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
   8  *    Copyright (C) 1997-1999 Ian Jackson <ian@davenant.greenend.org.uk>
   9  *
  10  *  It is part of adns, which is
  11  *    Copyright (C) 1997-1999 Ian Jackson <ian@davenant.greenend.org.uk>
  12  *    Copyright (C) 1999 Tony Finch <dot@dotat.at>
  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 2, 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  *  Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
  27  */
  28
  29 #include <stdlib.h>
  30 #include <errno.h>
  31 #include <limits.h>
  32 #include <unistd.h>
  33 #include <fcntl.h>
  34
  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);
  43
  44 static void addserver(adns_state ads, struct in_addr addr) {
  45   int i;
  46   struct server *ss;
  47
  48   for (i=0; i<ads->nservers; i++) {
  49     if (ads->servers[i].addr.s_addr == addr.s_addr) {
  50       adns__debug(ads,-1,0,"duplicate nameserver %s ignored",inet_ntoa(addr));
  51       return;
  52     }
  53   }
  54
  55   if (ads->nservers>=MAXSERVERS) {
  56     adns__diag(ads,-1,0,"too many nameservers, ignoring %s",inet_ntoa(addr));
  57     return;
  58   }
  59
  60   ss= ads->servers+ads->nservers;
  61   ss->addr= addr;
  62   ads->nservers++;
  63 }
  64
  65 static void saveerr(adns_state ads, int en) {
  66   if (!ads->configerrno) ads->configerrno= en;
  67 }
  68
  69 static void configparseerr(adns_state ads, const char *fn, int lno,
  70                            const char *fmt, ...) {
  71   va_list al;
  72
  73   saveerr(ads,EINVAL);
  74   if (!ads->diagfile || (ads->iflags & adns_if_noerrprint)) return;
  75
  76   if (lno==-1) fprintf(ads->diagfile,"adns: %s: ",fn);
  77   else fprintf(ads->diagfile,"adns: %s:%d: ",fn,lno);
  78   va_start(al,fmt);
  79   vfprintf(ads->diagfile,fmt,al);
  80   va_end(al);
  81   fputc('\n',ads->diagfile);
  82 }
  83
  84 static int nextword(const char **bufp_io, const char **word_r, int *l_r) {
  85   const char *p, *q;
  86
  87   p= *bufp_io;
  88   while (ctype_whitespace(*p)) p++;
  89   if (!*p) return 0;
  90
  91   q= p;
  92   while (*q && !ctype_whitespace(*q)) q++;
  93
  94   *l_r= q-p;
  95   *word_r= p;
  96   *bufp_io= q;
  97
  98   return 1;
  99 }
 100
 101 static void ccf_nameserver(adns_state ads, const char *fn, int lno, const char *buf) {
 102   struct in_addr ia;
 103
 104   if (!inet_aton(buf,&ia)) {
 105     configparseerr(ads,fn,lno,"invalid nameserver address `%s'",buf);
 106     return;
 107   }
 108   adns__debug(ads,-1,0,"using nameserver %s",inet_ntoa(ia));
 109   addserver(ads,ia);
 110 }
 111
 112 static void ccf_search(adns_state ads, const char *fn, int lno, const char *buf) {
 113   const char *bufp, *word;
 114   char *newchars, **newptrs, **pp;
 115   int count, tl, l;
 116
 117   if (!buf) return;
 118
 119   bufp= buf;
 120   count= 0;
 121   tl= 0;
 122   while (nextword(&bufp,&word,&l)) { count++; tl += l+1; }
 123
 124   newptrs= malloc(sizeof(char*)*count);  if (!newptrs) { saveerr(ads,errno); return; }
 125   newchars= malloc(tl);  if (!newchars) { saveerr(ads,errno); free(newptrs); return; }
 126
 127   bufp= buf;
 128   pp= newptrs;
 129   while (nextword(&bufp,&word,&l)) {
 130     *pp++= newchars;
 131     memcpy(newchars,word,l);
 132     newchars += l;
 133     *newchars++ = 0;
 134   }
 135
 136   free(ads->searchlist);
 137   ads->nsearchlist= count;
 138   ads->searchlist= newptrs;
 139 }
 140
 141 static void ccf_sortlist(adns_state ads, const char *fn, int lno, const char *buf) {
 142   const char *word;
