1 /*- 2 * Copyright (c) 1985, 1988, 1993 3 * The Regents of the University of California. All rights reserved. 4 * 5 * Portions copyright (c) 1999, 2000 6 * Intel Corporation. 7 * All rights reserved. 8 * 9 * Redistribution and use in source and binary forms, with or without 10 * modification, are permitted provided that the following conditions 11 * are met: 12 * 13 * 1. Redistributions of source code must retain the above copyright 14 * notice, this list of conditions and the following disclaimer. 15 * 16 * 2. Redistributions in binary form must reproduce the above copyright 17 * notice, this list of conditions and the following disclaimer in the 18 * documentation and/or other materials provided with the distribution. 19 * 20 * 3. All advertising materials mentioning features or use of this software 21 * must display the following acknowledgement: 22 * 23 * This product includes software developed by the University of 24 * California, Berkeley, Intel Corporation, and its contributors. 25 * 26 * 4. Neither the name of University, Intel Corporation, or their respective 27 * contributors may be used to endorse or promote products derived from 28 * this software without specific prior written permission. 29 * 30 * THIS SOFTWARE IS PROVIDED BY THE REGENTS, INTEL CORPORATION AND 31 * CONTRIBUTORS ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, 32 * BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS 33 * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS, 34 * INTEL CORPORATION OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, 35 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 36 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 37 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 38 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 39 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 40 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 41 * - 42 * Portions Copyright (c) 1993 by Digital Equipment Corporation. 43 * 44 * Permission to use, copy, modify, and distribute this software for any 45 * purpose with or without fee is hereby granted, provided that the above 46 * copyright notice and this permission notice appear in all copies, and that 47 * the name of Digital Equipment Corporation not be used in advertising or 48 * publicity pertaining to distribution of the document or software without 49 * specific, written prior permission. 50 * 51 * THE SOFTWARE IS PROVIDED "AS IS" AND DIGITAL EQUIPMENT CORP. DISCLAIMS ALL 52 * WARRANTIES WITH REGARD TO THIS SOFTWARE, INCLUDING ALL IMPLIED WARRANTIES 53 * OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL DIGITAL EQUIPMENT 54 * CORPORATION BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL 55 * DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR 56 * PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS 57 * ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS 58 * SOFTWARE. 59 * - 60 * --Copyright-- 61 */ 62 /* Portions Copyright (c) 1993 Carlos Leandro and Rui Salgueiro 63 * Dep. Matematica Universidade de Coimbra, Portugal, Europe 64 * 65 * Permission to use, copy, modify, and distribute this software for any 66 * purpose with or without fee is hereby granted, provided that the above 67 * copyright notice and this permission notice appear in all copies. 68 */ 69 70 #if defined(LIBC_SCCS) && !defined(lint) 71 static char sccsid[] = "@(#)gethostnamadr.c 8.1 (Berkeley) 6/4/93"; 72 static char rcsid[] = "$Id: getnetbydns.c,v 1.1.1.1 2003/11/19 01:51:27 kyu3 Exp $"; 73 #endif /* LIBC_SCCS and not lint */ 74 75 #include <sys/param.h> 76 #include <sys/socket.h> 77 #include <netinet/in.h> 78 #include <arpa/inet.h> 79 #include <arpa/nameser.h> 80 81 #include <stdio.h> 82 #include <netdb.h> 83 #include <resolv.h> 84 #include <ctype.h> 85 #include <errno.h> 86 #include <string.h> 87 #include <unistd.h> 88 #ifdef _ORG_FREEBSD_ 89 #include <syslog.h> 90 #endif 91 92 #include "res_config.h" 93 #include "Socklib_internals.h" 94 95 extern int h_errno; 96 97 #define BYADDR 0 98 #define BYNAME 1 99 #define MAXALIASES 35 100 101 #if PACKETSZ > 1024 102 #define MAXPACKET PACKETSZ 103 #else 104 #define MAXPACKET 1024 105 #endif 106 107 typedef union { 108 HEADER hdr; 109 u_char buf[MAXPACKET]; 110 } querybuf; 111 112 typedef union { 113 long al; 114 char ac; 115 } align; 116 117 static struct netent * 118 getnetanswer(querybuf *answer, int anslen, 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[MAXHOSTNAMELEN], aux2[MAXHOSTNAMELEN], ans[MAXHOSTNAMELEN]; 127 char *in, *st, *pauxt, *bp, **ap; 128 char *paux1 = &aux1[0], *paux2 = &aux2[0], flag = 0; 129 static struct netent net_entry; 130 static char *net_aliases[MAXALIASES], netbuf[PACKETSZ]; 