Commit d692f113 authored by Andrey Ignatov's avatar Andrey Ignatov Committed by Daniel Borkmann
Browse files

bpf: Support bpf_get_socket_cookie in more prog types 



bpf_get_socket_cookie() helper can be used to identify skb that
correspond to the same socket.

Though socket cookie can be useful in many other use-cases where socket is
available in program context. Specifically BPF_PROG_TYPE_CGROUP_SOCK_ADDR
and BPF_PROG_TYPE_SOCK_OPS programs can benefit from it so that one of
them can augment a value in a map prepared earlier by other program for
the same socket.

The patch adds support to call bpf_get_socket_cookie() from
BPF_PROG_TYPE_CGROUP_SOCK_ADDR and BPF_PROG_TYPE_SOCK_OPS.

It doesn't introduce new helpers. Instead it reuses same helper name
bpf_get_socket_cookie() but adds support to this helper to accept
`struct bpf_sock_addr` and `struct bpf_sock_ops`.

Documentation in bpf.h is changed in a way that should not break
automatic generation of markdown.

Signed-off-by: default avatarAndrey Ignatov <rdna@fb.com>
Acked-by: default avatarYonghong Song <yhs@fb.com>
Signed-off-by: default avatarDaniel Borkmann <daniel@iogearbox.net>
parent 240b74fd

include/uapi/linux/bpf.h

+14 −0
Original line number Diff line number Diff line
@@ -1371,6 +1371,20 @@ union bpf_attr { 
 * 		A 8-byte long non-decreasing number on success, or 0 if the

 * 		socket field is missing inside *skb*.

 *

 * u64 bpf_get_socket_cookie(struct bpf_sock_addr *ctx)

 * 	Description

 * 		Equivalent to bpf_get_socket_cookie() helper that accepts

 * 		*skb*, but gets socket from **struct bpf_sock_addr** contex.

 * 	Return

 * 		A 8-byte long non-decreasing number.

 *

 * u64 bpf_get_socket_cookie(struct bpf_sock_ops *ctx)

 * 	Description

 * 		Equivalent to bpf_get_socket_cookie() helper that accepts

 * 		*skb*, but gets socket from **struct bpf_sock_ops** contex.

 * 	Return

 * 		A 8-byte long non-decreasing number.

 *

 * u32 bpf_get_socket_uid(struct sk_buff *skb)

 * 	Return

 * 		The owner UID of the socket associated to *skb*. If the socket

net/core/filter.c

+28 −0
Original line number Diff line number Diff line
@@ -3812,6 +3812,30 @@ static const struct bpf_func_proto bpf_get_socket_cookie_proto = { 
	.arg1_type      = ARG_PTR_TO_CTX,

};



BPF_CALL_1(bpf_get_socket_cookie_sock_addr, struct bpf_sock_addr_kern *, ctx)

{

	return sock_gen_cookie(ctx->sk);

}



static const struct bpf_func_proto bpf_get_socket_cookie_sock_addr_proto = {

	.func		= bpf_get_socket_cookie_sock_addr,

	.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);

}



static const struct bpf_func_proto bpf_get_socket_cookie_sock_ops_proto = {

	.func		= bpf_get_socket_cookie_sock_ops,

	.gpl_only	= false,

	.ret_type	= RET_INTEGER,

	.arg1_type	= ARG_PTR_TO_CTX,

};



BPF_CALL_1(bpf_get_socket_uid, struct sk_buff *, skb)

{

	struct sock *sk = sk_to_full_sk(skb->sk);
@@ -4818,6 +4842,8 @@ sock_addr_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog) 
		default:

			return NULL;

		}

	case BPF_FUNC_get_socket_cookie:

		return &bpf_get_socket_cookie_sock_addr_proto;

	default:

		return bpf_base_func_proto(func_id);

	}
@@ -4960,6 +4986,8 @@ sock_ops_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog) 
		return &bpf_sock_map_update_proto;

	case BPF_FUNC_sock_hash_update:

		return &bpf_sock_hash_update_proto;

	case BPF_FUNC_get_socket_cookie:

		return &bpf_get_socket_cookie_sock_ops_proto;

	default:

		return bpf_base_func_proto(func_id);

	}

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