Add constants

main.go

@@ -14,7 +14,7 @@ func main() {
 	defer cancel() // cancel when we are finished consuming integers
 	go mdnsserver.Run(ctx)
 
-	http.HandleFunc("/", handle)
+	http.HandleFunc("/ipp/print", handle)
 
 	log.Info("http server started on :1234")
 	err := http.ListenAndServe(":1234", nil)
@@ -25,6 +25,10 @@ func main() {
 
 func handle(w http.ResponseWriter, r *http.Request) {
 	log.Infoln("handle")
+	if r.Method != "POST" {
+		http.Error(w, "Unsupported method", http.StatusMethodNotAllowed)
+
+	}
 	// Disable caching of this page
 
 	// Check if user is logged in, if not redirect to login page

messages.go

@@ -0,0 +1,44 @@
+package main
+
+// References
+// https://tools.ietf.org/html/rfc8010
+// https://tools.ietf.org/html/rfc8011
+
+// Defined atribute group tags
+const (
+	beginAttributeGroupTag   = 0x00
+	operationAttributesTag   = 0x01
+	jobAttributesTag         = 0x02
+	endOfAttributesTag       = 0x03
+	printerAttributesTag     = 0x04
+	unsupportedAttributesTag = 0x05
+)
+
+// Defined value tags
+// from rfc8010
+const (
+	// Out of band
+	unsupportedValueTag = 0x10
+	unknownValueTag     = 0x12
+	noValueValueTag     = 0x13
+	// Integer values
+	integerValueTag   = 0x21
+	booleanIntegerTag = 0x22
+	enumValueTag      = 0x23
+	// Character string values
+	textWithoutLanguagage = 0x41
+	nameWithoutLanguagage = 0x42
+	keyword               = 0x44
+	uri                   = 0x45
+	uriScheme             = 0x46
+	charset               = 0x47
+	naturalLanguagage     = 0x48
+	mimeMediaType         = 0x49
+	memberAttrName        = 0x4a
+)
+
+type ippRequestHeader struct {
+	versionNumber uint16
+	operationId   uint16
+	requestId     uint32
+}