linux/include/net/bpf_sk_storage.h
Martin KaFai Lau 8e4597c627 bpf: Allow using bpf_sk_storage in FENTRY/FEXIT/RAW_TP
This patch enables the FENTRY/FEXIT/RAW_TP tracing program to use
the bpf_sk_storage_(get|delete) helper, so those tracing programs
can access the sk's bpf_local_storage and the later selftest
will show some examples.

The bpf_sk_storage is currently used in bpf-tcp-cc, tc,
cg sockops...etc which is running either in softirq or
task context.

This patch adds bpf_sk_storage_get_tracing_proto and
bpf_sk_storage_delete_tracing_proto.  They will check
in runtime that the helpers can only be called when serving
softirq or running in a task context.  That should enable
most common tracing use cases on sk.

During the load time, the new tracing_allowed() function
will ensure the tracing prog using the bpf_sk_storage_(get|delete)
helper is not tracing any bpf_sk_storage*() function itself.
The sk is passed as "void *" when calling into bpf_local_storage.

This patch only allows tracing a kernel function.

Signed-off-by: Martin KaFai Lau <kafai@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Song Liu <songliubraving@fb.com>
Link: https://lore.kernel.org/bpf/20201112211313.2587383-1-kafai@fb.com
2020-11-12 18:39:28 -08:00

65 lines
1.8 KiB
C

/* SPDX-License-Identifier: GPL-2.0 */
/* Copyright (c) 2019 Facebook */
#ifndef _BPF_SK_STORAGE_H
#define _BPF_SK_STORAGE_H
#include <linux/rculist.h>
#include <linux/list.h>
#include <linux/hash.h>
#include <linux/types.h>
#include <linux/spinlock.h>
#include <linux/bpf.h>
#include <net/sock.h>
#include <uapi/linux/sock_diag.h>
#include <uapi/linux/btf.h>
#include <linux/bpf_local_storage.h>
struct sock;
void bpf_sk_storage_free(struct sock *sk);
extern const struct bpf_func_proto bpf_sk_storage_get_proto;
extern const struct bpf_func_proto bpf_sk_storage_delete_proto;
extern const struct bpf_func_proto bpf_sk_storage_get_tracing_proto;
extern const struct bpf_func_proto bpf_sk_storage_delete_tracing_proto;
struct bpf_local_storage_elem;
struct bpf_sk_storage_diag;
struct sk_buff;
struct nlattr;
struct sock;
#ifdef CONFIG_BPF_SYSCALL
int bpf_sk_storage_clone(const struct sock *sk, struct sock *newsk);
struct bpf_sk_storage_diag *
bpf_sk_storage_diag_alloc(const struct nlattr *nla_stgs);
void bpf_sk_storage_diag_free(struct bpf_sk_storage_diag *diag);
int bpf_sk_storage_diag_put(struct bpf_sk_storage_diag *diag,
struct sock *sk, struct sk_buff *skb,
int stg_array_type,
unsigned int *res_diag_size);
#else
static inline int bpf_sk_storage_clone(const struct sock *sk,
struct sock *newsk)
{
return 0;
}
static inline struct bpf_sk_storage_diag *
bpf_sk_storage_diag_alloc(const struct nlattr *nla)
{
return NULL;
}
static inline void bpf_sk_storage_diag_free(struct bpf_sk_storage_diag *diag)
{
}
static inline int bpf_sk_storage_diag_put(struct bpf_sk_storage_diag *diag,
struct sock *sk, struct sk_buff *skb,
int stg_array_type,
unsigned int *res_diag_size)
{
return 0;
}
#endif
#endif /* _BPF_SK_STORAGE_H */