xref: /openbmc/linux/samples/bpf/bpf_insn.h (revision b4e18b29)
1 /* SPDX-License-Identifier: GPL-2.0 */
2 /* eBPF instruction mini library */
3 #ifndef __BPF_INSN_H
4 #define __BPF_INSN_H
5 
6 struct bpf_insn;
7 
8 /* ALU ops on registers, bpf_add|sub|...: dst_reg += src_reg */
9 
10 #define BPF_ALU64_REG(OP, DST, SRC)				\
11 	((struct bpf_insn) {					\
12 		.code  = BPF_ALU64 | BPF_OP(OP) | BPF_X,	\
13 		.dst_reg = DST,					\
14 		.src_reg = SRC,					\
15 		.off   = 0,					\
16 		.imm   = 0 })
17 
18 #define BPF_ALU32_REG(OP, DST, SRC)				\
19 	((struct bpf_insn) {					\
20 		.code  = BPF_ALU | BPF_OP(OP) | BPF_X,		\
21 		.dst_reg = DST,					\
22 		.src_reg = SRC,					\
23 		.off   = 0,					\
24 		.imm   = 0 })
25 
26 /* ALU ops on immediates, bpf_add|sub|...: dst_reg += imm32 */
27 
28 #define BPF_ALU64_IMM(OP, DST, IMM)				\
29 	((struct bpf_insn) {					\
30 		.code  = BPF_ALU64 | BPF_OP(OP) | BPF_K,	\
31 		.dst_reg = DST,					\
32 		.src_reg = 0,					\
33 		.off   = 0,					\
34 		.imm   = IMM })
35 
36 #define BPF_ALU32_IMM(OP, DST, IMM)				\
37 	((struct bpf_insn) {					\
38 		.code  = BPF_ALU | BPF_OP(OP) | BPF_K,		\
39 		.dst_reg = DST,					\
40 		.src_reg = 0,					\
41 		.off   = 0,					\
42 		.imm   = IMM })
43 
44 /* Short form of mov, dst_reg = src_reg */
45 
46 #define BPF_MOV64_REG(DST, SRC)					\
47 	((struct bpf_insn) {					\
48 		.code  = BPF_ALU64 | BPF_MOV | BPF_X,		\
49 		.dst_reg = DST,					\
50 		.src_reg = SRC,					\
51 		.off   = 0,					\
52 		.imm   = 0 })
53 
54 #define BPF_MOV32_REG(DST, SRC)					\
55 	((struct bpf_insn) {					\
56 		.code  = BPF_ALU | BPF_MOV | BPF_X,		\
57 		.dst_reg = DST,					\
58 		.src_reg = SRC,					\
59 		.off   = 0,					\
60 		.imm   = 0 })
61 
62 /* Short form of mov, dst_reg = imm32 */
63 
64 #define BPF_MOV64_IMM(DST, IMM)					\
65 	((struct bpf_insn) {					\
66 		.code  = BPF_ALU64 | BPF_MOV | BPF_K,		\
67 		.dst_reg = DST,					\
68 		.src_reg = 0,					\
69 		.off   = 0,					\
70 		.imm   = IMM })
71 
72 #define BPF_MOV32_IMM(DST, IMM)					\
73 	((struct bpf_insn) {					\
74 		.code  = BPF_ALU | BPF_MOV | BPF_K,		\
75 		.dst_reg = DST,					\
76 		.src_reg = 0,					\
77 		.off   = 0,					\
78 		.imm   = IMM })
79 
80 /* BPF_LD_IMM64 macro encodes single 'load 64-bit immediate' insn */
81 #define BPF_LD_IMM64(DST, IMM)					\
82 	BPF_LD_IMM64_RAW(DST, 0, IMM)
83 
84 #define BPF_LD_IMM64_RAW(DST, SRC, IMM)				\
85 	((struct bpf_insn) {					\
86 		.code  = BPF_LD | BPF_DW | BPF_IMM,		\
87 		.dst_reg = DST,					\
88 		.src_reg = SRC,					\
89 		.off   = 0,					\
90 		.imm   = (__u32) (IMM) }),			\
91 	((struct bpf_insn) {					\
92 		.code  = 0, /* zero is reserved opcode */	\
93 		.dst_reg = 0,					\
94 		.src_reg = 0,					\
95 		.off   = 0,					\
96 		.imm   = ((__u64) (IMM)) >> 32 })
97 
98 #ifndef BPF_PSEUDO_MAP_FD
99 # define BPF_PSEUDO_MAP_FD	1
100 #endif
101 
102 /* pseudo BPF_LD_IMM64 insn used to refer to process-local map_fd */
103 #define BPF_LD_MAP_FD(DST, MAP_FD)				\
104 	BPF_LD_IMM64_RAW(DST, BPF_PSEUDO_MAP_FD, MAP_FD)
105 
106 
107 /* Direct packet access, R0 = *(uint *) (skb->data + imm32) */
108 
109 #define BPF_LD_ABS(SIZE, IMM)					\
110 	((struct bpf_insn) {					\
