[linux-2.6-block.git] / samples / bpf / tracex5_kern.c

/* Copyright (c) 2015 PLUMgrid, http://plumgrid.com
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of version 2 of the GNU General Public
 * License as published by the Free Software Foundation.
 */
#include <linux/ptrace.h>
#include <linux/version.h>
#include <uapi/linux/bpf.h>
#include <uapi/linux/seccomp.h>
#include <uapi/linux/unistd.h>
#include "syscall_nrs.h"
#include <bpf/bpf_helpers.h>
#include <bpf/bpf_tracing.h>

#define PROG(F) SEC("kprobe/"__stringify(F)) int bpf_func_##F

struct {
	__uint(type, BPF_MAP_TYPE_PROG_ARRAY);
	__uint(key_size, sizeof(u32));
	__uint(value_size, sizeof(u32));
#ifdef __mips__
	__uint(max_entries, 6000); /* MIPS n64 syscalls start at 5000 */
#else
	__uint(max_entries, 1024);
#endif
} progs SEC(".maps");

SEC("kprobe/__seccomp_filter")
int bpf_prog1(struct pt_regs *ctx)
{
	int sc_nr = (int)PT_REGS_PARM1(ctx);

	/* dispatch into next BPF program depending on syscall number */
	bpf_tail_call(ctx, &progs, sc_nr);

	/* fall through -> unknown syscall */
	if (sc_nr >= __NR_getuid && sc_nr <= __NR_getsid) {
		char fmt[] = "syscall=%d (one of get/set uid/pid/gid)\n";
		bpf_trace_printk(fmt, sizeof(fmt), sc_nr);
	}
	return 0;
}

/* we jump here when syscall number == __NR_write */
PROG(SYS__NR_write)(struct pt_regs *ctx)
{
	struct seccomp_data sd;

	bpf_probe_read_kernel(&sd, sizeof(sd), (void *)PT_REGS_PARM2(ctx));
	if (sd.args[2] == 512) {
		char fmt[] = "write(fd=%d, buf=%p, size=%d)\n";
		bpf_trace_printk(fmt, sizeof(fmt),
				 sd.args[0], sd.args[1], sd.args[2]);
	}
	return 0;
}

PROG(SYS__NR_read)(struct pt_regs *ctx)
{
	struct seccomp_data sd;

	bpf_probe_read_kernel(&sd, sizeof(sd), (void *)PT_REGS_PARM2(ctx));
	if (sd.args[2] > 128 && sd.args[2] <= 1024) {
		char fmt[] = "read(fd=%d, buf=%p, size=%d)\n";
		bpf_trace_printk(fmt, sizeof(fmt),
				 sd.args[0], sd.args[1], sd.args[2]);
	}
	return 0;
}

#ifdef __NR_mmap2
PROG(SYS__NR_mmap2)(struct pt_regs *ctx)
{
	char fmt[] = "mmap2\n";

	bpf_trace_printk(fmt, sizeof(fmt));
	return 0;
}
#endif

#ifdef __NR_mmap
PROG(SYS__NR_mmap)(struct pt_regs *ctx)
{
	char fmt[] = "mmap\n";

