1 /*
2 * setup.c
3 * - configuration file parsing
4 * - management of global state
5 */
6 /*
7 * This file is
8 * Copyright (C) 1997-1999 Ian Jackson <ian@davenant.greenend.org.uk>
9 *
10 * It is part of adns, which is
11 * Copyright (C) 1997-2000 Ian Jackson <ian@davenant.greenend.org.uk>
12 * Copyright (C) 1999-2000 Tony Finch <dot@dotat.at>
13 *
14 * This program is free software; you can redistribute it and/or modify
15 * it under the terms of the GNU General Public License as published by
16 * the Free Software Foundation; either version 2, or (at your option)
17 * any later version.
18 *
19 * This program is distributed in the hope that it will be useful,
20 * but WITHOUT ANY WARRANTY; without even the implied warranty of
21 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
22 * GNU General Public License for more details.
23 *
24 * You should have received a copy of the GNU General Public License
25 * along with this program; if not, write to the Free Software Foundation,
26 * Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
27 */
28
29 #include <stdlib.h>
30 #include <errno.h>
31 #include <limits.h>
32 #include <unistd.h>
33 #include <fcntl.h>
34
35 #include <netdb.h>
36 #include <sys/socket.h>
37 #include <netinet/in.h>
38 #include <arpa/inet.h>
39
40 #include "internal.h"
41
42 static void readconfig(adns_state ads, const char *filename, int warnmissing);
43
addserver(adns_state ads,struct in_addr addr)44 static void addserver(adns_state ads, struct in_addr addr) {
45 int i;
46 struct server *ss;
47
48 for (i=0; i<ads->nservers; i++) {
49 if (ads->servers[i].addr.s_addr == addr.s_addr) {
50 adns__debug(ads,-1,0,"duplicate nameserver %s ignored",inet_ntoa(addr));
51 return;
52 }
53 }
54
55 if (ads->nservers>=MAXSERVERS) {
56 adns__diag(ads,-1,0,"too many nameservers, ignoring %s",inet_ntoa(addr));
57 return;
58 }
59
60 ss= ads->servers+ads->nservers;
61 ss->addr= addr;
62 ads->nservers++;
63 }
64
freesearchlist(adns_state ads)65 static void freesearchlist(adns_state ads) {
66 if (ads->nsearchlist) free(*ads->searchlist);
67 free(ads->searchlist);
68 }
69
saveerr(adns_state ads,int en)70 static void saveerr(adns_state ads, int en) {
71 if (!ads->configerrno) ads->configerrno= en;
72 }
73
configparseerr(adns_state ads,const char * fn,int lno,const char * fmt,...)74 static void configparseerr(adns_state ads, const char *fn, int lno,
75 const char *fmt, ...) {
76 va_list al;
77
78 saveerr(ads,EINVAL);
79 if (!ads->diagfile || (ads->iflags & adns_if_noerrprint)) return;
80
81 if (lno==-1) fprintf(ads->diagfile,"adns: %s: ",fn);
82 else fprintf(ads->diagfile,"adns: %s:%d: ",fn,lno);
83 va_start(al,fmt);
84 vfprintf(ads->diagfile,fmt,al);
85 va_end(al);
86 fputc('\n',ads->diagfile);
87 }
88
nextword(const char ** bufp_io,const char ** word_r,int * l_r)89 static int nextword(const char **bufp_io, const char **word_r, int *l_r) {
90 const char *p, *q;
91
92 p= *bufp_io;
93 while (ctype_whitespace(*p)) p++;
94 if (!*p) return 0;
95
96 q= p;
97 while (*q && !ctype_whitespace(*q)) q++;
98
99 *l_r= q-p;
100 *word_r= p;
101 *bufp_io= q;
102
103 return 1;
104 }
105
ccf_nameserver(adns_state ads,const char * fn,int lno,const char * buf)106 static void ccf_nameserver(adns_state ads, const char *fn, int lno, const char *buf) {
107 struct in_addr ia;
108
109 if (!inet_aton(buf,&ia)) {
110 configparseerr(ads,fn,lno,"invalid nameserver address `%s'",buf);
111 return;
112 }
113 adns__debug(ads,-1,0,"using nameserver %s",inet_ntoa(ia));
114 addserver(ads,ia);
115 }
116
ccf_search(adns_state ads,const char * fn,int lno,const char * buf)117 static void ccf_search(adns_state ads, const char *fn, int lno, const char *buf) {
