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   socklen_t salen;
 117
 118   salen= sizeof(a.addr);
 119   err= adns_text2addr(buf,DNS_PORT, 0, &a.addr.sa,&salen);
 120   a.len= salen;
 121   switch (err) {
 122   case 0:
 123     break;
 124   case EINVAL:
 125     configparseerr(ads,fn,lno,"invalid nameserver address `%s'",buf);
 126     return;
 127   default:
 128     configparseerr(ads,fn,lno,"failed to parse nameserver address `%s': %s",
 129                    buf,strerror(err));
 130     return;
 131   }
 132   adns__debug(ads,-1,0,"using nameserver %s",
 133               adns__sockaddr_ntoa(&a.addr.sa, addrbuf));
 134   addserver(ads,&a.addr.sa,salen);
 135 }
 136
 137 static void ccf_search(adns_state ads, const char *fn,
 138                        int lno, const char *buf) {
 139   const char *bufp, *word;
 140   char *newchars, **newptrs, **pp;
 141   int count, tl, l;
 142
 143   if (!buf) return;
 144
 145   bufp= buf;
 146   count= 0;
 147   tl= 0;
 148   while (nextword(&bufp,&word,&l)) { count++; tl += l+1; }
 149
 150   newptrs= malloc(sizeof(char*)*count);
 151   if (!newptrs) { saveerr(ads,errno); return; }
 152
 153   newchars= malloc(tl);
 154   if (!newchars) { saveerr(ads,errno); free(newptrs); return; }
 155
 156   bufp= buf;
 157   pp= newptrs;
 158   while (nextword(&bufp,&word,&l)) {
 159     *pp++= newchars;
 160     memcpy(newchars,word,l);
 161     newchars += l;
 162     *newchars++ = 0;
 163   }
 164
 165   freesearchlist(ads);
 166   ads->nsearchlist= count;
 167   ads->searchlist= newptrs;
 168 }
 169
 170 static int gen_pton(const char *text, int want_af, adns_sockaddr *a) {
 171   int err;
 172   socklen_t len;
 173
 174   len= sizeof(*a);
 175   err= adns_text2addr(text,0, adns_qf_addrlit_scope_forbid,
 176                       &a->sa, &len);
 177   if (err) { assert(err == EINVAL); return 0; }
 178   if (want_af != AF_UNSPEC && a->sa.sa_family != want_af) return 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 initial= -1;
 190
 191   if (!buf) return;
 192
 193   ads->nsortlist= 0;
 194   while (nextword(&buf,&word,&l)) {
 195     if (ads->nsortlist >= MAXSORTLIST) {
 196       adns__diag(ads,-1,0,"too many sortlist entries,"
 197                  " ignoring %.*s onwards",l,word);
 198       return;
 199     }
 200
 201     if (l >= sizeof(tbuf)) {
 202       configparseerr(ads,fn,lno,"sortlist entry `%.*s' too long",l,word);
 203       continue;
 204     }
 205
 206     memcpy(tbuf,word,l); tbuf[l]= 0;
 207     slash= strchr(tbuf,'/');
 208     if (slash) *slash++= 0;
 209
 210     sl= &ads->sortlist[ads->nsortlist];
 211     if (!gen_pton(tbuf, AF_UNSPEC, &sl->base)) {
 212       configparseerr(ads,fn,lno,"invalid address `%s' in sortlist",tbuf);
 213       continue;
 214     }
 215
 216     if (slash) {
 217       if (slash[strspn(slash, "0123456789")]) {
 218         maskwhat = "mask";
 219         if (!gen_pton(slash, sl->base.sa.sa_family, &sl->mask)) {
 220           configparseerr(ads,fn,lno,"invalid mask `%s' in sortlist",slash);
 221           continue;
 222         }
 223       } else {
 224         maskwhat = "prefix length";
 225         initial= strtoul(slash,&ep,10);
 226         if (*ep || initial>adns__addr_width(sl->base.sa.sa_family)) {
 227           configparseerr(ads,fn,lno,"mask length `%s' invalid",slash);
 228           continue;
 229         }
 230         sl->mask.sa.sa_family= sl->base.sa.sa_family;
 231         adns__prefix_mask(&sl->mask, initial);
