[PATCH net-next] tcp: inline tcp_filter()

[PATCH net-next] tcp: inline tcp_filter()

[Eric Dumazet]

This helper is already (auto)inlined from IPv4 TCP stack.

Make it an inline function to benefit IPv6 as well.

$ scripts/bloat-o-meter -t vmlinux.old vmlinux.new
add/remove: 0/2 grow/shrink: 1/0 up/down: 30/-49 (-19)
Function                                     old     new   delta
tcp_v6_rcv                                  3448    3478     +30
__pfx_tcp_filter                              16       -     -16
tcp_filter                                    33       -     -33
Total: Before=24891904, After=24891885, chg -0.00%

Signed-off-by: Eric Dumazet <edumazet@google.com>
---
 include/net/tcp.h   | 8 +++++++-
 net/ipv4/tcp_ipv4.c | 8 --------
 2 files changed, 7 insertions(+), 9 deletions(-)

diff --git a/include/net/tcp.h b/include/net/tcp.h
index 8f9f52f3408c2e87adaad3e26ffc7162776309f1..40e72b9cb85f08714d3f458c0bd1402a5fb1eb4e 100644
--- a/include/net/tcp.h
+++ b/include/net/tcp.h
@@ -1633,8 +1633,14 @@ static inline bool tcp_checksum_complete(struct sk_buff *skb)
 bool tcp_add_backlog(struct sock *sk, struct sk_buff *skb,
 		     enum skb_drop_reason *reason);
 
+static inline int tcp_filter(struct sock *sk, struct sk_buff *skb,
+			     enum skb_drop_reason *reason)
+{
+	const struct tcphdr *th = (const struct tcphdr *)skb->data;
+
+	return sk_filter_trim_cap(sk, skb, __tcp_hdrlen(th), reason);
+}
 
-int tcp_filter(struct sock *sk, struct sk_buff *skb, enum skb_drop_reason *reason);
 void tcp_set_state(struct sock *sk, int state);
 void tcp_done(struct sock *sk);
 int tcp_abort(struct sock *sk, int err);
diff --git a/net/ipv4/tcp_ipv4.c b/net/ipv4/tcp_ipv4.c
index 01fd563472608cc10744d3a5d4fb998b83c4be97..6264fc0b2be53854598d7c37ce1c7928d2e0b507 100644
--- a/net/ipv4/tcp_ipv4.c
+++ b/net/ipv4/tcp_ipv4.c
@@ -2109,14 +2109,6 @@ bool tcp_add_backlog(struct sock *sk, struct sk_buff *skb,
 }
 EXPORT_IPV6_MOD(tcp_add_backlog);
 
-int tcp_filter(struct sock *sk, struct sk_buff *skb, enum skb_drop_reason *reason)
-{
-	struct tcphdr *th = (struct tcphdr *)skb->data;
-
-	return sk_filter_trim_cap(sk, skb, th->doff * 4, reason);
-}
-EXPORT_IPV6_MOD(tcp_filter);
-
 static void tcp_v4_restore_cb(struct sk_buff *skb)
 {
 	memmove(IPCB(skb), &TCP_SKB_CB(skb)->header.h4,
-- 
2.53.0.rc2.204.g2597b5adb4-goog

Re: [PATCH net-next] tcp: inline tcp_filter()

[Kuniyuki Iwashima]

On Thu, Feb 5, 2026 at 8:43 AM Eric Dumazet <edumazet@google.com> wrote:
>
> This helper is already (auto)inlined from IPv4 TCP stack.
>
> Make it an inline function to benefit IPv6 as well.
>
> $ scripts/bloat-o-meter -t vmlinux.old vmlinux.new
> add/remove: 0/2 grow/shrink: 1/0 up/down: 30/-49 (-19)
> Function                                     old     new   delta
> tcp_v6_rcv                                  3448    3478     +30
> __pfx_tcp_filter                              16       -     -16
> tcp_filter                                    33       -     -33
> Total: Before=24891904, After=24891885, chg -0.00%
>
> Signed-off-by: Eric Dumazet <edumazet@google.com>

Reviewed-by: Kuniyuki Iwashima <kuniyu@google.com>

Re: [PATCH net-next] tcp: inline tcp_filter()

[patchwork-bot+netdevbpf]

Hello:

This patch was applied to netdev/net-next.git (main)
by Jakub Kicinski <kuba@kernel.org>:

On Thu,  5 Feb 2026 16:43:29 +0000 you wrote:
> This helper is already (auto)inlined from IPv4 TCP stack.
> 
> Make it an inline function to benefit IPv6 as well.
> 
> $ scripts/bloat-o-meter -t vmlinux.old vmlinux.new
> add/remove: 0/2 grow/shrink: 1/0 up/down: 30/-49 (-19)
> Function                                     old     new   delta
> tcp_v6_rcv                                  3448    3478     +30
> __pfx_tcp_filter                              16       -     -16
> tcp_filter                                    33       -     -33
> Total: Before=24891904, After=24891885, chg -0.00%
> 
> [...]

Here is the summary with links:
  - [net-next] tcp: inline tcp_filter()
    https://git.kernel.org/netdev/net-next/c/a35b6e4863d8

You are awesome, thank you!
-- 
Deet-doot-dot, I am a bot.
https://korg.docs.kernel.org/patchwork/pwbot.html