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 "lib/tdb_wrap/tdb_wrap.h"
  24 #include "tdb_compat.h"
  25 #include "vfs_posix.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 tdb_wrap *ea_tdb, TALLOC_CTX *ctx, 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(ctx);
  47
  48         status = pull_xattr_blob_tdb_raw(ea_tdb, 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_raw(ea_tdb,ctx, 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_tdb
  79 */
  80 static NTSTATUS get_ea_tdb_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
 113 /*
 114   pull a xattr as a blob, using the ea_tdb_context tdb
 115 */
 116 NTSTATUS pull_xattr_blob_tdb_raw(struct tdb_wrap *ea_tdb,
 117                              TALLOC_CTX *mem_ctx,
 118                              const char *attr_name,
 119                              const char *fname,
 120                              int fd,
 121                              size_t estimated_size,
 122                              DATA_BLOB *blob)
 123 {
 124         TDB_DATA tkey, tdata;
 125         NTSTATUS status;
 126
 127         status = get_ea_tdb_key(mem_ctx, attr_name, fname, fd, &tkey);
 128         if (!NT_STATUS_IS_OK(status)) {
 129                 return status;
 130         }
 131
 132         tdata = tdb_fetch_compat(ea_tdb->tdb, tkey);
 133         if (tdata.dptr == NULL) {
 134                 return NT_STATUS_NOT_FOUND;
 135         }
 136
 137         *blob = data_blob_talloc(mem_ctx, tdata.dptr, tdata.dsize);
 138         free(tdata.dptr);
 139         if (blob->data == NULL) {
 140                 return NT_STATUS_NO_MEMORY;
 141         }
 142
 143         return NT_STATUS_OK;
 144 }
 145
 146 NTSTATUS pull_xattr_blob_tdb(struct pvfs_state *pvfs,
 147                              TALLOC_CTX *mem_ctx,
 148                              const char *attr_name,
 149                              const char *fname,
 150                              int fd,
 151                              size_t estimated_size,
 152                              DATA_BLOB *blob)
 153 {
 154         return pull_xattr_blob_tdb_raw(pvfs->ea_db,mem_ctx,attr_name,fname,fd,estimated_size,blob);
 155 }
 156
 157 /*
 158   push a xattr as a blob, using ea_tdb
 159 */
 160 NTSTATUS push_xattr_blob_tdb_raw(struct tdb_wrap *ea_tdb,
 161                              TALLOC_CTX *mem_ctx,
 162                              const char *attr_name,
 163                              const char *fname,
 164                              int fd,
 165                              const DATA_BLOB *blob)
 166 {
 167         TDB_DATA tkey, tdata;
 168         NTSTATUS status;
 169
 170         status = get_ea_tdb_key(mem_ctx, attr_name, fname, fd, &tkey);
 171         if (!NT_STATUS_IS_OK(status)) {
 172                 return status;
 173         }
 174
 175         tdata.dptr = blob->data;
 176         tdata.dsize = blob->length;
 177
 178         if (tdb_chainlock(ea_tdb->tdb, tkey) != 0) {
 179                 talloc_free(tkey.dptr);
 180                 return NT_STATUS_INTERNAL_DB_CORRUPTION;
 181         }
 182
 183         status = xattr_tdb_add_list(ea_tdb,mem_ctx, attr_name, fname, fd);
 184         if (!NT_STATUS_IS_OK(status)) {
 185                 goto done;
 186         }
 187
 188         if (tdb_store(ea_tdb->tdb, tkey, tdata, TDB_REPLACE) != 0) {
 189                 status = NT_STATUS_INTERNAL_DB_CORRUPTION;
 190         }
 191
 192 done:
 193         tdb_chainunlock(ea_tdb->tdb, tkey);
 194         talloc_free(tkey.dptr);
 195         return status;
 196 }
 197 NTSTATUS push_xattr_blob_tdb(struct pvfs_state *pvfs,
 198                              const char *attr_name,
 199                              const char *fname,
 200                              int fd,
 201                              const DATA_BLOB *blob)
 202 {
 203         return push_xattr_blob_tdb_raw(pvfs->ea_db,pvfs,attr_name,fname,fd,blob);
 204 }
 205
 206
 207 /*
 208   delete a xattr
 209 */
 210 NTSTATUS delete_xattr_tdb(struct pvfs_state *pvfs, const char *attr_name,
 211                           const char *fname, int fd)
 212 {
 213         TDB_DATA tkey;
 214         NTSTATUS status;
 215
 216         status = get_ea_tdb_key(NULL, attr_name, fname, fd, &tkey);
 217         if (!NT_STATUS_IS_OK(status)) {
 218                 return status;
 219         }
 220
 221         if (tdb_delete(pvfs->ea_db->tdb, tkey) != 0) {
 222                 talloc_free(tkey.dptr);
 223                 return NT_STATUS_INTERNAL_DB_CORRUPTION;
 224         }
 225
 226         talloc_free(tkey.dptr);
 227         return NT_STATUS_OK;
 228 }
 229
 230
 231
 232 /*
 233   delete all xattrs for a file
 234 */
 235 NTSTATUS unlink_xattr_tdb(struct pvfs_state *pvfs, const char *fname)
 236 {
 237         TALLOC_CTX *mem_ctx = talloc_new(pvfs);
 238         DATA_BLOB blob;
 239         const char *s;
 240         NTSTATUS status;
 241
 242         status = pull_xattr_blob_tdb(pvfs, mem_ctx, XATTR_LIST_ATTR,
 243                                      fname, -1, 100, &blob);
 244         if (!NT_STATUS_IS_OK(status)) {
 245                 talloc_free(mem_ctx);
 246                 return NT_STATUS_OK;
 247         }
 248
 249         for (s=(const char *)blob.data; s < (const char *)(blob.data+blob.length); s += strlen(s) + 1) {
 250                 delete_xattr_tdb(pvfs, s, fname, -1);
 251         }
 252
 253         status = delete_xattr_tdb(pvfs, XATTR_LIST_ATTR, fname, -1);
 254         talloc_free(mem_ctx);
 255         return status;
 256 }