1 /*
2 * CDDL HEADER START
3 *
4 * The contents of this file are subject to the terms of the
5 * Common Development and Distribution License (the "License").
6 * You may not use this file except in compliance with the License.
7 *
8 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
9 * or http://www.opensolaris.org/os/licensing.
10 * See the License for the specific language governing permissions
11 * and limitations under the License.
12 *
13 * When distributing Covered Code, include this CDDL HEADER in each
14 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
15 * If applicable, add the following below this CDDL HEADER, with the
16 * fields enclosed by brackets "[]" replaced with your own identifying
17 * information: Portions Copyright [yyyy] [name of copyright owner]
18 *
19 * CDDL HEADER END
20 */
21
22 /*
23 * Copyright (c) 1991, 2010, Oracle and/or its affiliates. All rights reserved.
24 */
25
26 #include <netdb.h>
27 #include "files_common.h"
28 #include <string.h>
29 #include <strings.h>
30 #include <stddef.h>
31 #include <stdlib.h>
32 #include <sys/types.h>
33 #include <sys/socket.h>
34 #include <netinet/in.h>
35 #include <arpa/nameser.h>
36 #include <arpa/inet.h>
37 #include <ctype.h>
38
39 static int check_name(nss_XbyY_args_t *, const char *, int,
40 int, const char **, int *, void *, int *);
41 static char *do_aliases();
42 nss_status_t __nss_files_XY_hostbyname();
43 int __nss_files_2herrno();
44 static int __nss_files_get_addr(int, const char *, int,
45 void *, int, int *);
46
47 static int
check_name(nss_XbyY_args_t * argp,const char * line,int linelen,int type,const char ** namep,int * namelen,void * addrp,int * addrsize)48 check_name(nss_XbyY_args_t *argp, const char *line, int linelen,
49 int type, const char **namep, int *namelen,
50 void *addrp, int *addrsize)
51 {
52 const char *limit, *linep, *keyp, *addrstart;
53 int v6flag = 0, addrlen;
54
55 linep = line;
56 limit = line + linelen;
57
58 /* Address */
59 addrstart = linep;
60 while (linep < limit && !isspace(*linep)) {
61 if (*linep == ':')
62 v6flag++;
63 linep++;
64 }
65 addrlen = linep - addrstart;
66
67 /* skip the delimiting spaces */
68 while (linep < limit && isspace(*linep))
69 linep++;
70
71 /* Canonical name */
72 keyp = argp->key.name;
73 *namep = linep;
74 while (*keyp && linep < limit && !isspace(*linep) &&
75 tolower(*keyp) == tolower(*linep)) {
76 keyp++;
77 linep++;
78 }
79 if (*keyp == '\0' && (linep == limit || isspace(*linep))) {
80 if (__nss_files_get_addr(type, addrstart, addrlen,
81 addrp, v6flag, addrsize)) {
82 *namelen = linep - *namep;
83 return (1);
84 }
85 }
86 while (linep < limit && !isspace(*linep))
87 linep++;
88 *namelen = linep - *namep;
89
90 /* Aliases */
91 while (linep < limit) {
92 /* skip the delimiting spaces */
93 while (linep < limit && isspace(*linep))
94 linep++;
95
96 /* compare name (case insensitive) */
97 keyp = argp->key.name;
98 while (*keyp && linep < limit && !isspace(*linep) &&
