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 void ccf_nameserver(adns_state ads, const char *fn, int lno, const char *buf) {
  78   struct in_addr ia;
  79
  80   if (!inet_aton(buf,&ia)) {
  81     configparseerr(ads,fn,lno,"invalid nameserver address `%s'",buf);
  82     return;
  83   }
  84   adns__debug(ads,-1,0,"using nameserver %s",inet_ntoa(ia));
  85   addserver(ads,ia);
  86 }
  87
  88 static void ccf_search(adns_state ads, const char *fn, int lno, const char *buf) {
  89   if (!buf) return;
  90   adns__diag(ads,-1,0,"warning - `search' ignored fixme");
  91 }
  92
  93 static void ccf_sortlist(adns_state ads, const char *fn, int lno, const char *bufp) {
  94   const char *p, *q;
  95   char tbuf[200], *slash, *ep;
  96   struct in_addr base, mask;
  97   int l;
  98   unsigned long initial, baselocal;
  99
 100   ads->nsortlist= 0;
 101   if (!bufp) return;
 102
 103   for (;;) {
 104     while (ctype_whitespace(*bufp)) bufp++;
 105     if (!*bufp) return;
 106
 107     q= bufp;
 108     while (*q && !ctype_whitespace(*q)) q++;
 109
 110     p= bufp;
 111     l= q-p;
 112     bufp= q;
 113
 114     if (ads->nsortlist >= MAXSORTLIST) {
 115       adns__diag(ads,-1,0,"too many sortlist entries, ignoring %.*s onwards",l,p);
 116       return;
 117     }
 118
 119     if (l >= sizeof(tbuf)) {
 120       configparseerr(ads,fn,lno,"sortlist entry `%.*s' too long",l,p);
 121       continue;
 122     }
 123
 124     memcpy(tbuf,p,l);
 125     slash= strchr(tbuf,'/');
 126     if (slash) *slash++= 0;
 127
 128     if (!inet_aton(tbuf,&base)) {
 129       configparseerr(ads,fn,lno,"invalid address `%s' in sortlist",tbuf);
 130       continue;
 131     }
 132
 133     if (slash) {
 134       if (strchr(slash,'.')) {
 135         if (!inet_aton(slash,&mask)) {
 136           configparseerr(ads,fn,lno,"invalid mask `%s' in sortlist",slash);
 137           continue;
 138         }
 139         if (base.s_addr & ~mask.s_addr) {
 140           configparseerr(ads,fn,lno,
 141                          "mask `%s' in sortlist overlaps address `%s'",slash,tbuf);
 142           continue;
 143         }
 144       } else {
 145         initial= strtoul(slash,&ep,10);
 146         if (*ep || initial>32) {
 147           configparseerr(ads,fn,lno,"mask length `%s' invalid",slash);
 148           continue;
 149         }
 150         mask.s_addr= htonl((0x0ffffffffUL) << (32-initial));
 151       }
 152     } else {
 153       baselocal= ntohl(base.s_addr);
 154       if (!baselocal & 0x080000000UL) /* class A */
 155         mask.s_addr= htonl(0x0ff000000UL);
 156       else if ((baselocal & 0x0c0000000UL) == 0x080000000UL)
 157         mask.s_addr= htonl(0x0ffff0000UL); /* class B */
 158       else if ((baselocal & 0x0f0000000UL) == 0x0e0000000UL)
 159         mask.s_addr= htonl(0x0ff000000UL); /* class C */
 160       else {
 161         configparseerr(ads,fn,lno,
 162                        "network address `%s' in sortlist is not in classed ranges,"
 163                        " must specify mask explicitly", tbuf);
 164         continue;
 165       }
 166     }
 167
 168     ads->sortlist[ads->nsortlist].base= base;
 169     ads->sortlist[ads->nsortlist].mask= mask;
 170     ads->nsortlist++;
 171   }
 172 }
 173
 174 static void ccf_options(adns_state ads, const char *fn, int lno, const char *buf) {
 175   if (!buf) return;