111 		.code  = BPF_LD | BPF_SIZE(SIZE) | BPF_ABS,	\
112 		.dst_reg = 0,					\
113 		.src_reg = 0,					\
114 		.off   = 0,					\
115 		.imm   = IMM })
116 
117 /* Memory load, dst_reg = *(uint *) (src_reg + off16) */
118 
119 #define BPF_LDX_MEM(SIZE, DST, SRC, OFF)			\
120 	((struct bpf_insn) {					\
121 		.code  = BPF_LDX | BPF_SIZE(SIZE) | BPF_MEM,	\
122 		.dst_reg = DST,					\
123 		.src_reg = SRC,					\
124 		.off   = OFF,					\
125 		.imm   = 0 })
126 
127 /* Memory store, *(uint *) (dst_reg + off16) = src_reg */
128 
129 #define BPF_STX_MEM(SIZE, DST, SRC, OFF)			\
130 	((struct bpf_insn) {					\
131 		.code  = BPF_STX | BPF_SIZE(SIZE) | BPF_MEM,	\
132 		.dst_reg = DST,					\
133 		.src_reg = SRC,					\
134 		.off   = OFF,					\
135 		.imm   = 0 })
136 
137 /* Atomic memory add, *(uint *)(dst_reg + off16) += src_reg */
138 
139 #define BPF_STX_XADD(SIZE, DST, SRC, OFF)			\
140 	((struct bpf_insn) {					\
141 		.code  = BPF_STX | BPF_SIZE(SIZE) | BPF_ATOMIC,	\
142 		.dst_reg = DST,					\
143 		.src_reg = SRC,					\
144 		.off   = OFF,					\
145 		.imm   = BPF_ADD })
146 
147 /* Memory store, *(uint *) (dst_reg + off16) = imm32 */
148 
149 #define BPF_ST_MEM(SIZE, DST, OFF, IMM)				\
150 	((struct bpf_insn) {					\
151 		.code  = BPF_ST | BPF_SIZE(SIZE) | BPF_MEM,	\
152 		.dst_reg = DST,					\
153 		.src_reg = 0,					\
154 		.off   = OFF,					\
155 		.imm   = IMM })
156 
157 /* Conditional jumps against registers, if (dst_reg 'op' src_reg) goto pc + off16 */
158 
159 #define BPF_JMP_REG(OP, DST, SRC, OFF)				\
160 	((struct bpf_insn) {					\
161 		.code  = BPF_JMP | BPF_OP(OP) | BPF_X,		\
162 		.dst_reg = DST,					\
163 		.src_reg = SRC,					\
164 		.off   = OFF,					\
165 		.imm   = 0 })
166 
167 /* Like BPF_JMP_REG, but with 32-bit wide operands for comparison. */
168 
169 #define BPF_JMP32_REG(OP, DST, SRC, OFF)			\
170 	((struct bpf_insn) {					\
171 		.code  = BPF_JMP32 | BPF_OP(OP) | BPF_X,	\
172 		.dst_reg = DST,					\
173 		.src_reg = SRC,					\
174 		.off   = OFF,					\
175 		.imm   = 0 })
176 
177 /* Conditional jumps against immediates, if (dst_reg 'op' imm32) goto pc + off16 */
178 
179 #define BPF_JMP_IMM(OP, DST, IMM, OFF)				\
180 	((struct bpf_insn) {					\
181 		.code  = BPF_JMP | BPF_OP(OP) | BPF_K,		\
182 		.dst_reg = DST,					\
183 		.src_reg = 0,					\
184 		.off   = OFF,					\
185 		.imm   = IMM })
186 
187 /* Like BPF_JMP_IMM, but with 32-bit wide operands for comparison. */
188 
189 #define BPF_JMP32_IMM(OP, DST, IMM, OFF)			\
190 	((struct bpf_insn) {					\
191 		.code  = BPF_JMP32 | BPF_OP(OP) | BPF_K,	\
192 		.dst_reg = DST,					\
193 		.src_reg = 0,					\
194 		.off   = OFF,					\
195 		.imm   = IMM })
196 
197 /* Raw code statement block */
198 
199 #define BPF_RAW_INSN(CODE, DST, SRC, OFF, IMM)			\
200 	((struct bpf_insn) {					\
201 		.code  = CODE,					\
202 		.dst_reg = DST,					\
203 		.src_reg = SRC,					\
204 		.off   = OFF,					\
205 		.imm   = IMM })
206 
207 /* Program exit */
208 
209 #define BPF_EXIT_INSN()						\
210 	((struct bpf_insn) {					\
211 		.code  = BPF_JMP | BPF_EXIT,			\
212 		.dst_reg = 0,					\
213 		.src_reg = 0,					\
214 		.off   = 0,					\
215 		.imm   = 0 })
216 
217 #endif
218