 232       }
 233     } else {
 234       maskwhat = "implied prefix length";
 235       initial= adns__guess_prefix_length(&sl->base);
 236       if (initial < 0) {
 237         configparseerr(ads,fn,lno, "network address `%s'"
 238                        " in sortlist is not in classed ranges,"
 239                        " must specify mask explicitly", tbuf);
 240         continue;
 241       }
 242       sl->mask.sa.sa_family= sl->base.sa.sa_family;
 243       adns__prefix_mask(&sl->mask, initial);
 244     }
 245
 246     if (!adns__addr_matches(sl->base.sa.sa_family,
 247                             adns__sockaddr_addr(&sl->base.sa),
 248                             &sl->base,&sl->mask)) {
 249       if (initial >= 0) {
 250         configparseerr(ads,fn,lno, "%s %d in sortlist"
 251                        " overlaps address `%s'",maskwhat,initial,tbuf);
 252       } else {
 253         configparseerr(ads,fn,lno, "%s `%s' in sortlist"
 254                        " overlaps address `%s'",maskwhat,slash,tbuf);
 255       }
 256       continue;
 257     }
 258
 259     ads->nsortlist++;
 260   }
 261 }
 262
 263 static void ccf_options(adns_state ads, const char *fn,
 264                         int lno, const char *buf) {
 265   const char *opt, *word, *endword, *endopt;
 266   char *ep;
 267   unsigned long v;
 268   int l;
 269
 270   if (!buf) return;
 271
 272 #define WORD__IS(s,op) ((endword-word) op (sizeof(s)-1) && \
 273                           !memcmp(word,s,(sizeof(s)-1)))
 274 #define WORD_IS(s)     (WORD__IS(s,==))
 275 #define WORD_STARTS(s) (WORD__IS(s,>=) ? ((word+=sizeof(s)-1)) : 0)
 276
 277   while (nextword(&buf,&word,&l)) {
 278     opt=word;
 279     endopt=endword=word+l;
 280     if (WORD_IS("debug")) {
 281       ads->iflags |= adns_if_debug;
 282       continue;
 283     }
 284     if (WORD_STARTS("ndots:")) {
 285       v= strtoul(word,&ep,10);
 286       if (ep==word || ep != endword || v > INT_MAX) {
 287         configparseerr(ads,fn,lno,"option `%.*s' malformed"
 288                        " or has bad value",l,opt);
 289         continue;
 290       }
 291       ads->searchndots= v;
 292       continue;
 293     }
 294     if (WORD_STARTS("adns_checkc:")) {
 295       if (WORD_IS("none")) {
 296         ads->iflags &= ~adns_if_checkc_freq;
 297         ads->iflags |= adns_if_checkc_entex;
 298       } else if (WORD_IS("entex")) {
 299         ads->iflags &= ~adns_if_checkc_freq;
 300         ads->iflags |= adns_if_checkc_entex;
 301       } else if (WORD_IS("freq")) {
 302         ads->iflags |= adns_if_checkc_freq;
 303       } else {
 304         configparseerr(ads,fn,lno, "option adns_checkc has bad value `%s' "
 305                        "(must be none, entex or freq", word);
 306       }
 307       continue;
 308     }
 309     if (WORD_STARTS("adns_af:")) {
 310       ads->iflags &= ~adns_if_afmask;
 311       if (!WORD_IS("any")) for (;;) {
 312         const char *comma= memchr(word,',',endopt-word);
 313         endword=comma?comma:endopt;
 314         if (WORD_IS("ipv4"))
 315           ads->iflags |= adns_if_permit_ipv4;
 316         else if (WORD_IS("ipv6"))
 317           ads->iflags |= adns_if_permit_ipv6;
 318         else {
 319           if (ads->config_report_unknown)
 320             adns__diag(ads,-1,0,"%s:%d: "
 321                        "option adns_af has bad value or entry `%.*s' "
 322                        "(option must be `any', or list of `ipv4',`ipv6')",
