mdw@git.distorted.org.uk Git - adns/blob - src/setup.c

   1 /*
   2  * setup.c
   3  * - configuration file parsing
   4  * - management of global state
   5  */
   6 /*
   7  *  This file is part of adns, which is
   8  *    Copyright (C) 1997-2000,2003,2006,2014  Ian Jackson
   9  *    Copyright (C) 1999-2000,2003,2006  Tony Finch
  10  *    Copyright (C) 1991 Massachusetts Institute of Technology
  11  *  (See the file INSTALL for full details.)
  12  *
  13  *  This program is free software; you can redistribute it and/or modify
  14  *  it under the terms of the GNU General Public License as published by
  15  *  the Free Software Foundation; either version 3, or (at your option)
  16  *  any later version.
  17  *
  18  *  This program is distributed in the hope that it will be useful,
  19  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
  20  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  21  *  GNU General Public License for more details.
  22  *
  23  *  You should have received a copy of the GNU General Public License
  24  *  along with this program; if not, write to the Free Software Foundation.
  25  */
  26
  27 #include <stdlib.h>
  28 #include <errno.h>
  29 #include <limits.h>
  30 #include <unistd.h>
  31 #include <fcntl.h>
  32
  33 #include <sys/types.h>
  34 #include <netdb.h>
  35 #include <sys/socket.h>
  36 #include <netinet/in.h>
  37 #include <arpa/inet.h>
  38
  39 #include "internal.h"
  40
  41 static void readconfig(adns_state ads, const char *filename, int warnmissing);
  42
  43 static void addserver(adns_state ads, const struct sockaddr *sa, int salen) {
  44   int i;
  45   adns_rr_addr *ss;
  46   char buf[ADNS_ADDR2TEXT_BUFLEN];
  47
  48   for (i=0; i<ads->nservers; i++) {
  49     if (adns__sockaddrs_equal(sa, &ads->servers[i].addr.sa)) {
  50       adns__debug(ads,-1,0,"duplicate nameserver %s ignored",
  51                   adns__sockaddr_ntoa(sa, buf));
  52       return;
  53     }
  54   }
  55
  56   if (ads->nservers>=MAXSERVERS) {
  57     adns__diag(ads,-1,0,"too many nameservers, ignoring %s",
  58                adns__sockaddr_ntoa(sa, buf));
  59     return;
  60   }
  61
  62   ss= ads->servers+ads->nservers;
  63   assert(salen <= sizeof(ss->addr));
  64   ss->len = salen;
  65   memcpy(&ss->addr, sa, salen);
  66   ads->nservers++;
  67 }
  68
  69 static void freesearchlist(adns_state ads) {
  70   if (ads->nsearchlist) free(*ads->searchlist);
  71   free(ads->searchlist);
  72 }
  73
  74 static void saveerr(adns_state ads, int en) {
  75   if (!ads->configerrno) ads->configerrno= en;
  76 }
  77
  78 static void configparseerr(adns_state ads, const char *fn, int lno,
  79                            const char *fmt, ...) {
  80   va_list al;
  81
  82   saveerr(ads,EINVAL);
  83   if (!ads->logfn || (ads->iflags & adns_if_noerrprint)) return;
  84
  85   if (lno==-1) adns__lprintf(ads,"adns: %s: ",fn);
  86   else adns__lprintf(ads,"adns: %s:%d: ",fn,lno);
  87   va_start(al,fmt);
  88   adns__vlprintf(ads,fmt,al);
  89   va_end(al);
  90   adns__lprintf(ads,"\n");
  91 }
  92
  93 static int nextword(const char **bufp_io, const char **word_r, int *l_r) {
  94   const char *p, *q;
  95
  96   p= *bufp_io;
  97   while (ctype_whitespace(*p)) p++;
  98   if (!*p) return 0;
  99
 100   q= p;
