4.10.PRE

fuzz/backend/README.md

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+# Clixon fuzzing
+
+This dir contains code for fuzzing clixon backend. 
+
+It requires the preeny package to change sockets to stdio. 
+
+## Prereqs
+
+Preeny has a "desocketizing" module necessary to map stdio to the internal sockets that the backend uses. Install preeny example:
+```
+  sudo apt install libini-config-dev # debian/ubuntu
+  sudo apt install libseccomp-dev # debian/ubuntu
+  git clone https://github.com/zardus/preeny.git
+  cd preeny
+  make
+  sudo cp x86_64-linux-gnu/desock.so /usr/local/lib/ # install
+```
+
+See [AFL docs](https://afl-1.readthedocs.io/en/latest) for installing afl.
+On ubuntu this may be enough:
+```
+  sudo apt install afl
+```
+
+You may have to change cpu frequency:
+```
+  cd /sys/devices/system/cpu
+  echo performance | tee cpu?/cpufreq/scaling_governor
+```
+
+And possibly change core behaviour:
+```
+  echo core >/proc/sys/kernel/core_pattern
+```
+
+## Build
+
+Make a modification to how Clixon sends internal messages in `include/clixon_custom.h`:
+```
+  #define CLIXON_PROTO_PLAIN
+```
+
+Build clixon statically with the afl-clang compiler:
+```
+  CC=/usr/bin/afl-clang-fast LINKAGE=static ./configure --with-restconf=evhtp
+  make clean
+  make
+  sudo make install
+```
+
+## Run tests
+
+Populate the input/ dir with input usecases, there are two examples already in this dir that can be modified.
+Use the script `runfuzz.sh` to run one test:
+```
+  ./runfuzz.sh
+```
+
+After (or during) the test, investigate results in the output dir.