122 lines
3.8 KiB
C
122 lines
3.8 KiB
C
/*
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* (C) 2007-08 - Luca Deri <deri@ntop.org>
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*
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* This program 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 3 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 this program; if not, see <http://www.gnu.org/licenses/>
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*/
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#include "n2n.h"
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#ifdef __linux__
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static void read_mac(char *ifname, char *mac_addr) {
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int _sock, res;
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struct ifreq ifr;
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macstr_t mac_addr_buf;
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memset (&ifr,0,sizeof(struct ifreq));
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/* Dummy socket, just to make ioctls with */
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_sock=socket(PF_INET, SOCK_DGRAM, 0);
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strcpy(ifr.ifr_name, ifname);
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res = ioctl(_sock,SIOCGIFHWADDR,&ifr);
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if (res<0) {
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perror ("Get hw addr");
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} else
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memcpy(mac_addr, ifr.ifr_ifru.ifru_hwaddr.sa_data, 6);
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traceEvent(TRACE_NORMAL, "Interface %s has MAC %s",
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ifname,
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macaddr_str(mac_addr, mac_addr_buf, sizeof(mac_addr_buf)));
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close(_sock);
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}
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/* ********************************** */
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/** @brief Open and configure the TAP device for packet read/write.
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*
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* This routine creates the interface via the tuntap driver then uses ifconfig
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* to configure address/mask and MTU.
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*
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* @param device - [inout] a device info holder object
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* @param dev - user-defined name for the new iface,
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* if NULL system will assign a name
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* @param device_ip - address of iface
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* @param device_mask - netmask for device_ip
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*
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* @return - negative value on error
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* - non-negative file-descriptor on success
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*/
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int tuntap_open(tuntap_dev *device,
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char *dev, /* user-definable interface name, eg. edge0 */
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char *device_ip,
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char *device_mask,
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const char * device_mac ) {
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char *tuntap_device = "/dev/net/tun";
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#define N2N_LINUX_SYSTEMCMD_SIZE 128
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char buf[N2N_LINUX_SYSTEMCMD_SIZE];
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struct ifreq ifr;
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int rc;
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device->fd = open(tuntap_device, O_RDWR);
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if(device->fd < 0) {
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printf("ERROR: ioctl() [%s][%d]\n", strerror(errno), rc);
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return -1;
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}
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memset(&ifr, 0, sizeof(ifr));
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ifr.ifr_flags = IFF_TAP|IFF_NO_PI; /* Want a TAP device for layer 2 frames. */
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strncpy(ifr.ifr_name, dev, IFNAMSIZ);
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rc = ioctl(device->fd, TUNSETIFF, (void *)&ifr);
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if(rc < 0) {
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traceEvent(TRACE_ERROR, "ioctl() [%s][%d]\n", strerror(errno), rc);
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close(device->fd);
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return -1;
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}
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/* REVISIT: BbMja7: MTU should be related to MTU of the interface the tuntap
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* is built on. The value 1400 assumes an eth iface with MTU 1500, but would
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* fail for ppp at mtu=576.
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*/
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if ( device_mac )
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{
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/* Set the hw address before bringing the if up. */
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snprintf(buf, sizeof(buf), "/sbin/ifconfig %s hw ether %s",
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ifr.ifr_name, device_mac );
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system(buf);
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traceEvent(TRACE_INFO, "Setting MAC: %s", buf);
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}
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snprintf(buf, sizeof(buf), "/sbin/ifconfig %s %s netmask %s mtu 1400 up",
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ifr.ifr_name, device_ip, device_mask);
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system(buf);
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traceEvent(TRACE_INFO, "Bringing up: %s", buf);
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device->ip_addr = inet_addr(device_ip);
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read_mac(dev, (char*)device->mac_addr);
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return(device->fd);
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}
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int tuntap_read(struct tuntap_dev *tuntap, unsigned char *buf, int len) {
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return(read(tuntap->fd, buf, len));
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}
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int tuntap_write(struct tuntap_dev *tuntap, unsigned char *buf, int len) {
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return(write(tuntap->fd, buf, len));
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}
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void tuntap_close(struct tuntap_dev *tuntap) {
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close(tuntap->fd);
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}
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#endif /* #ifdef __linux__ */
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