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 1.2 1999/10/14 21:56:44 wsanchez 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 <netdb.h>
  78 #include <resolv.h>
  79 #include <ctype.h>
  80 #include <errno.h>
  81 #include <string.h>
  82
  83 extern int h_errno;
  84
  85 #if defined(mips) && defined(SYSTYPE_BSD43)
  86 extern int errno;
  87 #endif
  88
  89 struct netent *_getnetbyaddr __P((long net, int type));
  90 struct netent *_getnetbyname __P((const char *name));
  91
  92 #define BYADDR 0
  93 #define BYNAME 1
  94 #define MAXALIASES      35
  95
  96 #if PACKETSZ > 1024
  97 #define MAXPACKET       PACKETSZ
  98 #else
  99 #define MAXPACKET       1024
 100 #endif
 101
 102 typedef union {
 103         HEADER  hdr;
 104         u_char  buf[MAXPACKET];
 105 } querybuf;
 106
 107 typedef union {
 108         long    al;
 109         char    ac;
 110 } align;
 111
 112 static struct netent *
 113 getnetanswer(answer, anslen, net_i)
 114         querybuf *answer;
 115         int anslen;
 116         int net_i;
 117 {
 118
 119         register HEADER *hp;
 120         register u_char *cp;
 121         register int n;
 122         u_char *eom;
 123         int type, class, buflen, ancount, qdcount, haveanswer, i, nchar;
 124         char aux1[30], aux2[30], ans[30], *in, *st, *pauxt, *bp, **ap,
 125                 *paux1 = &aux1[0], *paux2 = &aux2[0], flag = 0;
 126 static  struct netent net_entry;
 127 static  char *net_aliases[MAXALIASES], netbuf[BUFSIZ+1];
 128
 129         /*
 130          * find first satisfactory answer
 131          *
 132          *      answer --> +------------+  ( MESSAGE )
 133          *                 |   Header   |
 134          *                 +------------+
 135          *                 |  Question  | the question for the name server
 136          *                 +------------+
 137          *                 |   Answer   | RRs answering the question
 138          *                 +------------+
 139          *                 | Authority  | RRs pointing toward an authority
 140          *                 | Additional | RRs holding additional information
 141          *                 +------------+
 142          */
 143         eom = answer->buf + anslen;
 144         hp = &answer->hdr;
 145         ancount = ntohs(hp->ancount); /* #/records in the answer section */
 146         qdcount = ntohs(hp->qdcount); /* #/entries in the question section */
 147         bp = netbuf;
 148         buflen = sizeof(netbuf);
 149         cp = answer->buf + HFIXEDSZ;
 150         if (!qdcount) {
 151                 if (hp->aa)
 152                         h_errno = HOST_NOT_FOUND;
 153                 else
 154                         h_errno = TRY_AGAIN;
 155                 return (NULL);
 156         }
 157         while (qdcount-- > 0)
 158                 cp += __dn_skipname(cp, eom) + QFIXEDSZ;
 159         ap = net_aliases;
 160         *ap = NULL;
 161         net_entry.n_aliases = net_aliases;
 162         haveanswer = 0;
 163         while (--ancount >= 0 && cp < eom) {
 164                 n = dn_expand(answer->buf, eom, cp, bp, buflen);
 165                 if (n < 0)
 166                         break;
 167                 cp += n;
 168                 ans[0] = '\0';
 169                 (void)strcpy(&ans[0], bp);
 170                 GETSHORT(type, cp);
 171                 GETSHORT(class, cp);
 172                 cp += INT32SZ;          /* TTL */
 173                 GETSHORT(n, cp);
 174                 if (class == C_IN && type == T_PTR) {
 175                         n = dn_expand(answer->buf, eom, cp, bp, buflen);
 176                         if (n < 0) {
 177                                 cp += n;
 178                                 return (NULL);
 179                         }
 180                         cp += n;
 181                         *ap++ = bp;
 182                         bp += strlen(bp) + 1;
 183                         net_entry.n_addrtype =
 184                                 (class == C_IN) ? AF_INET : AF_UNSPEC;
 185                         haveanswer++;
 186                 }
 187         }
 188         if (haveanswer) {
 189                 *ap = NULL;
 190                 switch (net_i) {
 191                 case BYADDR:
 192                         net_entry.n_name = *net_entry.n_aliases;
 193                         net_entry.n_net = 0L;
 194                         break;
 195                 case BYNAME:
 196                         in = *net_entry.n_aliases;
 197                         net_entry.n_name = &ans[0];
 198                         aux2[0] = '\0';
 199                         for (i = 0; i < 4; i++) {
 200                                 for (st = in, nchar = 0;
 201                                      *st != '.';
