# Run a fuzz test to verify robustness against corrupted/malicious data.

import sys
import time
import zipfile
import random
import subprocess

Import("env", "malloc_env")

def set_pkgname(src, dst, pkgname):
    data = open(str(src)).read()
    placeholder = '// package name placeholder'
    assert placeholder in data
    data = data.replace(placeholder, 'package %s;' % pkgname)
    open(str(dst), 'w').write(data)

# We want both pointer and static versions of the AllTypes message
# Prefix them with package name.
env.Command("alltypes_static.proto", "#alltypes/alltypes.proto",
            lambda target, source, env: set_pkgname(source[0], target[0], 'alltypes_static'))
env.Command("alltypes_pointer.proto", "#alltypes/alltypes.proto",
            lambda target, source, env: set_pkgname(source[0], target[0], 'alltypes_pointer'))

env.NanopbProto(["alltypes_pointer", "alltypes_pointer.options"])
env.NanopbProto(["alltypes_static", "alltypes_static.options"])

# Do the same for proto3 versions
env.Command("alltypes_proto3_static.proto", "#alltypes_proto3/alltypes.proto",
            lambda target, source, env: set_pkgname(source[0], target[0], 'alltypes_proto3_static'))
env.Command("alltypes_proto3_pointer.proto", "#alltypes_proto3/alltypes.proto",
            lambda target, source, env: set_pkgname(source[0], target[0], 'alltypes_proto3_pointer'))

env.NanopbProto(["alltypes_proto3_pointer", "alltypes_proto3_pointer.options"])
env.NanopbProto(["alltypes_proto3_static", "alltypes_proto3_static.options"])

# And also a callback version
env.Command("alltypes_callback.proto", "#alltypes/alltypes.proto",
            lambda target, source, env: set_pkgname(source[0], target[0], 'alltypes_callback'))
env.NanopbProto(["alltypes_callback", "alltypes_callback.options"])

common_objs = [env.Object("random_data.c"),
               env.Object("validation.c"),
               env.Object("flakystream.c"),
               env.Object("alltypes_pointer.pb.c"),
               env.Object("alltypes_static.pb.c"),
               env.Object("alltypes_callback.pb.c"),
               env.Object("alltypes_proto3_pointer.pb.c"),
               env.Object("alltypes_proto3_static.pb.c"),
                "$COMMON/malloc_wrappers.o"]
objs_malloc = ["$COMMON/pb_encode_with_malloc.o",
               "$COMMON/pb_decode_with_malloc.o",
               "$COMMON/pb_common_with_malloc.o"] + common_objs
objs_static = ["$COMMON/pb_encode.o",
               "$COMMON/pb_decode.o",
               "$COMMON/pb_common.o"] + common_objs

fuzz = malloc_env.Program(["fuzztest.c"] + objs_malloc)

# Run the stand-alone fuzz tester
seed = int(time.time())
if env.get('EMBEDDED'):
    iterations = 100
else:
    iterations = 1000
env.RunTest(fuzz, ARGS = [str(seed), str(iterations)])

generate_message = malloc_env.Program(["generate_message.c"] + objs_static)

# Test the message generator
env.RunTest(generate_message, ARGS = [str(seed)])
env.RunTest("generate_message.output.fuzzed", [fuzz, "generate_message.output"])

# Run against the latest corpus from ossfuzz
# This allows quick testing against regressions and also lets us more
# completely test slow embedded targets. To reduce runtime, only a subset
# of the corpus is fuzzed each time.
def run_against_corpus(target, source, env):
    corpus = zipfile.ZipFile(str(source[1]), 'r')
    count = 0
    args = [str(source[0])]

    if "TEST_RUNNER" in env:
        args = [env["TEST_RUNNER"]] + args

    if "FUZZTEST_CORPUS_SAMPLESIZE" in env:
        samplesize = int(env["FUZZTEST_CORPUS_SAMPLESIZE"])
    elif env.get('EMBEDDED'):
        samplesize = 100
    else:
        samplesize = 4096

    files = [n for n in corpus.namelist() if not n.endswith('/')]
    files = random.sample(files, min(samplesize, len(files)))
    for filename in files:
        sys.stdout.write("Fuzzing: %5d/%5d: %-40.40s\r" % (count, len(files), filename))
        sys.stdout.flush()

        count += 1

        maxsize = env.get('CPPDEFINES', {}).get('FUZZTEST_BUFSIZE', 256*1024)
        data_in = corpus.read(filename)[:maxsize]

        try:
            process = subprocess.Popen(args, stdin=subprocess.PIPE,
                                       stdout=subprocess.PIPE, stderr=subprocess.PIPE)
            stdout, stderr = process.communicate(input = data_in)
            result = process.wait()
        except OSError as e:
            if e.errno == 22:
                print("Warning: OSError 22 when running with input " + filename)
                result = process.wait()
            else:
                raise

        if result != 0:
            stdout += stderr
            print(stdout)
            print('\033[31m[FAIL]\033[0m   Program ' + str(args) + ' returned ' + str(result) + ' with input ' + filename + ' from ' + str(source[1]))
            return result

    open(str(target[0]), 'w').write(str(count))
    print('\033[32m[ OK ]\033[0m   Ran ' + str(args) + " against " + str(source[1]) + " (" + str(count) + " entries)")

env.Command("corpus.zip.fuzzed", [fuzz, "corpus.zip"], run_against_corpus)
env.Command("regressions.zip.fuzzed", [fuzz, "regressions.zip"], run_against_corpus)

# Build separate fuzzers for each test case.
# Having them separate speeds up control flow based fuzzer engines.
# These are mainly used by oss-fuzz project.
env_proto2_static = env.Clone()
env_proto2_static.Append(CPPDEFINES = {'FUZZTEST_PROTO2_STATIC': '1'})
env_proto2_static.Program("fuzztest_proto2_static",
    [env_proto2_static.Object("fuzztest_proto2_static.o", "fuzztest.c")] + objs_static)

env_proto2_pointer = malloc_env.Clone()
env_proto2_pointer.Append(CPPDEFINES = {'FUZZTEST_PROTO2_POINTER': '1'})
env_proto2_pointer.Program("fuzztest_proto2_pointer",
    [env_proto2_pointer.Object("fuzztest_proto2_pointer.o", "fuzztest.c")] + objs_malloc)

env_proto3_static = env.Clone()
env_proto3_static.Append(CPPDEFINES = {'FUZZTEST_PROTO3_STATIC': '1'})
env_proto3_static.Program("fuzztest_proto3_static",
    [env_proto3_static.Object("fuzztest_proto3_static.o", "fuzztest.c")] + objs_static)

env_proto3_pointer = malloc_env.Clone()
env_proto3_pointer.Append(CPPDEFINES = {'FUZZTEST_PROTO3_POINTER': '1'})
env_proto3_pointer.Program("fuzztest_proto3_pointer",
    [env_proto3_pointer.Object("fuzztest_proto3_pointer.o", "fuzztest.c")] + objs_malloc)

env_io_errors = malloc_env.Clone()
env_io_errors.Append(CPPDEFINES = {'FUZZTEST_IO_ERRORS': '1'})
env_io_errors.Program("fuzztest_io_errors",
    [env_io_errors.Object("fuzztest_io_errors.o", "fuzztest.c")] + objs_malloc)