[msgpack-c] Get the fuzzers from the source repo, use a for loop for future fuzzers (#1359)

projects/msgpack-c/Dockerfile

@@ -20,4 +20,4 @@ RUN apt-get update && apt-get install -y cmake
 RUN git clone --depth 1 https://github.com/msgpack/msgpack-c.git msgpack-c
 RUN git clone --depth 1 https://github.com/derwolfe/msgpack-corpora.git msgpack-corpora
 WORKDIR msgpack-c
-COPY build.sh unpack_pack_fuzzer.cc $SRC/
+COPY build.sh $SRC/

projects/msgpack-c/build.sh

@@ -20,8 +20,11 @@ cmake -DCMAKE_C_COMPILER="$CC" -DCMAKE_CXX_COMPILER="$CXX" \
       -DMSGPACK_CXX11=ON .
 make -j$(nproc) all
 
-$CXX $CXXFLAGS -std=c++11 -Iinclude -I"$SRC/msgpack-c/include" \
-     "$SRC/unpack_pack_fuzzer.cc" -o "$OUT/unpack_pack_fuzzer" \
-     -lFuzzingEngine "$SRC/msgpack-c/libmsgpackc.a"
+for f in $SRC/msgpack-c/fuzz/*_fuzzer.cpp; do
+    fuzzer=$(basename "$f" _fuzzer.cpp)
+    $CXX $CXXFLAGS -std=c++11 -Iinclude -I"$SRC/msgpack-c/include" \
+         "$f" -o "$OUT/${fuzzer}_fuzzer" \
+         -lFuzzingEngine "$SRC/msgpack-c/libmsgpackc.a"
+done
 
 zip -rj "$OUT/unpack_pack_fuzzer_seed_corpus.zip" "$SRC/msgpack-corpora/packed/"

projects/msgpack-c/unpack_pack_fuzzer.cc

@@ -1,21 +0,0 @@
-#include <msgpack.hpp>
-
-extern "C" int LLVMFuzzerTestOneInput(const uint8_t *data, size_t size) {
-  try {
-    // NOTE(derwolfe): by default the limits are set at 2^32-1 length. I'm
-    // setting these at far smaller values to avoid OOMs
-    const int test_limit = 10000;
-    msgpack::object_handle unpacked = msgpack::unpack(reinterpret_cast<const char *>(data),
-                                                      size,
-                                                      nullptr,
-                                                      nullptr,
-                                                      msgpack::unpack_limit(test_limit,
-                                                                            test_limit,
-                                                                            test_limit,
-                                                                            test_limit));
-    msgpack::sbuffer sbuf;
-    msgpack::pack(sbuf, unpacked.get());
-  } catch (...) {
-  }
-  return 0;
-}