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