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Commit | Line | Data |
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d7ce7006 | 1 | /*\r |
2 | * Copyright (c) 1988, 1993\r | |
3 | * The Regents of the University of California. All rights reserved.\r | |
4 | *\r | |
5 | * Portions copyright (c) 1999, 2000\r | |
6 | * Intel Corporation.\r | |
7 | * All rights reserved.\r | |
8 | *\r | |
9 | * Redistribution and use in source and binary forms, with or without\r | |
10 | * modification, are permitted provided that the following conditions\r | |
11 | * are met:\r | |
12 | *\r | |
13 | * 1. Redistributions of source code must retain the above copyright\r | |
14 | * notice, this list of conditions and the following disclaimer.\r | |
15 | *\r | |
16 | * 2. Redistributions in binary form must reproduce the above copyright\r | |
17 | * notice, this list of conditions and the following disclaimer in the\r | |
18 | * documentation and/or other materials provided with the distribution.\r | |
19 | *\r | |
20 | * 3. All advertising materials mentioning features or use of this software\r | |
21 | * must display the following acknowledgement:\r | |
22 | *\r | |
23 | * This product includes software developed by the University of\r | |
24 | * California, Berkeley, Intel Corporation, and its contributors.\r | |
25 | *\r | |
26 | * 4. Neither the name of University, Intel Corporation, or their respective\r | |
27 | * contributors may be used to endorse or promote products derived from\r | |
28 | * this software without specific prior written permission.\r | |
29 | *\r | |
30 | * THIS SOFTWARE IS PROVIDED BY THE REGENTS, INTEL CORPORATION AND\r | |
31 | * CONTRIBUTORS ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING,\r | |
32 | * BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS\r | |
33 | * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS,\r | |
34 | * INTEL CORPORATION OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,\r | |
35 | * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT\r | |
36 | * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,\r | |
37 | * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY\r | |
38 | * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT\r | |
39 | * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF\r | |
40 | * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.\r | |
41 | *\r | |
42 | */\r | |
43 | \r | |
44 | /*\r | |
45 | * Portions Copyright (c) 1993 by Digital Equipment Corporation.\r | |
46 | *\r | |
47 | * Permission to use, copy, modify, and distribute this software for any\r | |
48 | * purpose with or without fee is hereby granted, provided that the above\r | |
49 | * copyright notice and this permission notice appear in all copies, and that\r | |
50 | * the name of Digital Equipment Corporation not be used in advertising or\r | |
51 | * publicity pertaining to distribution of the document or software without\r | |
52 | * specific, written prior permission.\r | |
53 | *\r | |
54 | * THE SOFTWARE IS PROVIDED "AS IS" AND DIGITAL EQUIPMENT CORP. DISCLAIMS ALL\r | |
55 | * WARRANTIES WITH REGARD TO THIS SOFTWARE, INCLUDING ALL IMPLIED WARRANTIES\r | |
56 | * OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL DIGITAL EQUIPMENT\r | |
57 | * CORPORATION BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL\r | |
