source: trunk/server/source4/ntvfs/posix/pvfs_xattr.c

/* 
   Unix SMB/CIFS implementation.

   POSIX NTVFS backend - xattr support

   Copyright (C) Andrew Tridgell 2004

   This program is free software; you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
   the Free Software Foundation; either version 3 of the License, or
   (at your option) any later version.
   
   This program is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   GNU General Public License for more details.
   
   You should have received a copy of the GNU General Public License
   along with this program.  If not, see <http://www.gnu.org/licenses/>.
*/

#include "includes.h"
#include "vfs_posix.h"
#include "../lib/util/unix_privs.h"
#include "librpc/gen_ndr/ndr_xattr.h"
#include "param/param.h"

/*
  pull a xattr as a blob
*/
static NTSTATUS pull_xattr_blob(struct pvfs_state *pvfs,
                                TALLOC_CTX *mem_ctx,
                                const char *attr_name, 
                                const char *fname, 
                                int fd, 
                                size_t estimated_size,
                                DATA_BLOB *blob)
{
        NTSTATUS status;

        if (pvfs->ea_db) {
                return pull_xattr_blob_tdb(pvfs, mem_ctx, attr_name, fname, 
                                           fd, estimated_size, blob);
        }

        status = pull_xattr_blob_system(pvfs, mem_ctx, attr_name, fname, 
                                        fd, estimated_size, blob);

        /* if the filesystem doesn't support them, then tell pvfs not to try again */
        if (NT_STATUS_EQUAL(status, NT_STATUS_NOT_SUPPORTED)||
            NT_STATUS_EQUAL(status, NT_STATUS_NOT_IMPLEMENTED)||
            NT_STATUS_EQUAL(status, NT_STATUS_INVALID_SYSTEM_SERVICE)) {
                DEBUG(2,("pvfs_xattr: xattr not supported in filesystem: %s\n", nt_errstr(status)));
                pvfs->flags &= ~PVFS_FLAG_XATTR_ENABLE;
                status = NT_STATUS_NOT_FOUND;
        }

        return status;
}

/*
  push a xattr as a blob
*/
static NTSTATUS push_xattr_blob(struct pvfs_state *pvfs,
                                const char *attr_name, 
                                const char *fname, 
                                int fd, 
                                const DATA_BLOB *blob)
{
        if (pvfs->ea_db) {
                return push_xattr_blob_tdb(pvfs, attr_name, fname, fd, blob);
        }
        return push_xattr_blob_system(pvfs, attr_name, fname, fd, blob);
}


/*
  delete a xattr
*/
static NTSTATUS delete_xattr(struct pvfs_state *pvfs, const char *attr_name, 
                             const char *fname, int fd)
{
        if (pvfs->ea_db) {
                return delete_xattr_tdb(pvfs, attr_name, fname, fd);
        }
        return delete_xattr_system(pvfs, attr_name, fname, fd);
}

/*
  a hook called on unlink - allows the tdb xattr backend to cleanup
*/
NTSTATUS pvfs_xattr_unlink_hook(struct pvfs_state *pvfs, const char *fname)
{
        if (pvfs->ea_db) {
                return unlink_xattr_tdb(pvfs, fname);
        }
        return unlink_xattr_system(pvfs, fname);
}


/*
  load a NDR structure from a xattr
*/
NTSTATUS pvfs_xattr_ndr_load(struct pvfs_state *pvfs,
                             TALLOC_CTX *mem_ctx,
                             const char *fname, int fd, const char *attr_name,
                             void *p, void *pull_fn)
{
        NTSTATUS status;
        DATA_BLOB blob;
        enum ndr_err_code ndr_err;

        status = pull_xattr_blob(pvfs, mem_ctx, attr_name, fname, 
                                 fd, XATTR_DOSATTRIB_ESTIMATED_SIZE, &blob);
        if (!NT_STATUS_IS_OK(status)) {
                return status;
        }

