Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
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linux
1/*
2 * Linux Socket Filter Data Structures
3 */
4#ifndef __LINUX_FILTER_H__
5#define __LINUX_FILTER_H__
6
7#include <stdarg.h>
8
9#include <linux/atomic.h>
10#include <linux/compat.h>
11#include <linux/skbuff.h>
12#include <linux/linkage.h>
13#include <linux/printk.h>
14#include <linux/workqueue.h>
15#include <linux/sched.h>
16#include <net/sch_generic.h>
17
18#include <asm/cacheflush.h>
19
20#include <uapi/linux/filter.h>
21#include <uapi/linux/bpf.h>
22
23struct sk_buff;
24struct sock;
25struct seccomp_data;
26struct bpf_prog_aux;
27
28/* ArgX, context and stack frame pointer register positions. Note,
29 * Arg1, Arg2, Arg3, etc are used as argument mappings of function
30 * calls in BPF_CALL instruction.
31 */
32#define BPF_REG_ARG1 BPF_REG_1
33#define BPF_REG_ARG2 BPF_REG_2
34#define BPF_REG_ARG3 BPF_REG_3
35#define BPF_REG_ARG4 BPF_REG_4
36#define BPF_REG_ARG5 BPF_REG_5
37#define BPF_REG_CTX BPF_REG_6
38#define BPF_REG_FP BPF_REG_10
39
40/* Additional register mappings for converted user programs. */
41#define BPF_REG_A BPF_REG_0
42#define BPF_REG_X BPF_REG_7
43#define BPF_REG_TMP BPF_REG_8
44
45/* BPF program can access up to 512 bytes of stack space. */
46#define MAX_BPF_STACK 512
47
48/* Helper macros for filter block array initializers. */
49
50/* ALU ops on registers, bpf_add|sub|...: dst_reg += src_reg */
51
52#define BPF_ALU64_REG(OP, DST, SRC) \
53 ((struct bpf_insn) { \
54 .code = BPF_ALU64 | BPF_OP(OP) | BPF_X, \
55 .dst_reg = DST, \
56 .src_reg = SRC, \
57 .off = 0, \
58 .imm = 0 })
59
60#define BPF_ALU32_REG(OP, DST, SRC) \
61 ((struct bpf_insn) { \
62 .code = BPF_ALU | BPF_OP(OP) | BPF_X, \
63 .dst_reg = DST, \
64 .src_reg = SRC, \
65 .off = 0, \
66 .imm = 0 })
67
68/* ALU ops on immediates, bpf_add|sub|...: dst_reg += imm32 */
69
70#define BPF_ALU64_IMM(OP, DST, IMM) \
71 ((struct bpf_insn) { \
72 .code = BPF_ALU64 | BPF_OP(OP) | BPF_K, \
73 .dst_reg = DST, \
74 .src_reg = 0, \
75 .off = 0, \
76 .imm = IMM })
77
78#define BPF_ALU32_IMM(OP, DST, IMM) \
79 ((struct bpf_insn) { \
80 .code = BPF_ALU | BPF_OP(OP) | BPF_K, \
81 .dst_reg = DST, \
82 .src_reg = 0, \
83 .off = 0, \
84 .imm = IMM })
85
86/* Endianess conversion, cpu_to_{l,b}e(), {l,b}e_to_cpu() */
87
88#define BPF_ENDIAN(TYPE, DST, LEN) \
89 ((struct bpf_insn) { \
90 .code = BPF_ALU | BPF_END | BPF_SRC(TYPE), \
91 .dst_reg = DST, \
92 .src_reg = 0, \
93 .off = 0, \
94 .imm = LEN })
95
96/* Short form of mov, dst_reg = src_reg */
97
98#define BPF_MOV64_REG(DST, SRC) \
99 ((struct bpf_insn) { \
100 .code = BPF_ALU64 | BPF_MOV | BPF_X, \
101 .dst_reg = DST, \
102 .src_reg = SRC, \
103 .off = 0, \
104 .imm = 0 })
105
106#define BPF_MOV32_REG(DST, SRC) \
107 ((struct bpf_insn) { \
108 .code = BPF_ALU | BPF_MOV | BPF_X, \
109 .dst_reg = DST, \
110 .src_reg = SRC, \
111 .off = 0, \
112 .imm = 0 })
113
114/* Short form of mov, dst_reg = imm32 */
115
116#define BPF_MOV64_IMM(DST, IMM) \
