first commit

Signed-off-by: Michael <michael.lindman@gmail.com>
2020-09-01 22:46:44 +01:00 · 2020-09-01 22:46:44 +01:00 · 20edf2a7d5
commit 20edf2a7d5
3 changed files with 193 additions and 0 deletions
--- a/19
+++ b/19
@ -0,0 +1,19 @@
+MIT License Copyright (c) 2020 Michael Lindman
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is furnished
+to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice (including the next
+paragraph) shall be included in all copies or substantial portions of the
+Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS
+FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS
+OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
+WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF
+OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
--- a/README.md
+++ b/README.md
@ -0,0 +1,39 @@
+# mcstatus
+
+Simple golang app to get the current online status of Minecraft servers
+
+## Usage
+
+from a terminal session run `mcstatus` with the address and port arguemnts for the server:
+
+```sh
+./mcstatus -addr 127.0.0.1 -port 25565
+Name: A Minecraft Server
+Players: 0/20
+Version: 1.16.2
+Ping: 123.698µs
+```
+
+## Licesne
+
+```text
+MIT License Copyright (c) 2020 Michael Lindman
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is furnished
+to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice (including the next
+paragraph) shall be included in all copies or substantial portions of the
+Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS
+FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS
+OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
+WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF
+OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+```
--- a/main.go
+++ b/main.go
@ -0,0 +1,135 @@
+package main
+
+import (
+	"bytes"
+	"encoding/binary"
+	"encoding/json"
+	"flag"
+	"fmt"
+	"log"
+	"net"
+	"strconv"
+	"time"
+)
+
+func packetlength(b ...[]byte) (length int) {
+	for _, bytes := range b {
+		length += len(bytes)
+	}
+	return length
+}
+
+func handshake(addr string, port int, ver uint64) []byte {
+	id := []byte{0x00}
+	state := []byte{0x01}
+
+	version := make([]byte, 2)
+	binary.PutUvarint(version, ver)
+	p := make([]byte, 2)
+	binary.BigEndian.PutUint16(p, uint16(port))
+	length := packetlength(id, version, []byte(addr), []byte(p), state) + 1
+
+	var handshake bytes.Buffer
+	handshake.WriteByte(byte(length))
+	handshake.Write(id)
+	handshake.Write(version)
+	handshake.WriteByte(byte(len(addr)))
+	handshake.WriteString(addr)
+	handshake.Write(p)
+	handshake.Write(state)
+	return handshake.Bytes()
+}
+
+func main() {
+	addr := flag.String("addr", "127.0.0.1", "Server address")
+	port := flag.Int("port", 25565, "Server Port")
+	ver := flag.Uint64("ver", 751, "Minecraft protocol version number")
+	flag.Parse()
+
+	conn, err := net.Dial("tcp", *addr+":"+strconv.Itoa(*port))
+	if err != nil {
+		log.Fatal(err)
+	}
+
+	for {
+		err := conn.SetWriteDeadline(time.Now().Add(30 * time.Second))
+		if err != nil {
+			log.Println("WriteDealine failed:", err)
+			return
+		}
+
+		conn.Write(handshake(*addr, *port, *ver))
+		conn.Write([]byte{0x01, 0x00})
+
+		recvBuf := make([]byte, 512)
+		var resp response
+
+		err = conn.SetReadDeadline(time.Now().Add(10 * time.Second))
+		if err != nil {
+			log.Println("SetReadDealine failed:", err)
+			return
+		}
+
+		n, err := conn.Read(recvBuf)
+		if err != nil {
+			if netErr, ok := err.(net.Error); ok && netErr.Timeout() {
+				log.Println("read timeout:", err)
+			} else {
+				log.Println("read error", err)
+			}
+		}
+
+		requestright := recvBuf[:n]
+		b := bytes.Split(requestright, []byte("{"))
+		ne := bytes.SplitAfterN(requestright, b[0], 2)
+		after := bytes.TrimSuffix(ne[1], []byte("\x00"))
+
+		if err := json.Unmarshal(after, &resp); err != nil {
+			log.Println(err)
+			conn.Close()
+			return
+		}
+		fmt.Printf("Name: %s\nPlayers: %d/%d\nVersion: %s\n",
+			resp.Description.Text,
+			resp.Players.Online,
+			resp.Players.Max,
+			resp.Version.Name)
+		if resp.Players.Online >= 1 {
+			fmt.Println("Online:")
+			for _, player := range resp.Players.Sample {
+				fmt.Printf("\t%s\n", player.Name)
+			}
+		}
+
+		recvBuf = make([]byte, 1)
+		start := time.Now()
+		conn.Write([]byte{0x01, 0x00})
+		_, _ = conn.Read(recvBuf[:])
+		diff := time.Now().Sub(start)
+		fmt.Printf("Ping: %+v\n", diff)
+		if err = conn.Close(); err != nil {
+			log.Println(err)
+			return
+		}
+		return
+	}
+}
+
+type response struct {
+	Version struct {
+		Name     string `json:"name"`
+		Protocol int    `json:"protocol"`
+	} `json:"version"`
+	Players struct {
+		Max    int `json:"max"`
+		Online int `json:"online"`
+		Sample []struct {
+			Name string `json:"name"`
+			ID   string `json:"id"`
+		} `json:"sample"`
+	} `json:"players"`
+	Description struct {
+		Text string `json:"text"`
+	} `json:"description"`
+	Favicon string `json:"favicon"`
+}