Move libcoap test harness to its source repo (#1586)

projects/libcoap/Dockerfile

@@ -20,4 +20,4 @@ RUN apt-get update && apt-get install -y make autoconf automake libtool \
     pkg-config
 RUN git clone --depth 1 https://github.com/obgm/libcoap.git libcoap
 WORKDIR libcoap
-COPY build.sh *_target.c $SRC/
+COPY build.sh $SRC/

projects/libcoap/build.sh

@@ -18,12 +18,10 @@
 ./autogen.sh && ./configure --disable-doxygen --disable-manpages \
     && make -j$(nproc)
 
-for file in $SRC/*target.c; do
+for file in $SRC/libcoap/tests/oss-fuzz/*target.c; do
 	b=$(basename $file _target.c)
-	$CC $CFLAGS -c $file -I include/coap \
-		-o $OUT/${b}_target.o
-	$CXX $CXXFLAGS $OUT/${b}_target.o ./.libs/libcoap-2.a \
-	-lFuzzingEngine \
-	-o $OUT/${b}_fuzzer
+	$CC $CFLAGS -c $file -I include/coap -o $OUT/${b}_target.o
+	$CXX $CXXFLAGS $OUT/${b}_target.o .libs/libcoap-2.a \
+	-lFuzzingEngine -o $OUT/${b}_fuzzer
 	rm -f $OUT/${b}_target.o
 done

projects/libcoap/pdu_parse_target.c

@@ -1,29 +0,0 @@
-/*
-# Copyright 2018 Google Inc.
-#
-# Licensed under the Apache License, Version 2.0 (the "License");
-# you may not use this file except in compliance with the License.
-# You may obtain a copy of the License at
-#
-#      http://www.apache.org/licenses/LICENSE-2.0
-#
-# Unless required by applicable law or agreed to in writing, software
-# distributed under the License is distributed on an "AS IS" BASIS,
-# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-# See the License for the specific language governing permissions and
-# limitations under the License.
-#
-################################################################################
-*/
-
-#include <coap.h>
-
-int LLVMFuzzerTestOneInput(const uint8_t* data, size_t size)
-{
-    coap_pdu_t *pdu = coap_pdu_init(0, 0, 0, size);
-    if (!pdu) return 0;
-    
-    coap_pdu_parse(COAP_PROTO_UDP, data, size, pdu);
-    coap_delete_pdu(pdu);
-    return 0;
-}