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, see
  17    <http://www.gnu.org/licenses/>.  */
  18
  19 #include <atomic.h>
  20 #include <nss.h>
  21 #include <grp.h>
  22 #include <ctype.h>
  23 #include <errno.h>
  24 #include <string.h>
  25 #include <bits/libc-lock.h>
  26 #include <rpcsvc/nis.h>
  27
  28 #include "nss-nisplus.h"
  29 #include "nisplus-parser.h"
  30 #include <libnsl.h>
  31 #include <nis_intern.h>
  32 #include <nis_xdr.h>
  33
  34 #define NISOBJVAL(col, obj) \
  35   ((obj)->EN_data.en_cols.en_cols_val[col].ec_value.ec_value_val)
  36
  37 #define NISOBJLEN(col, obj) \
  38   ((obj)->EN_data.en_cols.en_cols_val[col].ec_value.ec_value_len)
  39
  40 extern nis_name grp_tablename_val attribute_hidden;
  41 extern size_t grp_tablename_len attribute_hidden;
  42 extern enum nss_status _nss_grp_create_tablename (int *errnop);
  43
  44
  45 enum nss_status
  46 _nss_nisplus_initgroups_dyn (const char *user, gid_t group, long int *start,
  47                              long int *size, gid_t **groupsp, long int limit,
  48                              int *errnop)
  49 {
  50   if (grp_tablename_val == NULL)
  51     {
  52       enum nss_status status = _nss_grp_create_tablename (errnop);
  53
  54       if (status != NSS_STATUS_SUCCESS)
  55         return status;
  56     }
  57
  58   nis_result *result;
  59   char buf[strlen (user) + 12 + grp_tablename_len];
  60
  61   snprintf (buf, sizeof (buf), "[members=%s],%s", user, grp_tablename_val);
  62
  63   result = nis_list (buf, FOLLOW_LINKS | FOLLOW_PATH | ALL_RESULTS, NULL, NULL);
  64
  65   if (result == NULL)
  66     {
  67       *errnop = ENOMEM;
  68       return NSS_STATUS_TRYAGAIN;
  69     }
  70
  71   if (__builtin_expect (niserr2nss (result->status) != NSS_STATUS_SUCCESS, 0))
  72     {
  73       enum nss_status status = niserr2nss (result->status);
  74
  75       nis_freeresult (result);
  76       return status;
  77     }
  78
  79   if (NIS_RES_NUMOBJ (result) == 0)
  80     {
  81     errout:
  82       nis_freeresult (result);
  83       return NSS_STATUS_NOTFOUND;
  84     }
  85
  86   gid_t *groups = *groupsp;
  87   nis_object *obj = NIS_RES_OBJECT (result);
  88   for (unsigned int cnt = 0; cnt < NIS_RES_NUMOBJ (result); ++cnt, ++obj)
  89     {
  90       if (__type_of (obj) != NIS_ENTRY_OBJ
  91           || strcmp (obj->EN_data.en_type, "group_tbl") != 0
  92           || obj->EN_data.en_cols.en_cols_len < 4)
  93         continue;
  94
  95       char *numstr = NISOBJVAL (2, obj);
  96       size_t len = NISOBJLEN (2, obj);
  97       if (len == 0 || numstr[0] == '\0')
  98         continue;
  99
 100       gid_t gid;
 101       char *endp;
 102       if (__builtin_expect (numstr[len - 1] != '\0', 0))
 103         {
 104           char numstrbuf[len + 1];
 105           memcpy (numstrbuf, numstr, len);
 106           numstrbuf[len] = '\0';
 107           gid = strtoul (numstrbuf, &endp, 10);
 108           if (*endp)
 109             continue;
 110         }
 111       else
 112         {
 113           gid = strtoul (numstr, &endp, 10);
 114           if (*endp)
 115             continue;
 116         }
 117
 118       if (gid == group)
 119         continue;
 120
 121       /* Insert this group.  */
 122       if (*start == *size)
 123         {
 124           /* Need a bigger buffer.  */
 125           long int newsize;
 126
 127           if (limit > 0 && *size == limit)
 128             /* We reached the maximum.  */
 129             break;
 130
 131           if (limit <= 0)
 132             newsize = 2 * *size;
 133           else
 134             newsize = MIN (limit, 2 * *size);
 135
 136           gid_t *newgroups = realloc (groups, newsize * sizeof (*groups));
 137           if (newgroups == NULL)
 138             goto errout;
 139           *groupsp = groups = newgroups;
 140           *size = newsize;
 141         }
 142
 143       groups[*start] = gid;
 144       *start += 1;
 145     }
 146
 147   nis_freeresult (result);
 148   return NSS_STATUS_SUCCESS;
 149 }