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  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 2, or (at your option)
  16  *  any later version.
  17  *
  18  *  This program is distributed in the hope that it will be useful,
  19  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
  20  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  21  *  GNU General Public License for more details.
  22  *
  23  *  You should have received a copy of the GNU General Public License
  24  *  along with this program; if not, write to the Free Software Foundation,
  25  *  Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
  26  */
  27
  28 #include <stdlib.h>
  29 #include <errno.h>
  30 #include <limits.h>
  31 #include <unistd.h>
  32 #include <fcntl.h>
  33
  34 #include <sys/types.h>
  35 #include <netdb.h>
  36 #include <sys/socket.h>
  37 #include <netinet/in.h>
  38 #include <arpa/inet.h>
  39
  40 #include "internal.h"
  41
  42 static void readconfig(adns_state ads, const char *filename, int warnmissing);
  43
  44 static void addserver(adns_state ads, const struct sockaddr *sa, int n) {
  45   int i;
  46   adns_rr_addr *ss;
  47   char buf[ADNS_ADDR2TEXT_BUFLEN];
  48
  49   for (i=0; i<ads->nservers; i++) {
  50     if (adns__sockaddr_equal_p(sa, &ads->servers[i].addr.sa)) {
  51       adns__debug(ads,-1,0,"duplicate nameserver %s ignored",
  52                   adns__sockaddr_ntoa(sa, buf));
  53       return;
  54     }
  55   }
  56
  57   if (ads->nservers>=MAXSERVERS) {
  58     adns__diag(ads,-1,0,"too many nameservers, ignoring %s",
  59                adns__sockaddr_ntoa(sa, buf));
  60     return;
  61   }
  62
  63   ss= ads->servers+ads->nservers;
  64   assert(n <= sizeof(ss->addr));
  65   ss->len = n;
  66   memcpy(&ss->addr, sa, n);
  67   ads->nservers++;
  68 }
  69
  70 static void freesearchlist(adns_state ads) {
  71   if (ads->nsearchlist) free(*ads->searchlist);
  72   free(ads->searchlist);
  73 }
  74
  75 static void saveerr(adns_state ads, int en) {
  76   if (!ads->configerrno) ads->configerrno= en;
  77 }
  78
  79 static void configparseerr(adns_state ads, const char *fn, int lno,
  80                            const char *fmt, ...) {
  81   va_list al;
  82
  83   saveerr(ads,EINVAL);
  84   if (!ads->logfn || (ads->iflags & adns_if_noerrprint)) return;
  85
  86   if (lno==-1) adns__lprintf(ads,"adns: %s: ",fn);
  87   else adns__lprintf(ads,"adns: %s:%d: ",fn,lno);
  88   va_start(al,fmt);
  89   adns__vlprintf(ads,fmt,al);
  90   va_end(al);
  91   adns__lprintf(ads,"\n");
  92 }
  93
  94 static int nextword(const char **bufp_io, const char **word_r, int *l_r) {
  95   const char *p, *q;
  96
  97   p= *bufp_io;
  98   while (ctype_whitespace(*p)) p++;
  99   if (!*p) return 0;
 100
 101   q= p;
 102   while (*q && !ctype_whitespace(*q)) q++;
 103
 104   *l_r= q-p;
 105   *word_r= p;
 106   *bufp_io= q;
 107
 108   return 1;
 109 }
 110
 111 static void ccf_nameserver(adns_state ads, const char *fn,
 112                            int lno, const char *buf) {
 113   adns_rr_addr a;
 114   char addrbuf[ADNS_ADDR2TEXT_BUFLEN];
 115   int err;
 116
 117   a.len= sizeof(a.addr);
 118   err= adns_text2addr(buf,DNS_PORT, 0, &a.addr.sa,&a.len);
