/**
 * Copyright (C) 2012-2013 Steven Barth <steven@midlink.org>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License v2 as published by
 * the Free Software Foundation.
 *
 * 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.
 *
 */

#ifndef _ROUTER_H_
#define _ROUTER_H_

#include <stdint.h>
#include <netinet/in.h>
#include <netinet/icmp6.h>

struct icmpv6_opt {
	uint8_t type;
	uint8_t len;
	uint8_t data[6];
};


#define icmpv6_for_each_option(opt, start, end)\
	for (opt = (struct icmpv6_opt*)(start);\
	(void*)(opt + 1) <= (void*)(end) && opt->len > 0 &&\
	(void*)(opt + opt->len) <= (void*)(end); opt += opt->len)


#define MaxInitialRtrAdvInterval	16
#define MaxInitialRtAdvs		3
/* RFC8319 §4
 * This document updates §4.2 and 6.2.1 of [RFC4861] to change
 * the following router configuration variables.
 *
 * In §6.2.1, inside the paragraph that defines
 * MaxRtrAdvInterval, change 1800 to 65535 seconds.
 *
 * In §6.2.1, inside the paragraph that defines
 * AdvDefaultLifetime, change 9000 to 65535 seconds.
 */
#define MaxRtrAdvInterval				65535
#define MinRtrAdvInterval				3
#define AdvDefaultLifetime				65535
/* RFC8319 §4
 * This document updates §4.2 and 6.2.1 of [RFC4861] to change
 * the following router configuration variables.
 *
 * In §4.2, inside the paragraph that defines Router Lifetime,
 * change 9000 to 65535 seconds.
 *
 * Note: this is 16 bit Router Lifetime field in RA packets
 */
/* RFC9096 defines recommended option lifetimes configuration values
 * ND_PREFERRED_LIMIT 2700
 * ND_VALID_LIMIT 5400
 *
 * RFC9096 §3.4
 * CE routers SHOULD set the "Router Lifetime" of Router Advertisement
 * (RA) messages to ND_PREFERRED_LIMIT.
 *
 * Note: while the RFC recommends SHOULD of ND_PREFERRED_LIMIT, this
 * define is used to cap values to a sane ceiling, i.e. ND_VALID_LIMIT.
 */
#define RouterLifetime					5400
/* RFC4861 §6.2.1 : AdvReachableTime :
 * MUST be no greater than 3,600,000 msec
 */
#define AdvReachableTime				3600000
/* RFC4861 §6.2.1 : AdvCurHopLimit
 * The value should be set to the current
 * diameter of the Internet. The value zero means
 * unspecified (by this router).
 *
 * Note: this value is an 8 bit int, so max 255.
 */
#define AdvCurHopLimit					255
/* RFC4861 §10 - constants
 * Node constants:
 *     RETRANS_TIMER 1,000 milliseconds
 */
#define RETRANS_TIMER_MAX				60000
/* RFC2460 §5
 * IPv6 requires that every link in the internet have an MTU of 1280
 * octets or greater.
 */
#define RA_MTU_MIN						1280
#define RA_MTU_MAX						65535

#define ND_RA_FLAG_PROXY		0x4
#define ND_RA_PREF_HIGH			(1 << 3)
#define ND_RA_PREF_LOW			(3 << 3)

/* RFC9762 DHCPv6 PD Availability - Preferred Flag
 * use this until it is defined in netinet/icmp6.h
 */
#define ND_OPT_PI_FLAG_PD_PREFERRED		0x10

#endif /* _ROUTER_H_ */