xref: /titanic_41/usr/src/lib/libresolv2/common/irs/lcl_ho.c (revision 8eea8e29cc4374d1ee24c25a07f45af132db3499)
1 /*
2  * Copyright 1997-2003 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 #ifdef	SUNW_AVOIDSTDIO_FDLIMIT
91 #include "../../../libnsl/include/nsl_stdio_prv.h"
92 #endif
93 
94 #include "irs_p.h"
95 #include "dns_p.h"
96 #include "lcl_p.h"
97 
98 #ifdef SPRINTF_CHAR
99 # define SPRINTF(x) strlen(sprintf/**/x)
100 #else
101 # define SPRINTF(x) sprintf x
102 #endif
103 
104 /* Definitions. */
105 
106 #define	MAXALIASES	35
107 #define	MAXADDRS	35
108 #define	Max(a,b)	((a) > (b) ? (a) : (b))
109 
110 #if PACKETSZ > 1024
111 #define	MAXPACKET	PACKETSZ
112 #else
113 #define	MAXPACKET	1024
114 #endif
115 
116 struct pvt {
117 #ifdef	SUNW_AVOIDSTDIO_FDLIMIT
118 	__NSL_FILE *	fp;
119 #else
120 	FILE *		fp;
121 #endif
122 	struct hostent	host;
123 	char *		h_addr_ptrs[MAXADDRS + 1];
124 	char *		host_aliases[MAXALIASES];
125 	char		hostbuf[8*1024];
126 	u_char		host_addr[16];	/* IPv4 or IPv6 */
127 	struct __res_state  *res;
128 	void		(*free_res)(void *);
129 };
130 
131 typedef union {
132 	int32_t al;
133 	char ac;
134 } align;
135 
136 static const u_char mapped[] = { 0,0, 0,0, 0,0, 0,0, 0,0, 0xff,0xff };
137 static const u_char tunnelled[] = { 0,0, 0,0, 0,0, 0,0, 0,0, 0,0 };
138 
139 /* Forward. */
140 
141 static void		ho_close(struct irs_ho *this);
142 static struct hostent *	ho_byname(struct irs_ho *this, const char *name);
143 static struct hostent *	ho_byname2(struct irs_ho *this, const char *name,
144 				   int af);
145 static struct hostent *	ho_byaddr(struct irs_ho *this, const void *addr,
146 				  int len, int af);
147 static struct hostent *	ho_next(struct irs_ho *this);
148 static void		ho_rewind(struct irs_ho *this);
149 static void		ho_minimize(struct irs_ho *this);
150 static struct __res_state * ho_res_get(struct irs_ho *this);
151 static void		ho_res_set(struct irs_ho *this,
152 				   struct __res_state *res,
153 				   void (*free_res)(void *));
154 static struct addrinfo * ho_addrinfo(struct irs_ho *this, const char *name,
155 				     const struct addrinfo *pai);
156 
157 static size_t		ns_namelen(const char *);
158 static int		init(struct irs_ho *this);
159 
160 /* Portability. */
161 
162 #ifndef SEEK_SET
163 # define SEEK_SET 0
164 #endif
165 
166 /* Public. */
167 
168 struct irs_ho *
169 irs_lcl_ho(struct irs_acc *this) {
170 	struct irs_ho *ho;
171 	struct pvt *pvt;
172 
173 	UNUSED(this);
174 
175 	if (!(pvt = memget(sizeof *pvt))) {
176 		errno = ENOMEM;
177 		return (NULL);
178 	}
179 	memset(pvt, 0, sizeof *pvt);
180 	if (!(ho = memget(sizeof *ho))) {
181 		memput(pvt, sizeof *pvt);
182 		errno = ENOMEM;
183 		return (NULL);
184 	}
185 	memset(ho, 0x5e, sizeof *ho);
186 	ho->private = pvt;
187 	ho->close = ho_close;
188 	ho->byname = ho_byname;
189 	ho->byname2 = ho_byname2;
190 	ho->byaddr = ho_byaddr;
191 	ho->next = ho_next;
