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filter.h (32723B)


      1 /* SPDX-License-Identifier: GPL-2.0 */
      2 /*
      3  * Linux Socket Filter Data Structures
      4  */
      5 #ifndef __LINUX_FILTER_H__
      6 #define __LINUX_FILTER_H__
      7 
      8 #include <stdarg.h>
      9 
     10 #include <linux/atomic.h>
     11 #include <linux/refcount.h>
     12 #include <linux/compat.h>
     13 #include <linux/skbuff.h>
     14 #include <linux/linkage.h>
     15 #include <linux/printk.h>
     16 #include <linux/workqueue.h>
     17 #include <linux/sched.h>
     18 #include <linux/capability.h>
     19 #include <linux/cryptohash.h>
     20 #include <linux/set_memory.h>
     21 #include <linux/kallsyms.h>
     22 #include <linux/if_vlan.h>
     23 
     24 #include <net/sch_generic.h>
     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 struct xdp_rxq_info;
     34 struct xdp_buff;
     35 struct sock_reuseport;
     36 
     37 /* ArgX, context and stack frame pointer register positions. Note,
     38  * Arg1, Arg2, Arg3, etc are used as argument mappings of function
     39  * calls in BPF_CALL instruction.
     40  */
     41 #define BPF_REG_ARG1	BPF_REG_1
     42 #define BPF_REG_ARG2	BPF_REG_2
     43 #define BPF_REG_ARG3	BPF_REG_3
     44 #define BPF_REG_ARG4	BPF_REG_4
     45 #define BPF_REG_ARG5	BPF_REG_5
     46 #define BPF_REG_CTX	BPF_REG_6
     47 #define BPF_REG_FP	BPF_REG_10
     48 
     49 /* Additional register mappings for converted user programs. */
     50 #define BPF_REG_A	BPF_REG_0
     51 #define BPF_REG_X	BPF_REG_7
     52 #define BPF_REG_TMP	BPF_REG_2	/* scratch reg */
     53 #define BPF_REG_D	BPF_REG_8	/* data, callee-saved */
     54 #define BPF_REG_H	BPF_REG_9	/* hlen, callee-saved */
     55 
     56 /* Kernel hidden auxiliary/helper register. */
     57 #define BPF_REG_AX		MAX_BPF_REG
     58 #define MAX_BPF_EXT_REG		(MAX_BPF_REG + 1)
     59 #define MAX_BPF_JIT_REG		MAX_BPF_EXT_REG
     60 
     61 /* unused opcode to mark special call to bpf_tail_call() helper */
     62 #define BPF_TAIL_CALL	0xf0
     63 
     64 /* unused opcode to mark call to interpreter with arguments */
     65 #define BPF_CALL_ARGS	0xe0
     66 
     67 /* As per nm, we expose JITed images as text (code) section for
     68  * kallsyms. That way, tools like perf can find it to match
     69  * addresses.
     70  */
     71 #define BPF_SYM_ELF_TYPE	't'
     72 
     73 /* BPF program can access up to 512 bytes of stack space. */
     74 #define MAX_BPF_STACK	512
     75 
     76 /* Helper macros for filter block array initializers. */
     77 
     78 /* ALU ops on registers, bpf_add|sub|...: dst_reg += src_reg */
     79 
     80 #define BPF_ALU64_REG(OP, DST, SRC)				\
     81 	((struct bpf_insn) {					\
     82 		.code  = BPF_ALU64 | BPF_OP(OP) | BPF_X,	\
     83 		.dst_reg = DST,					\
     84 		.src_reg = SRC,					\
     85 		.off   = 0,					\
     86 		.imm   = 0 })
     87 
     88 #define BPF_ALU32_REG(OP, DST, SRC)				\
     89 	((struct bpf_insn) {					\
     90 		.code  = BPF_ALU | BPF_OP(OP) | BPF_X,		\
     91 		.dst_reg = DST,					\
     92 		.src_reg = SRC,					\
     93 		.off   = 0,					\
     94 		.imm   = 0 })
     95 
     96 /* ALU ops on immediates, bpf_add|sub|...: dst_reg += imm32 */
     97 
     98 #define BPF_ALU64_IMM(OP, DST, IMM)				\
     99 	((struct bpf_insn) {					\
    100 		.code  = BPF_ALU64 | BPF_OP(OP) | BPF_K,	\
    101 		.dst_reg = DST,					\
    102 		.src_reg = 0,					\
    103 		.off   = 0,					\
    104 		.imm   = IMM })
    105 
    106 #define BPF_ALU32_IMM(OP, DST, IMM)				\
    107 	((struct bpf_insn) {					\
    108 		.code  = BPF_ALU | BPF_OP(OP) | BPF_K,		\
    109 		.dst_reg = DST,					\
    110 		.src_reg = 0,					\
    111 		.off   = 0,					\
    112 		.imm   = IMM })
    113 
    114 /* Endianess conversion, cpu_to_{l,b}e(), {l,b}e_to_cpu() */
    115 
    116 #define BPF_ENDIAN(TYPE, DST, LEN)				\
    117 	((struct bpf_insn) {					\
    118 		.code  = BPF_ALU | BPF_END | BPF_SRC(TYPE),	\
    119 		.dst_reg = DST,					\
    120 		.src_reg = 0,					\
    121 		.off   = 0,					\
    122 		.imm   = LEN })
    123 
    124 /* Short form of mov, dst_reg = src_reg */
    125 
    126 #define BPF_MOV64_REG(DST, SRC)					\
    127 	((struct bpf_insn) {					\
    128 		.code  = BPF_ALU64 | BPF_MOV | BPF_X,		\
    129 		.dst_reg = DST,					\
    130 		.src_reg = SRC,					\
    131 		.off   = 0,					\
    132 		.imm   = 0 })
    133 
    134 #define BPF_MOV32_REG(DST, SRC)					\
    135 	((struct bpf_insn) {					\
    136 		.code  = BPF_ALU | BPF_MOV | BPF_X,		\
    137 		.dst_reg = DST,					\
    138 		.src_reg = SRC,					\
    139 		.off   = 0,					\
    140 		.imm   = 0 })
    141 
    142 /* Short form of mov, dst_reg = imm32 */
    143 
    144 #define BPF_MOV64_IMM(DST, IMM)					\
    145 	((struct bpf_insn) {					\
    146 		.code  = BPF_ALU64 | BPF_MOV | BPF_K,		\
    147 		.dst_reg = DST,					\
    148 		.src_reg = 0,					\
    149 		.off   = 0,					\
    150 		.imm   = IMM })
    151 
    152 #define BPF_MOV32_IMM(DST, IMM)					\
    153 	((struct bpf_insn) {					\
    154 		.code  = BPF_ALU | BPF_MOV | BPF_K,		\
    155 		.dst_reg = DST,					\
