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 Copyright (C) 1997-1999 Ian Jackson
   8  *
   9  *  This program is free software; you can redistribute it and/or modify
  10  *  it under the terms of the GNU General Public License as published by
  11  *  the Free Software Foundation; either version 2, or (at your option)
  12  *  any later version.
  13  *
  14  *  This program is distributed in the hope that it will be useful,
  15  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
  16  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  17  *  GNU General Public License for more details.
  18  *
  19  *  You should have received a copy of the GNU General Public License
  20  *  along with this program; if not, write to the Free Software Foundation,
  21  *  Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
  22  */
  23
  24 #include <stdlib.h>
  25 #include <errno.h>
  26 #include <string.h>
  27 #include <unistd.h>
  28 #include <fcntl.h>
  29
  30 #include <netdb.h>
  31 #include <arpa/inet.h>
  32
  33 #include "internal.h"
  34
  35 static void readconfig(adns_state ads, const char *filename);
  36
  37 static void addserver(adns_state ads, struct in_addr addr) {
  38   int i;
  39   struct server *ss;
  40
  41   for (i=0; i<ads->nservers; i++) {
  42     if (ads->servers[i].addr.s_addr == addr.s_addr) {
  43       adns__debug(ads,-1,0,"duplicate nameserver %s ignored",inet_ntoa(addr));
  44       return;
  45     }
  46   }
  47
  48   if (ads->nservers>=MAXSERVERS) {
  49     adns__diag(ads,-1,0,"too many nameservers, ignoring %s",inet_ntoa(addr));
  50     return;
  51   }
  52
  53   ss= ads->servers+ads->nservers;
  54   ss->addr= addr;
  55   ads->nservers++;
  56 }
  57
  58 static void saveerr(adns_state ads, int en) {
  59   if (!ads->configerrno) ads->configerrno= en;
  60 }
  61
  62 static void configparseerr(adns_state ads, const char *fn, int lno,
  63                            const char *fmt, ...) {
  64   va_list al;
  65
  66   saveerr(ads,EINVAL);
  67   if (!ads->diagfile || (ads->iflags & adns_if_noerrprint)) return;
  68
  69   if (lno==-1) fprintf(ads->diagfile,"adns: %s: ",fn);
  70   else fprintf(ads->diagfile,"adns: %s:%d: ",fn,lno);
  71   va_start(al,fmt);
  72   vfprintf(ads->diagfile,fmt,al);
  73   va_end(al);
  74   fputc('\n',ads->diagfile);
  75 }
  76
  77 static int nextword(const char **bufp_io, const char **word_r, int *l_r) {
  78   const char *p, *q;
  79
  80   p= *bufp_io;
  81   while (ctype_whitespace(*p)) p++;
  82   if (!*p) return 0;
  83
  84   q= p;
  85   while (*q && !ctype_whitespace(*q)) q++;
  86
  87   *l_r= q-p;
  88   *word_r= p;
  89   *bufp_io= q;
  90
  91   return 1;
  92 }
  93
  94 static void ccf_nameserver(adns_state ads, const char *fn, int lno, const char *buf) {
  95   struct in_addr ia;
  96
  97   if (!inet_aton(buf,&ia)) {
  98     configparseerr(ads,fn,lno,"invalid nameserver address `%s'",buf);
  99     return;
 100   }
 101   adns__debug(ads,-1,0,"using nameserver %s",inet_ntoa(ia));
 102   addserver(ads,ia);
 103 }
 104
 105 static void ccf_search(adns_state ads, const char *fn, int lno, const char *buf) {
 106   const char *bufp, *word;
 107   char *newchars, **newptrs, **pp;
 108   int count, tl, l;
 109
 110   if (!buf) return;
 111
 112   bufp= buf;
 113   count= 0;
