/*
 * Copyright (C) 1998 and 1999 WIDE Project.
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. Neither the name of the project 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 BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 */
/*
 * draft-ietf-dhc-dhcpv6-26.txt
 */

#ifndef lint
static const char rcsid[] =
    "@(#) $Header: /tcpdump/master/tcpdump/print-dhcp6.c,v 1.20 2002-06-15 02:49:54 itojun Exp $";
#endif

#ifdef HAVE_CONFIG_H
#include "config.h"
#endif

#include <sys/param.h>
#include <sys/time.h>
#include <sys/socket.h>

#include <netinet/in.h>

#include <ctype.h>
#include <stdio.h>
#include <string.h>
#include <arpa/inet.h>

#include "interface.h"
#include "addrtoname.h"

/* lease duration */
#define DHCP6_DURATITION_INFINITE 0xffffffff

/* Error Values */
#define DH6ERR_FAILURE		16
#define DH6ERR_AUTHFAIL		17
#define DH6ERR_POORLYFORMED	18
#define DH6ERR_UNAVAIL		19
#define DH6ERR_OPTUNAVAIL	20

/* Message type */
#define DH6_SOLICIT	1
#define DH6_ADVERTISE	2
#define DH6_REQUEST	3
#define DH6_CONFIRM	4
#define DH6_RENEW	5
#define DH6_REBIND	6
#define DH6_REPLY	7
#define DH6_INFORM_REQ	11

/* DHCP6 base packet format */
struct dhcp6 {
	union {
		u_int8_t m;
		u_int32_t x;
	} dh6_msgtypexid;
	/* options follow */
} __attribute__ ((__packed__));
#define dh6_msgtype	dh6_msgtypexid.m
#define dh6_xid		dh6_msgtypexid.x
#define DH6_XIDMASK	0x00ffffff

/* option */
#define DH6OPT_CLIENTID	1
#define DH6OPT_SERVERID	2
#define DH6OPT_IA 3
#define DH6OPT_IA_TMP 4
#define DH6OPT_IADDR 5
#define DH6OPT_ORO 6
#define DH6OPT_PREFERENCE 7
#  define DH6OPT_PREF_UNDEF -1
#  define DH6OPT_PREF_MAX 255
#define DH6OPT_ELAPSED_TIME 8
#define DH6OPT_CLIENT_MSG 9
#define DH6OPT_SERVER_MSG 10
#define DH6OPT_AUTH 11
#define DH6OPT_UNICAST 12
#define DH6OPT_STATUS_CODE 13
#  define DH6OPT_STCODE_SUCCESS 0
#  define DH6OPT_STCODE_UNSPECFAIL 1
#  define DH6OPT_STCODE_AUTHFAILED 2
#  define DH6OPT_STCODE_ADDRUNAVAIL 3
#  define DH6OPT_STCODE_NOADDRAVAIL 4
#  define DH6OPT_STCODE_NOBINDING 5
#  define DH6OPT_STCODE_CONFNOMATCH 6
#  define DH6OPT_STCODE_NOTONLINK 7
#  define DH6OPT_STCODE_USEMULTICAST 8
#define DH6OPT_RAPID_COMMIT 14
#define DH6OPT_USER_CLASS 15
#define DH6OPT_VENDOR_CLASS 16
#define DH6OPT_VENDOR_OPTS 17
#define DH6OPT_INTERFACE_ID 18
#define DH6OPT_RECONF_MSG 19

/*
 * The option type has not been assigned for the following options.
 * We temporarily adopt values used in the service specification document
 * (200206xx version) by NTT Communications.
 * Note that we'll change the following definitions if different type values
 * are officially assigned.
 */
#define DH6OPT_DNS 25
#define DH6OPT_PREFIX_DELEGATION 30
#define DH6OPT_PREFIX_INFORMATION 31
#define DH6OPT_PREFIX_REQUEST 32

struct dhcp6opt {
	u_int16_t dh6opt_type;
	u_int16_t dh6opt_len;
	/* type-dependent data follows */
} __attribute__ ((__packed__));