 101   while (*q && !ctype_whitespace(*q)) q++;
 102
 103   *l_r= q-p;
 104   *word_r= p;
 105   *bufp_io= q;
 106
 107   return 1;
 108 }
 109
 110 static void ccf_nameserver(adns_state ads, const char *fn,
 111                            int lno, const char *buf) {
 112   adns_rr_addr a;
 113   char addrbuf[ADNS_ADDR2TEXT_BUFLEN];
 114   int err;
 115
 116   a.len= sizeof(a.addr);
 117   err= adns_text2addr(buf,DNS_PORT, 0, &a.addr.sa,&a.len);
 118   switch (err) {
 119   case 0:
 120     break;
 121   case EINVAL:
 122     configparseerr(ads,fn,lno,"invalid nameserver address `%s'",buf);
 123     return;
 124   default:
 125     configparseerr(ads,fn,lno,"failed to parse nameserver address `%s': %s",
 126                    buf,strerror(err));
 127     return;
 128   }
 129   adns__debug(ads,-1,0,"using nameserver %s",
 130               adns__sockaddr_ntoa(&a.addr.sa, addrbuf));
 131   addserver(ads,&a.addr.sa,a.len);
 132 }
 133
 134 static void ccf_search(adns_state ads, const char *fn,
 135                        int lno, const char *buf) {
 136   const char *bufp, *word;
 137   char *newchars, **newptrs, **pp;
 138   int count, tl, l;
 139
 140   if (!buf) return;
 141
 142   bufp= buf;
 143   count= 0;
 144   tl= 0;
 145   while (nextword(&bufp,&word,&l)) { count++; tl += l+1; }
 146
 147   newptrs= malloc(sizeof(char*)*count);
 148   if (!newptrs) { saveerr(ads,errno); return; }
 149
 150   newchars= malloc(tl);
 151   if (!newchars) { saveerr(ads,errno); free(newptrs); return; }
 152
 153   bufp= buf;
 154   pp= newptrs;
 155   while (nextword(&bufp,&word,&l)) {
 156     *pp++= newchars;
 157     memcpy(newchars,word,l);
 158     newchars += l;
 159     *newchars++ = 0;
 160   }
 161
 162   freesearchlist(ads);
 163   ads->nsearchlist= count;
 164   ads->searchlist= newptrs;
 165 }
 166
 167 static int gen_pton(const char *text, int want_af, adns_sockaddr *a) {
 168   int err;
 169   int len;
 170
 171   len= sizeof(*a);
 172   err= adns_text2addr(text,0, adns_qf_addrlit_scope_forbid,
 173                       &a->sa, &len);
 174   if (err) { assert(err == EINVAL); return 0; }
 175   if (want_af != AF_UNSPEC && a->sa.sa_family != want_af) return 0;
 176   return 1;
 177 }
 178
 179 static void ccf_sortlist(adns_state ads, const char *fn,
 180                          int lno, const char *buf) {
 181   const char *word;
 182   char tbuf[200], *slash, *ep;
 183   const char *maskwhat;
 184   struct sortlist *sl;
 185   int l;
 186   int initial= -1;
 187
 188   if (!buf) return;
 189
 190   ads->nsortlist= 0;
 191   while (nextword(&buf,&word,&l)) {
 192     if (ads->nsortlist >= MAXSORTLIST) {
 193       adns__diag(ads,-1,0,"too many sortlist entries,"
 194                  " ignoring %.*s onwards",l,word);
 195       return;
 196     }
 197
 198     if (l >= sizeof(tbuf)) {
 199       configparseerr(ads,fn,lno,"sortlist entry `%.*s' too long",l,word);
 200       continue;
 201     }
 202
 203     memcpy(tbuf,word,l); tbuf[l]= 0;
 204     slash= strchr(tbuf,'/');
 205     if (slash) *slash++= 0;
 206
 207     sl= &ads->sortlist[ads->nsortlist];
 208     if (!gen_pton(tbuf, AF_UNSPEC, &sl->base)) {
 209       configparseerr(ads,fn,lno,"invalid address `%s' in sortlist",tbuf);
 210       continue;
 211     }
 212
 213     if (slash) {
