1// SPDX-License-Identifier: GPL-2.0
2/* Copyright (c) 2021 Google LLC. */
3
4#include <linux/bpf.h>
5#include <bpf/bpf_helpers.h>
6
7__u32 pid = 0;
8
9char num_out[64] = {};
10long num_ret = 0;
11
12char ip_out[64] = {};
13long ip_ret = 0;
14
15char sym_out[64] = {};
16long sym_ret = 0;
17
18char addr_out[64] = {};
19long addr_ret = 0;
20
21char str_out[64] = {};
22long str_ret = 0;
23
24char over_out[6] = {};
25long over_ret = 0;
26
27char pad_out[10] = {};
28long pad_ret = 0;
29
30char noarg_out[64] = {};
31long noarg_ret = 0;
32
33long nobuf_ret = 0;
34
35extern const void schedule __ksym;
36
37SEC("raw_tp/sys_enter")
38int handler(const void *ctx)
39{
40	/* Convenient values to pretty-print */
41	const __u8 ex_ipv4[] = {127, 0, 0, 1};
42	const __u8 ex_ipv6[] = {0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1};
43	static const char str1[] = "str1";
44	static const char longstr[] = "longstr";
45
46	if ((int)bpf_get_current_pid_tgid() != pid)
47		return 0;
48
49	/* Integer types */
50	num_ret  = BPF_SNPRINTF(num_out, sizeof(num_out),
51				"%d %u %x %li %llu %lX",
52				-8, 9, 150, -424242, 1337, 0xDABBAD00);
53	/* IP addresses */
54	ip_ret   = BPF_SNPRINTF(ip_out, sizeof(ip_out), "%pi4 %pI6",
55				&ex_ipv4, &ex_ipv6);
56	/* Symbol lookup formatting */
57	sym_ret  = BPF_SNPRINTF(sym_out,  sizeof(sym_out), "%ps %pS %pB",
58				&schedule, &schedule, &schedule);
59	/* Kernel pointers */
60	addr_ret = BPF_SNPRINTF(addr_out, sizeof(addr_out), "%pK %px %p",
61				0, 0xFFFF00000ADD4E55, 0xFFFF00000ADD4E55);
62	/* Strings and single-byte character embedding */
63	str_ret  = BPF_SNPRINTF(str_out, sizeof(str_out), "%s % 9c %+2c %-3c %04c %0c %+05s",
64				str1, 'a', 'b', 'c', 'd', 'e', longstr);
65	/* Overflow */
66	over_ret = BPF_SNPRINTF(over_out, sizeof(over_out), "%%overflow");
67	/* Padding of fixed width numbers */
68	pad_ret = BPF_SNPRINTF(pad_out, sizeof(pad_out), "%5d %0900000X", 4, 4);
69	/* No args */
70	noarg_ret = BPF_SNPRINTF(noarg_out, sizeof(noarg_out), "simple case");
71	/* No buffer */
72	nobuf_ret = BPF_SNPRINTF(NULL, 0, "only interested in length %d", 60);
73
74	return 0;
75}
76
77char _license[] SEC("license") = "GPL";
78