net/tools/dns_fuzz_stub/dns_fuzz_stub.cc

   1 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
   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 <algorithm>
   6 #include <sstream>
   7 #include <string>
   8 #include <vector>
   9
  10 #include "base/basictypes.h"
  11 #include "base/files/file_path.h"
  12 #include "base/files/file_util.h"
  13 #include "base/json/json_reader.h"
  14 #include "base/memory/scoped_ptr.h"
  15 #include "base/time/time.h"
  16 #include "base/values.h"
  17 #include "net/base/address_list.h"
  18 #include "net/base/dns_util.h"
  19 #include "net/base/io_buffer.h"
  20 #include "net/base/ip_endpoint.h"
  21 #include "net/dns/dns_protocol.h"
  22 #include "net/dns/dns_query.h"
  23 #include "net/dns/dns_response.h"
  24
  25 namespace {
  26
  27 void CrashDoubleFree(void) {
  28   // Cause ASAN to detect a double-free
  29   void *p = malloc(1);
  30   LOG(INFO) << "Allocated p=" << p << ".  Double-freeing...";
  31   free(p);
  32   free(p);
  33 }
  34
  35 void CrashNullPointerDereference(void) {
  36   // Cause the program to segfault with a NULL pointer dereference
  37   int *p = NULL;
  38   *p = 0;
  39 }
  40
  41 bool FitsUint8(int num) {
  42   return (num >= 0) && (num <= kuint8max);
  43 }
  44
  45 bool FitsUint16(int num) {
  46   return (num >= 0) && (num <= kuint16max);
  47 }
  48
  49 bool ReadTestCase(const char* filename,
  50                   uint16* id, std::string* qname, uint16* qtype,
  51                   std::vector<char>* resp_buf,
  52                   bool* crash_test) {
  53   base::FilePath filepath = base::FilePath::FromUTF8Unsafe(filename);
  54
  55   std::string json;
  56   if (!base::ReadFileToString(filepath, &json)) {
  57     LOG(ERROR) << filename << ": couldn't read file.";
  58     return false;
  59   }
  60
  61   scoped_ptr<base::Value> value(base::JSONReader::Read(json));
  62   if (!value.get()) {
  63     LOG(ERROR) << filename << ": couldn't parse JSON.";
  64     return false;
  65   }
  66
  67   base::DictionaryValue* dict;
  68   if (!value->GetAsDictionary(&dict)) {
  69     LOG(ERROR) << filename << ": test case is not a dictionary.";
  70     return false;
  71   }
  72
  73   *crash_test = dict->HasKey("crash_test");
  74   if (*crash_test) {
  75     LOG(INFO) << filename << ": crash_test is set!";
  76     return true;
  77   }
  78
  79   int id_int;
  80   if (!dict->GetInteger("id", &id_int)) {
  81     LOG(ERROR) << filename << ": id is missing or not an integer.";
  82     return false;
  83   }
  84   if (!FitsUint16(id_int)) {
  85     LOG(ERROR) << filename << ": id is out of range.";
  86     return false;
  87   }
  88   *id = static_cast<uint16>(id_int);
  89
  90   if (!dict->GetStringASCII("qname", qname)) {
  91     LOG(ERROR) << filename << ": qname is missing or not a string.";
  92     return false;
  93   }
  94
  95   int qtype_int;
  96   if (!dict->GetInteger("qtype", &qtype_int)) {
  97     LOG(ERROR) << filename << ": qtype is missing or not an integer.";
  98     return false;
  99   }
 100   if (!FitsUint16(qtype_int)) {
 101     LOG(ERROR) << filename << ": qtype is out of range.";
 102     return false;
 103   }
 104   *qtype = static_cast<uint16>(qtype_int);
 105
 106   base::ListValue* resp_list;
 107   if (!dict->GetList("response", &resp_list)) {
 108     LOG(ERROR) << filename << ": response is missing or not a list.";