99 tolower(*keyp) == tolower(*linep)) {
100 keyp++;
101 linep++;
102 }
103 if (*keyp == '\0' && (linep == limit || isspace(*linep)))
104 return (__nss_files_get_addr(type, addrstart, addrlen,
105 addrp, v6flag, addrsize));
106
107 /* skip remainder of alias, if any */
108 while (linep < limit && !isspace(*linep))
109 linep++;
110 }
111 return (0);
112
113 }
114
115 static nss_status_t
getbyname(be,a)116 getbyname(be, a)
117 files_backend_ptr_t be;
118 void *a;
119 {
120 nss_XbyY_args_t *argp = (nss_XbyY_args_t *)a;
121 nss_status_t res;
122
123 res = __nss_files_XY_hostbyname(be, argp, argp->key.name, AF_INET);
124 if (res != NSS_SUCCESS)
125 argp->h_errno = __nss_files_2herrno(res);
126 return (res);
127 }
128
129 static int
__nss_files_get_addr(int af,const char * addrstart,int addrlen,void * addrp,int v6flag,int * h_length)130 __nss_files_get_addr(int af, const char *addrstart, int addrlen,
131 void *addrp, int v6flag, int *h_length)
132 {
133 struct in_addr addr_ipv4;
134 struct in6_addr *addrpv6;
135 in_addr_t *addrpv4;
136 char addrbuf[INET6_ADDRSTRLEN + 1];
137
138 if (addrlen >= sizeof (addrbuf))
139 return (0);
140 (void) memcpy(addrbuf, addrstart, addrlen);
141 addrbuf[addrlen] = '\0';
142
143 if (af == AF_INET) {
144 addrpv4 = (in_addr_t *)addrp;
145 if ((*addrpv4 = inet_addr(addrbuf)) == 0xffffffffU)
146 return (0);
147 *h_length = sizeof (in_addr_t);
148 } else if (af == AF_INET6) {
149 addrpv6 = (struct in6_addr *)addrp;
150 if (v6flag) {
151 if (inet_pton(af, addrbuf, addrpv6) != 1)
152 return (0);
153 } else {
154 if ((addr_ipv4.s_addr = inet_addr(addrbuf)) ==
155 0xffffffffU)
156 return (0);
157 IN6_INADDR_TO_V4MAPPED(&addr_ipv4, addrpv6);
158 }
159 *h_length = sizeof (struct in6_addr);
160 } else {
161 return (0);
162 }
163 return (1);
164 }
165
166
167 int
__nss_files_check_addr(int af,nss_XbyY_args_t * argp,const char * line,int linelen)168 __nss_files_check_addr(int af, nss_XbyY_args_t *argp, const char *line,
169 int linelen)
170 {
171 const char *limit, *linep, *addrstart;
172 int v6flag = 0, addrlen, h_length;
173 in_addr_t addr_ipv4;
174 struct in6_addr addr_ipv6;
175 char *h_addrp;
176
177 /* Compare the address type */
178 if (argp->key.hostaddr.type != af)
179 return (0);
180
181 /* Retrieve the address */
182 if (af == AF_INET)
183 h_addrp = (char *)&addr_ipv4;
184 else
185 h_addrp = (char *)&addr_ipv6;
186 linep = line;
187 limit = line + linelen;
188 addrstart = linep;
189 while (linep < limit && !isspace(*linep)) {
190 if (*linep == ':')
191 v6flag++;
192 linep++;
193 }
194 addrlen = linep - addrstart;
195 if (__nss_files_get_addr(af, addrstart, addrlen, h_addrp,
196 v6flag, &h_length) == 0)
197 return (0);
198
199 /* Compare the address */
200 return (h_length == argp->key.hostaddr.len &&
201 memcmp(h_addrp, argp->key.hostaddr.addr,
202 argp->key.hostaddr.len) == 0);
203 }
204
205 static int
check_addr(nss_XbyY_args_t * argp,const char * line,int linelen)206 check_addr(nss_XbyY_args_t *argp, const char *line, int linelen)
