xref: /illumos-gate/usr/src/lib/libresolv2/common/irs/lcl_ho.c (revision 55fea89dcaa64928bed4327112404dcb3e07b79f)
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 
34 /*
35  * Copyright (c) 2004 by Internet Systems Consortium, Inc. ("ISC")
36  * Portions Copyright (c) 1996-1999 by Internet Software Consortium.
37  *
38  * Permission to use, copy, modify, and distribute this software for any
39  * purpose with or without fee is hereby granted, provided that the above
40  * copyright notice and this permission notice appear in all copies.
41  *
42  * THE SOFTWARE IS PROVIDED "AS IS" AND ISC DISCLAIMS ALL WARRANTIES
43  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
44  * MERCHANTABILITY AND FITNESS.  IN NO EVENT SHALL ISC BE LIABLE FOR
45  * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
46  * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
47  * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT
48  * OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
49  */
50 
51 /* from gethostnamadr.c	8.1 (Berkeley) 6/4/93 */
52 /* BIND Id: gethnamaddr.c,v 8.15 1996/05/22 04:56:30 vixie Exp $ */
53 
54 /* Imports. */
55 
56 #include "port_before.h"
57 
58 #include <sys/types.h>
59 #include <sys/param.h>
60 #include <sys/socket.h>
61 
62 #include <netinet/in.h>
63 #include <arpa/inet.h>
64 #include <arpa/nameser.h>
65 
66 #include <ctype.h>
67 #include <errno.h>
68 #include <fcntl.h>
69 #include <netdb.h>
70 #include <resolv.h>
71 #include <stdio.h>
72 #include <stdlib.h>
73 #include <string.h>
74 
75 #include <irs.h>
76 #include <isc/memcluster.h>
77 
78 #include "port_after.h"
79 
80 #include "irs_p.h"
81 #include "dns_p.h"
82 #include "lcl_p.h"
83 
84 #ifdef SPRINTF_CHAR
85 # define SPRINTF(x) strlen(sprintf/**/x)
86 #else
87 # define SPRINTF(x) sprintf x
88 #endif
89 
90 /* Definitions. */
91 
92 #define	MAXALIASES	35
93 #define	MAXADDRS	35
94 #define	Max(a,b)	((a) > (b) ? (a) : (b))
95 
96 #if PACKETSZ > 1024
97 #define	MAXPACKET	PACKETSZ
98 #else
99 #define	MAXPACKET	1024
100 #endif
101 
102 struct pvt {
103 	FILE *		fp;
104 	struct hostent	host;
105 	char *		h_addr_ptrs[MAXADDRS + 1];
106 	char *		host_aliases[MAXALIASES];
107 	char		hostbuf[8*1024];
108 	u_char		host_addr[16];	/*%< IPv4 or IPv6 */
109 	struct __res_state  *res;
110 	void		(*free_res)(void *);
111 };
112 
113 typedef union {
114 	int32_t al;
115 	char ac;
116 } align;
117 
118 static const u_char mapped[] = { 0,0, 0,0, 0,0, 0,0, 0,0, 0xff,0xff };
119 static const u_char tunnelled[] = { 0,0, 0,0, 0,0, 0,0, 0,0, 0,0 };
120 
121 /* Forward. */
122 
123 static void		ho_close(struct irs_ho *this);
124 static struct hostent *	ho_byname(struct irs_ho *this, const char *name);
125 static struct hostent *	ho_byname2(struct irs_ho *this, const char *name,
126 				   int af);
127 static struct hostent *	ho_byaddr(struct irs_ho *this, const void *addr,
128 				  int len, int af);
129 static struct hostent *	ho_next(struct irs_ho *this);
