592aa664 |
1 | /* |
2 | * adnsresfilter.c |
3 | * - filter which does resolving, not part of the library |
4 | */ |
5 | /* |
6 | * This file is |
5a0be244 |
7 | * Copyright (C) 1999-2000 Ian Jackson <ian@davenant.greenend.org.uk> |
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8 | * |
9 | * It is part of adns, which is |
3d5cde09 |
10 | * Copyright (C) 1997-2000 Ian Jackson <ian@davenant.greenend.org.uk> |
592aa664 |
11 | * Copyright (C) 1999 Tony Finch <dot@dotat.at> |
12 | * |
13 | * This program is free software; you can redistribute it and/or modify |
14 | * it under the terms of the GNU General Public License as published by |
15 | * the Free Software Foundation; either version 2, or (at your option) |
16 | * any later version. |
17 | * |
18 | * This program is distributed in the hope that it will be useful, |
19 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
20 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
21 | * GNU General Public License for more details. |
22 | * |
23 | * You should have received a copy of the GNU General Public License |
24 | * along with this program; if not, write to the Free Software Foundation, |
25 | * Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. |
26 | */ |
27 | |
28 | #include <stdio.h> |
29 | #include <stdlib.h> |
30 | #include <string.h> |
31 | #include <errno.h> |
32 | #include <search.h> |
33 | #include <assert.h> |
34 | #include <ctype.h> |
35 | |
bbede9a3 |
36 | #include <sys/types.h> |
37 | #include <unistd.h> |
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38 | #include <fcntl.h> |
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39 | |
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40 | #include "config.h" |
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41 | #include "adns.h" |
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42 | #include "dlist.h" |
43 | #include "tvarith.h" |
44 | |
45 | struct outqueuenode { |
46 | struct outqueuenode *next, *back; |
47 | void *buffer; |
48 | char *textp; |
49 | int textlen; |
50 | struct timeval printbefore; |
51 | struct treething *addr; |
52 | }; |
53 | |
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54 | static int bracket, forever, address; |
51cc4d90 |
55 | static unsigned long timeout= 1000; |
2953d358 |
56 | static adns_rrtype rrt= adns_r_ptr; |
57 | |
58 | static int outblocked, inputeof; |
59 | static struct { struct outqueuenode *head, *tail; } outqueue; |
60 | static int peroutqueuenode, outqueuelen; |
61 | |
62 | static struct sockaddr_in sa; |
63 | static adns_state ads; |
64 | |
65 | static char addrtextbuf[14]; |
66 | static int cbyte, inbyte, inbuf; |
67 | static unsigned char bytes[4]; |
68 | static struct timeval printbefore; |
69 | |
70 | struct treething { |
71 | unsigned char bytes[4]; |
72 | adns_query qu; |
73 | adns_answer *ans; |
74 | }; |
75 | |
76 | static struct treething *newthing; |
77 | static void *treeroot; |
78 | |
79 | static int nonblock(int fd, int isnonblock) { |
80 | int r; |
81 | |
82 | r= fcntl(fd,F_GETFL); |
83 | if (r==-1) return -1; |
84 | r= fcntl(fd,F_SETFL, isnonblock ? r|O_NONBLOCK : r&~O_NONBLOCK); |
85 | if (r==-1) return -1; |
86 | return 0; |
87 | } |
88 | |
89 | static void quit(int exitstatus) NONRETURNING; |
90 | static void quit(int exitstatus) { |
91 | nonblock(0,0); |
92 | nonblock(1,0); |
93 | exit(exitstatus); |
94 | } |
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95 | |