 143   char tbuf[200], *slash, *ep;
 144   struct in_addr base, mask;
 145   int l;
 146   unsigned long initial, baselocal;
 147
 148   if (!buf) return;
 149
 150   ads->nsortlist= 0;
 151   while (nextword(&buf,&word,&l)) {
 152     if (ads->nsortlist >= MAXSORTLIST) {
 153       adns__diag(ads,-1,0,"too many sortlist entries, ignoring %.*s onwards",l,word);
 154       return;
 155     }
 156
 157     if (l >= sizeof(tbuf)) {
 158       configparseerr(ads,fn,lno,"sortlist entry `%.*s' too long",l,word);
 159       continue;
 160     }
 161
 162     memcpy(tbuf,word,l); tbuf[l]= 0;
 163     slash= strchr(tbuf,'/');
 164     if (slash) *slash++= 0;
 165
 166     if (!inet_aton(tbuf,&base)) {
 167       configparseerr(ads,fn,lno,"invalid address `%s' in sortlist",tbuf);
 168       continue;
 169     }
 170
 171     if (slash) {
 172       if (strchr(slash,'.')) {
 173         if (!inet_aton(slash,&mask)) {
 174           configparseerr(ads,fn,lno,"invalid mask `%s' in sortlist",slash);
 175           continue;
 176         }
 177         if (base.s_addr & ~mask.s_addr) {
 178           configparseerr(ads,fn,lno,
 179                          "mask `%s' in sortlist overlaps address `%s'",slash,tbuf);
 180           continue;
 181         }
 182       } else {
 183         initial= strtoul(slash,&ep,10);
 184         if (*ep || initial>32) {
 185           configparseerr(ads,fn,lno,"mask length `%s' invalid",slash);
 186           continue;
 187         }
 188         mask.s_addr= htonl((0x0ffffffffUL) << (32-initial));
 189       }
 190     } else {
 191       baselocal= ntohl(base.s_addr);
 192       if (!baselocal & 0x080000000UL) /* class A */
 193         mask.s_addr= htonl(0x0ff000000UL);
 194       else if ((baselocal & 0x0c0000000UL) == 0x080000000UL)
 195         mask.s_addr= htonl(0x0ffff0000UL); /* class B */
 196       else if ((baselocal & 0x0f0000000UL) == 0x0e0000000UL)
 197         mask.s_addr= htonl(0x0ff000000UL); /* class C */
 198       else {
 199         configparseerr(ads,fn,lno,
 200                        "network address `%s' in sortlist is not in classed ranges,"
 201                        " must specify mask explicitly", tbuf);
 202         continue;
 203       }
 204     }
 205
 206     ads->sortlist[ads->nsortlist].base= base;
 207     ads->sortlist[ads->nsortlist].mask= mask;
 208     ads->nsortlist++;
 209   }
 210 }
 211
 212 static void ccf_options(adns_state ads, const char *fn, int lno, const char *buf) {
 213   const char *word;
 214   char *ep;
 215   unsigned long v;
 216   int l;
 217
 218   if (!buf) return;
 219
 220   while (nextword(&buf,&word,&l)) {
 221     if (l==5 && !memcmp(word,"debug",5)) {
 222       ads->iflags |= adns_if_debug;
 223       continue;
 224     }
 225     if (l>=6 && !memcmp(word,"ndots:",6)) {
 226       v= strtoul(word+6,&ep,10);
 227       if (l==6 || ep != word+l || v > INT_MAX) {
 228         configparseerr(ads,fn,lno,"option `%.*s' malformed or has bad value",l,word);
 229         continue;
 230       }
 231       ads->searchndots= v;
 232       continue;
 233     }
 234     if (l>=12 && !memcmp(word,"adns_checkc:",12)) {
 235       if (!strcmp(word+12,"none")) {
 236         ads->iflags &= ~adns_if_checkc_freq;
 237         ads->iflags |= adns_if_checkc_entex;
 238       } else if (!strcmp(word+12,"entex")) {
 239         ads->iflags &= ~adns_if_checkc_freq;
 240         ads->iflags |= adns_if_checkc_entex;
 241       } else if (!strcmp(word+12,"freq")) {
 242         ads->iflags |= adns_if_checkc_freq;
 243       } else {
 244         configparseerr(ads,fn,lno, "option adns_checkc has bad value `%s' "
