int yr_arena_allocate_memory(
YR_ARENA* arena,
size_t size,
void** allocated_memory)
{
FAIL_ON_ERROR(yr_arena_reserve_memory(arena, size));
*allocated_memory = arena->current_page->address + \
arena->current_page->used;
arena->current_page->used += size;
return ERROR_SUCCESS;
}
int yr_re_emit_code(
RE* re,
YR_ARENA* arena)
{
RE_EMIT_CONTEXT emit_context;
int code_size;
int total_size;
int emit_flags = 0;
if (re->flags & RE_FLAGS_NO_CASE)
emit_flags |= EMIT_NO_CASE;
if (re->flags & RE_FLAGS_DOT_ALL)
emit_flags |= EMIT_DOT_ALL;
emit_context.arena = arena;
emit_context.next_split_id = 0;
// Ensure that we have enough contiguous memory space in the arena to
// contain the regular expression code. The code can't span over multiple
// non-contiguous pages.
yr_arena_reserve_memory(arena, RE_MAX_CODE_SIZE);
// Emit code for matching the regular expressions forwards.
total_size = 0;
FAIL_ON_ERROR(_yr_re_emit(
&emit_context,
re->root_node,
emit_flags,
&re->code,
&code_size));
total_size += code_size;
FAIL_ON_ERROR(_yr_emit_inst(
&emit_context,
RE_OPCODE_MATCH,
NULL,
&code_size));
total_size += code_size;
if (total_size > RE_MAX_CODE_SIZE)
return ERROR_REGULAR_EXPRESSION_TOO_LARGE;
yr_arena_reserve_memory(arena, RE_MAX_CODE_SIZE);
// Emit code for matching the regular expressions backwards.
total_size = 0;
FAIL_ON_ERROR(_yr_re_emit(
&emit_context,
re->root_node,
emit_flags | EMIT_BACKWARDS,
NULL,
&code_size));
total_size += code_size;
FAIL_ON_ERROR(_yr_emit_inst(
&emit_context,
RE_OPCODE_MATCH,
NULL,
&code_size));
total_size += code_size;
if (total_size > RE_MAX_CODE_SIZE)
return ERROR_REGULAR_EXPRESSION_TOO_LARGE;
return ERROR_SUCCESS;
}
int yr_re_emit_code(
RE* re,
YR_ARENA* arena)
{
int code_size;
int total_size;
int emit_flags = 0;
if (re->flags & RE_FLAGS_NO_CASE)
emit_flags |= EMIT_NO_CASE;
if (re->flags & RE_FLAGS_DOT_ALL)
emit_flags |= EMIT_DOT_ALL;
// Ensure that we have enough contiguos memory space in the arena to
// contain the regular expression code. The code can't span over multiple
// non-contiguos pages.
yr_arena_reserve_memory(arena, RE_MAX_CODE_SIZE);
// Emit code for matching the regular expressions forwards.
total_size = 0;
FAIL_ON_ERROR(_yr_re_emit(
re->root_node,
arena,
emit_flags,
&re->code,
&code_size));
total_size += code_size;
FAIL_ON_ERROR(_yr_emit_inst(
arena,
RE_OPCODE_MATCH,
NULL,
&code_size));
total_size += code_size;
assert(total_size < RE_MAX_CODE_SIZE);
yr_arena_reserve_memory(arena, RE_MAX_CODE_SIZE);
// Emit code for matching the regular expressions backwards.
total_size = 0;
FAIL_ON_ERROR(_yr_re_emit(
re->root_node,
arena,
emit_flags | EMIT_BACKWARDS,
NULL,
&code_size));
total_size += code_size;
FAIL_ON_ERROR(_yr_emit_inst(
arena,
RE_OPCODE_MATCH,
NULL,
&code_size));
total_size += code_size;
assert(total_size < RE_MAX_CODE_SIZE);
return ERROR_SUCCESS;
}
int yr_ac_compile(
YR_AC_AUTOMATON* automaton,
YR_ARENA* arena,
YR_AC_TABLES* tables)
{
uint32_t i;
FAIL_ON_ERROR(_yr_ac_create_failure_links(automaton));
FAIL_ON_ERROR(_yr_ac_optimize_failure_links(automaton));
FAIL_ON_ERROR(_yr_ac_build_transition_table(automaton));
FAIL_ON_ERROR(yr_arena_reserve_memory(
arena,
automaton->tables_size * sizeof(tables->transitions[0]) +
automaton->tables_size * sizeof(tables->matches[0])));
FAIL_ON_ERROR(yr_arena_write_data(
arena,
automaton->t_table,
sizeof(YR_AC_TRANSITION),
(void**) &tables->transitions));
for (i = 1; i < automaton->tables_size; i++)
{
FAIL_ON_ERROR(yr_arena_write_data(
arena,
automaton->t_table + i,
sizeof(YR_AC_TRANSITION),
NULL));
}
FAIL_ON_ERROR(yr_arena_write_data(
arena,
automaton->m_table,
sizeof(YR_AC_MATCH_TABLE_ENTRY),
(void**) &tables->matches));
FAIL_ON_ERROR(yr_arena_make_relocatable(
arena,
tables->matches,
offsetof(YR_AC_MATCH_TABLE_ENTRY, match),
EOL));
for (i = 1; i < automaton->tables_size; i++)
{
void* ptr;
FAIL_ON_ERROR(yr_arena_write_data(
arena,
automaton->m_table + i,
sizeof(YR_AC_MATCH_TABLE_ENTRY),
(void**) &ptr));
FAIL_ON_ERROR(yr_arena_make_relocatable(
arena,
ptr,
offsetof(YR_AC_MATCH_TABLE_ENTRY, match),
EOL));
}
return ERROR_SUCCESS;
}
