int yr_execute_code(
YR_RULES* rules,
EVALUATION_CONTEXT* context,
int timeout,
time_t start_time)
{
int64_t r1;
int64_t r2;
int64_t r3;
int64_t mem[MEM_SIZE];
int64_t stack[STACK_SIZE];
int32_t sp = 0;
uint8_t* ip = rules->code_start;
YR_RULE* rule;
YR_STRING* string;
YR_MATCH* match;
YR_EXTERNAL_VARIABLE* external;
int i;
int found;
int count;
int result;
int flags;
int cycle = 0;
int tidx = yr_get_tidx();
while(1)
{
switch(*ip)
{
case HALT:
// When the halt instruction is reached the stack
// should be empty.
assert(sp == 0);
return ERROR_SUCCESS;
case PUSH:
r1 = *(uint64_t*)(ip + 1);
ip += sizeof(uint64_t);
push(r1);
break;
case POP:
pop(r1);
break;
case CLEAR_M:
r1 = *(uint64_t*)(ip + 1);
ip += sizeof(uint64_t);
mem[r1] = 0;
break;
case ADD_M:
r1 = *(uint64_t*)(ip + 1);
ip += sizeof(uint64_t);
pop(r2);
mem[r1] += r2;
break;
case INCR_M:
r1 = *(uint64_t*)(ip + 1);
ip += sizeof(uint64_t);
mem[r1]++;
break;
case PUSH_M:
r1 = *(uint64_t*)(ip + 1);
ip += sizeof(uint64_t);
push(mem[r1]);
break;
case POP_M:
r1 = *(uint64_t*)(ip + 1);
ip += sizeof(uint64_t);
pop(mem[r1]);
break;
case SWAPUNDEF:
r1 = *(uint64_t*)(ip + 1);
ip += sizeof(uint64_t);
pop(r2);
if (r2 != UNDEFINED)
push(r2);
else
push(mem[r1]);
break;
case JNUNDEF:
pop(r1);
push(r1);
if (r1 != UNDEFINED)
{
ip = *(uint8_t**)(ip + 1);
// ip will be incremented at the end of the loop,
// decrement it here to compensate.
ip--;
}
else
{
ip += sizeof(uint64_t);
}
break;
case JLE:
pop(r2);
pop(r1);
push(r1);
push(r2);
if (r1 <= r2)
{
ip = *(uint8_t**)(ip + 1);
// ip will be incremented at the end of the loop,
// decrement it here to compensate.
ip--;
}
else
{
ip += sizeof(uint64_t);
}
break;
case AND:
pop(r2);
pop(r1);
push(r1 & r2);
break;
case OR:
pop(r2);
pop(r1);
push(r1 | r2);
break;
case NOT:
pop(r1);
push(!r1);
break;
case LT:
pop(r2);
pop(r1);
push(comparison(<, r1, r2));
break;
case GT:
pop(r2);
pop(r1);
push(comparison(>, r1, r2));
break;
case LE:
pop(r2);
pop(r1);
push(comparison(<=, r1, r2));
break;
case GE:
pop(r2);
pop(r1);
push(comparison(>=, r1, r2));
break;
case EQ:
pop(r2);
pop(r1);
push(comparison(==, r1, r2));
break;
case NEQ:
pop(r2);
pop(r1);
push(comparison(!=, r1, r2));
break;
case ADD:
pop(r2);
pop(r1);
push(operation(+, r1, r2));
break;
case SUB:
pop(r2);
pop(r1);
push(operation(-, r1, r2));
break;
case MUL:
pop(r2);
pop(r1);
push(operation(*, r1, r2));
break;
case DIV:
pop(r2);
pop(r1);
push(operation(/, r1, r2));
break;
case MOD:
pop(r2);
pop(r1);
push(operation(%, r1, r2));
break;
case NEG:
pop(r1);
push(IS_UNDEFINED(r1) ? UNDEFINED : ~r1);
break;
case SHR:
pop(r2);
pop(r1);
push(operation(>>, r1, r2));
break;
case SHL:
pop(r2);
pop(r1);
push(operation(<<, r1, r2));
break;
case XOR:
pop(r2);
pop(r1);
push(operation(^, r1, r2));
break;
case RULE_PUSH:
rule = *(YR_RULE**)(ip + 1);
ip += sizeof(uint64_t);
push(rule->t_flags[tidx] & RULE_TFLAGS_MATCH ? 1 : 0);
break;
case RULE_POP:
pop(r1);
rule = *(YR_RULE**)(ip + 1);
ip += sizeof(uint64_t);
if (r1)
rule->t_flags[tidx] |= RULE_TFLAGS_MATCH;
break;
case EXT_INT:
external = *(YR_EXTERNAL_VARIABLE**)(ip + 1);
