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 <linux/atomic.h> 13#include <linux/compat.h> 14#endif 15 16/* 17 * Current version of the filter code architecture. 18 */ 19#define BPF_MAJOR_VERSION 1 20#define BPF_MINOR_VERSION 1 21 22/* 23 * Try and keep these values and structures similar to BSD, especially 24 * the BPF code definitions which need to match so you can share filters 25 */ 26 27struct sock_filter { /* Filter block */ 28 __u16 code; /* Actual filter code */ 29 __u8 jt; /* Jump true */ 30 __u8 jf; /* Jump false */ 31 __u32 k; /* Generic multiuse field */ 32}; 33 34struct sock_fprog { /* Required for SO_ATTACH_FILTER. */ 35 unsigned short len; /* Number of filter blocks */ 36 struct sock_filter __user *filter; 37}; 38 39/* 40 * Instruction classes 41 */ 42 43#define BPF_CLASS(code) ((code) & 0x07) 44#define BPF_LD 0x00 45#define BPF_LDX 0x01 46#define BPF_ST 0x02 47#define BPF_STX 0x03 48#define BPF_ALU 0x04 49#define BPF_JMP 0x05 50#define BPF_RET 0x06 51#define BPF_MISC 0x07 52 53/* ld/ldx fields */ 54#define BPF_SIZE(code) ((code) & 0x18) 55#define BPF_W 0x00 56#define BPF_H 0x08 57#define BPF_B 0x10 58#define BPF_MODE(code) ((code) & 0xe0) 59#define BPF_IMM 0x00 60#define BPF_ABS 0x20 61#define BPF_IND 0x40 62#define BPF_MEM 0x60 63#define BPF_LEN 0x80 64#define BPF_MSH 0xa0 65 66/* alu/jmp fields */ 67#define BPF_OP(code) ((code) & 0xf0) 68#define BPF_ADD 0x00 69#define BPF_SUB 0x10 70#define BPF_MUL 0x20 71#define BPF_DIV 0x30 72#define BPF_OR 0x40 73#define BPF_AND 0x50 74#define BPF_LSH 0x60 75#define BPF_RSH 0x70 76#define BPF_NEG 0x80 77#define BPF_JA 0x00 78#define BPF_JEQ 0x10 79#define BPF_JGT 0x20 80#define BPF_JGE 0x30 81#define BPF_JSET 0x40 82#define BPF_SRC(code) ((code) & 0x08) 83#define BPF_K 0x00 84#define BPF_X 0x08 85 86/* ret - BPF_K and BPF_X also apply */ 87#define BPF_RVAL(code) ((code) & 0x18) 88#define BPF_A 0x10 89 90/* misc */ 91#define BPF_MISCOP(code) ((code) & 0xf8) 92#define BPF_TAX 0x00 93#define BPF_TXA 0x80 94 95#ifndef BPF_MAXINSNS 96#define BPF_MAXINSNS 4096 97#endif 98 99/* 100 * Macros for filter block array initializers. 101 */ 102#ifndef BPF_STMT 103#define BPF_STMT(code, k) { (unsigned short)(code), 0, 0, k } 104#endif 105#ifndef BPF_JUMP 106#define BPF_JUMP(code, k, jt, jf) { (unsigned short)(code), jt, jf, k } 107#endif 108 109/* 110 * Number of scratch memory words for: BPF_ST and BPF_STX 111 */ 112#define BPF_MEMWORDS 16 113 114/* RATIONALE. Negative offsets are invalid in BPF. 115 We use them to reference ancillary data. 116 Unlike introduction new instructions, it does not break 117 existing compilers/optimizers. 118 */ 119#define SKF_AD_OFF (-0x1000) 120#define SKF_AD_PROTOCOL 0 121#define SKF_AD_PKTTYPE 4 122#define SKF_AD_IFINDEX 8 123#define SKF_AD_NLATTR 12 124#define SKF_AD_NLATTR_NEST 16 125#define SKF_AD_MARK 20 126#define SKF_AD_QUEUE 24 127#define SKF_AD_HATYPE 28 128#define SKF_AD_RXHASH 32 129#define SKF_AD_CPU 36 130#define SKF_AD_ALU_XOR_X 40 131#define SKF_AD_MAX 44 132#define SKF_NET_OFF (-0x100000) 133#define SKF_LL_OFF (-0x200000) 134 135#ifdef __KERNEL__ 136 137#ifdef CONFIG_COMPAT 138/* 139 * A struct sock_filter is architecture independent. 