58 | * DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR\r | |
59 | * PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS\r | |
60 | * ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS\r | |
61 | * SOFTWARE.\r | |
62 | */\r | |
63 | \r | |
64 | /*\r | |
65 | * Portions Copyright (c) 1996 by Internet Software Consortium.\r | |
66 | *\r | |
67 | * Permission to use, copy, modify, and distribute this software for any\r | |
68 | * purpose with or without fee is hereby granted, provided that the above\r | |
69 | * copyright notice and this permission notice appear in all copies.\r | |
70 | *\r | |
71 | * THE SOFTWARE IS PROVIDED "AS IS" AND INTERNET SOFTWARE CONSORTIUM DISCLAIMS\r | |
72 | * ALL WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES\r | |
73 | * OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL INTERNET SOFTWARE\r | |
74 | * CONSORTIUM BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL\r | |
75 | * DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR\r | |
76 | * PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS\r | |
77 | * ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS\r | |
78 | * SOFTWARE.\r | |
79 | */\r | |
80 | \r | |
81 | #if defined(LIBC_SCCS) && !defined(lint)\r | |
82 | static char sccsid[] = "@(#)res_query.c 8.1 (Berkeley) 6/4/93";\r | |
83 | static char orig_rcsid = "From: Id: res_query.c,v 8.14 1997/06/09 17:47:05 halley Exp $";\r | |
84 | static char rcsid[] = "$Id: res_query.c,v 1.1.1.1 2003/11/19 01:51:38 kyu3 Exp $";\r | |
85 | #endif /* LIBC_SCCS and not lint */\r | |
86 | \r | |
87 | #include <sys/types.h>\r | |
88 | #include <sys/param.h>\r | |
89 | #include <netinet/in.h>\r | |
90 | #include <arpa/inet.h>\r | |
91 | #include <arpa/nameser.h>\r | |
92 | #include <ctype.h>\r | |
93 | #include <errno.h>\r | |
94 | #include <netdb.h>\r | |
95 | #include <resolv.h>\r | |
96 | #include <stdio.h>\r | |
97 | #include <stdlib.h>\r | |
98 | #include <string.h>\r | |
99 | \r | |
100 | #include "res_config.h"\r | |
101 | \r | |
102 | #if PACKETSZ > 1024\r | |
103 | #define MAXPACKET PACKETSZ\r | |
104 | #else\r | |
105 | #define MAXPACKET 1024\r | |
106 | #endif\r | |
107 | \r | |
108 | /*\r | |
109 | * Formulate a normal query, send, and await answer.\r | |
110 | * Returned answer is placed in supplied buffer "answer".\r | |
111 | * Perform preliminary check of answer, returning success only\r | |
112 | * if no error is indicated and the answer count is nonzero.\r | |
113 | * Return the size of the response on success, -1 on error.\r | |
114 | * Error number is left in h_errno.\r | |
115 | *\r | |
116 | * Caller must parse answer and determine whether it answers the question.\r | |
117 | */\r | |
118 | int\r | |
119 | res_query(\r | |
120 | const char *name, /* domain name */\r | |
121 | int class, /* class of query */\r | |
122 | int type, /* type of query */\r | |
123 | u_char *answer, /* buffer to put answer */\r | |
124 | int anslen /* size of answer buffer */\r | |
125 | )\r | |
126 | {\r | |
127 | u_char buf[MAXPACKET];\r | |
128 | HEADER *hp = (HEADER *) answer;\r | |
129 | int n;\r | |
130 | \r | |
131 | hp->rcode = NOERROR; /* default */\r | |
132 | \r | |
133 | if ((_res.options & RES_INIT) == 0 && res_init() == -1) {\r | |
134 | h_errno = NETDB_INTERNAL;\r | |
135 | return (-1);\r | |
136 | }\r | |
