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/* |
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device-linux.C -- Interaction with Linux tun/tap device |
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Copyright (C) 2003-2005 Marc Lehmann <gvpe@schmorp.de> |
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|
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This file is part of GVPE. |
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|
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GVPE is free software; you can redistribute it and/or modify |
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it under the terms of the GNU General Public License as published by |
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the Free Software Foundation; either version 2 of the License, or |
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(at your option) any later version. |
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|
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This program is distributed in the hope that it will be useful, |
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but WITHOUT ANY WARRANTY; without even the implied warranty of |
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
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GNU General Public License for more details. |
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|
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You should have received a copy of the GNU General Public License |
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along with gvpe; if not, write to the Free Software |
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Foundation, Inc. 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA |
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*/ |
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|
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#include "config.h" |
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|
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#include <cstdio> |
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#include <cstring> |
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#include <cstdlib> |
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|
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#include <errno.h> |
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#include <sys/types.h> |
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#include <sys/stat.h> |
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#include <fcntl.h> |
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#include <net/if.h> |
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#include <unistd.h> |
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#include <sys/ioctl.h> |
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|
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#include <net/if.h> |
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|
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#ifdef LINUX_IF_TUN_H |
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# include LINUX_IF_TUN_H |
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#else |
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#include <linux/if_tun.h> |
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#endif |
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#define DEFAULT_DEVICE "/dev/net/tun" |
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|
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#include "conf.h" |
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|
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#if TEST_ETHEREMU |
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# define IF_istun |
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# include "ether_emu.C" |
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#endif |
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|
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const char * |
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tap_device::info () |
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{ |
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return _("Linux tun/tap device"); |
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} |
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|
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tap_device::tap_device () |
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{ |
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struct ifreq ifr; |
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|
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device = DEFAULT_DEVICE; |
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|
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fd = open (device, O_RDWR); |
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|
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if (fd < 0) |
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{ |
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slog (L_ERR, _("could not open device %s: %s"), device, strerror (errno)); |
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exit (EXIT_FAILURE); |
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} |
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|
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memset (&ifr, 0, sizeof (ifr)); |
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#if TEST_ETHEREMU |
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ifr.ifr_flags = IFF_TUN | IFF_NO_PI; |
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#else |
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ifr.ifr_flags = IFF_TAP | IFF_NO_PI; |
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#endif |
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|
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if (conf.ifname) |
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strncpy (ifr.ifr_name, conf.ifname, IFNAMSIZ); |
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else |
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ifr.ifr_name[0] = 0; |
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|
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if (!ioctl (fd, TUNSETIFF, &ifr)) |
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{ |
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strncpy (ifrname, ifr.ifr_name, IFNAMSIZ); |
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ifrname [IFNAMSIZ] = 0; |
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} |
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else |
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{ |
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slog (L_CRIT, _("unable to configure tun/tap interface: %s"), strerror (errno)); |
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exit (EXIT_FAILURE); |
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} |
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|
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if (ioctl (fd, TUNSETPERSIST, conf.ifpersist ? 1 : 0)) |
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slog (L_WARN, _("cannot set persistency mode for device %s: %s"), ifrname, strerror (errno)); |
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|
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slog (L_DEBUG, _("%s is a %s"), device, info ()); |
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} |
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|
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tap_device::~tap_device () |
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{ |
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close (fd); |
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} |
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|
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tap_packet * |
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tap_device::recv () |
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{ |
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tap_packet *pkt = new tap_packet; |
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|
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#if TEST_ETHEREMU |
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pkt->len = read (fd, &((*pkt)[14]), MAX_MTU - 14); |
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#else |
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pkt->len = read (fd, &((*pkt)[0]), MAX_MTU); |
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#endif |
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|
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if (pkt->len <= 0) |
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{ |
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delete pkt; |
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slog (L_ERR, _("error while reading from %s %s: %s"), |
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info (), DEFAULT_DEVICE, strerror (errno)); |
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return 0; |
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} |
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|
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#if TEST_ETHEREMU |
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pkt->len += 14; |
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|
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// assume ipv4 |
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(*pkt)[12] = 0x08; |
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(*pkt)[13] = 0x00; |
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|
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if (!ether_emu.tun_to_tap (pkt)) |
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{ |
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delete pkt; |
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return 0; |
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} |
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#endif |
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|
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return pkt; |
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} |
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|
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void |
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tap_device::send (tap_packet *pkt) |
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{ |
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#if TEST_ETHEREMU |
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if (ether_emu.tap_to_tun (pkt) && |
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write (fd, &((*pkt)[14]), pkt->len - 14) < 0) |
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#else |
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if (write (fd, &((*pkt)[0]), pkt->len) < 0) |
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#endif |
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slog (L_ERR, _("can't write to %s %s: %s"), info (), DEFAULT_DEVICE, |
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strerror (errno)); |
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} |
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|
