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0710cbcd | 1 | |
2 | /* | |
262a0e14 | 3 | * $Id$ |
0710cbcd | 4 | * |
5 | * Low level DNS protocol routines | |
6 | * AUTHOR: Amos Jeffries, Rafael Martinez Torres | |
7 | * | |
8 | * SQUID Web Proxy Cache http://www.squid-cache.org/ | |
9 | * ---------------------------------------------------------- | |
10 | * | |
11 | * Squid is the result of efforts by numerous individuals from | |
12 | * the Internet community; see the CONTRIBUTORS file for full | |
13 | * details. Many organizations have provided support for Squid's | |
14 | * development; see the SPONSORS file for full details. Squid is | |
15 | * Copyrighted (C) 2001 by the Regents of the University of | |
16 | * California; see the COPYRIGHT file for full details. Squid | |
17 | * incorporates software developed and/or copyrighted by other | |
18 | * sources; see the CREDITS file for full details. | |
19 | * | |
20 | * This code is copyright (C) 2007 by Treehouse Networks Ltd of | |
21 | * New Zealand. It is published and Lisenced as an extension of | |
22 | * squid under the same conditions as the main squid application. | |
23 | * | |
24 | * This program is free software; you can redistribute it and/or modify | |
25 | * it under the terms of the GNU General Public License as published by | |
26 | * the Free Software Foundation; either version 2 of the License, or | |
27 | * (at your option) any later version. | |
26ac0430 | 28 | * |
0710cbcd | 29 | * This program is distributed in the hope that it will be useful, |
30 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | |
31 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
32 | * GNU General Public License for more details. | |
26ac0430 | 33 | * |
0710cbcd | 34 | * You should have received a copy of the GNU General Public License |
35 | * along with this program; if not, write to the Free Software | |
36 | * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111, USA. | |
37 | * | |
38 | */ | |
39 | ||
40 | /* | |
41 | * KNOWN BUGS: | |
26ac0430 | 42 | * |
0710cbcd | 43 | * UDP replies with TC set should be retried via TCP |
44 | */ | |
45 | ||
46 | /** | |
47 | * April 2007 | |
26ac0430 | 48 | * |
0710cbcd | 49 | * Provides RFC3596 functions to handle purely IPv6 DNS. |
50 | * Adds AAAA and IPv6 PTR records. | |
51 | * Other IPv6 records are not mentioned by this RFC. | |
26ac0430 | 52 | * |
0710cbcd | 53 | * IPv4 equivalents are taken care of by the RFC1035 library. |
54 | * Where one protocol lookup must be followed by another, the caller | |
55 | * is resposible for the order and handling of the lookups. | |
56 | * | |
57 | */ | |
58 | ||
59 | #include "config.h" | |
27bc2077 | 60 | #include "compat/inet_pton.h" |
0710cbcd | 61 | #include "util.h" |
62 | ||
63 | #if HAVE_STDIO_H | |
64 | #include <stdio.h> | |
65 | #endif | |
66 | #if HAVE_UNISTD_H | |
67 | #include <unistd.h> | |
68 | #endif | |
69 | #if HAVE_STDLIB_H | |
70 | #include <stdlib.h> | |
71 | #endif | |
72 | #if HAVE_MEMORY_H | |
73 | #include <memory.h> | |
74 | #endif | |
75 | #if HAVE_SYS_TYPES_H | |
76 | #include <sys/types.h> | |
77 | #endif | |
78 | #if HAVE_ASSERT_H | |
79 | #include <assert.h> | |
80 | #endif | |
81 | #if HAVE_NETINET_IN_H | |
82 | #include <netinet/in.h> | |
83 | #endif | |
84 | #if HAVE_STRINGS_H | |
85 | #include <strings.h> | |
86 | #endif | |
87 | ||
88 | #include "rfc3596.h" | |
89 | ||
