hesiod/nss_hesiod/hesiod-grp.c

   1 /* Copyright (C) 1997-2015 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, see
  17    <http://www.gnu.org/licenses/>.  */
  18
  19 #include <ctype.h>
  20 #include <errno.h>
  21 #include <grp.h>
  22 #include <hesiod.h>
  23 #include <nss.h>
  24 #include <stdio.h>
  25 #include <stdlib.h>
  26 #include <string.h>
  27 #include <sys/param.h>
  28
  29 #include "nss_hesiod.h"
  30
  31 /* Get the declaration of the parser function.  */
  32 #define ENTNAME grent
  33 #define STRUCTURE group
  34 #define EXTERN_PARSER
  35 #include <nss/nss_files/files-parse.c>
  36
  37 enum nss_status
  38 _nss_hesiod_setgrent (int stayopen)
  39 {
  40   return NSS_STATUS_SUCCESS;
  41 }
  42
  43 enum nss_status
  44 _nss_hesiod_endgrent (void)
  45 {
  46   return NSS_STATUS_SUCCESS;
  47 }
  48
  49 static enum nss_status
  50 lookup (const char *name, const char *type, struct group *grp,
  51         char *buffer, size_t buflen, int *errnop)
  52 {
  53   struct parser_data *data = (void *) buffer;
  54   size_t linebuflen;
  55   void *context;
  56   char **list;
  57   int parse_res;
  58   size_t len;
  59   int olderr = errno;
  60
  61   context = _nss_hesiod_init ();
  62   if (context == NULL)
  63     return NSS_STATUS_UNAVAIL;
  64
  65   list = hesiod_resolve (context, name, type);
  66   if (list == NULL)
  67     {
  68       int err = errno;
  69       hesiod_end (context);
  70       __set_errno (olderr);
  71       return err == ENOENT ? NSS_STATUS_NOTFOUND : NSS_STATUS_UNAVAIL;
  72     }
  73
  74   linebuflen = buffer + buflen - data->linebuffer;
  75   len = strlen (*list) + 1;
  76   if (linebuflen < len)
  77     {
  78       hesiod_free_list (context, list);
  79       hesiod_end (context);
  80       *errnop = ERANGE;
  81       return NSS_STATUS_TRYAGAIN;
  82     }
  83
  84   memcpy (data->linebuffer, *list, len);
  85   hesiod_free_list (context, list);
  86   hesiod_end (context);
  87
  88   parse_res = _nss_files_parse_grent (buffer, grp, data, buflen, errnop);
  89   if (parse_res < 1)
  90     {
  91       __set_errno (olderr);
  92       return parse_res == -1 ? NSS_STATUS_TRYAGAIN : NSS_STATUS_NOTFOUND;
  93     }
  94
  95   return NSS_STATUS_SUCCESS;
  96 }
  97
  98 enum nss_status
  99 _nss_hesiod_getgrnam_r (const char *name, struct group *grp,
 100                         char *buffer, size_t buflen, int *errnop)
 101 {
 102   return lookup (name, "group", grp, buffer, buflen, errnop);
 103 }
 104
 105 enum nss_status
 106 _nss_hesiod_getgrgid_r (gid_t gid, struct group *grp,
 107                         char *buffer, size_t buflen, int *errnop)
 108 {
 109   char gidstr[21];      /* We will probably never have a gid_t with more
 110                            than 64 bits.  */
 111
 112   snprintf (gidstr, sizeof gidstr, "%d", gid);
 113
 114   return lookup (gidstr, "gid", grp, buffer, buflen, errnop);
 115 }
 116
 117 static int
 118 internal_gid_in_list (const gid_t *list, const gid_t g, long int len)
 119 {
 120   while (len > 0)
 121     {
 122       if (*list == g)
 123         return 1;
 124       --len;
 125       ++list;
 126     }
 127   return 0;
 128 }
 129
 130 static enum nss_status
 131 internal_gid_from_group (void *context, const char *groupname, gid_t *group)
 132 {
 133   char **grp_res;
 134   enum nss_status status = NSS_STATUS_NOTFOUND;
 135
 136   grp_res = hesiod_resolve (context, groupname, "group");
 137   if (grp_res != NULL && *grp_res != NULL)
 138     {
 139       char *p = *grp_res;
 140
 141       /* Skip to third field.  */
 142       while (*p != '\0' && *p != ':')
 143         ++p;
