Merge tag 'master-2014-09-08' of git://git.kernel.org/pub/scm/linux/kernel/git/linvil...
[linux-2.6-block.git] / include / linux / filter.h
CommitLineData
1da177e4
LT
1/*
2 * Linux Socket Filter Data Structures
3 */
1da177e4
LT
4#ifndef __LINUX_FILTER_H__
5#define __LINUX_FILTER_H__
6
60063497 7#include <linux/atomic.h>
0c5fe1b4 8#include <linux/compat.h>
9f12fbe6 9#include <linux/skbuff.h>
d45ed4a4 10#include <linux/workqueue.h>
607ca46e 11#include <uapi/linux/filter.h>
60a3b225
DB
12#include <asm/cacheflush.h>
13
14struct sk_buff;
15struct sock;
16struct seccomp_data;
792d4b5c 17
bd4cf0ed
AS
18/* Internally used and optimized filter representation with extended
19 * instruction set based on top of classic BPF.
0c5fe1b4 20 */
bd4cf0ed
AS
21
22/* instruction classes */
23#define BPF_ALU64 0x07 /* alu mode in double word width */
24
25/* ld/ldx fields */
26#define BPF_DW 0x18 /* double word */
27#define BPF_XADD 0xc0 /* exclusive add */
28
29/* alu/jmp fields */
30#define BPF_MOV 0xb0 /* mov reg to reg */
31#define BPF_ARSH 0xc0 /* sign extending arithmetic shift right */
32
33/* change endianness of a register */
34#define BPF_END 0xd0 /* flags for endianness conversion: */
35#define BPF_TO_LE 0x00 /* convert to little-endian */
36#define BPF_TO_BE 0x08 /* convert to big-endian */
37#define BPF_FROM_LE BPF_TO_LE
38#define BPF_FROM_BE BPF_TO_BE
39
40#define BPF_JNE 0x50 /* jump != */
41#define BPF_JSGT 0x60 /* SGT is signed '>', GT in x86 */
42#define BPF_JSGE 0x70 /* SGE is signed '>=', GE in x86 */
43#define BPF_CALL 0x80 /* function call */
44#define BPF_EXIT 0x90 /* function return */
45
30743837
DB
46/* Register numbers */
47enum {
48 BPF_REG_0 = 0,
49 BPF_REG_1,
50 BPF_REG_2,
51 BPF_REG_3,
52 BPF_REG_4,
53 BPF_REG_5,
54 BPF_REG_6,
55 BPF_REG_7,
56 BPF_REG_8,
57 BPF_REG_9,
58 BPF_REG_10,
59 __MAX_BPF_REG,
60};
61
bd4cf0ed 62/* BPF has 10 general purpose 64-bit registers and stack frame. */
30743837
DB
63#define MAX_BPF_REG __MAX_BPF_REG
64
65/* ArgX, context and stack frame pointer register positions. Note,
66 * Arg1, Arg2, Arg3, etc are used as argument mappings of function
67 * calls in BPF_CALL instruction.
