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TOMOYO Linux Cross Reference
Linux/include/linux/filter.h

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  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 <linux/capability.h>
 17 #include <linux/cryptohash.h>
 18 
 19 #include <net/sch_generic.h>
 20 
 21 #include <asm/cacheflush.h>
 22 
 23 #include <uapi/linux/filter.h>
 24 #include <uapi/linux/bpf.h>
 25 
 26 struct sk_buff;
 27 struct sock;
 28 struct seccomp_data;
 29 struct bpf_prog_aux;
 30 
 31 /* ArgX, context and stack frame pointer register positions. Note,
 32  * Arg1, Arg2, Arg3, etc are used as argument mappings of function
 33  * calls in BPF_CALL instruction.
 34  */
 35 #define BPF_REG_ARG1    BPF_REG_1
 36 #define BPF_REG_ARG2    BPF_REG_2
 37 #define BPF_REG_ARG3    BPF_REG_3
 38 #define BPF_REG_ARG4    BPF_REG_4
 39 #define BPF_REG_ARG5    BPF_REG_5
 40 #define BPF_REG_CTX     BPF_REG_6
 41 #define BPF_REG_FP      BPF_REG_10
 42 
 43 /* Additional register mappings for converted user programs. */
 44 #define BPF_REG_A       BPF_REG_0
 45 #define BPF_REG_X       BPF_REG_7
 46 #define BPF_REG_TMP     BPF_REG_8
 47 
 48 /* Kernel hidden auxiliary/helper register for hardening step.
 49  * Only used by eBPF JITs. It's nothing more than a temporary
 50  * register that JITs use internally, only that here it's part
 51  * of eBPF instructions that have been rewritten for blinding
 52  * constants. See JIT pre-step in bpf_jit_blind_constants().
 53  */
 54 #define BPF_REG_AX              MAX_BPF_REG
 55 #define MAX_BPF_JIT_REG         (MAX_BPF_REG + 1)
 56 
 57 /* As per nm, we expose JITed images as text (code) section for
 58  * kallsyms. That way, tools like perf can find it to match
 59  * addresses.
 60  */
 61 #define BPF_SYM_ELF_TYPE        't'
 62 
 63 /* BPF program can access up to 512 bytes of stack space. */
 64 #define MAX_BPF_STACK   512
 65 
 66 #define BPF_TAG_SIZE    8
 67 
 68 /* Helper macros for filter block array initializers. */
 69 
 70 /* ALU ops on registers, bpf_add|sub|...: dst_reg += src_reg */
 71 
 72 #define BPF_ALU64_REG(OP, DST, SRC)                             \
 73         ((struct bpf_insn) {                                    \
 74                 .code  = BPF_ALU64 | BPF_OP(OP) | BPF_X,        \
 75                 .dst_reg = DST,                                 \
 76                 .src_reg = SRC,                                 \
 77                 .off   = 0,                                     \
 78                 .imm   = 0 })
 79 
 80 #define BPF_ALU32_REG(OP, DST, SRC)                             \
 81         ((struct bpf_insn) {                                    \
 82                 .code  = BPF_ALU | BPF_OP(OP) | BPF_X,          \
 83                 .dst_reg = DST,                                 \
 84                 .src_reg = SRC,                                 \
 85                 .off   = 0,                                     \
 86                 .imm   = 0 })
 87 
 88 /* ALU ops on immediates, bpf_add|sub|...: dst_reg += imm32 */
 89 
 90 #define BPF_ALU64_IMM(OP, DST, IMM)                             \
 91         ((struct bpf_insn) {                                    \
 92                 .code  = BPF_ALU64 | BPF_OP(OP) | BPF_K,        \
 93                 .dst_reg = DST,                                 \
 94                 .src_reg = 0,                                   \
 95                 .off   = 0,                                     \
 96                 .imm   = IMM })
 97 
 98 #define BPF_ALU32_IMM(OP, DST, IMM)                             \
 99         ((struct bpf_insn) {                                    \
100                 .code  = BPF_ALU | BPF_OP(OP) | BPF_K,          \
101                 .dst_reg = DST,                                 \
102                 .src_reg = 0,                                   \
103                 .off   = 0,                                     \
104                 .imm   = IMM })
105 
106 /* Endianess conversion, cpu_to_{l,b}e(), {l,b}e_to_cpu() */
107 
108 #define BPF_ENDIAN(TYPE, DST, LEN)                              \
109         ((struct bpf_insn) {                                    \
110                 .code  = BPF_ALU | BPF_END | BPF_SRC(TYPE),     \
111                 .dst_reg = DST,                                 \
112                 .src_reg = 0,                                   \
113                 .off   = 0,                                     \
114                 .imm   = LEN })
115 
116 /* Short form of mov, dst_reg = src_reg */
117 
118 #define BPF_MOV64_REG(DST, SRC)                                 \
119         ((struct bpf_insn) {                                    \
120                 .code  = BPF_ALU64 | BPF_MOV | BPF_X,           \
121                 .dst_reg = DST,                                 \
122                 .src_reg = SRC,                                 \
123                 .off   = 0,                                     \