    156 		.src_reg = 0,					\
    157 		.off   = 0,					\
    158 		.imm   = IMM })
    159 
    160 /* BPF_LD_IMM64 macro encodes single 'load 64-bit immediate' insn */
    161 #define BPF_LD_IMM64(DST, IMM)					\
    162 	BPF_LD_IMM64_RAW(DST, 0, IMM)
    163 
    164 #define BPF_LD_IMM64_RAW(DST, SRC, IMM)				\
    165 	((struct bpf_insn) {					\
    166 		.code  = BPF_LD | BPF_DW | BPF_IMM,		\
    167 		.dst_reg = DST,					\
    168 		.src_reg = SRC,					\
    169 		.off   = 0,					\
    170 		.imm   = (__u32) (IMM) }),			\
    171 	((struct bpf_insn) {					\
    172 		.code  = 0, /* zero is reserved opcode */	\
    173 		.dst_reg = 0,					\
    174 		.src_reg = 0,					\
    175 		.off   = 0,					\
    176 		.imm   = ((__u64) (IMM)) >> 32 })
    177 
    178 /* pseudo BPF_LD_IMM64 insn used to refer to process-local map_fd */
    179 #define BPF_LD_MAP_FD(DST, MAP_FD)				\
    180 	BPF_LD_IMM64_RAW(DST, BPF_PSEUDO_MAP_FD, MAP_FD)
    181 
    182 /* Short form of mov based on type, BPF_X: dst_reg = src_reg, BPF_K: dst_reg = imm32 */
    183 
    184 #define BPF_MOV64_RAW(TYPE, DST, SRC, IMM)			\
    185 	((struct bpf_insn) {					\
    186 		.code  = BPF_ALU64 | BPF_MOV | BPF_SRC(TYPE),	\
    187 		.dst_reg = DST,					\
    188 		.src_reg = SRC,					\
    189 		.off   = 0,					\
    190 		.imm   = IMM })
    191 
    192 #define BPF_MOV32_RAW(TYPE, DST, SRC, IMM)			\
    193 	((struct bpf_insn) {					\
    194 		.code  = BPF_ALU | BPF_MOV | BPF_SRC(TYPE),	\
    195 		.dst_reg = DST,					\
    196 		.src_reg = SRC,					\
    197 		.off   = 0,					\
    198 		.imm   = IMM })
    199 
    200 /* Direct packet access, R0 = *(uint *) (skb->data + imm32) */
    201 
    202 #define BPF_LD_ABS(SIZE, IMM)					\
    203 	((struct bpf_insn) {					\
    204 		.code  = BPF_LD | BPF_SIZE(SIZE) | BPF_ABS,	\
    205 		.dst_reg = 0,					\
    206 		.src_reg = 0,					\
    207 		.off   = 0,					\
    208 		.imm   = IMM })
    209 
    210 /* Indirect packet access, R0 = *(uint *) (skb->data + src_reg + imm32) */
    211 
    212 #define BPF_LD_IND(SIZE, SRC, IMM)				\
    213 	((struct bpf_insn) {					\
    214 		.code  = BPF_LD | BPF_SIZE(SIZE) | BPF_IND,	\
    215 		.dst_reg = 0,					\
    216 		.src_reg = SRC,					\
    217 		.off   = 0,					\
    218 		.imm   = IMM })
    219 
    220 /* Memory load, dst_reg = *(uint *) (src_reg + off16) */
    221 
    222 #define BPF_LDX_MEM(SIZE, DST, SRC, OFF)			\
    223 	((struct bpf_insn) {					\
    224 		.code  = BPF_LDX | BPF_SIZE(SIZE) | BPF_MEM,	\
    225 		.dst_reg = DST,					\
    226 		.src_reg = SRC,					\
    227 		.off   = OFF,					\
    228 		.imm   = 0 })
    229 
    230 /* Memory store, *(uint *) (dst_reg + off16) = src_reg */
    231 
    232 #define BPF_STX_MEM(SIZE, DST, SRC, OFF)			\
    233 	((struct bpf_insn) {					\
    234 		.code  = BPF_STX | BPF_SIZE(SIZE) | BPF_MEM,	\
    235 		.dst_reg = DST,					\
    236 		.src_reg = SRC,					\
    237 		.off   = OFF,					\
    238 		.imm   = 0 })
    239 
    240 /* Atomic memory add, *(uint *)(dst_reg + off16) += src_reg */
    241 
    242 #define BPF_STX_XADD(SIZE, DST, SRC, OFF)			\
    243 	((struct bpf_insn) {					\
    244 		.code  = BPF_STX | BPF_SIZE(SIZE) | BPF_XADD,	\
    245 		.dst_reg = DST,					\
    246 		.src_reg = SRC,					\
    247 		.off   = OFF,					\
    248 		.imm   = 0 })
    249 
    250 /* Memory store, *(uint *) (dst_reg + off16) = imm32 */
    251 
    252 #define BPF_ST_MEM(SIZE, DST, OFF, IMM)				\
    253 	((struct bpf_insn) {					\
    254 		.code  = BPF_ST | BPF_SIZE(SIZE) | BPF_MEM,	\
    255 		.dst_reg = DST,					\
    256 		.src_reg = 0,					\
    257 		.off   = OFF,					\
    258 		.imm   = IMM })
    259 
    260 /* Conditional jumps against registers, if (dst_reg 'op' src_reg) goto pc + off16 */
    261 
    262 #define BPF_JMP_REG(OP, DST, SRC, OFF)				\
    263 	((struct bpf_insn) {					\
    264 		.code  = BPF_JMP | BPF_OP(OP) | BPF_X,		\
    265 		.dst_reg = DST,					\
    266 		.src_reg = SRC,					\
    267 		.off   = OFF,					\
    268 		.imm   = 0 })
    269 
    270 /* Conditional jumps against immediates, if (dst_reg 'op' imm32) goto pc + off16 */
    271 
    272 #define BPF_JMP_IMM(OP, DST, IMM, OFF)				\
    273 	((struct bpf_insn) {					\
    274 		.code  = BPF_JMP | BPF_OP(OP) | BPF_K,		\
    275 		.dst_reg = DST,					\
    276 		.src_reg = 0,					\
    277 		.off   = OFF,					\
    278 		.imm   = IMM })
    279 
    280 /* Like BPF_JMP_REG, but with 32-bit wide operands for comparison. */
    281 
    282 #define BPF_JMP32_REG(OP, DST, SRC, OFF)			\
    283 	((struct bpf_insn) {					\
    284 		.code  = BPF_JMP32 | BPF_OP(OP) | BPF_X,	\
    285 		.dst_reg = DST,					\
    286 		.src_reg = SRC,					\
    287 		.off   = OFF,					\
    288 		.imm   = 0 })
    289 
    290 /* Like BPF_JMP_IMM, but with 32-bit wide operands for comparison. */
    291 
    292 #define BPF_JMP32_IMM(OP, DST, IMM, OFF)			\
    293 	((struct bpf_insn) {					\
    294 		.code  = BPF_JMP32 | BPF_OP(OP) | BPF_K,	\
    295 		.dst_reg = DST,					\
    296 		.src_reg = 0,					\
    297 		.off   = OFF,					\
    298 		.imm   = IMM })
    299 
    300 /* Unconditional jumps, goto pc + off16 */
    301 
    302 #define BPF_JMP_A(OFF)						\