 323                        fn,lno, (int)(endword-word),word);
 324           break;
 325         }
 326         if (!comma) break;
 327         word= comma+1;
 328       }
 329       continue;
 330     }
 331     if (WORD_IS("adns_ignoreunkcfg")) {
 332       ads->config_report_unknown=0;
 333       continue;
 334     }
 335     if (/* adns's query strategy is not configurable */
 336         WORD_STARTS("timeout:") ||
 337         WORD_STARTS("attempts:") ||
 338         WORD_IS("rotate") ||
 339         /* adns provides the application with knob for this */
 340         WORD_IS("no-check-names") ||
 341         /* adns normally does IPv6 if the application wants it; control
 342          * this with the adns_af: option if you like */
 343         WORD_IS("inet6") ||
 344         /* adns does not do edns0 and this is not a problem */
 345         WORD_IS("edns0"))
 346       continue;
 347     if (ads->config_report_unknown)
 348       adns__diag(ads,-1,0,"%s:%d: unknown option `%.*s'", fn,lno, l,opt);
 349   }
 350
 351 #undef WORD__IS
 352 #undef WORD_IS
 353 #undef WORD_STARTS
 354 }
 355
 356 static void ccf_clearnss(adns_state ads, const char *fn,
 357                          int lno, const char *buf) {
 358   ads->nservers= 0;
 359 }
 360
 361 static void ccf_include(adns_state ads, const char *fn,
 362                         int lno, const char *buf) {
 363   if (!*buf) {
 364     configparseerr(ads,fn,lno,"`include' directive with no filename");
 365     return;
 366   }
 367   readconfig(ads,buf,1);
 368 }
 369
 370 static void ccf_lookup(adns_state ads, const char *fn, int lno,
 371                        const char *buf) {
 372   int found_bind=0;
 373   const char *word;
 374   int l;
 375
 376   if (!*buf) {
 377     configparseerr(ads,fn,lno,"`lookup' directive with no databases");
 378     return;
 379   }
 380
 381   while (nextword(&buf,&word,&l)) {
 382     if (l==4 && !memcmp(word,"bind",4)) {
 383       found_bind=1;
 384     } else if (l==4 && !memcmp(word,"file",4)) {
 385       /* ignore this and hope /etc/hosts is not essential */
 386     } else if (l==2 && !memcmp(word,"yp",2)) {
 387       adns__diag(ads,-1,0,"%s:%d: yp lookups not supported by adns", fn,lno);
 388       found_bind=-1;
 389     } else {
 390       if (ads->config_report_unknown)
 391         adns__diag(ads,-1,0,"%s:%d: unknown `lookup' database `%.*s'",
 392                    fn,lno, l,word);
 393       found_bind=-1;
 394     }
 395   }
 396   if (!found_bind)
 397     adns__diag(ads,-1,0,"%s:%d: `lookup' specified, but not `bind'", fn,lno);
 398 }
 399
 400 static void ccf_ignore(adns_state ads, const char *fn, int lno,
 401                        const char *buf) {
 402 }
 403
 404 static const struct configcommandinfo {
 405   const char *name;
 406   void (*fn)(adns_state ads, const char *fn, int lno, const char *buf);
 407 } configcommandinfos[]= {
 408   { "nameserver",        ccf_nameserver  },
 409   { "domain",            ccf_search      },
 410   { "search",            ccf_search      },
 411   { "sortlist",          ccf_sortlist    },
 412   { "options",           ccf_options     },
 413   { "clearnameservers",  ccf_clearnss    },
 414   { "include",           ccf_include     },
 415   { "lookup",            ccf_lookup      }, /* OpenBSD */
 416   { "lwserver",          ccf_ignore      }, /* BIND9 lwresd */
 417   {  0                                   }
 418 };
 419
