source/lib/interface.c

   1 /*
   2    Unix SMB/Netbios implementation.
   3    Version 1.9.
   4    multiple interface handling
   5    Copyright (C) Andrew Tridgell 1992-1995
   6
   7    This program is free software; you can redistribute it and/or modify
   8    it under the terms of the GNU General Public License as published by
   9    the Free Software Foundation; either version 2 of the License, or
  10    (at your option) any later version.
  11
  12    This program is distributed in the hope that it will be useful,
  13    but WITHOUT ANY WARRANTY; without even the implied warranty of
  14    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15    GNU General Public License for more details.
  16
  17    You should have received a copy of the GNU General Public License
  18    along with this program; if not, write to the Free Software
  19    Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  20 */
  21
  22 #include "includes.h"
  23
  24 extern int DEBUGLEVEL;
  25
  26 struct in_addr ipzero;
  27 struct in_addr wins_ip;
  28 static struct in_addr default_ip;
  29 static struct in_addr default_bcast;
  30 static struct in_addr default_nmask;
  31 static BOOL got_ip=False;
  32 static BOOL got_bcast=False;
  33 static BOOL got_nmask=False;
  34
  35 struct interface *local_interfaces  = NULL;
  36
  37 struct interface *last_iface;
  38
  39 /****************************************************************************
  40 calculate the default netmask for an address
  41 ****************************************************************************/
  42 static void default_netmask(struct in_addr *inm, struct in_addr *iad)
  43 {
  44   uint32 ad = ntohl(iad->s_addr);
  45   uint32 nm;
  46   /*
  47   ** Guess a netmask based on the class of the IP address given.
  48   */
  49   if ( (ad & 0x80000000) == 0 ) {
  50     /* class A address */
  51     nm = 0xFF000000;
  52   } else if ( (ad & 0xC0000000) == 0x80000000 ) {
  53     /* class B address */
  54     nm = 0xFFFF0000;
  55   } else if ( (ad & 0xE0000000) == 0xC0000000 ) {
  56     /* class C address */
  57     nm = 0xFFFFFF00;
  58   }  else {
  59     /* class D or E; netmask doesn't make much sense - guess 4 bits */
  60     nm =  0xFFFFFFF0;
  61   }
  62   inm->s_addr = htonl(nm);
  63 }
  64
  65
  66 /****************************************************************************
  67   get the broadcast address for our address
  68 (troyer@saifr00.ateng.az.honeywell.com)
  69 ****************************************************************************/
  70 static void get_broadcast(struct in_addr *if_ipaddr,
  71                           struct in_addr *if_bcast,
  72                           struct in_addr *if_nmask)
  73 {
  74   BOOL found = False;
  75 #ifndef NO_GET_BROADCAST
  76   int sock = -1;               /* AF_INET raw socket desc */
  77   char buff[1024];
  78   struct ifreq *ifr=NULL;
  79   int i;
  80
  81 #if defined(EVEREST)
  82   int n_interfaces;
  83   struct ifconf ifc;
  84   struct ifreq  *ifreqs;
  85 #elif defined(USE_IFREQ)
  86   struct ifreq ifreq;
  87   struct strioctl strioctl;
  88   struct ifconf *ifc;
  89 #else
  90   struct ifconf ifc;
  91 #endif
  92 #endif
  93
  94   /* get a default netmask and broadcast */
  95   default_netmask(if_nmask, if_ipaddr);
  96
  97 #ifndef NO_GET_BROADCAST
  98   /* Create a socket to the INET kernel. */
  99 #if USE_SOCKRAW
 100   if ((sock = socket(AF_INET, SOCK_RAW, PF_INET )) < 0)
 101 #else
 102     if ((sock = socket(AF_INET, SOCK_DGRAM, 0 )) < 0)
 103 #endif
 104       {
 105         DEBUG(0,( "Unable to open socket to get broadcast address\n"));
 106         return;
 107       }
 108
