# brintOS wasm32-hwjs: the router-advertisement configuration radvd reads at
# startup, and the subject of `radvd -c -C /etc/radvd.conf'.
#
# UPSTREAM SHIPS THIS FILE ENTIRELY COMMENTED OUT, AND radvd ITSELF REJECTS THAT.
# meta-networking's radvd/files/radvd.conf is a worked example with every line
# commented, so readin_config() parses it, builds no interface and returns a NULL
# IfaceList -- which radvd.c reads as `exiting, failed to read config file' and
# exits 1. A stock image therefore has NO configuration that `radvd -c' accepts,
# and the criterion this port was taken on has no subject at all. This file is
# one radvd accepts, so that the configuration path can be exercised.
#
# IT NAMES `lo' BECAUSE THAT IS THE ONLY INTERFACE THIS IMAGE HAS. Nothing here
# depends on that: the config parser never resolves an interface name (gram.y's
# ifacehead only checks for a duplicate), and IgnoreIfMissing defaults on, so a
# name that is not there is tolerated rather than fatal. Naming the one interface
# that does exist keeps the file honest about the machine it ships to.
#
# NOTHING IS EVER ADVERTISED FROM IT ON THIS IMAGE. radvd opens
# socket(AF_INET6, SOCK_RAW, IPPROTO_ICMPV6) immediately after reading this file
# and exits when that fails; this kernel is built `# CONFIG_IPV6 is not set'
# (brintos/linux#54), so the address family does not exist. That is the platform
# and not the configuration -- see 88-radvd.test, which scores the two apart.
#
# EVERY VALUE BELOW IS DELIBERATELY NON-DEFAULT, against defaults.h. A suite that
# asserts a configured value against a value radvd would have defaulted to proves
# nothing, so each number here differs from what radvd would have chosen: the
# DFLT_ macro it displaces is named in the comment beside it.

interface lo
{
	# Off by default (DFLT_AdvSendAdv 0). Without it radvd holds the
	# interface but sends nothing, so it is the flag that makes this a
	# router-advertisement configuration rather than an inert one.
	AdvSendAdvert on;

	# DFLT_MaxRtrAdvInterval 600; DFLT_MinRtrAdvInterval is 0.33 * Max,
	# i.e. 39.6 s against the 120/30 set here.
	MaxRtrAdvInterval 120;
	MinRtrAdvInterval 30;

	# DFLT_AdvDefaultLifetime is 3 * MaxRtrAdvInterval = 360 s here, so 300
	# is a value only this file can have set.
	AdvDefaultLifetime 300;

	# Both default off (DFLT_AdvManagedFlag / DFLT_AdvOtherConfigFlag 0).
	# Together they say "address and other configuration come from DHCPv6",
	# which is a coherent thing to advertise beside an on-link prefix.
	AdvManagedFlag on;
	AdvOtherConfigFlag on;

	# DFLT_AdvLinkMTU 0 (advertise no MTU option); 1280 is the IPv6 minimum
	# link MTU, so advertising it is meaningful as well as non-default.
	AdvLinkMTU 1280;

	# DFLT_AdvCurHopLimit is the kernel's default hop limit, 64.
	AdvCurHopLimit 48;

	# RFC 3849 reserves 2001:db8::/32 for documentation, so this prefix can
	# never collide with a real network a machine of ours is attached to.
	prefix 2001:db8:d5f0:1::/64
	{
		# Defaults on (DFLT_AdvOnLinkFlag / DFLT_AdvAutonomousFlag 1).
		# Set explicitly because they are two of the three flags the
		# prefix option carries and a configuration that leaves them
		# implicit says nothing about them.
		AdvOnLink on;
		AdvAutonomous on;

		# DFLT_AdvRouterAddr is off: with it on the prefix option
		# carries this router's full address rather than the prefix
		# alone, which is what Mobile IPv6 home agents look for.
		AdvRouterAddr on;

		# DFLT_AdvValidLifetime 86400, DFLT_AdvPreferredLifetime 14400.
		# Valid must exceed preferred -- gram.y rejects the file at
		# parse time otherwise, which is the check 88-radvd.test uses to
		# establish that BOTH numbers reached the parser by value.
		AdvValidLifetime 7200;
		AdvPreferredLifetime 3600;
	};
};