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 2002/06/12 17:40:29 epeyton 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], ans[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
 130         if (netbuf == NULL) {
 131                 netbuf = malloc(BUFSIZ+1);
 132                 if (netbuf == NULL)
 133                         return (NULL);
 134         }
 135         buflen = BUFSIZ+1;
 136
 137         /*
 138          * find first satisfactory answer
 139          *
 140          *      answer --> +------------+  ( MESSAGE )
 141          *                 |   Header   |
 142          *                 +------------+
 143          *                 |  Question  | the question for the name server
 144          *                 +------------+
 145          *                 |   Answer   | RRs answering the question
 146          *                 +------------+
 147          *                 | Authority  | RRs pointing toward an authority
 148          *                 | Additional | RRs holding additional information
 149          *                 +------------+
 150          */
 151         eom = answer->buf + anslen;
 152         hp = &answer->hdr;
 153         ancount = ntohs(hp->ancount); /* #/records in the answer section */
 154         qdcount = ntohs(hp->qdcount); /* #/entries in the question section */
 155         bp = netbuf;
 156         cp = answer->buf + HFIXEDSZ;
 157         if (!qdcount) {
 158                 if (hp->aa)
 159                         h_errno = HOST_NOT_FOUND;
 160                 else
 161                         h_errno = TRY_AGAIN;
 162                 return (NULL);
 163         }
 164         while (qdcount-- > 0)
 165                 cp += __dn_skipname(cp, eom) + QFIXEDSZ;
 166         ap = net_aliases;
 167         *ap = NULL;
 168         net_entry.n_aliases = net_aliases;
 169         haveanswer = 0;
 170         while (--ancount >= 0 && cp < eom) {
 171                 n = dn_expand(answer->buf, eom, cp, bp, buflen);
 172                 if (n < 0)
 173                         break;
 174                 cp += n;
 175                 ans[0] = '\0';
 176                 (void)strcpy(&ans[0], bp);
 177                 GETSHORT(type, cp);
 178                 GETSHORT(class, cp);
 179                 cp += INT32SZ;          /* TTL */
 180                 GETSHORT(n, cp);
 181                 if (class == C_IN && type == T_PTR) {
 182                         n = dn_expand(answer->buf, eom, cp, bp, buflen);
 183                         if (n < 0) {
 184                                 cp += n;
 185                                 return (NULL);
 186                         }
 187                         cp += n;
 188                         *ap++ = bp;
 189                         bp += strlen(bp) + 1;
 190                         net_entry.n_addrtype =
 191                                 (class == C_IN) ? AF_INET : AF_UNSPEC;
 192                         haveanswer++;
 193                 }
 194         }
 195         if (haveanswer) {
 196                 *ap = NULL;
 197                 switch (net_i) {
 198                 case BYADDR:
 199                         net_entry.n_name = *net_entry.n_aliases;
 200                         net_entry.n_net = 0L;
 201                         break;
 202                 case BYNAME:
 203                         in = *net_entry.n_aliases;
 204                         net_entry.n_name = &ans[0];
 205                         aux2[0] = '\0';
 206                         for (i = 0; i < 4; i++) {
 207                                 for (st = in, nchar = 0;
 208                                      *st != '.';
 209                                      st++, nchar++)
 210                                         ;
 211                                 if (nchar != 1 || *in != '0' || flag) {
 212                                         flag = 1;
 213                                         (void)strncpy(paux1,
 214                                                       (i==0) ? in : in-1,
 215                                                       (i==0) ?nchar : nchar+1);
 216                                         paux1[(i==0) ? nchar : nchar+1] = '\0';