192 	ho->rewind = ho_rewind;
193 	ho->minimize = ho_minimize;
194 	ho->res_get = ho_res_get;
195 	ho->res_set = ho_res_set;
196 	ho->addrinfo = ho_addrinfo;
197 	return (ho);
198 }
199 
200 /* Methods. */
201 
202 static void
203 ho_close(struct irs_ho *this) {
204 	struct pvt *pvt = (struct pvt *)this->private;
205 
206 	ho_minimize(this);
207 	if (pvt->fp)
208 #ifdef	SUNW_AVOIDSTDIO_FDLIMIT
209 		(void) __nsl_fclose(pvt->fp);
210 #else
211 		(void) fclose(pvt->fp);
212 #endif
213 	if (pvt->res && pvt->free_res)
214 		(*pvt->free_res)(pvt->res);
215 	memput(pvt, sizeof *pvt);
216 	memput(this, sizeof *this);
217 }
218 
219 static struct hostent *
220 ho_byname(struct irs_ho *this, const char *name) {
221 	struct pvt *pvt = (struct pvt *)this->private;
222 	struct hostent *hp;
223 
224 	if (init(this) == -1)
225 		return (NULL);
226 
227 	if (pvt->res->options & RES_USE_INET6) {
228 		hp = ho_byname2(this, name, AF_INET6);
229 		if (hp)
230 			return (hp);
231 	}
232 	return (ho_byname2(this, name, AF_INET));
233 }
234 
235 static struct hostent *
236 ho_byname2(struct irs_ho *this, const char *name, int af) {
237 	struct pvt *pvt = (struct pvt *)this->private;
238 	struct hostent *hp;
239 	char **hap;
240 	size_t n;
241 
242 	if (init(this) == -1)
243 		return (NULL);
244 
245 	ho_rewind(this);
246 	n = ns_namelen(name);
247 	while ((hp = ho_next(this)) != NULL) {
248 		size_t nn;
249 
250 		if (hp->h_addrtype != af)
251 			continue;
252 		nn = ns_namelen(hp->h_name);
253 		if (strncasecmp(hp->h_name, name, Max(n, nn)) == 0)
254 			goto found;
255 		for (hap = hp->h_aliases; *hap; hap++) {
256 			nn = ns_namelen(*hap);
257 			if (strncasecmp(*hap, name, Max(n, nn)) == 0)
258 				goto found;
259 		}
260 	}
261  found:
262 	if (!hp) {
263 		RES_SET_H_ERRNO(pvt->res, HOST_NOT_FOUND);
264 		return (NULL);
265 	}
266 	RES_SET_H_ERRNO(pvt->res, NETDB_SUCCESS);
267 	return (hp);
268 }
269 
270 static struct hostent *
271 ho_byaddr(struct irs_ho *this, const void *addr, int len, int af) {
272 	struct pvt *pvt = (struct pvt *)this->private;
273 	const u_char *uaddr = addr;
274 	struct hostent *hp;
275 	int size;
276 
277 	if (init(this) == -1)
278 		return (NULL);
279 
280 	if (af == AF_INET6 && len == IN6ADDRSZ &&
281 	    (!memcmp(uaddr, mapped, sizeof mapped) ||
282 	     !memcmp(uaddr, tunnelled, sizeof tunnelled))) {
283 		/* Unmap. */
284 		addr = (const u_char *)addr + sizeof mapped;
285 		uaddr += sizeof mapped;
286 		af = AF_INET;
287 		len = INADDRSZ;
288 	}
289 	switch (af) {
290 	case AF_INET:
291 		size = INADDRSZ;
292 		break;
293 	case AF_INET6:
294 		size = IN6ADDRSZ;
295 		break;
296 	default:
297 		errno = EAFNOSUPPORT;
298 		RES_SET_H_ERRNO(pvt->res, NETDB_INTERNAL);
299 		return (NULL);
300 	}
301 	if (size > len) {
302 		errno = EINVAL;
303 		RES_SET_H_ERRNO(pvt->res, NETDB_INTERNAL);
304 		return (NULL);
305 	}
306 
307 	/*
308 	 * Do the search.
