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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/refcount.h>
 11 #include <linux/compat.h>
 12 #include <linux/skbuff.h>
 13 #include <linux/linkage.h>
 14 #include <linux/printk.h>
 15 #include <linux/workqueue.h>
 16 #include <linux/sched.h>
 17 #include <linux/capability.h>
 18 #include <linux/cryptohash.h>
 19 
 20 #include <net/sch_generic.h>
 21 
 22 #ifdef CONFIG_ARCH_HAS_SET_MEMORY
 23 #include <asm/set_memory.h>
 24 #endif
 25 
 26 #include <uapi/linux/filter.h>
 27 #include <uapi/linux/bpf.h>
 28 
 29 struct sk_buff;
 30 struct sock;
 31 struct seccomp_data;
 32 struct bpf_prog_aux;
 33 
 34 /* ArgX, context and stack frame pointer register positions. Note,
 35  * Arg1, Arg2, Arg3, etc are used as argument mappings of function
 36  * calls in BPF_CALL instruction.
 37  */
 38 #define BPF_REG_ARG1    BPF_REG_1
 39 #define BPF_REG_ARG2    BPF_REG_2
 40 #define BPF_REG_ARG3    BPF_REG_3
 41 #define BPF_REG_ARG4    BPF_REG_4
 42 #define BPF_REG_ARG5    BPF_REG_5
 43 #define BPF_REG_CTX     BPF_REG_6
 44 #define BPF_REG_FP      BPF_REG_10
 45 
 46 /* Additional register mappings for converted user programs. */
 47 #define BPF_REG_A       BPF_REG_0
 48 #define BPF_REG_X       BPF_REG_7
 49 #define BPF_REG_TMP     BPF_REG_8
 50 
 51 /* Kernel hidden auxiliary/helper register for hardening step.
 52  * Only used by eBPF JITs. It's nothing more than a temporary
 53  * register that JITs use internally, only that here it's part
 54  * of eBPF instructions that have been rewritten for blinding
 55  * constants. See JIT pre-step in bpf_jit_blind_constants().
 56  */
 57 #define BPF_REG_AX              MAX_BPF_REG
 58 #define MAX_BPF_JIT_REG         (MAX_BPF_REG + 1)
 59 
 60 /* As per nm, we expose JITed images as text (code) section for
 61  * kallsyms. That way, tools like perf can find it to match
 62  * addresses.
 63  */
 64 #define BPF_SYM_ELF_TYPE        't'
 65 
 66 /* BPF program can access up to 512 bytes of stack space. */
 67 #define MAX_BPF_STACK   512
 68 
 69 #define BPF_TAG_SIZE    8
 70 
 71 /* Helper macros for filter block array initializers. */
 72 
 73 /* ALU ops on registers, bpf_add|sub|...: dst_reg += src_reg */
 74 
 75 #define BPF_ALU64_REG(OP, DST, SRC)                             \
 76         ((struct bpf_insn) {                                    \
 77                 .code  = BPF_ALU64 | BPF_OP(OP) | BPF_X,        \
 78                 .dst_reg = DST,                                 \
 79                 .src_reg = SRC,                                 \
 80                 .off   = 0,                                     \
 81                 .imm   = 0 })
 82 
 83 #define BPF_ALU32_REG(OP, DST, SRC)                             \
 84         ((struct bpf_insn) {                                    \
 85                 .code  = BPF_ALU | BPF_OP(OP) | BPF_X,          \
 86                 .dst_reg = DST,                                 \
 87                 .src_reg = SRC,                                 \
 88                 .off   = 0,                                     \
 89                 .imm   = 0 })
 90 
 91 /* ALU ops on immediates, bpf_add|sub|...: dst_reg += imm32 */
 92 
 93 #define BPF_ALU64_IMM(OP, DST, IMM)                             \
 94         ((struct bpf_insn) {                                    \
 95                 .code  = BPF_ALU64 | BPF_OP(OP) | BPF_K,        \
 96                 .dst_reg = DST,                                 \
 97                 .src_reg = 0,                                   \
 98                 .off   = 0,                                     \
 99                 .imm   = IMM })
100 
101 #define BPF_ALU32_IMM(OP, DST, IMM)                             \
102         ((struct bpf_insn) {                                    \
103                 .code  = BPF_ALU | BPF_OP(OP) | BPF_K,          \
104                 .dst_reg = DST,                                 \
105                 .src_reg = 0,                                   \
106                 .off   = 0,                                     \
107                 .imm   = IMM })
108 
109 /* Endianess conversion, cpu_to_{l,b}e(), {l,b}e_to_cpu() */
110 
111 #define BPF_ENDIAN(TYPE, DST, LEN)                              \
112         ((struct bpf_insn) {                                    \
113                 .code  = BPF_ALU | BPF_END | BPF_SRC(TYPE),     \
114                 .dst_reg = DST,                                 \
115                 .src_reg = 0,                                   \
116                 .off   = 0,                                     \
117                 .imm   = LEN })
118 
119 /* Short form of mov, dst_reg = src_reg */
120 
121 #define BPF_MOV64_REG(DST, SRC)                                 \
122         ((struct bpf_insn) {                                    \
123                 .code  = BPF_ALU64 | BPF_MOV | BPF_X,           \
124                 .dst_reg = DST,                                 \
125                 .src_reg = SRC,                                 \