96 | static void sysfail(const char *what) NONRETURNING; |
97 | static void sysfail(const char *what) { |
98 | fprintf(stderr,"adnsresfilter: system call failed: %s: %s\n",what,strerror(errno)); |
2953d358 |
99 | quit(2); |
100 | } |
101 | |
102 | static void *xmalloc(size_t sz) { |
103 | void *r; |
104 | r= malloc(sz); if (r) return r; |
105 | sysfail("malloc"); |
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106 | } |
107 | |
108 | static void outputerr(void) NONRETURNING; |
109 | static void outputerr(void) { sysfail("write to stdout"); } |
110 | |
111 | static void usage(void) { |
112 | if (printf("usage: adnsresfilter [<options ...>]\n" |
113 | " adnsresfilter -h|--help\n" |
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114 | "options: -t<milliseconds>|--timeout <milliseconds>\n" |
115 | " -w|--wait (always wait for queries to time out or fail)\n" |
116 | " -b|--brackets (require [...] around IP addresses)\n" |
117 | " -a|--address (always include [address] in output)\n" |
118 | " -u|--unchecked (do not forward map for checking)\n" |
119 | "Timeout is the maximum amount to delay any particular bit of output for.\n" |
120 | "Lookups will go on in the background. Default timeout = 100 (ms).\n") |
592aa664 |
121 | == EOF) outputerr(); |
122 | } |
123 | |
124 | static void usageerr(const char *why) NONRETURNING; |
125 | static void usageerr(const char *why) { |
126 | fprintf(stderr,"adnsresfilter: bad usage: %s\n",why); |
127 | usage(); |
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128 | quit(1); |
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129 | } |
130 | |
131 | static void adnsfail(const char *what, int e) NONRETURNING; |
132 | static void adnsfail(const char *what, int e) { |
133 | fprintf(stderr,"adnsresfilter: adns call failed: %s: %s\n",what,strerror(e)); |
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134 | quit(2); |
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135 | } |
136 | |
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137 | static void settimeout(const char *arg) { |
138 | char *ep; |
139 | timeout= strtoul(arg,&ep,0); |
140 | if (*ep) usageerr("invalid timeout"); |
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141 | } |
142 | |
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143 | static void parseargs(const char *const *argv) { |
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144 | const char *arg; |
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145 | int c; |
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146 | |
147 | while ((arg= *++argv)) { |
148 | if (arg[0] != '-') usageerr("no non-option arguments are allowed"); |
149 | if (arg[1] == '-') { |
150 | if (!strcmp(arg,"--brackets")) { |
151 | bracket= 1; |
152 | } else if (!strcmp(arg,"--unchecked")) { |
153 | rrt= adns_r_ptr_raw; |
154 | } else if (!strcmp(arg,"--wait")) { |
155 | forever= 1; |
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156 | } else if (!strcmp(arg,"--address")) { |
157 | address= 1; |
592aa664 |
158 | } else if (!strcmp(arg,"--help")) { |
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159 | usage(); quit(0); |
41559f53 |
160 | } else if (!strcmp(arg,"--timeout")) { |
161 | if (!(arg= *++argv)) usageerr("--timeout needs a value"); |
162 | settimeout(arg); |
163 | forever= 0; |
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164 | } else { |