 245                        "(must be none, entex or freq", word+12);
 246       }
 247       continue;
 248     }
 249     adns__diag(ads,-1,0,"%s:%d: unknown option `%.*s'", fn,lno, l,word);
 250   }
 251 }
 252
 253 static void ccf_clearnss(adns_state ads, const char *fn, int lno, const char *buf) {
 254   ads->nservers= 0;
 255 }
 256
 257 static void ccf_include(adns_state ads, const char *fn, int lno, const char *buf) {
 258   if (!*buf) {
 259     configparseerr(ads,fn,lno,"`include' directive with no filename");
 260     return;
 261   }
 262   readconfig(ads,buf);
 263 }
 264
 265 static const struct configcommandinfo {
 266   const char *name;
 267   void (*fn)(adns_state ads, const char *fn, int lno, const char *buf);
 268 } configcommandinfos[]= {
 269   { "nameserver",        ccf_nameserver  },
 270   { "domain",            ccf_search      },
 271   { "search",            ccf_search      },
 272   { "sortlist",          ccf_sortlist    },
 273   { "options",           ccf_options     },
 274   { "clearnameservers",  ccf_clearnss    },
 275   { "include",           ccf_include     },
 276   {  0                                   }
 277 };
 278
 279 typedef union {
 280   FILE *file;
 281   const char *text;
 282 } getline_ctx;
 283
 284 static int gl_file(adns_state ads, getline_ctx *src_io, const char *filename,
 285                    int lno, char *buf, int buflen) {
 286   FILE *file= src_io->file;
 287   int c, i;
 288   char *p;
 289
 290   p= buf;
 291   buflen--;
 292   i= 0;
 293
 294   for (;;) { /* loop over chars */
 295     if (i == buflen) {
 296       adns__diag(ads,-1,0,"%s:%d: line too long, ignored",filename,lno);
 297       goto x_badline;
 298     }
 299     c= getc(file);
 300     if (!c) {
 301       adns__diag(ads,-1,0,"%s:%d: line contains nul, ignored",filename,lno);
 302       goto x_badline;
 303     } else if (c == '\n') {
 304       break;
 305     } else if (c == EOF) {
 306       if (ferror(file)) {
 307         saveerr(ads,errno);
 308         adns__diag(ads,-1,0,"%s:%d: read error: %s",filename,lno,strerror(errno));
 309         return -1;
 310       }
 311       if (!i) return -1;
 312       break;
 313     } else {
 314       *p++= c;
 315       i++;
 316     }
 317   }
 318
 319   *p++= 0;
 320   return i;
 321
 322  x_badline:
 323   saveerr(ads,EINVAL);
 324   while ((c= getc(file)) != EOF && c != '\n');
 325   return -2;
 326 }
 327
 328 static int gl_text(adns_state ads, getline_ctx *src_io, const char *filename,
 329                    int lno, char *buf, int buflen) {
 330   const char *cp= src_io->text;
 331   int l;
 332
 333   if (!cp || !*cp) return -1;
 334
 335   if (*cp == ';' || *cp == '\n') cp++;
 336   l= strcspn(cp,";\n");
 337   src_io->text = cp+l;
 338
 339   if (l >= buflen) {
 340     adns__diag(ads,-1,0,"%s:%d: line too long, ignored",filename,lno);
 341     saveerr(ads,EINVAL);
 342     return -2;
 343   }
 344
 345   memcpy(buf,cp,l);
 346   buf[l]= 0;
 347   return l;
 348 }
 349
 350 static void readconfiggeneric(adns_state ads, const char *filename,
 351                               int (*getline)(adns_state ads, getline_ctx*,
 352                                              const char *filename, int lno,
 353                                              char *buf, int buflen),
 354                               /* Returns >=0 for success, -1 for EOF or error
 355                                * (error will have been reported), or -2 for
 356                                * bad line was encountered, try again.
