xref: /illumos-gate/usr/src/lib/libresolv2/common/irs/lcl_ho.c (revision 711890bc9379ceea66272dc8d4981812224ea86e)
1 /*
2  * Copyright 2006 Sun Microsystems, Inc.  All rights reserved.
3  * Use is subject to license terms.
4  */
5 
6 /*
7  * Copyright (c) 1985, 1988, 1993
8  *    The Regents of the University of California.  All rights reserved.
9  *
10  * Redistribution and use in source and binary forms, with or without
11  * modification, are permitted provided that the following conditions
12  * are met:
13  * 1. Redistributions of source code must retain the above copyright
14  *    notice, this list of conditions and the following disclaimer.
15  * 2. Redistributions in binary form must reproduce the above copyright
16  *    notice, this list of conditions and the following disclaimer in the
17  *    documentation and/or other materials provided with the distribution.
18  * 3. All advertising materials mentioning features or use of this software
19  *    must display the following acknowledgement:
20  * 	This product includes software developed by the University of
21  * 	California, Berkeley and its contributors.
22  * 4. Neither the name of the University nor the names of its contributors
23  *    may be used to endorse or promote products derived from this software
24  *    without specific prior written permission.
25  *
26  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
27  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
28  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
29  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
30  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
31  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
32  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
33  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
34  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
35  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
36  * SUCH DAMAGE.
37  */
38 
39 /*
40  * Portions Copyright (c) 1996-1999 by Internet Software Consortium.
41  *
42  * Permission to use, copy, modify, and distribute this software for any
43  * purpose with or without fee is hereby granted, provided that the above
44  * copyright notice and this permission notice appear in all copies.
45  *
46  * THE SOFTWARE IS PROVIDED "AS IS" AND INTERNET SOFTWARE CONSORTIUM DISCLAIMS
47  * ALL WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES
48  * OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL INTERNET SOFTWARE
49  * CONSORTIUM BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL
50  * DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR
51  * PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS
52  * ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS
53  * SOFTWARE.
54  */
55 
56 #pragma ident	"%Z%%M%	%I%	%E% SMI"
57 
58 /* from gethostnamadr.c	8.1 (Berkeley) 6/4/93 */
59 /* BIND Id: gethnamaddr.c,v 8.15 1996/05/22 04:56:30 vixie Exp $ */
60 
61 #if defined(LIBC_SCCS) && !defined(lint)
62 static const char rcsid[] = "$Id: lcl_ho.c,v 1.26 2001/05/29 05:49:04 marka Exp $";
63 #endif /* LIBC_SCCS and not lint */
64 
65 /* Imports. */
66 
67 #include "port_before.h"
68 
69 #include <sys/types.h>
70 #include <sys/param.h>
71 #include <sys/socket.h>
