bpf: Factor out socket lookup functions for the TC hookpoint.

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.

Signed-off-by: Gilad Sever <gilad9366@gmail.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Reviewed-by: Shmulik Ladkani <shmulik.ladkani@gmail.com>
Reviewed-by: Eyal Birger <eyal.birger@gmail.com>
Acked-by: Stanislav Fomichev <sdf@google.com>
Link: https://lore.kernel.org/bpf/20230621104211.301902-2-gilad9366@gmail.com

1 files changed, 60 insertions, 3 deletions

diff --git a/net/core/filter.c b/net/core/filter.c
index 428df050d021..11e2afbfdce9 100644
--- a/net/core/filter.c
+++ b/net/core/filter.c
@@ -6740,6 +6740,63 @@ 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))
@@ -7995,9 +8052,9 @@ 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:
@@ -8005,7 +8062,7 @@ 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: