release/src-rt-6.x.4708/router/samba-3.5.8/source4/ntvfs/posix/xattr_tdb.c

   1 /*
   2    Unix SMB/CIFS implementation.
   3
   4    POSIX NTVFS backend - xattr support using a tdb
   5
   6    Copyright (C) Andrew Tridgell 2004
   7
   8    This program is free software; you can redistribute it and/or modify
   9    it under the terms of the GNU General Public License as published by
  10    the Free Software Foundation; either version 3 of the License, or
  11    (at your option) any later version.
  12
  13    This program is distributed in the hope that it will be useful,
  14    but WITHOUT ANY WARRANTY; without even the implied warranty of
  15    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16    GNU General Public License for more details.
  17
  18    You should have received a copy of the GNU General Public License
  19    along with this program.  If not, see <http://www.gnu.org/licenses/>.
  20 */
  21
  22 #include "includes.h"
  23 #include "vfs_posix.h"
  24 #include "../tdb/include/tdb.h"
  25 #include "tdb_wrap.h"
  26
  27 #define XATTR_LIST_ATTR ".xattr_list"
  28
  29 /*
  30   we need to maintain a list of attributes on each file, so that unlink
  31   can automatically clean them up
  32 */
  33 static NTSTATUS xattr_tdb_add_list(struct pvfs_state *pvfs, const char *attr_name,
  34                                    const char *fname, int fd)
  35 {
  36         DATA_BLOB blob;
  37         TALLOC_CTX *mem_ctx;
  38         const char *s;
  39         NTSTATUS status;
  40         size_t len;
  41
  42         if (strcmp(attr_name, XATTR_LIST_ATTR) == 0) {
  43                 return NT_STATUS_OK;
  44         }
  45
  46         mem_ctx = talloc_new(pvfs);
  47
  48         status = pull_xattr_blob_tdb(pvfs, mem_ctx, XATTR_LIST_ATTR,
  49                                      fname, fd, 100, &blob);
  50         if (!NT_STATUS_IS_OK(status)) {
  51                 blob = data_blob(NULL, 0);
  52         }
  53
  54         for (s=(const char *)blob.data; s < (const char *)(blob.data+blob.length); s += strlen(s) + 1) {
  55                 if (strcmp(attr_name, s) == 0) {
  56                         talloc_free(mem_ctx);
  57                         return NT_STATUS_OK;
  58                 }
  59         }
  60
  61         len = strlen(attr_name) + 1;
  62
  63         blob.data = talloc_realloc(mem_ctx, blob.data, uint8_t, blob.length + len);
  64         if (blob.data == NULL) {
  65                 talloc_free(mem_ctx);
  66                 return NT_STATUS_NO_MEMORY;
  67         }
  68         memcpy(blob.data + blob.length, attr_name, len);
  69         blob.length += len;
  70
  71         status = push_xattr_blob_tdb(pvfs, XATTR_LIST_ATTR, fname, fd, &blob);
  72         talloc_free(mem_ctx);
  73
  74         return status;
  75 }
  76
  77 /*
  78   form a key for using in the ea_db
  79 */
  80 static NTSTATUS get_ea_db_key(TALLOC_CTX *mem_ctx,
  81                               const char *attr_name,
  82                               const char *fname, int fd,
  83                               TDB_DATA *key)
  84 {
  85         struct stat st;
  86         size_t len = strlen(attr_name);
  87
  88         if (fd == -1) {
  89                 if (stat(fname, &st) == -1) {
  90                         return NT_STATUS_NOT_FOUND;
  91                 }
  92         } else {
  93                 if (fstat(fd, &st) == -1) {
  94                         return NT_STATUS_NOT_FOUND;
  95                 }
  96         }
  97
  98         key->dptr = talloc_array(mem_ctx, uint8_t, 16 + len);
  99         if (key->dptr == NULL) {
 100                 return NT_STATUS_NO_MEMORY;
 101         }
 102         key->dsize = 16 + len;
 103
 104         SBVAL(key->dptr, 0, st.st_dev);
 105         SBVAL(key->dptr, 8, st.st_ino);
 106         memcpy(key->dptr+16, attr_name, len);
 107
 108         return NT_STATUS_OK;
 109 }
 110
 111 /*
 112   pull a xattr as a blob, using the ea_db tdb