 357                                */
 358                               getline_ctx gl_ctx) {
 359   char linebuf[2000], *p, *q;
 360   int lno, l, dirl;
 361   const struct configcommandinfo *ccip;
 362
 363   for (lno=1;
 364        (l= getline(ads,&gl_ctx, filename,lno, linebuf,sizeof(linebuf))) != -1;
 365        lno++) {
 366     if (l == -2) continue;
 367     while (l>0 && ctype_whitespace(linebuf[l-1])) l--;
 368     linebuf[l]= 0;
 369     p= linebuf;
 370     while (ctype_whitespace(*p)) p++;
 371     if (*p == '#' || !*p) continue;
 372     q= p;
 373     while (*q && !ctype_whitespace(*q)) q++;
 374     dirl= q-p;
 375     for (ccip=configcommandinfos;
 376          ccip->name && !(strlen(ccip->name)==dirl && !memcmp(ccip->name,p,q-p));
 377          ccip++);
 378     if (!ccip->name) {
 379       adns__diag(ads,-1,0,"%s:%d: unknown configuration directive `%.*s'",
 380                  filename,lno,q-p,p);
 381       continue;
 382     }
 383     while (ctype_whitespace(*q)) q++;
 384     ccip->fn(ads,filename,lno,q);
 385   }
 386 }
 387
 388 static const char *instrum_getenv(adns_state ads, const char *envvar) {
 389   const char *value;
 390
 391   value= getenv(envvar);
 392   if (!value) adns__debug(ads,-1,0,"environment variable %s not set",envvar);
 393   else adns__debug(ads,-1,0,"environment variable %s set to `%s'",envvar,value);
 394   return value;
 395 }
 396
 397 static void readconfig(adns_state ads, const char *filename) {
 398   getline_ctx gl_ctx;
 399
 400   gl_ctx.file= fopen(filename,"r");
 401   if (!gl_ctx.file) {
 402     if (errno == ENOENT) {
 403       adns__debug(ads,-1,0,"configuration file `%s' does not exist",filename);
 404       return;
 405     }
 406     saveerr(ads,errno);
 407     adns__diag(ads,-1,0,"cannot open configuration file `%s': %s",
 408                filename,strerror(errno));
 409     return;
 410   }
 411
 412   readconfiggeneric(ads,filename,gl_file,gl_ctx);
 413
 414   fclose(gl_ctx.file);
 415 }
 416
 417 static void readconfigtext(adns_state ads, const char *text, const char *showname) {
 418   getline_ctx gl_ctx;
 419
 420   gl_ctx.text= text;
 421   readconfiggeneric(ads,showname,gl_text,gl_ctx);
 422 }
 423
 424 static void readconfigenv(adns_state ads, const char *envvar) {
 425   const char *filename;
 426
 427   if (ads->iflags & adns_if_noenv) {
 428     adns__debug(ads,-1,0,"not checking environment variable `%s'",envvar);
 429     return;
 430   }
 431   filename= instrum_getenv(ads,envvar);
 432   if (filename) readconfig(ads,filename);
 433 }
 434
 435 static void readconfigenvtext(adns_state ads, const char *envvar) {
 436   const char *textdata;
 437
 438   if (ads->iflags & adns_if_noenv) {
 439     adns__debug(ads,-1,0,"not checking environment variable `%s'",envvar);
 440     return;
 441   }
