ebpf_fuzzer.h

#ifndef EBPF_FUZZER_H_LEVT96MB
#define EBPF_FUZZER_H_LEVT96MB

#include <clib.h>
#include "./common.h"

#define	BODY_LEN	0x10000

struct ebpf_fuzz_target {
	struct list_head	sibling;
	char			*target_name;
	char			*sample_header;
	char			*sample_tail;

	int			(*init)(struct ebpf_fuzz_target *target);
	int			(*gen_sample_body)(char *b, size_t len,
						   u32 body1_max);
};

extern int insn_print_common(char *buf, size_t buflen, struct bpf_insn *insn,
				size_t cnt);
extern int init(void);
extern struct ebpf_fuzz_target *find_target(char *version);

#ifndef BPF_JMP32
#define	BPF_JMP32	0x06
#endif

/* 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_2	/* scratch reg */
#define BPF_REG_D	BPF_REG_8	/* data, callee-saved */
#define BPF_REG_H	BPF_REG_9	/* hlen, callee-saved */

/* Kernel hidden auxiliary/helper register. */
#define BPF_REG_AX		MAX_BPF_REG
#define MAX_BPF_EXT_REG		(MAX_BPF_REG + 1)
#define MAX_BPF_JIT_REG		MAX_BPF_EXT_REG

/* unused opcode to mark special call to bpf_tail_call() helper */
#define BPF_TAIL_CALL	0xf0

/* unused opcode to mark call to interpreter with arguments */
#define BPF_CALL_ARGS	0xe0

/* As per nm, we expose JITed images as text (code) section for
 * kallsyms. That way, tools like perf can find it to match
 * addresses.
 */
#define BPF_SYM_ELF_TYPE	't'

/* 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 })

/* Special form of mov32, used for doing explicit zero extension on dst. */
#define BPF_ZEXT_REG(DST)					\
	((struct bpf_insn) {					\
		.code  = BPF_ALU | BPF_MOV | BPF_X,		\
		.dst_reg = DST,					\
		.src_reg = DST,					\
		.off   = 0,					\
		.imm   = 1 })

/* 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 })

/* Atomic memory add, *(uint *)(dst_reg + off16) += src_reg */

#define BPF_STX_XADD(SIZE, DST, SRC, OFF)			\
	((struct bpf_insn) {					\
		.code  = BPF_STX | BPF_SIZE(SIZE) | BPF_XADD,	\
		.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 })

/* Like BPF_JMP_REG, but with 32-bit wide operands for comparison. */

#define BPF_JMP32_REG(OP, DST, SRC, OFF)			\
	((struct bpf_insn) {					\
		.code  = BPF_JMP32 | BPF_OP(OP) | BPF_X,	\
		.dst_reg = DST,					\
		.src_reg = SRC,					\
		.off   = OFF,					\
		.imm   = 0 })

/* Like BPF_JMP_IMM, but with 32-bit wide operands for comparison. */

#define BPF_JMP32_IMM(OP, DST, IMM, OFF)			\
	((struct bpf_insn) {					\
		.code  = BPF_JMP32 | BPF_OP(OP) | BPF_K,	\
		.dst_reg = DST,					\
		.src_reg = 0,					\
		.off   = OFF,					\
		.imm   = IMM })

/* Unconditional jumps, goto pc + off16 */

#define BPF_JMP_A(OFF)						\
	((struct bpf_insn) {					\
		.code  = BPF_JMP | BPF_JA,			\
		.dst_reg = 0,					\
		.src_reg = 0,					\
		.off   = OFF,					\
		.imm   = 0 })

/* Relative call */

#define BPF_CALL_REL(TGT)					\
	((struct bpf_insn) {					\
		.code  = BPF_JMP | BPF_CALL,			\
		.dst_reg = 0,					\
		.src_reg = BPF_PSEUDO_CALL,			\
		.off   = 0,					\
		.imm   = TGT })

