Re: [RFC PATCH 03/13] net: Add net protocol offload registration infrustructure

[Nicolas Dichtel <nicolas.dichtel@6wind.com>]

Le 14/11/2012 02:24, Vlad Yasevich a écrit :
> Create a new data structure for IPv4 protocols that holds GRO/GSO
> callbacks and a new array to track the protocols that register GRO/GSO.
>
> Signed-off-by: Vlad Yasevich <vyasevic@redhat.com>
> ---
>   include/net/protocol.h |   12 ++++++++++++
>   net/ipv4/af_inet.c     |   12 ++++++++++++
>   net/ipv4/protocol.c    |   22 +++++++++++++++++++++-
>   3 files changed, 45 insertions(+), 1 deletions(-)
>
> diff --git a/include/net/protocol.h b/include/net/protocol.h
> index 929528c..d8ecb17 100644
> --- a/include/net/protocol.h
> +++ b/include/net/protocol.h
> @@ -77,6 +77,15 @@ struct inet6_protocol {
>   #define INET6_PROTO_GSO_EXTHDR	0x4
>   #endif
>
> +struct net_offload {
> +	int			(*gso_send_check)(struct sk_buff *skb);
> +	struct sk_buff	       *(*gso_segment)(struct sk_buff *skb,
> +					       netdev_features_t features);
> +	struct sk_buff	      **(*gro_receive)(struct sk_buff **head,
> +					       struct sk_buff *skb);
> +	int			(*gro_complete)(struct sk_buff *skb);
> +};
> +
>   /* This is used to register socket interfaces for IP protocols.  */
>   struct inet_protosw {
>   	struct list_head list;
> @@ -96,6 +105,7 @@ struct inet_protosw {
>   #define INET_PROTOSW_ICSK      0x04  /* Is this an inet_connection_sock? */
>
>   extern const struct net_protocol __rcu *inet_protos[MAX_INET_PROTOS];
> +extern const struct net_offload __rcu *inet_offloads[MAX_INET_PROTOS];
>
>   #if IS_ENABLED(CONFIG_IPV6)
>   extern const struct inet6_protocol __rcu *inet6_protos[MAX_INET_PROTOS];
> @@ -103,6 +113,8 @@ extern const struct inet6_protocol __rcu *inet6_protos[MAX_INET_PROTOS];
>
>   extern int	inet_add_protocol(const struct net_protocol *prot, unsigned char num);
>   extern int	inet_del_protocol(const struct net_protocol *prot, unsigned char num);
> +extern int	inet_add_offload(const struct net_offload *prot, unsigned char num);
> +extern int	inet_del_offload(const struct net_offload *prot, unsigned char num);
>   extern void	inet_register_protosw(struct inet_protosw *p);
>   extern void	inet_unregister_protosw(struct inet_protosw *p);
>
> diff --git a/net/ipv4/af_inet.c b/net/ipv4/af_inet.c
> index 4c99c5f..3918d86 100644
> --- a/net/ipv4/af_inet.c
> +++ b/net/ipv4/af_inet.c
> @@ -1566,6 +1566,13 @@ static const struct net_protocol tcp_protocol = {
>   	.netns_ok	=	1,
>   };
>
> +static const struct net_offload tcp_offload = {
> +	.gso_send_check	=	tcp_v4_gso_send_check,
> +	.gso_segment	=	tcp_tso_segment,
> +	.gro_receive	=	tcp4_gro_receive,
> +	.gro_complete	=	tcp4_gro_complete,
> +};
> +
>   static const struct net_protocol udp_protocol = {
>   	.handler =	udp_rcv,
>   	.err_handler =	udp_err,
> @@ -1575,6 +1582,11 @@ static const struct net_protocol udp_protocol = {
>   	.netns_ok =	1,
>   };
>
> +static const struct net_offload udp_offload = {
> +	.gso_send_check = udp4_ufo_send_check,
> +	.gso_segment = udp4_ufo_fragment,
> +};
> +
>   static const struct net_protocol icmp_protocol = {
>   	.handler =	icmp_rcv,
>   	.err_handler =	ping_err,
> diff --git a/net/ipv4/protocol.c b/net/ipv4/protocol.c
> index 8918eff..1278db8 100644
> --- a/net/ipv4/protocol.c
> +++ b/net/ipv4/protocol.c
> @@ -29,6 +29,7 @@
>   #include <net/protocol.h>
>
>   const struct net_protocol __rcu *inet_protos[MAX_INET_PROTOS] __read_mostly;
> +const struct net_offload __rcu *inet_offloads[MAX_INET_PROTOS] __read_mostly;
>
>   /*
>    *	Add a protocol handler to the hash tables
> @@ -41,6 +42,13 @@ int inet_add_protocol(const struct net_protocol *prot, unsigned char protocol)
>   }
>   EXPORT_SYMBOL(inet_add_protocol);
>
> +int inet_add_offload(const struct net_offload *prot, unsigned char protocol)
> +{
> +	return !cmpxchg((const struct net_offload **)&inet_offloads[protocol],
> +			NULL, prot) ? 0 : -1;
> +}
> +EXPORT_SYMBOL(inet_add_offload);
> +
>   /*
>    *	Remove a protocol from the hash tables.
>    */
> @@ -56,4 +64,16 @@ int inet_del_protocol(const struct net_protocol *prot, unsigned char protocol)
>
>   	return ret;
>   }
> -EXPORT_SYMBOL(inet_del_protocol);
This line should probably not be removed ;-)