net: bareudp: Remove generic .ndo_get_stats64

Commit 3e2f544dd8a33 ("net: get stats64 if device if driver is
configured") moved the callback to dev_get_tstats64() to net core, so,
unless the driver is doing some custom stats collection, it does not
need to set .ndo_get_stats64.

Since this driver is now relying in NETDEV_PCPU_STAT_TSTATS, then, it
doesn't need to set the dev_get_tstats64() generic .ndo_get_stats64
function pointer.

Signed-off-by: Breno Leitao <leitao@debian.org>
Reviewed-by: Simon Horman <horms@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: bareudp: Do not allocate stats in the driver

With commit 34d21de99cea9 ("net: Move {l,t,d}stats allocation to core and
convert veth & vrf"), stats allocation could be done on net core
instead of this driver.

With this new approach, the driver doesn't have to bother with error
handling (allocation failure checking, making sure free happens in the
right spot, etc). This is core responsibility now.

Remove the allocation in the bareudp driver and leverage the network
core allocation.

Signed-off-by: Breno Leitao <leitao@debian.org>
Reviewed-by: Simon Horman <horms@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

bareudp: use exit_batch_rtnl() method

exit_batch_rtnl() is called while RTNL is held,
and devices to be unregistered can be queued in the dev_kill_list.

This saves one rtnl_lock()/rtnl_unlock() pair,
and one unregister_netdevice_many() call.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Reviewed-by: Antoine Tenart <atenart@kernel.org>
Link: https://lore.kernel.org/r/20240206144313.2050392-5-edumazet@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

bareudp: use ports to lookup route

The source and destination ports should be taken into account when
determining the route destination; they can affect the result, for
example in case there are routing rules defined.

Signed-off-by: Beniamino Galvani <b.galvani@gmail.com>
Reviewed-by: Przemek Kitszel <przemyslaw.kitszel@intel.com>
Reviewed-by: David Ahern <dsahern@kernel.org>
Link: https://lore.kernel.org/r/20231025094441.417464-1-b.galvani@gmail.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>

ipv6: add new arguments to udp_tunnel6_dst_lookup()

We want to make the function more generic so that it can be used by
other UDP tunnel implementations such as geneve and vxlan. To do that,
add the following arguments:

- source and destination UDP port;
- ifindex of the output interface, needed by vxlan;
- the tos, because in some cases it is not taken from struct
ip_tunnel_info (for example, when it's inherited from the inner
packet);
- the dst cache, because not all tunnel types (e.g. vxlan) want to
use the one from struct ip_tunnel_info.

With these parameters, the function no longer needs the full struct
ip_tunnel_info as argument and we can pass only the relevant part of
it (struct ip_tunnel_key).

This is similar to what already done for IPv4 in commit 72fc68c6356b
("ipv4: add new arguments to udp_tunnel_dst_lookup()").

Suggested-by: Guillaume Nault <gnault@redhat.com>
Signed-off-by: Beniamino Galvani <b.galvani@gmail.com>
Reviewed-by: David Ahern <dsahern@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

ipv6: remove "proto" argument from udp_tunnel6_dst_lookup()

The function is now UDP-specific, the protocol is always IPPROTO_UDP.

This is similar to what already done for IPv4 in commit 78f3655adcb5
("ipv4: remove "proto" argument from udp_tunnel_dst_lookup()").

Suggested-by: Guillaume Nault <gnault@redhat.com>
Signed-off-by: Beniamino Galvani <b.galvani@gmail.com>
Reviewed-by: David Ahern <dsahern@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

ipv6: rename and move ip6_dst_lookup_tunnel()

At the moment ip6_dst_lookup_tunnel() is used only by bareudp.
Ideally, other UDP tunnel implementations should use it, but to do so
the function needs to accept new parameters that are specific for UDP
tunnels, such as the ports.

Prepare for these changes by renaming the function to
udp_tunnel6_dst_lookup() and move it to file
net/ipv6/ip6_udp_tunnel.c.

This is similar to what already done for IPv4 in commit bf3fcbf7e7a0
("ipv4: rename and move ip_route_output_tunnel()").

