dns.subproj/getnetnamadr.c

   1 /*
   2  * Copyright (c) 1999 Apple Computer, Inc. All rights reserved.
   3  *
   4  * @APPLE_LICENSE_HEADER_START@
   5  *
   6  * Portions Copyright (c) 1999 Apple Computer, Inc.  All Rights
   7  * Reserved.  This file contains Original Code and/or Modifications of
   8  * Original Code as defined in and that are subject to the Apple Public
   9  * Source License Version 1.1 (the "License").  You may not use this file
  10  * except in compliance with the License.  Please obtain a copy of the
  11  * License at http://www.apple.com/publicsource and read it before using
  12  * this file.
  13  *
  14  * The Original Code and all software distributed under the License are
  15  * distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY KIND, EITHER
  16  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
  17  * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
  18  * FITNESS FOR A PARTICULAR PURPOSE OR NON- INFRINGEMENT.  Please see the
  19  * License for the specific language governing rights and limitations
  20  * under the License.
  21  *
  22  * @APPLE_LICENSE_HEADER_END@
  23  */
  24 /* Copyright (c) 1993 Carlos Leandro and Rui Salgueiro
  25  *      Dep. Matematica Universidade de Coimbra, Portugal, Europe
  26  *
  27  * Permission to use, copy, modify, and distribute this software for any
  28  * purpose with or without fee is hereby granted, provided that the above
  29  * copyright notice and this permission notice appear in all copies.
  30  */
  31 /*
  32  * Copyright (c) 1983, 1993
  33  *      The Regents of the University of California.  All rights reserved.
  34  *
  35  * Redistribution and use in source and binary forms, with or without
  36  * modification, are permitted provided that the following conditions
  37  * are met:
  38  * 1. Redistributions of source code must retain the above copyright
  39  *    notice, this list of conditions and the following disclaimer.
  40  * 2. Redistributions in binary form must reproduce the above copyright
  41  *    notice, this list of conditions and the following disclaimer in the
  42  *    documentation and/or other materials provided with the distribution.
  43  * 3. All advertising materials mentioning features or use of this software
  44  *    must display the following acknowledgement:
  45  *      This product includes software developed by the University of
  46  *      California, Berkeley and its contributors.
  47  * 4. Neither the name of the University nor the names of its contributors
  48  *    may be used to endorse or promote products derived from this software
  49  *    without specific prior written permission.
  50  *
  51  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  52  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  53  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  54  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  55  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  56  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  57  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  58  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  59  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  60  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  61  * SUCH DAMAGE.
  62  */
  63
  64 #if defined(LIBC_SCCS) && !defined(lint)
  65 static char sccsid[] = "@(#)getnetbyaddr.c      8.1 (Berkeley) 6/4/93";
  66 static char sccsid_[] = "from getnetnamadr.c    1.4 (Coimbra) 93/06/03";
  67 static char rcsid[] = "$Id: getnetnamadr.c,v 1.3.44.1 2002/11/19 01:20:51 bbraun Exp $";
  68 #endif /* LIBC_SCCS and not lint */
  69
  70 #include <sys/param.h>
  71 #include <sys/socket.h>
  72 #include <netinet/in.h>
  73 #include <arpa/inet.h>
  74 #include <arpa/nameser.h>
  75
  76 #include <stdio.h>
  77 #include <stdlib.h>
  78 #include <netdb.h>
  79 #include <resolv.h>
  80 #include <ctype.h>
  81 #include <errno.h>
  82 #include <string.h>
  83
  84 extern int h_errno;
  85
  86 #if defined(mips) && defined(SYSTYPE_BSD43)
  87 extern int errno;
  88 #endif
  89
  90 struct netent *_getnetbyaddr __P((long net, int type));
  91 struct netent *_getnetbyname __P((const char *name));
  92
  93 #define BYADDR 0
  94 #define BYNAME 1
  95 #define MAXALIASES      35
  96
  97 #if PACKETSZ > 1024
  98 #define MAXPACKET       PACKETSZ
  99 #else
 100 #define MAXPACKET       1024
 101 #endif
 102
 103 typedef union {
 104         HEADER  hdr;
 105         u_char  buf[MAXPACKET];
 106 } querybuf;
 107
 108 typedef union {
 109         long    al;
 110         char    ac;
 111 } align;
 112
 113 static struct netent *
 114 getnetanswer(answer, anslen, net_i)
 115         querybuf *answer;
