mpls: Do not orphan the skb

We observed that TCP-pacing was falling back to the TCP-layer pacing
instead of utilizing sch_fq for the pacing. This causes significant
CPU-usage due to the hrtimer running on a per-TCP-connection basis.

The issue is that mpls_xmit() calls skb_orphan() and thus sets
skb->sk to NULL. Which implies that many of the goodies of TCP won't
work. Pacing falls back to TCP-layer pacing. TCP Small Queues does not
work, ...

It is safe to remove this call to skb_orphan() in mpls_xmit() as there
really is not reason for it to be there. It appears that this call to
skb_orphan comes from the very initial implementation of MPLS.

Cc: Roopa Prabhu <roopa@nvidia.com>
Reported-by: Craig Taylor <cmtaylor@apple.com>
Signed-off-by: Christoph Paasch <cpaasch@apple.com>
Link: https://lore.kernel.org/r/20240306181117.77419-1-cpaasch@apple.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

mpls: load mpls_gso after mpls_iptunnel

mpls_iptunnel is used only for mpls encapsuation, and if encaplusated
packet is larger than MTU we need mpls_gso for segmentation.

Signed-off-by: Alexander Ovechkin <ovov@yandex-team.ru>
Acked-by: Dmitry Yakunin <zeil@yandex-team.ru>
Reviewed-by: David Ahern <dsahern@gmail.com>
Link: https://lore.kernel.org/r/20201020114333.26866-1-ovov@yandex-team.ru
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

net: add net available in build_state

The build_state callback of lwtunnel doesn't contain the net namespace
structure yet. This patch will add it so we can check on specific
address configuration at creation time of rpl source routes.

Signed-off-by: Alexander Aring <alex.aring@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

ipv4: mpls: fix mpls_xmit for iptunnel

When using mpls over gre/gre6 setup, rt->rt_gw4 address is not set, the
same for rt->rt_gw_family. Therefore, when rt->rt_gw_family is checked
in mpls_xmit(), neigh_xmit() call is skipped. As a result, such setup
doesn't work anymore.

This issue was found with LTP mpls03 tests.

Fixes: 1550c171935d ("ipv4: Prepare rtable for IPv6 gateway")
Signed-off-by: Alexey Kodanev <alexey.kodanev@oracle.com>
Reviewed-by: David Ahern <dsahern@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

mpls: fix warning with multi-label encap

If you configure a route with multiple labels, e.g.
ip route add 10.10.3.0/24 encap mpls 16/100 via 10.10.2.2 dev ens4
A warning is logged:
kernel: [ 130.561819] netlink: 'ip': attribute type 1 has an invalid
length.

This happens because mpls_iptunnel_policy has set the type of
MPLS_IPTUNNEL_DST to fixed size NLA_U32.
Change it to a minimum size.
nla_get_labels() does the remaining validation.

Fixes: e3e4712ec096 ("mpls: ip tunnel support")
Signed-off-by: George Wilkie <gwilkie@vyatta.att-mail.com>
Reviewed-by: David Ahern <dsahern@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152

Based on 1 normalized pattern(s):

this program is free software you can redistribute it and or modify
it under the terms of the gnu general public license as published by
the free software foundation either version 2 of the license or at
your option any later version

extracted by the scancode license scanner the SPDX license identifier

GPL-2.0-or-later

has been chosen to replace the boilerplate/reference in 3029 file(s).

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Allison Randal <allison@lohutok.net>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190527070032.746973796@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

netlink: make validation more configurable for future strictness

We currently have two levels of strict validation:

1) liberal (default)
- undefined (type >= max) & NLA_UNSPEC attributes accepted
- attribute length >= expected accepted
- garbage at end of message accepted
2) strict (opt-in)
- NLA_UNSPEC attributes accepted
- attribute length >= expected accepted

Split out parsing strictness into four different options:
* TRAILING - check that there's no trailing data after parsing
attributes (in message or nested)
* MAXTYPE - reject attrs > max known type
* UNSPEC - reject attributes with NLA_UNSPEC policy entries
* STRICT_ATTRS - strictly validate attribute size

The default for future things should be *everything*.
The current *_strict() is a combination of TRAILING and MAXTYPE,
and is renamed to _deprecated_strict().
The current regular parsing has none of this, and is renamed to
*_parse_deprecated().