 114   tl= 0;
 115   while (nextword(&bufp,&word,&l)) { count++; tl += l+1; }
 116
 117   newptrs= malloc(sizeof(char*)*count);  if (!newptrs) { saveerr(ads,errno); return; }
 118   newchars= malloc(tl);  if (!newchars) { saveerr(ads,errno); free(newptrs); return; }
 119
 120   bufp= buf;
 121   pp= newptrs;
 122   while (nextword(&bufp,&word,&l)) {
 123     *pp++= newchars;
 124     memcpy(newchars,word,l);
 125     newchars += l;
 126     *newchars++ = 0;
 127   }
 128
 129   free(ads->searchlist);
 130   ads->nsearchlist= count;
 131   ads->searchlist= newptrs;
 132   /* fixme: actually pay attention */
 133 }
 134
 135 static void ccf_sortlist(adns_state ads, const char *fn, int lno, const char *buf) {
 136   const char *word;
 137   char tbuf[200], *slash, *ep;
 138   struct in_addr base, mask;
 139   int l;
 140   unsigned long initial, baselocal;
 141
 142   if (!buf) return;
 143
 144   ads->nsortlist= 0;
 145   while (nextword(&buf,&word,&l)) {
 146     if (ads->nsortlist >= MAXSORTLIST) {
 147       adns__diag(ads,-1,0,"too many sortlist entries, ignoring %.*s onwards",l,word);
 148       return;
 149     }
 150
 151     if (l >= sizeof(tbuf)) {
 152       configparseerr(ads,fn,lno,"sortlist entry `%.*s' too long",l,word);
 153       continue;
 154     }
 155
 156     memcpy(tbuf,word,l);
 157     slash= strchr(tbuf,'/');
 158     if (slash) *slash++= 0;
 159
 160     if (!inet_aton(tbuf,&base)) {
 161       configparseerr(ads,fn,lno,"invalid address `%s' in sortlist",tbuf);
 162       continue;
 163     }
 164
 165     if (slash) {
 166       if (strchr(slash,'.')) {
 167         if (!inet_aton(slash,&mask)) {
 168           configparseerr(ads,fn,lno,"invalid mask `%s' in sortlist",slash);
 169           continue;
 170         }
 171         if (base.s_addr & ~mask.s_addr) {
 172           configparseerr(ads,fn,lno,
 173                          "mask `%s' in sortlist overlaps address `%s'",slash,tbuf);
 174           continue;
 175         }
 176       } else {
 177         initial= strtoul(slash,&ep,10);
 178         if (*ep || initial>32) {
 179           configparseerr(ads,fn,lno,"mask length `%s' invalid",slash);
 180           continue;
 181         }
 182         mask.s_addr= htonl((0x0ffffffffUL) << (32-initial));
 183       }
 184     } else {
 185       baselocal= ntohl(base.s_addr);
 186       if (!baselocal & 0x080000000UL) /* class A */
 187         mask.s_addr= htonl(0x0ff000000UL);
 188       else if ((baselocal & 0x0c0000000UL) == 0x080000000UL)
 189         mask.s_addr= htonl(0x0ffff0000UL); /* class B */
 190       else if ((baselocal & 0x0f0000000UL) == 0x0e0000000UL)
 191         mask.s_addr= htonl(0x0ff000000UL); /* class C */
 192       else {
 193         configparseerr(ads,fn,lno,
 194                        "network address `%s' in sortlist is not in classed ranges,"
 195                        " must specify mask explicitly", tbuf);
 196         continue;
 197       }
 198     }
 199
 200     ads->sortlist[ads->nsortlist].base= base;
 201     ads->sortlist[ads->nsortlist].mask= mask;
 202     ads->nsortlist++;
 203   }
 204 }
 205
 206 static void ccf_options(adns_state ads, const char *fn, int lno, const char *buf) {
 207   if (!buf) return;
 208   adns__diag(ads,-1,0,"warning - `options' ignored fixme");
 209 }
 210