118 const char *bufp, *word;
119 char *newchars, **newptrs, **pp;
120 int count, tl, l;
121
122 if (!buf) return;
123
124 bufp= buf;
125 count= 0;
126 tl= 0;
127 while (nextword(&bufp,&word,&l)) { count++; tl += l+1; }
128
129 newptrs= malloc(sizeof(char*)*count); if (!newptrs) { saveerr(ads,errno); return; }
130 newchars= malloc(tl); if (!newchars) { saveerr(ads,errno); free(newptrs); return; }
131
132 bufp= buf;
133 pp= newptrs;
134 while (nextword(&bufp,&word,&l)) {
135 *pp++= newchars;
136 memcpy(newchars,word,l);
137 newchars += l;
138 *newchars++ = 0;
139 }
140
141 freesearchlist(ads);
142 ads->nsearchlist= count;
143 ads->searchlist= newptrs;
144 }
145
ccf_sortlist(adns_state ads,const char * fn,int lno,const char * buf)146 static void ccf_sortlist(adns_state ads, const char *fn, int lno, const char *buf) {
147 const char *word;
148 char tbuf[200], *slash, *ep;
149 struct in_addr base, mask;
150 int l;
151 unsigned long initial, baselocal;
152
153 if (!buf) return;
154
155 ads->nsortlist= 0;
156 while (nextword(&buf,&word,&l)) {
157 if (ads->nsortlist >= MAXSORTLIST) {
158 adns__diag(ads,-1,0,"too many sortlist entries, ignoring %.*s onwards",l,word);
159 return;
160 }
161
162 if (l >= sizeof(tbuf)) {
163 configparseerr(ads,fn,lno,"sortlist entry `%.*s' too long",l,word);
164 continue;
165 }
166
167 memcpy(tbuf,word,l); tbuf[l]= 0;
168 slash= strchr(tbuf,'/');
169 if (slash) *slash++= 0;
170
171 if (!inet_aton(tbuf,&base)) {
172 configparseerr(ads,fn,lno,"invalid address `%s' in sortlist",tbuf);
173 continue;
174 }
175
176 if (slash) {
177 if (strchr(slash,'.')) {
178 if (!inet_aton(slash,&mask)) {
179 configparseerr(ads,fn,lno,"invalid mask `%s' in sortlist",slash);
180 continue;
181 }
182 if (base.s_addr & ~mask.s_addr) {
183 configparseerr(ads,fn,lno,
184 "mask `%s' in sortlist overlaps address `%s'",slash,tbuf);
185 continue;
186 }
187 } else {
188 initial= strtoul(slash,&ep,10);
189 if (*ep || initial>32) {
190 configparseerr(ads,fn,lno,"mask length `%s' invalid",slash);
191 continue;
192 }
193 mask.s_addr= htonl((0x0ffffffffUL) << (32-initial));
194 }
195 } else {
196 baselocal= ntohl(base.s_addr);
197 if (!baselocal & 0x080000000UL) /* class A */
198 mask.s_addr= htonl(0x0ff000000UL);
199 else if ((baselocal & 0x0c0000000UL) == 0x080000000UL)
200 mask.s_addr= htonl(0x0ffff0000UL); /* class B */
201 else if ((baselocal & 0x0f0000000UL) == 0x0e0000000UL)
202 mask.s_addr= htonl(0x0ff000000UL); /* class C */
203 else {
204 configparseerr(ads,fn,lno,
205 "network address `%s' in sortlist is not in classed ranges,"
206 " must specify mask explicitly", tbuf);
207 continue;
208 }
209 }
210
211 ads->sortlist[ads->nsortlist].base= base;
212 ads->sortlist[ads->nsortlist].mask= mask;
213 ads->nsortlist++;
214 }
215 }
216
ccf_options(adns_state ads,const char * fn,int lno,const char * buf)217 static void ccf_options(adns_state ads, const char *fn, int lno, const char *buf) {
218 const char *word;
219 char *ep;
220 unsigned long v;
221 int l;
222
223 if (!buf) return;
224
225 while (nextword(&buf,&word,&l)) {
226 if (l==5 && !memcmp(word,"debug",5)) {
227 ads->iflags |= adns_if_debug;
228 continue;
229 }
230 if (l>=6 && !memcmp(word,"ndots:",6)) {
231 v= strtoul(word+6,&ep,10);
232 if (l==6 || ep != word+l || v > INT_MAX) {
233 configparseerr(ads,fn,lno,"option `%.*s' malformed or has bad value",l,word);
234 continue;
235 }
236 ads->searchndots= v;
237 continue;
238 }
239 if (l>=12 && !memcmp(word,"adns_checkc:",12)) {
240 if (!strcmp(word+12,"none")) {
241 ads->iflags &= ~adns_if_checkc_freq;
