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This commit is contained in:
Alex
413
getifname.c
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413
getifname.c
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/* getifname.c -- network interface handling
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* Copyright(C) 1999,2000,2001 Salvatore Sanfilippo <antirez@invece.org>
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* Copyright(C) 2001 by Nicolas Jombart <Nicolas.Jombart@hsc.fr>
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* This code is under the GPL license */
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/* BSD support thanks to Nicolas Jombart <Nicolas.Jombart@hsc.fr> */
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#include <stdio.h> /* perror */
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#include <stdlib.h>
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#include <string.h>
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#include <sys/ioctl.h>
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#include <sys/types.h>
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#include <sys/socket.h>
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#include <netinet/in.h> /* struct sockaddr_in */
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#include <arpa/inet.h> /* inet_ntoa */
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#include <net/if.h>
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#include <unistd.h> /* close */
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#if defined(__FreeBSD__) || defined(__OpenBSD__) || defined(__NetBSD__) || \
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defined(__bsdi__) || defined(__APPLE__)
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#include <stdlib.h>
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#include <ifaddrs.h>
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#include <net/route.h>
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#endif /* defined(__*BSD__) */
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#include "hping2.h"
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#include "globals.h"
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#if !defined(__FreeBSD__) && !defined(__OpenBSD__) && !defined(__NetBSD__) && \
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!defined(__linux__) && !defined(__sun__) && !defined(__bsdi__) && \
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!defined(__APPLE__)
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#error Sorry, interface code not implemented.
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#endif
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#ifdef __sun__
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#include <sys/sockio.h>
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#include <net/route.h>
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#include <net/if_dl.h>
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#endif
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static int get_output_if(struct SOCKADDR *dest, struct SOCKADDR *ifip);
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#if (defined OSTYPE_LINUX) || (defined __sun__)
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char *
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get_v6_if_name(__u8 *ip)
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{
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FILE *fd;
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char buf[1024];
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char addr[33];
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int i;
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for(i = 0; i < 16; i++)
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sprintf(addr + i * 2, "%02x", ip[i]);
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if(!(fd = fopen("/proc/net/if_inet6", "r")))
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{
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perror("Warning: Unable to open /proc/net/if_inet6\n");
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return NULL;
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}
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while(fgets(buf, sizeof(buf), fd))
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{
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if(!strncmp(buf, addr, 32))
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{
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sscanf(buf, "%*32s %*02x %*02x %*02x %*02x %40s\n", ifname);
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return ifname;
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}
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}
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fclose(fd);
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return NULL;
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}
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int get_if_name(void)
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{
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int fd;
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struct ifconf ifc;
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struct ifreq ibuf[16],
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ifr,
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*ifrp,
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*ifend;
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struct SOCKADDR sa;
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struct SOCKADDR output_if_addr;
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int known_output_if = 0;
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/* Try to get the output interface address according to
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* the OS routing table */
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if (ifname[0] == '\0') {
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if (get_output_if(&remote, &output_if_addr) == 0) {
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known_output_if = 1;
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inet_ntop(opt_af, ADDR(&output_if_addr), ifstraddr, sizeof(ifstraddr));
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if(opt_ipv6)
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get_v6_if_name((__u8 *)&((struct sockaddr_in6*)&output_if_addr)->sin6_addr.s6_addr);
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memcpy(&local, &output_if_addr, sizeof(local));
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if (opt_debug)
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printf("DEBUG: Output interface address: %s\n",
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ifstraddr);
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} else {
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fprintf(stderr, "Warning: Unable to guess the output "
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"interface\n");
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}
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}
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if ( (fd = socket(opt_af, SOCK_DGRAM, 0)) == -1) {
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perror("[get_if_name] socket(AF_INET, SOCK_DGRAM, 0)");
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return -1;
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}
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memset(ibuf, 0, sizeof(struct ifreq)*16);
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ifc.ifc_len = sizeof ibuf;
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ifc.ifc_buf = (caddr_t) ibuf;
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ifrp = ibuf;
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if(ifname[0] == 0)
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{
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/* gets interfaces list */
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if ( ioctl(fd, SIOCGIFCONF, (char*)&ifc) == -1 ||
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ifc.ifc_len < sizeof(struct ifreq) ) {
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perror("[get_if_name] ioctl(SIOCGIFCONF)");
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close(fd);
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return -1;
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}
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/* ifrp points to buffer and ifend points to buffer's end */
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ifend = (struct ifreq*) ((char*)ibuf + ifc.ifc_len);
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}
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else
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ifend = ifrp + 1;
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for (; ifrp < ifend; ifrp++) {
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if(ifname[0] == 0)
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strlcpy(ifr.ifr_name, ifrp->ifr_name, sizeof(ifr.ifr_name));
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else
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strlcpy(ifr.ifr_name, ifname, sizeof(ifr.ifr_name));
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if ( ioctl(fd, SIOCGIFFLAGS, (char*)&ifr) == -1) {
