source4/ntvfs/posix/posix_eadb.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 #include "posix_eadb.h"
  27
  28 #define XATTR_LIST_ATTR ".xattr_list"
  29
  30 /*
  31   we need to maintain a list of attributes on each file, so that unlink
  32   can automatically clean them up
  33 */
  34 static NTSTATUS posix_eadb_add_list(struct tdb_wrap *ea_tdb, TALLOC_CTX *ctx, const char *attr_name,
  35                                    const char *fname, int fd)
  36 {
  37         DATA_BLOB blob;
  38         TALLOC_CTX *mem_ctx;
  39         const char *s;
  40         NTSTATUS status;
  41         size_t len;
  42
  43         if (strcmp(attr_name, XATTR_LIST_ATTR) == 0) {
  44                 return NT_STATUS_OK;
  45         }
  46
  47         mem_ctx = talloc_new(ctx);
  48
  49         status = pull_xattr_blob_tdb_raw(ea_tdb, mem_ctx, XATTR_LIST_ATTR,
  50                                      fname, fd, 100, &blob);
  51         if (!NT_STATUS_IS_OK(status)) {
  52                 blob = data_blob(NULL, 0);
  53         }
  54
  55         for (s=(const char *)blob.data; s < (const char *)(blob.data+blob.length); s += strlen(s) + 1) {
  56                 if (strcmp(attr_name, s) == 0) {
  57                         talloc_free(mem_ctx);
  58                         return NT_STATUS_OK;
  59                 }
  60         }
  61
  62         len = strlen(attr_name) + 1;
  63
  64         blob.data = talloc_realloc(mem_ctx, blob.data, uint8_t, blob.length + len);
  65         if (blob.data == NULL) {
  66                 talloc_free(mem_ctx);
  67                 return NT_STATUS_NO_MEMORY;
  68         }
  69         memcpy(blob.data + blob.length, attr_name, len);
  70         blob.length += len;
  71
  72         status = push_xattr_blob_tdb_raw(ea_tdb, XATTR_LIST_ATTR, fname, fd, &blob);
  73         talloc_free(mem_ctx);
  74
  75         return status;
  76 }
  77
  78 /*
  79   form a key for using in the ea_tdb
  80 */
  81 static NTSTATUS get_ea_tdb_key(TALLOC_CTX *mem_ctx,
  82                               const char *attr_name,
  83                               const char *fname, int fd,
  84                               TDB_DATA *key)
  85 {
  86         struct stat st;
  87         size_t len = strlen(attr_name);
  88
  89         if (fd == -1) {
  90                 if (stat(fname, &st) == -1) {
  91                         return NT_STATUS_NOT_FOUND;
  92                 }
  93         } else {
  94                 if (fstat(fd, &st) == -1) {
  95                         return NT_STATUS_NOT_FOUND;
  96                 }
  97         }
  98
  99         key->dptr = talloc_array(mem_ctx, uint8_t, 16 + len);
 100         if (key->dptr == NULL) {
 101                 return NT_STATUS_NO_MEMORY;
 102         }
 103         key->dsize = 16 + len;
 104
 105         SBVAL(key->dptr, 0, st.st_dev);
 106         SBVAL(key->dptr, 8, st.st_ino);
 107         memcpy(key->dptr+16, attr_name, len);
 108
 109         return NT_STATUS_OK;
 110 }
 111
 112
 113
 114 /*
 115   pull a xattr as a blob, using the ea_tdb_context tdb
 116 */
 117 NTSTATUS pull_xattr_blob_tdb_raw(struct tdb_wrap *ea_tdb,
 118                              TALLOC_CTX *mem_ctx,
 119                              const char *attr_name,
 120                              const char *fname,
 121                              int fd,
 122                              size_t estimated_size,
 123                              DATA_BLOB *blob)
 124 {
 125         TDB_DATA tkey, tdata;
 126         NTSTATUS status;
 127
 128         status = get_ea_tdb_key(mem_ctx, attr_name, fname, fd, &tkey);
 129         if (!NT_STATUS_IS_OK(status)) {
 130                 return status;
 131         }
 132
 133         tdata = tdb_fetch_compat(ea_tdb->tdb, tkey);
 134         if (tdata.dptr == NULL) {
 135                 return NT_STATUS_NOT_FOUND;
 136         }
 137
 138         *blob = data_blob_talloc(mem_ctx, tdata.dptr, tdata.dsize);
 139         free(tdata.dptr);
 140         if (blob->data == NULL) {
 141                 return NT_STATUS_NO_MEMORY;
 142         }
 143
 144         return NT_STATUS_OK;
 145 }
 146
 147 NTSTATUS pull_xattr_blob_tdb(struct pvfs_state *pvfs_state,
 148                              TALLOC_CTX *mem_ctx,
 149                              const char *attr_name,
 150                              const char *fname,
 151                              int fd,
 152                              size_t estimated_size,
