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17cb910eae5901dc54d69d02022c2870621b5b23
[adns] / src / types.c
1 /*
2 * types.c
3 * - RR-type-specific code, and the machinery to call it
4 */
5 /*
6 * This file is part of adns, which is
7 * Copyright (C) 1997-2000,2003,2006 Ian Jackson
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.)
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
14 * the Free Software Foundation; either version 2, or (at your option)
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
23 * along with this program; if not, write to the Free Software Foundation,
24 * Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
25 */
26
27 #include <stdlib.h>
28
29 #include <sys/types.h>
30 #include <sys/socket.h>
31 #include <netinet/in.h>
32 #include <arpa/inet.h>
33
34 #include "internal.h"
35
36 #define R_NOMEM return adns_s_nomemory
37 #define CSP_ADDSTR(s) do { \
38 if (!adns__vbuf_appendstr(vb,(s))) R_NOMEM; \
39 } while (0)
40
41 /*
42 * order of sections:
43 *
44 * _string (pap)
45 * _textdata, _qstring (csp)
46 * _str (mf,cs)
47 * _intstr (mf,csp,cs)
48 * _manyistr (mf,cs)
49 * _txt (pa)
50 * _inaddr (pa,di,cs
51 * +search_sortlist, dip_genaddr, csp_genaddr)
52 * _addr (pa,di,div,csp,cs,gsz
53 * +search_sortlist_sa, dip_sockaddr)
54 * _domain (pap,csp,cs)
55 * _dom_raw (pa)
56 * _host_raw (pa)
57 * _hostaddr (pap,pa,dip,di,mfp,mf,csp,cs
58 * +pap_findaddrs, icb_hostaddr)
59 * _mx_raw (pa,di)
60 * _mx (pa,di)
61 * _inthostaddr (mf,cs)
62 * _inthost (cs)
63 * _ptr (ckl,pa +icb_ptr)
64 * _strpair (mf)
65 * _intstrpair (mf)
66 * _hinfo (pa)
67 * _mailbox (pap,csp +pap_mailbox822)
68 * _rp (pa,cs)
69 * _soa (pa,mf,cs)
70 * _srv* (ckl,(pap),pa*2,mf*2,di,(csp),cs*2,postsort)
71 * _byteblock (mf)
72 * _opaque (pa,cs)
73 * _flat (mf)
74 *
75 * within each section:
76 * ckl_*
77 * pap_*
78 * pa_*
79 * dip_*
80 * di_*
81 * mfp_*
82 * mf_*
83 * csp_*
84 * cs_*
85 * gsz_*
86 * postsort_*
87 */
88
89 /*
90 * _qstring (pap,csp)
91 */
92
93 static adns_status pap_qstring(const parseinfo *pai, int *cbyte_io, int max,
94 int *len_r, char **str_r) {
95 /* Neither len_r nor str_r may be null.
96 * End of datagram (overrun) is indicated by returning adns_s_invaliddata;
97 */
98 const byte *dgram= pai->dgram;
99 int l, cbyte;
100 char *str;
101
102 cbyte= *cbyte_io;
103
104 if (cbyte >= max) return adns_s_invaliddata;
105 GET_B(cbyte,l);
106 if (cbyte+l > max) return adns_s_invaliddata;
107
108 str= adns__alloc_interim(pai->qu, l+1);
109 if (!str) R_NOMEM;
110
111 str[l]= 0;
112 memcpy(str,dgram+cbyte,l);
113
114 *len_r= l;
115 *str_r= str;
116 *cbyte_io= cbyte+l;
117
118 return adns_s_ok;
119 }
120
121 static adns_status csp_qstring(vbuf *vb, const char *dp, int len) {
122 unsigned char ch;
123 char buf[10];
124 int cn;
125
126 CSP_ADDSTR("\"");
127 for (cn=0; cn<len; cn++) {
128 ch= *dp++;
129 if (ch == '\\') {
130 CSP_ADDSTR("\\\\");
131 } else if (ch == '"') {
132 CSP_ADDSTR("\\\"");
133 } else if (ch >= 32 && ch <= 126) {
134 if (!adns__vbuf_append(vb,&ch,1)) R_NOMEM;
135 } else {
136 sprintf(buf,"\\x%02x",ch);
137 CSP_ADDSTR(buf);
138 }
139 }
140 CSP_ADDSTR("\"");
141
142 return adns_s_ok;
143 }
144
145 /*
146 * _str (mf)
147 */
148
149 static void mf_str(adns_query qu, void *datap) {
150 char **rrp= datap;
151
152 adns__makefinal_str(qu,rrp);
153 }
154
155 /*
156 * _intstr (mf)
157 */
158
159 static void mf_intstr(adns_query qu, void *datap) {
160 adns_rr_intstr *rrp= datap;
161
162 adns__makefinal_str(qu,&rrp->str);
163 }
164
165 /*
166 * _manyistr (mf)
167 */
168
169 static void mf_manyistr(adns_query qu, void *datap) {
170 adns_rr_intstr **rrp= datap;
171 adns_rr_intstr *te, *table;
172 void *tablev;
173 int tc;
174
175 for (tc=0, te= *rrp; te->i >= 0; te++, tc++);
176 tablev= *rrp;
177 adns__makefinal_block(qu,&tablev,sizeof(*te)*(tc+1));
178 *rrp= table= tablev;
179 for (te= *rrp; te->i >= 0; te++)
180 adns__makefinal_str(qu,&te->str);
181 }
182
183 /*
184 * _txt (pa,cs)
185 */
186
187 static adns_status pa_txt(const parseinfo *pai, int cbyte,
188 int max, void *datap) {
189 adns_rr_intstr **rrp= datap, *table, *te;
190 const byte *dgram= pai->dgram;
191 int ti, tc, l, startbyte;
192 adns_status st;
193
194 startbyte= cbyte;
195 if (cbyte >= max) return adns_s_invaliddata;
196 tc= 0;
197 while (cbyte < max) {
198 GET_B(cbyte,l);
199 cbyte+= l;
200 tc++;
201 }
202 if (cbyte != max || !tc) return adns_s_invaliddata;
203
204 table= adns__alloc_interim(pai->qu,sizeof(*table)*(tc+1));
205 if (!table) R_NOMEM;
206
207 for (cbyte=startbyte, ti=0, te=table; ti<tc; ti++, te++) {
