Fuzzers: Add a DNS packet fuzzer

Meta/Lagom/Fuzzers/FuzzDNSPacket.cpp

@@ -0,0 +1,18 @@
+/*
+ * Copyright (c) 2023, the SerenityOS developers.
+ *
+ * SPDX-License-Identifier: BSD-2-Clause
+ */
+
+#include <LibDNS/Packet.h>
+
+extern "C" int LLVMFuzzerTestOneInput(uint8_t const* data, size_t size)
+{
+    AK::set_debug_enabled(false);
+    auto maybe_packet = DNS::Packet::from_raw_packet({ data, size });
+    if (!maybe_packet.has_value())
+        return 0;
+
+    (void)maybe_packet.value().to_byte_buffer();
+    return 0;
+}

Meta/Lagom/Fuzzers/fuzzers.cmake

@@ -5,6 +5,7 @@ set(FUZZER_TARGETS
     Brotli
     CyrillicDecoder
     DDSLoader
+    DNSPacket
     DeflateCompression
     DeflateDecompression
     ELF
@@ -80,6 +81,7 @@ set(FUZZER_DEPENDENCIES_Brotli LibCompress)
 set(FUZZER_DEPENDENCIES_CSSParser LibWeb)
 set(FUZZER_DEPENDENCIES_CyrillicDecoder LibTextCodec)
 set(FUZZER_DEPENDENCIES_DDSLoader LibGfx)
+set(FUZZER_DEPENDENCIES_DNSPacket LibDNS)
 set(FUZZER_DEPENDENCIES_DeflateCompression LibCompress)
 set(FUZZER_DEPENDENCIES_DeflateDecompression LibCompress)
 set(FUZZER_DEPENDENCIES_ELF LibELF)

Userland/Utilities/test-fuzz.cpp

@@ -19,6 +19,7 @@
     T(CSSParser)             \
     T(CyrillicDecoder)       \
     T(DDSLoader)             \
+    T(DNSPacket)             \
     T(DeflateCompression)    \
     T(DeflateDecompression)  \
     T(ELF)                   \