309 	 */
310 	ho_rewind(this);
311 	while ((hp = ho_next(this)) != NULL) {
312 		char **hap;
313 
314 		for (hap = hp->h_addr_list; *hap; hap++) {
315 			const u_char *taddr = (const u_char *)*hap;
316 			int taf = hp->h_addrtype;
317 			int tlen = hp->h_length;
318 
319 			if (taf == AF_INET6 && tlen == IN6ADDRSZ &&
320 			    (!memcmp(taddr, mapped, sizeof mapped) ||
321 			     !memcmp(taddr, tunnelled, sizeof tunnelled))) {
322 				/* Unmap. */
323 				taddr += sizeof mapped;
324 				taf = AF_INET;
325 				tlen = INADDRSZ;
326 			}
327 			if (taf == af && tlen == len &&
328 			    !memcmp(taddr, uaddr, tlen))
329 				goto found;
330 		}
331 	}
332  found:
333 	if (!hp) {
334 		RES_SET_H_ERRNO(pvt->res, HOST_NOT_FOUND);
335 		return (NULL);
336 	}
337 	RES_SET_H_ERRNO(pvt->res, NETDB_SUCCESS);
338 	return (hp);
339 }
340 
341 static struct hostent *
342 ho_next(struct irs_ho *this) {
343 	struct pvt *pvt = (struct pvt *)this->private;
344 	char *cp, **q, *p;
345 	char *bufp, *ndbuf, *dbuf = NULL;
346 	int c, af, len, bufsiz, offset;
347 
348 	if (init(this) == -1)
349 		return (NULL);
350 
351 	if (!pvt->fp)
352 		ho_rewind(this);
353 	if (!pvt->fp) {
354 		RES_SET_H_ERRNO(pvt->res, NETDB_INTERNAL);
355 		return (NULL);
356 	}
357 	bufp = pvt->hostbuf;
358 	bufsiz = sizeof pvt->hostbuf;
359 	offset = 0;
360  again:
361 #ifdef	SUNW_AVOIDSTDIO_FDLIMIT
362 	if (!(p = __nsl_fgets(bufp + offset, bufsiz - offset, pvt->fp))) {
363 #else
364 	if (!(p = fgets(bufp + offset, bufsiz - offset, pvt->fp))) {
365 #endif
366 		RES_SET_H_ERRNO(pvt->res, HOST_NOT_FOUND);
367 		if (dbuf)
368 			free(dbuf);
369 		return (NULL);
370 	}
371 #ifdef	SUNW_AVOIDSTDIO_FDLIMIT
372 	if (!strchr(p, '\n') && !__nsl_feof(pvt->fp)) {
373 #else
374 	if (!strchr(p, '\n') && !feof(pvt->fp)) {
375 #endif
376 #define GROWBUF 1024
377 		/* allocate space for longer line */
378 		if (dbuf == NULL) {
379 			if ((ndbuf = malloc(bufsiz + GROWBUF)) != NULL)
380 				strcpy(ndbuf, bufp);
381 		} else
382 			ndbuf = realloc(dbuf, bufsiz + GROWBUF);
383 		if (ndbuf) {
384 			dbuf = ndbuf;
385 			bufp = dbuf;
386 			bufsiz += GROWBUF;
387 			offset = strlen(dbuf);
388 		} else {
389 			/* allocation failed; skip this long line */
390 #ifdef	SUNW_AVOIDSTDIO_FDLIMIT
391 			while ((c = __nsl_getc(pvt->fp)) != EOF)
392 #else
393 			while ((c = getc(pvt->fp)) != EOF)
394 #endif
395 				if (c == '\n')
396 					break;
397 			if (c != EOF)
398 #ifdef	SUNW_AVOIDSTDIO_FDLIMIT
399 				__nsl_ungetc(c, pvt->fp);
400 #else
401 				ungetc(c, pvt->fp);
402 #endif
403 		}
404 		goto again;
405 	}
406 
407 	p -= offset;
408 	offset = 0;
409 
410 	if (*p == '#')
411 		goto again;
412 	if ((cp = strpbrk(p, "#\n")) != NULL)
