When Segment Routing is disabled, if isisd received LSP with Segment Routing
information, in particular prefix SIDs, it installs corresponding MPLS entries
while it should not as SR is disabled.
This patch adds extra control to verify if SR is enabled or not before
configuring MPLS LFIB & IP FIB with prefix SIDs and adjust SR & TI-LFA
tests accordingly.
Signed-off-by: Olivier Dugeon <olivier.dugeon@orange.com>
If ISIS is running on an IPv6 only topology, the command "spf interval"
has no effect.
Only the IPv4 SPF tree timers are taken into account.
Base the next SPF scheduling on the last running SPF tree.
Fixes: be985ba059 ("isisd: make use of advanced concepts like arrays and loops")
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>
Firstly, *keep no change* for `hash_get()` with NULL
`alloc_func`.
Only focus on cases with non-NULL `alloc_func` of
`hash_get()`.
Since `hash_get()` with non-NULL `alloc_func` parameter
shall not fail, just ignore the returned value of it.
The returned value must not be NULL.
So in this case, remove the unnecessary checking NULL
or not for the returned value and add `void` in front
of it.
Importantly, also *keep no change* for the two cases with
non-NULL `alloc_func` -
1) Use `assert(<returned_data> == <searching_data>)` to
ensure it is a created node, not a found node.
Refer to `isis_vertex_queue_insert()` of isisd, there
are many examples of this case in isid.
2) Use `<returned_data> != <searching_data>` to judge it
is a found node, then free <searching_data>.
Refer to `aspath_intern()` of bgpd, there are many
examples of this case in bgpd.
Here, <returned_data> is the returned value from `hash_get()`,
and <searching_data> is the data, which is to be put into
hash table.
Signed-off-by: anlan_cs <vic.lan@pica8.com>
FRR should only ever use the appropriate THREAD_ON/THREAD_OFF
semantics. This is espacially true for the functions we
end up calling the thread for.
Signed-off-by: Donatas Abraitis <donatas.abraitis@gmail.com>
There are two problems with the current code for processing the attached
bit:
- we should process it when acting both a level-1-only and level-1-2
- we should add the default route when we don't have L2 adjacensies, not
when we don't have other routers configured on the device
Signed-off-by: Igor Ryzhov <iryzhov@nfware.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>
Add support for read only mib objects from RFC4444.
Signed-off-by: Lynne Morrison <lynne@voltanet.io>
Signed-off-by: Karen Schoener <karen@voltanet.io>
When adjacencies change state the attached-bits in LSPs in other areas
on the router may need to be modified.
1. If a router no longer has a L2 adjacency to another area the
attached-bit must no longer be sent in the LSP
2. If a new L2 adjacency comes up in a different area then the
attached-bit should be sent in the LSP
Signed-off-by: Lynne Morrison <lynne@voltanet.io>
The purpose of the Attach-bit is to accomplish inter-area routing. In other
venders, the Attached-bit is automatically set when a router is configured
as a L1|L2 router and has two adjacencies. When a L1 router receives a LSP
with the Attached-bit set it is supposed to create a default route pointing
toward the neighbor to provide a default path out of the L1 area.
ISIS implementation has been fixed to support the above definition:
Setting the Attach-bit is now the default behavior and we allow the user to
turn it off.
We will only set the Default Attach-bit when creating a L1 LSP, if we are
a L1|L2 router and have a L2 adjacency up.
When a L1 router receives a LSP with the Attach-bit set, we will create a
default route pointing to the L1|L2 router as the nexthop.
The default route will be removed if the LSP is received with the Attach-bit
cleared.
Signed-off-by: Lynne Morrison <lynne@voltanet.io>
Currently the transition metric style is redundant because isis will
always read both reachability TLVs regardless of the configured
metric style. Correct this by only considering TLVs matching our
configuration.
Signed-off-by: Emanuele Di Pascale <emanuele@voltanet.io>
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>
Instead of storing the LSP associated to pseudonodes only, store the
LSP associated to all SPF adjacencies instead.
The upcoming LFA work will need to have that piece of information
for all SPF adjacencies in order to know which ones have the overload
bit set or not. Other use cases might arise in the future.
