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) 2014  Mark Wooding
  10  *    Copyright (C) 1999-2000,2003,2006  Tony Finch
  11  *    Copyright (C) 1991 Massachusetts Institute of Technology
  12  *  (See the file INSTALL for full details.)
  13  *
  14  *  This program is free software; you can redistribute it and/or modify
  15  *  it under the terms of the GNU General Public License as published by
  16  *  the Free Software Foundation; either version 3, or (at your option)
  17  *  any later version.
  18  *
  19  *  This program is distributed in the hope that it will be useful,
  20  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
  21  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  22  *  GNU General Public License for more details.
  23  *
  24  *  You should have received a copy of the GNU General Public License
  25  *  along with this program; if not, write to the Free Software Foundation.
  26  */
  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 salen) {
  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__sockaddrs_equal(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(salen <= sizeof(ss->addr));
  65   ss->len = salen;
  66   memcpy(&ss->addr, sa, salen);
  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 want_af, adns_sockaddr *a) {
 169   int err;
 170   int len;
 171
 172   len= sizeof(*a);
 173   err= adns_text2addr(text,0, adns_qf_addrlit_scope_forbid,
 174                       &a->sa, &len);
 175   if (err) { assert(err == EINVAL); return 0; }
 176   if (want_af != AF_UNSPEC && a->sa.sa_family != want_af) return 0;
 177   return 1;
 178 }
 179
 180 static void ccf_sortlist(adns_state ads, const char *fn,
 181                          int lno, const char *buf) {
 182   const char *word;
 183   char tbuf[200], *slash, *ep;
 184   const char *maskwhat;
 185   struct sortlist *sl;
 186   int l;
 187   int initial= -1;
 188
 189   if (!buf) return;
 190
 191   ads->nsortlist= 0;
 192   while (nextword(&buf,&word,&l)) {
 193     if (ads->nsortlist >= MAXSORTLIST) {
 194       adns__diag(ads,-1,0,"too many sortlist entries,"
 195                  " ignoring %.*s onwards",l,word);
 196       return;
 197     }
 198
 199     if (l >= sizeof(tbuf)) {
 200       configparseerr(ads,fn,lno,"sortlist entry `%.*s' too long",l,word);
 201       continue;
 202     }
 203
 204     memcpy(tbuf,word,l); tbuf[l]= 0;
 205     slash= strchr(tbuf,'/');
 206     if (slash) *slash++= 0;
 207
 208     sl= &ads->sortlist[ads->nsortlist];
 209     if (!gen_pton(tbuf, AF_UNSPEC, &sl->base)) {
 210       configparseerr(ads,fn,lno,"invalid address `%s' in sortlist",tbuf);
 211       continue;
 212     }
 213
 214     if (slash) {
 215       if (slash[strspn(slash, "0123456789")]) {
 216         maskwhat = "mask";
 217         if (!gen_pton(slash, sl->base.sa.sa_family, &sl->mask)) {
 218           configparseerr(ads,fn,lno,"invalid mask `%s' in sortlist",slash);
 219           continue;
 220         }
 221       } else {
 222         maskwhat = "prefix length";
 223         initial= strtoul(slash,&ep,10);
 224         if (*ep || initial>adns__addr_width(sl->base.sa.sa_family)) {
 225           configparseerr(ads,fn,lno,"mask length `%s' invalid",slash);
 226           continue;
 227         }
 228         sl->mask.sa.sa_family= sl->base.sa.sa_family;
 229         adns__prefix_mask(&sl->mask, initial);
 230       }
