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#include "parser/parser.h"
#include <stdlib.h>
#include "parser/find_parse_functions.h"
#include "utils/memory.h"
// find earliest data to parse in stream
byte_t *find_earliest_data(TCPStream *stream, int stream_offset, int *earliest_length, parse_function_t **earliest_parse_fun) {
byte_t *earliest_data = NULL;
for (size_t i = 0; i < ARR_LEN(all_find_parse_functions); i++) {
// ignore if not correct stream
if (stream->src != all_find_parse_functions[i].stream_src)
continue;
int length;
byte_t *data = all_find_parse_functions[i].find_fn(stream, stream_offset, &length);
// if it's the first found or earlier than earliest - save it
if (data && (!earliest_data || data < earliest_data)) {
earliest_data = data;
*earliest_length = length;
*earliest_parse_fun = all_find_parse_functions[i].parse_fn;
}
}
return earliest_data;
}
ParsedData *parse_stream(TCPStream *stream, size_t *parsed_len, size_t *n_parsed_data) {
size_t parsed_data_capacity = INIT_PARSED_DATA_CAPACITY;
ParsedData *parsed_data = safe_malloc(parsed_data_capacity * sizeof(ParsedData));
*n_parsed_data = 0;
int stream_offset = 0;
byte_t *earliest_data;
do {
// find earliest data to parse
int earliest_length;
parse_function_t *earliest_parse_fun;
earliest_data = find_earliest_data(stream, stream_offset, &earliest_length, &earliest_parse_fun);
// if start of data to parse was found, but not the end, then finish here
// set parsed_len, so that the beginning of that data is at the beginning of the stream
if (earliest_data && earliest_length == -1) {
*parsed_len = earliest_data - stream->data;
return parsed_data;
}
// if data to parse was found, parse it and update the offset
if (earliest_data) {
ParsedData new_parsed = earliest_parse_fun(earliest_data, earliest_length);
parsed_data = array_append(parsed_data, sizeof(ParsedData), n_parsed_data, &parsed_data_capacity, &new_parsed);
stream_offset = earliest_data - stream->data + earliest_length;
}
} while (earliest_data);
// if all was parsed - set parsed_len to stream_len and return the data
*parsed_len = stream->len;
return parsed_data;
}
void free_parsed_data(ParsedData *parsed_data, size_t n_parsed_data) {
for (size_t i = 0; i < n_parsed_data; i++) {
if (parsed_data[i].data_cleanup)
parsed_data[i].data_cleanup(parsed_data[i].data);
free(parsed_data[i].data);
}
free(parsed_data);
}
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