Additionally it allows us to selectively set one of the new flags
even on old policies. Notably, the UNSPEC flag could be useful in
this case, since it can be arranged (by filling in the policy) to
not be an incompatible userspace ABI change, but would then going
forward prevent forgetting attribute entries. Similar can apply
to the POLICY flag.

We end up with the following renames:
* nla_parse -> nla_parse_deprecated
* nla_parse_strict -> nla_parse_deprecated_strict
* nlmsg_parse -> nlmsg_parse_deprecated
* nlmsg_parse_strict -> nlmsg_parse_deprecated_strict
* nla_parse_nested -> nla_parse_nested_deprecated
* nla_validate_nested -> nla_validate_nested_deprecated

Using spatch, of course:
@@
expression TB, MAX, HEAD, LEN, POL, EXT;
@@
-nla_parse(TB, MAX, HEAD, LEN, POL, EXT)
+nla_parse_deprecated(TB, MAX, HEAD, LEN, POL, EXT)

@@
expression NLH, HDRLEN, TB, MAX, POL, EXT;
@@
-nlmsg_parse(NLH, HDRLEN, TB, MAX, POL, EXT)
+nlmsg_parse_deprecated(NLH, HDRLEN, TB, MAX, POL, EXT)

@@
expression NLH, HDRLEN, TB, MAX, POL, EXT;
@@
-nlmsg_parse_strict(NLH, HDRLEN, TB, MAX, POL, EXT)
+nlmsg_parse_deprecated_strict(NLH, HDRLEN, TB, MAX, POL, EXT)

@@
expression TB, MAX, NLA, POL, EXT;
@@
-nla_parse_nested(TB, MAX, NLA, POL, EXT)
+nla_parse_nested_deprecated(TB, MAX, NLA, POL, EXT)

@@
expression START, MAX, POL, EXT;
@@
-nla_validate_nested(START, MAX, POL, EXT)
+nla_validate_nested_deprecated(START, MAX, POL, EXT)

@@
expression NLH, HDRLEN, MAX, POL, EXT;
@@
-nlmsg_validate(NLH, HDRLEN, MAX, POL, EXT)
+nlmsg_validate_deprecated(NLH, HDRLEN, MAX, POL, EXT)

For this patch, don't actually add the strict, non-renamed versions
yet so that it breaks compile if I get it wrong.

Also, while at it, make nla_validate and nla_parse go down to a
common __nla_validate_parse() function to avoid code duplication.

Ultimately, this allows us to have very strict validation for every
new caller of nla_parse()/nlmsg_parse() etc as re-introduced in the
next patch, while existing things will continue to work as is.

In effect then, this adds fully strict validation for any new command.

Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

ipv4: Add support to rtable for ipv6 gateway

Add support for an IPv6 gateway to rtable. Since a gateway is either
IPv4 or IPv6, make it a union with rt_gw4 where rt_gw_family decides
which address is in use.

When dumping the route data, encode an ipv6 nexthop using RTA_VIA.

Signed-off-by: David Ahern <dsahern@gmail.com>
Reviewed-by: Ido Schimmel <idosch@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

ipv4: Prepare rtable for IPv6 gateway

To allow the gateway to be either an IPv4 or IPv6 address, remove
rt_uses_gateway from rtable and replace with rt_gw_family. If
rt_gw_family is set it implies rt_uses_gateway. Rename rt_gateway
to rt_gw4 to represent the IPv4 version.

Signed-off-by: David Ahern <dsahern@gmail.com>
Reviewed-by: Ido Schimmel <idosch@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

mpls: Fix 6PE forwarding

This patch adds support for 6PE (RFC 4798) which uses IPv4-mapped IPv6
nexthop to connect IPv6 islands over IPv4 only MPLS network core.

