We will remove RTNL for neigh_get() and run it under RCU instead.
neigh_get_reply() and pneigh_get_reply() allocate skb with GFP_KERNEL.
Let's move the allocation before __dev_get_by_index() in neigh_get().
Now, neigh_get_reply() and pneigh_get_reply() are inlined and
rtnl_unicast() is factorised.
We will convert pneigh_lookup() to __pneigh_lookup() later.
Signed-off-by: Kuniyuki Iwashima <kuniyu@google.com>
Link: https://patch.msgid.link/20250716221221.442239-4-kuniyu@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
We will remove RTNL for neigh_get() and run it under RCU instead.
neigh_get() returns -EINVAL in the following cases:
* NDA_DST is not specified
* Both ndm->ndm_ifindex and NTF_PROXY are not specified
These validations do not require RCU.
Let's move them to neigh_valid_get_req().
While at it, the extack string for the first case is replaced with
NL_SET_ERR_ATTR_MISS().
Signed-off-by: Kuniyuki Iwashima <kuniyu@google.com>
Link: https://patch.msgid.link/20250716221221.442239-3-kuniyu@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
A net device has a threaded sysctl that can be used to enable threaded
NAPI polling on all of the NAPI contexts under that device. Allow
enabling threaded NAPI polling at individual NAPI level using netlink.
Extend the netlink operation `napi-set` and allow setting the threaded
attribute of a NAPI. This will enable the threaded polling on a NAPI
context.
Add a test in `nl_netdev.py` that verifies various cases of threaded
NAPI being set at NAPI and at device level.
Tested
./tools/testing/selftests/net/nl_netdev.py
TAP version 13
1..7
ok 1 nl_netdev.empty_check
ok 2 nl_netdev.lo_check
ok 3 nl_netdev.page_pool_check
ok 4 nl_netdev.napi_list_check
ok 5 nl_netdev.dev_set_threaded
ok 6 nl_netdev.napi_set_threaded
ok 7 nl_netdev.nsim_rxq_reset_down
# Totals: pass:7 fail:0 xfail:0 xpass:0 skip:0 error:0
Signed-off-by: Samiullah Khawaja <skhawaja@google.com>
Reviewed-by: Willem de Bruijn <willemb@google.com>
Link: https://patch.msgid.link/20250710211203.3979655-1-skhawaja@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
inet6_sk(sk)->ipv6_ac_list is protected by lock_sock().
In ipv6_sock_ac_join(), only __dev_get_by_index(), __dev_get_by_flags(),
and __in6_dev_get() require RTNL.
__dev_get_by_flags() is only used by ipv6_sock_ac_join() and can be
converted to RCU version.
Let's replace RCU version helper and drop RTNL from IPV6_JOIN_ANYCAST.
setsockopt_needs_rtnl() will be removed in the next patch.
Signed-off-by: Kuniyuki Iwashima <kuniyu@google.com>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Link: https://patch.msgid.link/20250702230210.3115355-15-kuni1840@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Since its introduction in commit 6fa01ccd88 ("skbuff: Add pskb_extract()
helper function"), pskb_carve_frag_list() never used the argument @skb.
Drop it and adapt the only caller.
No functional change intended.
Reviewed-by: Simon Horman <horms@kernel.org>
Signed-off-by: Michal Luczaj <mhal@rbox.co>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Since its introduction in commit ce098da149 ("skbuff: Introduce
slab_build_skb()"), __slab_build_skb() never used the @skb argument. Remove
it and adapt both callers.
No functional change intended.
Reviewed-by: Simon Horman <horms@kernel.org>
Signed-off-by: Michal Luczaj <mhal@rbox.co>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Move UDP header construction from netpoll_send_udp() into a new
static helper function push_udp(). This completes the protocol
layer refactoring by:
1. Creating a dedicated helper for UDP header assembly
2. Removing UDP-specific logic from the main send function
3. Establishing a consistent pattern with existing IPv4/IPv6 helpers:
- push_udp()
- push_ipv4()
- push_ipv6()
The change improves code organization and maintains the encapsulation
pattern established in previous refactorings.
Signed-off-by: Breno Leitao <leitao@debian.org>
Reviewed-by: Simon Horman <horms@kernel.org>
Link: https://patch.msgid.link/20250702-netpoll_untagle_ip-v2-5-13cf3db24e2b@debian.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Move IPv4 header construction from netpoll_send_udp() into a new
static helper function push_ipv4(). This completes the refactoring
started with IPv6 header handling, creating symmetric helper functions
for both IP versions.
Changes include:
1. Extracting IPv4 header setup logic into push_ipv4()
2. Replacing inline IPv4 code with helper call
3. Moving eth assignment after helper calls for consistency
The refactoring reduces code duplication and improves maintainability
by isolating IP version-specific logic.