 420 typedef union {
 421   FILE *file;
 422   const char *text;
 423 } getline_ctx;
 424
 425 static int gl_file(adns_state ads, getline_ctx *src_io, const char *filename,
 426                    int lno, char *buf, int buflen) {
 427   FILE *file= src_io->file;
 428   int c, i;
 429   char *p;
 430
 431   p= buf;
 432   buflen--;
 433   i= 0;
 434
 435   for (;;) { /* loop over chars */
 436     if (i == buflen) {
 437       adns__diag(ads,-1,0,"%s:%d: line too long, ignored",filename,lno);
 438       goto x_badline;
 439     }
 440     c= getc(file);
 441     if (!c) {
 442       adns__diag(ads,-1,0,"%s:%d: line contains nul, ignored",filename,lno);
 443       goto x_badline;
 444     } else if (c == '\n') {
 445       break;
 446     } else if (c == EOF) {
 447       if (ferror(file)) {
 448         saveerr(ads,errno);
 449         adns__diag(ads,-1,0,"%s:%d: read error: %s",
 450                    filename,lno,strerror(errno));
 451         return -1;
 452       }
 453       if (!i) return -1;
 454       break;
 455     } else {
 456       *p++= c;
 457       i++;
 458     }
 459   }
 460
 461   *p++= 0;
 462   return i;
 463
 464  x_badline:
 465   saveerr(ads,EINVAL);
 466   while ((c= getc(file)) != EOF && c != '\n');
 467   return -2;
 468 }
 469
 470 static int gl_text(adns_state ads, getline_ctx *src_io, const char *filename,
 471                    int lno, char *buf, int buflen) {
 472   const char *cp= src_io->text;
 473   int l;
 474
 475   if (!cp || !*cp) return -1;
 476
 477   if (*cp == ';' || *cp == '\n') cp++;
 478   l= strcspn(cp,";\n");
 479   src_io->text = cp+l;
 480
 481   if (l >= buflen) {
 482     adns__diag(ads,-1,0,"%s:%d: line too long, ignored",filename,lno);
 483     saveerr(ads,EINVAL);
 484     return -2;
 485   }
 486
 487   memcpy(buf,cp,l);
 488   buf[l]= 0;
 489   return l;
 490 }
 491
 492 static void readconfiggeneric(adns_state ads, const char *filename,
 493                               int (*getline)(adns_state ads, getline_ctx*,
 494                                              const char *filename, int lno,
 495                                              char *buf, int buflen),
 496                               /* Returns >=0 for success, -1 for EOF or error
 497                                * (error will have been reported), or -2 for
 498                                * bad line was encountered, try again.
 499                                */
 500                               getline_ctx gl_ctx) {
 501   char linebuf[2000], *p, *q;
 502   int lno, l, dirl;
 503   const struct configcommandinfo *ccip;
 504
 505   for (lno=1;
 506        (l= getline(ads,&gl_ctx, filename,lno, linebuf,sizeof(linebuf))) != -1;
 507        lno++) {
 508     if (l == -2) continue;
 509     while (l>0 && ctype_whitespace(linebuf[l-1])) l--;
 510     linebuf[l]= 0;
 511     p= linebuf;
 512     while (ctype_whitespace(*p)) p++;
 513     if (*p == '#' || *p == ';' || !*p) continue;
 514     q= p;
 515     while (*q && !ctype_whitespace(*q)) q++;
 516     dirl= q-p;
 517     for (ccip=configcommandinfos;
 518          ccip->name &&
 519            !(strlen(ccip->name)==dirl && !memcmp(ccip->name,p,q-p));
 520          ccip++);
 521     if (!ccip->name) {
 522       if (ads->config_report_unknown)
 523         adns__diag(ads,-1,0,"%s:%d: unknown configuration directive `%.*s'",
 524                    filename,lno,(int)(q-p),p);
 525       continue;
 526     }
 527     while (ctype_whitespace(*q)) q++;