	bpf_trace_printk(fmt, sizeof(fmt));
	return 0;
}
#endif

char _license[] SEC("license") = "GPL";
u32 _version SEC("version") = LINUX_VERSION_CODE;
Commit	Line	Data
5bacd780 AS	1	/* Copyright (c) 2015 PLUMgrid, http://plumgrid.com
	2	*
	3	* This program is free software; you can redistribute it and/or
	4	* modify it under the terms of version 2 of the GNU General Public
	5	* License as published by the Free Software Foundation.
	6	*/
	7	#include <linux/ptrace.h>
	8	#include <linux/version.h>
	9	#include <uapi/linux/bpf.h>
	10	#include <uapi/linux/seccomp.h>
af392a8f	11	#include <uapi/linux/unistd.h>
4b7190e8	12	#include "syscall_nrs.h"
7cf245a3 THJ	13	#include <bpf/bpf_helpers.h>
7cf245a3 THJ	14	#include <bpf/bpf_tracing.h>
5bacd780 AS	15
	16	#define PROG(F) SEC("kprobe/"__stringify(F)) int bpf_func_##F
	17
59929cd1 DL	18	struct {
	19	__uint(type, BPF_MAP_TYPE_PROG_ARRAY);
	20	__uint(key_size, sizeof(u32));
	21	__uint(value_size, sizeof(u32));
4b7190e8	22	#ifdef __mips__
59929cd1	23	__uint(max_entries, 6000); /* MIPS n64 syscalls start at 5000 */
4b7190e8	24	#else
59929cd1	25	__uint(max_entries, 1024);
4b7190e8	26	#endif
59929cd1	27	} progs SEC(".maps");
5bacd780	28
973d94d8	29	SEC("kprobe/__seccomp_filter")
5bacd780 AS	30	int bpf_prog1(struct pt_regs *ctx)
5bacd780 AS	31	{
973d94d8	32	int sc_nr = (int)PT_REGS_PARM1(ctx);
5bacd780 AS	33
5bacd780 AS	34	/* dispatch into next BPF program depending on syscall number */
973d94d8	35	bpf_tail_call(ctx, &progs, sc_nr);
5bacd780 AS	36
5bacd780 AS	37	/* fall through -> unknown syscall */
973d94d8	38	if (sc_nr >= __NR_getuid && sc_nr <= __NR_getsid) {
5bacd780	39	char fmt[] = "syscall=%d (one of get/set uid/pid/gid)\n";
973d94d8	40	bpf_trace_printk(fmt, sizeof(fmt), sc_nr);
5bacd780 AS	41	}
	42	return 0;
	43	}
	44
	45	/* we jump here when syscall number == __NR_write */
4b7190e8	46	PROG(SYS__NR_write)(struct pt_regs *ctx)
5bacd780	47	{
02413cab	48	struct seccomp_data sd;
5bacd780	49
e4d9c232	50	bpf_probe_read_kernel(&sd, sizeof(sd), (void *)PT_REGS_PARM2(ctx));
5bacd780 AS	51	if (sd.args[2] == 512) {
	52	char fmt[] = "write(fd=%d, buf=%p, size=%d)\n";
	53	bpf_trace_printk(fmt, sizeof(fmt),
	54	sd.args[0], sd.args[1], sd.args[2]);
	55	}
	56	return 0;
	57	}
	58
4b7190e8	59	PROG(SYS__NR_read)(struct pt_regs *ctx)
5bacd780	60	{
02413cab	61	struct seccomp_data sd;
5bacd780	62
e4d9c232	63	bpf_probe_read_kernel(&sd, sizeof(sd), (void *)PT_REGS_PARM2(ctx));
5bacd780 AS	64	if (sd.args[2] > 128 && sd.args[2] <= 1024) {
	65	char fmt[] = "read(fd=%d, buf=%p, size=%d)\n";
	66	bpf_trace_printk(fmt, sizeof(fmt),
	67	sd.args[0], sd.args[1], sd.args[2]);
	68	}
	69	return 0;
	70	}
	71
bb4b5c08 IK	72	#ifdef __NR_mmap2
	73	PROG(SYS__NR_mmap2)(struct pt_regs *ctx)
	74	{
	75	char fmt[] = "mmap2\n";
	76
	77	bpf_trace_printk(fmt, sizeof(fmt));
	78	return 0;
	79	}
	80	#endif
	81
	82	#ifdef __NR_mmap
4b7190e8	83	PROG(SYS__NR_mmap)(struct pt_regs *ctx)
5bacd780 AS	84	{
5bacd780 AS	85	char fmt[] = "mmap\n";
bb4b5c08	86
5bacd780 AS	87	bpf_trace_printk(fmt, sizeof(fmt));
	88	return 0;
	89	}
bb4b5c08	90	#endif
5bacd780 AS	91
	92	char _license[] SEC("license") = "GPL";
	93	u32 _version SEC("version") = LINUX_VERSION_CODE;