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 | |
52 | static int bracket, forever, timeout=10; |
53 | static adns_rrtype rrt= adns_r_ptr; |
54 | |
55 | static int outblocked, inputeof; |
56 | static struct { struct outqueuenode *head, *tail; } outqueue; |
57 | static int peroutqueuenode, outqueuelen; |
58 | |
59 | static struct sockaddr_in sa; |
60 | static adns_state ads; |
61 | |
62 | static char addrtextbuf[14]; |
63 | static int cbyte, inbyte, inbuf; |
64 | static unsigned char bytes[4]; |
65 | static struct timeval printbefore; |
66 | |
67 | struct treething { |
68 | unsigned char bytes[4]; |
69 | adns_query qu; |
70 | adns_answer *ans; |
71 | }; |
72 | |
73 | static struct treething *newthing; |
74 | static void *treeroot; |
75 | |
76 | static int nonblock(int fd, int isnonblock) { |
77 | int r; |
78 | |
79 | r= fcntl(fd,F_GETFL); |
80 | if (r==-1) return -1; |
81 | r= fcntl(fd,F_SETFL, isnonblock ? r|O_NONBLOCK : r&~O_NONBLOCK); |
82 | if (r==-1) return -1; |
83 | return 0; |
84 | } |
85 | |
86 | static void quit(int exitstatus) NONRETURNING; |
87 | static void quit(int exitstatus) { |
88 | nonblock(0,0); |
89 | nonblock(1,0); |
90 | exit(exitstatus); |
91 | } |
592aa664 |
92 | |
93 | static void sysfail(const char *what) NONRETURNING; |
94 | static void sysfail(const char *what) { |
95 | fprintf(stderr,"adnsresfilter: system call failed: %s: %s\n",what,strerror(errno)); |
2953d358 |
96 | quit(2); |
97 | } |
98 | |
99 | static void *xmalloc(size_t sz) { |
100 | void *r; |
101 | r= malloc(sz); if (r) return r; |
102 | sysfail("malloc"); |
592aa664 |
103 | } |
104 | |
105 | static void outputerr(void) NONRETURNING; |
106 | static void outputerr(void) { sysfail("write to stdout"); } |
107 | |
108 | static void usage(void) { |
109 | if (printf("usage: adnsresfilter [<options ...>]\n" |
110 | " adnsresfilter -h|--help\n" |
111 | "options: -b|--brackets\n" |
112 | " -w|--wait\n" |
2953d358 |
113 | " -t<timeout>|--timeout <timeout>\n" |
592aa664 |
114 | " -u|--unchecked\n") |
115 | == EOF) outputerr(); |
116 | } |
117 | |
118 | static void usageerr(const char *why) NONRETURNING; |
119 | static void usageerr(const char *why) { |
120 | fprintf(stderr,"adnsresfilter: bad usage: %s\n",why); |
121 | usage(); |
2953d358 |
122 | quit(1); |
592aa664 |
123 | } |
124 | |
125 | static void adnsfail(const char *what, int e) NONRETURNING; |
126 | static void adnsfail(const char *what, int e) { |
127 | fprintf(stderr,"adnsresfilter: adns call failed: %s: %s\n",what,strerror(e)); |
2953d358 |
128 | quit(2); |
592aa664 |
129 | } |
130 | |
592aa664 |
131 | static int comparer(const void *a, const void *b) { |
132 | return memcmp(a,b,4); |
133 | } |
134 | |
2953d358 |
135 | static void parseargs(const char *const *argv) { |
592aa664 |
136 | const char *arg; |
2953d358 |
137 | int c; |
592aa664 |
138 | |
139 | while ((arg= *++argv)) { |