 231     } else {
 232       maskwhat = "implied prefix length";
 233       initial= adns__guess_prefix_length(&sl->base);
 234       if (initial < 0) {
 235         configparseerr(ads,fn,lno, "network address `%s'"
 236                        " in sortlist is not in classed ranges,"
 237                        " must specify mask explicitly", tbuf);
 238         continue;
 239       }
 240       sl->mask.sa.sa_family= sl->base.sa.sa_family;
 241       adns__prefix_mask(&sl->mask, initial);
 242     }
 243
 244     if (!adns__addr_matches(sl->base.sa.sa_family,
 245                             adns__sockaddr_addr(&sl->base.sa),
 246                             &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     ads->nsortlist++;
 258   }
 259 }
 260
 261 static void ccf_options(adns_state ads, const char *fn,
 262                         int lno, const char *buf) {
 263   const char *opt, *word, *endword, *endopt;
 264   char *ep;
 265   unsigned long v;
 266   int l;
 267
 268   if (!buf) return;
 269
 270 #define WORD__IS(s,op) ((endword-word) op (sizeof(s)-1) && \
 271                           !memcmp(word,s,(sizeof(s)-1)))
 272 #define WORD_IS(s)     (WORD__IS(s,==))
 273 #define WORD_STARTS(s) (WORD__IS(s,>=) ? ((word+=sizeof(s)-1)) : 0)
 274
 275   while (nextword(&buf,&word,&l)) {
 276     opt=word;
 277     endopt=endword=word+l;
 278     if (WORD_IS("debug")) {
 279       ads->iflags |= adns_if_debug;
 280       continue;
 281     }
 282     if (WORD_STARTS("ndots:")) {
 283       v= strtoul(word,&ep,10);
 284       if (ep==word || ep != endword || v > INT_MAX) {
 285         configparseerr(ads,fn,lno,"option `%.*s' malformed"
 286                        " or has bad value",l,opt);
 287         continue;
 288       }
 289       ads->searchndots= v;
 290       continue;
 291     }
 292     if (WORD_STARTS("adns_checkc:")) {
 293       if (WORD_IS("none")) {
 294         ads->iflags &= ~adns_if_checkc_freq;
 295         ads->iflags |= adns_if_checkc_entex;
 296       } else if (WORD_IS("entex")) {
 297         ads->iflags &= ~adns_if_checkc_freq;
 298         ads->iflags |= adns_if_checkc_entex;
 299       } else if (WORD_IS("freq")) {
 300         ads->iflags |= adns_if_checkc_freq;
 301       } else {
 302         configparseerr(ads,fn,lno, "option adns_checkc has bad value `%s' "
 303                        "(must be none, entex or freq", word);
 304       }
 305       continue;
 306     }
 307     if (WORD_STARTS("adns_af:")) {
 308       ads->iflags &= ~adns_if_afmask;
 309       if (!WORD_IS("any")) for (;;) {
 310         const char *comma= memchr(word,',',endopt-word);
 311         endword=comma?comma:endopt;
 312         if (WORD_IS("ipv4"))
 313           ads->iflags |= adns_if_permit_ipv4;
 314         else if (WORD_IS("ipv6"))
 315           ads->iflags |= adns_if_permit_ipv6;
 316         else {
 317           if (ads->config_report_unknown)
 318             adns__diag(ads,-1,0,"%s:%d: "
 319                        "option adns_af has bad value or entry `%.*s' "
 320                        "(option must be `any', or list of `ipv4',`ipv6')",
 321                        fn,lno, (int)(endword-word),word);
 322           break;
 323         }
 324         if (!comma) break;
 325         word= comma+1;
 326       }
 327       continue;
 328     }
 329     if (WORD_IS("adns_ignoreunkcfg")) {
 330       ads->config_report_unknown=0;
