fuzz: some cleanups (#3143)

* fuzz: some cleanups
Signed-off-by: Miek Gieben <miek@miek.nl>

* smaller
Signed-off-by: Miek Gieben <miek@miek.nl>

* documentation
Signed-off-by: Miek Gieben <miek@miek.nl>

* comments
Signed-off-by: Miek Gieben <miek@miek.nl>

Makefile

@@ -47,22 +47,17 @@ endif
 ifeq ($(TEST_TYPE),fuzzit)
 	# skip fuzzing for PR
 	if [ "$(TRAVIS_PULL_REQUEST)" = "false" ] || [ "$(FUZZIT_TYPE)" = "local-regression" ] ; then \
-        export GO111MODULE=off; \
-        go get -u github.com/dvyukov/go-fuzz/go-fuzz-build; \
-        go get -u -v .; \
-        cd ../../go-acme/lego; \
-        git checkout v2.5.0; \
-        cd ../../coredns/coredns; \
-        LIBFUZZER=YES make -f Makefile.fuzz cache chaos file rewrite whoami corefile; \
-        wget -O fuzzit https://github.com/fuzzitdev/fuzzit/releases/download/v2.4.27/fuzzit_Linux_x86_64; \
-        chmod a+x fuzzit; \
-        ./fuzzit create job --type $(FUZZIT_TYPE) coredns/cache ./cache; \
-        ./fuzzit create job --type $(FUZZIT_TYPE) coredns/chaos ./chaos; \
-        ./fuzzit create job --type $(FUZZIT_TYPE) coredns/file ./file; \
-        ./fuzzit create job --type $(FUZZIT_TYPE) coredns/rewrite ./rewrite; \
-        ./fuzzit create job --type $(FUZZIT_TYPE) coredns/whoami ./whoami; \
-        ./fuzzit create job --type $(FUZZIT_TYPE) coredns/corefile ./corefile; \
-    fi;
+		export GO111MODULE=off; \
+		go get -u github.com/dvyukov/go-fuzz/go-fuzz-build; \
+		go get -u -v .; \
+		cd ../../go-acme/lego && git checkout v2.5.0; \
+		cd ../../coredns/coredns; \
+		LIBFUZZER=YES $(MAKE) -f Makefile.fuzz all; \
+		$(MAKE) -sf Makefile.fuzz fuzzit; \
+		for i in `$(MAKE) -sf Makefile.fuzz echo`; do echo $$i; \
+			./fuzzit create job --type $(FUZZIT_TYPE) coredns/$$i ./$$i; \
+		done; \
+	fi;
 endif
 
 core/plugin/zplugin.go core/dnsserver/zdirectives.go: plugin.cfg

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.
@@ -9,11 +11,13 @@
 # Each plugin that wants to join the fuzzing fray only needs to add a fuzz.go that calls
 # the plugins's ServeDNS and used the plugin/pkg/fuzz for the Do function.
 #
-# Installing go-fuzz
-#$ go get github.com/dvyukov/go-fuzz/go-fuzz
-#$ go get github.com/dvyukov/go-fuzz/go-fuzz-build
+# 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:=v2.4.28
 # set LIBFUZZER=YES to build libfuzzer compatible targets
 
 FUZZ:=$(dir $(wildcard plugin/*/fuzz.go)) # plugin/cache/
@@ -22,7 +26,9 @@ PLUGINS:=$(foreach f,$(PLUGINS),$(subst /, ,$(f))) # > cache
 
 .PHONY: echo
 echo:
-	@echo fuzz targets: $(PLUGINS)
+	@echo $(PLUGINS) corefile
+
+all: $(PLUGINS) corefile
 
 .PHONY: $(PLUGINS)
 $(PLUGINS): echo
@@ -34,7 +40,6 @@ else
 	go-fuzz -bin=./$(@)-fuzz.zip -workdir=fuzz/$(@)
 endif
 
-
 .PHONY: corefile
 corefile:
 ifeq ($(LIBFUZZER), YES)
@@ -45,7 +50,8 @@ else
 	go-fuzz -bin=./test-fuzz.zip -workdir=fuzz/$(@)
 endif
 
-
+fuzzit:
+	wget -O fuzzit https://github.com/fuzzitdev/fuzzit/releases/download/$(FUZZIT)/fuzzit_Linux_x86_64 && chmod +x fuzzit
 
 .PHONY: clean
 clean:

plugin/pkg/fuzz/do.go

@@ -10,7 +10,7 @@ import (
 	"github.com/miekg/dns"
 )
 
-// Do will fuzz p - used by gofuzz. See Maefile.fuzz for comments and context.
+// Do will fuzz p - used by gofuzz. See Makefile.fuzz for comments and context.
 func Do(p plugin.Handler, data []byte) int {
 	ctx := context.TODO()
 	ret := 1