Prior to this fix, to find the link-layer destination mac address, 6PE
enabled host/router was sending IPv6 ND requests for IPv4-mapped IPv6
nexthop address over the interface facing the IPv4 only core which
wouldn't success as the core is IPv6 free.

This fix changes that behavior on 6PE host to treat the nexthop as IPv4
address and send ARP requests whenever the next-hop address is an
IPv4-mapped IPv6 address.

Below topology illustrates the issue and how the patch addresses it.

abcd::1.1.1.1 (lo) abcd::2.2.2.2 (lo)
R0 (PE/host)------------------------R1--------------------------------R2 (PE/host)
<--- IPv4 MPLS core ---> <------ IPv4 MPLS core -------->
eth1 eth2 eth3 eth4
172.18.0.10 172.18.0.11 172.19.0.11 172.19.0.12
ffff::172.18.0.10 ffff::172.19.0.12
<------------------IPv6 MPLS tunnel ---------------------->

R0 and R2 act as 6PE routers of IPv6 islands. R1 is IPv4 only with MPLS tunnels
between R0,R1 and R1,R2.

docker exec r0 ip -f inet6 route add abcd::2.2.2.2/128 nexthop encap mpls 100 via ::ffff:172.18.0.11 dev eth1
docker exec r2 ip -f inet6 route add abcd::1.1.1.1/128 nexthop encap mpls 200 via ::ffff:172.19.0.11 dev eth4

docker exec r1 ip -f mpls route add 100 via inet 172.19.0.12 dev eth3
docker exec r1 ip -f mpls route add 200 via inet 172.18.0.10 dev eth2

With the change, when R0 sends an IPv6 packet over MPLS tunnel to abcd::2.2.2.2,
using ::ffff:172.18.0.11 as the nexthop, it does neighbor discovery for
172.18.18.0.11.

Signed-off-by: Vinay K Nallamothu <nvinay@juniper.net>
Tested-by: Avinash Lingala <ar977m@att.com>
Tested-by: Aravind Srinivas Srinivasa Prabhakar <aprabh@juniper.net>
Signed-off-by: David S. Miller <davem@davemloft.net>

mpls_iptunnel: use struct_size() helper

One of the more common cases of allocation size calculations is finding
the size of a structure that has a zero-sized array at the end, along
with memory for some number of elements for that array. For example:

struct foo {
int stuff;
struct boo entry[];
};

instance = alloc(sizeof(struct foo) + count * sizeof(struct boo));

Instead of leaving these open-coded and prone to type mistakes, we can
now use the new struct_size() helper:

instance = alloc(struct_size(instance, entry, count));

This code was detected with the help of Coccinelle.

Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

mpls: remove trailing whitepace

Signed-off-by: Stephen Hemminger <stephen@networkplumber.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: Fill in extack for mpls lwt encap

Fill in extack for errors in build_state for mpls lwt encap including
passing extack to nla_get_labels and adding error messages for failures
in it.

Signed-off-by: David Ahern <dsahern@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: add extack arg to lwtunnel build state

Pass extack arg down to lwtunnel_build_state and the build_state callbacks.
Add messages for failures in lwtunnel_build_state, and add the extarg to
nla_parse where possible in the build_state callbacks.

Signed-off-by: David Ahern <dsahern@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

netlink: pass extended ACK struct to parsing functions

Pass the new extended ACK reporting struct to all of the generic
netlink parsing functions. For now, pass NULL in almost all callers
(except for some in the core.)

Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: mpls: Increase max number of labels for lwt encap

Alow users to push down more labels per MPLS encap. Similar to LSR case,
move label array to the end of mpls_iptunnel_encap and allocate based on
the number of labels for the route.

For consistency with the LSR case, re-use the same maximum number of
labels.

Signed-off-by: David Ahern <dsa@cumulusnetworks.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

mpls: allow TTL propagation from IP packets to be configured

Allow TTL propagation from IP packets to MPLS packets to be
configured. Add a new optional LWT attribute, MPLS_IPTUNNEL_TTL, which
allows the TTL to be set in the resulting MPLS packet, with the value
of 0 having the semantics of enabling propagation of the TTL from the
IP header (i.e. non-zero values disable propagation).

