bpf: verifier (add ability to receive verification log)
[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
b954d834
DB
7#include <stdarg.h>
8
60063497 9#include <linux/atomic.h>
0c5fe1b4 10#include <linux/compat.h>
9f12fbe6 11#include <linux/skbuff.h>
b954d834
DB
12#include <linux/linkage.h>
13#include <linux/printk.h>
d45ed4a4 14#include <linux/workqueue.h>
b954d834 15
60a3b225 16#include <asm/cacheflush.h>
b954d834
DB
17
18#include <uapi/linux/filter.h>
daedfb22 19#include <uapi/linux/bpf.h>
60a3b225
DB
20
21struct sk_buff;
22struct sock;
23struct seccomp_data;
09756af4 24struct bpf_prog_aux;
792d4b5c 25
30743837
DB
26/* ArgX, context and stack frame pointer register positions. Note,
27 * Arg1, Arg2, Arg3, etc are used as argument mappings of function
28 * calls in BPF_CALL instruction.
29 */
30#define BPF_REG_ARG1 BPF_REG_1
31#define BPF_REG_ARG2 BPF_REG_2
32#define BPF_REG_ARG3 BPF_REG_3
33#define BPF_REG_ARG4 BPF_REG_4
34#define BPF_REG_ARG5 BPF_REG_5
35#define BPF_REG_CTX BPF_REG_6
36#define BPF_REG_FP BPF_REG_10
37
38/* Additional register mappings for converted user programs. */
39#define BPF_REG_A BPF_REG_0
40#define BPF_REG_X BPF_REG_7
41#define BPF_REG_TMP BPF_REG_8
bd4cf0ed
AS
42
43/* BPF program can access up to 512 bytes of stack space. */
44#define MAX_BPF_STACK 512
45
f8f6d679
DB
46/* Helper macros for filter block array initializers. */
47
e430f34e 48/* ALU ops on registers, bpf_add|sub|...: dst_reg += src_reg */
f8f6d679 49
e430f34e 50#define BPF_ALU64_REG(OP, DST, SRC) \
2695fb55 51 ((struct bpf_insn) { \
f8f6d679 52 .code = BPF_ALU64 | BPF_OP(OP) | BPF_X, \
e430f34e
AS
53 .dst_reg = DST, \
54 .src_reg = SRC, \
f8f6d679
DB
55 .off = 0, \
56 .imm = 0 })
57
e430f34e 58#define BPF_ALU32_REG(OP, DST, SRC) \
2695fb55 59 ((struct bpf_insn) { \
f8f6d679 60 .code = BPF_ALU | BPF_OP(OP) | BPF_X, \
e430f34e
AS
61 .dst_reg = DST, \
62 .src_reg = SRC, \
f8f6d679
DB
63 .off = 0, \
64 .imm = 0 })
65
e430f34e 66/* ALU ops on immediates, bpf_add|sub|...: dst_reg += imm32 */
f8f6d679 67
e430f34e 68#define BPF_ALU64_IMM(OP, DST, IMM) \
2695fb55 69 ((struct bpf_insn) { \
f8f6d679 70 .code = BPF_ALU64 | BPF_OP(OP) | BPF_K, \
e430f34e
AS
71 .dst_reg = DST, \
72 .src_reg = 0, \
f8f6d679
DB
73 .off = 0, \
74 .imm = IMM })
75
e430f34e 76#define BPF_ALU32_IMM(OP, DST, IMM) \
2695fb55 77 ((struct bpf_insn) { \
f8f6d679 78 .code = BPF_ALU | BPF_OP(OP) | BPF_K, \
e430f34e
AS
79 .dst_reg = DST, \
80 .src_reg = 0, \
f8f6d679
DB
81 .off = 0, \
82 .imm = IMM })
83
84/* Endianess conversion, cpu_to_{l,b}e(), {l,b}e_to_cpu() */
85
e430f34e 86#define BPF_ENDIAN(TYPE, DST, LEN) \
2695fb55 87 ((struct bpf_insn) { \
f8f6d679 88 .code = BPF_ALU | BPF_END | BPF_SRC(TYPE), \
e430f34e
AS
89 .dst_reg = DST, \
90 .src_reg = 0, \
f8f6d679
DB
91 .off = 0, \
92 .imm = LEN })
93
e430f34e 94/* Short form of mov, dst_reg = src_reg */
f8f6d679 95
e430f34e 96#define BPF_MOV64_REG(DST, SRC) \
2695fb55 97 ((struct bpf_insn) { \