208 st= pap_qstring(pai, &cbyte, max, &te->i, &te->str);
209 if (st) return st;
210 }
211 assert(cbyte == max);
212
213 te->i= -1;
214 te->str= 0;
215
216 *rrp= table;
217 return adns_s_ok;
218 }
219
220 static adns_status cs_txt(vbuf *vb, const void *datap) {
221 const adns_rr_intstr *const *rrp= datap;
222 const adns_rr_intstr *current;
223 adns_status st;
224 int spc;
225
226 for (current= *rrp, spc=0; current->i >= 0; current++, spc=1) {
227 if (spc) CSP_ADDSTR(" ");
228 st= csp_qstring(vb,current->str,current->i); if (st) return st;
229 }
230 return adns_s_ok;
231 }
232
233 /*
234 * _hinfo (cs)
235 */
236
237 static adns_status cs_hinfo(vbuf *vb, const void *datap) {
238 const adns_rr_intstrpair *rrp= datap;
239 adns_status st;
240
241 st= csp_qstring(vb,rrp->array[0].str,rrp->array[0].i); if (st) return st;
242 CSP_ADDSTR(" ");
243 st= csp_qstring(vb,rrp->array[1].str,rrp->array[1].i); if (st) return st;
244 return adns_s_ok;
245 }
246
247 /*
248 * _inaddr (pa,di,cs +search_sortlist, dip_genaddr, csp_genaddr)
249 */
250
251 static adns_status pa_inaddr(const parseinfo *pai, int cbyte,
252 int max, void *datap) {
253 struct in_addr *storeto= datap;
254
255 if (max-cbyte != 4) return adns_s_invaliddata;
256 memcpy(storeto, pai->dgram + cbyte, 4);
257 return adns_s_ok;
258 }
259
260 static int search_sortlist(adns_state ads, int af, const void *ad) {
261 const struct sortlist *slp;
262 int i;
263
264 for (i=0, slp=ads->sortlist;
265 i<ads->nsortlist &&
266 !adns__addr_match_p(af,ad, slp->af,&slp->base,&slp->mask);
267 i++, slp++);
268 return i;
269 }
270
271 static int dip_genaddr(adns_state ads, int af, const void *a, const void *b) {
272 int ai, bi;
273
274 if (!ads->nsortlist) return 0;
275
276 ai= search_sortlist(ads,af,a);
277 bi= search_sortlist(ads,af,b);
278 return bi<ai;
279 }
280
281 static int di_inaddr(adns_state ads,
282 const void *datap_a, const void *datap_b) {
283 return dip_genaddr(ads,AF_INET,datap_a,datap_b);
284 }
285
286 static adns_status csp_genaddr(vbuf *vb, int af, const void *p) {
287 char buf[ADNS_ADDR2TEXT_BUFLEN];
288 int len= sizeof(buf);
289 adns_rr_addr a;
290 int err;
291
292 memset(&a, 0, sizeof(a));
293 a.addr.sa.sa_family= af;
294 adns__sockaddr_inject(p, 0, &a.addr.sa);
295 err= adns_addr2text(&a.addr.sa,0, buf,&len, 0); assert(!err);
296 CSP_ADDSTR(buf);
297 return adns_s_ok;
298 }
299
300 static adns_status cs_inaddr(vbuf *vb, const void *datap) {
301 return csp_genaddr(vb, AF_INET,datap);
302 }
303
304 /*
305 * _addr (pa,di,div,csp,cs,gsz +search_sortlist_sa, dip_sockaddr)
306 */
307
308 static adns_status pa_addr(const parseinfo *pai, int cbyte,
309 int max, void *datap) {
310 adns_rr_addr *storeto= datap;
311 const byte *dgram= pai->dgram;
312
313 if (max-cbyte != 4) return adns_s_invaliddata;
314 storeto->len= sizeof(storeto->addr.inet);
315 memset(&storeto->addr,0,sizeof(storeto->addr.inet));
316 storeto->addr.inet.sin_family= AF_INET;
317 memcpy(&storeto->addr.inet.sin_addr,dgram+cbyte,4);
318 return adns_s_ok;
319 }
320
321 static int search_sortlist_sa(adns_state ads, const struct sockaddr *sa) {
322 union gen_addr a;
323 adns__sockaddr_extract(sa, &a, 0);
324 return search_sortlist(ads, sa->sa_family, &a);
325 }
326
327 static int dip_sockaddr(adns_state ads,
328 const struct sockaddr *sa,
329 const struct sockaddr *sb) {
330 if (!ads->sortlist) return 0;
331 return search_sortlist_sa(ads, sa) > search_sortlist_sa(ads, sb);
332 }
333
334 static int di_addr(adns_state ads, const void *datap_a, const void *datap_b) {
335 const adns_rr_addr *ap= datap_a, *bp= datap_b;
336 return dip_sockaddr(ads, &ap->addr.sa, &bp->addr.sa);
337 }
338
339 static int div_addr(void *context, const void *datap_a, const void *datap_b) {
340 const adns_state ads= context;
341
342 return di_addr(ads, datap_a, datap_b);
343 }
344
345 static adns_status csp_addr(vbuf *vb, const adns_rr_addr *rrp) {
346 char buf[ADNS_ADDR2TEXT_BUFLEN];
347 int len= sizeof(buf);
348 int err;
349
350 switch (rrp->addr.inet.sin_family) {
351 case AF_INET:
352 CSP_ADDSTR("INET ");
353 goto a2t;
354 case AF_INET6:
355 CSP_ADDSTR("INET6 ");
356 goto a2t;
357 a2t:
358 err= adns_addr2text(&rrp->addr.sa,0, buf,&len, 0); assert(!err);
359 CSP_ADDSTR(buf);
360 break;
361 default:
362 sprintf(buf,"AF=%u",rrp->addr.sa.sa_family);
363 CSP_ADDSTR(buf);
364 break;
365 }
366 return adns_s_ok;
367 }
368
369 static adns_status cs_addr(vbuf *vb, const void *datap) {
370 const adns_rr_addr *rrp= datap;
371
372 return csp_addr(vb,rrp);
373 }
374
375 static int gsz_addr(const typeinfo *typei, adns_rrtype type) {
376 return type & adns__qtf_bigaddr ?
