From 57f0f512b273f60d52568b8c6b77e17f5636edc0 Mon Sep 17 00:00:00 2001 From: André Fabian Silva Delgado Date: Wed, 5 Aug 2015 17:04:01 -0300 Subject: Initial import --- include/linux/filter.h | 482 +++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 482 insertions(+) create mode 100644 include/linux/filter.h (limited to 'include/linux/filter.h') diff --git a/include/linux/filter.h b/include/linux/filter.h new file mode 100644 index 000000000..fa11b3a36 --- /dev/null +++ b/include/linux/filter.h @@ -0,0 +1,482 @@ +/* + * Linux Socket Filter Data Structures + */ +#ifndef __LINUX_FILTER_H__ +#define __LINUX_FILTER_H__ + +#include + +#include +#include +#include +#include +#include +#include + +#include + +#include +#include + +struct sk_buff; +struct sock; +struct seccomp_data; +struct bpf_prog_aux; + +/* ArgX, context and stack frame pointer register positions. Note, + * Arg1, Arg2, Arg3, etc are used as argument mappings of function + * calls in BPF_CALL instruction. + */ +#define BPF_REG_ARG1 BPF_REG_1 +#define BPF_REG_ARG2 BPF_REG_2 +#define BPF_REG_ARG3 BPF_REG_3 +#define BPF_REG_ARG4 BPF_REG_4 +#define BPF_REG_ARG5 BPF_REG_5 +#define BPF_REG_CTX BPF_REG_6 +#define BPF_REG_FP BPF_REG_10 + +/* Additional register mappings for converted user programs. */ +#define BPF_REG_A BPF_REG_0 +#define BPF_REG_X BPF_REG_7 +#define BPF_REG_TMP BPF_REG_8 + +/* BPF program can access up to 512 bytes of stack space. */ +#define MAX_BPF_STACK 512 + +/* Helper macros for filter block array initializers. */ + +/* ALU ops on registers, bpf_add|sub|...: dst_reg += src_reg */ + +#define BPF_ALU64_REG(OP, DST, SRC) \ + ((struct bpf_insn) { \ + .code = BPF_ALU64 | BPF_OP(OP) | BPF_X, \ + .dst_reg = DST, \ + .src_reg = SRC, \ + .off = 0, \ + .imm = 0 }) + +#define BPF_ALU32_REG(OP, DST, SRC) \ + ((struct bpf_insn) { \ + .code = BPF_ALU | BPF_OP(OP) | BPF_X, \ + .dst_reg = DST, \ + .src_reg = SRC, \ + .off = 0, \ + .imm = 0 }) + +/* ALU ops on immediates, bpf_add|sub|...: dst_reg += imm32 */ + +#define BPF_ALU64_IMM(OP, DST, IMM) \ + ((struct bpf_insn) { \ + .code = BPF_ALU64 | BPF_OP(OP) | BPF_K, \ + .dst_reg = DST, \ + .src_reg = 0, \ + .off = 0, \ + .imm = IMM }) + +#define BPF_ALU32_IMM(OP, DST, IMM) \ + ((struct bpf_insn) { \ + .code = BPF_ALU | BPF_OP(OP) | BPF_K, \ + .dst_reg = DST, \ + .src_reg = 0, \ + .off = 0, \ + .imm = IMM }) + +/* Endianess conversion, cpu_to_{l,b}e(), {l,b}e_to_cpu() */ + +#define BPF_ENDIAN(TYPE, DST, LEN) \ + ((struct bpf_insn) { \ + .code = BPF_ALU | BPF_END | BPF_SRC(TYPE), \ + .dst_reg = DST, \ + .src_reg = 0, \ + .off = 0, \ + .imm = LEN }) + +/* Short form of mov, dst_reg = src_reg */ + +#define BPF_MOV64_REG(DST, SRC) \ + ((struct bpf_insn) { \ + .code = BPF_ALU64 | BPF_MOV | BPF_X, \ + .dst_reg = DST, \ + .src_reg = SRC, \ + .off = 0, \ + .imm = 0 }) + +#define BPF_MOV32_REG(DST, SRC) \ + ((struct bpf_insn) { \ + .code = BPF_ALU | BPF_MOV | BPF_X, \ + .dst_reg = DST, \ + .src_reg = SRC, \ + .off = 0, \ + .imm = 0 }) + +/* Short form of mov, dst_reg = imm32 */ + +#define BPF_MOV64_IMM(DST, IMM) \ + ((struct bpf_insn) { \ + .code = BPF_ALU64 | BPF_MOV | BPF_K, \ + .dst_reg = DST, \ + .src_reg = 0, \ + .off = 0, \ + .imm = IMM }) + +#define BPF_MOV32_IMM(DST, IMM) \ + ((struct bpf_insn) { \ + .code = BPF_ALU | BPF_MOV | BPF_K, \ + .dst_reg = DST, \ + .src_reg = 0, \ + .off = 0, \ + .imm = IMM }) + +/* BPF_LD_IMM64 macro encodes single 'load 64-bit immediate' insn */ +#define BPF_LD_IMM64(DST, IMM) \ + BPF_LD_IMM64_RAW(DST, 0, IMM) + +#define BPF_LD_IMM64_RAW(DST, SRC, IMM) \ + ((struct bpf_insn) { \ + .code = BPF_LD | BPF_DW | BPF_IMM, \ + .dst_reg = DST, \ + .src_reg = SRC, \ + .off = 0, \ + .imm = (__u32) (IMM) }), \ + ((struct bpf_insn) { \ + .code = 0, /* zero is reserved opcode */ \ + .dst_reg = 0, \ + .src_reg = 0, \ + .off = 0, \ + .imm = ((__u64) (IMM)) >> 32 }) + +/* pseudo BPF_LD_IMM64 insn used to refer to process-local map_fd */ +#define BPF_LD_MAP_FD(DST, MAP_FD) \ + BPF_LD_IMM64_RAW(DST, BPF_PSEUDO_MAP_FD, MAP_FD) + +/* Short form of mov based on type, BPF_X: dst_reg = src_reg, BPF_K: dst_reg = imm32 */ + +#define BPF_MOV64_RAW(TYPE, DST, SRC, IMM) \ + ((struct bpf_insn) { \ + .code = BPF_ALU64 | BPF_MOV | BPF_SRC(TYPE), \ + .dst_reg = DST, \ + .src_reg = SRC, \ + .off = 0, \ + .imm = IMM }) + +#define BPF_MOV32_RAW(TYPE, DST, SRC, IMM) \ + ((struct bpf_insn) { \ + .code = BPF_ALU | BPF_MOV | BPF_SRC(TYPE), \ + .dst_reg = DST, \ + .src_reg = SRC, \ + .off = 0, \ + .imm = IMM }) + +/* Direct packet access, R0 = *(uint *) (skb->data + imm32) */ + +#define BPF_LD_ABS(SIZE, IMM) \ + ((struct bpf_insn) { \ + .code = BPF_LD | BPF_SIZE(SIZE) | BPF_ABS, \ + .dst_reg = 0, \ + .src_reg = 0, \ + .off = 0, \ + .imm = IMM }) + +/* Indirect packet access, R0 = *(uint *) (skb->data + src_reg + imm32) */ + +#define BPF_LD_IND(SIZE, SRC, IMM) \ + ((struct bpf_insn) { \ + .code = BPF_LD | BPF_SIZE(SIZE) | BPF_IND, \ + .dst_reg = 0, \ + .src_reg = SRC, \ + .off = 0, \ + .imm = IMM }) + +/* Memory load, dst_reg = *(uint *) (src_reg + off16) */ + +#define BPF_LDX_MEM(SIZE, DST, SRC, OFF) \ + ((struct bpf_insn) { \ + .code = BPF_LDX | BPF_SIZE(SIZE) | BPF_MEM, \ + .dst_reg = DST, \ + .src_reg = SRC, \ + .off = OFF, \ + .imm = 0 }) + +/* Memory store, *(uint *) (dst_reg + off16) = src_reg */ + +#define BPF_STX_MEM(SIZE, DST, SRC, OFF) \ + ((struct bpf_insn) { \ + .code = BPF_STX | BPF_SIZE(SIZE) | BPF_MEM, \ + .dst_reg = DST, \ + .src_reg = SRC, \ + .off = OFF, \ + .imm = 0 }) + +/* Memory store, *(uint *) (dst_reg + off16) = imm32 */ + +#define BPF_ST_MEM(SIZE, DST, OFF, IMM) \ + ((struct bpf_insn) { \ + .code = BPF_ST | BPF_SIZE(SIZE) | BPF_MEM, \ + .dst_reg = DST, \ + .src_reg = 0, \ + .off = OFF, \ + .imm = IMM }) + +/* Conditional jumps against registers, if (dst_reg 'op' src_reg) goto pc + off16 */ + +#define BPF_JMP_REG(OP, DST, SRC, OFF) \ + ((struct bpf_insn) { \ + .code = BPF_JMP | BPF_OP(OP) | BPF_X, \ + .dst_reg = DST, \ + .src_reg = SRC, \ + .off = OFF, \ + .imm = 0 }) + +/* Conditional jumps against immediates, if (dst_reg 'op' imm32) goto pc + off16 */ + +#define BPF_JMP_IMM(OP, DST, IMM, OFF) \ + ((struct bpf_insn) { \ + .code = BPF_JMP | BPF_OP(OP) | BPF_K, \ + .dst_reg = DST, \ + .src_reg = 0, \ + .off = OFF, \ + .imm = IMM }) + +/* Function call */ + +#define BPF_EMIT_CALL(FUNC) \ + ((struct bpf_insn) { \ + .code = BPF_JMP | BPF_CALL, \ + .dst_reg = 0, \ + .src_reg = 0, \ + .off = 0, \ + .imm = ((FUNC) - __bpf_call_base) }) + +/* Raw code statement block */ + +#define BPF_RAW_INSN(CODE, DST, SRC, OFF, IMM) \ + ((struct bpf_insn) { \ + .code = CODE, \ + .dst_reg = DST, \ + .src_reg = SRC, \ + .off = OFF, \ + .imm = IMM }) + +/* Program exit */ + +#define BPF_EXIT_INSN() \ + ((struct bpf_insn) { \ + .code = BPF_JMP | BPF_EXIT, \ + .dst_reg = 0, \ + .src_reg = 0, \ + .off = 0, \ + .imm = 0 }) + +#define bytes_to_bpf_size(bytes) \ +({ \ + int bpf_size = -EINVAL; \ + \ + if (bytes == sizeof(u8)) \ + bpf_size = BPF_B; \ + else if (bytes == sizeof(u16)) \ + bpf_size = BPF_H; \ + else if (bytes == sizeof(u32)) \ + bpf_size = BPF_W; \ + else if (bytes == sizeof(u64)) \ + bpf_size = BPF_DW; \ + \ + bpf_size; \ +}) + +/* Macro to invoke filter function. */ +#define SK_RUN_FILTER(filter, ctx) \ + (*filter->prog->bpf_func)(ctx, filter->prog->insnsi) + +#ifdef CONFIG_COMPAT +/* A struct sock_filter is architecture independent. */ +struct compat_sock_fprog { + u16 len; + compat_uptr_t filter; /* struct sock_filter * */ +}; +#endif + +struct sock_fprog_kern { + u16 len; + struct sock_filter *filter; +}; + +struct bpf_binary_header { + unsigned int pages; + u8 image[]; +}; + +struct bpf_prog { + u16 pages; /* Number of allocated pages */ + bool jited; /* Is our filter JIT'ed? */ + bool gpl_compatible; /* Is our filter GPL compatible? */ + u32 len; /* Number of filter blocks */ + enum bpf_prog_type type; /* Type of BPF program */ + struct bpf_prog_aux *aux; /* Auxiliary fields */ + struct sock_fprog_kern *orig_prog; /* Original BPF program */ + unsigned int (*bpf_func)(const struct sk_buff *skb, + const struct bpf_insn *filter); + /* Instructions for interpreter */ + union { + struct sock_filter insns[0]; + struct bpf_insn insnsi[0]; + }; +}; + +struct sk_filter { + atomic_t refcnt; + struct rcu_head rcu; + struct bpf_prog *prog; +}; + +#define BPF_PROG_RUN(filter, ctx) (*filter->bpf_func)(ctx, filter->insnsi) + +static inline unsigned int bpf_prog_size(unsigned int proglen) +{ + return max(sizeof(struct bpf_prog), + offsetof(struct bpf_prog, insns[proglen])); +} + +#define bpf_classic_proglen(fprog) (fprog->len * sizeof(fprog->filter[0])) + +#ifdef CONFIG_DEBUG_SET_MODULE_RONX +static inline void bpf_prog_lock_ro(struct bpf_prog *fp) +{ + set_memory_ro((unsigned long)fp, fp->pages); +} + +static inline void bpf_prog_unlock_ro(struct bpf_prog *fp) +{ + set_memory_rw((unsigned long)fp, fp->pages); +} +#else +static inline void bpf_prog_lock_ro(struct bpf_prog *fp) +{ +} + +static inline void bpf_prog_unlock_ro(struct bpf_prog *fp) +{ +} +#endif /* CONFIG_DEBUG_SET_MODULE_RONX */ + +int sk_filter(struct sock *sk, struct sk_buff *skb); + +void bpf_prog_select_runtime(struct bpf_prog *fp); +void bpf_prog_free(struct bpf_prog *fp); + +int bpf_convert_filter(struct sock_filter *prog, int len, + struct bpf_insn *new_prog, int *new_len); + +struct bpf_prog *bpf_prog_alloc(unsigned int size, gfp_t gfp_extra_flags); +struct bpf_prog *bpf_prog_realloc(struct