117 ((struct bpf_insn) { \
118 .code = BPF_ALU64 | BPF_MOV | BPF_K, \
119 .dst_reg = DST, \
120 .src_reg = 0, \
121 .off = 0, \
122 .imm = IMM })
123
124#define BPF_MOV32_IMM(DST, IMM) \
125 ((struct bpf_insn) { \
126 .code = BPF_ALU | BPF_MOV | BPF_K, \
127 .dst_reg = DST, \
128 .src_reg = 0, \
129 .off = 0, \
130 .imm = IMM })
131
132/* BPF_LD_IMM64 macro encodes single 'load 64-bit immediate' insn */
133#define BPF_LD_IMM64(DST, IMM) \
134 BPF_LD_IMM64_RAW(DST, 0, IMM)
135
136#define BPF_LD_IMM64_RAW(DST, SRC, IMM) \
137 ((struct bpf_insn) { \
138 .code = BPF_LD | BPF_DW | BPF_IMM, \
139 .dst_reg = DST, \
140 .src_reg = SRC, \
141 .off = 0, \
142 .imm = (__u32) (IMM) }), \
143 ((struct bpf_insn) { \
144 .code = 0, /* zero is reserved opcode */ \
145 .dst_reg = 0, \
146 .src_reg = 0, \
147 .off = 0, \
148 .imm = ((__u64) (IMM)) >> 32 })
149
150/* pseudo BPF_LD_IMM64 insn used to refer to process-local map_fd */
151#define BPF_LD_MAP_FD(DST, MAP_FD) \
152 BPF_LD_IMM64_RAW(DST, BPF_PSEUDO_MAP_FD, MAP_FD)
153
154/* Short form of mov based on type, BPF_X: dst_reg = src_reg, BPF_K: dst_reg = imm32 */
155
156#define BPF_MOV64_RAW(TYPE, DST, SRC, IMM) \
157 ((struct bpf_insn) { \
158 .code = BPF_ALU64 | BPF_MOV | BPF_SRC(TYPE), \
159 .dst_reg = DST, \
160 .src_reg = SRC, \
161 .off = 0, \
162 .imm = IMM })
163
164#define BPF_MOV32_RAW(TYPE, DST, SRC, IMM) \
165 ((struct bpf_insn) { \
166 .code = BPF_ALU | BPF_MOV | BPF_SRC(TYPE), \
167 .dst_reg = DST, \
168 .src_reg = SRC, \
169 .off = 0, \
170 .imm = IMM })
171
172/* Direct packet access, R0 = *(uint *) (skb->data + imm32) */
173
174#define BPF_LD_ABS(SIZE, IMM) \
175 ((struct bpf_insn) { \
176 .code = BPF_LD | BPF_SIZE(SIZE) | BPF_ABS, \
177 .dst_reg = 0, \
178 .src_reg = 0, \
179 .off = 0, \
180 .imm = IMM })
181
182/* Indirect packet access, R0 = *(uint *) (skb->data + src_reg + imm32) */
183
184#define BPF_LD_IND(SIZE, SRC, IMM) \
185 ((struct bpf_insn) { \
186 .code = BPF_LD | BPF_SIZE(SIZE) | BPF_IND, \
187 .dst_reg = 0, \
188 .src_reg = SRC, \
189 .off = 0, \
190 .imm = IMM })
191
192/* Memory load, dst_reg = *(uint *) (src_reg + off16) */
193
194#define BPF_LDX_MEM(SIZE, DST, SRC, OFF) \
195 ((struct bpf_insn) { \
196 .code = BPF_LDX | BPF_SIZE(SIZE) | BPF_MEM, \
197 .dst_reg = DST, \
198 .src_reg = SRC, \
199 .off = OFF, \
200 .imm = 0 })
201
202/* Memory store, *(uint *) (dst_reg + off16) = src_reg */
203
204#define BPF_STX_MEM(SIZE, DST, SRC, OFF) \
205 ((struct bpf_insn) { \
206 .code = BPF_STX | BPF_SIZE(SIZE) | BPF_MEM, \
207 .dst_reg = DST, \
208 .src_reg = SRC, \
209 .off = OFF, \
210 .imm = 0 })
211
212/* Atomic memory add, *(uint *)(dst_reg + off16) += src_reg */
213
214#define BPF_STX_XADD(SIZE, DST, SRC, OFF) \
215 ((struct bpf_insn) { \
216 .code = BPF_STX | BPF_SIZE(SIZE) | BPF_XADD, \
217 .dst_reg = DST, \
218 .src_reg = SRC, \
219 .off = OFF, \
220 .imm = 0 })
221
222/* Memory store, *(uint *) (dst_reg + off16) = imm32 */
223
224#define BPF_ST_MEM(SIZE, DST, OFF, IMM) \
225 ((struct bpf_insn) { \
