/* 

   Unix SMB/CIFS implementation.

   Copyright (C) Andrew Tridgell 2005

   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/>.

*/

/*

  a composite API for loading a whole file into memory

*/

#include "includes.h"

#include "libcli/raw/libcliraw.h"

#include "libcli/composite/composite.h"

#include "libcli/smb_composite/smb_composite.h"

/* the stages of this call */

enum loadfile_stage {LOADFILE_OPEN, LOADFILE_READ, LOADFILE_CLOSE};

static void loadfile_handler(struct smbcli_request *req);

struct loadfile_state {

  enum loadfile_stage stage;

  struct smb_composite_loadfile *io;

  struct smbcli_request *req;

  union smb_open *io_open;

  union smb_read *io_read;

};

/*

  setup for the close

*/

static NTSTATUS setup_close(struct composite_context *c, 

          struct smbcli_tree *tree, uint16_t fnum)

{

  struct loadfile_state *state = talloc_get_type(c->private_data, struct loadfile_state);

  union smb_close *io_close;

  /* nothing to read, setup the close */

  io_close = talloc(c, union smb_close);

  NT_STATUS_HAVE_NO_MEMORY(io_close);

  io_close->close.level = RAW_CLOSE_CLOSE;

  io_close->close.in.file.fnum = fnum;

  io_close->close.in.write_time = 0;

  state->req = smb_raw_close_send(tree, io_close);

  NT_STATUS_HAVE_NO_MEMORY(state->req);

  /* call the handler again when the close is done */

  state->req->async.fn = loadfile_handler;

  state->req->async.private_data = c;

  state->stage = LOADFILE_CLOSE;

  return NT_STATUS_OK;

}

/*

  called when the open is done - pull the results and setup for the

  first readx, or close if the file is zero size

*/

static NTSTATUS loadfile_open(struct composite_context *c, 

            struct smb_composite_loadfile *io)

{

  struct loadfile_state *state = talloc_get_type(c->private_data, struct loadfile_state);

  struct smbcli_tree *tree = state->req->tree;

  NTSTATUS status;

  status = smb_raw_open_recv(state->req, c, state->io_open);

  NT_STATUS_NOT_OK_RETURN(status);

  /* don't allow stupidly large loads */

  if (state->io_open->ntcreatex.out.size > 100*1000*1000) {

    return NT_STATUS_INSUFFICIENT_RESOURCES;

  }

  /* allocate space for the file data */

  io->out.size = state->io_open->ntcreatex.out.size;

  io->out.data = talloc_array(c, uint8_t, io->out.size);

  NT_STATUS_HAVE_NO_MEMORY(io->out.data);

  if (io->out.size == 0) {

    return setup_close(c, tree, state->io_open->ntcreatex.out.file.fnum);

  }

  /* setup for the read */

  state->io_read = talloc(c, union smb_read);

  NT_STATUS_HAVE_NO_MEMORY(state->io_read);

  state->io_read->readx.level        = RAW_READ_READX;

  state->io_read->readx.in.file.fnum = state->io_open->ntcreatex.out.file.fnum;

  state->io_read->readx.in.offset    = 0;

  state->io_read->readx.in.mincnt    = MIN(32768, io->out.size);

  state->io_read->readx.in.maxcnt    = state->io_read->readx.in.mincnt;

  state->io_read->readx.in.remaining = 0;

  state->io_read->readx.in.read_for_execute = false;

  state->io_read->readx.out.data     = io->out.data;

  state->req = smb_raw_read_send(tree, state->io_read);

  NT_STATUS_HAVE_NO_MEMORY(state->req);

  /* call the handler again when the first read is done */

  state->req->async.fn = loadfile_handler;

  state->req->async.private_data = c;

  state->stage = LOADFILE_READ;

  talloc_free(state->io_open);

  return NT_STATUS_OK;

}

/*

  called when a read is done - pull the results and setup for the

  next read, or close if the file is all done

*/

static NTSTATUS loadfile_read(struct composite_context *c, 

            struct smb_composite_loadfile *io)

{

  struct loadfile_state *state = talloc_get_type(c->private_data, struct loadfile_state);

  struct smbcli_tree *tree = state->req->tree;

  NTSTATUS status;

  status = smb_raw_read_recv(state->req, state->io_read);

  NT_STATUS_NOT_OK_RETURN(status);

  /* we might be done */

  if (state->io_read->readx.in.offset +

      state->io_read->readx.out.nread == io->out.size) {

    return setup_close(c, tree, state->io_read->readx.in.file.fnum);

