Initial commit.

LICENSE

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+The MIT License (MIT)
+
+Copyright (c) 2015 Michael Bang
+
+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 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.

README.md

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+This is a very simple minecraft (and source engine?) RCON client. See [cli/main.go](cli/main.go) for an example on how to use it.
+
+# Shortcomings
+- Long (split) responses aren't handled correctly.
+- Probably a lot more.
+
+
+# License
+See the [LICENSE](LICENSE) file.
+

cli/main.go

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+package main
+
+import (
+	"bufio"
+	"fmt"
+	"os"
+	"strings"
+
+	"github.com/katnegermis/pocketmine-rcon"
+)
+
+func main() {
+	if len(os.Args) < 2 {
+		fmt.Printf("Usage: ./rcon address password")
+		return
+	}
+	addr := os.Args[1]
+	pass := os.Args[2]
+
+	conn, err := rcon.NewConnection(addr, pass)
+	if err != nil {
+		fmt.Println(err)
+		return
+	}
+	fmt.Printf("Successfully logged in at %s!\n", addr)
+
+	prompt()
+	stdin := bufio.NewReader(os.Stdin)
+	input := ""
+	for {
+		if input, err = stdin.ReadString('\n'); err != nil {
+			fmt.Println(err)
+			return
+		}
+		input = strings.Trim(input[:len(input)-1], " ")
+		if input == ".exit" {
+			break
+		}
+		if len(input) == 0 {
+			prompt()
+			continue
+		}
+		r := conn.SendCommand(input)
+		fmt.Printf("Server:\n%s\n", r)
+		prompt()
+	}
+}
+
+func prompt() {
+	fmt.Print("Enter command:\n>")
+}

connection.go

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+package rcon
+
+import (
+	"bytes"
+	"encoding/binary"
+	"errors"
+	"log"
+	"net"
+)
+
+type Connection struct {
+	conn net.Conn
+	pass string
+	addr string
+}
+
+var uniqueId int32 = 0
+
+func NewConnection(addr, pass string) (*Connection, error) {
+	conn, err := net.Dial("tcp", addr)
+	if err != nil {
+		log.Fatal(err)
+	}
+	c := &Connection{conn: conn, pass: pass, addr: addr}
+	if err := c.auth(); err != nil {
+		return nil, err
+	}
+	return c, nil
+}
+
+func (c *Connection) SendCommand(cmd string) string {
+	c.sendCommand(2, []byte(cmd))
+	pkg := c.readPkg()
+	return string(pkg.Body)
+}
+
+func (c *Connection) auth() error {
+	c.sendCommand(3, []byte(c.pass))
+	pkg := c.readPkg()
+	if pkg.Type != 2 || pkg.Id != uniqueId {
+		return errors.New("Incorrect password.")
+	}
+	return nil
+}
+
+func (c *Connection) sendCommand(typ int32, body []byte) {
+	size := int32(4 + 4 + len(body) + 2)
+	uniqueId += 1
+	id := uniqueId
+
+	wtr := binaryReadWriter{ByteOrder: binary.LittleEndian}
+	wtr.Write(size)
+	wtr.Write(id)
+	wtr.Write(typ)
+	wtr.Write(body)
+	wtr.Write([]byte{0x0, 0x0})
+	if wtr.err != nil {
+		log.Fatal(wtr.err)
+	}
+
+	c.conn.Write(wtr.buf.Bytes())
+}
+
+func (c *Connection) readPkg() Pkg {
+	const bufSize = 4096
+	b := make([]byte, bufSize)
+
+	// Doesn't handle split messages correctly.
+	read, err := c.conn.Read(b)
+	if err != nil {
+		log.Fatal(err)
+	}
+
+	p := Pkg{}
+	rdr := binaryReadWriter{ByteOrder: binary.LittleEndian,
+		buf: bytes.NewBuffer(b)}
+	rdr.Read(&p.Size)
+	rdr.Read(&p.Id)
+	rdr.Read(&p.Type)
+	body := [bufSize - 12]byte{}
+	rdr.Read(&body)
+	if rdr.err != nil {
+		log.Fatal(rdr.err)
+	}
+	p.Body = body[:read-12]
+	return p
+}
+
+type Pkg struct {
+	Size  int32
+	Id    int32
+	Type  int32
+	Body  []byte
+	_null int16
+}
+
+type binaryReadWriter struct {
+	ByteOrder binary.ByteOrder
+	err       error
+	buf       *bytes.Buffer
+}
+
+func (b *binaryReadWriter) Write(v interface{}) {
+	if b.err != nil {
+		return
+	}
+	if b.buf == nil {
+		b.buf = new(bytes.Buffer)
+	}
+	b.err = binary.Write(b.buf, b.ByteOrder, v)
+}
+
+func (b *binaryReadWriter) Read(v interface{}) {
+	if b.err != nil || b.buf == nil {
+		return
+	}
+	binary.Read(b.buf, b.ByteOrder, v)
+}