Also allow the configuration to be overridden globally by reusing the
same sysctl to control whether the TTL is propagated from IP packets
into the MPLS header. If the per-LWT attribute is set then it
overrides the global configuration. If the TTL isn't propagated then a
default TTL value is used which can be configured via a new sysctl,
"net.mpls.default_ttl". This is kept separate from the configuration
of whether IP TTL propagation is enabled as it can be used in the
future when non-IP payloads are supported (i.e. where there is no
payload TTL that can be propagated).

Signed-off-by: Robert Shearman <rshearma@brocade.com>
Acked-by: David Ahern <dsa@cumulusnetworks.com>
Tested-by: David Ahern <dsa@cumulusnetworks.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

lwtunnel: remove device arg to lwtunnel_build_state

Nothing about lwt state requires a device reference, so remove the
input argument.

Signed-off-by: David Ahern <dsa@cumulusnetworks.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: Specify the owning module for lwtunnel ops

Modules implementing lwtunnel ops should not be allowed to unload
while there is state alive using those ops, so specify the owning
module for all lwtunnel ops.

Signed-off-by: Robert Shearman <rshearma@brocade.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

mpls: Packet stats

Having MPLS packet stats is useful for observing network operation and
for diagnosing network problems. In the absence of anything better,
RFC2863 and RFC3813 are used for guidance for which stats to expose
and the semantics of them. In particular rx_noroutes maps to in
unknown protos in RFC2863. The stats are exposed to userspace via
AF_MPLS attributes embedded in the IFLA_STATS_AF_SPEC attribute of
RTM_GETSTATS messages.

All the introduced fields are 64-bit, even error ones, to ensure no
overflow with long uptimes. Per-CPU counters are used to avoid
cache-line contention on the commonly used fields. The other fields
have also been made per-CPU for code to avoid performance problems in
error conditions on the assumption that on some platforms the cost of
atomic operations could be more expensive than sending the packet
(which is what would be done in the success case). If that's not the
case, we could instead not use per-CPU counters for these fields.

Only unicast and non-fragment are exposed at the moment, but other
counters can be exposed in the future either by adding to the end of
struct mpls_link_stats or by additional netlink attributes in the
AF_MPLS IFLA_STATS_AF_SPEC nested attribute.

Signed-off-by: Robert Shearman <rshearma@brocade.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

lwt: Remove unused len field

The field is initialized by ILA and MPLS but never used. Remove it.

Signed-off-by: Thomas Graf <tgraf@suug.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: mpls: Fixups for GSO

As reported by Lennert the MPLS GSO code is failing to properly segment
large packets. There are a couple of problems:

1. the inner protocol is not set so the gso segment functions for inner
protocol layers are not getting run, and

2 MPLS labels for packets that use the "native" (non-OVS) MPLS code
are not properly accounted for in mpls_gso_segment.

The MPLS GSO code was added for OVS. It is re-using skb_mac_gso_segment
to call the gso segment functions for the higher layer protocols. That
means skb_mac_gso_segment is called twice -- once with the network
protocol set to MPLS and again with the network protocol set to the
inner protocol.

This patch sets the inner skb protocol addressing item 1 above and sets
the network_header and inner_network_header to mark where the MPLS labels
start and end. The MPLS code in OVS is also updated to set the two
network markers.

>From there the MPLS GSO code uses the difference between the network
header and the inner network header to know the size of the MPLS header
that was pushed. It then pulls the MPLS header, resets the mac_len and
protocol for the inner protocol and then calls skb_mac_gso_segment
to segment the skb.

Afterward the inner protocol segmentation is done the skb protocol
is set to mpls for each segment and the network and mac headers
restored.

Reported-by: Lennert Buytenhek <buytenh@wantstofly.org>
Signed-off-by: David Ahern <dsa@cumulusnetworks.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: lwtunnel: Handle fragmentation

Today mpls iptunnel lwtunnel_output redirect expects the tunnel
output function to handle fragmentation. This is ok but can be
avoided if we did not do the mpls output redirect too early.
ie we could wait until ip fragmentation is done and then call
mpls output for each ip fragment.

