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, 1998 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 *buf) {
  94   adns__diag(ads,-1,0,"warning - `sortlist' ignored fixme");
  95 }
  96
  97 static void ccf_options(adns_state ads, const char *fn, int lno, const char *buf) {
  98   if (!buf) return;
  99   adns__diag(ads,-1,0,"warning - `options' ignored fixme");
 100 }
 101
 102 static void ccf_clearnss(adns_state ads, const char *fn, int lno, const char *buf) {
 103   ads->nservers= 0;
 104 }
 105
 106 static void ccf_include(adns_state ads, const char *fn, int lno, const char *buf) {
 107   if (!*buf) {
 108     configparseerr(ads,fn,lno,"`include' directive with no filename");
 109     return;
 110   }
 111   readconfig(ads,buf);
 112 }
 113
 114 static const struct configcommandinfo {
 115   const char *name;
 116   void (*fn)(adns_state ads, const char *fn, int lno, const char *buf);
 117 } configcommandinfos[]= {
 118   { "nameserver",        ccf_nameserver  },
 119   { "domain",            ccf_search      },
 120   { "search",            ccf_search      },
 121   { "sortlist",          ccf_sortlist    },
 122   { "options",           ccf_options     },
 123   { "clearnameservers",  ccf_clearnss    },
 124   { "include",           ccf_include     },
 125   {  0                                   }
 126 };
 127
 128 typedef union {
 129   FILE *file;
 130   const char *text;
 131 } getline_ctx;
 132
 133 static int gl_file(adns_state ads, getline_ctx *src_io, const char *filename,
 134                    int lno, char *buf, int buflen) {
 135   FILE *file= src_io->file;
 136   int c, i;
 137   char *p;
 138
 139   p= buf;
 140   buflen--;
 141   i= 0;
 142
 143   for (;;) { /* loop over chars */
 144     if (i == buflen) {
 145       adns__diag(ads,-1,0,"%s:%d: line too long, ignored",filename,lno);
 146       goto x_badline;
 147     }
 148     c= getc(file);
 149     if (!c) {
 150       adns__diag(ads,-1,0,"%s:%d: line contains nul, ignored",filename,lno);
 151       goto x_badline;
 152     } else if (c == '\n') {
 153       break;
 154     } else if (c == EOF) {
 155       if (ferror(file)) {
 156         saveerr(ads,errno);
 157         adns__diag(ads,-1,0,"%s:%d: read error: %s",filename,lno,strerror(errno));
 158         return -1;
 159       }
 160       if (!i) return -1;
 161       break;
 162     } else {
 163       *p++= c;
 164       i++;
 165     }
 166   }
 167
 168   *p++= 0;
 169   return i;
 170
 171  x_badline:
 172   saveerr(ads,EINVAL);
 173   while ((c= getc(file)) != EOF && c != '\n');
 174   return -2;
 175 }
 176
 177 static int gl_text(adns_state ads, getline_ctx *src_io, const char *filename,
 178                    int lno, char *buf, int buflen) {
 179   const char *cp= src_io->text, *nn;
 180   int l;
 181
 182   if (!cp) return -1;
 183
 184   nn= strchr(cp,'\n');
 185
 186   l= nn ? nn-cp : strlen(cp);
 187   src_io->text= nn ? nn+1 : 0;
 188
 189   if (l >= buflen) {
 190     adns__diag(ads,-1,0,"%s:%d: line too long, ignored",filename,lno);
 191     saveerr(ads,EINVAL);
 192     return -2;
 193   }
 194
 195   memcpy(buf,cp,l);
 196   buf[l]= 0;
 197   return l;
 198 }
 199
 200 static void readconfiggeneric(adns_state ads, const char *filename,
 201                               int (*getline)(adns_state ads, getline_ctx*,
 202                                              const char *filename, int lno,
 203                                              char *buf, int buflen),
 204                               /* Returns >=0 for success, -1 for EOF or error
 205                                * (error will have been reported), or -2 for
 206                                * bad line was encountered, try again.