Signed-off-by: Breno Leitao <leitao@debian.org>
Reviewed-by: Simon Horman <horms@kernel.org>
Link: https://patch.msgid.link/20250702-netpoll_untagle_ip-v2-4-13cf3db24e2b@debian.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Replace pointer-dereference sizeof() operations with explicit struct names
for improved readability and maintainability. This change:
1. Replaces `sizeof(*udph)` with `sizeof(struct udphdr)`
2. Replaces `sizeof(*ip6h)` with `sizeof(struct ipv6hdr)`
3. Replaces `sizeof(*iph)` with `sizeof(struct iphdr)`
This will make it easy to move code in the upcoming patches.
No functional changes are introduced by this patch.
Signed-off-by: Breno Leitao <leitao@debian.org>
Reviewed-by: Simon Horman <horms@kernel.org>
Link: https://patch.msgid.link/20250702-netpoll_untagle_ip-v2-1-13cf3db24e2b@debian.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
MSG_ZEROCOPY data must be copied before data is queued to local
sockets, to avoid indefinite timeout until memory release.
This test is performed by skb_orphan_frags_rx, which is called when
looping an egress skb to packet sockets, error queue or ingress path.
To preserve zerocopy for skbs that are looped to ingress but are then
forwarded to an egress device rather than delivered locally, defer
this last check until an skb enters the local IP receive path.
This is analogous to existing behavior of skb_clear_delivery_time.
Signed-off-by: Willem de Bruijn <willemb@google.com>
Link: https://patch.msgid.link/20250630194312.1571410-2-willemdebruijn.kernel@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
dst->dev is read locklessly in many contexts,
and written in dst_dev_put().
Fixing all the races is going to need many changes.
We probably will have to add full RCU protection.
Add three helpers to ease this painful process.
static inline struct net_device *dst_dev(const struct dst_entry *dst)
{
return READ_ONCE(dst->dev);
}
static inline struct net_device *skb_dst_dev(const struct sk_buff *skb)
{
return dst_dev(skb_dst(skb));
}
static inline struct net *skb_dst_dev_net(const struct sk_buff *skb)
{
return dev_net(skb_dst_dev(skb));
}
static inline struct net *skb_dst_dev_net_rcu(const struct sk_buff *skb)
{
return dev_net_rcu(skb_dst_dev(skb));
}
Fixes: 4a6ce2b6f2 ("net: introduce a new function dst_dev_put()")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reviewed-by: Kuniyuki Iwashima <kuniyu@google.com>
Link: https://patch.msgid.link/20250630121934.3399505-7-edumazet@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
dst_dev_put() can overwrite dst->output while other
cpus might read this field (for instance from dst_output())
Add READ_ONCE()/WRITE_ONCE() annotations to suppress
potential issues.
We will likely need RCU protection in the future.
Fixes: 4a6ce2b6f2 ("net: introduce a new function dst_dev_put()")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reviewed-by: Kuniyuki Iwashima <kuniyu@google.com>
Link: https://patch.msgid.link/20250630121934.3399505-6-edumazet@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
____cacheline_aligned_in_smp attribute only makes sure to align
a field to a cache line. It does not prevent the linker to use
the remaining of the cache line for other variables, causing
potential false sharing.
Move tcp_memory_allocated into a dedicated cache line.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reviewed-by: Willem de Bruijn <willemb@google.com>
Link: https://patch.msgid.link/20250630093540.3052835-4-edumazet@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
tl;dr
=====
Add a new neighbor flag ("extern_valid") that can be used to indicate to
the kernel that a neighbor entry was learned and determined to be valid
externally. The kernel will not try to remove or invalidate such an
entry, leaving these decisions to the user space control plane. This is
needed for EVPN multi-homing where a neighbor entry for a multi-homed
host needs to be synced across all the VTEPs among which the host is
multi-homed.
Background
==========
In a typical EVPN multi-homing setup each host is multi-homed using a
set of links called ES (Ethernet Segment, i.e., LAG) to multiple leaf
switches (VTEPs). VTEPs that are connected to the same ES are called ES
peers.
When a neighbor entry is learned on a VTEP, it is distributed to both ES
peers and remote VTEPs using EVPN MAC/IP advertisement routes. ES peers
use the neighbor entry when routing traffic towards the multi-homed host
and remote VTEPs use it for ARP/NS suppression.
Motivation
==========
If the ES link between a host and the VTEP on which the neighbor entry
was locally learned goes down, the EVPN MAC/IP advertisement route will
be withdrawn and the neighbor entries will be removed from both ES peers
and remote VTEPs. Routing towards the multi-homed host and ARP/NS
suppression can fail until another ES peer locally learns the neighbor
entry and distributes it via an EVPN MAC/IP advertisement route.
