Add debugging information for DenyIP and fix linting recommendations

.gitignore

@@ -6,6 +6,9 @@
 # The binary.
 cashshuffle
 
+# VSCode
+.vscode
+
 # Folders
 _obj
 _test

cmd/main.go

@@ -18,7 +18,7 @@ import (
 
 const (
 	appName                 = "cashshuffle"
-	version                 = "0.6.15"
+	version                 = "0.6.16"
 	defaultPort             = 1337
 	defaultWebSocketPort    = 1338
 	defaultTorPort          = 1339

server/banned.go

@@ -2,6 +2,7 @@ package server
 
 import (
 	"errors"
+	"fmt"
 
 	"github.com/cashshuffle/cashshuffle/message"
 )
@@ -72,6 +73,9 @@ func (pi *packetInfo) checkBlameMessage() error {
 		if blamer.pool.IsBanned(accused) {
 			blamer.pool.firstBan = accused
 			pi.tracker.increaseBanScore(accused.conn, false)
+			if debugMode {
+				fmt.Printf("[DenyIP] User blamed out of round: %s\n", accused.verificationKey)
+			}
 			pi.tracker.addDenyIPMatch(accused.conn, accused.pool, false)
 			pi.tracker.remove(accused.conn)
 		}

server/broadcast.go

@@ -101,7 +101,7 @@ func (pi *packetInfo) announceStart() {
 	}
 }
 
-func (pi *packetInfo) broadcastJoinedPool(p *playerData) {
+func (pi *packetInfo) broadcastJoinedPool(p *PlayerData) {
 	m := message.Signed{
 		Packet: &message.Packet{
 			Number: p.number,

server/messages.go

@@ -42,7 +42,7 @@ func startPacketInfoChan(c chan *packetInfo) {
 
 // processReceivedMessage reads the message and processes it.
 func (pi *packetInfo) processReceivedMessage() error {
-	var player *playerData
+	var player *PlayerData
 	// If we are not tracking the connection yet, the user must be
 	// registering with the server.
 	if pi.tracker.playerByConnection(pi.conn) == nil {
@@ -54,7 +54,7 @@ func (pi *packetInfo) processReceivedMessage() error {
 		player = pi.tracker.playerByConnection(pi.conn)
 
 		// If a malicious client is connecting and disconnecting
-		// quickly it is possible that playerData will be nil.
+		// quickly it is possible that PlayerData will be nil.
 		// No need to return an error, just don't register them.
 		if player == nil {
 			return nil

server/player_data.go

@@ -7,8 +7,8 @@ import (
 	"github.com/cashshuffle/cashshuffle/message"
 )
 
-// playerData is data needed about each connection.
-type playerData struct {
+// PlayerData is data needed about each connection.
+type PlayerData struct {
 	mutex           sync.RWMutex
 	sessionID       []byte
 	number          uint32
@@ -23,7 +23,7 @@ type playerData struct {
 }
 
 // addBlame adds a verification key to the blamedBy map.
-func (p *playerData) addBlame(verificationKey string) bool {
+func (p *PlayerData) addBlame(verificationKey string) bool {
 	p.mutex.Lock()
 	defer p.mutex.Unlock()
 

server/pool.go

@@ -15,28 +15,28 @@ const (
 type Pool struct {
 	num            int
 	mutex          sync.RWMutex
-	players        map[uint32]*playerData
+	players        map[uint32]*PlayerData
 	size           int
 	amount         uint64
-	firstBan       *playerData
+	firstBan       *PlayerData
 	version        uint64
 	shuffleType    message.ShuffleType
-	frozenSnapshot map[string]*playerData // vk > player
+	frozenSnapshot map[string]*PlayerData // vk > player
 }
 
 // newPool creates a new pool and enforces the rule that pools only exist
 // with at least one player.
-func newPool(num int, player *playerData, size int) *Pool {
+func newPool(num int, player *PlayerData, size int) *Pool {
 	pool := &Pool{
 		num:            num,
 		size:           size,
 		mutex:          sync.RWMutex{},
-		players:        make(map[uint32]*playerData),
+		players:        make(map[uint32]*PlayerData),
 		amount:         player.amount,
 		firstBan:       nil,
 		version:        player.version,
 		shuffleType:    player.shuffleType,
-		frozenSnapshot: make(map[string]*playerData),
+		frozenSnapshot: make(map[string]*PlayerData),
 	}
 	pool.AddPlayer(player)
 	return pool
@@ -52,7 +52,7 @@ func (pool *Pool) IsFrozen() bool {
 
 // IsBanned returns true if the player has been banned by their pool.
 // This assumes that only one ban will happen per pool.
-func (pool *Pool) IsBanned(player *playerData) bool {
+func (pool *Pool) IsBanned(player *PlayerData) bool {
 	pool.mutex.RLock()
 	defer pool.mutex.RUnlock()
 
@@ -69,7 +69,7 @@ func (pool *Pool) PlayerCount() int {
 }
 
 // AddPlayer attempts to place player in the pool and returns success boolean
-func (pool *Pool) AddPlayer(player *playerData) bool {
+func (pool *Pool) AddPlayer(player *PlayerData) bool {
 	pool.mutex.Lock()
 	defer pool.mutex.Unlock()
 