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if (opt_debug)
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perror("DEBUG: [get_if_name] ioctl(SIOCGIFFLAGS)");
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continue;
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}
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if (opt_debug)
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printf("DEBUG: if %s: ", ifr.ifr_name);
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/* Down interface? */
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if ( !(ifr.ifr_flags & IFF_UP) )
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{
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if (opt_debug)
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printf("DOWN\n");
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continue;
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}
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if(!opt_ipv6)
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{
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if (known_output_if) {
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/* Get the interface address */
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if (ioctl(fd, SIOCGIFADDR, (char*)&ifr) == -1) {
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perror("[get_if_name] ioctl(SIOCGIFADDR)");
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continue;
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}
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/* Copy it */
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memcpy(&sa, &ifr.ifr_addr,
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sizeof(struct sockaddr_in));
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/* Check if it is what we are looking for */
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if ((*(struct sockaddr_in*)&sa).sin_addr.s_addr !=
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(*(struct sockaddr_in*)&output_if_addr).sin_addr.s_addr) {
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if (opt_debug)
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printf("The address doesn't match\n");
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continue;
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}
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} else if (ifname[0] != '\0' && !strstr(ifr.ifr_name, ifname)) {
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if (opt_debug)
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printf("Don't Match (but seems to be UP)\n");
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continue;
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}
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}
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if (opt_debug)
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printf("OK\n");
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/* interface found, save if name */
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strlcpy(ifname, ifr.ifr_name, 1024);
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/* get if address */
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if(!known_output_if)
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{
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if ( ioctl(fd, SIOCGIFADDR, (char*)&ifr) == -1) {
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perror("DEBUG: [get_if_name] ioctl(SIOCGIFADDR)");
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exit(1);
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}
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/* save if address */
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memcpy(&sa, &ifr.ifr_addr,
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sizeof(struct sockaddr_in));
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inet_ntop(opt_af, ADDR(&output_if_addr), ifstraddr, sizeof(ifstraddr));
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}
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/* get if mtu */
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if ( ioctl(fd, SIOCGIFMTU, (char*)&ifr) == -1) {
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perror("Warning: [get_if_name] ioctl(SIOCGIFMTU)");
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fprintf(stderr, "Using a fixed MTU of 1500\n");
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h_if_mtu = 1500;
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}
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else
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{
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#ifdef __sun__
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/* somehow solaris is braidamaged in wrt ifr_mtu */
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h_if_mtu = ifr.ifr_metric;
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#else
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h_if_mtu = ifr.ifr_mtu;
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#endif
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}
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close(fd);
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return 0;
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}
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/* interface not found, use 'lo' */
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strlcpy(ifname, "lo", 1024);
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if(ifstraddr[0] == 0)
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{
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if(opt_ipv6)
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strcpy(ifstraddr, "::1");
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else
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strcpy(ifstraddr, "127.0.0.1");
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}
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h_if_mtu = 1500;
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close(fd);
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return 0;
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}
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#elif defined(__FreeBSD__) || defined(__NetBSD__) || defined(__OpenBSD__) || \
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defined(__bsdi__) || defined(__APPLE__)
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/* return interface informations :
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- from the specified (-I) interface
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- from the routing table
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- or at least from the first UP interface found
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*/
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int get_if_name(void)
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{
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/* variable declarations */
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struct ifaddrs *ifap, *ifa;
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char current_if_name[24];
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char saved_ifname[24];
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struct SOCKADDR output_if_addr;
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char tmp[1024];
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#ifdef __NetBSD__
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int s;
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struct ifreq ifr;
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#endif /* __NetBSD__ */
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if (getifaddrs(&ifap) < 0)
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perror("getifaddrs");
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saved_ifname[0] = 0;
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/* lookup desired interface */
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if(ifname[0] == 0) {
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/* find gateway interface from kernel */
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if (get_output_if(&remote, &output_if_addr) == 0) {
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if (opt_debug)
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printf("DEBUG: Output interface address: %s\n",
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inet_ntop(opt_af, ADDR(&output_if_addr), tmp, sizeof(tmp)));
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/* Put something in saved_ifname in order to tell
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that the output adress is known */
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saved_ifname[0] = 'X'; saved_ifname[1] = 0;
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} else {
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fprintf(stderr, "Warning: Unable to guess the output "
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"interface\n");
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}
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}
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else {
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/* use the forced interface name */
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strlcpy(saved_ifname,ifname,24);
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}