72 
73 #include <netinet/in.h>
74 #include <arpa/inet.h>
75 #include <arpa/nameser.h>
76 
77 #include <ctype.h>
78 #include <errno.h>
79 #include <fcntl.h>
80 #include <netdb.h>
81 #include <resolv.h>
82 #include <stdio.h>
83 #include <stdlib.h>
84 #include <string.h>
85 
86 #include <irs.h>
87 #include <isc/memcluster.h>
88 
89 #include "port_after.h"
90 
91 #include "irs_p.h"
92 #include "dns_p.h"
93 #include "lcl_p.h"
94 
95 #ifdef SPRINTF_CHAR
96 # define SPRINTF(x) strlen(sprintf/**/x)
97 #else
98 # define SPRINTF(x) sprintf x
99 #endif
100 
101 /* Definitions. */
102 
103 #define	MAXALIASES	35
104 #define	MAXADDRS	35
105 #define	Max(a,b)	((a) > (b) ? (a) : (b))
106 
107 #if PACKETSZ > 1024
108 #define	MAXPACKET	PACKETSZ
109 #else
110 #define	MAXPACKET	1024
111 #endif
112 
113 struct pvt {
114 	FILE *		fp;
115 	struct hostent	host;
116 	char *		h_addr_ptrs[MAXADDRS + 1];
117 	char *		host_aliases[MAXALIASES];
118 	char		hostbuf[8*1024];
119 	u_char		host_addr[16];	/* IPv4 or IPv6 */
120 	struct __res_state  *res;
121 	void		(*free_res)(void *);
122 };
123 
124 typedef union {
125 	int32_t al;
126 	char ac;
127 } align;
128 
129 static const u_char mapped[] = { 0,0, 0,0, 0,0, 0,0, 0,0, 0xff,0xff };
130 static const u_char tunnelled[] = { 0,0, 0,0, 0,0, 0,0, 0,0, 0,0 };
131 
132 /* Forward. */
133 
134 static void		ho_close(struct irs_ho *this);
135 static struct hostent *	ho_byname(struct irs_ho *this, const char *name);
136 static struct hostent *	ho_byname2(struct irs_ho *this, const char *name,
137 				   int af);
138 static struct hostent *	ho_byaddr(struct irs_ho *this, const void *addr,
139 				  int len, int af);
140 static struct hostent *	ho_next(struct irs_ho *this);
141 static void		ho_rewind(struct irs_ho *this);
142 static void		ho_minimize(struct irs_ho *this);
143 static struct __res_state * ho_res_get(struct irs_ho *this);
144 static void		ho_res_set(struct irs_ho *this,
145 				   struct __res_state *res,
146 				   void (*free_res)(void *));
147 static struct addrinfo * ho_addrinfo(struct irs_ho *this, const char *name,
148 				     const struct addrinfo *pai);
149 
150 static size_t		ns_namelen(const char *);
151 static int		init(struct irs_ho *this);
152 
153 /* Portability. */
154 
155 #ifndef SEEK_SET
156 # define SEEK_SET 0
157 #endif
158 
159 /* Public. */
160 
161 struct irs_ho *
162 irs_lcl_ho(struct irs_acc *this) {
163 	struct irs_ho *ho;
164 	struct pvt *pvt;
165 
166 	UNUSED(this);
167 
168 	if (!(pvt = memget(sizeof *pvt))) {
169 		errno = ENOMEM;
170 		return (NULL);
171 	}
172 	memset(pvt, 0, sizeof *pvt);
173 	if (!(ho = memget(sizeof *ho))) {
174 		memput(pvt, sizeof *pvt);
175 		errno = ENOMEM;
176 		return (NULL);
177 	}
178 	memset(ho, 0x5e, sizeof *ho);
179 	ho->private = pvt;
180 	ho->close = ho_close;
181 	ho->byname = ho_byname;
182 	ho->byname2 = ho_byname2;
183 	ho->byaddr = ho_byaddr;
184 	ho->next = ho_next;
185 	ho->rewind = ho_rewind;
186 	ho->minimize = ho_minimize;
187 	ho->res_get = ho_res_get;
188 	ho->res_set = ho_res_set;
189 	ho->addrinfo = ho_addrinfo;
190 	return (ho);
191 }
192 
193 /* Methods. */
194 
195 static void
196 ho_close(struct irs_ho *this) {
197 	struct pvt *pvt = (struct pvt *)this->private;
198 
199 	ho_minimize(this);