90 | #ifndef SQUID_RFC1035_H | |
91 | #error RFC3596 Library depends on RFC1035 | |
92 | #endif | |
93 | ||
94 | /** | |
95 | * Builds a message buffer with a QUESTION to lookup records | |
96 | * for a hostname. Caller must allocate 'buf' which should | |
97 | * probably be at least 512 octets. The 'szp' initially | |
98 | * specifies the size of the buffer, on return it contains | |
99 | * the size of the message (i.e. how much to write). | |
100 | * Returns the size of the query | |
101 | */ | |
102 | ssize_t | |
103 | rfc3596BuildHostQuery(const char *hostname, char *buf, size_t sz, unsigned short qid, rfc1035_query * query, int qtype) | |
104 | { | |
105 | static rfc1035_message h; | |
106 | size_t offset = 0; | |
107 | memset(&h, '\0', sizeof(h)); | |
108 | h.id = qid; | |
109 | h.qr = 0; | |
110 | h.rd = 1; | |
111 | h.opcode = 0; /* QUERY */ | |
112 | h.qdcount = (unsigned int) 1; | |
113 | offset += rfc1035HeaderPack(buf + offset, sz - offset, &h); | |
114 | offset += rfc1035QuestionPack(buf + offset, | |
115 | sz - offset, | |
116 | hostname, | |
117 | qtype, | |
118 | RFC1035_CLASS_IN); | |
119 | ||
120 | if (query) { | |
121 | query->qtype = qtype; | |
122 | query->qclass = RFC1035_CLASS_IN; | |
123 | xstrncpy(query->name, hostname, sizeof(query->name)); | |
124 | } | |
125 | ||
126 | assert(offset <= sz); | |
127 | return offset; | |
128 | } | |
129 | ||
130 | /** | |
131 | * Builds a message buffer with a QUESTION to lookup A records | |
132 | * for a hostname. Caller must allocate 'buf' which should | |
133 | * probably be at least 512 octets. The 'szp' initially | |
134 | * specifies the size of the buffer, on return it contains | |
135 | * the size of the message (i.e. how much to write). | |
136 | * \return the size of the query | |
137 | */ | |
138 | ssize_t | |
139 | rfc3596BuildAQuery(const char *hostname, char *buf, size_t sz, unsigned short qid, rfc1035_query * query) | |
140 | { | |
141 | return rfc3596BuildHostQuery(hostname, buf, sz, qid, query, RFC1035_TYPE_A); | |
142 | } | |
143 | ||
144 | /** | |
145 | * Builds a message buffer with a QUESTION to lookup AAAA records | |
146 | * for a hostname. Caller must allocate 'buf' which should | |
147 | * probably be at least 512 octets. The 'szp' initially | |
148 | * specifies the size of the buffer, on return it contains | |
149 | * the size of the message (i.e. how much to write). | |
150 | * \return the size of the query | |
151 | */ | |
152 | ssize_t | |
153 | rfc3596BuildAAAAQuery(const char *hostname, char *buf, size_t sz, unsigned short qid, rfc1035_query * query) | |
154 | { | |
155 | return rfc3596BuildHostQuery(hostname, buf, sz, qid, query, RFC1035_TYPE_AAAA); | |
156 | } | |
157 | ||
158 | ||
159 | /** | |
160 | * Builds a message buffer with a QUESTION to lookup PTR records | |
161 | * for an address. Caller must allocate 'buf' which should | |
162 | * probably be at least 512 octets. The 'szp' initially | |
163 | * specifies the size of the buffer, on return it contains | |
164 | * the size of the message (i.e. how much to write). | |
165 | * \return the size of the query | |
166 | */ | |
167 | ssize_t | |
168 | ||
169 | rfc3596BuildPTRQuery4(const struct in_addr addr, char *buf, size_t sz, unsigned short qid, rfc1035_query * query) | |
170 | { | |
171 | static char rev[RFC1035_MAXHOSTNAMESZ]; | |
172 | unsigned int i; | |
173 | ||
174 | i = (unsigned int) ntohl(addr.s_addr); | |