 217                                         pauxt = paux2;
 218                                         paux2 = strcat(paux1, paux2);
 219                                         paux1 = pauxt;
 220                                 }
 221                                 in = ++st;
 222                         }
 223                         net_entry.n_net = inet_network(paux2);
 224                         break;
 225                 }
 226                 net_entry.n_aliases++;
 227                 return (&net_entry);
 228         }
 229         h_errno = TRY_AGAIN;
 230         return (NULL);
 231 }
 232
 233 struct netent *
 234 getnetbyaddr(net, net_type)
 235         register long net;
 236         register int net_type;
 237 {
 238         unsigned int netbr[4];
 239         int nn, anslen;
 240         querybuf buf;
 241         char qbuf[MAXDNAME];
 242         unsigned long net2;
 243         struct netent *net_entry;
 244
 245         if (net_type != AF_INET)
 246 #if defined(__APPLE__)
 247                 return NULL;
 248 #else
 249                 return (_getnetbyaddr(net, net_type));
 250 #endif /* !NeXT */
 251
 252         for (nn = 4, net2 = net; net2; net2 >>= 8)
 253                 netbr[--nn] = net2 & 0xff;
 254         switch (nn) {
 255         case 3:         /* Class A */
 256                 sprintf(qbuf, "0.0.0.%u.in-addr.arpa", netbr[3]);
 257                 break;
 258         case 2:         /* Class B */
 259                 sprintf(qbuf, "0.0.%u.%u.in-addr.arpa", netbr[3], netbr[2]);
 260                 break;
 261         case 1:         /* Class C */
 262                 sprintf(qbuf, "0.%u.%u.%u.in-addr.arpa", netbr[3], netbr[2],
 263                     netbr[1]);
 264                 break;
 265         case 0:         /* Class D - E */
 266                 sprintf(qbuf, "%u.%u.%u.%u.in-addr.arpa", netbr[3], netbr[2],
 267                     netbr[1], netbr[0]);
 268                 break;
 269         }
 270         anslen = res_query(qbuf, C_IN, T_PTR, (u_char *)&buf, sizeof(buf));
 271         if (anslen < 0) {
 272 #ifdef DEBUG
 273                 if (_res.options & RES_DEBUG)
 274                         printf("res_query failed\n");
 275 #endif
 276 #if !defined(__APPLE__)
 277                 if (errno == ECONNREFUSED)
 278                         return (_getnetbyaddr(net, net_type));
 279 #endif /* !NeXT */
 280                 return (NULL);
 281         }
 282         net_entry = getnetanswer(&buf, anslen, BYADDR);
 283         if (net_entry) {
 284                 unsigned u_net = net;   /* maybe net should be unsigned ? */
 285
 286                 /* Strip trailing zeros */
 287                 while ((u_net & 0xff) == 0 && u_net != 0)
 288                         u_net >>= 8;
 289                 net_entry->n_net = u_net;
 290                 return (net_entry);
 291         }
 292 #if defined(__APPLE__)
 293         return NULL;
 294 #else
 295         return (_getnetbyaddr(net, net_type));
 296 #endif /* !NeXT */
 297 }
 298
 299 struct netent *
 300 getnetbyname(net)
 301         register const char *net;
 302 {
 303         int anslen;
 304         querybuf buf;
 305         char qbuf[MAXDNAME];
 306         struct netent *net_entry;
 307
 308         if ((_res.options & RES_INIT) == 0 && res_init() == -1) {
 309                 h_errno = NETDB_INTERNAL;
 310                 return (NULL);
 311         }
 312         strcpy(&qbuf[0], net);
 313         anslen = res_search(qbuf, C_IN, T_PTR, (u_char *)&buf, sizeof(buf));
 314         if (anslen < 0) {
 315 #ifdef DEBUG
 316                 if (_res.options & RES_DEBUG)
 317                         printf("res_query failed\n");
 318 #endif
 319 #if defined(__APPLE__)
 320                 return NULL;
 321 #else
 322                 if (errno == ECONNREFUSED)
 323                         return (_getnetbyname(net));
 324                 return (_getnetbyname(net));
 325 #endif /* !NeXT */
 326         }
 327         net_entry = getnetanswer(&buf, anslen, BYNAME);
 328         if (net_entry)
 329                 return (net_entry);
 330 #if defined(__APPLE__)
 331         return NULL;
 332 #else
 333         return (_getnetbyname(net));
 334 #endif /* !NeXT */
 335 }