[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]
Date: Sun, 18 Feb 2024 20:13:49 -0800
From: Kuniyuki Iwashima <kuniyu@...zon.com>
To: <kerneljasonxing@...il.com>
CC: <davem@...emloft.net>, <dsahern@...nel.org>, <edumazet@...gle.com>,
<kernelxing@...cent.com>, <kuba@...nel.org>, <kuniyu@...zon.com>,
<netdev@...r.kernel.org>, <pabeni@...hat.com>
Subject: Re: [PATCH net-next v6 02/11] tcp: directly drop skb in cookie check for ipv4
From: Jason Xing <kerneljasonxing@...il.com>
Date: Mon, 19 Feb 2024 11:28:29 +0800
> From: Jason Xing <kernelxing@...cent.com>
>
> Only move the skb drop from tcp_v4_do_rcv() to cookie_v4_check() itself,
> no other changes made. It can help us refine the specific drop reasons
> later.
>
> Signed-off-by: Jason Xing <kernelxing@...cent.com>
Reviewed-by: Kuniyuki Iwashima <kuniyu@...zon.com>
> ---
> net/ipv4/syncookies.c | 4 ++++
> net/ipv4/tcp_ipv4.c | 2 +-
> 2 files changed, 5 insertions(+), 1 deletion(-)
>
> diff --git a/net/ipv4/syncookies.c b/net/ipv4/syncookies.c
> index be88bf586ff9..38f331da6677 100644
> --- a/net/ipv4/syncookies.c
> +++ b/net/ipv4/syncookies.c
> @@ -408,6 +408,7 @@ struct sock *cookie_v4_check(struct sock *sk, struct sk_buff *skb)
> struct rtable *rt;
> __u8 rcv_wscale;
> int full_space;
> + SKB_DR(reason);
>
> if (!READ_ONCE(net->ipv4.sysctl_tcp_syncookies) ||
> !th->ack || th->rst)
> @@ -477,10 +478,13 @@ struct sock *cookie_v4_check(struct sock *sk, struct sk_buff *skb)
> */
> if (ret)
> inet_sk(ret)->cork.fl.u.ip4 = fl4;
> + else
> + goto out_drop;
> out:
> return ret;
> out_free:
> reqsk_free(req);
> out_drop:
> + kfree_skb_reason(skb, reason);
> return NULL;
> }
> diff --git a/net/ipv4/tcp_ipv4.c b/net/ipv4/tcp_ipv4.c
> index 0c50c5a32b84..0a944e109088 100644
> --- a/net/ipv4/tcp_ipv4.c
> +++ b/net/ipv4/tcp_ipv4.c
> @@ -1915,7 +1915,7 @@ int tcp_v4_do_rcv(struct sock *sk, struct sk_buff *skb)
> struct sock *nsk = tcp_v4_cookie_check(sk, skb);
>
> if (!nsk)
> - goto discard;
> + return 0;
> if (nsk != sk) {
> if (tcp_child_process(sk, nsk, skb)) {
> rsk = nsk;
> --
> 2.37.3
>
Powered by blists - more mailing lists