 207                                */
 208                               getline_ctx gl_ctx) {
 209   char linebuf[2000], *p, *q;
 210   int lno, l, dirl;
 211   const struct configcommandinfo *ccip;
 212
 213   for (lno=1;
 214        (l= getline(ads,&gl_ctx, filename,lno, linebuf,sizeof(linebuf))) != -1;
 215        lno++) {
 216     if (l == -2) continue;
 217     while (l>0 && ctype_whitespace(linebuf[l-1])) l--;
 218     linebuf[l]= 0;
 219     p= linebuf;
 220     while (ctype_whitespace(*p)) p++;
 221     if (*p == '#' || !*p) continue;
 222     q= p;
 223     while (*q && !ctype_whitespace(*q)) q++;
 224     dirl= q-p;
 225     for (ccip=configcommandinfos;
 226          ccip->name && !(strlen(ccip->name)==dirl && !memcmp(ccip->name,p,q-p));
 227          ccip++);
 228     if (!ccip->name) {
 229       adns__diag(ads,-1,0,"%s:%d: unknown configuration directive `%.*s'",
 230                  filename,lno,q-p,p);
 231       continue;
 232     }
 233     while (ctype_whitespace(*q)) q++;
 234     ccip->fn(ads,filename,lno,q);
 235   }
 236 }
 237
 238 static const char *instrum_getenv(adns_state ads, const char *envvar) {
 239   const char *value;
 240
 241   value= getenv(envvar);
 242   if (!value) adns__debug(ads,-1,0,"environment variable %s not set",envvar);
 243   else adns__debug(ads,-1,0,"environment variable %s set to `%s'",envvar,value);
 244   return value;
 245 }
 246
 247 static void readconfig(adns_state ads, const char *filename) {
 248   getline_ctx gl_ctx;
 249
 250   gl_ctx.file= fopen(filename,"r");
 251   if (!gl_ctx.file) {
 252     if (errno == ENOENT) {
 253       adns__debug(ads,-1,0,"configuration file `%s' does not exist",filename);
 254       return;
 255     }
 256     saveerr(ads,errno);
 257     adns__diag(ads,-1,0,"cannot open configuration file `%s': %s",
 258                filename,strerror(errno));
 259     return;
 260   }
 261
 262   readconfiggeneric(ads,filename,gl_file,gl_ctx);
 263
 264   fclose(gl_ctx.file);
 265 }
 266
 267 static void readconfigtext(adns_state ads, const char *text, const char *showname) {
 268   getline_ctx gl_ctx;
 269
 270   gl_ctx.text= text;
 271   readconfiggeneric(ads,showname,gl_text,gl_ctx);
 272 }
 273
 274 static void readconfigenv(adns_state ads, const char *envvar) {
 275   const char *filename;
 276
 277   if (ads->iflags & adns_if_noenv) {
 278     adns__debug(ads,-1,0,"not checking environment variable `%s'",envvar);
 279     return;
 280   }
 281   filename= instrum_getenv(ads,envvar);
 282   if (filename) readconfig(ads,filename);
 283 }
 284
 285
 286 int adns__setnonblock(adns_state ads, int fd) {
 287   int r;
 288
 289   r= fcntl(fd,F_GETFL,0); if (r<0) return errno;
 290   r |= O_NONBLOCK;
 291   r= fcntl(fd,F_SETFL,r); if (r<0) return errno;
 292   return 0;
 293 }
 294
 295 static int init_begin(adns_state *ads_r, adns_initflags flags, FILE *diagfile) {
 296   adns_state ads;
 297
 298   ads= malloc(sizeof(*ads)); if (!ads) return errno;
 299
 300   ads->iflags= flags;
 301   ads->diagfile= diagfile;
 302   LIST_INIT(ads->timew);
 303   LIST_INIT(ads->childw);
 304   LIST_INIT(ads->output);