68 */
69#define BPF_REG_ARG1 BPF_REG_1
70#define BPF_REG_ARG2 BPF_REG_2
71#define BPF_REG_ARG3 BPF_REG_3
72#define BPF_REG_ARG4 BPF_REG_4
73#define BPF_REG_ARG5 BPF_REG_5
74#define BPF_REG_CTX BPF_REG_6
75#define BPF_REG_FP BPF_REG_10
76
77/* Additional register mappings for converted user programs. */
78#define BPF_REG_A BPF_REG_0
79#define BPF_REG_X BPF_REG_7
80#define BPF_REG_TMP BPF_REG_8
bd4cf0ed
AS
81
82/* BPF program can access up to 512 bytes of stack space. */
83#define MAX_BPF_STACK 512
84
f8f6d679
DB
85/* Helper macros for filter block array initializers. */
86
e430f34e 87/* ALU ops on registers, bpf_add|sub|...: dst_reg += src_reg */
f8f6d679 88
e430f34e 89#define BPF_ALU64_REG(OP, DST, SRC) \
2695fb55 90 ((struct bpf_insn) { \
f8f6d679 91 .code = BPF_ALU64 | BPF_OP(OP) | BPF_X, \
e430f34e
AS
92 .dst_reg = DST, \
93 .src_reg = SRC, \
f8f6d679
DB
94 .off = 0, \
95 .imm = 0 })
96
e430f34e 97#define BPF_ALU32_REG(OP, DST, SRC) \
2695fb55 98 ((struct bpf_insn) { \
f8f6d679 99 .code = BPF_ALU | BPF_OP(OP) | BPF_X, \
e430f34e
AS
100 .dst_reg = DST, \
101 .src_reg = SRC, \
f8f6d679
DB
102 .off = 0, \
103 .imm = 0 })
104
e430f34e 105/* ALU ops on immediates, bpf_add|sub|...: dst_reg += imm32 */
f8f6d679 106
e430f34e 107#define BPF_ALU64_IMM(OP, DST, IMM) \
2695fb55 108 ((struct bpf_insn) { \
f8f6d679 109 .code = BPF_ALU64 | BPF_OP(OP) | BPF_K, \
e430f34e
AS
110 .dst_reg = DST, \
111 .src_reg = 0, \
f8f6d679
DB
112 .off = 0, \
113 .imm = IMM })
114
e430f34e 115#define BPF_ALU32_IMM(OP, DST, IMM) \
2695fb55 116 ((struct bpf_insn) { \
f8f6d679 117 .code = BPF_ALU | BPF_OP(OP) | BPF_K, \
e430f34e
AS
118 .dst_reg = DST, \
119 .src_reg = 0, \
f8f6d679
DB
120 .off = 0, \
121 .imm = IMM })
122
123/* Endianess conversion, cpu_to_{l,b}e(), {l,b}e_to_cpu() */
124
e430f34e 125#define BPF_ENDIAN(TYPE, DST, LEN) \
2695fb55 126 ((struct bpf_insn) { \
f8f6d679 127 .code = BPF_ALU | BPF_END | BPF_SRC(TYPE), \
e430f34e
AS
128 .dst_reg = DST, \
129 .src_reg = 0, \
f8f6d679
DB
130 .off = 0, \
131 .imm = LEN })
132
e430f34e 133/* Short form of mov, dst_reg = src_reg */
f8f6d679 134
e430f34e 135#define BPF_MOV64_REG(DST, SRC) \
2695fb55 136 ((struct bpf_insn) { \
f8f6d679 137 .code = BPF_ALU64 | BPF_MOV | BPF_X, \
e430f34e
AS
138 .dst_reg = DST, \
139 .src_reg = SRC, \
f8f6d679
DB
140 .off = 0, \
141 .imm = 0 })
142
e430f34e 143#define BPF_MOV32_REG(DST, SRC) \
2695fb55 144 ((struct bpf_insn) { \
f8f6d679 145 .code = BPF_ALU | BPF_MOV | BPF_X, \
e430f34e
AS
146 .dst_reg = DST, \
147 .src_reg = SRC, \
f8f6d679
DB
148 .off = 0, \
149 .imm = 0 })
150
e430f34e 151/* Short form of mov, dst_reg = imm32 */
f8f6d679 152
e430f34e 153#define BPF_MOV64_IMM(DST, IMM) \
2695fb55 154 ((struct bpf_insn) { \
