contrib/dhcp-3.0/minires/res_init.c

   1 /*
   2  * Copyright (c) 1985, 1989, 1993
   3  *    The Regents of the University of California.  All rights reserved.
   4  *
   5  * Redistribution and use in source and binary forms, with or without
   6  * modification, are permitted provided that the following conditions
   7  * are met:
   8  * 1. Redistributions of source code must retain the above copyright
   9  *    notice, this list of conditions and the following disclaimer.
  10  * 2. Redistributions in binary form must reproduce the above copyright
  11  *    notice, this list of conditions and the following disclaimer in the
  12  *    documentation and/or other materials provided with the distribution.
  13  * 3. All advertising materials mentioning features or use of this software
  14  *    must display the following acknowledgement:
  15  *      This product includes software developed by the University of
  16  *      California, Berkeley and its contributors.
  17  * 4. Neither the name of the University nor the names of its contributors
  18  *    may be used to endorse or promote products derived from this software
  19  *    without specific prior written permission.
  20  *
  21  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  22  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  23  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  24  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  25  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  26  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  27  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  28  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  29  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  30  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  31  * SUCH DAMAGE.
  32  */
  33
  34 /*
  35  * Portions Copyright (c) 1993 by Digital Equipment Corporation.
  36  *
  37  * Permission to use, copy, modify, and distribute this software for any
  38  * purpose with or without fee is hereby granted, provided that the above
  39  * copyright notice and this permission notice appear in all copies, and that
  40  * the name of Digital Equipment Corporation not be used in advertising or
  41  * publicity pertaining to distribution of the document or software without
  42  * specific, written prior permission.
  43  *
  44  * THE SOFTWARE IS PROVIDED "AS IS" AND DIGITAL EQUIPMENT CORP. DISCLAIMS ALL
  45  * WARRANTIES WITH REGARD TO THIS SOFTWARE, INCLUDING ALL IMPLIED WARRANTIES
  46  * OF MERCHANTABILITY AND FITNESS.   IN NO EVENT SHALL DIGITAL EQUIPMENT
  47  * CORPORATION BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL
  48  * DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR
  49  * PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS
  50  * ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS
  51  * SOFTWARE.
  52  */
  53
  54 /*
  55  * Portions Copyright (c) 2004 by Internet Systems Consortium, Inc. ("ISC")
  56  * Portions Copyright (c) 1995-2003 by Internet Software Consortium
  57  *
  58  * Permission to use, copy, modify, and distribute this software for any
  59  * purpose with or without fee is hereby granted, provided that the above
  60  * copyright notice and this permission notice appear in all copies.
  61  *
  62  * THE SOFTWARE IS PROVIDED "AS IS" AND ISC DISCLAIMS ALL WARRANTIES
  63  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
  64  * MERCHANTABILITY AND FITNESS.  IN NO EVENT SHALL ISC BE LIABLE FOR
  65  * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
  66  * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
  67  * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT
  68  * OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
  69  *
  70  *   Internet Systems Consortium, Inc.
  71  *   950 Charter Street
  72  *   Redwood City, CA 94063
  73  *   <info@isc.org>
  74  *   http://www.isc.org/
  75  */
  76
  77 #if defined(LIBC_SCCS) && !defined(lint)
  78 static const char sccsid[] = "@(#)res_init.c    8.1 (Berkeley) 6/7/93";
  79 static const char rcsid[] = "$Id: res_init.c,v 1.4.2.2 2004/06/10 17:59:43 dhankins Exp $";
  80 #endif /* LIBC_SCCS and not lint */
  81
  82 #include <sys/types.h>
  83 #include <sys/param.h>
  84 #include <sys/socket.h>
  85 #include <sys/time.h>
  86
  87 #include <netinet/in.h>
  88 #include <arpa/inet.h>
  89
  90 #include <ctype.h>
  91 #include <stdio.h>
  92 #include <stdlib.h>
  93 #include <string.h>
  94 #include <unistd.h>
  95
  96 #include "minires/minires.h"
  97 #include "arpa/nameser.h"
  98
  99 /* Options.  Should all be left alone. */
 100 #define RESOLVSORT
 101 #define RFC1535
 102 #define DEBUG
 103
 104 static void res_setoptions (res_state, const char *, const char *);
 105
 106 #ifdef RESOLVSORT
 107 static const char sort_mask[] = "/&";
 108 #define ISSORTMASK(ch) (strchr(sort_mask, ch) != NULL)
 109 static u_int32_t net_mask (struct in_addr);
 110 #endif
 111
 112 #if !defined(isascii)   /* XXX - could be a function */
 113 # define isascii(c) (!(c & 0200))
 114 #endif
 115
 116 /*
 117  * Resolver state default settings.