242 ads->iflags |= adns_if_checkc_entex;
243 } else if (!strcmp(word+12,"entex")) {
244 ads->iflags &= ~adns_if_checkc_freq;
245 ads->iflags |= adns_if_checkc_entex;
246 } else if (!strcmp(word+12,"freq")) {
247 ads->iflags |= adns_if_checkc_freq;
248 } else {
249 configparseerr(ads,fn,lno, "option adns_checkc has bad value `%s' "
250 "(must be none, entex or freq", word+12);
251 }
252 continue;
253 }
254 adns__diag(ads,-1,0,"%s:%d: unknown option `%.*s'", fn,lno, l,word);
255 }
256 }
257
ccf_clearnss(adns_state ads,const char * fn,int lno,const char * buf)258 static void ccf_clearnss(adns_state ads, const char *fn, int lno, const char *buf) {
259 ads->nservers= 0;
260 }
261
ccf_include(adns_state ads,const char * fn,int lno,const char * buf)262 static void ccf_include(adns_state ads, const char *fn, int lno, const char *buf) {
263 if (!*buf) {
264 configparseerr(ads,fn,lno,"`include' directive with no filename");
265 return;
266 }
267 readconfig(ads,buf,1);
268 }
269
270 static const struct configcommandinfo {
271 const char *name;
272 void (*fn)(adns_state ads, const char *fn, int lno, const char *buf);
273 } configcommandinfos[]= {
274 { "nameserver", ccf_nameserver },
275 { "domain", ccf_search },
276 { "search", ccf_search },
277 { "sortlist", ccf_sortlist },
278 { "options", ccf_options },
279 { "clearnameservers", ccf_clearnss },
280 { "include", ccf_include },
281 { 0 }
282 };
283
284 typedef union {
285 FILE *file;
286 const char *text;
287 } getline_ctx;
288
gl_file(adns_state ads,getline_ctx * src_io,const char * filename,int lno,char * buf,int buflen)289 static int gl_file(adns_state ads, getline_ctx *src_io, const char *filename,
290 int lno, char *buf, int buflen) {
291 FILE *file= src_io->file;
292 int c, i;
293 char *p;
294
295 p= buf;
296 buflen--;
297 i= 0;
298
299 for (;;) { /* loop over chars */
300 if (i == buflen) {
301 adns__diag(ads,-1,0,"%s:%d: line too long, ignored",filename,lno);
302 goto x_badline;
303 }
304 c= getc(file);
305 if (!c) {
306 adns__diag(ads,-1,0,"%s:%d: line contains nul, ignored",filename,lno);
307 goto x_badline;
308 } else if (c == '\n') {
309 break;
310 } else if (c == EOF) {
311 if (ferror(file)) {
312 saveerr(ads,errno);
313 adns__diag(ads,-1,0,"%s:%d: read error: %s",filename,lno,strerror(errno));
314 return -1;
315 }
316 if (!i) return -1;
317 break;
318 } else {
319 *p++= c;
320 i++;
321 }
322 }
323
324 *p++= 0;
325 return i;
326
327 x_badline:
328 saveerr(ads,EINVAL);
329 while ((c= getc(file)) != EOF && c != '\n');
330 return -2;
331 }
332
gl_text(adns_state ads,getline_ctx * src_io,const char * filename,int lno,char * buf,int buflen)333 static int gl_text(adns_state ads, getline_ctx *src_io, const char *filename,
334 int lno, char *buf, int buflen) {
335 const char *cp= src_io->text;
336 int l;
337
338 if (!cp || !*cp) return -1;
339
340 if (*cp == ';' || *cp == '\n') cp++;
341 l= strcspn(cp,";\n");
342 src_io->text = cp+l;
343
344 if (l >= buflen) {
345 adns__diag(ads,-1,0,"%s:%d: line too long, ignored",filename,lno);
346 saveerr(ads,EINVAL);
347 return -2;
348 }
349
350 memcpy(buf,cp,l);
351 buf[l]= 0;
352 return l;
353 }
354
readconfiggeneric(adns_state ads,const char * filename,int (* getline)(adns_state ads,getline_ctx *,const char * filename,int lno,char * buf,int buflen),getline_ctx gl_ctx)355 static void readconfiggeneric(adns_state ads, const char *filename,
356 int (*getline)(adns_state ads, getline_ctx*,
357 const char *filename, int lno,
358 char *buf, int buflen),
359 /* Returns >=0 for success, -1 for EOF or error
360 * (error will have been reported), or -2 for
361 * bad line was encountered, try again.