126                 .off   = 0,                                     \
127                 .imm   = 0 })
128 
129 #define BPF_MOV32_REG(DST, SRC)                                 \
130         ((struct bpf_insn) {                                    \
131                 .code  = BPF_ALU | BPF_MOV | BPF_X,             \
132                 .dst_reg = DST,                                 \
133                 .src_reg = SRC,                                 \
134                 .off   = 0,                                     \
135                 .imm   = 0 })
136 
137 /* Short form of mov, dst_reg = imm32 */
138 
139 #define BPF_MOV64_IMM(DST, IMM)                                 \
140         ((struct bpf_insn) {                                    \
141                 .code  = BPF_ALU64 | BPF_MOV | BPF_K,           \
142                 .dst_reg = DST,                                 \
143                 .src_reg = 0,                                   \
144                 .off   = 0,                                     \
145                 .imm   = IMM })
146 
147 #define BPF_MOV32_IMM(DST, IMM)                                 \
148         ((struct bpf_insn) {                                    \
149                 .code  = BPF_ALU | BPF_MOV | BPF_K,             \
150                 .dst_reg = DST,                                 \
151                 .src_reg = 0,                                   \
152                 .off   = 0,                                     \
153                 .imm   = IMM })
154 
155 /* BPF_LD_IMM64 macro encodes single 'load 64-bit immediate' insn */
156 #define BPF_LD_IMM64(DST, IMM)                                  \
157         BPF_LD_IMM64_RAW(DST, 0, IMM)
158 
159 #define BPF_LD_IMM64_RAW(DST, SRC, IMM)                         \
160         ((struct bpf_insn) {                                    \
161                 .code  = BPF_LD | BPF_DW | BPF_IMM,             \
162                 .dst_reg = DST,                                 \
163                 .src_reg = SRC,                                 \
164                 .off   = 0,                                     \
165                 .imm   = (__u32) (IMM) }),                      \
166         ((struct bpf_insn) {                                    \
167                 .code  = 0, /* zero is reserved opcode */       \
168                 .dst_reg = 0,                                   \
169                 .src_reg = 0,                                   \
170                 .off   = 0,                                     \
171                 .imm   = ((__u64) (IMM)) >> 32 })
172 
173 /* pseudo BPF_LD_IMM64 insn used to refer to process-local map_fd */
174 #define BPF_LD_MAP_FD(DST, MAP_FD)                              \
175         BPF_LD_IMM64_RAW(DST, BPF_PSEUDO_MAP_FD, MAP_FD)
176 
177 /* Short form of mov based on type, BPF_X: dst_reg = src_reg, BPF_K: dst_reg = imm32 */
178 
179 #define BPF_MOV64_RAW(TYPE, DST, SRC, IMM)                      \
180         ((struct bpf_insn) {                                    \
181                 .code  = BPF_ALU64 | BPF_MOV | BPF_SRC(TYPE),   \
182                 .dst_reg = DST,                                 \
183                 .src_reg = SRC,                                 \
184                 .off   = 0,                                     \
185                 .imm   = IMM })
186 
187 #define BPF_MOV32_RAW(TYPE, DST, SRC, IMM)                      \
188         ((struct bpf_insn) {                                    \
189                 .code  = BPF_ALU | BPF_MOV | BPF_SRC(TYPE),     \
190                 .dst_reg = DST,                                 \
191                 .src_reg = SRC,                                 \
192                 .off   = 0,                                     \
193                 .imm   = IMM })
194 
195 /* Direct packet access, R0 = *(uint *) (skb->data + imm32) */
196 
197 #define BPF_LD_ABS(SIZE, IMM)                                   \
198         ((struct bpf_insn) {                                    \
199                 .code  = BPF_LD | BPF_SIZE(SIZE) | BPF_ABS,     \
200                 .dst_reg = 0,                                   \
201                 .src_reg = 0,                                   \
202                 .off   = 0,                                     \
203                 .imm   = IMM })
204 
205 /* Indirect packet access, R0 = *(uint *) (skb->data + src_reg + imm32) */
206 
207 #define BPF_LD_IND(SIZE, SRC, IMM)                              \
208         ((struct bpf_insn) {                                    \
209                 .code  = BPF_LD | BPF_SIZE(SIZE) | BPF_IND,     \
210                 .dst_reg = 0,                                   \
211                 .src_reg = SRC,                                 \
212                 .off   = 0,                                     \
213                 .imm   = IMM })
214 
215 /* Memory load, dst_reg = *(uint *) (src_reg + off16) */
216 
217 #define BPF_LDX_MEM(SIZE, DST, SRC, OFF)                        \
