mdw@git.distorted.org.uk Git - adns/blob - 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 <stddef.h>
  28 #include <stdlib.h>
  29
  30 #include <sys/types.h>
  31 #include <sys/socket.h>
  32 #include <netinet/in.h>
  33 #include <arpa/inet.h>
  34
  35 #include "internal.h"
  36
  37 #define R_NOMEM       return adns_s_nomemory
  38 #define CSP_ADDSTR(s) do {                      \
  39     if (!adns__vbuf_appendstr(vb,(s))) R_NOMEM; \
  40   } while (0)
  41
  42 /*
  43  * order of sections:
  44  *
  45  * _string                    (pap)
  46  * _textdata, _qstring        (csp)
  47  * _str                       (mf,cs)
  48  * _intstr                    (mf,csp,cs)
  49  * _manyistr                  (mf,cs)
  50  * _txt                       (pa)
  51  * _inaddr                    (pa,di,cs
  52  *                              +search_sortlist, dip_genaddr, csp_genaddr)
  53  * _in6addr                   (pa,di,cs)
  54  * _addr                      (pap,pa,di,div,csp,cs,gsz,qs
  55  *                              +search_sortlst_sa, dip_sockaddr,
  56  *                               addr_rrtypes, icb_addr)
  57  * _domain                    (pap,csp,cs)
  58  * _dom_raw                   (pa)
  59  * _host_raw                  (pa)
  60  * _hostaddr                  (pap,pa,dip,di,mfp,mf,csp,cs
  61  *                              +pap_findaddrs, icb_hostaddr)
  62  * _mx_raw                    (pa,di)
  63  * _mx                        (pa,di)
  64  * _inthostaddr               (mf,cs)
  65  * _inthost                   (cs)
  66  * _ptr                       (ckl,pa +icb_ptr)
  67  * _strpair                   (mf)
  68  * _intstrpair                (mf)
  69  * _hinfo                     (pa)
  70  * _mailbox                   (pap,csp +pap_mailbox822)
  71  * _rp                        (pa,cs)
  72  * _soa                       (pa,mf,cs)
  73  * _srv*                      (ckl,(pap),pa*2,mf*2,di,(csp),cs*2,postsort)
  74  * _byteblock                 (mf)
  75  * _opaque                    (pa,cs)
  76  * _flat                      (mf)
  77  *
  78  * within each section:
  79  *    ckl_*
  80  *    pap_*
  81  *    pa_*
  82  *    dip_*
  83  *    di_*
  84  *    mfp_*
  85  *    mf_*
  86  *    csp_*
  87  *    cs_*
  88  *    gsz_*
  89  *    postsort_*
  90  *    qs_*
  91  */
  92
  93 /*
  94  * _qstring               (pap,csp)
  95  */
  96
  97 static adns_status pap_qstring(const parseinfo *pai, int *cbyte_io, int max,
  98                               int *len_r, char **str_r) {
  99   /* Neither len_r nor str_r may be null.
 100    * End of datagram (overrun) is indicated by returning adns_s_invaliddata;
 101    */
 102   const byte *dgram= pai->dgram;
 103   int l, cbyte;
 104   char *str;
 105
 106   cbyte= *cbyte_io;
 107
 108   if (cbyte >= max) return adns_s_invaliddata;
 109   GET_B(cbyte,l);
 110   if (cbyte+l > max) return adns_s_invaliddata;
 111
 112   str= adns__alloc_interim(pai->qu, l+1);
 113   if (!str) R_NOMEM;
 114
 115   str[l]= 0;
 116   memcpy(str,dgram+cbyte,l);
 117
 118   *len_r= l;
 119   *str_r= str;
 120   *cbyte_io= cbyte+l;
 121
 122   return adns_s_ok;
 123 }
 124
 125 static adns_status csp_qstring(vbuf *vb, const char *dp, int len) {
 126   unsigned char ch;
 127   char buf[10];
 128   int cn;
 129
 130   CSP_ADDSTR("\"");
 131   for (cn=0; cn<len; cn++) {
 132     ch= *dp++;
 133     if (ch == '\\') {
 134       CSP_ADDSTR("\\\\");
 135     } else if (ch == '"') {
 136       CSP_ADDSTR("\\\"");
 137     } else if (ch >= 32 && ch <= 126) {
 138       if (!adns__vbuf_append(vb,&ch,1)) R_NOMEM;
 139     } else {
 140       sprintf(buf,"\\x%02x",ch);
 141       CSP_ADDSTR(buf);
 142     }
 143   }
 144   CSP_ADDSTR("\"");
 145
 146   return adns_s_ok;
 147 }
 148
 149 /*
 150  * _str  (mf)
 151  */
 152
 153 static void mf_str(adns_query qu, void *datap) {
 154   char **rrp= datap;
 155
 156   adns__makefinal_str(qu,rrp);
 157 }
 158
 159 /*
 160  * _intstr  (mf)
 161  */
 162
 163 static void mf_intstr(adns_query qu, void *datap) {
 164   adns_rr_intstr *rrp= datap;
 165
 166   adns__makefinal_str(qu,&rrp->str);
 167 }
 168
 169 /*
 170  * _manyistr   (mf)
 171  */
 172
 173 static void mf_manyistr(adns_query qu, void *datap) {
 174   adns_rr_intstr **rrp= datap;
 175   adns_rr_intstr *te, *table;
 176   void *tablev;
 177   int tc;
 178
 179   for (tc=0, te= *rrp; te->i >= 0; te++, tc++);
 180   tablev= *rrp;
 181   adns__makefinal_block(qu,&tablev,sizeof(*te)*(tc+1));
 182   *rrp= table= tablev;
 183   for (te= *rrp; te->i >= 0; te++)
 184     adns__makefinal_str(qu,&te->str);
 185 }
 186
 187 /*
 188  * _txt   (pa,cs)
 189  */
 190
 191 static adns_status pa_txt(const parseinfo *pai, int cbyte,
 192                           int max, void *datap) {
 193   adns_rr_intstr **rrp= datap, *table, *te;
 194   const byte *dgram= pai->dgram;
 195   int ti, tc, l, startbyte;
 196   adns_status st;
 197
 198   startbyte= cbyte;
 199   if (cbyte >= max) return adns_s_invaliddata;
 200   tc= 0;
 201   while (cbyte < max) {
 202     GET_B(cbyte,l);
 203     cbyte+= l;
 204     tc++;
 205   }
 206   if (cbyte != max || !tc) return adns_s_invaliddata;
 207
 208   table= adns__alloc_interim(pai->qu,sizeof(*table)*(tc+1));
 209   if (!table) R_NOMEM;
 210
 211   for (cbyte=startbyte, ti=0, te=table; ti<tc; ti++, te++) {
 212     st= pap_qstring(pai, &cbyte, max, &te->i, &te->str);
 213     if (st) return st;
 214   }
 215   assert(cbyte == max);
 216
 217   te->i= -1;
 218   te->str= 0;
 219
 220   *rrp= table;
 221   return adns_s_ok;
 222 }
 223
 224 static adns_status cs_txt(vbuf *vb, const void *datap) {
 225   const adns_rr_intstr *const *rrp= datap;
 226   const adns_rr_intstr *current;
 227   adns_status st;
 228   int spc;
 229
 230   for (current= *rrp, spc=0;  current->i >= 0;  current++, spc=1) {
 231     if (spc) CSP_ADDSTR(" ");
 232     st= csp_qstring(vb,current->str,current->i); if (st) return st;
 233   }
 234   return adns_s_ok;
 235 }
 236
 237 /*
 238  * _hinfo   (cs)
 239  */
 240
 241 static adns_status cs_hinfo(vbuf *vb, const void *datap) {
 242   const adns_rr_intstrpair *rrp= datap;
 243   adns_status st;
 244
 245   st= csp_qstring(vb,rrp->array[0].str,rrp->array[0].i);  if (st) return st;
 246   CSP_ADDSTR(" ");
 247   st= csp_qstring(vb,rrp->array[1].str,rrp->array[1].i);  if (st) return st;
 248   return adns_s_ok;
 249 }
 250
 251 /*
 252  * _inaddr   (pa,di,cs +search_sortlist, dip_genaddr, csp_genaddr)
 253  */
 254
 255 static adns_status pa_inaddr(const parseinfo *pai, int cbyte,
 256                              int max, void *datap) {
 257   struct in_addr *storeto= datap;
 258
 259   if (max-cbyte != 4) return adns_s_invaliddata;
