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 "vfs_posix.h"
  25 #include "posix_eadb.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 posix_eadb_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, 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(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_state,
 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_state->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                              const char *attr_name,
 162                              const char *fname,
 163                              int fd,
 164                              const DATA_BLOB *blob)
 165 {
 166         TDB_DATA tkey, tdata;
 167         NTSTATUS status;
 168         TALLOC_CTX *mem_ctx = talloc_new(ea_tdb);
 169         if (!mem_ctx) {
 170                 return NT_STATUS_NO_MEMORY;
 171         }
 172
 173         status = get_ea_tdb_key(mem_ctx, attr_name, fname, fd, &tkey);
 174         if (!NT_STATUS_IS_OK(status)) {
 175                 talloc_free(mem_ctx);
 176                 return status;
 177         }
 178
 179         tdata.dptr = blob->data;
 180         tdata.dsize = blob->length;
 181
 182         if (tdb_chainlock(ea_tdb->tdb, tkey) != 0) {
 183                 talloc_free(mem_ctx);
 184                 return NT_STATUS_INTERNAL_DB_CORRUPTION;
 185         }
 186
 187         status = posix_eadb_add_list(ea_tdb,mem_ctx, attr_name, fname, fd);
 188         if (!NT_STATUS_IS_OK(status)) {
 189                 talloc_free(mem_ctx);
 190                 goto done;
 191         }
 192
 193         if (tdb_store(ea_tdb->tdb, tkey, tdata, TDB_REPLACE) != 0) {
 194                 status = NT_STATUS_INTERNAL_DB_CORRUPTION;
 195         }
 196
 197 done:
 198         tdb_chainunlock(ea_tdb->tdb, tkey);
 199         talloc_free(mem_ctx);
 200         return status;
 201 }
 202 NTSTATUS push_xattr_blob_tdb(struct pvfs_state *pvfs_state,
 203                              const char *attr_name,
 204                              const char *fname,
 205                              int fd,
 206                              const DATA_BLOB *blob)
 207 {
 208         return push_xattr_blob_tdb_raw(pvfs_state->ea_db, attr_name, fname, fd, blob);
 209 }
 210
 211
 212 /*
 213   delete a xattr
 214 */
 215 NTSTATUS delete_posix_eadb_raw(struct tdb_wrap *ea_tdb, const char *attr_name,
 216                           const char *fname, int fd)
 217 {
 218         TDB_DATA tkey;
 219         NTSTATUS status;
 220
 221         status = get_ea_tdb_key(NULL, attr_name, fname, fd, &tkey);
 222         if (!NT_STATUS_IS_OK(status)) {
 223                 return status;
 224         }
 225
 226         if (tdb_delete(ea_tdb->tdb, tkey) != 0) {
 227                 talloc_free(tkey.dptr);
 228                 return NT_STATUS_INTERNAL_DB_CORRUPTION;
 229         }
 230
 231         talloc_free(tkey.dptr);
 232         return NT_STATUS_OK;
 233 }
 234
 235
 236 /*
 237   delete a xattr
 238 */
 239 NTSTATUS delete_posix_eadb(struct pvfs_state *pvfs_state, const char *attr_name,
 240                           const char *fname, int fd)
 241 {
 242         return delete_posix_eadb_raw(pvfs_state->ea_db,
 243                                     attr_name, fname, fd);
 244 }
 245
 246
 247 /*
 248   delete all xattrs for a file
 249 */
 250 NTSTATUS unlink_posix_eadb_raw(struct tdb_wrap *ea_tdb, const char *fname, int fd)
 251 {
 252         TALLOC_CTX *mem_ctx = talloc_new(ea_tdb);
 253         DATA_BLOB blob;
 254         const char *s;
 255         NTSTATUS status;
 256
 257         status = pull_xattr_blob_tdb_raw(ea_tdb, mem_ctx, XATTR_LIST_ATTR,
 258                                      fname, fd, 100, &blob);
 259         if (!NT_STATUS_IS_OK(status)) {
 260                 talloc_free(mem_ctx);
 261                 return NT_STATUS_OK;
 262         }
 263
 264         for (s=(const char *)blob.data; s < (const char *)(blob.data+blob.length); s += strlen(s) + 1) {
 265                 delete_posix_eadb_raw(ea_tdb, s, fname, -1);
 266         }
 267
 268         status = delete_posix_eadb_raw(ea_tdb, XATTR_LIST_ATTR, fname, fd);
 269         talloc_free(mem_ctx);
 270         return status;
 271 }
 272
 273 /*
 274   delete all xattrs for a file
 275 */
 276 NTSTATUS unlink_posix_eadb(struct pvfs_state *pvfs_state, const char *fname)
 277 {
 278         return unlink_posix_eadb_raw(pvfs_state->ea_db, fname, -1);
 279 }
 280
 281 /*
 282   list all xattrs for a file
 283 */
 284 NTSTATUS list_posix_eadb_raw(struct tdb_wrap *ea_tdb, TALLOC_CTX *mem_ctx,
 285                             const char *fname, int fd,
 286                             DATA_BLOB *list)
 287 {
 288         return pull_xattr_blob_tdb_raw(ea_tdb, mem_ctx, XATTR_LIST_ATTR,
 289                                      fname, fd, 100, list);
 290 }