124                 .imm   = 0 })
125 
126 #define BPF_MOV32_REG(DST, SRC)                                 \
127         ((struct bpf_insn) {                                    \
128                 .code  = BPF_ALU | BPF_MOV | BPF_X,             \
129                 .dst_reg = DST,                                 \
130                 .src_reg = SRC,                                 \
131                 .off   = 0,                                     \
132                 .imm   = 0 })
133 
134 /* Short form of mov, dst_reg = imm32 */
135 
136 #define BPF_MOV64_IMM(DST, IMM)                                 \
137         ((struct bpf_insn) {                                    \
138                 .code  = BPF_ALU64 | BPF_MOV | BPF_K,           \
139                 .dst_reg = DST,                                 \
140                 .src_reg = 0,                                   \
141                 .off   = 0,                                     \
142                 .imm   = IMM })
143 
144 #define BPF_MOV32_IMM(DST, IMM)                                 \
145         ((struct bpf_insn) {                                    \
146                 .code  = BPF_ALU | BPF_MOV | BPF_K,             \
147                 .dst_reg = DST,                                 \
148                 .src_reg = 0,                                   \
149                 .off   = 0,                                     \
150                 .imm   = IMM })
151 
152 /* BPF_LD_IMM64 macro encodes single 'load 64-bit immediate' insn */
153 #define BPF_LD_IMM64(DST, IMM)                                  \
154         BPF_LD_IMM64_RAW(DST, 0, IMM)
155 
156 #define BPF_LD_IMM64_RAW(DST, SRC, IMM)                         \
157         ((struct bpf_insn) {                                    \
158                 .code  = BPF_LD | BPF_DW | BPF_IMM,             \
159                 .dst_reg = DST,                                 \
160                 .src_reg = SRC,                                 \
161                 .off   = 0,                                     \
162                 .imm   = (__u32) (IMM) }),                      \
163         ((struct bpf_insn) {                                    \
164                 .code  = 0, /* zero is reserved opcode */       \
165                 .dst_reg = 0,                                   \
166                 .src_reg = 0,                                   \
167                 .off   = 0,                                     \
168                 .imm   = ((__u64) (IMM)) >> 32 })
169 
170 /* pseudo BPF_LD_IMM64 insn used to refer to process-local map_fd */
171 #define BPF_LD_MAP_FD(DST, MAP_FD)                              \
172         BPF_LD_IMM64_RAW(DST, BPF_PSEUDO_MAP_FD, MAP_FD)
173 
174 /* Short form of mov based on type, BPF_X: dst_reg = src_reg, BPF_K: dst_reg = imm32 */
175 
176 #define BPF_MOV64_RAW(TYPE, DST, SRC, IMM)                      \
177         ((struct bpf_insn) {                                    \
178                 .code  = BPF_ALU64 | BPF_MOV | BPF_SRC(TYPE),   \
179                 .dst_reg = DST,                                 \
180                 .src_reg = SRC,                                 \
181                 .off   = 0,                                     \
182                 .imm   = IMM })
183 
184 #define BPF_MOV32_RAW(TYPE, DST, SRC, IMM)                      \
185         ((struct bpf_insn) {                                    \
186                 .code  = BPF_ALU | BPF_MOV | BPF_SRC(TYPE),     \
187                 .dst_reg = DST,                                 \
188                 .src_reg = SRC,                                 \
189                 .off   = 0,                                     \
190                 .imm   = IMM })
191 
192 /* Direct packet access, R0 = *(uint *) (skb->data + imm32) */
193 
194 #define BPF_LD_ABS(SIZE, IMM)                                   \
195         ((struct bpf_insn) {                                    \
196                 .code  = BPF_LD | BPF_SIZE(SIZE) | BPF_ABS,     \
197                 .dst_reg = 0,                                   \
198                 .src_reg = 0,                                   \
199                 .off   = 0,                                     \
200                 .imm   = IMM })
201 
202 /* Indirect packet access, R0 = *(uint *) (skb->data + src_reg + imm32) */
203 
204 #define BPF_LD_IND(SIZE, SRC, IMM)                              \
205         ((struct bpf_insn) {                                    \
206                 .code  = BPF_LD | BPF_SIZE(SIZE) | BPF_IND,     \
207                 .dst_reg = 0,                                   \
208                 .src_reg = SRC,                                 \
209                 .off   = 0,                                     \
210                 .imm   = IMM })
211 
212 /* Memory load, dst_reg = *(uint *) (src_reg + off16) */
213 
