592aa664 |
1 | /* |
2 | * adnsresfilter.c |
3 | * - filter which does resolving, not part of the library |
4 | */ |
5 | /* |
ae8cc977 |
6 | * This file is part of adns, which is |
26e1c3d6 |
7 | * Copyright (C) 1997-2000,2003,2006,2014 Ian Jackson |
ae8cc977 |
8 | * Copyright (C) 1999-2000,2003,2006 Tony Finch |
9 | * Copyright (C) 1991 Massachusetts Institute of Technology |
10 | * (See the file INSTALL for full details.) |
592aa664 |
11 | * |
12 | * This program is free software; you can redistribute it and/or modify |
13 | * it under the terms of the GNU General Public License as published by |
7f8bbe29 |
14 | * the Free Software Foundation; either version 3, or (at your option) |
592aa664 |
15 | * any later version. |
16 | * |
17 | * This program is distributed in the hope that it will be useful, |
18 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
19 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
20 | * GNU General Public License for more details. |
21 | * |
22 | * You should have received a copy of the GNU General Public License |
8c09a4c6 |
23 | * along with this program; if not, write to the Free Software Foundation. |
592aa664 |
24 | */ |
25 | |
26 | #include <stdio.h> |
27 | #include <stdlib.h> |
28 | #include <string.h> |
29 | #include <errno.h> |
30 | #include <search.h> |
31 | #include <assert.h> |
32 | #include <ctype.h> |
33 | |
bbede9a3 |
34 | #include <sys/types.h> |
35 | #include <unistd.h> |
0a4fd9ed |
36 | #include <fcntl.h> |
2953d358 |
37 | |
592aa664 |
38 | #include "config.h" |
5a0be244 |
39 | #include "adns.h" |
2953d358 |
40 | #include "dlist.h" |
41 | #include "tvarith.h" |
aa3ffb57 |
42 | #include "client.h" |
2953d358 |
43 | |
98e3fa81 |
44 | #ifdef ADNS_REGRESS_TEST |
45 | # include "hredirect.h" |
46 | #endif |
47 | |
2953d358 |
48 | struct outqueuenode { |
49 | struct outqueuenode *next, *back; |
e22eb8c7 |
50 | char *buffer, *textp; |
2953d358 |
51 | int textlen; |
52 | struct timeval printbefore; |
53 | struct treething *addr; |
54 | }; |
55 | |
fd60df66 |
56 | static int bracket, forever, address; |
51cc4d90 |
57 | static unsigned long timeout= 1000; |
2953d358 |
58 | static adns_rrtype rrt= adns_r_ptr; |
98e3fa81 |
59 | static adns_initflags initflags= 0; |
60 | static const char *config_text; |
2953d358 |
61 | |
62 | static int outblocked, inputeof; |
63 | static struct { struct outqueuenode *head, *tail; } outqueue; |
64 | static int peroutqueuenode, outqueuelen; |
65 | |
66 | static struct sockaddr_in sa; |
67 | static adns_state ads; |
68 | |
69 | static char addrtextbuf[14]; |
70 | static int cbyte, inbyte, inbuf; |
71 | static unsigned char bytes[4]; |
72 | static struct timeval printbefore; |
73 | |
74 | struct treething { |
75 | unsigned char bytes[4]; |
76 | adns_query qu; |
77 | adns_answer *ans; |
78 | }; |
79 | |
80 | static struct treething *newthing; |
81 | static void *treeroot; |
82 | |
83 | static int nonblock(int fd, int isnonblock) { |
84 | int r; |
85 | |
86 | r= fcntl(fd,F_GETFL); |
87 | if (r==-1) return -1; |
88 | r= fcntl(fd,F_SETFL, isnonblock ? r|O_NONBLOCK : r&~O_NONBLOCK); |
89 | if (r==-1) return -1; |
90 | return 0; |
91 | } |
92 | |
aa3ffb57 |
93 | void quitnow(int exitstatus) { |
2953d358 |
