From ba905d3fcd7648142d04b361b75d19dbefa5e1d0 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Henrik=20S=C3=B6lver?= <henrik.solver@gmail.com>
Date: Sat, 31 Oct 2020 21:56:18 +0100
Subject: [PATCH] initial parsing of requests

---
 main.go     | 69 ++++++++++++++++++++++++++++++++++++++++++++++++++---
 messages.go | 44 +++++++++++++++++++++++++++-------
 2 files changed, 101 insertions(+), 12 deletions(-)

diff --git a/main.go b/main.go
index 4a6547c..73586b4 100644
--- a/main.go
+++ b/main.go
@@ -2,6 +2,7 @@ package main
 
 import (
 	"context"
+	"encoding/binary"
 	"ippserver/packages/mdnsserver"
 	"net/http"
 
@@ -25,12 +26,74 @@ func main() {
 
 func handle(w http.ResponseWriter, r *http.Request) {
 	log.Infoln("handle")
-	if r.Method != "POST" {
+	if r.Method != http.MethodPost {
 		http.Error(w, "Unsupported method", http.StatusMethodNotAllowed)
 
 	}
-	// Disable caching of this page
+	var request ippRequest
+	request.operationAttributes = make(map[string]string)
+	request.requestedAttributes = make([]string, 0)
+	log.Info(r.Header)
+	log.Info(r.ContentLength)
+	//body := make([]byte, r.ContentLength)
+	//r.Body.Read(body)
+	binary.Read(r.Body, binary.BigEndian, &request.header.versionNumber)
+	binary.Read(r.Body, binary.BigEndian, &request.header.operationId)
+	binary.Read(r.Body, binary.BigEndian, &request.header.requestId)
+	var tag uint8
+	binary.Read(r.Body, binary.BigEndian, &tag)
+	if tag == operationAttributesTag {
+		var length uint16
+		binary.Read(r.Body, binary.BigEndian, &tag)
+		for tag != endOfAttributesTag {
+			log.Infof("Value tag %x", tag)
+			switch tag {
+			case charsetValueTag, uriValueTag, naturalLanguagageValueTag:
+				binary.Read(r.Body, binary.BigEndian, &length)
+				attributeName := make([]byte, length)
+				binary.Read(r.Body, binary.BigEndian, attributeName)
+				binary.Read(r.Body, binary.BigEndian, &length)
+				attributeValue := make([]byte, length)
+				binary.Read(r.Body, binary.BigEndian, attributeValue)
+				request.operationAttributes[string(attributeName)] = string(attributeValue)
+				log.Infof("%v %v", string(attributeName), string(attributeValue))
+				binary.Read(r.Body, binary.BigEndian, &tag)
+			case keywordValueTag:
+				binary.Read(r.Body, binary.BigEndian, &length)
+				attributeName := make([]byte, length)
+				set := make([]string, 0)
+				binary.Read(r.Body, binary.BigEndian, &attributeName)
+				binary.Read(r.Body, binary.BigEndian, &length)
+				value := make([]byte, length)
+				binary.Read(r.Body, binary.BigEndian, &value)
+				set = append(set, string(value))
+				binary.Read(r.Body, binary.BigEndian, &tag)
+				for tag == keywordValueTag {
+					var additionalValue uint16
+					binary.Read(r.Body, binary.BigEndian, &additionalValue)
+					binary.Read(r.Body, binary.BigEndian, &length)
+					value = make([]byte, length)
+					binary.Read(r.Body, binary.BigEndian, &value)
+					set = append(set, string(value))
+					binary.Read(r.Body, binary.BigEndian, &tag)
+				}
+				if string(attributeName) == "requested-attributes" {
+					request.requestedAttributes = set
+				}
+				log.Infof("%v %v", string(attributeName), set)
+			default:
+				log.Error("Unsupported tag")
 
-	// Check if user is logged in, if not redirect to login page
+			}
+		}
+		log.Infof("Value tag %x", tag)
+	} else {
+		log.Error("unexpected tag")
+		// TODO Return something sensible here
+
+	}
+
+	log.Infof("request %+v", request)
+	//log.Infof("Body %v", string(body))
 
 }
diff --git a/messages.go b/messages.go
index 7ae5661..130dd4a 100644
--- a/messages.go
+++ b/messages.go
@@ -26,15 +26,35 @@ const (
 	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
+	textWithoutLanguagageValueTag = 0x41
+	nameWithoutLanguagageValueTag = 0x42
+	keywordValueTag               = 0x44
+	uriValueTag                   = 0x45
+	uriSchemeValueTag             = 0x46
+	charsetValueTag               = 0x47
+	naturalLanguagageValueTag     = 0x48
+	mimeMediaTypeValueTag         = 0x49
+	memberAttrNameValueTag        = 0x4a
+)
+
+// Operation-id, defined in rfc8011
+const (
+	PrintJob             = 0x0002
+	PrintURI             = 0x0003
+	ValidateJob          = 0x0004
+	CreateJob            = 0x0005
+	SendDocument         = 0x0006
+	SendURI              = 0x0007
+	CancelJob            = 0x0008
+	GetJobAttributes     = 0x0009
+	GetJobs              = 0x000a
+	GetPrinterAttributes = 0x000b
+	HoldJob              = 0x000c
+	ReleaseJob           = 0x000d
+	RestartJob           = 0x000e
+	PausePrinter         = 0x0010
+	ResumePrinter        = 0x0011
+	PurgeJobs            = 0x0012
 )
 
 type ippRequestHeader struct {
@@ -42,3 +62,9 @@ type ippRequestHeader struct {
 	operationId   uint16
 	requestId     uint32
 }
+
+type ippRequest struct {
+	header              ippRequestHeader
+	operationAttributes map[string]string
+	requestedAttributes []string
+}