linux.git/net/ipv4/ip_tunnel.c, branch v6.17

net: ipv4: Add a flags argument to iptunnel_xmit(), udp_tunnel_xmit_skb()

2025-06-18T01:18:44+00:00

iptunnel_xmit() erases the contents of the SKB control block. In order to
be able to set particular IPCB flags on the SKB, add a corresponding
parameter, and propagate it to udp_tunnel_xmit_skb() as well.

In one of the following patches, VXLAN driver will use this facility to
mark packets as subject to IP multicast routing.

Signed-off-by: Petr Machata 
Reviewed-by: Ido Schimmel 
Reviewed-by: Nikolay Aleksandrov 
Acked-by: Antonio Quartulli 
Link: https://patch.msgid.link/89c9daf9f2dc088b6b92ccebcc929f51742de91f.1750113335.git.petrm@nvidia.com
Signed-off-by: Jakub Kicinski

ipv4: ip_tunnel: Replace strcpy use with strscpy

2025-05-06T01:16:11+00:00

Use of strcpy is decpreated, replaces the use of strcpy with strscpy as
recommended.

strscpy was chosen as it requires a NUL terminated non-padded string,
which is the case here.

I am aware there is an explicit bounds check above the second instance,
however using strscpy protects against buffer overflows in any future
code, and there is no good reason I can see to not use it.

I have also replaced the scrscpy above that had 3 params with the
version using 2 params. These are functionally equivalent, but it is
cleaner to have both using 2 params.

Signed-off-by: Ruben Wauters 
Reviewed-by: Simon Horman 
Link: https://patch.msgid.link/20250501202935.46318-1-rubenru09@aol.com
Signed-off-by: Jakub Kicinski

ipv4: ip_tunnel: Convert ip_tunnel_delete_nets() callers to ->exit_rtnl().

2025-04-15T00:08:42+00:00

ip_tunnel_delete_nets() iterates the dying netns list and performs the
same operations for each.

Let's export ip_tunnel_destroy() as ip_tunnel_delete_net() and call it
from ->exit_rtnl().

Signed-off-by: Kuniyuki Iwashima 
Reviewed-by: David Ahern 
Reviewed-by: Sabrina Dubroca 
Link: https://patch.msgid.link/20250411205258.63164-7-kuniyu@amazon.com
Signed-off-by: Jakub Kicinski

net: move misc netdev_lock flavors to a separate header

2025-03-08T17:06:50+00:00

Move the more esoteric helpers for netdev instance lock to
a dedicated header. This avoids growing netdevice.h to infinity
and makes rebuilding the kernel much faster (after touching
the header with the helpers).

The main netdev_lock() / netdev_unlock() functions are used
in static inlines in netdevice.h and will probably be used
most commonly, so keep them in netdevice.h.

Acked-by: Stanislav Fomichev 
Link: https://patch.msgid.link/20250307183006.2312761-1-kuba@kernel.org
Signed-off-by: Jakub Kicinski

net: rename netns_local to netns_immutable

2025-03-04T11:44:48+00:00

The name 'netns_local' is confusing. A following commit will export it via
netlink, so let's use a more explicit name.

Reported-by: Eric Dumazet 
Suggested-by: Kuniyuki Iwashima 
Signed-off-by: Nicolas Dichtel 
Reviewed-by: Kuniyuki Iwashima 
Signed-off-by: Paolo Abeni

net: ip_tunnel: Use link netns in newlink() of rtnl_link_ops

2025-02-21T23:28:02+00:00

When link_net is set, use it as link netns instead of dev_net(). This
prepares for rtnetlink core to create device in target netns directly,
in which case the two namespaces may be different.

Convert common ip_tunnel_newlink() to accept an extra link netns
argument.

Signed-off-by: Xiao Liang 
Reviewed-by: Kuniyuki Iwashima 
Link: https://patch.msgid.link/20250219125039.18024-7-shaw.leon@gmail.com
Signed-off-by: Jakub Kicinski

net: ip_tunnel: Don't set tunnel->net in ip_tunnel_init()

2025-02-21T23:28:02+00:00

ip_tunnel_init() is called from register_netdevice(). In all code paths
reaching here, tunnel->net should already have been set (either in
ip_tunnel_newlink() or __ip_tunnel_create()). So don't set it again.