static char *
dhcp6opt_name(int type)
{
	static char genstr[sizeof("opt_65535") + 1]; /* XXX thread unsafe */

	if (type > 65535)
		return "INVALID option";

	switch(type) {
	case DH6OPT_CLIENTID:
		return "client ID";
	case DH6OPT_SERVERID:
		return "server ID";
	case DH6OPT_ORO:
		return "option request";
	case DH6OPT_PREFERENCE:
		return "preference";
	case DH6OPT_STATUS_CODE:
		return "status code";
	case DH6OPT_RAPID_COMMIT:
		return "rapid commit";
	case DH6OPT_DNS:
		return "DNS";
	case DH6OPT_PREFIX_DELEGATION:
		return "prefix delegation";
	case DH6OPT_PREFIX_INFORMATION:
		return "prefix information";
	default:
		sprintf(genstr, "opt_%d", type);
		return(genstr);
	}
}

static char *
dhcp6stcode(int code)
{
	static char genstr[sizeof("code255") + 1]; /* XXX thread unsafe */

	if (code > 255)
		return "INVALID code";

	switch(code) {
	case DH6OPT_STCODE_SUCCESS:
		return "success";
	case DH6OPT_STCODE_UNSPECFAIL:
		return "unspec failure";
	case DH6OPT_STCODE_AUTHFAILED:
		return "auth fail";
	case DH6OPT_STCODE_ADDRUNAVAIL:
		return "address unavailable";
	case DH6OPT_STCODE_NOADDRAVAIL:
		return "no addresses";
	case DH6OPT_STCODE_NOBINDING:
		return "no binding";
	case DH6OPT_STCODE_CONFNOMATCH:
		return "confirm no match";
	case DH6OPT_STCODE_NOTONLINK:
		return "not on-link";
	case DH6OPT_STCODE_USEMULTICAST:
		return "use multicast";
	default:
		sprintf(genstr, "code%d", code);
		return(genstr);
	}
}

static void
dhcp6opt_print(u_char *cp, u_char *ep)
{
	struct dhcp6opt *dh6o;
	u_char *tp;
	int i, opttype;
	size_t optlen;
	u_int16_t val16;
	u_int32_t val32;
	struct in6_addr addr6;

	if (cp == ep)
		return;
	while (cp < ep) {
		if (ep - cp < sizeof(*dh6o))
			goto trunc;
		dh6o = (struct dhcp6opt *)cp;
		optlen = ntohs(dh6o->dh6opt_len);
		if (ep - cp < sizeof(*dh6o) + optlen)
			goto trunc;
		opttype = ntohs(dh6o->dh6opt_type);
		printf(" (%s", dhcp6opt_name(opttype));
		switch (opttype) {
		case DH6OPT_CLIENTID:
		case DH6OPT_SERVERID:
			if (optlen < 2) {
				/*(*/
				printf(" ?)");
				break;
			}
			tp = (u_char *)(dh6o + 1);
			switch (ntohs(*(u_int16_t *)tp)) {
			case 1:
				if (optlen >= 2 + 6) {
					printf(" hwaddr/time type %u time %u ",
					    ntohs(*(u_int16_t *)&tp[2]),
					    ntohl(*(u_int32_t *)&tp[4]));
					for (i = 8; i < optlen; i++)
						printf("%02x", tp[i]);
					/*(*/
					printf(")");
				} else {
					/*(*/
					printf(" ?)");
				}
				break;
			case 2:
				if (optlen >= 2 + 8) {
					printf(" vid ");
					for (i = 2; i < 2 + 8; i++)
						printf("%02x", tp[i]);
					/*(*/
					printf(")");
				} else {
					/*(*/
					printf(" ?)");
				}
				break;
			case 3:
				if (optlen >= 2 + 2) {
					printf(" hwaddr type %u ",
					    ntohs(*(u_int16_t *)&tp[2]));
					for (i = 4; i < optlen; i++)
						printf("%02x", tp[i]);
					/*(*/
					printf(")");
				} else {
					/*(*/
					printf(" ?)");
				}
				break;
			default:
				printf(" type %d)", ntohs(*(u_int16_t *)tp));
				break;
			}
			break;
		case DH6OPT_ORO:
			if (optlen % 2) {
				printf(" ?)");
				break;
			}
			tp = (u_char *)(dh6o + 1);
			for (i = 0; i < optlen; i += 2) {
				u_int16_t opt;