 116         int anslen;
 117         int net_i;
 118 {
 119
 120         register HEADER *hp;
 121         register u_char *cp;
 122         register int n;
 123         u_char *eom;
 124         int type, class, buflen, ancount, qdcount, haveanswer, i, nchar;
 125         char aux1[30], aux2[30], *in, *st, *pauxt, *bp, **ap,
 126                 *paux1 = &aux1[0], *paux2 = &aux2[0], flag = 0;
 127         static  struct netent net_entry;
 128         static  char *net_aliases[MAXALIASES], *netbuf = NULL;
 129         static  char ans[MAXDNAME];
 130
 131         if (netbuf == NULL) {
 132                 netbuf = malloc(BUFSIZ+1);
 133                 if (netbuf == NULL)
 134                         return (NULL);
 135         }
 136         buflen = BUFSIZ+1;
 137
 138         /*
 139          * find first satisfactory answer
 140          *
 141          *      answer --> +------------+  ( MESSAGE )
 142          *                 |   Header   |
 143          *                 +------------+
 144          *                 |  Question  | the question for the name server
 145          *                 +------------+
 146          *                 |   Answer   | RRs answering the question
 147          *                 +------------+
 148          *                 | Authority  | RRs pointing toward an authority
 149          *                 | Additional | RRs holding additional information
 150          *                 +------------+
 151          */
 152         eom = answer->buf + anslen;
 153         hp = &answer->hdr;
 154         ancount = ntohs(hp->ancount); /* #/records in the answer section */
 155         qdcount = ntohs(hp->qdcount); /* #/entries in the question section */
 156         bp = netbuf;
 157         cp = answer->buf + HFIXEDSZ;
 158         if (!qdcount) {
 159                 if (hp->aa)
 160                         h_errno = HOST_NOT_FOUND;
 161                 else
 162                         h_errno = TRY_AGAIN;
 163                 return (NULL);
 164         }
 165         while (qdcount-- > 0) {
 166                 n = __dn_skipname(cp, eom);
 167                 if (n < 0 || (cp + n + QFIXEDSZ) > eom) {
 168                         h_errno = NO_RECOVERY;
 169                         return(NULL);
 170                 }
 171                 cp += n + QFIXEDSZ;
 172         }
 173         ap = net_aliases;
 174         *ap = NULL;
 175         net_entry.n_aliases = net_aliases;
 176         haveanswer = 0;
 177         while (--ancount >= 0 && cp < eom) {
 178                 n = dn_expand(answer->buf, eom, cp, bp, buflen);
 179                 if (n < 0)
 180                         break;
 181                 cp += n;
 182                 ans[0] = '\0';
 183                 (void)strcpy(ans, bp);
 184                 GETSHORT(type, cp);
 185                 GETSHORT(class, cp);
 186                 cp += INT32SZ;          /* TTL */
 187                 GETSHORT(n, cp);
 188                 if (class == C_IN && type == T_PTR) {
 189                         n = dn_expand(answer->buf, eom, cp, bp, buflen);
 190                         if (n < 0) {
 191                                 cp += n;
 192                                 return (NULL);
 193                         }
 194                         cp += n;
 195                         if ((ap + 2) < &net_aliases[MAXALIASES]) {
 196                                 *ap++ = bp;
 197                                 bp += strlen(bp) + 1;
 198                                 net_entry.n_addrtype =
 199                                         (class == C_IN) ? AF_INET : AF_UNSPEC;
 200                                 haveanswer++;
 201                         }
 202                 }
 203         }
 204         if (haveanswer) {
 205                 *ap = NULL;
 206                 switch (net_i) {
 207                 case BYADDR:
 208                         net_entry.n_name = *net_entry.n_aliases;
 209                         net_entry.n_net = 0L;
 210                         break;
 211                 case BYNAME:
 212                         ap = net_entry.n_aliases;
 213                 next_alias:
 214                         in = *ap++;
 215                         if (in == NULL) {
 216                                 h_errno = HOST_NOT_FOUND;
 217                                 return (NULL);
 218                         }
 219                         net_entry.n_name = ans;
 220                         aux2[0] = '\0';
 221                         for (i = 0; i < 4; i++) {
 222                                 for (st = in, nchar = 0;
 223                                      isdigit((unsigned char)*st);
 224                                      st++, nchar++)
