IPv6 routes currently lack nexthop flags as in IPv4. This has several
implications.

In the forwarding path, it requires us to check the carrier state of the
nexthop device and potentially ignore a linkdown route, instead of
checking for RTNH_F_LINKDOWN.

It also requires capable drivers to use the user facing IPv6-specific
route flags to provide offload indication, instead of using the nexthop
flags as in IPv4.

Add nexthop flags to IPv6 routes in the 40 bytes hole and use it to
provide offload indication instead of the RTF_OFFLOAD flag, which is
removed while it's still not part of any official kernel release.

In the near future we would like to use the field for the
RTNH_F_{LINKDOWN,DEAD} flags, but this change is more involved and might
not be ready in time for the current cycle.
Signed-off-by: NIdo Schimmel <idosch@mellanox.com>
Signed-off-by: NJiri Pirko <jiri@mellanox.com>
Acked-by: NDavid Ahern <dsahern@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Due to limited ASIC resources the maximum number of routes is limited by
the nexthop resource. In order to improve the routing scale nexthop
consolidation should be performed.

This patch adds support for IPv6 neighbor consolidation. The hash value
is calculated based on the nexthop set, by performing bitwise xor on the
ifindexs of the nexthops, in a similar way to IPv4's kernel implementation.
In case of collision a full match is performed between the sets which
include address and ifindex comparison.

Non gateway nexthop groups are not inserted to the hash table due to
lack of nexthop device (ifindex).
Signed-off-by: NArkadi Sharshevsky <arkadis@mellanox.com>
Reviewed-by: NIdo Schimmel <idosch@mellanox.com>
Signed-off-by: NJiri Pirko <jiri@mellanox.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This patch does preparation before introducing IPv6 nexthop group
consolidation. Currently the nexthop group hash table is used only by
IPv4 and uses fixed key size. In order to support the IPv6's variable
length key the current table is changed.
Signed-off-by: NArkadi Sharshevsky <arkadis@mellanox.com>
Reviewed-by: NIdo Schimmel <idosch@mellanox.com>
Signed-off-by: NJiri Pirko <jiri@mellanox.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The number of LPM trees available for lookup is much smaller than the
number of virtual routers, which are used to implement VRFs. In
addition, an LPM tree can only be used by one protocol - either IPv4 or
IPv6.

Therefore, in order to increase the number of supported virtual routers
to the maximum we need to be able to share LPM trees across virtual
routers instead of trying to find an optimized tree for each.

Do that by allocating one LPM tree for each protocol, but make sure it
will only include prefixes that are actually used, so as to not perform
unnecessary lookups.

Since changing the structure of a bound tree isn't recommended, whenever
a new tree it required, it's first created and then bound to each
virtual router, replacing the old one.
Signed-off-by: NIdo Schimmel <idosch@mellanox.com>
Signed-off-by: NJiri Pirko <jiri@mellanox.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Instead of relying on the LPM tree to be assigned to the virtual router
before binding the two, lets pass it explicitly.

This will later allow us to return upon binding error instead of having
to perform a rollback of the assignment.
Signed-off-by: NIdo Schimmel <idosch@mellanox.com>
Signed-off-by: NJiri Pirko <jiri@mellanox.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

There is no point in returning a value from function whose return value
is never checked.

Even if the return value was checked, there wouldn't be anything to do
about it, as these functions are either called from error or deletion
paths.
Signed-off-by: NIdo Schimmel <idosch@mellanox.com>
Signed-off-by: NJiri Pirko <jiri@mellanox.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

We now have all the necessary IPv6 infrastructure in place, so stop
ignoring these notifications.
Signed-off-by: NIdo Schimmel <idosch@mellanox.com>
Signed-off-by: NJiri Pirko <jiri@mellanox.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Without resorting to ACLs, the device performs route lookup solely based
on the destination IP address.

In case source-specific routing is needed, an error is returned and the
abort mechanism is activated, thus allowing the kernel to take over
forwarding decisions.

Instead of aborting, we can trap specific destination prefixes where
source-specific routes are present, but this will result in a lot more
code that is unlikely to ever be used.
Signed-off-by: NIdo Schimmel <idosch@mellanox.com>
Signed-off-by: NJiri Pirko <jiri@mellanox.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

In case we got a replace event, then the replaced route must exist. If
the route isn't capable of multipath, then replace first matching
non-multipath capable route.

If the route is capable of multipath and matching multipath capable
route is found, then replace it. Otherwise, replace first matching
non-multipath capable route.

