xref: /aosp_15_r20/external/cronet/testing/libfuzzer/fuzzers/template_url_parser_fuzzer.cc (revision 6777b5387eb2ff775bb5750e3f5d96f37fb7352b)
1 // Copyright 2016 The Chromium Authors
2 // Use of this source code is governed by a BSD-style license that can be
3 // found in the LICENSE file.
4 
5 #include <stddef.h>
6 #include <stdint.h>
7 
8 #include <random>
9 #include <string>
10 
11 #include "libxml/parser.h"
12 
13 #include "base/at_exit.h"
14 #include "base/command_line.h"
15 #include "base/functional/bind.h"
16 #include "base/i18n/icu_util.h"
17 #include "base/run_loop.h"
18 #include "base/task/single_thread_task_executor.h"
19 #include "components/search_engines/search_terms_data.h"
20 #include "components/search_engines/template_url.h"
21 #include "components/search_engines/template_url_parser.h"
22 #include "mojo/core/embedder/embedder.h"
23 #include "services/data_decoder/public/cpp/test_support/in_process_data_decoder.h"
24 #include "testing/libfuzzer/libfuzzer_exports.h"
25 
PseudoRandomFilter(std::mt19937 * generator,std::uniform_int_distribution<uint16_t> * pool,const std::string &,const std::string &)26 bool PseudoRandomFilter(std::mt19937* generator,
27                         std::uniform_int_distribution<uint16_t>* pool,
28                         const std::string&,
29                         const std::string&) {
30   // Return true 254/255 times, ie: as if pool only returned uint8_t.
31   return (*pool)(*generator) % (UINT8_MAX + 1);
32 }
33 
34 struct FuzzerFixedParams {
35   uint32_t seed_;
36 };
37 
38 base::AtExitManager at_exit_manager;  // used by ICU integration
39 
LLVMFuzzerInitialize(int * argc,char *** argv)40 extern "C" int LLVMFuzzerInitialize(int* argc, char*** argv) {
41   CHECK(base::i18n::InitializeICU());
42   CHECK(base::CommandLine::Init(*argc, *argv));
43   return 0;
44 }
45 
ignore(void * ctx,const char * msg,...)46 void ignore(void* ctx, const char* msg, ...) {
47   // Error handler to avoid error message spam from libxml parser.
48 }
49 
50 class Env {
51  public:
Env()52   Env() : executor_(base::MessagePumpType::IO) {
53     mojo::core::Init();
54     xmlSetGenericErrorFunc(nullptr, &ignore);
55   }
56 
57  private:
58   base::SingleThreadTaskExecutor executor_;
59   data_decoder::test::InProcessDataDecoder data_decoder_;
60 };
61 
LLVMFuzzerTestOneInput(const uint8_t * data,size_t size)62 extern "C" int LLVMFuzzerTestOneInput(const uint8_t* data, size_t size) {
63   static Env env;
64   if (size < sizeof(FuzzerFixedParams)) {
65     return 0;
66   }
67 
68   const FuzzerFixedParams* params =
69       reinterpret_cast<const FuzzerFixedParams*>(data);
70   size -= sizeof(FuzzerFixedParams);
71 
72   std::mt19937 generator(params->seed_);
73   // Use a uint16_t here instead of uint8_t because uniform_int_distribution
74   // does not support 8 bit types on Windows.
75   std::uniform_int_distribution<uint16_t> pool(0, 1);
76 
77   base::RunLoop run_loop;
78 
79   SearchTermsData search_terms_data;
80   std::string string_data(reinterpret_cast<const char*>(params + 1), size);
81   TemplateURLParser::ParameterFilter filter =
82       base::BindRepeating(&PseudoRandomFilter, base::Unretained(&generator),
83                           base::Unretained(&pool));
84   TemplateURLParser::Parse(&search_terms_data, string_data, filter,
85                            base::BindOnce(
86                                [](base::OnceClosure quit_closure,
87                                   std::unique_ptr<TemplateURL> ignored) {
88                                  std::move(quit_closure).Run();
89                                },
90                                run_loop.QuitClosure()));
91 
92   run_loop.Run();
93 
94   return 0;
95 }
96