Initial commit after restructure

intel/domainfronting.go

@@ -0,0 +1,48 @@
+// Copyright Safing ICS Technologies GmbH. Use of this source code is governed by the AGPL license that can be found in the LICENSE file.
+
+package intel
+
+import (
+	"github.com/Safing/safing-core/log"
+	"sync"
+
+	"github.com/miekg/dns"
+)
+
+var (
+	dfMap     = make(map[string]string)
+	dfMapLock sync.RWMutex
+)
+
+func checkDomainFronting(hidden string, qtype dns.Type, securityLevel int8) (*RRCache, bool) {
+	dfMapLock.RLock()
+	front, ok := dfMap[hidden]
+	dfMapLock.RUnlock()
+	if !ok {
+		return nil, false
+	}
+	log.Tracef("intel: applying domain fronting %s -> %s", hidden, front)
+	// get domain name
+	rrCache := resolveAndCache(front, qtype, securityLevel)
+	if rrCache == nil {
+		return nil, true
+	}
+	// replace domain name
+	var header *dns.RR_Header
+	for _, rr := range rrCache.Answer {
+		header = rr.Header()
+		if header.Name == front {
+			header.Name = hidden
+		}
+	}
+	// save under front
+	rrCache.CreateWithType(hidden, qtype)
+	return rrCache, true
+}
+
+func addDomainFronting(hidden string, front string) {
+	dfMapLock.Lock()
+	dfMap[hidden] = front
+	dfMapLock.Unlock()
+	return
+}