1 /*-
2 * Copyright (c) 1985, 1988, 1993
3 * The Regents of the University of California. All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 * 1. Redistributions of source code must retain the above copyright
9 * notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 * notice, this list of conditions and the following disclaimer in the
12 * documentation and/or other materials provided with the distribution.
13 * 3. All advertising materials mentioning features or use of this software
14 * must display the following acknowledgement:
15 * This product includes software developed by the University of
16 * California, Berkeley and its contributors.
17 * 4. Neither the name of the University nor the names of its contributors
18 * may be used to endorse or promote products derived from this software
19 * without specific prior written permission.
20 *
21 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
22 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
23 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
24 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
25 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
26 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
27 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
28 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
29 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
30 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
31 * SUCH DAMAGE.
32 * -
33 * Portions Copyright (c) 1993 by Digital Equipment Corporation.
34 *
35 * Permission to use, copy, modify, and distribute this software for any
36 * purpose with or without fee is hereby granted, provided that the above
37 * copyright notice and this permission notice appear in all copies, and that
38 * the name of Digital Equipment Corporation not be used in advertising or
39 * publicity pertaining to distribution of the document or software without
40 * specific, written prior permission.
41 *
42 * THE SOFTWARE IS PROVIDED "AS IS" AND DIGITAL EQUIPMENT CORP. DISCLAIMS ALL
43 * WARRANTIES WITH REGARD TO THIS SOFTWARE, INCLUDING ALL IMPLIED WARRANTIES
44 * OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL DIGITAL EQUIPMENT
45 * CORPORATION BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL
46 * DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR
47 * PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS
48 * ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS
49 * SOFTWARE.
50 * -
51 * --Copyright--
52 */
53 /* Portions Copyright (c) 1993 Carlos Leandro and Rui Salgueiro
54 * Dep. Matematica Universidade de Coimbra, Portugal, Europe
55 *
56 * Permission to use, copy, modify, and distribute this software for any
57 * purpose with or without fee is hereby granted, provided that the above
58 * copyright notice and this permission notice appear in all copies.
59 */
60
61 #if defined(LIBC_SCCS) && !defined(lint)
62 static char sccsid[] = "@(#)gethostnamadr.c 8.1 (Berkeley) 6/4/93";
63 #endif /* LIBC_SCCS and not lint */
64 #include <sys/cdefs.h>
65 #include <sys/types.h>
66 #include <sys/types.h>
67
68 #include <sys/param.h>
69 #include <sys/socket.h>
70 #include <netinet/in.h>
71 #include <arpa/inet.h>