f8f6d679 98 .code = BPF_ALU64 | BPF_MOV | BPF_X, \
e430f34e
AS
99 .dst_reg = DST, \
100 .src_reg = SRC, \
f8f6d679
DB
101 .off = 0, \
102 .imm = 0 })
103
e430f34e 104#define BPF_MOV32_REG(DST, SRC) \
2695fb55 105 ((struct bpf_insn) { \
f8f6d679 106 .code = BPF_ALU | BPF_MOV | BPF_X, \
e430f34e
AS
107 .dst_reg = DST, \
108 .src_reg = SRC, \
f8f6d679
DB
109 .off = 0, \
110 .imm = 0 })
111
e430f34e 112/* Short form of mov, dst_reg = imm32 */
f8f6d679 113
e430f34e 114#define BPF_MOV64_IMM(DST, IMM) \
2695fb55 115 ((struct bpf_insn) { \
f8f6d679 116 .code = BPF_ALU64 | BPF_MOV | BPF_K, \
e430f34e
AS
117 .dst_reg = DST, \
118 .src_reg = 0, \
f8f6d679
DB
119 .off = 0, \
120 .imm = IMM })
121
e430f34e 122#define BPF_MOV32_IMM(DST, IMM) \
2695fb55 123 ((struct bpf_insn) { \
f8f6d679 124 .code = BPF_ALU | BPF_MOV | BPF_K, \
e430f34e
AS
125 .dst_reg = DST, \
126 .src_reg = 0, \
f8f6d679
DB
127 .off = 0, \
128 .imm = IMM })
129
02ab695b
AS
130/* BPF_LD_IMM64 macro encodes single 'load 64-bit immediate' insn */
131#define BPF_LD_IMM64(DST, IMM) \
132 BPF_LD_IMM64_RAW(DST, 0, IMM)
133
134#define BPF_LD_IMM64_RAW(DST, SRC, IMM) \
135 ((struct bpf_insn) { \
136 .code = BPF_LD | BPF_DW | BPF_IMM, \
137 .dst_reg = DST, \
138 .src_reg = SRC, \
139 .off = 0, \
140 .imm = (__u32) (IMM) }), \
141 ((struct bpf_insn) { \
142 .code = 0, /* zero is reserved opcode */ \
143 .dst_reg = 0, \
144 .src_reg = 0, \
145 .off = 0, \
146 .imm = ((__u64) (IMM)) >> 32 })
147
e430f34e 148/* Short form of mov based on type, BPF_X: dst_reg = src_reg, BPF_K: dst_reg = imm32 */
f8f6d679 149
e430f34e 150#define BPF_MOV64_RAW(TYPE, DST, SRC, IMM) \
2695fb55 151 ((struct bpf_insn) { \
f8f6d679 152 .code = BPF_ALU64 | BPF_MOV | BPF_SRC(TYPE), \
e430f34e
AS
153 .dst_reg = DST, \
154 .src_reg = SRC, \
f8f6d679
DB
155 .off = 0, \
156 .imm = IMM })
157
e430f34e 158#define BPF_MOV32_RAW(TYPE, DST, SRC, IMM) \
2695fb55 159 ((struct bpf_insn) { \
f8f6d679 160 .code = BPF_ALU | BPF_MOV | BPF_SRC(TYPE), \
e430f34e
AS
161 .dst_reg = DST, \
162 .src_reg = SRC, \
f8f6d679
DB
163 .off = 0, \
164 .imm = IMM })
165
e430f34e 166/* Direct packet access, R0 = *(uint *) (skb->data + imm32) */
f8f6d679 167
e430f34e 168#define BPF_LD_ABS(SIZE, IMM) \
2695fb55 169 ((struct bpf_insn) { \
f8f6d679 170 .code = BPF_LD | BPF_SIZE(SIZE) | BPF_ABS, \
e430f34e
AS
171 .dst_reg = 0, \
172 .src_reg = 0, \
f8f6d679 173 .off = 0, \
e430f34e 174 .imm = IMM })
f8f6d679 175
e430f34e 176/* Indirect packet access, R0 = *(uint *) (skb->data + src_reg + imm32) */
f8f6d679 177
e430f34e 178#define BPF_LD_IND(SIZE, SRC, IMM) \
2695fb55 179 ((struct bpf_insn) { \
f8f6d679 180 .code = BPF_LD | BPF_SIZE(SIZE) | BPF_IND, \
e430f34e
AS
181 .dst_reg = 0, \
182 .src_reg = SRC, \
f8f6d679 183 .off = 0, \
e430f34e 184 .imm = IMM })
f8f6d679 185
e430f34e 186/* Memory load, dst_reg = *(uint *) (src_reg + off16) */
f8f6d679 187
e430f34e 188#define BPF_LDX_MEM(SIZE, DST, SRC, OFF) \
