nis/nss_nisplus/nisplus-initgroups.c

   1 /* Copyright (C) 1997, 2001, 2002, 2003, 2005, 2006
   2    Free Software Foundation, Inc.
   3    This file is part of the GNU C Library.
   4
   5    The GNU C Library is free software; you can redistribute it and/or
   6    modify it under the terms of the GNU Lesser General Public
   7    License as published by the Free Software Foundation; either
   8    version 2.1 of the License, or (at your option) any later version.
   9
  10    The GNU C Library is distributed in the hope that it will be useful,
  11    but WITHOUT ANY WARRANTY; without even the implied warranty of
  12    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  13    Lesser General Public License for more details.
  14
  15    You should have received a copy of the GNU Lesser General Public
  16    License along with the GNU C Library; if not, write to the Free
  17    Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
  18    02111-1307 USA.  */
  19
  20 #include <atomic.h>
  21 #include <nss.h>
  22 #include <grp.h>
  23 #include <ctype.h>
  24 #include <errno.h>
  25 #include <string.h>
  26 #include <bits/libc-lock.h>
  27 #include <rpcsvc/nis.h>
  28
  29 #include "nss-nisplus.h"
  30 #include "nisplus-parser.h"
  31 #include <libnsl.h>
  32 #include <nis_intern.h>
  33 #include <nis_xdr.h>
  34
  35 #define NISOBJVAL(col, obj) \
  36   ((obj)->EN_data.en_cols.en_cols_val[col].ec_value.ec_value_val)
  37
  38 #define NISOBJLEN(col, obj) \
  39   ((obj)->EN_data.en_cols.en_cols_val[col].ec_value.ec_value_len)
  40
  41 extern nis_name grp_tablename_val attribute_hidden;
  42 extern size_t grp_tablename_len attribute_hidden;
  43 extern enum nss_status _nss_grp_create_tablename (int *errnop);
  44
  45
  46 enum nss_status
  47 _nss_nisplus_initgroups_dyn (const char *user, gid_t group, long int *start,
  48                              long int *size, gid_t **groupsp, long int limit,
  49                              int *errnop)
  50 {
  51   if (grp_tablename_val == NULL)
  52     {
  53       enum nss_status status = _nss_grp_create_tablename (errnop);
  54
  55       if (status != NSS_STATUS_SUCCESS)
  56         return status;
  57     }
  58
  59   nis_result *result;
  60   char buf[strlen (user) + 12 + grp_tablename_len];
  61
  62   snprintf (buf, sizeof (buf), "[members=%s],%s", user, grp_tablename_val);
  63
  64   result = nis_list (buf, FOLLOW_LINKS | FOLLOW_PATH | ALL_RESULTS, NULL, NULL);
  65
  66   if (result == NULL)
  67     {
  68       *errnop = ENOMEM;
  69       return NSS_STATUS_TRYAGAIN;
  70     }
  71
  72   if (__builtin_expect (niserr2nss (result->status) != NSS_STATUS_SUCCESS, 0))
  73     {
  74       enum nss_status status = niserr2nss (result->status);
  75
  76       nis_freeresult (result);
  77       return status;
  78     }
  79
  80   if (NIS_RES_NUMOBJ (result) == 0)
  81     {
  82     errout:
  83       nis_freeresult (result);
  84       return NSS_STATUS_NOTFOUND;
  85     }
  86
  87   gid_t *groups = *groupsp;
  88   nis_object *obj = NIS_RES_OBJECT (result);
  89   for (unsigned int cnt = 0; cnt < NIS_RES_NUMOBJ (result); ++cnt, ++obj)
  90     {
  91       if (__type_of (obj) != NIS_ENTRY_OBJ
  92           || strcmp (obj->EN_data.en_type, "group_tbl") != 0
  93           || obj->EN_data.en_cols.en_cols_len < 4)
  94         continue;
  95
  96       char *numstr = NISOBJVAL (2, obj);
  97       size_t len = NISOBJLEN (2, obj);
  98       if (len == 0 || numstr[0] == '\0')
  99         continue;
 100
 101       gid_t gid;
 102       char *endp;
 103       if (__builtin_expect (numstr[len - 1] != '\0', 0))
 104         {
 105           char numstrbuf[len + 1];
 106           memcpy (numstrbuf, numstr, len);
 107           numstrbuf[len] = '\0';
 108           gid = strtoul (numstrbuf, &endp, 10);
 109           if (*endp)
 110             continue;
 111         }
 112       else
 113         {
 114           gid = strtoul (numstr, &endp, 10);
 115           if (*endp)
 116             continue;
 117         }
 118
 119       if (gid == group)
 120         continue;
 121
 122       /* Insert this group.  */
 123       if (*start == *size)
 124         {
 125           /* Need a bigger buffer.  */
 126           long int newsize;
 127
 128           if (limit > 0 && *size == limit)
 129             /* We reached the maximum.  */
 130             break;
 131
 132           if (limit <= 0)
 133             newsize = 2 * *size;
 134           else
 135             newsize = MIN (limit, 2 * *size);
 136
 137           gid_t *newgroups = realloc (groups, newsize * sizeof (*groups));
 138           if (newgroups == NULL)
 139             goto errout;
 140           *groupsp = groups = newgroups;
 141           *size = newsize;
 142         }
 143
 144       groups[*start] = gid;
 145       *start += 1;
 146     }
 147
 148   nis_freeresult (result);
 149   return NSS_STATUS_SUCCESS;
 150 }