    303 	((struct bpf_insn) {					\
    304 		.code  = BPF_JMP | BPF_JA,			\
    305 		.dst_reg = 0,					\
    306 		.src_reg = 0,					\
    307 		.off   = OFF,					\
    308 		.imm   = 0 })
    309 
    310 /* Relative call */
    311 
    312 #define BPF_CALL_REL(TGT)					\
    313 	((struct bpf_insn) {					\
    314 		.code  = BPF_JMP | BPF_CALL,			\
    315 		.dst_reg = 0,					\
    316 		.src_reg = BPF_PSEUDO_CALL,			\
    317 		.off   = 0,					\
    318 		.imm   = TGT })
    319 
    320 /* Function call */
    321 
    322 #define BPF_CAST_CALL(x)					\
    323 		((u64 (*)(u64, u64, u64, u64, u64))(x))
    324 
    325 #define BPF_EMIT_CALL(FUNC)					\
    326 	((struct bpf_insn) {					\
    327 		.code  = BPF_JMP | BPF_CALL,			\
    328 		.dst_reg = 0,					\
    329 		.src_reg = 0,					\
    330 		.off   = 0,					\
    331 		.imm   = ((FUNC) - __bpf_call_base) })
    332 
    333 /* Raw code statement block */
    334 
    335 #define BPF_RAW_INSN(CODE, DST, SRC, OFF, IMM)			\
    336 	((struct bpf_insn) {					\
    337 		.code  = CODE,					\
    338 		.dst_reg = DST,					\
    339 		.src_reg = SRC,					\
    340 		.off   = OFF,					\
    341 		.imm   = IMM })
    342 
    343 /* Program exit */
    344 
    345 #define BPF_EXIT_INSN()						\
    346 	((struct bpf_insn) {					\
    347 		.code  = BPF_JMP | BPF_EXIT,			\
    348 		.dst_reg = 0,					\
    349 		.src_reg = 0,					\
    350 		.off   = 0,					\
    351 		.imm   = 0 })
    352 
    353 /* Internal classic blocks for direct assignment */
    354 
    355 #define __BPF_STMT(CODE, K)					\
    356 	((struct sock_filter) BPF_STMT(CODE, K))
    357 
    358 #define __BPF_JUMP(CODE, K, JT, JF)				\
    359 	((struct sock_filter) BPF_JUMP(CODE, K, JT, JF))
    360 
    361 #define bytes_to_bpf_size(bytes)				\
    362 ({								\
    363 	int bpf_size = -EINVAL;					\
    364 								\
    365 	if (bytes == sizeof(u8))				\
    366 		bpf_size = BPF_B;				\
    367 	else if (bytes == sizeof(u16))				\
    368 		bpf_size = BPF_H;				\
    369 	else if (bytes == sizeof(u32))				\
    370 		bpf_size = BPF_W;				\
    371 	else if (bytes == sizeof(u64))				\
    372 		bpf_size = BPF_DW;				\
    373 								\
    374 	bpf_size;						\
    375 })
    376 
    377 #define bpf_size_to_bytes(bpf_size)				\
    378 ({								\
    379 	int bytes = -EINVAL;					\
    380 								\
    381 	if (bpf_size == BPF_B)					\
    382 		bytes = sizeof(u8);				\
    383 	else if (bpf_size == BPF_H)				\
    384 		bytes = sizeof(u16);				\
    385 	else if (bpf_size == BPF_W)				\
    386 		bytes = sizeof(u32);				\
    387 	else if (bpf_size == BPF_DW)				\
    388 		bytes = sizeof(u64);				\
    389 								\
    390 	bytes;							\
    391 })
    392 
    393 #define BPF_SIZEOF(type)					\
    394 	({							\
    395 		const int __size = bytes_to_bpf_size(sizeof(type)); \
    396 		BUILD_BUG_ON(__size < 0);			\
    397 		__size;						\
    398 	})
    399 
    400 #define BPF_FIELD_SIZEOF(type, field)				\
    401 	({							\
    402 		const int __size = bytes_to_bpf_size(FIELD_SIZEOF(type, field)); \
    403 		BUILD_BUG_ON(__size < 0);			\
    404 		__size;						\
    405 	})
    406 
    407 #define BPF_LDST_BYTES(insn)					\
    408 	({							\
    409 		const int __size = bpf_size_to_bytes(BPF_SIZE((insn)->code)); \
    410 		WARN_ON(__size < 0);				\
    411 		__size;						\
    412 	})
    413 
    414 #define __BPF_MAP_0(m, v, ...) v
    415 #define __BPF_MAP_1(m, v, t, a, ...) m(t, a)
    416 #define __BPF_MAP_2(m, v, t, a, ...) m(t, a), __BPF_MAP_1(m, v, __VA_ARGS__)
    417 #define __BPF_MAP_3(m, v, t, a, ...) m(t, a), __BPF_MAP_2(m, v, __VA_ARGS__)
    418 #define __BPF_MAP_4(m, v, t, a, ...) m(t, a), __BPF_MAP_3(m, v, __VA_ARGS__)
    419 #define __BPF_MAP_5(m, v, t, a, ...) m(t, a), __BPF_MAP_4(m, v, __VA_ARGS__)
    420 
    421 #define __BPF_REG_0(...) __BPF_PAD(5)
    422 #define __BPF_REG_1(...) __BPF_MAP(1, __VA_ARGS__), __BPF_PAD(4)
    423 #define __BPF_REG_2(...) __BPF_MAP(2, __VA_ARGS__), __BPF_PAD(3)
    424 #define __BPF_REG_3(...) __BPF_MAP(3, __VA_ARGS__), __BPF_PAD(2)
    425 #define __BPF_REG_4(...) __BPF_MAP(4, __VA_ARGS__), __BPF_PAD(1)
    426 #define __BPF_REG_5(...) __BPF_MAP(5, __VA_ARGS__)
    427 
    428 #define __BPF_MAP(n, ...) __BPF_MAP_##n(__VA_ARGS__)
    429 #define __BPF_REG(n, ...) __BPF_REG_##n(__VA_ARGS__)
    430 
    431 #define __BPF_CAST(t, a)						       \
    432 	(__force t)							       \
    433 	(__force							       \
    434 	 typeof(__builtin_choose_expr(sizeof(t) == sizeof(unsigned long),      \
    435 				      (unsigned long)0, (t)0))) a
    436 #define __BPF_V void
    437 #define __BPF_N
    438 
    439 #define __BPF_DECL_ARGS(t, a) t   a
    440 #define __BPF_DECL_REGS(t, a) u64 a
    441 
    442 #define __BPF_PAD(n)							       \
    443 	__BPF_MAP(n, __BPF_DECL_ARGS, __BPF_N, u64, __ur_1, u64, __ur_2,       \
    444 		  u64, __ur_3, u64, __ur_4, u64, __ur_5)
    445 
    446 #define BPF_CALL_x(x, name, ...)					       \
    447 	static __always_inline						       \
    448 	u64 ____##name(__BPF_MAP(x, __BPF_DECL_ARGS, __BPF_V, __VA_ARGS__));   \
    449 	u64 name(__BPF_REG(x, __BPF_DECL_REGS, __BPF_N, __VA_ARGS__));	       \
