fix bugs related to vendoring

go.mod

@@ -1,2 +1,3 @@
-module git.skdevstudios.com/specCon18/reforgerds-updater 
+module git.skdevstudios.com/specCon18/reforgerds-updater
-go 1.16
+
+go 1.18

internal/a2s/client.go

@@ -0,0 +1,202 @@
+package a2s
+
+import (
+	"encoding/binary"
+	"errors"
+	"fmt"
+	"net"
+	"time"
+)
+
+// Errors
+var (
+	ErrPlayerRead          = errors.New("failed to read player data")
+	ErrMultiPacketInvalid  = errors.New("invalid multi-packet ID mismatch")
+	ErrMultiPacketMismatch = errors.New("multi-packet assembly failed")
+	errBzip2               = errors.New("bzip2 compressed response not supported")
+)
+
+// Flag type for request/response types
+type Flag byte
+
+const (
+	PlayerRequest    Flag = 0x55
+	ChallengeResponse Flag = 0x41
+
+	DefaultBufferSize       = 1400
+	DefaultDeadlineTimeout  = 5
+	singlePacket     uint32 = 0xFFFFFFFF
+)
+
+// Client handles connection and options
+type Client struct {
+	Conn       *net.UDPConn
+	Address    *net.UDPAddr
+	Timeout    time.Duration
+	BufferSize uint16
+}
+
+// New creates a new Client and dials the connection
+func New(ip string, port int) (*Client, error) {
+	return NewWithAddr(&net.UDPAddr{IP: net.ParseIP(ip), Port: port})
+}
+
+func NewWithString(addr string) (*Client, error) {
+	udpAddr, err := net.ResolveUDPAddr("udp", addr)
+	if err != nil {
+		return nil, err
+	}
+	return NewWithAddr(udpAddr)
+}
+
+func NewWithAddr(addr *net.UDPAddr) (*Client, error) {
+	client := &Client{
+		Address:    addr,
+		Timeout:    DefaultDeadlineTimeout * time.Second,
+		BufferSize: DefaultBufferSize,
+	}
+	return client, client.Dial()
+}
+
+func (c *Client) Dial() error {
+	conn, err := net.DialUDP("udp", nil, c.Address)
+	if err != nil {
+		return err
+	}
+	c.Conn = conn
+	return nil
+}
+
+func (c *Client) Close() error {
+	return c.Conn.Close()
+}
+
+func (c *Client) SetBufferSize(size uint16) {
+	c.BufferSize = size
+}
+
+func (c *Client) SetDeadlineTimeout(seconds int) {
+	c.Timeout = time.Duration(seconds) * time.Second
+}
+
+func (c *Client) Get(requestType Flag) ([]byte, Flag, time.Duration, error) {
+	resp, duration, err := c.request(requestType, singlePacket)
+	if err != nil {
+		return nil, 0, 0, err
+	}
+	flag := Flag(resp[4])
+
+	if flag == ChallengeResponse {
+		challenge := binary.BigEndian.Uint32(resp[5:9])
+		resp, _, err = c.request(requestType, challenge)
+		if err != nil {
+			return nil, 0, 0, err
+		}
+		flag = Flag(resp[4])
+	}
+
+	if err := validateResponseType(requestType, flag); err != nil {
+		return resp[5:], flag, duration, err
+	}
+
+	return resp[5:], flag, duration, nil
+}
+
+func (c *Client) request(requestType Flag, challenge uint32) ([]byte, time.Duration, error) {
+	req, err := createHeader(requestType, challenge)
+	if err != nil {
+		return nil, 0, err
+	}
+
+	start := time.Now()
+
+	if _, err := c.Conn.Write(req); err != nil {
+		return nil, 0, err
+	}
+	if err := c.Conn.SetReadDeadline(time.Now().Add(c.Timeout)); err != nil {
+		return nil, 0, err
+	}
+
+	resp := make([]byte, c.BufferSize)
+	n, err := c.Conn.Read(resp)
+	if err != nil {
+		return nil, 0, err
+	}
+
+	duration := time.Since(start)
+
+	multi, err := isMultiPacket(resp)
+	if err != nil {
+		return resp, 0, err
+	}
+
+	if !multi {
+		return resp[:n], duration, nil
+	}
+
+	packetID := binary.LittleEndian.Uint32(resp[4:8])
+	packetCount := int(resp[8] & 0x0F)
+	currentPacket := int(resp[9] & 0x0F)
+
+	if (packetID & 0x80000000) != 0 {
+		return nil, 0, errBzip2
+	}
+
+	packets := make(map[int][]byte)
+	packets[currentPacket] = resp[12:n]
+
+	for len(packets) < packetCount {
+		buf := make([]byte, c.BufferSize)
+		n, err := c.Conn.Read(buf)
+		if err != nil {
+			return nil, 0, err
+		}
+		if binary.LittleEndian.Uint32(buf[4:8]) != packetID {
+			return nil, 0, ErrMultiPacketInvalid
+		}
+
+		currentPacket = int(buf[9] & 0x0F)
+		if _, exists := packets[currentPacket]; !exists {
+			packets[currentPacket] = buf[12:n]
+		}
+	}
+
+	var assembledResp []byte
+	for i := 0; i < packetCount; i++ {
+		data, exists := packets[i]
+		if !exists {
+			return nil, 0, ErrMultiPacketMismatch
+		}
+		assembledResp = append(assembledResp, data...)
+	}
+
+	return assembledResp, duration, nil
+}
+
+// Helpers
+
+func createHeader(requestType Flag, challenge uint32) ([]byte, error) {
+	header := []byte{0xFF, 0xFF, 0xFF, 0xFF, byte(requestType)}
+	if challenge != singlePacket {
+		challengeBytes := make([]byte, 4)
+		binary.BigEndian.PutUint32(challengeBytes, challenge)
+		header = append(header, challengeBytes...)
+	}
+	return header, nil
+}
+
+func validateResponseType(request, response Flag) error {
+	if request == PlayerRequest && response != 0x44 {
+		return fmt.Errorf("unexpected player response flag: 0x%X", response)
+	}
+	return nil
+}
+
+func isMultiPacket(buf []byte) (bool, error) {
+	if len(buf) < 4 {
+		return false, errors.New("packet too short")
+	}
+	header := binary.LittleEndian.Uint32(buf[:4])
+	return header == 0xFFFFFFFE, nil
+}
+

