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1da177e4 LT |
1 | /* |
2 | * Linux Socket Filter Data Structures | |
3 | */ | |
4 | ||
5 | #ifndef __LINUX_FILTER_H__ | |
6 | #define __LINUX_FILTER_H__ | |
7 | ||
8 | #include <linux/compiler.h> | |
9 | #include <linux/types.h> | |
10 | ||
11 | #ifdef __KERNEL__ | |
12 | #include <asm/atomic.h> | |
13 | #endif | |
14 | ||
15 | /* | |
16 | * Current version of the filter code architecture. | |
17 | */ | |
18 | #define BPF_MAJOR_VERSION 1 | |
19 | #define BPF_MINOR_VERSION 1 | |
20 | ||
21 | /* | |
22 | * Try and keep these values and structures similar to BSD, especially | |
23 | * the BPF code definitions which need to match so you can share filters | |
24 | */ | |
25 | ||
d94d9fee | 26 | struct sock_filter { /* Filter block */ |
fda9ef5d DM |
27 | __u16 code; /* Actual filter code */ |
28 | __u8 jt; /* Jump true */ | |
29 | __u8 jf; /* Jump false */ | |
30 | __u32 k; /* Generic multiuse field */ | |
1da177e4 LT |
31 | }; |
32 | ||
d94d9fee | 33 | struct sock_fprog { /* Required for SO_ATTACH_FILTER. */ |
1da177e4 LT |
34 | unsigned short len; /* Number of filter blocks */ |
35 | struct sock_filter __user *filter; | |
36 | }; | |
37 | ||
1da177e4 LT |
38 | /* |
39 | * Instruction classes | |
40 | */ | |
41 | ||
42 | #define BPF_CLASS(code) ((code) & 0x07) | |
43 | #define BPF_LD 0x00 | |
44 | #define BPF_LDX 0x01 | |
45 | #define BPF_ST 0x02 | |
46 | #define BPF_STX 0x03 | |
47 | #define BPF_ALU 0x04 | |
48 | #define BPF_JMP 0x05 | |
49 | #define BPF_RET 0x06 | |
50 | #define BPF_MISC 0x07 | |
51 | ||
52 | /* ld/ldx fields */ | |
53 | #define BPF_SIZE(code) ((code) & 0x18) | |
54 | #define BPF_W 0x00 | |
55 | #define BPF_H 0x08 | |
56 | #define BPF_B 0x10 | |
57 | #define BPF_MODE(code) ((code) & 0xe0) | |
58 | #define BPF_IMM 0x00 | |
59 | #define BPF_ABS 0x20 | |
60 | #define BPF_IND 0x40 | |
61 | #define BPF_MEM 0x60 | |
62 | #define BPF_LEN 0x80 | |
63 | #define BPF_MSH 0xa0 | |
64 | ||
65 | /* alu/jmp fields */ | |
66 | #define BPF_OP(code) ((code) & 0xf0) | |
67 | #define BPF_ADD 0x00 | |
68 | #define BPF_SUB 0x10 | |
69 | #define BPF_MUL 0x20 | |
70 | #define BPF_DIV 0x30 | |
71 | #define BPF_OR 0x40 | |
72 | #define BPF_AND 0x50 | |
73 | #define BPF_LSH 0x60 | |
74 | #define BPF_RSH 0x70 | |
75 | #define BPF_NEG 0x80 | |
76 | #define BPF_JA 0x00 | |
77 | #define BPF_JEQ 0x10 | |
78 | #define BPF_JGT 0x20 | |
79 | #define BPF_JGE 0x30 | |
80 | #define BPF_JSET 0x40 | |
81 | #define BPF_SRC(code) ((code) & 0x08) | |
82 | #define BPF_K 0x00 | |
83 | #define BPF_X 0x08 | |
84 | ||
85 | /* ret - BPF_K and BPF_X also apply */ | |
86 | #define BPF_RVAL(code) ((code) & 0x18) | |
87 | #define BPF_A 0x10 | |
88 | ||
89 | /* misc */ | |
90 | #define BPF_MISCOP(code) ((code) & 0xf8) | |
91 | #define BPF_TAX 0x00 | |
92 | #define BPF_TXA 0x80 | |
93 | ||
94 | #ifndef BPF_MAXINSNS | |
95 | #define BPF_MAXINSNS 4096 | |
96 | #endif | |
97 | ||
98 | /* | |
99 | * Macros for filter block array initializers. | |
100 | */ | |
101 | #ifndef BPF_STMT | |
102 | #define BPF_STMT(code, k) { (unsigned short)(code), 0, 0, k } | |
103 | #endif | |
104 | #ifndef BPF_JUMP | |
105 | #define BPF_JUMP(code, k, jt, jf) { (unsigned short)(code), jt, jf, k } | |
106 | #endif | |
107 | ||
108 | /* | |
109 | * Number of scratch memory words for: BPF_ST and BPF_STX | |
110 | */ | |
111 | #define BPF_MEMWORDS 16 | |
112 | ||
113 | /* RATIONALE. Negative offsets are invalid in BPF. | |
114 | We use them to reference ancillary data. | |
115 | Unlike introduction new instructions, it does not break | |
116 | existing compilers/optimizers. | |
117 | */ | |
118 | #define SKF_AD_OFF (-0x1000) | |
119 | #define SKF_AD_PROTOCOL 0 | |
120 | #define SKF_AD_PKTTYPE 4 | |