Suggested-by: Guillaume Nault <gnault@redhat.com>
Signed-off-by: Beniamino Galvani <b.galvani@gmail.com>
Reviewed-by: David Ahern <dsahern@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

ipv4: add new arguments to udp_tunnel_dst_lookup()

We want to make the function more generic so that it can be used by
other UDP tunnel implementations such as geneve and vxlan. To do that,
add the following arguments:

- source and destination UDP port;
- ifindex of the output interface, needed by vxlan;
- the tos, because in some cases it is not taken from struct
ip_tunnel_info (for example, when it's inherited from the inner
packet);
- the dst cache, because not all tunnel types (e.g. vxlan) want to
use the one from struct ip_tunnel_info.

With these parameters, the function no longer needs the full struct
ip_tunnel_info as argument and we can pass only the relevant part of
it (struct ip_tunnel_key).

Suggested-by: Guillaume Nault <gnault@redhat.com>
Signed-off-by: Beniamino Galvani <b.galvani@gmail.com>
Reviewed-by: David Ahern <dsahern@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

ipv4: remove "proto" argument from udp_tunnel_dst_lookup()

The function is now UDP-specific, the protocol is always IPPROTO_UDP.

Suggested-by: Guillaume Nault <gnault@redhat.com>
Signed-off-by: Beniamino Galvani <b.galvani@gmail.com>
Reviewed-by: David Ahern <dsahern@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

ipv4: rename and move ip_route_output_tunnel()

At the moment ip_route_output_tunnel() is used only by bareudp.
Ideally, other UDP tunnel implementations should use it, but to do so
the function needs to accept new parameters that are specific for UDP
tunnels, such as the ports.

Prepare for these changes by renaming the function to
udp_tunnel_dst_lookup() and move it to file
net/ipv4/udp_tunnel_core.c.

Suggested-by: Guillaume Nault <gnault@redhat.com>
Signed-off-by: Beniamino Galvani <b.galvani@gmail.com>
Reviewed-by: David Ahern <dsahern@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

bareudp: use ipv6_mod_enabled to check if IPv6 enabled

bareudp_create_sock() use AF_INET6 by default if IPv6 CONFIG enabled.
But if user start kernel with ipv6.disable=1, the bareudp sock will
created failed, which cause the interface open failed even with ethertype
ip. e.g.

# ip link add bareudp1 type bareudp dstport 2 ethertype ip
# ip link set bareudp1 up
RTNETLINK answers: Address family not supported by protocol

Fix it by using ipv6_mod_enabled() to check if IPv6 enabled. There is
no need to check IS_ENABLED(CONFIG_IPV6) as ipv6_mod_enabled() will
return false when CONFIG_IPV6 no enabled in include/linux/ipv6.h.

Reported-by: Jianlin Shi <jishi@redhat.com>
Fixes: 571912c69f0e ("net: UDP tunnel encapsulation module for tunnelling different protocols like MPLS, IP, NSH etc.")
Signed-off-by: Hangbin Liu <liuhangbin@gmail.com>
Link: https://lore.kernel.org/r/20220315062618.156230-1-liuhangbin@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

bareudp: Add extack support to bareudp_configure()

Add missing extacks for common configuration errors.

Signed-off-by: Guillaume Nault <gnault@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

bareudp: Move definition of struct bareudp_conf to bareudp.c

This structure is used only in bareudp.c.

While there, adjust include files: we need netdevice.h, not skbuff.h.

Signed-off-by: Guillaume Nault <gnault@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

bareudp: Remove bareudp_dev_create()

There's no user for this function.

Signed-off-by: Guillaume Nault <gnault@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: bareudp: fix duplicate checks of data[] expressions

Both !data[IFLA_BAREUDP_PORT] and !data[IFLA_BAREUDP_ETHERTYPE] are
checked. We should remove the checks of data[IFLA_BAREUDP_PORT] and
data[IFLA_BAREUDP_ETHERTYPE] that follow since they are always true.

Put both statements together in group and balance the space on both
sides of '=' sign.

Signed-off-by: Jean Sacren <sakiwit@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

bareudp: Fix invalid read beyond skb's linear data

Data beyond the UDP header might not be part of the skb's linear data.
Use skb_copy_bits() instead of direct access to skb->data+X, so that
we read the correct bytes even on a fragmented skb.

Fixes: 4b5f67232d95 ("net: Special handling for IP & MPLS.")
Signed-off-by: Guillaume Nault <gnault@redhat.com>
Link: https://lore.kernel.org/r/7741c46545c6ef02e70c80a9b32814b22d9616b3.1628264975.git.gnault@redhat.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

bareudp: allow redirecting bareudp packets to eth devices

Even though bareudp transports L3 data (typically IP or MPLS), it needs
to reset the mac_header pointer, so that other parts of the stack don't
mistakenly access the outer header after the packet has been
decapsulated.

