dns.subproj/getnetnamadr.c

   1 /*
   2  * Copyright (c) 1999 Apple Computer, Inc. All rights reserved.
   3  *
   4  * @APPLE_LICENSE_HEADER_START@
   5  *
   6  * Copyright (c) 1999-2003 Apple Computer, Inc.  All Rights Reserved.
   7  *
   8  * This file contains Original Code and/or Modifications of Original Code
   9  * as defined in and that are subject to the Apple Public Source License
  10  * Version 2.0 (the 'License'). You may not use this file except in
  11  * compliance with the License. Please obtain a copy of the License at
  12  * http://www.opensource.apple.com/apsl/ and read it before using this
  13  * file.
  14  *
  15  * The Original Code and all software distributed under the License are
  16  * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
  17  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
  18  * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
  19  * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
  20  * Please see the License for the specific language governing rights and
  21  * limitations under the License.
  22  *
  23  * @APPLE_LICENSE_HEADER_END@
  24  */
  25 /* Copyright (c) 1993 Carlos Leandro and Rui Salgueiro
  26  *      Dep. Matematica Universidade de Coimbra, Portugal, Europe
  27  *
  28  * Permission to use, copy, modify, and distribute this software for any
  29  * purpose with or without fee is hereby granted, provided that the above
  30  * copyright notice and this permission notice appear in all copies.
  31  */
  32 /*
  33  * Copyright (c) 1983, 1993
  34  *      The Regents of the University of California.  All rights reserved.
  35  *
  36  * Redistribution and use in source and binary forms, with or without
  37  * modification, are permitted provided that the following conditions
  38  * are met:
  39  * 1. Redistributions of source code must retain the above copyright
  40  *    notice, this list of conditions and the following disclaimer.
  41  * 2. Redistributions in binary form must reproduce the above copyright
  42  *    notice, this list of conditions and the following disclaimer in the
  43  *    documentation and/or other materials provided with the distribution.
  44  * 3. All advertising materials mentioning features or use of this software
  45  *    must display the following acknowledgement:
  46  *      This product includes software developed by the University of
  47  *      California, Berkeley and its contributors.
  48  * 4. Neither the name of the University nor the names of its contributors
  49  *    may be used to endorse or promote products derived from this software
  50  *    without specific prior written permission.
  51  *
  52  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  53  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  54  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  55  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  56  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  57  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  58  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  59  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  60  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  61  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  62  * SUCH DAMAGE.
  63  */
  64
  65 #if defined(LIBC_SCCS) && !defined(lint)
  66 static char sccsid[] = "@(#)getnetbyaddr.c      8.1 (Berkeley) 6/4/93";
  67 static char sccsid_[] = "from getnetnamadr.c    1.4 (Coimbra) 93/06/03";
  68 static char rcsid[] = "$Id: getnetnamadr.c,v 1.4 2003/02/18 17:29:23 majka Exp $";
  69 #endif /* LIBC_SCCS and not lint */
  70
  71 #include <sys/param.h>
  72 #include <sys/socket.h>
  73 #include <netinet/in.h>
  74 #include <arpa/inet.h>
  75 #include <arpa/nameser8_compat.h>
  76
  77 #include <stdio.h>
  78 #include <stdlib.h>
  79 #include <netdb.h>
  80 #include <resolv8_compat.h>
  81 #include <ctype.h>
  82 #include <errno.h>
  83 #include <string.h>
  84
  85 extern int h_errno;
  86
  87 #if defined(mips) && defined(SYSTYPE_BSD43)
  88 extern int errno;
  89 #endif
  90
  91 struct netent *_getnetbyaddr __P((long net, int type));
  92 struct netent *_getnetbyname __P((const char *name));
  93
  94 #define BYADDR 0
  95 #define BYNAME 1
  96 #define MAXALIASES      35
  97
  98 #if PACKETSZ > 1024
  99 #define MAXPACKET       PACKETSZ
 100 #else
 101 #define MAXPACKET       1024
 102 #endif
 103
 104 typedef union {
 105         HEADER  hdr;
 106         u_char  buf[MAXPACKET];
 107 } querybuf;
 108
 109 typedef union {
 110         long    al;
 111         char    ac;
 112 } align;
 113
 114 static struct netent *
 115 getnetanswer(answer, anslen, net_i)
 116         querybuf *answer;
 117         int anslen;
 118         int net_i;
 119 {
 120
 121         register HEADER *hp;
 122         register u_char *cp;
 123         register int n;
 124         u_char *eom;
 125         int type, class, buflen, ancount, qdcount, haveanswer, i, nchar;
 126         char aux1[30], aux2[30], ans[30], *in, *st, *pauxt, *bp, **ap,
 127                 *paux1 = &aux1[0], *paux2 = &aux2[0], flag = 0;
 128 static  struct netent net_entry;
 129 static  char *net_aliases[MAXALIASES], *netbuf = NULL;
 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                 cp += __dn_skipname(cp, eom) + QFIXEDSZ;
 167         ap = net_aliases;
 168         *ap = NULL;
 169         net_entry.n_aliases = net_aliases;
 170         haveanswer = 0;
 171         while (--ancount >= 0 && cp < eom) {
 172                 n = dn_expand(answer->buf, eom, cp, bp, buflen);
 173                 if (n < 0)
 174                         break;
 175                 cp += n;
 176                 ans[0] = '\0';
 177                 (void)strcpy(&ans[0], bp);
 178                 GETSHORT(type, cp);
 179                 GETSHORT(class, cp);
 180                 cp += INT32SZ;          /* TTL */
 181                 GETSHORT(n, cp);
 182                 if (class == C_IN && type == T_PTR) {