 109   /* Get a list of the configured interfaces */
 110 #ifdef EVEREST
 111   /* This is part of SCO Openserver 5: The ioctls are no longer part
 112      if the lower level STREAMS interface glue. They are now real
 113      ioctl calls */
 114
 115   if (ioctl(sock, SIOCGIFANUM, &n_interfaces) < 0) {
 116     DEBUG(0,( "SIOCGIFANUM: %s\n", strerror(errno)));
 117   } else {
 118     DEBUG(0,( "number of interfaces returned is: %d\n", n_interfaces));
 119
 120     ifc.ifc_len = sizeof(struct ifreq) * n_interfaces;
 121     ifc.ifc_buf = (caddr_t) alloca(ifc.ifc_len);
 122
 123     if (ioctl(sock, SIOCGIFCONF, &ifc) < 0)
 124       DEBUG(0, ( "SIOCGIFCONF: %s\n", strerror(errno)));
 125     else {
 126       ifr = ifc.ifc_req;
 127
 128       for (i = 0; i < n_interfaces; ++i) {
 129         if (if_ipaddr->s_addr ==
 130             ((struct sockaddr_in *) &ifr[i].ifr_addr)->sin_addr.s_addr) {
 131           found = True;
 132           break;
 133         }
 134       }
 135     }
 136   }
 137 #elif defined(USE_IFREQ)
 138   ifc = (struct ifconf *)buff;
 139   ifc->ifc_len = BUFSIZ - sizeof(struct ifconf);
 140   strioctl.ic_cmd = SIOCGIFCONF;
 141   strioctl.ic_dp  = (char *)ifc;
 142   strioctl.ic_len = sizeof(buff);
 143   if (ioctl(sock, I_STR, &strioctl) < 0) {
 144     DEBUG(0,( "I_STR/SIOCGIFCONF: %s\n", strerror(errno)));
 145   } else {
 146     ifr = (struct ifreq *)ifc->ifc_req;
 147
 148     /* Loop through interfaces, looking for given IP address */
 149     for (i = ifc->ifc_len / sizeof(struct ifreq); --i >= 0; ifr++) {
 150       if (if_ipaddr->s_addr ==
 151           (*(struct sockaddr_in *) &ifr->ifr_addr).sin_addr.s_addr) {
 152         found = True;
 153         break;
 154       }
 155     }
 156   }
 157 #elif defined(__FreeBSD__) || defined(NETBSD) || defined(AMIGA)
 158   ifc.ifc_len = sizeof(buff);
 159   ifc.ifc_buf = buff;
 160   if (ioctl(sock, SIOCGIFCONF, &ifc) < 0) {
 161     DEBUG(0,("SIOCGIFCONF: %s\n", strerror(errno)));
 162   } else {
 163     ifr = ifc.ifc_req;
 164     /* Loop through interfaces, looking for given IP address */
 165     i = ifc.ifc_len;
 166     while (i > 0) {
 167       if (if_ipaddr->s_addr ==
 168           (*(struct sockaddr_in *) &ifr->ifr_addr).sin_addr.s_addr) {
 169         found = True;
 170         break;
 171       }
 172       i -= ifr->ifr_addr.sa_len + IFNAMSIZ;
 173       ifr = (struct ifreq*) ((char*) ifr + ifr->ifr_addr.sa_len + IFNAMSIZ);
 174     }
 175   }
 176 #else
 177   ifc.ifc_len = sizeof(buff);
 178   ifc.ifc_buf = buff;
 179   if (ioctl(sock, SIOCGIFCONF, &ifc) < 0) {
 180     DEBUG(0,("SIOCGIFCONF: %s\n", strerror(errno)));
 181   } else {
 182     ifr = ifc.ifc_req;
 183
 184     /* Loop through interfaces, looking for given IP address */
 185     for (i = ifc.ifc_len / sizeof(struct ifreq); --i >= 0; ifr++) {
 186 #ifdef BSDI
 187       if (ioctl(sock, SIOCGIFADDR, ifr) < 0) break;
 188 #endif
 189       if (if_ipaddr->s_addr ==
 190           (*(struct sockaddr_in *) &ifr->ifr_addr).sin_addr.s_addr) {
 191         found = True;
 192         break;
 193       }
 194     }
 195   }
 196 #endif
 197
 198   if (!found) {
 199     DEBUG(0,("No interface found for address %s\n", inet_ntoa(*if_ipaddr)));
 200   } else {
 201     /* Get the netmask address from the kernel */
 202 #ifdef USE_IFREQ
 203     ifreq = *ifr;
 204
 205     strioctl.ic_cmd = SIOCGIFNETMASK;
 206     strioctl.ic_dp  = (char *)&ifreq;
 207     strioctl.ic_len = sizeof(struct ifreq);
 208     if (ioctl(sock, I_STR, &strioctl) < 0)
 209       DEBUG(0,("Failed I_STR/SIOCGIFNETMASK: %s\n", strerror(errno)));
 210     else
 211       *if_nmask = ((struct sockaddr_in *)&ifreq.ifr_addr)->sin_addr;
 212 #else