f8f6d679 155 .code = BPF_ALU64 | BPF_MOV | BPF_K, \
e430f34e
AS
156 .dst_reg = DST, \
157 .src_reg = 0, \
f8f6d679
DB
158 .off = 0, \
159 .imm = IMM })
160
e430f34e 161#define BPF_MOV32_IMM(DST, IMM) \
2695fb55 162 ((struct bpf_insn) { \
f8f6d679 163 .code = BPF_ALU | BPF_MOV | BPF_K, \
e430f34e
AS
164 .dst_reg = DST, \
165 .src_reg = 0, \
f8f6d679
DB
166 .off = 0, \
167 .imm = IMM })
168
e430f34e 169/* Short form of mov based on type, BPF_X: dst_reg = src_reg, BPF_K: dst_reg = imm32 */
f8f6d679 170
e430f34e 171#define BPF_MOV64_RAW(TYPE, DST, SRC, IMM) \
2695fb55 172 ((struct bpf_insn) { \
f8f6d679 173 .code = BPF_ALU64 | BPF_MOV | BPF_SRC(TYPE), \
e430f34e
AS
174 .dst_reg = DST, \
175 .src_reg = SRC, \
f8f6d679
DB
176 .off = 0, \
177 .imm = IMM })
178
e430f34e 179#define BPF_MOV32_RAW(TYPE, DST, SRC, IMM) \
2695fb55 180 ((struct bpf_insn) { \
f8f6d679 181 .code = BPF_ALU | BPF_MOV | BPF_SRC(TYPE), \
e430f34e
AS
182 .dst_reg = DST, \
183 .src_reg = SRC, \
f8f6d679
DB
184 .off = 0, \
185 .imm = IMM })
186
e430f34e 187/* Direct packet access, R0 = *(uint *) (skb->data + imm32) */
f8f6d679 188
e430f34e 189#define BPF_LD_ABS(SIZE, IMM) \
2695fb55 190 ((struct bpf_insn) { \
f8f6d679 191 .code = BPF_LD | BPF_SIZE(SIZE) | BPF_ABS, \
e430f34e
AS
192 .dst_reg = 0, \
193 .src_reg = 0, \
f8f6d679 194 .off = 0, \
e430f34e 195 .imm = IMM })
f8f6d679 196
e430f34e 197/* Indirect packet access, R0 = *(uint *) (skb->data + src_reg + imm32) */
f8f6d679 198
e430f34e 199#define BPF_LD_IND(SIZE, SRC, IMM) \
2695fb55 200 ((struct bpf_insn) { \
f8f6d679 201 .code = BPF_LD | BPF_SIZE(SIZE) | BPF_IND, \
e430f34e
AS
202 .dst_reg = 0, \
203 .src_reg = SRC, \
f8f6d679 204 .off = 0, \
e430f34e 205 .imm = IMM })
f8f6d679 206
e430f34e 207/* Memory load, dst_reg = *(uint *) (src_reg + off16) */
f8f6d679 208
e430f34e 209#define BPF_LDX_MEM(SIZE, DST, SRC, OFF) \
2695fb55 210 ((struct bpf_insn) { \
f8f6d679 211 .code = BPF_LDX | BPF_SIZE(SIZE) | BPF_MEM, \
e430f34e
AS
212 .dst_reg = DST, \
213 .src_reg = SRC, \
f8f6d679
DB
214 .off = OFF, \
215 .imm = 0 })
216
e430f34e
AS
217/* Memory store, *(uint *) (dst_reg + off16) = src_reg */
218
219#define BPF_STX_MEM(SIZE, DST, SRC, OFF) \
2695fb55 220 ((struct bpf_insn) { \
f8f6d679 221 .code = BPF_STX | BPF_SIZE(SIZE) | BPF_MEM, \
e430f34e
AS
222 .dst_reg = DST, \
223 .src_reg = SRC, \
f8f6d679
DB
224 .off = OFF, \
225 .imm = 0 })
226
e430f34e
AS
227/* Memory store, *(uint *) (dst_reg + off16) = imm32 */
228
229#define BPF_ST_MEM(SIZE, DST, OFF, IMM) \
2695fb55 230 ((struct bpf_insn) { \
e430f34e
AS
231 .code = BPF_ST | BPF_SIZE(SIZE) | BPF_MEM, \
232 .dst_reg = DST, \
233 .src_reg = 0, \
234 .off = OFF, \
235 .imm = IMM })
236
237/* Conditional jumps against registers, if (dst_reg 'op' src_reg) goto pc + off16 */
