Initial commit of a fuzzer for Meshtastic (#5790)

* Initial commit of a fuzzer for Meshtastic.

* Use a max of 5 for the phone queues

* Only write files to the temp dir

* Limitless queue + fuzzer = lots of ram :)

* Use $PIO_ENV for path to program

* spelling: s/is/to/

* Use loopCanSleep instead of a lock in Router

* realHardware allows full use of a CPU core

* Ignore checkov CKV_DOCKER_2 & CKV_DOCKER_3

* Add Atak seed

* Fix lint issues in build.sh

* Use exception to exit from portduino_main

* Separate build & source files into $WORK & $SRC

* Use an ephemeral port for the API server

* Include CXXFLAGS in the link step

* Read all shared libraries

* Use a separate work directory for each sanitizer

---------

Co-authored-by: Ben Meadors <benmmeadors@gmail.com>

.clusterfuzzlite/platformio-clusterfuzzlite-pre.py

@@ -0,0 +1,52 @@
+"""PlatformIO build script (pre: runs before other Meshtastic scripts).
+
+ClusterFuzzLite executes in a different container from the build. During the build,
+attempt to link statically to as many dependencies as possible. For dependencies that
+do not have static libraries, the shared library files are copied to the output
+directory by the build.sh script.
+"""
+
+import glob
+import os
+import shlex
+
+from SCons.Script import DefaultEnvironment, Literal
+
+env = DefaultEnvironment()
+
+cxxflags = shlex.split(os.getenv("CXXFLAGS"))
+sanitizer_flags = shlex.split(os.getenv("SANITIZER_FLAGS"))
+lib_fuzzing_engine = shlex.split(os.getenv("LIB_FUZZING_ENGINE"))
+statics = glob.glob("/usr/lib/lib*.a") + glob.glob("/usr/lib/*/lib*.a")
+no_static = set(("-ldl",))
+
+
+def replaceStatic(lib):
+    """Replace -l<libname> with the static .a file for the library."""
+    if not lib.startswith("-l") or lib in no_static:
+        return lib
+    static_name = f"/lib{lib[2:]}.a"
+    static = [s for s in statics if s.endswith(static_name)]
+    if len(static) == 1:
+        return static[0]
+    return lib
+
+
+# Setup the environment for building with Clang and the OSS-Fuzz required build flags.
+env.Append(
+    CFLAGS=os.getenv("CFLAGS"),
+    CXXFLAGS=cxxflags,
+    LIBSOURCE_DIRS=["/usr/lib/x86_64-linux-gnu"],
+    LINKFLAGS=cxxflags
+    + sanitizer_flags
+    + lib_fuzzing_engine
+    + ["-stdlib=libc++", "-std=c++17"],
+    _LIBFLAGS=[replaceStatic(s) for s in shlex.split(os.getenv("STATIC_LIBS"))]
+    + [
+        "/usr/lib/x86_64-linux-gnu/libunistring.a",  # Needs to be at the end.
+        # Find the shared libraries in a subdirectory named lib
+        # within the same directory as the binary.
+        Literal("-Wl,-rpath,$ORIGIN/lib"),
+        "-Wl,-z,origin",
+    ],
+)