net: dst_cache: add two DEBUG_NET warnings

After fixing four different bugs involving dst_cache
users, it might be worth adding a check about BH being
blocked by dst_cache callers.

DEBUG_NET_WARN_O

net: dst_cache: add two DEBUG_NET warnings

After fixing four different bugs involving dst_cache
users, it might be worth adding a check about BH being
blocked by dst_cache callers.

DEBUG_NET_WARN_ON_ONCE(!in_softirq());

It is not fatal, if we missed valid case where no
BH deadlock is to be feared, we might change this.

Signed-off-by: Eric Dumazet <[email protected]>
Acked-by: Paolo Abeni <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Jakub Kicinski <[email protected]>

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net: dst_cache: minor optimization in dst_cache_set_ip6()

There is no need to use this_cpu_ptr(dst_cache->cache) twice.

Compiler is unable to optimize the second call, because of
per-cpu constraint

net: dst_cache: minor optimization in dst_cache_set_ip6()

There is no need to use this_cpu_ptr(dst_cache->cache) twice.

Compiler is unable to optimize the second call, because of
per-cpu constraints.

Signed-off-by: Eric Dumazet <[email protected]>
Acked-by: Paolo Abeni <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Jakub Kicinski <[email protected]>

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net: dst_cache: annotate data-races around dst_cache->reset_ts

dst_cache->reset_ts is read or written locklessly,
add READ_ONCE() and WRITE_ONCE() annotations.

Signed-off-by: Eric Dumazet <edumazet

net: dst_cache: annotate data-races around dst_cache->reset_ts

dst_cache->reset_ts is read or written locklessly,
add READ_ONCE() and WRITE_ONCE() annotations.

Signed-off-by: Eric Dumazet <[email protected]>
Acked-by: Paolo Abeni <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Jakub Kicinski <[email protected]>

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inet: introduce dst_rtable() helper

I added dst_rt6_info() in commit
e8dfd42c17fa ("ipv6: introduce dst_rt6_info() helper")

This patch does a similar change for IPv4.

Instead of (struct rtable *)d

inet: introduce dst_rtable() helper

I added dst_rt6_info() in commit
e8dfd42c17fa ("ipv6: introduce dst_rt6_info() helper")

This patch does a similar change for IPv4.

Instead of (struct rtable *)dst casts, we can use :

#define dst_rtable(_ptr) \
container_of_const(_ptr, struct rtable, dst)

Patch is smaller than IPv6 one, because IPv4 has skb_rtable() helper.

Signed-off-by: Eric Dumazet <[email protected]>
Reviewed-by: David Ahern <[email protected]>
Reviewed-by: Sabrina Dubroca <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Jakub Kicinski <[email protected]>

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ipv6: introduce dst_rt6_info() helper

Instead of (struct rt6_info *)dst casts, we can use :

#define dst_rt6_info(_ptr) \
container_of_const(_ptr, struct rt6_info, dst)

Some places needed

ipv6: introduce dst_rt6_info() helper

Instead of (struct rt6_info *)dst casts, we can use :

#define dst_rt6_info(_ptr) \
container_of_const(_ptr, struct rt6_info, dst)

Some places needed missing const qualifiers :

ip6_confirm_neigh(), ipv6_anycast_destination(),
ipv6_unicast_destination(), has_gateway()

v2: added missing parts (David Ahern)

Signed-off-by: Eric Dumazet <[email protected]>
Reviewed-by: David Ahern <[email protected]>
Signed-off-by: David S. Miller <[email protected]>

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wireguard: device: reset peer src endpoint when netns exits

Each peer's endpoint contains a dst_cache entry that takes a reference
to another netdev. When the containing namespace exits, we take dow

wireguard: device: reset peer src endpoint when netns exits

Each peer's endpoint contains a dst_cache entry that takes a reference
to another netdev. When the containing namespace exits, we take down the
socket and prevent future sockets from being created (by setting
creating_net to NULL), which removes that potential reference on the
netns. However, it doesn't release references to the netns that a netdev
cached in dst_cache might be taking, so the netns still might fail to
exit. Since the socket is gimped anyway, we can simply clear all the
dst_caches (by way of clearing the endpoint src), which will release all
references.