ip += sizeof(uint64_t);
push(external->integer);
break;
case EXT_STR:
external = *(YR_EXTERNAL_VARIABLE**)(ip + 1);
ip += sizeof(uint64_t);
push(PTR_TO_UINT64(external->string));
break;
case EXT_BOOL:
external = *(YR_EXTERNAL_VARIABLE**)(ip + 1);
ip += sizeof(uint64_t);
if (external->type == EXTERNAL_VARIABLE_TYPE_FIXED_STRING ||
external->type == EXTERNAL_VARIABLE_TYPE_MALLOC_STRING)
push(external->string[0] != '\0');
else
push(external->integer);
break;
case SFOUND:
pop(r1);
string = UINT64_TO_PTR(YR_STRING*, r1);
push(string->matches[tidx].tail != NULL ? 1 : 0);
break;
case SFOUND_AT:
pop(r2);
pop(r1);
if (IS_UNDEFINED(r1))
{
push(0);
break;
}
string = UINT64_TO_PTR(YR_STRING*, r2);
match = string->matches[tidx].head;
found = 0;
while (match != NULL)
{
if (r1 == match->offset)
{
push(1);
found = 1;
break;
}
if (r1 < match->offset)
break;
match = match->next;
}
if (!found)
push(0);
break;
case SFOUND_IN:
pop(r3);
pop(r2);
pop(r1);
if (IS_UNDEFINED(r1) || IS_UNDEFINED(r2))
{
push(0);
break;
}
string = UINT64_TO_PTR(YR_STRING*, r3);
match = string->matches[tidx].head;
found = FALSE;
while (match != NULL && !found)
{
if (match->offset >= r1 && match->offset <= r2)
{
push(1);
found = TRUE;
}
if (match->offset > r2)
break;
match = match->next;
}
if (!found)
push(0);
break;
case SCOUNT:
pop(r1);
string = UINT64_TO_PTR(YR_STRING*, r1);
match = string->matches[tidx].head;
found = 0;
while (match != NULL)
{
found++;
match = match->next;
}
push(found);
break;
case SOFFSET:
pop(r2);
pop(r1);
if (IS_UNDEFINED(r1))
{
push(UNDEFINED);
break;
}
string = UINT64_TO_PTR(YR_STRING*, r2);
match = string->matches[tidx].head;
i = 1;
found = FALSE;
while (match != NULL && !found)
{
if (r1 == i)
{
push(match->offset);
found = TRUE;
}
i++;
match = match->next;
}
if (!found)
push(UNDEFINED);
break;
case OF:
found = 0;
count = 0;
pop(r1);
while (r1 != UNDEFINED)
{
string = UINT64_TO_PTR(YR_STRING*, r1);
if (string->matches[tidx].tail != NULL)
found++;
count++;
pop(r1);
}
pop(r2);
if (r2 != UNDEFINED)
push(found >= r2 ? 1 : 0);
else
push(found >= count ? 1 : 0);
break;
case SIZE:
push(context->file_size);
break;
case ENTRYPOINT:
push(context->entry_point);
break;
case INT8:
pop(r1);
push(read_int8_t(context->mem_block, r1));
break;
case INT16:
pop(r1);
push(read_int16_t(context->mem_block, r1));
break;
case INT32:
pop(r1);
push(read_int32_t(context->mem_block, r1));
break;
case UINT8:
pop(r1);
push(read_uint8_t(context->mem_block, r1));
break;
case UINT16:
pop(r1);
push(read_uint16_t(context->mem_block, r1));
break;
case UINT32:
pop(r1);
push(read_uint32_t(context->mem_block, r1));
break;
case CONTAINS:
pop(r2);
pop(r1);
push(strstr(UINT64_TO_PTR(char*, r1),
UINT64_TO_PTR(char*, r2)) != NULL);
break;
case MATCHES:
pop(r3);
pop(r2);
pop(r1);
flags = (int) r3;
count = strlen(UINT64_TO_PTR(char*, r1));
if (count == 0)
{
push(FALSE);
break;
}
result = yr_re_exec(
UINT64_TO_PTR(uint8_t*, r2),
UINT64_TO_PTR(uint8_t*, r1),
count,
flags | RE_FLAGS_SCAN,
NULL,
NULL);
push(result >= 0);
break;
default:
// Unknown instruction, this shouldn't happen.