bpf_prog *fp_old, unsigned int size, + gfp_t gfp_extra_flags); +void __bpf_prog_free(struct bpf_prog *fp); + +static inline void bpf_prog_unlock_free(struct bpf_prog *fp) +{ + bpf_prog_unlock_ro(fp); + __bpf_prog_free(fp); +} + +int bpf_prog_create(struct bpf_prog **pfp, struct sock_fprog_kern *fprog); +void bpf_prog_destroy(struct bpf_prog *fp); + +int sk_attach_filter(struct sock_fprog *fprog, struct sock *sk); +int sk_attach_bpf(u32 ufd, struct sock *sk); +int sk_detach_filter(struct sock *sk); + +int bpf_check_classic(const struct sock_filter *filter, unsigned int flen); +int sk_get_filter(struct sock *sk, struct sock_filter __user *filter, + unsigned int len); + +bool sk_filter_charge(struct sock *sk, struct sk_filter *fp); +void sk_filter_uncharge(struct sock *sk, struct sk_filter *fp); + +u64 __bpf_call_base(u64 r1, u64 r2, u64 r3, u64 r4, u64 r5); +void bpf_int_jit_compile(struct bpf_prog *fp); + +#ifdef CONFIG_BPF_JIT +typedef void (*bpf_jit_fill_hole_t)(void *area, unsigned int size); + +struct bpf_binary_header * +bpf_jit_binary_alloc(unsigned int proglen, u8 **image_ptr, + unsigned int alignment, + bpf_jit_fill_hole_t bpf_fill_ill_insns); +void bpf_jit_binary_free(struct bpf_binary_header *hdr); + +void bpf_jit_compile(struct bpf_prog *fp); +void bpf_jit_free(struct bpf_prog *fp); + +static inline void bpf_jit_dump(unsigned int flen, unsigned int proglen, + u32 pass, void *image) +{ + pr_err("flen=%u proglen=%u pass=%u image=%pK\n", + flen, proglen, pass, image); + if (image) + print_hex_dump(KERN_ERR, "JIT code: ", DUMP_PREFIX_OFFSET, + 16, 1, image, proglen, false); +} +#else +static inline void bpf_jit_compile(struct bpf_prog *fp) +{ +} + +static inline void bpf_jit_free(struct bpf_prog *fp) +{ + bpf_prog_unlock_free(fp); +} +#endif /* CONFIG_BPF_JIT */ + +#define BPF_ANC BIT(15) + +static inline u16 bpf_anc_helper(const struct sock_filter *ftest) +{ + BUG_ON(ftest->code & BPF_ANC); + + switch (ftest->code) { + case BPF_LD | BPF_W | BPF_ABS: + case BPF_LD | BPF_H | BPF_ABS: + case BPF_LD | BPF_B | BPF_ABS: +#define BPF_ANCILLARY(CODE) case SKF_AD_OFF + SKF_AD_##CODE: \ + return BPF_ANC | SKF_AD_##CODE + switch (ftest->k) { + BPF_ANCILLARY(PROTOCOL); + BPF_ANCILLARY(PKTTYPE); + BPF_ANCILLARY(IFINDEX); + BPF_ANCILLARY(NLATTR); + BPF_ANCILLARY(NLATTR_NEST); + BPF_ANCILLARY(MARK); + BPF_ANCILLARY(QUEUE); + BPF_ANCILLARY(HATYPE); + BPF_ANCILLARY(RXHASH); + BPF_ANCILLARY(CPU); + BPF_ANCILLARY(ALU_XOR_X); + BPF_ANCILLARY(VLAN_TAG); + BPF_ANCILLARY(VLAN_TAG_PRESENT); + BPF_ANCILLARY(PAY_OFFSET); + BPF_ANCILLARY(RANDOM); + BPF_ANCILLARY(VLAN_TPID); + } + /* Fallthrough. */ + default: + return ftest->code; + } +} + +void *bpf_internal_load_pointer_neg_helper(const struct sk_buff *skb, + int k, unsigned int size); + +static inline void *bpf_load_pointer(const struct sk_buff *skb, int k, + unsigned int size, void *buffer) +{ + if (k >= 0) + return skb_header_pointer(skb, k, size, buffer); + + return bpf_internal_load_pointer_neg_helper(skb, k, size); +} + +static inline int bpf_tell_extensions(void) +{ + return SKF_AD_MAX; +} + +#endif /* __LINUX_FILTER_H__ */ -- cgit v1.2.3-54-g00ecf