 260   memcpy(storeto, pai->dgram + cbyte, 4);
 261   return adns_s_ok;
 262 }
 263
 264 static int search_sortlist(adns_state ads, int af, const void *ad) {
 265   const struct sortlist *slp;
 266   const struct in6_addr *a6;
 267   union gen_addr a;
 268   int i;
 269   int v6mappedp= 0;
 270
 271   if (af == AF_INET6) {
 272     a6= ad;
 273     if (IN6_IS_ADDR_V4MAPPED(a6)) {
 274       a.v4.s_addr= htonl(((unsigned long)a6->s6_addr[12] << 24) |
 275                          ((unsigned long)a6->s6_addr[13] << 16) |
 276                          ((unsigned long)a6->s6_addr[14] <<  8) |
 277                          ((unsigned long)a6->s6_addr[15] <<  0));
 278       v6mappedp= 1;
 279     }
 280   }
 281
 282   for (i=0, slp=ads->sortlist;
 283        i<ads->nsortlist &&
 284          !adns__addr_match_p(af,ad, slp->af,&slp->base,&slp->mask) &&
 285          !(v6mappedp &&
 286            adns__addr_match_p(AF_INET,&a, slp->af,&slp->base,&slp->mask));
 287        i++, slp++);
 288   return i;
 289 }
 290
 291 static int dip_genaddr(adns_state ads, int af, const void *a, const void *b) {
 292   int ai, bi;
 293
 294   if (!ads->nsortlist) return 0;
 295
 296   ai= search_sortlist(ads,af,a);
 297   bi= search_sortlist(ads,af,b);
 298   return bi<ai;
 299 }
 300
 301 static int di_inaddr(adns_state ads,
 302                      const void *datap_a, const void *datap_b) {
 303   return dip_genaddr(ads,AF_INET,datap_a,datap_b);
 304 }
 305
 306 static adns_status csp_genaddr(vbuf *vb, int af, const void *p) {
 307   char buf[ADNS_ADDR2TEXT_BUFLEN];
 308   int len= sizeof(buf);
 309   adns_rr_addr a;
 310   int err;
 311
 312   memset(&a, 0, sizeof(a));
 313   a.addr.sa.sa_family= af;
 314   adns__sockaddr_inject(p, 0, &a.addr.sa);
 315   err= adns_addr2text(&a.addr.sa,0, buf,&len, 0); assert(!err);
 316   CSP_ADDSTR(buf);
 317   return adns_s_ok;
 318 }
 319
 320 static adns_status cs_inaddr(vbuf *vb, const void *datap) {
 321   return csp_genaddr(vb, AF_INET,datap);
 322 }
 323
 324 /*
 325  * _in6addr   (pa,di,cs)
 326  */
 327
 328 static adns_status pa_in6addr(const parseinfo *pai, int cbyte,
 329                              int max, void *datap) {
 330   struct in6_addr *storeto= datap;
 331
 332   if (max-cbyte != 16) return adns_s_invaliddata;
 333   memcpy(storeto->s6_addr, pai->dgram + cbyte, 16);
 334   return adns_s_ok;
 335 }
 336
 337 static int di_in6addr(adns_state ads,
 338                      const void *datap_a, const void *datap_b) {
 339   return dip_genaddr(ads,AF_INET6,datap_a,datap_b);
 340 }
 341
 342 static adns_status cs_in6addr(vbuf *vb, const void *datap) {
 343   return csp_genaddr(vb,AF_INET6,datap);
 344 }
 345
 346 /*
 347  * _addr   (pap,pa,di,div,csp,cs,gsz,qs
 348  *              +search_sortlist_sa, dip_sockaddr, addr_rrtypes, icb_addr)
 349  */
 350
 351 static const typeinfo tinfo_addrsub;
 352
 353 #define ADDR_RRTYPES(_) _(a)
 354
 355 static const adns_rrtype addr_all_rrtypes[] = {
 356 #define RRTY_CODE(ty) adns_r_##ty,
 357   ADDR_RRTYPES(RRTY_CODE)
 358 #undef RRTY_CODE
 359 };
 360
 361 enum {
 362 #define RRTY_INDEX(ty) addr__ri_##ty,
 363   ADDR_RRTYPES(RRTY_INDEX)
 364 #undef RRTY_INDEX
 365   addr_nrrtypes,
 366 #define RRTY_FLAG(ty) addr_rf_##ty = 1 << addr__ri_##ty,
 367   ADDR_RRTYPES(RRTY_FLAG)
 368   addr__rrty_hunoz
 369 #undef RRTY_FLAG
 370 };
 371
 372 static unsigned addr_rrtypeflag(adns_rrtype type) {
 373   int i;
 374
 375   type &= adns_rrt_typemask;
 376   for (i=0; i<addr_nrrtypes && type!=addr_all_rrtypes[i]; i++);
 377   return i < addr_nrrtypes ? 1 << i : 0;
 378 }
 379
 380 static adns_status pap_addr(const parseinfo *pai, int rrty, size_t rrsz,
 381                             int *cbyte_io, int max, adns_rr_addr *storeto) {
 382   const byte *dgram= pai->dgram;
 383   int af, addrlen, salen;
 384   const void *oaddr= dgram + *cbyte_io;
 385   int avail= max - *cbyte_io;
 386   int step= -1;
 387   void *addrp= 0;
 388
 389   switch (rrty) {
 390   case adns_r_a:
 391     af= AF_INET; addrlen= 4;
 392     addrp= &storeto->addr.inet.sin_addr;
 393     salen= sizeof(storeto->addr.inet);
 394     break;
 395   }
 396   assert(addrp);
 397
 398   assert(offsetof(adns_rr_addr, addr) + salen <= rrsz);
 399   if (addrlen < avail) return adns_s_invaliddata;
 400   if (step < 0) step= addrlen;
 401   *cbyte_io += step;
 402   memset(&storeto->addr, 0, salen);
 403   storeto->len= salen;
 404   storeto->addr.sa.sa_family= af;
 405   memcpy(addrp, oaddr, addrlen);
 406
 407   return adns_s_ok;
 408 }
 409
 410 static adns_status pa_addr(const parseinfo *pai, int cbyte,
 411                            int max, void *datap) {
 412   int err= pap_addr(pai, pai->qu->answer->type & adns_rrt_typemask,
 413                     pai->qu->answer->rrsz, &cbyte, max, datap);
 414   if (err) return err;
 415   if (cbyte != max) return adns_s_invaliddata;
 416   return adns_s_ok;
 417 }
 418
 419 static int search_sortlist_sa(adns_state ads, const struct sockaddr *sa) {
 420   union gen_addr a;
 421   adns__sockaddr_extract(sa, &a, 0);
 422   return search_sortlist(ads, sa->sa_family, &a);
 423 }
 424
 425 static int dip_sockaddr(adns_state ads,
 426                         const struct sockaddr *sa,
 427                         const struct sockaddr *sb) {
 428   if (!ads->sortlist) return 0;
 429   return search_sortlist_sa(ads, sa) > search_sortlist_sa(ads, sb);
 430 }
 431
 432 static int di_addr(adns_state ads, const void *datap_a, const void *datap_b) {
 433   const adns_rr_addr *ap= datap_a, *bp= datap_b;
 434   return dip_sockaddr(ads, &ap->addr.sa, &bp->addr.sa);
 435 }
 436
 437 static int div_addr(void *context, const void *datap_a, const void *datap_b) {
 438   const adns_state ads= context;
 439
 440   return di_addr(ads, datap_a, datap_b);
 441 }
 442
 443 static adns_status csp_addr(vbuf *vb, const adns_rr_addr *rrp) {
 444   char buf[ADNS_ADDR2TEXT_BUFLEN];
 445   int len= sizeof(buf);
 446   int err;
 447
 448   switch (rrp->addr.inet.sin_family) {
 449   case AF_INET:
 450     CSP_ADDSTR("INET ");
 451     goto a2t;
 452   case AF_INET6:
 453     CSP_ADDSTR("INET6 ");
 454     goto a2t;
 455   a2t:
 456     err= adns_addr2text(&rrp->addr.sa,0, buf,&len, 0); assert(!err);
 457     CSP_ADDSTR(buf);
 458     break;
 459   default:
 460     sprintf(buf,"AF=%u",rrp->addr.sa.sa_family);
 461     CSP_ADDSTR(buf);
 462     break;
 463   }
 464   return adns_s_ok;
 465 }
 466
 467 static adns_status cs_addr(vbuf *vb, const void *datap) {
 468   const adns_rr_addr *rrp= datap;
 469
 470   return csp_addr(vb,rrp);
 471 }
 472
 473 static int gsz_addr(const typeinfo *typei, adns_rrtype type) {
 474   return type & adns__qtf_bigaddr ?