The new route is inserted before the replaced one. In case the replaced
route is currently offloaded, then it's overwritten in the device's table
by the new route and later deleted, thus not impacting routed traffic.
Signed-off-by: NIdo Schimmel <idosch@mellanox.com>
Signed-off-by: NJiri Pirko <jiri@mellanox.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Allow directly connected and remote unicast IPv6 routes to be programmed
to the device's tables.

As with IPv4, identical routes - sharing the same destination prefix -
are ordered in a FIB node according to their table ID and then the
metric. While the kernel doesn't share the same trie for the local and
main table, this does happen in the device, so ordering according to
table ID is needed.

Since individual nexthops can be added and deleted in IPv6, each FIB
entry stores a linked list of the rt6_info structs it represents. Upon
the addition or deletion of a nexthop, a new nexthop group is allocated
according to the new configuration and the old one is destroyed.
Identical groups aren't currently consolidated, but will be in a
follow-up patchset.
Signed-off-by: NIdo Schimmel <idosch@mellanox.com>
Signed-off-by: NJiri Pirko <jiri@mellanox.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

We only allow FIB offload in the presence of default rules or an l3mdev
rule. In a similar fashion to IPv4 FIB rules, sanitize IPv6 rules.
Signed-off-by: NIdo Schimmel <idosch@mellanox.com>
Signed-off-by: NJiri Pirko <jiri@mellanox.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The FIB notification block currently only handles IPv4 events, but we
want to start handling IPv6 events soon, so lay the groundwork now.

Do that by preparing the work item and process it according to the
notified address family.
Signed-off-by: NIdo Schimmel <idosch@mellanox.com>
Signed-off-by: NJiri Pirko <jiri@mellanox.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

We're about to add IPv6 notifications in the FIB notification chain, but
the driver currently doesn't support these, so ignore them.
Signed-off-by: NIdo Schimmel <idosch@mellanox.com>
Signed-off-by: NJiri Pirko <jiri@mellanox.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The FIB notification chain is currently soley used by IPv4 code.
However, we're going to introduce IPv6 FIB offload support, which
requires these notification as well.

As explained in commit c3852ef7 ("ipv4: fib: Replay events when
registering FIB notifier"), upon registration to the chain, the callee
receives a full dump of the FIB tables and rules by traversing all the
net namespaces. The integrity of the dump is ensured by a per-namespace
sequence counter that is incremented whenever a change to the tables or
rules occurs.

In order to allow more address families to use the chain, each family is
expected to register its fib_notifier_ops in its pernet init. These
operations allow the common code to read the family's sequence counter
as well as dump its tables and rules in the given net namespace.

Additionally, a 'family' parameter is added to sent notifications, so
that listeners could distinguish between the different families.

Implement the common code that allows listeners to register to the chain
and for address families to register their fib_notifier_ops. Subsequent
patches will implement these operations in IPv6.

In the future, ipmr and ip6mr will be extended to provide these
notifications as well.
Signed-off-by: NIdo Schimmel <idosch@mellanox.com>
Signed-off-by: NJiri Pirko <jiri@mellanox.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Now that we provide offload indication using the nexthop's flags we must
refresh the offload indication whenever the offload state within the
group changes.

This didn't matter until now, as offload indication was provided using
the FIB info flags and multipath routes were marked as offloaded as long
as one of the nexthops was offloaded.
Signed-off-by: NIdo Schimmel <idosch@mellanox.com>
Signed-off-by: NJiri Pirko <jiri@mellanox.com>
Tested-by: NDavid Ahern <dsahern@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Previous patch removed the reliance on the counter in the FIB info to
set the offload indication, so we no longer need to keep an offload
state on each FIB entry and can just set or unset the RTNH_F_OFFLOAD
flag in each nexthop.

This is also necessary because we're going to need to refresh the
offload indication whenever the nexthop group associated with the FIB
entry is refreshed. Current check would prevent us from marking a newly
resolved nexthop as offloaded if the FIB entry is already marked as
offloaded.
Signed-off-by: NIdo Schimmel <idosch@mellanox.com>
Signed-off-by: NJiri Pirko <jiri@mellanox.com>
Tested-by: NDavid Ahern <dsahern@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

In a similar fashion to previous patch, use the nexthop flags to provide
offload indication instead of the FIB info's flags.