131 132 /* 133 * find first satisfactory answer 134 * 135 * answer --> +------------+ ( MESSAGE ) 136 * | Header | 137 * +------------+ 138 * | Question | the question for the name server 139 * +------------+ 140 * | Answer | RRs answering the question 141 * +------------+ 142 * | Authority | RRs pointing toward an authority 143 * | Additional | RRs holding additional information 144 * +------------+ 145 */ 146 eom = answer->buf + anslen; 147 hp = &answer->hdr; 148 ancount = ntohs(hp->ancount); /* #/records in the answer section */ 149 qdcount = ntohs(hp->qdcount); /* #/entries in the question section */ 150 bp = netbuf; 151 buflen = sizeof(netbuf); 152 cp = answer->buf + HFIXEDSZ; 153 if (!qdcount) { 154 if (hp->aa) 155 h_errno = HOST_NOT_FOUND; 156 else 157 h_errno = TRY_AGAIN; 158 return (NULL); 159 } 160 while (qdcount-- > 0) 161 cp += __dn_skipname(cp, eom) + QFIXEDSZ; 162 ap = net_aliases; 163 *ap = NULL; 164 net_entry.n_aliases = net_aliases; 165 haveanswer = 0; 166 while (--ancount >= 0 && cp < eom) { 167 n = dn_expand(answer->buf, eom, cp, bp, buflen); 168 if ((n < 0) || !res_dnok(bp)) 169 break; 170 cp += n; 171 ans[0] = '\0'; 172 (void)strncpy(&ans[0], bp, sizeof(ans) - 1); 173 ans[sizeof(ans) - 1] = '\0'; 174 GETSHORT(type, cp); 175 GETSHORT(class, cp); 176 cp += INT32SZ; /* TTL */ 177 GETSHORT(n, cp); 178 if (class == C_IN && type == T_PTR) { 179 n = dn_expand(answer->buf, eom, cp, bp, buflen); 180 if ((n < 0) || !res_hnok(bp)) { 181 cp += n; 182 return (NULL); 183 } 184 cp += n; 185 *ap++ = bp; 186 bp += strlen(bp) + 1; 187 net_entry.n_addrtype = 188 (class == C_IN) ? AF_INET : AF_UNSPEC; 189 haveanswer++; 190 } 191 } 192 if (haveanswer) { 193 *ap = NULL; 194 switch (net_i) { 195 case BYADDR: 196 net_entry.n_name = *net_entry.n_aliases; 197 net_entry.n_net = 0L; 198 break; 199 case BYNAME: 200 in = *net_entry.n_aliases; 201 net_entry.n_name = &ans[0]; 202 aux2[0] = '\0'; 203 for (i = 0; i < 4; i++) { 204 for (st = in, nchar = 0; 205 *st != '.'; 206 st++, nchar++) 207 ; 208 if (nchar != 1 || *in != '0' || flag) { 209 flag = 1; 210 (void)strncpy(paux1, 211 (i==0) ? in : in-1, 212 (i==0) ?nchar : nchar+1); 213 paux1[(i==0) ? nchar : nchar+1] = '\0'; 214 pauxt = paux2; 215 paux2 = strcat(paux1, paux2); 216 paux1 = pauxt; 217 } 218 in = ++st; 219 } 220 net_entry.n_net = inet_network(paux2); 221 break; 222 } 223 net_entry.n_aliases++; 224 return (&net_entry); 225 } 226 h_errno = TRY_AGAIN; 227 return (NULL); 228 } 229 230 struct netent * 231 _getnetbydnsaddr(register unsigned long net, register int net_type) 232 { 233 unsigned int netbr[4]; 234 int nn, anslen; 235 querybuf buf; 236 char qbuf[MAXDNAME]; 237 unsigned long net2; 238 struct netent *net_entry; 239 240 if (net_type != AF_INET) 241 return (NULL); 242 243 for (nn = 4, net2 = net; net2; net2 >>= 8) 244 netbr[--nn] = net2 & 0xff; 245 switch (nn) { 246 case 3: /* Class A */ 247 sprintf(qbuf, "0.0.0.%u.in-addr.arpa", netbr[3]); 248 break; 249 case 2: /* Class B */ 250 sprintf(qbuf, "0.0.%u.%u.in-addr.arpa", netbr[3], netbr[2]); 251 break; 252 case 1: /* Class C */ 253 sprintf(qbuf, "0.%u.%u.%u.in-addr.arpa", netbr[3], netbr[2], 254 netbr[1]); 255 break; 256 case 0: /* Class D - E */ 257 sprintf(qbuf, "%u.%u.%u.%u.in-addr.arpa", netbr[3], netbr[2], 258 netbr[1], netbr[0]); 259 break; 260 } 261 anslen = res_query(qbuf, C_IN, T_PTR, (u_char *)&buf, sizeof(buf)); 262 if (anslen < 0) { 263 #ifdef DEBUG 264 if (_res.options & RES_DEBUG) 265 printf("res_query failed\n"); 266 #endif 267 return (NULL); 268 } 269 net_entry = getnetanswer(&buf, anslen, BYADDR); 270 if (net_entry) { 271 unsigned u_net = net; /* maybe net should be unsigned ? */ 272 273 /* Strip trailing zeros */ 274 while ((u_net & 0xff) == 0 && u_net != 0) 275 u_net >>= 8; 276 net_entry->n_net = u_net; 277 return (net_entry); 278 } 279 return (NULL); 280 } 281 282 struct netent * 283 _getnetbydnsname(register const char *net) 284 { 285 int anslen; 286 querybuf buf; 287 char qbuf[MAXDNAME]; 288 289 if ((_res.options & RES_INIT) == 0 && res_init() == -1) { 290 h_errno = NETDB_INTERNAL; 291 return (NULL); 292 } 293 strncpy(qbuf, net, sizeof(qbuf) - 1); 294 qbuf[sizeof(qbuf) - 1] = '\0'; 295 anslen = res_search(qbuf, C_IN, T_PTR, (u_char *)&buf, sizeof(buf)); 296 if (anslen < 0) { 297 #ifdef DEBUG 298 if (_res.options & RES_DEBUG) 299 printf("res_query failed\n"); 300 #endif 301 return (NULL); 302 } 303 return getnetanswer(&buf, anslen, BYNAME); 304 } 305 306 void 307 _setnetdnsent(int stayopen) 308 { 309 if (stayopen) 310 _res.options |= RES_STAYOPEN | RES_USEVC; 311 } 312 313 void 314 _endnetdnsent() 315 { 316 _res.options &= ~(RES_STAYOPEN | RES_USEVC); 317 res_close(); 318 } 319