130 static void		ho_rewind(struct irs_ho *this);
131 static void		ho_minimize(struct irs_ho *this);
132 static struct __res_state * ho_res_get(struct irs_ho *this);
133 static void		ho_res_set(struct irs_ho *this,
134 				   struct __res_state *res,
135 				   void (*free_res)(void *));
136 static struct addrinfo * ho_addrinfo(struct irs_ho *this, const char *name,
137 				     const struct addrinfo *pai);
138 
139 static size_t		ns_namelen(const char *);
140 static int		init(struct irs_ho *this);
141 
142 /* Portability. */
143 
144 #ifndef SEEK_SET
145 # define SEEK_SET 0
146 #endif
147 
148 /* Public. */
149 
150 struct irs_ho *
irs_lcl_ho(struct irs_acc * this)151 irs_lcl_ho(struct irs_acc *this) {
152 	struct irs_ho *ho;
153 	struct pvt *pvt;
154 
155 	UNUSED(this);
156 
157 	if (!(pvt = memget(sizeof *pvt))) {
158 		errno = ENOMEM;
159 		return (NULL);
160 	}
161 	memset(pvt, 0, sizeof *pvt);
162 	if (!(ho = memget(sizeof *ho))) {
163 		memput(pvt, sizeof *pvt);
164 		errno = ENOMEM;
165 		return (NULL);
166 	}
167 	memset(ho, 0x5e, sizeof *ho);
168 	ho->private = pvt;
169 	ho->close = ho_close;
170 	ho->byname = ho_byname;
171 	ho->byname2 = ho_byname2;
172 	ho->byaddr = ho_byaddr;
173 	ho->next = ho_next;
174 	ho->rewind = ho_rewind;
175 	ho->minimize = ho_minimize;
176 	ho->res_get = ho_res_get;
177 	ho->res_set = ho_res_set;
178 	ho->addrinfo = ho_addrinfo;
179 	return (ho);
180 }
181 
182 /* Methods. */
183 
184 static void
ho_close(struct irs_ho * this)185 ho_close(struct irs_ho *this) {
186 	struct pvt *pvt = (struct pvt *)this->private;
187 
188 	ho_minimize(this);
189 	if (pvt->fp)
190 		(void) fclose(pvt->fp);
191 	if (pvt->res && pvt->free_res)
192 		(*pvt->free_res)(pvt->res);
193 	memput(pvt, sizeof *pvt);
194 	memput(this, sizeof *this);
195 }
196 
197 static struct hostent *
ho_byname(struct irs_ho * this,const char * name)198 ho_byname(struct irs_ho *this, const char *name) {
199 	struct pvt *pvt = (struct pvt *)this->private;
200 	struct hostent *hp;
201 
202 	if (init(this) == -1)
203 		return (NULL);
204 
205 	if (pvt->res->options & RES_USE_INET6) {
206 		hp = ho_byname2(this, name, AF_INET6);
207 		if (hp)
208 			return (hp);
209 	}
210 	return (ho_byname2(this, name, AF_INET));
211 }
212 
213 static struct hostent *
ho_byname2(struct irs_ho * this,const char * name,int af)214 ho_byname2(struct irs_ho *this, const char *name, int af) {
215 	struct pvt *pvt = (struct pvt *)this->private;
216 	struct hostent *hp;
217 	char **hap;
218 	size_t n;
219 
220 	if (init(this) == -1)
221 		return (NULL);
222 
223 	ho_rewind(this);
224 	n = ns_namelen(name);
225 	while ((hp = ho_next(this)) != NULL) {
226 		size_t nn;
227 
228 		if (hp->h_addrtype != af)
229 			continue;
230 		nn = ns_namelen(hp->h_name);
231 		if (strncasecmp(hp->h_name, name, Max(n, nn)) == 0)
232 			goto found;
233 		for (hap = hp->h_aliases; *hap; hap++) {
234 			nn = ns_namelen(*hap);