207 {
208 return (__nss_files_check_addr(AF_INET, argp, line, linelen));
209 }
210
211 static nss_status_t
getbyaddr(be,a)212 getbyaddr(be, a)
213 files_backend_ptr_t be;
214 void *a;
215 {
216 nss_XbyY_args_t *argp = (nss_XbyY_args_t *)a;
217 nss_status_t res;
218
219 res = _nss_files_XY_all(be, argp, 1, 0, check_addr);
220 if (res != NSS_SUCCESS)
221 argp->h_errno = __nss_files_2herrno(res);
222 return (res);
223 }
224
225 /*
226 * filter_ipv6
227 *
228 * Return - NSS_STR_PARSE_SUCCESS: An IPv4 address
229 * NSS_STR_PARSE_PARSE: An IPv6 address or other errors
230 */
231 static int
filter_ipv6(char * instr,int lenstr)232 filter_ipv6(char *instr, int lenstr) {
233 char *p, *addrstart, *limit, c;
234 int rc;
235 struct in_addr addr;
236
237 p = instr;
238 limit = p + lenstr;
239
240 addrstart = p;
241
242 /* parse IP address */
243 while (p < limit && !isspace(*p)) {
244 if (*p == ':')
245 /* IPv6 */
246 return (NSS_STR_PARSE_PARSE);
247 else
248 p++;
249 }
250
251 if (p >= limit)
252 /* invalid IP */
253 return (NSS_STR_PARSE_PARSE);
254
255 /* extract IP address */
256 c = *p;
257 *p = '\0';
258 rc = inet_aton(addrstart, &addr);
259 *p = c;
260
261 if (rc == 0)
262 /* invalid IP */
263 return (NSS_STR_PARSE_PARSE);
264 else
265 /* IPv4 */
266 return (NSS_STR_PARSE_SUCCESS);
267
268
269 }
270 static nss_status_t
getent_hosts(files_backend_ptr_t be,void * a)271 getent_hosts(files_backend_ptr_t be, void *a)
272 {
273 nss_XbyY_args_t *args = (nss_XbyY_args_t *)a;
274 nss_status_t rc = NSS_SUCCESS;
275
276 if (args->buf.result != NULL) {
277 return (_nss_files_XY_all(be, args, 1, 0, 0));
278 } else {
279 /*
280 * Called by nscd
281 */
282 /*CONSTCOND*/
283 while (1) {
284 rc = _nss_files_XY_all(be, args, 1, 0, 0);
285 /*
286 * NSS_NOTFOUND, end of file or other errors.
287 */
288 if (rc != NSS_SUCCESS)
289 break;
290 /*
291 * /etc/hosts and /etc/ipnodes are merged and
292 * /etc/hosts can contain IPv6 addresses.
293 * These addresses have to be filtered.
294 */
295 if (filter_ipv6(args->returnval, args->returnlen)
296 == NSS_STR_PARSE_SUCCESS)
297 break;
298 /*
299 * The entry is an IPv6 address or other errors.
300 * Skip it and continue to find next one.
301 */
302 args->returnval = NULL;
303 args->returnlen = 0;
304
305 }
306 return (rc);
307 }
308
309 }
310
311 static files_backend_op_t host_ops[] = {
312 _nss_files_destr,
313 _nss_files_endent,
314 _nss_files_setent,
315 getent_hosts,
316 getbyname,
317 getbyaddr,
318 };
319
320 /*ARGSUSED*/
321 nss_backend_t *
_nss_files_hosts_constr(dummy1,dummy2,dummy3)322 _nss_files_hosts_constr(dummy1, dummy2, dummy3)
323 const char *dummy1, *dummy2, *dummy3;
324 {
325 return (_nss_files_constr(host_ops,
326 sizeof (host_ops) / sizeof (host_ops[0]),
327 _PATH_HOSTS,
328 NSS_LINELEN_HOSTS,
329 NULL));
330 }
331
332
333 /*
334 * XXX - this duplicates code from files_common.c because we need to keep
335 * going after we've found a match to satisfy the multihomed host case.
