1  // Copyright (c) 2020-2021 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 <util/asmap.h>
 7  #include <test/fuzz/fuzz.h>
 8  
 9  #include <cstdint>
10  #include <optional>
11  #include <vector>
12  
13  #include <assert.h>
14  
15  FUZZ_TARGET(asmap_direct)
16  {
17      // Encoding: [asmap using 1 bit / byte] 0xFF [addr using 1 bit / byte]
18      std::optional<size_t> sep_pos_opt;
19      for (size_t pos = 0; pos < buffer.size(); ++pos) {
20          uint8_t x = buffer[pos];
21          if ((x & 0xFE) == 0) continue;
22          if (x == 0xFF) {
23              if (sep_pos_opt) return;
24              sep_pos_opt = pos;
25          } else {
26              return;
27          }
28      }
29      if (!sep_pos_opt) return; // Needs exactly 1 separator
30      const size_t sep_pos{sep_pos_opt.value()};
31      if (buffer.size() - sep_pos - 1 > 128) return; // At most 128 bits in IP address
32  
33      // Checks on asmap
34      std::vector<bool> asmap(buffer.begin(), buffer.begin() + sep_pos);
35      if (SanityCheckASMap(asmap, buffer.size() - 1 - sep_pos)) {
36          // Verify that for valid asmaps, no prefix (except up to 7 zero padding bits) is valid.
37          std::vector<bool> asmap_prefix = asmap;
38          while (!asmap_prefix.empty() && asmap_prefix.size() + 7 > asmap.size() && asmap_prefix.back() == false) {
39              asmap_prefix.pop_back();
40          }
41          while (!asmap_prefix.empty()) {
42              asmap_prefix.pop_back();
43              assert(!SanityCheckASMap(asmap_prefix, buffer.size() - 1 - sep_pos));
44          }
45          // No address input should trigger assertions in interpreter
46          std::vector<bool> addr(buffer.begin() + sep_pos + 1, buffer.end());
47          (void)Interpret(asmap, addr);
48      }
49  }