137 | #ifdef DEBUG\r | |
138 | if (_res.options & RES_DEBUG)\r | |
139 | printf(";; res_query(%s, %d, %d)\n", name, class, type);\r | |
140 | #endif\r | |
141 | \r | |
142 | n = res_mkquery(QUERY, name, class, type, NULL, 0, NULL,\r | |
143 | buf, sizeof(buf));\r | |
144 | if (n <= 0) {\r | |
145 | #ifdef DEBUG\r | |
146 | if (_res.options & RES_DEBUG)\r | |
147 | printf(";; res_query: mkquery failed\n");\r | |
148 | #endif\r | |
149 | h_errno = NO_RECOVERY;\r | |
150 | return (n);\r | |
151 | }\r | |
152 | n = res_send(buf, n, answer, anslen);\r | |
153 | if (n < 0) {\r | |
154 | #ifdef DEBUG\r | |
155 | if (_res.options & RES_DEBUG)\r | |
156 | printf(";; res_query: send error\n");\r | |
157 | #endif\r | |
158 | h_errno = TRY_AGAIN;\r | |
159 | return (n);\r | |
160 | }\r | |
161 | \r | |
162 | if (hp->rcode != NOERROR || ntohs(hp->ancount) == 0) {\r | |
163 | #ifdef DEBUG\r | |
164 | if (_res.options & RES_DEBUG)\r | |
165 | printf(";; rcode = %d, ancount=%d\n", hp->rcode,\r | |
166 | ntohs(hp->ancount));\r | |
167 | #endif\r | |
168 | switch (hp->rcode) {\r | |
169 | case NXDOMAIN:\r | |
170 | h_errno = HOST_NOT_FOUND;\r | |
171 | break;\r | |
172 | case SERVFAIL:\r | |
173 | h_errno = TRY_AGAIN;\r | |
174 | break;\r | |
175 | case NOERROR:\r | |
176 | h_errno = NO_DATA;\r | |
177 | break;\r | |
178 | case FORMERR:\r | |
179 | case NOTIMP:\r | |
180 | case REFUSED:\r | |
181 | default:\r | |
182 | h_errno = NO_RECOVERY;\r | |
183 | break;\r | |
184 | }\r | |
185 | return (-1);\r | |
186 | }\r | |
187 | return (n);\r | |
188 | }\r | |
189 | \r | |
190 | /*\r | |
191 | * Formulate a normal query, send, and retrieve answer in supplied buffer.\r | |
192 | * Return the size of the response on success, -1 on error.\r | |
193 | * If enabled, implement search rules until answer or unrecoverable failure\r | |
194 | * is detected. Error code, if any, is left in h_errno.\r | |
195 | */\r | |
196 | int\r | |
197 | res_search(\r | |
198 | const char *name, /* domain name */\r | |
199 | int class, /* class of query */\r | |
200 | int type, /* type of query */\r | |
201 | u_char *answer, /* buffer to put answer */\r | |
202 | int anslen /* size of answer */\r | |
203 | )\r | |
204 | {\r | |
205 | const char *cp, * const *domain;\r | |
206 | HEADER *hp = (HEADER *) answer;\r | |
207 | u_int dots;\r | |
208 | int trailing_dot, ret, saved_herrno;\r | |
209 | int got_nodata = 0, got_servfail = 0, tried_as_is = 0;\r | |
210 | \r | |
211 | if ((_res.options & RES_INIT) == 0 && res_init() == -1) {\r | |
212 | h_errno = NETDB_INTERNAL;\r | |
213 | return (-1);\r | |
214 | }\r | |
215 | errno = 0;\r | |
216 | h_errno = HOST_NOT_FOUND; /* default, if we never query */\r | |
217 | dots = 0;\r | |
218 | for (cp = name; *cp; cp++)\r | |
219 | dots += (*cp == '.');\r | |
220 | trailing_dot = 0;\r | |
221 | if (cp > name && *--cp == '.')\r | |
222 | trailing_dot++;\r | |
223 | \r | |
224 | /* If there aren't any dots, it could be a user-level alias */\r | |
225 | if (!dots && (cp = hostalias(name)) != NULL)\r | |
226 | return (res_query(cp, class, type, answer, anslen));\r | |
227 | \r | |
228 | /*\r | |
229 | * If there are dots in the name already, let's just give it a try\r | |
230 | * 'as is'. The threshold can be set with the "ndots" option.\r | |
231 | */\r | |
232 | saved_herrno = -1;\r | |