165 | usageerr("unknown long option"); |
166 | } |
167 | } else { |
168 | while ((c= *++arg)) { |
169 | switch (c) { |
170 | case 'b': |
171 | bracket= 1; |
172 | break; |
173 | case 'u': |
174 | rrt= adns_r_ptr_raw; |
175 | break; |
176 | case 'w': |
177 | forever= 1; |
178 | break; |
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179 | case 'a': |
180 | address= 1; |
181 | break; |
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182 | case 'h': |
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183 | usage(); |
184 | quit(0); |
185 | case 't': |
186 | if (*++arg) settimeout(arg); |
187 | else if ((arg= *++argv)) settimeout(arg); |
188 | else usageerr("-t needs a value"); |
189 | forever= 0; |
190 | arg= "\0"; |
191 | break; |
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192 | default: |
193 | usageerr("unknown short option"); |
194 | } |
195 | } |
196 | } |
197 | } |
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198 | } |
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199 | |
2953d358 |
200 | static void queueoutchar(int c) { |
201 | struct outqueuenode *entry; |
202 | |
203 | entry= outqueue.tail; |
41559f53 |
204 | if (!entry || entry->addr || entry->textlen >= peroutqueuenode) { |
205 | peroutqueuenode= !peroutqueuenode || !entry || entry->addr ? 128 : |
206 | peroutqueuenode >= 1024 ? 4096 : peroutqueuenode<<2; |
2953d358 |
207 | entry= xmalloc(sizeof(*entry)); |
2953d358 |
208 | entry->buffer= xmalloc(peroutqueuenode); |
209 | entry->textp= entry->buffer; |
210 | entry->textlen= 0; |
211 | entry->addr= 0; |
212 | LIST_LINK_TAIL(outqueue,entry); |
213 | outqueuelen++; |
214 | } |
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215 | entry->textp[entry->textlen++]= c; |
2953d358 |
216 | } |
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217 | |
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218 | static void queueoutstr(const char *str, int len) { |
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219 | while (len-- > 0) queueoutchar(*str++); |
2953d358 |
220 | } |
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221 | |
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222 | static void writestdout(struct outqueuenode *entry) { |
223 | int r; |
224 | |
225 | while (entry->textlen) { |
226 | r= write(1, entry->textp, entry->textlen); |
227 | if (r < 0) { |
228 | if (errno == EINTR) continue; |
229 | if (errno == EAGAIN) { outblocked= 1; break; } |
230 | sysfail("write stdout"); |
231 | } |
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232 | assert(r <= entry->textlen); |
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233 | entry->textp += r; |
234 | entry->textlen -= r; |
235 | } |
236 | if (!entry->textlen) { |
237 | LIST_UNLINK(outqueue,entry); |
238 | free(entry->buffer); |
239 | free(entry); |
240 | outqueuelen--; |
241 | } |
242 | } |
243 | |
244 | static void replacetextwithname(struct outqueuenode *entry) { |
fd60df66 |
245 | char *name, *newbuf; |
246 | int namelen, newlen; |
247 | |
248 | name= entry->addr->ans->rrs.str[0]; |
249 | namelen= strlen(name); |
250 | if (!address) { |
251 | free(entry->buffer); |
252 | entry->buffer= 0; |
253 | entry->textp= name; |
254 | entry->textlen= namelen; |
255 | } else { |
256 | newlen= entry->textlen + namelen + (bracket ? 0 : 2); |
257 | newbuf= xmalloc(newlen + 1); |
258 | sprintf(newbuf, bracket ? "%s%.*s" : "%s[%.*s]", name, entry->textlen, entry->textp); |