 119   switch (err) {
 120   case 0:
 121     break;
 122   case EINVAL:
 123     configparseerr(ads,fn,lno,"invalid nameserver address `%s'",buf);
 124     return;
 125   default:
 126     configparseerr(ads,fn,lno,"failed to parse nameserver address `%s': %s",
 127                    buf,strerror(err));
 128     return;
 129   }
 130   adns__debug(ads,-1,0,"using nameserver %s",
 131               adns__sockaddr_ntoa(&a.addr.sa, addrbuf));
 132   addserver(ads,&a.addr.sa,a.len);
 133 }
 134
 135 static void ccf_search(adns_state ads, const char *fn,
 136                        int lno, const char *buf) {
 137   const char *bufp, *word;
 138   char *newchars, **newptrs, **pp;
 139   int count, tl, l;
 140
 141   if (!buf) return;
 142
 143   bufp= buf;
 144   count= 0;
 145   tl= 0;
 146   while (nextword(&bufp,&word,&l)) { count++; tl += l+1; }
 147
 148   newptrs= malloc(sizeof(char*)*count);
 149   if (!newptrs) { saveerr(ads,errno); return; }
 150
 151   newchars= malloc(tl);
 152   if (!newchars) { saveerr(ads,errno); free(newptrs); return; }
 153
 154   bufp= buf;
 155   pp= newptrs;
 156   while (nextword(&bufp,&word,&l)) {
 157     *pp++= newchars;
 158     memcpy(newchars,word,l);
 159     newchars += l;
 160     *newchars++ = 0;
 161   }
 162
 163   freesearchlist(ads);
 164   ads->nsearchlist= count;
 165   ads->searchlist= newptrs;
 166 }
 167
 168 static int gen_pton(const char *text, int *af_io, union gen_addr *a) {
 169   adns_rr_addr addr;
 170   int err;
 171
 172   addr.len= sizeof(addr.addr);
 173   err= adns_text2addr(text,0, adns_qf_addrlit_scope_forbid,
 174                       &addr.addr.sa, &addr.len);
 175   if (err) { assert(err == EINVAL); return 0; }
 176   if (*af_io == AF_UNSPEC) *af_io= addr.addr.sa.sa_family;
 177   else if (*af_io != addr.addr.sa.sa_family) return 0;
 178   adns__sockaddr_extract(&addr.addr.sa, a, 0);
 179   return 1;
 180 }
 181
 182 static void ccf_sortlist(adns_state ads, const char *fn,
 183                          int lno, const char *buf) {
 184   const char *word;
 185   char tbuf[200], *slash, *ep;
 186   const char *maskwhat;
 187   struct sortlist *sl;
 188   int l;
 189   int af;
 190   int initial= -1;
 191
 192   if (!buf) return;
 193
 194   ads->nsortlist= 0;
 195   while (nextword(&buf,&word,&l)) {
 196     if (ads->nsortlist >= MAXSORTLIST) {
 197       adns__diag(ads,-1,0,"too many sortlist entries,"
 198                  " ignoring %.*s onwards",l,word);
 199       return;
 200     }
 201
 202     if (l >= sizeof(tbuf)) {
 203       configparseerr(ads,fn,lno,"sortlist entry `%.*s' too long",l,word);
 204       continue;
 205     }
 206
 207     memcpy(tbuf,word,l); tbuf[l]= 0;
 208     slash= strchr(tbuf,'/');
 209     if (slash) *slash++= 0;
 210
 211     sl= &ads->sortlist[ads->nsortlist];
 212     af= AF_UNSPEC;
 213     if (!gen_pton(tbuf, &af, &sl->base)) {
 214       configparseerr(ads,fn,lno,"invalid address `%s' in sortlist",tbuf);
 215       continue;
 216     }
 217
 218     if (slash) {
 219       if (slash[strspn(slash, "0123456789")]) {
 220         maskwhat = "mask";
 221         if (!gen_pton(slash,&af,&sl->mask)) {
 222           configparseerr(ads,fn,lno,"invalid mask `%s' in sortlist",slash);
