1 | /* Convert socket address to string using Name Service Switch modules. |
2 | Copyright (C) 1997-2017 Free Software Foundation, Inc. |
3 | This file is part of the GNU C Library. |
4 | |
5 | The GNU C Library is free software; you can redistribute it and/or |
6 | modify it under the terms of the GNU Lesser General Public |
7 | License as published by the Free Software Foundation; either |
8 | version 2.1 of the License, or (at your option) any later version. |
9 | |
10 | The GNU C Library is distributed in the hope that it will be useful, |
11 | but WITHOUT ANY WARRANTY; without even the implied warranty of |
12 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
13 | Lesser General Public License for more details. |
14 | |
15 | You should have received a copy of the GNU Lesser General Public |
16 | License along with the GNU C Library; if not, see |
17 | <http://www.gnu.org/licenses/>. */ |
18 | |
19 | /* The Inner Net License, Version 2.00 |
20 | |
21 | The author(s) grant permission for redistribution and use in source and |
22 | binary forms, with or without modification, of the software and documentation |
23 | provided that the following conditions are met: |
24 | |
25 | 0. If you receive a version of the software that is specifically labelled |
26 | as not being for redistribution (check the version message and/or README), |
27 | you are not permitted to redistribute that version of the software in any |
28 | way or form. |
29 | 1. All terms of the all other applicable copyrights and licenses must be |
30 | followed. |
31 | 2. Redistributions of source code must retain the authors' copyright |
32 | notice(s), this list of conditions, and the following disclaimer. |
33 | 3. Redistributions in binary form must reproduce the authors' copyright |
34 | notice(s), this list of conditions, and the following disclaimer in the |
35 | documentation and/or other materials provided with the distribution. |
36 | 4. [The copyright holder has authorized the removal of this clause.] |
37 | 5. Neither the name(s) of the author(s) nor the names of its contributors |
38 | may be used to endorse or promote products derived from this software |
39 | without specific prior written permission. |
40 | |
41 | THIS SOFTWARE IS PROVIDED BY ITS AUTHORS AND CONTRIBUTORS ``AS IS'' AND ANY |
42 | EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED |
43 | WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE |
44 | DISCLAIMED. IN NO EVENT SHALL THE AUTHORS OR CONTRIBUTORS BE LIABLE FOR ANY |
45 | DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES |
46 | (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; |
47 | LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON |
48 | ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT |
49 | (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS |
50 | SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. |
51 | |
52 | If these license terms cause you a real problem, contact the author. */ |
53 | |
54 | /* This software is Copyright 1996 by Craig Metz, All Rights Reserved. */ |
55 | |
56 | #include <errno.h> |
57 | #include <netdb.h> |
58 | #include <stddef.h> |
59 | #include <stdlib.h> |
60 | #include <stdio.h> |
61 | #include <string.h> |
62 | #include <unistd.h> |
63 | #include <stdint.h> |
64 | #include <arpa/inet.h> |
65 | #include <net/if.h> |
66 | #include <netinet/in.h> |
67 | #include <sys/param.h> |
68 | #include <sys/socket.h> |
69 | #include <sys/types.h> |
70 | #include <sys/un.h> |
71 | #include <sys/utsname.h> |
72 | #include <libc-lock.h> |
73 | #include <scratch_buffer.h> |
