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/* Capstone Disassembly Engine */
/* By david942j <david942j@gmail.com>, 2019 */
#include <capstone/capstone.h>
#include <capstone/platform.h>
static csh handle;
struct platform {
cs_arch arch;
cs_mode mode;
const unsigned char *code;
size_t size;
const char *comment;
};
static void print_string_hex(const char *comment, const unsigned char *str, size_t len)
{
const unsigned char *c;
printf("%s", comment);
for (c = str; c < str + len; c++) {
printf(" 0x%02x", *c & 0xff);
}
printf("\n");
}
static const char * ext_name[] = {
[BPF_EXT_LEN] = "#len",
};
static void print_insn_detail(csh cs_handle, cs_insn *ins)
{
cs_bpf *bpf;
cs_regs regs_read, regs_write;
uint8_t regs_read_count, regs_write_count;
unsigned i;
// detail can be NULL on "data" instruction if SKIPDATA option is turned ON
if (ins->detail == NULL)
return;
if (ins->detail->groups_count) {
int j;
printf("\tGroups:");
for(j = 0; j < ins->detail->groups_count; j++)
printf(" %s", cs_group_name(handle, ins->detail->groups[j]));
printf("\n");
}
bpf = &(ins->detail->bpf);
printf("\tOperand count: %u\n", bpf->op_count);
for (i = 0; i < bpf->op_count; i++) {
cs_bpf_op *op = &(bpf->operands[i]);
printf("\t\toperands[%u].type: ", i);
switch (op->type) {
case BPF_OP_INVALID:
printf("INVALID\n");
break;
case BPF_OP_REG:
printf("REG = %s\n", cs_reg_name(handle, op->reg));
break;
case BPF_OP_IMM:
printf("IMM = 0x%" PRIx64 "\n", op->imm);
break;
case BPF_OP_OFF:
printf("OFF = +0x%x\n", op->off);
break;
case BPF_OP_MEM:
printf("MEM\n");
if (op->mem.base != BPF_REG_INVALID)
printf("\t\t\toperands[%u].mem.base: REG = %s\n",
i, cs_reg_name(handle, op->mem.base));
printf("\t\t\toperands[%u].mem.disp: 0x%x\n", i, op->mem.disp);
break;
case BPF_OP_MMEM:
printf("MMEM = M[0x%x]\n", op->mmem);
break;
case BPF_OP_MSH:
printf("MSH = 4*([0x%x]&0xf)\n", op->msh);
break;
case BPF_OP_EXT:
printf("EXT = %s\n", ext_name[op->ext]);
break;
}
}
/* print all registers that are involved in this instruction */
if (!cs_regs_access(cs_handle, ins,
regs_read, ®s_read_count,
regs_write, ®s_write_count)) {
if (regs_read_count) {
printf("\tRegisters read:");
for(i = 0; i < regs_read_count; i++)
printf(" %s", cs_reg_name(cs_handle, regs_read[i]));
printf("\n");
}
if (regs_write_count) {
printf("\tRegisters modified:");
for(i = 0; i < regs_write_count; i++)
printf(" %s", cs_reg_name(cs_handle, regs_write[i]));
printf("\n");
}
}
puts("");
}
static void test()
{
#define CBPF_CODE "\x94\x09\x00\x00\x37\x13\x03\x00" \
"\x87\x00\x00\x00\x00\x00\x00\x00" \
"\x07\x00\x00\x00\x00\x00\x00\x00" \
"\x16\x00\x00\x00\x00\x00\x00\x00" \
"\x80\x00\x00\x00\x00\x00\x00\x00"
#define EBPF_CODE "\x97\x09\x00\x00\x37\x13\x03\x00" \
"\xdc\x02\x00\x00\x20\x00\x00\x00" \
"\x30\x00\x00\x00\x00\x00\x00\x00" \
"\xdb\x3a\x00\x01\x00\x00\x00\x00" \
"\x84\x02\x00\x00\x00\x00\x00\x00" \
"\x6d\x33\x17\x02\x00\x00\x00\x00"
struct platform platforms[] = {
{
CS_ARCH_BPF,
CS_MODE_LITTLE_ENDIAN | CS_MODE_BPF_CLASSIC,
(unsigned char *)CBPF_CODE,
sizeof(CBPF_CODE) - 1,
"cBPF Le"
},
{
CS_ARCH_BPF,
CS_MODE_LITTLE_ENDIAN | CS_MODE_BPF_EXTENDED,
(unsigned char *)EBPF_CODE,
sizeof(EBPF_CODE) - 1,
"eBPF Le"
},
};
uint64_t address = 0x0;
cs_insn *insn;
int i;
size_t count;
for (i = 0; i < sizeof(platforms)/sizeof(platforms[0]); i++) {
cs_err err = cs_open(platforms[i].arch, platforms[i].mode, &handle);
if (err) {
printf("Failed on cs_open() with error returned: %u\n", err);
abort();
}
cs_option(handle, CS_OPT_DETAIL, CS_OPT_ON);
count = cs_disasm(handle, platforms[i].code, platforms[i].size, address, 0, &insn);
if (count) {
size_t j;
printf("****************\n");
printf("Platform: %s\n", platforms[i].comment);
print_string_hex("Code:", platforms[i].code, platforms[i].size);
printf("Disasm:\n");
for (j = 0; j < count; j++) {
printf("0x%" PRIx64 ":\t%s\t%s\n", insn[j].address, insn[j].mnemonic, insn[j].op_str);
print_insn_detail(handle, &insn[j]);
}
// free memory allocated by cs_disasm()
cs_free(insn, count);
} else {
printf("****************\n");
printf("Platform: %s\n", platforms[i].comment);
print_string_hex("Code:", platforms[i].code, platforms[i].size);
printf("ERROR: Failed to disasm given code!\n");
abort();
}
cs_close(&handle);
}
}
int main()
{
test();
return 0;
}
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