 223           continue;
 224         }
 225       } else {
 226         maskwhat = "prefix length";
 227         initial= strtoul(slash,&ep,10);
 228         if (*ep || initial>adns__addr_width(af)) {
 229           configparseerr(ads,fn,lno,"mask length `%s' invalid",slash);
 230           continue;
 231         }
 232         adns__prefix_mask(af, initial, &sl->mask);
 233       }
 234     } else {
 235       maskwhat = "implied prefix length";
 236       initial= adns__guess_prefix_length(af, &sl->base);
 237       if (initial < 0) {
 238         configparseerr(ads,fn,lno, "network address `%s'"
 239                        " in sortlist is not in classed ranges,"
 240                        " must specify mask explicitly", tbuf);
 241         continue;
 242       }
 243       adns__prefix_mask(af, initial, &sl->mask);
 244     }
 245
 246     if (!adns__addr_match_p(af,&sl->base, af,&sl->base,&sl->mask)) {
 247       if (initial >= 0) {
 248         configparseerr(ads,fn,lno, "%s %d in sortlist"
 249                        " overlaps address `%s'",maskwhat,initial,tbuf);
 250       } else {
 251         configparseerr(ads,fn,lno, "%s `%s' in sortlist"
 252                        " overlaps address `%s'",maskwhat,slash,tbuf);
 253       }
 254       continue;
 255     }
 256
 257     sl->af= af;
 258     ads->nsortlist++;
 259   }
 260 }
 261
 262 static void ccf_options(adns_state ads, const char *fn,
 263                         int lno, const char *buf) {
 264   const char *word;
 265   char *ep;
 266   unsigned long v;
 267   int i,l;
 268
 269   if (!buf) return;
 270
 271   while (nextword(&buf,&word,&l)) {
 272     if (l==5 && !memcmp(word,"debug",5)) {
 273       ads->iflags |= adns_if_debug;
 274       continue;
 275     }
 276     if (l>=6 && !memcmp(word,"ndots:",6)) {
 277       v= strtoul(word+6,&ep,10);
 278       if (l==6 || ep != word+l || v > INT_MAX) {
 279         configparseerr(ads,fn,lno,"option `%.*s' malformed"
 280                        " or has bad value",l,word);
 281         continue;
 282       }
 283       ads->searchndots= v;
 284       continue;
 285     }
 286     if (l>=12 && !memcmp(word,"adns_checkc:",12)) {
 287       if (!strcmp(word+12,"none")) {
 288         ads->iflags &= ~adns_if_checkc_freq;
 289         ads->iflags |= adns_if_checkc_entex;
 290       } else if (!strcmp(word+12,"entex")) {
 291         ads->iflags &= ~adns_if_checkc_freq;
 292         ads->iflags |= adns_if_checkc_entex;
 293       } else if (!strcmp(word+12,"freq")) {
 294         ads->iflags |= adns_if_checkc_freq;
 295       } else {
 296         configparseerr(ads,fn,lno, "option adns_checkc has bad value `%s' "
 297                        "(must be none, entex or freq", word+12);
 298       }
 299       continue;
 300     }
 301     if (l>=8 && !memcmp(word,"adns_af:",8)) {
 302       word += 8;
 303       ads->iflags &= ~adns_if_afmask;
 304       if (strcmp(word,"any")) for (;;) {
 305         i= strcspn(word,",");
 306         if (i>=4 && !memcmp(word,"ipv4",4))
 307           ads->iflags |= adns_if_permit_ipv4;
 308         else if (i>=4 && !memcmp(word,"ipv6",4))
 309           ads->iflags |= adns_if_permit_ipv6;
 310         else {