362 */
363 getline_ctx gl_ctx) {
364 char linebuf[2000], *p, *q;
365 int lno, l, dirl;
366 const struct configcommandinfo *ccip;
367
368 for (lno=1;
369 (l= getline(ads,&gl_ctx, filename,lno, linebuf,sizeof(linebuf))) != -1;
370 lno++) {
371 if (l == -2) continue;
372 while (l>0 && ctype_whitespace(linebuf[l-1])) l--;
373 linebuf[l]= 0;
374 p= linebuf;
375 while (ctype_whitespace(*p)) p++;
376 if (*p == '#' || !*p) continue;
377 q= p;
378 while (*q && !ctype_whitespace(*q)) q++;
379 dirl= q-p;
380 for (ccip=configcommandinfos;
381 ccip->name && !(strlen(ccip->name)==dirl && !memcmp(ccip->name,p,q-p));
382 ccip++);
383 if (!ccip->name) {
384 adns__diag(ads,-1,0,"%s:%d: unknown configuration directive `%.*s'",
385 filename,lno,q-p,p);
386 continue;
387 }
388 while (ctype_whitespace(*q)) q++;
389 ccip->fn(ads,filename,lno,q);
390 }
391 }
392
instrum_getenv(adns_state ads,const char * envvar)393 static const char *instrum_getenv(adns_state ads, const char *envvar) {
394 const char *value;
395
396 value= getenv(envvar);
397 if (!value) adns__debug(ads,-1,0,"environment variable %s not set",envvar);
398 else adns__debug(ads,-1,0,"environment variable %s set to `%s'",envvar,value);
399 return value;
400 }
401
readconfig(adns_state ads,const char * filename,int warnmissing)402 static void readconfig(adns_state ads, const char *filename, int warnmissing) {
403 getline_ctx gl_ctx;
404
405 gl_ctx.file= fopen(filename,"r");
406 if (!gl_ctx.file) {
407 if (errno == ENOENT) {
408 if (warnmissing)
409 adns__debug(ads,-1,0,"configuration file `%s' does not exist",filename);
410 return;
411 }
412 saveerr(ads,errno);
413 adns__diag(ads,-1,0,"cannot open configuration file `%s': %s",
414 filename,strerror(errno));
415 return;
416 }
417
418 readconfiggeneric(ads,filename,gl_file,gl_ctx);
419
420 fclose(gl_ctx.file);
421 }
422
readconfigtext(adns_state ads,const char * text,const char * showname)423 static void readconfigtext(adns_state ads, const char *text, const char *showname) {
424 getline_ctx gl_ctx;
425
426 gl_ctx.text= text;
427 readconfiggeneric(ads,showname,gl_text,gl_ctx);
428 }
429
readconfigenv(adns_state ads,const char * envvar)430 static void readconfigenv(adns_state ads, const char *envvar) {
431 const char *filename;
432
433 if (ads->iflags & adns_if_noenv) {
434 adns__debug(ads,-1,0,"not checking environment variable `%s'",envvar);
435 return;
436 }
437 filename= instrum_getenv(ads,envvar);
438 if (filename) readconfig(ads,filename,1);
439 }
440
readconfigenvtext(adns_state ads,const char * envvar)441 static void readconfigenvtext(adns_state ads, const char *envvar) {
442 const char *textdata;
443
444 if (ads->iflags & adns_if_noenv) {
445 adns__debug(ads,-1,0,"not checking environment variable `%s'",envvar);
446 return;
447 }
448 textdata= instrum_getenv(ads,envvar);
449 if (textdata) readconfigtext(ads,textdata,envvar);