				memcpy(&opt, &tp[i], sizeof(opt));
				printf(" %s", dhcp6opt_name(ntohs(opt)));
			}
			printf(")");
			break;
		case DH6OPT_PREFERENCE:
			if (optlen != 1) {
				printf(" ?)");
				break;
			}
			printf(" %d)", *((u_char *)(dh6o + 1) + 1));
			break;
		case DH6OPT_RAPID_COMMIT: /* nothing todo */
			printf(")");
			break;
		case DH6OPT_DNS:
			if (optlen % 16) {
				printf(" ?)");
				break;
			}
			tp = (u_char *)(dh6o + 1);
			for (i = 0; i < optlen; i += 16)
				printf(" %s", ip6addr_string(&tp[i]));
			printf(")");
			break;
		case DH6OPT_PREFIX_DELEGATION:
			dhcp6opt_print((u_char *)(dh6o + 1),
			    (u_char *)(dh6o + 1) + optlen);
			printf(")");
			break;
		case DH6OPT_PREFIX_INFORMATION:
			if (optlen % 21)
				printf(" ?)");
			memcpy(&addr6, (u_char *)(dh6o + 1) + 5,
			    sizeof(addr6));
			printf(" %s/%d", ip6addr_string(&addr6),
			    (int)*((u_char *)(dh6o + 1) + 4));
			memcpy(&val32, dh6o + 1, sizeof(val32));
			val32 = ntohl(val32);
			if (val32 == DHCP6_DURATITION_INFINITE)
				printf(" lease-duration: infinite)");
			else
				printf(" lease-duration: %u)", val32);
			break;
		case DH6OPT_STATUS_CODE:
			if (optlen < 2)
				printf(" ?)");
			memcpy(&val16, (u_char *)(dh6o + 1), sizeof(val16));
			val16 = ntohs(val16);
			printf(" %s)", dhcp6stcode(val16));
			break;
		default:
			printf(")", ntohs(dh6o->dh6opt_type));
			break;
		}

		cp += sizeof(*dh6o) + optlen;
	}
	return;

trunc:
	printf("[|dhcp6ext]");
}

/*
 * Print dhcp6 packets
 */
void
dhcp6_print(register const u_char *cp, u_int length,
	    u_int16_t sport, u_int16_t dport)
{
	struct dhcp6 *dh6;
	u_char *ep;
	u_char *extp;
	const char *name;

	printf("dhcp6");

	ep = (u_char *)snapend;

	dh6 = (struct dhcp6 *)cp;
	TCHECK(dh6->dh6_xid);
	switch (dh6->dh6_msgtype) {
	case DH6_SOLICIT:
		name = "solicit";
		break;
	case DH6_ADVERTISE:
		name = "advertise";
		break;
	case DH6_REQUEST:
		name = "request";
		break;
	case DH6_CONFIRM:
		name = "confirm";
		break;
	case DH6_RENEW:
		name = "renew";
		break;
	case DH6_REBIND:
		name = "rebind";
		break;
	case DH6_REPLY:
		name = "reply";
		break;
	case DH6_INFORM_REQ:
		name= "inf-req";
		break;
	default:
		name = NULL;
		break;
	}

	if (!vflag) {
		if (name)
			printf(" %s", name);
		else
			printf(" msgtype-%u", dh6->dh6_msgtype);
		return;
	}

	/* XXX relay agent messages have to be handled differently */

	if (name)
		printf(" %s (", name);	/*)*/
	else
		printf(" msgtype-%u (", dh6->dh6_msgtype);	/*)*/
	printf("xid=%x", ntohl(dh6->dh6_xid) & DH6_XIDMASK);
	extp = (u_char *)(dh6 + 1);
	dhcp6opt_print(extp, ep);
	/*(*/
	printf(")");
	return;

trunc:
	printf("[|dhcp6]");
}