f8f6d679 238
e430f34e 239#define BPF_JMP_REG(OP, DST, SRC, OFF) \
2695fb55 240 ((struct bpf_insn) { \
f8f6d679 241 .code = BPF_JMP | BPF_OP(OP) | BPF_X, \
e430f34e
AS
242 .dst_reg = DST, \
243 .src_reg = SRC, \
f8f6d679
DB
244 .off = OFF, \
245 .imm = 0 })
246
e430f34e 247/* Conditional jumps against immediates, if (dst_reg 'op' imm32) goto pc + off16 */
f8f6d679 248
e430f34e 249#define BPF_JMP_IMM(OP, DST, IMM, OFF) \
2695fb55 250 ((struct bpf_insn) { \
f8f6d679 251 .code = BPF_JMP | BPF_OP(OP) | BPF_K, \
e430f34e
AS
252 .dst_reg = DST, \
253 .src_reg = 0, \
f8f6d679
DB
254 .off = OFF, \
255 .imm = IMM })
256
257/* Function call */
258
259#define BPF_EMIT_CALL(FUNC) \
2695fb55 260 ((struct bpf_insn) { \
f8f6d679 261 .code = BPF_JMP | BPF_CALL, \
e430f34e
AS
262 .dst_reg = 0, \
263 .src_reg = 0, \
f8f6d679
DB
264 .off = 0, \
265 .imm = ((FUNC) - __bpf_call_base) })
266
267/* Raw code statement block */
268
e430f34e 269#define BPF_RAW_INSN(CODE, DST, SRC, OFF, IMM) \
2695fb55 270 ((struct bpf_insn) { \
f8f6d679 271 .code = CODE, \
e430f34e
AS
272 .dst_reg = DST, \
273 .src_reg = SRC, \
f8f6d679
DB
274 .off = OFF, \
275 .imm = IMM })
276
277/* Program exit */
278
279#define BPF_EXIT_INSN() \
2695fb55 280 ((struct bpf_insn) { \
f8f6d679 281 .code = BPF_JMP | BPF_EXIT, \
e430f34e
AS
282 .dst_reg = 0, \
283 .src_reg = 0, \
f8f6d679
DB
284 .off = 0, \
285 .imm = 0 })
286
287#define bytes_to_bpf_size(bytes) \
288({ \
289 int bpf_size = -EINVAL; \
290 \
291 if (bytes == sizeof(u8)) \
292 bpf_size = BPF_B; \
293 else if (bytes == sizeof(u16)) \
294 bpf_size = BPF_H; \
295 else if (bytes == sizeof(u32)) \
296 bpf_size = BPF_W; \
297 else if (bytes == sizeof(u64)) \
298 bpf_size = BPF_DW; \
299 \
300 bpf_size; \
301})
9739eef1 302
30743837 303/* Macro to invoke filter function. */
7ae457c1
AS
304#define SK_RUN_FILTER(filter, ctx) \
305 (*filter->prog->bpf_func)(ctx, filter->prog->insnsi)
bd4cf0ed 306
2695fb55 307struct bpf_insn {
bd4cf0ed 308 __u8 code; /* opcode */
e430f34e
AS
309 __u8 dst_reg:4; /* dest register */
310 __u8 src_reg:4; /* source register */
bd4cf0ed
AS
311 __s16 off; /* signed offset */
312 __s32 imm; /* signed immediate constant */
313};
314
315#ifdef CONFIG_COMPAT
316/* A struct sock_filter is architecture independent. */
0c5fe1b4
WD
317struct compat_sock_fprog {
318 u16 len;
bd4cf0ed 319 compat_uptr_t filter; /* struct sock_filter * */
0c5fe1b4
WD
320};
321#endif
322
a3ea269b
DB
323struct sock_fprog_kern {
324 u16 len;
325 struct sock_filter *filter;
326};
327
60a3b225
DB
328struct bpf_work_struct {
329 struct bpf_prog *prog;
330 struct work_struct work;
331};
792d4b5c 332
7ae457c1 333struct bpf_prog {
60a3b225 334 u32 pages; /* Number of allocated pages */
f8bbbfc3