This allows to push an Ethernet header to bareudp packets and redirect
them to an Ethernet device:

$ tc filter add dev bareudp0 ingress matchall \
action vlan push_eth dst_mac 00:00:5e:00:53:01 \
src_mac 00:00:5e:00:53:00 \
action mirred egress redirect dev eth0

Without this patch, push_eth refuses to add an ethernet header because
the skb appears to already have a MAC header.

Signed-off-by: Guillaume Nault <gnault@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

bareudp: allow UDP L4 GRO passthrou

Similar to the previous commit, let even geneve
passthrou the L4 GRO packets

Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

udp: call udp_encap_enable for v6 sockets when enabling encap

When enabling encap for a ipv6 socket without udp_encap_needed_key
increased, UDP GRO won't work for v4 mapped v6 address packets as
sk will be NULL in udp4_gro_receive().

This patch is to enable it by increasing udp_encap_needed_key for
v6 sockets in udp_tunnel_encap_enable(), and correspondingly
decrease udp_encap_needed_key in udpv6_destroy_sock().

v1->v2:
- add udp_encap_disable() and export it.
v2->v3:
- add the change for rxrpc and bareudp into one patch, as Alex
suggested.
v3->v4:
- move rxrpc part to another patch.

Acked-by: Willem de Bruijn <willemb@google.com>
Signed-off-by: Xin Long <lucien.xin@gmail.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

bareudp: add NETIF_F_FRAGLIST flag for dev features

Like vxlan and geneve, bareudp also needs this dev feature
to support some protocol's HW GSO.

Signed-off-by: Xin Long <lucien.xin@gmail.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

net: bareudp: simplify error paths calling dellink

bareudp_dellink() only needs the device list to hand it to
unregister_netdevice_queue(). We can pass NULL in, and
unregister_netdevice_queue() will do the unregistering.
There is no chance for batching on the error path, anyway.

Suggested-by: Cong Wang <xiyou.wangcong@gmail.com>
Reviewed-by: Cong Wang <xiyou.wangcong@gmail.com>
Link: https://lore.kernel.org/r/20210111052922.2145003-1-kuba@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

net: bareudp: add missing error handling for bareudp_link_config()

.dellink does not get called after .newlink fails,
bareudp_newlink() must undo what bareudp_configure()
has done if bareudp_link_config() fails.

v2: call bareudp_dellink(), like bareudp_dev_create() does

Fixes: 571912c69f0e ("net: UDP tunnel encapsulation module for tunnelling different protocols like MPLS, IP, NSH etc.")
Link: https://lore.kernel.org/r/20210105190725.1736246-1-kuba@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

bareudp: Fix use of incorrect min_headroom size

In the bareudp6_xmit_skb(), it calculates min_headroom.
At that point, it uses struct iphdr, but it's not correct.
So panic could occur.
The struct ipv6hdr should be used.

Test commands:
ip netns add A
ip netns add B
ip link add veth0 netns A type veth peer name veth1 netns B
ip netns exec A ip link set veth0 up
ip netns exec A ip a a 2001:db8:0::1/64 dev veth0
ip netns exec B ip link set veth1 up
ip netns exec B ip a a 2001:db8:0::2/64 dev veth1

for i in {10..1}
do
let A=$i-1
ip netns exec A ip link add bareudp$i type bareudp dstport $i \
ethertype 0x86dd
ip netns exec A ip link set bareudp$i up
ip netns exec A ip -6 a a 2001:db8:$i::1/64 dev bareudp$i
ip netns exec A ip -6 r a 2001:db8:$i::2 encap ip6 src \
2001:db8:$A::1 dst 2001:db8:$A::2 via 2001:db8:$i::2 \
dev bareudp$i

ip netns exec B ip link add bareudp$i type bareudp dstport $i \
ethertype 0x86dd
ip netns exec B ip link set bareudp$i up
ip netns exec B ip -6 a a 2001:db8:$i::2/64 dev bareudp$i
ip netns exec B ip -6 r a 2001:db8:$i::1 encap ip6 src \
2001:db8:$A::2 dst 2001:db8:$A::1 via 2001:db8:$i::1 \
dev bareudp$i
done
ip netns exec A ping 2001:db8:7::2