74 | |
75 | #ifdef HAVE_LIBIDN |
76 | # include <libidn/idna.h> |
77 | extern int __idna_to_unicode_lzlz (const char *input, char **output, |
78 | int flags); |
79 | #endif |
80 | |
81 | #ifndef min |
82 | # define min(x,y) (((x) > (y)) ? (y) : (x)) |
83 | #endif /* min */ |
84 | |
85 | libc_freeres_ptr (static char *domain); |
86 | |
87 | |
88 | static char * |
89 | internal_function |
90 | nrl_domainname (void) |
91 | { |
92 | static int not_first; |
93 | |
94 | if (! not_first) |
95 | { |
96 | __libc_lock_define_initialized (static, lock); |
97 | __libc_lock_lock (lock); |
98 | |
99 | if (! not_first) |
100 | { |
101 | char *c; |
102 | struct hostent *h, th; |
103 | int herror; |
104 | struct scratch_buffer tmpbuf; |
105 | |
106 | scratch_buffer_init (&tmpbuf); |
107 | not_first = 1; |
108 | |
109 | while (__gethostbyname_r ("localhost" , &th, |
110 | tmpbuf.data, tmpbuf.length, |
111 | &h, &herror)) |
112 | { |
113 | if (herror == NETDB_INTERNAL && errno == ERANGE) |
114 | { |
115 | if (!scratch_buffer_grow (&tmpbuf)) |
116 | goto done; |
117 | } |
118 | else |
119 | break; |
120 | } |
121 | |
122 | if (h && (c = strchr (h->h_name, '.'))) |
123 | domain = __strdup (++c); |
124 | else |
125 | { |
126 | /* The name contains no domain information. Use the name |
127 | now to get more information. */ |
128 | while (__gethostname (tmpbuf.data, tmpbuf.length)) |
129 | if (!scratch_buffer_grow (&tmpbuf)) |
130 | goto done; |
131 | |
132 | if ((c = strchr (tmpbuf.data, '.'))) |
133 | domain = __strdup (++c); |
134 | else |
135 | { |
136 | /* We need to preserve the hostname. */ |
137 | const char *hstname = strdupa (tmpbuf.data); |
138 | |
139 | while (__gethostbyname_r (hstname, &th, |
140 | tmpbuf.data, tmpbuf.length, |
141 | &h, &herror)) |
142 | { |
143 | if (herror == NETDB_INTERNAL && errno == ERANGE) |
144 | { |
145 | if (!scratch_buffer_grow (&tmpbuf)) |
146 | goto done; |
147 | } |
148 | else |
149 | break; |
150 | } |
151 | |
152 | if (h && (c = strchr(h->h_name, '.'))) |
153 | domain = __strdup (++c); |
154 | else |
155 | { |
156 | struct in_addr in_addr; |
157 | |
158 | in_addr.s_addr = htonl (INADDR_LOOPBACK); |
159 | |
160 | while (__gethostbyaddr_r ((const char *) &in_addr, |
161 | sizeof (struct in_addr), |
162 | AF_INET, &th, |
163 | tmpbuf.data, tmpbuf.length, |
164 | &h, &herror)) |
165 | { |
166 | if (herror == NETDB_INTERNAL && errno == ERANGE) |
167 | { |
168 | if (!scratch_buffer_grow (&tmpbuf)) |
169 | goto done; |
170 | } |
171 | else |
172 | break; |
173 | } |
174 | |
175 | if (h && (c = strchr (h->h_name, '.'))) |
176 | domain = __strdup (++c); |
177 | } |
178 | } |
179 | } |
180 | done: |
181 | scratch_buffer_free (&tmpbuf); |
182 | } |
183 | |
184 | __libc_lock_unlock (lock); |
185 | } |
186 | |
187 | return domain; |
188 | }; |
189 | |
190 | /* Copy a string to a destination buffer with length checking. Return |
191 | EAI_OVERFLOW if the buffer is not large enough, and 0 on |
192 | success. */ |
193 | static int |
194 | checked_copy (char *dest, size_t destlen, const char *source) |
195 | { |
196 | size_t source_length = strlen (source); |
197 | if (source_length + 1 > destlen) |
198 | return EAI_OVERFLOW; |
199 | memcpy (dest, source, source_length + 1); |
200 | return 0; |
201 | } |
202 | |
203 | /* Helper function for CHECKED_SNPRINTF below. */ |
204 | static int |
205 | check_sprintf_result (int result, size_t destlen) |
206 | { |
207 | if (result < 0) |
208 | return EAI_SYSTEM; |
209 | if ((size_t) result >= destlen) |
210 | /* If ret == destlen, there was no room for the terminating NUL |