226 .code = BPF_ST | BPF_SIZE(SIZE) | BPF_MEM, \
227 .dst_reg = DST, \
228 .src_reg = 0, \
229 .off = OFF, \
230 .imm = IMM })
231
232/* Conditional jumps against registers, if (dst_reg 'op' src_reg) goto pc + off16 */
233
234#define BPF_JMP_REG(OP, DST, SRC, OFF) \
235 ((struct bpf_insn) { \
236 .code = BPF_JMP | BPF_OP(OP) | BPF_X, \
237 .dst_reg = DST, \
238 .src_reg = SRC, \
239 .off = OFF, \
240 .imm = 0 })
241
242/* Conditional jumps against immediates, if (dst_reg 'op' imm32) goto pc + off16 */
243
244#define BPF_JMP_IMM(OP, DST, IMM, OFF) \
245 ((struct bpf_insn) { \
246 .code = BPF_JMP | BPF_OP(OP) | BPF_K, \
247 .dst_reg = DST, \
248 .src_reg = 0, \
249 .off = OFF, \
250 .imm = IMM })
251
252/* Function call */
253
254#define BPF_EMIT_CALL(FUNC) \
255 ((struct bpf_insn) { \
256 .code = BPF_JMP | BPF_CALL, \
257 .dst_reg = 0, \
258 .src_reg = 0, \
259 .off = 0, \
260 .imm = ((FUNC) - __bpf_call_base) })
261
262/* Raw code statement block */
263
264#define BPF_RAW_INSN(CODE, DST, SRC, OFF, IMM) \
265 ((struct bpf_insn) { \
266 .code = CODE, \
267 .dst_reg = DST, \
268 .src_reg = SRC, \
269 .off = OFF, \
270 .imm = IMM })
271
272/* Program exit */
273
274#define BPF_EXIT_INSN() \
275 ((struct bpf_insn) { \
276 .code = BPF_JMP | BPF_EXIT, \
277 .dst_reg = 0, \
278 .src_reg = 0, \
279 .off = 0, \
280 .imm = 0 })
281
282/* Internal classic blocks for direct assignment */
283
284#define __BPF_STMT(CODE, K) \
285 ((struct sock_filter) BPF_STMT(CODE, K))
286
287#define __BPF_JUMP(CODE, K, JT, JF) \
288 ((struct sock_filter) BPF_JUMP(CODE, K, JT, JF))
289
290#define bytes_to_bpf_size(bytes) \
291({ \
292 int bpf_size = -EINVAL; \
293 \
294 if (bytes == sizeof(u8)) \
295 bpf_size = BPF_B; \
296 else if (bytes == sizeof(u16)) \
297 bpf_size = BPF_H; \
298 else if (bytes == sizeof(u32)) \
299 bpf_size = BPF_W; \
300 else if (bytes == sizeof(u64)) \
301 bpf_size = BPF_DW; \
302 \
303 bpf_size; \
304})
305
306#ifdef CONFIG_COMPAT
307/* A struct sock_filter is architecture independent. */
308struct compat_sock_fprog {
309 u16 len;
310 compat_uptr_t filter; /* struct sock_filter * */
311};
312#endif
313
314struct sock_fprog_kern {
315 u16 len;
316 struct sock_filter *filter;
317};
318
319struct bpf_binary_header {
320 unsigned int pages;
321 u8 image[];
322};
323
324struct bpf_prog {
325 u16 pages; /* Number of allocated pages */
326 kmemcheck_bitfield_begin(meta);
327 u16 jited:1, /* Is our filter JIT'ed? */
328 gpl_compatible:1, /* Is filter GPL compatible? */
329 cb_access:1, /* Is control block accessed? */
330 dst_needed:1; /* Do we need dst entry? */
331 kmemcheck_bitfield_end(meta);
332 u32 len; /* Number of filter blocks */
333 enum bpf_prog_type type; /* Type of BPF program */
334 struct bpf_prog_aux *aux; /* Auxiliary fields */
335 struct sock_fprog_kern *orig_prog; /* Original BPF program */
336 unsigned int (*bpf_func)(const struct sk_buff *skb,
337 const struct bpf_insn *filter);
338 /* Instructions for interpreter */
339 union {
340 struct sock_filter insns[0];