72 #include <arpa/nameser.h>
73
74 #include <stdio.h>
75 #include <netdb.h>
76 #include <resolv.h>
77 #include <ctype.h>
78 #include <string.h>
79 #include <unistd.h>
80 #include <syslog.h>
81 #include <stdarg.h>
82 #include <nsswitch.h>
83
84 #include "res_config.h"
85
86 extern int h_errno;
87
88 #define BYADDR 0
89 #define BYNAME 1
90 #define MAXALIASES 35
91
92 #if PACKETSZ > 1024
93 #define MAXPACKET PACKETSZ
94 #else
95 #define MAXPACKET 1024
96 #endif
97
98 typedef union {
99 HEADER hdr;
100 u_char buf[MAXPACKET];
101 } querybuf;
102
103 typedef union {
104 long al;
105 char ac;
106 } align;
107
108 static struct netent *
getnetanswer(answer,anslen,net_i)109 getnetanswer(answer, anslen, net_i)
110 querybuf *answer;
111 int anslen;
112 int net_i;
113 {
114
115 HEADER *hp;
116 u_char *cp;
117 int n;
118 u_char *eom;
119 int type, class, buflen, ancount, qdcount, haveanswer, i, nchar;
120 char aux1[MAXHOSTNAMELEN], aux2[MAXHOSTNAMELEN], ans[MAXHOSTNAMELEN];
121 char *in, *st, *pauxt, *bp, **ap;
122 char *paux1 = &aux1[0], *paux2 = &aux2[0], flag = 0;
123 static struct netent net_entry;
124 static char *net_aliases[MAXALIASES], netbuf[PACKETSZ];
125
126 /*
127 * find first satisfactory answer
128 *
129 * answer --> +------------+ ( MESSAGE )
130 * | Header |
131 * +------------+
132 * | Question | the question for the name server
133 * +------------+
134 * | Answer | RRs answering the question
135 * +------------+
136 * | Authority | RRs pointing toward an authority
137 * | Additional | RRs holding additional information
138 * +------------+
139 */
140 eom = answer->buf + anslen;
141 hp = &answer->hdr;
142 ancount = ntohs(hp->ancount); /* #/records in the answer section */
143 qdcount = ntohs(hp->qdcount); /* #/entries in the question section */
144 bp = netbuf;
145 buflen = sizeof(netbuf);
146 cp = answer->buf + HFIXEDSZ;
147 if (!qdcount) {
148 if (hp->aa)
149 h_errno = HOST_NOT_FOUND;
150 else
151 h_errno = TRY_AGAIN;
152 return (NULL);
153 }
154 while (qdcount-- > 0)
155 cp += __dn_skipname(cp, eom) + QFIXEDSZ;
156 ap = net_aliases;
157 *ap = NULL;
158 net_entry.n_aliases = net_aliases;
159 haveanswer = 0;
160 while (--ancount >= 0 && cp < eom) {
161 n = dn_expand(answer->buf, eom, cp, bp, buflen);
162 if ((n < 0) || !res_dnok(bp))
163 break;
164 cp += n;
165 ans[0] = '\0';
166 (void)strncpy(&ans[0], bp, sizeof(ans) - 1);
167 ans[sizeof(ans) - 1] = '\0';
168 GETSHORT(type, cp);
169 GETSHORT(class, cp);
170 cp += INT32SZ; /* TTL */
171 GETSHORT(n, cp);
172 if (class == C_IN && type == T_PTR) {
173 n = dn_expand(answer->buf, eom, cp, bp, buflen);
174 if ((n < 0) || !res_hnok(bp)) {
175 cp += n;
176 return (NULL);
177 }
178 cp += n;
179 *ap++ = bp;
180 bp += strlen(bp) + 1;
181 net_entry.n_addrtype =
182 (class == C_IN) ? AF_INET : AF_UNSPEC;
183 haveanswer++;
184 }
185 }
186 if (haveanswer) {
187 *ap = NULL;
188 switch (net_i) {
189 case BYADDR:
190 net_entry.n_name = *net_entry.n_aliases;
191 net_entry.n_net = 0L;
192 break;
193 case BYNAME:
194 in = *net_entry.n_aliases;
195 net_entry.n_name = &ans[0];
196 aux2[0] = '\0';
197 for (i = 0; i < 4; i++) {
198 for (st = in, nchar = 0;
199 *st != '.';
200 st++, nchar++)
201 ;