#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	LISTENER_PORT		(1337)
#define	LISTENER_BACKLOG	(0x30)
#define	STORAGE_MAP_SIZE	(8192)
#define	FUZZ_MAP_SIZE		(8192)

#define	ARRAY_CNT(arr)	(sizeof(arr) / sizeof(arr[0]))

#define	CORRUPT_FD_CONST	10
#define	STORAGE_FD_CONST	11
#define	CORRUPT_REG		BPF_REG_9
#define	STORAGE_REG		BPF_REG_8
#define	SPECIAL_REG		BPF_REG_7
#define	INVALID_P_REG		BPF_REG_6
#define	LEAKED_V_REG		BPF_REG_5
#define	UMAX_REG		BPF_REG_4
#define	EXTRA0_REG		BPF_REG_3
#define	EXTRA1_REG		BPF_REG_2
#define	EXTRA2_REG		BPF_REG_1
#define	MAGIC_VAL1		0x4142434445464748
#define	MAGIC_VAL2		0x494a4b4c4d4e4f40

#define EBPF_INSN_GET_MAP_ADDR(fd, reg) \
	BPF_MOV64_IMM(BPF_REG_0, 0), \
	BPF_STX_MEM(BPF_W, BPF_REG_10, BPF_REG_0, -4), \
	BPF_MOV64_REG(BPF_REG_2, BPF_REG_10), \
	BPF_ALU64_IMM(BPF_ADD, BPF_REG_2, -4), \
	BPF_LD_MAP_FD(BPF_REG_1, fd), \
	BPF_RAW_INSN(BPF_JMP | BPF_CALL, 0, 0, 0, BPF_FUNC_map_lookup_elem), \
	BPF_JMP_IMM(BPF_JNE, BPF_REG_0, 0, 1), \
	BPF_EXIT_INSN(), \
	BPF_MOV64_REG((reg), BPF_REG_0), \
	BPF_MOV64_IMM(BPF_REG_0, 0)

/* TODO */
struct reg_usage {
	int	id;
	int	in_use: 1;
	int	exclusive: 1;
};

static inline int insn_add_one(struct bpf_insn *insns, int *idx, int max,
			struct bpf_insn insn)
{
	int start = *idx;
	int end = start + 1;
	if (end > max) {
		return -1;
	}

	insns[start] = insn;
	*idx = end;
	return 0;
}

static inline int insn_add(struct bpf_insn *insns, int *idx, int max,
		    struct bpf_insn *src_insn, int src_insn_count)
{
	int err = 0;

	for (int i = 0; i < src_insn_count; i++) {
		err = insn_add_one(insns, idx, max, src_insn[i]);
		if (err < 0)
			return -1;
	}

	return 0;
}

static inline int insn_get_map_ptr(struct bpf_insn *insns, int *idx, int max,
				  int fd, int reg)
{
	struct bpf_insn map_p[] = {
		EBPF_INSN_GET_MAP_ADDR(fd, reg),
	};

	return insn_add(insns, idx, max, map_p, ARRAY_CNT(map_p));
}

#define	COPY_INSNS(dst, IDX, src) \
({\
	int err = 0;\
	struct bpf_insn ____insns[] = {src};\
	err = insn_add(dst, (int *)&IDX, BPF_MAXINSNS, ____insns, ARRAY_CNT(____insns));\
	if (err < 0) \
		return -1;\
})

extern int gen_non_insn(struct bpf_insn *insns, int *idx);
extern int gen_jmp_insn_common(struct bpf_insn *insns, int *idx, int is_imm,
			int is_64, int reg0, int reg1, long imm_v, int op);
extern int gen_alu_insn_common(struct bpf_insn *insns, int *idx, int is_imm,
			int is_64, int reg0, int reg1, long imm_v, int op);
extern int gen_mov_insn_common(struct bpf_insn *insns, int *idx, int is_imm,
			int is_64, int reg0, int reg1, long imm_v);
extern int gen_ld_insn_common(struct bpf_insn *insn, int *idx, int reg0, long imm_v);

#endif /* end of include guard: EBPF_FUZZER_H_LEVT96MB */