 475     sizeof(adns_rr_addr) : sizeof(adns_rr_addr_v4only);
 476 }
 477
 478 static unsigned addr_rrtypes(adns_state ads, adns_rrtype type,
 479                              adns_queryflags qf) {
 480   /* Return a mask of addr_rf_... flags indicating which address families are
 481    * wanted, given a query type and flags.
 482    */
 483   return addr_rf_a;
 484 }
 485
 486 static void icb_addr(adns_query parent, adns_query child);
 487
 488 static void addr_subqueries(adns_query qu, struct timeval now,
 489                             adns_queryflags qf_extra,
 490                             const byte *qd_dgram, int qd_dglen) {
 491   int i, err, id;
 492   adns_query cqu;
 493   adns_queryflags qf= (qu->flags & ~adns_qf_search) | qf_extra;
 494   adns_rrtype qtf= qu->answer->type & adns__qtf_deref;
 495   unsigned which= qu->ctx.tinfo.addr.want & ~qu->ctx.tinfo.addr.have;
 496   qcontext ctx;
 497
 498   memset(&ctx, 0, sizeof(ctx));
 499   ctx.callback= icb_addr;
 500   for (i=0; i<addr_nrrtypes; i++) {
 501     if (!(which & (1 << i))) continue;
 502     err= adns__mkquery_frdgram(qu->ads, &qu->vb, &id, qd_dgram,qd_dglen,
 503                                DNS_HDRSIZE, addr_all_rrtypes[i], qf);
 504     if (err) goto x_error;
 505     err= adns__internal_submit(qu->ads, &cqu, &tinfo_addrsub,
 506                                addr_all_rrtypes[i] | qtf,
 507                                &qu->vb, id, qf, now, &ctx);
 508     if (err) goto x_error;
 509     cqu->answer->rrsz= qu->answer->rrsz;
 510     cqu->parent= qu;
 511     LIST_LINK_TAIL_PART(qu->children, cqu,siblings.);
 512   }
 513   qu->state= query_childw;
 514   LIST_LINK_TAIL(qu->ads->childw, qu);
 515   return;
 516
 517 x_error:
 518   adns__query_fail(qu, err);
 519 }
 520
 521 static adns_status append_addrs(adns_query qu, size_t rrsz,
 522                                 adns_rr_addr **dp, int *dlen,
 523                                 const adns_rr_addr *sp, int slen) {
 524   /* Append a vector of slen addr records, each of size rrsz, starting at ap,
 525    * to a vector starting at *dp, of length *dlen.  On successful completion,
 526    * *dp and *dlen are updated.
 527    */
 528
 529   size_t drrsz= *dlen*rrsz, srrsz= slen*rrsz;
 530   byte *p;
 531
 532   if (!slen) return adns_s_ok;
 533   p= adns__alloc_interim(qu, drrsz + srrsz);
 534   if (!p) R_NOMEM;
 535   if (*dlen) {
 536     memcpy(p, *dp, drrsz);
 537     adns__free_interim(qu, *dp);
 538   }
 539   memcpy(p + drrsz, sp, srrsz);
 540   *dlen += slen;
 541   *dp= (adns_rr_addr *)p;
 542   return adns_s_ok;
 543 }
 544
 545 static void propagate_ttl(adns_query to, adns_query from)
 546   { if (to->expires > from->expires) to->expires= from->expires; }
 547
 548 static adns_status copy_cname_from_child(adns_query parent, adns_query child) {
 549   adns_answer *pans= parent->answer, *cans= child->answer;
 550   size_t n= strlen(cans->cname) + 1;
 551
 552   pans->cname= adns__alloc_preserved(parent, n);
 553   if (!pans->cname) R_NOMEM;
 554   memcpy(pans->cname, cans->cname, n);
 555   return adns_s_ok;
 556 }
 557
 558 static void done_addr_type(adns_query qu, adns_rrtype type) {
 559   unsigned f= addr_rrtypeflag(type);
 560   assert(f); qu->ctx.tinfo.addr.have |= f;
 561 }
 562
 563 static void icb_addr(adns_query parent, adns_query child) {
 564   adns_state ads= parent->ads;
 565   adns_answer *pans= parent->answer, *cans= child->answer;
 566   struct timeval now;
 567   adns_status err;
 568
 569   propagate_ttl(parent, child);
 570
 571   if (cans->cname && !pans->cname) {
 572     err= copy_cname_from_child(parent, child);
 573     if (err) goto x_err;
 574   }
 575
 576   if ((parent->flags & adns_qf_search) &&
 577       !pans->cname && cans->status == adns_s_nxdomain) {
 578     /* We're searching a list of suffixes, and the name doesn't exist.  Try
 579      * the next one.