 176   adns__diag(ads,-1,0,"warning - `options' ignored fixme");
 177 }
 178
 179 static void ccf_clearnss(adns_state ads, const char *fn, int lno, const char *buf) {
 180   ads->nservers= 0;
 181 }
 182
 183 static void ccf_include(adns_state ads, const char *fn, int lno, const char *buf) {
 184   if (!*buf) {
 185     configparseerr(ads,fn,lno,"`include' directive with no filename");
 186     return;
 187   }
 188   readconfig(ads,buf);
 189 }
 190
 191 static const struct configcommandinfo {
 192   const char *name;
 193   void (*fn)(adns_state ads, const char *fn, int lno, const char *buf);
 194 } configcommandinfos[]= {
 195   { "nameserver",        ccf_nameserver  },
 196   { "domain",            ccf_search      },
 197   { "search",            ccf_search      },
 198   { "sortlist",          ccf_sortlist    },
 199   { "options",           ccf_options     },
 200   { "clearnameservers",  ccf_clearnss    },
 201   { "include",           ccf_include     },
 202   {  0                                   }
 203 };
 204
 205 typedef union {
 206   FILE *file;
 207   const char *text;
 208 } getline_ctx;
 209
 210 static int gl_file(adns_state ads, getline_ctx *src_io, const char *filename,
 211                    int lno, char *buf, int buflen) {
 212   FILE *file= src_io->file;
 213   int c, i;
 214   char *p;
 215
 216   p= buf;
 217   buflen--;
 218   i= 0;
 219
 220   for (;;) { /* loop over chars */
 221     if (i == buflen) {
 222       adns__diag(ads,-1,0,"%s:%d: line too long, ignored",filename,lno);
 223       goto x_badline;
 224     }
 225     c= getc(file);
 226     if (!c) {
 227       adns__diag(ads,-1,0,"%s:%d: line contains nul, ignored",filename,lno);
 228       goto x_badline;
 229     } else if (c == '\n') {
 230       break;
 231     } else if (c == EOF) {
 232       if (ferror(file)) {
 233         saveerr(ads,errno);
 234         adns__diag(ads,-1,0,"%s:%d: read error: %s",filename,lno,strerror(errno));
 235         return -1;
 236       }
 237       if (!i) return -1;
 238       break;
 239     } else {
 240       *p++= c;
 241       i++;
 242     }
 243   }
 244
 245   *p++= 0;
 246   return i;
 247
 248  x_badline:
 249   saveerr(ads,EINVAL);
 250   while ((c= getc(file)) != EOF && c != '\n');
 251   return -2;
 252 }
 253
 254 static int gl_text(adns_state ads, getline_ctx *src_io, const char *filename,
 255                    int lno, char *buf, int buflen) {
 256   const char *cp= src_io->text;
 257   int l;
 258
 259   if (!cp || !*cp) return -1;
 260
 261   if (*cp == ';' || *cp == '\n') cp++;
 262   l= strcspn(cp,";\n");
 263   src_io->text = cp+l;
 264
 265   if (l >= buflen) {
 266     adns__diag(ads,-1,0,"%s:%d: line too long, ignored",filename,lno);
 267     saveerr(ads,EINVAL);
 268     return -2;
 269   }
 270
 271   memcpy(buf,cp,l);
 272   buf[l]= 0;
 273   return l;
 274 }
 275
 276 static void readconfiggeneric(adns_state ads, const char *filename,
 277                               int (*getline)(adns_state ads, getline_ctx*,
 278                                              const char *filename, int lno,
 279                                              char *buf, int buflen),
 280                               /* Returns >=0 for success, -1 for EOF or error
 281                                * (error will have been reported), or -2 for
 282                                * bad line was encountered, try again.