233 | if (dots >= _res.ndots) {\r | |
234 | ret = res_querydomain(name, NULL, class, type, answer, anslen);\r | |
235 | if (ret > 0)\r | |
236 | return (ret);\r | |
237 | saved_herrno = h_errno;\r | |
238 | tried_as_is++;\r | |
239 | }\r | |
240 | \r | |
241 | /*\r | |
242 | * We do at least one level of search if\r | |
243 | * - there is no dot and RES_DEFNAME is set, or\r | |
244 | * - there is at least one dot, there is no trailing dot,\r | |
245 | * and RES_DNSRCH is set.\r | |
246 | */\r | |
247 | if ((!dots && (_res.options & RES_DEFNAMES)) ||\r | |
248 | (dots && !trailing_dot && (_res.options & RES_DNSRCH))) {\r | |
249 | int done = 0;\r | |
250 | \r | |
251 | for (domain = (const char * const *)_res.dnsrch;\r | |
252 | *domain && !done;\r | |
253 | domain++) {\r | |
254 | \r | |
255 | ret = res_querydomain(name, *domain, class, type,\r | |
256 | answer, anslen);\r | |
257 | if (ret > 0)\r | |
258 | return (ret);\r | |
259 | \r | |
260 | /*\r | |
261 | * If no server present, give up.\r | |
262 | * If name isn't found in this domain,\r | |
263 | * keep trying higher domains in the search list\r | |
264 | * (if that's enabled).\r | |
265 | * On a NO_DATA error, keep trying, otherwise\r | |
266 | * a wildcard entry of another type could keep us\r | |
267 | * from finding this entry higher in the domain.\r | |
268 | * If we get some other error (negative answer or\r | |
269 | * server failure), then stop searching up,\r | |
270 | * but try the input name below in case it's\r | |
271 | * fully-qualified.\r | |
272 | */\r | |
273 | if (errno == ECONNREFUSED) {\r | |
274 | h_errno = TRY_AGAIN;\r | |
275 | return (-1);\r | |
276 | }\r | |
277 | \r | |
278 | switch (h_errno) {\r | |
279 | case NO_DATA:\r | |
280 | got_nodata++;\r | |
281 | /* FALLTHROUGH */\r | |
282 | case HOST_NOT_FOUND:\r | |
283 | /* keep trying */\r | |
284 | break;\r | |
285 | case TRY_AGAIN:\r | |
286 | if (hp->rcode == SERVFAIL) {\r | |
287 | /* try next search element, if any */\r | |
288 | got_servfail++;\r | |
289 | break;\r | |
290 | }\r | |
291 | /* FALLTHROUGH */\r | |
292 | default:\r | |
293 | /* anything else implies that we're done */\r | |
294 | done++;\r | |
295 | }\r | |
296 | \r | |
297 | /* if we got here for some reason other than DNSRCH,\r | |
298 | * we only wanted one iteration of the loop, so stop.\r | |
299 | */\r | |
300 | if (!(_res.options & RES_DNSRCH))\r | |
301 | done++;\r | |
302 | }\r | |
303 | }\r | |
304 | \r | |
305 | /*\r | |
306 | * If we have not already tried the name "as is", do that now.\r | |
307 | * note that we do this regardless of how many dots were in the\r | |
308 | * name or whether it ends with a dot unless NOTLDQUERY is set.\r | |
309 | */\r | |
310 | if (!tried_as_is && (dots || !(_res.options & RES_NOTLDQUERY))) {\r | |
311 | ret = res_querydomain(name, NULL, class, type, answer, anslen);\r | |
312 | if (ret > 0)\r | |
313 | return (ret);\r | |
314 | }\r | |
315 | \r | |
316 | /* if we got here, we didn't satisfy the search.\r | |
317 | * if we did an initial full query, return that query's h_errno\r | |
318 | * (note that we wouldn't be here if that query had succeeded).\r | |
319 | * else if we ever got a nodata, send that back as the reason.\r | |
320 | * else send back meaningless h_errno, that being the one from\r | |
321 | * the last DNSRCH we did.\r | |
322 | */\r | |