413 		*cp = '\0';
414 	if (!(cp = strpbrk(p, " \t")))
415 		goto again;
416 	*cp++ = '\0';
417 	if (inet_pton(AF_INET6, p, pvt->host_addr) > 0) {
418 		af = AF_INET6;
419 		len = IN6ADDRSZ;
420 	} else if (inet_aton(p, (struct in_addr *)pvt->host_addr) > 0) {
421 		if (pvt->res->options & RES_USE_INET6) {
422 			map_v4v6_address((char*)pvt->host_addr,
423 					 (char*)pvt->host_addr);
424 			af = AF_INET6;
425 			len = IN6ADDRSZ;
426 		} else {
427 			af = AF_INET;
428 			len = INADDRSZ;
429 		}
430 	} else {
431 		goto again;
432 	}
433 	pvt->h_addr_ptrs[0] = (char *)pvt->host_addr;
434 	pvt->h_addr_ptrs[1] = NULL;
435 	pvt->host.h_addr_list = pvt->h_addr_ptrs;
436 	pvt->host.h_length = len;
437 	pvt->host.h_addrtype = af;
438 	while (*cp == ' ' || *cp == '\t')
439 		cp++;
440 	pvt->host.h_name = cp;
441 	q = pvt->host.h_aliases = pvt->host_aliases;
442 	if ((cp = strpbrk(cp, " \t")) != NULL)
443 		*cp++ = '\0';
444 	while (cp && *cp) {
445 		if (*cp == ' ' || *cp == '\t') {
446 			cp++;
447 			continue;
448 		}
449 		if (q < &pvt->host_aliases[MAXALIASES - 1])
450 			*q++ = cp;
451 		if ((cp = strpbrk(cp, " \t")) != NULL)
452 			*cp++ = '\0';
453 	}
454 	*q = NULL;
455 	if (dbuf)
456 		free(dbuf);
457 	RES_SET_H_ERRNO(pvt->res, NETDB_SUCCESS);
458 	return (&pvt->host);
459 }
460 
461 static void
462 ho_rewind(struct irs_ho *this) {
463 	struct pvt *pvt = (struct pvt *)this->private;
464 
465 #ifdef	SUNW_AVOIDSTDIO_FDLIMIT
466 	if (pvt->fp) {
467 		if (__nsl_fseek(pvt->fp, 0L, SEEK_SET) == 0)
468 			return;
469 		(void)__nsl_fclose(pvt->fp);
470 	}
471 	if (!(pvt->fp = __nsl_fopen(_PATH_HOSTS, "r")))
472 		return;
473 	if (fcntl(__nsl_fileno(pvt->fp), F_SETFD, 1) < 0) {
474 		(void)__nsl_fclose(pvt->fp);
475 		pvt->fp = NULL;
476 	}
477 #else
478 	if (pvt->fp) {
479 		if (fseek(pvt->fp, 0L, SEEK_SET) == 0)
480 			return;
481 		(void)fclose(pvt->fp);
482 	}
483 	if (!(pvt->fp = fopen(_PATH_HOSTS, "r")))
484 		return;
485 	if (fcntl(fileno(pvt->fp), F_SETFD, 1) < 0) {
486 		(void)fclose(pvt->fp);
487 		pvt->fp = NULL;
488 	}
489 #endif
490 
491 }
492 
493 static void
494 ho_minimize(struct irs_ho *this) {
495 	struct pvt *pvt = (struct pvt *)this->private;
496 
497 	if (pvt->fp != NULL) {
498 #ifdef	SUNW_AVOIDSTDIO_FDLIMIT
499 		(void)__nsl_fclose(pvt->fp);
500 #else
501 		(void)fclose(pvt->fp);
502 #endif
503 		pvt->fp = NULL;
504 	}
505 	if (pvt->res)
506 		res_nclose(pvt->res);
507 }
508 
509 static struct __res_state *
510 ho_res_get(struct irs_ho *this) {
511 	struct pvt *pvt = (struct pvt *)this->private;
512 
513 	if (!pvt->res) {
514 		struct __res_state *res;
515 		res = (struct __res_state *)malloc(sizeof *res);
516 		if (!res) {
517 			errno = ENOMEM;