214 #define BPF_LDX_MEM(SIZE, DST, SRC, OFF)                        \
215         ((struct bpf_insn) {                                    \
216                 .code  = BPF_LDX | BPF_SIZE(SIZE) | BPF_MEM,    \
217                 .dst_reg = DST,                                 \
218                 .src_reg = SRC,                                 \
219                 .off   = OFF,                                   \
220                 .imm   = 0 })
221 
222 /* Memory store, *(uint *) (dst_reg + off16) = src_reg */
223 
224 #define BPF_STX_MEM(SIZE, DST, SRC, OFF)                        \
225         ((struct bpf_insn) {                                    \
226                 .code  = BPF_STX | BPF_SIZE(SIZE) | BPF_MEM,    \
227                 .dst_reg = DST,                                 \
228                 .src_reg = SRC,                                 \
229                 .off   = OFF,                                   \
230                 .imm   = 0 })
231 
232 /* Atomic memory add, *(uint *)(dst_reg + off16) += src_reg */
233 
234 #define BPF_STX_XADD(SIZE, DST, SRC, OFF)                       \
235         ((struct bpf_insn) {                                    \
236                 .code  = BPF_STX | BPF_SIZE(SIZE) | BPF_XADD,   \
237                 .dst_reg = DST,                                 \
238                 .src_reg = SRC,                                 \
239                 .off   = OFF,                                   \
240                 .imm   = 0 })
241 
242 /* Memory store, *(uint *) (dst_reg + off16) = imm32 */
243 
244 #define BPF_ST_MEM(SIZE, DST, OFF, IMM)                         \
245         ((struct bpf_insn) {                                    \
246                 .code  = BPF_ST | BPF_SIZE(SIZE) | BPF_MEM,     \
247                 .dst_reg = DST,                                 \
248                 .src_reg = 0,                                   \
249                 .off   = OFF,                                   \
250                 .imm   = IMM })
251 
252 /* Conditional jumps against registers, if (dst_reg 'op' src_reg) goto pc + off16 */
253 
254 #define BPF_JMP_REG(OP, DST, SRC, OFF)                          \
255         ((struct bpf_insn) {                                    \
256                 .code  = BPF_JMP | BPF_OP(OP) | BPF_X,          \
257                 .dst_reg = DST,                                 \
258                 .src_reg = SRC,                                 \
259                 .off   = OFF,                                   \
260                 .imm   = 0 })
261 
262 /* Conditional jumps against immediates, if (dst_reg 'op' imm32) goto pc + off16 */
263 
264 #define BPF_JMP_IMM(OP, DST, IMM, OFF)                          \
265         ((struct bpf_insn) {                                    \
266                 .code  = BPF_JMP | BPF_OP(OP) | BPF_K,          \
267                 .dst_reg = DST,                                 \
268                 .src_reg = 0,                                   \
269                 .off   = OFF,                                   \
270                 .imm   = IMM })
271 
272 /* Function call */
273 
274 #define BPF_EMIT_CALL(FUNC)                                     \
275         ((struct bpf_insn) {                                    \
276                 .code  = BPF_JMP | BPF_CALL,                    \
277                 .dst_reg = 0,                                   \
278                 .src_reg = 0,                                   \
279                 .off   = 0,                                     \
280                 .imm   = ((FUNC) - __bpf_call_base) })
281 
282 /* Raw code statement block */
283 
284 #define BPF_RAW_INSN(CODE, DST, SRC, OFF, IMM)                  \
285         ((struct bpf_insn) {                                    \
286                 .code  = CODE,                                  \
287                 .dst_reg = DST,                                 \
288                 .src_reg = SRC,                                 \
289                 .off   = OFF,                                   \
290                 .imm   = IMM })
291 
292 /* Program exit */
293 
294 #define BPF_EXIT_INSN()                                         \
295         ((struct bpf_insn) {                                    \
296                 .code  = BPF_JMP | BPF_EXIT,                    \
297                 .dst_reg = 0,                                   \
298                 .src_reg = 0,                                   \
299                 .off   = 0,                                     \
300                 .imm   = 0 })
301 
302 /* Internal classic blocks for direct assignment */
303 
304 #define __BPF_STMT(CODE, K)                                     \
305         ((struct sock_filter) BPF_STMT(CODE, K))
306 
307 #define __BPF_JUMP(CODE, K, JT, JF)                             \
308         ((struct sock_filter) BPF_JUMP(CODE, K, JT, JF))
309 