assert(FALSE);
}
if (timeout > 0) // timeout == 0 means no timeout
{
// Check for timeout every 10 instruction cycles.
if (++cycle == 10)
{
if (difftime(time(NULL), start_time) > timeout)
return ERROR_SCAN_TIMEOUT;
cycle = 0;
}
}
ip++;
}
// After executing the code the stack should be empty.
assert(sp == 0);
return ERROR_SUCCESS;
}
int yr_execute_code(
YR_RULES* rules,
YR_SCAN_CONTEXT* context,
int timeout,
time_t start_time)
{
int64_t r1;
int64_t r2;
int64_t r3;
int64_t mem[MEM_SIZE];
int64_t stack[STACK_SIZE];
int64_t args[MAX_FUNCTION_ARGS];
int32_t sp = 0;
uint8_t* ip = rules->code_start;
YR_RULE* rule;
YR_STRING* string;
YR_MATCH* match;
YR_OBJECT* object;
YR_OBJECT_FUNCTION* function;
char* identifier;
char* args_fmt;
int i;
int found;
int count;
int result;
int cycle = 0;
int tidx = yr_get_tidx();
#ifdef PROFILING_ENABLED
clock_t start = clock();
#endif
while(1)
{
switch(*ip)
{
case OP_HALT:
// When the halt instruction is reached the stack
// should be empty.
assert(sp == 0);
return ERROR_SUCCESS;
case OP_PUSH:
r1 = *(uint64_t*)(ip + 1);
ip += sizeof(uint64_t);
push(r1);
break;
case OP_POP:
pop(r1);
break;
case OP_CLEAR_M:
r1 = *(uint64_t*)(ip + 1);
ip += sizeof(uint64_t);
mem[r1] = 0;
break;
case OP_ADD_M:
r1 = *(uint64_t*)(ip + 1);
ip += sizeof(uint64_t);
pop(r2);
mem[r1] += r2;
break;
case OP_INCR_M:
r1 = *(uint64_t*)(ip + 1);
ip += sizeof(uint64_t);
mem[r1]++;
break;
case OP_PUSH_M:
r1 = *(uint64_t*)(ip + 1);
ip += sizeof(uint64_t);
push(mem[r1]);
break;
case OP_POP_M:
r1 = *(uint64_t*)(ip + 1);
ip += sizeof(uint64_t);
pop(mem[r1]);
break;
case OP_SWAPUNDEF:
r1 = *(uint64_t*)(ip + 1);
ip += sizeof(uint64_t);
pop(r2);
if (r2 != UNDEFINED)
push(r2);
else
push(mem[r1]);
break;
case OP_JNUNDEF:
pop(r1);
push(r1);
if (r1 != UNDEFINED)
{
ip = *(uint8_t**)(ip + 1);
// ip will be incremented at the end of the loop,
// decrement it here to compensate.