140 */ 141struct compat_sock_fprog { 142 u16 len; 143 compat_uptr_t filter; /* struct sock_filter * */ 144}; 145#endif 146 147struct sk_buff; 148struct sock; 149 150struct sk_filter 151{ 152 atomic_t refcnt; 153 unsigned int len; /* Number of filter blocks */ 154 unsigned int (*bpf_func)(const struct sk_buff *skb, 155 const struct sock_filter *filter); 156 struct rcu_head rcu; 157 struct sock_filter insns[0]; 158}; 159 160static inline unsigned int sk_filter_len(const struct sk_filter *fp) 161{ 162 return fp->len * sizeof(struct sock_filter) + sizeof(*fp); 163} 164 165extern int sk_filter(struct sock *sk, struct sk_buff *skb); 166extern unsigned int sk_run_filter(const struct sk_buff *skb, 167 const struct sock_filter *filter); 168extern int sk_unattached_filter_create(struct sk_filter **pfp, 169 struct sock_fprog *fprog); 170extern void sk_unattached_filter_destroy(struct sk_filter *fp); 171extern int sk_attach_filter(struct sock_fprog *fprog, struct sock *sk); 172extern int sk_detach_filter(struct sock *sk); 173extern int sk_chk_filter(struct sock_filter *filter, unsigned int flen); 174 175#ifdef CONFIG_BPF_JIT 176extern void bpf_jit_compile(struct sk_filter *fp); 177extern void bpf_jit_free(struct sk_filter *fp); 178#define SK_RUN_FILTER(FILTER, SKB) (*FILTER->bpf_func)(SKB, FILTER->insns) 179#else 180static inline void bpf_jit_compile(struct sk_filter *fp) 181{ 182} 183static inline void bpf_jit_free(struct sk_filter *fp) 184{ 185} 186#define SK_RUN_FILTER(FILTER, SKB) sk_run_filter(SKB, FILTER->insns) 187#endif 188 189enum { 190 BPF_S_RET_K = 1, 191 BPF_S_RET_A, 192 BPF_S_ALU_ADD_K, 193 BPF_S_ALU_ADD_X, 194 BPF_S_ALU_SUB_K, 195 BPF_S_ALU_SUB_X, 196 BPF_S_ALU_MUL_K, 197 BPF_S_ALU_MUL_X, 198 BPF_S_ALU_DIV_X, 199 BPF_S_ALU_AND_K, 200 BPF_S_ALU_AND_X, 201 BPF_S_ALU_OR_K, 202 BPF_S_ALU_OR_X, 203 BPF_S_ALU_LSH_K, 204 BPF_S_ALU_LSH_X, 205 BPF_S_ALU_RSH_K, 206 BPF_S_ALU_RSH_X, 207 BPF_S_ALU_NEG, 208 BPF_S_LD_W_ABS, 209 BPF_S_LD_H_ABS, 210 BPF_S_LD_B_ABS, 211 BPF_S_LD_W_LEN, 212 BPF_S_LD_W_IND, 213 BPF_S_LD_H_IND, 214 BPF_S_LD_B_IND, 215 BPF_S_LD_IMM, 216 BPF_S_LDX_W_LEN, 217 BPF_S_LDX_B_MSH, 218 BPF_S_LDX_IMM, 219 BPF_S_MISC_TAX, 220 BPF_S_MISC_TXA, 221 BPF_S_ALU_DIV_K, 222 BPF_S_LD_MEM, 223 BPF_S_LDX_MEM, 224 BPF_S_ST, 225 BPF_S_STX, 226 BPF_S_JMP_JA, 227 BPF_S_JMP_JEQ_K, 228 BPF_S_JMP_JEQ_X, 229 BPF_S_JMP_JGE_K, 230 BPF_S_JMP_JGE_X, 231 BPF_S_JMP_JGT_K, 232 BPF_S_JMP_JGT_X, 233 BPF_S_JMP_JSET_K, 234 BPF_S_JMP_JSET_X, 235 /* Ancillary data */ 236 BPF_S_ANC_PROTOCOL, 237 BPF_S_ANC_PKTTYPE, 238 BPF_S_ANC_IFINDEX, 239 BPF_S_ANC_NLATTR, 240 BPF_S_ANC_NLATTR_NEST, 241 BPF_S_ANC_MARK, 242 BPF_S_ANC_QUEUE, 243 BPF_S_ANC_HATYPE, 244 BPF_S_ANC_RXHASH, 245 BPF_S_ANC_CPU, 246 BPF_S_ANC_ALU_XOR_X, 247 BPF_S_ANC_SECCOMP_LD_W, 248}; 249 250#endif /* __KERNEL__ */ 251 252#endif /* __LINUX_FILTER_H__ */ 253