377 sizeof(adns_rr_addr) : sizeof(adns_rr_addr_v4only);
378 }
379
380 /*
381 * _domain (pap,csp,cs)
382 * _dom_raw (pa)
383 */
384
385 static adns_status pap_domain(const parseinfo *pai, int *cbyte_io, int max,
386 char **domain_r, parsedomain_flags flags) {
387 adns_status st;
388 char *dm;
389
390 st= adns__parse_domain(pai->qu->ads, pai->serv, pai->qu, &pai->qu->vb, flags,
391 pai->dgram,pai->dglen, cbyte_io, max);
392 if (st) return st;
393 if (!pai->qu->vb.used) return adns_s_invaliddata;
394
395 dm= adns__alloc_interim(pai->qu, pai->qu->vb.used+1);
396 if (!dm) R_NOMEM;
397
398 dm[pai->qu->vb.used]= 0;
399 memcpy(dm,pai->qu->vb.buf,pai->qu->vb.used);
400
401 *domain_r= dm;
402 return adns_s_ok;
403 }
404
405 static adns_status csp_domain(vbuf *vb, const char *domain) {
406 CSP_ADDSTR(domain);
407 if (!*domain) CSP_ADDSTR(".");
408 return adns_s_ok;
409 }
410
411 static adns_status cs_domain(vbuf *vb, const void *datap) {
412 const char *const *domainp= datap;
413 return csp_domain(vb,*domainp);
414 }
415
416 static adns_status pa_dom_raw(const parseinfo *pai, int cbyte,
417 int max, void *datap) {
418 char **rrp= datap;
419 adns_status st;
420
421 st= pap_domain(pai, &cbyte, max, rrp, pdf_quoteok);
422 if (st) return st;
423
424 if (cbyte != max) return adns_s_invaliddata;
425 return adns_s_ok;
426 }
427
428 /*
429 * _host_raw (pa)
430 */
431
432 static adns_status pa_host_raw(const parseinfo *pai, int cbyte,
433 int max, void *datap) {
434 char **rrp= datap;
435 adns_status st;
436
437 st= pap_domain(pai, &cbyte, max, rrp,
438 pai->qu->flags & adns_qf_quoteok_anshost ? pdf_quoteok : 0);
439 if (st) return st;
440
441 if (cbyte != max) return adns_s_invaliddata;
442 return adns_s_ok;
443 }
444
445 /*
446 * _hostaddr (pap,pa,dip,di,mfp,mf,csp,cs +pap_findaddrs, icb_hostaddr)
447 */
448
449 static adns_status pap_findaddrs(const parseinfo *pai, adns_rr_hostaddr *ha,
450 size_t addrsz,
451 int *cbyte_io, int count, int dmstart) {
452 int rri, naddrs;
453 int type, class, rdlen, rdstart, ownermatched;
454 unsigned long ttl;
455 adns_status st;
456
457 for (rri=0, naddrs=-1; rri<count; rri++) {
458 st= adns__findrr_anychk(pai->qu, pai->serv, pai->dgram,
459 pai->dglen, cbyte_io,
460 &type, &class, &ttl, &rdlen, &rdstart,
461 pai->dgram, pai->dglen, dmstart, &ownermatched);
462 if (st) return st;
463 if (!ownermatched || class != DNS_CLASS_IN || type != adns_r_a) {
464 if (naddrs>0) break; else continue;
465 }
466 if (naddrs == -1) {
467 naddrs= 0;
468 }
469 if (!adns__vbuf_ensure(&pai->qu->vb, (naddrs+1)*addrsz))
470 R_NOMEM;
471 adns__update_expires(pai->qu,ttl,pai->now);
472 st= pa_addr(pai, rdstart,rdstart+rdlen, pai->qu->vb.buf + naddrs*addrsz);
473 if (st) return st;
474 naddrs++;
475 }
476 if (naddrs >= 0) {
477 ha->addrs= adns__alloc_interim(pai->qu, naddrs*addrsz);
478 if (!ha->addrs) R_NOMEM;
479 memcpy(ha->addrs, pai->qu->vb.buf, naddrs*addrsz);
480 ha->naddrs= naddrs;
481 ha->astatus= adns_s_ok;
482
483 adns__isort(ha->addrs, naddrs, addrsz, pai->qu->vb.buf,
484 div_addr, pai->ads);
485 }
486 return adns_s_ok;
487 }
488
489 static void icb_hostaddr(adns_query parent, adns_query child) {
490 adns_answer *cans= child->answer;
491 adns_rr_hostaddr *rrp= child->ctx.pinfo.hostaddr;
492 adns_state ads= parent->ads;
493 adns_status st;
494 size_t addrsz= gsz_addr(0, parent->answer->type);
495
496 st= cans->status;
497 rrp->astatus= st;
498 rrp->naddrs= (st>0 && st<=adns_s_max_tempfail) ? -1 : cans->nrrs;
499 rrp->addrs= cans->rrs.addr;
500 adns__transfer_interim(child, parent, rrp->addrs, rrp->naddrs*addrsz);
501
502 if (parent->children.head) {
503 LIST_LINK_TAIL(ads->childw,parent);
504 } else {
505 adns__query_done(parent);
506 }
507 }
508
509 static adns_status pap_hostaddr(const parseinfo *pai, int *cbyte_io,
510 int max, adns_rr_hostaddr *rrp) {
511 adns_status st;
512 int dmstart, cbyte;
513 qcontext ctx;
514 int id;
515 adns_query nqu;
516 adns_queryflags nflags;
517 size_t addrsz= gsz_addr(0, pai->qu->answer->type);
518
519 dmstart= cbyte= *cbyte_io;
520 st= pap_domain(pai, &cbyte, max, &rrp->host,
521 pai->qu->flags & adns_qf_quoteok_anshost ? pdf_quoteok : 0);
522 if (st) return st;
523 *cbyte_io= cbyte;
524
525 rrp->astatus= adns_s_ok;
526 rrp->naddrs= -1;
527 rrp->addrs= 0;
528
529 cbyte= pai->nsstart;
530
531 st= pap_findaddrs(pai, rrp,addrsz, &cbyte, pai->nscount, dmstart);
532 if (st) return st;
533 if (rrp->naddrs != -1) return adns_s_ok;
534
535 st= pap_findaddrs(pai, rrp,addrsz, &cbyte, pai->arcount, dmstart);
536 if (st) return st;
537 if (rrp->naddrs != -1) return adns_s_ok;
538
539 st= adns__mkquery_frdgram(pai->ads, &pai->qu->vb, &id,