218         ((struct bpf_insn) {                                    \
219                 .code  = BPF_LDX | BPF_SIZE(SIZE) | BPF_MEM,    \
220                 .dst_reg = DST,                                 \
221                 .src_reg = SRC,                                 \
222                 .off   = OFF,                                   \
223                 .imm   = 0 })
224 
225 /* Memory store, *(uint *) (dst_reg + off16) = src_reg */
226 
227 #define BPF_STX_MEM(SIZE, DST, SRC, OFF)                        \
228         ((struct bpf_insn) {                                    \
229                 .code  = BPF_STX | BPF_SIZE(SIZE) | BPF_MEM,    \
230                 .dst_reg = DST,                                 \
231                 .src_reg = SRC,                                 \
232                 .off   = OFF,                                   \
233                 .imm   = 0 })
234 
235 /* Atomic memory add, *(uint *)(dst_reg + off16) += src_reg */
236 
237 #define BPF_STX_XADD(SIZE, DST, SRC, OFF)                       \
238         ((struct bpf_insn) {                                    \
239                 .code  = BPF_STX | BPF_SIZE(SIZE) | BPF_XADD,   \
240                 .dst_reg = DST,                                 \
241                 .src_reg = SRC,                                 \
242                 .off   = OFF,                                   \
243                 .imm   = 0 })
244 
245 /* Memory store, *(uint *) (dst_reg + off16) = imm32 */
246 
247 #define BPF_ST_MEM(SIZE, DST, OFF, IMM)                         \
248         ((struct bpf_insn) {                                    \
249                 .code  = BPF_ST | BPF_SIZE(SIZE) | BPF_MEM,     \
250                 .dst_reg = DST,                                 \
251                 .src_reg = 0,                                   \
252                 .off   = OFF,                                   \
253                 .imm   = IMM })
254 
255 /* Conditional jumps against registers, if (dst_reg 'op' src_reg) goto pc + off16 */
256 
257 #define BPF_JMP_REG(OP, DST, SRC, OFF)                          \
258         ((struct bpf_insn) {                                    \
259                 .code  = BPF_JMP | BPF_OP(OP) | BPF_X,          \
260                 .dst_reg = DST,                                 \
261                 .src_reg = SRC,                                 \
262                 .off   = OFF,                                   \
263                 .imm   = 0 })
264 
265 /* Conditional jumps against immediates, if (dst_reg 'op' imm32) goto pc + off16 */
266 
267 #define BPF_JMP_IMM(OP, DST, IMM, OFF)                          \
268         ((struct bpf_insn) {                                    \
269                 .code  = BPF_JMP | BPF_OP(OP) | BPF_K,          \
270                 .dst_reg = DST,                                 \
271                 .src_reg = 0,                                   \
272                 .off   = OFF,                                   \
273                 .imm   = IMM })
274 
275 /* Unconditional jumps, goto pc + off16 */
276 
277 #define BPF_JMP_A(OFF)                                          \
278         ((struct bpf_insn) {                                    \
279                 .code  = BPF_JMP | BPF_JA,                      \
280                 .dst_reg = 0,                                   \
281                 .src_reg = 0,                                   \
282                 .off   = OFF,                                   \
283                 .imm   = 0 })
284 
285 /* Function call */
286 
287 #define BPF_EMIT_CALL(FUNC)                                     \
288         ((struct bpf_insn) {                                    \
289                 .code  = BPF_JMP | BPF_CALL,                    \
290                 .dst_reg = 0,                                   \
291                 .src_reg = 0,                                   \
292                 .off   = 0,                                     \
293                 .imm   = ((FUNC) - __bpf_call_base) })
294 
295 /* Raw code statement block */
296 
297 #define BPF_RAW_INSN(CODE, DST, SRC, OFF, IMM)                  \
298         ((struct bpf_insn) {                                    \
299                 .code  = CODE,                                  \
300                 .dst_reg = DST,                                 \
301                 .src_reg = SRC,                                 \
302                 .off   = OFF,                                   \
303                 .imm   = IMM })
304 
305 /* Program exit */
306 
307 #define BPF_EXIT_INSN()                                         \
308         ((struct bpf_insn) {                                    \
309                 .code  = BPF_JMP | BPF_EXIT,                    \
310                 .dst_reg = 0,                                   \
311                 .src_reg = 0,                                   \
312                 .off   = 0,                                     \
313                 .imm   = 0 })
314 
