contrib/bind-9.2.4rc7/lib/lwres/gethost.c

   1 /*
   2  * Copyright (C) 2004  Internet Systems Consortium, Inc. ("ISC")
   3  * Copyright (C) 2000, 2001  Internet Software Consortium.
   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 ISC DISCLAIMS ALL WARRANTIES WITH
  10  * REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY
  11  * AND FITNESS.  IN NO EVENT SHALL ISC BE LIABLE FOR ANY SPECIAL, DIRECT,
  12  * INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM
  13  * LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE
  14  * OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
  15  * PERFORMANCE OF THIS SOFTWARE.
  16  */
  17
  18 /* $Id: gethost.c,v 1.29.2.1 2004/03/09 06:12:33 marka Exp $ */
  19
  20 #include <config.h>
  21
  22 #include <errno.h>
  23 #include <string.h>
  24
  25 #include <lwres/net.h>
  26 #include <lwres/netdb.h>
  27
  28 #include "assert_p.h"
  29
  30 #define LWRES_ALIGNBYTES (sizeof(char *) - 1)
  31 #define LWRES_ALIGN(p) \
  32         (((unsigned long)(p) + LWRES_ALIGNBYTES) &~ LWRES_ALIGNBYTES)
  33
  34 static struct hostent *he = NULL;
  35 static int copytobuf(struct hostent *, struct hostent *, char *, int);
  36
  37 struct hostent *
  38 lwres_gethostbyname(const char *name) {
  39
  40         if (he != NULL)
  41                 lwres_freehostent(he);
  42
  43         he = lwres_getipnodebyname(name, AF_INET, 0, &lwres_h_errno);
  44         return (he);
  45 }
  46
  47 struct hostent *
  48 lwres_gethostbyname2(const char *name, int af) {
  49         if (he != NULL)
  50                 lwres_freehostent(he);
  51
  52         he = lwres_getipnodebyname(name, af, 0, &lwres_h_errno);
  53         return (he);
  54 }
  55
  56 struct hostent *
  57 lwres_gethostbyaddr(const char *addr, int len, int type) {
  58
  59         if (he != NULL)
  60                 lwres_freehostent(he);
  61
  62         he = lwres_getipnodebyaddr(addr, len, type, &lwres_h_errno);
  63         return (he);
  64 }
  65
  66 struct hostent *
  67 lwres_gethostent(void) {
  68         if (he != NULL)
  69                 lwres_freehostent(he);
  70
  71         return (NULL);
  72 }
  73
  74 void
  75 lwres_sethostent(int stayopen) {
  76         /*
  77          * Empty.
  78          */
  79         UNUSED(stayopen);
  80 }
  81
  82 void
  83 lwres_endhostent(void) {
  84         /*
  85          * Empty.
  86          */
  87 }
  88
  89 struct hostent *
  90 lwres_gethostbyname_r(const char *name, struct hostent *resbuf,
  91                 char *buf, int buflen, int *error)
  92 {
  93         struct hostent *he;
  94         int res;
  95
  96         he = lwres_getipnodebyname(name, AF_INET, 0, error);
  97         if (he == NULL)
  98                 return (NULL);
  99         res = copytobuf(he, resbuf, buf, buflen);
 100         lwres_freehostent(he);
 101         if (res != 0) {
 102                 errno = ERANGE;
 103                 return (NULL);
 104         }
 105         return (resbuf);
 106 }
 107
 108 struct hostent  *
 109 lwres_gethostbyaddr_r(const char *addr, int len, int type,
 110                       struct hostent *resbuf, char *buf, int buflen,
 111                       int *error)
 112 {
 113         struct hostent *he;
 114         int res;
 115
 116         he = lwres_getipnodebyaddr(addr, len, type, error);
 117         if (he == NULL)
 118                 return (NULL);
 119         res = copytobuf(he, resbuf, buf, buflen);
 120         lwres_freehostent(he);
 121         if (res != 0) {
 122                 errno = ERANGE;
 123                 return (NULL);
 124         }
 125         return (resbuf);
 126 }
 127
 128 struct hostent  *
 129 lwres_gethostent_r(struct hostent *resbuf, char *buf, int buflen, int *error) {
 130         UNUSED(resbuf);
 131         UNUSED(buf);
 132         UNUSED(buflen);
 133         *error = 0;
 134         return (NULL);
 135 }
 136
 137 void
 138 lwres_sethostent_r(int stayopen) {
 139         /*
 140          * Empty.
 141          */
 142         UNUSED(stayopen);
 143 }
 144
 145 void
 146 lwres_endhostent_r(void) {
 147         /*
 148          * Empty.
 149          */
 150 }
 151
 152 static int
 153 copytobuf(struct hostent *he, struct hostent *hptr, char *buf, int buflen) {
 154         char *cp;
 155         char **ptr;
 156         int i, n;
 157         int nptr, len;
 158
 159         /*
 160          * Find out the amount of space required to store the answer.
 161          */
 162         nptr = 2; /* NULL ptrs */
 163         len = (char *)LWRES_ALIGN(buf) - buf;
 164         for (i = 0; he->h_addr_list[i]; i++, nptr++) {
 165                 len += he->h_length;
 166         }
 167         for (i = 0; he->h_aliases[i]; i++, nptr++) {
 168                 len += strlen(he->h_aliases[i]) + 1;
 169         }
 170         len += strlen(he->h_name) + 1;
 171         len += nptr * sizeof(char*);
 172
 173         if (len > buflen) {
 174                 return (-1);
 175         }
 176
 177         /*
 178          * Copy address size and type.
 179          */
 180         hptr->h_addrtype = he->h_addrtype;
 181         n = hptr->h_length = he->h_length;
 182
 183         ptr = (char **)LWRES_ALIGN(buf);
 184         cp = (char *)LWRES_ALIGN(buf) + nptr * sizeof(char *);
 185
 186         /*
 187          * Copy address list.
 188          */
 189         hptr->h_addr_list = ptr;
 190         for (i = 0; he->h_addr_list[i]; i++, ptr++) {
 191                 memcpy(cp, he->h_addr_list[i], n);
 192                 hptr->h_addr_list[i] = cp;
 193                 cp += n;
 194         }
 195         hptr->h_addr_list[i] = NULL;
 196         ptr++;
 197
 198         /*
 199          * Copy official name.
 200          */
 201         n = strlen(he->h_name) + 1;
 202         strcpy(cp, he->h_name);
 203         hptr->h_name = cp;
 204         cp += n;
 205
 206         /*
 207          * Copy aliases.
 208          */
 209         hptr->h_aliases = ptr;
 210         for (i = 0; he->h_aliases[i]; i++) {
 211                 n = strlen(he->h_aliases[i]) + 1;
 212                 strcpy(cp, he->h_aliases[i]);
 213                 hptr->h_aliases[i] = cp;
 214                 cp += n;
 215         }
 216         hptr->h_aliases[i] = NULL;
 217
 218         return (0);
 219 }