###############################################################################
# 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 = $(EXE:=.out)
PAT = core_pattern
PTH = /proc/sys/kernel/$(PAT)
PKG = american-fuzzy-lop
SRC = $(wildcard *.c *.cc)

CC       = afl-gcc
CXX      = afl-g++
CFLAGS   = -fanalyzer -fsanitize={address,pointer-compare,pointer-subtract,undefined} -Wall
CXXFLAGS = $(CFLAGS)
FUZ = AFL_BENCH_UNTIL_CRASH=1 AFL_SKIP_CPUFREQ=1 afl-fuzz

all: $(OUT)

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

# default: "|/usr/lib/systemd/systemd-coredump %P %u %g %s %t %c %h"
core_off: $(PAT)
	@cat $< | sudo tee $(PTH) &> /dev/null

core_on: $(PAT)
	@echo core | sudo tee $(PTH) &> /dev/null

$(PAT):
	@cat $(PTH) > $@

exe: $(EXE)

pkg:
	sudo dnf -y install $(PKG)

%.in: %
	mkdir -p $@
	case '$*' in
		integer) echo {0..9} | tr ' ' '\n';;                # digits
#		*      ) printf "%b" $$(printf '\\x%x' {0..255});;  # every char
		*      ) printf "%b" $$(printf '\\x%x' {30..127});; # printable chars
	esac | sort | uniq > ./$@/samples.txt

%.out: %.in
	-make -s core_on
	-case '$*' in
		writeme) $(FUZ) -D -i ./$< -o ./$@ -T $* -- ./$* @@;; # file
		*      ) $(FUZ) -D -i ./$< -o ./$@ -T $* -- ./$*   ;; # stdio
	esac
	-make -s core_off

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