540 pai->dgram, pai->dglen, dmstart,
541 adns_r_addr, adns_qf_quoteok_query);
542 if (st) return st;
543
544 ctx.ext= 0;
545 ctx.callback= icb_hostaddr;
546 ctx.pinfo.hostaddr= rrp;
547 memset(&ctx.tinfo, 0, sizeof(ctx.tinfo));
548
549 nflags= adns_qf_quoteok_query;
550 if (!(pai->qu->flags & adns_qf_cname_loose)) nflags |= adns_qf_cname_forbid;
551
552 st= adns__internal_submit(pai->ads, &nqu, adns__findtype(adns_r_addr),
553 ((adns_r_addr & adns_rrt_reprmask) |
554 (pai->qu->answer->type & ~adns_rrt_reprmask)),
555 &pai->qu->vb, id, nflags, pai->now, &ctx);
556 if (st) return st;
557
558 nqu->parent= pai->qu;
559 LIST_LINK_TAIL_PART(pai->qu->children,nqu,siblings.);
560
561 return adns_s_ok;
562 }
563
564 static adns_status pa_hostaddr(const parseinfo *pai, int cbyte,
565 int max, void *datap) {
566 adns_rr_hostaddr *rrp= datap;
567 adns_status st;
568
569 st= pap_hostaddr(pai, &cbyte, max, rrp);
570 if (st) return st;
571 if (cbyte != max) return adns_s_invaliddata;
572
573 return adns_s_ok;
574 }
575
576 static int dip_hostaddr(adns_state ads,
577 const adns_rr_hostaddr *ap, const adns_rr_hostaddr *bp) {
578 if (ap->astatus != bp->astatus) return ap->astatus;
579 if (ap->astatus) return 0;
580
581 return dip_sockaddr(ads, &ap->addrs[0].addr.sa, &bp->addrs[0].addr.sa);
582 }
583
584 static int di_hostaddr(adns_state ads,
585 const void *datap_a, const void *datap_b) {
586 const adns_rr_hostaddr *ap= datap_a, *bp= datap_b;
587
588 return dip_hostaddr(ads, ap,bp);
589 }
590
591 static void mfp_hostaddr(adns_query qu, adns_rr_hostaddr *rrp) {
592 void *tablev;
593 size_t addrsz= gsz_addr(0, qu->answer->type);
594
595 adns__makefinal_str(qu,&rrp->host);
596 tablev= rrp->addrs;
597 adns__makefinal_block(qu, &tablev, rrp->naddrs*addrsz);
598 rrp->addrs= tablev;
599 }
600
601 static void mf_hostaddr(adns_query qu, void *datap) {
602 adns_rr_hostaddr *rrp= datap;
603
604 mfp_hostaddr(qu,rrp);
605 }
606
607 static adns_status csp_hostaddr(vbuf *vb, const adns_rr_hostaddr *rrp) {
608 const char *errstr;
609 adns_status st;
610 char buf[20];
611 int i;
612
613 st= csp_domain(vb,rrp->host); if (st) return st;
614
615 CSP_ADDSTR(" ");
616 CSP_ADDSTR(adns_errtypeabbrev(rrp->astatus));
617
618 sprintf(buf," %d ",rrp->astatus);
619 CSP_ADDSTR(buf);
620
621 CSP_ADDSTR(adns_errabbrev(rrp->astatus));
622 CSP_ADDSTR(" ");
623
624 errstr= adns_strerror(rrp->astatus);
625 st= csp_qstring(vb,errstr,strlen(errstr)); if (st) return st;
626
627 if (rrp->naddrs >= 0) {
628 CSP_ADDSTR(" (");
629 for (i=0; i<rrp->naddrs; i++) {
630 CSP_ADDSTR(" ");
631 st= csp_addr(vb,&rrp->addrs[i]);
632 }
633 CSP_ADDSTR(" )");
634 } else {
635 CSP_ADDSTR(" ?");
636 }
637 return adns_s_ok;
638 }
639
640 static adns_status cs_hostaddr(vbuf *vb, const void *datap) {
641 const adns_rr_hostaddr *rrp= datap;
642
643 return csp_hostaddr(vb,rrp);
644 }
645
646 /*
647 * _mx_raw (pa,di)
648 */
649
650 static adns_status pa_mx_raw(const parseinfo *pai, int cbyte,
651 int max, void *datap) {
652 const byte *dgram= pai->dgram;
653 adns_rr_intstr *rrp= datap;
654 adns_status st;
655 int pref;
656
657 if (cbyte+2 > max) return adns_s_invaliddata;
658 GET_W(cbyte,pref);
659 rrp->i= pref;
660 st= pap_domain(pai, &cbyte, max, &rrp->str,
661 pai->qu->flags & adns_qf_quoteok_anshost ? pdf_quoteok : 0);
662 if (st) return st;
663
664 if (cbyte != max) return adns_s_invaliddata;
665 return adns_s_ok;
666 }
667
668 static int di_mx_raw(adns_state ads, const void *datap_a, const void *datap_b) {
669 const adns_rr_intstr *ap= datap_a, *bp= datap_b;
670
671 if (ap->i < bp->i) return 0;
672 if (ap->i > bp->i) return 1;
673 return 0;
674 }
675
676 /*
677 * _mx (pa,di)
678 */
679
680 static adns_status pa_mx(const parseinfo *pai, int cbyte,
681 int max, void *datap) {
682 const byte *dgram= pai->dgram;
683 adns_rr_inthostaddr *rrp= datap;
684 adns_status st;
685 int pref;
686
687 if (cbyte+2 > max) return adns_s_invaliddata;
688 GET_W(cbyte,pref);
689 rrp->i= pref;
690 st= pap_hostaddr(pai, &cbyte, max, &rrp->ha);
691 if (st) return st;
692
693 if (cbyte != max) return adns_s_invaliddata;
694 return adns_s_ok;
695 }
696
697 static int di_mx(adns_state ads, const void *datap_a, const void *datap_b) {
698 const adns_rr_inthostaddr *ap= datap_a, *bp= datap_b;
699
700 if (ap->i < bp->i) return 0;
701 if (ap->i > bp->i) return 1;
702 return dip_hostaddr(ads, &ap->ha, &bp->ha);
703 }
704
705 /*
706 * _inthostaddr (mf,cs)
707 */
708
709 static void mf_inthostaddr(adns_query qu, void *datap) {
710 adns_rr_inthostaddr *rrp= datap;
711
712 mfp_hostaddr(qu,&rrp->ha);
713 }
714