200 	if (pvt->fp)
201 		(void) fclose(pvt->fp);
202 	if (pvt->res && pvt->free_res)
203 		(*pvt->free_res)(pvt->res);
204 	memput(pvt, sizeof *pvt);
205 	memput(this, sizeof *this);
206 }
207 
208 static struct hostent *
209 ho_byname(struct irs_ho *this, const char *name) {
210 	struct pvt *pvt = (struct pvt *)this->private;
211 	struct hostent *hp;
212 
213 	if (init(this) == -1)
214 		return (NULL);
215 
216 	if (pvt->res->options & RES_USE_INET6) {
217 		hp = ho_byname2(this, name, AF_INET6);
218 		if (hp)
219 			return (hp);
220 	}
221 	return (ho_byname2(this, name, AF_INET));
222 }
223 
224 static struct hostent *
225 ho_byname2(struct irs_ho *this, const char *name, int af) {
226 	struct pvt *pvt = (struct pvt *)this->private;
227 	struct hostent *hp;
228 	char **hap;
229 	size_t n;
230 
231 	if (init(this) == -1)
232 		return (NULL);
233 
234 	ho_rewind(this);
235 	n = ns_namelen(name);
236 	while ((hp = ho_next(this)) != NULL) {
237 		size_t nn;
238 
239 		if (hp->h_addrtype != af)
240 			continue;
241 		nn = ns_namelen(hp->h_name);
242 		if (strncasecmp(hp->h_name, name, Max(n, nn)) == 0)
243 			goto found;
244 		for (hap = hp->h_aliases; *hap; hap++) {
245 			nn = ns_namelen(*hap);
246 			if (strncasecmp(*hap, name, Max(n, nn)) == 0)
247 				goto found;
248 		}
249 	}
250  found:
251 	if (!hp) {
252 		RES_SET_H_ERRNO(pvt->res, HOST_NOT_FOUND);
253 		return (NULL);
254 	}
255 	RES_SET_H_ERRNO(pvt->res, NETDB_SUCCESS);
256 	return (hp);
257 }
258 
259 static struct hostent *
260 ho_byaddr(struct irs_ho *this, const void *addr, int len, int af) {
261 	struct pvt *pvt = (struct pvt *)this->private;
262 	const u_char *uaddr = addr;
263 	struct hostent *hp;
264 	int size;
265 
266 	if (init(this) == -1)
267 		return (NULL);
268 
269 	if (af == AF_INET6 && len == IN6ADDRSZ &&
270 	    (!memcmp(uaddr, mapped, sizeof mapped) ||
271 	     !memcmp(uaddr, tunnelled, sizeof tunnelled))) {
272 		/* Unmap. */
273 		addr = (const u_char *)addr + sizeof mapped;
274 		uaddr += sizeof mapped;
275 		af = AF_INET;
276 		len = INADDRSZ;
277 	}
278 	switch (af) {
279 	case AF_INET:
280 		size = INADDRSZ;
281 		break;
282 	case AF_INET6:
283 		size = IN6ADDRSZ;
284 		break;
285 	default:
286 		errno = EAFNOSUPPORT;
287 		RES_SET_H_ERRNO(pvt->res, NETDB_INTERNAL);
288 		return (NULL);
289 	}
290 	if (size > len) {
291 		errno = EINVAL;
292 		RES_SET_H_ERRNO(pvt->res, NETDB_INTERNAL);
293 		return (NULL);
294 	}
295 
296 	/*
297 	 * Do the search.
298 	 */
299 	ho_rewind(this);
300 	while ((hp = ho_next(this)) != NULL) {
301 		char **hap;
302 
303 		for (hap = hp->h_addr_list; *hap; hap++) {
304 			const u_char *taddr = (const u_char *)*hap;
305 			int taf = hp->h_addrtype;
306 			int tlen = hp->h_length;
307 
308 			if (taf == AF_INET6 && tlen == IN6ADDRSZ &&
309 			    (!memcmp(taddr, mapped, sizeof mapped) ||
310 			     !memcmp(taddr, tunnelled, sizeof tunnelled))) {
311 				/* Unmap. */
312 				taddr += sizeof mapped;
313 				taf = AF_INET;
314 				tlen = INADDRSZ;
315 			}
316 			if (taf == af && tlen == len &&
317 			    !memcmp(taddr, uaddr, tlen))
318 				goto found;
319 		}
320 	}
321  found:
322 	if (!hp) {
323 		RES_SET_H_ERRNO(pvt->res, HOST_NOT_FOUND);
324 		return (NULL);
325 	}
326 	RES_SET_H_ERRNO(pvt->res, NETDB_SUCCESS);
