/*
   Unix SMB/CIFS implementation.

   Async transfer of winbindd_request and _response structs

   Copyright (C) Volker Lendecke 2008

   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 "winbindd/winbindd.h"

#undef DBGC_CLASS
#define DBGC_CLASS DBGC_WINBIND

struct req_read_state {
	struct winbindd_request *wb_req;
	struct event_context *ev;
	size_t max_extra_data;
	int fd;
};

static void wb_req_read_len(struct async_req *subreq);
static void wb_req_read_main(struct async_req *subreq);
static void wb_req_read_extra(struct async_req *subreq);

struct async_req *wb_req_read_send(TALLOC_CTX *mem_ctx,
				   struct event_context *ev,
				   int fd, size_t max_extra_data)
{
	struct async_req *result, *subreq;
	struct req_read_state *state;

	result = async_req_new(mem_ctx);
	if (result == NULL) {
		return NULL;
	}

	state = talloc(result, struct req_read_state);
	if (state == NULL) {
		goto nomem;
	}
	result->private_data = state;

	state->fd = fd;
	state->ev = ev;
	state->max_extra_data = max_extra_data;
	state->wb_req = talloc(state, struct winbindd_request);
	if (state->wb_req == NULL) {
		goto nomem;
	}

	subreq = recvall_send(state, ev, state->fd, &(state->wb_req->length),
			      sizeof(state->wb_req->length), 0);
	if (subreq == NULL) {
		goto nomem;
	}

	subreq->async.fn = wb_req_read_len;
	subreq->async.priv = result;
	return result;

 nomem:
	TALLOC_FREE(result);
	return NULL;
}

static void wb_req_read_len(struct async_req *subreq)
{
	struct async_req *req = talloc_get_type_abort(
		subreq->async.priv, struct async_req);
	struct req_read_state *state = talloc_get_type_abort(
		req->private_data, struct req_read_state);
	NTSTATUS status;

	status = recvall_recv(subreq);
	TALLOC_FREE(subreq);
	if (!NT_STATUS_IS_OK(status)) {
		async_req_error(req, status);
		return;
	}

	if (state->wb_req->length != sizeof(struct winbindd_request)) {
		DEBUG(0, ("wb_req_read_len: Invalid request size received: "
			  "%d (expected %d)\n", (int)state->wb_req->length,
			  (int)sizeof(struct winbindd_request)));
		async_req_error(req, NT_STATUS_INVALID_BUFFER_SIZE);
		return;
	}

	subreq = recvall_send(
		req, state->ev, state->fd, (uint32 *)(state->wb_req)+1,
		sizeof(struct winbindd_request) - sizeof(uint32), 0);
	if (async_req_nomem(subreq, req)) {
		return;
	}

	subreq->async.fn = wb_req_read_main;
	subreq->async.priv = req;
}

static void wb_req_read_main(struct async_req *subreq)
{
	struct async_req *req = talloc_get_type_abort(
		subreq->async.priv, struct async_req);
	struct req_read_state *state = talloc_get_type_abort(
		req->private_data, struct req_read_state);
	NTSTATUS status;

	status = recvall_recv(subreq);
	TALLOC_FREE(subreq);
	if (!NT_STATUS_IS_OK(status)) {
		async_req_error(req, status);
		return;
	}

	if ((state->max_extra_data != 0)
	    && (state->wb_req->extra_len > state->max_extra_data)) {
		DEBUG(3, ("Got request with %d bytes extra data on "
			  "unprivileged socket\n",
			  (int)state->wb_req->extra_len));
		async_req_error(req, NT_STATUS_INVALID_BUFFER_SIZE);
		return;
	}

	if (state->wb_req->extra_len == 0) {
		async_req_done(req);
		return;
	}

	state->wb_req->extra_data.data = TALLOC_ARRAY(
		state->wb_req, char, state->wb_req->extra_len + 1);
	if (async_req_nomem(state->wb_req->extra_data.data, req)) {
		return;
	}

	state->wb_req->extra_data.data[state->wb_req->extra_len] = 0;

	subreq = recvall_send(
		req, state->ev, state->fd, state->wb_req->extra_data.data,
		state->wb_req->extra_len, 0);
	if (async_req_nomem(subreq, req)) {
		return;
	}

	subreq->async.fn = wb_req_read_extra;
	subreq->async.priv = req;
}

static void wb_req_read_extra(struct async_req *subreq)
{
	struct async_req *req = talloc_get_type_abort(
		subreq->async.priv, struct async_req);
	NTSTATUS status;

	status = recvall_recv(subreq);
	TALLOC_FREE(subreq);
	if (!NT_STATUS_IS_OK(status)) {
		async_req_error(req, status);
		return;
	}
	async_req_done(req);
}


