Commit | Line | Data |
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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 | ||
01f2f3f6 HPP |
94 | enum { |
95 | BPF_S_RET_K = 0, | |
96 | BPF_S_RET_A, | |
97 | BPF_S_ALU_ADD_K, | |
98 | BPF_S_ALU_ADD_X, | |
99 | BPF_S_ALU_SUB_K, | |
100 | BPF_S_ALU_SUB_X, | |
101 | BPF_S_ALU_MUL_K, | |
102 | BPF_S_ALU_MUL_X, | |
103 | BPF_S_ALU_DIV_X, | |
104 | BPF_S_ALU_AND_K, | |
105 | BPF_S_ALU_AND_X, | |
106 | BPF_S_ALU_OR_K, | |
107 | BPF_S_ALU_OR_X, | |
108 | BPF_S_ALU_LSH_K, | |
109 | BPF_S_ALU_LSH_X, | |
110 | BPF_S_ALU_RSH_K, | |
111 | BPF_S_ALU_RSH_X, | |
112 | BPF_S_ALU_NEG, | |
113 | BPF_S_LD_W_ABS, | |
114 | BPF_S_LD_H_ABS, | |
115 | BPF_S_LD_B_ABS, | |
116 | BPF_S_LD_W_LEN, | |
117 | BPF_S_LD_W_IND, | |
118 | BPF_S_LD_H_IND, | |
119 | BPF_S_LD_B_IND, | |
120 | BPF_S_LD_IMM, | |
121 | BPF_S_LDX_W_LEN, | |
122 | BPF_S_LDX_B_MSH, | |
123 | BPF_S_LDX_IMM, | |
124 | BPF_S_MISC_TAX, | |
125 | BPF_S_MISC_TXA, | |
126 | BPF_S_ALU_DIV_K, | |
127 | BPF_S_LD_MEM, | |
128 | BPF_S_LDX_MEM, | |
129 | BPF_S_ST, | |
130 | BPF_S_STX, | |
131 | BPF_S_JMP_JA, | |
132 | BPF_S_JMP_JEQ_K, | |
133 | BPF_S_JMP_JEQ_X, | |
134 | BPF_S_JMP_JGE_K, | |
135 | BPF_S_JMP_JGE_X, | |
136 | BPF_S_JMP_JGT_K, | |
137 | BPF_S_JMP_JGT_X, | |
138 | BPF_S_JMP_JSET_K, | |
139 | BPF_S_JMP_JSET_X, | |
140 | }; | |
141 | ||
1da177e4 LT |
142 | #ifndef BPF_MAXINSNS |
143 | #define BPF_MAXINSNS 4096 | |
144 | #endif | |
145 | ||
146 | /* | |
147 | * Macros for filter block array initializers. | |
148 | */ | |
149 | #ifndef BPF_STMT | |
150 | #define BPF_STMT(code, k) { (unsigned short)(code), 0, 0, k } | |
151 | #endif | |
152 | #ifndef BPF_JUMP | |
153 | #define BPF_JUMP(code, k, jt, jf) { (unsigned short)(code), jt, jf, k } | |
154 | #endif | |
155 | ||
156 | /* | |
157 | * Number of scratch memory words for: BPF_ST and BPF_STX | |
158 | */ | |
159 | #define BPF_MEMWORDS 16 | |
160 | ||
161 | /* RATIONALE. Negative offsets are invalid in BPF. | |
162 | We use them to reference ancillary data. | |
163 | Unlike introduction new instructions, it does not break | |
164 | existing compilers/optimizers. | |
165 | */ | |
166 | #define SKF_AD_OFF (-0x1000) | |
167 | #define SKF_AD_PROTOCOL 0 | |
168 | #define SKF_AD_PKTTYPE 4 | |
169 | #define SKF_AD_IFINDEX 8 | |
4738c1db | 170 | #define SKF_AD_NLATTR 12 |
d214c753 | 171 | #define SKF_AD_NLATTR_NEST 16 |
7e75f93e | 172 | #define SKF_AD_MARK 20 |
d19742fb | 173 | #define SKF_AD_QUEUE 24 |
40eaf962 PLE |
174 | #define SKF_AD_HATYPE 28 |
175 | #define SKF_AD_MAX 32 | |
1da177e4 LT |
176 | #define SKF_NET_OFF (-0x100000) |
177 | #define SKF_LL_OFF (-0x200000) | |
178 | ||
179 | #ifdef __KERNEL__ | |
b715631f SH |
180 | struct sk_filter |
181 | { | |
182 | atomic_t refcnt; | |
183 | unsigned int len; /* Number of filter blocks */ | |
184 | struct rcu_head rcu; | |
185 | struct sock_filter insns[0]; | |
186 | }; | |
187 | ||
188 | static inline unsigned int sk_filter_len(const struct sk_filter *fp) | |
189 | { | |
190 | return fp->len * sizeof(struct sock_filter) + sizeof(*fp); | |
191 | } | |
192 | ||
1da177e4 LT |
193 | struct sk_buff; |
194 | struct sock; | |
195 | ||
43db6d65 | 196 | extern int sk_filter(struct sock *sk, struct sk_buff *skb); |
b715631f SH |
197 | extern unsigned int sk_run_filter(struct sk_buff *skb, |
198 | struct sock_filter *filter, int flen); | |
1da177e4 | 199 | extern int sk_attach_filter(struct sock_fprog *fprog, struct sock *sk); |
55b33325 | 200 | extern int sk_detach_filter(struct sock *sk); |
1da177e4 LT |
201 | extern int sk_chk_filter(struct sock_filter *filter, int flen); |
202 | #endif /* __KERNEL__ */ | |
203 | ||
204 | #endif /* __LINUX_FILTER_H__ */ |