    450 	u64 name(__BPF_REG(x, __BPF_DECL_REGS, __BPF_N, __VA_ARGS__))	       \
    451 	{								       \
    452 		return ____##name(__BPF_MAP(x,__BPF_CAST,__BPF_N,__VA_ARGS__));\
    453 	}								       \
    454 	static __always_inline						       \
    455 	u64 ____##name(__BPF_MAP(x, __BPF_DECL_ARGS, __BPF_V, __VA_ARGS__))
    456 
    457 #define BPF_CALL_0(name, ...)	BPF_CALL_x(0, name, __VA_ARGS__)
    458 #define BPF_CALL_1(name, ...)	BPF_CALL_x(1, name, __VA_ARGS__)
    459 #define BPF_CALL_2(name, ...)	BPF_CALL_x(2, name, __VA_ARGS__)
    460 #define BPF_CALL_3(name, ...)	BPF_CALL_x(3, name, __VA_ARGS__)
    461 #define BPF_CALL_4(name, ...)	BPF_CALL_x(4, name, __VA_ARGS__)
    462 #define BPF_CALL_5(name, ...)	BPF_CALL_x(5, name, __VA_ARGS__)
    463 
    464 #define bpf_ctx_range(TYPE, MEMBER)						\
    465 	offsetof(TYPE, MEMBER) ... offsetofend(TYPE, MEMBER) - 1
    466 #define bpf_ctx_range_till(TYPE, MEMBER1, MEMBER2)				\
    467 	offsetof(TYPE, MEMBER1) ... offsetofend(TYPE, MEMBER2) - 1
    468 #if BITS_PER_LONG == 64
    469 # define bpf_ctx_range_ptr(TYPE, MEMBER)					\
    470 	offsetof(TYPE, MEMBER) ... offsetofend(TYPE, MEMBER) - 1
    471 #else
    472 # define bpf_ctx_range_ptr(TYPE, MEMBER)					\
    473 	offsetof(TYPE, MEMBER) ... offsetof(TYPE, MEMBER) + 8 - 1
    474 #endif /* BITS_PER_LONG == 64 */
    475 
    476 #define bpf_target_off(TYPE, MEMBER, SIZE, PTR_SIZE)				\
    477 	({									\
    478 		BUILD_BUG_ON(FIELD_SIZEOF(TYPE, MEMBER) != (SIZE));		\
    479 		*(PTR_SIZE) = (SIZE);						\
    480 		offsetof(TYPE, MEMBER);						\
    481 	})
    482 
    483 #ifdef CONFIG_COMPAT
    484 /* A struct sock_filter is architecture independent. */
    485 struct compat_sock_fprog {
    486 	u16		len;
    487 	compat_uptr_t	filter;	/* struct sock_filter * */
    488 };
    489 #endif
    490 
    491 struct sock_fprog_kern {
    492 	u16			len;
    493 	struct sock_filter	*filter;
    494 };
    495 
    496 struct bpf_binary_header {
    497 	u32 pages;
    498 	/* Some arches need word alignment for their instructions */
    499 	u8 image[] __aligned(4);
    500 };
    501 
    502 struct bpf_prog {
    503 	u16			pages;		/* Number of allocated pages */
    504 	u16			jited:1,	/* Is our filter JIT'ed? */
    505 				jit_requested:1,/* archs need to JIT the prog */
    506 				undo_set_mem:1,	/* Passed set_memory_ro() checkpoint */
    507 				gpl_compatible:1, /* Is filter GPL compatible? */
    508 				cb_access:1,	/* Is control block accessed? */
    509 				dst_needed:1,	/* Do we need dst entry? */
    510 				blinded:1,	/* Was blinded */
    511 				is_func:1,	/* program is a bpf function */
    512 				kprobe_override:1, /* Do we override a kprobe? */
    513 				has_callchain_buf:1; /* callchain buffer allocated? */
    514 	enum bpf_prog_type	type;		/* Type of BPF program */
    515 	enum bpf_attach_type	expected_attach_type; /* For some prog types */
    516 	u32			len;		/* Number of filter blocks */
    517 	u32			jited_len;	/* Size of jited insns in bytes */
    518 	u8			tag[BPF_TAG_SIZE];
    519 	struct bpf_prog_aux	*aux;		/* Auxiliary fields */
    520 	struct sock_fprog_kern	*orig_prog;	/* Original BPF program */
    521 	unsigned int		(*bpf_func)(const void *ctx,
    522 					    const struct bpf_insn *insn);
    523 	/* Instructions for interpreter */
    524 	union {
    525 		struct sock_filter	insns[0];
    526 		struct bpf_insn		insnsi[0];
    527 	};
    528 };
    529 
    530 struct sk_filter {
    531 	refcount_t	refcnt;
    532 	struct rcu_head	rcu;
    533 	struct bpf_prog	*prog;
    534 };
    535 
    536 DECLARE_STATIC_KEY_FALSE(bpf_stats_enabled_key);
    537 
    538 #define BPF_PROG_RUN(prog, ctx)	({				\
    539 	u32 ret;						\
    540 	cant_sleep();						\
    541 	if (static_branch_unlikely(&bpf_stats_enabled_key)) {	\
    542 		struct bpf_prog_stats *stats;			\
    543 		u64 start = sched_clock();			\
    544 		ret = (*(prog)->bpf_func)(ctx, (prog)->insnsi);	\
    545 		stats = this_cpu_ptr(prog->aux->stats);		\
    546 		u64_stats_update_begin(&stats->syncp);		\
    547 		stats->cnt++;					\
    548 		stats->nsecs += sched_clock() - start;		\
    549 		u64_stats_update_end(&stats->syncp);		\
    550 	} else {						\
    551 		ret = (*(prog)->bpf_func)(ctx, (prog)->insnsi);	\
    552 	}							\
    553 	ret; })
    554 
    555 #define BPF_SKB_CB_LEN QDISC_CB_PRIV_LEN
    556 
    557 struct bpf_skb_data_end {
    558 	struct qdisc_skb_cb qdisc_cb;
    559 	void *data_meta;
    560 	void *data_end;
    561 };
    562 
    563 struct bpf_redirect_info {
    564 	u32 ifindex;
    565 	u32 flags;
    566 	struct bpf_map *map;
    567 	struct bpf_map *map_to_flush;
    568 	u32 kern_flags;
    569 };
    570 
    571 DECLARE_PER_CPU(struct bpf_redirect_info, bpf_redirect_info);
    572 
    573 /* flags for bpf_redirect_info kern_flags */
    574 #define BPF_RI_F_RF_NO_DIRECT	BIT(0)	/* no napi_direct on return_frame */
    575 
    576 /* Compute the linear packet data range [data, data_end) which
    577  * will be accessed by various program types (cls_bpf, act_bpf,
    578  * lwt, ...). Subsystems allowing direct data access must (!)