 183                         n = dn_expand(answer->buf, eom, cp, bp, buflen);
 184                         if (n < 0) {
 185                                 cp += n;
 186                                 return (NULL);
 187                         }
 188                         cp += n;
 189                         *ap++ = bp;
 190                         bp += strlen(bp) + 1;
 191                         net_entry.n_addrtype =
 192                                 (class == C_IN) ? AF_INET : AF_UNSPEC;
 193                         haveanswer++;
 194                 }
 195         }
 196         if (haveanswer) {
 197                 *ap = NULL;
 198                 switch (net_i) {
 199                 case BYADDR:
 200                         net_entry.n_name = *net_entry.n_aliases;
 201                         net_entry.n_net = 0L;
 202                         break;
 203                 case BYNAME:
 204                         in = *net_entry.n_aliases;
 205                         net_entry.n_name = &ans[0];
 206                         aux2[0] = '\0';
 207                         for (i = 0; i < 4; i++) {
 208                                 for (st = in, nchar = 0;
 209                                      *st != '.';
 210                                      st++, nchar++)
 211                                         ;
 212                                 if (nchar != 1 || *in != '0' || flag) {
 213                                         flag = 1;
 214                                         (void)strncpy(paux1,
 215                                                       (i==0) ? in : in-1,
 216                                                       (i==0) ?nchar : nchar+1);
 217                                         paux1[(i==0) ? nchar : nchar+1] = '\0';
 218                                         pauxt = paux2;
 219                                         paux2 = strcat(paux1, paux2);
 220                                         paux1 = pauxt;
 221                                 }
 222                                 in = ++st;
 223                         }
 224                         net_entry.n_net = inet_network(paux2);
 225                         break;
 226                 }
 227                 net_entry.n_aliases++;
 228                 return (&net_entry);
 229         }
 230         h_errno = TRY_AGAIN;
 231         return (NULL);
 232 }
 233
 234 struct netent *
 235 getnetbyaddr(net, net_type)
 236         register long net;
 237         register int net_type;
 238 {
 239         unsigned int netbr[4];
 240         int nn, anslen;
 241         querybuf buf;
 242         char qbuf[MAXDNAME];
 243         unsigned long net2;
 244         struct netent *net_entry;
 245
 246         if (net_type != AF_INET)
 247 #if defined(__APPLE__)
 248                 return NULL;
 249 #else
 250                 return (_getnetbyaddr(net, net_type));
 251 #endif /* !NeXT */
 252
 253         for (nn = 4, net2 = net; net2; net2 >>= 8)
 254                 netbr[--nn] = net2 & 0xff;
 255         switch (nn) {
 256         case 3:         /* Class A */
 257                 sprintf(qbuf, "0.0.0.%u.in-addr.arpa", netbr[3]);
 258                 break;
 259         case 2:         /* Class B */
 260                 sprintf(qbuf, "0.0.%u.%u.in-addr.arpa", netbr[3], netbr[2]);
 261                 break;
 262         case 1:         /* Class C */
 263                 sprintf(qbuf, "0.%u.%u.%u.in-addr.arpa", netbr[3], netbr[2],
 264                     netbr[1]);
 265                 break;
 266         case 0:         /* Class D - E */
 267                 sprintf(qbuf, "%u.%u.%u.%u.in-addr.arpa", netbr[3], netbr[2],
 268                     netbr[1], netbr[0]);
 269                 break;
 270         }
 271         anslen = res_query(qbuf, C_IN, T_PTR, (u_char *)&buf, sizeof(buf));
 272         if (anslen < 0) {
 273 #ifdef DEBUG
 274                 if (_res.options & RES_DEBUG)
 275                         printf("res_query failed\n");
 276 #endif
 277 #if !defined(__APPLE__)
 278                 if (errno == ECONNREFUSED)
 279                         return (_getnetbyaddr(net, net_type));
 280 #endif /* !NeXT */
 281                 return (NULL);
 282         }
 283         net_entry = getnetanswer(&buf, anslen, BYADDR);
 284         if (net_entry) {
 285                 unsigned u_net = net;   /* maybe net should be unsigned ? */
 286
 287                 /* Strip trailing zeros */
 288                 while ((u_net & 0xff) == 0 && u_net != 0)
 289                         u_net >>= 8;
 290                 net_entry->n_net = u_net;
 291                 return (net_entry);
 292         }
 293 #if defined(__APPLE__)
 294         return NULL;
 295 #else
 296         return (_getnetbyaddr(net, net_type));
 297 #endif /* !NeXT */
 298 }
 299
 300 struct netent *
 301 getnetbyname(net)
 302         register const char *net;
 303 {
 304         int anslen;
 305         querybuf buf;
 306         char qbuf[MAXDNAME];
 307         struct netent *net_entry;
 308
 309         if ((_res.options & RES_INIT) == 0 && res_init() == -1) {
 310                 h_errno = NETDB_INTERNAL;
 311                 return (NULL);
 312         }
 313         strcpy(&qbuf[0], net);
 314         anslen = res_search(qbuf, C_IN, T_PTR, (u_char *)&buf, sizeof(buf));
 315         if (anslen < 0) {
 316 #ifdef DEBUG
 317                 if (_res.options & RES_DEBUG)
 318                         printf("res_query failed\n");
 319 #endif
 320 #if defined(__APPLE__)
 321                 return NULL;
 322 #else
 323                 if (errno == ECONNREFUSED)
 324                         return (_getnetbyname(net));
 325                 return (_getnetbyname(net));
 326 #endif /* !NeXT */
 327         }
 328         net_entry = getnetanswer(&buf, anslen, BYNAME);
 329         if (net_entry)
 330                 return (net_entry);
 331 #if defined(__APPLE__)
 332         return NULL;
 333 #else
 334         return (_getnetbyname(net));
 335 #endif /* !NeXT */
 336 }