 283                                */
 284                               getline_ctx gl_ctx) {
 285   char linebuf[2000], *p, *q;
 286   int lno, l, dirl;
 287   const struct configcommandinfo *ccip;
 288
 289   for (lno=1;
 290        (l= getline(ads,&gl_ctx, filename,lno, linebuf,sizeof(linebuf))) != -1;
 291        lno++) {
 292     if (l == -2) continue;
 293     while (l>0 && ctype_whitespace(linebuf[l-1])) l--;
 294     linebuf[l]= 0;
 295     p= linebuf;
 296     while (ctype_whitespace(*p)) p++;
 297     if (*p == '#' || !*p) continue;
 298     q= p;
 299     while (*q && !ctype_whitespace(*q)) q++;
 300     dirl= q-p;
 301     for (ccip=configcommandinfos;
 302          ccip->name && !(strlen(ccip->name)==dirl && !memcmp(ccip->name,p,q-p));
 303          ccip++);
 304     if (!ccip->name) {
 305       adns__diag(ads,-1,0,"%s:%d: unknown configuration directive `%.*s'",
 306                  filename,lno,q-p,p);
 307       continue;
 308     }
 309     while (ctype_whitespace(*q)) q++;
 310     ccip->fn(ads,filename,lno,q);
 311   }
 312 }
 313
 314 static const char *instrum_getenv(adns_state ads, const char *envvar) {
 315   const char *value;
 316
 317   value= getenv(envvar);
 318   if (!value) adns__debug(ads,-1,0,"environment variable %s not set",envvar);
 319   else adns__debug(ads,-1,0,"environment variable %s set to `%s'",envvar,value);
 320   return value;
 321 }
 322
 323 static void readconfig(adns_state ads, const char *filename) {
 324   getline_ctx gl_ctx;
 325
 326   gl_ctx.file= fopen(filename,"r");
 327   if (!gl_ctx.file) {
 328     if (errno == ENOENT) {
 329       adns__debug(ads,-1,0,"configuration file `%s' does not exist",filename);
 330       return;
 331     }
 332     saveerr(ads,errno);
 333     adns__diag(ads,-1,0,"cannot open configuration file `%s': %s",
 334                filename,strerror(errno));
 335     return;
 336   }
 337
 338   readconfiggeneric(ads,filename,gl_file,gl_ctx);
 339
 340   fclose(gl_ctx.file);
 341 }
 342
 343 static void readconfigtext(adns_state ads, const char *text, const char *showname) {
 344   getline_ctx gl_ctx;
 345
 346   gl_ctx.text= text;
 347   readconfiggeneric(ads,showname,gl_text,gl_ctx);
 348 }
 349
 350 static void readconfigenv(adns_state ads, const char *envvar) {
 351   const char *filename;
 352
 353   if (ads->iflags & adns_if_noenv) {
 354     adns__debug(ads,-1,0,"not checking environment variable `%s'",envvar);
 355     return;
 356   }
 357   filename= instrum_getenv(ads,envvar);
 358   if (filename) readconfig(ads,filename);
 359 }
 360
 361 static void readconfigenvtext(adns_state ads, const char *envvar) {
 362   const char *textdata;
 363
 364   if (ads->iflags & adns_if_noenv) {
 365     adns__debug(ads,-1,0,"not checking environment variable `%s'",envvar);
 366     return;
 367   }
 368   textdata= instrum_getenv(ads,envvar);
 369   if (textdata) readconfigtext(ads,textdata,envvar);
 370 }
 371
 372
 373 int adns__setnonblock(adns_state ads, int fd) {
 374   int r;
 375
 376   r= fcntl(fd,F_GETFL,0); if (r<0) return errno;
 377   r |= O_NONBLOCK;
 378   r= fcntl(fd,F_SETFL,r); if (r<0) return errno;
 379   return 0;
 380 }
 381
 382 static int init_begin(adns_state *ads_r, adns_initflags flags, FILE *diagfile) {
 383   adns_state ads;
 384
 385   ads= malloc(sizeof(*ads)); if (!ads) return errno;
 386
 387   ads->iflags= flags;