Splat looks like:
[ 66.436679][ C2] skbuff: skb_under_panic: text:ffffffff928614c8 len:454 put:14 head:ffff88810abb4000 data:ffff88810abb3ffa tail:0x1c0 end:0x3ec0 dev:veth0
[ 66.441626][ C2] ------------[ cut here ]------------
[ 66.443458][ C2] kernel BUG at net/core/skbuff.c:109!
[ 66.445313][ C2] invalid opcode: 0000 [#1] SMP DEBUG_PAGEALLOC KASAN PTI
[ 66.447606][ C2] CPU: 2 PID: 913 Comm: ping Not tainted 5.10.0+ #819
[ 66.450251][ C2] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.10.2-1ubuntu1 04/01/2014
[ 66.453713][ C2] RIP: 0010:skb_panic+0x15d/0x15f
[ 66.455345][ C2] Code: 98 fe 4c 8b 4c 24 10 53 8b 4d 70 45 89 e0 48 c7 c7 60 8b 78 93 41 57 41 56 41 55 48 8b 54 24 20 48 8b 74 24 28 e8 b5 40 f9 ff <0f> 0b 48 8b 6c 24 20 89 34 24 e8 08 c9 98 fe 8b 34 24 48 c7 c1 80
[ 66.462314][ C2] RSP: 0018:ffff888119209648 EFLAGS: 00010286
[ 66.464281][ C2] RAX: 0000000000000089 RBX: ffff888003159000 RCX: 0000000000000000
[ 66.467216][ C2] RDX: 0000000000000089 RSI: 0000000000000008 RDI: ffffed10232412c0
[ 66.469768][ C2] RBP: ffff88810a53d440 R08: ffffed102328018d R09: ffffed102328018d
[ 66.472297][ C2] R10: ffff888119400c67 R11: ffffed102328018c R12: 000000000000000e
[ 66.474833][ C2] R13: ffff88810abb3ffa R14: 00000000000001c0 R15: 0000000000003ec0
[ 66.477361][ C2] FS: 00007f37c0c72f00(0000) GS:ffff888119200000(0000) knlGS:0000000000000000
[ 66.480214][ C2] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 66.482296][ C2] CR2: 000055a058808570 CR3: 000000011039e002 CR4: 00000000003706e0
[ 66.484811][ C2] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[ 66.487793][ C2] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
[ 66.490424][ C2] Call Trace:
[ 66.491469][ C2] <IRQ>
[ 66.492374][ C2] ? eth_header+0x28/0x190
[ 66.494054][ C2] ? eth_header+0x28/0x190
[ 66.495401][ C2] skb_push.cold.99+0x22/0x22
[ 66.496700][ C2] eth_header+0x28/0x190
[ 66.497867][ C2] neigh_resolve_output+0x3de/0x720
[ 66.499615][ C2] ? __neigh_update+0x7e8/0x20a0
[ 66.501176][ C2] __neigh_update+0x8bd/0x20a0
[ 66.502749][ C2] ndisc_update+0x34/0xc0
[ 66.504010][ C2] ndisc_recv_na+0x8da/0xb80
[ 66.505041][ C2] ? pndisc_redo+0x20/0x20
[ 66.505888][ C2] ? rcu_read_lock_sched_held+0xc0/0xc0
[ 66.506965][ C2] ndisc_rcv+0x3a0/0x470
[ 66.507797][ C2] icmpv6_rcv+0xad9/0x1b00
[ 66.508645][ C2] ip6_protocol_deliver_rcu+0xcd6/0x1560
[ 66.509719][ C2] ip6_input_finish+0x5b/0xf0
[ 66.510615][ C2] ip6_input+0xcd/0x2d0
[ 66.511406][ C2] ? ip6_input_finish+0xf0/0xf0
[ 66.512327][ C2] ? rcu_read_lock_held+0x91/0xa0
[ 66.513279][ C2] ? ip6_protocol_deliver_rcu+0x1560/0x1560
[ 66.514414][ C2] ipv6_rcv+0xe8/0x300
[ ... ]

Acked-by: Guillaume Nault <gnault@redhat.com>
Fixes: 571912c69f0e ("net: UDP tunnel encapsulation module for tunnelling different protocols like MPLS, IP, NSH etc.")
Signed-off-by: Taehee Yoo <ap420073@gmail.com>
Link: https://lore.kernel.org/r/20201228152146.24270-1-ap420073@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

bareudp: set NETIF_F_LLTX flag

Like other tunneling interfaces, the bareudp doesn't need TXLOCK.
So, It is good to set the NETIF_F_LLTX flag to improve performance and
to avoid lockdep's false-positive warning.