2695fb55 189 ((struct bpf_insn) { \
f8f6d679 190 .code = BPF_LDX | BPF_SIZE(SIZE) | BPF_MEM, \
e430f34e
AS
191 .dst_reg = DST, \
192 .src_reg = SRC, \
f8f6d679
DB
193 .off = OFF, \
194 .imm = 0 })
195
e430f34e
AS
196/* Memory store, *(uint *) (dst_reg + off16) = src_reg */
197
198#define BPF_STX_MEM(SIZE, DST, SRC, OFF) \
2695fb55 199 ((struct bpf_insn) { \
f8f6d679 200 .code = BPF_STX | BPF_SIZE(SIZE) | BPF_MEM, \
e430f34e
AS
201 .dst_reg = DST, \
202 .src_reg = SRC, \
f8f6d679
DB
203 .off = OFF, \
204 .imm = 0 })
205
e430f34e
AS
206/* Memory store, *(uint *) (dst_reg + off16) = imm32 */
207
208#define BPF_ST_MEM(SIZE, DST, OFF, IMM) \
2695fb55 209 ((struct bpf_insn) { \
e430f34e
AS
210 .code = BPF_ST | BPF_SIZE(SIZE) | BPF_MEM, \
211 .dst_reg = DST, \
212 .src_reg = 0, \
213 .off = OFF, \
214 .imm = IMM })
215
216/* Conditional jumps against registers, if (dst_reg 'op' src_reg) goto pc + off16 */
f8f6d679 217
e430f34e 218#define BPF_JMP_REG(OP, DST, SRC, OFF) \
2695fb55 219 ((struct bpf_insn) { \
f8f6d679 220 .code = BPF_JMP | BPF_OP(OP) | BPF_X, \
e430f34e
AS
221 .dst_reg = DST, \
222 .src_reg = SRC, \
f8f6d679
DB
223 .off = OFF, \
224 .imm = 0 })
225
e430f34e 226/* Conditional jumps against immediates, if (dst_reg 'op' imm32) goto pc + off16 */
f8f6d679 227
e430f34e 228#define BPF_JMP_IMM(OP, DST, IMM, OFF) \
2695fb55 229 ((struct bpf_insn) { \
f8f6d679 230 .code = BPF_JMP | BPF_OP(OP) | BPF_K, \
e430f34e
AS
231 .dst_reg = DST, \
232 .src_reg = 0, \
f8f6d679
DB
233 .off = OFF, \
234 .imm = IMM })
235
236/* Function call */
237
238#define BPF_EMIT_CALL(FUNC) \
2695fb55 239 ((struct bpf_insn) { \
f8f6d679 240 .code = BPF_JMP | BPF_CALL, \
e430f34e
AS
241 .dst_reg = 0, \
242 .src_reg = 0, \
f8f6d679
DB
243 .off = 0, \
244 .imm = ((FUNC) - __bpf_call_base) })
245
246/* Raw code statement block */
247
e430f34e 248#define BPF_RAW_INSN(CODE, DST, SRC, OFF, IMM) \
2695fb55 249 ((struct bpf_insn) { \
f8f6d679 250 .code = CODE, \
e430f34e
AS
251 .dst_reg = DST, \
252 .src_reg = SRC, \
f8f6d679
DB
253 .off = OFF, \
254 .imm = IMM })
255
256/* Program exit */
257
258#define BPF_EXIT_INSN() \
2695fb55 259 ((struct bpf_insn) { \
f8f6d679 260 .code = BPF_JMP | BPF_EXIT, \
e430f34e
AS
261 .dst_reg = 0, \
262 .src_reg = 0, \
f8f6d679
DB
263 .off = 0, \
264 .imm = 0 })
265
266#define bytes_to_bpf_size(bytes) \
267({ \
268 int bpf_size = -EINVAL; \
269 \
270 if (bytes == sizeof(u8)) \
271 bpf_size = BPF_B; \
272 else if (bytes == sizeof(u16)) \
273 bpf_size = BPF_H; \
274 else if (bytes == sizeof(u32)) \
275 bpf_size = BPF_W; \
276 else if (bytes == sizeof(u64)) \
277 bpf_size = BPF_DW; \
278 \
279 bpf_size; \
280})
9739eef1 281
30743837 282/* Macro to invoke filter function. */
7ae457c1
AS
283#define SK_RUN_FILTER(filter, ctx) \
284 (*filter->prog->bpf_func)(ctx, filter->prog->insnsi)
bd4cf0ed 285
bd4cf0ed
AS
286#ifdef CONFIG_COMPAT
287/* A struct sock_filter is architecture independent. */
0c5fe1b4
