/* 
   Unix SMB/CIFS implementation.
   process incoming packets - main loop
   Copyright (C) Andrew Tridgell	2004-2005
   Copyright (C) Stefan Metzmacher	2004-2005
   
   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 2 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, write to the Free Software
   Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
*/

#include "includes.h"
#include "lib/events/events.h"
#include "system/time.h"
#include "dlinklist.h"
#include "smbd/service_stream.h"
#include "smb_server/smb_server.h"
#include "lib/messaging/irpc.h"
#include "lib/stream/packet.h"

static NTSTATUS smbsrv_recv_generic_request(void *private, DATA_BLOB blob)
{
	NTSTATUS status;
	struct smbsrv_connection *smb_conn = talloc_get_type(private, struct smbsrv_connection);
	uint32_t protocol_version;

	/* see if its a special NBT packet */
	if (CVAL(blob.data,0) != 0) {
		status = smbsrv_init_smb_connection(smb_conn);
		NT_STATUS_NOT_OK_RETURN(status);
		packet_set_callback(smb_conn->packet, smbsrv_recv_smb_request);
		return smbsrv_recv_smb_request(smb_conn, blob);
	}

	if (blob.length < (NBT_HDR_SIZE + MIN_SMB_SIZE)) {
		DEBUG(2,("Invalid SMB packet length count %d\n", blob.length));
		smbsrv_terminate_connection(smb_conn, "Invalid SMB packet");
		return NT_STATUS_OK;
	}

	protocol_version = IVAL(blob.data, NBT_HDR_SIZE);

	switch (protocol_version) {
	case SMB_MAGIC:
		status = smbsrv_init_smb_connection(smb_conn);
		NT_STATUS_NOT_OK_RETURN(status);
		packet_set_callback(smb_conn->packet, smbsrv_recv_smb_request);
		return smbsrv_recv_smb_request(smb_conn, blob);
	}

	DEBUG(2,("Invalid SMB packet: protocl prefix: 0x%08X\n", protocol_version));
	smbsrv_terminate_connection(smb_conn, "NON-SMB packet");
	return NT_STATUS_OK;
}

/*
  close the socket and shutdown a server_context
*/
void smbsrv_terminate_connection(struct smbsrv_connection *smb_conn, const char *reason)
{
	smb_conn->terminate = reason;
}

/*
  called when a SMB socket becomes readable
*/
static void smbsrv_recv(struct stream_connection *conn, uint16_t flags)
{
	struct smbsrv_connection *smb_conn = talloc_get_type(conn->private, struct smbsrv_connection);

	DEBUG(10,("smbsrv_recv\n"));

	packet_recv(smb_conn->packet);
	if (smb_conn->terminate) {
		talloc_free(conn->event.fde);
		conn->event.fde = NULL;
		stream_terminate_connection(smb_conn->connection, smb_conn->terminate);
		return;
	}

	/* free up temporary memory */
	lp_talloc_free();
}

/*
  called when a SMB socket becomes writable
*/
static void smbsrv_send(struct stream_connection *conn, uint16_t flags)
{
	struct smbsrv_connection *smb_conn = talloc_get_type(conn->private, 
							     struct smbsrv_connection);
	packet_queue_run(smb_conn->packet);
}


/*
  handle socket recv errors
*/
static void smbsrv_recv_error(void *private, NTSTATUS status)
{
	struct smbsrv_connection *smb_conn = talloc_get_type(private, struct smbsrv_connection);
	
	smbsrv_terminate_connection(smb_conn, nt_errstr(status));
}

/*
  initialise a server_context from a open socket and register a event handler
  for reading from that socket
*/
static void smbsrv_accept(struct stream_connection *conn)
{
	struct smbsrv_connection *smb_conn;

	DEBUG(5,("smbsrv_accept\n"));

	smb_conn = talloc_zero(conn, struct smbsrv_connection);
	if (!smb_conn) return;

	smb_conn->packet = packet_init(smb_conn);
	if (smb_conn->packet == NULL) {
		stream_terminate_connection(conn, "out of memory");
		return;
	}
	packet_set_private(smb_conn->packet, smb_conn);
	packet_set_socket(smb_conn->packet, conn->socket);
	packet_set_callback(smb_conn->packet, smbsrv_recv_generic_request);
	packet_set_full_request(smb_conn->packet, packet_full_request_nbt);
	packet_set_error_handler(smb_conn->packet, smbsrv_recv_error);
	packet_set_event_context(smb_conn->packet, conn->event.ctx);
	packet_set_fde(smb_conn->packet, conn->event.fde);
	packet_set_serialise(smb_conn->packet);

	smb_conn->connection = conn;
	conn->private = smb_conn;

	irpc_add_name(conn->msg_ctx, "smb_server");

	smbsrv_management_init(smb_conn);
}

static const struct stream_server_ops smb_stream_ops = {
	.name			= "smb",
	.accept_connection	= smbsrv_accept,
	.recv_handler		= smbsrv_recv,
	.send_handler		= smbsrv_send,
};

/*
  setup a listening socket on all the SMB ports for a particular address
*/
static NTSTATUS smb_add_socket(struct event_context *event_context,
			       const struct model_ops *model_ops,
			       const char *address)
{
	const char **ports = lp_smb_ports();
	int i;
	NTSTATUS status;

	for (i=0;ports[i];i++) {
		uint16_t port = atoi(ports[i]);
		if (port == 0) continue;
		status = stream_setup_socket(event_context, model_ops, &smb_stream_ops, 
					     "ipv4", address, &port, NULL);
		NT_STATUS_NOT_OK_RETURN(status);
	}

	return NT_STATUS_OK;
}

/*
  called on startup of the smb server service It's job is to start
  listening on all configured SMB server sockets
*/
static NTSTATUS smbsrv_init(struct event_context *event_context, const struct model_ops *model_ops)
{	
	NTSTATUS status;

	if (lp_interfaces() && lp_bind_interfaces_only()) {
		int num_interfaces = iface_count();
		int i;

		/* We have been given an interfaces line, and been 
		   told to only bind to those interfaces. Create a
		   socket per interface and bind to only these.
		*/
		for(i = 0; i < num_interfaces; i++) {
			const char *address = iface_n_ip(i);
			status = smb_add_socket(event_context, model_ops, address);
			NT_STATUS_NOT_OK_RETURN(status);
		}
	} else {
		/* Just bind to lp_socket_address() (usually 0.0.0.0) */
		status = smb_add_socket(event_context, model_ops, lp_socket_address());
		NT_STATUS_NOT_OK_RETURN(status);
	}

	return NT_STATUS_OK;
}

/* called at smbd startup - register ourselves as a server service */
NTSTATUS server_service_smb_init(void)
{
	return register_server_service("smb", smbsrv_init);
}