Test commands:
ip netns add A
ip netns add B
ip link add veth0 netns A type veth peer name veth1 netns B
ip netns exec A ip link set veth0 up
ip netns exec A ip a a 10.0.0.1/24 dev veth0
ip netns exec B ip link set veth1 up
ip netns exec B ip a a 10.0.0.2/24 dev veth1

for i in {2..1}
do
let A=$i-1
ip netns exec A ip link add bareudp$i type bareudp \
dstport $i ethertype ip
ip netns exec A ip link set bareudp$i up
ip netns exec A ip a a 10.0.$i.1/24 dev bareudp$i
ip netns exec A ip r a 10.0.$i.2 encap ip src 10.0.$A.1 \
dst 10.0.$A.2 via 10.0.$i.2 dev bareudp$i

ip netns exec B ip link add bareudp$i type bareudp \
dstport $i ethertype ip
ip netns exec B ip link set bareudp$i up
ip netns exec B ip a a 10.0.$i.2/24 dev bareudp$i
ip netns exec B ip r a 10.0.$i.1 encap ip src 10.0.$A.2 \
dst 10.0.$A.1 via 10.0.$i.1 dev bareudp$i
done
ip netns exec A ping 10.0.2.2

Splat looks like:
[ 96.992803][ T822] ============================================
[ 96.993954][ T822] WARNING: possible recursive locking detected
[ 96.995102][ T822] 5.10.0+ #819 Not tainted
[ 96.995927][ T822] --------------------------------------------
[ 96.997091][ T822] ping/822 is trying to acquire lock:
[ 96.998083][ T822] ffff88810f753898 (_xmit_NONE#2){+.-.}-{2:2}, at: __dev_queue_xmit+0x1f52/0x2960
[ 96.999813][ T822]
[ 96.999813][ T822] but task is already holding lock:
[ 97.001192][ T822] ffff88810c385498 (_xmit_NONE#2){+.-.}-{2:2}, at: __dev_queue_xmit+0x1f52/0x2960
[ 97.002908][ T822]
[ 97.002908][ T822] other info that might help us debug this:
[ 97.004401][ T822] Possible unsafe locking scenario:
[ 97.004401][ T822]
[ 97.005784][ T822] CPU0
[ 97.006407][ T822] ----
[ 97.007010][ T822] lock(_xmit_NONE#2);
[ 97.007779][ T822] lock(_xmit_NONE#2);
[ 97.008550][ T822]
[ 97.008550][ T822] *** DEADLOCK ***
[ 97.008550][ T822]
[ 97.010057][ T822] May be due to missing lock nesting notation
[ 97.010057][ T822]
[ 97.011594][ T822] 7 locks held by ping/822:
[ 97.012426][ T822] #0: ffff888109a144f0 (sk_lock-AF_INET){+.+.}-{0:0}, at: raw_sendmsg+0x12f7/0x2b00
[ 97.014191][ T822] #1: ffffffffbce2f5a0 (rcu_read_lock_bh){....}-{1:2}, at: ip_finish_output2+0x249/0x2020
[ 97.016045][ T822] #2: ffffffffbce2f5a0 (rcu_read_lock_bh){....}-{1:2}, at: __dev_queue_xmit+0x1fd/0x2960
[ 97.017897][ T822] #3: ffff88810c385498 (_xmit_NONE#2){+.-.}-{2:2}, at: __dev_queue_xmit+0x1f52/0x2960
[ 97.019684][ T822] #4: ffffffffbce2f600 (rcu_read_lock){....}-{1:2}, at: bareudp_xmit+0x31b/0x3690 [bareudp]
[ 97.021573][ T822] #5: ffffffffbce2f5a0 (rcu_read_lock_bh){....}-{1:2}, at: ip_finish_output2+0x249/0x2020
[ 97.023424][ T822] #6: ffffffffbce2f5a0 (rcu_read_lock_bh){....}-{1:2}, at: __dev_queue_xmit+0x1fd/0x2960
[ 97.025259][ T822]
[ 97.025259][ T822] stack backtrace:
[ 97.026349][ T822] CPU: 3 PID: 822 Comm: ping Not tainted 5.10.0+ #819
[ 97.027609][ T822] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.10.2-1ubuntu1 04/01/2014
[ 97.029407][ T822] Call Trace:
[ 97.030015][ T822] dump_stack+0x99/0xcb
[ 97.030783][ T822] __lock_acquire.cold.77+0x149/0x3a9
[ 97.031773][ T822] ? stack_trace_save+0x81/0xa0
[ 97.032661][ T822] ? register_lock_class+0x1910/0x1910
[ 97.033673][ T822] ? register_lock_class+0x1910/0x1910
[ 97.034679][ T822] ? rcu_read_lock_sched_held+0x91/0xc0
[ 97.035697][ T822] ? rcu_read_lock_bh_held+0xa0/0xa0
[ 97.036690][ T822] lock_acquire+0x1b2/0x730
[ 97.037515][ T822] ? __dev_queue_xmit+0x1f52/0x2960
[ 97.038466][ T822] ? check_flags+0x50/0x50
[ 97.039277][ T822] ? netif_skb_features+0x296/0x9c0
[ 97.040226][ T822] ? validate_xmit_skb+0x29/0xb10
[ 97.041151][ T822] _raw_spin_lock+0x30/0x70
[ 97.041977][ T822] ? __dev_queue_xmit+0x1f52/0x2960
[ 97.042927][ T822] __dev_queue_xmit+0x1f52/0x2960
[ 97.043852][ T822] ? netdev_core_pick_tx+0x290/0x290
[ 97.044824][ T822] ? mark_held_locks+0xb7/0x120
[ 97.045712][ T822] ? lockdep_hardirqs_on_prepare+0x12c/0x3e0
[ 97.046824][ T822] ? __local_bh_enable_ip+0xa5/0xf0
[ 97.047771][ T822] ? ___neigh_create+0x12a8/0x1eb0
[ 97.048710][ T822] ? trace_hardirqs_on+0x41/0x120
[ 97.049626][ T822] ? ___neigh_create+0x12a8/0x1eb0
[ 97.050556][ T822] ? __local_bh_enable_ip+0xa5/0xf0
[ 97.051509][ T822] ? ___neigh_create+0x12a8/0x1eb0
[ 97.052443][ T822] ? check_chain_key+0x244/0x5f0
[ 97.053352][ T822] ? rcu_read_lock_bh_held+0x56/0xa0
[ 97.054317][ T822] ? ip_finish_output2+0x6ea/0x2020
[ 97.055263][ T822] ? pneigh_lookup+0x410/0x410
[ 97.056135][ T822] ip_finish_output2+0x6ea/0x2020
[ ... ]