 214       if (slash[strspn(slash, "0123456789")]) {
 215         maskwhat = "mask";
 216         if (!gen_pton(slash, sl->base.sa.sa_family, &sl->mask)) {
 217           configparseerr(ads,fn,lno,"invalid mask `%s' in sortlist",slash);
 218           continue;
 219         }
 220       } else {
 221         maskwhat = "prefix length";
 222         initial= strtoul(slash,&ep,10);
 223         if (*ep || initial>adns__addr_width(sl->base.sa.sa_family)) {
 224           configparseerr(ads,fn,lno,"mask length `%s' invalid",slash);
 225           continue;
 226         }
 227         sl->mask.sa.sa_family= sl->base.sa.sa_family;
 228         adns__prefix_mask(&sl->mask, initial);
 229       }
 230     } else {
 231       maskwhat = "implied prefix length";
 232       initial= adns__guess_prefix_length(&sl->base);
 233       if (initial < 0) {
 234         configparseerr(ads,fn,lno, "network address `%s'"
 235                        " in sortlist is not in classed ranges,"
 236                        " must specify mask explicitly", tbuf);
 237         continue;
 238       }
 239       sl->mask.sa.sa_family= sl->base.sa.sa_family;
 240       adns__prefix_mask(&sl->mask, initial);
 241     }
 242
 243     if (!adns__addr_matches(sl->base.sa.sa_family,
 244                             adns__sockaddr_addr(&sl->base.sa),
 245                             &sl->base,&sl->mask)) {
 246       if (initial >= 0) {
 247         configparseerr(ads,fn,lno, "%s %d in sortlist"
 248                        " overlaps address `%s'",maskwhat,initial,tbuf);
 249       } else {
 250         configparseerr(ads,fn,lno, "%s `%s' in sortlist"
 251                        " overlaps address `%s'",maskwhat,slash,tbuf);
 252       }
 253       continue;
 254     }
 255
 256     ads->nsortlist++;
 257   }
 258 }
 259
 260 static void ccf_options(adns_state ads, const char *fn,
 261                         int lno, const char *buf) {
 262   const char *word;
 263   char *ep;
 264   unsigned long v;
 265   int i,l;
 266
 267   if (!buf) return;
 268
 269   while (nextword(&buf,&word,&l)) {
 270     if (l==5 && !memcmp(word,"debug",5)) {
 271       ads->iflags |= adns_if_debug;
 272       continue;
 273     }
 274     if (l>=6 && !memcmp(word,"ndots:",6)) {
 275       v= strtoul(word+6,&ep,10);
 276       if (l==6 || ep != word+l || v > INT_MAX) {
 277         configparseerr(ads,fn,lno,"option `%.*s' malformed"
 278                        " or has bad value",l,word);
 279         continue;
 280       }
 281       ads->searchndots= v;
 282       continue;
 283     }
 284     if (l>=12 && !memcmp(word,"adns_checkc:",12)) {
 285       if (!strcmp(word+12,"none")) {
 286         ads->iflags &= ~adns_if_checkc_freq;
 287         ads->iflags |= adns_if_checkc_entex;
 288       } else if (!strcmp(word+12,"entex")) {
 289         ads->iflags &= ~adns_if_checkc_freq;
 290         ads->iflags |= adns_if_checkc_entex;
 291       } else if (!strcmp(word+12,"freq")) {
 292         ads->iflags |= adns_if_checkc_freq;
 293       } else {
 294         configparseerr(ads,fn,lno, "option adns_checkc has bad value `%s' "
 295                        "(must be none, entex or freq", word+12);
 296       }
 297       continue;
 298     }
 299     if (l>=8 && !memcmp(word,"adns_af:",8)) {
 300       word += 8;