259 | free(entry->buffer); |
260 | entry->buffer= entry->textp= newbuf; |
261 | entry->textlen= newlen; |
262 | } |
2953d358 |
263 | } |
264 | |
265 | static void checkadnsqueries(void) { |
266 | adns_query qu; |
267 | adns_answer *ans; |
268 | void *context; |
269 | struct treething *foundthing; |
270 | int r; |
271 | |
272 | for (;;) { |
273 | qu= 0; context= 0; ans= 0; |
274 | r= adns_check(ads,&qu,&ans,&context); |
275 | if (r == ESRCH || r == EAGAIN) break; |
276 | assert(!r); |
277 | foundthing= context; |
278 | foundthing->ans= ans; |
279 | foundthing->qu= 0; |
280 | } |
281 | } |
282 | |
283 | static void restartbuf(void) { |
284 | if (inbuf>0) queueoutstr(addrtextbuf,inbuf); |
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285 | inbuf= 0; |
2953d358 |
286 | } |
287 | |
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288 | static int comparer(const void *a, const void *b) { |
289 | return memcmp(a,b,4); |
290 | } |
291 | |
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292 | static void procaddr(void) { |
293 | struct treething *foundthing; |
294 | void **searchfound; |
295 | struct outqueuenode *entry; |
296 | int r; |
297 | |
298 | if (!newthing) { |
299 | newthing= xmalloc(sizeof(struct treething)); |
300 | newthing->qu= 0; |
301 | newthing->ans= 0; |
302 | } |
303 | |
304 | memcpy(newthing->bytes,bytes,4); |
305 | searchfound= tsearch(newthing,&treeroot,comparer); |
306 | if (!searchfound) sysfail("tsearch"); |
307 | foundthing= *searchfound; |
308 | |
309 | if (foundthing == newthing) { |
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310 | newthing= 0; |
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311 | memcpy(&sa.sin_addr,bytes,4); |
312 | r= adns_submit_reverse(ads, (const struct sockaddr*)&sa, |
313 | rrt,0,foundthing,&foundthing->qu); |
314 | if (r) adnsfail("submit",r); |
315 | } |
316 | entry= xmalloc(sizeof(*entry)); |
317 | entry->buffer= xmalloc(inbuf); |
318 | entry->textp= entry->buffer; |
319 | memcpy(entry->textp,addrtextbuf,inbuf); |
320 | entry->textlen= inbuf; |
321 | entry->addr= foundthing; |
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322 | entry->printbefore= printbefore; |
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323 | LIST_LINK_TAIL(outqueue,entry); |
324 | outqueuelen++; |
325 | inbuf= 0; |
326 | cbyte= -1; |
327 | } |
328 | |
329 | static void startaddr(void) { |
330 | bytes[cbyte=0]= 0; |
331 | inbyte= 0; |
332 | } |
333 | |
334 | static void readstdin(void) { |
335 | char readbuf[512], *p; |
336 | int r, c, nbyte; |
337 | |
338 | while ((r= read(0,readbuf,sizeof(readbuf))) <= 0) { |
339 | if (r == 0) { inputeof= 1; return; } |
340 | if (r == EAGAIN) return; |
341 | if (r != EINTR) sysfail("read stdin"); |
342 | } |
343 | for (p=readbuf; r>0; r--,p++) { |
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344 | c= *p; |
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345 | if (cbyte==-1 && bracket && c=='[') { |
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346 | addrtextbuf[inbuf++]= c; |
592aa664 |
347 | startaddr(); |
348 | } else if (cbyte==-1 && !bracket && !isalnum(c)) { |
2953d358 |
349 | queueoutchar(c); |
592aa664 |
350 | startaddr(); |
351 | } else if (cbyte>=0 && inbyte<3 && c>='0' && c<='9' && |
352 | (nbyte= bytes[cbyte]*10 + (c-'0')) <= 255) { |
353 | bytes[cbyte]= nbyte; |
2953d358 |
354 | addrtextbuf[inbuf++]= c; |
592aa664 |
355 | inbyte++; |