 211 static void ccf_clearnss(adns_state ads, const char *fn, int lno, const char *buf) {
 212   ads->nservers= 0;
 213 }
 214
 215 static void ccf_include(adns_state ads, const char *fn, int lno, const char *buf) {
 216   if (!*buf) {
 217     configparseerr(ads,fn,lno,"`include' directive with no filename");
 218     return;
 219   }
 220   readconfig(ads,buf);
 221 }
 222
 223 static const struct configcommandinfo {
 224   const char *name;
 225   void (*fn)(adns_state ads, const char *fn, int lno, const char *buf);
 226 } configcommandinfos[]= {
 227   { "nameserver",        ccf_nameserver  },
 228   { "domain",            ccf_search      },
 229   { "search",            ccf_search      },
 230   { "sortlist",          ccf_sortlist    },
 231   { "options",           ccf_options     },
 232   { "clearnameservers",  ccf_clearnss    },
 233   { "include",           ccf_include     },
 234   {  0                                   }
 235 };
 236
 237 typedef union {
 238   FILE *file;
 239   const char *text;
 240 } getline_ctx;
 241
 242 static int gl_file(adns_state ads, getline_ctx *src_io, const char *filename,
 243                    int lno, char *buf, int buflen) {
 244   FILE *file= src_io->file;
 245   int c, i;
 246   char *p;
 247
 248   p= buf;
 249   buflen--;
 250   i= 0;
 251
 252   for (;;) { /* loop over chars */
 253     if (i == buflen) {
 254       adns__diag(ads,-1,0,"%s:%d: line too long, ignored",filename,lno);
 255       goto x_badline;
 256     }
 257     c= getc(file);
 258     if (!c) {
 259       adns__diag(ads,-1,0,"%s:%d: line contains nul, ignored",filename,lno);
 260       goto x_badline;
 261     } else if (c == '\n') {
 262       break;
 263     } else if (c == EOF) {
 264       if (ferror(file)) {
 265         saveerr(ads,errno);
 266         adns__diag(ads,-1,0,"%s:%d: read error: %s",filename,lno,strerror(errno));
 267         return -1;
 268       }
 269       if (!i) return -1;
 270       break;
 271     } else {
 272       *p++= c;
 273       i++;
 274     }
 275   }
 276
 277   *p++= 0;
 278   return i;
 279
 280  x_badline:
 281   saveerr(ads,EINVAL);
 282   while ((c= getc(file)) != EOF && c != '\n');
 283   return -2;
 284 }
 285
 286 static int gl_text(adns_state ads, getline_ctx *src_io, const char *filename,
 287                    int lno, char *buf, int buflen) {
 288   const char *cp= src_io->text;
 289   int l;
 290
 291   if (!cp || !*cp) return -1;
 292
 293   if (*cp == ';' || *cp == '\n') cp++;
 294   l= strcspn(cp,";\n");
 295   src_io->text = cp+l;
 296
 297   if (l >= buflen) {
 298     adns__diag(ads,-1,0,"%s:%d: line too long, ignored",filename,lno);
 299     saveerr(ads,EINVAL);
 300     return -2;
 301   }
 302
 303   memcpy(buf,cp,l);
 304   buf[l]= 0;
 305   return l;
 306 }
 307
 308 static void readconfiggeneric(adns_state ads, const char *filename,
 309                               int (*getline)(adns_state ads, getline_ctx*,
 310                                              const char *filename, int lno,
 311                                              char *buf, int buflen),
 312                               /* Returns >=0 for success, -1 for EOF or error
 313                                * (error will have been reported), or -2 for
 314                                * bad line was encountered, try again.