 301       ads->iflags &= ~adns_if_afmask;
 302       if (strcmp(word,"any")) for (;;) {
 303         i= strcspn(word,",");
 304         if (i>=4 && !memcmp(word,"ipv4",4))
 305           ads->iflags |= adns_if_permit_ipv4;
 306         else if (i>=4 && !memcmp(word,"ipv6",4))
 307           ads->iflags |= adns_if_permit_ipv6;
 308         else {
 309           configparseerr(ads,fn,lno, "option adns_af has bad value `%.*s' "
 310                          "(must be `any' or list {`ipv4',`ipv6'},...)",
 311                          i, word);
 312           break;
 313         }
 314         if (!word[i]) break;
 315         word= word + i + 1;
 316       }
 317       continue;
 318     }
 319     adns__diag(ads,-1,0,"%s:%d: unknown option `%.*s'", fn,lno, l,word);
 320   }
 321 }
 322
 323 static void ccf_clearnss(adns_state ads, const char *fn,
 324                          int lno, const char *buf) {
 325   ads->nservers= 0;
 326 }
 327
 328 static void ccf_include(adns_state ads, const char *fn,
 329                         int lno, const char *buf) {
 330   if (!*buf) {
 331     configparseerr(ads,fn,lno,"`include' directive with no filename");
 332     return;
 333   }
 334   readconfig(ads,buf,1);
 335 }
 336
 337 static void ccf_lookup(adns_state ads, const char *fn, int lno,
 338                        const char *buf) {
 339   int found_bind=0;
 340   const char *word;
 341   int l;
 342
 343   if (!*buf) {
 344     configparseerr(ads,fn,lno,"`lookup' directive with no databases");
 345     return;
 346   }
 347
 348   while (nextword(&buf,&word,&l)) {
 349     if (l==4 && !memcmp(word,"bind",4)) {
 350       found_bind=1;
 351     } else if (l==4 && !memcmp(word,"file",4)) {
 352       /* ignore this and hope /etc/hosts is not essential */
 353     } else if (l==2 && !memcmp(word,"yp",2)) {
 354       adns__diag(ads,-1,0,"%s:%d: yp lookups not supported by adns", fn,lno);
 355       found_bind=-1;
 356     } else {
 357       adns__diag(ads,-1,0,"%s:%d: unknown `lookup' database `%.*s'",
 358                  fn,lno, l,word);
 359       found_bind=-1;
 360     }
 361   }
 362   if (!found_bind)
 363     adns__diag(ads,-1,0,"%s:%d: `lookup' specified, but not `bind'", fn,lno);
 364 }
 365
 366 static const struct configcommandinfo {
 367   const char *name;
 368   void (*fn)(adns_state ads, const char *fn, int lno, const char *buf);
 369 } configcommandinfos[]= {
 370   { "nameserver",        ccf_nameserver  },
 371   { "domain",            ccf_search      },
 372   { "search",            ccf_search      },
 373   { "sortlist",          ccf_sortlist    },
 374   { "options",           ccf_options     },
 375   { "clearnameservers",  ccf_clearnss    },
 376   { "include",           ccf_include     },
 377   { "lookup",            ccf_lookup      }, /* OpenBSD */
 378   {  0                                   }
 379 };
 380
 381 typedef union {
 382   FILE *file;
 383   const char *text;
 384 } getline_ctx;
 385
 386 static int gl_file(adns_state ads, getline_ctx *src_io, const char *filename,
 387                    int lno, char *buf, int buflen) {
 388   FILE *file= src_io->file;
 389   int c, i;
 390   char *p;
 391
 392   p= buf;
 393   buflen--;
 394   i= 0;
 395
 396   for (;;) { /* loop over chars */
 397     if (i == buflen) {
