Add basic VRF (virtual routing and forwarding) support. Protocols can be
associated with VRFs, such protocols will be restricted to interfaces
assigned to the VRF (as reported by Linux kernel) and will use sockets
bound to the VRF. E.g., different multihop BGP instances can use diffent
kernel routing tables to handle BGP TCP connections.
The VRF support is preliminary, currently there are several limitations:
- Recent Linux kernels (4.11) do not handle correctly sockets bound
to interaces that are part of VRF, so most protocols other than multihop
BGP do not work. This will be fixed by future kernel versions.
- Neighbor cache ignores VRFs. Breaks config with the same prefix on
local interfaces in different VRFs. Not much problem as single hop
protocols do not work anyways.
- Olock code ignores VRFs. Breaks config with multiple BGP peers with the
same IP address in different VRFs.
- Incoming BGP connections are not dispatched according to VRFs.
Breaks config with multiple BGP peers with the same IP address in
different VRFs. Perhaps we would need some kernel API to read VRF of
incoming connection? Or probably use multiple listening sockets in
int-new branch.
- We should handle master VRF interface up/down events and perhaps
disable associated protocols when VRF goes down. Or at least disable
associated interfaces.
- Also we should check if the master iface is really VRF iface and
not some other kind of master iface.
- BFD session request dispatch should be aware of VRFs.
- Perhaps kernel protocol should read default kernel table ID from VRF
iface so it is not necessary to configure it.
- Perhaps we should have per-VRF default table.
Now the order is:
Up -> iface, addr, neigh
Down -> neigh, addr, iface
It fixes the case when an iface appears, related static routes are
activated and exported to OSPF before the iface notification and
therefore forwarding addresses are not encoded in generated external
LSAs.
Router ID could be automatically determined based of subset of
ifaces/addresses specified by 'router id from' option. The patch also
does some minor changes related to router ID reconfiguration.
Thanks to Alexander V. Chernikov for most of the work.
When device protocol goes down, interfaces should be flushed
asynchronously (in the same way like routes from protocols are flushed),
when protocol goes to DOWN/HUNGRY.
This fixes the problem with static routes staying in kernel routing
table after BIRD shutdown.
Allows to add more interface patterns to one common 'options'
section like:
interface "eth3", "eth4" { options common to eth3 and eth4 };
Also removes undocumented and unnecessary ability to specify
more interface patterns with different 'options' sections:
interface "eth3" { options ... }, "eth4" { options ... };
Please try compiling your code with --enable-warnings to see them. (The
unused parameter warnings are usually bogus, the unused variable ones
are very useful, but gcc is unable to control them separately.)
address, not per interface (hence it's ifa->flags & IA_UNNUMBERED) and
should be set reliably. IF_MULTIACCESS should be fixed now, but it isn't
wise to rely on it on interfaces configured with /30 prefix.
but the core routines are there and seem to be working.
o lib/ipv6.[ch] written
o Lexical analyser recognizes IPv6 addresses and when in IPv6
mode, treats pure IPv4 addresses as router IDs.
o Router ID must be configured manually on IPv6 systems.
o Added SCOPE_ORGANIZATION for org-scoped IPv6 multicasts.
o Fixed few places where ipa_(hton|ntoh) was called as a function
returning converted address.
o Parsing of interface patterns moved to generic code,
introduced this_ipatt which works similarly to this_iface.
o Interface patterns now support selection by both interface
names and primary IP addresses.
o Proto `direct' updated.
o RIP updated as well, it also seems the memory corruption
bug there is gone.
addresses per interface (needed for example for IPv6 support).
Visible changes:
o struct iface now contains a list of all interface addresses (represented
by struct ifa), iface->addr points to the primary address (if any).
o Interface has IF_UP set iff it's up and it has a primary address.
o IF_UP is now independent on IF_IGNORED (i.e., you need to test IF_IGNORED
in the protocols; I've added this, but please check).
o The if_notify_change hook has been simplified (only one interface pointer
etc.).
o Introduced a ifa_notify_change hook. (For now, only the Direct protocol
does use it -- it's wise to just listen to device routes in all other
protocols.)
o Removed IF_CHANGE_FLAGS notifier flag (it was meaningless anyway).
o Updated all the code except netlink (I'll look at it tomorrow) to match
the new semantics (please look at your code to ensure I did it right).
Things to fix:
o Netlink.
o Make krt-iface interpret "eth0:1"-type aliases as secondary addresses.
o Introduced if_find_by_index()
o Recognizing two types of interface updates: full update (starting with
if_start_update(), ending with if_end_update(), guaranteed to see
all existing interfaces) and a partial update (only if_update(),
usually due to asynchronous interface notifications).
o Introduced IF_LINK_UP flag corresponding to real link state.
o Allowed addressless interfaces.
o IF_UP is now automatically calculated and set iff the interface
is administratively up, has link up and has an IP address assigned.
It may be IF_IGNORED, though (as in case of the loopback).
o Any changes which include up/down transition are considered small
enough to not provoke artificial upping and downing of the interface.
o When an interface disappears (i.e., it wasn't seen in the last scan),
we announce this change only once.
o IF_LOOPBACK implies IF_IGNORE.