518 			return (NULL);
519 		}
520 		memset(res, 0, sizeof *res);
521 		ho_res_set(this, res, free);
522 	}
523 
524 	return (pvt->res);
525 }
526 
527 static void
528 ho_res_set(struct irs_ho *this, struct __res_state *res,
529 		void (*free_res)(void *)) {
530 	struct pvt *pvt = (struct pvt *)this->private;
531 
532 	if (pvt->res && pvt->free_res) {
533 		res_nclose(pvt->res);
534 		(*pvt->free_res)(pvt->res);
535 	}
536 
537 	pvt->res = res;
538 	pvt->free_res = free_res;
539 }
540 
541 struct lcl_res_target {
542 	struct lcl_res_target *next;
543 	int family;
544 };
545 
546 /* XXX */
547 extern struct addrinfo *hostent2addrinfo __P((struct hostent *,
548 					      const struct addrinfo *pai));
549 
550 static struct addrinfo *
551 ho_addrinfo(struct irs_ho *this, const char *name, const struct addrinfo *pai)
552 {
553 	struct pvt *pvt = (struct pvt *)this->private;
554 	struct hostent *hp;
555 	struct lcl_res_target q, q2, *p;
556 	struct addrinfo sentinel, *cur;
557 
558 	memset(&q, 0, sizeof(q2));
559 	memset(&q2, 0, sizeof(q2));
560 	memset(&sentinel, 0, sizeof(sentinel));
561 	cur = &sentinel;
562 
563 	switch(pai->ai_family) {
564 	case AF_UNSPEC:		/* INET6 then INET4 */
565 		q.family = AF_INET6;
566 		q.next = &q2;
567 		q2.family = AF_INET;
568 		break;
569 	case AF_INET6:
570 		q.family = AF_INET6;
571 		break;
572 	case AF_INET:
573 		q.family = AF_INET;
574 		break;
575 	default:
576 		RES_SET_H_ERRNO(pvt->res, NO_RECOVERY); /* ??? */
577 		return(NULL);
578 	}
579 
580 	for (p = &q; p; p = p->next) {
581 		struct addrinfo *ai;
582 
583 		hp = (*this->byname2)(this, name, p->family);
584 		if (hp == NULL) {
585 			/* byname2 should've set an appropriate error */
586 			continue;
587 		}
588 		if ((hp->h_name == NULL) || (hp->h_name[0] == 0) ||
589 		    (hp->h_addr_list[0] == NULL)) {
590 			RES_SET_H_ERRNO(pvt->res, NO_RECOVERY);
591 			continue;
592 		}
593 
594 		ai = hostent2addrinfo(hp, pai);
595 		if (ai) {
596 			cur->ai_next = ai;
597 			while (cur && cur->ai_next)
598 				cur = cur->ai_next;
599 		}
600 	}
601 
602 	if (sentinel.ai_next == NULL)
603 		RES_SET_H_ERRNO(pvt->res, HOST_NOT_FOUND);
604 
605 	return(sentinel.ai_next);
606 }
607 
608 /* Private. */
609 
610 static size_t
611 ns_namelen(const char *s) {
612 	int i;
613 
614 	for (i = strlen(s); i > 0 && s[i-1] == '.'; i--)
615 		(void)NULL;
616 	return ((size_t) i);
617 }
618 
619 static int
620 init(struct irs_ho *this) {
621 	struct pvt *pvt = (struct pvt *)this->private;
622 
623 	if (!pvt->res && !ho_res_get(this))
624 		return (-1);
625 	if (((pvt->res->options & RES_INIT) == 0) &&
626 	    res_ninit(pvt->res) == -1)
627 		return (-1);
628 	return (0);
629 }
630