 315                                */
 316                               getline_ctx gl_ctx) {
 317   char linebuf[2000], *p, *q;
 318   int lno, l, dirl;
 319   const struct configcommandinfo *ccip;
 320
 321   for (lno=1;
 322        (l= getline(ads,&gl_ctx, filename,lno, linebuf,sizeof(linebuf))) != -1;
 323        lno++) {
 324     if (l == -2) continue;
 325     while (l>0 && ctype_whitespace(linebuf[l-1])) l--;
 326     linebuf[l]= 0;
 327     p= linebuf;
 328     while (ctype_whitespace(*p)) p++;
 329     if (*p == '#' || !*p) continue;
 330     q= p;
 331     while (*q && !ctype_whitespace(*q)) q++;
 332     dirl= q-p;
 333     for (ccip=configcommandinfos;
 334          ccip->name && !(strlen(ccip->name)==dirl && !memcmp(ccip->name,p,q-p));
 335          ccip++);
 336     if (!ccip->name) {
 337       adns__diag(ads,-1,0,"%s:%d: unknown configuration directive `%.*s'",
 338                  filename,lno,q-p,p);
 339       continue;
 340     }
 341     while (ctype_whitespace(*q)) q++;
 342     ccip->fn(ads,filename,lno,q);
 343   }
 344 }
 345
 346 static const char *instrum_getenv(adns_state ads, const char *envvar) {
 347   const char *value;
 348
 349   value= getenv(envvar);
 350   if (!value) adns__debug(ads,-1,0,"environment variable %s not set",envvar);
 351   else adns__debug(ads,-1,0,"environment variable %s set to `%s'",envvar,value);
 352   return value;
 353 }
 354
 355 static void readconfig(adns_state ads, const char *filename) {
 356   getline_ctx gl_ctx;
 357
 358   gl_ctx.file= fopen(filename,"r");
 359   if (!gl_ctx.file) {
 360     if (errno == ENOENT) {
 361       adns__debug(ads,-1,0,"configuration file `%s' does not exist",filename);
 362       return;
 363     }
 364     saveerr(ads,errno);
 365     adns__diag(ads,-1,0,"cannot open configuration file `%s': %s",
 366                filename,strerror(errno));
 367     return;
 368   }
 369
 370   readconfiggeneric(ads,filename,gl_file,gl_ctx);
 371
 372   fclose(gl_ctx.file);
 373 }
 374
 375 static void readconfigtext(adns_state ads, const char *text, const char *showname) {
 376   getline_ctx gl_ctx;
 377
 378   gl_ctx.text= text;
 379   readconfiggeneric(ads,showname,gl_text,gl_ctx);
 380 }
 381
 382 static void readconfigenv(adns_state ads, const char *envvar) {
 383   const char *filename;
 384
 385   if (ads->iflags & adns_if_noenv) {
 386     adns__debug(ads,-1,0,"not checking environment variable `%s'",envvar);
 387     return;
 388   }
 389   filename= instrum_getenv(ads,envvar);
 390   if (filename) readconfig(ads,filename);
 391 }
 392
 393 static void readconfigenvtext(adns_state ads, const char *envvar) {
 394   const char *textdata;
 395
 396   if (ads->iflags & adns_if_noenv) {
 397     adns__debug(ads,-1,0,"not checking environment variable `%s'",envvar);
 398     return;
 399   }
 400   textdata= instrum_getenv(ads,envvar);
 401   if (textdata) readconfigtext(ads,textdata,envvar);
 402 }
 403
 404
 405 int adns__setnonblock(adns_state ads, int fd) {
 406   int r;
 407
 408   r= fcntl(fd,F_GETFL,0); if (r<0) return errno;
 409   r |= O_NONBLOCK;
 410   r= fcntl(fd,F_SETFL,r); if (r<0) return errno;
 411   return 0;
 412 }
 413
 414 static int init_begin(adns_state *ads_r, adns_initflags flags, FILE *diagfile) {
 415   adns_state ads;
 416
 417   ads= malloc(sizeof(*ads)); if (!ads) return errno;
 418
 419   ads->iflags= flags;
 420   ads->diagfile= diagfile;
 421   LIST_INIT(ads->timew);
 422   LIST_INIT(ads->childw);
 423   LIST_INIT(ads->output);
 424   ads->nextid= 0x311f;
 425   ads->udpsocket= ads->tcpsocket= -1;