 305   ads->nextid= 0x311f;
 306   ads->udpsocket= ads->tcpsocket= -1;
 307   adns__vbuf_init(&ads->tcpsend);
 308   adns__vbuf_init(&ads->tcprecv);
 309   ads->nservers= ads->tcpserver= 0;
 310   ads->tcpstate= server_disconnected;
 311   timerclear(&ads->tcptimeout);
 312
 313   *ads_r= ads;
 314   return 0;
 315 }
 316
 317 static int init_finish(adns_state ads) {
 318   struct in_addr ia;
 319   struct protoent *proto;
 320   int r;
 321
 322   if (!ads->nservers) {
 323     if (ads->diagfile && ads->iflags & adns_if_debug)
 324       fprintf(ads->diagfile,"adns: no nameservers, using localhost\n");
 325     ia.s_addr= INADDR_LOOPBACK;
 326     addserver(ads,ia);
 327   }
 328
 329   proto= getprotobyname("udp"); if (!proto) { r= ENOPROTOOPT; goto x_free; }
 330   ads->udpsocket= socket(AF_INET,SOCK_DGRAM,proto->p_proto);
 331   if (ads->udpsocket<0) { r= errno; goto x_free; }
 332
 333   r= adns__setnonblock(ads,ads->udpsocket);
 334   if (r) { r= errno; goto x_closeudp; }
 335
 336   return 0;
 337
 338  x_closeudp:
 339   close(ads->udpsocket);
 340  x_free:
 341   free(ads);
 342   return r;
 343 }
 344
 345 int adns_init(adns_state *ads_r, adns_initflags flags, FILE *diagfile) {
 346   adns_state ads;
 347   const char *res_options, *adns_res_options;
 348   int r;
 349
 350   r= init_begin(&ads, flags, diagfile ? diagfile : stderr);
 351   if (r) return r;
 352
 353   res_options= instrum_getenv(ads,"RES_OPTIONS");
 354   adns_res_options= instrum_getenv(ads,"ADNS_RES_OPTIONS");
 355   ccf_options(ads,"RES_OPTIONS",-1,res_options);
 356   ccf_options(ads,"ADNS_RES_OPTIONS",-1,adns_res_options);
 357
 358   readconfig(ads,"/etc/resolv.conf");
 359   readconfigenv(ads,"RES_CONF");
 360   readconfigenv(ads,"ADNS_RES_CONF");
 361
 362   ccf_options(ads,"RES_OPTIONS",-1,res_options);
 363   ccf_options(ads,"ADNS_RES_OPTIONS",-1,adns_res_options);
 364
 365   ccf_search(ads,"LOCALDOMAIN",-1,instrum_getenv(ads,"LOCALDOMAIN"));
 366   ccf_search(ads,"ADNS_LOCALDOMAIN",-1,instrum_getenv(ads,"ADNS_LOCALDOMAIN"));
 367
 368   r= init_finish(ads);
 369   if (r) return r;
 370
 371   *ads_r= ads;
 372   return 0;
 373 }
 374
 375 int adns_init_strcfg(adns_state *ads_r, adns_initflags flags,
 376                      FILE *diagfile, const char *configtext) {
 377   adns_state ads;
 378   int r;
 379
 380   r= init_begin(&ads, flags, diagfile);  if (r) return r;
 381
 382   readconfigtext(ads,configtext,"<supplied configuration text>");
 383   if (ads->configerrno) {
 384     r= ads->configerrno;
 385     free(ads);
 386     return r;
 387   }
 388
 389   r= init_finish(ads);  if (r) return r;
 390   *ads_r= ads;
 391   return 0;
 392 }
 393
 394 void adns_finish(adns_state ads) {
 395   for (;;) {
 396     if (ads->timew.head) adns_cancel(ads->timew.head);
 397     else if (ads->childw.head) adns_cancel(ads->childw.head);
 398     else if (ads->output.head) adns_cancel(ads->output.head);
 399     else break;
 400   }
 401   close(ads->udpsocket);
 402   if (ads->tcpsocket >= 0) close(ads->tcpsocket);
 403   adns__vbuf_free(&ads->tcpsend);
 404   adns__vbuf_free(&ads->tcprecv);
 405   free(ads);
 406 }