bind9/fuzz/FUZZING.md

= Fuzzing

The tests in this directory can be operated in three modes:

• non-fuzzing - the test just runs over all input located in <test_name>.in/ directory by compiling with mock main.c that walks through the directory and runs LLVMFuzzerTestOneInput() over the input files
• AFL - meson setup -Dfuzzing=afl will either feed the stdin to LLVMFuzzerTestOneInput() or run the __AFL_LOOP(10000) if compiled with afl-clang-fast. You have to compile using CC=afl-<gcc|clang>.
• LibFuzzer - meson setup -Dfuzzing=libfuzzer will disable main.c completely and it uses the standard LibFuzzer mechanims to feed LLVMFuzzerTestOneInput with the fuzzer

== Test Cases

Each test case should be called descriptively and the executable target must link testcase.o and main.o and the test_case.c must have a function LLVMFuzzerTestOneInput(const uint8_t* data, size_t size).

== Adding more fuzzers

To add a different fuzzer, main.c must be modified to include main() function for a specific fuzzer (or no function as is case with LibFuzzer).