 311           configparseerr(ads,fn,lno, "option adns_af has bad value `%.*s' "
 312                          "(must be `any' or list {`ipv4',`ipv6'},...)",
 313                          i, word);
 314           break;
 315         }
 316         if (!word[i]) break;
 317         word= word + i + 1;
 318       }
 319       continue;
 320     }
 321     adns__diag(ads,-1,0,"%s:%d: unknown option `%.*s'", fn,lno, l,word);
 322   }
 323 }
 324
 325 static void ccf_clearnss(adns_state ads, const char *fn,
 326                          int lno, const char *buf) {
 327   ads->nservers= 0;
 328 }
 329
 330 static void ccf_include(adns_state ads, const char *fn,
 331                         int lno, const char *buf) {
 332   if (!*buf) {
 333     configparseerr(ads,fn,lno,"`include' directive with no filename");
 334     return;
 335   }
 336   readconfig(ads,buf,1);
 337 }
 338
 339 static void ccf_lookup(adns_state ads, const char *fn, int lno,
 340                        const char *buf) {
 341   int found_bind=0;
 342   const char *word;
 343   int l;
 344
 345   if (!*buf) {
 346     configparseerr(ads,fn,lno,"`lookup' directive with no databases");
 347     return;
 348   }
 349
 350   while (nextword(&buf,&word,&l)) {
 351     if (l==4 && !memcmp(word,"bind",4)) {
 352       found_bind=1;
 353     } else if (l==4 && !memcmp(word,"file",4)) {
 354       /* ignore this and hope /etc/hosts is not essential */
 355     } else if (l==2 && !memcmp(word,"yp",2)) {
 356       adns__diag(ads,-1,0,"%s:%d: yp lookups not supported by adns", fn,lno);
 357       found_bind=-1;
 358     } else {
 359       adns__diag(ads,-1,0,"%s:%d: unknown `lookup' database `%.*s'",
 360                  fn,lno, l,word);
 361       found_bind=-1;
 362     }
 363   }
 364   if (!found_bind)
 365     adns__diag(ads,-1,0,"%s:%d: `lookup' specified, but not `bind'", fn,lno);
 366 }
 367
 368 static const struct configcommandinfo {
 369   const char *name;
 370   void (*fn)(adns_state ads, const char *fn, int lno, const char *buf);
 371 } configcommandinfos[]= {
 372   { "nameserver",        ccf_nameserver  },
 373   { "domain",            ccf_search      },
 374   { "search",            ccf_search      },
 375   { "sortlist",          ccf_sortlist    },
 376   { "options",           ccf_options     },
 377   { "clearnameservers",  ccf_clearnss    },
 378   { "include",           ccf_include     },
 379   { "lookup",            ccf_lookup      }, /* OpenBSD */
 380   {  0                                   }
 381 };
 382
 383 typedef union {
 384   FILE *file;
 385   const char *text;
 386 } getline_ctx;
 387
 388 static int gl_file(adns_state ads, getline_ctx *src_io, const char *filename,
 389                    int lno, char *buf, int buflen) {
 390   FILE *file= src_io->file;
 391   int c, i;
 392   char *p;
 393
 394   p= buf;
 395   buflen--;
 396   i= 0;
 397
 398   for (;;) { /* loop over chars */
 399     if (i == buflen) {
 400       adns__diag(ads,-1,0,"%s:%d: line too long, ignored",filename,lno);
 401       goto x_badline;
 402     }
 403     c= getc(file);
 404     if (!c) {
 405       adns__diag(ads,-1,0,"%s:%d: line contains nul, ignored",filename,lno);
 406       goto x_badline;
