hesiod/nss_hesiod/hesiod-grp.c

   1 /* Copyright (C) 1997, 1999, 2000, 2002 Free Software Foundation, Inc.
   2    This file is part of the GNU C Library.
   3    Contributed by Mark Kettenis <kettenis@phys.uva.nl>, 1997.
   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 <ctype.h>
  21 #include <errno.h>
  22 #include <grp.h>
  23 #include <hesiod.h>
  24 #include <nss.h>
  25 #include <stdio.h>
  26 #include <stdlib.h>
  27 #include <string.h>
  28 #include <sys/param.h>
  29
  30 #include "nss_hesiod.h"
  31
  32 /* Get the declaration of the parser function.  */
  33 #define ENTNAME grent
  34 #define STRUCTURE group
  35 #define EXTERN_PARSER
  36 #include <nss/nss_files/files-parse.c>
  37
  38 enum nss_status
  39 _nss_hesiod_setgrent (int stayopen)
  40 {
  41   return NSS_STATUS_SUCCESS;
  42 }
  43
  44 enum nss_status
  45 _nss_hesiod_endgrent (void)
  46 {
  47   return NSS_STATUS_SUCCESS;
  48 }
  49
  50 static enum nss_status
  51 lookup (const char *name, const char *type, struct group *grp,
  52         char *buffer, size_t buflen, int *errnop)
  53 {
  54   struct parser_data *data = (void *) buffer;
  55   size_t linebuflen;
  56   void *context;
  57   char **list;
  58   int parse_res;
  59   size_t len;
  60   int olderr = errno;
  61
  62   context = _nss_hesiod_init ();
  63   if (context == NULL)
  64     return NSS_STATUS_UNAVAIL;
  65
  66   list = hesiod_resolve (context, name, type);
  67   if (list == NULL)
  68     {
  69       int err = errno;
  70       hesiod_end (context);
  71       __set_errno (olderr);
  72       return err == ENOENT ? NSS_STATUS_NOTFOUND : NSS_STATUS_UNAVAIL;
  73     }
  74
  75   linebuflen = buffer + buflen - data->linebuffer;
  76   len = strlen (*list) + 1;
  77   if (linebuflen < len)
  78     {
  79       hesiod_free_list (context, list);
  80       hesiod_end (context);
  81       *errnop = ERANGE;
  82       return NSS_STATUS_TRYAGAIN;
  83     }
  84
  85   memcpy (data->linebuffer, *list, len);
  86   hesiod_free_list (context, list);
  87   hesiod_end (context);
  88
  89   parse_res = _nss_files_parse_grent (buffer, grp, data, buflen, errnop);
  90   if (parse_res < 1)
  91     {
  92       __set_errno (olderr);
  93       return parse_res == -1 ? NSS_STATUS_TRYAGAIN : NSS_STATUS_NOTFOUND;
  94     }
  95
  96   return NSS_STATUS_SUCCESS;
  97 }
  98
  99 enum nss_status
 100 _nss_hesiod_getgrnam_r (const char *name, struct group *grp,
 101                         char *buffer, size_t buflen, int *errnop)
 102 {
 103   return lookup (name, "group", grp, buffer, buflen, errnop);
 104 }
 105
 106 enum nss_status
 107 _nss_hesiod_getgrgid_r (gid_t gid, struct group *grp,
 108                         char *buffer, size_t buflen, int *errnop)
 109 {
 110   char gidstr[21];      /* We will probably never have a gid_t with more
 111                            than 64 bits.  */
 112
 113   snprintf (gidstr, sizeof gidstr, "%d", gid);
 114
 115   return lookup (gidstr, "gid", grp, buffer, buflen, errnop);
 116 }
 117
 118 static int
 119 internal_gid_in_list (const gid_t *list, const gid_t g, long int len)
 120 {
 121   while (len > 0)
 122     {
 123       if (*list == g)
 124         return 1;
 125       --len;
 126       ++list;
 127     }
 128   return 0;
 129 }
 130
 131 static enum nss_status
 132 internal_gid_from_group (void *context, const char *groupname, gid_t *group)
 133 {
 134   char **grp_res;
 135   enum nss_status status = NSS_STATUS_NOTFOUND;
 136
 137   grp_res = hesiod_resolve (context, groupname, "group");
 138   if (grp_res != NULL && *grp_res != NULL)
 139     {
 140       char *p = *grp_res;
 141
 142       /* Skip to third field.  */
 143       while (*p != '\0' && *p != ':')
 144         ++p;
 145       if (*p != '\0')
 146         ++p;
 147       while (*p != '\0' && *p != ':')
 148         ++p;
 149       if (*p != '\0')
 150         {
 151           char *endp;
 152           char *q = ++p;
 153           long int val;
 154
 155           while (*q != '\0' && *q != ':')
 156             ++q;
 157
 158           val = strtol (p, &endp, 10);