 331       continue;
 332     }
 333     if (/* adns's query strategy is not configurable */
 334         WORD_STARTS("timeout:") ||
 335         WORD_STARTS("attempts:") ||
 336         WORD_IS("rotate") ||
 337         /* adns provides the application with knob for this */
 338         WORD_IS("no-check-names") ||
 339         /* adns normally does IPv6 if the application wants it; control
 340          * this with the adns_af: option if you like */
 341         WORD_IS("inet6") ||
 342         /* adns does not do edns0 and this is not a problem */
 343         WORD_IS("edns0"))
 344       continue;
 345     if (ads->config_report_unknown)
 346       adns__diag(ads,-1,0,"%s:%d: unknown option `%.*s'", fn,lno, l,opt);
 347   }
 348
 349 #undef WORD__IS
 350 #undef WORD_IS
 351 #undef WORD_STARTS
 352 }
 353
 354 static void ccf_clearnss(adns_state ads, const char *fn,
 355                          int lno, const char *buf) {
 356   ads->nservers= 0;
 357 }
 358
 359 static void ccf_include(adns_state ads, const char *fn,
 360                         int lno, const char *buf) {
 361   if (!*buf) {
 362     configparseerr(ads,fn,lno,"`include' directive with no filename");
 363     return;
 364   }
 365   readconfig(ads,buf,1);
 366 }
 367
 368 static void ccf_lookup(adns_state ads, const char *fn, int lno,
 369                        const char *buf) {
 370   int found_bind=0;
 371   const char *word;
 372   int l;
 373
 374   if (!*buf) {
 375     configparseerr(ads,fn,lno,"`lookup' directive with no databases");
 376     return;
 377   }
 378
 379   while (nextword(&buf,&word,&l)) {
 380     if (l==4 && !memcmp(word,"bind",4)) {
 381       found_bind=1;
 382     } else if (l==4 && !memcmp(word,"file",4)) {
 383       /* ignore this and hope /etc/hosts is not essential */
 384     } else if (l==2 && !memcmp(word,"yp",2)) {
 385       adns__diag(ads,-1,0,"%s:%d: yp lookups not supported by adns", fn,lno);
 386       found_bind=-1;
 387     } else {
 388       if (ads->config_report_unknown)
 389         adns__diag(ads,-1,0,"%s:%d: unknown `lookup' database `%.*s'",
 390                    fn,lno, l,word);
 391       found_bind=-1;
 392     }
 393   }
 394   if (!found_bind)
 395     adns__diag(ads,-1,0,"%s:%d: `lookup' specified, but not `bind'", fn,lno);
 396 }
 397
 398 static void ccf_ignore(adns_state ads, const char *fn, int lno,
 399                        const char *buf) {
 400 }
 401
 402 static const struct configcommandinfo {
 403   const char *name;
 404   void (*fn)(adns_state ads, const char *fn, int lno, const char *buf);
 405 } configcommandinfos[]= {
 406   { "nameserver",        ccf_nameserver  },
 407   { "domain",            ccf_search      },
 408   { "search",            ccf_search      },
 409   { "sortlist",          ccf_sortlist    },
 410   { "options",           ccf_options     },
 411   { "clearnameservers",  ccf_clearnss    },
 412   { "include",           ccf_include     },
 413   { "lookup",            ccf_lookup      }, /* OpenBSD */
 414   { "lwserver",          ccf_ignore      }, /* BIND9 lwresd */
 415   {  0                                   }
 416 };
 417
 418 typedef union {
 419   FILE *file;
 420   const char *text;
 421 } getline_ctx;
 422
 423 static int gl_file(adns_state ads, getline_ctx *src_io, const char *filename,
 424                    int lno, char *buf, int buflen) {
 425   FILE *file= src_io->file;