 580      */
 581
 582     adns__cancel_children(parent);
 583     adns__free_interim(parent, pans->rrs.bytes);
 584     pans->rrs.bytes= 0; pans->nrrs= 0;
 585     if (gettimeofday(&now, 0)) goto x_gtod;
 586     adns__search_next(ads, parent, now);
 587     return;
 588   }
 589
 590   if (cans->status && cans->status != adns_s_nodata)
 591     { err= cans->status; goto x_err; }
 592
 593   assert(pans->rrsz == cans->rrsz);
 594   err= append_addrs(parent, pans->rrsz,
 595                     &pans->rrs.addr, &pans->nrrs,
 596                     cans->rrs.addr, cans->nrrs);
 597   if (err) goto x_err;
 598   done_addr_type(parent, cans->type);
 599
 600   if (parent->children.head) LIST_LINK_TAIL(ads->childw, parent);
 601   else if (!pans->nrrs) adns__query_fail(parent, adns_s_nodata);
 602   else adns__query_done(parent);
 603   return;
 604
 605 x_gtod:
 606   adns__diag(ads, -1, parent, "gettimeofday failed: %s", strerror(errno));
 607   err= adns_s_systemfail;
 608   goto x_err;
 609
 610 x_err:
 611   adns__query_fail(parent, err);
 612 }
 613
 614 static void qs_addr(adns_query qu, struct timeval now) {
 615   if (!qu->ctx.tinfo.addr.want) {
 616     qu->ctx.tinfo.addr.want= addr_rrtypes(qu->ads, qu->answer->type,
 617                                           qu->flags);
 618     qu->ctx.tinfo.addr.have= 0;
 619   }
 620   addr_subqueries(qu, now, 0, qu->query_dgram, qu->query_dglen);
 621 }
 622
 623 /*
 624  * _domain      (pap,csp,cs)
 625  * _dom_raw     (pa)
 626  */
 627
 628 static adns_status pap_domain(const parseinfo *pai, int *cbyte_io, int max,
 629                               char **domain_r, parsedomain_flags flags) {
 630   adns_status st;
 631   char *dm;
 632
 633   st= adns__parse_domain(pai->qu->ads, pai->serv, pai->qu, &pai->qu->vb, flags,
 634                          pai->dgram,pai->dglen, cbyte_io, max);
 635   if (st) return st;
 636   if (!pai->qu->vb.used) return adns_s_invaliddata;
 637
 638   dm= adns__alloc_interim(pai->qu, pai->qu->vb.used+1);
 639   if (!dm) R_NOMEM;
 640
 641   dm[pai->qu->vb.used]= 0;
 642   memcpy(dm,pai->qu->vb.buf,pai->qu->vb.used);
 643
 644   *domain_r= dm;
 645   return adns_s_ok;
 646 }
 647
 648 static adns_status csp_domain(vbuf *vb, const char *domain) {
 649   CSP_ADDSTR(domain);
 650   if (!*domain) CSP_ADDSTR(".");
 651   return adns_s_ok;
 652 }
 653
 654 static adns_status cs_domain(vbuf *vb, const void *datap) {
 655   const char *const *domainp= datap;
 656   return csp_domain(vb,*domainp);
 657 }
 658
 659 static adns_status pa_dom_raw(const parseinfo *pai, int cbyte,
 660                               int max, void *datap) {
 661   char **rrp= datap;
 662   adns_status st;
 663
 664   st= pap_domain(pai, &cbyte, max, rrp, pdf_quoteok);
 665   if (st) return st;
 666
 667   if (cbyte != max) return adns_s_invaliddata;
 668   return adns_s_ok;
 669 }
 670
 671 /*
 672  * _host_raw   (pa)
 673  */
 674
 675 static adns_status pa_host_raw(const parseinfo *pai, int cbyte,
 676                                int max, void *datap) {
 677   char **rrp= datap;
 678   adns_status st;
 679
 680   st= pap_domain(pai, &cbyte, max, rrp,
 681                  pai->qu->flags & adns_qf_quoteok_anshost ? pdf_quoteok : 0);
 682   if (st) return st;
 683
 684   if (cbyte != max) return adns_s_invaliddata;
 685   return adns_s_ok;
 686 }
 687
 688 /*
 689  * _hostaddr   (pap,pa,dip,di,mfp,mf,csp,cs +pap_findaddrs, icb_hostaddr)
 690  */
 691
 692 static adns_status pap_findaddrs(const parseinfo *pai, adns_rr_hostaddr *ha,
 693                                  size_t addrsz,
 694                                  int *cbyte_io, int count, int dmstart) {
 695   int rri, naddrs;
 696   int type, class, rdlen, rdstart, rdend, ownermatched;
 697   unsigned long ttl;
 698   adns_status st;
 699
 700   for (rri=0, naddrs=-1; rri<count; rri++) {
 701     st= adns__findrr_anychk(pai->qu, pai->serv, pai->dgram,
 702                             pai->dglen, cbyte_io,
 703                             &type, &class, &ttl, &rdlen, &rdstart,
 704                             pai->dgram, pai->dglen, dmstart, &ownermatched);
 705     if (st) return st;
 706     if (!ownermatched || class != DNS_CLASS_IN || type != adns_r_a) {
 707       if (naddrs>0) break; else continue;
 708     }
 709     if (naddrs == -1) {
 710       naddrs= 0;
 711     }
 712     if (!adns__vbuf_ensure(&pai->qu->vb, (naddrs+1)*addrsz))
 713       R_NOMEM;
 714     adns__update_expires(pai->qu,ttl,pai->now);
 715     rdend= rdstart + rdlen;
 716     st= pap_addr(pai, adns_r_a, addrsz, &rdstart, rdend,
 717                  (adns_rr_addr *)(pai->qu->vb.buf + naddrs*addrsz));
 718     if (st) return st;
 719     if (rdstart != rdend) return adns_s_invaliddata;
 720     naddrs++;
 721   }
 722   if (naddrs >= 0) {
 723     ha->addrs= adns__alloc_interim(pai->qu, naddrs*addrsz);
 724     if (!ha->addrs) R_NOMEM;
 725     memcpy(ha->addrs, pai->qu->vb.buf, naddrs*addrsz);
 726     ha->naddrs= naddrs;
 727     ha->astatus= adns_s_ok;
 728
 729     adns__isort(ha->addrs, naddrs, addrsz, pai->qu->vb.buf,
 730                 div_addr, pai->ads);
 731   }
 732   return adns_s_ok;
 733 }
 734
 735 static void icb_hostaddr(adns_query parent, adns_query child) {
 736   adns_answer *cans= child->answer;
 737   adns_rr_hostaddr *rrp= child->ctx.pinfo.hostaddr;
 738   adns_state ads= parent->ads;
 739   adns_status st;
 740
 741   st= cans->status;
 742   rrp->astatus= st;
 743   rrp->naddrs= (st>0 && st<=adns_s_max_tempfail) ? -1 : cans->nrrs;
 744   rrp->addrs= cans->rrs.addr;
 745   adns__transfer_interim(child, parent, rrp->addrs);
 746
 747   if (parent->children.head) {
 748     LIST_LINK_TAIL(ads->childw,parent);
 749   } else {
 750     adns__query_done(parent);
 751   }
 752 }
 753
 754 static adns_status pap_hostaddr(const parseinfo *pai, int *cbyte_io,
 755                                 int max, adns_rr_hostaddr *rrp) {
 756   adns_status st;
 757   int dmstart, cbyte;
 758   qcontext ctx;
 759   int id;
 760   adns_query nqu;
 761   adns_queryflags nflags;
 762   size_t addrsz= gsz_addr(0, pai->qu->answer->type);
 763
 764   dmstart= cbyte= *cbyte_io;
 765   st= pap_domain(pai, &cbyte, max, &rrp->host,
 766                  pai->qu->flags & adns_qf_quoteok_anshost ? pdf_quoteok : 0);
 767   if (st) return st;
 768   *cbyte_io= cbyte;
 769
 770   rrp->astatus= adns_s_ok;
 771   rrp->naddrs= -1;
 772   rrp->addrs= 0;
 773
 774   cbyte= pai->nsstart;
 775
 776   st= pap_findaddrs(pai, rrp,addrsz, &cbyte, pai->nscount, dmstart);
 777   if (st) return st;
 778   if (rrp->naddrs != -1) return adns_s_ok;
 779
 780   st= pap_findaddrs(pai, rrp,addrsz, &cbyte, pai->arcount, dmstart);