 213     if (ioctl(sock, SIOCGIFNETMASK, ifr) < 0)
 214       DEBUG(0,("SIOCGIFNETMASK failed\n"));
 215     else
 216       *if_nmask = ((struct sockaddr_in *)&ifr->ifr_addr)->sin_addr;
 217 #endif
 218
 219     DEBUG(4,("Netmask for %s = %s\n", ifr->ifr_name,
 220              inet_ntoa(*if_nmask)));
 221   }
 222
 223   /* Close up shop */
 224   (void) close(sock);
 225
 226 #endif
 227
 228   /* sanity check on the netmask */
 229   {
 230     uint32 nm = ntohl(if_nmask->s_addr);
 231     if ((nm >> 24) != 0xFF) {
 232       DEBUG(0,("Impossible netmask %s - using defaults\n",inet_ntoa(*if_nmask)));
 233       default_netmask(if_nmask, if_ipaddr);
 234     }
 235   }
 236
 237   /* derive the broadcast assuming a 1's broadcast, as this is what
 238      all MS operating systems do, we have to comply even if the unix
 239      box is setup differently */
 240   {
 241     uint32 ad = ntohl(if_ipaddr->s_addr);
 242     uint32 nm = ntohl(if_nmask->s_addr);
 243     uint32 bc = (ad & nm) | (0xffffffff & ~nm);
 244     if_bcast->s_addr = htonl(bc);
 245   }
 246
 247   DEBUG(4,("Derived broadcast address %s\n", inet_ntoa(*if_bcast)));
 248 }  /* get_broadcast */
 249
 250
 251
 252 /****************************************************************************
 253 load a list of network interfaces
 254 ****************************************************************************/
 255 static void interpret_interfaces(char *s, struct interface **interfaces,
 256                 char *description)
 257 {
 258   char *ptr = s;
 259   fstring token;
 260   struct interface *iface;
 261   struct in_addr ip;
 262
 263   ipzero = *interpret_addr2("0.0.0.0");
 264   wins_ip = *interpret_addr2("255.255.255.255");
 265
 266   while (next_token(&ptr,token,NULL)) {
 267     /* parse it into an IP address/netmasklength pair */
 268     char *p = strchr(token,'/');
 269     if (p) *p = 0;
 270
 271     ip = *interpret_addr2(token);
 272
 273     /* maybe we already have it listed */
 274     {
 275       struct interface *i;
 276       for (i=(*interfaces);i;i=i->next)
 277         if (ip_equal(ip,i->ip)) break;
 278       if (i) continue;
 279     }
 280
 281     iface = (struct interface *)malloc(sizeof(*iface));
 282     if (!iface) return;
 283
 284     iface->ip = ip;
 285
 286     if (p) {
 287       if (strlen(p+1)>2)
 288         iface->nmask = *interpret_addr2(p+1);
 289       else
 290         iface->nmask.s_addr = htonl(~((1<<(32-atoi(p+1)))-1));
 291     } else {
 292       default_netmask(&iface->nmask,&iface->ip);
 293     }
 294     iface->bcast.s_addr = iface->ip.s_addr | ~iface->nmask.s_addr;
 295     iface->next = NULL;
 296
 297     if (!(*interfaces)) {
 298       (*interfaces) = iface;
 299     } else {
 300       last_iface->next = iface;
 301     }
 302     last_iface = iface;
 303     DEBUG(1,("Added %s ip=%s ",description,inet_ntoa(iface->ip)));
 304     DEBUG(1,("bcast=%s ",inet_ntoa(iface->bcast)));
 305     DEBUG(1,("nmask=%s\n",inet_ntoa(iface->nmask)));
 306   }
 307
 308   if (*interfaces) return;
 309
 310   /* setup a default interface */
 311   iface = (struct interface *)malloc(sizeof(*iface));
 312   if (!iface) return;
 313
 314   iface->next = NULL;
 315
 316   if (got_ip) {
 317     iface->ip = default_ip;
 318   } else {
 319     get_myname(NULL,&iface->ip);
 320   }
 321
 322   if (got_bcast) {
 323     iface->bcast = default_bcast;
 324   } else {
 325     get_broadcast(&iface->ip,&iface->bcast,&iface->nmask);
 326   }
 327
 328   if (got_nmask) {
 329     iface->nmask = default_nmask;
 330     iface->bcast.s_addr = iface->ip.s_addr | ~iface->nmask.s_addr;
 331   }
 332
 333   if (iface->bcast.s_addr != (iface->ip.s_addr | ~iface->nmask.s_addr)) {
