1/* Capstone Disassembler Engine */
2/* By David Hogarty, 2014 */
3
4// the following must precede stdio (woo, thanks msft)
5#if defined(_MSC_VER) && _MSC_VER < 1900
6#define _CRT_SECURE_NO_WARNINGS
7#define snprintf _snprintf
8#endif
9#include <stdio.h>
10#include <stdlib.h>
11#include <string.h>
12
13#include <platform.h>
14#include <capstone.h>
15
16static csh handle;
17
18struct platform {
19	cs_arch arch;
20	cs_mode mode;
21	unsigned char *code;
22	size_t size;
23	char *comment;
24	int syntax;
25};
26
27static char *hex_string(unsigned char *str, size_t len)
28{
29	// returns a malloced string that has the hex version of the string in it
30	// null if failed to malloc
31	char *hex_out;
32	size_t i;
33
34	hex_out = (char *) malloc(len*2 + 1); // two ascii characters per input character, plus trailing null
35	if (!hex_out) { goto Exit; }
36
37	for (i = 0; i < len; ++i) {
38		snprintf(hex_out + (i*2), 2, "%02x", str[i]);
39	}
40
41	hex_out[len*2] = 0; // trailing null
42
43Exit:
44	return hex_out;
45}
46
47static void snprint_insn_detail(char * buf, size_t * cur, size_t * left, cs_insn *ins)
48{
49	size_t used = 0;
50
51#define _this_printf(...) \
52	{ \
53		size_t used = 0; \
54		used = snprintf(buf + *cur, *left, __VA_ARGS__); \
55		*left -= used; \
56		*cur += used; \
57	}
58
59	cs_arm *arm;
60	int i;
61
62	// detail can be NULL on "data" instruction if SKIPDATA option is turned ON
63	if (ins->detail == NULL)
64		return;
65
66	arm = &(ins->detail->arm);
67
68	if (arm->op_count)
69		_this_printf("\top_count: %u\n", arm->op_count);
70
71	for (i = 0; i < arm->op_count; i++) {
72		cs_arm_op *op = &(arm->operands[i]);
73		switch((int)op->type) {
74			default:
75				break;
76			case ARM_OP_REG:
77				_this_printf("\t\toperands[%u].type: REG = %s\n", i, cs_reg_name(handle, op->reg));
78				break;
79			case ARM_OP_IMM:
80				_this_printf("\t\toperands[%u].type: IMM = 0x%x\n", i, op->imm);
81				break;
82			case ARM_OP_FP:
83				_this_printf("\t\toperands[%u].type: FP = %f\n", i, op->fp);
84				break;
85			case ARM_OP_MEM:
86				_this_printf("\t\toperands[%u].type: MEM\n", i);
87				if (op->mem.base != X86_REG_INVALID)
88					_this_printf("\t\t\toperands[%u].mem.base: REG = %s\n",
89							i, cs_reg_name(handle, op->mem.base));
90				if (op->mem.index != X86_REG_INVALID)
91					_this_printf("\t\t\toperands[%u].mem.index: REG = %s\n",
92							i, cs_reg_name(handle, op->mem.index));
93				if (op->mem.scale != 1)
94					_this_printf("\t\t\toperands[%u].mem.scale: %u\n", i, op->mem.scale);
95				if (op->mem.disp != 0)
96					_this_printf("\t\t\toperands[%u].mem.disp: 0x%x\n", i, op->mem.disp);
97
98				break;
99			case ARM_OP_PIMM:
100				_this_printf("\t\toperands[%u].type: P-IMM = %u\n", i, op->imm);
101				break;
102			case ARM_OP_CIMM:
103				_this_printf("\t\toperands[%u].type: C-IMM = %u\n", i, op->imm);
104				break;
105		}
106
107		if (op->shift.type != ARM_SFT_INVALID && op->shift.value) {
108			if (op->shift.type < ARM_SFT_ASR_REG) {
109				// shift with constant value
110				_this_printf("\t\t\tShift: %u = %u\n", op->shift.type, op->shift.value);
111			} else {
112				// shift with register
113				_this_printf("\t\t\tShift: %u = %s\n", op->shift.type,
114						cs_reg_name(handle, op->shift.value));
115			}
116		}
117	}
118
119	if (arm->cc != ARM_CC_AL && arm->cc != ARM_CC_INVALID) {
