/* Copyright 2023 Google LLC

Licensed under the Apache License, Version 2.0 (the "License");

you may not use this file except in compliance with the License.

You may obtain a copy of the License at

      http://www.apache.org/licenses/LICENSE-2.0

Unless required by applicable law or agreed to in writing, software

distributed under the License is distributed on an "AS IS" BASIS,

WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.

See the License for the specific language governing permissions and

limitations under the License.

*/

#include <stddef.h>

#include <stdint.h>

#include <stdlib.h>

#include <string>

#include <sys/socket.h>

#include <fuzzer/FuzzedDataProvider.h>

extern "C" {

#include "libevent/include/event2/event.h"

#include "libevent/include/event2/buffer.h"

#include "libevent/include/event2/buffer_compat.h"

#include "libevent/include/event2/util.h"

#include "libevent/include/event2/event.h"

#include "libevent/include/event2/http.h"

#include "libevent/include/event2/http_struct.h"

#include "libevent/include/event2/buffer.h"

#include "libevent/include/event2/bufferevent.h"

#include "libevent/http-internal.h"

}

extern "C" int LLVMFuzzerTestOneInput(const uint8_t *data, size_t size) {

  if (size < 5) {

    return 0;

  }

  // Decider to determine which request type to parse.

  uint8_t decider = data[0];

  data++;

  size--;

  int maxHeaderSize = *(int*)data;

  data += 4;

  size -= 4;

  if (maxHeaderSize < 0) {

    return 0;

  }

  // Prepare in case it's used.

  struct evhttp_connection evcon;

  evcon.ext_method_cmp = NULL;

  evcon.max_headers_size = maxHeaderSize % 2048;

  struct evhttp *http_val = NULL;

  http_val = evhttp_new(NULL);

  if (http_val == NULL) {

    return 0;

  }

  evcon.http_server = http_val;

  FuzzedDataProvider data_provider(data, size);

  std::string s1 = data_provider.ConsumeRandomLengthString();

  struct evbuffer *buf = evbuffer_new();

  evbuffer_add(buf, s1.c_str(), s1.size());

  struct evhttp_request *req = evhttp_request_new(NULL, NULL);

  // Use either the defailt request type or EVHTTP_REQUEST

  if (decider % 2 == 1) {

    req->kind=EVHTTP_REQUEST;

    req->evcon = &evcon;

  }

  enum message_read_status data_read;

  data_read = evhttp_parse_firstline_(req, buf);

  if (data_read != ALL_DATA_READ) {

    data_read = evhttp_parse_headers_(req, buf);

    if (data_read != ALL_DATA_READ) {

      data_read = evhttp_parse_headers_(req, buf);

      if (data_read != ALL_DATA_READ) {

        evhttp_request_get_input_headers(req);

      }

    }

  }

  evhttp_request_get_host(req);

  char *encoded = evhttp_encode_uri(s1.c_str());

  if (encoded != NULL) {

    free(encoded);

  }

  // Minor utils function

  char *tmp_escaped = evhttp_htmlescape(s1.c_str());

  if (tmp_escaped != NULL) {

    free(tmp_escaped);

  }

  // URI utils

  struct evhttp_uri *uri;

  uri = evhttp_uri_parse(s1.c_str());

  if (uri != NULL) {

    char uri_buf[256];

    evhttp_uri_join(uri, uri_buf, 256);

    evhttp_uri_free(uri);

  }

  // Cleanup

  evhttp_request_free(req);

  evbuffer_free(buf);

  evhttp_free(http_val);

  return 0;

}