94 | nonblock(0,0); |
95 | nonblock(1,0); |
96 | exit(exitstatus); |
97 | } |
592aa664 |
98 | |
99 | static void sysfail(const char *what) NONRETURNING; |
100 | static void sysfail(const char *what) { |
101 | fprintf(stderr,"adnsresfilter: system call failed: %s: %s\n",what,strerror(errno)); |
aa3ffb57 |
102 | quitnow(2); |
2953d358 |
103 | } |
104 | |
105 | static void *xmalloc(size_t sz) { |
106 | void *r; |
107 | r= malloc(sz); if (r) return r; |
108 | sysfail("malloc"); |
592aa664 |
109 | } |
110 | |
111 | static void outputerr(void) NONRETURNING; |
112 | static void outputerr(void) { sysfail("write to stdout"); } |
113 | |
114 | static void usage(void) { |
115 | if (printf("usage: adnsresfilter [<options ...>]\n" |
aa3ffb57 |
116 | " adnsresfilter -h|--help | --version\n" |
70da58ac |
117 | "options: -t<milliseconds>|--timeout <milliseconds>\n" |
118 | " -w|--wait (always wait for queries to time out or fail)\n" |
119 | " -b|--brackets (require [...] around IP addresses)\n" |
120 | " -a|--address (always include [address] in output)\n" |
121 | " -u|--unchecked (do not forward map for checking)\n" |
98e3fa81 |
122 | " --config <text> (use this instead of resolv.conf)\n" |
123 | " --debug (turn on adns resolver debugging)\n" |
70da58ac |
124 | "Timeout is the maximum amount to delay any particular bit of output for.\n" |
98e3fa81 |
125 | "Lookups will go on in the background. Default timeout = 1000 (ms).\n") |
592aa664 |
126 | == EOF) outputerr(); |
67a57aae |
127 | if (fflush(stdout)) sysfail("flush stdout"); |
592aa664 |
128 | } |
129 | |
130 | static void usageerr(const char *why) NONRETURNING; |
131 | static void usageerr(const char *why) { |
132 | fprintf(stderr,"adnsresfilter: bad usage: %s\n",why); |
133 | usage(); |
aa3ffb57 |
134 | quitnow(1); |
592aa664 |
135 | } |
136 | |
137 | static void adnsfail(const char *what, int e) NONRETURNING; |
138 | static void adnsfail(const char *what, int e) { |
139 | fprintf(stderr,"adnsresfilter: adns call failed: %s: %s\n",what,strerror(e)); |
aa3ffb57 |
140 | quitnow(2); |
592aa664 |
141 | } |
142 | |
41559f53 |
143 | static void settimeout(const char *arg) { |
144 | char *ep; |
145 | timeout= strtoul(arg,&ep,0); |
146 | if (*ep) usageerr("invalid timeout"); |
592aa664 |
147 | } |
148 | |
2953d358 |
149 | static void parseargs(const char *const *argv) { |
592aa664 |
150 | const char *arg; |
2953d358 |
151 | int c; |
592aa664 |
152 | |
153 | while ((arg= *++argv)) { |
154 | if (arg[0] != '-') usageerr("no non-option arguments are allowed"); |
155 | if (arg[1] == '-') { |
98e3fa81 |
156 | if (!strcmp(arg,"--timeout")) { |
157 | if (!(arg= *++argv)) usageerr("--timeout needs a value"); |
158 | settimeout(arg); |
159 | forever= 0; |
592aa664 |
160 | } else if (!strcmp(arg,"--wait")) { |
161 | forever= 1; |
98e3fa81 |
162 | } else if (!strcmp(arg,"--brackets")) { |
163 | bracket= 1; |
fd60df66 |
164 | } else if (!strcmp(arg,"--address")) { |
165 | address= 1; |
98e3fa81 |
166 | } else if (!strcmp(arg,"--unchecked")) { |
167 | rrt= adns_r_ptr_raw; |
168 | } else if (!strcmp(arg,"--config")) { |
169 | if (!(arg= *++argv)) usageerr("--config needs a value"); |
170 | config_text= arg; |
171 | } else if (!strcmp(arg,"--debug")) { |