120		_this_printf("\tCode condition: %u\n", arm->cc);
121	}
122
123	if (arm->update_flags) {
124		_this_printf("\tUpdate-flags: True\n");
125	}
126
127	if (arm->writeback) {
128		_this_printf("\tWrite-back: True\n");
129	}
130
131#undef _this_printf
132}
133
134static void print_insn_detail(cs_insn *ins)
135{
136	char a_buf[2048];
137	size_t cur=0, left=2048;
138	snprint_insn_detail(a_buf, &cur, &left, ins);
139	printf("%s\n", a_buf);
140}
141
142struct invalid_code {
143	unsigned char *code;
144	size_t size;
145	char *comment;
146};
147
148#define MAX_INVALID_CODES 16
149
150struct invalid_instructions {
151	cs_arch arch;
152	cs_mode mode;
153	char *platform_comment;
154	int num_invalid_codes;
155	struct invalid_code invalid_codes[MAX_INVALID_CODES];
156};
157
158static void test_invalids()
159{
160	struct invalid_instructions invalids[] = {{
161		CS_ARCH_ARM,
162			CS_MODE_THUMB,
163			"Thumb",
164			1,
165			{{
166				 (unsigned char *)"\xbd\xe8\x1e\xff",
167				 4,
168				 "invalid thumb2 pop because sp used and because both pc and lr are "
169					 "present at the same time"
170			 }},
171	}};
172
173	struct invalid_instructions * invalid = NULL;
174
175	uint64_t address = 0x1000;
176	cs_insn *insn;
177	int i;
178	int j;
179	size_t count;
180
181	printf("\nShould be invalid\n"
182			"-----------------\n");
183
184	for (i = 0; i < sizeof(invalids)/sizeof(invalids[0]); i++) {
185		cs_err err;
186
187		invalid = invalids + i;
188		err = cs_open(invalid->arch, invalid->mode, &handle);
189
190		if (err) {
191			printf("Failed on cs_open() with error returned: %u\n", err);
192			continue;
193		}
194
195		cs_option(handle, CS_OPT_DETAIL, CS_OPT_ON);
196		cs_option(handle, CS_OPT_SYNTAX, CS_OPT_SYNTAX_NOREGNAME);
197
198		for (j = 0; j < invalid->num_invalid_codes; ++j) {
199			struct invalid_code *invalid_code = NULL;
200			char *hex_str = NULL;
201
202			invalid_code = invalid->invalid_codes + j;
203
204			hex_str = hex_string(invalid_code->code, invalid_code->size);
205
206			printf("%s %s: %s\n", invalid->platform_comment, hex_str, invalid_code->comment);
207
208			free(hex_str);
209
210			count = cs_disasm(handle,
211					invalid_code->code, invalid_code->size, address, 0, &insn
212					);
213
214			if (count) {
215				size_t k;
216				printf("    ERROR:\n");
217
218				for (k = 0; k < count; k++) {
219					printf("    0x%"PRIx64":\t%s\t%s\n",
220							insn[k].address, insn[k].mnemonic, insn[k].op_str);
221					print_insn_detail(&insn[k]);
222				}
223				cs_free(insn, count);
224
225			} else {
226				printf("    SUCCESS: invalid\n");
227			}
228		}
229
230		cs_close(&handle);
231	}
232}
233
234struct valid_code {
235	unsigned char *code;
236	size_t size;
237	uint32_t start_addr;
238	char *expected_out;
239	char *comment;
240};
241
242#define MAX_VALID_CODES 16
243struct valid_instructions {
244	cs_arch arch;
245	cs_mode mode;
246	char *platform_comment;
247	int num_valid_codes;
248	struct valid_code valid_codes[MAX_VALID_CODES];
249};
250
251static void test_valids()
252{
253	struct valid_instructions valids[] = {{
254		CS_ARCH_ARM,
255			CS_MODE_THUMB,
256			"Thumb",
257			3,
258			{{ (unsigned char *)"\x00\xf0\x26\xe8", 4, 0x352,
259				"0x352:\tblx\t#0x3a0\n"
260					"\top_count: 1\n"
261					"\t\toperands[0].type: IMM = 0x3a0\n",
262
263				"thumb2 blx with misaligned immediate"
