src/chbind.c

   1 // $Id: chbind.c,v 1.1.4.1 2003/10/14 00:42:32 ensc Exp $
   2
   3 // Copyright (C) 2003 Enrico Scholz <enrico.scholz@informatik.tu-chemnitz.de>
   4 // based on chbind.cc by Jacques Gelinas
   5 //
   6 // This program is free software; you can redistribute it and/or modify
   7 // it under the terms of the GNU General Public License as published by
   8 // the Free Software Foundation; either version 2, or (at your option)
   9 // any later version.
  10 //
  11 // This program is distributed in the hope that it will be useful,
  12 // but WITHOUT ANY WARRANTY; without even the implied warranty of
  13 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14 // GNU General Public License for more details.
  15 //
  16 // You should have received a copy of the GNU General Public License
  17 // along with this program; if not, write to the Free Software
  18 // Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
  19
  20 #ifdef HAVE_CONFIG_H
  21 #  include <config.h>
  22 #endif
  23 #include "compat.h"
  24
  25 #include <stdio.h>
  26 #include <stdlib.h>
  27 #include <string.h>
  28 #include <netdb.h>
  29 #include <sys/socket.h>
  30 #include <sys/ioctl.h>
  31 #include <netinet/in.h>
  32 #include <net/if.h>
  33 #include <unistd.h>
  34 #include <errno.h>
  35
  36 #include "vserver.h"
  37
  38 static void usage()
  39 {
  40         fprintf (stderr,"chbind version %s\n",VERSION);
  41         fprintf (stderr,"chbind [ --silent ] [ --ip ip_num[/mask] ] [ --bcast broadcast ] command argument\n");
  42         exit (-1);
  43 }
  44
  45 /*
  46         Check if a network device exist in /proc/net/dev.
  47         This is used because ifconfig_ioctl triggers modprobe if requesting
  48         information about non existant devices.
  49
  50         Return != 0 if the device exist.
  51 */
  52 static int chbind_devexist (const char *dev)
  53 {
  54         int ret = 0;
  55         FILE *fin = fopen ("/proc/net/dev","r");
  56         if (fin != NULL){
  57                 int len = strlen(dev);
  58                 char buf[1000];
  59                 fgets(buf,sizeof(buf)-1,fin);   // Skip one line
  60                 while (fgets(buf,sizeof(buf)-1,fin)!=NULL){
  61                         const char *pt = strstr(buf,dev);
  62                         if (pt != NULL && pt[len] == ':'){
  63                                 ret = 1;
  64                                 break;
  65                         }
  66                 }
  67                 fclose (fin);
  68         }
  69         return ret;
  70 }
  71
  72
  73 static int ifconfig_ioctl(
  74         int fd,
  75         const char *ifname,
  76         int cmd,
  77         struct ifreq *ifr)
  78 {
  79         strcpy(ifr->ifr_name, ifname);
  80         return ioctl(fd, cmd,ifr);
  81 }
  82
  83 /*
  84         Fetch the IP number of an interface from the kernel.
  85         Assume the device is already available in the kernel
  86         Return -1 if any error.
  87 */
  88 int ifconfig_getaddr (
  89         const char *ifname,
  90         unsigned long *addr,
  91         unsigned long *mask,
  92         unsigned long *bcast)
  93 {
  94         int ret = -1;
  95         if (chbind_devexist(ifname)){
  96                 int skfd = socket(AF_INET, SOCK_DGRAM, 0);
  97                 *addr = 0;
  98                 *bcast = 0xffffffff;
  99                 if (skfd != -1){
 100                         struct ifreq ifr;
 101                         if (ifconfig_ioctl(skfd,ifname,SIOCGIFADDR, &ifr) >= 0){
 102                                 struct sockaddr_in *sin = (struct sockaddr_in*)&ifr.ifr_addr;
 103                                 *addr = sin->sin_addr.s_addr;
 104                                 ret = 0;
 105                         }
 106                         if (ifconfig_ioctl(skfd,ifname,SIOCGIFNETMASK, &ifr) >= 0){
 107                                 struct sockaddr_in *sin = (struct sockaddr_in*)&ifr.ifr_addr;
 108                                 *mask = sin->sin_addr.s_addr;
 109                                 ret = 0;
 110                         }
 111                         if (ifconfig_ioctl(skfd,ifname,SIOCGIFBRDADDR, &ifr) >= 0){
 112                                 struct sockaddr_in *sin = (struct sockaddr_in*)&ifr.ifr_addr;
 113                                 *bcast = sin->sin_addr.s_addr;
 114                                 ret = 0;
 115                         }
 116                         close (skfd);
 117                 }
 118         }
 119         return ret;
 120 }
 121
 122
 123
 124
 125 int main (int argc, char *argv[])
 126 {
 127         int ret = -1;
 128         int silent = 0;
 129         int i;
 130         struct vc_ip_mask_pair  ips[16];
 131         int nbaddrs = 0;
 132         unsigned long bcast = 0xffffffff;
 133         for (i=1; i<argc; i++){
 134                 const char *arg = argv[i];
 135                 const char *opt = argv[i+1];
 136                 if (strcmp(arg,"--ip")==0){
 137                         unsigned long addr,mask;
 138                         if (nbaddrs == 16){
 139                                 fprintf (stderr,"Too many IP numbers, max 16, ignored\n");
 140