202 if (nchar != 1 || *in != '0' || flag) {
203 flag = 1;
204 (void)strncpy(paux1,
205 (i==0) ? in : in-1,
206 (i==0) ?nchar : nchar+1);
207 paux1[(i==0) ? nchar : nchar+1] = '\0';
208 pauxt = paux2;
209 paux2 = strcat(paux1, paux2);
210 paux1 = pauxt;
211 }
212 in = ++st;
213 }
214 net_entry.n_net = inet_network(paux2);
215 break;
216 }
217 net_entry.n_aliases++;
218 return (&net_entry);
219 }
220 h_errno = TRY_AGAIN;
221 return (NULL);
222 }
223
224 int
_dns_getnetbyaddr(void * rval,void * cb_data,va_list ap)225 _dns_getnetbyaddr(void *rval, void *cb_data, va_list ap)
226 {
227 unsigned long net;
228 int net_type;
229 unsigned int netbr[4];
230 int nn, anslen;
231 querybuf buf;
232 char qbuf[MAXDNAME];
233 unsigned long net2;
234 struct netent *net_entry;
235
236 net = va_arg(ap, unsigned long);
237 net_type = va_arg(ap, int);
238
239 *(struct netent **)rval = NULL;
240
241 if (net_type != AF_INET)
242 return NS_UNAVAIL;
243
244 for (nn = 4, net2 = net; net2; net2 >>= 8)
245 netbr[--nn] = net2 & 0xff;
246 switch (nn) {
247 case 3: /* Class A */
248 sprintf(qbuf, "0.0.0.%u.in-addr.arpa", netbr[3]);
249 break;
250 case 2: /* Class B */
251 sprintf(qbuf, "0.0.%u.%u.in-addr.arpa", netbr[3], netbr[2]);
252 break;
253 case 1: /* Class C */
254 sprintf(qbuf, "0.%u.%u.%u.in-addr.arpa", netbr[3], netbr[2],
255 netbr[1]);
256 break;
257 case 0: /* Class D - E */
258 sprintf(qbuf, "%u.%u.%u.%u.in-addr.arpa", netbr[3], netbr[2],
259 netbr[1], netbr[0]);
260 break;
261 }
262 anslen = res_query(qbuf, C_IN, T_PTR, (u_char *)&buf, sizeof(buf));
263 if (anslen < 0) {
264 #ifdef DEBUG
265 if (_res.options & RES_DEBUG)
266 printf("res_query failed\n");
267 #endif
268 return NS_UNAVAIL;
269 }
270 net_entry = getnetanswer(&buf, anslen, BYADDR);
271 if (net_entry) {
272 unsigned u_net = net; /* maybe net should be unsigned ? */
273
274 /* Strip trailing zeros */
275 while ((u_net & 0xff) == 0 && u_net != 0)
276 u_net >>= 8;
277 net_entry->n_net = u_net;
278 *(struct netent **)rval = net_entry;
279 return NS_SUCCESS;
280 }
281 return NS_NOTFOUND;
282 }
283
284 int
_dns_getnetbyname(void * rval,void * cb_data,va_list ap)285 _dns_getnetbyname(void *rval, void *cb_data, va_list ap)
286 {
287 const char *net;
288 int anslen;
289 querybuf buf;
290 char qbuf[MAXDNAME];
291
292 net = va_arg(ap, const char *);
293
294 *(struct netent**)rval = NULL;
295
296 if ((_res.options & RES_INIT) == 0 && res_init() == -1) {
297 h_errno = NETDB_INTERNAL;
298 return NS_UNAVAIL;
299 }
300 strncpy(qbuf, net, sizeof(qbuf) - 1);
301 qbuf[sizeof(qbuf) - 1] = '\0';
302 anslen = res_search(qbuf, C_IN, T_PTR, (u_char *)&buf, sizeof(buf));
303 if (anslen < 0) {
304 #ifdef DEBUG
305 if (_res.options & RES_DEBUG)
306 printf("res_query failed\n");
307 #endif
308 return NS_UNAVAIL;
309 }
310 *(struct netent**)rval = getnetanswer(&buf, anslen, BYNAME);
311 return (*(struct netent**)rval != NULL) ? NS_SUCCESS : NS_NOTFOUND;
312 }
313
314 void
_setnetdnsent(stayopen)315 _setnetdnsent(stayopen)
316 int stayopen;
317 {
318 if (stayopen)
319 _res.options |= RES_STAYOPEN | RES_USEVC;
320 }
321
322 void
_endnetdnsent()323 _endnetdnsent()
324 {
325 _res.options &= ~(RES_STAYOPEN | RES_USEVC);
326 res_close();
327 }
328