Merge #18512: Improve asmap checks and add sanity check

748977690e0519110cda9628162a7ccf73a5934b Add asmap_direct fuzzer that tests Interpreter directly (Pieter Wuille)
7cf97fda154ba837933eb05be5aeecfb69a06641 Make asmap Interpreter errors fatal and fuzz test it (Pieter Wuille)
c81aefc5377888c7ac4f29f570249fd6c2fdb352 Add additional effiency checks to sanity checker (Pieter Wuille)
fffd8dca2de39ad4a683f0dce57cdca55ed2f600 Add asmap sanity checker (Pieter Wuille)
5feefbe6e7b6cdd809eba4074d41dc95a7035f7e Improve asmap Interpret checks and document failures (Pieter Wuille)
2b3dbfa5a63cb5a6625ec00294ebd933800f0255 Deal with decoding failures explicitly in asmap Interpret (Pieter Wuille)
1479007a335ab43af46f527d0543e254fc2a8e86 Introduce Instruction enum in asmap (Pieter Wuille)

Pull request description:

  This improves/documents the failure cases inside the asmap interpreter. None of the changes are bug fixes (they only change behavior for corrupted asmap files), but they may make things easier to follow.

  In a second step, a sanity checker is added that effectively executes every potential code path through the asmap file, checking the same failure cases as the interpreter, and more. It takes around 30 ms to run for me for a 1.2 MB asmap file.

  I've verified that this accepts asmap files constructed by https://github.com/sipa/asmap/blob/master/buildmap.py with a large dataset, and no longer accepts it with 1 bit changed in it.

ACKs for top commit:
  practicalswift:
    ACK 748977690e0519110cda9628162a7ccf73a5934b modulo feedback below.
  jonatack:
    ACK 748977690e0519110cda9628162a7ccf73a5934b code review, regular build/tests/ran bitcoin with -asmap, fuzz build/ran both fuzzers overnight.
  fjahr:
    ACK 748977690e0519110cda9628162a7ccf73a5934b

Tree-SHA512: d876df3859735795c857c83e7155ba6851ce839bdfa10c18ce2698022cc493ce024b5578c1828e2a94bcdf2552c2f46c392a251ed086691b41959e62a6970821

1 files changed, 4 insertions, 0 deletions

diff --git a/src/addrman.cpp b/src/addrman.cpp
index 02fb2fd491..7aba340d9d 100644
--- a/src/addrman.cpp
+++ b/src/addrman.cpp
@@ -644,5 +644,9 @@ std::vector<bool> CAddrMan::DecodeAsmap(fs::path path)
             bits.push_back((cur_byte >> bit) & 1);
         }
     }
+    if (!SanityCheckASMap(bits)) {
+        LogPrintf("Sanity check of asmap file %s failed\n", path);
+        return {};
+    }
     return bits;
 }