 398       adns__diag(ads,-1,0,"%s:%d: line too long, ignored",filename,lno);
 399       goto x_badline;
 400     }
 401     c= getc(file);
 402     if (!c) {
 403       adns__diag(ads,-1,0,"%s:%d: line contains nul, ignored",filename,lno);
 404       goto x_badline;
 405     } else if (c == '\n') {
 406       break;
 407     } else if (c == EOF) {
 408       if (ferror(file)) {
 409         saveerr(ads,errno);
 410         adns__diag(ads,-1,0,"%s:%d: read error: %s",
 411                    filename,lno,strerror(errno));
 412         return -1;
 413       }
 414       if (!i) return -1;
 415       break;
 416     } else {
 417       *p++= c;
 418       i++;
 419     }
 420   }
 421
 422   *p++= 0;
 423   return i;
 424
 425  x_badline:
 426   saveerr(ads,EINVAL);
 427   while ((c= getc(file)) != EOF && c != '\n');
 428   return -2;
 429 }
 430
 431 static int gl_text(adns_state ads, getline_ctx *src_io, const char *filename,
 432                    int lno, char *buf, int buflen) {
 433   const char *cp= src_io->text;
 434   int l;
 435
 436   if (!cp || !*cp) return -1;
 437
 438   if (*cp == ';' || *cp == '\n') cp++;
 439   l= strcspn(cp,";\n");
 440   src_io->text = cp+l;
 441
 442   if (l >= buflen) {
 443     adns__diag(ads,-1,0,"%s:%d: line too long, ignored",filename,lno);
 444     saveerr(ads,EINVAL);
 445     return -2;
 446   }
 447
 448   memcpy(buf,cp,l);
 449   buf[l]= 0;
 450   return l;
 451 }
 452
 453 static void readconfiggeneric(adns_state ads, const char *filename,
 454                               int (*getline)(adns_state ads, getline_ctx*,
 455                                              const char *filename, int lno,
 456                                              char *buf, int buflen),
 457                               /* Returns >=0 for success, -1 for EOF or error
 458                                * (error will have been reported), or -2 for
 459                                * bad line was encountered, try again.
 460                                */
 461                               getline_ctx gl_ctx) {
 462   char linebuf[2000], *p, *q;
 463   int lno, l, dirl;
 464   const struct configcommandinfo *ccip;
 465
 466   for (lno=1;
 467        (l= getline(ads,&gl_ctx, filename,lno, linebuf,sizeof(linebuf))) != -1;
 468        lno++) {
 469     if (l == -2) continue;
 470     while (l>0 && ctype_whitespace(linebuf[l-1])) l--;
 471     linebuf[l]= 0;
 472     p= linebuf;
 473     while (ctype_whitespace(*p)) p++;
 474     if (*p == '#' || *p == ';' || !*p) continue;
 475     q= p;
 476     while (*q && !ctype_whitespace(*q)) q++;
 477     dirl= q-p;
 478     for (ccip=configcommandinfos;
 479          ccip->name &&
 480            !(strlen(ccip->name)==dirl && !memcmp(ccip->name,p,q-p));
 481          ccip++);
 482     if (!ccip->name) {
 483       adns__diag(ads,-1,0,"%s:%d: unknown configuration directive `%.*s'",
 484                  filename,lno,(int)(q-p),p);
 485       continue;
 486     }
 487     while (ctype_whitespace(*q)) q++;
 488     ccip->fn(ads,filename,lno,q);
 489   }
 490 }
 491
 492 static const char *instrum_getenv(adns_state ads, const char *envvar) {
 493   const char *value;
 494
 495   value= getenv(envvar);
 496   if (!value) adns__debug(ads,-1,0,"environment variable %s not set",envvar);