 407     } else if (c == '\n') {
 408       break;
 409     } else if (c == EOF) {
 410       if (ferror(file)) {
 411         saveerr(ads,errno);
 412         adns__diag(ads,-1,0,"%s:%d: read error: %s",
 413                    filename,lno,strerror(errno));
 414         return -1;
 415       }
 416       if (!i) return -1;
 417       break;
 418     } else {
 419       *p++= c;
 420       i++;
 421     }
 422   }
 423
 424   *p++= 0;
 425   return i;
 426
 427  x_badline:
 428   saveerr(ads,EINVAL);
 429   while ((c= getc(file)) != EOF && c != '\n');
 430   return -2;
 431 }
 432
 433 static int gl_text(adns_state ads, getline_ctx *src_io, const char *filename,
 434                    int lno, char *buf, int buflen) {
 435   const char *cp= src_io->text;
 436   int l;
 437
 438   if (!cp || !*cp) return -1;
 439
 440   if (*cp == ';' || *cp == '\n') cp++;
 441   l= strcspn(cp,";\n");
 442   src_io->text = cp+l;
 443
 444   if (l >= buflen) {
 445     adns__diag(ads,-1,0,"%s:%d: line too long, ignored",filename,lno);
 446     saveerr(ads,EINVAL);
 447     return -2;
 448   }
 449
 450   memcpy(buf,cp,l);
 451   buf[l]= 0;
 452   return l;
 453 }
 454
 455 static void readconfiggeneric(adns_state ads, const char *filename,
 456                               int (*getline)(adns_state ads, getline_ctx*,
 457                                              const char *filename, int lno,
 458                                              char *buf, int buflen),
 459                               /* Returns >=0 for success, -1 for EOF or error
 460                                * (error will have been reported), or -2 for
 461                                * bad line was encountered, try again.
 462                                */
 463                               getline_ctx gl_ctx) {
 464   char linebuf[2000], *p, *q;
 465   int lno, l, dirl;
 466   const struct configcommandinfo *ccip;
 467
 468   for (lno=1;
 469        (l= getline(ads,&gl_ctx, filename,lno, linebuf,sizeof(linebuf))) != -1;
 470        lno++) {
 471     if (l == -2) continue;
 472     while (l>0 && ctype_whitespace(linebuf[l-1])) l--;
 473     linebuf[l]= 0;
 474     p= linebuf;
 475     while (ctype_whitespace(*p)) p++;
 476     if (*p == '#' || *p == ';' || !*p) continue;
 477     q= p;
 478     while (*q && !ctype_whitespace(*q)) q++;
 479     dirl= q-p;
 480     for (ccip=configcommandinfos;
 481          ccip->name &&
 482            !(strlen(ccip->name)==dirl && !memcmp(ccip->name,p,q-p));
 483          ccip++);
 484     if (!ccip->name) {
 485       adns__diag(ads,-1,0,"%s:%d: unknown configuration directive `%.*s'",
 486                  filename,lno,(int)(q-p),p);
 487       continue;
 488     }
 489     while (ctype_whitespace(*q)) q++;
 490     ccip->fn(ads,filename,lno,q);
 491   }
 492 }
 493
 494 static const char *instrum_getenv(adns_state ads, const char *envvar) {
 495   const char *value;
 496
 497   value= getenv(envvar);
 498   if (!value) adns__debug(ads,-1,0,"environment variable %s not set",envvar);
 499   else adns__debug(ads,-1,0,"environment variable %s"
 500                    " set to `%s'",envvar,value);
 501   return value;
 502 }
 503
 504 static void readconfig(adns_state ads, const char *filename, int warnmissing) {
