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/skbuff.h>
10 #include <linux/workqueue.h>
11 #include <uapi/linux/filter.h>
12 #include <asm/cacheflush.h>
13 #include <uapi/linux/bpf.h>
19 /* ArgX, context and stack frame pointer register positions. Note,
20 * Arg1, Arg2, Arg3, etc are used as argument mappings of function
21 * calls in BPF_CALL instruction.
23 #define BPF_REG_ARG1 BPF_REG_1
24 #define BPF_REG_ARG2 BPF_REG_2
25 #define BPF_REG_ARG3 BPF_REG_3
26 #define BPF_REG_ARG4 BPF_REG_4
27 #define BPF_REG_ARG5 BPF_REG_5
28 #define BPF_REG_CTX BPF_REG_6
29 #define BPF_REG_FP BPF_REG_10
31 /* Additional register mappings for converted user programs. */
32 #define BPF_REG_A BPF_REG_0
33 #define BPF_REG_X BPF_REG_7
34 #define BPF_REG_TMP BPF_REG_8
36 /* BPF program can access up to 512 bytes of stack space. */
37 #define MAX_BPF_STACK 512
39 /* Helper macros for filter block array initializers. */
41 /* ALU ops on registers, bpf_add|sub|...: dst_reg += src_reg */
43 #define BPF_ALU64_REG(OP, DST, SRC) \
44 ((struct bpf_insn) { \
45 .code = BPF_ALU64 | BPF_OP(OP) | BPF_X, \
51 #define BPF_ALU32_REG(OP, DST, SRC) \
52 ((struct bpf_insn) { \
53 .code = BPF_ALU | BPF_OP(OP) | BPF_X, \
59 /* ALU ops on immediates, bpf_add|sub|...: dst_reg += imm32 */
61 #define BPF_ALU64_IMM(OP, DST, IMM) \
62 ((struct bpf_insn) { \
63 .code = BPF_ALU64 | BPF_OP(OP) | BPF_K, \
69 #define BPF_ALU32_IMM(OP, DST, IMM) \
70 ((struct bpf_insn) { \
71 .code = BPF_ALU | BPF_OP(OP) | BPF_K, \
77 /* Endianess conversion, cpu_to_{l,b}e(), {l,b}e_to_cpu() */
79 #define BPF_ENDIAN(TYPE, DST, LEN) \
80 ((struct bpf_insn) { \
81 .code = BPF_ALU | BPF_END | BPF_SRC(TYPE), \
87 /* Short form of mov, dst_reg = src_reg */
89 #define BPF_MOV64_REG(DST, SRC) \
90 ((struct bpf_insn) { \
91 .code = BPF_ALU64 | BPF_MOV | BPF_X, \
97 #define BPF_MOV32_REG(DST, SRC) \
98 ((struct bpf_insn) { \
99 .code = BPF_ALU | BPF_MOV | BPF_X, \
105 /* Short form of mov, dst_reg = imm32 */
107 #define BPF_MOV64_IMM(DST, IMM) \
108 ((struct bpf_insn) { \
109 .code = BPF_ALU64 | BPF_MOV | BPF_K, \
115 #define BPF_MOV32_IMM(DST, IMM) \
116 ((struct bpf_insn) { \
117 .code = BPF_ALU | BPF_MOV | BPF_K, \
123 /* BPF_LD_IMM64 macro encodes single 'load 64-bit immediate' insn */
124 #define BPF_LD_IMM64(DST, IMM) \
125 BPF_LD_IMM64_RAW(DST, 0, IMM)
127 #define BPF_LD_IMM64_RAW(DST, SRC, IMM) \
128 ((struct bpf_insn) { \
129 .code = BPF_LD | BPF_DW | BPF_IMM, \
133 .imm = (__u32) (IMM) }), \
134 ((struct bpf_insn) { \
135 .code = 0, /* zero is reserved opcode */ \
139 .imm = ((__u64) (IMM)) >> 32 })
141 /* Short form of mov based on type, BPF_X: dst_reg = src_reg, BPF_K: dst_reg = imm32 */
143 #define BPF_MOV64_RAW(TYPE, DST, SRC, IMM) \
144 ((struct bpf_insn) { \
145 .code = BPF_ALU64 | BPF_MOV | BPF_SRC(TYPE), \
151 #define BPF_MOV32_RAW(TYPE, DST, SRC, IMM) \
152 ((struct bpf_insn) { \
153 .code = BPF_ALU | BPF_MOV | BPF_SRC(TYPE), \
159 /* Direct packet access, R0 = *(uint *) (skb->data + imm32) */
161 #define BPF_LD_ABS(SIZE, IMM) \
162 ((struct bpf_insn) { \
163 .code = BPF_LD | BPF_SIZE(SIZE) | BPF_ABS, \
169 /* Indirect packet access, R0 = *(uint *) (skb->data + src_reg + imm32) */