 781   if (st) return st;
 782   if (rrp->naddrs != -1) return adns_s_ok;
 783
 784   st= adns__mkquery_frdgram(pai->ads, &pai->qu->vb, &id,
 785                             pai->dgram, pai->dglen, dmstart,
 786                             adns_r_addr, adns_qf_quoteok_query);
 787   if (st) return st;
 788
 789   ctx.ext= 0;
 790   ctx.callback= icb_hostaddr;
 791   ctx.pinfo.hostaddr= rrp;
 792   memset(&ctx.tinfo, 0, sizeof(ctx.tinfo));
 793
 794   nflags= adns_qf_quoteok_query;
 795   if (!(pai->qu->flags & adns_qf_cname_loose)) nflags |= adns_qf_cname_forbid;
 796
 797   st= adns__internal_submit(pai->ads, &nqu, adns__findtype(adns_r_addr),
 798                             ((adns_r_addr & adns_rrt_reprmask) |
 799                              (pai->qu->answer->type & ~adns_rrt_reprmask)),
 800                             &pai->qu->vb, id, nflags, pai->now, &ctx);
 801   if (st) return st;
 802
 803   nqu->parent= pai->qu;
 804   LIST_LINK_TAIL_PART(pai->qu->children,nqu,siblings.);
 805
 806   return adns_s_ok;
 807 }
 808
 809 static adns_status pa_hostaddr(const parseinfo *pai, int cbyte,
 810                                int max, void *datap) {
 811   adns_rr_hostaddr *rrp= datap;
 812   adns_status st;
 813
 814   st= pap_hostaddr(pai, &cbyte, max, rrp);
 815   if (st) return st;
 816   if (cbyte != max) return adns_s_invaliddata;
 817
 818   return adns_s_ok;
 819 }
 820
 821 static int dip_hostaddr(adns_state ads,
 822                         const adns_rr_hostaddr *ap, const adns_rr_hostaddr *bp) {
 823   if (ap->astatus != bp->astatus) return ap->astatus;
 824   if (ap->astatus) return 0;
 825
 826   return dip_sockaddr(ads, &ap->addrs[0].addr.sa, &bp->addrs[0].addr.sa);
 827 }
 828
 829 static int di_hostaddr(adns_state ads,
 830                        const void *datap_a, const void *datap_b) {
 831   const adns_rr_hostaddr *ap= datap_a, *bp= datap_b;
 832
 833   return dip_hostaddr(ads, ap,bp);
 834 }
 835
 836 static void mfp_hostaddr(adns_query qu, adns_rr_hostaddr *rrp) {
 837   void *tablev;
 838   size_t addrsz= gsz_addr(0, qu->answer->type);
 839
 840   adns__makefinal_str(qu,&rrp->host);
 841   tablev= rrp->addrs;
 842   adns__makefinal_block(qu, &tablev, rrp->naddrs*addrsz);
 843   rrp->addrs= tablev;
 844 }
 845
 846 static void mf_hostaddr(adns_query qu, void *datap) {
 847   adns_rr_hostaddr *rrp= datap;
 848
 849   mfp_hostaddr(qu,rrp);
 850 }
 851
 852 static adns_status csp_hostaddr(vbuf *vb, const adns_rr_hostaddr *rrp) {
 853   const char *errstr;
 854   adns_status st;
 855   char buf[20];
 856   int i;
 857
 858   st= csp_domain(vb,rrp->host);  if (st) return st;
 859
 860   CSP_ADDSTR(" ");
 861   CSP_ADDSTR(adns_errtypeabbrev(rrp->astatus));
 862
 863   sprintf(buf," %d ",rrp->astatus);
 864   CSP_ADDSTR(buf);
 865
 866   CSP_ADDSTR(adns_errabbrev(rrp->astatus));
 867   CSP_ADDSTR(" ");
 868
 869   errstr= adns_strerror(rrp->astatus);
 870   st= csp_qstring(vb,errstr,strlen(errstr));  if (st) return st;
 871
 872   if (rrp->naddrs >= 0) {
 873     CSP_ADDSTR(" (");
 874     for (i=0; i<rrp->naddrs; i++) {
 875       CSP_ADDSTR(" ");
 876       st= csp_addr(vb,&rrp->addrs[i]);
 877     }
 878     CSP_ADDSTR(" )");
 879   } else {
 880     CSP_ADDSTR(" ?");
 881   }
 882   return adns_s_ok;
 883 }
 884
 885 static adns_status cs_hostaddr(vbuf *vb, const void *datap) {
 886   const adns_rr_hostaddr *rrp= datap;
 887
 888   return csp_hostaddr(vb,rrp);
 889 }
 890
 891 /*
 892  * _mx_raw   (pa,di)
 893  */
 894
 895 static adns_status pa_mx_raw(const parseinfo *pai, int cbyte,
 896                              int max, void *datap) {
 897   const byte *dgram= pai->dgram;
 898   adns_rr_intstr *rrp= datap;
 899   adns_status st;
 900   int pref;
 901
 902   if (cbyte+2 > max) return adns_s_invaliddata;
 903   GET_W(cbyte,pref);
 904   rrp->i= pref;
 905   st= pap_domain(pai, &cbyte, max, &rrp->str,
 906                  pai->qu->flags & adns_qf_quoteok_anshost ? pdf_quoteok : 0);
 907   if (st) return st;
 908
 909   if (cbyte != max) return adns_s_invaliddata;
 910   return adns_s_ok;
 911 }
 912
 913 static int di_mx_raw(adns_state ads, const void *datap_a, const void *datap_b) {
 914   const adns_rr_intstr *ap= datap_a, *bp= datap_b;
 915
 916   if (ap->i < bp->i) return 0;
 917   if (ap->i > bp->i) return 1;
 918   return 0;
 919 }
 920
 921 /*
 922  * _mx   (pa,di)
 923  */
 924
 925 static adns_status pa_mx(const parseinfo *pai, int cbyte,
 926                          int max, void *datap) {
 927   const byte *dgram= pai->dgram;
 928   adns_rr_inthostaddr *rrp= datap;
 929   adns_status st;
 930   int pref;
 931
 932   if (cbyte+2 > max) return adns_s_invaliddata;
 933   GET_W(cbyte,pref);
 934   rrp->i= pref;
 935   st= pap_hostaddr(pai, &cbyte, max, &rrp->ha);
 936   if (st) return st;
 937
 938   if (cbyte != max) return adns_s_invaliddata;
 939   return adns_s_ok;
 940 }
 941
 942 static int di_mx(adns_state ads, const void *datap_a, const void *datap_b) {
 943   const adns_rr_inthostaddr *ap= datap_a, *bp= datap_b;
 944
 945   if (ap->i < bp->i) return 0;
 946   if (ap->i > bp->i) return 1;
 947   return dip_hostaddr(ads, &ap->ha, &bp->ha);
 948 }
 949
 950 /*
 951  * _inthostaddr  (mf,cs)
 952  */
 953
 954 static void mf_inthostaddr(adns_query qu, void *datap) {
 955   adns_rr_inthostaddr *rrp= datap;
 956
 957   mfp_hostaddr(qu,&rrp->ha);
 958 }
 959
 960 static adns_status cs_inthostaddr(vbuf *vb, const void *datap) {
 961   const adns_rr_inthostaddr *rrp= datap;
 962   char buf[10];
 963
 964   sprintf(buf,"%u ",rrp->i);
 965   CSP_ADDSTR(buf);
 966
 967   return csp_hostaddr(vb,&rrp->ha);
 968 }
 969
 970 /*
 971  * _inthost  (cs)
 972  */
 973
 974 static adns_status cs_inthost(vbuf *vb, const void *datap) {
 975   const adns_rr_intstr *rrp= datap;
 976   char buf[10];
 977
 978   sprintf(buf,"%u ",rrp->i);
 979   CSP_ADDSTR(buf);
 980   return csp_domain(vb,rrp->str);
 981 }
 982
 983 /*
 984  * _ptr   (ckl,pa +icb_ptr)
 985  */
 986
 987 static adns_status ckl_ptr(adns_state ads, adns_queryflags flags,
 988                            union checklabel_state *cls, qcontext *ctx,
 989                            int labnum, const char *label, int lablen) {
 990   if (lablen) {
 991     if (adns__revparse_label(&cls->ptr, labnum, label,lablen))
 992       return adns_s_querydomainwrong;
 993   } else {
 994     if (adns__revparse_done(&cls->ptr, labnum,
 995                             &ctx->tinfo.ptr.rev_rrtype,
 996                             &ctx->tinfo.ptr.addr))
 997       return adns_s_querydomainwrong;
 998   }
 999   return adns_s_ok;
1000 }
1001
1002 static void icb_ptr(adns_query parent, adns_query child) {
1003   adns_answer *cans= child->answer;
