/*
 * Copyright (c) 2007 - Andrey "nording" Chernyak <andrew@nording.ru>
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that: (1) source code distributions
 * retain the above copyright notice and this paragraph in its entirety, (2)
 * distributions including binary code include the above copyright notice and
 * this paragraph in its entirety in the documentation or other materials
 * provided with the distribution, and (3) all advertising materials mentioning
 * features or use of this software display the following acknowledgement:
 * ``This product includes software developed by the University of California,
 * Lawrence Berkeley Laboratory and its contributors.'' Neither the name of
 * the University nor the names of its contributors may be used to endorse
 * or promote products derived from this software without specific prior
 * written permission.
 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR IMPLIED
 * WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED WARRANTIES OF
 * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
 *
 * Format and print Realtek Remote Control Protocol (RRCP)
 * and Realtek Echo Protocol (RRCP-REP) packets.
 */

/* \summary: Realtek Remote Control Protocol (RRCP) printer */

/*
 * See, for example, section 8.20 "Realtek Remote Control Protocol" of
 *
 *    http://realtek.info/pdf/rtl8324.pdf
 *
 * and section 7.22 "Realtek Remote Control Protocol" of
 *
 *    http://realtek.info/pdf/rtl8326.pdf
 *
 * and this page on the OpenRRCP Wiki:
 *
 *    http://openrrcp.org.ru/wiki/rrcp_protocol
 *
 * NOTE: none of them indicate the byte order of multi-byte fields in any
 * obvious fashion.
 */

#ifdef HAVE_CONFIG_H
#include <config.h>
#endif

#include "netdissect-stdinc.h"

#include "netdissect.h"
#include "addrtoname.h"
#include "extract.h"

#define RRCP_OPCODE_MASK	0x7F	/* 0x00 = hello, 0x01 = get, 0x02 = set */
#define RRCP_ISREPLY		0x80	/* 0 = request to switch, 0x80 = reply from switch */

#define RRCP_PROTO_OFFSET		0	/* proto - 1 byte, must be 1 */
#define RRCP_OPCODE_ISREPLY_OFFSET	1	/* opcode and isreply flag - 1 byte */
#define RRCP_AUTHKEY_OFFSET		2	/* authorization key - 2 bytes, 0x2379 by default */

/* most packets */
#define RRCP_REG_ADDR_OFFSET		4	/* register address - 2 bytes */
#define RRCP_REG_DATA_OFFSET		6	/* register data - 4 bytes */
#define RRCP_COOKIE1_OFFSET		10	/* 4 bytes */
#define RRCP_COOKIE2_OFFSET		14	/* 4 bytes */

/* hello reply packets */
#define RRCP_DOWNLINK_PORT_OFFSET	4	/* 1 byte */
#define RRCP_UPLINK_PORT_OFFSET		5	/* 1 byte */
#define RRCP_UPLINK_MAC_OFFSET		6	/* 6 byte MAC address */
#define RRCP_CHIP_ID_OFFSET		12	/* 2 bytes */
#define RRCP_VENDOR_ID_OFFSET		14	/* 4 bytes */

static const struct tok proto_values[] = {
	{ 1, "RRCP" },
	{ 2, "RRCP-REP" },
	{ 0, NULL }
};

static const struct tok opcode_values[] = {
	{ 0, "hello" },
	{ 1, "get" },
	{ 2, "set" },
	{ 0, NULL }
};

/*
 * Print RRCP requests
 */
void
rrcp_print(netdissect_options *ndo,
	  const u_char *cp,
	  u_int length _U_,
	  const struct lladdr_info *src,
	  const struct lladdr_info *dst)
{
	uint8_t rrcp_proto;
	uint8_t rrcp_opcode;

	ndo->ndo_protocol = "rrcp";
	rrcp_proto = GET_U_1(cp + RRCP_PROTO_OFFSET);
	ND_TCHECK_1(cp + RRCP_OPCODE_ISREPLY_OFFSET);
	rrcp_opcode = GET_U_1((cp + RRCP_OPCODE_ISREPLY_OFFSET)) & RRCP_OPCODE_MASK;
	if (src != NULL && dst != NULL) {
		ND_PRINT("%s > %s, ",
			(src->addr_string)(ndo, src->addr),
			(dst->addr_string)(ndo, dst->addr));
	}
	ND_PRINT("%s %s",
		tok2str(proto_values,"RRCP-0x%02x",rrcp_proto),
		((GET_U_1(cp + RRCP_OPCODE_ISREPLY_OFFSET)) & RRCP_ISREPLY) ? "reply" : "query");
	if (rrcp_proto==1){
    	    ND_PRINT(": %s",
		     tok2str(opcode_values,"unknown opcode (0x%02x)",rrcp_opcode));
	}
	if (rrcp_opcode==1 || rrcp_opcode==2){
	    ND_TCHECK_6(cp + RRCP_REG_ADDR_OFFSET);
    	    ND_PRINT(" addr=0x%04x, data=0x%08x",
		     GET_LE_U_2(cp + RRCP_REG_ADDR_OFFSET),
		     GET_LE_U_4(cp + RRCP_REG_DATA_OFFSET));
	}
	if (rrcp_proto==1){
    	    ND_PRINT(", auth=0x%04x",
		  GET_BE_U_2(cp + RRCP_AUTHKEY_OFFSET));
	}
	if (rrcp_proto==1 && rrcp_opcode==0 &&
	     ((GET_U_1(cp + RRCP_OPCODE_ISREPLY_OFFSET)) & RRCP_ISREPLY)){
	    ND_PRINT(" downlink_port=%u, uplink_port=%u, uplink_mac=%s, vendor_id=%08x ,chip_id=%04x ",
		     GET_U_1(cp + RRCP_DOWNLINK_PORT_OFFSET),
		     GET_U_1(cp + RRCP_UPLINK_PORT_OFFSET),
		     GET_ETHERADDR_STRING(cp + RRCP_UPLINK_MAC_OFFSET),
		     GET_BE_U_4(cp + RRCP_VENDOR_ID_OFFSET),
		     GET_BE_U_2(cp + RRCP_CHIP_ID_OFFSET));
	}else if (rrcp_opcode==1 || rrcp_opcode==2 || rrcp_proto==2){
	    ND_PRINT(", cookie=0x%08x%08x ",
		    GET_BE_U_4(cp + RRCP_COOKIE2_OFFSET),
		    GET_BE_U_4(cp + RRCP_COOKIE1_OFFSET));
	}
	return;

trunc:
	nd_print_trunc(ndo);
}