310 #define bytes_to_bpf_size(bytes)                                \
311 ({                                                              \
312         int bpf_size = -EINVAL;                                 \
313                                                                 \
314         if (bytes == sizeof(u8))                                \
315                 bpf_size = BPF_B;                               \
316         else if (bytes == sizeof(u16))                          \
317                 bpf_size = BPF_H;                               \
318         else if (bytes == sizeof(u32))                          \
319                 bpf_size = BPF_W;                               \
320         else if (bytes == sizeof(u64))                          \
321                 bpf_size = BPF_DW;                              \
322                                                                 \
323         bpf_size;                                               \
324 })
325 
326 #define BPF_SIZEOF(type)                                        \
327         ({                                                      \
328                 const int __size = bytes_to_bpf_size(sizeof(type)); \
329                 BUILD_BUG_ON(__size < 0);                       \
330                 __size;                                         \
331         })
332 
333 #define BPF_FIELD_SIZEOF(type, field)                           \
334         ({                                                      \
335                 const int __size = bytes_to_bpf_size(FIELD_SIZEOF(type, field)); \
336                 BUILD_BUG_ON(__size < 0);                       \
337                 __size;                                         \
338         })
339 
340 #define __BPF_MAP_0(m, v, ...) v
341 #define __BPF_MAP_1(m, v, t, a, ...) m(t, a)
342 #define __BPF_MAP_2(m, v, t, a, ...) m(t, a), __BPF_MAP_1(m, v, __VA_ARGS__)
343 #define __BPF_MAP_3(m, v, t, a, ...) m(t, a), __BPF_MAP_2(m, v, __VA_ARGS__)
344 #define __BPF_MAP_4(m, v, t, a, ...) m(t, a), __BPF_MAP_3(m, v, __VA_ARGS__)
345 #define __BPF_MAP_5(m, v, t, a, ...) m(t, a), __BPF_MAP_4(m, v, __VA_ARGS__)
346 
347 #define __BPF_REG_0(...) __BPF_PAD(5)
348 #define __BPF_REG_1(...) __BPF_MAP(1, __VA_ARGS__), __BPF_PAD(4)
349 #define __BPF_REG_2(...) __BPF_MAP(2, __VA_ARGS__), __BPF_PAD(3)
350 #define __BPF_REG_3(...) __BPF_MAP(3, __VA_ARGS__), __BPF_PAD(2)
351 #define __BPF_REG_4(...) __BPF_MAP(4, __VA_ARGS__), __BPF_PAD(1)
352 #define __BPF_REG_5(...) __BPF_MAP(5, __VA_ARGS__)
353 
354 #define __BPF_MAP(n, ...) __BPF_MAP_##n(__VA_ARGS__)
355 #define __BPF_REG(n, ...) __BPF_REG_##n(__VA_ARGS__)
356 
357 #define __BPF_CAST(t, a)                                                       \
358         (__force t)                                                            \
359         (__force                                                               \
360          typeof(__builtin_choose_expr(sizeof(t) == sizeof(unsigned long),      \
361                                       (unsigned long)0, (t)0))) a
362 #define __BPF_V void
363 #define __BPF_N
364 
365 #define __BPF_DECL_ARGS(t, a) t   a
366 #define __BPF_DECL_REGS(t, a) u64 a
367 
368 #define __BPF_PAD(n)                                                           \
369         __BPF_MAP(n, __BPF_DECL_ARGS, __BPF_N, u64, __ur_1, u64, __ur_2,       \
370                   u64, __ur_3, u64, __ur_4, u64, __ur_5)
371 
372 #define BPF_CALL_x(x, name, ...)                                               \
373         static __always_inline                                                 \
374         u64 ____##name(__BPF_MAP(x, __BPF_DECL_ARGS, __BPF_V, __VA_ARGS__));   \
375         u64 name(__BPF_REG(x, __BPF_DECL_REGS, __BPF_N, __VA_ARGS__));         \
376         u64 name(__BPF_REG(x, __BPF_DECL_REGS, __BPF_N, __VA_ARGS__))          \
377         {                                                                      \
378                 return ____##name(__BPF_MAP(x,__BPF_CAST,__BPF_N,__VA_ARGS__));\
379         }                                                                      \
380         static __always_inline                                                 \
381         u64 ____##name(__BPF_MAP(x, __BPF_DECL_ARGS, __BPF_V, __VA_ARGS__))
382 
383 #define BPF_CALL_0(name, ...)   BPF_CALL_x(0, name, __VA_ARGS__)
384 #define BPF_CALL_1(name, ...)   BPF_CALL_x(1, name, __VA_ARGS__)
385 #define BPF_CALL_2(name, ...)   BPF_CALL_x(2, name, __VA_ARGS__)
386 #define BPF_CALL_3(name, ...)   BPF_CALL_x(3, name, __VA_ARGS__)
387 #define BPF_CALL_4(name, ...)   BPF_CALL_x(4, name, __VA_ARGS__)
388 #define BPF_CALL_5(name, ...)   BPF_CALL_x(5, name, __VA_ARGS__)
389 
390 #ifdef CONFIG_COMPAT
391 /* A struct sock_filter is architecture independent. */
392 struct compat_sock_fprog {
393         u16             len;
394         compat_uptr_t   filter; /* struct sock_filter * */
395 };
396 #endif
397 
398 struct sock_fprog_kern {