336 */
337 nss_status_t
__nss_files_XY_hostbyname(be,args,filter,type)338 __nss_files_XY_hostbyname(be, args, filter, type)
339 files_backend_ptr_t be;
340 nss_XbyY_args_t *args;
341 const char *filter; /* hint for name string */
342 int type;
343 {
344 nss_status_t res;
345 char *abuf = NULL, *abuf_start = NULL, *abuf_end;
346 char *first, *last, *buffer;
347 int parsestat, i, nhosts = 0, buflen;
348 const char *namep;
349 char *h_name;
350 int h_namelen, namelen;
351 struct hostent *hp;
352 in_addr_t *taddr = NULL;
353 struct in6_addr *taddr6 = NULL;
354 size_t ntaddr;
355 void *addrp;
356 char *alias_end = NULL;
357
358 if (be->buf == 0 && (be->buf = malloc(be->minbuf)) == 0) {
359 return (NSS_UNAVAIL);
360 }
361
362 if (be->f == 0) {
363 if ((res = _nss_files_setent(be, 0)) != NSS_SUCCESS)
364 return (res);
365 }
366
367 ntaddr = MAXADDRS;
368 if (type == AF_INET) {
369 taddr = (in_addr_t *)calloc(ntaddr, sizeof (*taddr));
370 if (taddr == NULL)
371 return (NSS_UNAVAIL);
372 } else {
373 taddr6 = (struct in6_addr *)calloc(ntaddr, sizeof (*taddr6));
374 if (taddr6 == NULL)
375 return (NSS_UNAVAIL);
376 }
377
378 res = NSS_NOTFOUND;
379 args->returnval = (char *)0;
380 args->returnlen = 0;
381 hp = (struct hostent *)args->buf.result;
382 buffer = args->buf.buffer;
383 buflen = args->buf.buflen;
384 h_namelen = 0;
385 h_name = NULL;
386
387 for (;;) {
388 char *instr = be->buf;
389 int linelen;
390
391 if ((linelen = _nss_files_read_line(be->f,
392 instr, be->minbuf)) < 0) {
393 break; /* EOF */
394 }
395
396 /*
397 * This check avoids a malloc()/free() for the common
398 * case. Also, if we're trying to match an alias and an
399 * already matched entry doesn't share a canonical name
400 * with the current one, bail.
401 */
402 if (nhosts == 0 && strcasestr(instr, filter) == 0) {
403 continue;
404 }
405
406 if ((last = strchr(instr, '#')) == 0)
407 last = instr + linelen;
408 *last-- = '\0';
409 for (first = instr; isspace(*first); first++)
410 ;
411 /* Ignore blank and comment lines */
412 if (*first == '\0')
413 continue;
414
415 while (isspace(*last))
416 --last;
417 linelen = last - first + 1;
418 if (first != instr)
419 instr = first;
420
421 /* Bail out if the canonical name does not match */
422 if (nhosts && strcasestr(instr, h_name) == 0) {
423 continue;
424 }
425
426 /*
427 * Still need to check, strcasestr() above is just a hint.
428 */
429 addrp = (type == AF_INET)?
430 (void *)&taddr[nhosts]:
431 (void *)&taddr6[nhosts];
432
433 if (check_name(args, instr, linelen,
434 type, &namep, &namelen,
435 addrp, &i)) {
436
437 /*
438 * If we've already matched once and have a possible
439 * match on this line, copy the aliases where they're
440 * safe from being overwritten when we look at the
441 * next entry. They're saved as a string of blank
442 * separated names for the alias parser. On errors,
443 * we return failure whether or not we have already
444 * obtained a valid address.