"draft-rbickhart-evpn-ip-mac-proxy-adv-03" [1] suggests avoiding these
intermittent failures by having the ES peers install the neighbor
entries as before, but also injecting EVPN MAC/IP advertisement routes
with a proxy indication. When the previously mentioned ES link goes down
and the original EVPN MAC/IP advertisement route is withdrawn, the ES
peers will not withdraw their neighbor entries, but instead start aging
timers for the proxy indication.
If an ES peer locally learns the neighbor entry (i.e., it becomes
"reachable"), it will restart its aging timer for the entry and emit an
EVPN MAC/IP advertisement route without a proxy indication. An ES peer
will stop its aging timer for the proxy indication if it observes the
removal of the proxy indication from at least one of the ES peers
advertising the entry.
In the event that the aging timer for the proxy indication expired, an
ES peer will withdraw its EVPN MAC/IP advertisement route. If the timer
expired on all ES peers and they all withdrew their proxy
advertisements, the neighbor entry will be completely removed from the
EVPN fabric.
Implementation
==============
In the above scheme, when the control plane (e.g., FRR) advertises a
neighbor entry with a proxy indication, it expects the corresponding
entry in the data plane (i.e., the kernel) to remain valid and not be
removed due to garbage collection or loss of carrier. The control plane
also expects the kernel to notify it if the entry was learned locally
(i.e., became "reachable") so that it will remove the proxy indication
from the EVPN MAC/IP advertisement route. That is why these entries
cannot be programmed with dummy states such as "permanent" or "noarp".
Instead, add a new neighbor flag ("extern_valid") which indicates that
the entry was learned and determined to be valid externally and should
not be removed or invalidated by the kernel. The kernel can probe the
entry and notify user space when it becomes "reachable" (it is initially
installed as "stale"). However, if the kernel does not receive a
confirmation, have it return the entry to the "stale" state instead of
the "failed" state.
In other words, an entry marked with the "extern_valid" flag behaves
like any other dynamically learned entry other than the fact that the
kernel cannot remove or invalidate it.
One can argue that the "extern_valid" flag should not prevent garbage
collection and that instead a neighbor entry should be programmed with
both the "extern_valid" and "extern_learn" flags. There are two reasons
for not doing that:
1. Unclear why a control plane would like to program an entry that the
kernel cannot invalidate but can completely remove.
2. The "extern_learn" flag is used by FRR for neighbor entries learned
on remote VTEPs (for ARP/NS suppression) whereas here we are
concerned with local entries. This distinction is currently irrelevant
for the kernel, but might be relevant in the future.
Given that the flag only makes sense when the neighbor has a valid
state, reject attempts to add a neighbor with an invalid state and with
this flag set. For example:
# ip neigh add 192.0.2.1 nud none dev br0.10 extern_valid
Error: Cannot create externally validated neighbor with an invalid state.
# ip neigh add 192.0.2.1 lladdr 00:11:22:33:44:55 nud stale dev br0.10 extern_valid
# ip neigh replace 192.0.2.1 nud failed dev br0.10 extern_valid
Error: Cannot mark neighbor as externally validated with an invalid state.
The above means that a neighbor cannot be created with the
"extern_valid" flag and flags such as "use" or "managed" as they result
in a neighbor being created with an invalid state ("none") and
immediately getting probed:
# ip neigh add 192.0.2.1 lladdr 00:11:22:33:44:55 nud stale dev br0.10 extern_valid use
Error: Cannot create externally validated neighbor with an invalid state.
However, these flags can be used together with "extern_valid" after the
neighbor was created with a valid state:
# ip neigh add 192.0.2.1 lladdr 00:11:22:33:44:55 nud stale dev br0.10 extern_valid
# ip neigh replace 192.0.2.1 lladdr 00:11:22:33:44:55 nud stale dev br0.10 extern_valid use
One consequence of preventing the kernel from invalidating a neighbor
entry is that by default it will only try to determine reachability
using unicast probes. This can be changed using the "mcast_resolicit"
sysctl:
# sysctl net.ipv4.neigh.br0/10.mcast_resolicit
0
# tcpdump -nn -e -i br0.10 -Q out arp &
# ip neigh replace 192.0.2.1 lladdr 00:11:22:33:44:55 nud stale dev br0.10 extern_valid use
62:50:1d:11:93:6f > 00:11:22:33:44:55, ethertype ARP (0x0806), length 42: Request who-has 192.0.2.1 tell 192.0.2.2, length 28
62:50:1d:11:93:6f > 00:11:22:33:44:55, ethertype ARP (0x0806), length 42: Request who-has 192.0.2.1 tell 192.0.2.2, length 28
62:50:1d:11:93:6f > 00:11:22:33:44:55, ethertype ARP (0x0806), length 42: Request who-has 192.0.2.1 tell 192.0.2.2, length 28
# sysctl -wq net.ipv4.neigh.br0/10.mcast_resolicit=3
# ip neigh replace 192.0.2.1 lladdr 00:11:22:33:44:55 nud stale dev br0.10 extern_valid use
62:50:1d:11:93:6f > 00:11:22:33:44:55, ethertype ARP (0x0806), length 42: Request who-has 192.0.2.1 tell 192.0.2.2, length 28
62:50:1d:11:93:6f > 00:11:22:33:44:55, ethertype ARP (0x0806), length 42: Request who-has 192.0.2.1 tell 192.0.2.2, length 28
62:50:1d:11:93:6f > 00:11:22:33:44:55, ethertype ARP (0x0806), length 42: Request who-has 192.0.2.1 tell 192.0.2.2, length 28
62:50:1d:11:93:6f > ff:ff:ff:ff:ff:ff, ethertype ARP (0x0806), length 42: Request who-has 192.0.2.1 tell 192.0.2.2, length 28
62:50:1d:11:93:6f > ff:ff:ff:ff:ff:ff, ethertype ARP (0x0806), length 42: Request who-has 192.0.2.1 tell 192.0.2.2, length 28
62:50:1d:11:93:6f > ff:ff:ff:ff:ff:ff, ethertype ARP (0x0806), length 42: Request who-has 192.0.2.1 tell 192.0.2.2, length 28
iproute2 patches can be found here [2].
