Re: [PATCH v2 net-next 1/2] net: bpf: handle return value of BPF_CGROUP_RUN_PROG_INET{4,6}_POST_BIND()

[Daniel Borkmann <daniel@xxxxxxxxxxxxx>]

On 12/30/21 9:03 AM, menglong8.dong@xxxxxxxxx wrote:
[...]
> diff --git a/include/net/sock.h b/include/net/sock.h
> index 44cc25f0bae7..f5fc0432374e 100644
> --- a/include/net/sock.h
> +++ b/include/net/sock.h
> @@ -1209,6 +1209,7 @@ struct proto {
>   	void			(*unhash)(struct sock *sk);
>   	void			(*rehash)(struct sock *sk);
>   	int			(*get_port)(struct sock *sk, unsigned short snum);
> +	void			(*put_port)(struct sock *sk);
>   #ifdef CONFIG_BPF_SYSCALL
>   	int			(*psock_update_sk_prot)(struct sock *sk,
>   							struct sk_psock *psock,
> diff --git a/net/ipv4/af_inet.c b/net/ipv4/af_inet.c
> index 5d18d32557d2..8784e72d4b8b 100644
> --- a/net/ipv4/af_inet.c
> +++ b/net/ipv4/af_inet.c
> @@ -531,6 +531,8 @@ int __inet_bind(struct sock *sk, struct sockaddr *uaddr, int addr_len,
>   			err = BPF_CGROUP_RUN_PROG_INET4_POST_BIND(sk);
>   			if (err) {
>   				inet->inet_saddr = inet->inet_rcv_saddr = 0;
> +				if (sk->sk_prot->get_port)
> +					sk->sk_prot->put_port(sk);
>   				goto out_release_sock;
>   			}
>   		}
[...]
> diff --git a/net/ipv6/af_inet6.c b/net/ipv6/af_inet6.c
> index d1636425654e..ddfc6821e682 100644
> --- a/net/ipv6/af_inet6.c
> +++ b/net/ipv6/af_inet6.c
> @@ -413,6 +413,8 @@ static int __inet6_bind(struct sock *sk, struct sockaddr *uaddr, int addr_len,
>   			if (err) {
>   				sk->sk_ipv6only = saved_ipv6only;
>   				inet_reset_saddr(sk);
> +				if (sk->sk_prot->get_port)
> +					sk->sk_prot->put_port(sk);
>   				goto out;
>   			}
>   		}

I presume both tests above should test for non-zero sk->sk_prot->put_port
callback given that is what they end up calling when true, no?

Thanks,
Daniel