445 */
446 if (nhosts == 1 && hp) {
447 if (h_namelen + 1 > args->buf.buflen) {
448 args->erange = 1;
449 res = NSS_NOTFOUND;
450 break;
451 }
452 abuf = (char *)malloc(args->buf.buflen);
453 if (abuf == NULL) {
454 res = NSS_UNAVAIL;
455 break;
456 }
457 abuf_start = abuf;
458 abuf_end = abuf_start + args->buf.buflen;
459 (void) memcpy(abuf, h_name, h_namelen);
460 abuf += h_namelen;
461 *abuf = '\0';
462 abuf = do_aliases(hp, abuf, abuf_end);
463 if (abuf == NULL) {
464 args->erange = 1;
465 res = NSS_NOTFOUND;
466 break;
467 }
468 }
469
470 if (hp != NULL) {
471 /* inside the application */
472 parsestat = (*args->str2ent)(instr, linelen,
473 hp, buffer, buflen);
474 if (parsestat != NSS_STR_PARSE_SUCCESS) {
475 if (parsestat == NSS_STR_PARSE_ERANGE)
476 args->erange = 1;
477 (void) memset(buffer, 0, buflen);
478 continue;
479 }
480 } else {
481 /* inside nscd */
482 int alen, cplen, erange = 0;
483 char *ap;
484
485 /* Add alias to the first line if any */
486 if (nhosts > 0) {
487
488 /* get to the start of alias */
489 ap = (char *)namep + namelen;
490 /* see if there's any alias */
491 if (ap == instr + linelen)
492 alen = 0;
493 else
494 alen = linelen - (ap - instr);
495 if (alen + 1 >= buflen)
496 erange = 1;
497 if (erange == 0 && alen != 0) {
498 /* make room for the alias */
499 if (alias_end != NULL)
500 (void) memmove(alias_end +
501 alen, alias_end, buffer -
502 alias_end);
503 /* copy in the alias */
504 (void) memmove(alias_end,
505 ap, alen);
506 buffer += alen;
507 buflen -= alen;
508 args->returnlen += alen;
509 alias_end += alen;
510 }
511
512 /* Add delimiter to the buffer */
513 *buffer++ = '\n';
514 buflen--;
515 args->returnlen++;
516 }
517
518 /* copy just the addr if not first one */
519 if (alias_end == NULL)
520 cplen = linelen;
521 else
522 cplen = namep - instr;
523
524 if (cplen >= buflen || erange == 1) {
525 args->erange = 1;
526 if (nhosts > 0) {
527 *(--buffer) = '\0';
528 buflen++;
529 args->returnlen--;
530 }
531 continue;
532 }
533
534 (void) memcpy(buffer, instr, cplen);
535 /* Adjust buffer */
536 buffer += cplen;
537 *buffer = '\0';
538 buflen -= cplen;
539 args->returnlen += cplen;
540 if (alias_end == NULL)
541 alias_end = buffer;
542 }
543
544 /*
545 * If this is the first one, save the canonical
546 * name for future matches and continue.
547 */
548 if (++nhosts == 1) {
549 h_name = malloc(namelen + 1);
550 if (h_name == NULL) {
551 res = NSS_UNAVAIL;
552 break;
553 }
554 res = NSS_SUCCESS;
555 (void) memcpy(h_name, namep, namelen);
556 h_name[namelen] = '\0';
557 h_namelen = namelen;
558 if (hp)
559 args->returnval = hp;
560 else
561 args->returnval = args->buf.buffer;
562 continue;
563 }
564
565
566 /* Extend the array */
567 if (nhosts >= ntaddr) {
568 ntaddr *= 2;
569 if (type == AF_INET) {
570 addrp = realloc(taddr,
571 sizeof (*taddr) * ntaddr);
572 if (addrp == NULL) {
573 res = NSS_UNAVAIL;
574 break;
575 }
576 taddr = (in_addr_t *)addrp;
577 } else {
578 addrp = realloc(taddr6,
579 sizeof (*taddr6) * ntaddr);
580 if (addrp == NULL) {
581 res = NSS_UNAVAIL;
582 break;
583 }
584 taddr6 = (struct in6_addr *)addrp;
585 }
586 }
587
588 /*
589 * For non-nscd, save aliases in a temporary buffer
590 * Don't have to do this for nscd as 'buffer' already
591 * contains the required data in the appropriate
592 * format
593 */
594 if (hp) {
595 abuf = do_aliases(hp, abuf, abuf_end);
596 if (abuf == NULL) {
597 args->erange = 1;
598 res = NSS_NOTFOUND;
599 break;
600 }
601 }
602 } else if (namep && h_namelen == namelen &&
603 strncasecmp(h_name, namep, namelen) == 0) {
604 /*
605 * This line didn't have the requested name but
606 * is part of the same multihomed host (i.e. it
607 * has the same canonical name as the previous
608 * line), so march on...