DB
335 u32 jited:1, /* Is our filter JIT'ed? */
336 len:31; /* Number of filter blocks */
a3ea269b 337 struct sock_fprog_kern *orig_prog; /* Original BPF program */
60a3b225 338 struct bpf_work_struct *work; /* Deferred free work struct */
0a14842f 339 unsigned int (*bpf_func)(const struct sk_buff *skb,
2695fb55 340 const struct bpf_insn *filter);
60a3b225 341 /* Instructions for interpreter */
d45ed4a4 342 union {
bd4cf0ed 343 struct sock_filter insns[0];
2695fb55 344 struct bpf_insn insnsi[0];
d45ed4a4 345 };
b715631f
SH
346};
347
7ae457c1
AS
348struct sk_filter {
349 atomic_t refcnt;
350 struct rcu_head rcu;
351 struct bpf_prog *prog;
352};
353
354#define BPF_PROG_RUN(filter, ctx) (*filter->bpf_func)(ctx, filter->insnsi)
355
356static inline unsigned int bpf_prog_size(unsigned int proglen)
b715631f 357{
7ae457c1
AS
358 return max(sizeof(struct bpf_prog),
359 offsetof(struct bpf_prog, insns[proglen]));
b715631f
SH
360}
361
009937e7 362#define bpf_classic_proglen(fprog) (fprog->len * sizeof(fprog->filter[0]))
a3ea269b 363
60a3b225
DB
364#ifdef CONFIG_DEBUG_SET_MODULE_RONX
365static inline void bpf_prog_lock_ro(struct bpf_prog *fp)
366{
367 set_memory_ro((unsigned long)fp, fp->pages);
368}
369
370static inline void bpf_prog_unlock_ro(struct bpf_prog *fp)
371{
372 set_memory_rw((unsigned long)fp, fp->pages);
373}
374#else
375static inline void bpf_prog_lock_ro(struct bpf_prog *fp)
376{
377}
378
379static inline void bpf_prog_unlock_ro(struct bpf_prog *fp)
380{
381}
382#endif /* CONFIG_DEBUG_SET_MODULE_RONX */
383
fbc907f0 384int sk_filter(struct sock *sk, struct sk_buff *skb);
bd4cf0ed 385
7ae457c1
AS
386void bpf_prog_select_runtime(struct bpf_prog *fp);
387void bpf_prog_free(struct bpf_prog *fp);
bd4cf0ed 388
8fb575ca
AS
389int bpf_convert_filter(struct sock_filter *prog, int len,
390 struct bpf_insn *new_prog, int *new_len);
a3ea269b 391
60a3b225
DB
392struct bpf_prog *bpf_prog_alloc(unsigned int size, gfp_t gfp_extra_flags);
393struct bpf_prog *bpf_prog_realloc(struct bpf_prog *fp_old, unsigned int size,
394 gfp_t gfp_extra_flags);
395void __bpf_prog_free(struct bpf_prog *fp);
396
397static inline void bpf_prog_unlock_free(struct bpf_prog *fp)
398{
399 bpf_prog_unlock_ro(fp);
400 __bpf_prog_free(fp);
401}
402
7ae457c1
AS
403int bpf_prog_create(struct bpf_prog **pfp, struct sock_fprog_kern *fprog);
404void bpf_prog_destroy(struct bpf_prog *fp);
a3ea269b 405
fbc907f0
DB
406int sk_attach_filter(struct sock_fprog *fprog, struct sock *sk);
407int sk_detach_filter(struct sock *sk);
a3ea269b 408
4df95ff4 409int bpf_check_classic(const struct sock_filter *filter, unsigned int flen);
fbc907f0
DB
410int sk_get_filter(struct sock *sk, struct sock_filter __user *filter,
411 unsigned int len);
fbc907f0 412