 118  */
 119
 120 /*
 121  * Set up default settings.  If the configuration file exist, the values
 122  * there will have precedence.  Otherwise, the server address is set to
 123  * INADDR_ANY and the default domain name comes from the gethostname().
 124  *
 125  * An interrim version of this code (BIND 4.9, pre-4.4BSD) used 127.0.0.1
 126  * rather than INADDR_ANY ("0.0.0.0") as the default name server address
 127  * since it was noted that INADDR_ANY actually meant ``the first interface
 128  * you "ifconfig"'d at boot time'' and if this was a SLIP or PPP interface,
 129  * it had to be "up" in order for you to reach your own name server.  It
 130  * was later decided that since the recommended practice is to always
 131  * install local static routes through 127.0.0.1 for all your network
 132  * interfaces, that we could solve this problem without a code change.
 133  *
 134  * The configuration file should always be used, since it is the only way
 135  * to specify a default domain.  If you are running a server on your local
 136  * machine, you should say "nameserver 0.0.0.0" or "nameserver 127.0.0.1"
 137  * in the configuration file.
 138  *
 139  * Return 0 if completes successfully, -1 on error
 140  */
 141 extern int minires_vinit(res_state, int);
 142
 143 #if defined (TRACING)
 144 u_int trace_mr_res_randomid(u_int);
 145 #endif
 146
 147 int
 148 res_ninit(res_state statp) {
 149
 150         return (minires_vinit(statp, 0));
 151 }
 152
 153 /* This function has to be reachable by res_data.c but not publically. */
 154 int
 155 minires_vinit(res_state statp, int preinit) {
 156         register FILE *fp;
 157         register char *cp, **pp;
 158         register int n;
 159         char buf[BUFSIZ];
 160         int nserv = 0;    /* number of nameserver records read from file */
 161         int haveenv = 0;
 162         int havesearch = 0;
 163 #ifdef RESOLVSORT
 164         int nsort = 0;
 165         char *net;
 166 #endif
 167 #ifndef RFC1535
 168         int dots;
 169 #endif
 170
 171         if (!preinit) {
 172                 statp->retrans = RES_TIMEOUT;
 173                 statp->retry = RES_DFLRETRY;
 174                 statp->options = RES_DEFAULT;
 175                 statp->id = res_randomid();
 176 #if defined (TRACING)
 177                 statp->id = trace_mr_res_randomid (statp -> id);
 178 #endif
 179         }
 180
 181 #ifdef USELOOPBACK
 182         statp->nsaddr.sin_addr = inet_makeaddr(IN_LOOPBACKNET, 1);
 183 #else
 184         statp->nsaddr.sin_addr.s_addr = INADDR_ANY;
 185 #endif
 186         statp->nsaddr.sin_family = AF_INET;
 187         statp->nsaddr.sin_port = htons(NAMESERVER_PORT);
 188         statp->nscount = 1;
 189         statp->ndots = 1;
 190         statp->pfcode = 0;
 191         statp->_sock = -1;
 192         statp->_flags = 0;
 193         statp->qhook = NULL;
 194         statp->rhook = NULL;
 195
 196         /* Allow user to override the local domain definition */
 197         if ((cp = getenv("LOCALDOMAIN")) != NULL) {
 198                 (void)strncpy(statp->defdname, cp, sizeof(statp->defdname) - 1);
 199                 statp->defdname[sizeof(statp->defdname) - 1] = '\0';
 200                 haveenv++;
 201
 202                 /*
 203                  * Set search list to be blank-separated strings
 204                  * from rest of env value.  Permits users of LOCALDOMAIN
 205                  * to still have a search list, and anyone to set the