450 }
451
452
adns__setnonblock(adns_state ads,int fd)453 int adns__setnonblock(adns_state ads, int fd) {
454 int r;
455
456 r= fcntl(fd,F_GETFL,0); if (r<0) return errno;
457 r |= O_NONBLOCK;
458 r= fcntl(fd,F_SETFL,r); if (r<0) return errno;
459 return 0;
460 }
461
init_begin(adns_state * ads_r,adns_initflags flags,FILE * diagfile)462 static int init_begin(adns_state *ads_r, adns_initflags flags, FILE *diagfile) {
463 adns_state ads;
464
465 ads= malloc(sizeof(*ads)); if (!ads) return errno;
466
467 ads->iflags= flags;
468 ads->diagfile= diagfile;
469 ads->configerrno= 0;
470 LIST_INIT(ads->udpw);
471 LIST_INIT(ads->tcpw);
472 LIST_INIT(ads->childw);
473 LIST_INIT(ads->output);
474 ads->forallnext= 0;
475 ads->nextid= 0x311f;
476 ads->udpsocket= ads->tcpsocket= -1;
477 adns__vbuf_init(&ads->tcpsend);
478 adns__vbuf_init(&ads->tcprecv);
479 ads->tcprecv_skip= 0;
480 ads->nservers= ads->nsortlist= ads->nsearchlist= ads->tcpserver= 0;
481 ads->searchndots= 1;
482 ads->tcpstate= server_disconnected;
483 timerclear(&ads->tcptimeout);
484 ads->searchlist= 0;
485
486 *ads_r= ads;
487 return 0;
488 }
489
init_finish(adns_state ads)490 static int init_finish(adns_state ads) {
491 struct in_addr ia;
492 struct protoent *proto;
493 int r;
494
495 if (!ads->nservers) {
496 if (ads->diagfile && ads->iflags & adns_if_debug)
497 fprintf(ads->diagfile,"adns: no nameservers, using localhost\n");
498 ia.s_addr= htonl(INADDR_LOOPBACK);
499 addserver(ads,ia);
500 }
501
502 proto= getprotobyname("udp"); if (!proto) { r= ENOPROTOOPT; goto x_free; }
503 ads->udpsocket= socket(AF_INET,SOCK_DGRAM,proto->p_proto);
504 if (ads->udpsocket<0) { r= errno; goto x_free; }
505
506 r= adns__setnonblock(ads,ads->udpsocket);
507 if (r) { r= errno; goto x_closeudp; }
508
509 return 0;
510
511 x_closeudp:
512 close(ads->udpsocket);
513 x_free:
514 free(ads);
515 return r;
516 }
517
init_abort(adns_state ads)518 static void init_abort(adns_state ads) {
519 if (ads->nsearchlist) {
520 free(ads->searchlist[0]);
521 free(ads->searchlist);
522 }
523 free(ads);
524 }
525
adns_init(adns_state * ads_r,adns_initflags flags,FILE * diagfile)526 int adns_init(adns_state *ads_r, adns_initflags flags, FILE *diagfile) {
527 adns_state ads;
528 const char *res_options, *adns_res_options;
529 int r;
530
531 r= init_begin(&ads, flags, diagfile ? diagfile : stderr);
532 if (r) return r;
533
534 res_options= instrum_getenv(ads,"RES_OPTIONS");
535 adns_res_options= instrum_getenv(ads,"ADNS_RES_OPTIONS");
536 ccf_options(ads,"RES_OPTIONS",-1,res_options);
537 ccf_options(ads,"ADNS_RES_OPTIONS",-1,adns_res_options);
538
539 readconfig(ads,"/etc/resolv.conf",1);
540 readconfig(ads,"/etc/resolv-adns.conf",0);
541 readconfigenv(ads,"RES_CONF");
542 readconfigenv(ads,"ADNS_RES_CONF");
543
544 readconfigenvtext(ads,"RES_CONF_TEXT");