1004   const struct af_addr *queried;
1005   const unsigned char *found;
1006   adns_state ads= parent->ads;
1007   int i;
1008
1009   if (cans->status == adns_s_nxdomain || cans->status == adns_s_nodata) {
1010     adns__query_fail(parent,adns_s_inconsistent);
1011     return;
1012   } else if (cans->status) {
1013     adns__query_fail(parent,cans->status);
1014     return;
1015   }
1016
1017   queried= &parent->ctx.tinfo.ptr.addr;
1018   for (i=0, found=cans->rrs.bytes; i<cans->nrrs; i++, found+=cans->rrsz) {
1019     if (adns__genaddr_equal_p(queried->af,&queried->addr,
1020                               parent->ctx.tinfo.ptr.addr.af,found)) {
1021       if (!parent->children.head) {
1022         adns__query_done(parent);
1023         return;
1024       } else {
1025         LIST_LINK_TAIL(ads->childw,parent);
1026         return;
1027       }
1028     }
1029   }
1030
1031   adns__query_fail(parent,adns_s_inconsistent);
1032 }
1033
1034 static adns_status pa_ptr(const parseinfo *pai, int dmstart,
1035                           int max, void *datap) {
1036   char **rrp= datap;
1037   adns_status st;
1038   adns_rrtype rrtype= pai->qu->ctx.tinfo.ptr.rev_rrtype;
1039   int cbyte, id;
1040   adns_query nqu;
1041   qcontext ctx;
1042
1043   cbyte= dmstart;
1044   st= pap_domain(pai, &cbyte, max, rrp,
1045                  pai->qu->flags & adns_qf_quoteok_anshost ? pdf_quoteok : 0);
1046   if (st) return st;
1047   if (cbyte != max) return adns_s_invaliddata;
1048
1049   st= adns__mkquery_frdgram(pai->ads, &pai->qu->vb, &id,
1050                             pai->dgram, pai->dglen, dmstart,
1051                             rrtype, adns_qf_quoteok_query);
1052   if (st) return st;
1053
1054   ctx.ext= 0;
1055   ctx.callback= icb_ptr;
1056   memset(&ctx.pinfo,0,sizeof(ctx.pinfo));
1057   memset(&ctx.tinfo,0,sizeof(ctx.tinfo));
1058   st= adns__internal_submit(pai->ads, &nqu, adns__findtype(rrtype),
1059                             rrtype, &pai->qu->vb, id,
1060                             adns_qf_quoteok_query, pai->now, &ctx);
1061   if (st) return st;
1062
1063   nqu->parent= pai->qu;
1064   LIST_LINK_TAIL_PART(pai->qu->children,nqu,siblings.);
1065   return adns_s_ok;
1066 }
1067
1068 /*
1069  * _strpair   (mf)
1070  */
1071
1072 static void mf_strpair(adns_query qu, void *datap) {
1073   adns_rr_strpair *rrp= datap;
1074
1075   adns__makefinal_str(qu,&rrp->array[0]);
1076   adns__makefinal_str(qu,&rrp->array[1]);
1077 }
1078
1079 /*
1080  * _intstrpair   (mf)
1081  */
1082
1083 static void mf_intstrpair(adns_query qu, void *datap) {
1084   adns_rr_intstrpair *rrp= datap;
1085
1086   adns__makefinal_str(qu,&rrp->array[0].str);
1087   adns__makefinal_str(qu,&rrp->array[1].str);
1088 }
1089
1090 /*
1091  * _hinfo   (pa)
1092  */
1093
1094 static adns_status pa_hinfo(const parseinfo *pai, int cbyte,
1095                             int max, void *datap) {
1096   adns_rr_intstrpair *rrp= datap;
1097   adns_status st;
1098   int i;
1099
1100   for (i=0; i<2; i++) {
1101     st= pap_qstring(pai, &cbyte, max, &rrp->array[i].i, &rrp->array[i].str);
1102     if (st) return st;
1103   }
1104
1105   if (cbyte != max) return adns_s_invaliddata;
1106
1107   return adns_s_ok;
1108 }
1109
1110 /*
1111  * _mailbox   (pap,cs +pap_mailbox822)
1112  */
1113
1114 static adns_status pap_mailbox822(const parseinfo *pai,
1115                                   int *cbyte_io, int max, char **mb_r) {
1116   int lablen, labstart, i, needquote, c, r, neednorm;
1117   const unsigned char *p;
1118   char *str;
1119   findlabel_state fls;
1120   adns_status st;
1121   vbuf *vb;
1122
1123   vb= &pai->qu->vb;
1124   vb->used= 0;
1125   adns__findlabel_start(&fls, pai->ads,
1126                         -1, pai->qu,
1127                         pai->dgram, pai->dglen, max,
1128                         *cbyte_io, cbyte_io);
1129   st= adns__findlabel_next(&fls,&lablen,&labstart);
1130   if (!lablen) {
1131     adns__vbuf_appendstr(vb,".");
1132     goto x_ok;
1133   }
1134
1135   neednorm= 1;
1136   for (i=0, needquote=0, p= pai->dgram+labstart; i<lablen; i++) {
1137     c= *p++;
1138     if ((c&~128) < 32 || (c&~128) == 127) return adns_s_invaliddata;
1139     if (c == '.' && !neednorm) neednorm= 1;
1140     else if (c==' ' || c>=127 || ctype_822special(c)) needquote++;
1141     else neednorm= 0;
1142   }
1143
1144   if (needquote || neednorm) {
1145     r= adns__vbuf_ensure(vb, lablen+needquote+4); if (!r) R_NOMEM;
1146     adns__vbuf_appendq(vb,"\"",1);
1147     for (i=0, needquote=0, p= pai->dgram+labstart; i<lablen; i++, p++) {
1148       c= *p;
1149       if (c == '"' || c=='\\') adns__vbuf_appendq(vb,"\\",1);
1150       adns__vbuf_appendq(vb,p,1);
1151     }
1152     adns__vbuf_appendq(vb,"\"",1);
1153   } else {
1154     r= adns__vbuf_append(vb, pai->dgram+labstart, lablen); if (!r) R_NOMEM;
1155   }
1156
1157   r= adns__vbuf_appendstr(vb,"@"); if (!r) R_NOMEM;
1158
1159   st= adns__parse_domain_more(&fls,pai->ads, pai->qu,vb,0, pai->dgram);
1160   if (st) return st;
1161
1162  x_ok:
1163   str= adns__alloc_interim(pai->qu, vb->used+1); if (!str) R_NOMEM;
1164   memcpy(str,vb->buf,vb->used);
1165   str[vb->used]= 0;
1166   *mb_r= str;
1167   return adns_s_ok;
1168 }
1169
1170 static adns_status pap_mailbox(const parseinfo *pai, int *cbyte_io, int max,
1171                                char **mb_r) {
1172   if (pai->qu->typei->typekey & adns__qtf_mail822) {
1173     return pap_mailbox822(pai, cbyte_io, max, mb_r);
1174   } else {
1175     return pap_domain(pai, cbyte_io, max, mb_r, pdf_quoteok);
1176   }
1177 }
1178
1179 static adns_status csp_mailbox(vbuf *vb, const char *mailbox) {
1180   return csp_domain(vb,mailbox);
1181 }
1182
1183 /*
1184  * _rp   (pa,cs)
1185  */
1186
1187 static adns_status pa_rp(const parseinfo *pai, int cbyte,
1188                          int max, void *datap) {
1189   adns_rr_strpair *rrp= datap;
1190   adns_status st;
1191
1192   st= pap_mailbox(pai, &cbyte, max, &rrp->array[0]);
1193   if (st) return st;
1194
1195   st= pap_domain(pai, &cbyte, max, &rrp->array[1], pdf_quoteok);
1196   if (st) return st;
1197
1198   if (cbyte != max) return adns_s_invaliddata;
1199   return adns_s_ok;
1200 }
1201
1202 static adns_status cs_rp(vbuf *vb, const void *datap) {
1203   const adns_rr_strpair *rrp= datap;
1204   adns_status st;
1205
1206   st= csp_mailbox(vb,rrp->array[0]);  if (st) return st;
1207   CSP_ADDSTR(" ");
1208   st= csp_domain(vb,rrp->array[1]);  if (st) return st;
1209
1210   return adns_s_ok;
1211 }
1212
1213 /*
1214  * _soa   (pa,mf,cs)
1215  */
1216
1217 static adns_status pa_soa(const parseinfo *pai, int cbyte,
1218                           int max, void *datap) {
1219   adns_rr_soa *rrp= datap;
1220   const byte *dgram= pai->dgram;
1221   adns_status st;
1222   int msw, lsw, i;
1223
1224   st= pap_domain(pai, &cbyte, max, &rrp->mname,
1225                  pai->qu->flags & adns_qf_quoteok_anshost ? pdf_quoteok : 0);
1226   if (st) return st;
1227
1228   st= pap_mailbox(pai, &cbyte, max, &rrp->rname);
1229   if (st) return st;
1230
1231   if (cbyte+20 != max) return adns_s_invaliddata;
1232
1233   for (i=0; i<5; i++) {
1234     GET_W(cbyte,msw);
1235     GET_W(cbyte,lsw);
1236     (&rrp->serial)[i]= (msw<<16) | lsw;
1237   }
1238
1239   return adns_s_ok;
1240 }
1241
1242 static void mf_soa(adns_query qu, void *datap) {
1243   adns_rr_soa *rrp= datap;
1244
1245   adns__makefinal_str(qu,&rrp->mname);
1246   adns__makefinal_str(qu,&rrp->rname);
1247 }
1248
1249 static adns_status cs_soa(vbuf *vb, const void *datap) {
1250   const adns_rr_soa *rrp= datap;
1251   char buf[20];
1252   int i;
1253   adns_status st;
1254
1255   st= csp_domain(vb,rrp->mname);  if (st) return st;
1256   CSP_ADDSTR(" ");
1257   st= csp_mailbox(vb,rrp->rname);  if (st) return st;
1258
1259   for (i=0; i<5; i++) {
1260     sprintf(buf," %lu",(&rrp->serial)[i]);
1261     CSP_ADDSTR(buf);
1262   }
1263
1264   return adns_s_ok;
1265 }
1266
1267 /*
1268  * _srv*  (ckl,(pap),pa*2,mf*2,di,(csp),cs*2,postsort)
1269  */
1270
1271 static adns_status ckl_srv(adns_state ads, adns_queryflags flags,
1272                            union checklabel_state *cls, qcontext *ctx,
1273                            int labnum, const char *label, int lablen) {
1274   if (labnum < 2 && !(flags & adns_qf_quoteok_query)) {
1275     if (!lablen || label[0] != '_') return adns_s_querydomaininvalid;
1276     return adns_s_ok;
1277   }
1278   return adns__ckl_hostname(ads, flags, cls, ctx, labnum, label, lablen);
1279 }
1280
1281 static adns_status pap_srv_begin(const parseinfo *pai, int *cbyte_io, int max,
1282                                  adns_rr_srvha *rrp
1283                                    /* might be adns_rr_srvraw* */) {
1284   const byte *dgram= pai->dgram;
1285   int ti, cbyte;
1286
1287   cbyte= *cbyte_io;
1288   if ((*cbyte_io += 6) > max) return adns_s_invaliddata;
1289
1290   rrp->priority= GET_W(cbyte, ti);
1291   rrp->weight=   GET_W(cbyte, ti);
1292   rrp->port=     GET_W(cbyte, ti);
1293   return adns_s_ok;
1294 }
1295
1296 static adns_status pa_srvraw(const parseinfo *pai, int cbyte,
1297                              int max, void *datap) {
1298   adns_rr_srvraw *rrp= datap;
1299   adns_status st;
1300
1301   st= pap_srv_begin(pai,&cbyte,max,datap);
1302   if (st) return st;
1303
1304   st= pap_domain(pai, &cbyte, max, &rrp->host,
1305                  pai->qu->flags & adns_qf_quoteok_anshost ? pdf_quoteok : 0);
1306   if (st) return st;
1307
1308   if (cbyte != max) return adns_s_invaliddata;
1309   return adns_s_ok;
1310 }
1311
1312 static adns_status pa_srvha(const parseinfo *pai, int cbyte,
1313                             int max, void *datap) {
1314   adns_rr_srvha *rrp= datap;
1315   adns_status st;
1316
1317   st= pap_srv_begin(pai,&cbyte,max,datap);       if (st) return st;
1318   st= pap_hostaddr(pai, &cbyte, max, &rrp->ha);  if (st) return st;
1319   if (cbyte != max) return adns_s_invaliddata;
1320   return adns_s_ok;
1321 }
1322
1323 static void mf_srvraw(adns_query qu, void *datap) {
1324   adns_rr_srvraw *rrp= datap;
1325   adns__makefinal_str(qu, &rrp->host);
1326 }
1327
1328 static void mf_srvha(adns_query qu, void *datap) {
1329   adns_rr_srvha *rrp= datap;
1330   mfp_hostaddr(qu,&rrp->ha);
1331 }
1332
1333 static int di_srv(adns_state ads, const void *datap_a, const void *datap_b) {
1334   const adns_rr_srvraw *ap= datap_a, *bp= datap_b;
1335     /* might be const adns_rr_svhostaddr* */
1336
1337   if (ap->priority < bp->priority) return 0;
1338   if (ap->priority > bp->priority) return 1;
1339   return 0;
1340 }
1341
1342 static adns_status csp_srv_begin(vbuf *vb, const adns_rr_srvha *rrp
1343                                    /* might be adns_rr_srvraw* */) {
1344   char buf[30];
1345   sprintf(buf,"%u %u %u ", rrp->priority, rrp->weight, rrp->port);
1346   CSP_ADDSTR(buf);
1347   return adns_s_ok;
1348 }
1349
1350 static adns_status cs_srvraw(vbuf *vb, const void *datap) {
1351   const adns_rr_srvraw *rrp= datap;
1352   adns_status st;
1353
1354   st= csp_srv_begin(vb,(const void*)rrp);  if (st) return st;
1355   return csp_domain(vb,rrp->host);
1356 }
1357
1358 static adns_status cs_srvha(vbuf *vb, const void *datap) {
1359   const adns_rr_srvha *rrp= datap;
1360   adns_status st;
1361
1362   st= csp_srv_begin(vb,(const void*)datap);  if (st) return st;
1363   return csp_hostaddr(vb,&rrp->ha);
1364 }
1365
1366 static void postsort_srv(adns_state ads, void *array, int nrrs,int rrsz,
1367                          const struct typeinfo *typei) {
1368   /* we treat everything in the array as if it were an adns_rr_srvha
1369    * even though the array might be of adns_rr_srvraw.  That's OK
1370    * because they have the same prefix, which is all we access.
1371    * We use rrsz, too, rather than naive array indexing, of course.
1372    */
1373   char *workbegin, *workend, *search, *arrayend;
1374   const adns_rr_srvha *rr;
1375   union { adns_rr_srvha ha; adns_rr_srvraw raw; } rrtmp;
1376   int cpriority, totalweight, runtotal;
1377   long randval;
1378
1379   assert(rrsz <= sizeof(rrtmp));
1380   for (workbegin= array, arrayend= workbegin + rrsz * nrrs;
1381        workbegin < arrayend;
1382        workbegin= workend) {
1383     cpriority= (rr=(void*)workbegin)->priority;
1384
1385     for (workend= workbegin, totalweight= 0;
1386          workend < arrayend && (rr=(void*)workend)->priority == cpriority;
1387          workend += rrsz) {
1388       totalweight += rr->weight;
1389     }
1390
1391     /* Now workbegin..(workend-1) incl. are exactly all of the RRs of
1392      * cpriority.  From now on, workbegin points to the `remaining'
1393      * records: we select one record at a time (RFC2782 `Usage rules'
1394      * and `Format of the SRV RR' subsection `Weight') to place at
1395      * workbegin (swapping with the one that was there, and then
1396      * advance workbegin. */
1397     for (;
1398          workbegin + rrsz < workend; /* don't bother if just one */
1399          workbegin += rrsz) {
1400
1401       randval= nrand48(ads->rand48xsubi);
1402       randval %= (totalweight + 1);
1403         /* makes it into 0..totalweight inclusive; with 2^10 RRs,
1404          * totalweight must be <= 2^26 so probability nonuniformity is
1405          * no worse than 1 in 2^(31-26) ie 1 in 2^5, ie
1406          *  abs(log(P_intended(RR_i) / P_actual(RR_i)) <= log(2^-5).