172 | initflags |= adns_if_debug; |
592aa664 |
173 | } else if (!strcmp(arg,"--help")) { |
aa3ffb57 |
174 | usage(); quitnow(0); |
175 | } else if (!strcmp(arg,"--version")) { |
176 | VERSION_PRINT_QUIT("adnsresfilter"); quitnow(0); |
592aa664 |
177 | } else { |
178 | usageerr("unknown long option"); |
179 | } |
180 | } else { |
181 | while ((c= *++arg)) { |
182 | switch (c) { |
98e3fa81 |
183 | case 't': |
184 | if (*++arg) settimeout(arg); |
185 | else if ((arg= *++argv)) settimeout(arg); |
186 | else usageerr("-t needs a value"); |
187 | forever= 0; |
188 | arg= "\0"; |
592aa664 |
189 | break; |
190 | case 'w': |
191 | forever= 1; |
192 | break; |
98e3fa81 |
193 | case 'b': |
194 | bracket= 1; |
195 | break; |
fd60df66 |
196 | case 'a': |
197 | address= 1; |
198 | break; |
98e3fa81 |
199 | case 'u': |
200 | rrt= adns_r_ptr_raw; |
201 | break; |
592aa664 |
202 | case 'h': |
41559f53 |
203 | usage(); |
aa3ffb57 |
204 | quitnow(0); |
592aa664 |
205 | default: |
206 | usageerr("unknown short option"); |
207 | } |
208 | } |
209 | } |
210 | } |
2953d358 |
211 | } |
592aa664 |
212 | |
2953d358 |
213 | static void queueoutchar(int c) { |
214 | struct outqueuenode *entry; |
215 | |
216 | entry= outqueue.tail; |
e22eb8c7 |
217 | if (!entry || entry->addr || |
218 | entry->textlen >= peroutqueuenode - (entry->textp - entry->buffer)) { |
41559f53 |
219 | peroutqueuenode= !peroutqueuenode || !entry || entry->addr ? 128 : |
220 | peroutqueuenode >= 1024 ? 4096 : peroutqueuenode<<2; |
2953d358 |
221 | entry= xmalloc(sizeof(*entry)); |
2953d358 |
222 | entry->buffer= xmalloc(peroutqueuenode); |
223 | entry->textp= entry->buffer; |
224 | entry->textlen= 0; |
225 | entry->addr= 0; |
226 | LIST_LINK_TAIL(outqueue,entry); |
227 | outqueuelen++; |
228 | } |
41559f53 |
229 | entry->textp[entry->textlen++]= c; |
2953d358 |
230 | } |
592aa664 |
231 | |
2953d358 |
232 | static void queueoutstr(const char *str, int len) { |
41559f53 |
233 | while (len-- > 0) queueoutchar(*str++); |
2953d358 |
234 | } |
592aa664 |
235 | |
2953d358 |
236 | static void writestdout(struct outqueuenode *entry) { |
237 | int r; |
238 | |
239 | while (entry->textlen) { |
240 | r= write(1, entry->textp, entry->textlen); |
241 | if (r < 0) { |
242 | if (errno == EINTR) continue; |
243 | if (errno == EAGAIN) { outblocked= 1; break; } |
244 | sysfail("write stdout"); |
245 | } |
41559f53 |
246 | assert(r <= entry->textlen); |
2953d358 |
247 | entry->textp += r; |
248 | entry->textlen -= r; |
249 | } |
250 | if (!entry->textlen) { |
251 | LIST_UNLINK(outqueue,entry); |
252 | free(entry->buffer); |
253 | free(entry); |
254 | outqueuelen--; |
255 | } |
256 | } |
257 | |
258 | static void replacetextwithname(struct outqueuenode *entry) { |
fd60df66 |
259 | char *name, *newbuf; |
260 | int namelen, newlen; |
261 | |
262 | name= entry->addr->ans->rrs.str[0]; |
263 | namelen= strlen(name); |
264 | if (!address) { |
265 | free(entry->buffer); |
266 | entry->buffer= 0; |
267 | entry->textp= name; |
268 | entry->textlen= namelen; |
269 | } else { |
270 | newlen= entry->textlen + namelen + (bracket ? 0 : 2); |
271 | newbuf= xmalloc(newlen + 1); |
272 | sprintf(newbuf, bracket ? "%s%.*s" : "%s[%.*s]", name, entry->textlen, entry->textp); |
273 | free(entry->buffer); |