235 			if (strncasecmp(*hap, name, Max(n, nn)) == 0)
236 				goto found;
237 		}
238 	}
239  found:
240 	if (!hp) {
241 		RES_SET_H_ERRNO(pvt->res, HOST_NOT_FOUND);
242 		return (NULL);
243 	}
244 	RES_SET_H_ERRNO(pvt->res, NETDB_SUCCESS);
245 	return (hp);
246 }
247 
248 static struct hostent *
ho_byaddr(struct irs_ho * this,const void * addr,int len,int af)249 ho_byaddr(struct irs_ho *this, const void *addr, int len, int af) {
250 	struct pvt *pvt = (struct pvt *)this->private;
251 	const u_char *uaddr = addr;
252 	struct hostent *hp;
253 	int size;
254 
255 	if (init(this) == -1)
256 		return (NULL);
257 
258 	if (af == AF_INET6 && len == IN6ADDRSZ &&
259 	    (!memcmp(uaddr, mapped, sizeof mapped) ||
260 	     !memcmp(uaddr, tunnelled, sizeof tunnelled))) {
261 		/* Unmap. */
262 		addr = (const u_char *)addr + sizeof mapped;
263 		uaddr += sizeof mapped;
264 		af = AF_INET;
265 		len = INADDRSZ;
266 	}
267 	switch (af) {
268 	case AF_INET:
269 		size = INADDRSZ;
270 		break;
271 	case AF_INET6:
272 		size = IN6ADDRSZ;
273 		break;
274 	default:
275 		errno = EAFNOSUPPORT;
276 		RES_SET_H_ERRNO(pvt->res, NETDB_INTERNAL);
277 		return (NULL);
278 	}
279 	if (size > len) {
280 		errno = EINVAL;
281 		RES_SET_H_ERRNO(pvt->res, NETDB_INTERNAL);
282 		return (NULL);
283 	}
284 
285 	/*
286 	 * Do the search.
287 	 */
288 	ho_rewind(this);
289 	while ((hp = ho_next(this)) != NULL) {
290 		char **hap;
291 
292 		for (hap = hp->h_addr_list; *hap; hap++) {
293 			const u_char *taddr = (const u_char *)*hap;
294 			int taf = hp->h_addrtype;
295 			int tlen = hp->h_length;
296 
297 			if (taf == AF_INET6 && tlen == IN6ADDRSZ &&
298 			    (!memcmp(taddr, mapped, sizeof mapped) ||
299 			     !memcmp(taddr, tunnelled, sizeof tunnelled))) {
300 				/* Unmap. */
301 				taddr += sizeof mapped;
302 				taf = AF_INET;
303 				tlen = INADDRSZ;
304 			}
305 			if (taf == af && tlen == len &&
306 			    !memcmp(taddr, uaddr, tlen))
307 				goto found;
308 		}
309 	}
310  found:
311 	if (!hp) {
312 		RES_SET_H_ERRNO(pvt->res, HOST_NOT_FOUND);
313 		return (NULL);
314 	}
315 	RES_SET_H_ERRNO(pvt->res, NETDB_SUCCESS);
316 	return (hp);
317 }
318 
319 static struct hostent *
ho_next(struct irs_ho * this)320 ho_next(struct irs_ho *this) {
321 	struct pvt *pvt = (struct pvt *)this->private;
322 	char *cp, **q, *p;
323 	char *bufp, *ndbuf, *dbuf = NULL;
324 	int c, af, len, bufsiz, offset;
325 
326 	if (init(this) == -1)
327 		return (NULL);
328 
329 	if (!pvt->fp)
330 		ho_rewind(this);
331 	if (!pvt->fp) {
332 		RES_SET_H_ERRNO(pvt->res, NETDB_INTERNAL);
333 		return (NULL);
334 	}
335 	bufp = pvt->hostbuf;
336 	bufsiz = sizeof pvt->hostbuf;
337 	offset = 0;
338  again:
339 	if (!(p = fgets(bufp + offset, bufsiz - offset, pvt->fp))) {
340 		RES_SET_H_ERRNO(pvt->res, HOST_NOT_FOUND);
341 		if (dbuf)
342 			free(dbuf);
343 		return (NULL);
344 	}
345 	if (!strchr(p, '\n') && !feof(pvt->fp)) {
346 #define GROWBUF 1024
347 		/* allocate space for longer line */