 334     DEBUG(2,("Warning: inconsistant interface %s\n",inet_ntoa(iface->ip)));
 335   }
 336
 337   iface->next = NULL;
 338   (*interfaces) = last_iface = iface;
 339
 340   DEBUG(1,("Added interface ip=%s ",inet_ntoa(iface->ip)));
 341   DEBUG(1,("bcast=%s ",inet_ntoa(iface->bcast)));
 342   DEBUG(1,("nmask=%s\n",inet_ntoa(iface->nmask)));
 343 }
 344
 345
 346 /****************************************************************************
 347 load the remote and local interfaces
 348 ****************************************************************************/
 349 void load_interfaces(void)
 350 {
 351   /* add the machine's interfaces to local interface structure*/
 352   interpret_interfaces(lp_interfaces(), &local_interfaces,"interface");
 353 }
 354
 355
 356 /****************************************************************************
 357   override the defaults
 358   **************************************************************************/
 359 void iface_set_default(char *ip,char *bcast,char *nmask)
 360 {
 361   if (ip) {
 362     got_ip = True;
 363     default_ip = *interpret_addr2(ip);
 364   }
 365
 366   if (bcast) {
 367     got_bcast = True;
 368     default_bcast = *interpret_addr2(bcast);
 369   }
 370
 371   if (nmask) {
 372     got_nmask = True;
 373     default_nmask = *interpret_addr2(nmask);
 374   }
 375 }
 376
 377
 378 /****************************************************************************
 379   check if an IP is one of mine
 380   **************************************************************************/
 381 BOOL ismyip(struct in_addr ip)
 382 {
 383   struct interface *i;
 384   for (i=local_interfaces;i;i=i->next)
 385     if (ip_equal(i->ip,ip)) return True;
 386   return False;
 387 }
 388
 389 /****************************************************************************
 390   check if a bcast is one of mine
 391   **************************************************************************/
 392 BOOL ismybcast(struct in_addr bcast)
 393 {
 394   struct interface *i;
 395   for (i=local_interfaces;i;i=i->next)
 396     if (ip_equal(i->bcast,bcast)) return True;
 397   return False;
 398 }
 399
 400 /****************************************************************************
 401   how many interfaces do we have
 402   **************************************************************************/
 403 int iface_count(void)
 404 {
 405   int ret = 0;
 406   struct interface *i;
 407
 408   for (i=local_interfaces;i;i=i->next)
 409     ret++;
 410   return ret;
 411 }
 412
 413 /****************************************************************************
 414   return IP of the Nth interface
 415   **************************************************************************/
 416 struct in_addr *iface_n_ip(int n)
 417 {
 418   struct interface *i;
 419
 420   for (i=local_interfaces;i && n;i=i->next)
 421     n--;
 422
 423   if (i) return &i->ip;
 424   return NULL;
 425 }
 426
 427 static struct interface *iface_find(struct in_addr ip)
 428 {
 429   struct interface *i;
 430   if (zero_ip(ip)) return local_interfaces;
 431
 432   for (i=local_interfaces;i;i=i->next)
 433     if (same_net(i->ip,ip,i->nmask)) return i;
 434
 435   return local_interfaces;
 436 }
 437
 438 /* these 3 functions return the ip/bcast/nmask for the interface
 439    most appropriate for the given ip address */
 440
 441 struct in_addr *iface_bcast(struct in_addr ip)
 442 {
 443   return(&iface_find(ip)->bcast);
 444 }
 445
 446 struct in_addr *iface_nmask(struct in_addr ip)
 447 {
 448   return(&iface_find(ip)->nmask);
 449 }
 450
 451 struct in_addr *iface_ip(struct in_addr ip)
 452 {
 453   return(&iface_find(ip)->ip);
 454 }
 455
 456
 457