399         u16                     len;
400         struct sock_filter      *filter;
401 };
402 
403 struct bpf_binary_header {
404         unsigned int pages;
405         u8 image[];
406 };
407 
408 struct bpf_prog {
409         u16                     pages;          /* Number of allocated pages */
410         kmemcheck_bitfield_begin(meta);
411         u16                     jited:1,        /* Is our filter JIT'ed? */
412                                 locked:1,       /* Program image locked? */
413                                 gpl_compatible:1, /* Is filter GPL compatible? */
414                                 cb_access:1,    /* Is control block accessed? */
415                                 dst_needed:1,   /* Do we need dst entry? */
416                                 xdp_adjust_head:1; /* Adjusting pkt head? */
417         kmemcheck_bitfield_end(meta);
418         enum bpf_prog_type      type;           /* Type of BPF program */
419         u32                     len;            /* Number of filter blocks */
420         u8                      tag[BPF_TAG_SIZE];
421         struct bpf_prog_aux     *aux;           /* Auxiliary fields */
422         struct sock_fprog_kern  *orig_prog;     /* Original BPF program */
423         unsigned int            (*bpf_func)(const void *ctx,
424                                             const struct bpf_insn *insn);
425         /* Instructions for interpreter */
426         union {
427                 struct sock_filter      insns[0];
428                 struct bpf_insn         insnsi[0];
429         };
430 };
431 
432 struct sk_filter {
433         atomic_t        refcnt;
434         struct rcu_head rcu;
435         struct bpf_prog *prog;
436 };
437 
438 #define BPF_PROG_RUN(filter, ctx)  (*filter->bpf_func)(ctx, filter->insnsi)
439 
440 #define BPF_SKB_CB_LEN QDISC_CB_PRIV_LEN
441 
442 struct bpf_skb_data_end {
443         struct qdisc_skb_cb qdisc_cb;
444         void *data_end;
445 };
446 
447 struct xdp_buff {
448         void *data;
449         void *data_end;
450         void *data_hard_start;
451 };
452 
453 /* compute the linear packet data range [data, data_end) which
454  * will be accessed by cls_bpf, act_bpf and lwt programs
455  */
456 static inline void bpf_compute_data_end(struct sk_buff *skb)
457 {
458         struct bpf_skb_data_end *cb = (struct bpf_skb_data_end *)skb->cb;
459 
460         BUILD_BUG_ON(sizeof(*cb) > FIELD_SIZEOF(struct sk_buff, cb));
461         cb->data_end = skb->data + skb_headlen(skb);
462 }
463 
464 static inline u8 *bpf_skb_cb(struct sk_buff *skb)
465 {
466         /* eBPF programs may read/write skb->cb[] area to transfer meta
467          * data between tail calls. Since this also needs to work with
468          * tc, that scratch memory is mapped to qdisc_skb_cb's data area.
469          *
470          * In some socket filter cases, the cb unfortunately needs to be
471          * saved/restored so that protocol specific skb->cb[] data won't
472          * be lost. In any case, due to unpriviledged eBPF programs
473          * attached to sockets, we need to clear the bpf_skb_cb() area
474          * to not leak previous contents to user space.
475          */
476         BUILD_BUG_ON(FIELD_SIZEOF(struct __sk_buff, cb) != BPF_SKB_CB_LEN);
477         BUILD_BUG_ON(FIELD_SIZEOF(struct __sk_buff, cb) !=
478                      FIELD_SIZEOF(struct qdisc_skb_cb, data));
479 
480         return qdisc_skb_cb(skb)->data;
481 }
482 
483 static inline u32 bpf_prog_run_save_cb(const struct bpf_prog *prog,
484                                        struct sk_buff *skb)
485 {
486         u8 *cb_data = bpf_skb_cb(skb);
487         u8 cb_saved[BPF_SKB_CB_LEN];
488         u32 res;
489 
490         if (unlikely(prog->cb_access)) {
491                 memcpy(cb_saved, cb_data, sizeof(cb_saved));
492                 memset(cb_data, 0, sizeof(cb_saved));
493         }
494 
495         res = BPF_PROG_RUN(prog, skb);
496 
497         if (unlikely(prog->cb_access))
498                 memcpy(cb_data, cb_saved, sizeof(cb_saved));
499 
500         return res;
501 }
502 
503 static inline u32 bpf_prog_run_clear_cb(const struct bpf_prog *prog,
504                                         struct sk_buff *skb)
505 {
506         u8 *cb_data = bpf_skb_cb(skb);
507 
508         if (unlikely(prog->cb_access))
509                 memset(cb_data, 0, BPF_SKB_CB_LEN);
510 
511         return BPF_PROG_RUN(prog, skb);
512 }
513 
514 static __always_inline u32 bpf_prog_run_xdp(const struct bpf_prog *prog,
515                                             struct xdp_buff *xdp)
516 {
517         /* Caller needs to hold rcu_read_lock() (!), otherwise program
518          * can be released while still running, or map elements could be
519          * freed early while still having concurrent users. XDP fastpath
520          * already takes rcu_read_lock() when fetching the program, so
521          * it's not necessary here anymore.
