On Fri, Jan 15, 2021 at 8:34 PM Xin Long <lucien....@gmail.com> wrote:
>
> When enabling encap for a ipv6 socket without udp_encap_needed_key
> increased, UDP GRO won't work for v4 mapped v6 address packets as
> sk will be NULL in udp4_gro_receive().
>
> This patch is to enable it by increasing udp_encap_needed_key for
> v6 sockets in udp_tunnel_encap_enable(), and correspondingly
> decrease udp_encap_needed_key in udpv6_destroy_sock().
>
> v1->v2:
> - add udp_encap_disable() and export it.
>
> Signed-off-by: Xin Long <lucien....@gmail.com>
> ---
> include/net/udp.h | 1 +
> include/net/udp_tunnel.h | 3 +--
> net/ipv4/udp.c | 6 ++++++
> net/ipv6/udp.c | 4 +++-
> 4 files changed, 11 insertions(+), 3 deletions(-)
>
> diff --git a/include/net/udp.h b/include/net/udp.h
> index 877832b..1e7b6cd 100644
> --- a/include/net/udp.h
> +++ b/include/net/udp.h
> @@ -467,6 +467,7 @@ void udp_init(void);
>
> DECLARE_STATIC_KEY_FALSE(udp_encap_needed_key);
> void udp_encap_enable(void);
> +void udp_encap_disable(void);
> #if IS_ENABLED(CONFIG_IPV6)
> DECLARE_STATIC_KEY_FALSE(udpv6_encap_needed_key);
> void udpv6_encap_enable(void);
> diff --git a/include/net/udp_tunnel.h b/include/net/udp_tunnel.h
> index 282d10e..afc7ce7 100644
> --- a/include/net/udp_tunnel.h
> +++ b/include/net/udp_tunnel.h
> @@ -181,9 +181,8 @@ static inline void udp_tunnel_encap_enable(struct socket
> *sock)
> #if IS_ENABLED(CONFIG_IPV6)
> if (sock->sk->sk_family == PF_INET6)
> ipv6_stub->udpv6_encap_enable();
> - else
> #endif
> - udp_encap_enable();
> + udp_encap_enable();
> }
>
> #define UDP_TUNNEL_NIC_MAX_TABLES 4
> diff --git a/net/ipv4/udp.c b/net/ipv4/udp.c
> index 7103b0a..28bfe60 100644
> --- a/net/ipv4/udp.c
> +++ b/net/ipv4/udp.c
> @@ -596,6 +596,12 @@ void udp_encap_enable(void)
> }
> EXPORT_SYMBOL(udp_encap_enable);
>
> +void udp_encap_disable(void)
> +{
> + static_branch_dec(&udp_encap_needed_key);
> +}
> +EXPORT_SYMBOL(udp_encap_disable);
> +
> /* Handler for tunnels with arbitrary destination ports: no socket lookup, go
> * through error handlers in encapsulations looking for a match.
> */
So this seems unbalanced to me. We are adding/modifying one spot where
we are calling the enable function, but the other callers don't call
the disable function? Specifically I am curious about how to deal with
the rxrpc_open_socket usage.
If we don't balance out all the callers I am not sure adding the
udp_encap_disable makes much sense.
> diff --git a/net/ipv6/udp.c b/net/ipv6/udp.c
> index b9f3dfd..d754292 100644
> --- a/net/ipv6/udp.c
> +++ b/net/ipv6/udp.c
> @@ -1608,8 +1608,10 @@ void udpv6_destroy_sock(struct sock *sk)
> if (encap_destroy)
> encap_destroy(sk);
> }
> - if (up->encap_enabled)
> + if (up->encap_enabled) {
> static_branch_dec(&udpv6_encap_needed_key);
> + udp_encap_disable();
> + }
> }
>
> inet6_destroy_sock(sk);
> --
> 2.1.0
>
