_device ()
{
  close (fd);
}

tap_packet *
tap_device::recv ()
{
  tap_packet *pkt = new tap_packet;

#if TEST_ETHEREMU
  pkt->len = read (fd, &((*pkt)[14]), MAX_MTU - 14);
#else
  pkt->len = read (fd, &((*pkt)[0]), MAX_MTU);
#endif

  if (pkt->len <= 0)
    {
      delete pkt;
      slog (L_ERR, _("error while reading from %s %s: %s"),
            info (), DEFAULT_DEVICE, strerror (errno));
      return 0;
    }

#if TEST_ETHEREMU
  pkt->len += 14;

  // assume ipv4
  (*pkt)[12] = 0x08;
  (*pkt)[13] = 0x00;

  if (!ether_emu.tun_to_tap (pkt))
    {
      delete pkt;
      return 0;
    }
#endif

  return pkt;
}

void
tap_device::send (tap_packet *pkt)
{
#if TEST_ETHEREMU
  if (ether_emu.tap_to_tun (pkt) &&
      write (fd, &((*pkt)[14]), pkt->len - 14) < 0)
#else
  if (write (fd, &((*pkt)[0]), pkt->len) < 0)
#endif
    slog (L_ERR, _("can't write to %s %s: %s"), info (), DEFAULT_DEVICE,
          strerror (errno));
}

Revision:	1.11
Committed:	Fri Mar 18 02:32:20 2005 UTC (19 years, 2 months ago) by pcg
Content type:	text/plain
Branch:	MAIN
CVS Tags:	rel-1_8
Changes since 1.10:	+2 -0 lines
Log Message:	* empty log message *
#	User	Rev	Content
1	pcg	1.1	/*
2			device-linux.C -- Interaction with Linux tun/tap device
3	pcg	1.9	Copyright (C) 2003-2005 Marc Lehmann <gvpe@schmorp.de>
4	pcg	1.1
5	pcg	1.9	This file is part of GVPE.
6
7			GVPE is free software; you can redistribute it and/or modify
8	pcg	1.1	it under the terms of the GNU General Public License as published by
9			the Free Software Foundation; either version 2 of the License, or
10			(at your option) any later version.
11
12			This program is distributed in the hope that it will be useful,
13			but WITHOUT ANY WARRANTY; without even the implied warranty of
14			MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15			GNU General Public License for more details.
16
17			You should have received a copy of the GNU General Public License
18	pcg	1.9	along with gvpe; if not, write to the Free Software
19	pcg	1.1	Foundation, Inc. 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
20			*/
21
22			#include "config.h"
23
24			#include <cstdio>
25			#include <cstring>
26			#include <cstdlib>
27
28			#include <errno.h>
29			#include <sys/types.h>
30			#include <sys/stat.h>
31			#include <fcntl.h>
32			#include <net/if.h>
33			#include <unistd.h>
34			#include <sys/ioctl.h>
35
36	pcg	1.3	#include <net/if.h>
37
38	pcg	1.1	#ifdef LINUX_IF_TUN_H
39	pcg	1.3	# include LINUX_IF_TUN_H
40	pcg	1.1	#else
41			#include <linux/if_tun.h>
42			#endif
43			#define DEFAULT_DEVICE "/dev/net/tun"
44
45	pcg	1.11	#include "gettext.h"
46
47	pcg	1.1	#include "conf.h"
48
49	pcg	1.4	#if TEST_ETHEREMU
50	pcg	1.6	# define IF_istun
51	pcg	1.4	# include "ether_emu.C"
52			#endif
53
54	pcg	1.3	const char *
55			tap_device::info ()
56			{
57			return _("Linux tun/tap device");
58			}
59
60	pcg	1.1	tap_device::tap_device ()
61			{
62			struct ifreq ifr;
63
64			device = DEFAULT_DEVICE;
65
66			fd = open (device, O_RDWR);
67
68			if (fd < 0)
69			{
70			slog (L_ERR, _("could not open device %s: %s"), device, strerror (errno));
71	pcg	1.8	exit (EXIT_FAILURE);
72	pcg	1.1	}
73
74			memset (&ifr, 0, sizeof (ifr));
75	pcg	1.4	#if TEST_ETHEREMU
76			ifr.ifr_flags = IFF_TUN \| IFF_NO_PI;
77			#else
78	pcg	1.1	ifr.ifr_flags = IFF_TAP \| IFF_NO_PI;
79	pcg	1.4	#endif
80	pcg	1.1
81			if (conf.ifname)
82			strncpy (ifr.ifr_name, conf.ifname, IFNAMSIZ);
83			else
84			ifr.ifr_name[0] = 0;
85
86			if (!ioctl (fd, TUNSETIFF, &ifr))
87			{
88			strncpy (ifrname, ifr.ifr_name, IFNAMSIZ);
89			ifrname [IFNAMSIZ] = 0;
90			}
91			else
92			{
93			slog (L_CRIT, _("unable to configure tun/tap interface: %s"), strerror (errno));
94	pcg	1.8	exit (EXIT_FAILURE);
95	pcg	1.1	}
96
97	pcg	1.2	if (ioctl (fd, TUNSETPERSIST, conf.ifpersist ? 1 : 0))
98			slog (L_WARN, _("cannot set persistency mode for device %s: %s"), ifrname, strerror (errno));
99	pcg	1.1
100			slog (L_DEBUG, _("%s is a %s"), device, info ());
101			}
102
103			tap_device::~tap_device ()
104			{
105			close (fd);
106			}
107
108			tap_packet *
109			tap_device::recv ()
110			{
111			tap_packet *pkt = new tap_packet;
112
113	pcg	1.4	#if TEST_ETHEREMU
114			pkt->len = read (fd, &((*pkt)[14]), MAX_MTU - 14);
115			#else
116	pcg	1.1	pkt->len = read (fd, &((*pkt)[0]), MAX_MTU);
117	pcg	1.4	#endif
118	pcg	1.1
119			if (pkt->len <= 0)
120			{
121	pcg	1.3	delete pkt;
122	pcg	1.1	slog (L_ERR, _("error while reading from %s %s: %s"),
123			info (), DEFAULT_DEVICE, strerror (errno));
124			return 0;
125			}
126
127	pcg	1.4	#if TEST_ETHEREMU
128			pkt->len += 14;
129
130			// assume ipv4
131			(*pkt)[12] = 0x08;
132			(*pkt)[13] = 0x00;
133
134			if (!ether_emu.tun_to_tap (pkt))
135			{
136			delete pkt;
137			return 0;
138			}
139			#endif
140
141	pcg	1.1	return pkt;
142			}
143
144			void
145			tap_device::send (tap_packet *pkt)
146			{
147	pcg	1.4	#if TEST_ETHEREMU
148			if (ether_emu.tap_to_tun (pkt) &&
149			write (fd, &((*pkt)[14]), pkt->len - 14) < 0)
150			#else
151	pcg	1.1	if (write (fd, &((*pkt)[0]), pkt->len) < 0)
152	pcg	1.4	#endif
153	pcg	1.1	slog (L_ERR, _("can't write to %s %s: %s"), info (), DEFAULT_DEVICE,
154			strerror (errno));
155			}
156