NTSTATUS wb_req_read_recv(struct async_req *req, TALLOC_CTX *mem_ctx,
			  struct winbindd_request **preq)
{
	struct req_read_state *state = talloc_get_type_abort(
		req->private_data, struct req_read_state);
	NTSTATUS status;

	if (async_req_is_error(req, &status)) {
		return status;
	}
	*preq = talloc_move(mem_ctx, &state->wb_req);
	return NT_STATUS_OK;
}

struct req_write_state {
	struct winbindd_request *wb_req;
	struct event_context *ev;
	int fd;
};

static void wb_req_write_main(struct async_req *subreq);
static void wb_req_write_extra(struct async_req *subreq);

struct async_req *wb_req_write_send(TALLOC_CTX *mem_ctx,
				    struct event_context *ev, int fd,
				    struct winbindd_request *wb_req)
{
	struct async_req *result, *subreq;
	struct req_write_state *state;

	result = async_req_new(mem_ctx);
	if (result == NULL) {
		return NULL;
	}

	state = talloc(result, struct req_write_state);
	if (state == NULL) {
		goto nomem;
	}
	result->private_data = state;

	state->fd = fd;
	state->ev = ev;
	state->wb_req = wb_req;

	subreq = sendall_send(state, state->ev, state->fd, state->wb_req,
			      sizeof(struct winbindd_request), 0);
	if (subreq == NULL) {
		goto nomem;
	}

	subreq->async.fn = wb_req_write_main;
	subreq->async.priv = result;
	return result;

 nomem:
	TALLOC_FREE(result);
	return NULL;
}

static void wb_req_write_main(struct async_req *subreq)
{
	struct async_req *req = talloc_get_type_abort(
		subreq->async.priv, struct async_req);
	struct req_write_state *state = talloc_get_type_abort(
		req->private_data, struct req_write_state);
	NTSTATUS status;

	status = sendall_recv(subreq);
	TALLOC_FREE(subreq);
	if (!NT_STATUS_IS_OK(status)) {
		async_req_error(req, status);
		return;
	}

	if (state->wb_req->extra_len == 0) {
		async_req_done(req);
		return;
	}

	subreq = sendall_send(state, state->ev, state->fd,
			      state->wb_req->extra_data.data,
			      state->wb_req->extra_len, 0);
	if (async_req_nomem(subreq, req)) {
		return;
	}

	subreq->async.fn = wb_req_write_extra;
	subreq->async.priv = req;
}

static void wb_req_write_extra(struct async_req *subreq)
{
	struct async_req *req = talloc_get_type_abort(
		subreq->async.priv, struct async_req);
	NTSTATUS status;

	status = sendall_recv(subreq);
	TALLOC_FREE(subreq);
	if (!NT_STATUS_IS_OK(status)) {
		async_req_error(req, status);
		return;
	}

	async_req_done(req);
}

NTSTATUS wb_req_write_recv(struct async_req *req)
{
	return async_req_simple_recv(req);
}

struct resp_read_state {
	struct winbindd_response *wb_resp;
	struct event_context *ev;
	size_t max_extra_data;
	int fd;
};

static void wb_resp_read_len(struct async_req *subreq);
static void wb_resp_read_main(struct async_req *subreq);
static void wb_resp_read_extra(struct async_req *subreq);

struct async_req *wb_resp_read_send(TALLOC_CTX *mem_ctx,
				    struct event_context *ev, int fd)
{
	struct async_req *result, *subreq;
	struct resp_read_state *state;

	result = async_req_new(mem_ctx);
	if (result == NULL) {
		return NULL;
	}

	state = talloc(result, struct resp_read_state);
	if (state == NULL) {
		goto nomem;
	}
	result->private_data = state;

	state->fd = fd;
	state->ev = ev;
	state->wb_resp = talloc(state, struct winbindd_response);
	if (state->wb_resp == NULL) {
		goto nomem;
	}

	subreq = recvall_send(state, ev, state->fd, &(state->wb_resp->length),
			      sizeof(state->wb_resp->length), 0);
	if (subreq == NULL) {
		goto nomem;
	}

	subreq->async.fn = wb_resp_read_len;
	subreq->async.priv = result;
	return result;

 nomem:
	TALLOC_FREE(result);
	return NULL;
}

static void wb_resp_read_len(struct async_req *subreq)
{
	struct async_req *req = talloc_get_type_abort(
		subreq->async.priv, struct async_req);
	struct resp_read_state *state = talloc_get_type_abort(
		req->private_data, struct resp_read_state);
	NTSTATUS status;

	status = recvall_recv(subreq);
	TALLOC_FREE(subreq);
	if (!NT_STATUS_IS_OK(status)) {
		async_req_error(req, status);
		return;
	}

	if (state->wb_resp->length < sizeof(struct winbindd_response)) {
		DEBUG(0, ("wb_resp_read_len: Invalid response size received: "
			  "%d (expected at least%d)\n",
			  (int)state->wb_resp->length,
			  (int)sizeof(struct winbindd_response)));
		async_req_error(req, NT_STATUS_INVALID_BUFFER_SIZE);
		return;
	}

