usr/src/lib/libc/port/gen/getgrnam.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 2008 Sun Microsystems, Inc.  All rights reserved.
  24  * Use is subject to license terms.
  25  */
  26
  27 /*      Copyright (c) 1988 AT&T */
  28 /*        All Rights Reserved   */
  29
  30 #pragma ident   "%Z%%M% %I%     %E% SMI"
  31
  32 #pragma weak _getgrnam  = getgrnam
  33 #pragma weak _getgrgid  = getgrgid
  34
  35 #include "lint.h"
  36 #include <sys/types.h>
  37 #include <grp.h>
  38 #include <nss_dbdefs.h>
  39 #include <stdio.h>
  40 #include "tsd.h"
  41
  42 extern size_t _nss_get_bufsizes(int arg);
  43
  44 /*
  45  * Ye olde non-reentrant interface (MT-unsafe, caveat utor)
  46  */
  47
  48 static void
  49 free_grbuf(void *arg)
  50 {
  51         nss_XbyY_buf_t **buffer = arg;
  52
  53         NSS_XbyY_FREE(buffer);
  54 }
  55
  56 static nss_XbyY_buf_t *
  57 get_grbuf(int max_buf)
  58 {
  59         nss_XbyY_buf_t **buffer =
  60             tsdalloc(_T_GRBUF, sizeof (nss_XbyY_buf_t *), free_grbuf);
  61         nss_XbyY_buf_t *b;
  62         size_t  blen;
  63
  64         if (buffer == NULL)
  65                 return (NULL);
  66         if (max_buf == 0)
  67                 blen = _nss_get_bufsizes(0);            /* default size */
  68         else
  69                 blen = sysconf(_SC_GETGR_R_SIZE_MAX);   /* max size */
  70         if (*buffer) {
  71                 if ((*buffer)->buflen >= blen)  /* existing size fits */
  72                         return (*buffer);
  73                 NSS_XbyY_FREE(buffer);          /* existing is too small */
  74         }
  75         b = NSS_XbyY_ALLOC(buffer, sizeof (struct group), blen);
  76         return (b);
  77 }
  78
  79 struct group *
  80 getgrgid(gid_t gid)
  81 {
  82         nss_XbyY_buf_t  *b = get_grbuf(0);
  83         struct group *ret;
  84
  85         if (b == NULL)
  86                 return (NULL);
  87
  88         ret = getgrgid_r(gid, b->result, b->buffer, b->buflen);
  89         if (ret == NULL && errno == ERANGE) {
  90                 b = get_grbuf(1);
  91                 if (b == NULL)
  92                         return (NULL);
  93                 ret = getgrgid_r(gid, b->result, b->buffer, b->buflen);
  94         }
  95         return (ret);
  96 }
  97
  98 struct group *
  99 getgrnam(const char *nam)
 100 {
 101         nss_XbyY_buf_t  *b = get_grbuf(0);
 102         struct group *ret;
 103
 104         if (b == NULL)
 105                 return (NULL);
 106
 107         ret = getgrnam_r(nam, b->result, b->buffer, b->buflen);
 108         if (ret == NULL && errno == ERANGE && nam != NULL) {
 109                 b = get_grbuf(1);
 110                 if (b == NULL)
 111                         return (NULL);
 112                 ret = getgrnam_r(nam, b->result, b->buffer, b->buflen);
 113         }
 114         return (ret);
 115 }
 116
 117 struct group *
 118 getgrent(void)
 119 {
 120         nss_XbyY_buf_t  *b = get_grbuf(1);
 121
 122         return (b == NULL ? NULL :
 123             getgrent_r(b->result, b->buffer, b->buflen));
 124 }
 125
 126 struct group *
 127 fgetgrent(FILE *f)
 128 {
 129         nss_XbyY_buf_t  *b = get_grbuf(1);
 130
 131         return (b == NULL ? NULL :
 132             fgetgrent_r(f, b->result, b->buffer, b->buflen));
 133 }