175 | snprintf(rev, RFC1035_MAXHOSTNAMESZ, "%u.%u.%u.%u.in-addr.arpa.", | |
176 | i & 255, | |
177 | (i >> 8) & 255, | |
178 | (i >> 16) & 255, | |
179 | (i >> 24) & 255); | |
180 | ||
181 | return rfc3596BuildHostQuery(rev, buf, sz, qid, query, RFC1035_TYPE_PTR); | |
182 | } | |
183 | ||
184 | ssize_t | |
185 | ||
186 | rfc3596BuildPTRQuery6(const struct in6_addr addr, char *buf, size_t sz, unsigned short qid, rfc1035_query * query) | |
187 | { | |
188 | static char rev[RFC1035_MAXHOSTNAMESZ]; | |
189 | const uint8_t* r = addr.s6_addr; | |
190 | char* p = rev; | |
191 | int i; // NP: MUST allow signed for loop termination. | |
192 | ||
193 | /* work from the raw addr field. anything else may have representation changes. */ | |
194 | /* The sin6_port and sin6_addr members shall be in network byte order. */ | |
26ac0430 | 195 | for (i = 15; i >= 0; i--, p+=4) { |
0710cbcd | 196 | snprintf(p, 5, "%1x.%1x.", ((r[i]>>4)&0xf), (r[i])&0xf ); |
197 | } | |
198 | ||
199 | snprintf(p,10,"ip6.arpa."); | |
200 | ||
201 | return rfc3596BuildHostQuery(rev, buf, sz, qid, query, RFC1035_TYPE_PTR); | |
202 | } | |
203 | ||
204 | ||
205 | #if DRIVER | |
206 | ||
207 | /* driver needs the rfc1035 code _without_ the main() */ | |
208 | # define main(a,b) rfc1035_main(a,b) | |
209 | # include "rfc1035.c" | |
210 | # undef main(a,b) | |
211 | ||
212 | #include <sys/socket.h> | |
213 | #include <sys/time.h> | |
214 | ||
215 | int | |
216 | main(int argc, char *argv[]) | |
217 | { | |
218 | char input[512]; | |
219 | char buf[512]; | |
220 | char rbuf[512]; | |
221 | size_t sz = 512; | |
222 | unsigned short sid, sidb; | |
223 | int s; | |
224 | int rl; | |
225 | ||
226 | struct sockaddr* S; | |
227 | int var = 1; | |
228 | ||
229 | if ( argc < 3 || argc > 4) { | |
230 | fprintf(stderr, "usage: %s [-6|-4] ip port\n", argv[0]); | |
231 | return 1; | |
232 | } | |
233 | ||
234 | setbuf(stdout, NULL); | |
235 | setbuf(stderr, NULL); | |
236 | ||
26ac0430 AJ |
237 | if (argv[var][0] == '-') { |
238 | if (argv[var][1] == '4') | |
0710cbcd | 239 | prefer = AF_INET; |
26ac0430 | 240 | else if (argv[var][1] == '6') |
0710cbcd | 241 | prefer = AF_INET6; |
242 | else { | |
243 | fprintf(stderr, "usage: %s [-6|-4] ip port\n", argv[0]); | |
244 | return 1; | |
245 | } | |
246 | ||
247 | var++; | |
248 | } | |
249 | ||
250 | s = socket(PF_INET, SOCK_DGRAM, 0); | |
251 | ||
252 | if (s < 0) { | |
253 | perror("socket"); | |
254 | return 1; | |
255 | } | |
256 | ||
257 | ||
258 | memset(&S, '\0', sizeof(S)); | |
259 | ||
26ac0430 | 260 | if (prefer == 6) { |
0710cbcd | 261 | S = (struct sockaddr *) new sockaddr_in6; |
262 | memset(S,0,sizeof(struct sockaddr_in6)); | |
263 | ||
264 | ((struct sockaddr_in6 *)S)->sin6_family = AF_INET6; | |
265 | ((struct sockaddr_in6 *)S)->sin6_port = htons(atoi(argv[var+1])); | |
266 | ||
27bc2077 | 267 | if ( ! inet_pton(AF_INET6, argv[var], &((struct sockaddr_in6 *)S)->sin6_addr.s_addr) ) |
0710cbcd | 268 | perror("listen address"); |
26ac0430 AJ |
269 | return 1; |
270 | } | |
0710cbcd | 271 | |
26ac0430 AJ |
272 | s = socket(PF_INET6, SOCK_DGRAM, 0); |
273 | } | |
274 | else | |
275 | { | |
276 | S = (struct sockaddr *) new sockaddr_in; | |
277 | memset(S,0,sizeof(struct sockaddr_in)); | |
0710cbcd | 278 | |
26ac0430 AJ |
279 | ((struct sockaddr_in *)S)->sin_family = AF_INET; |
280 | ((struct sockaddr_in *)S)->sin_port = htons(atoi(argv[var+1])); | |
0710cbcd | 281 | |