315 /* Internal classic blocks for direct assignment */
316 
317 #define __BPF_STMT(CODE, K)                                     \
318         ((struct sock_filter) BPF_STMT(CODE, K))
319 
320 #define __BPF_JUMP(CODE, K, JT, JF)                             \
321         ((struct sock_filter) BPF_JUMP(CODE, K, JT, JF))
322 
323 #define bytes_to_bpf_size(bytes)                                \
324 ({                                                              \
325         int bpf_size = -EINVAL;                                 \
326                                                                 \
327         if (bytes == sizeof(u8))                                \
328                 bpf_size = BPF_B;                               \
329         else if (bytes == sizeof(u16))                          \
330                 bpf_size = BPF_H;                               \
331         else if (bytes == sizeof(u32))                          \
332                 bpf_size = BPF_W;                               \
333         else if (bytes == sizeof(u64))                          \
334                 bpf_size = BPF_DW;                              \
335                                                                 \
336         bpf_size;                                               \
337 })
338 
339 #define BPF_SIZEOF(type)                                        \
340         ({                                                      \
341                 const int __size = bytes_to_bpf_size(sizeof(type)); \
342                 BUILD_BUG_ON(__size < 0);                       \
343                 __size;                                         \
344         })
345 
346 #define BPF_FIELD_SIZEOF(type, field)                           \
347         ({                                                      \
348                 const int __size = bytes_to_bpf_size(FIELD_SIZEOF(type, field)); \
349                 BUILD_BUG_ON(__size < 0);                       \
350                 __size;                                         \
351         })
352 
353 #define __BPF_MAP_0(m, v, ...) v
354 #define __BPF_MAP_1(m, v, t, a, ...) m(t, a)
355 #define __BPF_MAP_2(m, v, t, a, ...) m(t, a), __BPF_MAP_1(m, v, __VA_ARGS__)
356 #define __BPF_MAP_3(m, v, t, a, ...) m(t, a), __BPF_MAP_2(m, v, __VA_ARGS__)
357 #define __BPF_MAP_4(m, v, t, a, ...) m(t, a), __BPF_MAP_3(m, v, __VA_ARGS__)
358 #define __BPF_MAP_5(m, v, t, a, ...) m(t, a), __BPF_MAP_4(m, v, __VA_ARGS__)
359 
360 #define __BPF_REG_0(...) __BPF_PAD(5)
361 #define __BPF_REG_1(...) __BPF_MAP(1, __VA_ARGS__), __BPF_PAD(4)
362 #define __BPF_REG_2(...) __BPF_MAP(2, __VA_ARGS__), __BPF_PAD(3)
363 #define __BPF_REG_3(...) __BPF_MAP(3, __VA_ARGS__), __BPF_PAD(2)
364 #define __BPF_REG_4(...) __BPF_MAP(4, __VA_ARGS__), __BPF_PAD(1)
365 #define __BPF_REG_5(...) __BPF_MAP(5, __VA_ARGS__)
366 
367 #define __BPF_MAP(n, ...) __BPF_MAP_##n(__VA_ARGS__)
368 #define __BPF_REG(n, ...) __BPF_REG_##n(__VA_ARGS__)
369 
370 #define __BPF_CAST(t, a)                                                       \
371         (__force t)                                                            \
372         (__force                                                               \
373          typeof(__builtin_choose_expr(sizeof(t) == sizeof(unsigned long),      \
374                                       (unsigned long)0, (t)0))) a
375 #define __BPF_V void
376 #define __BPF_N
377 
378 #define __BPF_DECL_ARGS(t, a) t   a
379 #define __BPF_DECL_REGS(t, a) u64 a
380 
381 #define __BPF_PAD(n)                                                           \
382         __BPF_MAP(n, __BPF_DECL_ARGS, __BPF_N, u64, __ur_1, u64, __ur_2,       \
383                   u64, __ur_3, u64, __ur_4, u64, __ur_5)
384 
385 #define BPF_CALL_x(x, name, ...)                                               \
386         static __always_inline                                                 \
387         u64 ____##name(__BPF_MAP(x, __BPF_DECL_ARGS, __BPF_V, __VA_ARGS__));   \
388         u64 name(__BPF_REG(x, __BPF_DECL_REGS, __BPF_N, __VA_ARGS__));         \
389         u64 name(__BPF_REG(x, __BPF_DECL_REGS, __BPF_N, __VA_ARGS__))          \
390         {                                                                      \
391                 return ____##name(__BPF_MAP(x,__BPF_CAST,__BPF_N,__VA_ARGS__));\
392         }                                                                      \
393         static __always_inline                                                 \
394         u64 ____##name(__BPF_MAP(x, __BPF_DECL_ARGS, __BPF_V, __VA_ARGS__))
395 
396 #define BPF_CALL_0(name, ...)   BPF_CALL_x(0, name, __VA_ARGS__)
397 #define BPF_CALL_1(name, ...)   BPF_CALL_x(1, name, __VA_ARGS__)
398 #define BPF_CALL_2(name, ...)   BPF_CALL_x(2, name, __VA_ARGS__)
399 #define BPF_CALL_3(name, ...)   BPF_CALL_x(3, name, __VA_ARGS__)
400 #define BPF_CALL_4(name, ...)   BPF_CALL_x(4, name, __VA_ARGS__)
401 #define BPF_CALL_5(name, ...)   BPF_CALL_x(5, name, __VA_ARGS__)
402 
403 #ifdef CONFIG_COMPAT
404 /* A struct sock_filter is architecture independent. */