327 	return (hp);
328 }
329 
330 static struct hostent *
331 ho_next(struct irs_ho *this) {
332 	struct pvt *pvt = (struct pvt *)this->private;
333 	char *cp, **q, *p;
334 	char *bufp, *ndbuf, *dbuf = NULL;
335 	int c, af, len, bufsiz, offset;
336 
337 	if (init(this) == -1)
338 		return (NULL);
339 
340 	if (!pvt->fp)
341 		ho_rewind(this);
342 	if (!pvt->fp) {
343 		RES_SET_H_ERRNO(pvt->res, NETDB_INTERNAL);
344 		return (NULL);
345 	}
346 	bufp = pvt->hostbuf;
347 	bufsiz = sizeof pvt->hostbuf;
348 	offset = 0;
349  again:
350 	if (!(p = fgets(bufp + offset, bufsiz - offset, pvt->fp))) {
351 		RES_SET_H_ERRNO(pvt->res, HOST_NOT_FOUND);
352 		if (dbuf)
353 			free(dbuf);
354 		return (NULL);
355 	}
356 	if (!strchr(p, '\n') && !feof(pvt->fp)) {
357 #define GROWBUF 1024
358 		/* allocate space for longer line */
359 		if (dbuf == NULL) {
360 			if ((ndbuf = malloc(bufsiz + GROWBUF)) != NULL)
361 				strcpy(ndbuf, bufp);
362 		} else
363 			ndbuf = realloc(dbuf, bufsiz + GROWBUF);
364 		if (ndbuf) {
365 			dbuf = ndbuf;
366 			bufp = dbuf;
367 			bufsiz += GROWBUF;
368 			offset = strlen(dbuf);
369 		} else {
370 			/* allocation failed; skip this long line */
371 			while ((c = getc(pvt->fp)) != EOF)
372 				if (c == '\n')
373 					break;
374 			if (c != EOF)
375 				ungetc(c, pvt->fp);
376 		}
377 		goto again;
378 	}
379 
380 	p -= offset;
381 	offset = 0;
382 
383 	if (*p == '#')
384 		goto again;
385 	if ((cp = strpbrk(p, "#\n")) != NULL)
386 		*cp = '\0';
387 	if (!(cp = strpbrk(p, " \t")))
388 		goto again;
389 	*cp++ = '\0';
390 	if (inet_pton(AF_INET6, p, pvt->host_addr) > 0) {
391 		af = AF_INET6;
392 		len = IN6ADDRSZ;
393 	} else if (inet_aton(p, (struct in_addr *)pvt->host_addr) > 0) {
394 		if (pvt->res->options & RES_USE_INET6) {
395 			map_v4v6_address((char*)pvt->host_addr,
396 					 (char*)pvt->host_addr);
397 			af = AF_INET6;
398 			len = IN6ADDRSZ;
399 		} else {
400 			af = AF_INET;
401 			len = INADDRSZ;
402 		}
403 	} else {
404 		goto again;
405 	}
406 	pvt->h_addr_ptrs[0] = (char *)pvt->host_addr;
407 	pvt->h_addr_ptrs[1] = NULL;
408 	pvt->host.h_addr_list = pvt->h_addr_ptrs;
409 	pvt->host.h_length = len;
410 	pvt->host.h_addrtype = af;
411 	while (*cp == ' ' || *cp == '\t')
412 		cp++;
413 	pvt->host.h_name = cp;
414 	q = pvt->host.h_aliases = pvt->host_aliases;
415 	if ((cp = strpbrk(cp, " \t")) != NULL)
416 		*cp++ = '\0';
417 	while (cp && *cp) {
418 		if (*cp == ' ' || *cp == '\t') {
419 			cp++;
420 			continue;
421 		}
422 		if (q < &pvt->host_aliases[MAXALIASES - 1])
423 			*q++ = cp;
424 		if ((cp = strpbrk(cp, " \t")) != NULL)
425 			*cp++ = '\0';
426 	}
427 	*q = NULL;
428 	if (dbuf)
429 		free(dbuf);
430 	RES_SET_H_ERRNO(pvt->res, NETDB_SUCCESS);
431 	return (&pvt->host);
432 }
433 
434 static void
435 ho_rewind(struct irs_ho *this) {
436 	struct pvt *pvt = (struct pvt *)this->private;
437 
438 	if (pvt->fp) {
439 		if (fseek(pvt->fp, 0L, SEEK_SET) == 0)
440 			return;
441 		(void)fclose(pvt->fp);
442 	}
443 #ifdef SUNW_AVOIDSTDIO_FDLIMIT
444 	if (!(pvt->fp = fopen(_PATH_HOSTS, "rF")))
445 #else
446 	if (!(pvt->fp = fopen(_PATH_HOSTS, "r")))
447 #endif
448 		return;
449 	if (fcntl(fileno(pvt->fp), F_SETFD, 1) < 0) {
450 		(void)fclose(pvt->fp);
