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>

Before we add IPv6 constructs like traps and router interfaces, we first
need to enable IPv6 routing in the device.
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>

While working on IPv6 route replace I realized we can have a
use-after-free in IPv4 in case the replaced route is offloaded and the
only one using its FIB info.

The problem is that fib_table_insert() drops the reference on the FIB
info of the replaced routes which is eventually freed via call_rcu().
Since the driver doesn't hold a reference on this FIB info it can cause
a use-after-free when it tries to clear the RTNH_F_OFFLOAD flag stored
in fi->fib_flags.

After running the following commands in a loop for enough time with a
KASAN enabled kernel I finally got the below trace.

$ ip route add 192.168.50.0/24 via 192.168.200.1 dev enp3s0np3
$ ip route replace 192.168.50.0/24 dev enp3s0np5
$ ip route del 192.168.50.0/24 dev enp3s0np5

BUG: KASAN: use-after-free in mlxsw_sp_fib_entry_offload_unset+0xa7/0x120 [mlxsw_spectrum]
Read of size 4 at addr ffff8803717d9820 by task kworker/u4:2/55
[...]
? mlxsw_sp_fib_entry_offload_unset+0xa7/0x120 [mlxsw_spectrum]
? mlxsw_sp_fib_entry_offload_unset+0xa7/0x120 [mlxsw_spectrum]
? mlxsw_sp_router_neighs_update_work+0x1cd0/0x1ce0 [mlxsw_spectrum]
? mlxsw_sp_fib_entry_offload_unset+0xa7/0x120 [mlxsw_spectrum]
__asan_load4+0x61/0x80
mlxsw_sp_fib_entry_offload_unset+0xa7/0x120 [mlxsw_spectrum]
mlxsw_sp_fib_entry_offload_refresh+0xb6/0x370 [mlxsw_spectrum]
mlxsw_sp_router_fib_event_work+0xd1c/0x2780 [mlxsw_spectrum]
[...]
Freed by task 5131:
 save_stack_trace+0x16/0x20
 save_stack+0x46/0xd0
 kasan_slab_free+0x70/0xc0
 kfree+0x144/0x570
 free_fib_info_rcu+0x2e7/0x410
 rcu_process_callbacks+0x4f8/0xe30
 __do_softirq+0x1d3/0x9e2

Fix this by taking a reference on the FIB info when creating the nexthop
group it represents and drop it when the group is destroyed.

Fixes: 599cf8f9 ("mlxsw: spectrum_router: Add support for route replace")
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>

With this patch the error path of mlxsw_sp_nexthop_init() is symmetric
with mlxsw_sp_nexthop_fini(). Noticed during code review.

Fixes: a8c97014 ("mlxsw: spectrum_router: Refactor nexthop init routine")
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 a VLAN device is enslaved to a bridge we shouldn't create a
router interface (RIF) for it when it's configured with an IP address.
This is already handled by the driver for other types of netdevs, such
as physical ports and LAG devices.

If this IP address is then removed and the interface is subsequently
unlinked from the bridge, a NULL pointer dereference can happen, as the
original 802.1d FID was replaced with an rFID which was then deleted.

To reproduce:
$ ip link set dev enp3s0np9 up
$ ip link add name enp3s0np9.111 link enp3s0np9 type vlan id 111
$ ip link set dev enp3s0np9.111 up
$ ip link add name br0 type bridge
$ ip link set dev br0 up
$ ip link set enp3s0np9.111 master br0
$ ip address add dev enp3s0np9.111 192.168.0.1/24
$ ip address del dev enp3s0np9.111 192.168.0.1/24
$ ip link set dev enp3s0np9.111 nomaster

Fixes: 99724c18 ("mlxsw: spectrum: Introduce support for router interfaces")
Signed-off-by: NIdo Schimmel <idosch@mellanox.com>
Reported-by: NPetr Machata <petrm@mellanox.com>
Tested-by: NPetr Machata <petrm@mellanox.com>
Reviewed-by: NPetr Machata <petrm@mellanox.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

In new firmware versions (that we can now enforce via
request_firmware()), only the first LPM tree is reserved and not the
first two as in older versions.
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 way we usually allocate an index is by letting the allocation
function return an error instead of an invalid index.

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

The mlxsw driver currently implements three types of RIFs. VLAN and FID
RIFs for L3 interfaces on top of VLAN-aware and VLAN-unaware bridges
(respectively) and Subport RIFs for all other L3 interfaces.

All the RIF types follow a common configuration procedure, which only
differs in the type-specific bits. The patch exploits this fact and
consolidates the common code paths, thereby simplifying the code and
making it more extensible.

This work also prepares the driver for use with future ASICs, where the
range of the Subport RIFs will be extended and their configuration
modified accordingly. By merely implementing a new RIF operations and
selecting it during initialization, the same driver could be re-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>

The device supports three types of FIDs. 802.1Q and 802.1D FIDs for
VLAN-aware and VLAN-unaware bridges (respectively) and rFIDs to
transport packets to the router block.

The different users (e.g., bridge, router, ACLs) of the FIDs
infrastructure need not know about the internal FIDs implementation and
can therefore interact with it using a restricted set of exported
functions.

By encapsulating the entire FID logic and hiding it from the rest of the
driver we get a code base that it much simpler and easier to work with
and extend.

For example, in the current Spectrum ASIC only 802.1D FIDs can be
assigned a VNI, but future ASICs will also support 802.1Q FIDs. With
this patch in place, support for future ASICs can be easily added by
implementing a new FID operations according to their capabilities.
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>

All RIF types are associated with a virtual router (VR), so determine VR
first when creating a RIF.

That way, we can more easily integrate the common RIF core in the
following 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>

If a packet ingress the router but can't be assigned an ingress RIF,
it's dropped.

Therefore, in the case of RIF configured on top of a bridge, it makes
sense to start flooding broadcast packets to the router only after the
RIF was created.
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 all the information to create a RIF is contained within the RIF
struct itself, we can also simplify the destruction logic.
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>

All the information necessary for the configuration of RIFs can now be
found in the RIF struct itself, so reduce the arguments list.

This gets us one step closer to the common RIF core.
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>

Currently, when a Subport RIF is configured, the LAG status and VLAN of
the underlying port are read from the port itself. This is problematic,
as we would like to have common code to configure all types of RIFs,
which aren't necessarily bound to a port.

Instead, embed the RIF in a struct specific to the Subport type, which
contains all the necessary information.
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>