Acked-by: Guillaume Nault <gnault@redhat.com>
Fixes: 571912c69f0e ("net: UDP tunnel encapsulation module for tunnelling different protocols like MPLS, IP, NSH etc.")
Signed-off-by: Taehee Yoo <ap420073@gmail.com>
Link: https://lore.kernel.org/r/20201228152136.24215-1-ap420073@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

bareudp: constify device_type declaration

device_type may be declared as const.

Signed-off-by: Jonas Bonn <jonas@norrbonn.se>
Link: https://lore.kernel.org/r/20201202122324.564918-1-jonas@norrbonn.se
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

net: switch to dev_get_tstats64

Replace ip_tunnel_get_stats64() with the new identical core function
dev_get_tstats64().

Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

bareudp: use dev_sw_netstats_rx_add()

use new helper for netstats settings

Signed-off-by: Fabian Frederick <fabf@skynet.be>
Signed-off-by: David S. Miller <davem@davemloft.net>

tunnels: PMTU discovery support for directly bridged IP packets

It's currently possible to bridge Ethernet tunnels carrying IP
packets directly to external interfaces without assigning them
addresses and routes on the bridged network itself: this is the case
for UDP tunnels bridged with a standard bridge or by Open vSwitch.

PMTU discovery is currently broken with those configurations, because
the encapsulation effectively decreases the MTU of the link, and
while we are able to account for this using PMTU discovery on the
lower layer, we don't have a way to relay ICMP or ICMPv6 messages
needed by the sender, because we don't have valid routes to it.

On the other hand, as a tunnel endpoint, we can't fragment packets
as a general approach: this is for instance clearly forbidden for
VXLAN by RFC 7348, section 4.3:

VTEPs MUST NOT fragment VXLAN packets. Intermediate routers may
fragment encapsulated VXLAN packets due to the larger frame size.
The destination VTEP MAY silently discard such VXLAN fragments.