    579  * ensure that cb[] area can be written to when BPF program is
    580  * invoked (otherwise cb[] save/restore is necessary).
    581  */
    582 static inline void bpf_compute_data_pointers(struct sk_buff *skb)
    583 {
    584 	struct bpf_skb_data_end *cb = (struct bpf_skb_data_end *)skb->cb;
    585 
    586 	BUILD_BUG_ON(sizeof(*cb) > FIELD_SIZEOF(struct sk_buff, cb));
    587 	cb->data_meta = skb->data - skb_metadata_len(skb);
    588 	cb->data_end  = skb->data + skb_headlen(skb);
    589 }
    590 
    591 /* Similar to bpf_compute_data_pointers(), except that save orginal
    592  * data in cb->data and cb->meta_data for restore.
    593  */
    594 static inline void bpf_compute_and_save_data_end(
    595 	struct sk_buff *skb, void **saved_data_end)
    596 {
    597 	struct bpf_skb_data_end *cb = (struct bpf_skb_data_end *)skb->cb;
    598 
    599 	*saved_data_end = cb->data_end;
    600 	cb->data_end  = skb->data + skb_headlen(skb);
    601 }
    602 
    603 /* Restore data saved by bpf_compute_data_pointers(). */
    604 static inline void bpf_restore_data_end(
    605 	struct sk_buff *skb, void *saved_data_end)
    606 {
    607 	struct bpf_skb_data_end *cb = (struct bpf_skb_data_end *)skb->cb;
    608 
    609 	cb->data_end = saved_data_end;
    610 }
    611 
    612 static inline u8 *bpf_skb_cb(struct sk_buff *skb)
    613 {
    614 	/* eBPF programs may read/write skb->cb[] area to transfer meta
    615 	 * data between tail calls. Since this also needs to work with
    616 	 * tc, that scratch memory is mapped to qdisc_skb_cb's data area.
    617 	 *
    618 	 * In some socket filter cases, the cb unfortunately needs to be
    619 	 * saved/restored so that protocol specific skb->cb[] data won't
    620 	 * be lost. In any case, due to unpriviledged eBPF programs
    621 	 * attached to sockets, we need to clear the bpf_skb_cb() area
    622 	 * to not leak previous contents to user space.
    623 	 */
    624 	BUILD_BUG_ON(FIELD_SIZEOF(struct __sk_buff, cb) != BPF_SKB_CB_LEN);
    625 	BUILD_BUG_ON(FIELD_SIZEOF(struct __sk_buff, cb) !=
    626 		     FIELD_SIZEOF(struct qdisc_skb_cb, data));
    627 
    628 	return qdisc_skb_cb(skb)->data;
    629 }
    630 
    631 static inline u32 __bpf_prog_run_save_cb(const struct bpf_prog *prog,
    632 					 struct sk_buff *skb)
    633 {
    634 	u8 *cb_data = bpf_skb_cb(skb);
    635 	u8 cb_saved[BPF_SKB_CB_LEN];
    636 	u32 res;
    637 
    638 	if (unlikely(prog->cb_access)) {
    639 		memcpy(cb_saved, cb_data, sizeof(cb_saved));
    640 		memset(cb_data, 0, sizeof(cb_saved));
    641 	}
    642 
    643 	res = BPF_PROG_RUN(prog, skb);
    644 
    645 	if (unlikely(prog->cb_access))
    646 		memcpy(cb_data, cb_saved, sizeof(cb_saved));
    647 
    648 	return res;
    649 }
    650 
    651 static inline u32 bpf_prog_run_save_cb(const struct bpf_prog *prog,
    652 				       struct sk_buff *skb)
    653 {
    654 	u32 res;
    655 
    656 	preempt_disable();
    657 	res = __bpf_prog_run_save_cb(prog, skb);
    658 	preempt_enable();
    659 	return res;
    660 }
    661 
    662 static inline u32 bpf_prog_run_clear_cb(const struct bpf_prog *prog,
    663 					struct sk_buff *skb)
    664 {
    665 	u8 *cb_data = bpf_skb_cb(skb);
    666 	u32 res;
    667 
    668 	if (unlikely(prog->cb_access))
    669 		memset(cb_data, 0, BPF_SKB_CB_LEN);
    670 
    671 	preempt_disable();
    672 	res = BPF_PROG_RUN(prog, skb);
    673 	preempt_enable();
    674 	return res;
    675 }
    676 
    677 static __always_inline u32 bpf_prog_run_xdp(const struct bpf_prog *prog,
    678 					    struct xdp_buff *xdp)
    679 {
    680 	/* Caller needs to hold rcu_read_lock() (!), otherwise program
    681 	 * can be released while still running, or map elements could be
    682 	 * freed early while still having concurrent users. XDP fastpath
    683 	 * already takes rcu_read_lock() when fetching the program, so
    684 	 * it's not necessary here anymore.
    685 	 */
    686 	return BPF_PROG_RUN(prog, xdp);
    687 }
    688 
    689 static inline u32 bpf_prog_insn_size(const struct bpf_prog *prog)
    690 {
    691 	return prog->len * sizeof(struct bpf_insn);
    692 }
    693 
    694 static inline u32 bpf_prog_tag_scratch_size(const struct bpf_prog *prog)
    695 {
    696 	return round_up(bpf_prog_insn_size(prog) +
    697 			sizeof(__be64) + 1, SHA_MESSAGE_BYTES);
    698 }
    699 
    700 static inline unsigned int bpf_prog_size(unsigned int proglen)
    701 {
    702 	return max(sizeof(struct bpf_prog),
    703 		   offsetof(struct bpf_prog, insns[proglen]));
    704 }
    705 
    706 static inline bool bpf_prog_was_classic(const struct bpf_prog *prog)
    707 {
    708 	/* When classic BPF programs have been loaded and the arch
    709 	 * does not have a classic BPF JIT (anymore), they have been
    710 	 * converted via bpf_migrate_filter() to eBPF and thus always
    711 	 * have an unspec program type.