 206                  * one that they want to use as an individual (even more
 207                  * important now that the rfc1535 stuff restricts searches)
 208                  */
 209                 cp = statp->defdname;
 210                 pp = statp->dnsrch;
 211                 *pp++ = cp;
 212                 for (n = 0; *cp && pp < statp->dnsrch + MAXDNSRCH; cp++) {
 213                         if (*cp == '\n')        /* silly backwards compat */
 214                                 break;
 215                         else if (*cp == ' ' || *cp == '\t') {
 216                                 *cp = 0;
 217                                 n = 1;
 218                         } else if (n) {
 219                                 *pp++ = cp;
 220                                 n = 0;
 221                                 havesearch = 1;
 222                         }
 223                 }
 224                 /* null terminate last domain if there are excess */
 225                 while (*cp != '\0' && *cp != ' ' && *cp != '\t' && *cp != '\n')
 226                         cp++;
 227                 *cp = '\0';
 228                 *pp++ = 0;
 229         }
 230
 231 #define MATCH(line, name) \
 232         (!strncmp(line, name, sizeof(name) - 1) && \
 233         (line[sizeof(name) - 1] == ' ' || \
 234          line[sizeof(name) - 1] == '\t'))
 235
 236         if ((fp = fopen(_PATH_RESCONF, "r")) != NULL) {
 237             /* read the config file */
 238             while (fgets(buf, sizeof(buf), fp) != NULL) {
 239                 /* skip comments */
 240                 if (*buf == ';' || *buf == '#')
 241                         continue;
 242                 /* read default domain name */
 243                 if (MATCH(buf, "domain")) {
 244                     if (haveenv)        /* skip if have from environ */
 245                             continue;
 246                     cp = buf + sizeof("domain") - 1;
 247                     while (*cp == ' ' || *cp == '\t')
 248                             cp++;
 249                     if ((*cp == '\0') || (*cp == '\n'))
 250                             continue;
 251                     strncpy(statp->defdname, cp, sizeof(statp->defdname) - 1);
 252                     statp->defdname[sizeof(statp->defdname) - 1] = '\0';
 253                     if ((cp = strpbrk(statp->defdname, " \t\n")) != NULL)
 254                             *cp = '\0';
 255                     havesearch = 0;
 256                     continue;
 257                 }
 258                 /* set search list */
 259                 if (MATCH(buf, "search")) {
 260                     if (haveenv)        /* skip if have from environ */
 261                             continue;
 262                     cp = buf + sizeof("search") - 1;
 263                     while (*cp == ' ' || *cp == '\t')
 264                             cp++;
 265                     if ((*cp == '\0') || (*cp == '\n'))
 266                             continue;
 267                     strncpy(statp->defdname, cp, sizeof(statp->defdname) - 1);
 268                     statp->defdname[sizeof(statp->defdname) - 1] = '\0';
 269                     if ((cp = strchr(statp->defdname, '\n')) != NULL)
 270                             *cp = '\0';
 271                     /*
 272                      * Set search list to be blank-separated strings
 273                      * on rest of line.
