compat/initgroups.c

   1 /*
   2  * Copyright (C) 1996-2015 The Squid Software Foundation and contributors
   3  *
   4  * Squid software is distributed under GPLv2+ license and includes
   5  * contributions from numerous individuals and organizations.
   6  * Please see the COPYING and CONTRIBUTORS files for details.
   7  */
   8
   9 #include "squid.h"
  10 #include "compat/initgroups.h"
  11
  12 #if HAVE_GRP_H
  13 #include <grp.h>
  14 #endif
  15 #if HAVE_UNISTD_H
  16 #include <unistd.h>
  17 #endif
  18 #if HAVE_STRING_H
  19 #include <string.h>
  20 #endif
  21 #if HAVE_STRINGS_H
  22 #include <strings.h>
  23 #endif
  24 #if HAVE_LIMITS_H
  25 #include <limits.h>
  26 #endif
  27
  28 int initgroups(const char *name, gid_t basegid)
  29 {
  30 #if HAVE_SETGROUPS
  31 #ifndef NGROUPS_MAX
  32 #define NGROUPS_MAX 16
  33 #endif
  34
  35     gid_t groups[NGROUPS_MAX];
  36     struct group *g;
  37     int index = 0;
  38
  39     setgrent();
  40
  41     groups[index++] = basegid;
  42
  43     while (index < NGROUPS_MAX && ((g = getgrent()) != NULL)) {
  44         if (g->gr_gid != basegid) {
  45             char **names;
  46
  47             for (names = g->gr_mem; *names != NULL; ++names) {
  48
  49                 if (!strcmp(*names, name))
  50                     groups[index++] = g->gr_gid;
  51
  52             }
  53         }
  54     }
  55
  56     endgrent();
  57
  58     return setgroups(index, groups);
  59
  60 #else
  61
  62     return 0;
  63
  64 #endif /* def HAVE_SETGROUPS */
  65 }
  66