 505   getline_ctx gl_ctx;
 506
 507   gl_ctx.file= fopen(filename,"r");
 508   if (!gl_ctx.file) {
 509     if (errno == ENOENT) {
 510       if (warnmissing)
 511         adns__debug(ads,-1,0, "configuration file"
 512                     " `%s' does not exist",filename);
 513       return;
 514     }
 515     saveerr(ads,errno);
 516     adns__diag(ads,-1,0,"cannot open configuration file `%s': %s",
 517                filename,strerror(errno));
 518     return;
 519   }
 520
 521   readconfiggeneric(ads,filename,gl_file,gl_ctx);
 522
 523   fclose(gl_ctx.file);
 524 }
 525
 526 static void readconfigtext(adns_state ads, const char *text,
 527                            const char *showname) {
 528   getline_ctx gl_ctx;
 529
 530   gl_ctx.text= text;
 531   readconfiggeneric(ads,showname,gl_text,gl_ctx);
 532 }
 533
 534 static void readconfigenv(adns_state ads, const char *envvar) {
 535   const char *filename;
 536
 537   if (ads->iflags & adns_if_noenv) {
 538     adns__debug(ads,-1,0,"not checking environment variable `%s'",envvar);
 539     return;
 540   }
 541   filename= instrum_getenv(ads,envvar);
 542   if (filename) readconfig(ads,filename,1);
 543 }
 544
 545 static void readconfigenvtext(adns_state ads, const char *envvar) {
 546   const char *textdata;
 547
 548   if (ads->iflags & adns_if_noenv) {
 549     adns__debug(ads,-1,0,"not checking environment variable `%s'",envvar);
 550     return;
 551   }
 552   textdata= instrum_getenv(ads,envvar);
 553   if (textdata) readconfigtext(ads,textdata,envvar);
 554 }
 555
 556
 557 int adns__setnonblock(adns_state ads, int fd) {
 558   int r;
 559
 560   r= fcntl(fd,F_GETFL,0); if (r<0) return errno;
 561   r |= O_NONBLOCK;
 562   r= fcntl(fd,F_SETFL,r); if (r<0) return errno;
 563   return 0;
 564 }
 565
 566 static int init_begin(adns_state *ads_r, adns_initflags flags,
 567                       adns_logcallbackfn *logfn, void *logfndata) {
 568   adns_state ads;
 569   pid_t pid;
 570
 571   ads= malloc(sizeof(*ads)); if (!ads) return errno;
 572
 573   ads->iflags= flags;
 574   ads->logfn= logfn;
 575   ads->logfndata= logfndata;
 576   ads->configerrno= 0;
 577   LIST_INIT(ads->udpw);
 578   LIST_INIT(ads->tcpw);
 579   LIST_INIT(ads->childw);
 580   LIST_INIT(ads->output);
 581   LIST_INIT(ads->intdone);
 582   ads->forallnext= 0;
 583   ads->nextid= 0x311f;
 584   ads->nudp= 0;
 585   ads->tcpsocket= -1;
 586   adns__vbuf_init(&ads->tcpsend);
 587   adns__vbuf_init(&ads->tcprecv);
 588   ads->tcprecv_skip= 0;
 589   ads->nservers= ads->nsortlist= ads->nsearchlist= ads->tcpserver= 0;
 590   ads->searchndots= 1;
 591   ads->tcpstate= server_disconnected;
 592   timerclear(&ads->tcptimeout);
 593   ads->searchlist= 0;
 594
 595   pid= getpid();
 596   ads->rand48xsubi[0]= pid;
 597   ads->rand48xsubi[1]= (unsigned long)pid >> 16;
 598   ads->rand48xsubi[2]= pid ^ ((unsigned long)pid >> 16);
 599
 600   *ads_r= ads;
 601   return 0;
 602 }
 603
 604 static int init_finish(adns_state ads) {
 605   struct sockaddr_in sin;
 606   struct protoent *proto;
 607   struct udpsocket *udp;
 608   int i, j;
 609   int r;
 610
 611   if (!ads->nservers) {
 612     if (ads->logfn && ads->iflags & adns_if_debug)