ip--;
}
else
{
ip += sizeof(uint64_t);
}
break;
case OP_JLE:
pop(r2);
pop(r1);
push(r1);
push(r2);
if (r1 <= r2)
{
ip = *(uint8_t**)(ip + 1);
// ip will be incremented at the end of the loop,
// decrement it here to compensate.
ip--;
}
else
{
ip += sizeof(uint64_t);
}
break;
case OP_AND:
pop(r2);
pop(r1);
if (IS_UNDEFINED(r1) || IS_UNDEFINED(r2))
push(0);
else
push(r1 && r2);
break;
case OP_OR:
pop(r2);
pop(r1);
if (IS_UNDEFINED(r1))
push(r2);
else if (IS_UNDEFINED(r2))
push(r1);
else
push(r1 || r2);
break;
case OP_NOT:
pop(r1);
if (IS_UNDEFINED(r1))
push(UNDEFINED);
else
push(!r1);
break;
case OP_LT:
pop(r2);
pop(r1);
push(COMPARISON(<, r1, r2));
break;
case OP_GT:
pop(r2);
pop(r1);
push(COMPARISON(>, r1, r2));
break;
case OP_LE:
pop(r2);
pop(r1);
push(COMPARISON(<=, r1, r2));
break;
case OP_GE:
pop(r2);
pop(r1);
push(COMPARISON(>=, r1, r2));
break;
case OP_EQ:
pop(r2);
pop(r1);
push(COMPARISON(==, r1, r2));
break;
case OP_NEQ:
pop(r2);
pop(r1);
push(COMPARISON(!=, r1, r2));
break;
case OP_SZ_EQ:
pop(r2);
pop(r1);
if (IS_UNDEFINED(r1) || IS_UNDEFINED(r2))
push(UNDEFINED);
else
push(strcmp(UINT64_TO_PTR(char*, r1),
UINT64_TO_PTR(char*, r2)) == 0);
break;
case OP_SZ_NEQ:
pop(r2);
pop(r1);
if (IS_UNDEFINED(r1) || IS_UNDEFINED(r2))
push(UNDEFINED);
else
push(strcmp(UINT64_TO_PTR(char*, r1),
UINT64_TO_PTR(char*, r2)) != 0);
break;
case OP_SZ_TO_BOOL:
pop(r1);
if (IS_UNDEFINED(r1))
push(UNDEFINED);
else
push(strlen(UINT64_TO_PTR(char*, r1)) > 0);
break;
case OP_ADD:
pop(r2);
pop(r1);
push(OPERATION(+, r1, r2));
break;
case OP_SUB:
pop(r2);
pop(r1);
push(OPERATION(-, r1, r2));
break;
case OP_MUL:
pop(r2);
pop(r1);
push(OPERATION(*, r1, r2));
break;
case OP_DIV:
pop(r2);
pop(r1);
push(OPERATION(/, r1, r2));
break;
case OP_MOD:
pop(r2);
pop(r1);
push(OPERATION(%, r1, r2));
break;
case OP_SHR:
pop(r2);
pop(r1);
push(OPERATION(>>, r1, r2));
break;
case OP_SHL:
pop(r2);
pop(r1);
push(OPERATION(<<, r1, r2));
break;
case OP_BITWISE_NOT:
pop(r1);
push(IS_UNDEFINED(r1) ? UNDEFINED : ~r1);
break;
case OP_BITWISE_AND:
pop(r2);
pop(r1);
push(OPERATION(&, r1, r2));
break;
case OP_BITWISE_OR:
pop(r2);
pop(r1);
push(OPERATION(|, r1, r2));
break;
case OP_BITWISE_XOR:
pop(r2);
pop(r1);
push(OPERATION(^, r1, r2));
break;
case OP_PUSH_RULE:
rule = *(YR_RULE**)(ip + 1);
ip += sizeof(uint64_t);
push(rule->t_flags[tidx] & RULE_TFLAGS_MATCH ? 1 : 0);
break;
case OP_MATCH_RULE:
pop(r1);
rule = *(YR_RULE**)(ip + 1);
ip += sizeof(uint64_t);
if (!IS_UNDEFINED(r1) && r1)
rule->t_flags[tidx] |= RULE_TFLAGS_MATCH;
#ifdef PROFILING_ENABLED
rule->clock_ticks += clock() - start;
start = clock();
#endif
break;
case OP_OBJ_LOAD:
identifier = *(char**)(ip + 1);
ip += sizeof(uint64_t);
