/*

   Unix SMB/CIFS implementation.

   Utilities around tsocket

   Copyright (C) Volker Lendecke 2009

   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 "replace.h"

#include "system/network.h"

#include <tevent.h>

#include "lib/util_tsock.h"

#include "../lib/tsocket/tsocket.h"

#include "../lib/util/tevent_unix.h"

struct tstream_read_packet_state {

  struct tevent_context *ev;

  struct tstream_context *stream;

  ssize_t (*more)(uint8_t *buf, size_t buflen, void *private_data);

  void *private_data;

  uint8_t *buf;

  struct iovec iov;

};

static void tstream_read_packet_done(struct tevent_req *subreq);

struct tevent_req *tstream_read_packet_send(TALLOC_CTX *mem_ctx,

              struct tevent_context *ev,

              struct tstream_context *stream,

              size_t initial,

              ssize_t (*more)(uint8_t *buf,

                  size_t buflen,

                  void *private_data),

              void *private_data)

{

  struct tevent_req *req, *subreq;

  struct tstream_read_packet_state *state;

  req = tevent_req_create(mem_ctx, &state,

        struct tstream_read_packet_state);

  if (req == NULL) {

    return NULL;

  }

  state->buf = talloc_array(state, uint8_t, initial);

  if (tevent_req_nomem(state->buf, req)) {

    return tevent_req_post(req, ev);

  }

  state->iov.iov_base = (void *)state->buf;

  state->iov.iov_len = initial;

  state->ev = ev;

  state->stream = stream;

  state->more = more;

  state->private_data = private_data;

  subreq = tstream_readv_send(state, ev, stream, &state->iov, 1);

  if (tevent_req_nomem(subreq, req)) {

    return tevent_req_post(req, ev);

  }

  tevent_req_set_callback(subreq, tstream_read_packet_done, req);

  return req;

}

static void tstream_read_packet_done(struct tevent_req *subreq)

{

  struct tevent_req *req = tevent_req_callback_data(

    subreq, struct tevent_req);

  struct tstream_read_packet_state *state = tevent_req_data(

    req, struct tstream_read_packet_state);

  int ret, err;

  size_t total;

  ssize_t more;

  uint8_t *tmp;

  ret = tstream_readv_recv(subreq, &err);

  TALLOC_FREE(subreq);

  if (ret == 0) {

    err = EPIPE;

  }

  if (ret <= 0) {

    tevent_req_error(req, err);

    return;

  }

  if (state->more == NULL) {

    /* Nobody to ask, this is a async read_data */

    tevent_req_done(req);

    return;

  }

  total = talloc_array_length(state->buf);

  more = state->more(state->buf, total, state->private_data);

  if (more == -1) {

    /* We got an invalid packet, tell the caller */

    tevent_req_error(req, EIO);

    return;

  }

  if (more == 0) {

    /* We're done, full packet received */

    tevent_req_done(req);

    return;

  }

  if (total + more < total) {

    tevent_req_error(req, EMSGSIZE);

    return;

  }

  tmp = talloc_realloc(state, state->buf, uint8_t, total+more);

  if (tevent_req_nomem(tmp, req)) {

    return;

  }

  state->buf = tmp;

  state->iov.iov_base = (void *)(state->buf + total);

  state->iov.iov_len = more;

  subreq = tstream_readv_send(state, state->ev, state->stream,

            &state->iov, 1);

  if (tevent_req_nomem(subreq, req)) {

    return;

  }

  tevent_req_set_callback(subreq, tstream_read_packet_done, req);

}

ssize_t tstream_read_packet_recv(struct tevent_req *req, TALLOC_CTX *mem_ctx,

         uint8_t **pbuf, int *perrno)

{

  struct tstream_read_packet_state *state =

    tevent_req_data(req, struct tstream_read_packet_state);

  if (tevent_req_is_unix_error(req, perrno)) {

    return -1;

  }

  *pbuf = talloc_move(mem_ctx, &state->buf);

  return talloc_array_length(*pbuf);

}