Allow the nexthoplookup function to return the first nexthop found on
ifindex interface if the IP is unspecified.
Signed-off-by: Louis Scalbert <louis.scalbert@6wind.com>
When a adjacency falls down, the primary routes are not deleted on the
dataplane until the SPF is recomputed. Even the backup routes are
pre-installed on the dataplane, there is no fast-route optimization.
Reasons for an adjacency to come down are:
- BFD down
- Hello timer timeout
- User adjacency clear
Apply the backup route switchover for fast-reroute as soon an IS-IS
adjacency falls down before the first SPF re-computation. Pre-computed
backup routes are applied sooner.
Signed-off-by: Louis Scalbert <louis.scalbert@6wind.com>
- Add advertisement of Global IPv6 address in IIH pdu
- Add new CLI to set IPv6 Router ID
- Add advertisement of IPv6 Router ID
- Correctly advertise IPv6 local and neighbor addresses in Extended IS and MT
Reachability TLVs
- Correct output of Neighbor IPv6 address in 'show isis database detail'
- Manage IPv6 addresses advertisement and corresponiding Adjacency SID when
IS-IS is not using Multi-Topology by introducing a new ISIS_MT_DISABLE
value for mtid (== 4096 i.e. first reserved flag set to 1)
Signed-off-by: Olivier Dugeon <olivier.dugeon@orange.com>
Convert most DEFINE_MTYPE into the _STATIC variant, and move the
remaining non-static ones to appropriate places.
Signed-off-by: David Lamparter <equinox@diac24.net>
Remote LFA (RFC 7490) is an extension to the base LFA mechanism
that uses dynamically determined tunnels to extend the IP-FRR
protection coverage.
RLFA is similar to TI-LFA in that it computes a post-convergence
SPT (with the protected interface pruned from the network topology)
and the P/Q spaces based on that SPT. There are a few differences
however:
* RLFAs can push at most one label, so the P/Q spaces need to
intersect otherwise the destination can't be protected (the
protection coverage is topology dependent).
* isisd needs to interface with ldpd to obtain the labels it needs to
create a tunnel to the PQ node. That interaction needs to be done
asynchronously to prevent blocking the daemon for too long. With
TI-LFA all required labels are already available in the LSPDB.
RLFA and TI-LFA have more similarities than differences though,
and thanks to that both features share a lot of code.
Limitations:
* Only RLFA link protection is implemented. The algorithm used
to find node-protecting RLFAs (RFC 8102) is too CPU intensive and
doesn't always work. Most vendors implement RLFA link protection
only.
* RFC 7490 says it should be a local matter whether the repair path
selection policy favors LFA repairs over RLFA repairs. It might be
desirable, for instance, to prefer RLFAs that satisfy the downstream
condition over LFAs that don't. In this implementation, however,
RLFAs are only computed for destinations that can't be protected
by local LFAs.
Signed-off-by: Renato Westphal <renato@opensourcerouting.org>
Embed Prefix-SID information inside SPF data structures so that
Prefix-SIDs can be installed together with their associated routes
at the end of the SPF algorithm. This is different from the current
implementation where Prefix-SIDs are parsed and processed separately,
which is vastly suboptimal.
Advantages of the new code:
* No need to parse the LSPDB an additional time to detect and process
SR-related changes;
* Routes are installed with their Prefix-SID labels in the same ZAPI
message. This can prevent packet dropping for a few milliseconds
after each SPF run if there are BGP-labeled routes (e.g. L3VPN) that
recurse on IGP labeled routes;
* Much easier to support Anycast-SIDs, as the SPF code will naturally
figure out the best nexthops and use only them (that can't be done
in any reasonable way if the Prefix-SID Sub-TVLs are processed
separately);
* Less code to maintain and reduced memory footprint;
The "show isis segment-routing prefix-sids" command was removed as
it doesn't make sense anymore now that "show isis route" exists.
Prefix-SIDs are a property of routes, so what was done was to extend
the "show isis route" command with a new "prefix-sid" option that
changes the output table to show the Prefix-SID information associated
to each route.
Signed-off-by: Renato Westphal <renato@opensourcerouting.org>
TI-LFA is a modern fast-reroute (FRR) solution that leverages Segment
Routing to pre-compute backup nexthops for all destinations in the
network, helping to reduce traffic restoration times whenever a
failure occurs. The backup nexthops are expected to be installed
in the FIB so that they can be activated as soon as a failure
is detected, making sub-50ms recovery possible (assuming an
hierarchical FIB).