522          */
523         return BPF_PROG_RUN(prog, xdp);
524 }
525 
526 static inline u32 bpf_prog_insn_size(const struct bpf_prog *prog)
527 {
528         return prog->len * sizeof(struct bpf_insn);
529 }
530 
531 static inline u32 bpf_prog_tag_scratch_size(const struct bpf_prog *prog)
532 {
533         return round_up(bpf_prog_insn_size(prog) +
534                         sizeof(__be64) + 1, SHA_MESSAGE_BYTES);
535 }
536 
537 static inline unsigned int bpf_prog_size(unsigned int proglen)
538 {
539         return max(sizeof(struct bpf_prog),
540                    offsetof(struct bpf_prog, insns[proglen]));
541 }
542 
543 static inline bool bpf_prog_was_classic(const struct bpf_prog *prog)
544 {
545         /* When classic BPF programs have been loaded and the arch
546          * does not have a classic BPF JIT (anymore), they have been
547          * converted via bpf_migrate_filter() to eBPF and thus always
548          * have an unspec program type.
549          */
550         return prog->type == BPF_PROG_TYPE_UNSPEC;
551 }
552 
553 #define bpf_classic_proglen(fprog) (fprog->len * sizeof(fprog->filter[0]))
554 
555 #ifdef CONFIG_ARCH_HAS_SET_MEMORY
556 static inline void bpf_prog_lock_ro(struct bpf_prog *fp)
557 {
558         fp->locked = 1;
559         WARN_ON_ONCE(set_memory_ro((unsigned long)fp, fp->pages));
560 }
561 
562 static inline void bpf_prog_unlock_ro(struct bpf_prog *fp)
563 {
564         if (fp->locked) {
565                 WARN_ON_ONCE(set_memory_rw((unsigned long)fp, fp->pages));
566                 /* In case set_memory_rw() fails, we want to be the first
567                  * to crash here instead of some random place later on.
568                  */
569                 fp->locked = 0;
570         }
571 }
572 
573 static inline void bpf_jit_binary_lock_ro(struct bpf_binary_header *hdr)
574 {
575         WARN_ON_ONCE(set_memory_ro((unsigned long)hdr, hdr->pages));
576 }
577 
578 static inline void bpf_jit_binary_unlock_ro(struct bpf_binary_header *hdr)
579 {
580         WARN_ON_ONCE(set_memory_rw((unsigned long)hdr, hdr->pages));
581 }
582 #else
583 static inline void bpf_prog_lock_ro(struct bpf_prog *fp)
584 {
585 }
586 
587 static inline void bpf_prog_unlock_ro(struct bpf_prog *fp)
588 {
589 }
590 
591 static inline void bpf_jit_binary_lock_ro(struct bpf_binary_header *hdr)
592 {
593 }
594 
595 static inline void bpf_jit_binary_unlock_ro(struct bpf_binary_header *hdr)
596 {
597 }
598 #endif /* CONFIG_ARCH_HAS_SET_MEMORY */
599 
600 static inline struct bpf_binary_header *
601 bpf_jit_binary_hdr(const struct bpf_prog *fp)
602 {
603         unsigned long real_start = (unsigned long)fp->bpf_func;
604         unsigned long addr = real_start & PAGE_MASK;
605 
606         return (void *)addr;
607 }
608 
609 int sk_filter_trim_cap(struct sock *sk, struct sk_buff *skb, unsigned int cap);
610 static inline int sk_filter(struct sock *sk, struct sk_buff *skb)
611 {
612         return sk_filter_trim_cap(sk, skb, 1);
613 }
614 
615 struct bpf_prog *bpf_prog_select_runtime(struct bpf_prog *fp, int *err);
616 void bpf_prog_free(struct bpf_prog *fp);
617 
618 struct bpf_prog *bpf_prog_alloc(unsigned int size, gfp_t gfp_extra_flags);
619 struct bpf_prog *bpf_prog_realloc(struct bpf_prog *fp_old, unsigned int size,
620                                   gfp_t gfp_extra_flags);
621 void __bpf_prog_free(struct bpf_prog *fp);
622 
623 static inline void bpf_prog_unlock_free(struct bpf_prog *fp)
624 {
625         bpf_prog_unlock_ro(fp);
626         __bpf_prog_free(fp);
627 }
628 
629 typedef int (*bpf_aux_classic_check_t)(struct sock_filter *filter,