 225                                         ;
 226
 227                                 if (*st != '.' || nchar == 0 || nchar > 3)
 228                                         goto next_alias;
 229                                 if (i != 0)
 230                                         nchar++;
 231                                 (void)strncpy(paux1, in, nchar);
 232                                 paux1[nchar] = '\0';
 233                                 pauxt = paux2;
 234                                 paux2 = strcat(paux1, paux2);
 235                                 paux1 = pauxt;
 236                                 in = ++st;
 237                         }
 238
 239                         if (strcasecmp(in, "IN-ADDR.ARPA") != 0)
 240                                 goto next_alias;
 241                         net_entry.n_net = inet_network(paux2);
 242                         break;
 243                 }
 244                 net_entry.n_aliases++;
 245                 return (&net_entry);
 246         }
 247         h_errno = TRY_AGAIN;
 248         return (NULL);
 249 }
 250
 251 struct netent *
 252 getnetbyaddr(net, net_type)
 253         register long net;
 254         register int net_type;
 255 {
 256         unsigned int netbr[4];
 257         int nn, anslen;
 258         querybuf buf;
 259         char qbuf[MAXDNAME];
 260         unsigned long net2;
 261         struct netent *net_entry;
 262
 263         if (net_type != AF_INET)
 264 #if defined(__APPLE__)
 265                 return NULL;
 266 #else
 267                 return (_getnetbyaddr(net, net_type));
 268 #endif /* !NeXT */
 269
 270         for (nn = 4, net2 = net; net2; net2 >>= 8)
 271                 netbr[--nn] = net2 & 0xff;
 272         switch (nn) {
 273         case 3:         /* Class A */
 274                 sprintf(qbuf, "0.0.0.%u.in-addr.arpa", netbr[3]);
 275                 break;
 276         case 2:         /* Class B */
 277                 sprintf(qbuf, "0.0.%u.%u.in-addr.arpa", netbr[3], netbr[2]);
 278                 break;
 279         case 1:         /* Class C */
 280                 sprintf(qbuf, "0.%u.%u.%u.in-addr.arpa", netbr[3], netbr[2],
 281                     netbr[1]);
 282                 break;
 283         case 0:         /* Class D - E */
 284                 sprintf(qbuf, "%u.%u.%u.%u.in-addr.arpa", netbr[3], netbr[2],
 285                     netbr[1], netbr[0]);
 286                 break;
 287         }
 288         anslen = res_query(qbuf, C_IN, T_PTR, (u_char *)&buf, sizeof(buf));
 289         if (anslen < 0) {
 290 #ifdef DEBUG
 291                 if (_res.options & RES_DEBUG)
 292                         printf("res_query failed\n");
 293 #endif
 294 #if !defined(__APPLE__)
 295                 if (errno == ECONNREFUSED)
 296                         return (_getnetbyaddr(net, net_type));
 297 #endif /* !NeXT */
 298                 return (NULL);
 299         }
 300         net_entry = getnetanswer(&buf, anslen, BYADDR);
 301         if (net_entry) {
 302                 unsigned u_net = net;   /* maybe net should be unsigned ? */
 303
 304                 /* Strip trailing zeros */
 305                 while ((u_net & 0xff) == 0 && u_net != 0)
 306                         u_net >>= 8;
 307                 net_entry->n_net = u_net;
 308                 return (net_entry);
 309         }
 310 #if defined(__APPLE__)
 311         return NULL;
 312 #else
 313         return (_getnetbyaddr(net, net_type));
 314 #endif /* !NeXT */
 315 }
 316
 317 struct netent *
 318 getnetbyname(net)
 319         register const char *net;
 320 {
 321         int anslen;
 322         querybuf buf;
 323         char qbuf[MAXDNAME];
 324         struct netent *net_entry;
 325
 326         if ((_res.options & RES_INIT) == 0 && res_init() == -1) {
 327                 h_errno = NETDB_INTERNAL;
 328                 return (NULL);
 329         }
 330         strcpy(&qbuf[0], net);
 331         anslen = res_search(qbuf, C_IN, T_PTR, (u_char *)&buf, sizeof(buf));
 332         if (anslen < 0) {
 333 #ifdef DEBUG
 334                 if (_res.options & RES_DEBUG)
 335                         printf("res_query failed\n");
 336 #endif
 337 #if defined(__APPLE__)
 338                 return NULL;
 339 #else
 340                 if (errno == ECONNREFUSED)
 341                         return (_getnetbyname(net));
 342                 return (_getnetbyname(net));
 343 #endif /* !NeXT */
 344         }
 345         net_entry = getnetanswer(&buf, anslen, BYNAME);
 346         if (net_entry)
 347                 return (net_entry);
 348 #if defined(__APPLE__)
 349         return NULL;
 350 #else
 351         return (_getnetbyname(net));
 352 #endif /* !NeXT */
 353 }