Linux kernel mirror (for testing)
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linux
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
26struct sock_filter { /* Filter block */
27 __u16 code; /* Actual filter code */
28 __u8 jt; /* Jump true */
29 __u8 jf; /* Jump false */
30 __u32 k; /* Generic multiuse field */
31};
32
33struct sock_fprog { /* Required for SO_ATTACH_FILTER. */
34 unsigned short len; /* Number of filter blocks */
35 struct sock_filter __user *filter;
36};
37
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
122#define SKF_AD_NLATTR 12
123#define SKF_AD_NLATTR_NEST 16
124#define SKF_AD_MARK 20
125#define SKF_AD_QUEUE 24
126#define SKF_AD_HATYPE 28
127#define SKF_AD_RXHASH 32
128#define SKF_AD_CPU 36
129#define SKF_AD_MAX 40
130#define SKF_NET_OFF (-0x100000)
131#define SKF_LL_OFF (-0x200000)
132
133#ifdef __KERNEL__
134
135struct sk_buff;
136struct sock;
137
138struct sk_filter
139{
140 atomic_t refcnt;
141 unsigned int len; /* Number of filter blocks */
142 unsigned int (*bpf_func)(const struct sk_buff *skb,
143 const struct sock_filter *filter);
144 struct rcu_head rcu;
145 struct sock_filter insns[0];
146};
147
148static inline unsigned int sk_filter_len(const struct sk_filter *fp)
149{
150 return fp->len * sizeof(struct sock_filter) + sizeof(*fp);
151}
152
153extern int sk_filter(struct sock *sk, struct sk_buff *skb);
154extern unsigned int sk_run_filter(const struct sk_buff *skb,
155 const struct sock_filter *filter);
156extern int sk_attach_filter(struct sock_fprog *fprog, struct sock *sk);
157extern int sk_detach_filter(struct sock *sk);
158extern int sk_chk_filter(struct sock_filter *filter, int flen);
159
160#ifdef CONFIG_BPF_JIT
161extern void bpf_jit_compile(struct sk_filter *fp);
162extern void bpf_jit_free(struct sk_filter *fp);
163#define SK_RUN_FILTER(FILTER, SKB) (*FILTER->bpf_func)(SKB, FILTER->insns)
164#else
165static inline void bpf_jit_compile(struct sk_filter *fp)
166{
167}
168static inline void bpf_jit_free(struct sk_filter *fp)
169{
170}
171#define SK_RUN_FILTER(FILTER, SKB) sk_run_filter(SKB, FILTER->insns)
172#endif
173
174enum {
175 BPF_S_RET_K = 1,
176 BPF_S_RET_A,
177 BPF_S_ALU_ADD_K,
178 BPF_S_ALU_ADD_X,
179 BPF_S_ALU_SUB_K,
180 BPF_S_ALU_SUB_X,
181 BPF_S_ALU_MUL_K,
182 BPF_S_ALU_MUL_X,
183 BPF_S_ALU_DIV_X,
184 BPF_S_ALU_AND_K,
185 BPF_S_ALU_AND_X,
186 BPF_S_ALU_OR_K,
187 BPF_S_ALU_OR_X,
188 BPF_S_ALU_LSH_K,
189 BPF_S_ALU_LSH_X,
190 BPF_S_ALU_RSH_K,
191 BPF_S_ALU_RSH_X,
192 BPF_S_ALU_NEG,
193 BPF_S_LD_W_ABS,
194 BPF_S_LD_H_ABS,
195 BPF_S_LD_B_ABS,
196 BPF_S_LD_W_LEN,
197 BPF_S_LD_W_IND,
198 BPF_S_LD_H_IND,
199 BPF_S_LD_B_IND,
200 BPF_S_LD_IMM,
201 BPF_S_LDX_W_LEN,
202 BPF_S_LDX_B_MSH,
203 BPF_S_LDX_IMM,
204 BPF_S_MISC_TAX,
205 BPF_S_MISC_TXA,
206 BPF_S_ALU_DIV_K,
207 BPF_S_LD_MEM,
208 BPF_S_LDX_MEM,
209 BPF_S_ST,
210 BPF_S_STX,
211 BPF_S_JMP_JA,
212 BPF_S_JMP_JEQ_K,
213 BPF_S_JMP_JEQ_X,
214 BPF_S_JMP_JGE_K,
215 BPF_S_JMP_JGE_X,
216 BPF_S_JMP_JGT_K,
217 BPF_S_JMP_JGT_X,
218 BPF_S_JMP_JSET_K,
219 BPF_S_JMP_JSET_X,
220 /* Ancillary data */
221 BPF_S_ANC_PROTOCOL,
222 BPF_S_ANC_PKTTYPE,
223 BPF_S_ANC_IFINDEX,
224 BPF_S_ANC_NLATTR,
225 BPF_S_ANC_NLATTR_NEST,
226 BPF_S_ANC_MARK,
227 BPF_S_ANC_QUEUE,
228 BPF_S_ANC_HATYPE,
229 BPF_S_ANC_RXHASH,
230 BPF_S_ANC_CPU,
231};
232
233#endif /* __KERNEL__ */
234
235#endif /* __LINUX_FILTER_H__ */