171 #define BPF_LD_IND(SIZE, SRC, IMM) \
172 ((struct bpf_insn) { \
173 .code = BPF_LD | BPF_SIZE(SIZE) | BPF_IND, \
179 /* Memory load, dst_reg = *(uint *) (src_reg + off16) */
181 #define BPF_LDX_MEM(SIZE, DST, SRC, OFF) \
182 ((struct bpf_insn) { \
183 .code = BPF_LDX | BPF_SIZE(SIZE) | BPF_MEM, \
189 /* Memory store, *(uint *) (dst_reg + off16) = src_reg */
191 #define BPF_STX_MEM(SIZE, DST, SRC, OFF) \
192 ((struct bpf_insn) { \
193 .code = BPF_STX | BPF_SIZE(SIZE) | BPF_MEM, \
199 /* Memory store, *(uint *) (dst_reg + off16) = imm32 */
201 #define BPF_ST_MEM(SIZE, DST, OFF, IMM) \
202 ((struct bpf_insn) { \
203 .code = BPF_ST | BPF_SIZE(SIZE) | BPF_MEM, \
209 /* Conditional jumps against registers, if (dst_reg 'op' src_reg) goto pc + off16 */
211 #define BPF_JMP_REG(OP, DST, SRC, OFF) \
212 ((struct bpf_insn) { \
213 .code = BPF_JMP | BPF_OP(OP) | BPF_X, \
219 /* Conditional jumps against immediates, if (dst_reg 'op' imm32) goto pc + off16 */
221 #define BPF_JMP_IMM(OP, DST, IMM, OFF) \
222 ((struct bpf_insn) { \
223 .code = BPF_JMP | BPF_OP(OP) | BPF_K, \
231 #define BPF_EMIT_CALL(FUNC) \
232 ((struct bpf_insn) { \
233 .code = BPF_JMP | BPF_CALL, \
237 .imm = ((FUNC) - __bpf_call_base) })
239 /* Raw code statement block */
241 #define BPF_RAW_INSN(CODE, DST, SRC, OFF, IMM) \
242 ((struct bpf_insn) { \
251 #define BPF_EXIT_INSN() \
252 ((struct bpf_insn) { \
253 .code = BPF_JMP | BPF_EXIT, \
259 #define bytes_to_bpf_size(bytes) \
261 int bpf_size = -EINVAL; \
263 if (bytes == sizeof(u8)) \
265 else if (bytes == sizeof(u16)) \
267 else if (bytes == sizeof(u32)) \
269 else if (bytes == sizeof(u64)) \
275 /* Macro to invoke filter function. */
276 #define SK_RUN_FILTER(filter, ctx) \
277 (*filter->prog->bpf_func)(ctx, filter->prog->insnsi)
280 /* A struct sock_filter is architecture independent. */
281 struct compat_sock_fprog {
283 compat_uptr_t filter; /* struct sock_filter * */
287 struct sock_fprog_kern {
289 struct sock_filter *filter;
292 struct bpf_work_struct {
293 struct bpf_prog *prog;
294 struct work_struct work;
298 u32 pages; /* Number of allocated pages */
299 u32 jited:1, /* Is our filter JIT'ed? */
300 len:31; /* Number of filter blocks */
301 struct sock_fprog_kern *orig_prog; /* Original BPF program */
302 struct bpf_work_struct *work; /* Deferred free work struct */
303 unsigned int (*bpf_func)(const struct sk_buff *skb,
304 const struct bpf_insn *filter);
305 /* Instructions for interpreter */
307 struct sock_filter insns[0];
308 struct bpf_insn insnsi[0];
315 struct bpf_prog *prog;
318 #define BPF_PROG_RUN(filter, ctx) (*filter->bpf_func)(ctx, filter->insnsi)
320 static inline unsigned int bpf_prog_size(unsigned int proglen)
322 return max(sizeof(struct bpf_prog),
323 offsetof(struct bpf_prog, insns[proglen]));
326 #define bpf_classic_proglen(fprog) (fprog->len * sizeof(fprog->filter[0]))
328 #ifdef CONFIG_DEBUG_SET_MODULE_RONX
329 static inline void bpf_prog_lock_ro(struct bpf_prog *fp)
331 set_memory_ro((unsigned long)fp, fp->pages);
334 static inline void bpf_prog_unlock_ro(struct bpf_prog *fp)
336 set_memory_rw((unsigned long)fp, fp->pages);
339 static inline void bpf_prog_lock_ro(struct bpf_prog *fp)