WD
288struct compat_sock_fprog {
289 u16 len;
bd4cf0ed 290 compat_uptr_t filter; /* struct sock_filter * */
0c5fe1b4
WD
291};
292#endif
293
a3ea269b
DB
294struct sock_fprog_kern {
295 u16 len;
296 struct sock_filter *filter;
297};
298
738cbe72
DB
299struct bpf_binary_header {
300 unsigned int pages;
301 u8 image[];
302};
303
7ae457c1 304struct bpf_prog {
286aad3c
DB
305 u16 pages; /* Number of allocated pages */
306 bool jited; /* Is our filter JIT'ed? */
307 u32 len; /* Number of filter blocks */
a3ea269b 308 struct sock_fprog_kern *orig_prog; /* Original BPF program */
09756af4 309 struct bpf_prog_aux *aux; /* Auxiliary fields */
0a14842f 310 unsigned int (*bpf_func)(const struct sk_buff *skb,
2695fb55 311 const struct bpf_insn *filter);
60a3b225 312 /* Instructions for interpreter */
d45ed4a4 313 union {
bd4cf0ed 314 struct sock_filter insns[0];
2695fb55 315 struct bpf_insn insnsi[0];
d45ed4a4 316 };
b715631f
SH
317};
318
7ae457c1
AS
319struct sk_filter {
320 atomic_t refcnt;
321 struct rcu_head rcu;
322 struct bpf_prog *prog;
323};
324
325#define BPF_PROG_RUN(filter, ctx) (*filter->bpf_func)(ctx, filter->insnsi)
326
327static inline unsigned int bpf_prog_size(unsigned int proglen)
b715631f 328{
7ae457c1
AS
329 return max(sizeof(struct bpf_prog),
330 offsetof(struct bpf_prog, insns[proglen]));
b715631f
SH
331}
332
009937e7 333#define bpf_classic_proglen(fprog) (fprog->len * sizeof(fprog->filter[0]))
a3ea269b 334
60a3b225
DB
335#ifdef CONFIG_DEBUG_SET_MODULE_RONX
336static inline void bpf_prog_lock_ro(struct bpf_prog *fp)
337{
338 set_memory_ro((unsigned long)fp, fp->pages);
339}
340
341static inline void bpf_prog_unlock_ro(struct bpf_prog *fp)
342{
343 set_memory_rw((unsigned long)fp, fp->pages);
344}
345#else
346static inline void bpf_prog_lock_ro(struct bpf_prog *fp)
347{
348}
349
350static inline void bpf_prog_unlock_ro(struct bpf_prog *fp)
351{
352}
353#endif /* CONFIG_DEBUG_SET_MODULE_RONX */
354
fbc907f0 355int sk_filter(struct sock *sk, struct sk_buff *skb);
bd4cf0ed 356
7ae457c1
AS
357void bpf_prog_select_runtime(struct bpf_prog *fp);
358void bpf_prog_free(struct bpf_prog *fp);
bd4cf0ed 359
8fb575ca
AS
360int bpf_convert_filter(struct sock_filter *prog, int len,
361 struct bpf_insn *new_prog, int *new_len);
a3ea269b 362
60a3b225
DB
363struct bpf_prog *bpf_prog_alloc(unsigned int size, gfp_t gfp_extra_flags);
364struct bpf_prog *bpf_prog_realloc(struct bpf_prog *fp_old, unsigned int size,
365 gfp_t gfp_extra_flags);
366void __bpf_prog_free(struct bpf_prog *fp);
367
368static inline void bpf_prog_unlock_free(struct bpf_prog *fp)
369{
370 bpf_prog_unlock_ro(fp);
371 __bpf_prog_free(fp);
372}
373
7ae457c1
AS
374int bpf_prog_create(struct bpf_prog **pfp, struct sock_fprog_kern *fprog);
375void bpf_prog_destroy(struct bpf_prog *fp);
a3ea269b 376
fbc907f0
DB
377int sk_attach_filter(struct sock_fprog *fprog, struct sock *sk);
378int sk_detach_filter(struct sock *sk);
a3ea269b 379