internal/a2s/players.go

@@ -5,7 +5,7 @@ import (
 	"fmt"
 	"time"
 
-	"reforgerds-updater/internal/bread"
+	"git.skdevstudios.com/specCon18/reforgerds-updater/internal/a2s/bread"
 )
 
 // https://developer.valvesoftware.com/wiki/Server_queries#Response_Format_2

main.go

@@ -8,6 +8,8 @@ import (
 	"os"
 	"os/exec"
 	"strings"
+	"time"
+
 	"git.skdevstudios.com/specCon18/reforgerds-updater/internal/a2s"
 )
 
@@ -18,9 +20,13 @@ type Update struct {
 }
 
 const (
-	updateURL      = "http://127.0.0.1:3000/updates"
+	updateURL     = "http://127.0.0.1:3000/updates"
-	stateFilePath  = "latest_version.txt"
+	stateFilePath = "latest_version.txt"
+
+	serverIP   = "127.0.0.1"
+	serverPort = 17777
 )
+
 func main() {
 	resp, err := http.Get(updateURL)
 	if err != nil {
@@ -59,19 +65,38 @@ func main() {
 	if versionCompare(latest, prevVersion) > 0 {
 		fmt.Printf("New version found! %s > %s\n", latest, prevVersion)
 
-		// Run steamcmd with reforger_update script
+		// Always update the state file
-		fmt.Println("Running update command...")
+		err := os.WriteFile(stateFilePath, []byte(latest), 0644)
+		if err != nil {
+			fmt.Printf("Failed to write version file: %v\n", err)
+		}
+
+		// Check for online players
+		players, err := fetchPlayers(serverIP, serverPort)
+		if err != nil {
+			fmt.Printf("Error checking players: %v\n", err)
+			return
+		}
+
+		if len(players) > 0 {
+			fmt.Printf("Players are currently online (%d):\n", len(players))
+			for _, p := range players {
+				fmt.Printf("- %-16s | Score: %d | Time: %s\n", p.Name, p.Score, formatDuration(p.Duration))
+			}
+			fmt.Println("Skipping update while players are online.")
+			return
+		}
+
+		// No players — run steamcmd
+		fmt.Println("No players online. Running update command...")
 		cmd := exec.Command("./steamcmd.sh", "+runscript", "reforger_update")
 		cmd.Stdout = os.Stdout
 		cmd.Stderr = os.Stderr
-		err := cmd.Run()
+		err = cmd.Run()
 		if err != nil {
 			fmt.Printf("Update command failed: %v\n", err)
 			return
 		}
-
-		// Store the new latest version
-		_ = os.WriteFile(stateFilePath, []byte(latest), 0644)
 	} else {
 		fmt.Printf("No new version. Latest seen: %s\n", prevVersion)
 	}
@@ -105,3 +130,26 @@ func versionCompare(a, b string) int {
 	return 0
 }
 
+func fetchPlayers(ip string, port int) ([]a2s.Player, error) {
+	client, err := a2s.New(ip, port)
+	if err != nil {
+		return nil, fmt.Errorf("create client: %w", err)
+	}
+	defer client.Close()
+
+	client.SetBufferSize(2048)
+	client.SetDeadlineTimeout(3)
+
+	players, err := client.GetPlayers()
+	if err != nil {
+		return nil, fmt.Errorf("get players: %w", err)
+	}
+
+	return *players, nil
+}
+
+func formatDuration(d time.Duration) string {
+	minutes := int(d.Minutes())
+	seconds := int(d.Seconds()) % 60
+	return fmt.Sprintf("%02d:%02d", minutes, seconds)
+}

scratch

@@ -0,0 +1,16 @@
+client, err := a2s.New("127.0.0.1", 27016)
+if err != nil {
+  panic(err)
+}
+
+client.SetBufferSize(2048)
+client.SetDeadlineTimeout(3)
+
+defer client.Close()
+
+players,err := client.GetPlayers()
+if err != nil {
+  panic(err)
+} else {
+  fmt.Printf("%+v\n", players)
+}