/* changeif.c -- change the configuration of a network interface   Copyright (C) 2001, 2002 Free Software Foundation, Inc.   Written by Marcus Brinkmann.   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., 51 Franklin Street, Fifth Floor, Boston,   MA 02110-1301 USA. */#ifdef HAVE_CONFIG_H#include <config.h>#endif#include <stdio.h>#include <errno.h>#if HAVE_STRING_H# include <string.h>#else# include <strings.h>#endif#include <sys/types.h>#include <sys/socket.h>#include <sys/ioctl.h>#include <net/if.h>#include <netinet/in.h>#include <arpa/inet.h>#include <netdb.h>#include "ifconfig.h"#define SIOCSIF(type, addr)						\  int err = 0;								\  struct sockaddr_in *sin = (struct sockaddr_in *) &ifr->ifr_addr;	\									\  sin->sin_family = AF_INET;						\  err = inet_aton (addr, &sin->sin_addr);				\  if (!err)								\    {									\      fprintf (stderr, "%s: `%s' is not a valid address\n",		\	       program_name, addr);					\      return -1;							\    }									\  err = ioctl (sfd, SIOCSIF##type, ifr);				\  if (err < 0)								\    {									\      fprintf (stderr, "%s: %s failed: %s\n", program_name,		\               "SIOCSIF" #type, strerror (errno));			\      return -1;							\    }extern void herror (const char *pfx);/* Set address of interface in IFR. Destroys union in IFR, but leaves   ifr_name intact.  ADDRESS may be an IP number or a hostname that   can be resolved.  */intset_address (int sfd, struct ifreq *ifr, char *address){#ifndef SIOCSIFADDR  fprintf (stderr, "%s: Don't know how to set an interface address on this system.\n",	  program_name);  return -1;#else  char *addr;  struct hostent *host = gethostbyname (address);  if (! host)    {      fprintf (stderr, "%s: can not resolve `%s': ", program_name,               address);      herror (NULL);      return -1;    }  if (host->h_addrtype != AF_INET)    {      fprintf (stderr, "%s: `%s' refers to an unknown address type", program_name,	       address);      return -1;    }  addr = inet_ntoa (* ((struct in_addr *) host->h_addr));  {    SIOCSIF(ADDR, addr)      if (verbose)	printf ("Set interface address of `%s' to %s.\n",		ifr->ifr_name, inet_ntoa (sin->sin_addr));  }  return 0;#endif}intset_netmask (int sfd, struct ifreq *ifr, char *netmask){#ifndef SIOCSIFNETMASK  printf ("%s: Don't know how to set an interface netmask on this system.\n",	  program_name);  return -1;#else  SIOCSIF(NETMASK, netmask)  if (verbose)    printf ("Set interface netmask of `%s' to %s.\n",	    ifr->ifr_name, inet_ntoa (sin->sin_addr));  return 0;#endif}intset_dstaddr (int sfd, struct ifreq *ifr, char *dstaddr){#ifndef SIOCSIFDSTADDR  printf ("%s: Don't know how to set an interface peer address on this system.\n",	  program_name);  return -1;#else  SIOCSIF(DSTADDR, dstaddr)  if (verbose)    printf ("Set interface peer address of `%s' to %s.\n",	    ifr->ifr_name, inet_ntoa (sin->sin_addr));  return 0;#endif}intset_brdaddr (int sfd, struct ifreq *ifr, char *brdaddr){#ifndef SIOCSIFBRDADDR  printf ("%s: Don't know how to set an interface broadcast address on this system.\n",	  program_name);  return -1;#else  SIOCSIF(BRDADDR, brdaddr)  if (verbose)    printf ("Set interface broadcast address of `%s' to %s.\n",	    ifr->ifr_name, inet_ntoa (sin->sin_addr));  return 0;#endif}intset_mtu (int sfd, struct ifreq *ifr, int mtu){#ifndef SIOCSIFMTU  printf ("%s: Don't know how to set the interface mtu on this system.\n",	  program_name);  return -1;#else  int err = 0;  ifr->ifr_mtu = mtu;  err = ioctl (sfd, SIOCSIFMTU, ifr);  if (err < 0)    {      fprintf (stderr, "%s: SIOCSIFMTU failed: %s\n",	       program_name, strerror (errno));      return -1;    }  if (verbose)    printf ("Set mtu value of `%s' to `%i'.\n",	    ifr->ifr_name, ifr->ifr_mtu);  return 0;#endif}intset_metric (int sfd, struct ifreq *ifr, int metric){#ifndef SIOCSIFMETRIC  printf ("%s: Don't know how to set the interface metric on this system.\n",	  program_name);  return -1;#else  int err = 0;  ifr->ifr_metric = metric;  err = ioctl (sfd, SIOCSIFMETRIC, ifr);  if (err < 0)    {      fprintf (stderr, "%s: SIOCSIFMETRIC failed: %s\n",	       program_name, strerror (errno));      return -1;    }  if (verbose)    printf ("Set metric value of `%s' to `%i'.\n",	    ifr->ifr_name, ifr->ifr_metric);  return 0;#endif}intconfigure_if (int sfd, struct ifconfig *ifp){  int err = 0;  struct ifreq ifr;  memset (&ifr, 0, sizeof (ifr));  strncpy (ifr.ifr_name, ifp->name, IFNAMSIZ);  ifr.ifr_name[IFNAMSIZ - 1] = '\0';  if (ifp->valid & IF_VALID_ADDR)    err = set_address (sfd, &ifr, ifp->address);  if (!err && ifp->valid & IF_VALID_NETMASK)    err = set_netmask (sfd, &ifr, ifp->netmask);  if (!err && ifp->valid & IF_VALID_DSTADDR)    err = set_dstaddr (sfd, &ifr, ifp->dstaddr);  if (!err && ifp->valid & IF_VALID_BRDADDR)    err = set_brdaddr (sfd, &ifr, ifp->brdaddr);  if (!err && ifp->valid & IF_VALID_MTU)    err = set_mtu (sfd, &ifr, ifp->mtu);  if (!err && ifp->valid & IF_VALID_METRIC)    err = set_metric (sfd, &ifr, ifp->metric);  if (!err && ifp->valid & IF_VALID_SYSTEM)    err = system_configure (sfd, &ifr, ifp->system);  if (!err && ifp->valid & IF_VALID_FORMAT)    print_interface (sfd, ifp->name, &ifr, ifp->format);  return err;}