TI-LFA is a huge step forward compared to prior IP-FRR solutions,
like classic LFA and Remote LFA, as it guarantees 100% coverage
for all destinations. This is possible thanks to the source routing
capabilities of SR, which allows the backup nexthops to steer traffic
around the failures (using as many SIDs as necessary). In addition
to that, the repair paths always follow the post-convergence SPF
tree, which prevents transient congestions and suboptimal routing
from happening.
Deploying TI-LFA is very simple as it only requires a single
configuration command for each interface that needs to be protected
(both link protection and node protection are available). In addition
to IPv4 and IPv6 routes, SR Prefix-SIDs and Adj-SIDs are also
protected by the backup nexthops computed by the TI-LFA algorithms.
Signed-off-by: Renato Westphal <renato@opensourcerouting.org>
suppress route-event logs that are uninformative and add more info to
the ones that matter, i.e. hints on what changed in a route update. The
suppressed logs can be enabled by defining EXTREME_DEBUG to 1, similarly
to what is done elsewhere in isisd (e.g. in isis_spf.c)
Signed-off-by: Emanuele Di Pascale <emanuele@voltanet.io>
Now that the IS-IS SPF code is more modular, write some unit tests
for it.
This commit includes a new test program called "test_isis_spf" which
can load any test topology (there are 13 different ones available)
and run SPF on any desired node. In the future this same test program
and topologies will also be used to test reverse SPF and TI-LFA.
The "test_common.c" file contains helper functions used to parse the
topology descriptions from "test_topologies.c" into LSP databases
that can be used as an input to the SPF code.
This commit also introduces the F_ISIS_UNIT_TEST flag which is used
to prevent the IS-IS code from scheduling any event when running
under the context of an unit test.
Signed-off-by: Renato Westphal <renato@opensourcerouting.org>
The goal of modularizing the SPF code is to make it possible for
isisd to run SPF in the behalf of other nodes in the network, which
is going to be necessary later when implementing the R-LFA/TI-LFA
solutions. On top of that, a modularized SPF opens the door for
much needed unit testing.
Summary of the changes:
* Change the isis_spf_preload_tent() function to use the local LSP
as an input (as per the ISO specification) instead of populating
the TENT based on the list of local interfaces;
* Introduce the "isis_spf_adj" structure to represent an SPF
adjacency. SPF adjacencies are inferred from the LSPDB, different
from normal adjacencies formed using IIH messages;
* Introduce the F_SPFTREE_NO_ROUTES flag to control whether the
SPT should create routes or not;
* Introduce the F_SPFTREE_NO_ADJACENCIES flag to specify whether
IS-IS adjacency information is available or not. When running SPF
in the behalf of other nodes, or under the context of an unit test,
no adjacency information will be present.
* On isis_area_create(), move some code around so that the area's isis
backpointer is set as early as possible.
Signed-off-by: Renato Westphal <renato@opensourcerouting.org>
This is an implementation of the IS-IS SR draft [1] for FRR.
The following features are supported:
* IPv4 and IPv6 Prefix-SIDs;
* IPv4 and IPv6 Adj-SIDs and LAN-Adj-SIDs;
* Index and absolute labels;
* The no-php and explicit-null Prefix-SID flags;
* Full integration with the Label Manager.
Known limitations:
* No support for Anycast-SIDs;
* No support for the SID/Label Binding TLV (required for LDP interop).
* No support for persistent Adj-SIDs;
* No support for multiple SRGBs.
[1] draft-ietf-isis-segment-routing-extensions-25
Signed-off-by: Olivier Dugeon <olivier.dugeon@orange.com>
Signed-off-by: Renato Westphal <renato@opensourcerouting.org>
isisd implements an optimization that allows multiple routes to
share the same nexthop (using a refcount) in order to save memory.
Now that SR support is coming, however, it will be necessary to
embed additional SR-related information inside the isis_nexthop
structure. But this can only be done if the nexthops aren't shared
among routes anymore.
Removing this memory optimization should have minimal impact since
the isis_nexthop structure is really small. On large networks with
thousands of routes, the memory saving would be in the order of a
few kilobytes. Not something we should be concerned about nowadays.
