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 27 struct 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 34 struct 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 */ 141 struct compat_sock_fprog { 142 u16 len; 143 compat_uptr_t filter; /* struct sock_filter * */ 144 }; 145 #endif 146 147 struct sk_buff; 148 struct sock; 149 150 struct 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 }; 159 160 static inline unsigned int sk_filter_len(const struct sk_filter *fp) 161 { 162 return fp->len * sizeof(struct sock_filter) + sizeof(*fp); 163 } 164 165 extern int sk_filter(struct sock *sk, struct sk_buff *skb); 166 extern unsigned int sk_run_filter(const struct sk_buff *skb, 167 const struct sock_filter *filter); 168 extern int sk_unattached_filter_create(struct sk_filter **pfp, 169 struct sock_fprog *fprog); 170 extern void sk_unattached_filter_destroy(struct sk_filter *fp); 171 extern int sk_attach_filter(struct sock_fprog *fprog, struct sock *sk); 172 extern int sk_detach_filter(struct sock *sk); 173 extern int sk_chk_filter(struct sock_filter *filter, unsigned int flen); 174 175 #ifdef CONFIG_BPF_JIT 176 extern void bpf_jit_compile(struct sk_filter *fp); 177 extern void bpf_jit_free(struct sk_filter *fp); 178 #define SK_RUN_FILTER(FILTER, SKB) (*FILTER->bpf_func)(SKB, FILTER->insns) 179 #else 180 static inline void bpf_jit_compile(struct sk_filter *fp) 181 { 182 } 183 static 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 188 189 enum { 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