object = (YR_OBJECT*) yr_hash_table_lookup(
context->objects_table,
identifier,
NULL);
assert(object != NULL);
push(PTR_TO_UINT64(object));
break;
case OP_OBJ_FIELD:
pop(r1);
identifier = *(char**)(ip + 1);
ip += sizeof(uint64_t);
if (IS_UNDEFINED(r1))
{
push(UNDEFINED);
break;
}
object = UINT64_TO_PTR(YR_OBJECT*, r1);
object = yr_object_lookup_field(object, identifier);
assert(object != NULL);
push(PTR_TO_UINT64(object));
break;
case OP_OBJ_VALUE:
pop(r1);
if (IS_UNDEFINED(r1))
{
push(UNDEFINED);
break;
}
object = UINT64_TO_PTR(YR_OBJECT*, r1);
switch(object->type)
{
case OBJECT_TYPE_INTEGER:
push(((YR_OBJECT_INTEGER*) object)->value);
break;
case OBJECT_TYPE_STRING:
if (((YR_OBJECT_STRING*) object)->value != NULL)
push(PTR_TO_UINT64(((YR_OBJECT_STRING*) object)->value));
else
push(UNDEFINED);
break;
default:
assert(FALSE);
}
break;
case OP_INDEX_ARRAY:
pop(r1); // index
pop(r2); // array
if (IS_UNDEFINED(r1))
{
push(UNDEFINED);
break;
}
object = UINT64_TO_PTR(YR_OBJECT*, r2);
assert(object->type == OBJECT_TYPE_ARRAY);
object = yr_object_array_get_item(object, 0, r1);
if (object != NULL)
push(PTR_TO_UINT64(object));
else
push(UNDEFINED);
break;
case OP_LOOKUP_DICT:
pop(r1); // key
pop(r2); // dictionary
if (IS_UNDEFINED(r1))
{
push(UNDEFINED);
break;
}
object = UINT64_TO_PTR(YR_OBJECT*, r2);
assert(object->type == OBJECT_TYPE_DICTIONARY);
object = yr_object_dict_get_item(
object, 0, UINT64_TO_PTR(const char*, r1));
if (object != NULL)
push(PTR_TO_UINT64(object));
else
push(UNDEFINED);
break;
case OP_CALL:
args_fmt = *(char**)(ip + 1);
ip += sizeof(uint64_t);
i = strlen(args_fmt);
// pop arguments from stack and copy them to args array
while (i > 0)
{
pop(args[i - 1]);
i--;
}
pop(r2);
function = UINT64_TO_PTR(YR_OBJECT_FUNCTION*, r2);
result = ERROR_INTERNAL_FATAL_ERROR;
for (i = 0; i < MAX_OVERLOADED_FUNCTIONS; i++)
{
if (function->prototypes[i].arguments_fmt == NULL)
break;
if (strcmp(function->prototypes[i].arguments_fmt, args_fmt) == 0)
{
result = function->prototypes[i].code(
(void*) args,
context,
function);
break;
}
}
assert(i < MAX_OVERLOADED_FUNCTIONS);
if (result == ERROR_SUCCESS)
push(PTR_TO_UINT64(function->return_obj));
else
return result;
break;
case OP_STR_FOUND:
pop(r1);
string = UINT64_TO_PTR(YR_STRING*, r1);
push(string->matches[tidx].tail != NULL ? 1 : 0);
break;
case OP_STR_FOUND_AT:
pop(r2);
pop(r1);
if (IS_UNDEFINED(r1))
{
push(0);
break;
}
string = UINT64_TO_PTR(YR_STRING*, r2);
match = string->matches[tidx].head;
found = 0;
while (match != NULL)
{
if (r1 == match->base + match->offset)
{
push(1);
found = 1;
break;
}
if (r1 < match->base + match->offset)
break;
match = match->next;
}
if (!found)
push(0);
break;
case OP_STR_FOUND_IN:
pop(r3);
pop(r2);
pop(r1);
if (IS_UNDEFINED(r1) || IS_UNDEFINED(r2))
{
push(UNDEFINED);
break;
}
string = UINT64_TO_PTR(YR_STRING*, r3);
match = string->matches[tidx].head;
found = FALSE;
while (match != NULL && !found)
{
if (match->base + match->offset >= r1 &&
match->base + match->offset <= r2)
{
push(1);
found = TRUE;
}
if (match->base + match->offset > r2)
break;
match = match->next;
}
if (!found)
push(0);
break;
case OP_STR_COUNT:
pop(r1);
string = UINT64_TO_PTR(YR_STRING*, r1);
push(string->matches[tidx].count);
break;
case OP_STR_OFFSET:
pop(r2);
pop(r1);
if (IS_UNDEFINED(r1))
{
push(UNDEFINED);
break;
}
string = UINT64_TO_PTR(YR_STRING*, r2);
match = string->matches[tidx].head;
i = 1;
found = FALSE;
while (match != NULL && !found)
{
if (r1 == i)
{
push(match->base + match->offset);
found = TRUE;
}
i++;
match = match->next;
}
if (!found)
push(UNDEFINED);
break;
case OP_OF:
found = 0;
count = 0;
pop(r1);
while (r1 != UNDEFINED)
{
string = UINT64_TO_PTR(YR_STRING*, r1);
if (string->matches[tidx].tail != NULL)
found++;
count++;
pop(r1);
}
pop(r2);
if (r2 != UNDEFINED)
push(found >= r2 ? 1 : 0);
else
push(found >= count ? 1 : 0);
break;
case OP_FILESIZE:
push(context->file_size);
break;
case OP_ENTRYPOINT:
push(context->entry_point);
break;
case OP_INT8:
pop(r1);
push(read_int8_t(context->mem_block, r1));
break;
case OP_INT16:
pop(r1);
push(read_int16_t(context->mem_block, r1));
break;
case OP_INT32:
pop(r1);
push(read_int32_t(context->mem_block, r1));
break;
case OP_UINT8:
pop(r1);
push(read_uint8_t(context->mem_block, r1));
break;
case OP_UINT16:
pop(r1);
push(read_uint16_t(context->mem_block, r1));
break;
case OP_UINT32:
pop(r1);
push(read_uint32_t(context->mem_block, r1));
break;
case OP_CONTAINS:
pop(r2);
pop(r1);
if (IS_UNDEFINED(r1) || IS_UNDEFINED(r2))
push(UNDEFINED);
else
push(strstr(UINT64_TO_PTR(char*, r1),
UINT64_TO_PTR(char*, r2)) != NULL);
break;
case OP_IMPORT:
r1 = *(uint64_t*)(ip + 1);
ip += sizeof(uint64_t);
FAIL_ON_ERROR(yr_modules_load(
UINT64_TO_PTR(char*, r1),
context));
break;
case OP_MATCHES:
pop(r2);
pop(r1);
count = strlen(UINT64_TO_PTR(char*, r1));
if (count == 0)
{
push(FALSE);
break;
}
result = yr_re_exec(
UINT64_TO_PTR(uint8_t*, r2),
UINT64_TO_PTR(uint8_t*, r1),
count,
RE_FLAGS_SCAN,
NULL,
NULL);
push(result >= 0);
break;
default:
// Unknown instruction, this shouldn't happen.
assert(FALSE);
}
if (timeout > 0) // timeout == 0 means no timeout
{
// Check for timeout every 10 instruction cycles.
if (++cycle == 10)
{
if (difftime(time(NULL), start_time) > timeout)
return ERROR_SCAN_TIMEOUT;
cycle = 0;
}
}
ip++;
}
// After executing the code the stack should be empty.
assert(sp == 0);
return ERROR_SUCCESS;
}