        /* pull the blob */
        ndr_err = ndr_pull_struct_blob(&blob, mem_ctx, p,
                                                                   (ndr_pull_flags_fn_t)pull_fn);
        if (!NDR_ERR_CODE_IS_SUCCESS(ndr_err)) {
                return ndr_map_error2ntstatus(ndr_err);
        }

        data_blob_free(&blob);

        return NT_STATUS_OK;
}

/*
  save a NDR structure into a xattr
*/
NTSTATUS pvfs_xattr_ndr_save(struct pvfs_state *pvfs,
                             const char *fname, int fd, const char *attr_name, 
                             void *p, void *push_fn)
{
        TALLOC_CTX *mem_ctx = talloc_new(NULL);
        DATA_BLOB blob;
        NTSTATUS status;
        enum ndr_err_code ndr_err;

        ndr_err = ndr_push_struct_blob(&blob, mem_ctx, p, (ndr_push_flags_fn_t)push_fn);
        if (!NDR_ERR_CODE_IS_SUCCESS(ndr_err)) {
                talloc_free(mem_ctx);
                return ndr_map_error2ntstatus(ndr_err);
        }

        status = push_xattr_blob(pvfs, attr_name, fname, fd, &blob);
        talloc_free(mem_ctx);

        return status;
}


/*
  fill in file attributes from extended attributes
*/
NTSTATUS pvfs_dosattrib_load(struct pvfs_state *pvfs, struct pvfs_filename *name, int fd)
{
        NTSTATUS status;
        struct xattr_DosAttrib attrib;
        TALLOC_CTX *mem_ctx = talloc_new(name);
        struct xattr_DosInfo1 *info1;
        struct xattr_DosInfo2Old *info2;

        if (name->stream_name != NULL) {
                name->stream_exists = false;
        } else {
                name->stream_exists = true;
        }

        if (!(pvfs->flags & PVFS_FLAG_XATTR_ENABLE)) {
                return NT_STATUS_OK;
        }

        status = pvfs_xattr_ndr_load(pvfs, mem_ctx, name->full_name, 
                                     fd, XATTR_DOSATTRIB_NAME,
                                     &attrib,
                                     (void *) ndr_pull_xattr_DosAttrib);

        /* not having a DosAttrib is not an error */
        if (NT_STATUS_EQUAL(status, NT_STATUS_NOT_FOUND)) {
                talloc_free(mem_ctx);
                return pvfs_stream_info(pvfs, name, fd);
        }

        if (!NT_STATUS_IS_OK(status)) {
                talloc_free(mem_ctx);
                return status;
        }

        switch (attrib.version) {
        case 1:
                info1 = &attrib.info.info1;
                name->dos.attrib = pvfs_attrib_normalise(info1->attrib, 
                                                         name->st.st_mode);
                name->dos.ea_size = info1->ea_size;
                if (name->st.st_size == info1->size) {
                        name->dos.alloc_size = 
                                pvfs_round_alloc_size(pvfs, info1->alloc_size);
                }
                if (!null_nttime(info1->create_time)) {
                        name->dos.create_time = info1->create_time;
                }
                if (!null_nttime(info1->change_time)) {
                        name->dos.change_time = info1->change_time;
                }
                name->dos.flags = 0;
                break;

        case 2:
                /*
                 * Note: This is only used to parse existing values from disk
                 *       We use xattr_DosInfo1 again for storing new values
                 */
                info2 = &attrib.info.oldinfo2;
                name->dos.attrib = pvfs_attrib_normalise(info2->attrib, 
                                                         name->st.st_mode);
                name->dos.ea_size = info2->ea_size;
                if (name->st.st_size == info2->size) {
                        name->dos.alloc_size = 
                                pvfs_round_alloc_size(pvfs, info2->alloc_size);
                }
                if (!null_nttime(info2->create_time)) {
                        name->dos.create_time = info2->create_time;
                }
                if (!null_nttime(info2->change_time)) {
                        name->dos.change_time = info2->change_time;
                }
                name->dos.flags = info2->flags;
                break;

        default:
                DEBUG(0,("ERROR: Unsupported xattr DosAttrib version %d on '%s'\n",
                         attrib.version, name->full_name));
                talloc_free(mem_ctx);
                return NT_STATUS_INVALID_LEVEL;
        }
        talloc_free(mem_ctx);
        
        status = pvfs_stream_info(pvfs, name, fd);