348 		if (dbuf == NULL) {
349 			if ((ndbuf = malloc(bufsiz + GROWBUF)) != NULL)
350 				strcpy(ndbuf, bufp);
351 		} else
352 			ndbuf = realloc(dbuf, bufsiz + GROWBUF);
353 		if (ndbuf) {
354 			dbuf = ndbuf;
355 			bufp = dbuf;
356 			bufsiz += GROWBUF;
357 			offset = strlen(dbuf);
358 		} else {
359 			/* allocation failed; skip this long line */
360 			while ((c = getc(pvt->fp)) != EOF)
361 				if (c == '\n')
362 					break;
363 			if (c != EOF)
364 				ungetc(c, pvt->fp);
365 		}
366 		goto again;
367 	}
368 
369 	p -= offset;
370 	offset = 0;
371 
372 	if (*p == '#')
373 		goto again;
374 	if ((cp = strpbrk(p, "#\n")) != NULL)
375 		*cp = '\0';
376 	if (!(cp = strpbrk(p, " \t")))
377 		goto again;
378 	*cp++ = '\0';
379 	if (inet_pton(AF_INET6, p, pvt->host_addr) > 0) {
380 		af = AF_INET6;
381 		len = IN6ADDRSZ;
382 	} else if (inet_aton(p, (struct in_addr *)pvt->host_addr) > 0) {
383 		if (pvt->res->options & RES_USE_INET6) {
384 			map_v4v6_address((char*)pvt->host_addr,
385 					 (char*)pvt->host_addr);
386 			af = AF_INET6;
387 			len = IN6ADDRSZ;
388 		} else {
389 			af = AF_INET;
390 			len = INADDRSZ;
391 		}
392 	} else {
393 		goto again;
394 	}
395 	pvt->h_addr_ptrs[0] = (char *)pvt->host_addr;
396 	pvt->h_addr_ptrs[1] = NULL;
397 	pvt->host.h_addr_list = pvt->h_addr_ptrs;
398 	pvt->host.h_length = len;
399 	pvt->host.h_addrtype = af;
400 	while (*cp == ' ' || *cp == '\t')
401 		cp++;
402 	pvt->host.h_name = cp;
403 	q = pvt->host.h_aliases = pvt->host_aliases;
404 	if ((cp = strpbrk(cp, " \t")) != NULL)
405 		*cp++ = '\0';
406 	while (cp && *cp) {
407 		if (*cp == ' ' || *cp == '\t') {
408 			cp++;
409 			continue;
410 		}
411 		if (q < &pvt->host_aliases[MAXALIASES - 1])
412 			*q++ = cp;
413 		if ((cp = strpbrk(cp, " \t")) != NULL)
414 			*cp++ = '\0';
415 	}
416 	*q = NULL;
417 	if (dbuf)
418 		free(dbuf);
419 	RES_SET_H_ERRNO(pvt->res, NETDB_SUCCESS);
420 	return (&pvt->host);
421 }
422 
423 static void
ho_rewind(struct irs_ho * this)424 ho_rewind(struct irs_ho *this) {
425 	struct pvt *pvt = (struct pvt *)this->private;
426 
427 	if (pvt->fp) {
428 		if (fseek(pvt->fp, 0L, SEEK_SET) == 0)
429 			return;
430 		(void)fclose(pvt->fp);
431 	}
432 	if (!(pvt->fp = fopen(_PATH_HOSTS, "r")))
433 		return;
434 	if (fcntl(fileno(pvt->fp), F_SETFD, 1) < 0) {
435 		(void)fclose(pvt->fp);
436 		pvt->fp = NULL;
437 	}
438 }
439 
440 static void
ho_minimize(struct irs_ho * this)441 ho_minimize(struct irs_ho *this) {
442 	struct pvt *pvt = (struct pvt *)this->private;
443 
444 	if (pvt->fp != NULL) {
445 		(void)fclose(pvt->fp);
446 		pvt->fp = NULL;
447 	}
448 	if (pvt->res)
449 		res_nclose(pvt->res);
450 }
451 
452 static struct __res_state *
ho_res_get(struct irs_ho * this)453 ho_res_get(struct irs_ho *this) {
454 	struct pvt *pvt = (struct pvt *)this->private;
455 
456 	if (!pvt->res) {
457 		struct __res_state *res;
458 		res = (struct __res_state *)malloc(sizeof *res);
459 		if (!res) {