121 | #define SKF_AD_IFINDEX 8 | |
4738c1db | 122 | #define SKF_AD_NLATTR 12 |
d214c753 | 123 | #define SKF_AD_NLATTR_NEST 16 |
7e75f93e | 124 | #define SKF_AD_MARK 20 |
d19742fb | 125 | #define SKF_AD_QUEUE 24 |
40eaf962 | 126 | #define SKF_AD_HATYPE 28 |
da2033c2 ED |
127 | #define SKF_AD_RXHASH 32 |
128 | #define SKF_AD_CPU 36 | |
129 | #define SKF_AD_MAX 40 | |
1da177e4 LT |
130 | #define SKF_NET_OFF (-0x100000) |
131 | #define SKF_LL_OFF (-0x200000) | |
132 | ||
133 | #ifdef __KERNEL__ | |
b715631f SH |
134 | struct sk_filter |
135 | { | |
136 | atomic_t refcnt; | |
137 | unsigned int len; /* Number of filter blocks */ | |
0a14842f ED |
138 | unsigned int (*bpf_func)(const struct sk_buff *skb, |
139 | const struct sock_filter *filter); | |
b715631f SH |
140 | struct rcu_head rcu; |
141 | struct sock_filter insns[0]; | |
142 | }; | |
143 | ||
144 | static inline unsigned int sk_filter_len(const struct sk_filter *fp) | |
145 | { | |
146 | return fp->len * sizeof(struct sock_filter) + sizeof(*fp); | |
147 | } | |
148 | ||
1da177e4 LT |
149 | struct sk_buff; |
150 | struct sock; | |
151 | ||
43db6d65 | 152 | extern int sk_filter(struct sock *sk, struct sk_buff *skb); |
62ab0812 | 153 | extern unsigned int sk_run_filter(const struct sk_buff *skb, |
93aaae2e | 154 | const struct sock_filter *filter); |
1da177e4 | 155 | extern int sk_attach_filter(struct sock_fprog *fprog, struct sock *sk); |
55b33325 | 156 | extern int sk_detach_filter(struct sock *sk); |
1da177e4 | 157 | extern int sk_chk_filter(struct sock_filter *filter, int flen); |
0a14842f ED |
158 | |
159 | #ifdef CONFIG_BPF_JIT | |
160 | extern void bpf_jit_compile(struct sk_filter *fp); | |
161 | extern void bpf_jit_free(struct sk_filter *fp); | |
162 | #define SK_RUN_FILTER(FILTER, SKB) (*FILTER->bpf_func)(SKB, FILTER->insns) | |
163 | #else | |
164 | static inline void bpf_jit_compile(struct sk_filter *fp) | |
165 | { | |
166 | } | |
167 | static inline void bpf_jit_free(struct sk_filter *fp) | |
168 | { | |
169 | } | |
170 | #define SK_RUN_FILTER(FILTER, SKB) sk_run_filter(SKB, FILTER->insns) | |
171 | #endif | |
172 | ||
173 | enum { | |
174 | BPF_S_RET_K = 1, | |
175 | BPF_S_RET_A, | |
176 | BPF_S_ALU_ADD_K, | |
177 | BPF_S_ALU_ADD_X, | |
178 | BPF_S_ALU_SUB_K, | |
179 | BPF_S_ALU_SUB_X, | |
180 | BPF_S_ALU_MUL_K, | |
181 | BPF_S_ALU_MUL_X, | |
182 | BPF_S_ALU_DIV_X, | |
183 | BPF_S_ALU_AND_K, | |
184 | BPF_S_ALU_AND_X, | |
185 | BPF_S_ALU_OR_K, | |
186 | BPF_S_ALU_OR_X, | |
187 | BPF_S_ALU_LSH_K, | |
188 | BPF_S_ALU_LSH_X, | |
189 | BPF_S_ALU_RSH_K, | |
190 | BPF_S_ALU_RSH_X, | |
191 | BPF_S_ALU_NEG, | |
192 | BPF_S_LD_W_ABS, | |
193 | BPF_S_LD_H_ABS, | |
194 | BPF_S_LD_B_ABS, | |
195 | BPF_S_LD_W_LEN, | |
196 | BPF_S_LD_W_IND, | |
197 | BPF_S_LD_H_IND, | |
198 | BPF_S_LD_B_IND, | |
199 | BPF_S_LD_IMM, | |
200 | BPF_S_LDX_W_LEN, | |
201 | BPF_S_LDX_B_MSH, | |
202 | BPF_S_LDX_IMM, | |
203 | BPF_S_MISC_TAX, | |
204 | BPF_S_MISC_TXA, | |
205 | BPF_S_ALU_DIV_K, | |
206 | BPF_S_LD_MEM, | |
207 | BPF_S_LDX_MEM, | |
208 | BPF_S_ST, | |
209 | BPF_S_STX, | |
210 | BPF_S_JMP_JA, | |
211 | BPF_S_JMP_JEQ_K, | |
212 | BPF_S_JMP_JEQ_X, | |
213 | BPF_S_JMP_JGE_K, | |
214 | BPF_S_JMP_JGE_X, | |
215 | BPF_S_JMP_JGT_K, | |
216 | BPF_S_JMP_JGT_X, | |
217 | BPF_S_JMP_JSET_K, | |
218 | BPF_S_JMP_JSET_X, | |
219 | /* Ancillary data */ | |
220 | BPF_S_ANC_PROTOCOL, | |
221 | BPF_S_ANC_PKTTYPE, | |
222 | BPF_S_ANC_IFINDEX, | |
223 | BPF_S_ANC_NLATTR, | |
224 | BPF_S_ANC_NLATTR_NEST, | |
225 | BPF_S_ANC_MARK, | |
226 | BPF_S_ANC_QUEUE, | |
227 | BPF_S_ANC_HATYPE, | |
228 | BPF_S_ANC_RXHASH, | |
229 | BPF_S_ANC_CPU, | |
230 | }; | |
231 | ||
1da177e4 LT |
232 | #endif /* __KERNEL__ */ |
233 | ||
234 | #endif /* __LINUX_FILTER_H__ */ |