211 | character. */ |
212 | return EAI_OVERFLOW; |
213 | return 0; |
214 | } |
215 | |
216 | /* Format a string in the destination buffer. Return 0 on success, |
217 | EAI_OVERFLOW in case the buffer is too small, or EAI_SYSTEM on any |
218 | other error. */ |
219 | #define CHECKED_SNPRINTF(dest, destlen, format, ...) \ |
220 | check_sprintf_result \ |
221 | (__snprintf (dest, destlen, format, __VA_ARGS__), destlen) |
222 | |
223 | /* Convert host name, AF_INET/AF_INET6 case, name only. */ |
224 | static int |
225 | gni_host_inet_name (struct scratch_buffer *tmpbuf, |
226 | const struct sockaddr *sa, socklen_t addrlen, |
227 | char *host, socklen_t hostlen, int flags) |
228 | { |
229 | int herrno; |
230 | struct hostent th; |
231 | struct hostent *h = NULL; |
232 | if (sa->sa_family == AF_INET6) |
233 | { |
234 | const struct sockaddr_in6 *sin6p = (const struct sockaddr_in6 *) sa; |
235 | while (__gethostbyaddr_r (&sin6p->sin6_addr, sizeof(struct in6_addr), |
236 | AF_INET6, &th, tmpbuf->data, tmpbuf->length, |
237 | &h, &herrno)) |
238 | if (herrno == NETDB_INTERNAL && errno == ERANGE) |
239 | { |
240 | if (!scratch_buffer_grow (tmpbuf)) |
241 | { |
242 | __set_h_errno (herrno); |
243 | return EAI_MEMORY; |
244 | } |
245 | } |
246 | else |
247 | break; |
248 | } |
249 | else |
250 | { |
251 | const struct sockaddr_in *sinp = (const struct sockaddr_in *) sa; |
252 | while (__gethostbyaddr_r (&sinp->sin_addr, sizeof(struct in_addr), |
253 | AF_INET, &th, tmpbuf->data, tmpbuf->length, |
254 | &h, &herrno)) |
255 | if (herrno == NETDB_INTERNAL && errno == ERANGE) |
256 | { |
257 | if (!scratch_buffer_grow (tmpbuf)) |
258 | { |
259 | __set_h_errno (herrno); |
260 | return EAI_MEMORY; |
261 | } |
262 | } |
263 | else |
264 | break; |
265 | } |
266 | |
267 | if (h == NULL) |
268 | { |
269 | if (herrno == NETDB_INTERNAL) |
270 | { |
271 | __set_h_errno (herrno); |
272 | return EAI_SYSTEM; |
273 | } |
274 | if (herrno == TRY_AGAIN) |
275 | { |
276 | __set_h_errno (herrno); |
277 | return EAI_AGAIN; |
278 | } |
279 | } |
280 | |
281 | if (h) |
282 | { |
283 | char *c; |
284 | if ((flags & NI_NOFQDN) |
285 | && (c = nrl_domainname ()) |
286 | && (c = strstr (h->h_name, c)) |
287 | && (c != h->h_name) && (*(--c) == '.')) |
288 | /* Terminate the string after the prefix. */ |
289 | *c = '\0'; |
290 | |
291 | #ifdef HAVE_LIBIDN |
292 | /* If requested, convert from the IDN format. */ |
293 | if (flags & NI_IDN) |
294 | { |
295 | int idn_flags = 0; |
296 | if (flags & NI_IDN_ALLOW_UNASSIGNED) |
297 | idn_flags |= IDNA_ALLOW_UNASSIGNED; |
298 | if (flags & NI_IDN_USE_STD3_ASCII_RULES) |
299 | idn_flags |= IDNA_USE_STD3_ASCII_RULES; |
300 | |
301 | char *out; |
302 | int rc = __idna_to_unicode_lzlz (h->h_name, &out, |
303 | idn_flags); |
304 | if (rc != IDNA_SUCCESS) |
305 | { |
306 | if (rc == IDNA_MALLOC_ERROR) |
307 | return EAI_MEMORY; |
308 | if (rc == IDNA_DLOPEN_ERROR) |
309 | return EAI_SYSTEM; |
310 | return EAI_IDN_ENCODE; |
311 | } |
312 | |
313 | if (out != h->h_name) |
314 | { |
315 | h->h_name = strdupa (out); |
316 | free (out); |
317 | } |
318 | } |
319 | #endif |
320 | |
321 | size_t len = strlen (h->h_name) + 1; |
322 | if (len > hostlen) |
323 | return EAI_OVERFLOW; |
324 | |
325 | memcpy (host, h->h_name, len); |
326 | |
327 | return 0; |
328 | } |
329 | |
330 | return EAI_NONAME; |
331 | } |
332 | |
333 | /* Convert host name, AF_INET/AF_INET6 case, numeric conversion. */ |
334 | static int |
335 | gni_host_inet_numeric (struct scratch_buffer *tmpbuf, |
336 | const struct sockaddr *sa, socklen_t addrlen, |