 528     ccip->fn(ads,filename,lno,q);
 529   }
 530 }
 531
 532 static const char *instrum_getenv(adns_state ads, const char *envvar) {
 533   const char *value;
 534
 535   value= getenv(envvar);
 536   if (!value) adns__debug(ads,-1,0,"environment variable %s not set",envvar);
 537   else adns__debug(ads,-1,0,"environment variable %s"
 538                    " set to `%s'",envvar,value);
 539   return value;
 540 }
 541
 542 static void readconfig(adns_state ads, const char *filename, int warnmissing) {
 543   getline_ctx gl_ctx;
 544
 545   gl_ctx.file= fopen(filename,"r");
 546   if (!gl_ctx.file) {
 547     if (errno == ENOENT) {
 548       if (warnmissing)
 549         adns__debug(ads,-1,0, "configuration file"
 550                     " `%s' does not exist",filename);
 551       return;
 552     }
 553     saveerr(ads,errno);
 554     adns__diag(ads,-1,0,"cannot open configuration file `%s': %s",
 555                filename,strerror(errno));
 556     return;
 557   }
 558
 559   readconfiggeneric(ads,filename,gl_file,gl_ctx);
 560
 561   fclose(gl_ctx.file);
 562 }
 563
 564 static void readconfigtext(adns_state ads, const char *text,
 565                            const char *showname) {
 566   getline_ctx gl_ctx;
 567
 568   gl_ctx.text= text;
 569   readconfiggeneric(ads,showname,gl_text,gl_ctx);
 570 }
 571
 572 static void readconfigenv(adns_state ads, const char *envvar) {
 573   const char *filename;
 574
 575   if (ads->iflags & adns_if_noenv) {
 576     adns__debug(ads,-1,0,"not checking environment variable `%s'",envvar);
 577     return;
 578   }
 579   filename= instrum_getenv(ads,envvar);
 580   if (filename) readconfig(ads,filename,1);
 581 }
 582
 583 static void readconfigenvtext(adns_state ads, const char *envvar) {
 584   const char *textdata;
 585
 586   if (ads->iflags & adns_if_noenv) {
 587     adns__debug(ads,-1,0,"not checking environment variable `%s'",envvar);
 588     return;
 589   }
 590   textdata= instrum_getenv(ads,envvar);
 591   if (textdata) readconfigtext(ads,textdata,envvar);
 592 }
 593
 594
 595 int adns__setnonblock(adns_state ads, int fd) {
 596   int r;
 597
 598   r= fcntl(fd,F_GETFL,0); if (r<0) return errno;
 599   r |= O_NONBLOCK;
 600   r= fcntl(fd,F_SETFL,r); if (r<0) return errno;
 601   return 0;
 602 }
 603
 604 static int init_begin(adns_state *ads_r, adns_initflags flags,
 605                       adns_logcallbackfn *logfn, void *logfndata) {
 606   adns_state ads;
 607   pid_t pid;
 608
 609   if (flags & ~(adns_initflags)(0x4fff))
 610     /* 0x4000 is reserved for `harmless' future expansion */
 611     return ENOSYS;
 612
 613   ads= malloc(sizeof(*ads)); if (!ads) return errno;
 614
 615   ads->iflags= flags;
 616   ads->logfn= logfn;
 617   ads->logfndata= logfndata;
 618   ads->configerrno= 0;
 619   LIST_INIT(ads->udpw);
 620   LIST_INIT(ads->tcpw);
 621   LIST_INIT(ads->childw);
 622   LIST_INIT(ads->output);
 623   LIST_INIT(ads->intdone);
 624   ads->forallnext= 0;
 625   ads->nextid= 0x311f;
 626   ads->nudpsockets= 0;
 627   ads->tcpsocket= -1;
 628   adns__vbuf_init(&ads->tcpsend);
 629   adns__vbuf_init(&ads->tcprecv);
 630   ads->tcprecv_skip= 0;
 631   ads->nservers= ads->nsortlist= ads->nsearchlist= ads->tcpserver= 0;
 632   ads->searchndots= 1;
 633   ads->tcpstate= server_disconnected;
 634   timerclear(&ads->tcptimeout);
 635   ads->searchlist= 0;
 636   ads->config_report_unknown=1;
 637
 638   pid= getpid();