630                                        unsigned int flen);
631 
632 int bpf_prog_create(struct bpf_prog **pfp, struct sock_fprog_kern *fprog);
633 int bpf_prog_create_from_user(struct bpf_prog **pfp, struct sock_fprog *fprog,
634                               bpf_aux_classic_check_t trans, bool save_orig);
635 void bpf_prog_destroy(struct bpf_prog *fp);
636 
637 int sk_attach_filter(struct sock_fprog *fprog, struct sock *sk);
638 int sk_attach_bpf(u32 ufd, struct sock *sk);
639 int sk_reuseport_attach_filter(struct sock_fprog *fprog, struct sock *sk);
640 int sk_reuseport_attach_bpf(u32 ufd, struct sock *sk);
641 int sk_detach_filter(struct sock *sk);
642 int sk_get_filter(struct sock *sk, struct sock_filter __user *filter,
643                   unsigned int len);
644 
645 bool sk_filter_charge(struct sock *sk, struct sk_filter *fp);
646 void sk_filter_uncharge(struct sock *sk, struct sk_filter *fp);
647 
648 u64 __bpf_call_base(u64 r1, u64 r2, u64 r3, u64 r4, u64 r5);
649 
650 struct bpf_prog *bpf_int_jit_compile(struct bpf_prog *prog);
651 void bpf_jit_compile(struct bpf_prog *prog);
652 bool bpf_helper_changes_pkt_data(void *func);
653 
654 struct bpf_prog *bpf_patch_insn_single(struct bpf_prog *prog, u32 off,
655                                        const struct bpf_insn *patch, u32 len);
656 void bpf_warn_invalid_xdp_action(u32 act);
657 
658 #ifdef CONFIG_BPF_JIT
659 extern int bpf_jit_enable;
660 extern int bpf_jit_harden;
661 extern int bpf_jit_kallsyms;
662 
663 typedef void (*bpf_jit_fill_hole_t)(void *area, unsigned int size);
664 
665 struct bpf_binary_header *
666 bpf_jit_binary_alloc(unsigned int proglen, u8 **image_ptr,
667                      unsigned int alignment,
668                      bpf_jit_fill_hole_t bpf_fill_ill_insns);
669 void bpf_jit_binary_free(struct bpf_binary_header *hdr);
670 
671 void bpf_jit_free(struct bpf_prog *fp);
672 
673 struct bpf_prog *bpf_jit_blind_constants(struct bpf_prog *fp);
674 void bpf_jit_prog_release_other(struct bpf_prog *fp, struct bpf_prog *fp_other);
675 
676 static inline void bpf_jit_dump(unsigned int flen, unsigned int proglen,
677                                 u32 pass, void *image)
678 {
679         pr_err("flen=%u proglen=%u pass=%u image=%pK from=%s pid=%d\n", flen,
680                proglen, pass, image, current->comm, task_pid_nr(current));
681 
682         if (image)
683                 print_hex_dump(KERN_ERR, "JIT code: ", DUMP_PREFIX_OFFSET,
684                                16, 1, image, proglen, false);
685 }
686 
687 static inline bool bpf_jit_is_ebpf(void)
688 {
689 # ifdef CONFIG_HAVE_EBPF_JIT
690         return true;
691 # else
692         return false;
693 # endif
694 }
695 
696 static inline bool bpf_prog_ebpf_jited(const struct bpf_prog *fp)
697 {
698         return fp->jited && bpf_jit_is_ebpf();
699 }
700 
701 static inline bool bpf_jit_blinding_enabled(void)
702 {
703         /* These are the prerequisites, should someone ever have the
704          * idea to call blinding outside of them, we make sure to
705          * bail out.
706          */
707         if (!bpf_jit_is_ebpf())
708                 return false;
709         if (!bpf_jit_enable)
710                 return false;
711         if (!bpf_jit_harden)
712                 return false;
713         if (bpf_jit_harden == 1 && capable(CAP_SYS_ADMIN))
714                 return false;
715 
716         return true;
717 }
718 
719 static inline bool bpf_jit_kallsyms_enabled(void)
720 {
721         /* There are a couple of corner cases where kallsyms should
722          * not be enabled f.e. on hardening.