	subreq = recvall_send(
		req, state->ev, state->fd, (uint32 *)(state->wb_resp)+1,
		sizeof(struct winbindd_response) - sizeof(uint32), 0);
	if (async_req_nomem(subreq, req)) {
		return;
	}

	subreq->async.fn = wb_resp_read_main;
	subreq->async.priv = req;
}

static void wb_resp_read_main(struct async_req *subreq)
{
	struct async_req *req = talloc_get_type_abort(
		subreq->async.priv, struct async_req);
	struct resp_read_state *state = talloc_get_type_abort(
		req->private_data, struct resp_read_state);
	NTSTATUS status;
	size_t extra_len;

	status = recvall_recv(subreq);
	TALLOC_FREE(subreq);
	if (!NT_STATUS_IS_OK(status)) {
		async_req_error(req, status);
		return;
	}

	extra_len = state->wb_resp->length - sizeof(struct winbindd_response);
	if (extra_len == 0) {
		async_req_done(req);
		return;
	}

	state->wb_resp->extra_data.data = TALLOC_ARRAY(
		state->wb_resp, char, extra_len+1);
	if (async_req_nomem(state->wb_resp->extra_data.data, req)) {
		return;
	}
	((char *)state->wb_resp->extra_data.data)[extra_len] = 0;

	subreq = recvall_send(
		req, state->ev, state->fd, state->wb_resp->extra_data.data,
		extra_len, 0);
	if (async_req_nomem(subreq, req)) {
		return;
	}

	subreq->async.fn = wb_resp_read_extra;
	subreq->async.priv = req;
}

static void wb_resp_read_extra(struct async_req *subreq)
{
	struct async_req *req = talloc_get_type_abort(
		subreq->async.priv, struct async_req);
	NTSTATUS status;

	status = recvall_recv(subreq);
	TALLOC_FREE(subreq);
	if (!NT_STATUS_IS_OK(status)) {
		async_req_error(req, status);
		return;
	}
	async_req_done(req);
}


NTSTATUS wb_resp_read_recv(struct async_req *req, TALLOC_CTX *mem_ctx,
			   struct winbindd_response **presp)
{
	struct resp_read_state *state = talloc_get_type_abort(
		req->private_data, struct resp_read_state);
	NTSTATUS status;

	if (async_req_is_error(req, &status)) {
		return status;
	}
	*presp = talloc_move(mem_ctx, &state->wb_resp);
	return NT_STATUS_OK;
}

struct resp_write_state {
	struct winbindd_response *wb_resp;
	struct event_context *ev;
	int fd;
};

static void wb_resp_write_main(struct async_req *subreq);
static void wb_resp_write_extra(struct async_req *subreq);

struct async_req *wb_resp_write_send(TALLOC_CTX *mem_ctx,
				    struct event_context *ev, int fd,
				    struct winbindd_response *wb_resp)
{
	struct async_req *result, *subreq;
	struct resp_write_state *state;

	result = async_req_new(mem_ctx);
	if (result == NULL) {
		return NULL;
	}

	state = talloc(result, struct resp_write_state);
	if (state == NULL) {
		goto nomem;
	}
	result->private_data = state;

	state->fd = fd;
	state->ev = ev;
	state->wb_resp = wb_resp;

	subreq = sendall_send(state, state->ev, state->fd, state->wb_resp,
			      sizeof(struct winbindd_response), 0);
	if (subreq == NULL) {
		goto nomem;
	}

	subreq->async.fn = wb_resp_write_main;
	subreq->async.priv = result;
	return result;

 nomem:
	TALLOC_FREE(result);
	return NULL;
}

static void wb_resp_write_main(struct async_req *subreq)
{
	struct async_req *req = talloc_get_type_abort(
		subreq->async.priv, struct async_req);
	struct resp_write_state *state = talloc_get_type_abort(
		req->private_data, struct resp_write_state);
	NTSTATUS status;

	status = sendall_recv(subreq);
	TALLOC_FREE(subreq);
	if (!NT_STATUS_IS_OK(status)) {
		async_req_error(req, status);
		return;
	}

	if (state->wb_resp->length == sizeof(struct winbindd_response)) {
		async_req_done(req);
		return;
	}

	subreq = sendall_send(
		state, state->ev, state->fd,
		state->wb_resp->extra_data.data,
		state->wb_resp->length - sizeof(struct winbindd_response), 0);
	if (async_req_nomem(subreq, req)) {
		return;
	}

	subreq->async.fn = wb_resp_write_extra;
	subreq->async.priv = req;
}

static void wb_resp_write_extra(struct async_req *subreq)
{
	struct async_req *req = talloc_get_type_abort(
		subreq->async.priv, struct async_req);
	NTSTATUS status;

	status = sendall_recv(subreq);
	TALLOC_FREE(subreq);
	if (!NT_STATUS_IS_OK(status)) {
		async_req_error(req, status);
		return;
	}

	async_req_done(req);
}

NTSTATUS wb_resp_write_recv(struct async_req *req)
{
	return async_req_simple_recv(req);
}