715 static adns_status cs_inthostaddr(vbuf *vb, const void *datap) {
716 const adns_rr_inthostaddr *rrp= datap;
717 char buf[10];
718
719 sprintf(buf,"%u ",rrp->i);
720 CSP_ADDSTR(buf);
721
722 return csp_hostaddr(vb,&rrp->ha);
723 }
724
725 /*
726 * _inthost (cs)
727 */
728
729 static adns_status cs_inthost(vbuf *vb, const void *datap) {
730 const adns_rr_intstr *rrp= datap;
731 char buf[10];
732
733 sprintf(buf,"%u ",rrp->i);
734 CSP_ADDSTR(buf);
735 return csp_domain(vb,rrp->str);
736 }
737
738 /*
739 * _ptr (ckl,pa +icb_ptr)
740 */
741
742 static adns_status ckl_ptr(adns_state ads, adns_queryflags flags,
743 union checklabel_state *cls, qcontext *ctx,
744 int labnum, const char *label, int lablen) {
745 static const char *const (expectdomain[])= { DNS_INADDR_ARPA };
746 char *ep;
747 const char *ed;
748 char labbuf[4];
749 int l;
750
751 if (labnum < 4) {
752 if (lablen<=0 || lablen>3) return adns_s_querydomainwrong;
753 memcpy(labbuf, label, lablen);
754 labbuf[lablen]= 0;
755 cls->ptr.ipv[3-labnum]= strtoul(labbuf,&ep,10);
756 if (*ep) return adns_s_querydomainwrong;
757 if (lablen>1 && *label=='0') return adns_s_querydomainwrong;
758 } else if (labnum < 4 + sizeof(expectdomain)/sizeof(*expectdomain)) {
759 ed= expectdomain[labnum-4];
760 l= strlen(ed);
761 if (lablen != l || memcmp(label, ed, l)) return adns_s_querydomainwrong;
762 } else {
763 if (lablen) return adns_s_querydomainwrong;
764 ctx->tinfo.ptr.addr.af= AF_INET;
765 ctx->tinfo.ptr.addr.addr.v4.s_addr=
766 htonl((cls->ptr.ipv[0]<<24) | (cls->ptr.ipv[1]<<16) |
767 (cls->ptr.ipv[2]<< 8) | (cls->ptr.ipv[3]));
768 }
769 return adns_s_ok;
770 }
771
772 static void icb_ptr(adns_query parent, adns_query child) {
773 adns_answer *cans= child->answer;
774 const struct af_addr *queried;
775 const unsigned char *found;
776 adns_state ads= parent->ads;
777 int i;
778
779 if (cans->status == adns_s_nxdomain || cans->status == adns_s_nodata) {
780 adns__query_fail(parent,adns_s_inconsistent);
781 return;
782 } else if (cans->status) {
783 adns__query_fail(parent,cans->status);
784 return;
785 }
786
787 queried= &parent->ctx.tinfo.ptr.addr;
788 assert(cans->type == adns_r_a);
789 for (i=0, found=cans->rrs.bytes; i<cans->nrrs; i++, found+=cans->rrsz) {
790 if (adns__genaddr_equal_p(queried->af,&queried->addr, AF_INET,found)) {
791 if (!parent->children.head) {
792 adns__query_done(parent);
793 return;
794 } else {
795 LIST_LINK_TAIL(ads->childw,parent);
796 return;
797 }
798 }
799 }
800
801 adns__query_fail(parent,adns_s_inconsistent);
802 }
803
804 static adns_status pa_ptr(const parseinfo *pai, int dmstart,
805 int max, void *datap) {
806 char **rrp= datap;
807 adns_status st;
808 int cbyte, id;
809 adns_query nqu;
810 qcontext ctx;
811
812 cbyte= dmstart;
813 st= pap_domain(pai, &cbyte, max, rrp,
814 pai->qu->flags & adns_qf_quoteok_anshost ? pdf_quoteok : 0);
815 if (st) return st;
816 if (cbyte != max) return adns_s_invaliddata;
817
818 st= adns__mkquery_frdgram(pai->ads, &pai->qu->vb, &id,
819 pai->dgram, pai->dglen, dmstart,
820 adns_r_a, adns_qf_quoteok_query);
821 if (st) return st;
822
823 ctx.ext= 0;
824 ctx.callback= icb_ptr;
825 memset(&ctx.pinfo,0,sizeof(ctx.pinfo));
826 memset(&ctx.tinfo,0,sizeof(ctx.tinfo));
827 st= adns__internal_submit(pai->ads, &nqu, adns__findtype(adns_r_a),
828 adns_r_a, &pai->qu->vb, id, adns_qf_quoteok_query,
829 pai->now, &ctx);
830 if (st) return st;
831
832 nqu->parent= pai->qu;
833 LIST_LINK_TAIL_PART(pai->qu->children,nqu,siblings.);
834 return adns_s_ok;
835 }
836
837 /*
838 * _strpair (mf)
839 */
840
841 static void mf_strpair(adns_query qu, void *datap) {
842 adns_rr_strpair *rrp= datap;
843
844 adns__makefinal_str(qu,&rrp->array[0]);
845 adns__makefinal_str(qu,&rrp->array[1]);
846 }
847
848 /*
849 * _intstrpair (mf)
850 */
851
852 static void mf_intstrpair(adns_query qu, void *datap) {
853 adns_rr_intstrpair *rrp= datap;
854
855 adns__makefinal_str(qu,&rrp->array[0].str);
856 adns__makefinal_str(qu,&rrp->array[1].str);
857 }
858
859 /*
860 * _hinfo (pa)
861 */
862
863 static adns_status pa_hinfo(const parseinfo *pai, int cbyte,
864 int max, void *datap) {
865 adns_rr_intstrpair *rrp= datap;
866 adns_status st;
867 int i;
868
869 for (i=0; i<2; i++) {
870 st= pap_qstring(pai, &cbyte, max, &rrp->array[i].i, &rrp->array[i].str);
871 if (st) return st;
872 }
873
874 if (cbyte != max) return adns_s_invaliddata;
875
876 return adns_s_ok;
877 }
878
879 /*
880 * _mailbox (pap,cs +pap_mailbox822)
881 */
882
883 static adns_status pap_mailbox822(const parseinfo *pai,
884 int *cbyte_io, int max, char **mb_r) {
885 int lablen, labstart, i, needquote, c, r, neednorm;
886 const unsigned char *p;
