Commit 549beec0 authored by Alexei Starovoitov's avatar Alexei Starovoitov
Browse files

Merge branch 'Add bpf_skc_to_unix_sock() helper' 



Hengqi Chen says:

====================

This patch set adds a new BPF helper bpf_skc_to_unix_sock().
The helper is used in tracing programs to cast a socket
pointer to a unix_sock pointer.

v2->v3:
 - Use abstract socket in selftest (Alexei)
 - Run checkpatch script over patches (Andrii)

v1->v2:
 - Update selftest, remove trailing spaces changes (Song)
====================

Signed-off-by: default avatarAlexei Starovoitov <ast@kernel.org>
parents 44ce0ac1 b6c4e715

include/linux/bpf.h

+1 −0
Original line number Diff line number Diff line
@@ -2093,6 +2093,7 @@ extern const struct bpf_func_proto bpf_skc_to_tcp_sock_proto; 
extern const struct bpf_func_proto bpf_skc_to_tcp_timewait_sock_proto;

extern const struct bpf_func_proto bpf_skc_to_tcp_request_sock_proto;

extern const struct bpf_func_proto bpf_skc_to_udp6_sock_proto;

extern const struct bpf_func_proto bpf_skc_to_unix_sock_proto;

extern const struct bpf_func_proto bpf_copy_from_user_proto;

extern const struct bpf_func_proto bpf_snprintf_btf_proto;

extern const struct bpf_func_proto bpf_snprintf_proto;

include/uapi/linux/bpf.h

+7 −0
Original line number Diff line number Diff line
@@ -4909,6 +4909,12 @@ union bpf_attr { 
 *	Return

 *		The number of bytes written to the buffer, or a negative error

 *		in case of failure.

 *

 * struct unix_sock *bpf_skc_to_unix_sock(void *sk)

 * 	Description

 *		Dynamically cast a *sk* pointer to a *unix_sock* pointer.

 *	Return

 *		*sk* if casting is valid, or **NULL** otherwise.

 */

#define __BPF_FUNC_MAPPER(FN)		\

	FN(unspec),			\
@@ -5089,6 +5095,7 @@ union bpf_attr { 
	FN(task_pt_regs),		\

	FN(get_branch_snapshot),	\

	FN(trace_vprintk),		\

	FN(skc_to_unix_sock),		\

	/* */



/* integer value in 'imm' field of BPF_CALL instruction selects which helper

kernel/trace/bpf_trace.c

+2 −0
Original line number Diff line number Diff line
@@ -1608,6 +1608,8 @@ tracing_prog_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog) 
		return &bpf_skc_to_tcp_request_sock_proto;

	case BPF_FUNC_skc_to_udp6_sock:

		return &bpf_skc_to_udp6_sock_proto;

	case BPF_FUNC_skc_to_unix_sock:

		return &bpf_skc_to_unix_sock_proto;

	case BPF_FUNC_sk_storage_get:

		return &bpf_sk_storage_get_tracing_proto;

	case BPF_FUNC_sk_storage_delete:

net/core/filter.c

+23 −0
Original line number Diff line number Diff line
@@ -10723,6 +10723,26 @@ const struct bpf_func_proto bpf_skc_to_udp6_sock_proto = { 
	.ret_btf_id		= &btf_sock_ids[BTF_SOCK_TYPE_UDP6],

};



BPF_CALL_1(bpf_skc_to_unix_sock, struct sock *, sk)

{

	/* unix_sock type is not generated in dwarf and hence btf,

	 * trigger an explicit type generation here.

	 */

	BTF_TYPE_EMIT(struct unix_sock);

	if (sk && sk_fullsock(sk) && sk->sk_family == AF_UNIX)

		return (unsigned long)sk;



	return (unsigned long)NULL;

}



const struct bpf_func_proto bpf_skc_to_unix_sock_proto = {

	.func			= bpf_skc_to_unix_sock,

	.gpl_only		= false,

	.ret_type		= RET_PTR_TO_BTF_ID_OR_NULL,

	.arg1_type		= ARG_PTR_TO_BTF_ID_SOCK_COMMON,

	.ret_btf_id		= &btf_sock_ids[BTF_SOCK_TYPE_UNIX],

};



BPF_CALL_1(bpf_sock_from_file, struct file *, file)

{

	return (unsigned long)sock_from_file(file);
@@ -10762,6 +10782,9 @@ bpf_sk_base_func_proto(enum bpf_func_id func_id) 
	case BPF_FUNC_skc_to_udp6_sock:

		func = &bpf_skc_to_udp6_sock_proto;

		break;

	case BPF_FUNC_skc_to_unix_sock:

		func = &bpf_skc_to_unix_sock_proto;

		break;

	default:

		return bpf_base_func_proto(func_id);

	}

scripts/bpf_doc.py

+2 −0
Original line number Diff line number Diff line
@@ -537,6 +537,7 @@ class PrinterHelpers(Printer): 
            'struct tcp_timewait_sock',

            'struct tcp_request_sock',

            'struct udp6_sock',

            'struct unix_sock',

            'struct task_struct',



            'struct __sk_buff',
@@ -589,6 +590,7 @@ class PrinterHelpers(Printer): 
            'struct tcp_timewait_sock',

            'struct tcp_request_sock',

            'struct udp6_sock',

            'struct unix_sock',

            'struct task_struct',

            'struct path',

            'struct btf_ptr',