323 | if (saved_herrno != -1)\r | |
324 | h_errno = saved_herrno;\r | |
325 | else if (got_nodata)\r | |
326 | h_errno = NO_DATA;\r | |
327 | else if (got_servfail)\r | |
328 | h_errno = TRY_AGAIN;\r | |
329 | return (-1);\r | |
330 | }\r | |
331 | \r | |
332 | /*\r | |
333 | * Perform a call on res_query on the concatenation of name and domain,\r | |
334 | * removing a trailing dot from name if domain is NULL.\r | |
335 | */\r | |
336 | int\r | |
337 | res_querydomain(\r | |
338 | const char *name,\r | |
339 | const char *domain,\r | |
340 | int class, /* class of query */\r | |
341 | int type, /* type of query */\r | |
342 | u_char *answer, /* buffer to put answer */\r | |
343 | int anslen /* size of answer */\r | |
344 | )\r | |
345 | {\r | |
346 | char nbuf[MAXDNAME];\r | |
347 | const char *longname = nbuf;\r | |
348 | int n, d;\r | |
349 | \r | |
350 | if ((_res.options & RES_INIT) == 0 && res_init() == -1) {\r | |
351 | h_errno = NETDB_INTERNAL;\r | |
352 | return (-1);\r | |
353 | }\r | |
354 | #ifdef DEBUG\r | |
355 | if (_res.options & RES_DEBUG)\r | |
356 | printf(";; res_querydomain(%s, %s, %d, %d)\n",\r | |
357 | name, domain?domain:"<Nil>", class, type);\r | |
358 | #endif\r | |
359 | if (domain == NULL) {\r | |
360 | /*\r | |
361 | * Check for trailing '.';\r | |
362 | * copy without '.' if present.\r | |
363 | */\r | |
364 | n = (int)strlen(name);\r | |
365 | if (n >= MAXDNAME) {\r | |
366 | h_errno = NO_RECOVERY;\r | |
367 | return (-1);\r | |
368 | }\r | |
369 | n--;\r | |
370 | if (n >= 0 && name[n] == '.') {\r | |
371 | strncpy(nbuf, name, n);\r | |
372 | nbuf[n] = '\0';\r | |
373 | } else\r | |
374 | longname = name;\r | |
375 | } else {\r | |
376 | n = (int)strlen(name);\r | |
377 | d = (int)strlen(domain);\r | |
378 | if (n + d + 1 >= MAXDNAME) {\r | |
379 | h_errno = NO_RECOVERY;\r | |
380 | return (-1);\r | |
381 | }\r | |
382 | sprintf(nbuf, "%s.%s", name, domain);\r | |
383 | }\r | |
384 | return (res_query(longname, class, type, answer, anslen));\r | |
385 | }\r | |
386 | \r | |
387 | const char *\r | |
388 | hostalias(\r | |
389 | const char *name\r | |
390 | )\r | |
391 | {\r | |
392 | register char *cp1, *cp2;\r | |
393 | FILE *fp;\r | |
394 | char *file;\r | |
395 | char buf[BUFSIZ];\r | |
396 | static char abuf[MAXDNAME];\r | |
397 | \r | |
398 | if (_res.options & RES_NOALIASES)\r | |
399 | return (NULL);\r | |
400 | #ifdef _ORG_FREEBSD_\r | |
401 | if (issetugid())\r | |
402 | return (NULL);\r | |
403 | #endif\r | |
404 | file = getenv("HOSTALIASES");\r | |
405 | if (file == NULL || (fp = fopen(file, "r")) == NULL)\r | |
406 | return (NULL);\r | |
407 | setbuf(fp, NULL);\r | |
408 | buf[sizeof(buf) - 1] = '\0';\r | |
409 | while (fgets(buf, sizeof(buf), fp)) {\r | |
410 | for (cp1 = buf; *cp1 && !isspace(*cp1); ++cp1)\r | |
411 | ;\r | |
412 | if (!*cp1)\r | |
413 | break;\r | |
414 | *cp1 = '\0';\r | |
415 | if (!strcasecmp(buf, name)) {\r | |
416 | while (isspace(*++cp1))\r | |
417 | ;\r | |
418 | if (!*cp1)\r | |
419 | break;\r | |
420 | for (cp2 = cp1 + 1; *cp2 && !isspace(*cp2); ++cp2)\r | |
421 | ;\r | |
422 | abuf[sizeof(abuf) - 1] = *cp2 = '\0';\r | |
423 | strncpy(abuf, cp1, sizeof(abuf) - 1);\r | |
424 | fclose(fp);\r | |
425 | return (abuf);\r | |
426 | }\r | |
427 | }\r | |
428 | fclose(fp);\r | |
429 | return (NULL);\r | |
430 | }\r |