545 readconfigenvtext(ads,"ADNS_RES_CONF_TEXT");
546
547 ccf_options(ads,"RES_OPTIONS",-1,res_options);
548 ccf_options(ads,"ADNS_RES_OPTIONS",-1,adns_res_options);
549
550 ccf_search(ads,"LOCALDOMAIN",-1,instrum_getenv(ads,"LOCALDOMAIN"));
551 ccf_search(ads,"ADNS_LOCALDOMAIN",-1,instrum_getenv(ads,"ADNS_LOCALDOMAIN"));
552
553 if (ads->configerrno && ads->configerrno != EINVAL) {
554 r= ads->configerrno;
555 init_abort(ads);
556 return r;
557 }
558
559 r= init_finish(ads);
560 if (r) return r;
561
562 adns__consistency(ads,0,cc_entex);
563 *ads_r= ads;
564 return 0;
565 }
566
adns_init_strcfg(adns_state * ads_r,adns_initflags flags,FILE * diagfile,const char * configtext)567 int adns_init_strcfg(adns_state *ads_r, adns_initflags flags,
568 FILE *diagfile, const char *configtext) {
569 adns_state ads;
570 int r;
571
572 r= init_begin(&ads, flags, diagfile); if (r) return r;
573
574 readconfigtext(ads,configtext,"<supplied configuration text>");
575 if (ads->configerrno) {
576 r= ads->configerrno;
577 init_abort(ads);
578 return r;
579 }
580
581 r= init_finish(ads); if (r) return r;
582 adns__consistency(ads,0,cc_entex);
583 *ads_r= ads;
584 return 0;
585 }
586
587
adns_finish(adns_state ads)588 void adns_finish(adns_state ads) {
589 adns__consistency(ads,0,cc_entex);
590 for (;;) {
591 if (ads->udpw.head) adns_cancel(ads->udpw.head);
592 else if (ads->tcpw.head) adns_cancel(ads->tcpw.head);
593 else if (ads->childw.head) adns_cancel(ads->childw.head);
594 else if (ads->output.head) adns_cancel(ads->output.head);
595 else break;
596 }
597 close(ads->udpsocket);
598 if (ads->tcpsocket >= 0) close(ads->tcpsocket);
599 adns__vbuf_free(&ads->tcpsend);
600 adns__vbuf_free(&ads->tcprecv);
601 freesearchlist(ads);
602 free(ads);
603 }
604
adns_forallqueries_begin(adns_state ads)605 void adns_forallqueries_begin(adns_state ads) {
606 adns__consistency(ads,0,cc_entex);
607 ads->forallnext=
608 ads->udpw.head ? ads->udpw.head :
609 ads->tcpw.head ? ads->tcpw.head :
610 ads->childw.head ? ads->childw.head :
611 ads->output.head;
612 }
613
adns_forallqueries_next(adns_state ads,void ** context_r)614 adns_query adns_forallqueries_next(adns_state ads, void **context_r) {
615 adns_query qu, nqu;
616
617 adns__consistency(ads,0,cc_entex);
618 nqu= ads->forallnext;
619 for (;;) {
620 qu= nqu;
621 if (!qu) return 0;
622 if (qu->next) {
623 nqu= qu->next;
624 } else if (qu == ads->udpw.tail) {
625 nqu=
626 ads->tcpw.head ? ads->tcpw.head :
627 ads->childw.head ? ads->childw.head :
628 ads->output.head;
629 } else if (qu == ads->tcpw.tail) {
630 nqu=
631 ads->childw.head ? ads->childw.head :
632 ads->output.head;
633 } else if (qu == ads->childw.tail) {
634 nqu= ads->output.head;
635 } else {
636 nqu= 0;
637 }
638 if (!qu->parent) break;
639 }
640 ads->forallnext= nqu;
641 if (context_r) *context_r= qu->ctx.ext;
642 return qu;
643 }
644