In case a nexthop in a multipath route can't be offloaded (gateway's MAC
can't be resolved, for example), then its offload flag isn't set.
Signed-off-by: NIdo Schimmel <idosch@mellanox.com>
Signed-off-by: NJiri Pirko <jiri@mellanox.com>
Tested-by: NDavid Ahern <dsahern@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Express the same logic more succinctly.
Signed-off-by: NPetr Machata <petrm@mellanox.com>
Reviewed-by: NIdo Schimmel <idosch@mellanox.com>
Signed-off-by: NJiri Pirko <jiri@mellanox.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Prefer logical operator that expresses the intent to bitwise one that
happens to give the same result.
Signed-off-by: NPetr Machata <petrm@mellanox.com>
Reviewed-by: NIdo Schimmel <idosch@mellanox.com>
Signed-off-by: NJiri Pirko <jiri@mellanox.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Signed-off-by: NPetr Machata <petrm@mellanox.com>
Reviewed-by: NIdo Schimmel <idosch@mellanox.com>
Signed-off-by: NJiri Pirko <jiri@mellanox.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Signed-off-by: NPetr Machata <petrm@mellanox.com>
Reviewed-by: NIdo Schimmel <idosch@mellanox.com>
Signed-off-by: NJiri Pirko <jiri@mellanox.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

When IPv6 isn't enabled the following error is generated:

ERROR: "nd_tbl" [drivers/net/ethernet/mellanox/mlxsw/mlxsw_spectrum.ko]
undefined!

Fix it by replacing 'arp_tbl' and 'nd_tbl' with 'tbl->family' wherever
possible and reference 'nd_tbl' only when IPV6 is enabled.

Fixes: d5eb89cf ("mlxsw: spectrum_router: Reflect IPv6 neighbours to the device")
Signed-off-by: NIdo Schimmel <idosch@mellanox.com>
Reported-by: Nkbuild test robot <fengguang.wu@intel.com>
Signed-off-by: NJiri Pirko <jiri@mellanox.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Current firmware supported by the driver doesn't support batch deletion
of IPv6 neighbours on a given router interface (RIF).

Until a new version that supports this functionality is made available,
delete neighbours one by one.
Signed-off-by: NIdo Schimmel <idosch@mellanox.com>
Signed-off-by: NJiri Pirko <jiri@mellanox.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Each FIB node holds a linked list of routes sharing the same prefix and
length. In the case of IPv4 it's ordered according to table ID, metric
and TOS and only the first route in the list is actually programmed to
the device.

In case a gatewayed route is added somewhere in the list, then after its
nexthop group will be refreshed and become valid (due to the resolution
of its gateway), it'll mistakenly overwrite the existing entry.

Example:
192.168.200.0/24 dev enp3s0np3 scope link metric 1000 offload
192.168.200.0/24 via 192.168.100.1 dev enp3s0np3 metric 1000 offload

Both routes are marked as offloaded despite the fact only the first one
should actually be present in the device's table.

When refreshing the nexthop group, don't write the route to the device's
table unless it's the first in its node.

Fixes: 9aecce1c ("mlxsw: spectrum_router: Correctly handle identical routes")
Signed-off-by: NIdo Schimmel <idosch@mellanox.com>
Signed-off-by: NJiri Pirko <jiri@mellanox.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The number of possible prefix lengths for IPv6 is 129 and not 128.

Fixes following warning from UBSAN when /128 routes are offloaded:

 UBSAN: Undefined behaviour in
drivers/net/ethernet/mellanox/mlxsw/spectrum_router.c:2510:27 index 128 is out
of range for type 'long unsigned int [128]'

Fixes: 5e9c16cc ("mlxsw: spectrum_router: Implement private fib")
Signed-off-by: NIdo Schimmel <idosch@mellanox.com>
Signed-off-by: NJiri Pirko <jiri@mellanox.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

These functions aren't specific to IPv4 and can be re-used for IPv6.

Drop the '4' designation from their name.
Signed-off-by: NIdo Schimmel <idosch@mellanox.com>
Signed-off-by: NJiri Pirko <jiri@mellanox.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Functions that take as argument a FIB entry don't need to take FIB node
as well, as it can be extracted from the entry.

Remove unnecessary FIB node parameter.
Signed-off-by: NIdo Schimmel <idosch@mellanox.com>
Signed-off-by: NJiri Pirko <jiri@mellanox.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The functions to create and destroy a nexthop group are IPv4 specific
and should be renamed accordingly, so that they won't be confused with
the IPv6 specific functions in follow-up patches.
Signed-off-by: NIdo Schimmel <idosch@mellanox.com>
Signed-off-by: NJiri Pirko <jiri@mellanox.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Some of the parameters stored in the FIB entry structure are specific to
IPv4 and therefore better placed in an IPv4 specific structure.

Create an IPv4 specific structure that encapsulates the common FIB entry
structure and contains IPv4 specific parameters.

