2 * Linux Socket Filter Data Structures
4 #ifndef __LINUX_FILTER_H__
5 #define __LINUX_FILTER_H__
7 #include <linux/atomic.h>
8 #include <linux/compat.h>
9 #include <linux/workqueue.h>
10 #include <uapi/linux/filter.h>
12 /* Internally used and optimized filter representation with extended
13 * instruction set based on top of classic BPF.
16 /* instruction classes */
17 #define BPF_ALU64 0x07 /* alu mode in double word width */
20 #define BPF_DW 0x18 /* double word */
21 #define BPF_XADD 0xc0 /* exclusive add */
24 #define BPF_MOV 0xb0 /* mov reg to reg */
25 #define BPF_ARSH 0xc0 /* sign extending arithmetic shift right */
27 /* change endianness of a register */
28 #define BPF_END 0xd0 /* flags for endianness conversion: */
29 #define BPF_TO_LE 0x00 /* convert to little-endian */
30 #define BPF_TO_BE 0x08 /* convert to big-endian */
31 #define BPF_FROM_LE BPF_TO_LE
32 #define BPF_FROM_BE BPF_TO_BE
34 #define BPF_JNE 0x50 /* jump != */
35 #define BPF_JSGT 0x60 /* SGT is signed '>', GT in x86 */
36 #define BPF_JSGE 0x70 /* SGE is signed '>=', GE in x86 */
37 #define BPF_CALL 0x80 /* function call */
38 #define BPF_EXIT 0x90 /* function return */
40 /* BPF has 10 general purpose 64-bit registers and stack frame. */
41 #define MAX_BPF_REG 11
43 /* BPF program can access up to 512 bytes of stack space. */
44 #define MAX_BPF_STACK 512
46 /* Arg1, context and stack frame pointer register positions. */
51 struct sock_filter_int {
52 __u8 code; /* opcode */
53 __u8 a_reg:4; /* dest register */
54 __u8 x_reg:4; /* source register */
55 __s16 off; /* signed offset */
56 __s32 imm; /* signed immediate constant */
60 /* A struct sock_filter is architecture independent. */
61 struct compat_sock_fprog {
63 compat_uptr_t filter; /* struct sock_filter * */
67 struct sock_fprog_kern {
69 struct sock_filter *filter;
78 u32 jited:1, /* Is our filter JIT'ed? */
79 len:31; /* Number of filter blocks */
80 struct sock_fprog_kern *orig_prog; /* Original BPF program */
82 unsigned int (*bpf_func)(const struct sk_buff *skb,
83 const struct sock_filter_int *filter);
85 struct sock_filter insns[0];
86 struct sock_filter_int insnsi[0];
87 struct work_struct work;
91 static inline unsigned int sk_filter_size(unsigned int proglen)
93 return max(sizeof(struct sk_filter),
94 offsetof(struct sk_filter, insns[proglen]));
97 #define sk_filter_proglen(fprog) \
98 (fprog->len * sizeof(fprog->filter[0]))
100 #define SK_RUN_FILTER(filter, ctx) \
101 (*filter->bpf_func)(ctx, filter->insnsi)
103 int sk_filter(struct sock *sk, struct sk_buff *skb);
105 u32 sk_run_filter_int_seccomp(const struct seccomp_data *ctx,
106 const struct sock_filter_int *insni);
107 u32 sk_run_filter_int_skb(const struct sk_buff *ctx,
108 const struct sock_filter_int *insni);
110 int sk_convert_filter(struct sock_filter *prog, int len,
111 struct sock_filter_int *new_prog, int *new_len);
113 int sk_unattached_filter_create(struct sk_filter **pfp,
114 struct sock_fprog *fprog);
115 void sk_unattached_filter_destroy(struct sk_filter *fp);
117 int sk_attach_filter(struct sock_fprog *fprog, struct sock *sk);
118 int sk_detach_filter(struct sock *sk);
120 int sk_chk_filter(struct sock_filter *filter, unsigned int flen);
121 int sk_get_filter(struct sock *sk, struct sock_filter __user *filter,
123 void sk_decode_filter(struct sock_filter *filt, struct sock_filter *to);
125 void sk_filter_charge(struct sock *sk, struct sk_filter *fp);
126 void sk_filter_uncharge(struct sock *sk, struct sk_filter *fp);
128 #ifdef CONFIG_BPF_JIT
130 #include <linux/linkage.h>
131 #include <linux/printk.h>
133 void bpf_jit_compile(struct sk_filter *fp);
134 void bpf_jit_free(struct sk_filter *fp);
136 static inline void bpf_jit_dump(unsigned int flen, unsigned int proglen,
137 u32 pass, void *image)
139 pr_err("flen=%u proglen=%u pass=%u image=%pK\n",
140 flen, proglen, pass, image);
142 print_hex_dump(KERN_ERR, "JIT code: ", DUMP_PREFIX_OFFSET,
143 16, 1, image, proglen, false);
146 #include <linux/slab.h>
147 static inline void bpf_jit_compile(struct sk_filter *fp)
150 static inline void bpf_jit_free(struct sk_filter *fp)
156 static inline int bpf_tell_extensions(void)
216 BPF_S_ANC_NLATTR_NEST,
224 BPF_S_ANC_VLAN_TAG_PRESENT,
225 BPF_S_ANC_PAY_OFFSET,
228 #endif /* __LINUX_FILTER_H__ */