Select the IPv6 source address and corresponding router (if any) using
a very simplified version of the algorithm from RFC6724:
- Ignore any source address that has a smaller scope than the
destination address. For example, do not use a link-local source
address when sending to a global destination address.
- If we have a source address which is on the same link as the
destination address, then use that source address.
- If we are left with multiple possible source addresses, then choose
the address with the smallest scope. For example, if we are sending
to a site-local destination address and we have both a global source
address and a site-local source address, then use the site-local
source address.
- If we are still left with multiple possible source addresses, then
choose the address with the longest matching prefix.
For the purposes of this algorithm, we treat RFC4193 Unique Local
Addresses as having organisation-local scope. Since we use only
link-local scope for our multicast transmissions, this approximation
should remain valid in all practical situations.
Originally-implemented-by: Thomas Bächler <thomas@archlinux.org>
Signed-off-by: Michael Brown <mcb30@ipxe.org>
[ipv6] Create routing table based on IPv6 settings
Use the IPv6 settings to construct the routing table, in a matter
analogous to the construction of the IPv4 routing table.
This allows for manual assignment of IPv6 addresses via e.g.
set net0/ip6 2001:ba8:0:1d4::6950:5845
set net0/len6 64
set net0/gateway6 fe80::226:bff:fedd:d3c0
The prefix length ("len6") may be omitted, in which case a default
prefix length of 64 will be assumed.
Multiple IPv6 addresses may be assigned manually by implicitly
creating child settings blocks. For example:
set net0/ip6 2001:ba8:0:1d4::6950:5845
set net0.ula/ip6 fda4:2496:e992::6950:5845
Signed-off-by: Michael Brown <mcb30@ipxe.org>
[ipv6] Match user expectations for IPv6 settings priorities
A reasonable user expectation is that ${net0/ip6} should show the
"highest-priority" of the IPv6 addresses, even when multiple IPv6
addresses are active. The expected order of priority is likely to be
manually-assigned addresses first, then stateful DHCPv6 addresses,
then SLAAC addresses, and lastly link-local addresses.
Using ${priority} to enforce an ordering is undesirable since that
would affect the priority assigned to each of the net<N> blocks as a
whole, so use the sibling ordering capability instead.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
Originally-implemented-by: Hannes Reinecke <hare@suse.de>
Originally-implemented-by: Marin Hannache <git@mareo.fr>
Signed-off-by: Michael Brown <mcb30@ipxe.org>
[settings] Allow for IPv6 setting types in non-IPv6 builds
Allow for the existence of references to IPv6 setting types without
dragging in the whole IPv6 stack, by placing the definition of
setting_type_ipv6 in core/settings.c and providing weak stub methods
for parse_ipv6_setting() and format_ipv6_setting().
Signed-off-by: Michael Brown <mcb30@ipxe.org>
[ipv6] Separate the concepts of prefix and address creation
Allow for IPv6 routing table entries to be created for an on-link
prefix where a local address has not yet been assigned to the network
device.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
Replace the existing partially-implemented IPv6 stack with a fresh
implementation.
This implementation is not yet complete. The IPv6 transmit and
receive datapaths are functional (including fragment reassembly and
parsing of arbitrary extension headers). NDP neighbour solicitations
and advertisements are supported. ICMPv6 echo is supported.
At present, only link-local addresses may be used, and there is no way
to specify an IPv6 address as part of a URI (either directly or via
a DNS lookup).
Signed-off-by: Michael Brown <mcb30@ipxe.org>
Michael Brown