The same paragraph recommends that the MTU over the physical network
accomodates for encapsulations, but this isn't a practical option for
complex topologies, especially for typical Open vSwitch use cases.

Further, it states that:

Other techniques like Path MTU discovery (see [RFC1191] and
[RFC1981]) MAY be used to address this requirement as well.

Now, PMTU discovery already works for routed interfaces, we get
route exceptions created by the encapsulation device as they receive
ICMP Fragmentation Needed and ICMPv6 Packet Too Big messages, and
we already rebuild those messages with the appropriate MTU and route
them back to the sender.

Add the missing bits for bridged cases:

- checks in skb_tunnel_check_pmtu() to understand if it's appropriate
to trigger a reply according to RFC 1122 section 3.2.2 for ICMP and
RFC 4443 section 2.4 for ICMPv6. This function is already called by
UDP tunnels

- a new function generating those ICMP or ICMPv6 replies. We can't
reuse icmp_send() and icmp6_send() as we don't see the sender as a
valid destination. This doesn't need to be generic, as we don't
cover any other type of ICMP errors given that we only provide an
encapsulation function to the sender

While at it, make the MTU check in skb_tunnel_check_pmtu() accurate:
we might receive GSO buffers here, and the passed headroom already
includes the inner MAC length, so we don't have to account for it
a second time (that would imply three MAC headers on the wire, but
there are just two).

This issue became visible while bridging IPv6 packets with 4500 bytes
of payload over GENEVE using IPv4 with a PMTU of 4000. Given the 50
bytes of encapsulation headroom, we would advertise MTU as 3950, and
we would reject fragmented IPv6 datagrams of 3958 bytes size on the
wire. We're exclusively dealing with network MTU here, though, so we
could get Ethernet frames up to 3964 octets in that case.

v2:
- moved skb_tunnel_check_pmtu() to ip_tunnel_core.c (David Ahern)
- split IPv4/IPv6 functions (David Ahern)

Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
Reviewed-by: David Ahern <dsahern@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

bareudp: forbid mixing IP and MPLS in multiproto mode

In multiproto mode, bareudp_xmit() accepts sending multicast MPLS and
IPv6 packets regardless of the bareudp ethertype. In practice, this
let an IP tunnel send multicast MPLS packets, or an MPLS tunnel send
IPv6 packets.

We need to restrict the test further, so that the multiproto mode only
enables
* IPv6 for IPv4 tunnels,
* or multicast MPLS for unicast MPLS tunnels.

To improve clarity, the protocol validation is moved to its own
function, where each logical test has its own condition.

v2: s/ntohs/htons/

Fixes: 4b5f67232d95 ("net: Special handling for IP & MPLS.")
Signed-off-by: Guillaume Nault <gnault@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

bareudp: Reverted support to enable & disable rx metadata collection

The commit fe80536acf83 ("bareudp: Added attribute to enable & disable
rx metadata collection") breaks the the original(5.7) default behavior of
bareudp module to collect RX metadadata at the receive. It was added to
avoid the crash at the kernel neighbour subsytem when packet with metadata
from bareudp is processed. But it is no more needed as the
commit 394de110a733 ("net: Added pointer check for
dst->ops->neigh_lookup in dst_neigh_lookup_skb") solves this crash.

Fixes: fe80536acf83 ("bareudp: Added attribute to enable & disable rx metadata collection")
Signed-off-by: Martin Varghese <martin.varghese@nokia.com>
Acked-by: Guillaume Nault <gnault@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

bareudp: Added attribute to enable & disable rx metadata collection

Metadata need not be collected in receive if the packet from bareudp
device is not targeted to openvswitch.

Signed-off-by: Martin <martin.varghese@nokia.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

bareudp: Fixed multiproto mode configuration

Code to handle multiproto configuration is missing.

Fixes: 4b5f67232d95 ("net: Special handling for IP & MPLS")
Signed-off-by: Martin <martin.varghese@nokia.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

bareudp: Fixed configuration to avoid having garbage values

Code to initialize the conf structure while gathering the configuration
of the device was missing.

