usr/src/lib/libc/port/nsl/gethostbyname_r.c

   1 /*
   2  * CDDL HEADER START
   3  *
   4  * The contents of this file are subject to the terms of the
   5  * Common Development and Distribution License (the "License").
   6  * You may not use this file except in compliance with the License.
   7  *
   8  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
   9  * or http://www.opensolaris.org/os/licensing.
  10  * See the License for the specific language governing permissions
  11  * and limitations under the License.
  12  *
  13  * When distributing Covered Code, include this CDDL HEADER in each
  14  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
  15  * If applicable, add the following below this CDDL HEADER, with the
  16  * fields enclosed by brackets "[]" replaced with your own identifying
  17  * information: Portions Copyright [yyyy] [name of copyright owner]
  18  *
  19  * CDDL HEADER END
  20  */
  21
  22 /*
  23  * Copyright 2006 Sun Microsystems, Inc.  All rights reserved.
  24  * Use is subject to license terms.
  25  */
  26
  27 #pragma ident   "%Z%%M% %I%     %E% SMI"
  28
  29 /*
  30  * gethostbyname_r() is defined in this file.  It is implemented on top of
  31  *   _get_hostserv_inetnetdir_byname() which is also used to implement
  32  *   netdir_getbyname() for inet family transports.  In turn the common code
  33  *   uses the name service switch policy for "hosts" and "services" unless
  34  *   the administrator chooses to bypass the name service switch by
  35  *   specifying third-party supplied nametoaddr libs for inet transports
  36  *   in /etc/netconfig.
  37  *
  38  * gethostbyaddr_r() is similarly related to _get_hostserv_inetnetdir_byaddr()
  39  *   and netdir_getbyaddr();
  40  *
  41  * The common code lives in netdir_inet.c.
  42  *
  43  * gethostent_r(), sethostent() and endhostent() are *not* implemented on top
  44  *   of the common interface;  they go straight to the switch and are
  45  *   defined in gethostent_r.c.
  46  *
  47  * There is absolutely no data sharing, not even the stayopen flag or
  48  *   enumeration state, between gethostbyYY_r() and gethostent_r();
  49  */
  50
  51 #include "mt.h"
  52 #include <netdb.h>
  53 #include <netdir.h>
  54 #include <sys/types.h>
  55 #include <nss_netdir.h>
  56 #include <string.h>
  57
  58 extern struct netconfig *__rpc_getconfip();
  59
  60 /*
  61  * h_errno POLICY: The frontends expect the name service
  62  * backends to modify the h_errno in "arg"; _switch_gethostbyYY_r()
  63  * will copy that over onto user's h_errnop pointer. This h_errno is
  64  * never used for "switching" -- status from nss_search serves
  65  * the purpose. There is no explicit zeroing in the case of success.
  66  */
  67
  68 extern struct hostent *
  69 _switch_gethostbyname_r(const char *nam, struct hostent *result, char *buffer,
  70         int buflen, int *h_errnop);
  71
  72 extern struct hostent *
  73 _switch_gethostbyaddr_r(const char *addr, int length, int type,
  74         struct hostent *result, char *buffer, int buflen, int *h_errnop);
  75
  76 #ifdef PIC
  77 struct hostent *
  78 _uncached_gethostbyname_r(const char *nam, struct hostent *result,
  79         char *buffer, int buflen, int *h_errnop)
  80 {
  81         return (_switch_gethostbyname_r(nam, result,
  82         buffer, buflen, h_errnop));
  83 }
  84
  85 struct hostent *
  86 _uncached_gethostbyaddr_r(const char *addr, int length, int type,
  87         struct hostent *result, char *buffer, int buflen, int *h_errnop)
  88 {
  89         return (_switch_gethostbyaddr_r(addr, length, type,
  90                                         result, buffer, buflen, h_errnop));
  91 }
  92
  93 #endif
  94
  95 extern struct hostent *
  96 gethostbyname_r(const char *nam, struct hostent *result, char *buffer,
  97         int buflen, int *h_errnop);
  98
  99 extern struct hostent *
 100 gethostbyaddr_r(const char *addr, int length, int type,
 101         struct hostent *result, char *buffer, int buflen, int *h_errnop);
 102
 103 struct hostent *
 104 gethostbyname_r(const char *nam, struct hostent *result, char *buffer,
 105         int buflen, int *h_errnop)
 106 {
 107         struct netconfig *nconf;
 108         struct  nss_netdirbyname_in nssin;
 109         union   nss_netdirbyname_out nssout;
 110         int neterr, dummy;
 111
 112         if (h_errnop == NULL)
 113                 h_errnop = &dummy;
 114
 115         if (strlen(nam) == 0) {
 116                 *h_errnop = HOST_NOT_FOUND;
 117                 return (NULL);
 118         }
 119
 120         if ((nconf = __rpc_getconfip("udp")) == NULL &&
 121             (nconf = __rpc_getconfip("tcp")) == NULL) {
 122                 *h_errnop = NO_RECOVERY;
 123                 return (NULL);
 124         }
 125
 126         nssin.op_t = NSS_HOST;
 127         nssin.arg.nss.host.name = nam;
 128         nssin.arg.nss.host.buf = buffer;
 129         nssin.arg.nss.host.buflen = buflen;
 130
 131         nssout.nss.host.hent = result;
 132         nssout.nss.host.herrno_p = h_errnop;
 133
 134         /*
 135          * We pass in nconf and let the implementation of the long-named func
 136          * decide whether to use the switch based on nc_nlookups.
 137          */
 138         neterr = _get_hostserv_inetnetdir_byname(nconf, &nssin, &nssout);
 139
 140         (void) freenetconfigent(nconf);
 141         if (neterr != ND_OK)
 142                 return (NULL);
 143         return (nssout.nss.host.hent);
 144 }
 145
 146 struct hostent *
 147 gethostbyaddr_r(const char *addr, int length, int type,
 148         struct hostent *result, char *buffer, int buflen, int *h_errnop)
 149 {
 150         struct netconfig *nconf;
 151         struct  nss_netdirbyaddr_in nssin;
 152         union   nss_netdirbyaddr_out nssout;
 153         int neterr, dummy;
 154
 155         if (h_errnop == NULL)
 156                 h_errnop = &dummy;
 157
 158         if (type != AF_INET) {
 159                 *h_errnop = HOST_NOT_FOUND;
 160                 return (NULL);
 161         }
 162
 163         if ((nconf = __rpc_getconfip("udp")) == NULL &&
 164             (nconf = __rpc_getconfip("tcp")) == NULL) {
 165                 *h_errnop = NO_RECOVERY;
 166                 return (NULL);
 167         }
 168
 169         nssin.op_t = NSS_HOST;
 170         nssin.arg.nss.host.addr = addr;
 171         nssin.arg.nss.host.len = length;
 172         nssin.arg.nss.host.type = type;
 173         nssin.arg.nss.host.buf = buffer;
 174         nssin.arg.nss.host.buflen = buflen;
 175
 176         nssout.nss.host.hent = result;
 177         nssout.nss.host.herrno_p = h_errnop;
 178
 179         /*
 180          * We pass in nconf and let the implementation of this long-named func
 181          * decide whether to use the switch based on nc_nlookups.
 182          */
 183         neterr = _get_hostserv_inetnetdir_byaddr(nconf, &nssin, &nssout);
 184
 185         (void) freenetconfigent(nconf);
 186         if (neterr != ND_OK)
 187                 return (NULL);
 188         return (nssout.nss.host.hent);
 189 }