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