1/*
2 * Linux Socket Filter Data Structures
3 */
4#ifndef __TOOLS_LINUX_FILTER_H
5#define __TOOLS_LINUX_FILTER_H
6
7#include <linux/bpf.h>
8
9/* ArgX, context and stack frame pointer register positions. Note,
10 * Arg1, Arg2, Arg3, etc are used as argument mappings of function
11 * calls in BPF_CALL instruction.
12 */
13#define BPF_REG_ARG1	BPF_REG_1
14#define BPF_REG_ARG2	BPF_REG_2
15#define BPF_REG_ARG3	BPF_REG_3
16#define BPF_REG_ARG4	BPF_REG_4
17#define BPF_REG_ARG5	BPF_REG_5
18#define BPF_REG_CTX	BPF_REG_6
19#define BPF_REG_FP	BPF_REG_10
20
21/* Additional register mappings for converted user programs. */
22#define BPF_REG_A	BPF_REG_0
23#define BPF_REG_X	BPF_REG_7
24#define BPF_REG_TMP	BPF_REG_8
25
26/* BPF program can access up to 512 bytes of stack space. */
27#define MAX_BPF_STACK	512
28
29/* Helper macros for filter block array initializers. */
30
31/* ALU ops on registers, bpf_add|sub|...: dst_reg += src_reg */
32
33#define BPF_ALU64_REG(OP, DST, SRC)				\
34	((struct bpf_insn) {					\
35		.code  = BPF_ALU64 | BPF_OP(OP) | BPF_X,	\
36		.dst_reg = DST,					\
37		.src_reg = SRC,					\
38		.off   = 0,					\
39		.imm   = 0 })
40
41#define BPF_ALU32_REG(OP, DST, SRC)				\
42	((struct bpf_insn) {					\
43		.code  = BPF_ALU | BPF_OP(OP) | BPF_X,		\
44		.dst_reg = DST,					\
45		.src_reg = SRC,					\
46		.off   = 0,					\
47		.imm   = 0 })
48
49/* ALU ops on immediates, bpf_add|sub|...: dst_reg += imm32 */
50
51#define BPF_ALU64_IMM(OP, DST, IMM)				\
52	((struct bpf_insn) {					\
53		.code  = BPF_ALU64 | BPF_OP(OP) | BPF_K,	\
54		.dst_reg = DST,					\
55		.src_reg = 0,					\
56		.off   = 0,					\
57		.imm   = IMM })
58
59#define BPF_ALU32_IMM(OP, DST, IMM)				\
60	((struct bpf_insn) {					\
61		.code  = BPF_ALU | BPF_OP(OP) | BPF_K,		\
62		.dst_reg = DST,					\
63		.src_reg = 0,					\
64		.off   = 0,					\
65		.imm   = IMM })
66
67/* Endianess conversion, cpu_to_{l,b}e(), {l,b}e_to_cpu() */
68
69#define BPF_ENDIAN(TYPE, DST, LEN)				\
70	((struct bpf_insn) {					\
71		.code  = BPF_ALU | BPF_END | BPF_SRC(TYPE),	\
72		.dst_reg = DST,					\
73		.src_reg = 0,					\
74		.off   = 0,					\
75		.imm   = LEN })
76
77/* Short form of mov, dst_reg = src_reg */
78
79#define BPF_MOV64_REG(DST, SRC)					\
80	((struct bpf_insn) {					\
81		.code  = BPF_ALU64 | BPF_MOV | BPF_X,		\
82		.dst_reg = DST,					\
83		.src_reg = SRC,					\
84		.off   = 0,					\
85		.imm   = 0 })
86
87#define BPF_MOV32_REG(DST, SRC)					\
88	((struct bpf_insn) {					\
89		.code  = BPF_ALU | BPF_MOV | BPF_X,		\
90		.dst_reg = DST,					\
91		.src_reg = SRC,					\
92		.off   = 0,					\
93		.imm   = 0 })
94
95/* Short form of mov, dst_reg = imm32 */
96
97#define BPF_MOV64_IMM(DST, IMM)					\
98	((struct bpf_insn) {					\
99		.code  = BPF_ALU64 | BPF_MOV | BPF_K,		\
100		.dst_reg = DST,					\
101		.src_reg = 0,					\
102		.off   = 0,					\
103		.imm   = IMM })
104
105#define BPF_MOV32_IMM(DST, IMM)					\
106	((struct bpf_insn) {					\
107		.code  = BPF_ALU | BPF_MOV | BPF_K,		\
108		.dst_reg = DST,					\
109		.src_reg = 0,					\
110		.off   = 0,					\
111		.imm   = IMM })
112
113/* Short form of mov based on type,  BPF_X: dst_reg = src_reg, BPF_K: dst_reg = imm32 */
114
115#define BPF_MOV64_RAW(TYPE, DST, SRC, IMM)			\
116	((struct bpf_insn) {					\
