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Date:   Fri, 12 Jun 2020 12:17:50 +0200
From:   Jakub Sitnicki <jakub@cloudflare.com>
To:     Lorenz Bauer <lmb@cloudflare.com>
Cc:     John Fastabend <john.fastabend@gmail.com>,
        Daniel Borkmann <daniel@iogearbox.net>,
        "David S. Miller" <davem@davemloft.net>,
        Jakub Kicinski <kuba@kernel.org>,
        Alexei Starovoitov <ast@kernel.org>,
        kernel-team@cloudflare.com, netdev@vger.kernel.org,
        bpf@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH bpf] bpf: sockmap: don't attach programs to UDP sockets
Message-ID: <20200612121750.0004c74d@toad>
In-Reply-To: <20200611172520.327602-1-lmb@cloudflare.com>
References: <20200611172520.327602-1-lmb@cloudflare.com>
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On Thu, 11 Jun 2020 18:25:20 +0100
Lorenz Bauer <lmb@cloudflare.com> wrote:

> The stream parser infrastructure isn't set up to deal with UDP
> sockets, so we mustn't try to attach programs to them.
> 
> I remember making this change at some point, but I must have lost
> it while rebasing or something similar.
> 
> Fixes: 7b98cd42b049 ("bpf: sockmap: Add UDP support")
> Signed-off-by: Lorenz Bauer <lmb@cloudflare.com>
> ---
>  net/core/sock_map.c | 10 ++++++----
>  1 file changed, 6 insertions(+), 4 deletions(-)
> 
> diff --git a/net/core/sock_map.c b/net/core/sock_map.c
> index 00a26cf2cfe9..35cea36f3892 100644
> --- a/net/core/sock_map.c
> +++ b/net/core/sock_map.c
> @@ -424,10 +424,7 @@ static int sock_map_get_next_key(struct bpf_map *map, void *key, void *next)
>  	return 0;
>  }
>  
> -static bool sock_map_redirect_allowed(const struct sock *sk)
> -{
> -	return sk->sk_state != TCP_LISTEN;
> -}
> +static bool sock_map_redirect_allowed(const struct sock *sk);
>  
>  static int sock_map_update_common(struct bpf_map *map, u32 idx,
>  				  struct sock *sk, u64 flags)
> @@ -508,6 +505,11 @@ static bool sk_is_udp(const struct sock *sk)
>  	       sk->sk_protocol == IPPROTO_UDP;
>  }
>  
> +static bool sock_map_redirect_allowed(const struct sock *sk)
> +{
> +	return sk_is_tcp(sk) && sk->sk_state != TCP_LISTEN;
> +}
> +
>  static bool sock_map_sk_is_suitable(const struct sock *sk)
>  {
>  	return sk_is_tcp(sk) || sk_is_udp(sk);

Acked-by: Jakub Sitnicki <jakub@cloudflare.com>