405 struct compat_sock_fprog {
406         u16             len;
407         compat_uptr_t   filter; /* struct sock_filter * */
408 };
409 #endif
410 
411 struct sock_fprog_kern {
412         u16                     len;
413         struct sock_filter      *filter;
414 };
415 
416 struct bpf_binary_header {
417         unsigned int pages;
418         u8 image[];
419 };
420 
421 struct bpf_prog {
422         u16                     pages;          /* Number of allocated pages */
423         kmemcheck_bitfield_begin(meta);
424         u16                     jited:1,        /* Is our filter JIT'ed? */
425                                 locked:1,       /* Program image locked? */
426                                 gpl_compatible:1, /* Is filter GPL compatible? */
427                                 cb_access:1,    /* Is control block accessed? */
428                                 dst_needed:1;   /* Do we need dst entry? */
429         kmemcheck_bitfield_end(meta);
430         enum bpf_prog_type      type;           /* Type of BPF program */
431         u32                     len;            /* Number of filter blocks */
432         u8                      tag[BPF_TAG_SIZE];
433         struct bpf_prog_aux     *aux;           /* Auxiliary fields */
434         struct sock_fprog_kern  *orig_prog;     /* Original BPF program */
435         unsigned int            (*bpf_func)(const void *ctx,
436                                             const struct bpf_insn *insn);
437         /* Instructions for interpreter */
438         union {
439                 struct sock_filter      insns[0];
440                 struct bpf_insn         insnsi[0];
441         };
442 };
443 
444 struct sk_filter {
445         refcount_t      refcnt;
446         struct rcu_head rcu;
447         struct bpf_prog *prog;
448 };
449 
450 #define BPF_PROG_RUN(filter, ctx)  (*filter->bpf_func)(ctx, filter->insnsi)
451 
452 #define BPF_SKB_CB_LEN QDISC_CB_PRIV_LEN
453 
454 struct bpf_skb_data_end {
455         struct qdisc_skb_cb qdisc_cb;
456         void *data_end;
457 };
458 
459 struct xdp_buff {
460         void *data;
461         void *data_end;
462         void *data_hard_start;
463 };
464 
465 /* compute the linear packet data range [data, data_end) which
466  * will be accessed by cls_bpf, act_bpf and lwt programs
467  */
468 static inline void bpf_compute_data_end(struct sk_buff *skb)
469 {
470         struct bpf_skb_data_end *cb = (struct bpf_skb_data_end *)skb->cb;
471 
472         BUILD_BUG_ON(sizeof(*cb) > FIELD_SIZEOF(struct sk_buff, cb));
473         cb->data_end = skb->data + skb_headlen(skb);
474 }
475 
476 static inline u8 *bpf_skb_cb(struct sk_buff *skb)
477 {
478         /* eBPF programs may read/write skb->cb[] area to transfer meta
479          * data between tail calls. Since this also needs to work with
480          * tc, that scratch memory is mapped to qdisc_skb_cb's data area.
481          *
482          * In some socket filter cases, the cb unfortunately needs to be
483          * saved/restored so that protocol specific skb->cb[] data won't
484          * be lost. In any case, due to unpriviledged eBPF programs
485          * attached to sockets, we need to clear the bpf_skb_cb() area
486          * to not leak previous contents to user space.
487          */
488         BUILD_BUG_ON(FIELD_SIZEOF(struct __sk_buff, cb) != BPF_SKB_CB_LEN);
489         BUILD_BUG_ON(FIELD_SIZEOF(struct __sk_buff, cb) !=
490                      FIELD_SIZEOF(struct qdisc_skb_cb, data));
491 
492         return qdisc_skb_cb(skb)->data;
493 }
494 
495 static inline u32 bpf_prog_run_save_cb(const struct bpf_prog *prog,
496                                        struct sk_buff *skb)
497 {
498         u8 *cb_data = bpf_skb_cb(skb);
499         u8 cb_saved[BPF_SKB_CB_LEN];
500         u32 res;
501 
502         if (unlikely(prog->cb_access)) {
503                 memcpy(cb_saved, cb_data, sizeof(cb_saved));
504                 memset(cb_data, 0, sizeof(cb_saved));
505         }
506 
507         res = BPF_PROG_RUN(prog, skb);
508 
509         if (unlikely(prog->cb_access))
510                 memcpy(cb_data, cb_saved, sizeof(cb_saved));
511 
512         return res;
513 }
514 
515 static inline u32 bpf_prog_run_clear_cb(const struct bpf_prog *prog,
516                                         struct sk_buff *skb)
517 {
518         u8 *cb_data = bpf_skb_cb(skb);
519 
520         if (unlikely(prog->cb_access))
521                 memset(cb_data, 0, BPF_SKB_CB_LEN);
522 
523         return BPF_PROG_RUN(prog, skb);
524 }
525 
526 static __always_inline u32 bpf_prog_run_xdp(const struct bpf_prog *prog,
527                                             struct xdp_buff *xdp)
528 {
529         /* Caller needs to hold rcu_read_lock() (!), otherwise program
530          * can be released while still running, or map elements could be
531          * freed early while still having concurrent users. XDP fastpath
532          * already takes rcu_read_lock() when fetching the program, so
533          * it's not necessary here anymore.