887 char *str;
888 findlabel_state fls;
889 adns_status st;
890 vbuf *vb;
891
892 vb= &pai->qu->vb;
893 vb->used= 0;
894 adns__findlabel_start(&fls, pai->ads,
895 -1, pai->qu,
896 pai->dgram, pai->dglen, max,
897 *cbyte_io, cbyte_io);
898 st= adns__findlabel_next(&fls,&lablen,&labstart);
899 if (!lablen) {
900 adns__vbuf_appendstr(vb,".");
901 goto x_ok;
902 }
903
904 neednorm= 1;
905 for (i=0, needquote=0, p= pai->dgram+labstart; i<lablen; i++) {
906 c= *p++;
907 if ((c&~128) < 32 || (c&~128) == 127) return adns_s_invaliddata;
908 if (c == '.' && !neednorm) neednorm= 1;
909 else if (c==' ' || c>=127 || ctype_822special(c)) needquote++;
910 else neednorm= 0;
911 }
912
913 if (needquote || neednorm) {
914 r= adns__vbuf_ensure(vb, lablen+needquote+4); if (!r) R_NOMEM;
915 adns__vbuf_appendq(vb,"\"",1);
916 for (i=0, needquote=0, p= pai->dgram+labstart; i<lablen; i++, p++) {
917 c= *p;
918 if (c == '"' || c=='\\') adns__vbuf_appendq(vb,"\\",1);
919 adns__vbuf_appendq(vb,p,1);
920 }
921 adns__vbuf_appendq(vb,"\"",1);
922 } else {
923 r= adns__vbuf_append(vb, pai->dgram+labstart, lablen); if (!r) R_NOMEM;
924 }
925
926 r= adns__vbuf_appendstr(vb,"@"); if (!r) R_NOMEM;
927
928 st= adns__parse_domain_more(&fls,pai->ads, pai->qu,vb,0, pai->dgram);
929 if (st) return st;
930
931 x_ok:
932 str= adns__alloc_interim(pai->qu, vb->used+1); if (!str) R_NOMEM;
933 memcpy(str,vb->buf,vb->used);
934 str[vb->used]= 0;
935 *mb_r= str;
936 return adns_s_ok;
937 }
938
939 static adns_status pap_mailbox(const parseinfo *pai, int *cbyte_io, int max,
940 char **mb_r) {
941 if (pai->qu->typei->typekey & adns__qtf_mail822) {
942 return pap_mailbox822(pai, cbyte_io, max, mb_r);
943 } else {
944 return pap_domain(pai, cbyte_io, max, mb_r, pdf_quoteok);
945 }
946 }
947
948 static adns_status csp_mailbox(vbuf *vb, const char *mailbox) {
949 return csp_domain(vb,mailbox);
950 }
951
952 /*
953 * _rp (pa,cs)
954 */
955
956 static adns_status pa_rp(const parseinfo *pai, int cbyte,
957 int max, void *datap) {
958 adns_rr_strpair *rrp= datap;
959 adns_status st;
960
961 st= pap_mailbox(pai, &cbyte, max, &rrp->array[0]);
962 if (st) return st;
963
964 st= pap_domain(pai, &cbyte, max, &rrp->array[1], pdf_quoteok);
965 if (st) return st;
966
967 if (cbyte != max) return adns_s_invaliddata;
968 return adns_s_ok;
969 }
970
971 static adns_status cs_rp(vbuf *vb, const void *datap) {
972 const adns_rr_strpair *rrp= datap;
973 adns_status st;
974
975 st= csp_mailbox(vb,rrp->array[0]); if (st) return st;
976 CSP_ADDSTR(" ");
977 st= csp_domain(vb,rrp->array[1]); if (st) return st;
978
979 return adns_s_ok;
980 }
981
982 /*
983 * _soa (pa,mf,cs)
984 */
985
986 static adns_status pa_soa(const parseinfo *pai, int cbyte,
987 int max, void *datap) {
988 adns_rr_soa *rrp= datap;
989 const byte *dgram= pai->dgram;
990 adns_status st;
991 int msw, lsw, i;
992
993 st= pap_domain(pai, &cbyte, max, &rrp->mname,
994 pai->qu->flags & adns_qf_quoteok_anshost ? pdf_quoteok : 0);
995 if (st) return st;
996
997 st= pap_mailbox(pai, &cbyte, max, &rrp->rname);
998 if (st) return st;
999
1000 if (cbyte+20 != max) return adns_s_invaliddata;
1001
1002 for (i=0; i<5; i++) {
1003 GET_W(cbyte,msw);
1004 GET_W(cbyte,lsw);
1005 (&rrp->serial)[i]= (msw<<16) | lsw;
1006 }
1007
1008 return adns_s_ok;
1009 }
1010
1011 static void mf_soa(adns_query qu, void *datap) {
1012 adns_rr_soa *rrp= datap;
1013
1014 adns__makefinal_str(qu,&rrp->mname);
1015 adns__makefinal_str(qu,&rrp->rname);
1016 }
1017
1018 static adns_status cs_soa(vbuf *vb, const void *datap) {
1019 const adns_rr_soa *rrp= datap;
1020 char buf[20];
1021 int i;
1022 adns_status st;
1023
1024 st= csp_domain(vb,rrp->mname); if (st) return st;
1025 CSP_ADDSTR(" ");
1026 st= csp_mailbox(vb,rrp->rname); if (st) return st;
1027
1028 for (i=0; i<5; i++) {
1029 sprintf(buf," %lu",(&rrp->serial)[i]);
1030 CSP_ADDSTR(buf);
1031 }
1032
1033 return adns_s_ok;
1034 }
1035
1036 /*
1037 * _srv* (ckl,(pap),pa*2,mf*2,di,(csp),cs*2,postsort)
1038 */
1039
1040 static adns_status ckl_srv(adns_state ads, adns_queryflags flags,
1041 union checklabel_state *cls, qcontext *ctx,
1042 int labnum, const char *label, int lablen) {
1043 if (labnum < 2 && !(flags & adns_qf_quoteok_query)) {
1044 if (!lablen || label[0] != '_') return adns_s_querydomaininvalid;
1045 return adns_s_ok;
1046 }
1047 return adns__ckl_hostname(ads, flags, cls, ctx, labnum, label, lablen);
1048 }
1049
1050 static adns_status pap_srv_begin(const parseinfo *pai, int *cbyte_io, int max,
1051 adns_rr_srvha *rrp
1052 /* might be adns_rr_srvraw* */) {
1053 const byte *dgram= pai->dgram;
1054 int ti, cbyte;
1055