460 			errno = ENOMEM;
461 			return (NULL);
462 		}
463 		memset(res, 0, sizeof *res);
464 		ho_res_set(this, res, free);
465 	}
466 
467 	return (pvt->res);
468 }
469 
470 static void
ho_res_set(struct irs_ho * this,struct __res_state * res,void (* free_res)(void *))471 ho_res_set(struct irs_ho *this, struct __res_state *res,
472 		void (*free_res)(void *)) {
473 	struct pvt *pvt = (struct pvt *)this->private;
474 
475 	if (pvt->res && pvt->free_res) {
476 		res_nclose(pvt->res);
477 		(*pvt->free_res)(pvt->res);
478 	}
479 
480 	pvt->res = res;
481 	pvt->free_res = free_res;
482 }
483 
484 struct lcl_res_target {
485 	struct lcl_res_target *next;
486 	int family;
487 };
488 
489 /* XXX */
490 extern struct addrinfo *hostent2addrinfo __P((struct hostent *,
491 					      const struct addrinfo *pai));
492 
493 static struct addrinfo *
ho_addrinfo(struct irs_ho * this,const char * name,const struct addrinfo * pai)494 ho_addrinfo(struct irs_ho *this, const char *name, const struct addrinfo *pai)
495 {
496 	struct pvt *pvt = (struct pvt *)this->private;
497 	struct hostent *hp;
498 	struct lcl_res_target q, q2, *p;
499 	struct addrinfo sentinel, *cur;
500 
501 	memset(&q, 0, sizeof(q2));
502 	memset(&q2, 0, sizeof(q2));
503 	memset(&sentinel, 0, sizeof(sentinel));
504 	cur = &sentinel;
505 
506 	switch(pai->ai_family) {
507 	case AF_UNSPEC:		/*%< INET6 then INET4 */
508 		q.family = AF_INET6;
509 		q.next = &q2;
510 		q2.family = AF_INET;
511 		break;
512 	case AF_INET6:
513 		q.family = AF_INET6;
514 		break;
515 	case AF_INET:
516 		q.family = AF_INET;
517 		break;
518 	default:
519 		RES_SET_H_ERRNO(pvt->res, NO_RECOVERY); /*%< ??? */
520 		return(NULL);
521 	}
522 
523 	for (p = &q; p; p = p->next) {
524 		struct addrinfo *ai;
525 
526 		hp = (*this->byname2)(this, name, p->family);
527 		if (hp == NULL) {
528 			/* byname2 should've set an appropriate error */
529 			continue;
530 		}
531 		if ((hp->h_name == NULL) || (hp->h_name[0] == 0) ||
532 		    (hp->h_addr_list[0] == NULL)) {
533 			RES_SET_H_ERRNO(pvt->res, NO_RECOVERY);
534 			continue;
535 		}
536 
537 		ai = hostent2addrinfo(hp, pai);
538 		if (ai) {
539 			cur->ai_next = ai;
540 			while (cur->ai_next)
541 				cur = cur->ai_next;
542 		}
543 	}
544 
545 	if (sentinel.ai_next == NULL)
546 		RES_SET_H_ERRNO(pvt->res, HOST_NOT_FOUND);
547 
548 	return(sentinel.ai_next);
549 }
550 
551 /* Private. */
552 
553 static size_t
ns_namelen(const char * s)554 ns_namelen(const char *s) {
555 	int i;
556 
557 	for (i = strlen(s); i > 0 && s[i-1] == '.'; i--)
558 		(void)NULL;
559 	return ((size_t) i);
560 }
561 
562 static int
init(struct irs_ho * this)563 init(struct irs_ho *this) {
564 	struct pvt *pvt = (struct pvt *)this->private;
565 
566 	if (!pvt->res && !ho_res_get(this))
567 		return (-1);
568 	if (((pvt->res->options & RES_INIT) == 0U) &&
569 	    res_ninit(pvt->res) == -1)
570 		return (-1);
571 	return (0);
572 }
573 
574 /*! \file */
575