###############################################################################
# https://en.wikipedia.org/wiki/American_fuzzy_lop_(fuzzer)
# lottery.c from https://events.static.linuxfound.org/sites/events/files/slides/AFL%20filesystem%20fuzzing%2C%20Vault%202016_0.pdf
###############################################################################

.ONESHELL:

EXE = $(basename $(SRC))
IN  = $(EXE:=.in)
OUT = $(EXE:=.out)
PAT = core_pattern
PKG = american-fuzzy-lop
SRC = $(wildcard *.c *.cc)

CC       = afl-gcc
CXX      = afl-g++
CFLAGS   = -fanalyzer -fsanitize={address,pointer-compare,pointer-subtract,undefined}
CXXFLAGS = $(CFLAGS)

FUZ = AFL_BENCH_UNTIL_CRASH=1 AFL_I_DONT_CARE_ABOUT_MISSING_CRASHES=1 AFL_SKIP_CPUFREQ=1 AFL_USE_ASAN=1 afl-fuzz

all: $(OUT)

clean: core_off
	-rm -frv $(EXE) $(IN) $(OUT) $(PAT) core.* *~

core_off: /proc/sys/kernel/$(PAT)
	@if [ -f "$(PAT)" ]; then
		pattern=$$(cat $(PAT))
	else
		pattern="|/usr/lib/systemd/systemd-coredump %P %u %g %s %t %c %h"
	fi
	echo "$$pattern" | sudo tee $< &> /dev/null

core_on: /proc/sys/kernel/$(PAT) | $(PAT)
	@echo "core" | sudo tee $< &> /dev/null

$(PAT): /proc/sys/kernel/$(PAT)
	@cat $< > $@

exe: $(EXE)

pkg:
	sudo dnf -y install $(PKG)

%.in: %
	mkdir -p $@
	case '$*' in
		rand  ) tr -cd '[:digit:]' < /dev/urandom | fold -c2 | head -n8;;
		hola  ) tr -cd '[:lower:]' < /dev/urandom | fold -c4 | head -n16;;
		memcpy) tr -cd '[:alpha:]' < /dev/urandom | fold -c64 | head -n1;
		        tr -cd '[:alpha:]' < /dev/urandom | fold -c8 | head -n1;;
		saludo) for ((i=1; i<1024; i*=2)); do
					tr -cd '[:alnum:]' < /dev/urandom | fold -c$$i | head -n1
				done;;
	esac > ./$@/samples.txt

%: %.rs
	rustc $< -o $@

%.out: %.in
	-make -s core_on
	$(FUZ) -i ./$< -m none -o ./$@ -T $* -- ./$*
	-make -s core_off

.PRECIOUS: $(IN) $(OUT) $(PAT)
.PHONY: all clean core_off core_on exe pkg