1  // Copyright (c) 2021-present The Bitcoin Core developers
 2  // Distributed under the MIT software license, see the accompanying
 3  // file COPYING or http://www.opensource.org/licenses/mit-license.php.
 4  
 5  #include <netaddress.h>
 6  #include <netbase.h>
 7  #include <test/fuzz/FuzzedDataProvider.h>
 8  #include <test/fuzz/fuzz.h>
 9  #include <test/fuzz/util/net.h>
10  
11  #include <cstdint>
12  #include <string>
13  #include <vector>
14  
15  FUZZ_TARGET(netbase_dns_lookup)
16  {
17      FuzzedDataProvider fuzzed_data_provider{buffer.data(), buffer.size()};
18      const std::string name = fuzzed_data_provider.ConsumeRandomLengthString(512);
19      const unsigned int max_results = fuzzed_data_provider.ConsumeIntegral<unsigned int>();
20      const bool allow_lookup = fuzzed_data_provider.ConsumeBool();
21      const uint16_t default_port = fuzzed_data_provider.ConsumeIntegral<uint16_t>();
22  
23      auto fuzzed_dns_lookup_function = [&](const std::string&, bool) {
24          std::vector<CNetAddr> resolved_addresses;
25          LIMITED_WHILE(fuzzed_data_provider.ConsumeBool(), 10000) {
26              resolved_addresses.push_back(ConsumeNetAddr(fuzzed_data_provider));
27          }
28          return resolved_addresses;
29      };
30  
31      {
32          const std::vector<CNetAddr> resolved_addresses{LookupHost(name, max_results, allow_lookup, fuzzed_dns_lookup_function)};
33          for (const CNetAddr& resolved_address : resolved_addresses) {
34              assert(!resolved_address.IsInternal());
35          }
36          assert(resolved_addresses.size() <= max_results || max_results == 0);
37      }
38      {
39          const std::optional<CNetAddr> resolved_address{LookupHost(name, allow_lookup, fuzzed_dns_lookup_function)};
40          if (resolved_address.has_value()) {
41              assert(!resolved_address.value().IsInternal());
42          }
43      }
44      {
45          const std::vector<CService> resolved_services{Lookup(name, default_port, allow_lookup, max_results, fuzzed_dns_lookup_function)};
46          for (const CNetAddr& resolved_service : resolved_services) {
47              assert(!resolved_service.IsInternal());
48          }
49          assert(resolved_services.size() <= max_results || max_results == 0);
50      }
51      {
52          const std::optional<CService> resolved_service{Lookup(name, default_port, allow_lookup, fuzzed_dns_lookup_function)};
53          if (resolved_service.has_value()) {
54              assert(!resolved_service.value().IsInternal());
55          }
56      }
57      {
58          CService resolved_service = LookupNumeric(name, default_port, fuzzed_dns_lookup_function);
59          assert(!resolved_service.IsInternal());
60      }
61      {
62          (void)LookupSubNet(name);
63      }
64  }