 141                         }else if (ifconfig_getaddr(opt,&addr,&mask,&bcast)==-1){
 142                                 unsigned long mask = 0x00ffffff;
 143                                 const char *pt = strchr(opt,'/');
 144                                 char tmpopt[strlen(opt)+1];
 145                                 struct hostent *h;
 146
 147                                 if (pt != NULL){
 148                                         strcpy (tmpopt,opt);
 149                                         tmpopt[pt-opt] = '\0';
 150                                         opt = tmpopt;
 151                                         pt++;
 152                                         if (strchr(pt,'.')==NULL){
 153                                                 // Ok, we have a network size, not a netmask
 154                                                 int size = atoi(pt);
 155                                                 int i;
 156                                                 mask = 0;
 157                                                 for (i=0; i<size; i++){
 158                                                         mask = mask >> 1;
 159                                                         mask |= 0x80000000;
 160                                                 }
 161                                                 mask = ntohl(mask);
 162                                         }else{
 163                                                 struct hostent *h = gethostbyname (pt);
 164                                                 if (h != NULL){
 165                                                         memcpy (&mask,h->h_addr,sizeof(mask));
 166                                                 }else{
 167                                                         fprintf (stderr,"Invalid netmask: %s\n",pt);
 168                                                         usage();
 169                                                 }
 170                                         }
 171
 172                                 }
 173
 174                                 h = gethostbyname (opt);
 175                                 if (h == NULL){
 176                                         fprintf (stderr,"Invalid IP number or host name: %s\n",opt);
 177                                         usage();
 178                                 }else{
 179                                         memcpy (&addr,h->h_addr,sizeof(addr));
 180                                         ips[nbaddrs].ip   = addr;
 181                                         ips[nbaddrs].mask = mask;
 182                                         ++nbaddrs;
 183                                 }
 184                         }else{
 185                               ips[nbaddrs].ip   = addr;
 186                               ips[nbaddrs].mask = mask;
 187                               ++nbaddrs;
 188                         }
 189                         i++;
 190                 }else if (strcmp(arg,"--bcast")==0){
 191                         unsigned long tmp;
 192                         if (ifconfig_getaddr(opt,&tmp,&tmp,&bcast)==-1){
 193                                 struct hostent *h = gethostbyname (opt);
 194                                 if (h == NULL){
 195                                         fprintf (stderr,"Invalid broadcast number: %s\n",opt);
 196                                         usage();
 197                                 }else{
 198                                         memcpy (&bcast,h->h_addr,sizeof(bcast));
 199                                 }
 200                         }
 201                         i++;
 202                 }else if (strcmp(arg,"--silent")==0){
 203                         silent = 1;
 204                 }else{
 205                         break;
 206                 }
 207         }
 208         if (i == argc){
 209                 usage();
 210         }else if (argv[i][0] == '-'){
 211                 usage();
 212         }else{
 213               if (vc_set_ipv4root(bcast,nbaddrs,ips)==0){
 214                         if (!silent){
 215                                 int i;
 216                                 printf ("ipv4root is now");
 217                                 for (i=0; i<nbaddrs; i++){
 218                                         unsigned long hostaddr = ntohl(ips[i].ip);
 219                                         printf (" %ld.%ld.%ld.%ld"
 220                                                 ,hostaddr>>24
 221                                                 ,(hostaddr>>16)&0xff
 222                                                 ,(hostaddr>>8)&0xff
 223                                                 ,hostaddr &0xff);
 224                                 }
 225                                 printf ("\n");
 226                         }
 227                         execvp (argv[i],argv+i);
 228                         fprintf (stderr,"Can't exec %s (%s)\n",argv[i],strerror(errno));
 229                 }else{
 230                         fprintf (stderr,"Can't set the ipv4 root (%s)\n",strerror(errno));
 231                 }
 232         }
 233         return ret;
 234 }
 235
 236