Merge bitcoin/bitcoin#22005: fuzz: Speed up banman fuzz target

fae0f83 fuzz: Speed up banman fuzz target (MarcoFalke)

Pull request description:

  Hopefully fixes https://bugs.chromium.org/p/oss-fuzz/issues/detail?id=34463

ACKs for top commit:
  practicalswift:
    cr ACK fae0f83: patch looks correct and touches only `src/test/fuzz/banman.cpp`

Tree-SHA512: edbad168c607d09a5f4a29639f2d0b852605dd61403334356ad35a1eac667b6ce3922b1b316fdf37a991195fbc24e947df9e37359231663f8a364e5889e28417

Author: MarcoFalke

src/test/fuzz/banman.cpp

@@ -32,13 +32,17 @@ void initialize_banman()
 
 FUZZ_TARGET_INIT(banman, initialize_banman)
 {
+    // The complexity is O(N^2), where N is the input size, because each call
+    // might call DumpBanlist (or other methods that are at least linear
+    // complexity of the input size).
+    int limit_max_ops{300};
     FuzzedDataProvider fuzzed_data_provider{buffer.data(), buffer.size()};
     SetMockTime(ConsumeTime(fuzzed_data_provider));
     const fs::path banlist_file = gArgs.GetDataDirNet() / "fuzzed_banlist.dat";
     fs::remove(banlist_file);
     {
         BanMan ban_man{banlist_file, nullptr, ConsumeBanTimeOffset(fuzzed_data_provider)};
-        while (fuzzed_data_provider.ConsumeBool()) {
+        while (--limit_max_ops >= 0 && fuzzed_data_provider.ConsumeBool()) {
             CallOneOf(
                 fuzzed_data_provider,
                 [&] {
@@ -52,7 +56,6 @@ FUZZ_TARGET_INIT(banman, initialize_banman)
                 [&] {
                     ban_man.ClearBanned();
                 },
-                [] {},
                 [&] {
                     ban_man.IsBanned(ConsumeNetAddr(fuzzed_data_provider));
                 },
@@ -72,7 +75,6 @@ FUZZ_TARGET_INIT(banman, initialize_banman)
                 [&] {
                     ban_man.DumpBanlist();
                 },
-                [] {},
                 [&] {
                     ban_man.Discourage(ConsumeNetAddr(fuzzed_data_provider));
                 });