The L3VPN protocol implements RFC 4364 BGP/MPLS VPNs using MPLS backbone.
It works similarly to pipe. It connects IP table (one per VRF) with (global)
VPN table. Routes passed from VPN table to IP table are stripped of RD and
filtered by import targets, routes passed in the other direction are extended
with RD, MPLS labels and export targets in extended communities. A separate
MPLS channel is used to announce MPLS routes for the labels.
The new labeling policy MPLS_POLICY_VRF assigns one label to all routes
(from the same FEC map associated with one VRF), while replaces their
next hops with a lookup to a VRF table. This is useful for L3VPN
protocol.
When MPLS is active, received routes on MPLS-aware SAFIs (ipvX-mpls,
vpnX-mpls) are automatically labeled according to active label policy and
corresponding MPLS routes are automatically generated. Also routes sent
on MPLS-aware SAFIs announce local labels when it should be done.
When MPLS is active, static IP/VPN routes are automatically labeled
according to active label policy and corresponding MPLS routes are
automatically generated.
The MPLS subsystem manages MPLS labels and handles their allocation to
MPLS-aware routing protocols. These labels are then attached to IP or VPN
routes representing label switched paths -- LSPs.
There was already a preliminary MPLS support consisting of MPLS label
net_addr, MPLS routing tables with static MPLS routes, remote labels in
next hops, and kernel protocol support.
This patch adds the MPLS domain as a basic structure representing local
label space with dynamic label allocator and configurable label ranges.
To represent LSPs, allocated local labels can be attached as route
attributes to IP or VPN routes with local labels as attributes.
There are several steps for handling LSP routes in routing protocols --
deciding to which forwarding equivalence class (FEC) the LSP route
belongs, allocating labels for new FECs, announcing MPLS routes for new
FECs, attaching labels to LSP routes. The FEC map structure implements
basic code for managing FECs in routing protocols, therefore existing
protocols can be made MPLS-aware by adding FEC map and delegating
most work related to local label management to it.
In general, private_id is sparse and protocols may want to map some
internal values directly into it. For example, L3VPN needs to
map VPN route discriminators to private_id.
OTOH, u32 is enough for global_id, as these identifiers are dense.
Add a new protocol offering route aggregation.
User can specify list of route attributes in the configuration file and
run route aggregation on the export side of the pipe protocol. Routes are
sorted and for every group of equivalent routes new route is created and
exported to the routing table. It is also possible to specify filter
which will run for every route before aggregation.
Furthermore, it will be possible to set attributes of new routes
according to attributes of the aggregated routes.
This is a work in progress.
Original work by Igor Putovny, subsequent cleanups and finalization by
Maria Matejka.
Undefined paths and clists should use typed f_val with empty adata
instead of just void f_val. Use common initializer to handle both
variables and eattrs.
List of arguments for function calls is constructed in reverse and then
reverted. This was done in function_call grammar rule. Do the reverse
directly in var_list grammar rule. This fixes reverse order of arguments
in method calls.
- Extend method descriptors with type signature
- Daisy chain method descriptors for the same symbol
- Dispatch methods for same symbol based on type signature
- Split add/delete/filter operations to multiple methods
- Replace ad-hoc dispatch of old-style syntax with scope-based dispatch
- Also change method->arg_num to count initial arg
It still needs some improvements, like better handling of untyped
expressions and better error reporting when no dispatch can be done.
The multiple dispatch could also be extended to dispatch regular
function-like expressions in a uniform way.
Methods can now be called as x.m(y), as long as x can have its type
inferred in config time. If used as a command, it modifies the object,
if used as a value, it keeps the original object intact.
Also functions add(x,y), delete(x,y), filter(x,y) and prepend(x,y) now
spit a warning and are considered deprecated.
It's also possible to call a method on a constant, see filter/test.conf
for examples like bgp_path = +empty+.prepend(1).
Inside instruction definitions (filter/f-inst.c), a METHOD_CONSTRUCTOR()
call is added, which registers the instruction as a method for the type
of its first argument. Each type has its own method symbol table and
filter parser switches between them based on the inferred type of the
object calling the method.
Also FI_CLIST_(ADD|DELETE|FILTER) instructions have been split to allow
for this method dispatch. With type inference, it's now possible.
This is a backport cherry-pick of commits
165156beebcce974e8ea
from the v3.0 branch as we need symbol hashes directly inside their
scopes for more general usage than before.
According to RFC 5882, system should not interpret the local or remote
session state transition to AdminDown as failure. We followed that for
the local session state but not for the remote session state (which
just triggered a transition of the local state to Down). The patch
fixes that.
We do not properly generate AdminDown on our side, so the patch is
relevant just for interoperability with other systems.
Thanks to Sunnat Samadov for the bugreport.
Most syntactic constructs in BIRD configuration (e.g. protocol options)
are defined as keywords, which are distinct from symbols (user-defined
names for protocols, variables, ...). That may cause backwards
compatibility issue when a new feature is added, as it may collide with
existing user names.
We can allow keywords to be shadowed by symbols in almost all cases to
avoid this issue.
This replaces the previous mechanism, where shadowable symbols have to be
explictly added to kw_syms.
The previous approach (use VOID constant for variable initialization)
failed due to dynamic type check failure.
Thanks to Alexander Zubkov <green@qrator.net> for the bugreport.
