source4/ntvfs/posix/xattr_system.c

   1 /*
   2    Unix SMB/CIFS implementation.
   3
   4    POSIX NTVFS backend - xattr support using filesystem xattrs
   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 "../lib/util/wrap_xattr.h"
  25
  26 /*
  27   pull a xattr as a blob, from either a file or a file descriptor
  28 */
  29 NTSTATUS pull_xattr_blob_system(struct pvfs_state *pvfs,
  30                                 TALLOC_CTX *mem_ctx,
  31                                 const char *attr_name,
  32                                 const char *fname,
  33                                 int fd,
  34                                 size_t estimated_size,
  35                                 DATA_BLOB *blob)
  36 {
  37         int ret;
  38
  39         *blob = data_blob_talloc(mem_ctx, NULL, estimated_size+16);
  40         if (blob->data == NULL) {
  41                 return NT_STATUS_NO_MEMORY;
  42         }
  43
  44 again:
  45         if (fd != -1) {
  46                 ret = wrap_fgetxattr(fd, attr_name, blob->data, estimated_size);
  47         } else {
  48                 ret = wrap_getxattr(fname, attr_name, blob->data, estimated_size);
  49         }
  50         if (ret == -1 && errno == ERANGE) {
  51                 estimated_size *= 2;
  52                 blob->data = talloc_realloc(mem_ctx, blob->data,
  53                                             uint8_t, estimated_size);
  54                 if (blob->data == NULL) {
  55                         return NT_STATUS_NO_MEMORY;
  56                 }
  57                 blob->length = estimated_size;
  58                 goto again;
  59         }
  60         if (ret == -1 && errno == EPERM) {
  61                 struct stat statbuf;
  62
  63                 if (fd != -1) {
  64                         ret = fstat(fd, &statbuf);
  65                 } else {
  66                         ret = stat(fname, &statbuf);
  67                 }
  68                 if (ret == 0) {
  69                         /* check if this is a directory and the sticky bit is set */
  70                         if (S_ISDIR(statbuf.st_mode) && (statbuf.st_mode & S_ISVTX)) {
  71                                 /* pretend we could not find the xattr */
  72
  73                                 data_blob_free(blob);
  74                                 return NT_STATUS_NOT_FOUND;
  75
  76                         } else {
  77                                 /* if not this was probably a legitimate error
  78                                  * reset ret and errno to the correct values */
  79                                 errno = EPERM;
  80                                 ret = -1;
  81                         }
  82                 }
  83         }
  84
  85         if (ret == -1) {
  86                 data_blob_free(blob);
  87                 return pvfs_map_errno(pvfs, errno);
  88         }
  89
  90         blob->length = ret;
  91
  92         return NT_STATUS_OK;
  93 }
  94
  95 /*
  96   push a xattr as a blob, from either a file or a file descriptor
  97 */
  98 NTSTATUS push_xattr_blob_system(struct pvfs_state *pvfs,
  99                                 const char *attr_name,
 100                                 const char *fname,
 101                                 int fd,
 102                                 const DATA_BLOB *blob)
 103 {
 104         int ret;
 105
 106         if (fd != -1) {
 107                 ret = wrap_fsetxattr(fd, attr_name, blob->data, blob->length, 0);
 108         } else {
 109                 ret = wrap_setxattr(fname, attr_name, blob->data, blob->length, 0);
 110         }
 111         if (ret == -1) {
 112                 return pvfs_map_errno(pvfs, errno);
 113         }
 114
 115         return NT_STATUS_OK;
 116 }
 117
 118
 119 /*
 120   delete a xattr
 121 */
 122 NTSTATUS delete_xattr_system(struct pvfs_state *pvfs, const char *attr_name,
 123                              const char *fname, int fd)
 124 {
 125         int ret;
 126
 127         if (fd != -1) {
 128                 ret = wrap_fremovexattr(fd, attr_name);
 129         } else {
 130                 ret = wrap_removexattr(fname, attr_name);
 131         }
 132         if (ret == -1) {
 133                 return pvfs_map_errno(pvfs, errno);
 134         }
 135
 136         return NT_STATUS_OK;
 137 }
 138
 139 /*
 140   unlink a file - cleanup any xattrs
 141 */
 142 NTSTATUS unlink_xattr_system(struct pvfs_state *pvfs, const char *fname)
 143 {
 144         /* nothing needs to be done for filesystem based xattrs */
 145         return NT_STATUS_OK;
 146 }