343 static inline void bpf_prog_unlock_ro(struct bpf_prog *fp)
346 #endif /* CONFIG_DEBUG_SET_MODULE_RONX */
348 int sk_filter(struct sock *sk, struct sk_buff *skb);
350 void bpf_prog_select_runtime(struct bpf_prog *fp);
351 void bpf_prog_free(struct bpf_prog *fp);
353 int bpf_convert_filter(struct sock_filter *prog, int len,
354 struct bpf_insn *new_prog, int *new_len);
356 struct bpf_prog *bpf_prog_alloc(unsigned int size, gfp_t gfp_extra_flags);
357 struct bpf_prog *bpf_prog_realloc(struct bpf_prog *fp_old, unsigned int size,
358 gfp_t gfp_extra_flags);
359 void __bpf_prog_free(struct bpf_prog *fp);
361 static inline void bpf_prog_unlock_free(struct bpf_prog *fp)
363 bpf_prog_unlock_ro(fp);
367 int bpf_prog_create(struct bpf_prog **pfp, struct sock_fprog_kern *fprog);
368 void bpf_prog_destroy(struct bpf_prog *fp);
370 int sk_attach_filter(struct sock_fprog *fprog, struct sock *sk);
371 int sk_detach_filter(struct sock *sk);
373 int bpf_check_classic(const struct sock_filter *filter, unsigned int flen);
374 int sk_get_filter(struct sock *sk, struct sock_filter __user *filter,
377 bool sk_filter_charge(struct sock *sk, struct sk_filter *fp);
378 void sk_filter_uncharge(struct sock *sk, struct sk_filter *fp);
380 u64 __bpf_call_base(u64 r1, u64 r2, u64 r3, u64 r4, u64 r5);
381 void bpf_int_jit_compile(struct bpf_prog *fp);
383 #define BPF_ANC BIT(15)
385 static inline u16 bpf_anc_helper(const struct sock_filter *ftest)
387 BUG_ON(ftest->code & BPF_ANC);
389 switch (ftest->code) {
390 case BPF_LD | BPF_W | BPF_ABS:
391 case BPF_LD | BPF_H | BPF_ABS:
392 case BPF_LD | BPF_B | BPF_ABS:
393 #define BPF_ANCILLARY(CODE) case SKF_AD_OFF + SKF_AD_##CODE: \
394 return BPF_ANC | SKF_AD_##CODE
396 BPF_ANCILLARY(PROTOCOL);
397 BPF_ANCILLARY(PKTTYPE);
398 BPF_ANCILLARY(IFINDEX);
399 BPF_ANCILLARY(NLATTR);
400 BPF_ANCILLARY(NLATTR_NEST);
402 BPF_ANCILLARY(QUEUE);
403 BPF_ANCILLARY(HATYPE);
404 BPF_ANCILLARY(RXHASH);
406 BPF_ANCILLARY(ALU_XOR_X);
407 BPF_ANCILLARY(VLAN_TAG);
408 BPF_ANCILLARY(VLAN_TAG_PRESENT);
409 BPF_ANCILLARY(PAY_OFFSET);
410 BPF_ANCILLARY(RANDOM);
418 void *bpf_internal_load_pointer_neg_helper(const struct sk_buff *skb,
419 int k, unsigned int size);
421 static inline void *bpf_load_pointer(const struct sk_buff *skb, int k,
422 unsigned int size, void *buffer)
425 return skb_header_pointer(skb, k, size, buffer);
427 return bpf_internal_load_pointer_neg_helper(skb, k, size);
430 #ifdef CONFIG_BPF_JIT
432 #include <linux/linkage.h>
433 #include <linux/printk.h>
435 void bpf_jit_compile(struct bpf_prog *fp);
436 void bpf_jit_free(struct bpf_prog *fp);
438 static inline void bpf_jit_dump(unsigned int flen, unsigned int proglen,
439 u32 pass, void *image)
441 pr_err("flen=%u proglen=%u pass=%u image=%pK\n",
442 flen, proglen, pass, image);
444 print_hex_dump(KERN_ERR, "JIT code: ", DUMP_PREFIX_OFFSET,
445 16, 1, image, proglen, false);
448 #include <linux/slab.h>
450 static inline void bpf_jit_compile(struct bpf_prog *fp)
454 static inline void bpf_jit_free(struct bpf_prog *fp)
456 bpf_prog_unlock_free(fp);
458 #endif /* CONFIG_BPF_JIT */
460 static inline int bpf_tell_extensions(void)
465 #endif /* __LINUX_FILTER_H__ */