 426   int c, i;
 427   char *p;
 428
 429   p= buf;
 430   buflen--;
 431   i= 0;
 432
 433   for (;;) { /* loop over chars */
 434     if (i == buflen) {
 435       adns__diag(ads,-1,0,"%s:%d: line too long, ignored",filename,lno);
 436       goto x_badline;
 437     }
 438     c= getc(file);
 439     if (!c) {
 440       adns__diag(ads,-1,0,"%s:%d: line contains nul, ignored",filename,lno);
 441       goto x_badline;
 442     } else if (c == '\n') {
 443       break;
 444     } else if (c == EOF) {
 445       if (ferror(file)) {
 446         saveerr(ads,errno);
 447         adns__diag(ads,-1,0,"%s:%d: read error: %s",
 448                    filename,lno,strerror(errno));
 449         return -1;
 450       }
 451       if (!i) return -1;
 452       break;
 453     } else {
 454       *p++= c;
 455       i++;
 456     }
 457   }
 458
 459   *p++= 0;
 460   return i;
 461
 462  x_badline:
 463   saveerr(ads,EINVAL);
 464   while ((c= getc(file)) != EOF && c != '\n');
 465   return -2;
 466 }
 467
 468 static int gl_text(adns_state ads, getline_ctx *src_io, const char *filename,
 469                    int lno, char *buf, int buflen) {
 470   const char *cp= src_io->text;
 471   int l;
 472
 473   if (!cp || !*cp) return -1;
 474
 475   if (*cp == ';' || *cp == '\n') cp++;
 476   l= strcspn(cp,";\n");
 477   src_io->text = cp+l;
 478
 479   if (l >= buflen) {
 480     adns__diag(ads,-1,0,"%s:%d: line too long, ignored",filename,lno);
 481     saveerr(ads,EINVAL);
 482     return -2;
 483   }
 484
 485   memcpy(buf,cp,l);
 486   buf[l]= 0;
 487   return l;
 488 }
 489
 490 static void readconfiggeneric(adns_state ads, const char *filename,
 491                               int (*getline)(adns_state ads, getline_ctx*,
 492                                              const char *filename, int lno,
 493                                              char *buf, int buflen),
 494                               /* Returns >=0 for success, -1 for EOF or error
 495                                * (error will have been reported), or -2 for
 496                                * bad line was encountered, try again.
 497                                */
 498                               getline_ctx gl_ctx) {
 499   char linebuf[2000], *p, *q;
 500   int lno, l, dirl;
 501   const struct configcommandinfo *ccip;
 502
 503   for (lno=1;
 504        (l= getline(ads,&gl_ctx, filename,lno, linebuf,sizeof(linebuf))) != -1;
 505        lno++) {
 506     if (l == -2) continue;
 507     while (l>0 && ctype_whitespace(linebuf[l-1])) l--;
 508     linebuf[l]= 0;
 509     p= linebuf;
 510     while (ctype_whitespace(*p)) p++;
 511     if (*p == '#' || *p == ';' || !*p) continue;
 512     q= p;
 513     while (*q && !ctype_whitespace(*q)) q++;
 514     dirl= q-p;
 515     for (ccip=configcommandinfos;
 516          ccip->name &&
 517            !(strlen(ccip->name)==dirl && !memcmp(ccip->name,p,q-p));
 518          ccip++);
 519     if (!ccip->name) {
 520       if (ads->config_report_unknown)
 521         adns__diag(ads,-1,0,"%s:%d: unknown configuration directive `%.*s'",
 522                    filename,lno,(int)(q-p),p);
 523       continue;
 524     }
 525     while (ctype_whitespace(*q)) q++;
 526     ccip->fn(ads,filename,lno,q);
 527   }
 528 }
 529
 530 static const char *instrum_getenv(adns_state ads, const char *envvar) {
 531   const char *value;
 532
