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1 /* eBPF mini library */
2 #ifndef __LIBBPF_H
3 #define __LIBBPF_H
4 
5 struct bpf_insn;
6 
7 int bpf_create_map(enum bpf_map_type map_type, int key_size, int value_size,
8 		   int max_entries);
9 int bpf_update_elem(int fd, void *key, void *value);
10 int bpf_lookup_elem(int fd, void *key, void *value);
11 int bpf_delete_elem(int fd, void *key);
12 int bpf_get_next_key(int fd, void *key, void *next_key);
13 
14 int bpf_prog_load(enum bpf_prog_type prog_type,
15 		  const struct bpf_insn *insns, int insn_len,
16 		  const char *license);
17 
18 #define LOG_BUF_SIZE 8192
19 extern char bpf_log_buf[LOG_BUF_SIZE];
20 
21 /* ALU ops on registers, bpf_add|sub|...: dst_reg += src_reg */
22 
23 #define BPF_ALU64_REG(OP, DST, SRC)				\
24 	((struct bpf_insn) {					\
25 		.code  = BPF_ALU64 | BPF_OP(OP) | BPF_X,	\
26 		.dst_reg = DST,					\
27 		.src_reg = SRC,					\
28 		.off   = 0,					\
29 		.imm   = 0 })
30 
31 #define BPF_ALU32_REG(OP, DST, SRC)				\
32 	((struct bpf_insn) {					\
33 		.code  = BPF_ALU | BPF_OP(OP) | BPF_X,		\
34 		.dst_reg = DST,					\
35 		.src_reg = SRC,					\
36 		.off   = 0,					\
37 		.imm   = 0 })
38 
39 /* ALU ops on immediates, bpf_add|sub|...: dst_reg += imm32 */
40 
41 #define BPF_ALU64_IMM(OP, DST, IMM)				\
42 	((struct bpf_insn) {					\
43 		.code  = BPF_ALU64 | BPF_OP(OP) | BPF_K,	\
44 		.dst_reg = DST,					\
45 		.src_reg = 0,					\
46 		.off   = 0,					\
47 		.imm   = IMM })
48 
49 #define BPF_ALU32_IMM(OP, DST, IMM)				\
50 	((struct bpf_insn) {					\
51 		.code  = BPF_ALU | BPF_OP(OP) | BPF_K,		\
52 		.dst_reg = DST,					\
53 		.src_reg = 0,					\
54 		.off   = 0,					\
55 		.imm   = IMM })
56 
57 /* Short form of mov, dst_reg = src_reg */
58 
59 #define BPF_MOV64_REG(DST, SRC)					\
60 	((struct bpf_insn) {					\
61 		.code  = BPF_ALU64 | BPF_MOV | BPF_X,		\
62 		.dst_reg = DST,					\
63 		.src_reg = SRC,					\
64 		.off   = 0,					\
65 		.imm   = 0 })
66 
67 /* Short form of mov, dst_reg = imm32 */
68 
69 #define BPF_MOV64_IMM(DST, IMM)					\
70 	((struct bpf_insn) {					\
71 		.code  = BPF_ALU64 | BPF_MOV | BPF_K,		\
72 		.dst_reg = DST,					\
73 		.src_reg = 0,					\
74 		.off   = 0,					\
75 		.imm   = IMM })
76 
77 /* BPF_LD_IMM64 macro encodes single 'load 64-bit immediate' insn */
78 #define BPF_LD_IMM64(DST, IMM)					\
79 	BPF_LD_IMM64_RAW(DST, 0, IMM)
80 
81 #define BPF_LD_IMM64_RAW(DST, SRC, IMM)				\
82 	((struct bpf_insn) {					\
83 		.code  = BPF_LD | BPF_DW | BPF_IMM,		\
84 		.dst_reg = DST,					\
85 		.src_reg = SRC,					\
86 		.off   = 0,					\
87 		.imm   = (__u32) (IMM) }),			\
88 	((struct bpf_insn) {					\
89 		.code  = 0, /* zero is reserved opcode */	\
90 		.dst_reg = 0,					\
91 		.src_reg = 0,					\
92 		.off   = 0,					\
93 		.imm   = ((__u64) (IMM)) >> 32 })
94 
95 #define BPF_PSEUDO_MAP_FD	1
96 
97 /* pseudo BPF_LD_IMM64 insn used to refer to process-local map_fd */
98 #define BPF_LD_MAP_FD(DST, MAP_FD)				\
99 	BPF_LD_IMM64_RAW(DST, BPF_PSEUDO_MAP_FD, MAP_FD)
100 
101 
102 /* Memory load, dst_reg = *(uint *) (src_reg + off16) */
103 
104 #define BPF_LDX_MEM(SIZE, DST, SRC, OFF)			\
105 	((struct bpf_insn) {					\
106 		.code  = BPF_LDX | BPF_SIZE(SIZE) | BPF_MEM,	\
107 		.dst_reg = DST,					\
108 		.src_reg = SRC,					\
109 		.off   = OFF,					\
110 		.imm   = 0 })
111 
112 /* Memory store, *(uint *) (dst_reg + off16) = src_reg */
113 
114 #define BPF_STX_MEM(SIZE, DST, SRC, OFF)			\
115 	((struct bpf_insn) {					\
116 		.code  = BPF_STX | BPF_SIZE(SIZE) | BPF_MEM,	\
117 		.dst_reg = DST,					\
118 		.src_reg = SRC,					\
119 		.off   = OFF,					\
120 		.imm   = 0 })
121 
122 /* Memory store, *(uint *) (dst_reg + off16) = imm32 */
123 
124 #define BPF_ST_MEM(SIZE, DST, OFF, IMM)				\
125 	((struct bpf_insn) {					\
126 		.code  = BPF_ST | BPF_SIZE(SIZE) | BPF_MEM,	\
127 		.dst_reg = DST,					\
128 		.src_reg = 0,					\
129 		.off   = OFF,					\
130 		.imm   = IMM })
131 
132 /* Conditional jumps against registers, if (dst_reg 'op' src_reg) goto pc + off16 */
133 
134 #define BPF_JMP_REG(OP, DST, SRC, OFF)				\
135 	((struct bpf_insn) {					\
136 		.code  = BPF_JMP | BPF_OP(OP) | BPF_X,		\
137 		.dst_reg = DST,					\
138 		.src_reg = SRC,					\
139 		.off   = OFF,					\
140 		.imm   = 0 })
141 
142 /* Conditional jumps against immediates, if (dst_reg 'op' imm32) goto pc + off16 */
143 
144 #define BPF_JMP_IMM(OP, DST, IMM, OFF)				\
145 	((struct bpf_insn) {					\
146 		.code  = BPF_JMP | BPF_OP(OP) | BPF_K,		\
147 		.dst_reg = DST,					\
148 		.src_reg = 0,					\
149 		.off   = OFF,					\
150 		.imm   = IMM })
151 
152 /* Raw code statement block */
153 
154 #define BPF_RAW_INSN(CODE, DST, SRC, OFF, IMM)			\
155 	((struct bpf_insn) {					\
156 		.code  = CODE,					\
157 		.dst_reg = DST,					\
158 		.src_reg = SRC,					\
159 		.off   = OFF,					\
160 		.imm   = IMM })
161 
162 /* Program exit */
163 
164 #define BPF_EXIT_INSN()						\
165 	((struct bpf_insn) {					\
166 		.code  = BPF_JMP | BPF_EXIT,			\
167 		.dst_reg = 0,					\
168 		.src_reg = 0,					\
169 		.off   = 0,					\
170 		.imm   = 0 })
171 
172 #endif
173