451 		pvt->fp = NULL;
452 	}
453 }
454 
455 static void
456 ho_minimize(struct irs_ho *this) {
457 	struct pvt *pvt = (struct pvt *)this->private;
458 
459 	if (pvt->fp != NULL) {
460 		(void)fclose(pvt->fp);
461 		pvt->fp = NULL;
462 	}
463 	if (pvt->res)
464 		res_nclose(pvt->res);
465 }
466 
467 static struct __res_state *
468 ho_res_get(struct irs_ho *this) {
469 	struct pvt *pvt = (struct pvt *)this->private;
470 
471 	if (!pvt->res) {
472 		struct __res_state *res;
473 		res = (struct __res_state *)malloc(sizeof *res);
474 		if (!res) {
475 			errno = ENOMEM;
476 			return (NULL);
477 		}
478 		memset(res, 0, sizeof *res);
479 		ho_res_set(this, res, free);
480 	}
481 
482 	return (pvt->res);
483 }
484 
485 static void
486 ho_res_set(struct irs_ho *this, struct __res_state *res,
487 		void (*free_res)(void *)) {
488 	struct pvt *pvt = (struct pvt *)this->private;
489 
490 	if (pvt->res && pvt->free_res) {
491 		res_nclose(pvt->res);
492 		(*pvt->free_res)(pvt->res);
493 	}
494 
495 	pvt->res = res;
496 	pvt->free_res = free_res;
497 }
498 
499 struct lcl_res_target {
500 	struct lcl_res_target *next;
501 	int family;
502 };
503 
504 /* XXX */
505 extern struct addrinfo *hostent2addrinfo __P((struct hostent *,
506 					      const struct addrinfo *pai));
507 
508 static struct addrinfo *
509 ho_addrinfo(struct irs_ho *this, const char *name, const struct addrinfo *pai)
510 {
511 	struct pvt *pvt = (struct pvt *)this->private;
512 	struct hostent *hp;
513 	struct lcl_res_target q, q2, *p;
514 	struct addrinfo sentinel, *cur;
515 
516 	memset(&q, 0, sizeof(q2));
517 	memset(&q2, 0, sizeof(q2));
518 	memset(&sentinel, 0, sizeof(sentinel));
519 	cur = &sentinel;
520 
521 	switch(pai->ai_family) {
522 	case AF_UNSPEC:		/* INET6 then INET4 */
523 		q.family = AF_INET6;
524 		q.next = &q2;
525 		q2.family = AF_INET;
526 		break;
527 	case AF_INET6:
528 		q.family = AF_INET6;
529 		break;
530 	case AF_INET:
531 		q.family = AF_INET;
532 		break;
533 	default:
534 		RES_SET_H_ERRNO(pvt->res, NO_RECOVERY); /* ??? */
535 		return(NULL);
536 	}
537 
538 	for (p = &q; p; p = p->next) {
539 		struct addrinfo *ai;
540 
541 		hp = (*this->byname2)(this, name, p->family);
542 		if (hp == NULL) {
543 			/* byname2 should've set an appropriate error */
544 			continue;
545 		}
546 		if ((hp->h_name == NULL) || (hp->h_name[0] == 0) ||
547 		    (hp->h_addr_list[0] == NULL)) {
548 			RES_SET_H_ERRNO(pvt->res, NO_RECOVERY);
549 			continue;
550 		}
551 
552 		ai = hostent2addrinfo(hp, pai);
553 		if (ai) {
554 			cur->ai_next = ai;
555 			while (cur && cur->ai_next)
556 				cur = cur->ai_next;
557 		}
558 	}
559 
560 	if (sentinel.ai_next == NULL)
561 		RES_SET_H_ERRNO(pvt->res, HOST_NOT_FOUND);
562 
563 	return(sentinel.ai_next);
564 }
565 
566 /* Private. */
567 
568 static size_t
569 ns_namelen(const char *s) {
570 	int i;
571 
572 	for (i = strlen(s); i > 0 && s[i-1] == '.'; i--)
573 		(void)NULL;
574 	return ((size_t) i);
575 }
576 
577 static int
578 init(struct irs_ho *this) {
579 	struct pvt *pvt = (struct pvt *)this->private;
580 
581 	if (!pvt->res && !ho_res_get(this))
582 		return (-1);
583 	if (((pvt->res->options & RES_INIT) == 0) &&
584 	    res_ninit(pvt->res) == -1)
585 		return (-1);
586 	return (0);
587 }
588