609 */
610 continue;
611 } else if (nhosts) {
612 continue;
613 }
614 }
615
616 if (abuf && res == NSS_SUCCESS) {
617
618 /* abuf != NULL implies hp and abuf_start != NULL */
619
620 struct in_addr *addrp;
621 struct in6_addr *addrp6;
622
623 if (type == AF_INET) {
624 addrp = (struct in_addr *)(ROUND_DOWN(args->buf.buffer +
625 args->buf.buflen, sizeof (*addrp)));
626 hp->h_addr_list = (char **)(ROUND_DOWN(addrp -
627 ((nhosts + 1) * sizeof (char *) +
628 (nhosts * sizeof (*addrp))), sizeof (char *)));
629 for (i = 0, --addrp; i < nhosts; i++, --addrp) {
630 (*(in_addr_t *)addrp) = taddr[i];
631 hp->h_addr_list[i] = (char *)addrp;
632 }
633 } else {
634 addrp6 = (struct in6_addr *)
635 (ROUND_DOWN(args->buf.buffer + args->buf.buflen,
636 sizeof (*addrp6)));
637 hp->h_addr_list = (char **)(ROUND_DOWN(addrp6 -
638 ((nhosts + 1) * sizeof (char *) +
639 (nhosts * sizeof (*addrp6))), sizeof (char *)));
640 for (i = 0, --addrp6; i < nhosts; i++, --addrp6) {
641 (void) memcpy(addrp6, &taddr6[i],
642 sizeof (struct in6_addr));
643 hp->h_addr_list[i] = (char *)addrp6;
644 }
645 }
646
647 hp->h_addr_list[nhosts] = 0;
648 hp->h_aliases = _nss_netdb_aliases(abuf_start,
649 abuf - abuf_start, args->buf.buffer,
650 (char *)hp->h_addr_list - args->buf.buffer);
651 if (hp->h_aliases == 0) {
652 args->erange = 1;
653 res = NSS_NOTFOUND;
654 } else {
655 hp->h_name = hp->h_aliases[0];
656 hp->h_aliases++;
657 }
658 }
659
660 /*
661 * stayopen is set to 0 by default in order to close the opened
662 * file. Some applications may break if it is set to 1.
663 */
664 if (!args->stayopen)
665 (void) _nss_files_endent(be, 0);
666
667 if (taddr)
668 free(taddr);
669 if (taddr6)
670 free(taddr6);
671 if (h_name)
672 free(h_name);
673 if (abuf_start)
674 free(abuf_start);
675
676 return (res);
677 }
678
679
680 static char *
do_aliases(struct hostent * hp,char * abuf,char * end)681 do_aliases(struct hostent *hp, char *abuf, char *end)
682 {
683 char **cp;
684 size_t len;
685
686 if ((cp = hp->h_aliases) == NULL)
687 return (abuf);
688
689 for (; *cp; cp++) {
690 len = strlen(*cp);
691 if (abuf+len+1 >= end) {
692 return (NULL);
693 }
694 *abuf++ = ' ';
695 (void) memcpy(abuf, *cp, len);
696 abuf += len;
697 }
698 *abuf = '\0';
699
700 return (abuf);
701 }
702
703
704 /*
705 * This is a copy of a routine in libnsl/nss/netdir_inet.c. It is
706 * here because /etc/lib/nss_files.so.1 cannot call routines
707 * in libnsl. Care should be taken to keep the two copies in sync.
708 */
709 int
__nss_files_2herrno(nsstat)710 __nss_files_2herrno(nsstat)
711 nss_status_t nsstat;
712 {
713 switch (nsstat) {
714 case NSS_SUCCESS:
715 /* no macro-defined success code for h_errno */
716 return (0);
717 case NSS_NOTFOUND:
718 return (HOST_NOT_FOUND);
719 case NSS_TRYAGAIN:
720 return (TRY_AGAIN);
721 case NSS_UNAVAIL:
722 return (NO_RECOVERY);
723 }
724 /* anything else */
725 return (NO_RECOVERY);
726 }
727