  }

  /* setup for the next read */

  state->io_read->readx.in.offset += state->io_read->readx.out.nread;

  state->io_read->readx.in.mincnt = MIN(32768, io->out.size - state->io_read->readx.in.offset);

  state->io_read->readx.out.data = io->out.data + state->io_read->readx.in.offset;

  state->req = smb_raw_read_send(tree, state->io_read);

  NT_STATUS_HAVE_NO_MEMORY(state->req);

  /* call the handler again when the read is done */

  state->req->async.fn = loadfile_handler;

  state->req->async.private_data = c;

  return NT_STATUS_OK;

}

/*

  called when the close is done, check the status and cleanup

*/

static NTSTATUS loadfile_close(struct composite_context *c, 

             struct smb_composite_loadfile *io)

{

  struct loadfile_state *state = talloc_get_type(c->private_data, struct loadfile_state);

  NTSTATUS status;

  status = smbcli_request_simple_recv(state->req);

  NT_STATUS_NOT_OK_RETURN(status);

  c->state = COMPOSITE_STATE_DONE;

  return NT_STATUS_OK;

}

/*

  handler for completion of a sub-request in loadfile

*/

static void loadfile_handler(struct smbcli_request *req)

{

  struct composite_context *c = (struct composite_context *)req->async.private_data;

  struct loadfile_state *state = talloc_get_type(c->private_data, struct loadfile_state);

  /* when this handler is called, the stage indicates what

     call has just finished */

  switch (state->stage) {

  case LOADFILE_OPEN:

    c->status = loadfile_open(c, state->io);

    break;

  case LOADFILE_READ:

    c->status = loadfile_read(c, state->io);

    break;

  case LOADFILE_CLOSE:

    c->status = loadfile_close(c, state->io);

    break;

  }

  if (!NT_STATUS_IS_OK(c->status)) {

    c->state = COMPOSITE_STATE_ERROR;

  }

  if (c->state >= COMPOSITE_STATE_DONE &&

      c->async.fn) {

    c->async.fn(c);

  }

}

/*

  composite loadfile call - does an openx followed by a number of readx calls,

  followed by a close

*/

struct composite_context *smb_composite_loadfile_send(struct smbcli_tree *tree, 

                 struct smb_composite_loadfile *io)

{

  struct composite_context *c;

  struct loadfile_state *state;

  c = talloc_zero(tree, struct composite_context);

  if (c == NULL) goto failed;

  state = talloc(c, struct loadfile_state);

  if (state == NULL) goto failed;

  state->io = io;

  c->private_data = state;

  c->state = COMPOSITE_STATE_IN_PROGRESS;

  c->event_ctx = tree->session->transport->ev;

  /* setup for the open */

  state->io_open = talloc_zero(c, union smb_open);

  if (state->io_open == NULL) goto failed;

  state->io_open->ntcreatex.level               = RAW_OPEN_NTCREATEX;

  state->io_open->ntcreatex.in.flags            = NTCREATEX_FLAGS_EXTENDED;

  state->io_open->ntcreatex.in.access_mask      = SEC_FILE_READ_DATA;

  state->io_open->ntcreatex.in.file_attr        = FILE_ATTRIBUTE_NORMAL;

  state->io_open->ntcreatex.in.share_access     = NTCREATEX_SHARE_ACCESS_READ | NTCREATEX_SHARE_ACCESS_WRITE;

  state->io_open->ntcreatex.in.open_disposition = NTCREATEX_DISP_OPEN;

  state->io_open->ntcreatex.in.impersonation    = NTCREATEX_IMPERSONATION_ANONYMOUS;

  state->io_open->ntcreatex.in.fname            = io->in.fname;

  /* send the open on its way */

  state->req = smb_raw_open_send(tree, state->io_open);

  if (state->req == NULL) goto failed;

  /* setup the callback handler */

  state->req->async.fn = loadfile_handler;

  state->req->async.private_data = c;

  state->stage = LOADFILE_OPEN;

  return c;

failed:

  talloc_free(c);

  return NULL;

}

/*

  composite loadfile call - recv side

*/

NTSTATUS smb_composite_loadfile_recv(struct composite_context *c, TALLOC_CTX *mem_ctx)

{

  NTSTATUS status;

  status = composite_wait(c);

  if (NT_STATUS_IS_OK(status)) {

    struct loadfile_state *state = talloc_get_type(c->private_data, struct loadfile_state);

    talloc_steal(mem_ctx, state->io->out.data);

  }

  talloc_free(c);

  return status;

}

/*

  composite loadfile call - sync interface

*/

NTSTATUS smb_composite_loadfile(struct smbcli_tree *tree, 

        TALLOC_CTX *mem_ctx,

        struct smb_composite_loadfile *io)

{

  struct composite_context *c = smb_composite_loadfile_send(tree, io);

  return smb_composite_loadfile_recv(c, mem_ctx);

}