341 struct bpf_insn insnsi[0];
342 };
343};
344
345struct sk_filter {
346 atomic_t refcnt;
347 struct rcu_head rcu;
348 struct bpf_prog *prog;
349};
350
351#define BPF_PROG_RUN(filter, ctx) (*filter->bpf_func)(ctx, filter->insnsi)
352
353static inline u32 bpf_prog_run_save_cb(const struct bpf_prog *prog,
354 struct sk_buff *skb)
355{
356 u8 *cb_data = qdisc_skb_cb(skb)->data;
357 u8 saved_cb[QDISC_CB_PRIV_LEN];
358 u32 res;
359
360 BUILD_BUG_ON(FIELD_SIZEOF(struct __sk_buff, cb) !=
361 QDISC_CB_PRIV_LEN);
362
363 if (unlikely(prog->cb_access)) {
364 memcpy(saved_cb, cb_data, sizeof(saved_cb));
365 memset(cb_data, 0, sizeof(saved_cb));
366 }
367
368 res = BPF_PROG_RUN(prog, skb);
369
370 if (unlikely(prog->cb_access))
371 memcpy(cb_data, saved_cb, sizeof(saved_cb));
372
373 return res;
374}
375
376static inline u32 bpf_prog_run_clear_cb(const struct bpf_prog *prog,
377 struct sk_buff *skb)
378{
379 u8 *cb_data = qdisc_skb_cb(skb)->data;
380
381 if (unlikely(prog->cb_access))
382 memset(cb_data, 0, QDISC_CB_PRIV_LEN);
383 return BPF_PROG_RUN(prog, skb);
384}
385
386static inline unsigned int bpf_prog_size(unsigned int proglen)
387{
388 return max(sizeof(struct bpf_prog),
389 offsetof(struct bpf_prog, insns[proglen]));
390}
391
392static inline bool bpf_prog_was_classic(const struct bpf_prog *prog)
393{
394 /* When classic BPF programs have been loaded and the arch
395 * does not have a classic BPF JIT (anymore), they have been
396 * converted via bpf_migrate_filter() to eBPF and thus always
397 * have an unspec program type.
398 */
399 return prog->type == BPF_PROG_TYPE_UNSPEC;
400}
401
402#define bpf_classic_proglen(fprog) (fprog->len * sizeof(fprog->filter[0]))
403
404#ifdef CONFIG_DEBUG_SET_MODULE_RONX
405static inline void bpf_prog_lock_ro(struct bpf_prog *fp)
406{
407 set_memory_ro((unsigned long)fp, fp->pages);
408}
409
410static inline void bpf_prog_unlock_ro(struct bpf_prog *fp)
411{
412 set_memory_rw((unsigned long)fp, fp->pages);
413}
414#else
415static inline void bpf_prog_lock_ro(struct bpf_prog *fp)
416{
417}
418
419static inline void bpf_prog_unlock_ro(struct bpf_prog *fp)
420{
421}
422#endif /* CONFIG_DEBUG_SET_MODULE_RONX */
423
424int sk_filter(struct sock *sk, struct sk_buff *skb);
425
426int bpf_prog_select_runtime(struct bpf_prog *fp);
427void bpf_prog_free(struct bpf_prog *fp);
428
429struct bpf_prog *bpf_prog_alloc(unsigned int size, gfp_t gfp_extra_flags);
430struct bpf_prog *bpf_prog_realloc(struct bpf_prog *fp_old, unsigned int size,
431 gfp_t gfp_extra_flags);
432void __bpf_prog_free(struct bpf_prog *fp);
433
434static inline void bpf_prog_unlock_free(struct bpf_prog *fp)
435{
436 bpf_prog_unlock_ro(fp);
437 __bpf_prog_free(fp);
438}
439
440typedef int (*bpf_aux_classic_check_t)(struct sock_filter *filter,
441 unsigned int flen);
442
443int bpf_prog_create(struct bpf_prog **pfp, struct sock_fprog_kern *fprog);
444int bpf_prog_create_from_user(struct bpf_prog **pfp, struct sock_fprog *fprog,
445 bpf_aux_classic_check_t trans, bool save_orig);
