[PATCH bpf-next 1/7] bpf: enable retrieval of socket cookie for bind/post-bind hook

From: Daniel Borkmann <daniel@iogearbox.net>
To: alexei.starovoitov@gmail.com
Cc: m@lambda.lt, joe@wand.net.nz, bpf@vger.kernel.org,
	netdev@vger.kernel.org, Daniel Borkmann <daniel@iogearbox.net>
Subject: [PATCH bpf-next 1/7] bpf: enable retrieval of socket cookie for bind/post-bind hook
Date: Fri, 27 Mar 2020 16:58:50 +0100	[thread overview]
Message-ID: <e9d71f310715332f12d238cc650c1edc5be55119.1585323121.git.daniel@iogearbox.net> (raw)
In-Reply-To: <cover.1585323121.git.daniel@iogearbox.net>

We currently make heavy use of the socket cookie in BPF's connect(),
sendmsg() and recvmsg() hooks for load-balancing decisions. However,
it is currently not enabled/implemented in BPF {post-}bind hooks
where it can later be used in combination for correlation in the tc
egress path, for example.

Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
---
 net/core/filter.c | 14 ++++++++++++++
 1 file changed, 14 insertions(+)

diff --git a/net/core/filter.c b/net/core/filter.c
index 96350a743539..0b6682517d45 100644
--- a/net/core/filter.c
+++ b/net/core/filter.c
@@ -4117,6 +4117,18 @@ static const struct bpf_func_proto bpf_get_socket_cookie_sock_addr_proto = {
 	.arg1_type	= ARG_PTR_TO_CTX,
 };
 
+BPF_CALL_1(bpf_get_socket_cookie_sock, struct sock *, ctx)
+{
+	return sock_gen_cookie(ctx);
+}
+
+static const struct bpf_func_proto bpf_get_socket_cookie_sock_proto = {
+	.func		= bpf_get_socket_cookie_sock,
+	.gpl_only	= false,
+	.ret_type	= RET_INTEGER,
+	.arg1_type	= ARG_PTR_TO_CTX,
+};
+
 BPF_CALL_1(bpf_get_socket_cookie_sock_ops, struct bpf_sock_ops_kern *, ctx)
 {
 	return sock_gen_cookie(ctx->sk);
@@ -5954,6 +5966,8 @@ sock_filter_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog)
 		return &bpf_get_current_uid_gid_proto;
 	case BPF_FUNC_get_local_storage:
 		return &bpf_get_local_storage_proto;
+	case BPF_FUNC_get_socket_cookie:
+		return &bpf_get_socket_cookie_sock_proto;
 	default:
 		return bpf_base_func_proto(func_id);
 	}
-- 
2.21.0