1407          */
1408
1409       for (search=workbegin, runtotal=0;
1410            (runtotal += (rr=(void*)search)->weight) < randval;
1411            search += rrsz);
1412       assert(search < arrayend);
1413       totalweight -= rr->weight;
1414       if (search != workbegin) {
1415         memcpy(&rrtmp, workbegin, rrsz);
1416         memcpy(workbegin, search, rrsz);
1417         memcpy(search, &rrtmp, rrsz);
1418       }
1419     }
1420   }
1421   /* tests:
1422    *  dig -t srv _srv._tcp.test.iwj.relativity.greenend.org.uk.
1423    *   ./adnshost_s -t srv- _sip._udp.voip.net.cam.ac.uk.
1424    *   ./adnshost_s -t srv- _jabber._tcp.jabber.org
1425    */
1426 }
1427
1428 /*
1429  * _byteblock   (mf)
1430  */
1431
1432 static void mf_byteblock(adns_query qu, void *datap) {
1433   adns_rr_byteblock *rrp= datap;
1434   void *bytes= rrp->data;
1435   adns__makefinal_block(qu,&bytes,rrp->len);
1436   rrp->data= bytes;
1437 }
1438
1439 /*
1440  * _opaque   (pa,cs)
1441  */
1442
1443 static adns_status pa_opaque(const parseinfo *pai, int cbyte,
1444                              int max, void *datap) {
1445   adns_rr_byteblock *rrp= datap;
1446
1447   rrp->len= max - cbyte;
1448   rrp->data= adns__alloc_interim(pai->qu, rrp->len);
1449   if (!rrp->data) R_NOMEM;
1450   memcpy(rrp->data, pai->dgram + cbyte, rrp->len);
1451   return adns_s_ok;
1452 }
1453
1454 static adns_status cs_opaque(vbuf *vb, const void *datap) {
1455   const adns_rr_byteblock *rrp= datap;
1456   char buf[10];
1457   int l;
1458   unsigned char *p;
1459
1460   sprintf(buf,"\\# %d",rrp->len);
1461   CSP_ADDSTR(buf);
1462
1463   for (l= rrp->len, p= rrp->data;
1464        l>=4;
1465        l -= 4, p += 4) {
1466     sprintf(buf," %02x%02x%02x%02x",p[0],p[1],p[2],p[3]);
1467     CSP_ADDSTR(buf);
1468   }
1469   for (;
1470        l>0;
1471        l--, p++) {
1472     sprintf(buf," %02x",*p);
1473     CSP_ADDSTR(buf);
1474   }
1475   return adns_s_ok;
1476 }
1477
1478 /*
1479  * _flat   (mf)
1480  */
1481
1482 static void mf_flat(adns_query qu, void *data) { }
1483
1484 /*
1485  * Now the table.
1486  */
1487
1488 #define TYPESZ_M(member)           (sizeof(*((adns_answer*)0)->rrs.member))
1489
1490 #define DEEP_TYPE(code,rrt,fmt,memb,parser,comparer,/*printer*/...)     \
1491  { adns_r_##code&adns_rrt_reprmask, rrt,fmt,TYPESZ_M(memb), mf_##memb,  \
1492      GLUE(cs_, CAR(__VA_ARGS__)),pa_##parser,di_##comparer,             \
1493      adns__ckl_hostname, 0, adns__getrrsz_default, adns__query_send,    \
1494      CDR(__VA_ARGS__) }
1495 #define FLAT_TYPE(code,rrt,fmt,memb,parser,comparer,/*printer*/...)     \
1496  { adns_r_##code&adns_rrt_reprmask, rrt,fmt,TYPESZ_M(memb), mf_flat,    \
1497      GLUE(cs_, CAR(__VA_ARGS__)),pa_##parser,di_##comparer,             \
1498      adns__ckl_hostname, 0, adns__getrrsz_default, adns__query_send,    \
1499      CDR(__VA_ARGS__) }
1500
1501 #define di_0 0
1502
1503 static const typeinfo typeinfos[] = {
1504 /* Must be in ascending order of rrtype ! */
1505 /* mem-mgmt code  rrt     fmt   member   parser      comparer  printer */
1506
1507 FLAT_TYPE(a,      "A",     0,   inaddr,    inaddr,  inaddr,inaddr          ),
1508 DEEP_TYPE(ns_raw, "NS",   "raw",str,       host_raw,0,     domain          ),
1509 DEEP_TYPE(cname,  "CNAME", 0,   str,       dom_raw, 0,     domain          ),
1510 DEEP_TYPE(soa_raw,"SOA",  "raw",soa,       soa,     0,     soa             ),
1511 DEEP_TYPE(ptr_raw,"PTR",  "raw",str,       host_raw,0,     domain          ),
1512 DEEP_TYPE(hinfo,  "HINFO", 0,   intstrpair,hinfo,   0,     hinfo           ),
1513 DEEP_TYPE(mx_raw, "MX",   "raw",intstr,    mx_raw,  mx_raw,inthost         ),
1514 DEEP_TYPE(txt,    "TXT",   0,   manyistr,  txt,     0,     txt             ),
1515 DEEP_TYPE(rp_raw, "RP",   "raw",strpair,   rp,      0,     rp              ),
1516 FLAT_TYPE(aaaa,   "AAAA",  0,   in6addr,   in6addr, in6addr,in6addr        ),
1517 DEEP_TYPE(srv_raw,"SRV",  "raw",srvraw ,   srvraw,  srv,   srvraw,
1518                               .checklabel= ckl_srv, .postsort= postsort_srv),
1519
1520 FLAT_TYPE(addr,   "A",  "addr", addr,      addr,    addr,  addr,
1521                                    .getrrsz= gsz_addr, .query_send= qs_addr),
1522 DEEP_TYPE(ns,     "NS", "+addr",hostaddr,  hostaddr,hostaddr,hostaddr      ),
1523 DEEP_TYPE(ptr,    "PTR","checked",str,     ptr,     0,     domain,
1524                                                        .checklabel= ckl_ptr),
1525 DEEP_TYPE(mx,     "MX", "+addr",inthostaddr,mx,     mx,    inthostaddr,    ),
1526 DEEP_TYPE(srv,    "SRV","+addr",srvha,     srvha,   srv,   srvha,
1527                               .checklabel= ckl_srv, .postsort= postsort_srv),
1528
1529 DEEP_TYPE(soa,    "SOA","822",  soa,       soa,     0,     soa             ),
1530 DEEP_TYPE(rp,     "RP", "822",  strpair,   rp,      0,     rp              ),
1531 };
1532
1533 static const typeinfo tinfo_addrsub =
1534 FLAT_TYPE(none,   "<addr>","sub",addr,     addr,    0,     addr,
1535                                                          .getrrsz= gsz_addr);
1536
1537 static const typeinfo typeinfo_unknown=
1538 DEEP_TYPE(unknown,0, "unknown",byteblock,opaque,  0,     opaque            );
1539
1540 const typeinfo *adns__findtype(adns_rrtype type) {
1541   const typeinfo *begin, *end, *mid;
1542
1543   if (type & adns_r_unknown) return &typeinfo_unknown;
1544   type &= adns_rrt_reprmask;
1545
1546   begin= typeinfos;  end= typeinfos+(sizeof(typeinfos)/sizeof(typeinfo));
1547
1548   while (begin < end) {
1549     mid= begin + ((end-begin)>>1);
1550     if (mid->typekey == type) return mid;
1551     if (type > mid->typekey) begin= mid+1;
1552     else end= mid;
1553   }
1554   return 0;
1555 }