feat(munch): :star:

7 files changed, 288 insertions, 0 deletions

diff --git a/pkg/config/config.go b/pkg/config/config.go
new file mode 100644
index 0000000..b3a3314
--- /dev/null
+++ b/pkg/config/config.go
@@ -0,0 +1,25 @@
+// Copyright (C) 2021-2021 The Whirlsplash Collective
+// SPDX-License-Identifier: GPL-3.0-only
+
+package config
+
+import (
+	"github.com/spf13/viper"
+	"log"
+)
+
+func Setup() {
+	viper.SetConfigName("config.yml")
+	viper.SetConfigType("yaml")
+	viper.AddConfigPath(".")
+
+	if err := viper.ReadInConfig(); err != nil {
+		if _, ok := err.(viper.ConfigFileNotFoundError); ok {
+			log.Panicln("Cannot read configuration file:", err)
+		} else {
+			log.Panicln("Read configuration file but an error occurred anyway:", err)
+		}
+	}
+
+	viper.WatchConfig()
+}
diff --git a/pkg/server/distributor.go b/pkg/server/distributor.go
new file mode 100644
index 0000000..d9c6bcf
--- /dev/null
+++ b/pkg/server/distributor.go
@@ -0,0 +1,58 @@
+// Copyright (C) 2021-2021 The Whirlsplash Collective
+// SPDX-License-Identifier: GPL-3.0-only
+
+package server
+
+import (
+	"encoding/binary"
+	"github.com/Whirlsplash/munch/pkg/server/utils"
+	"github.com/spf13/viper"
+	"log"
+	"net"
+	"strconv"
+)
+
+func doDistributor() string {
+	tcpAddr, _ := net.ResolveTCPAddr(
+		"tcp",
+		viper.GetString("worlds.server.ip")+":"+viper.GetString("worlds.server.port"),
+	)
+	conn, _ := net.DialTCP("tcp", nil, tcpAddr)
+
+	// PROPREQ
+	conn.Write([]byte("\x03\xff\x0a"))
+	reply := make([]byte, 1024)
+	conn.Read(reply)
+	log.Println("AutoServer: PROPREQ")
+
+	// SESSINIT
+	conn.Write(utils.EncodeSessionInitialization(
+		viper.GetString("worlds.account.username"),
+		viper.GetString("worlds.account.password"),
+		utils.AutoServer,
+	))
+	reply = make([]byte, 1024)
+	conn.Read(reply)
+	log.Println("AutoServer: SESSINIT")
+
+	// PROPUPD
+	conn.Write(utils.EncodePropertyUpdate(viper.GetString("worlds.account.avatar")))
+	reply = make([]byte, 1024)
+	conn.Read(reply)
+	log.Println("AutoServer: PROPUPD")
+
+	// ROOMIDRQ
+	conn.Write([]byte(
+		"\x26\x01\x14\x22\x47\x72\x6f\x75\x6e\x64\x5a\x65\x72\x6f\x23\x73" +
+			"\x74\x61\x69\x72\x63\x61\x73\x65\x31\x3c\x64\x69\x6d\x65\x6e\x73" +
+			"\x69\x6f\x6e\x2d\x31\x3e",
+	))
+	reply = make([]byte, 1024)
+	conn.Read(reply)
+	port := strconv.Itoa(int(binary.BigEndian.Uint16(reply[44:46])))
+	log.Println("AutoServer: ROOMIDRQ")
+
+	conn.Close()
+
+	return port
+}
diff --git a/pkg/server/hub.go b/pkg/server/hub.go
new file mode 100644
index 0000000..9e34523
--- /dev/null
+++ b/pkg/server/hub.go