However, the current dst_cache_reset function only releases those
references lazily. But it turns out that all of our usages of
wg_socket_clear_peer_endpoint_src are called from contexts that are not
exactly high-speed or bottle-necked. For example, when there's
connection difficulty, or when userspace is reconfiguring the interface.
And in particular for this patch, when the netns is exiting. So for
those cases, it makes more sense to call dst_release immediately. For
that, we add a small helper function to dst_cache.

This patch also adds a test to netns.sh from Hangbin Liu to ensure this
doesn't regress.

Tested-by: Hangbin Liu <[email protected]>
Reported-by: Xiumei Mu <[email protected]>
Cc: Toke Høiland-Jørgensen <[email protected]>
Cc: Paolo Abeni <[email protected]>
Fixes: 900575aa33a3 ("wireguard: device: avoid circular netns references")
Signed-off-by: Jason A. Donenfeld <[email protected]>
Signed-off-by: Jakub Kicinski <[email protected]>

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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 th

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 <[email protected]>
Reviewed-by: Allison Randal <[email protected]>
Cc: [email protected]
Link: https://lkml.kernel.org/r/[email protected]
Signed-off-by: Greg Kroah-Hartman <[email protected]>

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net: core: dst_cache_set_ip6: Rename 'addr' parameter to 'saddr' for consistency

The other dst_cache_{get,set}_ip{4,6} functions, and the doc comment for
dst_cache_set_ip6 use 'saddr' for their sour

net: core: dst_cache_set_ip6: Rename 'addr' parameter to 'saddr' for consistency

The other dst_cache_{get,set}_ip{4,6} functions, and the doc comment for
dst_cache_set_ip6 use 'saddr' for their source address parameter. Rename
the parameter to increase consistency.

This fixes the following kernel-doc warnings:

./include/net/dst_cache.h:58: warning: Function parameter or member 'addr' not described in 'dst_cache_set_ip6'
./include/net/dst_cache.h:58: warning: Excess function parameter 'saddr' description in 'dst_cache_set_ip6'

Fixes: 911362c70df5 ("net: add dst_cache support")
Signed-off-by: Jonathan Neuschäfer <[email protected]>
Signed-off-by: David S. Miller <[email protected]>

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net: dst_cache_per_cpu_dst_set() can be static

Signed-off-by: Fengguang Wu <[email protected]>
Signed-off-by: David S. Miller <[email protected]>

net: add dst_cache support

This patch add a generic, lockless dst cache implementation.
The need for lock is avoided updating the dst cache fields
only in per cpu scope, and requiring that the cache

net: add dst_cache support

This patch add a generic, lockless dst cache implementation.
The need for lock is avoided updating the dst cache fields
only in per cpu scope, and requiring that the cache manipulation
functions are invoked with the local bh disabled.

The refresh_ts and reset_ts fields are used to ensure the cache
consistency in case of cuncurrent cache update (dst_cache_set*) and
reset operation (dst_cache_reset).

Consider the following scenario:

CPU1: CPU2:
<cache lookup with emtpy cache: it fails>
<get dst via uncached route lookup>
<related configuration changes>
dst_cache_reset()
dst_cache_set()

The dst entry set passed to dst_cache_set() should not be used
for later dst cache lookup, because it's obtained using old
configuration values.

Since the refresh_ts is updated only on dst_cache lookup, the
cached value in the above scenario will be discarded on the next
lookup.

Signed-off-by: Paolo Abeni <[email protected]>
Suggested-and-acked-by: Hannes Frederic Sowa <[email protected]>
Signed-off-by: David S. Miller <[email protected]>

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