 497   else adns__debug(ads,-1,0,"environment variable %s"
 498                    " set to `%s'",envvar,value);
 499   return value;
 500 }
 501
 502 static void readconfig(adns_state ads, const char *filename, int warnmissing) {
 503   getline_ctx gl_ctx;
 504
 505   gl_ctx.file= fopen(filename,"r");
 506   if (!gl_ctx.file) {
 507     if (errno == ENOENT) {
 508       if (warnmissing)
 509         adns__debug(ads,-1,0, "configuration file"
 510                     " `%s' does not exist",filename);
 511       return;
 512     }
 513     saveerr(ads,errno);
 514     adns__diag(ads,-1,0,"cannot open configuration file `%s': %s",
 515                filename,strerror(errno));
 516     return;
 517   }
 518
 519   readconfiggeneric(ads,filename,gl_file,gl_ctx);
 520
 521   fclose(gl_ctx.file);
 522 }
 523
 524 static void readconfigtext(adns_state ads, const char *text,
 525                            const char *showname) {
 526   getline_ctx gl_ctx;
 527
 528   gl_ctx.text= text;
 529   readconfiggeneric(ads,showname,gl_text,gl_ctx);
 530 }
 531
 532 static void readconfigenv(adns_state ads, const char *envvar) {
 533   const char *filename;
 534
 535   if (ads->iflags & adns_if_noenv) {
 536     adns__debug(ads,-1,0,"not checking environment variable `%s'",envvar);
 537     return;
 538   }
 539   filename= instrum_getenv(ads,envvar);
 540   if (filename) readconfig(ads,filename,1);
 541 }
 542
 543 static void readconfigenvtext(adns_state ads, const char *envvar) {
 544   const char *textdata;
 545
 546   if (ads->iflags & adns_if_noenv) {
 547     adns__debug(ads,-1,0,"not checking environment variable `%s'",envvar);
 548     return;
 549   }
 550   textdata= instrum_getenv(ads,envvar);
 551   if (textdata) readconfigtext(ads,textdata,envvar);
 552 }
 553
 554
 555 int adns__setnonblock(adns_state ads, int fd) {
 556   int r;
 557
 558   r= fcntl(fd,F_GETFL,0); if (r<0) return errno;
 559   r |= O_NONBLOCK;
 560   r= fcntl(fd,F_SETFL,r); if (r<0) return errno;
 561   return 0;
 562 }
 563
 564 static int init_begin(adns_state *ads_r, adns_initflags flags,
 565                       adns_logcallbackfn *logfn, void *logfndata) {
 566   adns_state ads;
 567   pid_t pid;
 568
 569   ads= malloc(sizeof(*ads)); if (!ads) return errno;
 570
 571   ads->iflags= flags;
 572   ads->logfn= logfn;
 573   ads->logfndata= logfndata;
 574   ads->configerrno= 0;
 575   LIST_INIT(ads->udpw);
 576   LIST_INIT(ads->tcpw);
 577   LIST_INIT(ads->childw);
 578   LIST_INIT(ads->output);
 579   LIST_INIT(ads->intdone);
 580   ads->forallnext= 0;
 581   ads->nextid= 0x311f;
 582   ads->nudpsockets= 0;
 583   ads->tcpsocket= -1;
 584   adns__vbuf_init(&ads->tcpsend);
 585   adns__vbuf_init(&ads->tcprecv);
 586   ads->tcprecv_skip= 0;
 587   ads->nservers= ads->nsortlist= ads->nsearchlist= ads->tcpserver= 0;
 588   ads->searchndots= 1;
 589   ads->tcpstate= server_disconnected;
 590   timerclear(&ads->tcptimeout);
 591   ads->searchlist= 0;
 592
 593   pid= getpid();
 594   ads->rand48xsubi[0]= pid;
 595   ads->rand48xsubi[1]= (unsigned long)pid >> 16;
 596   ads->rand48xsubi[2]= pid ^ ((unsigned long)pid >> 16);
 597
 598   *ads_r= ads;
 599   return 0;
 600 }
 601
 602 static int init_finish(adns_state ads) {
 603   struct sockaddr_in sin;
 604   struct protoent *proto;
 605   struct udpsocket *udp;