    712 	 */
    713 	return prog->type == BPF_PROG_TYPE_UNSPEC;
    714 }
    715 
    716 static inline u32 bpf_ctx_off_adjust_machine(u32 size)
    717 {
    718 	const u32 size_machine = sizeof(unsigned long);
    719 
    720 	if (size > size_machine && size % size_machine == 0)
    721 		size = size_machine;
    722 
    723 	return size;
    724 }
    725 
    726 static inline bool
    727 bpf_ctx_narrow_access_ok(u32 off, u32 size, u32 size_default)
    728 {
    729 	return size <= size_default && (size & (size - 1)) == 0;
    730 }
    731 
    732 #define bpf_classic_proglen(fprog) (fprog->len * sizeof(fprog->filter[0]))
    733 
    734 static inline void bpf_prog_lock_ro(struct bpf_prog *fp)
    735 {
    736 	fp->undo_set_mem = 1;
    737 	set_memory_ro((unsigned long)fp, fp->pages);
    738 }
    739 
    740 static inline void bpf_prog_unlock_ro(struct bpf_prog *fp)
    741 {
    742 	if (fp->undo_set_mem)
    743 		set_memory_rw((unsigned long)fp, fp->pages);
    744 }
    745 
    746 static inline void bpf_jit_binary_lock_ro(struct bpf_binary_header *hdr)
    747 {
    748 	set_memory_ro((unsigned long)hdr, hdr->pages);
    749 }
    750 
    751 static inline void bpf_jit_binary_unlock_ro(struct bpf_binary_header *hdr)
    752 {
    753 	set_memory_rw((unsigned long)hdr, hdr->pages);
    754 }
    755 
    756 static inline struct bpf_binary_header *
    757 bpf_jit_binary_hdr(const struct bpf_prog *fp)
    758 {
    759 	unsigned long real_start = (unsigned long)fp->bpf_func;
    760 	unsigned long addr = real_start & PAGE_MASK;
    761 
    762 	return (void *)addr;
    763 }
    764 
    765 int sk_filter_trim_cap(struct sock *sk, struct sk_buff *skb, unsigned int cap);
    766 static inline int sk_filter(struct sock *sk, struct sk_buff *skb)
    767 {
    768 	return sk_filter_trim_cap(sk, skb, 1);
    769 }
    770 
    771 struct bpf_prog *bpf_prog_select_runtime(struct bpf_prog *fp, int *err);
    772 void bpf_prog_free(struct bpf_prog *fp);
    773 
    774 bool bpf_opcode_in_insntable(u8 code);
    775 
    776 void bpf_prog_free_linfo(struct bpf_prog *prog);
    777 void bpf_prog_fill_jited_linfo(struct bpf_prog *prog,
    778 			       const u32 *insn_to_jit_off);
    779 int bpf_prog_alloc_jited_linfo(struct bpf_prog *prog);
    780 void bpf_prog_free_jited_linfo(struct bpf_prog *prog);
    781 void bpf_prog_free_unused_jited_linfo(struct bpf_prog *prog);
    782 
    783 struct bpf_prog *bpf_prog_alloc(unsigned int size, gfp_t gfp_extra_flags);
    784 struct bpf_prog *bpf_prog_alloc_no_stats(unsigned int size, gfp_t gfp_extra_flags);
    785 struct bpf_prog *bpf_prog_realloc(struct bpf_prog *fp_old, unsigned int size,
    786 				  gfp_t gfp_extra_flags);
    787 void __bpf_prog_free(struct bpf_prog *fp);
    788 
    789 static inline void bpf_prog_unlock_free(struct bpf_prog *fp)
    790 {
    791 	bpf_prog_unlock_ro(fp);
    792 	__bpf_prog_free(fp);
    793 }
    794 
    795 typedef int (*bpf_aux_classic_check_t)(struct sock_filter *filter,
    796 				       unsigned int flen);
    797 
    798 int bpf_prog_create(struct bpf_prog **pfp, struct sock_fprog_kern *fprog);
    799 int bpf_prog_create_from_user(struct bpf_prog **pfp, struct sock_fprog *fprog,
    800 			      bpf_aux_classic_check_t trans, bool save_orig);
    801 void bpf_prog_destroy(struct bpf_prog *fp);
    802 
    803 int sk_attach_filter(struct sock_fprog *fprog, struct sock *sk);
    804 int sk_attach_bpf(u32 ufd, struct sock *sk);
    805 int sk_reuseport_attach_filter(struct sock_fprog *fprog, struct sock *sk);
    806 int sk_reuseport_attach_bpf(u32 ufd, struct sock *sk);
    807 void sk_reuseport_prog_free(struct bpf_prog *prog);
    808 int sk_detach_filter(struct sock *sk);
    809 int sk_get_filter(struct sock *sk, struct sock_filter __user *filter,
    810 		  unsigned int len);
    811 
    812 bool sk_filter_charge(struct sock *sk, struct sk_filter *fp);
    813 void sk_filter_uncharge(struct sock *sk, struct sk_filter *fp);
    814 
    815 u64 __bpf_call_base(u64 r1, u64 r2, u64 r3, u64 r4, u64 r5);
    816 #define __bpf_call_base_args \
    817 	((u64 (*)(u64, u64, u64, u64, u64, const struct bpf_insn *)) \
    818 	 __bpf_call_base)
    819 
    820 struct bpf_prog *bpf_int_jit_compile(struct bpf_prog *prog);
    821 void bpf_jit_compile(struct bpf_prog *prog);
    822 bool bpf_helper_changes_pkt_data(void *func);
    823 
    824 static inline bool bpf_dump_raw_ok(void)
    825 {
    826 	/* Reconstruction of call-sites is dependent on kallsyms,
    827 	 * thus make dump the same restriction.