 639   ads->rand48xsubi[0]= pid;
 640   ads->rand48xsubi[1]= (unsigned long)pid >> 16;
 641   ads->rand48xsubi[2]= pid ^ ((unsigned long)pid >> 16);
 642
 643   *ads_r= ads;
 644   return 0;
 645 }
 646
 647 static int init_finish(adns_state ads) {
 648   struct sockaddr_in sin;
 649   struct protoent *proto;
 650   struct udpsocket *udp;
 651   int i;
 652   int r;
 653
 654   if (!ads->nservers) {
 655     if (ads->logfn && ads->iflags & adns_if_debug)
 656       adns__lprintf(ads,"adns: no nameservers, using IPv4 localhost\n");
 657     memset(&sin, 0, sizeof(sin));
 658     sin.sin_family = AF_INET;
 659     sin.sin_port = htons(DNS_PORT);
 660     sin.sin_addr.s_addr = htonl(INADDR_LOOPBACK);
 661     addserver(ads,(struct sockaddr *)&sin, sizeof(sin));
 662   }
 663
 664   proto= getprotobyname("udp"); if (!proto) { r= ENOPROTOOPT; goto x_free; }
 665   ads->nudpsockets= 0;
 666   for (i=0; i<ads->nservers; i++) {
 667     if (adns__udpsocket_by_af(ads, ads->servers[i].addr.sa.sa_family))
 668       continue;
 669     assert(ads->nudpsockets < MAXUDP);
 670     udp= &ads->udpsockets[ads->nudpsockets];
 671     udp->af= ads->servers[i].addr.sa.sa_family;
 672     udp->fd= socket(udp->af,SOCK_DGRAM,proto->p_proto);
 673     if (udp->fd < 0) { r= errno; goto x_free; }
 674     ads->nudpsockets++;
 675     r= adns__setnonblock(ads,udp->fd);
 676     if (r) { r= errno; goto x_closeudp; }
 677   }
 678
 679   return 0;
 680
 681  x_closeudp:
 682   for (i=0; i<ads->nudpsockets; i++) close(ads->udpsockets[i].fd);
 683  x_free:
 684   free(ads);
 685   return r;
 686 }
 687
 688 static void init_abort(adns_state ads) {
 689   if (ads->nsearchlist) {
 690     free(ads->searchlist[0]);
 691     free(ads->searchlist);
 692   }
 693   free(ads);
 694 }
 695
 696 static void logfn_file(adns_state ads, void *logfndata,
 697                        const char *fmt, va_list al) {
 698   vfprintf(logfndata,fmt,al);
 699 }
 700
 701 static int init_files(adns_state *ads_r, adns_initflags flags,
 702                       adns_logcallbackfn *logfn, void *logfndata) {
 703   adns_state ads;
 704   const char *res_options, *adns_res_options;
 705   int r;
 706
 707   r= init_begin(&ads, flags, logfn, logfndata);
 708   if (r) return r;
 709
 710   res_options= instrum_getenv(ads,"RES_OPTIONS");
 711   adns_res_options= instrum_getenv(ads,"ADNS_RES_OPTIONS");
 712   ccf_options(ads,"RES_OPTIONS",-1,res_options);
 713   ccf_options(ads,"ADNS_RES_OPTIONS",-1,adns_res_options);
 714
 715   readconfig(ads,"/etc/resolv.conf",1);
 716   readconfig(ads,"/etc/resolv-adns.conf",0);
 717   readconfigenv(ads,"RES_CONF");
 718   readconfigenv(ads,"ADNS_RES_CONF");
 719
 720   readconfigenvtext(ads,"RES_CONF_TEXT");
 721   readconfigenvtext(ads,"ADNS_RES_CONF_TEXT");
 722
 723   ccf_options(ads,"RES_OPTIONS",-1,res_options);
 724   ccf_options(ads,"ADNS_RES_OPTIONS",-1,adns_res_options);
 725
 726   ccf_search(ads,"LOCALDOMAIN",-1,instrum_getenv(ads,"LOCALDOMAIN"));
 727   ccf_search(ads,"ADNS_LOCALDOMAIN",-1,instrum_getenv(ads,"ADNS_LOCALDOMAIN"));
 728
 729   if (ads->configerrno && ads->configerrno != EINVAL) {
 730     r= ads->configerrno;
 731     init_abort(ads);
 732     return r;
 733   }
 734
 735   r= init_finish(ads);
 736   if (r) return r;
 737
 738   adns__consistency(ads,0,cc_entex);
 739   *ads_r= ads;
 740   return 0;
 741 }
 742
 743 int adns_init(adns_state *ads_r, adns_initflags flags, FILE *diagfile) {