 606   int i;
 607   int r;
 608
 609   if (!ads->nservers) {
 610     if (ads->logfn && ads->iflags & adns_if_debug)
 611       adns__lprintf(ads,"adns: no nameservers, using IPv4 localhost\n");
 612     memset(&sin, 0, sizeof(sin));
 613     sin.sin_family = AF_INET;
 614     sin.sin_port = htons(DNS_PORT);
 615     sin.sin_addr.s_addr = htonl(INADDR_LOOPBACK);
 616     addserver(ads,(struct sockaddr *)&sin, sizeof(sin));
 617   }
 618
 619   proto= getprotobyname("udp"); if (!proto) { r= ENOPROTOOPT; goto x_free; }
 620   ads->nudpsockets= 0;
 621   for (i=0; i<ads->nservers; i++) {
 622     if (adns__udpsocket_by_af(ads, ads->servers[i].addr.sa.sa_family))
 623       continue;
 624     assert(ads->nudpsockets < MAXUDP);
 625     udp= &ads->udpsockets[ads->nudpsockets];
 626     udp->af= ads->servers[i].addr.sa.sa_family;
 627     udp->fd= socket(udp->af,SOCK_DGRAM,proto->p_proto);
 628     if (udp->fd < 0) { r= errno; goto x_free; }
 629     ads->nudpsockets++;
 630     r= adns__setnonblock(ads,udp->fd);
 631     if (r) { r= errno; goto x_closeudp; }
 632   }
 633
 634   return 0;
 635
 636  x_closeudp:
 637   for (i=0; i<ads->nudpsockets; i++) close(ads->udpsockets[i].fd);
 638  x_free:
 639   free(ads);
 640   return r;
 641 }
 642
 643 static void init_abort(adns_state ads) {
 644   if (ads->nsearchlist) {
 645     free(ads->searchlist[0]);
 646     free(ads->searchlist);
 647   }
 648   free(ads);
 649 }
 650
 651 static void logfn_file(adns_state ads, void *logfndata,
 652                        const char *fmt, va_list al) {
 653   vfprintf(logfndata,fmt,al);
 654 }
 655
 656 static int init_files(adns_state *ads_r, adns_initflags flags,
 657                       adns_logcallbackfn *logfn, void *logfndata) {
 658   adns_state ads;
 659   const char *res_options, *adns_res_options;
 660   int r;
 661
 662   r= init_begin(&ads, flags, logfn, logfndata);
 663   if (r) return r;
 664
 665   res_options= instrum_getenv(ads,"RES_OPTIONS");
 666   adns_res_options= instrum_getenv(ads,"ADNS_RES_OPTIONS");
 667   ccf_options(ads,"RES_OPTIONS",-1,res_options);
 668   ccf_options(ads,"ADNS_RES_OPTIONS",-1,adns_res_options);
 669
 670   readconfig(ads,"/etc/resolv.conf",1);
 671   readconfig(ads,"/etc/resolv-adns.conf",0);
 672   readconfigenv(ads,"RES_CONF");
 673   readconfigenv(ads,"ADNS_RES_CONF");
 674
 675   readconfigenvtext(ads,"RES_CONF_TEXT");
 676   readconfigenvtext(ads,"ADNS_RES_CONF_TEXT");
 677
 678   ccf_options(ads,"RES_OPTIONS",-1,res_options);
 679   ccf_options(ads,"ADNS_RES_OPTIONS",-1,adns_res_options);
 680
 681   ccf_search(ads,"LOCALDOMAIN",-1,instrum_getenv(ads,"LOCALDOMAIN"));
 682   ccf_search(ads,"ADNS_LOCALDOMAIN",-1,instrum_getenv(ads,"ADNS_LOCALDOMAIN"));
 683
 684   if (ads->configerrno && ads->configerrno != EINVAL) {
 685     r= ads->configerrno;
 686     init_abort(ads);
 687     return r;
 688   }
 689
 690   r= init_finish(ads);
 691   if (r) return r;
 692
 693   adns__consistency(ads,0,cc_entex);
 694   *ads_r= ads;
 695   return 0;
 696 }
 697
 698 int adns_init(adns_state *ads_r, adns_initflags flags, FILE *diagfile) {
 699   return init_files(ads_r, flags, logfn_file, diagfile ? diagfile : stderr);
 700 }
 701
 702 static int init_strcfg(adns_state *ads_r, adns_initflags flags,