356 | } else if (cbyte>=0 && cbyte<3 && inbyte>0 && c=='.') { |
357 | bytes[++cbyte]= 0; |
2953d358 |
358 | addrtextbuf[inbuf++]= c; |
592aa664 |
359 | inbyte= 0; |
360 | } else if (cbyte==3 && inbyte>0 && bracket && c==']') { |
2953d358 |
361 | addrtextbuf[inbuf++]= c; |
592aa664 |
362 | procaddr(); |
363 | } else if (cbyte==3 && inbyte>0 && !bracket && !isalnum(c)) { |
364 | procaddr(); |
2953d358 |
365 | queueoutchar(c); |
592aa664 |
366 | startaddr(); |
367 | } else { |
368 | restartbuf(); |
2953d358 |
369 | queueoutchar(c); |
592aa664 |
370 | cbyte= -1; |
371 | if (!bracket && !isalnum(c)) startaddr(); |
372 | } |
373 | } |
2953d358 |
374 | } |
375 | |
376 | static void startup(void) { |
377 | int r; |
378 | |
2953d358 |
379 | if (nonblock(0,1)) sysfail("set stdin to nonblocking mode"); |
380 | if (nonblock(1,1)) sysfail("set stdout to nonblocking mode"); |
381 | memset(&sa,0,sizeof(sa)); |
382 | sa.sin_family= AF_INET; |
383 | r= adns_init(&ads,0,0); if (r) adnsfail("init",r); |
384 | cbyte= -1; |
385 | inbyte= -1; |
386 | inbuf= 0; |
387 | if (!bracket) startaddr(); |
388 | } |
389 | |
390 | int main(int argc, const char *const *argv) { |
391 | int r, maxfd; |
392 | fd_set readfds, writefds, exceptfds; |
393 | struct outqueuenode *entry; |
394 | struct timeval *tv, tvbuf, now; |
395 | |
396 | parseargs(argv); |
397 | startup(); |
398 | |
399 | while (!inputeof || outqueue.head) { |
400 | maxfd= 2; |
401 | tv= 0; |
402 | FD_ZERO(&readfds); FD_ZERO(&writefds); FD_ZERO(&exceptfds); |
403 | if ((entry= outqueue.head) && !outblocked) { |
404 | if (!entry->addr) { |
405 | writestdout(entry); |
406 | continue; |
41559f53 |
407 | } |
408 | if (entry->addr->ans) { |
2953d358 |
409 | if (entry->addr->ans->nrrs) |
410 | replacetextwithname(entry); |
411 | entry->addr= 0; |
412 | continue; |
413 | } |
414 | r= gettimeofday(&now,0); if (r) sysfail("gettimeofday"); |
415 | if (forever) { |
416 | tv= 0; |
417 | } else if (!timercmp(&now,&entry->printbefore,<)) { |
418 | entry->addr= 0; |
419 | continue; |
420 | } else { |
41559f53 |
421 | tvbuf.tv_sec= entry->printbefore.tv_sec - now.tv_sec - 1; |
422 | tvbuf.tv_usec= entry->printbefore.tv_usec - now.tv_usec + 1000000; |
2953d358 |
423 | tvbuf.tv_sec += tvbuf.tv_usec / 1000000; |
424 | tvbuf.tv_usec %= 1000000; |
425 | tv= &tvbuf; |
426 | } |
427 | adns_beforeselect(ads,&maxfd,&readfds,&writefds,&exceptfds, |
428 | &tv,&tvbuf,&now); |
429 | } |
430 | if (outblocked) FD_SET(1,&writefds); |
41559f53 |
431 | if (!inputeof && outqueuelen<1024) FD_SET(0,&readfds); |
2953d358 |
432 | |
433 | r= select(maxfd,&readfds,&writefds,&exceptfds,tv); |
434 | if (r < 0) { if (r == EINTR) continue; else sysfail("select"); } |
435 | |
436 | r= gettimeofday(&now,0); if (r) sysfail("gettimeofday"); |
437 | adns_afterselect(ads,maxfd,&readfds,&writefds,&exceptfds,&now); |
438 | checkadnsqueries(); |
439 | |
440 | if (FD_ISSET(0,&readfds)) { |
441 | if (!forever) { |
442 | printbefore= now; |
443 | timevaladd(&printbefore,timeout); |
444 | } |
445 | readstdin(); |
446 | } else if (FD_ISSET(1,&writefds)) { |
447 | outblocked= 0; |
448 | } |
449 | } |
2953d358 |
450 | if (nonblock(0,0)) sysfail("un-nonblock stdin"); |
451 | if (nonblock(1,0)) sysfail("un-nonblock stdout"); |
41559f53 |
452 | if (ferror(stdin) || fclose(stdin)) sysfail("read stdin"); |
453 | if (fclose(stdout)) sysfail("close stdout"); |
592aa664 |
454 | exit(0); |
455 | } |