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/* get interface information */
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for (ifa = ifap; ifa; ifa = ifa->ifa_next) {
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if (opt_debug) printf("\n DEBUG: if %s: ", ifa->ifa_name);
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/* print if the data structure is null or not */
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if (ifa->ifa_data) {
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if(opt_debug) printf("DEBUG: (struct DATA) "); }
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else
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if(opt_debug) printf("DEBUG: (struct DATA is NULL) ");
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if (!(ifa->ifa_flags & IFF_UP)) { /* if down */
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if (opt_debug)
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printf("DEBUG: DOWN");
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continue;
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}
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if ((ifa->ifa_flags & IFF_LOOPBACK)&&
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(strncmp(saved_ifname,"lo0",3))) { /* if loopback */
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if (opt_debug)
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printf("DEBUG: LOOPBACK, SKIPPED");
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continue;
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}
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if (ifa->ifa_addr->sa_family == AF_LINK) {
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if (opt_debug)
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printf("DEBUG: AF_LINK ");
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strlcpy(ifname,ifa->ifa_name,1024);
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strlcpy(current_if_name,ifa->ifa_name,24);
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/* I don't know why NetBSD behavior is not the same */
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#ifdef __NetBSD__
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memset( &ifr, 0, sizeof(ifr));
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strlcpy(ifr.ifr_name, ifa->ifa_name, sizeof(ifr.ifr_name));
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if( sizeof(ifr.ifr_addr) >= ifa->ifa_addr->sa_len )
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memcpy(&ifr.ifr_addr, ifa->ifa_addr,
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ifa->ifa_addr->sa_len);
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if( (s = socket(PF_INET, SOCK_DGRAM, 0)) < 0) {
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perror("[get_if_name] socket");
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return -1;
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}
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if (ioctl(s, SIOCGIFMTU, (caddr_t)&ifr) < 0) h_if_mtu = 0;
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else h_if_mtu = ifr.ifr_mtu;
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close(s);
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#else
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if( ifa->ifa_data )
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h_if_mtu = ((struct if_data *)ifa->ifa_data)->ifi_mtu;
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else {
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h_if_mtu = 1500;
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fprintf(stderr, "Warning: fixing MTU to 1500 !\n");
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}
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#endif /* __NetBSD__ */
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continue;
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}
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if (ifa->ifa_addr->sa_family == AF_INET6) {
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if (opt_debug)
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printf("AF_INET6 ");
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continue;
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}
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if (ifa->ifa_addr->sa_family == AF_INET) {
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if (opt_debug)
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printf("AF_INET ");
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if(strncmp(ifa->ifa_name,current_if_name,24))
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continue; /* error */
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if(opt_debug) printf("OK\n");
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strlcpy(ifname,ifa->ifa_name,1024);
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strlcpy(ifstraddr,
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inet_ntoa(((struct sockaddr_in *)ifa->ifa_addr)->sin_addr),
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1024);
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if( (saved_ifname[0] == 0) ||
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(!strncmp(ifa->ifa_name, saved_ifname, 24)) ||
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(((struct sockaddr_in *)ifa->ifa_addr)->sin_addr.s_addr ==
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output_if_addr.sin_addr.s_addr) )
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break; /* asked if found or first UP interface */
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}
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/* interface not found, use hardcoded 'lo' */
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strlcpy(ifname, "lo0", 1024);
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strlcpy(ifstraddr, "127.0.0.1", 1024);
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h_if_mtu = 1500;
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}
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freeifaddrs(ifap);
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return 0;
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}
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#endif /* __*BSD__ */
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/* Try to obtain the IP address of the output interface according
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* to the OS routing table. Derived from R.Stevens */
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int get_output_if(struct SOCKADDR *dest, struct SOCKADDR *ifip)
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{
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int sock_rt, on=1;
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struct SOCKADDR iface_out;
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unsigned int len;
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if(opt_ipv6)
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len = sizeof(struct sockaddr_in6);
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else
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len = sizeof(struct sockaddr_in);
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memset(&iface_out, 0, sizeof(iface_out));
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sock_rt = socket(opt_af, SOCK_DGRAM, 0);
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// dest->sin_port = htons(11111);
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if (setsockopt(sock_rt, SOL_SOCKET, SO_BROADCAST, &on, sizeof(on))
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== -1) {
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if (opt_debug)
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perror("DEBUG: [get_output_if] setsockopt(SOL_SOCKET, "
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"SO_BROADCAST");
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close(sock_rt);
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return -1;
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}
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if (connect(sock_rt, (struct sockaddr*)dest, len) == -1 ) {
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if (opt_debug)
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perror("DEBUG: [get_output_if] connect");
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close(sock_rt);
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return -1;
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}
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if (getsockname(sock_rt, (struct sockaddr *)&iface_out, &len) == -1 ) {
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if (opt_debug)
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perror("DEBUG: [get_output_if] getsockname");
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close(sock_rt);
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return -1;
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}
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close(sock_rt);
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// if (iface_out.sin_addr.s_addr == 0)
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// return 1;
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memcpy(ifip, &iface_out, len);
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return 0;
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}
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