 703                        adns_logcallbackfn *logfn, void *logfndata,
 704                        const char *configtext) {
 705   adns_state ads;
 706   int r;
 707
 708   r= init_begin(&ads, flags, logfn, logfndata);
 709   if (r) return r;
 710
 711   readconfigtext(ads,configtext,"<supplied configuration text>");
 712   if (ads->configerrno) {
 713     r= ads->configerrno;
 714     init_abort(ads);
 715     return r;
 716   }
 717
 718   r= init_finish(ads);  if (r) return r;
 719   adns__consistency(ads,0,cc_entex);
 720   *ads_r= ads;
 721   return 0;
 722 }
 723
 724 int adns_init_strcfg(adns_state *ads_r, adns_initflags flags,
 725                      FILE *diagfile, const char *configtext) {
 726   return init_strcfg(ads_r, flags,
 727                      diagfile ? logfn_file : 0, diagfile,
 728                      configtext);
 729 }
 730
 731 int adns_init_logfn(adns_state *newstate_r, adns_initflags flags,
 732                     const char *configtext /*0=>use default config files*/,
 733                     adns_logcallbackfn *logfn /*0=>logfndata is a FILE* */,
 734                     void *logfndata /*0 with logfn==0 => discard*/) {
 735   if (!logfn && logfndata)
 736     logfn= logfn_file;
 737   if (configtext)
 738     return init_strcfg(newstate_r, flags, logfn, logfndata, configtext);
 739   else
 740     return init_files(newstate_r, flags, logfn, logfndata);
 741 }
 742
 743 void adns_finish(adns_state ads) {
 744   int i;
 745   adns__consistency(ads,0,cc_entex);
 746   for (;;) {
 747     if (ads->udpw.head) adns__cancel(ads->udpw.head);
 748     else if (ads->tcpw.head) adns__cancel(ads->tcpw.head);
 749     else if (ads->childw.head) adns__cancel(ads->childw.head);
 750     else if (ads->output.head) adns__cancel(ads->output.head);
 751     else if (ads->intdone.head) adns__cancel(ads->output.head);
 752     else break;
 753   }
 754   for (i=0; i<ads->nudpsockets; i++) close(ads->udpsockets[i].fd);
 755   if (ads->tcpsocket >= 0) close(ads->tcpsocket);
 756   adns__vbuf_free(&ads->tcpsend);
 757   adns__vbuf_free(&ads->tcprecv);
 758   freesearchlist(ads);
 759   free(ads);
 760 }
 761
 762 void adns_forallqueries_begin(adns_state ads) {
 763   adns__consistency(ads,0,cc_entex);
 764   ads->forallnext=
 765     ads->udpw.head ? ads->udpw.head :
 766     ads->tcpw.head ? ads->tcpw.head :
 767     ads->childw.head ? ads->childw.head :
 768     ads->output.head;
 769 }
 770
 771 adns_query adns_forallqueries_next(adns_state ads, void **context_r) {
 772   adns_query qu, nqu;
 773
 774   adns__consistency(ads,0,cc_entex);
 775   nqu= ads->forallnext;
 776   for (;;) {
 777     qu= nqu;
 778     if (!qu) return 0;
 779     if (qu->next) {
 780       nqu= qu->next;
 781     } else if (qu == ads->udpw.tail) {
 782       nqu=
 783         ads->tcpw.head ? ads->tcpw.head :
 784         ads->childw.head ? ads->childw.head :
 785         ads->output.head;
 786     } else if (qu == ads->tcpw.tail) {
 787       nqu=
 788         ads->childw.head ? ads->childw.head :
 789         ads->output.head;
 790     } else if (qu == ads->childw.tail) {
 791       nqu= ads->output.head;
 792     } else {
 793       nqu= 0;
 794     }
 795     if (!qu->parent) break;
 796   }
 797   ads->forallnext= nqu;
 798   if (context_r) *context_r= qu->ctx.ext;
 799   return qu;
 800 }