Signed-off-by: Renato Westphal <renato@opensourcerouting.org>
Rename "debug isis ti-lfa" to "debug isis lfa". Having different
debug guards for different kinds of LFA (classic, remote and TI-LFA)
doesn't make sense since all LFA solutions share code to certain
extent.
Signed-off-by: Renato Westphal <renato@opensourcerouting.org>
vertex->N is an union whose "id" and "ip" fields are only valid
depending on the vertex type (IS adjacency or IP reachability
information). As such, add a vertex type check before consulting
vertex->N.id in order to prevent unexpected behavior from happening.
Signed-off-by: Renato Westphal <renato@opensourcerouting.org>
When isis is being shutdown the area->spf_timer thread has
special data assigned to that was never being freed.
Free this data.
Signed-off-by: Donald Sharp <sharpd@nvidia.com>
isisd relies on its YANG module to prevent the same SID index
from being configured multiple times for different prefixes. It's
possible, however, to have different routers assigning the same SID
index for different prefixes. When that happens, we say we have a
Prefix-SID collision, which is ultimately a misconfiguration issue.
The problem with Prefix-SID collisions is that the Prefix-SID that
is processed later overwrites the previous ones. Then, once the
Prefix-SID collision is fixed in the configuration, the overwritten
Prefix-SID isn't reinstalled since it's already marked as installed
and it didn't change. To prevent such inconsistency from happening,
add a safeguard in the SPF code to detect Prefix-SID collisions and
handle them appropriately (i.e. log a warning + ignore the Prefix-SID
Sub-TLV since it's already in use by another prefix). That way,
once the configuration is fixed, no Prefix-SID label entry will be
missing in the LFIB.
Reported-by: Emanuele Di Pascale <emanuele@voltanet.io>
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>
This is preparatory change for the upcoming SR Prefix-SID
refactoring.
Since Prefix-SID information will be stored inside IS-IS routes
(instead of being maintained separately), it will be necessary to
have local routes in order to store local Prefix-SID information.
Signed-off-by: Renato Westphal <renato@opensourcerouting.org>
When both old and new-style TLVs exist for a particular prefix, give
precedence to the new-style TLV (like JUNOS does) when generating
routes from the SPT. This changes the current behavior which is to
generate a route for both TLVs, whereas the first is overwritten by
the second in a non-deterministic order (i.e. either the old-style
or the new-style TLV can "win" depending on how the SPF TENTative
list is arranged).
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>
RFC 7490 says:
"The reverse SPF computes the cost from each remote node to root. This
is achieved by running the normal SPF algorithm but using the link
cost in the direction from the next hop back towards root in place of
the link cost in the direction away from root towards the next hop".
Support for reverse SPF will be necessary later as it's one of the
algorithms used to compute R-LFA/TI-LFA repair paths.
Signed-off-by: Renato Westphal <renato@opensourcerouting.org>
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>
Introduce the "show isis route" command to display the routes
associated to an SPF tree. Different from the "show ip route" command,
"show isis route" displays the L1 and L2 routes separately (and not
the best routes only).
Signed-off-by: Renato Westphal <renato@opensourcerouting.org>
* Bring back some consts that were removed;
* Replace ALL_LIST_ELEMENTS by ALL_LIST_ELEMENTS_RO whenever
possible;
* Fix some CLI return values;
* Remove some unnecessary initializations.
Signed-off-by: Renato Westphal <renato@opensourcerouting.org>
This is mostly a cosmetic change to make the code more modular,
more elegant and easier to understand.
Signed-off-by: Renato Westphal <renato@opensourcerouting.org>
Always fill the buffer provided by the user to prevent unexpected
results and make the function fully reentrant.
Signed-off-by: Renato Westphal <renato@opensourcerouting.org>
1. Created a structure "isis master".
2. All the changes are related to handle ISIS with different vrf.
3. A new variable added in structure "isis" to store the vrf name.
4. The display commands for isis is changed to support different VRFs.
Signed-off-by: Kaushik <kaushik@niralnetworks.com>
Don't use the same starting time for all SPF trees otherwise the
results won't be accurate (they will accumulate instead of being
computed separately).
Signed-off-by: Renato Westphal <renato@opensourcerouting.org>