274 | entry->buffer= entry->textp= newbuf; |
275 | entry->textlen= newlen; |
276 | } |
2953d358 |
277 | } |
278 | |
279 | static void checkadnsqueries(void) { |
280 | adns_query qu; |
281 | adns_answer *ans; |
282 | void *context; |
283 | struct treething *foundthing; |
284 | int r; |
285 | |
286 | for (;;) { |
287 | qu= 0; context= 0; ans= 0; |
288 | r= adns_check(ads,&qu,&ans,&context); |
289 | if (r == ESRCH || r == EAGAIN) break; |
290 | assert(!r); |
291 | foundthing= context; |
292 | foundthing->ans= ans; |
293 | foundthing->qu= 0; |
294 | } |
295 | } |
296 | |
297 | static void restartbuf(void) { |
298 | if (inbuf>0) queueoutstr(addrtextbuf,inbuf); |
592aa664 |
299 | inbuf= 0; |
2953d358 |
300 | } |
301 | |
41559f53 |
302 | static int comparer(const void *a, const void *b) { |
303 | return memcmp(a,b,4); |
304 | } |
305 | |
2953d358 |
306 | static void procaddr(void) { |
307 | struct treething *foundthing; |
308 | void **searchfound; |
309 | struct outqueuenode *entry; |
310 | int r; |
311 | |
312 | if (!newthing) { |
313 | newthing= xmalloc(sizeof(struct treething)); |
314 | newthing->qu= 0; |
315 | newthing->ans= 0; |
316 | } |
317 | |
318 | memcpy(newthing->bytes,bytes,4); |
319 | searchfound= tsearch(newthing,&treeroot,comparer); |
320 | if (!searchfound) sysfail("tsearch"); |
321 | foundthing= *searchfound; |
322 | |
323 | if (foundthing == newthing) { |
41559f53 |
324 | newthing= 0; |
2953d358 |
325 | memcpy(&sa.sin_addr,bytes,4); |
326 | r= adns_submit_reverse(ads, (const struct sockaddr*)&sa, |
327 | rrt,0,foundthing,&foundthing->qu); |
328 | if (r) adnsfail("submit",r); |
329 | } |
330 | entry= xmalloc(sizeof(*entry)); |
331 | entry->buffer= xmalloc(inbuf); |
332 | entry->textp= entry->buffer; |
333 | memcpy(entry->textp,addrtextbuf,inbuf); |
334 | entry->textlen= inbuf; |
335 | entry->addr= foundthing; |
41559f53 |
336 | entry->printbefore= printbefore; |
2953d358 |
337 | LIST_LINK_TAIL(outqueue,entry); |
338 | outqueuelen++; |
339 | inbuf= 0; |
340 | cbyte= -1; |
341 | } |
342 | |
343 | static void startaddr(void) { |
344 | bytes[cbyte=0]= 0; |
345 | inbyte= 0; |
346 | } |
347 | |
348 | static void readstdin(void) { |
349 | char readbuf[512], *p; |
350 | int r, c, nbyte; |
351 | |
352 | while ((r= read(0,readbuf,sizeof(readbuf))) <= 0) { |
353 | if (r == 0) { inputeof= 1; return; } |
354 | if (r == EAGAIN) return; |
355 | if (r != EINTR) sysfail("read stdin"); |
356 | } |
357 | for (p=readbuf; r>0; r--,p++) { |
41559f53 |
358 | c= *p; |
592aa664 |
359 | if (cbyte==-1 && bracket && c=='[') { |
2953d358 |
360 | addrtextbuf[inbuf++]= c; |
592aa664 |
361 | startaddr(); |
362 | } else if (cbyte==-1 && !bracket && !isalnum(c)) { |
2953d358 |
363 | queueoutchar(c); |
592aa664 |
364 | startaddr(); |
365 | } else if (cbyte>=0 && inbyte<3 && c>='0' && c<='9' && |
366 | (nbyte= bytes[cbyte]*10 + (c-'0')) <= 255) { |
367 | bytes[cbyte]= nbyte; |
2953d358 |
368 | addrtextbuf[inbuf++]= c; |
592aa664 |
369 | inbyte++; |
370 | } else if (cbyte>=0 && cbyte<3 && inbyte>0 && c=='.') { |
371 | bytes[++cbyte]= 0; |
2953d358 |
372 | addrtextbuf[inbuf++]= c; |
592aa664 |
373 | inbyte= 0; |
374 | } else if (cbyte==3 && inbyte>0 && bracket && c==']') { |
2953d358 |