 744   return init_files(ads_r, flags, logfn_file, diagfile ? diagfile : stderr);
 745 }
 746
 747 static int init_strcfg(adns_state *ads_r, adns_initflags flags,
 748                        adns_logcallbackfn *logfn, void *logfndata,
 749                        const char *configtext) {
 750   adns_state ads;
 751   int r;
 752
 753   r= init_begin(&ads, flags, logfn, logfndata);
 754   if (r) return r;
 755
 756   readconfigtext(ads,configtext,"<supplied configuration text>");
 757   if (ads->configerrno) {
 758     r= ads->configerrno;
 759     init_abort(ads);
 760     return r;
 761   }
 762
 763   r= init_finish(ads);  if (r) return r;
 764   adns__consistency(ads,0,cc_entex);
 765   *ads_r= ads;
 766   return 0;
 767 }
 768
 769 int adns_init_strcfg(adns_state *ads_r, adns_initflags flags,
 770                      FILE *diagfile, const char *configtext) {
 771   return init_strcfg(ads_r, flags,
 772                      diagfile ? logfn_file : 0, diagfile,
 773                      configtext);
 774 }
 775
 776 int adns_init_logfn(adns_state *newstate_r, adns_initflags flags,
 777                     const char *configtext /*0=>use default config files*/,
 778                     adns_logcallbackfn *logfn /*0=>logfndata is a FILE* */,
 779                     void *logfndata /*0 with logfn==0 => discard*/) {
 780   if (!logfn && logfndata)
 781     logfn= logfn_file;
 782   if (configtext)
 783     return init_strcfg(newstate_r, flags, logfn, logfndata, configtext);
 784   else
 785     return init_files(newstate_r, flags, logfn, logfndata);
 786 }
 787
 788 void adns_finish(adns_state ads) {
 789   int i;
 790   adns__consistency(ads,0,cc_entex);
 791   for (;;) {
 792     if (ads->udpw.head) adns__cancel(ads->udpw.head);
 793     else if (ads->tcpw.head) adns__cancel(ads->tcpw.head);
 794     else if (ads->childw.head) adns__cancel(ads->childw.head);
 795     else if (ads->output.head) adns__cancel(ads->output.head);
 796     else if (ads->intdone.head) adns__cancel(ads->output.head);
 797     else break;
 798   }
 799   for (i=0; i<ads->nudpsockets; i++) close(ads->udpsockets[i].fd);
 800   if (ads->tcpsocket >= 0) close(ads->tcpsocket);
 801   adns__vbuf_free(&ads->tcpsend);
 802   adns__vbuf_free(&ads->tcprecv);
 803   freesearchlist(ads);
 804   free(ads);
 805 }
 806
 807 void adns_forallqueries_begin(adns_state ads) {
 808   adns__consistency(ads,0,cc_entex);
 809   ads->forallnext=
 810     ads->udpw.head ? ads->udpw.head :
 811     ads->tcpw.head ? ads->tcpw.head :
 812     ads->childw.head ? ads->childw.head :
 813     ads->output.head;
 814 }
 815
 816 adns_query adns_forallqueries_next(adns_state ads, void **context_r) {
 817   adns_query qu, nqu;
 818
 819   adns__consistency(ads,0,cc_entex);
 820   nqu= ads->forallnext;
 821   for (;;) {
 822     qu= nqu;
 823     if (!qu) return 0;
 824     if (qu->next) {
 825       nqu= qu->next;
 826     } else if (qu == ads->udpw.tail) {
 827       nqu=
 828         ads->tcpw.head ? ads->tcpw.head :
 829         ads->childw.head ? ads->childw.head :
 830         ads->output.head;
 831     } else if (qu == ads->tcpw.tail) {
 832       nqu=
 833         ads->childw.head ? ads->childw.head :
 834         ads->output.head;
 835     } else if (qu == ads->childw.tail) {
 836       nqu= ads->output.head;
 837     } else {
 838       nqu= 0;
 839     }
 840     if (!qu->parent) break;
 841   }
 842   ads->forallnext= nqu;
 843   if (context_r) *context_r= qu->ctx.ext;
 844   return qu;
 845 }