        return status;
}


/*
  save the file attribute into the xattr
*/
NTSTATUS pvfs_dosattrib_save(struct pvfs_state *pvfs, struct pvfs_filename *name, int fd)
{
        struct xattr_DosAttrib attrib;
        struct xattr_DosInfo1 *info1;

        if (!(pvfs->flags & PVFS_FLAG_XATTR_ENABLE)) {
                return NT_STATUS_OK;
        }

        attrib.version = 1;
        info1 = &attrib.info.info1;

        name->dos.attrib = pvfs_attrib_normalise(name->dos.attrib, name->st.st_mode);

        info1->attrib      = name->dos.attrib;
        info1->ea_size     = name->dos.ea_size;
        info1->size        = name->st.st_size;
        info1->alloc_size  = name->dos.alloc_size;
        info1->create_time = name->dos.create_time;
        info1->change_time = name->dos.change_time;

        return pvfs_xattr_ndr_save(pvfs, name->full_name, fd, 
                                   XATTR_DOSATTRIB_NAME, &attrib, 
                                   (void *) ndr_push_xattr_DosAttrib);
}


/*
  load the set of DOS EAs
*/
NTSTATUS pvfs_doseas_load(struct pvfs_state *pvfs, struct pvfs_filename *name, int fd,
                          struct xattr_DosEAs *eas)
{
        NTSTATUS status;
        ZERO_STRUCTP(eas);
        if (!(pvfs->flags & PVFS_FLAG_XATTR_ENABLE)) {
                return NT_STATUS_OK;
        }
        status = pvfs_xattr_ndr_load(pvfs, eas, name->full_name, fd, XATTR_DOSEAS_NAME,
                                     eas, (void *) ndr_pull_xattr_DosEAs);
        if (NT_STATUS_EQUAL(status, NT_STATUS_NOT_FOUND)) {
                return NT_STATUS_OK;
        }
        return status;
}

/*
  save the set of DOS EAs
*/
NTSTATUS pvfs_doseas_save(struct pvfs_state *pvfs, struct pvfs_filename *name, int fd,
                          struct xattr_DosEAs *eas)
{
        if (!(pvfs->flags & PVFS_FLAG_XATTR_ENABLE)) {
                return NT_STATUS_OK;
        }
        return pvfs_xattr_ndr_save(pvfs, name->full_name, fd, XATTR_DOSEAS_NAME, eas, 
                                   (void *) ndr_push_xattr_DosEAs);
}


/*
  load the set of streams from extended attributes
*/
NTSTATUS pvfs_streams_load(struct pvfs_state *pvfs, struct pvfs_filename *name, int fd,
                           struct xattr_DosStreams *streams)
{
        NTSTATUS status;
        ZERO_STRUCTP(streams);
        if (!(pvfs->flags & PVFS_FLAG_XATTR_ENABLE)) {
                return NT_STATUS_OK;
        }
        status = pvfs_xattr_ndr_load(pvfs, streams, name->full_name, fd, 
                                     XATTR_DOSSTREAMS_NAME,
                                     streams, 
                                     (void *) ndr_pull_xattr_DosStreams);
        if (NT_STATUS_EQUAL(status, NT_STATUS_NOT_FOUND)) {
                return NT_STATUS_OK;
        }
        return status;
}

/*
  save the set of streams into filesystem xattr
*/
NTSTATUS pvfs_streams_save(struct pvfs_state *pvfs, struct pvfs_filename *name, int fd,
                           struct xattr_DosStreams *streams)
{
        if (!(pvfs->flags & PVFS_FLAG_XATTR_ENABLE)) {
                return NT_STATUS_OK;
        }
        return pvfs_xattr_ndr_save(pvfs, name->full_name, fd, 
                                   XATTR_DOSSTREAMS_NAME, 
                                   streams, 
                                   (void *) ndr_push_xattr_DosStreams);
}


/*
  load the current ACL from extended attributes
*/
NTSTATUS pvfs_acl_load(struct pvfs_state *pvfs, struct pvfs_filename *name, int fd,
                       struct xattr_NTACL *acl)
{
        NTSTATUS status;
        ZERO_STRUCTP(acl);
        if (!(pvfs->flags & PVFS_FLAG_XATTR_ENABLE)) {
                return NT_STATUS_NOT_FOUND;
        }
        status = pvfs_xattr_ndr_load(pvfs, acl, name->full_name, fd, 
                                     XATTR_NTACL_NAME,
                                     acl, 
                                     (void *) ndr_pull_xattr_NTACL);
        return status;
}