375 | addrtextbuf[inbuf++]= c; |
592aa664 |
376 | procaddr(); |
377 | } else if (cbyte==3 && inbyte>0 && !bracket && !isalnum(c)) { |
378 | procaddr(); |
2953d358 |
379 | queueoutchar(c); |
592aa664 |
380 | startaddr(); |
381 | } else { |
382 | restartbuf(); |
2953d358 |
383 | queueoutchar(c); |
592aa664 |
384 | cbyte= -1; |
385 | if (!bracket && !isalnum(c)) startaddr(); |
386 | } |
387 | } |
2953d358 |
388 | } |
389 | |
390 | static void startup(void) { |
391 | int r; |
392 | |
2953d358 |
393 | if (nonblock(0,1)) sysfail("set stdin to nonblocking mode"); |
394 | if (nonblock(1,1)) sysfail("set stdout to nonblocking mode"); |
395 | memset(&sa,0,sizeof(sa)); |
396 | sa.sin_family= AF_INET; |
98e3fa81 |
397 | if (config_text) { |
398 | r= adns_init_strcfg(&ads,initflags,stderr,config_text); |
399 | } else { |
400 | r= adns_init(&ads,initflags,0); |
401 | } |
402 | if (r) adnsfail("init",r); |
2953d358 |
403 | cbyte= -1; |
404 | inbyte= -1; |
405 | inbuf= 0; |
406 | if (!bracket) startaddr(); |
407 | } |
408 | |
409 | int main(int argc, const char *const *argv) { |
410 | int r, maxfd; |
411 | fd_set readfds, writefds, exceptfds; |
412 | struct outqueuenode *entry; |
413 | struct timeval *tv, tvbuf, now; |
414 | |
415 | parseargs(argv); |
416 | startup(); |
417 | |
418 | while (!inputeof || outqueue.head) { |
419 | maxfd= 2; |
420 | tv= 0; |
421 | FD_ZERO(&readfds); FD_ZERO(&writefds); FD_ZERO(&exceptfds); |
422 | if ((entry= outqueue.head) && !outblocked) { |
423 | if (!entry->addr) { |
424 | writestdout(entry); |
425 | continue; |
41559f53 |
426 | } |
427 | if (entry->addr->ans) { |
2953d358 |
428 | if (entry->addr->ans->nrrs) |
429 | replacetextwithname(entry); |
430 | entry->addr= 0; |
431 | continue; |
432 | } |
433 | r= gettimeofday(&now,0); if (r) sysfail("gettimeofday"); |
434 | if (forever) { |
435 | tv= 0; |
436 | } else if (!timercmp(&now,&entry->printbefore,<)) { |
437 | entry->addr= 0; |
438 | continue; |
439 | } else { |
41559f53 |
440 | tvbuf.tv_sec= entry->printbefore.tv_sec - now.tv_sec - 1; |
441 | tvbuf.tv_usec= entry->printbefore.tv_usec - now.tv_usec + 1000000; |
2953d358 |
442 | tvbuf.tv_sec += tvbuf.tv_usec / 1000000; |
443 | tvbuf.tv_usec %= 1000000; |
444 | tv= &tvbuf; |
445 | } |
446 | adns_beforeselect(ads,&maxfd,&readfds,&writefds,&exceptfds, |
447 | &tv,&tvbuf,&now); |
448 | } |
449 | if (outblocked) FD_SET(1,&writefds); |
41559f53 |
450 | if (!inputeof && outqueuelen<1024) FD_SET(0,&readfds); |
2953d358 |
451 | |
452 | r= select(maxfd,&readfds,&writefds,&exceptfds,tv); |
453 | if (r < 0) { if (r == EINTR) continue; else sysfail("select"); } |
454 | |
455 | r= gettimeofday(&now,0); if (r) sysfail("gettimeofday"); |
456 | adns_afterselect(ads,maxfd,&readfds,&writefds,&exceptfds,&now); |
457 | checkadnsqueries(); |
458 | |
459 | if (FD_ISSET(0,&readfds)) { |
460 | if (!forever) { |
461 | printbefore= now; |
462 | timevaladd(&printbefore,timeout); |
463 | } |
464 | readstdin(); |
465 | } else if (FD_ISSET(1,&writefds)) { |
466 | outblocked= 0; |
467 | } |
468 | } |
2953d358 |
469 | if (nonblock(0,0)) sysfail("un-nonblock stdin"); |
470 | if (nonblock(1,0)) sysfail("un-nonblock stdout"); |
67a57aae |
471 | adns_finish(ads); |
592aa664 |
472 | exit(0); |
473 | } |