aboutsummaryrefslogtreecommitdiffstats
path: root/samples/bpf/bpf_helpers.h
blob: 7927a090fa0d03241ef379db6ab91c5330c5f44b (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
#ifndef __BPF_HELPERS_H
#define __BPF_HELPERS_H

/* helper macro to place programs, maps, license in
 * different sections in elf_bpf file. Section names
 * are interpreted by elf_bpf loader
 */
#define SEC(NAME) __attribute__((section(NAME), used))

/* helper functions called from eBPF programs written in C */
static void *(*bpf_map_lookup_elem)(void *map, void *key) =
	(void *) BPF_FUNC_map_lookup_elem;
static int (*bpf_map_update_elem)(void *map, void *key, void *value,
				  unsigned long long flags) =
	(void *) BPF_FUNC_map_update_elem;
static int (*bpf_map_delete_elem)(void *map, void *key) =
	(void *) BPF_FUNC_map_delete_elem;
static int (*bpf_probe_read)(void *dst, int size, void *unsafe_ptr) =
	(void *) BPF_FUNC_probe_read;
static unsigned long long (*bpf_ktime_get_ns)(void) =
	(void *) BPF_FUNC_ktime_get_ns;
static int (*bpf_trace_printk)(const char *fmt, int fmt_size, ...) =
	(void *) BPF_FUNC_trace_printk;
static void (*bpf_tail_call)(void *ctx, void *map, int index) =
	(void *) BPF_FUNC_tail_call;
static unsigned long long (*bpf_get_smp_processor_id)(void) =
	(void *) BPF_FUNC_get_smp_processor_id;
static unsigned long long (*bpf_get_current_pid_tgid)(void) =
	(void *) BPF_FUNC_get_current_pid_tgid;
static unsigned long long (*bpf_get_current_uid_gid)(void) =
	(void *) BPF_FUNC_get_current_uid_gid;
static int (*bpf_get_current_comm)(void *buf, int buf_size) =
	(void *) BPF_FUNC_get_current_comm;
static int (*bpf_perf_event_read)(void *map, int index) =
	(void *) BPF_FUNC_perf_event_read;
static int (*bpf_clone_redirect)(void *ctx, int ifindex, int flags) =
	(void *) BPF_FUNC_clone_redirect;
static int (*bpf_redirect)(int ifindex, int flags) =
	(void *) BPF_FUNC_redirect;
static int (*bpf_perf_event_output)(void *ctx, void *map, int index, void *data, int size) =
	(void *) BPF_FUNC_perf_event_output;
static int (*bpf_get_stackid)(void *ctx, void *map, int flags) =
	(void *) BPF_FUNC_get_stackid;
static int (*bpf_probe_write_user)(void *dst, void *src, int size) =
	(void *) BPF_FUNC_probe_write_user;

/* llvm builtin functions that eBPF C program may use to
 * emit BPF_LD_ABS and BPF_LD_IND instructions
 */
struct sk_buff;
unsigned long long load_byte(void *skb,
			     unsigned long long off) asm("llvm.bpf.load.byte");
unsigned long long load_half(void *skb,
			     unsigned long long off) asm("llvm.bpf.load.half");
unsigned long long load_word(void *skb,
			     unsigned long long off) asm("llvm.bpf.load.word");

/* a helper structure used by eBPF C program
 * to describe map attributes to elf_bpf loader
 */
struct bpf_map_def {
	unsigned int type;
	unsigned int key_size;
	unsigned int value_size;
	unsigned int max_entries;
	unsigned int map_flags;
};

static int (*bpf_skb_store_bytes)(void *ctx, int off, void *from, int len, int flags) =
	(void *) BPF_FUNC_skb_store_bytes;
static int (*bpf_l3_csum_replace)(void *ctx, int off, int from, int to, int flags) =
	(void *) BPF_FUNC_l3_csum_replace;
static int (*bpf_l4_csum_replace)(void *ctx, int off, int from, int to, int flags) =
	(void *) BPF_FUNC_l4_csum_replace;
static int (*bpf_skb_under_cgroup)(void *ctx, void *map, int index) =
	(void *) BPF_FUNC_skb_under_cgroup;

#if defined(__x86_64__)

#define PT_REGS_PARM1(x) ((x)->di)
#define PT_REGS_PARM2(x) ((x)->si)
#define PT_REGS_PARM3(x) ((x)->dx)
#define PT_REGS_PARM4(x) ((x)->cx)
#define PT_REGS_PARM5(x) ((x)->r8)
#define PT_REGS_RET(x) ((x)->sp)
#define PT_REGS_FP(x) ((x)->bp)
#define PT_REGS_RC(x) ((x)->ax)
#define PT_REGS_SP(x) ((x)->sp)
#define PT_REGS_IP(x) ((x)->ip)

#elif defined(__s390x__)

#define PT_REGS_PARM1(x) ((x)->gprs[2])
#define PT_REGS_PARM2(x) ((x)->gprs[3])
#define PT_REGS_PARM3(x) ((x)->gprs[4])
#define PT_REGS_PARM4(x) ((x)->gprs[5])
#define PT_REGS_PARM5(x) ((x)->gprs[6])
#define PT_REGS_RET(x) ((x)->gprs[14])
#define PT_REGS_FP(x) ((x)->gprs[11]) /* Works only with CONFIG_FRAME_POINTER */
#define PT_REGS_RC(x) ((x)->gprs[2])
#define PT_REGS_SP(x) ((x)->gprs[15])
#define PT_REGS_IP(x) ((x)->ip)

#elif defined(__aarch64__)

#define PT_REGS_PARM1(x) ((x)->regs[0])
#define PT_REGS_PARM2(x) ((x)->regs[1])
#define PT_REGS_PARM3(x) ((x)->regs[2])
#define PT_REGS_PARM4(x) ((x)->regs[3])
#define PT_REGS_PARM5(x) ((x)->regs[4])
#define PT_REGS_RET(x) ((x)->regs[30])
#define PT_REGS_FP(x) ((x)->regs[29]) /* Works only with CONFIG_FRAME_POINTER */
#define PT_REGS_RC(x) ((x)->regs[0])
#define PT_REGS_SP(x) ((x)->sp)
#define PT_REGS_IP(x) ((x)->pc)

#elif defined(__powerpc__)

#define PT_REGS_PARM1(x) ((x)->gpr[3])
#define PT_REGS_PARM2(x) ((x)->gpr[4])
#define PT_REGS_PARM3(x) ((x)->gpr[5])
#define PT_REGS_PARM4(x) ((x)->gpr[6])
#define PT_REGS_PARM5(x) ((x)->gpr[7])
#define PT_REGS_RC(x) ((x)->gpr[3])
#define PT_REGS_SP(x) ((x)->sp)
#define PT_REGS_IP(x) ((x)->nip)

#endif

#ifdef __powerpc__
#define BPF_KPROBE_READ_RET_IP(ip, ctx)		({ (ip) = (ctx)->link; })
#define BPF_KRETPROBE_READ_RET_IP		BPF_KPROBE_READ_RET_IP
#else
#define BPF_KPROBE_READ_RET_IP(ip, ctx)		({				\
		bpf_probe_read(&(ip), sizeof(ip), (void *)PT_REGS_RET(ctx)); })
#define BPF_KRETPROBE_READ_RET_IP(ip, ctx)	({				\
		bpf_probe_read(&(ip), sizeof(ip),				\
				(void *)(PT_REGS_FP(ctx) + sizeof(ip))); })
#endif

#endif