117		.code  = BPF_ALU64 | BPF_MOV | BPF_SRC(TYPE),	\
118		.dst_reg = DST,					\
119		.src_reg = SRC,					\
120		.off   = 0,					\
121		.imm   = IMM })
122
123#define BPF_MOV32_RAW(TYPE, DST, SRC, IMM)			\
124	((struct bpf_insn) {					\
125		.code  = BPF_ALU | BPF_MOV | BPF_SRC(TYPE),	\
126		.dst_reg = DST,					\
127		.src_reg = SRC,					\
128		.off   = 0,					\
129		.imm   = IMM })
130
131/* Direct packet access, R0 = *(uint *) (skb->data + imm32) */
132
133#define BPF_LD_ABS(SIZE, IMM)					\
134	((struct bpf_insn) {					\
135		.code  = BPF_LD | BPF_SIZE(SIZE) | BPF_ABS,	\
136		.dst_reg = 0,					\
137		.src_reg = 0,					\
138		.off   = 0,					\
139		.imm   = IMM })
140
141/* Indirect packet access, R0 = *(uint *) (skb->data + src_reg + imm32) */
142
143#define BPF_LD_IND(SIZE, SRC, IMM)				\
144	((struct bpf_insn) {					\
145		.code  = BPF_LD | BPF_SIZE(SIZE) | BPF_IND,	\
146		.dst_reg = 0,					\
147		.src_reg = SRC,					\
148		.off   = 0,					\
149		.imm   = IMM })
150
151/* Memory load, dst_reg = *(uint *) (src_reg + off16) */
152
153#define BPF_LDX_MEM(SIZE, DST, SRC, OFF)			\
154	((struct bpf_insn) {					\
155		.code  = BPF_LDX | BPF_SIZE(SIZE) | BPF_MEM,	\
156		.dst_reg = DST,					\
157		.src_reg = SRC,					\
158		.off   = OFF,					\
159		.imm   = 0 })
160
161/* Memory store, *(uint *) (dst_reg + off16) = src_reg */
162
163#define BPF_STX_MEM(SIZE, DST, SRC, OFF)			\
164	((struct bpf_insn) {					\
165		.code  = BPF_STX | BPF_SIZE(SIZE) | BPF_MEM,	\
166		.dst_reg = DST,					\
167		.src_reg = SRC,					\
168		.off   = OFF,					\
169		.imm   = 0 })
170
171/* Memory store, *(uint *) (dst_reg + off16) = imm32 */
172
173#define BPF_ST_MEM(SIZE, DST, OFF, IMM)				\
174	((struct bpf_insn) {					\
175		.code  = BPF_ST | BPF_SIZE(SIZE) | BPF_MEM,	\
176		.dst_reg = DST,					\
177		.src_reg = 0,					\
178		.off   = OFF,					\
179		.imm   = IMM })
180
181/* Conditional jumps against registers, if (dst_reg 'op' src_reg) goto pc + off16 */
182
183#define BPF_JMP_REG(OP, DST, SRC, OFF)				\
184	((struct bpf_insn) {					\
185		.code  = BPF_JMP | BPF_OP(OP) | BPF_X,		\
186		.dst_reg = DST,					\
187		.src_reg = SRC,					\
188		.off   = OFF,					\
189		.imm   = 0 })
190
191/* Conditional jumps against immediates, if (dst_reg 'op' imm32) goto pc + off16 */
192
193#define BPF_JMP_IMM(OP, DST, IMM, OFF)				\
194	((struct bpf_insn) {					\
195		.code  = BPF_JMP | BPF_OP(OP) | BPF_K,		\
196		.dst_reg = DST,					\
197		.src_reg = 0,					\
198		.off   = OFF,					\
199		.imm   = IMM })
200
201/* Function call */
202
203#define BPF_EMIT_CALL(FUNC)					\
204	((struct bpf_insn) {					\
205		.code  = BPF_JMP | BPF_CALL,			\
206		.dst_reg = 0,					\
207		.src_reg = 0,					\
208		.off   = 0,					\
209		.imm   = ((FUNC) - BPF_FUNC_unspec) })
210
211/* Raw code statement block */
212
213#define BPF_RAW_INSN(CODE, DST, SRC, OFF, IMM)			\
214	((struct bpf_insn) {					\
215		.code  = CODE,					\
216		.dst_reg = DST,					\
217		.src_reg = SRC,					\
218		.off   = OFF,					\
219		.imm   = IMM })
220
221/* Program exit */
222
223#define BPF_EXIT_INSN()						\
224	((struct bpf_insn) {					\
225		.code  = BPF_JMP | BPF_EXIT,			\
226		.dst_reg = 0,					\
227		.src_reg = 0,					\
228		.off   = 0,					\
229		.imm   = 0 })
230
231#endif /* __TOOLS_LINUX_FILTER_H */
232