/*

   Unix SMB/CIFS implementation.

   SMB2 POSIX code.

   Copyright (C) Jeremy Allison                 2022

   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 "smbd/smbd.h"

#include "passdb/lookup_sid.h"

#include "librpc/gen_ndr/ndr_security.h"

#include "librpc/gen_ndr/smb3posix.h"

#include "libcli/security/security.h"

#include "source3/modules/util_reparse.h"

#include "libcli/smb/reparse.h"

static NTSTATUS reparse_buffer_parse_posix_type(uint32_t reparse_tag,

            uint8_t *data,

            uint32_t len,

            mode_t *type)

{

  struct reparse_data_buffer *reparse = NULL;

  NTSTATUS status;

  if (reparse_tag == IO_REPARSE_TAG_SYMLINK) {

    *type = S_IFLNK;

    return NT_STATUS_OK;

  }

  if (reparse_tag != IO_REPARSE_TAG_NFS) {

    /*

     * Clients can create reparse points with arbitrary tags, return

     * anything that is not a NFS one (or symlink) as S_IFREG.

     */

    DBG_INFO("Unhandled NFS reparse tag: 0x%" PRIx32 "\n",

       reparse_tag);

    *type = S_IFREG;

    return NT_STATUS_OK;

  }

  reparse = talloc_zero(talloc_tos(), struct reparse_data_buffer);

  if (reparse == NULL) {

    DBG_ERR("talloc_zero() failed\n");

    return NT_STATUS_NO_MEMORY;

  }

  status = reparse_data_buffer_parse(reparse, reparse, data, len);

  if (!NT_STATUS_IS_OK(status)) {

    TALLOC_FREE(reparse);

    return status;

  }

  switch (reparse->parsed.nfs.type) {

  case NFS_SPECFILE_CHR:

    *type = S_IFCHR;

    break;

  case NFS_SPECFILE_BLK:

    *type = S_IFBLK;

    break;

  case NFS_SPECFILE_FIFO:

    *type = S_IFIFO;

    break;

  case NFS_SPECFILE_SOCK:

    *type = S_IFSOCK;

    break;

  default:

    DBG_ERR("Unhandled NFS reparse type: 0x%" PRIx64 "\n",

      reparse->parsed.nfs.type);

    TALLOC_FREE(reparse);

    return NT_STATUS_REPARSE_POINT_NOT_RESOLVED;

  }

  TALLOC_FREE(reparse);

  return status;

}

NTSTATUS smb3_file_posix_information_init(

  connection_struct *conn,

  const struct smb_filename *smb_fname,

  uint32_t dos_attributes,

  struct smb3_file_posix_information *dst)

{

  const struct stat_ex *st = &smb_fname->st;

  mode_t mode = st->st_ex_mode;

  uint32_t reparse_tag = 0;

  NTSTATUS status;

  switch (mode & S_IFMT) {

  case S_IFREG:

  case S_IFDIR:

    break;

  default:

    /*

     * All non-directory or regular files are reported

     * as reparse points. Client may or may not be able

     * to access these. This should already be set by

     * fdos_mode(), assert this.

     */

    SMB_ASSERT(dos_attributes & FILE_ATTRIBUTE_REPARSE_POINT);

    break;

  }

  if (dos_attributes & FILE_ATTRIBUTE_REPARSE_POINT) {

    uint8_t *reparse_data = NULL;

    uint32_t reparse_len;

    mode_t type = S_IFREG;

    status = fsctl_get_reparse_point(smb_fname->fsp,

             talloc_tos(),

             &reparse_tag,

             &reparse_data,

             UINT32_MAX,

             &reparse_len);

    if (!NT_STATUS_IS_OK(status)) {

      DBG_DEBUG("Could not get reparse point for %s: %s\n",

          smb_fname_str_dbg(smb_fname),

          nt_errstr(status));

      return status;

    }

    status = reparse_buffer_parse_posix_type(reparse_tag,

               reparse_data,

               reparse_len,

               &type);

    TALLOC_FREE(reparse_data);

    if (!NT_STATUS_IS_OK(status)) {

      DBG_DEBUG("Could not parse reparse data for %s: %s\n",

          smb_fname_str_dbg(smb_fname),

          nt_errstr(status));

      return status;

    }

    /*

     * Remove the type info we got via stat() and use what

     * we got from the reparse point.

     */

    mode &= ~S_IFMT;

    mode |= type;

  }

  *dst = (struct smb3_file_posix_information) {

    .end_of_file = get_file_size_stat(st),

    .allocation_size = SMB_VFS_GET_ALLOC_SIZE(conn,NULL,st),

    .inode = SMB_VFS_FS_FILE_ID(conn, st),

    .device = st->st_ex_dev,

    .creation_time = unix_timespec_to_nt_time(st->st_ex_btime),

    .last_access_time = unix_timespec_to_nt_time(st->st_ex_atime),

    .last_write_time = unix_timespec_to_nt_time(st->st_ex_mtime),

    .change_time = unix_timespec_to_nt_time(st->st_ex_ctime),

    .file_attributes = dos_attributes,

    .cc.nlinks = st->st_ex_nlink,

    .cc.reparse_tag = reparse_tag,

    .cc.posix_mode = unix_mode_to_wire(mode),

    .cc.owner = global_sid_NULL,

    .cc.group = global_sid_NULL,

  };

  if (st->st_ex_uid != (uid_t)-1) {

    uid_to_sid(&dst->cc.owner, st->st_ex_uid);

  }

  if (st->st_ex_gid != (uid_t)-1) {

    gid_to_sid(&dst->cc.group, st->st_ex_gid);

  }

  return NT_STATUS_OK;

}