Makefile.fuzz

# Makefile for fuzzing
#
# With https://app.fuzzit.dev/ we are continuously fuzzing CoreDNS.
#
# Use go-fuzz and needs the tools installed. For each fuzz.go in a plugin's directory
# you can start the fuzzing with: make -f Makefile.fuzz <plugin>
# e.g.
#
# 	make -f Makefile.fuzz forward
#
# Each plugin that wants to join the fuzzing fray only needs to add a fuzz.go that calls
# the plugin's ServeDNS and used the plugin/pkg/fuzz for the Do function.
#
# Installing go-fuzz is very tricky because it does not support Go modules, see the `Makefile`
# for the current trickery. The following may do the trick:
#
# GO111MODULE=off go get github.com/dvyukov/go-fuzz/go-fuzz-build

REPO:="github.com/coredns/coredns"
FUZZIT:=v2.4.35
# set LIBFUZZER=YES to build libfuzzer compatible targets

FUZZ:=$(dir $(wildcard plugin/*/fuzz.go)) # plugin/cache/
PLUGINS:=$(foreach f,$(FUZZ),$(subst plugin, ,$(f:/=))) # > /cache
PLUGINS:=$(foreach f,$(PLUGINS),$(subst /, ,$(f))) # > cache

.PHONY: echo
echo:
	@echo $(PLUGINS) corefile

all: $(PLUGINS) corefile

.PHONY: $(PLUGINS)
$(PLUGINS): echo
ifeq ($(LIBFUZZER), YES)
	go-fuzz-build -libfuzzer -o $(@).a ./plugin/$(@)
	clang -fsanitize=fuzzer $(@).a -o $(@)
else
	go-fuzz-build $(REPO)/plugin/$(@)
	go-fuzz -bin=./$(@)-fuzz.zip -workdir=fuzz/$(@)
endif

.PHONY: corefile
corefile:
ifeq ($(LIBFUZZER), YES)
	go-fuzz-build -libfuzzer -o $(@).a ./test
	clang -fsanitize=fuzzer $(@).a -o $(@)
else
	go-fuzz-build $(REPO)/test
	go-fuzz -bin=./test-fuzz.zip -workdir=fuzz/$(@)
endif

fuzzit:
	wget --quiet -O fuzzit https://github.com/fuzzitdev/fuzzit/releases/download/$(FUZZIT)/fuzzit_Linux_x86_64 && chmod +x fuzzit

.PHONY: clean
clean:
	rm *-fuzz.zip