4df95ff4 380int bpf_check_classic(const struct sock_filter *filter, unsigned int flen);
fbc907f0
DB
381int sk_get_filter(struct sock *sk, struct sock_filter __user *filter,
382 unsigned int len);
fbc907f0 383
278571ba 384bool sk_filter_charge(struct sock *sk, struct sk_filter *fp);
fbc907f0 385void sk_filter_uncharge(struct sock *sk, struct sk_filter *fp);
0a14842f 386
62258278 387u64 __bpf_call_base(u64 r1, u64 r2, u64 r3, u64 r4, u64 r5);
7ae457c1 388void bpf_int_jit_compile(struct bpf_prog *fp);
62258278 389
b954d834
DB
390#ifdef CONFIG_BPF_JIT
391typedef void (*bpf_jit_fill_hole_t)(void *area, unsigned int size);
392
393struct bpf_binary_header *
394bpf_jit_binary_alloc(unsigned int proglen, u8 **image_ptr,
395 unsigned int alignment,
396 bpf_jit_fill_hole_t bpf_fill_ill_insns);
397void bpf_jit_binary_free(struct bpf_binary_header *hdr);
398
399void bpf_jit_compile(struct bpf_prog *fp);
400void bpf_jit_free(struct bpf_prog *fp);
401
402static inline void bpf_jit_dump(unsigned int flen, unsigned int proglen,
403 u32 pass, void *image)
404{
405 pr_err("flen=%u proglen=%u pass=%u image=%pK\n",
406 flen, proglen, pass, image);
407 if (image)
408 print_hex_dump(KERN_ERR, "JIT code: ", DUMP_PREFIX_OFFSET,
409 16, 1, image, proglen, false);
410}
411#else
412static inline void bpf_jit_compile(struct bpf_prog *fp)
413{
414}
415
416static inline void bpf_jit_free(struct bpf_prog *fp)
417{
418 bpf_prog_unlock_free(fp);
419}
420#endif /* CONFIG_BPF_JIT */
421
34805931
DB
422#define BPF_ANC BIT(15)
423
424static inline u16 bpf_anc_helper(const struct sock_filter *ftest)
425{
426 BUG_ON(ftest->code & BPF_ANC);
427
428 switch (ftest->code) {
429 case BPF_LD | BPF_W | BPF_ABS:
430 case BPF_LD | BPF_H | BPF_ABS:
431 case BPF_LD | BPF_B | BPF_ABS:
432#define BPF_ANCILLARY(CODE) case SKF_AD_OFF + SKF_AD_##CODE: \
433 return BPF_ANC | SKF_AD_##CODE
434 switch (ftest->k) {
435 BPF_ANCILLARY(PROTOCOL);
436 BPF_ANCILLARY(PKTTYPE);
437 BPF_ANCILLARY(IFINDEX);
438 BPF_ANCILLARY(NLATTR);
439 BPF_ANCILLARY(NLATTR_NEST);
440 BPF_ANCILLARY(MARK);
441 BPF_ANCILLARY(QUEUE);
442 BPF_ANCILLARY(HATYPE);
443 BPF_ANCILLARY(RXHASH);
444 BPF_ANCILLARY(CPU);
445 BPF_ANCILLARY(ALU_XOR_X);
446 BPF_ANCILLARY(VLAN_TAG);
447 BPF_ANCILLARY(VLAN_TAG_PRESENT);
448 BPF_ANCILLARY(PAY_OFFSET);
449 BPF_ANCILLARY(RANDOM);
450 }
451 /* Fallthrough. */
452 default:
453 return ftest->code;
454 }
455}
456
9f12fbe6
ZSL
457void *bpf_internal_load_pointer_neg_helper(const struct sk_buff *skb,
458 int k, unsigned int size);
459
460static inline void *bpf_load_pointer(const struct sk_buff *skb, int k,
461 unsigned int size, void *buffer)
462{
463 if (k >= 0)
464 return skb_header_pointer(skb, k, size, buffer);
465
466 return bpf_internal_load_pointer_neg_helper(skb, k, size);
467}
468
ea02f941
MS
469static inline int bpf_tell_extensions(void)
470{
37692299 471 return SKF_AD_MAX;
ea02f941
MS
472}
473
1da177e4 474#endif /* __LINUX_FILTER_H__ */