 153                              DATA_BLOB *blob)
 154 {
 155         return pull_xattr_blob_tdb_raw(pvfs_state->ea_db,mem_ctx,attr_name,fname,fd,estimated_size,blob);
 156 }
 157
 158 /*
 159   push a xattr as a blob, using ea_tdb
 160 */
 161 NTSTATUS push_xattr_blob_tdb_raw(struct tdb_wrap *ea_tdb,
 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         TALLOC_CTX *mem_ctx = talloc_new(ea_tdb);
 170         if (!mem_ctx) {
 171                 return NT_STATUS_NO_MEMORY;
 172         }
 173
 174         status = get_ea_tdb_key(mem_ctx, attr_name, fname, fd, &tkey);
 175         if (!NT_STATUS_IS_OK(status)) {
 176                 talloc_free(mem_ctx);
 177                 return status;
 178         }
 179
 180         tdata.dptr = blob->data;
 181         tdata.dsize = blob->length;
 182
 183         if (tdb_chainlock(ea_tdb->tdb, tkey) != 0) {
 184                 talloc_free(mem_ctx);
 185                 return NT_STATUS_INTERNAL_DB_CORRUPTION;
 186         }
 187
 188         status = posix_eadb_add_list(ea_tdb,mem_ctx, attr_name, fname, fd);
 189         if (!NT_STATUS_IS_OK(status)) {
 190                 talloc_free(mem_ctx);
 191                 goto done;
 192         }
 193
 194         if (tdb_store(ea_tdb->tdb, tkey, tdata, TDB_REPLACE) != 0) {
 195                 status = NT_STATUS_INTERNAL_DB_CORRUPTION;
 196         }
 197
 198 done:
 199         tdb_chainunlock(ea_tdb->tdb, tkey);
 200         talloc_free(mem_ctx);
 201         return status;
 202 }
 203 NTSTATUS push_xattr_blob_tdb(struct pvfs_state *pvfs_state,
 204                              const char *attr_name,
 205                              const char *fname,
 206                              int fd,
 207                              const DATA_BLOB *blob)
 208 {
 209         return push_xattr_blob_tdb_raw(pvfs_state->ea_db, attr_name, fname, fd, blob);
 210 }
 211
 212
 213 /*
 214   delete a xattr
 215 */
 216 NTSTATUS delete_posix_eadb_raw(struct tdb_wrap *ea_tdb, const char *attr_name,
 217                           const char *fname, int fd)
 218 {
 219         TDB_DATA tkey;
 220         NTSTATUS status;
 221
 222         status = get_ea_tdb_key(NULL, attr_name, fname, fd, &tkey);
 223         if (!NT_STATUS_IS_OK(status)) {
 224                 return status;
 225         }
 226
 227         if (tdb_delete(ea_tdb->tdb, tkey) != 0) {
 228                 talloc_free(tkey.dptr);
 229                 return NT_STATUS_INTERNAL_DB_CORRUPTION;
 230         }
 231
 232         talloc_free(tkey.dptr);
 233         return NT_STATUS_OK;
 234 }
 235
 236
 237 /*
 238   delete a xattr
 239 */
 240 NTSTATUS delete_posix_eadb(struct pvfs_state *pvfs_state, const char *attr_name,
 241                           const char *fname, int fd)
 242 {
 243         return delete_posix_eadb_raw(pvfs_state->ea_db,
 244                                     attr_name, fname, fd);
 245 }
 246
 247
 248 /*
 249   delete all xattrs for a file
 250 */
 251 NTSTATUS unlink_posix_eadb_raw(struct tdb_wrap *ea_tdb, const char *fname, int fd)
 252 {
 253         TALLOC_CTX *mem_ctx = talloc_new(ea_tdb);
 254         DATA_BLOB blob;
 255         const char *s;
 256         NTSTATUS status;
 257
 258         status = pull_xattr_blob_tdb_raw(ea_tdb, mem_ctx, XATTR_LIST_ATTR,
 259                                      fname, fd, 100, &blob);
 260         if (!NT_STATUS_IS_OK(status)) {
 261                 talloc_free(mem_ctx);
 262                 return NT_STATUS_OK;
 263         }
 264
 265         for (s=(const char *)blob.data; s < (const char *)(blob.data+blob.length); s += strlen(s) + 1) {
 266                 delete_posix_eadb_raw(ea_tdb, s, fname, -1);
 267         }
 268
 269         status = delete_posix_eadb_raw(ea_tdb, XATTR_LIST_ATTR, fname, fd);
 270         talloc_free(mem_ctx);
 271         return status;
 272 }
 273
 274 /*
 275   delete all xattrs for a file
 276 */
 277 NTSTATUS unlink_posix_eadb(struct pvfs_state *pvfs_state, const char *fname)
 278 {
 279         return unlink_posix_eadb_raw(pvfs_state->ea_db, fname, -1);
 280 }
 281
 282 /*
 283   list all xattrs for a file
 284 */
 285 NTSTATUS list_posix_eadb_raw(struct tdb_wrap *ea_tdb, TALLOC_CTX *mem_ctx,
 286                             const char *fname, int fd,
 287                             DATA_BLOB *list)
 288 {
 289         return pull_xattr_blob_tdb_raw(ea_tdb, mem_ctx, XATTR_LIST_ATTR,
 290                                      fname, fd, 100, list);
 291 }