 442   textdata= instrum_getenv(ads,envvar);
 443   if (textdata) readconfigtext(ads,textdata,envvar);
 444 }
 445
 446
 447 int adns__setnonblock(adns_state ads, int fd) {
 448   int r;
 449
 450   r= fcntl(fd,F_GETFL,0); if (r<0) return errno;
 451   r |= O_NONBLOCK;
 452   r= fcntl(fd,F_SETFL,r); if (r<0) return errno;
 453   return 0;
 454 }
 455
 456 static int init_begin(adns_state *ads_r, adns_initflags flags, FILE *diagfile) {
 457   adns_state ads;
 458
 459   ads= malloc(sizeof(*ads)); if (!ads) return errno;
 460
 461   ads->iflags= flags;
 462   ads->diagfile= diagfile;
 463   ads->configerrno= 0;
 464   LIST_INIT(ads->timew);
 465   LIST_INIT(ads->childw);
 466   LIST_INIT(ads->output);
 467   ads->forallnext= 0;
 468   ads->nextid= 0x311f;
 469   ads->udpsocket= ads->tcpsocket= -1;
 470   adns__vbuf_init(&ads->tcpsend);
 471   adns__vbuf_init(&ads->tcprecv);
 472   ads->tcprecv_skip= 0;
 473   ads->nservers= ads->nsortlist= ads->nsearchlist= ads->tcpserver= 0;
 474   ads->searchndots= 1;
 475   ads->tcpstate= server_disconnected;
 476   timerclear(&ads->tcptimeout);
 477   ads->searchlist= 0;
 478
 479   *ads_r= ads;
 480   return 0;
 481 }
 482
 483 static int init_finish(adns_state ads) {
 484   struct in_addr ia;
 485   struct protoent *proto;
 486   int r;
 487
 488   if (!ads->nservers) {
 489     if (ads->diagfile && ads->iflags & adns_if_debug)
 490       fprintf(ads->diagfile,"adns: no nameservers, using localhost\n");
 491     ia.s_addr= htonl(INADDR_LOOPBACK);
 492     addserver(ads,ia);
 493   }
 494
 495   proto= getprotobyname("udp"); if (!proto) { r= ENOPROTOOPT; goto x_free; }
 496   ads->udpsocket= socket(AF_INET,SOCK_DGRAM,proto->p_proto);
 497   if (ads->udpsocket<0) { r= errno; goto x_free; }
 498
 499   r= adns__setnonblock(ads,ads->udpsocket);
 500   if (r) { r= errno; goto x_closeudp; }
 501
 502   return 0;
 503
 504  x_closeudp:
 505   close(ads->udpsocket);
 506  x_free:
 507   free(ads);
 508   return r;
 509 }
 510
 511 static void init_abort(adns_state ads) {
 512   if (ads->nsearchlist) {
 513     free(ads->searchlist[0]);
 514     free(ads->searchlist);
 515   }
 516   free(ads);
 517 }
 518
 519 int adns_init(adns_state *ads_r, int flags, FILE *diagfile) {
 520   adns_state ads;
 521   const char *res_options, *adns_res_options;
 522   int r;
 523
 524   r= init_begin(&ads, flags, diagfile ? diagfile : stderr);
 525   if (r) return r;
 526
 527   res_options= instrum_getenv(ads,"RES_OPTIONS");
 528   adns_res_options= instrum_getenv(ads,"ADNS_RES_OPTIONS");
 529   ccf_options(ads,"RES_OPTIONS",-1,res_options);
 530   ccf_options(ads,"ADNS_RES_OPTIONS",-1,adns_res_options);
 531
 532   readconfig(ads,"/etc/resolv.conf");
 533   readconfigenv(ads,"RES_CONF");
 534   readconfigenv(ads,"ADNS_RES_CONF");
 535
 536   readconfigenvtext(ads,"RES_CONF_TEXT");