Signed-off-by: Renato Westphal <renato@opensourcerouting.org>
This hook will be called whenever a route is added, updated or
deleted. It will be used, for instance, by the SR code to keep
Prefix-SIDs in sync with their associated routes.
Signed-off-by: Renato Westphal <renato@opensourcerouting.org>
For better modularity, isis_zebra.c should only contain code used
to communicate with zebra. The management of route flags belongs
to isis_route.c.
Signed-off-by: Renato Westphal <renato@opensourcerouting.org>
This unification allows us to write code that works for both IPv4 and
IPv6, reducing duplication.
Signed-off-by: Renato Westphal <renato@opensourcerouting.org>
These null checks don't make sense because a) these two functions
are never called with a NULL IP address and b) the same pointers are
dereferenced later without any protection. Remove these NULL checks
to make the code less confusing.
Signed-off-by: Renato Westphal <renato@opensourcerouting.org>
These fields were introduced by commit e38e0df01a, but they were
never put to any use. Remove them.
Signed-off-by: Renato Westphal <renato@opensourcerouting.org>
Historically, isisd has been carrying around its own red-black tree to
manage its LSP DB in. This replaces that with the newly-added
DECLARE_RBTREE_*. This allows completely removing the dict_* code.
Signed-off-by: David Lamparter <equinox@diac24.net>
This fixes multiple issues and inefficiencies regarding the usage of
route_tables in isis_route.c and removes some memory leaks.
Signed-off-by: Christian Franke <chris@opensourcerouting.org>
Take the source-prefix sub-TLV into consideration when running SPF
and support creation/deletion of dst-src routes as result.
Signed-off-by: Christian Franke <chris@opensourcerouting.org>
This addresses two issues for L1L2 operation:
a) If an L1 route has ROUTE_ACTIVE unset and an L2 route for the same
destination has ROUTE_ACTIVE set, isisd would still put the L1 route
into the merged table. This causes the route for the destination to
get uninstalled from zebra until the next SPF run, which is incorrect.
To fix this, look at the ROUTE_ACTIVE flag and allow L2 routes to win
against L1 routes, when the L1 has ROUTE_ACTIVE unset.
b) If an L1 route wins against an existing L2 route, the ZEBRA_SYNCED
flag would remain on the L2 route. This leads to the problem that when
the L1 route disappears again, the L2 doesn't get reinstalled, since
isisd assumes it's already in the RIB because ZEBRA_SYNCED is set.
Solve this by clearing ZEBRA_SYNCED on L2 routes, if they lose against
an L1 route.
Signed-off-by: Christian Franke <chris@opensourcerouting.org>
As isisd's route_tables are directly related to spf trees, move
the route tables into the spftree instead of maintaining them
alongside of the spftrees.
Signed-off-by: Christian Franke <chris@opensourcerouting.org>
The following types are nonstandard:
- u_char
- u_short
- u_int
- u_long
- u_int8_t
- u_int16_t
- u_int32_t
Replace them with the C99 standard types:
- uint8_t
- unsigned short
- unsigned int
- unsigned long
- uint8_t
- uint16_t
- uint32_t
Signed-off-by: Quentin Young <qlyoung@cumulusnetworks.com>
Convert the list_delete(struct list *) function to use
struct list **. This is to allow the list pointer to be nulled.
I keep running into uses of this list_delete function where we
forget to set the returned pointer to NULL and attempt to use
it and then experience a crash, usually after the developer
has long since left the building.
Let's make the api explicit in it setting the list pointer
to null.
Cynical Prediction: This code will expose a attempt
to use the NULL'ed list pointer in some obscure bit
of code.
Signed-off-by: Donald Sharp <sharpd@cumulusnetworks.com>
There is no point in building a multipath route via one neighbor
if there is only one link to the neighbor, but the neighbor has
multiple IPs on that link. So only create one nexthop per link.
Signed-off-by: Christian Franke <chris@opensourcerouting.org>
The FSF's address changed, and we had a mixture of comment styles for
the GPL file header. (The style with * at the beginning won out with
580 to 141 in existing files.)
Note: I've intentionally left intact other "variations" of the copyright
header, e.g. whether it says "Zebra", "Quagga", "FRR", or nothing.
Signed-off-by: David Lamparter <equinox@opensourcerouting.org>