140 | if (arg[0] != '-') usageerr("no non-option arguments are allowed"); |
141 | if (arg[1] == '-') { |
142 | if (!strcmp(arg,"--brackets")) { |
143 | bracket= 1; |
144 | } else if (!strcmp(arg,"--unchecked")) { |
145 | rrt= adns_r_ptr_raw; |
146 | } else if (!strcmp(arg,"--wait")) { |
147 | forever= 1; |
148 | } else if (!strcmp(arg,"--help")) { |
2953d358 |
149 | usage(); quit(0); |
592aa664 |
150 | } else { |
151 | usageerr("unknown long option"); |
152 | } |
153 | } else { |
154 | while ((c= *++arg)) { |
155 | switch (c) { |
156 | case 'b': |
157 | bracket= 1; |
158 | break; |
159 | case 'u': |
160 | rrt= adns_r_ptr_raw; |
161 | break; |
162 | case 'w': |
163 | forever= 1; |
164 | break; |
165 | case 'h': |
2953d358 |
166 | usage(); quit(0); |
592aa664 |
167 | default: |
168 | usageerr("unknown short option"); |
169 | } |
170 | } |
171 | } |
172 | } |
2953d358 |
173 | } |
592aa664 |
174 | |
2953d358 |
175 | static void queueoutchar(int c) { |
176 | struct outqueuenode *entry; |
177 | |
178 | entry= outqueue.tail; |
179 | if (!entry->back || entry->addr || entry->textlen >= peroutqueuenode) { |
180 | entry= xmalloc(sizeof(*entry)); |
181 | peroutqueuenode= !entry->back || entry->addr ? 32 : |
182 | peroutqueuenode >= 1024 ? 2048 : peroutqueuenode<<1; |
183 | entry->buffer= xmalloc(peroutqueuenode); |
184 | entry->textp= entry->buffer; |
185 | entry->textlen= 0; |
186 | entry->addr= 0; |
187 | LIST_LINK_TAIL(outqueue,entry); |
188 | outqueuelen++; |
189 | } |
190 | *entry->textp++= c; |
191 | entry->textlen++; |
192 | } |
592aa664 |
193 | |
2953d358 |
194 | static void queueoutstr(const char *str, int len) { |
195 | while (len > 0) queueoutchar(*str++); |
196 | } |
592aa664 |
197 | |
2953d358 |
198 | static void writestdout(struct outqueuenode *entry) { |
199 | int r; |
200 | |
201 | while (entry->textlen) { |
202 | r= write(1, entry->textp, entry->textlen); |
203 | if (r < 0) { |
204 | if (errno == EINTR) continue; |
205 | if (errno == EAGAIN) { outblocked= 1; break; } |
206 | sysfail("write stdout"); |
207 | } |
208 | assert(r < entry->textlen); |
209 | entry->textp += r; |
210 | entry->textlen -= r; |
211 | } |
212 | if (!entry->textlen) { |
213 | LIST_UNLINK(outqueue,entry); |
214 | free(entry->buffer); |
215 | free(entry); |
216 | outqueuelen--; |
217 | } |
218 | } |
219 | |
220 | static void replacetextwithname(struct outqueuenode *entry) { |
221 | free(entry->buffer); |
222 | entry->buffer= 0; |
223 | entry->textp= entry->addr->ans->rrs.str[0]; |
224 | entry->textlen= strlen(entry->textp); |
225 | } |
226 | |
227 | static void checkadnsqueries(void) { |
228 | adns_query qu; |
229 | adns_answer *ans; |
230 | void *context; |
231 | struct treething *foundthing; |
232 | int r; |
233 | |
234 | for (;;) { |
235 | qu= 0; context= 0; ans= 0; |
236 | r= adns_check(ads,&qu,&ans,&context); |
237 | if (r == ESRCH || r == EAGAIN) break; |
