bpf/include/api.h

// Licensed to Apache Software Foundation (ASF) under one or more contributor
// license agreements. See the NOTICE file distributed with
// this work for additional information regarding copyright
// ownership. Apache Software Foundation (ASF) licenses this file to you under
// the Apache License, Version 2.0 (the "License"); you may
// not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
//     http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing,
// software distributed under the License is distributed on an
// "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
// KIND, either express or implied.  See the License for the
// specific language governing permissions and limitations
// under the License.

#ifndef __BPF_API__
#define __BPF_API__

// include linux relate bpf
#include <stddef.h>
#include <linux/types.h>
#include <linux/sched.h>
#include <linux/bpf.h>
#include <linux/ptrace.h>
#include <bpf/bpf_helpers.h>
#include <bpf/bpf_tracing.h>
#include <bpf/bpf_core_read.h>

// Force a function to be emitted as a real BPF-to-BPF call instead of being
// inlined. The verifier checks a non-inlined sub-program only once, instead of
// re-verifying every inlined copy on every code path, which dramatically lowers
// the processed-instruction count for large programs (avoids the
// "BPF program is too large" / 1M instruction limit). BPF-to-BPF calls require
// kernel >= 4.16, which the network / access-log data path already mandates.
#ifndef __noinline
#define __noinline __attribute__((noinline))
#endif

// Define types commonly needed but not in BPF headers
typedef __s64 ssize_t;
typedef __s8 int8_t;
typedef __s16 int16_t;
typedef __s32 int32_t;
typedef __s64 int64_t;
typedef __u8 uint8_t;
typedef __u16 uint16_t;
typedef __u32 uint32_t;
typedef __u64 uint64_t;
// BSD-style type aliases
typedef __u8 u_int8_t;
typedef __u16 u_int16_t;
typedef __u32 u_int32_t;
typedef __u64 u_int64_t;

struct iovec {
    void *iov_base;
    __kernel_size_t iov_len;
};

// Socket address family constants (from linux/socket.h)
#ifndef AF_UNSPEC
#define AF_UNSPEC 0
#endif
#ifndef AF_INET
#define AF_INET 2
#endif
#ifndef AF_INET6
#define AF_INET6 10
#endif

// Socket address structures (simplified for BPF)
typedef unsigned short sa_family_t;
struct sockaddr {
    sa_family_t sa_family;
    char sa_data[14];
};

#define _KERNEL(P)                                                                   \
	({                                                                     \
		typeof(P) val;                                                 \
		bpf_probe_read_kernel(&val, sizeof(val), &(P));                \
		val;                                                           \
	})

#define _(P)                                                                   \
	({                                                                     \
		typeof(P) val;                                                 \
		bpf_probe_read(&val, sizeof(val), &(P));                \
		val;                                                           \
	})

typedef enum
{
    true=1, false=0
} bool;

struct trace_entry {
        short unsigned int type;
        unsigned char flags;
        unsigned char preempt_count;
        int pid;
} __attribute__((preserve_access_index));
struct syscall_trace_enter {
        struct trace_entry ent;
        int nr;
        long unsigned int args[0];
} __attribute__((preserve_access_index));
struct syscall_trace_exit {
    struct trace_entry ent;
    int nr;
    long int ret;
}__attribute__((preserve_access_index));

struct thread_struct {
    // x86_64
	long unsigned int fsbase;
	// arm64
	struct {
        unsigned long	tp_value;	/* TLS register */
        unsigned long	tp2_value;
    } uw;
}  __attribute__((preserve_access_index));

struct file {
	void *private_data;
} __attribute__((preserve_access_index));

struct fdtable {
	struct file **fd;      /* current fd array */
} __attribute__((preserve_access_index));

struct files_struct {
	struct fdtable *fdt;
} __attribute__((preserve_access_index));

struct task_struct {
	__u32 pid;
    __u32 tgid;
    struct thread_struct thread;
    struct files_struct *files;
}  __attribute__((preserve_access_index));
#endif