The udp-tunnel setup allows binding sockets to a network device. Prefer
the new SO_BINDTOIFINDEX to avoid temporarily resolving the device-name
just to look it up in the ioctl again.

Reviewed-by: Tom Gundersen <teg@jklm.no>
Signed-off-by: David Herrmann <dh.herrmann@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Lots of conflicts, by happily all cases of overlapping
changes, parallel adds, things of that nature.

Thanks to Stephen Rothwell, Saeed Mahameed, and others
for their guidance in these resolutions.

Signed-off-by: David S. Miller <davem@davemloft.net>

syzbot reported the use of uninitialized udp6_addr::sin6_scope_id.
We can just set ::sin6_scope_id to zero, as tunnels are unlikely
to use an IPv6 address that needs a scope id and there is no
interface to bind in this context.

For net-next, it looks different as we have cfg->bind_ifindex there
so we can probably call ipv6_iface_scope_id().

Same for ::sin6_flowinfo, tunnels don't use it.

Fixes: 8024e02879dd ("udp: Add udp_sock_create for UDP tunnels to open listener socket")
Reported-by: syzbot+c56449ed3652e6720f30@syzkaller.appspotmail.com
Cc: Jon Maloy <jon.maloy@ericsson.com>
Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

UDP tunnel sockets are always opened unbound to a specific device. This
patch allow the socket to be bound on a custom device, which
incidentally makes UDP tunnels VRF-aware if binding to an l3mdev.

Signed-off-by: Alexis Bauvin <abauvin@scaleway.com>
Reviewed-by: Amine Kherbouche <akherbouche@scaleway.com>
Tested-by: Amine Kherbouche <akherbouche@scaleway.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Some IPCB fields are currently set in udp_tunnel6_xmit_skb(), which are
never used before it reaches ip6tunnel_xmit(), and past that point the
control buffer is no longer interpreted as IPCB.

This clears these unused IPCB related codes. Currently there is no skb
scrubbing in ip6_udp_tunnel, otherwise IPCB(skb)->opt might need to be
cleared for IPv4 packets, as shown in 5146d1f1511
("tunnel: Clear IPCB(skb)->opt before dst_link_failure called").

Signed-off-by: Eli Cooper <elicooper@gmx.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

This patch extends udp_tunnel6_xmit_skb() to pass in the IPv6 flow label
from call sites. Currently, there's no such option and it's always set to
zero when writing ip6_flow_hdr(). Add a label member to ip_tunnel_key, so
that flow-based tunnels via collect metadata frontends can make use of it.
vxlan and geneve will be converted to add flow label support separately.

Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: David S. Miller <davem@davemloft.net>

By default (subject to the sysctl settings), IPv6 sockets listen also for
IPv4 traffic. Vxlan is not prepared for that and expects IPv6 header in
packets received through an IPv6 socket.

In addition, it's currently not possible to have both IPv4 and IPv6 vxlan
tunnel on the same port (unless bindv6only sysctl is enabled), as it's not
possible to create and bind both IPv4 and IPv6 vxlan interfaces and there's
no way to specify both IPv4 and IPv6 remote/group IP addresses.

Set IPV6_V6ONLY on vxlan sockets to fix both of these issues. This is not
done globally in udp_tunnel, as l2tp and tipc seems to work okay when
receiving IPv4 packets on IPv6 socket and people may rely on this behavior.
The other tunnels (geneve and fou) do not support IPv6.

Signed-off-by: Jiri Benc <jbenc@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Now that sk_alloc knows when a kernel socket is being allocated modify
it to not reference count the network namespace of kernel sockets.

Keep track of if a socket needs reference counting by adding a flag to
struct sock called sk_net_refcnt.

Update all of the callers of sock_create_kern to stop using
sk_change_net and sk_release_kernel as those hacks are no longer
needed, to avoid reference counting a kernel socket.

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

This is long overdue, and is part of cleaning up how we allocate kernel
sockets that don't reference count struct net.

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

That was we can make sure the output path of ipv4/ipv6 operate on
the UDP socket rather than whatever random thing happens to be in
skb->sk.

Based upon a patch by Jiri Pirko.

Signed-off-by: David S. Miller <davem@davemloft.net>
Acked-by: Hannes Frederic Sowa <hannes@stressinduktion.org>