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 #ifdef  NSS_INCLUDE_UNSAFE
  43
  44 extern size_t _nss_get_bufsizes(int arg);
  45
  46 /*
  47  * Ye olde non-reentrant interface (MT-unsafe, caveat utor)
  48  */
  49
  50 static void
  51 free_grbuf(void *arg)
  52 {
  53         nss_XbyY_buf_t **buffer = arg;
  54
  55         NSS_XbyY_FREE(buffer);
  56 }
  57
  58 static nss_XbyY_buf_t *
  59 get_grbuf(int max_buf)
  60 {
  61         nss_XbyY_buf_t **buffer =
  62             tsdalloc(_T_GRBUF, sizeof (nss_XbyY_buf_t *), free_grbuf);
  63         nss_XbyY_buf_t *b;
  64         size_t  blen;
  65
  66         if (buffer == NULL)
  67                 return (NULL);
  68         if (max_buf == 0)
  69                 blen = _nss_get_bufsizes(0);            /* default size */
  70         else
  71                 blen = sysconf(_SC_GETGR_R_SIZE_MAX);   /* max size */
  72         if (*buffer) {
  73                 if ((*buffer)->buflen >= blen)  /* existing size fits */
  74                         return (*buffer);
  75                 NSS_XbyY_FREE(buffer);          /* existing is too small */
  76         }
  77         b = NSS_XbyY_ALLOC(buffer, sizeof (struct group), blen);
  78         return (b);
  79 }
  80
  81 struct group *
  82 getgrgid(gid_t gid)
  83 {
  84         nss_XbyY_buf_t  *b = get_grbuf(0);
  85         struct group *ret;
  86
  87         if (b == NULL)
  88                 return (NULL);
  89
  90         ret = getgrgid_r(gid, b->result, b->buffer, b->buflen);
  91         if (ret == NULL && errno == ERANGE) {
  92                 b = get_grbuf(1);
  93                 if (b == NULL)
  94                         return (NULL);
  95                 ret = getgrgid_r(gid, b->result, b->buffer, b->buflen);
  96         }
  97         return (ret);
  98 }
  99
 100 struct group *
 101 getgrnam(const char *nam)
 102 {
 103         nss_XbyY_buf_t  *b = get_grbuf(0);
 104         struct group *ret;
 105
 106         if (b == NULL)
 107                 return (NULL);
 108
 109         ret = getgrnam_r(nam, b->result, b->buffer, b->buflen);
 110         if (ret == NULL && errno == ERANGE && nam != NULL) {
 111                 b = get_grbuf(1);
 112                 if (b == NULL)
 113                         return (NULL);
 114                 ret = getgrnam_r(nam, b->result, b->buffer, b->buflen);
 115         }
 116         return (ret);
 117 }
 118
 119 struct group *
 120 getgrent(void)
 121 {
 122         nss_XbyY_buf_t  *b = get_grbuf(1);
 123
 124         return (b == NULL ? NULL :
 125             getgrent_r(b->result, b->buffer, b->buflen));
 126 }
 127
 128 struct group *
 129 fgetgrent(FILE *f)
 130 {
 131         nss_XbyY_buf_t  *b = get_grbuf(1);
 132
 133         return (b == NULL ? NULL :
 134             fgetgrent_r(f, b->result, b->buffer, b->buflen));
 135 }
 136
 137 #endif  /* NSS_INCLUDE_UNSAFE */