cregit-Linux how code gets into the kernel

Release 4.10 samples/bpf/libbpf.h

Directory: samples/bpf
/* eBPF mini library */
#ifndef __LIBBPF_H

#define __LIBBPF_H

#include <bpf/bpf.h>

struct bpf_insn;

/* 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 })

/* 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 })

#ifndef BPF_PSEUDO_MAP_FD

# define BPF_PSEUDO_MAP_FD	1
#endif

/* 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)


/* 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 })

/* 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 })

/* 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 })

#endif

Overall Contributors

PersonTokensPropCommitsCommitProp
alexei starovoitovalexei starovoitov24493.13%350.00%
josef bacikjosef bacik103.82%116.67%
daniel borkmanndaniel borkmann51.91%116.67%
joe stringerjoe stringer31.15%116.67%
Total262100.00%6100.00%
Directory: samples/bpf
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