534          */
535         return BPF_PROG_RUN(prog, xdp);
536 }
537 
538 static inline u32 bpf_prog_insn_size(const struct bpf_prog *prog)
539 {
540         return prog->len * sizeof(struct bpf_insn);
541 }
542 
543 static inline u32 bpf_prog_tag_scratch_size(const struct bpf_prog *prog)
544 {
545         return round_up(bpf_prog_insn_size(prog) +
546                         sizeof(__be64) + 1, SHA_MESSAGE_BYTES);
547 }
548 
549 static inline unsigned int bpf_prog_size(unsigned int proglen)
550 {
551         return max(sizeof(struct bpf_prog),
552                    offsetof(struct bpf_prog, insns[proglen]));
553 }
554 
555 static inline bool bpf_prog_was_classic(const struct bpf_prog *prog)
556 {
557         /* When classic BPF programs have been loaded and the arch
558          * does not have a classic BPF JIT (anymore), they have been
559          * converted via bpf_migrate_filter() to eBPF and thus always
560          * have an unspec program type.
561          */
562         return prog->type == BPF_PROG_TYPE_UNSPEC;
563 }
564 
565 #define bpf_classic_proglen(fprog) (fprog->len * sizeof(fprog->filter[0]))
566 
567 #ifdef CONFIG_ARCH_HAS_SET_MEMORY
568 static inline void bpf_prog_lock_ro(struct bpf_prog *fp)
569 {
570         fp->locked = 1;
571         WARN_ON_ONCE(set_memory_ro((unsigned long)fp, fp->pages));
572 }
573 
574 static inline void bpf_prog_unlock_ro(struct bpf_prog *fp)
575 {
576         if (fp->locked) {
577                 WARN_ON_ONCE(set_memory_rw((unsigned long)fp, fp->pages));
578                 /* In case set_memory_rw() fails, we want to be the first
579                  * to crash here instead of some random place later on.
580                  */
581                 fp->locked = 0;
582         }
583 }
584 
585 static inline void bpf_jit_binary_lock_ro(struct bpf_binary_header *hdr)
586 {
587         WARN_ON_ONCE(set_memory_ro((unsigned long)hdr, hdr->pages));
588 }
589 
590 static inline void bpf_jit_binary_unlock_ro(struct bpf_binary_header *hdr)
591 {
592         WARN_ON_ONCE(set_memory_rw((unsigned long)hdr, hdr->pages));
593 }
594 #else
595 static inline void bpf_prog_lock_ro(struct bpf_prog *fp)
596 {
597 }
598 
599 static inline void bpf_prog_unlock_ro(struct bpf_prog *fp)
600 {
601 }
602 
603 static inline void bpf_jit_binary_lock_ro(struct bpf_binary_header *hdr)
604 {
605 }
606 
607 static inline void bpf_jit_binary_unlock_ro(struct bpf_binary_header *hdr)
608 {
609 }
610 #endif /* CONFIG_ARCH_HAS_SET_MEMORY */
611 
612 static inline struct bpf_binary_header *
613 bpf_jit_binary_hdr(const struct bpf_prog *fp)
614 {
615         unsigned long real_start = (unsigned long)fp->bpf_func;
616         unsigned long addr = real_start & PAGE_MASK;
617 
618         return (void *)addr;
619 }
620 
621 int sk_filter_trim_cap(struct sock *sk, struct sk_buff *skb, unsigned int cap);
622 static inline int sk_filter(struct sock *sk, struct sk_buff *skb)
623 {
624         return sk_filter_trim_cap(sk, skb, 1);
625 }
626 
627 struct bpf_prog *bpf_prog_select_runtime(struct bpf_prog *fp, int *err);
628 void bpf_prog_free(struct bpf_prog *fp);
629 
630 struct bpf_prog *bpf_prog_alloc(unsigned int size, gfp_t gfp_extra_flags);
631 struct bpf_prog *bpf_prog_realloc(struct bpf_prog *fp_old, unsigned int size,
632                                   gfp_t gfp_extra_flags);
633 void __bpf_prog_free(struct bpf_prog *fp);
634 
635 static inline void bpf_prog_unlock_free(struct bpf_prog *fp)
636 {
637         bpf_prog_unlock_ro(fp);
638         __bpf_prog_free(fp);
639 }
640 
641 typedef int (*bpf_aux_classic_check_t)(struct sock_filter *filter,
642                                        unsigned int flen);
