gvpe/src/device-linux.C

/*
    device-linux.C -- Interaction with Linux tun/tap device
 
    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 <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
# 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 (1);
    }

  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 (1);
    }

  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:	1.4
Committed:	Thu Oct 16 02:28:36 2003 UTC (20 years, 7 months ago) by pcg
Content type:	text/plain
Branch:	MAIN
Changes since 1.3:	+31 -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
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 <cstdio>
22			#include <cstring>
23			#include <cstdlib>
24
25			#include <errno.h>
26			#include <sys/types.h>
27			#include <sys/stat.h>
28			#include <fcntl.h>
29			#include <net/if.h>
30			#include <unistd.h>
31			#include <sys/ioctl.h>
32
33	pcg	1.3	#include <net/if.h>
34
35	pcg	1.1	#ifdef LINUX_IF_TUN_H
36	pcg	1.3	# include LINUX_IF_TUN_H
37	pcg	1.1	#else
38			#include <linux/if_tun.h>
39			#endif
40			#define DEFAULT_DEVICE "/dev/net/tun"
41
42			#include "gettext.h"
43
44			#include "conf.h"
45
46	pcg	1.4	#if TEST_ETHEREMU
47			# include "ether_emu.C"
48			#endif
49
50	pcg	1.3	const char *
51			tap_device::info ()
52			{
53			return _("Linux tun/tap device");
54			}
55
56	pcg	1.1	tap_device::tap_device ()
57			{
58			struct ifreq ifr;
59
60			device = DEFAULT_DEVICE;
61
62			fd = open (device, O_RDWR);
63
64			if (fd < 0)
65			{
66			slog (L_ERR, _("could not open device %s: %s"), device, strerror (errno));
67			exit (1);
68			}
69
70			memset (&ifr, 0, sizeof (ifr));
71	pcg	1.4	#if TEST_ETHEREMU
72			ifr.ifr_flags = IFF_TUN \| IFF_NO_PI;
73			#else
74	pcg	1.1	ifr.ifr_flags = IFF_TAP \| IFF_NO_PI;
75	pcg	1.4	#endif
76	pcg	1.1
77			if (conf.ifname)
78			strncpy (ifr.ifr_name, conf.ifname, IFNAMSIZ);
79			else
80			ifr.ifr_name[0] = 0;
81
82			if (!ioctl (fd, TUNSETIFF, &ifr))
83			{
84			strncpy (ifrname, ifr.ifr_name, IFNAMSIZ);
85			ifrname [IFNAMSIZ] = 0;
86			}
87			else
88			{
89			slog (L_CRIT, _("unable to configure tun/tap interface: %s"), strerror (errno));
90			exit (1);
91			}
92
93	pcg	1.2	if (ioctl (fd, TUNSETPERSIST, conf.ifpersist ? 1 : 0))
94			slog (L_WARN, _("cannot set persistency mode for device %s: %s"), ifrname, strerror (errno));
95	pcg	1.1
96			slog (L_DEBUG, _("%s is a %s"), device, info ());
97			}
98
99			tap_device::~tap_device ()
100			{
101			close (fd);
102			}
103
104			tap_packet *
105			tap_device::recv ()
106			{
107			tap_packet *pkt = new tap_packet;
108
109	pcg	1.4	#if TEST_ETHEREMU
110			pkt->len = read (fd, &((*pkt)[14]), MAX_MTU - 14);
111			#else
112	pcg	1.1	pkt->len = read (fd, &((*pkt)[0]), MAX_MTU);
113	pcg	1.4	#endif
114	pcg	1.1
115			if (pkt->len <= 0)
116			{
117	pcg	1.3	delete pkt;
118	pcg	1.1	slog (L_ERR, _("error while reading from %s %s: %s"),
119			info (), DEFAULT_DEVICE, strerror (errno));
120			return 0;
121			}
122
123	pcg	1.4	#if TEST_ETHEREMU
124			pkt->len += 14;
125
126			// assume ipv4
127			(*pkt)[12] = 0x08;
128			(*pkt)[13] = 0x00;
129
130			if (!ether_emu.tun_to_tap (pkt))
131			{
132			delete pkt;
133			return 0;
134			}
135			#endif
136
137	pcg	1.1	return pkt;
138			}
139
140			void
141			tap_device::send (tap_packet *pkt)
142			{
143	pcg	1.4	#if TEST_ETHEREMU
144			if (ether_emu.tap_to_tun (pkt) &&
145			write (fd, &((*pkt)[14]), pkt->len - 14) < 0)
146			#else
147	pcg	1.1	if (write (fd, &((*pkt)[0]), pkt->len) < 0)
148	pcg	1.4	#endif
149	pcg	1.1	slog (L_ERR, _("can't write to %s %s: %s"), info (), DEFAULT_DEVICE,
150			strerror (errno));
151			}
152