 613       adns__lprintf(ads,"adns: no nameservers, using IPv4 localhost\n");
 614     memset(&sin, 0, sizeof(sin));
 615     sin.sin_family = AF_INET;
 616     sin.sin_port = htons(DNS_PORT);
 617     sin.sin_addr.s_addr = htonl(INADDR_LOOPBACK);
 618     addserver(ads,(struct sockaddr *)&sin, sizeof(sin));
 619   }
 620
 621   proto= getprotobyname("udp"); if (!proto) { r= ENOPROTOOPT; goto x_free; }
 622   ads->nudp= 0;
 623   for (i=0; i<ads->nservers; i++) {
 624     if (adns__udpsocket_by_af(ads, ads->servers[i].addr.sa.sa_family))
 625       continue;
 626     assert(ads->nudp < MAXUDP);
 627     udp= &ads->udpsocket[ads->nudp];
 628     udp->af= ads->servers[i].addr.sa.sa_family;
 629     udp->fd= socket(udp->af,SOCK_DGRAM,proto->p_proto);
 630     if (udp->fd < 0) { r= errno; goto x_free; }
 631     ads->nudp++;
 632     r= adns__setnonblock(ads,udp->fd);
 633     if (r) { r= errno; goto x_closeudp; }
 634   }
 635
 636   return 0;
 637
 638  x_closeudp:
 639   for (j=0; j<ads->nudp; j++) close(ads->udpsocket[j].fd);
 640  x_free:
 641   free(ads);
 642   return r;
 643 }
 644
 645 static void init_abort(adns_state ads) {
 646   if (ads->nsearchlist) {
 647     free(ads->searchlist[0]);
 648     free(ads->searchlist);
 649   }
 650   free(ads);
 651 }
 652
 653 static void logfn_file(adns_state ads, void *logfndata,
 654                        const char *fmt, va_list al) {
 655   vfprintf(logfndata,fmt,al);
 656 }
 657
 658 static int init_files(adns_state *ads_r, adns_initflags flags,
 659                       adns_logcallbackfn *logfn, void *logfndata) {
 660   adns_state ads;
 661   const char *res_options, *adns_res_options;
 662   int r;
 663
 664   r= init_begin(&ads, flags, logfn, logfndata);
 665   if (r) return r;
 666
 667   res_options= instrum_getenv(ads,"RES_OPTIONS");
 668   adns_res_options= instrum_getenv(ads,"ADNS_RES_OPTIONS");
 669   ccf_options(ads,"RES_OPTIONS",-1,res_options);
 670   ccf_options(ads,"ADNS_RES_OPTIONS",-1,adns_res_options);
 671
 672   readconfig(ads,"/etc/resolv.conf",1);
 673   readconfig(ads,"/etc/resolv-adns.conf",0);
 674   readconfigenv(ads,"RES_CONF");
 675   readconfigenv(ads,"ADNS_RES_CONF");
 676
 677   readconfigenvtext(ads,"RES_CONF_TEXT");
 678   readconfigenvtext(ads,"ADNS_RES_CONF_TEXT");
 679
 680   ccf_options(ads,"RES_OPTIONS",-1,res_options);
 681   ccf_options(ads,"ADNS_RES_OPTIONS",-1,adns_res_options);
 682
 683   ccf_search(ads,"LOCALDOMAIN",-1,instrum_getenv(ads,"LOCALDOMAIN"));
 684   ccf_search(ads,"ADNS_LOCALDOMAIN",-1,instrum_getenv(ads,"ADNS_LOCALDOMAIN"));
 685
 686   if (ads->configerrno && ads->configerrno != EINVAL) {
 687     r= ads->configerrno;
 688     init_abort(ads);
 689     return r;
 690   }
 691
 692   r= init_finish(ads);
 693   if (r) return r;
 694
 695   adns__consistency(ads,0,cc_entex);
 696   *ads_r= ads;
 697   return 0;
 698 }
 699
 700 int adns_init(adns_state *ads_r, adns_initflags flags, FILE *diagfile) {
 701   return init_files(ads_r, flags, logfn_file, diagfile ? diagfile : stderr);
 702 }
 703
 704 static int init_strcfg(adns_state *ads_r, adns_initflags flags,
 705                        adns_logcallbackfn *logfn, void *logfndata,
 706                        const char *configtext) {