Fixes: 571912c69f0e ("net: UDP tunnel encapsulation module for tunnelling different protocols like MPLS, IP, NSH etc.")
Signed-off-by: Martin <martin.varghese@nokia.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: bareudp: avoid uninitialized variable warning

clang points out that building without IPv6 would lead to returning
an uninitialized variable if a packet with family!=AF_INET is
passed into bareudp_udp_encap_recv():

drivers/net/bareudp.c:139:6: error: variable 'err' is used uninitialized whenever 'if' condition is false [-Werror,-Wsometimes-uninitialized]
if (family == AF_INET)
^~~~~~~~~~~~~~~~~
drivers/net/bareudp.c:146:15: note: uninitialized use occurs here
if (unlikely(err)) {
^~~
include/linux/compiler.h:78:42: note: expanded from macro 'unlikely'
# define unlikely(x) __builtin_expect(!!(x), 0)
^
drivers/net/bareudp.c:139:2: note: remove the 'if' if its condition is always true
if (family == AF_INET)
^~~~~~~~~~~~~~~~~~~~~~

This cannot happen in practice, so change the condition in a way that
gcc sees the IPv4 case as unconditionally true here.
For consistency, change all the similar constructs in this file the
same way, using "if(IS_ENABLED())" instead of #if IS_ENABLED()".

Fixes: 571912c69f0e ("net: UDP tunnel encapsulation module for tunnelling different protocols like MPLS, IP, NSH etc.")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Reviewed-by: Nathan Chancellor <natechancellor@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

bareudp: Fixed bareudp receive handling

Reverted commit "2baecda bareudp: remove unnecessary udp_encap_enable() in
bareudp_socket_create()"

An explicit call to udp_encap_enable is needed as the setup_udp_tunnel_sock
does not call udp_encap_enable if the if the socket is of type v6.

Bareudp device uses v6 socket to receive v4 & v6 traffic

CC: Taehee Yoo <ap420073@gmail.com>
Fixes: 2baecda37f4e ("bareudp: remove unnecessary udp_encap_enable() in bareudp_socket_create()")
Signed-off-by: Martin Varghese <martin.varghese@nokia.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

bareudp: remove unnecessary udp_encap_enable() in bareudp_socket_create()

In the current code, udp_encap_enable() is called in
bareudp_socket_create().
But, setup_udp_tunnel_sock() internally calls udp_encap_enable().
So, udp_encap_enable() is unnecessary.

Signed-off-by: Taehee Yoo <ap420073@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

bareudp: print error message when command fails

When bareudp netlink command fails, it doesn't print any error message.
So, users couldn't know the exact reason.
In order to tell the exact reason to the user, the extack error message
is used in this patch.

Signed-off-by: Taehee Yoo <ap420073@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

bareudp: add module alias

In the current bareudp code, there is no module alias.
So, RTNL couldn't load bareudp module automatically.

Signed-off-by: Taehee Yoo <ap420073@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

bareudp: Fix uninitialized variable warnings.

drivers/net/bareudp.c: In function 'bareudp_xmit_skb':
drivers/net/bareudp.c:346:9: warning: 'err' may be used uninitialized in this function [-Wmaybe-uninitialized]
346 | return err;
| ^~~
drivers/net/bareudp.c: In function 'bareudp6_xmit_skb':
drivers/net/bareudp.c:407:9: warning: 'err' may be used uninitialized in this function [-Wmaybe-uninitialized]
407 | return err;

Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: Special handling for IP & MPLS.

Special handling is needed in bareudp module for IP & MPLS as they
support more than one ethertypes.

MPLS has 2 ethertypes. 0x8847 for MPLS unicast and 0x8848 for MPLS multicast.
While decapsulating MPLS packet from UDP packet the tunnel destination IP
address is checked to determine the ethertype. The ethertype of the packet
will be set to 0x8848 if the tunnel destination IP address is a multicast
IP address. The ethertype of the packet will be set to 0x8847 if the
tunnel destination IP address is a unicast IP address.

IP has 2 ethertypes.0x0800 for IPV4 and 0x86dd for IPv6. The version
field of the IP header tunnelled will be checked to determine the ethertype.

This special handling to tunnel additional ethertypes will be disabled
by default and can be enabled using a flag called multiproto. This flag can
be used only with ethertypes 0x8847 and 0x0800.

Signed-off-by: Martin Varghese <martin.varghese@nokia.com>
Acked-by: Willem de Bruijn <willemb@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: UDP tunnel encapsulation module for tunnelling different protocols like MPLS, IP, NSH etc.

The Bareudp tunnel module provides a generic L3 encapsulation
tunnelling module for tunnelling different protocols like MPLS,
IP,NSH etc inside a UDP tunnel.

Signed-off-by: Martin Varghese <martin.varghese@nokia.com>
Acked-by: Willem de Bruijn <willemb@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>