    828 	 */
    829 	return kallsyms_show_value() == 1;
    830 }
    831 
    832 struct bpf_prog *bpf_patch_insn_single(struct bpf_prog *prog, u32 off,
    833 				       const struct bpf_insn *patch, u32 len);
    834 int bpf_remove_insns(struct bpf_prog *prog, u32 off, u32 cnt);
    835 
    836 void bpf_clear_redirect_map(struct bpf_map *map);
    837 
    838 static inline bool xdp_return_frame_no_direct(void)
    839 {
    840 	struct bpf_redirect_info *ri = this_cpu_ptr(&bpf_redirect_info);
    841 
    842 	return ri->kern_flags & BPF_RI_F_RF_NO_DIRECT;
    843 }
    844 
    845 static inline void xdp_set_return_frame_no_direct(void)
    846 {
    847 	struct bpf_redirect_info *ri = this_cpu_ptr(&bpf_redirect_info);
    848 
    849 	ri->kern_flags |= BPF_RI_F_RF_NO_DIRECT;
    850 }
    851 
    852 static inline void xdp_clear_return_frame_no_direct(void)
    853 {
    854 	struct bpf_redirect_info *ri = this_cpu_ptr(&bpf_redirect_info);
    855 
    856 	ri->kern_flags &= ~BPF_RI_F_RF_NO_DIRECT;
    857 }
    858 
    859 static inline int xdp_ok_fwd_dev(const struct net_device *fwd,
    860 				 unsigned int pktlen)
    861 {
    862 	unsigned int len;
    863 
    864 	if (unlikely(!(fwd->flags & IFF_UP)))
    865 		return -ENETDOWN;
    866 
    867 	len = fwd->mtu + fwd->hard_header_len + VLAN_HLEN;
    868 	if (pktlen > len)
    869 		return -EMSGSIZE;
    870 
    871 	return 0;
    872 }
    873 
    874 /* The pair of xdp_do_redirect and xdp_do_flush_map MUST be called in the
    875  * same cpu context. Further for best results no more than a single map
    876  * for the do_redirect/do_flush pair should be used. This limitation is
    877  * because we only track one map and force a flush when the map changes.
    878  * This does not appear to be a real limitation for existing software.
    879  */
    880 int xdp_do_generic_redirect(struct net_device *dev, struct sk_buff *skb,
    881 			    struct xdp_buff *xdp, struct bpf_prog *prog);
    882 int xdp_do_redirect(struct net_device *dev,
    883 		    struct xdp_buff *xdp,
    884 		    struct bpf_prog *prog);
    885 void xdp_do_flush_map(void);
    886 
    887 void bpf_warn_invalid_xdp_action(u32 act);
    888 
    889 #ifdef CONFIG_INET
    890 struct sock *bpf_run_sk_reuseport(struct sock_reuseport *reuse, struct sock *sk,
    891 				  struct bpf_prog *prog, struct sk_buff *skb,
    892 				  u32 hash);
    893 #else
    894 static inline struct sock *
    895 bpf_run_sk_reuseport(struct sock_reuseport *reuse, struct sock *sk,
    896 		     struct bpf_prog *prog, struct sk_buff *skb,
    897 		     u32 hash)
    898 {
    899 	return NULL;
    900 }
    901 #endif
    902 
    903 #ifdef CONFIG_BPF_JIT
    904 extern int bpf_jit_enable;
    905 extern int bpf_jit_harden;
    906 extern int bpf_jit_kallsyms;
    907 extern long bpf_jit_limit;
    908 
    909 typedef void (*bpf_jit_fill_hole_t)(void *area, unsigned int size);
    910 
    911 struct bpf_binary_header *
    912 bpf_jit_binary_alloc(unsigned int proglen, u8 **image_ptr,
    913 		     unsigned int alignment,
    914 		     bpf_jit_fill_hole_t bpf_fill_ill_insns);
    915 void bpf_jit_binary_free(struct bpf_binary_header *hdr);
    916 u64 bpf_jit_alloc_exec_limit(void);
    917 void *bpf_jit_alloc_exec(unsigned long size);
    918 void bpf_jit_free_exec(void *addr);
    919 void bpf_jit_free(struct bpf_prog *fp);
    920 
    921 int bpf_jit_get_func_addr(const struct bpf_prog *prog,
    922 			  const struct bpf_insn *insn, bool extra_pass,
    923 			  u64 *func_addr, bool *func_addr_fixed);
    924 
    925 struct bpf_prog *bpf_jit_blind_constants(struct bpf_prog *fp);
    926 void bpf_jit_prog_release_other(struct bpf_prog *fp, struct bpf_prog *fp_other);
    927 
    928 static inline void bpf_jit_dump(unsigned int flen, unsigned int proglen,
    929 				u32 pass, void *image)
    930 {
    931 	pr_err("flen=%u proglen=%u pass=%u image=%pK from=%s pid=%d\n", flen,
    932 	       proglen, pass, image, current->comm, task_pid_nr(current));
    933 
    934 	if (image)
    935 		print_hex_dump(KERN_ERR, "JIT code: ", DUMP_PREFIX_OFFSET,
    936 			       16, 1, image, proglen, false);
    937 }
    938 
    939 static inline bool bpf_jit_is_ebpf(void)
    940 {
    941 # ifdef CONFIG_HAVE_EBPF_JIT
    942 	return true;
    943 # else
    944 	return false;
    945 # endif
    946 }
    947 
    948 static inline bool ebpf_jit_enabled(void)
    949 {
    950 	return bpf_jit_enable && bpf_jit_is_ebpf();
    951 }
    952 
    953 static inline bool bpf_prog_ebpf_jited(const struct bpf_prog *fp)
    954 {
    955 	return fp->jited && bpf_jit_is_ebpf();
    956 }
    957 
    958 static inline bool bpf_jit_blinding_enabled(struct bpf_prog *prog)
    959 {
    960 	/* These are the prerequisites, should someone ever have the
    961 	 * idea to call blinding outside of them, we make sure to
    962 	 * bail out.
    963 	 */
    964 	if (!bpf_jit_is_ebpf())
    965 		return false;
    966 	if (!prog->jit_requested)
    967 		return false;
    968 	if (!bpf_jit_harden)
    969 		return false;
    970 	if (bpf_jit_harden == 1 && capable(CAP_SYS_ADMIN))
    971 		return false;
    972 
    973 	return true;
    974 }
    975 
    976 static inline bool bpf_jit_kallsyms_enabled(void)
    977 {
    978 	/* There are a couple of corner cases where kallsyms should
    979 	 * not be enabled f.e. on hardening.
