Add missing fuzzer (#2844)

* fuzz: add missing fuzzer by fixing .gitignore adding a negation for caddyfile/ directory

* ci: print fuzzing type for debuggability and traceability

* README: update the Fuzzit badge to point to the correct Caddy server Github organization

.gitignore

@@ -1,6 +1,7 @@
 _gitignore/
 *.log
 Caddyfile
+!caddyfile/
 
 # artifacts from pprof tooling
 *.prof

README.md

@@ -2,7 +2,7 @@ Caddy 2 Development Branch
 ===========================
 
 [![Build Status](https://dev.azure.com/mholt-dev/Caddy/_apis/build/status/Multiplatform%20Tests?branchName=v2)](https://dev.azure.com/mholt-dev/Caddy/_build/latest?definitionId=5&branchName=v2)
-[![fuzzit](https://app.fuzzit.dev/badge?org_id=caddyserver)](https://app.fuzzit.dev/orgs/caddyserver/dashboard)
+[![fuzzit](https://app.fuzzit.dev/badge?org_id=caddyserver-gh)](https://app.fuzzit.dev/orgs/caddyserver-gh/dashboard)
 
 This is the development branch for Caddy 2. This code (version 2) is not yet feature-complete or production-ready, but is already being used in production, and we encourage you to deploy it today on sites that are not very visible or important so that it can obtain crucial experience in the field.
 

azure-pipelines.yml

@@ -226,6 +226,7 @@ jobs:
       if [[ $(Build.Reason) == "Schedule" ]]; then
         fuzz_type="fuzzing"
       fi
+      echo "Fuzzing type: $fuzz_type"
 
       for f in $(find . -name \*_fuzz.go); do
         FUZZER_DIRECTORY=$(dirname $f)

caddyconfig/caddyfile/parse_fuzz.go

@@ -0,0 +1,36 @@
+// Copyright 2015 Matthew Holt and The Caddy Authors
+//
+// 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.
+
+// +build gofuzz
+// +build gofuzz_libfuzzer
+
+package caddyfile
+
+import (
+	"bytes"
+)
+
+func FuzzParseCaddyfile(data []byte) (score int) {
+	sb, err := Parse("Caddyfile", bytes.NewReader(data))
+	if err != nil {
+		// if both an error is received and some ServerBlocks,
+		// then the parse was able to parse partially. Mark this
+		// result as interesting to push the fuzzer further through the parser.
+		if sb != nil && len(sb) > 0 {
+			return 1
+		}
+		return 0
+	}
+	return 1
+}