104 lines
2.8 KiB
C++
104 lines
2.8 KiB
C++
/* -*- C++ -*- */
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/*
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* Copyright 2008, 2009 Steve Glass
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*
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* This file is part of OP25.
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*
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* OP25 is free software; you can redistribute it and/or modify it
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* under the terms of the GNU General Public License as published by
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* the Free Software Foundation; either version 3, or (at your option)
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* any later version.
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*
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* OP25 is distributed in the hope that it will be useful, but WITHOUT
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* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
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* or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public
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* 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 OP25; see the file COPYING. If not, write to the Free
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* Software Foundation, Inc., 51 Franklin Street, Boston, MA
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* 02110-1301, USA.
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*/
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#include <cstring>
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#include <fcntl.h>
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#include <linux/if_tun.h>
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#include <net/if.h>
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#include <sniffer_du_handler.h>
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#include <sys/ioctl.h>
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#include <sys/stat.h>
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sniffer_du_handler::sniffer_du_handler(data_unit_handler_sptr next) :
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data_unit_handler(next),
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d_tap(-1),
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d_tap_device("unavailable")
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{
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d_tap = open("/dev/net/tun", O_WRONLY);
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if(-1 != d_tap) {
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struct ifreq ifr;
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memset(&ifr, 0, sizeof(ifr));
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ifr.ifr_flags = IFF_TAP | IFF_NO_PI;
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strncpy(ifr.ifr_name, "p25-%d", IFNAMSIZ);
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if(0 == ioctl(d_tap, TUNSETIFF, &ifr)) {
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// force the device into the UP state
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int s = socket(AF_INET, SOCK_DGRAM, 0);
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if(0 <= s) {
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if(0 == ioctl(s, SIOCGIFFLAGS, &ifr)) {
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ifr.ifr_flags = IFF_UP;
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if(0 == ioctl(s, SIOCSIFFLAGS, &ifr)) {
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d_tap_device = ifr.ifr_name;
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} else {
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perror("ioctl(d_tap, SIOCSIFFLAGS, &ifr)");
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close(d_tap);
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d_tap = -1;
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}
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} else {
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perror("ioctl(d_tap, SIOCGIFFLAGS, &ifr)");
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close(d_tap);
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d_tap = -1;
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}
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close(s);
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} else {
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perror("socket(AF_INET, SOCK_DGRAM, 0)");
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close(d_tap);
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d_tap = -1;
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}
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} else {
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perror("ioctl(d_tap, TUNSETIFF, &ifr)");
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close(d_tap);
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d_tap = -1;
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}
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}
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}
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sniffer_du_handler::~sniffer_du_handler()
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{
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if(-1 != d_tap) {
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close(d_tap);
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}
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}
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const char*
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sniffer_du_handler::device_name() const
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{
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return d_tap_device.c_str();
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}
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void
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sniffer_du_handler::handle(data_unit_sptr du)
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{
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if(-1 != d_tap) {
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const size_t du_sz = du->size();
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const size_t tap_hdr_sz = 14;
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const size_t tap_sz = du_sz + tap_hdr_sz;
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uint8_t tap[tap_sz];
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memset(&tap[0], 0x00, 6);
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memset(&tap[6], 0x00, 6);
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memset(&tap[12], 0xff, 2);
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du->decode_frame(du_sz, &tap[tap_hdr_sz]);
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write(d_tap, tap, tap_sz);
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}
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data_unit_handler::handle(du);
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}
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