In a follow-up patchset an IPv6 specific structure will be introduced.
Signed-off-by: NIdo Schimmel <idosch@mellanox.com>
Signed-off-by: NJiri Pirko <jiri@mellanox.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

When we fail to insert a route we invoke the abort mechanism which
flushes all the tables and inserts a default route in each, so that all
packets incoming to the router will be trapped to the CPU.

Upon abort, add an IPv6 default route to the IPv6 tables.
Signed-off-by: NIdo Schimmel <idosch@mellanox.com>
Signed-off-by: NJiri Pirko <jiri@mellanox.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Take advantage of previous patch and allow the RALUE register to be
called with IPv6 routes.

In order to re-use as much code as possible between IPv4 and IPv6, only
the lowest-level function that actually does the register packing is
demuxed based on the passed protocol.
Signed-off-by: NIdo Schimmel <idosch@mellanox.com>
Signed-off-by: NJiri Pirko <jiri@mellanox.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

A Virtual Router (VR) is an entity which corresponds to a VRF and
performs FIB lookup in an LPM tree according to the {VR, IP Proto} ->
Tree binding.

Extend the virtual router data structure towards IPv6 FIB offload.
Signed-off-by: NIdo Schimmel <idosch@mellanox.com>
Signed-off-by: NJiri Pirko <jiri@mellanox.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

A FIB node is an entity which stores routes sharing the same prefix and
length. The data structure itself is already family agnostic, but we
make some of its operations agnostic as well and thus re-use them for
IPv6 offload.

Instead of passing an IPv4-specific structure to fib4_node_get(), pass
general routing parameters and rename the function accordingly.
Signed-off-by: NIdo Schimmel <idosch@mellanox.com>
Signed-off-by: NJiri Pirko <jiri@mellanox.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

When looking up a FIB entry we shouldn't create the FIB node where it's
supposed to be linked in case the node doesn't already exist.

Instead, lookup the node and fail if it doesn't exist.
Signed-off-by: NIdo Schimmel <idosch@mellanox.com>
Signed-off-by: NJiri Pirko <jiri@mellanox.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Thankfully, the neighbour subsystem is agnostic to the upper protocol
and used by both IPv4 and IPv6. By removing assumptions regarding the
neighbour type we can thus re-use much of the neighbour-related code for
both IPv4 and IPv6.

For each nexthop, store its gateway IP and for nexthop group store the
neighbour table used by its nexthops.

Use this information throughout the code and remove assumption about the
neighbour type.
Signed-off-by: NIdo Schimmel <idosch@mellanox.com>
Signed-off-by: NJiri Pirko <jiri@mellanox.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The neighbours' activity is currently dumped according to the ARP
table's DELAY_PROBE time, but with the introduction of IPv6 offload we
should set the interval according to the minimum between the ARP and
ndisc tables.
Signed-off-by: NArkadi Sharshvesky <arkadis@mellanox.com>
Signed-off-by: NIdo Schimmel <idosch@mellanox.com>
Signed-off-by: NJiri Pirko <jiri@mellanox.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

In addition to IPv4, periodically dump IPv6 neighbours and update the
kernel about them.
Signed-off-by: NArkadi Sharshevsky <arkadis@mellanox.com>
Signed-off-by: NIdo Schimmel <idosch@mellanox.com>
Signed-off-by: NJiri Pirko <jiri@mellanox.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

As with IPv4, listen to NEIGH_UPDATE events from the ndisc table and
program relevant neighbours to the device's neighbour table.

Note that neighbours with a link-local IP address aren't programmed, as
packets with a link-local destination IP are trapped after LPM lookup
and never reach the neighbour table.
Signed-off-by: NArkadi Sharshevsky <arkadis@mellanox.com>
Signed-off-by: NIdo Schimmel <idosch@mellanox.com>
Signed-off-by: NJiri Pirko <jiri@mellanox.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

When a netdev is configured with an IP address a router interface (RIF)
should be configured for it in the device. Allow configuration of RIFs
based on IPv6 address notifications as well as IPv4.

Note that the RIF exists as long as an IP address is configured on the
netdev, regardless of the address family.
Signed-off-by: NArkadi Sharshevsky <arkadis@mellanox.com>
Signed-off-by: NIdo Schimmel <idosch@mellanox.com>
Signed-off-by: NJiri Pirko <jiri@mellanox.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Up until now we only flooded broadcast packets to the router when an L3
interface was configured on top of a bridge. However, IPv6 Neighbour
Discovery packets are trapped to the CPU inside the router and these can
be sent with a multicast address.

Flood unregistered multicast packets to the router port, so that
relevant packets could be trapped there.
Signed-off-by: NIdo Schimmel <idosch@mellanox.com>
Signed-off-by: NJiri Pirko <jiri@mellanox.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>