tests: Add fuzzing harness for functions in net_permissions.h

Author: practicalswift

src/Makefile.test.include

@@ -44,6 +44,7 @@ FUZZ_TARGETS = \
   test/fuzz/merkle_block_deserialize \
   test/fuzz/messageheader_deserialize \
   test/fuzz/multiplication_overflow \
+  test/fuzz/net_permissions \
   test/fuzz/netaddr_deserialize \
   test/fuzz/netaddress \
   test/fuzz/out_point_deserialize \
@@ -530,6 +531,12 @@ test_fuzz_multiplication_overflow_LDADD = $(FUZZ_SUITE_LD_COMMON)
 test_fuzz_multiplication_overflow_LDFLAGS = $(RELDFLAGS) $(AM_LDFLAGS) $(LIBTOOL_APP_LDFLAGS)
 test_fuzz_multiplication_overflow_SOURCES = $(FUZZ_SUITE) test/fuzz/multiplication_overflow.cpp
 
+test_fuzz_net_permissions_CPPFLAGS = $(AM_CPPFLAGS) $(BITCOIN_INCLUDES)
+test_fuzz_net_permissions_CXXFLAGS = $(AM_CXXFLAGS) $(PIE_FLAGS)
+test_fuzz_net_permissions_LDADD = $(FUZZ_SUITE_LD_COMMON)
+test_fuzz_net_permissions_LDFLAGS = $(RELDFLAGS) $(AM_LDFLAGS) $(LIBTOOL_APP_LDFLAGS)
+test_fuzz_net_permissions_SOURCES = $(FUZZ_SUITE) test/fuzz/net_permissions.cpp
+
 test_fuzz_netaddr_deserialize_CPPFLAGS = $(AM_CPPFLAGS) $(BITCOIN_INCLUDES) -DNETADDR_DESERIALIZE=1
 test_fuzz_netaddr_deserialize_CXXFLAGS = $(AM_CXXFLAGS) $(PIE_FLAGS)
 test_fuzz_netaddr_deserialize_LDADD = $(FUZZ_SUITE_LD_COMMON)

src/test/fuzz/net_permissions.cpp

@@ -0,0 +1,51 @@
+// Copyright (c) 2020 The Bitcoin Core developers
+// Distributed under the MIT software license, see the accompanying
+// file COPYING or http://www.opensource.org/licenses/mit-license.php.
+
+#include <net_permissions.h>
+#include <optional.h>
+#include <test/fuzz/FuzzedDataProvider.h>
+#include <test/fuzz/fuzz.h>
+#include <test/fuzz/util.h>
+
+#include <cassert>
+#include <cstdint>
+#include <string>
+#include <vector>
+
+void test_one_input(const std::vector<uint8_t>& buffer)
+{
+    FuzzedDataProvider fuzzed_data_provider(buffer.data(), buffer.size());
+    const std::string s = fuzzed_data_provider.ConsumeRandomLengthString(32);
+    const NetPermissionFlags net_permission_flags = fuzzed_data_provider.ConsumeBool() ? fuzzed_data_provider.PickValueInArray<NetPermissionFlags>({
+                                                                                             NetPermissionFlags::PF_NONE,
+                                                                                             NetPermissionFlags::PF_BLOOMFILTER,
+                                                                                             NetPermissionFlags::PF_RELAY,
+                                                                                             NetPermissionFlags::PF_FORCERELAY,
+                                                                                             NetPermissionFlags::PF_NOBAN,
+                                                                                             NetPermissionFlags::PF_MEMPOOL,
+                                                                                             NetPermissionFlags::PF_ISIMPLICIT,
+                                                                                             NetPermissionFlags::PF_ALL,
+                                                                                         }) :
+                                                                                         static_cast<NetPermissionFlags>(fuzzed_data_provider.ConsumeIntegral<uint32_t>());
+
+    NetWhitebindPermissions net_whitebind_permissions;
+    std::string error_net_whitebind_permissions;
+    if (NetWhitebindPermissions::TryParse(s, net_whitebind_permissions, error_net_whitebind_permissions)) {
+        (void)NetPermissions::ToStrings(net_whitebind_permissions.m_flags);
+        (void)NetPermissions::AddFlag(net_whitebind_permissions.m_flags, net_permission_flags);
+        assert(NetPermissions::HasFlag(net_whitebind_permissions.m_flags, net_permission_flags));
+        (void)NetPermissions::ClearFlag(net_whitebind_permissions.m_flags, net_permission_flags);
+        (void)NetPermissions::ToStrings(net_whitebind_permissions.m_flags);
+    }
+
+    NetWhitelistPermissions net_whitelist_permissions;
+    std::string error_net_whitelist_permissions;
+    if (NetWhitelistPermissions::TryParse(s, net_whitelist_permissions, error_net_whitelist_permissions)) {
+        (void)NetPermissions::ToStrings(net_whitelist_permissions.m_flags);
+        (void)NetPermissions::AddFlag(net_whitelist_permissions.m_flags, net_permission_flags);
+        assert(NetPermissions::HasFlag(net_whitelist_permissions.m_flags, net_permission_flags));
+        (void)NetPermissions::ClearFlag(net_whitelist_permissions.m_flags, net_permission_flags);
+        (void)NetPermissions::ToStrings(net_whitelist_permissions.m_flags);
+    }
+}