643 
644 int bpf_prog_create(struct bpf_prog **pfp, struct sock_fprog_kern *fprog);
645 int bpf_prog_create_from_user(struct bpf_prog **pfp, struct sock_fprog *fprog,
646                               bpf_aux_classic_check_t trans, bool save_orig);
647 void bpf_prog_destroy(struct bpf_prog *fp);
648 
649 int sk_attach_filter(struct sock_fprog *fprog, struct sock *sk);
650 int sk_attach_bpf(u32 ufd, struct sock *sk);
651 int sk_reuseport_attach_filter(struct sock_fprog *fprog, struct sock *sk);
652 int sk_reuseport_attach_bpf(u32 ufd, struct sock *sk);
653 int sk_detach_filter(struct sock *sk);
654 int sk_get_filter(struct sock *sk, struct sock_filter __user *filter,
655                   unsigned int len);
656 
657 bool sk_filter_charge(struct sock *sk, struct sk_filter *fp);
658 void sk_filter_uncharge(struct sock *sk, struct sk_filter *fp);
659 
660 u64 __bpf_call_base(u64 r1, u64 r2, u64 r3, u64 r4, u64 r5);
661 
662 struct bpf_prog *bpf_int_jit_compile(struct bpf_prog *prog);
663 void bpf_jit_compile(struct bpf_prog *prog);
664 bool bpf_helper_changes_pkt_data(void *func);
665 
666 struct bpf_prog *bpf_patch_insn_single(struct bpf_prog *prog, u32 off,
667                                        const struct bpf_insn *patch, u32 len);
668 void bpf_warn_invalid_xdp_action(u32 act);
669 
670 #ifdef CONFIG_BPF_JIT
671 extern int bpf_jit_enable;
672 extern int bpf_jit_harden;
673 extern int bpf_jit_kallsyms;
674 
675 typedef void (*bpf_jit_fill_hole_t)(void *area, unsigned int size);
676 
677 struct bpf_binary_header *
678 bpf_jit_binary_alloc(unsigned int proglen, u8 **image_ptr,
679                      unsigned int alignment,
680                      bpf_jit_fill_hole_t bpf_fill_ill_insns);
681 void bpf_jit_binary_free(struct bpf_binary_header *hdr);
682 
683 void bpf_jit_free(struct bpf_prog *fp);
684 
685 struct bpf_prog *bpf_jit_blind_constants(struct bpf_prog *fp);
686 void bpf_jit_prog_release_other(struct bpf_prog *fp, struct bpf_prog *fp_other);
687 
688 static inline void bpf_jit_dump(unsigned int flen, unsigned int proglen,
689                                 u32 pass, void *image)
690 {
691         pr_err("flen=%u proglen=%u pass=%u image=%pK from=%s pid=%d\n", flen,
692                proglen, pass, image, current->comm, task_pid_nr(current));
693 
694         if (image)
695                 print_hex_dump(KERN_ERR, "JIT code: ", DUMP_PREFIX_OFFSET,
696                                16, 1, image, proglen, false);
697 }
698 
699 static inline bool bpf_jit_is_ebpf(void)
700 {
701 # ifdef CONFIG_HAVE_EBPF_JIT
702         return true;
703 # else
704         return false;
705 # endif
706 }
707 
708 static inline bool ebpf_jit_enabled(void)
709 {
710         return bpf_jit_enable && bpf_jit_is_ebpf();
711 }
712 
713 static inline bool bpf_prog_ebpf_jited(const struct bpf_prog *fp)
714 {
715         return fp->jited && bpf_jit_is_ebpf();
716 }
717 
718 static inline bool bpf_jit_blinding_enabled(void)
719 {
720         /* These are the prerequisites, should someone ever have the
721          * idea to call blinding outside of them, we make sure to
722          * bail out.
723          */
724         if (!bpf_jit_is_ebpf())
725                 return false;
726         if (!bpf_jit_enable)
727                 return false;
728         if (!bpf_jit_harden)
729                 return false;
730         if (bpf_jit_harden == 1 && capable(CAP_SYS_ADMIN))
731                 return false;
732 
733         return true;
734 }
735 
736 static inline bool bpf_jit_kallsyms_enabled(void)
737 {
738         /* There are a couple of corner cases where kallsyms should
739          * not be enabled f.e. on hardening.