 144       if (*p != '\0')
 145         ++p;
 146       while (*p != '\0' && *p != ':')
 147         ++p;
 148       if (*p != '\0')
 149         {
 150           char *endp;
 151           char *q = ++p;
 152           long int val;
 153
 154           while (*q != '\0' && *q != ':')
 155             ++q;
 156
 157           val = strtol (p, &endp, 10);
 158           if (sizeof (gid_t) == sizeof (long int) || (gid_t) val == val)
 159             {
 160               *group = val;
 161               if (endp == q && endp != p)
 162                 status = NSS_STATUS_SUCCESS;
 163             }
 164         }
 165       hesiod_free_list (context, grp_res);
 166     }
 167   return status;
 168 }
 169
 170 enum nss_status
 171 _nss_hesiod_initgroups_dyn (const char *user, gid_t group, long int *start,
 172                             long int *size, gid_t **groupsp, long int limit,
 173                             int *errnop)
 174 {
 175   enum nss_status status = NSS_STATUS_SUCCESS;
 176   char **list = NULL;
 177   char *p;
 178   void *context;
 179   gid_t *groups = *groupsp;
 180   int save_errno;
 181
 182   context = _nss_hesiod_init ();
 183   if (context == NULL)
 184     return NSS_STATUS_UNAVAIL;
 185
 186   list = hesiod_resolve (context, user, "grplist");
 187
 188   if (list == NULL)
 189     {
 190       hesiod_end (context);
 191       return errno == ENOENT ? NSS_STATUS_NOTFOUND : NSS_STATUS_UNAVAIL;
 192     }
 193
 194   save_errno = errno;
 195
 196   p = *list;
 197   while (*p != '\0')
 198     {
 199       char *endp;
 200       char *q;
 201       long int val;
 202
 203       status = NSS_STATUS_NOTFOUND;
 204
 205       q = p;
 206       while (*q != '\0' && *q != ':' && *q != ',')
 207         ++q;
 208
 209       if (*q != '\0')
 210         *q++ = '\0';
 211
 212       __set_errno (0);
 213       val = strtol (p, &endp, 10);
 214       /* Test whether the number is representable in a variable of
 215          type `gid_t'.  If not ignore the number.  */
 216       if ((sizeof (gid_t) == sizeof (long int) || (gid_t) val == val)
 217           && errno == 0)
 218         {
 219           if (*endp == '\0' && endp != p)
 220             {
 221               group = val;
 222               status = NSS_STATUS_SUCCESS;
 223             }
 224           else
 225             status = internal_gid_from_group (context, p, &group);
 226
 227           if (status == NSS_STATUS_SUCCESS
 228               && !internal_gid_in_list (groups, group, *start))
 229             {
 230               if (__glibc_unlikely (*start == *size))
 231                 {
 232                   /* Need a bigger buffer.  */
 233                   gid_t *newgroups;
 234                   long int newsize;
 235
 236                   if (limit > 0 && *size == limit)
 237                     /* We reached the maximum.  */
 238                     goto done;
 239
 240                   if (limit <= 0)
 241                     newsize = 2 * *size;
 242                   else
 243                     newsize = MIN (limit, 2 * *size);
 244
 245                   newgroups = realloc (groups, newsize * sizeof (*groups));
 246                   if (newgroups == NULL)
 247                     goto done;
 248                   *groupsp = groups = newgroups;
 249                   *size = newsize;
 250                 }
 251
 252               groups[(*start)++] = group;
 253             }
 254         }
 255
 256       p = q;
 257     }
 258
 259   __set_errno (save_errno);
 260
 261  done:
 262   hesiod_free_list (context, list);
 263   hesiod_end (context);
 264
 265   return NSS_STATUS_SUCCESS;
 266 }