 113 */
 114 NTSTATUS pull_xattr_blob_tdb(struct pvfs_state *pvfs,
 115                              TALLOC_CTX *mem_ctx,
 116                              const char *attr_name,
 117                              const char *fname,
 118                              int fd,
 119                              size_t estimated_size,
 120                              DATA_BLOB *blob)
 121 {
 122         TDB_DATA tkey, tdata;
 123         NTSTATUS status;
 124
 125         status = get_ea_db_key(mem_ctx, attr_name, fname, fd, &tkey);
 126         if (!NT_STATUS_IS_OK(status)) {
 127                 return status;
 128         }
 129
 130         tdata = tdb_fetch(pvfs->ea_db->tdb, tkey);
 131         if (tdata.dptr == NULL) {
 132                 return NT_STATUS_NOT_FOUND;
 133         }
 134
 135         *blob = data_blob_talloc(mem_ctx, tdata.dptr, tdata.dsize);
 136         free(tdata.dptr);
 137         if (blob->data == NULL) {
 138                 return NT_STATUS_NO_MEMORY;
 139         }
 140
 141         return NT_STATUS_OK;
 142 }
 143
 144 /*
 145   push a xattr as a blob, using ea_db
 146 */
 147 NTSTATUS push_xattr_blob_tdb(struct pvfs_state *pvfs,
 148                              const char *attr_name,
 149                              const char *fname,
 150                              int fd,
 151                              const DATA_BLOB *blob)
 152 {
 153         TDB_DATA tkey, tdata;
 154         NTSTATUS status;
 155
 156         status = get_ea_db_key(pvfs, attr_name, fname, fd, &tkey);
 157         if (!NT_STATUS_IS_OK(status)) {
 158                 return status;
 159         }
 160
 161         tdata.dptr = blob->data;
 162         tdata.dsize = blob->length;
 163
 164         if (tdb_chainlock(pvfs->ea_db->tdb, tkey) != 0) {
 165                 talloc_free(tkey.dptr);
 166                 return NT_STATUS_INTERNAL_DB_CORRUPTION;
 167         }
 168
 169         status = xattr_tdb_add_list(pvfs, attr_name, fname, fd);
 170         if (!NT_STATUS_IS_OK(status)) {
 171                 goto done;
 172         }
 173
 174         if (tdb_store(pvfs->ea_db->tdb, tkey, tdata, TDB_REPLACE) == -1) {
 175                 status = NT_STATUS_INTERNAL_DB_CORRUPTION;
 176         }
 177
 178 done:
 179         tdb_chainunlock(pvfs->ea_db->tdb, tkey);
 180         talloc_free(tkey.dptr);
 181         return status;
 182 }
 183
 184
 185 /*
 186   delete a xattr
 187 */
 188 NTSTATUS delete_xattr_tdb(struct pvfs_state *pvfs, const char *attr_name,
 189                           const char *fname, int fd)
 190 {
 191         TDB_DATA tkey;
 192         NTSTATUS status;
 193
 194         status = get_ea_db_key(NULL, attr_name, fname, fd, &tkey);
 195         if (!NT_STATUS_IS_OK(status)) {
 196                 return status;
 197         }
 198
 199         if (tdb_delete(pvfs->ea_db->tdb, tkey) == -1) {
 200                 talloc_free(tkey.dptr);
 201                 return NT_STATUS_INTERNAL_DB_CORRUPTION;
 202         }
 203
 204         talloc_free(tkey.dptr);
 205         return NT_STATUS_OK;
 206 }
 207
 208
 209
 210 /*
 211   delete all xattrs for a file
 212 */
 213 NTSTATUS unlink_xattr_tdb(struct pvfs_state *pvfs, const char *fname)
 214 {
 215         TALLOC_CTX *mem_ctx = talloc_new(pvfs);
 216         DATA_BLOB blob;
 217         const char *s;
 218         NTSTATUS status;
 219
 220         status = pull_xattr_blob_tdb(pvfs, mem_ctx, XATTR_LIST_ATTR,
 221                                      fname, -1, 100, &blob);
 222         if (!NT_STATUS_IS_OK(status)) {
 223                 talloc_free(mem_ctx);
 224                 return NT_STATUS_OK;
 225         }
 226
 227         for (s=(const char *)blob.data; s < (const char *)(blob.data+blob.length); s += strlen(s) + 1) {
 228                 delete_xattr_tdb(pvfs, s, fname, -1);
 229         }
 230
 231         status = delete_xattr_tdb(pvfs, XATTR_LIST_ATTR, fname, -1);
 232         talloc_free(mem_ctx);
 233         return status;
 234 }