 388   ads->diagfile= diagfile;
 389   LIST_INIT(ads->timew);
 390   LIST_INIT(ads->childw);
 391   LIST_INIT(ads->output);
 392   ads->nextid= 0x311f;
 393   ads->udpsocket= ads->tcpsocket= -1;
 394   adns__vbuf_init(&ads->tcpsend);
 395   adns__vbuf_init(&ads->tcprecv);
 396   ads->nservers= ads->nsortlist= ads->tcpserver= 0;
 397   ads->tcpstate= server_disconnected;
 398   timerclear(&ads->tcptimeout);
 399
 400   *ads_r= ads;
 401   return 0;
 402 }
 403
 404 static int init_finish(adns_state ads) {
 405   struct in_addr ia;
 406   struct protoent *proto;
 407   int r;
 408
 409   if (!ads->nservers) {
 410     if (ads->diagfile && ads->iflags & adns_if_debug)
 411       fprintf(ads->diagfile,"adns: no nameservers, using localhost\n");
 412     ia.s_addr= htonl(INADDR_LOOPBACK);
 413     addserver(ads,ia);
 414   }
 415
 416   proto= getprotobyname("udp"); if (!proto) { r= ENOPROTOOPT; goto x_free; }
 417   ads->udpsocket= socket(AF_INET,SOCK_DGRAM,proto->p_proto);
 418   if (ads->udpsocket<0) { r= errno; goto x_free; }
 419
 420   r= adns__setnonblock(ads,ads->udpsocket);
 421   if (r) { r= errno; goto x_closeudp; }
 422
 423   return 0;
 424
 425  x_closeudp:
 426   close(ads->udpsocket);
 427  x_free:
 428   free(ads);
 429   return r;
 430 }
 431
 432 int adns_init(adns_state *ads_r, adns_initflags flags, FILE *diagfile) {
 433   adns_state ads;
 434   const char *res_options, *adns_res_options;
 435   int r;
 436
 437   r= init_begin(&ads, flags, diagfile ? diagfile : stderr);
 438   if (r) return r;
 439
 440   res_options= instrum_getenv(ads,"RES_OPTIONS");
 441   adns_res_options= instrum_getenv(ads,"ADNS_RES_OPTIONS");
 442   ccf_options(ads,"RES_OPTIONS",-1,res_options);
 443   ccf_options(ads,"ADNS_RES_OPTIONS",-1,adns_res_options);
 444
 445   readconfig(ads,"/etc/resolv.conf");
 446   readconfigenv(ads,"RES_CONF");
 447   readconfigenv(ads,"ADNS_RES_CONF");
 448
 449   readconfigenvtext(ads,"RES_CONF_TEXT");
 450   readconfigenvtext(ads,"ADNS_RES_CONF_TEXT");
 451
 452   ccf_options(ads,"RES_OPTIONS",-1,res_options);
 453   ccf_options(ads,"ADNS_RES_OPTIONS",-1,adns_res_options);
 454
 455   ccf_search(ads,"LOCALDOMAIN",-1,instrum_getenv(ads,"LOCALDOMAIN"));
 456   ccf_search(ads,"ADNS_LOCALDOMAIN",-1,instrum_getenv(ads,"ADNS_LOCALDOMAIN"));
 457
 458   r= init_finish(ads);
 459   if (r) return r;
 460
 461   *ads_r= ads;
 462   return 0;
 463 }
 464
 465 int adns_init_strcfg(adns_state *ads_r, adns_initflags flags,
 466                      FILE *diagfile, const char *configtext) {
 467   adns_state ads;
 468   int r;
 469
 470   r= init_begin(&ads, flags, diagfile);  if (r) return r;
 471
 472   readconfigtext(ads,configtext,"<supplied configuration text>");
 473   if (ads->configerrno) {
 474     r= ads->configerrno;
 475     free(ads);
 476     return r;
 477   }
 478
 479   r= init_finish(ads);  if (r) return r;
 480   *ads_r= ads;
 481   return 0;
 482 }
 483
 484 void adns_finish(adns_state ads) {
 485   for (;;) {
 486     if (ads->timew.head) adns_cancel(ads->timew.head);
 487     else if (ads->childw.head) adns_cancel(ads->childw.head);
 488     else if (ads->output.head) adns_cancel(ads->output.head);
 489     else break;
 490   }
 491   close(ads->udpsocket);
 492   if (ads->tcpsocket >= 0) close(ads->tcpsocket);
 493   adns__vbuf_free(&ads->tcpsend);
 494   adns__vbuf_free(&ads->tcprecv);
 495   free(ads);
 496 }