Re: [PATCH bpf,v3 1/4] bpf: factor out socket lookup functions for the TC hookpoint.

[Stanislav Fomichev <sdf@google.com>]

On 04/26, Gilad Sever wrote:
> Change BPF helper socket lookup functions to use TC specific variants:
> bpf_tc_sk_lookup_tcp() / bpf_tc_sk_lookup_udp() / bpf_tc_skc_lookup_tcp()
> instead of sharing implementation with the cg / sk_skb hooking points.
> This allows introducing a separate logic for the TC flow.
> 
> The tc functions are identical to the original code.
> 
> Reviewed-by: Shmulik Ladkani <shmulik.ladkani@gmail.com>
> Reviewed-by: Eyal Birger <eyal.birger@gmail.com>
> Signed-off-by: Gilad Sever <gilad9366@gmail.com>

Acked-by: Stanislav Fomichev <sdf@google.com>

> ---
>  net/core/filter.c | 63 ++++++++++++++++++++++++++++++++++++++++++++---
>  1 file changed, 60 insertions(+), 3 deletions(-)
> 
> diff --git a/net/core/filter.c b/net/core/filter.c
> index 1d6f165923bf..5910956f4e0d 100644
> --- a/net/core/filter.c
> +++ b/net/core/filter.c
> @@ -6701,6 +6701,63 @@ static const struct bpf_func_proto bpf_sk_lookup_udp_proto = {
>  	.arg5_type	= ARG_ANYTHING,
>  };
>  
> +BPF_CALL_5(bpf_tc_skc_lookup_tcp, struct sk_buff *, skb,
> +	   struct bpf_sock_tuple *, tuple, u32, len, u64, netns_id, u64, flags)
> +{
> +	return (unsigned long)bpf_skc_lookup(skb, tuple, len, IPPROTO_TCP,
> +					     netns_id, flags);
> +}
> +
> +static const struct bpf_func_proto bpf_tc_skc_lookup_tcp_proto = {
> +	.func		= bpf_tc_skc_lookup_tcp,
> +	.gpl_only	= false,
> +	.pkt_access	= true,
> +	.ret_type	= RET_PTR_TO_SOCK_COMMON_OR_NULL,
> +	.arg1_type	= ARG_PTR_TO_CTX,
> +	.arg2_type	= ARG_PTR_TO_MEM | MEM_RDONLY,
> +	.arg3_type	= ARG_CONST_SIZE,
> +	.arg4_type	= ARG_ANYTHING,
> +	.arg5_type	= ARG_ANYTHING,
> +};
> +
> +BPF_CALL_5(bpf_tc_sk_lookup_tcp, struct sk_buff *, skb,
> +	   struct bpf_sock_tuple *, tuple, u32, len, u64, netns_id, u64, flags)
> +{
> +	return (unsigned long)bpf_sk_lookup(skb, tuple, len, IPPROTO_TCP,
> +					    netns_id, flags);
> +}
> +
> +static const struct bpf_func_proto bpf_tc_sk_lookup_tcp_proto = {
> +	.func		= bpf_tc_sk_lookup_tcp,
> +	.gpl_only	= false,
> +	.pkt_access	= true,
> +	.ret_type	= RET_PTR_TO_SOCKET_OR_NULL,
> +	.arg1_type	= ARG_PTR_TO_CTX,
> +	.arg2_type	= ARG_PTR_TO_MEM | MEM_RDONLY,
> +	.arg3_type	= ARG_CONST_SIZE,
> +	.arg4_type	= ARG_ANYTHING,
> +	.arg5_type	= ARG_ANYTHING,
> +};
> +
> +BPF_CALL_5(bpf_tc_sk_lookup_udp, struct sk_buff *, skb,
> +	   struct bpf_sock_tuple *, tuple, u32, len, u64, netns_id, u64, flags)
> +{
> +	return (unsigned long)bpf_sk_lookup(skb, tuple, len, IPPROTO_UDP,
> +					    netns_id, flags);
> +}
> +
> +static const struct bpf_func_proto bpf_tc_sk_lookup_udp_proto = {
> +	.func		= bpf_tc_sk_lookup_udp,
> +	.gpl_only	= false,
> +	.pkt_access	= true,
> +	.ret_type	= RET_PTR_TO_SOCKET_OR_NULL,
> +	.arg1_type	= ARG_PTR_TO_CTX,
> +	.arg2_type	= ARG_PTR_TO_MEM | MEM_RDONLY,
> +	.arg3_type	= ARG_CONST_SIZE,
> +	.arg4_type	= ARG_ANYTHING,
> +	.arg5_type	= ARG_ANYTHING,
> +};
> +
>  BPF_CALL_1(bpf_sk_release, struct sock *, sk)
>  {
>  	if (sk && sk_is_refcounted(sk))
> @@ -7954,9 +8011,9 @@ tc_cls_act_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog)
>  #endif
>  #ifdef CONFIG_INET
>  	case BPF_FUNC_sk_lookup_tcp:
> -		return &bpf_sk_lookup_tcp_proto;
> +		return &bpf_tc_sk_lookup_tcp_proto;
>  	case BPF_FUNC_sk_lookup_udp:
> -		return &bpf_sk_lookup_udp_proto;
> +		return &bpf_tc_sk_lookup_udp_proto;
>  	case BPF_FUNC_sk_release:
>  		return &bpf_sk_release_proto;
>  	case BPF_FUNC_tcp_sock:
> @@ -7964,7 +8021,7 @@ tc_cls_act_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog)
>  	case BPF_FUNC_get_listener_sock:
>  		return &bpf_get_listener_sock_proto;
>  	case BPF_FUNC_skc_lookup_tcp:
> -		return &bpf_skc_lookup_tcp_proto;
> +		return &bpf_tc_skc_lookup_tcp_proto;
>  	case BPF_FUNC_tcp_check_syncookie:
>  		return &bpf_tcp_check_syncookie_proto;
>  	case BPF_FUNC_skb_ecn_set_ce:
> -- 
> 2.34.1
>