238 | assert(!r); |
239 | foundthing= context; |
240 | foundthing->ans= ans; |
241 | foundthing->qu= 0; |
242 | } |
243 | } |
244 | |
245 | static void restartbuf(void) { |
246 | if (inbuf>0) queueoutstr(addrtextbuf,inbuf); |
592aa664 |
247 | inbuf= 0; |
2953d358 |
248 | } |
249 | |
250 | static void procaddr(void) { |
251 | struct treething *foundthing; |
252 | void **searchfound; |
253 | struct outqueuenode *entry; |
254 | int r; |
255 | |
256 | if (!newthing) { |
257 | newthing= xmalloc(sizeof(struct treething)); |
258 | newthing->qu= 0; |
259 | newthing->ans= 0; |
260 | } |
261 | |
262 | memcpy(newthing->bytes,bytes,4); |
263 | searchfound= tsearch(newthing,&treeroot,comparer); |
264 | if (!searchfound) sysfail("tsearch"); |
265 | foundthing= *searchfound; |
266 | |
267 | if (foundthing == newthing) { |
268 | memcpy(&sa.sin_addr,bytes,4); |
269 | r= adns_submit_reverse(ads, (const struct sockaddr*)&sa, |
270 | rrt,0,foundthing,&foundthing->qu); |
271 | if (r) adnsfail("submit",r); |
272 | } |
273 | entry= xmalloc(sizeof(*entry)); |
274 | entry->buffer= xmalloc(inbuf); |
275 | entry->textp= entry->buffer; |
276 | memcpy(entry->textp,addrtextbuf,inbuf); |
277 | entry->textlen= inbuf; |
278 | entry->addr= foundthing; |
279 | LIST_LINK_TAIL(outqueue,entry); |
280 | outqueuelen++; |
281 | inbuf= 0; |
282 | cbyte= -1; |
283 | } |
284 | |
285 | static void startaddr(void) { |
286 | bytes[cbyte=0]= 0; |
287 | inbyte= 0; |
288 | } |
289 | |
290 | static void readstdin(void) { |
291 | char readbuf[512], *p; |
292 | int r, c, nbyte; |
293 | |
294 | while ((r= read(0,readbuf,sizeof(readbuf))) <= 0) { |
295 | if (r == 0) { inputeof= 1; return; } |
296 | if (r == EAGAIN) return; |
297 | if (r != EINTR) sysfail("read stdin"); |
298 | } |
299 | for (p=readbuf; r>0; r--,p++) { |
300 | c= *p++; |
592aa664 |
301 | if (cbyte==-1 && bracket && c=='[') { |
2953d358 |
302 | addrtextbuf[inbuf++]= c; |
592aa664 |
303 | startaddr(); |
304 | } else if (cbyte==-1 && !bracket && !isalnum(c)) { |
2953d358 |
305 | queueoutchar(c); |
592aa664 |
306 | startaddr(); |
307 | } else if (cbyte>=0 && inbyte<3 && c>='0' && c<='9' && |
308 | (nbyte= bytes[cbyte]*10 + (c-'0')) <= 255) { |
309 | bytes[cbyte]= nbyte; |
2953d358 |
310 | addrtextbuf[inbuf++]= c; |
592aa664 |
311 | inbyte++; |
312 | } else if (cbyte>=0 && cbyte<3 && inbyte>0 && c=='.') { |
313 | bytes[++cbyte]= 0; |
2953d358 |
314 | addrtextbuf[inbuf++]= c; |
592aa664 |
315 | inbyte= 0; |
316 | } else if (cbyte==3 && inbyte>0 && bracket && c==']') { |
2953d358 |
317 | addrtextbuf[inbuf++]= c; |
592aa664 |
318 | procaddr(); |
319 | } else if (cbyte==3 && inbyte>0 && !bracket && !isalnum(c)) { |
320 | procaddr(); |
2953d358 |
321 | queueoutchar(c); |
592aa664 |
322 | startaddr(); |
323 | } else { |
324 | restartbuf(); |
2953d358 |
325 | queueoutchar(c); |
592aa664 |
326 | cbyte= -1; |