 109     return false;
 110   }
 111
 112   size_t resp_size = resp_list->GetSize();
 113   resp_buf->clear();
 114   resp_buf->reserve(resp_size);
 115   for (size_t i = 0; i < resp_size; i++) {
 116     int resp_byte_int;
 117     if ((!resp_list->GetInteger(i, &resp_byte_int))) {
 118       LOG(ERROR) << filename << ": response[" << i << "] is not an integer.";
 119       return false;
 120     }
 121     if (!FitsUint8(resp_byte_int)) {
 122       LOG(ERROR) << filename << ": response[" << i << "] is out of range.";
 123       return false;
 124     }
 125     resp_buf->push_back(static_cast<char>(resp_byte_int));
 126   }
 127   DCHECK(resp_buf->size() == resp_size);
 128
 129   LOG(INFO) << "Query: id=" << id_int << ", "
 130             << "qname=" << *qname << ", "
 131             << "qtype=" << qtype_int << ", "
 132             << "resp_size=" << resp_size;
 133
 134   return true;
 135 }
 136
 137 void RunTestCase(uint16 id, std::string& qname, uint16 qtype,
 138                  std::vector<char>& resp_buf) {
 139   net::DnsQuery query(id, qname, qtype);
 140   net::DnsResponse response;
 141   std::copy(resp_buf.begin(), resp_buf.end(), response.io_buffer()->data());
 142
 143   if (!response.InitParse(resp_buf.size(), query)) {
 144     LOG(INFO) << "InitParse failed.";
 145     return;
 146   }
 147
 148   net::AddressList address_list;
 149   base::TimeDelta ttl;
 150   net::DnsResponse::Result result = response.ParseToAddressList(
 151       &address_list, &ttl);
 152   if (result != net::DnsResponse::DNS_PARSE_OK) {
 153     LOG(INFO) << "ParseToAddressList failed: " << result;
 154     return;
 155   }
 156
 157   // Print the response in one compact line.
 158   std::stringstream result_line;
 159   result_line << "Response: address_list={ ";
 160   for (unsigned int i = 0; i < address_list.size(); i++)
 161     result_line << address_list[i].ToString() << " ";
 162   result_line << "}, ttl=" << ttl.InSeconds() << "s";
 163
 164   LOG(INFO) << result_line.str();
 165 }
 166
 167 bool ReadAndRunTestCase(const char* filename) {
 168   uint16 id = 0;
 169   std::string qname;
 170   uint16 qtype = 0;
 171   std::vector<char> resp_buf;
 172   bool crash_test = false;
 173
 174   LOG(INFO) << "Test case: " << filename;
 175
 176   // ReadTestCase will print a useful error message if it fails.
 177   if (!ReadTestCase(filename, &id, &qname, &qtype, &resp_buf, &crash_test))
 178     return false;
 179
 180   if (crash_test) {
 181     LOG(INFO) << "Crashing.";
 182     CrashDoubleFree();
 183     // if we're not running under ASAN, that might not have worked
 184     CrashNullPointerDereference();
 185     NOTREACHED();
 186     return true;
 187   }
 188
 189   std::string qname_dns;
 190   if (!net::DNSDomainFromDot(qname, &qname_dns)) {
 191     LOG(ERROR) << filename << ": DNSDomainFromDot(" << qname << ") failed.";
 192     return false;
 193   }
 194
 195   RunTestCase(id, qname_dns, qtype, resp_buf);
 196
 197   return true;
 198 }
 199
 200 }
 201
 202 int main(int argc, char** argv) {
 203   int ret = 0;
 204
 205   for (int i = 1; i < argc; i++)
 206     if (!ReadAndRunTestCase(argv[i]))
 207       ret = 2;
 208
 209   // Cluster-Fuzz likes "#EOF" as the last line of output to help distinguish
 210   // successful runs from crashes.
 211   printf("#EOF\n");
 212
 213   return ret;
 214 }
 215