278571ba 413bool sk_filter_charge(struct sock *sk, struct sk_filter *fp);
fbc907f0 414void sk_filter_uncharge(struct sock *sk, struct sk_filter *fp);
0a14842f 415
62258278 416u64 __bpf_call_base(u64 r1, u64 r2, u64 r3, u64 r4, u64 r5);
7ae457c1 417void bpf_int_jit_compile(struct bpf_prog *fp);
62258278 418
34805931
DB
419#define BPF_ANC BIT(15)
420
421static inline u16 bpf_anc_helper(const struct sock_filter *ftest)
422{
423 BUG_ON(ftest->code & BPF_ANC);
424
425 switch (ftest->code) {
426 case BPF_LD | BPF_W | BPF_ABS:
427 case BPF_LD | BPF_H | BPF_ABS:
428 case BPF_LD | BPF_B | BPF_ABS:
429#define BPF_ANCILLARY(CODE) case SKF_AD_OFF + SKF_AD_##CODE: \
430 return BPF_ANC | SKF_AD_##CODE
431 switch (ftest->k) {
432 BPF_ANCILLARY(PROTOCOL);
433 BPF_ANCILLARY(PKTTYPE);
434 BPF_ANCILLARY(IFINDEX);
435 BPF_ANCILLARY(NLATTR);
436 BPF_ANCILLARY(NLATTR_NEST);
437 BPF_ANCILLARY(MARK);
438 BPF_ANCILLARY(QUEUE);
439 BPF_ANCILLARY(HATYPE);
440 BPF_ANCILLARY(RXHASH);
441 BPF_ANCILLARY(CPU);
442 BPF_ANCILLARY(ALU_XOR_X);
443 BPF_ANCILLARY(VLAN_TAG);
444 BPF_ANCILLARY(VLAN_TAG_PRESENT);
445 BPF_ANCILLARY(PAY_OFFSET);
446 BPF_ANCILLARY(RANDOM);
447 }
448 /* Fallthrough. */
449 default:
450 return ftest->code;
451 }
452}
453
9f12fbe6
ZSL
454void *bpf_internal_load_pointer_neg_helper(const struct sk_buff *skb,
455 int k, unsigned int size);
456
457static inline void *bpf_load_pointer(const struct sk_buff *skb, int k,
458 unsigned int size, void *buffer)
459{
460 if (k >= 0)
461 return skb_header_pointer(skb, k, size, buffer);
462
463 return bpf_internal_load_pointer_neg_helper(skb, k, size);
464}
465
0a14842f 466#ifdef CONFIG_BPF_JIT
20074f35 467#include <stdarg.h>
a691ce7f
CG
468#include <linux/linkage.h>
469#include <linux/printk.h>
470
7ae457c1
AS
471void bpf_jit_compile(struct bpf_prog *fp);
472void bpf_jit_free(struct bpf_prog *fp);
79617801
DB
473
474static inline void bpf_jit_dump(unsigned int flen, unsigned int proglen,
475 u32 pass, void *image)
476{
16495445 477 pr_err("flen=%u proglen=%u pass=%u image=%pK\n",
79617801
DB
478 flen, proglen, pass, image);
479 if (image)
16495445 480 print_hex_dump(KERN_ERR, "JIT code: ", DUMP_PREFIX_OFFSET,
79617801
DB
481 16, 1, image, proglen, false);
482}
0a14842f 483#else
d45ed4a4 484#include <linux/slab.h>
34805931 485
7ae457c1 486static inline void bpf_jit_compile(struct bpf_prog *fp)
0a14842f
ED
487{
488}
34805931 489
7ae457c1 490static inline void bpf_jit_free(struct bpf_prog *fp)
0a14842f 491{
60a3b225 492 bpf_prog_unlock_free(fp);
0a14842f 493}
34805931 494#endif /* CONFIG_BPF_JIT */
0a14842f 495
ea02f941
MS
496static inline int bpf_tell_extensions(void)
497{
37692299 498 return SKF_AD_MAX;
ea02f941
MS
499}
500
1da177e4 501#endif /* __LINUX_FILTER_H__ */