 533   value= getenv(envvar);
 534   if (!value) adns__debug(ads,-1,0,"environment variable %s not set",envvar);
 535   else adns__debug(ads,-1,0,"environment variable %s"
 536                    " set to `%s'",envvar,value);
 537   return value;
 538 }
 539
 540 static void readconfig(adns_state ads, const char *filename, int warnmissing) {
 541   getline_ctx gl_ctx;
 542
 543   gl_ctx.file= fopen(filename,"r");
 544   if (!gl_ctx.file) {
 545     if (errno == ENOENT) {
 546       if (warnmissing)
 547         adns__debug(ads,-1,0, "configuration file"
 548                     " `%s' does not exist",filename);
 549       return;
 550     }
 551     saveerr(ads,errno);
 552     adns__diag(ads,-1,0,"cannot open configuration file `%s': %s",
 553                filename,strerror(errno));
 554     return;
 555   }
 556
 557   readconfiggeneric(ads,filename,gl_file,gl_ctx);
 558
 559   fclose(gl_ctx.file);
 560 }
 561
 562 static void readconfigtext(adns_state ads, const char *text,
 563                            const char *showname) {
 564   getline_ctx gl_ctx;
 565
 566   gl_ctx.text= text;
 567   readconfiggeneric(ads,showname,gl_text,gl_ctx);
 568 }
 569
 570 static void readconfigenv(adns_state ads, const char *envvar) {
 571   const char *filename;
 572
 573   if (ads->iflags & adns_if_noenv) {
 574     adns__debug(ads,-1,0,"not checking environment variable `%s'",envvar);
 575     return;
 576   }
 577   filename= instrum_getenv(ads,envvar);
 578   if (filename) readconfig(ads,filename,1);
 579 }
 580
 581 static void readconfigenvtext(adns_state ads, const char *envvar) {
 582   const char *textdata;
 583
 584   if (ads->iflags & adns_if_noenv) {
 585     adns__debug(ads,-1,0,"not checking environment variable `%s'",envvar);
 586     return;
 587   }
 588   textdata= instrum_getenv(ads,envvar);
 589   if (textdata) readconfigtext(ads,textdata,envvar);
 590 }
 591
 592
 593 int adns__setnonblock(adns_state ads, int fd) {
 594   int r;
 595
 596   r= fcntl(fd,F_GETFL,0); if (r<0) return errno;
 597   r |= O_NONBLOCK;
 598   r= fcntl(fd,F_SETFL,r); if (r<0) return errno;
 599   return 0;
 600 }
 601
 602 static int init_begin(adns_state *ads_r, adns_initflags flags,
 603                       adns_logcallbackfn *logfn, void *logfndata) {
 604   adns_state ads;
 605   pid_t pid;
 606
 607   if (flags & ~(adns_initflags)(0x4fff))
 608     /* 0x4000 is reserved for `harmless' future expansion */
 609     return ENOSYS;
 610
 611   ads= malloc(sizeof(*ads)); if (!ads) return errno;
 612
 613   ads->iflags= flags;
 614   ads->logfn= logfn;
 615   ads->logfndata= logfndata;
 616   ads->configerrno= 0;
 617   LIST_INIT(ads->udpw);
 618   LIST_INIT(ads->tcpw);
 619   LIST_INIT(ads->childw);
 620   LIST_INIT(ads->output);
 621   LIST_INIT(ads->intdone);
 622   ads->forallnext= 0;
 623   ads->nextid= 0x311f;
 624   ads->nudpsockets= 0;
 625   ads->tcpsocket= -1;
 626   adns__vbuf_init(&ads->tcpsend);
 627   adns__vbuf_init(&ads->tcprecv);
 628   ads->tcprecv_skip= 0;
 629   ads->nservers= ads->nsortlist= ads->nsearchlist= ads->tcpserver= 0;
 630   ads->searchndots= 1;
 631   ads->tcpstate= server_disconnected;
 632   timerclear(&ads->tcptimeout);
 633   ads->searchlist= 0;
 634   ads->config_report_unknown=1;
 635
 636   pid= getpid();
 637   ads->rand48xsubi[0]= pid;
 638   ads->rand48xsubi[1]= (unsigned long)pid >> 16;
 639   ads->rand48xsubi[2]= pid ^ ((unsigned long)pid >> 16);