337 | char *host, socklen_t hostlen, int flags) |
338 | { |
339 | if (sa->sa_family == AF_INET6) |
340 | { |
341 | const struct sockaddr_in6 *sin6p = (const struct sockaddr_in6 *) sa; |
342 | if (inet_ntop (AF_INET6, &sin6p->sin6_addr, host, hostlen) == NULL) |
343 | return EAI_OVERFLOW; |
344 | |
345 | uint32_t scopeid = sin6p->sin6_scope_id; |
346 | if (scopeid != 0) |
347 | { |
348 | size_t used_hostlen = __strnlen (host, hostlen); |
349 | /* Location of the scope string in the host buffer. */ |
350 | char *scope_start = host + used_hostlen; |
351 | size_t scope_length = hostlen - used_hostlen; |
352 | |
353 | if (IN6_IS_ADDR_LINKLOCAL (&sin6p->sin6_addr) |
354 | || IN6_IS_ADDR_MC_LINKLOCAL (&sin6p->sin6_addr)) |
355 | { |
356 | char scopebuf[IFNAMSIZ]; |
357 | if (if_indextoname (scopeid, scopebuf) != NULL) |
358 | return CHECKED_SNPRINTF |
359 | (scope_start, scope_length, |
360 | "%c%s" , SCOPE_DELIMITER, scopebuf); |
361 | } |
362 | return CHECKED_SNPRINTF |
363 | (scope_start, scope_length, "%c%u" , SCOPE_DELIMITER, scopeid); |
364 | } |
365 | } |
366 | else |
367 | { |
368 | const struct sockaddr_in *sinp = (const struct sockaddr_in *) sa; |
369 | if (inet_ntop (AF_INET, &sinp->sin_addr, host, hostlen) == NULL) |
370 | return EAI_OVERFLOW; |
371 | } |
372 | return 0; |
373 | } |
374 | |
375 | /* Convert AF_INET or AF_INET6 socket address, host part. */ |
376 | static int |
377 | gni_host_inet (struct scratch_buffer *tmpbuf, |
378 | const struct sockaddr *sa, socklen_t addrlen, |
379 | char *host, socklen_t hostlen, int flags) |
380 | { |
381 | if (!(flags & NI_NUMERICHOST)) |
382 | { |
383 | int result = gni_host_inet_name |
384 | (tmpbuf, sa, addrlen, host, hostlen, flags); |
385 | if (result != EAI_NONAME) |
386 | return result; |
387 | } |
388 | |
389 | if (flags & NI_NAMEREQD) |
390 | return EAI_NONAME; |
391 | else |
392 | return gni_host_inet_numeric |
393 | (tmpbuf, sa, addrlen, host, hostlen, flags); |
394 | } |
395 | |
396 | /* Convert AF_LOCAL socket address, host part. */ |
397 | static int |
398 | gni_host_local (struct scratch_buffer *tmpbuf, |
399 | const struct sockaddr *sa, socklen_t addrlen, |
400 | char *host, socklen_t hostlen, int flags) |
401 | { |
402 | if (!(flags & NI_NUMERICHOST)) |
403 | { |
404 | struct utsname utsname; |
405 | if (uname (&utsname) == 0) |
406 | return checked_copy (host, hostlen, utsname.nodename); |
407 | } |
408 | |
409 | if (flags & NI_NAMEREQD) |
410 | return EAI_NONAME; |
411 | |
412 | return checked_copy (host, hostlen, "localhost" ); |
413 | } |
414 | |
415 | /* Convert the host part of an AF_LOCAK socket address. */ |
416 | static int |
417 | gni_host (struct scratch_buffer *tmpbuf, |
418 | const struct sockaddr *sa, socklen_t addrlen, |
419 | char *host, socklen_t hostlen, int flags) |
420 | { |
421 | switch (sa->sa_family) |
422 | { |
423 | case AF_INET: |
424 | case AF_INET6: |
425 | return gni_host_inet (tmpbuf, sa, addrlen, host, hostlen, flags); |
426 | |
427 | case AF_LOCAL: |
428 | return gni_host_local (tmpbuf, sa, addrlen, host, hostlen, flags); |
429 | |
430 | default: |
431 | return EAI_FAMILY; |
432 | } |
433 | } |
434 | |
435 | /* Convert service to string, AF_INET and AF_INET6 variant. */ |
436 | static int |
437 | gni_serv_inet (struct scratch_buffer *tmpbuf, |
438 | const struct sockaddr *sa, socklen_t addrlen, |
439 | char *serv, socklen_t servlen, int flags) |
440 | { |
441 | _Static_assert |
442 | (offsetof (struct sockaddr_in, sin_port) |
443 | == offsetof (struct sockaddr_in6, sin6_port) |
444 | && sizeof (((struct sockaddr_in) {}).sin_port) == sizeof (in_port_t) |
