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");
}

const char *
tap_device::if_up ()
{
  return "/sbin/ifconfig $IFNAME hw ether $MAC mtu $MTU";
}

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, exiting: %s"), strerror (errno));
      exit (EXIT_FAILURE);
    }

#if 0
  does not work
  id2mac (THISNODE->id, &ifr.ifr_hwaddr.sa_data);
  if (ioctl (fd, SIOCSIFHWADDR, &ifr))
    {
      slog (L_ERR, _("cannot set MAC address for device %s, exiting: %s"), ifrname, strerror (errno));
      exit (EXIT_FAILURE);
    }
#endif

  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:	1.15
Committed:	Fri Apr 8 16:48:16 2005 UTC (19 years, 1 month ago) by pcg
Content type:	text/plain
Branch:	MAIN
CVS Tags:	rel-1_9
Changes since 1.14:	+1 -1 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	1.12	const char *
61			tap_device::if_up ()
62			{
63	pcg	1.13	return "/sbin/ifconfig $IFNAME hw ether $MAC mtu $MTU";
64	pcg	1.12	}
65
66	pcg	1.1	tap_device::tap_device ()
67			{
68			struct ifreq ifr;
69
70			device = DEFAULT_DEVICE;
71
72			fd = open (device, O_RDWR);
73
74			if (fd < 0)
75			{
76			slog (L_ERR, _("could not open device %s: %s"), device, strerror (errno));
77	pcg	1.8	exit (EXIT_FAILURE);
78	pcg	1.1	}
79
80			memset (&ifr, 0, sizeof (ifr));
81	pcg	1.4	#if TEST_ETHEREMU
82			ifr.ifr_flags = IFF_TUN \| IFF_NO_PI;
83			#else
84	pcg	1.1	ifr.ifr_flags = IFF_TAP \| IFF_NO_PI;
85	pcg	1.4	#endif
86	pcg	1.1
87			if (conf.ifname)
88			strncpy (ifr.ifr_name, conf.ifname, IFNAMSIZ);
89			else
90			ifr.ifr_name[0] = 0;
91
92			if (!ioctl (fd, TUNSETIFF, &ifr))
93			{
94			strncpy (ifrname, ifr.ifr_name, IFNAMSIZ);
95			ifrname [IFNAMSIZ] = 0;
96			}
97			else
98			{
99	pcg	1.14	slog (L_CRIT, _("unable to configure tun/tap interface, exiting: %s"), strerror (errno));
100	pcg	1.8	exit (EXIT_FAILURE);
101	pcg	1.1	}
102
103	pcg	1.14	#if 0
104	pcg	1.15	does not work
105	pcg	1.14	id2mac (THISNODE->id, &ifr.ifr_hwaddr.sa_data);
106			if (ioctl (fd, SIOCSIFHWADDR, &ifr))
107			{
108			slog (L_ERR, _("cannot set MAC address for device %s, exiting: %s"), ifrname, strerror (errno));
109			exit (EXIT_FAILURE);
110			}
111			#endif
112
113	pcg	1.2	if (ioctl (fd, TUNSETPERSIST, conf.ifpersist ? 1 : 0))
114			slog (L_WARN, _("cannot set persistency mode for device %s: %s"), ifrname, strerror (errno));
115	pcg	1.1
116			slog (L_DEBUG, _("%s is a %s"), device, info ());
117			}
118
119			tap_device::~tap_device ()
120			{
121			close (fd);
122			}
123
124			tap_packet *
125			tap_device::recv ()
126			{
127			tap_packet *pkt = new tap_packet;
128
129	pcg	1.4	#if TEST_ETHEREMU
130			pkt->len = read (fd, &((*pkt)[14]), MAX_MTU - 14);
131			#else
132	pcg	1.1	pkt->len = read (fd, &((*pkt)[0]), MAX_MTU);
133	pcg	1.4	#endif
134	pcg	1.1
135			if (pkt->len <= 0)
136			{
137	pcg	1.3	delete pkt;
138	pcg	1.1	slog (L_ERR, _("error while reading from %s %s: %s"),
139			info (), DEFAULT_DEVICE, strerror (errno));
140			return 0;
141			}
142
143	pcg	1.4	#if TEST_ETHEREMU
144			pkt->len += 14;
145
146			// assume ipv4
147			(*pkt)[12] = 0x08;
148			(*pkt)[13] = 0x00;
149
150			if (!ether_emu.tun_to_tap (pkt))
151			{
152			delete pkt;
153			return 0;
154			}
155			#endif
156
157	pcg	1.1	return pkt;
158			}
159
160			void
161			tap_device::send (tap_packet *pkt)
162			{
163	pcg	1.4	#if TEST_ETHEREMU
164			if (ether_emu.tap_to_tun (pkt) &&
165			write (fd, &((*pkt)[14]), pkt->len - 14) < 0)
166			#else
167	pcg	1.1	if (write (fd, &((*pkt)[0]), pkt->len) < 0)
168	pcg	1.4	#endif
169	pcg	1.1	slog (L_ERR, _("can't write to %s %s: %s"), info (), DEFAULT_DEVICE,
170			strerror (errno));
171			}
172