740          */
741         if (bpf_jit_harden)
742                 return false;
743         if (!bpf_jit_kallsyms)
744                 return false;
745         if (bpf_jit_kallsyms == 1)
746                 return true;
747 
748         return false;
749 }
750 
751 const char *__bpf_address_lookup(unsigned long addr, unsigned long *size,
752                                  unsigned long *off, char *sym);
753 bool is_bpf_text_address(unsigned long addr);
754 int bpf_get_kallsym(unsigned int symnum, unsigned long *value, char *type,
755                     char *sym);
756 
757 static inline const char *
758 bpf_address_lookup(unsigned long addr, unsigned long *size,
759                    unsigned long *off, char **modname, char *sym)
760 {
761         const char *ret = __bpf_address_lookup(addr, size, off, sym);
762 
763         if (ret && modname)
764                 *modname = NULL;
765         return ret;
766 }
767 
768 void bpf_prog_kallsyms_add(struct bpf_prog *fp);
769 void bpf_prog_kallsyms_del(struct bpf_prog *fp);
770 
771 #else /* CONFIG_BPF_JIT */
772 
773 static inline bool ebpf_jit_enabled(void)
774 {
775         return false;
776 }
777 
778 static inline bool bpf_prog_ebpf_jited(const struct bpf_prog *fp)
779 {
780         return false;
781 }
782 
783 static inline void bpf_jit_free(struct bpf_prog *fp)
784 {
785         bpf_prog_unlock_free(fp);
786 }
787 
788 static inline bool bpf_jit_kallsyms_enabled(void)
789 {
790         return false;
791 }
792 
793 static inline const char *
794 __bpf_address_lookup(unsigned long addr, unsigned long *size,
795                      unsigned long *off, char *sym)
796 {
797         return NULL;
798 }
799 
800 static inline bool is_bpf_text_address(unsigned long addr)
801 {
802         return false;
803 }
804 
805 static inline int bpf_get_kallsym(unsigned int symnum, unsigned long *value,
806                                   char *type, char *sym)
807 {
808         return -ERANGE;
809 }
810 
811 static inline const char *
812 bpf_address_lookup(unsigned long addr, unsigned long *size,
813                    unsigned long *off, char **modname, char *sym)
814 {
815         return NULL;
816 }
817 
818 static inline void bpf_prog_kallsyms_add(struct bpf_prog *fp)
819 {
820 }
821 
822 static inline void bpf_prog_kallsyms_del(struct bpf_prog *fp)
823 {
824 }
825 #endif /* CONFIG_BPF_JIT */
826 
827 #define BPF_ANC         BIT(15)
828 
829 static inline bool bpf_needs_clear_a(const struct sock_filter *first)
830 {
831         switch (first->code) {
832         case BPF_RET | BPF_K:
833         case BPF_LD | BPF_W | BPF_LEN:
834                 return false;
835 
836         case BPF_LD | BPF_W | BPF_ABS:
837         case BPF_LD | BPF_H | BPF_ABS:
838         case BPF_LD | BPF_B | BPF_ABS:
839                 if (first->k == SKF_AD_OFF + SKF_AD_ALU_XOR_X)
840                         return true;
841                 return false;
842 
843         default:
844                 return true;
845         }
846 }
847 
848 static inline u16 bpf_anc_helper(const struct sock_filter *ftest)
849 {
850         BUG_ON(ftest->code & BPF_ANC);
851 
852         switch (ftest->code) {
853         case BPF_LD | BPF_W | BPF_ABS:
854         case BPF_LD | BPF_H | BPF_ABS:
855         case BPF_LD | BPF_B | BPF_ABS:
856 #define BPF_ANCILLARY(CODE)     case SKF_AD_OFF + SKF_AD_##CODE:        \
857                                 return BPF_ANC | SKF_AD_##CODE
858                 switch (ftest->k) {
859                 BPF_ANCILLARY(PROTOCOL);
860                 BPF_ANCILLARY(PKTTYPE);
861                 BPF_ANCILLARY(IFINDEX);
862                 BPF_ANCILLARY(NLATTR);
863                 BPF_ANCILLARY(NLATTR_NEST);
864                 BPF_ANCILLARY(MARK);
865                 BPF_ANCILLARY(QUEUE);
866                 BPF_ANCILLARY(HATYPE);
867                 BPF_ANCILLARY(RXHASH);
868                 BPF_ANCILLARY(CPU);
869                 BPF_ANCILLARY(ALU_XOR_X);
870                 BPF_ANCILLARY(VLAN_TAG);
871                 BPF_ANCILLARY(VLAN_TAG_PRESENT);
872                 BPF_ANCILLARY(PAY_OFFSET);
873                 BPF_ANCILLARY(RANDOM);
874                 BPF_ANCILLARY(VLAN_TPID);
875                 }
876                 /* Fallthrough. */
877         default:
878                 return ftest->code;
879         }
880 }
881 
882 void *bpf_internal_load_pointer_neg_helper(const struct sk_buff *skb,
883                                            int k, unsigned int size);
884 
885 static inline void *bpf_load_pointer(const struct sk_buff *skb, int k,
886                                      unsigned int size, void *buffer)
887 {
888         if (k >= 0)
889                 return skb_header_pointer(skb, k, size, buffer);
890 
891         return bpf_internal_load_pointer_neg_helper(skb, k, size);
892 }
893 
894 static inline int bpf_tell_extensions(void)
895 {
896         return SKF_AD_MAX;
897 }
898 
899 #endif /* __LINUX_FILTER_H__ */
900 

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