723          */
724         if (bpf_jit_harden)
725                 return false;
726         if (!bpf_jit_kallsyms)
727                 return false;
728         if (bpf_jit_kallsyms == 1)
729                 return true;
730 
731         return false;
732 }
733 
734 const char *__bpf_address_lookup(unsigned long addr, unsigned long *size,
735                                  unsigned long *off, char *sym);
736 bool is_bpf_text_address(unsigned long addr);
737 int bpf_get_kallsym(unsigned int symnum, unsigned long *value, char *type,
738                     char *sym);
739 
740 static inline const char *
741 bpf_address_lookup(unsigned long addr, unsigned long *size,
742                    unsigned long *off, char **modname, char *sym)
743 {
744         const char *ret = __bpf_address_lookup(addr, size, off, sym);
745 
746         if (ret && modname)
747                 *modname = NULL;
748         return ret;
749 }
750 
751 void bpf_prog_kallsyms_add(struct bpf_prog *fp);
752 void bpf_prog_kallsyms_del(struct bpf_prog *fp);
753 
754 #else /* CONFIG_BPF_JIT */
755 
756 static inline bool bpf_prog_ebpf_jited(const struct bpf_prog *fp)
757 {
758         return false;
759 }
760 
761 static inline void bpf_jit_free(struct bpf_prog *fp)
762 {
763         bpf_prog_unlock_free(fp);
764 }
765 
766 static inline bool bpf_jit_kallsyms_enabled(void)
767 {
768         return false;
769 }
770 
771 static inline const char *
772 __bpf_address_lookup(unsigned long addr, unsigned long *size,
773                      unsigned long *off, char *sym)
774 {
775         return NULL;
776 }
777 
778 static inline bool is_bpf_text_address(unsigned long addr)
779 {
780         return false;
781 }
782 
783 static inline int bpf_get_kallsym(unsigned int symnum, unsigned long *value,
784                                   char *type, char *sym)
785 {
786         return -ERANGE;
787 }
788 
789 static inline const char *
790 bpf_address_lookup(unsigned long addr, unsigned long *size,
791                    unsigned long *off, char **modname, char *sym)
792 {
793         return NULL;
794 }
795 
796 static inline void bpf_prog_kallsyms_add(struct bpf_prog *fp)
797 {
798 }
799 
800 static inline void bpf_prog_kallsyms_del(struct bpf_prog *fp)
801 {
802 }
803 #endif /* CONFIG_BPF_JIT */
804 
805 #define BPF_ANC         BIT(15)
806 
807 static inline bool bpf_needs_clear_a(const struct sock_filter *first)
808 {
809         switch (first->code) {
810         case BPF_RET | BPF_K:
811         case BPF_LD | BPF_W | BPF_LEN:
812                 return false;
813 
814         case BPF_LD | BPF_W | BPF_ABS:
815         case BPF_LD | BPF_H | BPF_ABS:
816         case BPF_LD | BPF_B | BPF_ABS:
817                 if (first->k == SKF_AD_OFF + SKF_AD_ALU_XOR_X)
818                         return true;
819                 return false;
820 
821         default:
822                 return true;
823         }
824 }
825 
826 static inline u16 bpf_anc_helper(const struct sock_filter *ftest)
827 {
828         BUG_ON(ftest->code & BPF_ANC);
829 
830         switch (ftest->code) {
831         case BPF_LD | BPF_W | BPF_ABS:
832         case BPF_LD | BPF_H | BPF_ABS:
833         case BPF_LD | BPF_B | BPF_ABS:
834 #define BPF_ANCILLARY(CODE)     case SKF_AD_OFF + SKF_AD_##CODE:        \
835                                 return BPF_ANC | SKF_AD_##CODE
836                 switch (ftest->k) {
837                 BPF_ANCILLARY(PROTOCOL);
838                 BPF_ANCILLARY(PKTTYPE);
839                 BPF_ANCILLARY(IFINDEX);
840                 BPF_ANCILLARY(NLATTR);
841                 BPF_ANCILLARY(NLATTR_NEST);
842                 BPF_ANCILLARY(MARK);
843                 BPF_ANCILLARY(QUEUE);
844                 BPF_ANCILLARY(HATYPE);
845                 BPF_ANCILLARY(RXHASH);
846                 BPF_ANCILLARY(CPU);
847                 BPF_ANCILLARY(ALU_XOR_X);
848                 BPF_ANCILLARY(VLAN_TAG);
849                 BPF_ANCILLARY(VLAN_TAG_PRESENT);
850                 BPF_ANCILLARY(PAY_OFFSET);
851                 BPF_ANCILLARY(RANDOM);
852                 BPF_ANCILLARY(VLAN_TPID);
853                 }
854                 /* Fallthrough. */
855         default:
856                 return ftest->code;
857         }
858 }
859 
860 void *bpf_internal_load_pointer_neg_helper(const struct sk_buff *skb,
861                                            int k, unsigned int size);
862 
863 static inline void *bpf_load_pointer(const struct sk_buff *skb, int k,
864                                      unsigned int size, void *buffer)
865 {
866         if (k >= 0)
867                 return skb_header_pointer(skb, k, size, buffer);
868 
869         return bpf_internal_load_pointer_neg_helper(skb, k, size);
870 }
871 
872 static inline int bpf_tell_extensions(void)
873 {
874         return SKF_AD_MAX;
875 }
876 
877 #endif /* __LINUX_FILTER_H__ */
878 

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