/*
  save the acl for a file into filesystem xattr
*/
NTSTATUS pvfs_acl_save(struct pvfs_state *pvfs, struct pvfs_filename *name, int fd,
                       struct xattr_NTACL *acl)
{
        NTSTATUS status;
        void *privs;

        if (!(pvfs->flags & PVFS_FLAG_XATTR_ENABLE)) {
                return NT_STATUS_OK;
        }

        /* this xattr is in the "system" namespace, so we need
           admin privileges to set it */
        privs = root_privileges();
        status = pvfs_xattr_ndr_save(pvfs, name->full_name, fd, 
                                     XATTR_NTACL_NAME, 
                                     acl, 
                                     (void *) ndr_push_xattr_NTACL);
        talloc_free(privs);
        return status;
}

/*
  create a zero length xattr with the given name
*/
NTSTATUS pvfs_xattr_create(struct pvfs_state *pvfs, 
                           const char *fname, int fd,
                           const char *attr_prefix,
                           const char *attr_name)
{
        NTSTATUS status;
        DATA_BLOB blob = data_blob(NULL, 0);
        char *aname = talloc_asprintf(NULL, "%s%s", attr_prefix, attr_name);
        if (aname == NULL) {
                return NT_STATUS_NO_MEMORY;
        }
        status = push_xattr_blob(pvfs, aname, fname, fd, &blob);
        talloc_free(aname);
        return status;
}


/*
  delete a xattr with the given name
*/
NTSTATUS pvfs_xattr_delete(struct pvfs_state *pvfs, 
                           const char *fname, int fd,
                           const char *attr_prefix,
                           const char *attr_name)
{
        NTSTATUS status;
        char *aname = talloc_asprintf(NULL, "%s%s", attr_prefix, attr_name);
        if (aname == NULL) {
                return NT_STATUS_NO_MEMORY;
        }
        status = delete_xattr(pvfs, aname, fname, fd);
        talloc_free(aname);
        return status;
}

/*
  load a xattr with the given name
*/
NTSTATUS pvfs_xattr_load(struct pvfs_state *pvfs, 
                         TALLOC_CTX *mem_ctx,
                         const char *fname, int fd,
                         const char *attr_prefix,
                         const char *attr_name,
                         size_t estimated_size,
                         DATA_BLOB *blob)
{
        NTSTATUS status;
        char *aname = talloc_asprintf(mem_ctx, "%s%s", attr_prefix, attr_name);
        if (aname == NULL) {
                return NT_STATUS_NO_MEMORY;
        }
        status = pull_xattr_blob(pvfs, mem_ctx, aname, fname, fd, estimated_size, blob);
        talloc_free(aname);
        return status;
}

/*
  save a xattr with the given name
*/
NTSTATUS pvfs_xattr_save(struct pvfs_state *pvfs, 
                         const char *fname, int fd,
                         const char *attr_prefix,
                         const char *attr_name,
                         const DATA_BLOB *blob)
{
        NTSTATUS status;
        char *aname = talloc_asprintf(NULL, "%s%s", attr_prefix, attr_name);
        if (aname == NULL) {
                return NT_STATUS_NO_MEMORY;
        }
        status = push_xattr_blob(pvfs, aname, fname, fd, blob);
        talloc_free(aname);
        return status;
}


/*
  probe for system support for xattrs
*/
void pvfs_xattr_probe(struct pvfs_state *pvfs)
{
        TALLOC_CTX *tmp_ctx = talloc_new(pvfs);
        DATA_BLOB blob;
        pull_xattr_blob(pvfs, tmp_ctx, "user.XattrProbe", pvfs->base_directory, 
                        -1, 1, &blob);
        pull_xattr_blob(pvfs, tmp_ctx, "security.XattrProbe", pvfs->base_directory, 
                        -1, 1, &blob);
        talloc_free(tmp_ctx);
}