1056 cbyte= *cbyte_io;
1057 if ((*cbyte_io += 6) > max) return adns_s_invaliddata;
1058
1059 rrp->priority= GET_W(cbyte, ti);
1060 rrp->weight= GET_W(cbyte, ti);
1061 rrp->port= GET_W(cbyte, ti);
1062 return adns_s_ok;
1063 }
1064
1065 static adns_status pa_srvraw(const parseinfo *pai, int cbyte,
1066 int max, void *datap) {
1067 adns_rr_srvraw *rrp= datap;
1068 adns_status st;
1069
1070 st= pap_srv_begin(pai,&cbyte,max,datap);
1071 if (st) return st;
1072
1073 st= pap_domain(pai, &cbyte, max, &rrp->host,
1074 pai->qu->flags & adns_qf_quoteok_anshost ? pdf_quoteok : 0);
1075 if (st) return st;
1076
1077 if (cbyte != max) return adns_s_invaliddata;
1078 return adns_s_ok;
1079 }
1080
1081 static adns_status pa_srvha(const parseinfo *pai, int cbyte,
1082 int max, void *datap) {
1083 adns_rr_srvha *rrp= datap;
1084 adns_status st;
1085
1086 st= pap_srv_begin(pai,&cbyte,max,datap); if (st) return st;
1087 st= pap_hostaddr(pai, &cbyte, max, &rrp->ha); if (st) return st;
1088 if (cbyte != max) return adns_s_invaliddata;
1089 return adns_s_ok;
1090 }
1091
1092 static void mf_srvraw(adns_query qu, void *datap) {
1093 adns_rr_srvraw *rrp= datap;
1094 adns__makefinal_str(qu, &rrp->host);
1095 }
1096
1097 static void mf_srvha(adns_query qu, void *datap) {
1098 adns_rr_srvha *rrp= datap;
1099 mfp_hostaddr(qu,&rrp->ha);
1100 }
1101
1102 static int di_srv(adns_state ads, const void *datap_a, const void *datap_b) {
1103 const adns_rr_srvraw *ap= datap_a, *bp= datap_b;
1104 /* might be const adns_rr_svhostaddr* */
1105
1106 if (ap->priority < bp->priority) return 0;
1107 if (ap->priority > bp->priority) return 1;
1108 return 0;
1109 }
1110
1111 static adns_status csp_srv_begin(vbuf *vb, const adns_rr_srvha *rrp
1112 /* might be adns_rr_srvraw* */) {
1113 char buf[30];
1114 sprintf(buf,"%u %u %u ", rrp->priority, rrp->weight, rrp->port);
1115 CSP_ADDSTR(buf);
1116 return adns_s_ok;
1117 }
1118
1119 static adns_status cs_srvraw(vbuf *vb, const void *datap) {
1120 const adns_rr_srvraw *rrp= datap;
1121 adns_status st;
1122
1123 st= csp_srv_begin(vb,(const void*)rrp); if (st) return st;
1124 return csp_domain(vb,rrp->host);
1125 }
1126
1127 static adns_status cs_srvha(vbuf *vb, const void *datap) {
1128 const adns_rr_srvha *rrp= datap;
1129 adns_status st;
1130
1131 st= csp_srv_begin(vb,(const void*)datap); if (st) return st;
1132 return csp_hostaddr(vb,&rrp->ha);
1133 }
1134
1135 static void postsort_srv(adns_state ads, void *array, int nrrs,int rrsz,
1136 const struct typeinfo *typei) {
1137 /* we treat everything in the array as if it were an adns_rr_srvha
1138 * even though the array might be of adns_rr_srvraw. That's OK
1139 * because they have the same prefix, which is all we access.
1140 * We use rrsz, too, rather than naive array indexing, of course.
1141 */
1142 char *workbegin, *workend, *search, *arrayend;
1143 const adns_rr_srvha *rr;
1144 union { adns_rr_srvha ha; adns_rr_srvraw raw; } rrtmp;
1145 int cpriority, totalweight, runtotal;
1146 long randval;
1147
1148 assert(rrsz <= sizeof(rrtmp));
1149 for (workbegin= array, arrayend= workbegin + rrsz * nrrs;
1150 workbegin < arrayend;
1151 workbegin= workend) {
1152 cpriority= (rr=(void*)workbegin)->priority;
1153
1154 for (workend= workbegin, totalweight= 0;
1155 workend < arrayend && (rr=(void*)workend)->priority == cpriority;
1156 workend += rrsz) {
1157 totalweight += rr->weight;
1158 }
1159
1160 /* Now workbegin..(workend-1) incl. are exactly all of the RRs of
1161 * cpriority. From now on, workbegin points to the `remaining'
1162 * records: we select one record at a time (RFC2782 `Usage rules'
1163 * and `Format of the SRV RR' subsection `Weight') to place at
1164 * workbegin (swapping with the one that was there, and then
1165 * advance workbegin. */
1166 for (;
1167 workbegin + rrsz < workend; /* don't bother if just one */
1168 workbegin += rrsz) {
1169
1170 randval= nrand48(ads->rand48xsubi);
1171 randval %= (totalweight + 1);
1172 /* makes it into 0..totalweight inclusive; with 2^10 RRs,
1173 * totalweight must be <= 2^26 so probability nonuniformity is
1174 * no worse than 1 in 2^(31-26) ie 1 in 2^5, ie
1175 * abs(log(P_intended(RR_i) / P_actual(RR_i)) <= log(2^-5).
1176 */
1177
1178 for (search=workbegin, runtotal=0;
1179 (runtotal += (rr=(void*)search)->weight) < randval;
1180 search += rrsz);
1181 assert(search < arrayend);
1182 totalweight -= rr->weight;
1183 if (search != workbegin) {
1184 memcpy(&rrtmp, workbegin, rrsz);
1185 memcpy(workbegin, search, rrsz);
1186 memcpy(search, &rrtmp, rrsz);
1187 }
1188 }
1189 }
1190 /* tests:
1191 * dig -t srv _srv._tcp.test.iwj.relativity.greenend.org.uk.