 426   adns__vbuf_init(&ads->tcpsend);
 427   adns__vbuf_init(&ads->tcprecv);
 428   ads->nservers= ads->nsortlist= ads->nsearchlist= ads->tcpserver= 0;
 429   ads->tcpstate= server_disconnected;
 430   ads->searchlist= 0;
 431   timerclear(&ads->tcptimeout);
 432
 433   *ads_r= ads;
 434   return 0;
 435 }
 436
 437 static int init_finish(adns_state ads) {
 438   struct in_addr ia;
 439   struct protoent *proto;
 440   int r;
 441
 442   if (!ads->nservers) {
 443     if (ads->diagfile && ads->iflags & adns_if_debug)
 444       fprintf(ads->diagfile,"adns: no nameservers, using localhost\n");
 445     ia.s_addr= htonl(INADDR_LOOPBACK);
 446     addserver(ads,ia);
 447   }
 448
 449   proto= getprotobyname("udp"); if (!proto) { r= ENOPROTOOPT; goto x_free; }
 450   ads->udpsocket= socket(AF_INET,SOCK_DGRAM,proto->p_proto);
 451   if (ads->udpsocket<0) { r= errno; goto x_free; }
 452
 453   r= adns__setnonblock(ads,ads->udpsocket);
 454   if (r) { r= errno; goto x_closeudp; }
 455
 456   return 0;
 457
 458  x_closeudp:
 459   close(ads->udpsocket);
 460  x_free:
 461   free(ads);
 462   return r;
 463 }
 464
 465 static void init_abort(adns_state ads) {
 466   if (ads->nsearchlist) {
 467     free(ads->searchlist[0]);
 468     free(ads->searchlist);
 469   }
 470   free(ads);
 471 }
 472
 473 int adns_init(adns_state *ads_r, adns_initflags flags, FILE *diagfile) {
 474   adns_state ads;
 475   const char *res_options, *adns_res_options;
 476   int r;
 477
 478   r= init_begin(&ads, flags, diagfile ? diagfile : stderr);
 479   if (r) return r;
 480
 481   res_options= instrum_getenv(ads,"RES_OPTIONS");
 482   adns_res_options= instrum_getenv(ads,"ADNS_RES_OPTIONS");
 483   ccf_options(ads,"RES_OPTIONS",-1,res_options);
 484   ccf_options(ads,"ADNS_RES_OPTIONS",-1,adns_res_options);
 485
 486   readconfig(ads,"/etc/resolv.conf");
 487   readconfigenv(ads,"RES_CONF");
 488   readconfigenv(ads,"ADNS_RES_CONF");
 489
 490   readconfigenvtext(ads,"RES_CONF_TEXT");
 491   readconfigenvtext(ads,"ADNS_RES_CONF_TEXT");
 492
 493   ccf_options(ads,"RES_OPTIONS",-1,res_options);
 494   ccf_options(ads,"ADNS_RES_OPTIONS",-1,adns_res_options);
 495
 496   ccf_search(ads,"LOCALDOMAIN",-1,instrum_getenv(ads,"LOCALDOMAIN"));
 497   ccf_search(ads,"ADNS_LOCALDOMAIN",-1,instrum_getenv(ads,"ADNS_LOCALDOMAIN"));
 498
 499   if (ads->configerrno && ads->configerrno != EINVAL) {
 500     r= ads->configerrno;
 501     init_abort(ads);
 502     return r;
 503   }
 504
 505   r= init_finish(ads);
 506   if (r) return r;
 507
 508   *ads_r= ads;
 509   return 0;
 510 }
 511
 512 int adns_init_strcfg(adns_state *ads_r, adns_initflags flags,
 513                      FILE *diagfile, const char *configtext) {
 514   adns_state ads;
 515   int r;
 516
 517   r= init_begin(&ads, flags, diagfile);  if (r) return r;
 518
 519   readconfigtext(ads,configtext,"<supplied configuration text>");
 520   if (ads->configerrno) {
 521     r= ads->configerrno;
 522     init_abort(ads);
 523     return r;
 524   }
 525
 526   r= init_finish(ads);  if (r) return r;
 527   *ads_r= ads;
 528   return 0;
 529 }
 530
 531 void adns_finish(adns_state ads) {
 532   for (;;) {
 533     if (ads->timew.head) adns_cancel(ads->timew.head);
 534     else if (ads->childw.head) adns_cancel(ads->childw.head);
 535     else if (ads->output.head) adns_cancel(ads->output.head);
 536     else break;
 537   }
 538   close(ads->udpsocket);
 539   if (ads->tcpsocket >= 0) close(ads->tcpsocket);
 540   adns__vbuf_free(&ads->tcpsend);
 541   adns__vbuf_free(&ads->tcprecv);
 542   free(ads);
 543 }