27bc2077 | 282 | if ( ! inet_pton(AF_INET, argv[var], &((struct sockaddr_in *)S)->sin_addr.s_addr) ) |
26ac0430 AJ |
283 | perror("listen address"); |
284 | return 1; | |
285 | } | |
286 | } | |
0710cbcd | 287 | |
26ac0430 AJ |
288 | while (fgets(input, 512, stdin)) |
289 | { | |
0710cbcd | 290 | |
26ac0430 | 291 | struct in6_addr junk6; |
0710cbcd | 292 | |
26ac0430 AJ |
293 | struct in_addr junk4; |
294 | strtok(input, "\r\n"); | |
295 | memset(buf, '\0', 512); | |
296 | sz = 512; | |
0710cbcd | 297 | |
27bc2077 | 298 | if (inet_pton(AF_INET6, input, &junk6)) { |
26ac0430 AJ |
299 | sid = rfc1035BuildPTRQuery6(junk6, buf, &sz); |
300 | sidb=0; | |
27bc2077 | 301 | } else if (inet_pton(AF_INET, input, &junk4)) { |
26ac0430 AJ |
302 | sid = rfc1035BuildPTRQuery4(junk4, buf, &sz); |
303 | sidb=0; | |
304 | } else { | |
305 | sid = rfc1035BuildAAAAQuery(input, buf, &sz); | |
306 | sidb = rfc1035BuildAQuery(input, buf, &sz); | |
307 | } | |
0710cbcd | 308 | |
26ac0430 | 309 | sendto(s, buf, sz, 0, S, sizeof(*S)); |
0710cbcd | 310 | |
26ac0430 AJ |
311 | do { |
312 | fd_set R; | |
0710cbcd | 313 | |
26ac0430 AJ |
314 | struct timeval to; |
315 | FD_ZERO(&R); | |
316 | FD_SET(s, &R); | |
317 | to.tv_sec = 10; | |
318 | to.tv_usec = 0; | |
319 | rl = select(s + 1, &R, NULL, NULL, &to); | |
320 | } while (0); | |
0710cbcd | 321 | |
26ac0430 AJ |
322 | if (rl < 1) { |
323 | printf("TIMEOUT\n"); | |
324 | continue; | |
325 | } | |
0710cbcd | 326 | |
26ac0430 AJ |
327 | memset(rbuf, '\0', 512); |
328 | rl = recv(s, rbuf, 512, 0); | |
329 | { | |
330 | unsigned short rid = 0; | |
331 | int i; | |
332 | int n; | |
333 | rfc1035_rr *answers = NULL; | |
334 | n = rfc1035AnswersUnpack(rbuf, | |
335 | rl, | |
336 | &answers, | |
337 | &rid); | |
338 | ||
339 | if (n < 0) { | |
340 | printf("ERROR %d\n", rfc1035_errno); | |
341 | } else if (rid != sid && rid != sidb) { | |
342 | printf("ERROR, ID mismatch (%#hx, %#hx)\n", sid, rid); | |
343 | printf("ERROR, ID mismatch (%#hx, %#hx)\n", sidb, rid); | |
344 | } else { | |
345 | printf("%d answers\n", n); | |
346 | ||
347 | for (i = 0; i < n; i++) { | |
348 | if (answers[i].type == RFC1035_TYPE_A) { | |
349 | ||
350 | struct in_addr a; | |
2f0b84f7 | 351 | char tmp[16]; |
26ac0430 | 352 | memcpy(&a, answers[i].rdata, 4); |
2f0b84f7 | 353 | printf("A\t%d\t%s\n", answers[i].ttl, inet_ntop(AF_INET,&a,tmp,16)); |
26ac0430 AJ |
354 | } else if (answers[i].type == RFC1035_TYPE_AAAA) { |
355 | ||
356 | struct in6_addr a; | |
2f0b84f7 | 357 | char tmp[INET6_ADDRSTRLEN]; |
26ac0430 | 358 | memcpy(&a, answers[i].rdata, 16); |
2f0b84f7 | 359 | printf("AAAA\t%d\t%s\n", answers[i].ttl, inet_ntop(AF_INET6,&a,tmp,sizeof(tmp))); |
26ac0430 AJ |
360 | } else if (answers[i].type == RFC1035_TYPE_PTR) { |
361 | char ptr[RFC1035_MAXHOSTNAMESZ]; | |
362 | strncpy(ptr, answers[i].rdata, answers[i].rdlength); | |
363 | printf("PTR\t%d\t%s\n", answers[i].ttl, ptr); | |
364 | } else if (answers[i].type == RFC1035_TYPE_CNAME) { | |
365 | char ptr[RFC1035_MAXHOSTNAMESZ]; | |
366 | strncpy(ptr, answers[i].rdata, answers[i].rdlength); | |
367 | printf("CNAME\t%d\t%s\n", answers[i].ttl, ptr); | |
368 | } else { | |
369 | fprintf(stderr, "can't print answer type %d\n", | |
370 | (int) answers[i].type); | |
0710cbcd | 371 | } |
372 | } | |
373 | } | |
374 | } | |
0710cbcd | 375 | } |
376 | ||
26ac0430 AJ |
377 | return 0; |
378 | } | |
379 | ||
0710cbcd | 380 | #endif |