@@ -0,0 +1,70 @@
+// Copyright (C) 2021-2021 The Whirlsplash Collective
+// SPDX-License-Identifier: GPL-3.0-only
+
+package server
+
+import (
+	"github.com/Whirlsplash/munch/pkg/server/utils"
+	"github.com/spf13/viper"
+	"log"
+	"net"
+)
+
+func doHub(port string) {
+	tcpAddr, _ := net.ResolveTCPAddr(
+		"tcp",
+		(viper.GetString("worlds.server.ip") + ":" + port),
+	)
+	conn, _ := net.DialTCP("tcp", nil, tcpAddr)
+
+	// PROPREQ
+	conn.Write([]byte("\x03\xff\x0a"))
+	reply := make([]byte, 1024)
+	conn.Read(reply)
+	log.Println("RoomServer: PROPREQ")
+
+	// SESSINIT
+	conn.Write(utils.EncodeSessionInitialization(
+		viper.GetString("worlds.account.username"),
+		viper.GetString("worlds.account.password"),
+		utils.RoomServer,
+	))
+	reply = make([]byte, 1024)
+	conn.Read(reply)
+	log.Println("RoomServer: SESSINIT")
+
+	// SUB-DIST
+	conn.Write([]byte(
+		"\x0d\x01\x16\x00\x02\x00\x00\x00\xfa\x00\x00\x0a\xf8" +
+			"\x0d\x01\x16\x00\x01\x00\x00\x02\xee\x00\x00\x0c\xf9" +
+			"\x0d\x01\x16\x00\x07\x00\x00\x36\xaf\x00\x00\x09\xbd" +
+			"\x0d\x01\x16\x00\x06\xf1\x77\x00\x00\x01\x90\x0d\xcf\x0d\x01\x16" +
+			"\x98\xee\x00\x00\x00\xc8\x00\x28\x0e\x67\x0d\x01\x16\x00\x04\x00" +
+			"\x00\x00\xfa\x00\x00\x0c\xb7\x0d\x01\x16\x00\x03\x00\x00\x02\xee" +
+			"\x00\x00\x0c\x30\x0d\x01\x16\x00\x09\x01\xf4\x03\xe8\x01\xf4\x09" +
+			"\xd5\x0d\x01\x16\x00\x08\x00\x00\x00\x00\x00\x00\xff\x9c\x0f\x01" +
+			"\x12\x00\x08\x00\x01\x04\xcc\x09\xa1\x00\x00\x01\x25\x07\x01\x18" +
+			"\x00\x01\x0c\xf9\x07\x01\x18\x00\x03\x0c\x30\x07\x01\x18\x00\x09" +
+			"\x09\xd5\x07\x01\x18\x00\x07\x09\xbd\x07\x01\x18\x00\x06\x0d\xcf" +
+			"\x07\x01\x18\x98\xee\x0e\x67\x07\x01\x18\x00\x04\x0c\xb7\x07\x01" +
+			"\x18\x00\x02\x0a\xf8",
+	))
+	reply = make([]byte, 1024)
+	conn.Read(reply)
+	log.Println("RoomServer: SUBSCRIB")
+
+	// Listen for whispers
+	for {
+		reply = make([]byte, 1024)
+		conn.Read(reply)
+		if reply[2] == 17 {
+			decodedText := utils.DecodeText(reply)
+			log.Printf(
+				"RoomServer: WHISPER: %s: %s\n",
+				decodedText.Author, decodedText.Message,
+			)
+		}
+	}
+
+	conn.Close()
+}
diff --git a/pkg/server/server.go b/pkg/server/server.go
new file mode 100644
index 0000000..d85a5ed
--- /dev/null
+++ b/pkg/server/server.go
@@ -0,0 +1,10 @@
+// Copyright (C) 2021-2021 The Whirlsplash Collective
+// SPDX-License-Identifier: GPL-3.0-only
+
+package server
+
+func Do() {
+	// The Distributor isn't actually needed for Munch to work, the only reason
+	// that we use it is because it gives us the correct Hub port to connect to.