445 | && sizeof (((struct sockaddr_in6) {}).sin6_port) == sizeof (in_port_t), |
446 | "AF_INET and AF_INET6 port consistency" ); |
447 | const struct sockaddr_in *sinp = (const struct sockaddr_in *) sa; |
448 | if (!(flags & NI_NUMERICSERV)) |
449 | { |
450 | struct servent *s, ts; |
451 | int e; |
452 | while ((e = __getservbyport_r (sinp->sin_port, |
453 | ((flags & NI_DGRAM) |
454 | ? "udp" : "tcp" ), &ts, |
455 | tmpbuf->data, tmpbuf->length, &s))) |
456 | { |
457 | if (e == ERANGE) |
458 | { |
459 | if (!scratch_buffer_grow (tmpbuf)) |
460 | return EAI_MEMORY; |
461 | } |
462 | else |
463 | break; |
464 | } |
465 | if (s) |
466 | return checked_copy (serv, servlen, s->s_name); |
467 | /* Fall through to numeric conversion. */ |
468 | } |
469 | return CHECKED_SNPRINTF (serv, servlen, "%d" , ntohs (sinp->sin_port)); |
470 | } |
471 | |
472 | /* Convert service to string, AF_LOCAL variant. */ |
473 | static int |
474 | gni_serv_local (struct scratch_buffer *tmpbuf, |
475 | const struct sockaddr *sa, socklen_t addrlen, |
476 | char *serv, socklen_t servlen, int flags) |
477 | { |
478 | return checked_copy |
479 | (serv, servlen, ((const struct sockaddr_un *) sa)->sun_path); |
480 | } |
481 | |
482 | /* Convert service to string, dispatching to the implementations |
483 | above. */ |
484 | static int |
485 | gni_serv (struct scratch_buffer *tmpbuf, |
486 | const struct sockaddr *sa, socklen_t addrlen, |
487 | char *serv, socklen_t servlen, int flags) |
488 | { |
489 | switch (sa->sa_family) |
490 | { |
491 | case AF_INET: |
492 | case AF_INET6: |
493 | return gni_serv_inet (tmpbuf, sa, addrlen, serv, servlen, flags); |
494 | case AF_LOCAL: |
495 | return gni_serv_local (tmpbuf, sa, addrlen, serv, servlen, flags); |
496 | default: |
497 | return EAI_FAMILY; |
498 | } |
499 | } |
500 | |
501 | int |
502 | getnameinfo (const struct sockaddr *sa, socklen_t addrlen, char *host, |
503 | socklen_t hostlen, char *serv, socklen_t servlen, |
504 | int flags) |
505 | { |
506 | if (flags & ~(NI_NUMERICHOST|NI_NUMERICSERV|NI_NOFQDN|NI_NAMEREQD|NI_DGRAM |
507 | #ifdef HAVE_LIBIDN |
508 | |NI_IDN|NI_IDN_ALLOW_UNASSIGNED|NI_IDN_USE_STD3_ASCII_RULES |
509 | #endif |
510 | )) |
511 | return EAI_BADFLAGS; |
512 | |
513 | if (sa == NULL || addrlen < sizeof (sa_family_t)) |
514 | return EAI_FAMILY; |
515 | |
516 | if ((flags & NI_NAMEREQD) && host == NULL && serv == NULL) |
517 | return EAI_NONAME; |
518 | |
519 | switch (sa->sa_family) |
520 | { |
521 | case AF_LOCAL: |
522 | if (addrlen < (socklen_t) offsetof (struct sockaddr_un, sun_path)) |
523 | return EAI_FAMILY; |
524 | break; |
525 | case AF_INET: |
526 | if (addrlen < sizeof (struct sockaddr_in)) |
527 | return EAI_FAMILY; |
528 | break; |
529 | case AF_INET6: |
530 | if (addrlen < sizeof (struct sockaddr_in6)) |
531 | return EAI_FAMILY; |
532 | break; |
533 | default: |
534 | return EAI_FAMILY; |
535 | } |
536 | |
537 | struct scratch_buffer tmpbuf; |
538 | scratch_buffer_init (&tmpbuf); |
539 | |
540 | if (host != NULL && hostlen > 0) |
541 | { |
542 | int result = gni_host (&tmpbuf, sa, addrlen, host, hostlen, flags); |
543 | if (result != 0) |
544 | { |
545 | scratch_buffer_free (&tmpbuf); |
546 | return result; |
547 | } |
548 | } |
549 | |
550 | if (serv && (servlen > 0)) |
551 | { |
552 | int result = gni_serv (&tmpbuf, sa, addrlen, serv, servlen, flags); |
553 | if (result != 0) |
554 | { |
555 | scratch_buffer_free (&tmpbuf); |
556 | return result; |
557 | } |
558 | } |
559 | |
560 | scratch_buffer_free (&tmpbuf); |
561 | return 0; |
562 | } |
563 | libc_hidden_def (getnameinfo) |
564 | |