1192 * ./adnshost_s -t srv- _sip._udp.voip.net.cam.ac.uk.
1193 * ./adnshost_s -t srv- _jabber._tcp.jabber.org
1194 */
1195 }
1196
1197 /*
1198 * _byteblock (mf)
1199 */
1200
1201 static void mf_byteblock(adns_query qu, void *datap) {
1202 adns_rr_byteblock *rrp= datap;
1203 void *bytes= rrp->data;
1204 adns__makefinal_block(qu,&bytes,rrp->len);
1205 rrp->data= bytes;
1206 }
1207
1208 /*
1209 * _opaque (pa,cs)
1210 */
1211
1212 static adns_status pa_opaque(const parseinfo *pai, int cbyte,
1213 int max, void *datap) {
1214 adns_rr_byteblock *rrp= datap;
1215
1216 rrp->len= max - cbyte;
1217 rrp->data= adns__alloc_interim(pai->qu, rrp->len);
1218 if (!rrp->data) R_NOMEM;
1219 memcpy(rrp->data, pai->dgram + cbyte, rrp->len);
1220 return adns_s_ok;
1221 }
1222
1223 static adns_status cs_opaque(vbuf *vb, const void *datap) {
1224 const adns_rr_byteblock *rrp= datap;
1225 char buf[10];
1226 int l;
1227 unsigned char *p;
1228
1229 sprintf(buf,"\\# %d",rrp->len);
1230 CSP_ADDSTR(buf);
1231
1232 for (l= rrp->len, p= rrp->data;
1233 l>=4;
1234 l -= 4, p += 4) {
1235 sprintf(buf," %02x%02x%02x%02x",p[0],p[1],p[2],p[3]);
1236 CSP_ADDSTR(buf);
1237 }
1238 for (;
1239 l>0;
1240 l--, p++) {
1241 sprintf(buf," %02x",*p);
1242 CSP_ADDSTR(buf);
1243 }
1244 return adns_s_ok;
1245 }
1246
1247 /*
1248 * _flat (mf)
1249 */
1250
1251 static void mf_flat(adns_query qu, void *data) { }
1252
1253 /*
1254 * Now the table.
1255 */
1256
1257 #define TYPESZ_M(member) (sizeof(*((adns_answer*)0)->rrs.member))
1258
1259 #define DEEP_TYPE(code,rrt,fmt,memb,parser,comparer,/*printer*/...) \
1260 { adns_r_##code&adns_rrt_reprmask, rrt,fmt,TYPESZ_M(memb), mf_##memb, \
1261 GLUE(cs_, CAR(__VA_ARGS__)),pa_##parser,di_##comparer, \
1262 adns__ckl_hostname, 0, adns__getrrsz_default, CDR(__VA_ARGS__) }
1263 #define FLAT_TYPE(code,rrt,fmt,memb,parser,comparer,/*printer*/...) \
1264 { adns_r_##code&adns_rrt_reprmask, rrt,fmt,TYPESZ_M(memb), mf_flat, \
1265 GLUE(cs_, CAR(__VA_ARGS__)),pa_##parser,di_##comparer, \
1266 adns__ckl_hostname, 0, adns__getrrsz_default, CDR(__VA_ARGS__) }
1267
1268 #define di_0 0
1269
1270 static const typeinfo typeinfos[] = {
1271 /* Must be in ascending order of rrtype ! */
1272 /* mem-mgmt code rrt fmt member parser comparer printer */
1273
1274 FLAT_TYPE(a, "A", 0, inaddr, inaddr, inaddr,inaddr ),
1275 DEEP_TYPE(ns_raw, "NS", "raw",str, host_raw,0, domain ),
1276 DEEP_TYPE(cname, "CNAME", 0, str, dom_raw, 0, domain ),
1277 DEEP_TYPE(soa_raw,"SOA", "raw",soa, soa, 0, soa ),
1278 DEEP_TYPE(ptr_raw,"PTR", "raw",str, host_raw,0, domain ),
1279 DEEP_TYPE(hinfo, "HINFO", 0, intstrpair,hinfo, 0, hinfo ),
1280 DEEP_TYPE(mx_raw, "MX", "raw",intstr, mx_raw, mx_raw,inthost ),
1281 DEEP_TYPE(txt, "TXT", 0, manyistr, txt, 0, txt ),
1282 DEEP_TYPE(rp_raw, "RP", "raw",strpair, rp, 0, rp ),
1283 DEEP_TYPE(srv_raw,"SRV", "raw",srvraw , srvraw, srv, srvraw,
1284 .checklabel= ckl_srv, .postsort= postsort_srv),
1285
1286 FLAT_TYPE(addr, "A", "addr", addr, addr, addr, addr,
1287 .getrrsz= gsz_addr),
1288 DEEP_TYPE(ns, "NS", "+addr",hostaddr, hostaddr,hostaddr,hostaddr ),
1289 DEEP_TYPE(ptr, "PTR","checked",str, ptr, 0, domain,
1290 .checklabel= ckl_ptr),
1291 DEEP_TYPE(mx, "MX", "+addr",inthostaddr,mx, mx, inthostaddr, ),
1292 DEEP_TYPE(srv, "SRV","+addr",srvha, srvha, srv, srvha,
1293 .checklabel= ckl_srv, .postsort= postsort_srv),
1294
1295 DEEP_TYPE(soa, "SOA","822", soa, soa, 0, soa ),
1296 DEEP_TYPE(rp, "RP", "822", strpair, rp, 0, rp ),
1297 };
1298
1299 static const typeinfo typeinfo_unknown=
1300 DEEP_TYPE(unknown,0, "unknown",byteblock,opaque, 0, opaque );
1301
1302 const typeinfo *adns__findtype(adns_rrtype type) {
1303 const typeinfo *begin, *end, *mid;
1304
1305 if (type & adns_r_unknown) return &typeinfo_unknown;
1306 type &= adns_rrt_reprmask;
1307
1308 begin= typeinfos; end= typeinfos+(sizeof(typeinfos)/sizeof(typeinfo));
1309
1310 while (begin < end) {
1311 mid= begin + ((end-begin)>>1);
1312 if (mid->typekey == type) return mid;
1313 if (type > mid->typekey) begin= mid+1;
1314 else end= mid;
1315 }
1316 return 0;
1317 }
GNU ADNS, an asynchronous DNS stub resolver -- local hacking