make: add fuzz-build and fuzz commands

scripts/fuzz.sh

@@ -0,0 +1,90 @@
+#!/bin/bash
+
+set -e
+
+function build_fuzz() {
+  PACKAGES=$1
+
+  for pkg in $PACKAGES; do
+    pushd fuzz/$pkg
+
+    for file in *.go; do
+      if [[ "$file" == "fuzz_utils.go" ]]; then
+        continue
+      fi
+
+      NAME=$(echo $file | sed 's/\.go$//1')
+      echo "Building zip file for $pkg/$NAME"
+      go-fuzz-build -func "Fuzz_$NAME" -o "$pkg-$NAME-fuzz.zip" "github.com/lightningnetwork/lnd/fuzz/$pkg"
+    done
+
+    popd
+  done
+}
+
+# timeout is a cross platform alternative to the GNU timeout command that
+# unfortunately isn't available on macOS by default.
+timeout() {
+    time=$1
+    $2 &
+    pid=$!
+    sleep $time
+    kill -s SIGINT $pid    
+}
+
+function run_fuzz() {
+  PACKAGES=$1
+  RUN_TIME=$2
+  TIMEOUT=$3
+  PROCS=$4
+  BASE_WORKDIR=$5
+
+  for pkg in $PACKAGES; do
+    pushd fuzz/$pkg
+
+    for file in *.go; do
+      if [[ "$file" == "fuzz_utils.go" ]]; then
+        continue
+      fi
+
+      NAME=$(echo $file | sed 's/\.go$//1')
+      WORKDIR=$BASE_WORKDIR/$pkg/$NAME
+      mkdir -p $WORKDIR
+      echo "Running fuzzer $pkg-$NAME-fuzz.zip with $PROCS processors for $RUN_TIME seconds"
+      COMMAND="go-fuzz -bin=$pkg-$NAME-fuzz.zip -workdir=$WORKDIR -procs=$PROCS -timeout=$TIMEOUT"
+      echo "$COMMAND"
+      timeout "$RUN_TIME" "$COMMAND"
+    done
+
+    popd
+  done
+}
+
+# usage prints the usage of the whole script.
+function usage() {
+  echo "Usage: "
+  echo "fuzz.sh build <packages>"
+  echo "fuzz.sh run <packages> <run_time> <timeout>"
+}
+
+# Extract the sub command and remove it from the list of parameters by shifting
+# them to the left.
+SUBCOMMAND=$1
+shift
+
+# Call the function corresponding to the specified sub command or print the
+# usage if the sub command was not found.
+case $SUBCOMMAND in
+build)
+  echo "Building fuzz packages"
+  build_fuzz "$@"
+  ;;
+run)
+  echo "Running fuzzer"
+  run_fuzz "$@"
+  ;;
+*)
+  usage
+  exit 1
+  ;;
+esac