xref: /dpdk/lib/bpf/bpf_dump.c (revision cbb44143be74e7dd19853f4f360b51104e02380f)
1 /* SPDX-License-Identifier: BSD-3-Clause
2  * Copyright (c) 2021 Stephen Hemminger
3  * Based on filter2xdp
4  * Copyright (C) 2017 Tobias Klauser
5  */
6 
7 #include <stdio.h>
8 #include <stdint.h>
9 
10 #include "rte_bpf.h"
11 
12 #define BPF_OP_INDEX(x) (BPF_OP(x) >> 4)
13 #define BPF_SIZE_INDEX(x) (BPF_SIZE(x) >> 3)
14 
15 static const char *const class_tbl[] = {
16 	[BPF_LD] = "ld",   [BPF_LDX] = "ldx",	 [BPF_ST] = "st",
17 	[BPF_STX] = "stx", [BPF_ALU] = "alu",	 [BPF_JMP] = "jmp",
18 	[BPF_RET] = "ret", [BPF_MISC] = "alu64",
19 };
20 
21 static const char *const alu_op_tbl[16] = {
22 	[BPF_ADD >> 4] = "add",	   [BPF_SUB >> 4] = "sub",
23 	[BPF_MUL >> 4] = "mul",	   [BPF_DIV >> 4] = "div",
24 	[BPF_OR >> 4] = "or",	   [BPF_AND >> 4] = "and",
25 	[BPF_LSH >> 4] = "lsh",	   [BPF_RSH >> 4] = "rsh",
26 	[BPF_NEG >> 4] = "neg",	   [BPF_MOD >> 4] = "mod",
27 	[BPF_XOR >> 4] = "xor",	   [EBPF_MOV >> 4] = "mov",
28 	[EBPF_ARSH >> 4] = "arsh", [EBPF_END >> 4] = "endian",
29 };
30 
31 static const char *const size_tbl[] = {
32 	[BPF_W >> 3] = "w",
33 	[BPF_H >> 3] = "h",
34 	[BPF_B >> 3] = "b",
35 	[EBPF_DW >> 3] = "dw",
36 };
37 
38 static const char *const jump_tbl[16] = {
39 	[BPF_JA >> 4] = "ja",	   [BPF_JEQ >> 4] = "jeq",
40 	[BPF_JGT >> 4] = "jgt",	   [BPF_JGE >> 4] = "jge",
41 	[BPF_JSET >> 4] = "jset",  [EBPF_JNE >> 4] = "jne",
42 	[EBPF_JSGT >> 4] = "jsgt", [EBPF_JSGE >> 4] = "jsge",
43 	[EBPF_CALL >> 4] = "call", [EBPF_EXIT >> 4] = "exit",
44 };
45 
46 void rte_bpf_dump(FILE *f, const struct ebpf_insn *buf, uint32_t len)
47 {
48 	uint32_t i;
49 
50 	for (i = 0; i < len; ++i) {
51 		const struct ebpf_insn *ins = buf + i;
52 		uint8_t cls = BPF_CLASS(ins->code);
53 		const char *op, *postfix = "";
54 
55 		fprintf(f, " L%u:\t", i);
56 
57 		switch (cls) {
58 		default:
59 			fprintf(f, "unimp 0x%x // class: %s\n",
60 				ins->code, class_tbl[cls]);
61 			break;
62 		case BPF_ALU:
63 			postfix = "32";
64 			/* fall through */
65 		case EBPF_ALU64:
66 			op = alu_op_tbl[BPF_OP_INDEX(ins->code)];
67 			if (BPF_SRC(ins->code) == BPF_X)
68 				fprintf(f, "%s%s r%u, r%u\n", op, postfix, ins->dst_reg,
69 					ins->src_reg);
70 			else
71 				fprintf(f, "%s%s r%u, #0x%x\n", op, postfix,
72 					ins->dst_reg, ins->imm);
73 			break;
74 		case BPF_LD:
75 			op = "ld";
76 			postfix = size_tbl[BPF_SIZE_INDEX(ins->code)];
77 			if (ins->code == (BPF_LD | BPF_IMM | EBPF_DW)) {
78 				uint64_t val;
79 
80 				val = (uint32_t)ins[0].imm |
81 					(uint64_t)(uint32_t)ins[1].imm << 32;
82 				fprintf(f, "%s%s r%d, #0x%"PRIx64"\n",
83 					op, postfix, ins->dst_reg, val);
84 				i++;
85 			} else if (BPF_MODE(ins->code) == BPF_IMM)
86 				fprintf(f, "%s%s r%d, #0x%x\n", op, postfix,
87 					ins->dst_reg, ins->imm);
88 			else if (BPF_MODE(ins->code) == BPF_ABS)
89 				fprintf(f, "%s%s r%d, [%d]\n", op, postfix,
90 					ins->dst_reg, ins->imm);
91 			else if (BPF_MODE(ins->code) == BPF_IND)
92 				fprintf(f, "%s%s r%d, [r%u + %d]\n", op, postfix,
93 					ins->dst_reg, ins->src_reg, ins->imm);
94 			else
95 				fprintf(f, "// BUG: LD opcode 0x%02x in eBPF insns\n",
96 					ins->code);
97 			break;
98 		case BPF_LDX:
99 			op = "ldx";
100 			postfix = size_tbl[BPF_SIZE_INDEX(ins->code)];
101 			fprintf(f, "%s%s r%d, [r%u + %d]\n", op, postfix, ins->dst_reg,
102 				ins->src_reg, ins->off);
103 			break;
104 		case BPF_ST:
105 			op = "st";
106 			postfix = size_tbl[BPF_SIZE_INDEX(ins->code)];
107 			if (BPF_MODE(ins->code) == BPF_MEM)
108 				fprintf(f, "%s%s [r%d + %d], #0x%x\n", op, postfix,
109 					ins->dst_reg, ins->off, ins->imm);
110 			else
111 				fprintf(f, "// BUG: ST opcode 0x%02x in eBPF insns\n",
112 					ins->code);
113 			break;
114 		case BPF_STX:
115 			op = "stx";
116 			postfix = size_tbl[BPF_SIZE_INDEX(ins->code)];
117 			fprintf(f, "%s%s [r%d + %d], r%u\n", op, postfix,
118 				ins->dst_reg, ins->off, ins->src_reg);
119 			break;
120 #define L(pc, off) ((int)(pc) + 1 + (off))
121 		case BPF_JMP:
122 			op = jump_tbl[BPF_OP_INDEX(ins->code)];
123 			if (op == NULL)
124 				fprintf(f, "invalid jump opcode: %#x\n", ins->code);
125 			else if (BPF_OP(ins->code) == BPF_JA)
126 				fprintf(f, "%s L%d\n", op, L(i, ins->off));
127 			else if (BPF_OP(ins->code) == EBPF_EXIT)
128 				fprintf(f, "%s\n", op);
129 			else
130 				fprintf(f, "%s r%u, #0x%x, L%d\n", op, ins->dst_reg,
131 					ins->imm, L(i, ins->off));
132 			break;
133 		case BPF_RET:
134 			fprintf(f, "// BUG: RET opcode 0x%02x in eBPF insns\n",
135 				ins->code);
136 			break;
137 		}
138 	}
139 }
140