    980 	 */
    981 	if (bpf_jit_harden)
    982 		return false;
    983 	if (!bpf_jit_kallsyms)
    984 		return false;
    985 	if (bpf_jit_kallsyms == 1)
    986 		return true;
    987 
    988 	return false;
    989 }
    990 
    991 const char *__bpf_address_lookup(unsigned long addr, unsigned long *size,
    992 				 unsigned long *off, char *sym);
    993 bool is_bpf_text_address(unsigned long addr);
    994 int bpf_get_kallsym(unsigned int symnum, unsigned long *value, char *type,
    995 		    char *sym);
    996 
    997 static inline const char *
    998 bpf_address_lookup(unsigned long addr, unsigned long *size,
    999 		   unsigned long *off, char **modname, char *sym)
   1000 {
   1001 	const char *ret = __bpf_address_lookup(addr, size, off, sym);
   1002 
   1003 	if (ret && modname)
   1004 		*modname = NULL;
   1005 	return ret;
   1006 }
   1007 
   1008 void bpf_prog_kallsyms_add(struct bpf_prog *fp);
   1009 void bpf_prog_kallsyms_del(struct bpf_prog *fp);
   1010 void bpf_get_prog_name(const struct bpf_prog *prog, char *sym);
   1011 
   1012 #else /* CONFIG_BPF_JIT */
   1013 
   1014 static inline bool ebpf_jit_enabled(void)
   1015 {
   1016 	return false;
   1017 }
   1018 
   1019 static inline bool bpf_prog_ebpf_jited(const struct bpf_prog *fp)
   1020 {
   1021 	return false;
   1022 }
   1023 
   1024 static inline void bpf_jit_free(struct bpf_prog *fp)
   1025 {
   1026 	bpf_prog_unlock_free(fp);
   1027 }
   1028 
   1029 static inline bool bpf_jit_kallsyms_enabled(void)
   1030 {
   1031 	return false;
   1032 }
   1033 
   1034 static inline const char *
   1035 __bpf_address_lookup(unsigned long addr, unsigned long *size,
   1036 		     unsigned long *off, char *sym)
   1037 {
   1038 	return NULL;
   1039 }
   1040 
   1041 static inline bool is_bpf_text_address(unsigned long addr)
   1042 {
   1043 	return false;
   1044 }
   1045 
   1046 static inline int bpf_get_kallsym(unsigned int symnum, unsigned long *value,
   1047 				  char *type, char *sym)
   1048 {
   1049 	return -ERANGE;
   1050 }
   1051 
   1052 static inline const char *
   1053 bpf_address_lookup(unsigned long addr, unsigned long *size,
   1054 		   unsigned long *off, char **modname, char *sym)
   1055 {
   1056 	return NULL;
   1057 }
   1058 
   1059 static inline void bpf_prog_kallsyms_add(struct bpf_prog *fp)
   1060 {
   1061 }
   1062 
   1063 static inline void bpf_prog_kallsyms_del(struct bpf_prog *fp)
   1064 {
   1065 }
   1066 
   1067 static inline void bpf_get_prog_name(const struct bpf_prog *prog, char *sym)
   1068 {
   1069 	sym[0] = '\0';
   1070 }
   1071 
   1072 #endif /* CONFIG_BPF_JIT */
   1073 
   1074 void bpf_prog_kallsyms_del_subprogs(struct bpf_prog *fp);
   1075 void bpf_prog_kallsyms_del_all(struct bpf_prog *fp);
   1076 
   1077 #define BPF_ANC		BIT(15)
   1078 
   1079 static inline bool bpf_needs_clear_a(const struct sock_filter *first)
   1080 {
   1081 	switch (first->code) {
   1082 	case BPF_RET | BPF_K:
   1083 	case BPF_LD | BPF_W | BPF_LEN:
   1084 		return false;
   1085 
   1086 	case BPF_LD | BPF_W | BPF_ABS:
   1087 	case BPF_LD | BPF_H | BPF_ABS:
   1088 	case BPF_LD | BPF_B | BPF_ABS:
   1089 		if (first->k == SKF_AD_OFF + SKF_AD_ALU_XOR_X)
   1090 			return true;
   1091 		return false;
   1092 
   1093 	default:
   1094 		return true;
   1095 	}
   1096 }
   1097 
   1098 static inline u16 bpf_anc_helper(const struct sock_filter *ftest)
   1099 {
   1100 	BUG_ON(ftest->code & BPF_ANC);
   1101 
   1102 	switch (ftest->code) {
   1103 	case BPF_LD | BPF_W | BPF_ABS:
   1104 	case BPF_LD | BPF_H | BPF_ABS:
   1105 	case BPF_LD | BPF_B | BPF_ABS:
   1106 #define BPF_ANCILLARY(CODE)	case SKF_AD_OFF + SKF_AD_##CODE:	\
   1107 				return BPF_ANC | SKF_AD_##CODE
   1108 		switch (ftest->k) {
   1109 		BPF_ANCILLARY(PROTOCOL);
   1110 		BPF_ANCILLARY(PKTTYPE);
   1111 		BPF_ANCILLARY(IFINDEX);
   1112 		BPF_ANCILLARY(NLATTR);
   1113 		BPF_ANCILLARY(NLATTR_NEST);
   1114 		BPF_ANCILLARY(MARK);
   1115 		BPF_ANCILLARY(QUEUE);
   1116 		BPF_ANCILLARY(HATYPE);
   1117 		BPF_ANCILLARY(RXHASH);
   1118 		BPF_ANCILLARY(CPU);
   1119 		BPF_ANCILLARY(ALU_XOR_X);
   1120 		BPF_ANCILLARY(VLAN_TAG);
   1121 		BPF_ANCILLARY(VLAN_TAG_PRESENT);
   1122 		BPF_ANCILLARY(PAY_OFFSET);
   1123 		BPF_ANCILLARY(RANDOM);
   1124 		BPF_ANCILLARY(VLAN_TPID);
   1125 		}
   1126 		/* Fallthrough. */
   1127 	default:
   1128 		return ftest->code;
   1129 	}
   1130 }
   1131 
   1132 void *bpf_internal_load_pointer_neg_helper(const struct sk_buff *skb,
   1133 					   int k, unsigned int size);
   1134 
   1135 static inline void *bpf_load_pointer(const struct sk_buff *skb, int k,
   1136 				     unsigned int size, void *buffer)
   1137 {
   1138 	if (k >= 0)
   1139 		return skb_header_pointer(skb, k, size, buffer);
   1140 
   1141 	return bpf_internal_load_pointer_neg_helper(skb, k, size);
   1142 }
   1143 
   1144 static inline int bpf_tell_extensions(void)
   1145 {
   1146 	return SKF_AD_MAX;
   1147 }
   1148 
   1149 struct bpf_sock_addr_kern {
   1150 	struct sock *sk;
   1151 	struct sockaddr *uaddr;
   1152 	/* Temporary "register" to make indirect stores to nested structures
   1153 	 * defined above. We need three registers to make such a store, but
   1154 	 * only two (src and dst) are available at convert_ctx_access time
   1155 	 */
   1156 	u64 tmp_reg;
   1157 	void *t_ctx;	/* Attach type specific context. */
   1158 };
   1159 
   1160 struct bpf_sock_ops_kern {
   1161 	struct	sock *sk;
   1162 	u32	op;
   1163 	union {
   1164 		u32 args[4];
   1165 		u32 reply;
   1166 		u32 replylong[4];
   1167 	};
   1168 	u32	is_fullsock;
   1169 	u64	temp;			/* temp and everything after is not
   1170 					 * initialized to 0 before calling
   1171 					 * the BPF program. New fields that
   1172 					 * should be initialized to 0 should
   1173 					 * be inserted before temp.
   1174 					 * temp is scratch storage used by
   1175 					 * sock_ops_convert_ctx_access
   1176 					 * as temporary storage of a register.
   1177 					 */
   1178 };
   1179 
   1180 #endif /* __LINUX_FILTER_H__ */