 640
 641   *ads_r= ads;
 642   return 0;
 643 }
 644
 645 static int init_finish(adns_state ads) {
 646   struct sockaddr_in sin;
 647   struct protoent *proto;
 648   struct udpsocket *udp;
 649   int i;
 650   int r;
 651
 652   if (!ads->nservers) {
 653     if (ads->logfn && ads->iflags & adns_if_debug)
 654       adns__lprintf(ads,"adns: no nameservers, using IPv4 localhost\n");
 655     memset(&sin, 0, sizeof(sin));
 656     sin.sin_family = AF_INET;
 657     sin.sin_port = htons(DNS_PORT);
 658     sin.sin_addr.s_addr = htonl(INADDR_LOOPBACK);
 659     addserver(ads,(struct sockaddr *)&sin, sizeof(sin));
 660   }
 661
 662   proto= getprotobyname("udp"); if (!proto) { r= ENOPROTOOPT; goto x_free; }
 663   ads->nudpsockets= 0;
 664   for (i=0; i<ads->nservers; i++) {
 665     if (adns__udpsocket_by_af(ads, ads->servers[i].addr.sa.sa_family))
 666       continue;
 667     assert(ads->nudpsockets < MAXUDP);
 668     udp= &ads->udpsockets[ads->nudpsockets];
 669     udp->af= ads->servers[i].addr.sa.sa_family;
 670     udp->fd= socket(udp->af,SOCK_DGRAM,proto->p_proto);
 671     if (udp->fd < 0) { r= errno; goto x_free; }
 672     ads->nudpsockets++;
 673     r= adns__setnonblock(ads,udp->fd);
 674     if (r) { r= errno; goto x_closeudp; }
 675   }
 676
 677   return 0;
 678
 679  x_closeudp:
 680   for (i=0; i<ads->nudpsockets; i++) close(ads->udpsockets[i].fd);
 681  x_free:
 682   free(ads);
 683   return r;
 684 }
 685
 686 static void init_abort(adns_state ads) {
 687   if (ads->nsearchlist) {
 688     free(ads->searchlist[0]);
 689     free(ads->searchlist);
 690   }
 691   free(ads);
 692 }
 693
 694 static void logfn_file(adns_state ads, void *logfndata,
 695                        const char *fmt, va_list al) {
 696   vfprintf(logfndata,fmt,al);
 697 }
 698
 699 static int init_files(adns_state *ads_r, adns_initflags flags,
 700                       adns_logcallbackfn *logfn, void *logfndata) {
 701   adns_state ads;
 702   const char *res_options, *adns_res_options;
 703   int r;
 704
 705   r= init_begin(&ads, flags, logfn, logfndata);
 706   if (r) return r;
 707
 708   res_options= instrum_getenv(ads,"RES_OPTIONS");
 709   adns_res_options= instrum_getenv(ads,"ADNS_RES_OPTIONS");
 710   ccf_options(ads,"RES_OPTIONS",-1,res_options);
 711   ccf_options(ads,"ADNS_RES_OPTIONS",-1,adns_res_options);
 712
 713   readconfig(ads,"/etc/resolv.conf",1);
 714   readconfig(ads,"/etc/resolv-adns.conf",0);
 715   readconfigenv(ads,"RES_CONF");
 716   readconfigenv(ads,"ADNS_RES_CONF");
 717
 718   readconfigenvtext(ads,"RES_CONF_TEXT");
 719   readconfigenvtext(ads,"ADNS_RES_CONF_TEXT");
 720
 721   ccf_options(ads,"RES_OPTIONS",-1,res_options);
 722   ccf_options(ads,"ADNS_RES_OPTIONS",-1,adns_res_options);
 723
 724   ccf_search(ads,"LOCALDOMAIN",-1,instrum_getenv(ads,"LOCALDOMAIN"));
 725   ccf_search(ads,"ADNS_LOCALDOMAIN",-1,instrum_getenv(ads,"ADNS_LOCALDOMAIN"));
 726
 727   if (ads->configerrno && ads->configerrno != EINVAL) {
 728     r= ads->configerrno;
 729     init_abort(ads);
 730     return r;
 731   }
 732
 733   r= init_finish(ads);
 734   if (r) return r;
 735
 736   adns__consistency(ads,0,cc_entex);
 737   *ads_r= ads;
 738   return 0;
 739 }
 740
 741 int adns_init(adns_state *ads_r, adns_initflags flags, FILE *diagfile) {
 742   return init_files(ads_r, flags, logfn_file, diagfile ? diagfile : stderr);
 743 }
 744