 159           if (sizeof (gid_t) == sizeof (long int) || (gid_t) val == val)
 160             {
 161               *group = val;
 162               if (endp == q && endp != p)
 163                 status = NSS_STATUS_SUCCESS;
 164             }
 165         }
 166       hesiod_free_list (context, grp_res);
 167     }
 168   return status;
 169 }
 170
 171 enum nss_status
 172 _nss_hesiod_initgroups_dyn (const char *user, gid_t group, long int *start,
 173                             long int *size, gid_t **groupsp, long int limit,
 174                             int *errnop)
 175 {
 176   enum nss_status status = NSS_STATUS_SUCCESS;
 177   char **list = NULL;
 178   char *p;
 179   void *context;
 180   gid_t *groups = *groupsp;
 181   int save_errno;
 182
 183   context = _nss_hesiod_init ();
 184   if (context == NULL)
 185     return NSS_STATUS_UNAVAIL;
 186
 187   list = hesiod_resolve (context, user, "grplist");
 188
 189   if (list == NULL)
 190     {
 191       hesiod_end (context);
 192       return errno == ENOENT ? NSS_STATUS_NOTFOUND : NSS_STATUS_UNAVAIL;
 193     }
 194
 195   if (!internal_gid_in_list (groups, group, *start))
 196     {
 197       if (__builtin_expect (*start == *size, 0))
 198         {
 199           /* Need a bigger buffer.  */
 200           gid_t *newgroups;
 201           long int newsize;
 202
 203           if (limit > 0 && *size == limit)
 204             /* We reached the maximum.  */
 205             goto done;
 206
 207           if (limit <= 0)
 208             newsize = 2 * *size;
 209           else
 210             newsize = MIN (limit, 2 * *size);
 211
 212           newgroups = realloc (groups, newsize * sizeof (*groups));
 213           if (newgroups == NULL)
 214             goto done;
 215           *groupsp = groups = newgroups;
 216           *size = newsize;
 217         }
 218
 219       groups[(*start)++] = group;
 220     }
 221
 222   save_errno = errno;
 223
 224   p = *list;
 225   while (*p != '\0')
 226     {
 227       char *endp;
 228       char *q;
 229       long int val;
 230
 231       status = NSS_STATUS_NOTFOUND;
 232
 233       q = p;
 234       while (*q != '\0' && *q != ':' && *q != ',')
 235         ++q;
 236
 237       if (*q != '\0')
 238         *q++ = '\0';
 239
 240       __set_errno (0);
 241       val = strtol (p, &endp, 10);
 242       /* Test whether the number is representable in a variable of
 243          type `gid_t'.  If not ignore the number.  */
 244       if ((sizeof (gid_t) == sizeof (long int) || (gid_t) val == val)
 245           && errno == 0)
 246         {
 247           if (*endp == '\0' && endp != p)
 248             {
 249               group = val;
 250               status = NSS_STATUS_SUCCESS;
 251             }
 252           else
 253             status = internal_gid_from_group (context, p, &group);
 254
 255           if (status == NSS_STATUS_SUCCESS
 256               && !internal_gid_in_list (groups, group, *start))
 257             {
 258               if (__builtin_expect (*start == *size, 0))
 259                 {
 260                   /* Need a bigger buffer.  */
 261                   gid_t *newgroups;
 262                   long int newsize;
 263
 264                   if (limit > 0 && *size == limit)
 265                     /* We reached the maximum.  */
 266                     goto done;
 267
 268                   if (limit <= 0)
 269                     newsize = 2 * *size;
 270                   else
 271                     newsize = MIN (limit, 2 * *size);
 272
 273                   newgroups = realloc (groups, newsize * sizeof (*groups));
 274                   if (newgroups == NULL)
 275                     goto done;
 276                   *groupsp = groups = newgroups;
 277                   *size = newsize;
 278                 }
 279
 280               groups[(*start)++] = group;
 281             }
 282         }
 283
 284       p = q;
 285     }
 286
 287   __set_errno (save_errno);
 288
 289  done:
 290   hesiod_free_list (context, list);
 291   hesiod_end (context);
 292
 293   return NSS_STATUS_SUCCESS;
 294 }