Signed-off-by: Xiao Liang 
Reviewed-by: Kuniyuki Iwashima 
Link: https://patch.msgid.link/20250219125039.18024-6-shaw.leon@gmail.com
Signed-off-by: Jakub Kicinski

net: Fix netns for ip_tunnel_init_flow()

2024-12-23T18:04:41+00:00

The device denoted by tunnel->parms.link resides in the underlay net
namespace. Therefore pass tunnel->net to ip_tunnel_init_flow().

Fixes: db53cd3d88dc ("net: Handle l3mdev in ip_tunnel_init_flow")
Signed-off-by: Xiao Liang 
Reviewed-by: Ido Schimmel 
Link: https://patch.msgid.link/20241219130336.103839-1-shaw.leon@gmail.com
Signed-off-by: Jakub Kicinski

ipv4: ip_tunnel: Fix suspicious RCU usage warning in ip_tunnel_find()

2024-10-29T18:12:53+00:00

The per-netns IP tunnel hash table is protected by the RTNL mutex and
ip_tunnel_find() is only called from the control path where the mutex is
taken.

Add a lockdep expression to hlist_for_each_entry_rcu() in
ip_tunnel_find() in order to validate that the mutex is held and to
silence the suspicious RCU usage warning [1].

[1]
WARNING: suspicious RCU usage
6.12.0-rc3-custom-gd95d9a31aceb #139 Not tainted
-----------------------------
net/ipv4/ip_tunnel.c:221 RCU-list traversed in non-reader section!!

other info that might help us debug this:

rcu_scheduler_active = 2, debug_locks = 1
1 lock held by ip/362:
 #0: ffffffff86fc7cb0 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x377/0xf60

stack backtrace:
CPU: 12 UID: 0 PID: 362 Comm: ip Not tainted 6.12.0-rc3-custom-gd95d9a31aceb #139
Hardware name: Bochs Bochs, BIOS Bochs 01/01/2011
Call Trace:
 
 dump_stack_lvl+0xba/0x110
 lockdep_rcu_suspicious.cold+0x4f/0xd6
 ip_tunnel_find+0x435/0x4d0
 ip_tunnel_newlink+0x517/0x7a0
 ipgre_newlink+0x14c/0x170
 __rtnl_newlink+0x1173/0x19c0
 rtnl_newlink+0x6c/0xa0
 rtnetlink_rcv_msg+0x3cc/0xf60
 netlink_rcv_skb+0x171/0x450
 netlink_unicast+0x539/0x7f0
 netlink_sendmsg+0x8c1/0xd80
 ____sys_sendmsg+0x8f9/0xc20
 ___sys_sendmsg+0x197/0x1e0
 __sys_sendmsg+0x122/0x1f0
 do_syscall_64+0xbb/0x1d0
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

Fixes: c54419321455 ("GRE: Refactor GRE tunneling code.")
Suggested-by: Eric Dumazet 
Signed-off-by: Ido Schimmel 
Reviewed-by: Eric Dumazet 
Link: https://patch.msgid.link/20241023123009.749764-1-idosch@nvidia.com
Signed-off-by: Jakub Kicinski

ipv4: ip_tunnel: Unmask upper DSCP bits in ip_tunnel_xmit()

2024-09-09T13:14:53+00:00

Unmask the upper DSCP bits when initializing an IPv4 flow key via
ip_tunnel_init_flow() before passing it to ip_route_output_key() so that
in the future we could perform the FIB lookup according to the full DSCP
value.

Note that the 'tos' variable includes the full DS field. Either the one
specified as part of the tunnel parameters or the one inherited from the
inner packet.

Signed-off-by: Ido Schimmel 
Reviewed-by: Guillaume Nault 
Signed-off-by: David S. Miller