+	doHub(doDistributor())
+}
diff --git a/pkg/server/utils/decode.go b/pkg/server/utils/decode.go
new file mode 100644
index 0000000..e819b31
--- /dev/null
+++ b/pkg/server/utils/decode.go
@@ -0,0 +1,24 @@
+// Copyright (C) 2021-2021 The Whirlsplash Collective
+// SPDX-License-Identifier: GPL-3.0-only
+
+package utils
+
+import "strconv"
+
+type Text struct {
+	Author  string
+	Message string
+}
+
+// Decode a TEXT command from hexadecimal to a Text struct
+func DecodeText(data []byte) Text {
+	authorLength, _ := strconv.ParseInt(strconv.Itoa(int(data[4])), 16, 32)
+	authorLast := authorLength + 5
+	messageLength, _ := strconv.ParseInt(strconv.Itoa(int(data[authorLast])), 16, 32)
+	messageStart := authorLast + 1
+
+	return Text{
+		Author:  string(data[5:(authorLast)]),
+		Message: string(data[messageStart : messageStart+(messageLength)]),
+	}
+}
diff --git a/pkg/server/utils/encode.go b/pkg/server/utils/encode.go
new file mode 100644
index 0000000..86e5500
--- /dev/null
+++ b/pkg/server/utils/encode.go
@@ -0,0 +1,70 @@
+// Copyright (C) 2021-2021 The Whirlsplash Collective
+// SPDX-License-Identifier: GPL-3.0-only
+
+package utils
+
+const (
+	AutoServer = iota
+	RoomServer
+)
+
+func EncodeSessionInitialization(username string, password string, serverType int) []byte {
+	data := ""
+
+	// Data length
+	if serverType == AutoServer {
+		data += "\x2b"
+	} else {
+		data += "\x2c"
+	}
+
+	// Command header and other stuff we don't need to worry about
+	data += "\x01\x06\x03\x02\x32\x34\x09\x0a\x32\x30\x32\x30\x30\x33\x31" +
+		"\x32\x30\x30"
+
+	if serverType == RoomServer {
+		data += "\x07\x02\x32\x34"
+	}
+
+	data +=
+		// Username
+		"\x02" + string(rune(len(username))) + ISO88591ToString(username) +
+
+			// Password
+			"\x06" + string(rune(len(password))) + ISO88591ToString(password)
+
+	if serverType == AutoServer {
+		data += "\x0c\x01\x31"
+	}
+
+	return []byte(data)
+}
+
+func EncodeBuddyListUpdate(buddy string) []byte {
+	// Command header
+	data := "\x01\x1d"
+
+	// Buddy UTF-8 length and UTF-8
+	data += string(rune(len(buddy))) + ISO88591ToString(buddy)
+
+	// Buddy "add"
+	data += "\x01"
+
+	// Data length
+	data = (string(rune(len(data) + 1))) + data
+
+	return []byte(data)
+}
+
+func EncodePropertyUpdate(avatar string) []byte {
+	// Command header and extra stuff we don't need to worry about
+	data := "\x01\x0f\x00\x05\x40\x01"
+
+	// Avatar UTF-8 length and UTF-8
+	data += string(rune(len("avatar:"+avatar))) + ISO88591ToString("avatar:"+avatar)
+
+	// Data length
+	data = (string(rune(len(data) + 1))) + data
+
+	return []byte(data)
+}
diff --git a/pkg/server/utils/hex.go b/pkg/server/utils/hex.go
new file mode 100644
index 0000000..a5393aa
--- /dev/null
+++ b/pkg/server/utils/hex.go
@@ -0,0 +1,31 @@
+package utils
+
+import "unicode/utf8"
+
+// https://stackoverflow.com/a/43461796/14452787
+//
+// I cannot explain the joy that flew through me once I found this ISO-8859-1
+// (Latin-1) to UTF-8 converter. I was looking for a valid solution on how to
+// insert the username and password into a hex-escaped string sequence for
+// EncodeSessionInitialization for hours and this finally solved all of my
+// problems.
+func ISO88591ToString(iso string) string {
+	var utf []rune
+	for i := 0; i < len(iso); i++ {
+		r := iso[i]
+		if utf == nil {
+			if r < utf8.RuneSelf {
+				continue
+			}
+			utf = make([]rune, len(iso))
+			for j, r := range iso[:i] {
+				utf[j] = rune(r)
+			}
+		}
+		utf[i] = rune(r)
+	}
+	if utf == nil {
+		return string(iso)
+	}
+	return string(utf)
+}