[1] https://datatracker.ietf.org/doc/html/draft-rbickhart-evpn-ip-mac-proxy-adv-03
[2] https://github.com/idosch/iproute2/tree/submit/extern_valid_v1
Signed-off-by: Ido Schimmel <idosch@nvidia.com>
Acked-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://patch.msgid.link/20250626073111.244534-2-idosch@nvidia.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Daniel Borkmann says:
====================
pull-request: bpf-next 2025-06-27
We've added 6 non-merge commits during the last 8 day(s) which contain
a total of 6 files changed, 120 insertions(+), 20 deletions(-).
The main changes are:
1) Fix RCU usage in task_cls_state() for BPF programs using helpers like
bpf_get_cgroup_classid_curr() outside of networking, from Charalampos
Mitrodimas.
2) Fix a sockmap race between map_update and a pending workqueue from
an earlier map_delete freeing the old psock where both pointed to the
same psock->sk, from Jiayuan Chen.
3) Fix a data corruption issue when using bpf_msg_pop_data() in kTLS which
failed to recalculate the ciphertext length, also from Jiayuan Chen.
4) Remove xdp_redirect_map{,_err} trace events since they are unused and
also hide XDP trace events under CONFIG_BPF_SYSCALL, from Steven Rostedt.
* tag 'for-netdev' of https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next:
xdp: tracing: Hide some xdp events under CONFIG_BPF_SYSCALL
xdp: Remove unused events xdp_redirect_map and xdp_redirect_map_err
net, bpf: Fix RCU usage in task_cls_state() for BPF programs
selftests/bpf: Add test to cover ktls with bpf_msg_pop_data
bpf, ktls: Fix data corruption when using bpf_msg_pop_data() in ktls
bpf, sockmap: Fix psock incorrectly pointing to sk
====================
Link: https://patch.msgid.link/20250626230111.24772-1-daniel@iogearbox.net
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Followup of commit 285975dd67 ("net: annotate data-races around
sk->sk_{rcv|snd}timeo").
Remove lock_sock()/release_sock() from ksmbd_tcp_rcv_timeout()
and add READ_ONCE()/WRITE_ONCE() where it is needed.
Also SO_RCVTIMEO_OLD and SO_RCVTIMEO_NEW can call sock_set_timeout()
without holding the socket lock.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Link: https://patch.msgid.link/20250620155536.335520-3-edumazet@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Followup of commit 285975dd67 ("net: annotate data-races around
sk->sk_{rcv|snd}timeo").
Remove lock_sock()/release_sock() from sock_set_sndtimeo(),
and add READ_ONCE()/WRITE_ONCE() where it is needed.
Also SO_SNDTIMEO_OLD and SO_SNDTIMEO_NEW can call sock_set_timeout()
without holding the socket lock.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Link: https://patch.msgid.link/20250620155536.335520-2-edumazet@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Difference between sock_i_uid() and sk_uid() is that
after sock_orphan(), sock_i_uid() returns GLOBAL_ROOT_UID
while sk_uid() returns the last cached sk->sk_uid value.
None of sock_i_uid() callers care about this.
Use sk_uid() which is much faster and inlined.
Note that diag/dump users are calling sock_i_ino() and
can not see the full benefit yet.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Lorenzo Colitti <lorenzo@google.com>
Reviewed-by: Maciej Żenczykowski <maze@google.com>
Link: https://patch.msgid.link/20250620133001.4090592-3-edumazet@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