446void bpf_prog_destroy(struct bpf_prog *fp);
447
448int sk_attach_filter(struct sock_fprog *fprog, struct sock *sk);
449int sk_attach_bpf(u32 ufd, struct sock *sk);
450int sk_detach_filter(struct sock *sk);
451int sk_get_filter(struct sock *sk, struct sock_filter __user *filter,
452 unsigned int len);
453
454bool sk_filter_charge(struct sock *sk, struct sk_filter *fp);
455void sk_filter_uncharge(struct sock *sk, struct sk_filter *fp);
456
457u64 __bpf_call_base(u64 r1, u64 r2, u64 r3, u64 r4, u64 r5);
458void bpf_int_jit_compile(struct bpf_prog *fp);
459bool bpf_helper_changes_skb_data(void *func);
460
461#ifdef CONFIG_BPF_JIT
462typedef void (*bpf_jit_fill_hole_t)(void *area, unsigned int size);
463
464struct bpf_binary_header *
465bpf_jit_binary_alloc(unsigned int proglen, u8 **image_ptr,
466 unsigned int alignment,
467 bpf_jit_fill_hole_t bpf_fill_ill_insns);
468void bpf_jit_binary_free(struct bpf_binary_header *hdr);
469
470void bpf_jit_compile(struct bpf_prog *fp);
471void bpf_jit_free(struct bpf_prog *fp);
472
473static inline void bpf_jit_dump(unsigned int flen, unsigned int proglen,
474 u32 pass, void *image)
475{
476 pr_err("flen=%u proglen=%u pass=%u image=%pK from=%s pid=%d\n", flen,
477 proglen, pass, image, current->comm, task_pid_nr(current));
478
479 if (image)
480 print_hex_dump(KERN_ERR, "JIT code: ", DUMP_PREFIX_OFFSET,
481 16, 1, image, proglen, false);
482}
483#else
484static inline void bpf_jit_compile(struct bpf_prog *fp)
485{
486}
487
488static inline void bpf_jit_free(struct bpf_prog *fp)
489{
490 bpf_prog_unlock_free(fp);
491}
492#endif /* CONFIG_BPF_JIT */
493
494#define BPF_ANC BIT(15)
495
496static inline u16 bpf_anc_helper(const struct sock_filter *ftest)
497{
498 BUG_ON(ftest->code & BPF_ANC);
499
500 switch (ftest->code) {
501 case BPF_LD | BPF_W | BPF_ABS:
502 case BPF_LD | BPF_H | BPF_ABS:
503 case BPF_LD | BPF_B | BPF_ABS:
504#define BPF_ANCILLARY(CODE) case SKF_AD_OFF + SKF_AD_##CODE: \
505 return BPF_ANC | SKF_AD_##CODE
506 switch (ftest->k) {
507 BPF_ANCILLARY(PROTOCOL);
508 BPF_ANCILLARY(PKTTYPE);
509 BPF_ANCILLARY(IFINDEX);
510 BPF_ANCILLARY(NLATTR);
511 BPF_ANCILLARY(NLATTR_NEST);
512 BPF_ANCILLARY(MARK);
513 BPF_ANCILLARY(QUEUE);
514 BPF_ANCILLARY(HATYPE);
515 BPF_ANCILLARY(RXHASH);
516 BPF_ANCILLARY(CPU);
517 BPF_ANCILLARY(ALU_XOR_X);
518 BPF_ANCILLARY(VLAN_TAG);
519 BPF_ANCILLARY(VLAN_TAG_PRESENT);
520 BPF_ANCILLARY(PAY_OFFSET);
521 BPF_ANCILLARY(RANDOM);
522 BPF_ANCILLARY(VLAN_TPID);
523 }
524 /* Fallthrough. */
525 default:
526 return ftest->code;
527 }
528}
529
530void *bpf_internal_load_pointer_neg_helper(const struct sk_buff *skb,
531 int k, unsigned int size);
532
533static inline void *bpf_load_pointer(const struct sk_buff *skb, int k,
534 unsigned int size, void *buffer)
535{
536 if (k >= 0)
537 return skb_header_pointer(skb, k, size, buffer);
538
539 return bpf_internal_load_pointer_neg_helper(skb, k, size);
540}
541
542static inline int bpf_tell_extensions(void)
543{
544 return SKF_AD_MAX;
545}
546
547#endif /* __LINUX_FILTER_H__ */