From: Eric Dumazet <edumazet@google.com>
To: "David S . Miller" <davem@davemloft.net>,
Jakub Kicinski <kuba@kernel.org>,
Paolo Abeni <pabeni@redhat.com>
Cc: Simon Horman <horms@kernel.org>,
netdev@vger.kernel.org, eric.dumazet@gmail.com,
Eric Dumazet <edumazet@google.com>
Subject: [PATCH net-next 4/5] tcp: change tcp_filter() to return the reason by value
Date: Thu, 9 Apr 2026 14:56:23 +0000 [thread overview]
Message-ID: <20260409145625.2306224-5-edumazet@google.com> (raw)
In-Reply-To: <20260409145625.2306224-1-edumazet@google.com>
sk_filter_trim_cap() will soon return the reason by value,
do the same for tcp_filter().
Note:
tcp_filter() is no longer inlined. Following patch will inline it again.
$ scripts/bloat-o-meter -t vmlinux.4 vmlinux.5
add/remove: 2/0 grow/shrink: 0/2 up/down: 186/-43 (143)
Function old new delta
tcp_filter - 154 +154
__pfx_tcp_filter - 32 +32
tcp_v4_rcv 3152 3143 -9
tcp_v6_rcv 3169 3135 -34
Total: Before=29722640, After=29722783, chg +0.00%
Signed-off-by: Eric Dumazet <edumazet@google.com>
---
include/net/tcp.h | 8 +++++---
net/ipv4/tcp_ipv4.c | 6 ++++--
net/ipv6/tcp_ipv6.c | 6 ++++--
3 files changed, 13 insertions(+), 7 deletions(-)
diff --git a/include/net/tcp.h b/include/net/tcp.h
index 6156d1d068e142f696ec9dfff63e3aaebb0171bc..098e52269a04cb8938812a8f43caf11f9d5c68a3 100644
--- a/include/net/tcp.h
+++ b/include/net/tcp.h
@@ -1683,12 +1683,14 @@ 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)
+static inline enum skb_drop_reason
+tcp_filter(struct sock *sk, struct sk_buff *skb)
{
const struct tcphdr *th = (const struct tcphdr *)skb->data;
+ enum skb_drop_reason reason;
- return sk_filter_trim_cap(sk, skb, __tcp_hdrlen(th), reason);
+ sk_filter_trim_cap(sk, skb, __tcp_hdrlen(th), &reason);
+ return reason;
}
void tcp_set_state(struct sock *sk, int state);
diff --git a/net/ipv4/tcp_ipv4.c b/net/ipv4/tcp_ipv4.c
index 69ab236072e7142d5ca9d0703d99f02c1e17c738..e2da3246a641e24328985cf558c322211df02b84 100644
--- a/net/ipv4/tcp_ipv4.c
+++ b/net/ipv4/tcp_ipv4.c
@@ -2164,7 +2164,8 @@ int tcp_v4_rcv(struct sk_buff *skb)
}
refcounted = true;
nsk = NULL;
- if (!tcp_filter(sk, skb, &drop_reason)) {
+ drop_reason = tcp_filter(sk, skb);
+ if (!drop_reason) {
th = (const struct tcphdr *)skb->data;
iph = ip_hdr(skb);
tcp_v4_fill_cb(skb, iph, th);
@@ -2225,7 +2226,8 @@ int tcp_v4_rcv(struct sk_buff *skb)
nf_reset_ct(skb);
- if (tcp_filter(sk, skb, &drop_reason))
+ drop_reason = tcp_filter(sk, skb);
+ if (drop_reason)
goto discard_and_relse;
th = (const struct tcphdr *)skb->data;
diff --git a/net/ipv6/tcp_ipv6.c b/net/ipv6/tcp_ipv6.c
index 8dc3874e8b9252da60f21ad77a5ca834532e650a..d64d28e9842f7db69389034ac2ecdc76f405d379 100644
--- a/net/ipv6/tcp_ipv6.c
+++ b/net/ipv6/tcp_ipv6.c
@@ -1794,7 +1794,8 @@ INDIRECT_CALLABLE_SCOPE int tcp_v6_rcv(struct sk_buff *skb)
}
refcounted = true;
nsk = NULL;
- if (!tcp_filter(sk, skb, &drop_reason)) {
+ drop_reason = tcp_filter(sk, skb);
+ if (!drop_reason) {
th = (const struct tcphdr *)skb->data;
hdr = ipv6_hdr(skb);
tcp_v6_fill_cb(skb, hdr, th);
@@ -1855,7 +1856,8 @@ INDIRECT_CALLABLE_SCOPE int tcp_v6_rcv(struct sk_buff *skb)
nf_reset_ct(skb);
- if (tcp_filter(sk, skb, &drop_reason))
+ drop_reason = tcp_filter(sk, skb);
+ if (drop_reason)
goto discard_and_relse;
th = (const struct tcphdr *)skb->data;
--
2.53.0.1213.gd9a14994de-goog
next prev parent reply other threads:[~2026-04-09 14:56 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-04-09 14:56 [PATCH net-next 0/5] net: reduce sk_filter() (and friends) bloat Eric Dumazet
2026-04-09 14:56 ` [PATCH net-next 1/5] net: change sock_queue_rcv_skb_reason() to return a drop_reason Eric Dumazet
2026-04-09 14:56 ` [PATCH net-next 2/5] net: always set reason in sk_filter_trim_cap() Eric Dumazet
2026-04-09 14:56 ` [PATCH net-next 3/5] net: change sk_filter_reason() to return the reason by value Eric Dumazet
2026-04-09 14:56 ` Eric Dumazet [this message]
2026-04-09 14:56 ` [PATCH net-next 5/5] net: change sk_filter_trim_cap() to return a drop_reason " Eric Dumazet
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