To make this work we will need,
1) the lwtunnel state to carry encap headroom
2) and do the redirect to the encap output handler on the ip fragment
(essentially do the output redirect after fragmentation)

This patch adds tunnel headroom in lwtstate to make sure we
account for tunnel data in mtu calculations during fragmentation
and adds new xmit redirect handler to redirect to lwtunnel xmit func
after ip fragmentation.

This includes IPV6 and some mtu fixes and testing from David Ahern.

Signed-off-by: Roopa Prabhu <roopa@cumulusnetworks.com>
Signed-off-by: David Ahern <dsa@cumulusnetworks.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

mpls: autoload lwt module

Avoid users having to manually load the module by adding a module
alias allowing it to be autoloaded by the lwt infra.

Signed-off-by: Robert Shearman <rshearma@brocade.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

mpls_iptunnel: add static qualifier to mpls_output

This gets rid of the following compile warn:
net/mpls/mpls_iptunnel.c:40:5: warning: no previous prototype for
mpls_output [-Wmissing-prototypes]

Signed-off-by: Roopa Prabhu <roopa@cumulusnetworks.com>
Acked-by: Robert Shearman <rshearma@brocade.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

mpls: fix sending of local encapped packets

Locally generated IPv4 and (probably) IPv6 packets are dropped because
skb->protocol isn't set. We could write wrappers to lwtunnel_output
for IPv4 and IPv6 that set the protocol accordingly and then call
lwtunnel_output, but mpls_output relies on the AF-specific type of dst
anyway to get the via address.

Therefore, make use of dst->dst_ops->family in mpls_output to
determine the type of nexthop and thus protocol of the packet instead
of checking skb->protocol.

Fixes: 61adedf3e3f1 ("route: move lwtunnel state to dst_entry")
Reported-by: Sam Russell <sam.h.russell@gmail.com>
Signed-off-by: Robert Shearman <rshearma@brocade.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

dst: Pass net into dst->output

The network namespace is already passed into dst_output pass it into
dst->output lwt->output and friends.

Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

lwt: Add cfg argument to build_state

Add cfg and family arguments to lwt build state functions. cfg is a void
pointer and will either be a pointer to a fib_config or fib6_config
structure. The family parameter indicates which one (either AF_INET
or AF_INET6).

LWT encpasulation implementation may use the fib configuration to build
the LWT state.

Signed-off-by: Tom Herbert <tom@herbertland.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

route: move lwtunnel state to dst_entry

Currently, the lwtunnel state resides in per-protocol data. This is
a problem if we encapsulate ipv6 traffic in an ipv4 tunnel (or vice versa).
The xmit function of the tunnel does not know whether the packet has been
routed to it by ipv4 or ipv6, yet it needs the lwtstate data. Moving the
lwtstate data to dst_entry makes such inter-protocol tunneling possible.

As a bonus, this brings a nice diffstat.

Signed-off-by: Jiri Benc <jbenc@redhat.com>
Acked-by: Roopa Prabhu <roopa@cumulusnetworks.com>
Acked-by: Thomas Graf <tgraf@suug.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>

mpls_iptunnel: fix sparse warn: remove incorrect rcu_dereference

fix for:
net/mpls/mpls_iptunnel.c:73:19: sparse: incompatible types in comparison
expression (different address spaces)

remove incorrect rcu_dereference possibly left over from
earlier revisions of the code.

Reported-by: kbuild test robot <fengguang.wu@intel.com>
Signed-off-by: Roopa Prabhu <roopa@cumulusnetworks.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

mpls: ip tunnel support

This implementation uses lwtunnel infrastructure to register
hooks for mpls tunnel encaps.

It picks cues from iptunnel_encaps infrastructure and previous
mpls iptunnel RFC patches from Eric W. Biederman and Robert Shearman

Signed-off-by: Roopa Prabhu <roopa@cumulusnetworks.com>
Signed-off-by: David S. Miller <davem@davemloft.net>