264			}, { (unsigned char *)"\x05\xdd", 2, 0x1f0,
265				"0x1f0:\tble\t#0x1fe\n"
266					"\top_count: 1\n"
267					"\t\toperands[0].type: IMM = 0x1fe\n"
268					"\tCode condition: 14\n",
269
270				"thumb b cc with thumb-aligned target"
271			}, { (unsigned char *)"\xbd\xe8\xf0\x8f", 4, 0,
272			 "0x0:\tpop.w\t{r4, r5, r6, r7, r8, r9, r10, r11, pc}\n"
273				 "\top_count: 9\n"
274				 "\t\toperands[0].type: REG = r4\n"
275				 "\t\toperands[1].type: REG = r5\n"
276				 "\t\toperands[2].type: REG = r6\n"
277				 "\t\toperands[3].type: REG = r7\n"
278				 "\t\toperands[4].type: REG = r8\n"
279				 "\t\toperands[5].type: REG = r9\n"
280				 "\t\toperands[6].type: REG = r10\n"
281				 "\t\toperands[7].type: REG = r11\n"
282				 "\t\toperands[8].type: REG = pc\n",
283
284				"thumb2 pop that should be valid"
285			},
286		}
287	}};
288
289	struct valid_instructions * valid = NULL;
290
291	uint64_t address = 0x1000;
292	cs_insn *insn;
293	int i;
294	int j;
295	size_t count;
296
297
298	for (i = 0; i < sizeof(valids)/sizeof(valids[0]); i++) {
299		cs_err err;
300
301		valid = valids + i;
302		err = cs_open(valid->arch, valid->mode, &handle);
303
304		if (err) {
305			printf("Failed on cs_open() with error returned: %u\n", err);
306			continue;
307		}
308
309		cs_option(handle, CS_OPT_DETAIL, CS_OPT_ON);
310		cs_option(handle, CS_OPT_SYNTAX, CS_OPT_SYNTAX_NOREGNAME);
311
312#define _this_printf(...) \
313		{ \
314			size_t used = 0; \
315			used = snprintf(tmp_buf + cur, left, __VA_ARGS__); \
316			left -= used; \
317			cur += used; \
318		}
319		printf("\nShould be valid\n"
320				"---------------\n");
321
322		for (j = 0; j < valid->num_valid_codes; ++j) {
323			char tmp_buf[2048];
324			size_t left = 2048;
325			size_t cur = 0;
326			size_t used = 0;
327			int success = 0;
328			char * hex_str = NULL;
329
330			struct valid_code * valid_code = NULL;
331			valid_code = valid->valid_codes + j;
332
333			hex_str = hex_string(valid_code->code, valid_code->size);
334
335			printf("%s %s @ 0x%04x: %s\n    %s",
336					valid->platform_comment, hex_str, valid_code->start_addr,
337					valid_code->comment, valid_code->expected_out);
338
339			count = cs_disasm(handle,
340					valid_code->code, valid_code->size,
341					valid_code->start_addr, 0, &insn
342					);
343
344			if (count) {
345				size_t k;
346				size_t max_len = 0;
347				size_t tmp_len = 0;
348
349				for (k = 0; k < count; k++) {
350					_this_printf(
351							"0x%"PRIx64":\t%s\t%s\n",
352							insn[k].address, insn[k].mnemonic,
353							insn[k].op_str
354							);
355
356					snprint_insn_detail(tmp_buf, &cur, &left, &insn[k]);
357				}
358
359				max_len = strlen(tmp_buf);
360				tmp_len = strlen(valid_code->expected_out);
361				if (tmp_len > max_len) {
362					max_len = tmp_len;
363				}
364
365				if (memcmp(tmp_buf, valid_code->expected_out, max_len)) {
366					printf(
367						"    ERROR: '''\n%s''' does not match"
368						" expected '''\n%s'''\n",
369						tmp_buf, valid_code->expected_out
370					);
371				} else {
372					printf("    SUCCESS: valid\n");
373				}
374
375				cs_free(insn, count);
376
377			} else {
378				printf("ERROR: invalid\n");
379			}
380		}
381
382		cs_close(&handle);
383	}
384
385#undef _this_prinf
386}
387
388int main()
389{
390	test_invalids();
391	test_valids();
392	return 0;
393}
394
395