 274                      */
 275                     cp = statp->defdname;
 276                     pp = statp->dnsrch;
 277                     *pp++ = cp;
 278                     for (n = 0; *cp && pp < statp->dnsrch + MAXDNSRCH; cp++) {
 279                             if (*cp == ' ' || *cp == '\t') {
 280                                     *cp = 0;
 281                                     n = 1;
 282                             } else if (n) {
 283                                     *pp++ = cp;
 284                                     n = 0;
 285                             }
 286                     }
 287                     /* null terminate last domain if there are excess */
 288                     while (*cp != '\0' && *cp != ' ' && *cp != '\t')
 289                             cp++;
 290                     *cp = '\0';
 291                     *pp++ = 0;
 292                     havesearch = 1;
 293                     continue;
 294                 }
 295                 /* read nameservers to query */
 296                 if (MATCH(buf, "nameserver") && nserv < MAXNS) {
 297                     struct in_addr a;
 298
 299                     cp = buf + sizeof("nameserver") - 1;
 300                     while (*cp == ' ' || *cp == '\t')
 301                         cp++;
 302                     if ((*cp != '\0') && (*cp != '\n') && inet_aton(cp, &a)) {
 303                         statp->nsaddr_list[nserv].sin_addr = a;
 304                         statp->nsaddr_list[nserv].sin_family = AF_INET;
 305                         statp->nsaddr_list[nserv].sin_port =
 306                                 htons(NAMESERVER_PORT);
 307                         nserv++;
 308                     }
 309                     continue;
 310                 }
 311 #ifdef RESOLVSORT
 312                 if (MATCH(buf, "sortlist")) {
 313                     struct in_addr a;
 314
 315                     cp = buf + sizeof("sortlist") - 1;
 316                     while (nsort < MAXRESOLVSORT) {
 317                         while (*cp == ' ' || *cp == '\t')
 318                             cp++;
 319                         if (*cp == '\0' || *cp == '\n' || *cp == ';')
 320                             break;
 321                         net = cp;
 322                         while (*cp && !ISSORTMASK(*cp) && *cp != ';' &&
 323                                isascii(*cp) && !isspace(*cp))
 324                                 cp++;
 325                         n = *cp;
 326                         *cp = 0;
 327                         if (inet_aton(net, &a)) {
 328                             statp->sort_list[nsort].addr = a;
 329                             if (ISSORTMASK(n)) {
 330                                 *cp++ = n;
 331                                 net = cp;
 332                                 while (*cp && *cp != ';' &&
 333                                         isascii(*cp) && !isspace(*cp))
 334                                     cp++;
 335                                 n = *cp;
 336                                 *cp = 0;
 337                                 if (inet_aton(net, &a)) {
 338                                     statp->sort_list[nsort].mask = a.s_addr;
 339                                 } else {
 340                                     statp->sort_list[nsort].mask =
 341                                         net_mask(statp->sort_list[nsort].addr);
 342                                 }
 343                             } else {
 344                                 statp->sort_list[nsort].mask =
 345                                     net_mask(statp->sort_list[nsort].addr);
 346                             }
 347                             nsort++;
 348                         }
 349                         *cp = n;
 350                     }
 351                     continue;
 352                 }
 353 #endif
 354                 if (MATCH(buf, "options")) {
 355                     res_setoptions(statp, buf + sizeof("options") - 1, "conf");
 356                     continue;
 357                 }
 358             }
 359             if (nserv > 1)
 360                 statp->nscount = nserv;
 361 #ifdef RESOLVSORT
 362             statp->nsort = nsort;
 363 #endif
 364             (void) fclose(fp);
 365         }
 366         if (statp->defdname[0] == 0 &&
 367             gethostname(buf, sizeof(statp->defdname) - 1) == 0 &&
 368             (cp = strchr(buf, '.')) != NULL)
 369                 strcpy(statp->defdname, cp + 1);
 370
 371         /* find components of local domain that might be searched */
 372         if (havesearch == 0) {
 373                 pp = statp->dnsrch;
 374                 *pp++ = statp->defdname;
 375                 *pp = NULL;
 376
 377 #ifndef RFC1535
 378                 dots = 0;
 379                 for (cp = statp->defdname; *cp; cp++)
