third_party/nss_wrapper/nss_utils.c

   1 /*
   2  * BSD 3-Clause License
   3  *
   4  * Copyright (c) 2007,      Stefan Metzmacher <metze@samba.org>
   5  * Copyright (c) 2009,      Guenther Deschner <gd@samba.org>
   6  * Copyright (c) 2014-2015, Michael Adam <obnox@samba.org>
   7  * Copyright (c) 2015,      Robin Hack <hack.robin@gmail.com>
   8  * Copyright (c) 2013-2018, Andreas Schneider <asn@samba.org>
   9  * All rights reserved.
  10  *
  11  * Redistribution and use in source and binary forms, with or without
  12  * modification, are permitted provided that the following conditions
  13  * are met:
  14  *
  15  * 1. Redistributions of source code must retain the above copyright
  16  *    notice, this list of conditions and the following disclaimer.
  17  *
  18  * 2. Redistributions in binary form must reproduce the above copyright
  19  *    notice, this list of conditions and the following disclaimer in the
  20  *    documentation and/or other materials provided with the distribution.
  21  *
  22  * 3. Neither the name of the author nor the names of its contributors
  23  *    may be used to endorse or promote products derived from this software
  24  *    without specific prior written permission.
  25  *
  26  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
  27  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  28  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  29  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
  30  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  31  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  32  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  33  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  34  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  35  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  36  * SUCH DAMAGE.
  37  */
  38
  39 #include <errno.h>
  40 #include <grp.h>
  41 #include <string.h>
  42 #include <stdint.h>
  43
  44 #include "nss_utils.h"
  45
  46 int nwrap_gr_copy_r(const struct group *src, struct group *dst,
  47                     char *buf, size_t buflen, struct group **dstp)
  48 {
  49         char *p = NULL;
  50         uintptr_t align = 0;
  51         unsigned int gr_mem_cnt = 0;
  52         unsigned i;
  53         size_t total_len;
  54         size_t gr_name_len = strlen(src->gr_name) + 1;
  55         size_t gr_passwd_len = strlen(src->gr_passwd) + 1;
  56         union {
  57                 char *ptr;
  58                 char **data;
  59         } g_mem;
  60
  61         for (i = 0; src->gr_mem[i] != NULL; i++) {
  62                 gr_mem_cnt++;
  63         }
  64
  65         /* Align the memory for storing pointers */
  66         align = __alignof__(char *) - ((p - (char *)0) % __alignof__(char *));
  67         total_len = align +
  68                     (1 + gr_mem_cnt) * sizeof(char *) +
  69                     gr_name_len + gr_passwd_len;
  70
  71         if (total_len > buflen) {
  72                 errno = ERANGE;
  73                 return -1;
  74         }
  75         buflen -= total_len;
  76
  77         /* gr_mem */
  78         p = buf + align;
  79         g_mem.ptr = p;
  80         dst->gr_mem = g_mem.data;
  81
  82         /* gr_name */
  83         p += (1 + gr_mem_cnt) * sizeof(char *);
  84         dst->gr_name = p;
  85
  86         /* gr_passwd */
  87         p += gr_name_len;
  88         dst->gr_passwd = p;
  89
  90         /* gr_mem[x] */
  91         p += gr_passwd_len;
  92
  93         /* gr_gid */
  94         dst->gr_gid = src->gr_gid;
  95
  96         memcpy(dst->gr_name, src->gr_name, gr_name_len);
  97
  98         memcpy(dst->gr_passwd, src->gr_passwd, gr_passwd_len);
  99
 100         /* Set the terminating entry */
 101         dst->gr_mem[gr_mem_cnt] = NULL;
 102
 103         /* Now add the group members content */
 104         total_len = 0;
 105         for (i = 0; i < gr_mem_cnt; i++) {
 106                 size_t len = strlen(src->gr_mem[i]) + 1;
 107
 108                 dst->gr_mem[i] = p;
 109                 total_len += len;
 110                 p += len;
 111         }
 112
 113         if (total_len > buflen) {
 114                 errno = ERANGE;
 115                 return -1;
 116         }
 117
 118         for (i = 0; i < gr_mem_cnt; i++) {
 119                 size_t len = strlen(src->gr_mem[i]) + 1;
 120
 121                 memcpy(dst->gr_mem[i],
 122                        src->gr_mem[i],
 123                        len);
 124         }
 125
 126         if (dstp != NULL) {
 127                 *dstp = dst;
 128         }
 129
 130         return 0;
 131 }