 537   readconfigenvtext(ads,"ADNS_RES_CONF_TEXT");
 538
 539   ccf_options(ads,"RES_OPTIONS",-1,res_options);
 540   ccf_options(ads,"ADNS_RES_OPTIONS",-1,adns_res_options);
 541
 542   ccf_search(ads,"LOCALDOMAIN",-1,instrum_getenv(ads,"LOCALDOMAIN"));
 543   ccf_search(ads,"ADNS_LOCALDOMAIN",-1,instrum_getenv(ads,"ADNS_LOCALDOMAIN"));
 544
 545   if (ads->configerrno && ads->configerrno != EINVAL) {
 546     r= ads->configerrno;
 547     init_abort(ads);
 548     return r;
 549   }
 550
 551   r= init_finish(ads);
 552   if (r) return r;
 553
 554   adns__consistency(ads,0,cc_entex);
 555   *ads_r= ads;
 556   return 0;
 557 }
 558
 559 int adns_init_strcfg(adns_state *ads_r, int flags,
 560                      FILE *diagfile, const char *configtext) {
 561   adns_state ads;
 562   int r;
 563
 564   r= init_begin(&ads, flags, diagfile);  if (r) return r;
 565
 566   readconfigtext(ads,configtext,"<supplied configuration text>");
 567   if (ads->configerrno) {
 568     r= ads->configerrno;
 569     init_abort(ads);
 570     return r;
 571   }
 572
 573   r= init_finish(ads);  if (r) return r;
 574   adns__consistency(ads,0,cc_entex);
 575   *ads_r= ads;
 576   return 0;
 577 }
 578
 579
 580 void adns_finish(adns_state ads) {
 581   adns__consistency(ads,0,cc_entex);
 582   for (;;) {
 583     if (ads->timew.head) adns_cancel(ads->timew.head);
 584     else if (ads->childw.head) adns_cancel(ads->childw.head);
 585     else if (ads->output.head) adns_cancel(ads->output.head);
 586     else break;
 587   }
 588   close(ads->udpsocket);
 589   if (ads->tcpsocket >= 0) close(ads->tcpsocket);
 590   adns__vbuf_free(&ads->tcpsend);
 591   adns__vbuf_free(&ads->tcprecv);
 592   free(ads);
 593 }
 594
 595 void adns_forallqueries_begin(adns_state ads) {
 596   adns__consistency(ads,0,cc_entex);
 597   ads->forallnext=
 598     ads->timew.head ? ads->timew.head :
 599     ads->childw.head ? ads->childw.head :
 600     ads->output.head;
 601 }
 602
 603 adns_query adns_forallqueries_next(adns_state ads, void **context_r) {
 604   adns_query qu, nqu;
 605
 606   adns__consistency(ads,0,cc_entex);
 607   nqu= ads->forallnext;
 608   for (;;) {
 609     qu= nqu;
 610     if (!qu) return 0;
 611     if (qu->next) {
 612       nqu= qu->next;
 613     } else if (qu == ads->timew.tail) {
 614       if (ads->childw.head) {
 615         nqu= ads->childw.head;
 616       } else {
 617         nqu= ads->output.head;
 618       }
 619     } else if (qu == ads->childw.tail) {
 620       nqu= ads->output.head;
 621     } else {
 622       nqu= 0;
 623     }
 624     if (!qu->parent) break;
 625   }
 626   ads->forallnext= nqu;
 627   if (context_r) *context_r= qu->ctx.ext;
 628   return qu;
 629 }
 630
 631 void adns__checkqueues(adns_state ads) {
 632   adns_forallqueries_begin(ads);
 633   while (adns_forallqueries_next(ads,0));
 634 }