 202                                      st++, nchar++)
 203                                         ;
 204                                 if (nchar != 1 || *in != '0' || flag) {
 205                                         flag = 1;
 206                                         (void)strncpy(paux1,
 207                                                       (i==0) ? in : in-1,
 208                                                       (i==0) ?nchar : nchar+1);
 209                                         paux1[(i==0) ? nchar : nchar+1] = '\0';
 210                                         pauxt = paux2;
 211                                         paux2 = strcat(paux1, paux2);
 212                                         paux1 = pauxt;
 213                                 }
 214                                 in = ++st;
 215                         }
 216                         net_entry.n_net = inet_network(paux2);
 217                         break;
 218                 }
 219                 net_entry.n_aliases++;
 220                 return (&net_entry);
 221         }
 222         h_errno = TRY_AGAIN;
 223         return (NULL);
 224 }
 225
 226 struct netent *
 227 getnetbyaddr(net, net_type)
 228         register long net;
 229         register int net_type;
 230 {
 231         unsigned int netbr[4];
 232         int nn, anslen;
 233         querybuf buf;
 234         char qbuf[MAXDNAME];
 235         unsigned long net2;
 236         struct netent *net_entry;
 237
 238         if (net_type != AF_INET)
 239 #if defined(__APPLE__)
 240                 return NULL;
 241 #else
 242                 return (_getnetbyaddr(net, net_type));
 243 #endif /* !NeXT */
 244
 245         for (nn = 4, net2 = net; net2; net2 >>= 8)
 246                 netbr[--nn] = net2 & 0xff;
 247         switch (nn) {
 248         case 3:         /* Class A */
 249                 sprintf(qbuf, "0.0.0.%u.in-addr.arpa", netbr[3]);
 250                 break;
 251         case 2:         /* Class B */
 252                 sprintf(qbuf, "0.0.%u.%u.in-addr.arpa", netbr[3], netbr[2]);
 253                 break;
 254         case 1:         /* Class C */
 255                 sprintf(qbuf, "0.%u.%u.%u.in-addr.arpa", netbr[3], netbr[2],
 256                     netbr[1]);
 257                 break;
 258         case 0:         /* Class D - E */
 259                 sprintf(qbuf, "%u.%u.%u.%u.in-addr.arpa", netbr[3], netbr[2],
 260                     netbr[1], netbr[0]);
 261                 break;
 262         }
 263         anslen = res_query(qbuf, C_IN, T_PTR, (u_char *)&buf, sizeof(buf));
 264         if (anslen < 0) {
 265 #ifdef DEBUG
 266                 if (_res.options & RES_DEBUG)
 267                         printf("res_query failed\n");
 268 #endif
 269 #if !defined(__APPLE__)
 270                 if (errno == ECONNREFUSED)
 271                         return (_getnetbyaddr(net, net_type));
 272 #endif /* !NeXT */
 273                 return (NULL);
 274         }
 275         net_entry = getnetanswer(&buf, anslen, BYADDR);
 276         if (net_entry) {
 277                 unsigned u_net = net;   /* maybe net should be unsigned ? */
 278
 279                 /* Strip trailing zeros */
 280                 while ((u_net & 0xff) == 0 && u_net != 0)
 281                         u_net >>= 8;
 282                 net_entry->n_net = u_net;
 283                 return (net_entry);
 284         }
 285 #if defined(__APPLE__)
 286         return NULL;
 287 #else
 288         return (_getnetbyaddr(net, net_type));
 289 #endif /* !NeXT */
 290 }
 291
 292 struct netent *
 293 getnetbyname(net)
 294         register const char *net;
 295 {
 296         int anslen;
 297         querybuf buf;
 298         char qbuf[MAXDNAME];
 299         struct netent *net_entry;
 300
 301         if ((_res.options & RES_INIT) == 0 && res_init() == -1) {
 302                 h_errno = NETDB_INTERNAL;
 303                 return (NULL);
 304         }
 305         strcpy(&qbuf[0], net);
 306         anslen = res_search(qbuf, C_IN, T_PTR, (u_char *)&buf, sizeof(buf));
 307         if (anslen < 0) {
 308 #ifdef DEBUG
 309                 if (_res.options & RES_DEBUG)
 310                         printf("res_query failed\n");
 311 #endif
 312 #if defined(__APPLE__)
 313                 return NULL;
 314 #else
 315                 if (errno == ECONNREFUSED)
 316                         return (_getnetbyname(net));
 317                 return (_getnetbyname(net));
 318 #endif /* !NeXT */
 319         }
 320         net_entry = getnetanswer(&buf, anslen, BYNAME);
 321         if (net_entry)
 322                 return (net_entry);
 323 #if defined(__APPLE__)
 324         return NULL;
 325 #else
 326         return (_getnetbyname(net));
 327 #endif /* !NeXT */
 328 }