 380                         dots += (*cp == '.');
 381
 382                 cp = statp->defdname;
 383                 while (pp < statp->dnsrch + MAXDFLSRCH) {
 384                         if (dots < LOCALDOMAINPARTS)
 385                                 break;
 386                         cp = strchr(cp, '.') + 1;    /* we know there is one */
 387                         *pp++ = cp;
 388                         dots--;
 389                 }
 390                 *pp = NULL;
 391 #ifdef DEBUG
 392                 if (statp->options & RES_DEBUG) {
 393                         printf(";; res_init()... default dnsrch list:\n");
 394                         for (pp = statp->dnsrch; *pp; pp++)
 395                                 printf(";;\t%s\n", *pp);
 396                         printf(";;\t..END..\n");
 397                 }
 398 #endif
 399 #endif /* !RFC1535 */
 400         }
 401
 402         if ((cp = getenv("RES_OPTIONS")) != NULL)
 403                 res_setoptions(statp, cp, "env");
 404         statp->options |= RES_INIT;
 405         return (0);
 406 }
 407
 408 static void
 409 res_setoptions(res_state statp, const char *options, const char *source) {
 410         const char *cp = options;
 411         int i;
 412
 413 #ifdef DEBUG
 414         if (statp->options & RES_DEBUG)
 415                 printf(";; res_setoptions(\"%s\", \"%s\")...\n",
 416                        options, source);
 417 #endif
 418         while (*cp) {
 419                 /* skip leading and inner runs of spaces */
 420                 while (*cp == ' ' || *cp == '\t')
 421                         cp++;
 422                 /* search for and process individual options */
 423                 if (!strncmp(cp, "ndots:", sizeof("ndots:") - 1)) {
 424                         i = atoi(cp + sizeof("ndots:") - 1);
 425                         if (i <= RES_MAXNDOTS)
 426                                 statp->ndots = i;
 427                         else
 428                                 statp->ndots = RES_MAXNDOTS;
 429 #ifdef DEBUG
 430                         if (statp->options & RES_DEBUG)
 431                                 printf(";;\tndots=%d\n", statp->ndots);
 432 #endif
 433                 } else if (!strncmp(cp, "timeout:", sizeof("timeout:") - 1)) {
 434                         i = atoi(cp + sizeof("timeout:") - 1);
 435                         if (i <= RES_MAXRETRANS)
 436                                 statp->retrans = i;
 437                         else
 438                                 statp->retrans = RES_MAXRETRANS;
 439                 } else if (!strncmp(cp, "attempts:", sizeof("attempts:") - 1)){
 440                         i = atoi(cp + sizeof("attempts:") - 1);
 441                         if (i <= RES_MAXRETRY)
 442                                 statp->retry = i;
 443                         else
 444                                 statp->retry = RES_MAXRETRY;
 445                 } else if (!strncmp(cp, "debug", sizeof("debug") - 1)) {
 446 #ifdef DEBUG
 447                         if (!(statp->options & RES_DEBUG)) {
 448                                 printf(";; res_setoptions(\"%s\", \"%s\")..\n",
 449                                        options, source);
 450                                 statp->options |= RES_DEBUG;
 451                         }
 452                         printf(";;\tdebug\n");
 453 #endif
 454                 } else if (!strncmp(cp, "inet6", sizeof("inet6") - 1)) {
 455                         statp->options |= RES_USE_INET6;
 456                 } else if (!strncmp(cp, "rotate", sizeof("rotate") - 1)) {
 457                         statp->options |= RES_ROTATE;
 458                 } else if (!strncmp(cp, "no-check-names",
 459                                     sizeof("no-check-names") - 1)) {
 460                         statp->options |= RES_NOCHECKNAME;
 461                 } else {
 462                         /* XXX - print a warning here? */
 463                 }
 464                 /* skip to next run of spaces */
 465                 while (*cp && *cp != ' ' && *cp != '\t')
 466                         cp++;
 467         }
 468 }
 469
 470 #ifdef RESOLVSORT
 471 /* XXX - should really support CIDR which means explicit masks always. */
 472 static u_int32_t
 473 net_mask(in)            /* XXX - should really use system's version of this */
 474         struct in_addr in;
 475 {
 476         register u_int32_t i = ntohl(in.s_addr);
 477
 478         if (IN_CLASSA(i))
 479                 return (htonl(IN_CLASSA_NET));
 480         else if (IN_CLASSB(i))
 481                 return (htonl(IN_CLASSB_NET));
 482         return (htonl(IN_CLASSC_NET));
 483 }
 484 #endif
 485
 486 u_int
 487 res_randomid(void) {
 488         struct timeval now;
 489
 490         gettimeofday(&now, NULL);
 491         return (0xffff & (now.tv_sec ^ now.tv_usec ^ getpid()));
 492 }