 707   adns_state ads;
 708   int r;
 709
 710   r= init_begin(&ads, flags, logfn, logfndata);
 711   if (r) return r;
 712
 713   readconfigtext(ads,configtext,"<supplied configuration text>");
 714   if (ads->configerrno) {
 715     r= ads->configerrno;
 716     init_abort(ads);
 717     return r;
 718   }
 719
 720   r= init_finish(ads);  if (r) return r;
 721   adns__consistency(ads,0,cc_entex);
 722   *ads_r= ads;
 723   return 0;
 724 }
 725
 726 int adns_init_strcfg(adns_state *ads_r, adns_initflags flags,
 727                      FILE *diagfile, const char *configtext) {
 728   return init_strcfg(ads_r, flags,
 729                      diagfile ? logfn_file : 0, diagfile,
 730                      configtext);
 731 }
 732
 733 int adns_init_logfn(adns_state *newstate_r, adns_initflags flags,
 734                     const char *configtext /*0=>use default config files*/,
 735                     adns_logcallbackfn *logfn /*0=>logfndata is a FILE* */,
 736                     void *logfndata /*0 with logfn==0 => discard*/) {
 737   if (!logfn && logfndata)
 738     logfn= logfn_file;
 739   if (configtext)
 740     return init_strcfg(newstate_r, flags, logfn, logfndata, configtext);
 741   else
 742     return init_files(newstate_r, flags, logfn, logfndata);
 743 }
 744
 745 void adns_finish(adns_state ads) {
 746   int i;
 747   adns__consistency(ads,0,cc_entex);
 748   for (;;) {
 749     if (ads->udpw.head) adns__cancel(ads->udpw.head);
 750     else if (ads->tcpw.head) adns__cancel(ads->tcpw.head);
 751     else if (ads->childw.head) adns__cancel(ads->childw.head);
 752     else if (ads->output.head) adns__cancel(ads->output.head);
 753     else if (ads->intdone.head) adns__cancel(ads->output.head);
 754     else break;
 755   }
 756   for (i=0; i<ads->nudp; i++) close(ads->udpsocket[i].fd);
 757   if (ads->tcpsocket >= 0) close(ads->tcpsocket);
 758   adns__vbuf_free(&ads->tcpsend);
 759   adns__vbuf_free(&ads->tcprecv);
 760   freesearchlist(ads);
 761   free(ads);
 762 }
 763
 764 void adns_forallqueries_begin(adns_state ads) {
 765   adns__consistency(ads,0,cc_entex);
 766   ads->forallnext=
 767     ads->udpw.head ? ads->udpw.head :
 768     ads->tcpw.head ? ads->tcpw.head :
 769     ads->childw.head ? ads->childw.head :
 770     ads->output.head;
 771 }
 772
 773 adns_query adns_forallqueries_next(adns_state ads, void **context_r) {
 774   adns_query qu, nqu;
 775
 776   adns__consistency(ads,0,cc_entex);
 777   nqu= ads->forallnext;
 778   for (;;) {
 779     qu= nqu;
 780     if (!qu) return 0;
 781     if (qu->next) {
 782       nqu= qu->next;
 783     } else if (qu == ads->udpw.tail) {
 784       nqu=
 785         ads->tcpw.head ? ads->tcpw.head :
 786         ads->childw.head ? ads->childw.head :
 787         ads->output.head;
 788     } else if (qu == ads->tcpw.tail) {
 789       nqu=
 790         ads->childw.head ? ads->childw.head :
 791         ads->output.head;
 792     } else if (qu == ads->childw.tail) {
 793       nqu= ads->output.head;
 794     } else {
 795       nqu= 0;
 796     }
 797     if (!qu->parent) break;
 798   }
 799   ads->forallnext= nqu;
 800   if (context_r) *context_r= qu->ctx.ext;
 801   return qu;
 802 }