327 | if (!bracket && !isalnum(c)) startaddr(); |
328 | } |
329 | } |
592aa664 |
330 | if (cbyte==3 && inbyte>0 && !bracket) procaddr(); |
2953d358 |
331 | } |
332 | |
333 | static void startup(void) { |
334 | int r; |
335 | |
336 | if (setvbuf(stdout,0,_IOLBF,0)) sysfail("setvbuf stdout"); |
337 | if (nonblock(0,1)) sysfail("set stdin to nonblocking mode"); |
338 | if (nonblock(1,1)) sysfail("set stdout to nonblocking mode"); |
339 | memset(&sa,0,sizeof(sa)); |
340 | sa.sin_family= AF_INET; |
341 | r= adns_init(&ads,0,0); if (r) adnsfail("init",r); |
342 | cbyte= -1; |
343 | inbyte= -1; |
344 | inbuf= 0; |
345 | if (!bracket) startaddr(); |
346 | } |
347 | |
348 | int main(int argc, const char *const *argv) { |
349 | int r, maxfd; |
350 | fd_set readfds, writefds, exceptfds; |
351 | struct outqueuenode *entry; |
352 | struct timeval *tv, tvbuf, now; |
353 | |
354 | parseargs(argv); |
355 | startup(); |
356 | |
357 | while (!inputeof || outqueue.head) { |
358 | maxfd= 2; |
359 | tv= 0; |
360 | FD_ZERO(&readfds); FD_ZERO(&writefds); FD_ZERO(&exceptfds); |
361 | if ((entry= outqueue.head) && !outblocked) { |
362 | if (!entry->addr) { |
363 | writestdout(entry); |
364 | continue; |
365 | } else if (entry->addr->ans) { |
366 | if (entry->addr->ans->nrrs) |
367 | replacetextwithname(entry); |
368 | entry->addr= 0; |
369 | continue; |
370 | } |
371 | r= gettimeofday(&now,0); if (r) sysfail("gettimeofday"); |
372 | if (forever) { |
373 | tv= 0; |
374 | } else if (!timercmp(&now,&entry->printbefore,<)) { |
375 | entry->addr= 0; |
376 | continue; |
377 | } else { |
378 | tvbuf.tv_sec= printbefore.tv_sec - now.tv_sec - 1; |
379 | tvbuf.tv_usec= printbefore.tv_usec - now.tv_usec + 1000000; |
380 | tvbuf.tv_sec += tvbuf.tv_usec / 1000000; |
381 | tvbuf.tv_usec %= 1000000; |
382 | tv= &tvbuf; |
383 | } |
384 | adns_beforeselect(ads,&maxfd,&readfds,&writefds,&exceptfds, |
385 | &tv,&tvbuf,&now); |
386 | } |
387 | if (outblocked) FD_SET(1,&writefds); |
388 | if (!inputeof && outqueuelen<1000) FD_SET(0,&readfds); |
389 | |
390 | r= select(maxfd,&readfds,&writefds,&exceptfds,tv); |
391 | if (r < 0) { if (r == EINTR) continue; else sysfail("select"); } |
392 | |
393 | r= gettimeofday(&now,0); if (r) sysfail("gettimeofday"); |
394 | adns_afterselect(ads,maxfd,&readfds,&writefds,&exceptfds,&now); |
395 | checkadnsqueries(); |
396 | |
397 | if (FD_ISSET(0,&readfds)) { |
398 | if (!forever) { |
399 | printbefore= now; |
400 | timevaladd(&printbefore,timeout); |
401 | } |
402 | readstdin(); |
403 | } else if (FD_ISSET(1,&writefds)) { |
404 | outblocked= 0; |
405 | } |
406 | } |
407 | if (ferror(stdin) || fclose(stdin)) sysfail("read stdin"); |
592aa664 |
408 | if (fclose(stdout)) sysfail("close stdout"); |
2953d358 |
409 | if (nonblock(0,0)) sysfail("un-nonblock stdin"); |
410 | if (nonblock(1,0)) sysfail("un-nonblock stdout"); |
592aa664 |
411 | exit(0); |
412 | } |