lib/libc/asr/res_mkquery.c

   1 /*      $OpenBSD: res_mkquery.c,v 1.5 2013/04/01 20:22:27 eric Exp $    */
   2 /*
   3  * Copyright (c) 2012 Eric Faurot <eric@openbsd.org>
   4  *
   5  * Permission to use, copy, modify, and distribute this software for any
   6  * purpose with or without fee is hereby granted, provided that the above
   7  * copyright notice and this permission notice appear in all copies.
   8  *
   9  * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
  10  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
  11  * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
  12  * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
  13  * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
  14  * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
  15  * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
  16  */
  17
  18 #include <sys/types.h>
  19 #include <netinet/in.h>
  20 #include <arpa/nameser.h> /* for MAXDNAME */
  21
  22 #include <errno.h>
  23 #include <resolv.h>
  24 #include <string.h>
  25
  26 #include "asr.h"
  27 #include "asr_private.h"
  28
  29 /* This function is apparently needed by some ports. */
  30 int
  31 res_mkquery(int op, const char *dname, int class, int type,
  32     const unsigned char *data, int datalen, const unsigned char *newrr,
  33     unsigned char *buf, int buflen)
  34 {
  35         struct asr_ctx  *ac;
  36         struct pack      p;
  37         struct header    h;
  38         char             fqdn[MAXDNAME];
  39         char             dn[MAXDNAME];
  40
  41         /* we currently only support QUERY */
  42         if (op != QUERY || data)
  43                 return (-1);
  44
  45         if (dname[0] == '\0' || dname[strlen(dname) - 1] != '.') {
  46                 if (strlcpy(fqdn, dname, sizeof(fqdn)) >= sizeof(fqdn) ||
  47                     strlcat(fqdn, ".", sizeof(fqdn)) >= sizeof(fqdn))
  48                         return (-1);
  49                 dname = fqdn;
  50         }
  51
  52         if (dname_from_fqdn(dname, dn, sizeof(dn)) == -1)
  53                 return (-1);
  54
  55         ac = asr_use_resolver(NULL);
  56
  57         memset(&h, 0, sizeof h);
  58         h.id = res_randomid();
  59         if (ac->ac_options & RES_RECURSE)
  60                 h.flags |= RD_MASK;
  61         h.qdcount = 1;
  62
  63         pack_init(&p, buf, buflen);
  64         pack_header(&p, &h);
  65         pack_query(&p, type, class, dn);
  66
  67         asr_ctx_unref(ac);
  68
  69         if (p.err)
  70                 return (-1);
  71
  72         return (p.offset);
  73 }
  74
  75 /*
  76  * This function is not documented, but used by sendmail.
  77  * Put here because it uses asr_private.h too.
  78  */
  79 int
  80 res_querydomain(const char *name,
  81     const char *domain,
  82     int class,
  83     int type,
  84     u_char *answer,
  85     int anslen)
  86 {
  87         char    fqdn[MAXDNAME], ndom[MAXDNAME];
  88         size_t  n;
  89
  90         /* we really want domain to end with a dot for now */
  91         if (domain && ((n = strlen(domain)) == 0 || domain[n - 1 ] != '.')) {
  92                 if (strlcpy(ndom, domain, sizeof(ndom)) >= sizeof(ndom) ||
  93                     strlcat(ndom, ".", sizeof(ndom)) >= sizeof(ndom)) {
  94                         h_errno = NETDB_INTERNAL;
  95                         errno = EINVAL;
  96                         return (-1);
  97                 }
  98                 domain = ndom;
  99         }
 100
 101         if (asr_make_fqdn(name, domain, fqdn, sizeof fqdn) == 0) {
 102                 h_errno = NETDB_INTERNAL;
 103                 errno = EINVAL;
 104                 return (-1);
 105         }
 106
 107         return (res_query(fqdn, class, type, answer, anslen));
 108 }