 745 static int init_strcfg(adns_state *ads_r, adns_initflags flags,
 746                        adns_logcallbackfn *logfn, void *logfndata,
 747                        const char *configtext) {
 748   adns_state ads;
 749   int r;
 750
 751   r= init_begin(&ads, flags, logfn, logfndata);
 752   if (r) return r;
 753
 754   readconfigtext(ads,configtext,"<supplied configuration text>");
 755   if (ads->configerrno) {
 756     r= ads->configerrno;
 757     init_abort(ads);
 758     return r;
 759   }
 760
 761   r= init_finish(ads);  if (r) return r;
 762   adns__consistency(ads,0,cc_entex);
 763   *ads_r= ads;
 764   return 0;
 765 }
 766
 767 int adns_init_strcfg(adns_state *ads_r, adns_initflags flags,
 768                      FILE *diagfile, const char *configtext) {
 769   return init_strcfg(ads_r, flags,
 770                      diagfile ? logfn_file : 0, diagfile,
 771                      configtext);
 772 }
 773
 774 int adns_init_logfn(adns_state *newstate_r, adns_initflags flags,
 775                     const char *configtext /*0=>use default config files*/,
 776                     adns_logcallbackfn *logfn /*0=>logfndata is a FILE* */,
 777                     void *logfndata /*0 with logfn==0 => discard*/) {
 778   if (!logfn && logfndata)
 779     logfn= logfn_file;
 780   if (configtext)
 781     return init_strcfg(newstate_r, flags, logfn, logfndata, configtext);
 782   else
 783     return init_files(newstate_r, flags, logfn, logfndata);
 784 }
 785
 786 void adns_finish(adns_state ads) {
 787   int i;
 788   adns__consistency(ads,0,cc_entex);
 789   for (;;) {
 790     if (ads->udpw.head) adns__cancel(ads->udpw.head);
 791     else if (ads->tcpw.head) adns__cancel(ads->tcpw.head);
 792     else if (ads->childw.head) adns__cancel(ads->childw.head);
 793     else if (ads->output.head) adns__cancel(ads->output.head);
 794     else if (ads->intdone.head) adns__cancel(ads->output.head);
 795     else break;
 796   }
 797   for (i=0; i<ads->nudpsockets; i++) close(ads->udpsockets[i].fd);
 798   if (ads->tcpsocket >= 0) close(ads->tcpsocket);
 799   adns__vbuf_free(&ads->tcpsend);
 800   adns__vbuf_free(&ads->tcprecv);
 801   freesearchlist(ads);
 802   free(ads);
 803 }
 804
 805 void adns_forallqueries_begin(adns_state ads) {
 806   adns__consistency(ads,0,cc_entex);
 807   ads->forallnext=
 808     ads->udpw.head ? ads->udpw.head :
 809     ads->tcpw.head ? ads->tcpw.head :
 810     ads->childw.head ? ads->childw.head :
 811     ads->output.head;
 812 }
 813
 814 adns_query adns_forallqueries_next(adns_state ads, void **context_r) {
 815   adns_query qu, nqu;
 816
 817   adns__consistency(ads,0,cc_entex);
 818   nqu= ads->forallnext;
 819   for (;;) {
 820     qu= nqu;
 821     if (!qu) return 0;
 822     if (qu->next) {
 823       nqu= qu->next;
 824     } else if (qu == ads->udpw.tail) {
 825       nqu=
 826         ads->tcpw.head ? ads->tcpw.head :
 827         ads->childw.head ? ads->childw.head :
 828         ads->output.head;
 829     } else if (qu == ads->tcpw.tail) {
 830       nqu=
 831         ads->childw.head ? ads->childw.head :
 832         ads->output.head;
 833     } else if (qu == ads->childw.tail) {
 834       nqu= ads->output.head;
 835     } else {
 836       nqu= 0;
 837     }
 838     if (!qu->parent) break;
 839   }
 840   ads->forallnext= nqu;
 841   if (context_r) *context_r= qu->ctx.ext;
 842   return qu;
 843 }