@@ -110,7 +110,7 @@ func (pool *Pool) AddPlayer(player *playerData) bool {
 
 // RemovePlayer removes a player from the pool
 // This method depends on the caller discard the pool if empty.
-func (pool *Pool) RemovePlayer(player *playerData) {
+func (pool *Pool) RemovePlayer(player *PlayerData) {
 	pool.mutex.Lock()
 	defer pool.mutex.Unlock()
 
@@ -119,7 +119,7 @@ func (pool *Pool) RemovePlayer(player *playerData) {
 
 // PlayerFromSnapshot returns the user for the key or nil if they
 // are not in the snapshot.
-func (pool *Pool) PlayerFromSnapshot(verificationKey string) *playerData {
+func (pool *Pool) PlayerFromSnapshot(verificationKey string) *PlayerData {
 	pool.mutex.RLock()
 	defer pool.mutex.RUnlock()
 
@@ -131,8 +131,8 @@ func (pool *Pool) PlayerFromSnapshot(verificationKey string) *playerData {
 
 // takeSnapshot gets a static lookup of all players in the pool
 // This method assumes the caller is holding the mutex.
-func (pool *Pool) takeSnapshot() map[string]*playerData {
-	snapshot := make(map[string]*playerData)
+func (pool *Pool) takeSnapshot() map[string]*PlayerData {
+	snapshot := make(map[string]*PlayerData)
 	for _, p := range pool.players {
 		snapshot[p.verificationKey] = p
 	}

server/register.go

@@ -9,7 +9,7 @@ import (
 
 // registerClient registers a new session.
 func (pi *packetInfo) registerClient() error {
-	var player *playerData
+	var player *PlayerData
 	if len(pi.message.Packet) == 1 {
 		signed := pi.message.Packet[0]
 
@@ -25,7 +25,7 @@ func (pi *packetInfo) registerClient() error {
 			}
 
 			if verificationKey != "" && registration != nil {
-				player = &playerData{
+				player = &PlayerData{
 					verificationKey: verificationKey,
 					conn:            pi.conn,
 					blamedBy:        make(map[string]interface{}),
@@ -54,7 +54,7 @@ func (pi *packetInfo) registerClient() error {
 }
 
 // registrationSuccess sends a registration success reply.
-func (pi *packetInfo) registrationSuccess(p *playerData) error {
+func (pi *packetInfo) registrationSuccess(p *PlayerData) error {
 	m := message.Signed{
 		Packet: &message.Packet{
 			Session: p.sessionID,

server/stats_test.go

@@ -10,7 +10,7 @@ import (
 
 func TestTrackStats(t *testing.T) {
 	tracker := &Tracker{
-		connections: map[net.Conn]*playerData{
+		connections: map[net.Conn]*PlayerData{
 			&fakeConn{}: {},
 			&fakeConn{}: {},
 			&fakeConn{}: {},
@@ -24,7 +24,7 @@ func TestTrackStats(t *testing.T) {
 		pools: map[int]*Pool{
 			1: {
 				num: 1,
-				players: map[uint32]*playerData{
+				players: map[uint32]*PlayerData{
 					1: nil,
 					2: nil,
 					3: nil,
@@ -35,7 +35,7 @@ func TestTrackStats(t *testing.T) {
 				amount:      100,
 				shuffleType: 0,
 				version:     0,
-				frozenSnapshot: map[string]*playerData{
+				frozenSnapshot: map[string]*PlayerData{
 					"1": nil,
 					"2": nil,
 					"3": nil,
@@ -45,7 +45,7 @@ func TestTrackStats(t *testing.T) {
 			},
 			2: {
 				num: 2,
-				players: map[uint32]*playerData{
+				players: map[uint32]*PlayerData{
 					6: nil,
 					7: nil,
 					8: nil,
@@ -54,7 +54,7 @@ func TestTrackStats(t *testing.T) {
 				amount:         1000,
 				shuffleType:    1,
 				version:        1,
-				frozenSnapshot: map[string]*playerData{},
+				frozenSnapshot: map[string]*PlayerData{},
 			},
 		},
 		poolSize:                5,

server/tracker.go

@@ -1,6 +1,7 @@
 package server
 
 import (
+	"fmt"
 	"net"
 	"sync"
 	"time"
@@ -31,7 +32,7 @@ const (
 // Tracker is used to track connections to the server.
 type Tracker struct {
 	banData                 map[string]*banData
-	connections             map[net.Conn]*playerData
+	connections             map[net.Conn]*PlayerData
 	verificationKeys        map[string]net.Conn
 	mutex                   sync.RWMutex
 	denyIPMatch             map[ipPair]time.Time
@@ -66,7 +67,7 @@ func NewTracker(poolSize int, shufflePort int, shuffleWebSocketPort int, torShuf
 	return &Tracker{
 		poolSize:                poolSize,
 		banData:                 make(map[string]*banData),
-		connections:             make(map[net.Conn]*playerData),
+		connections:             make(map[net.Conn]*PlayerData),
 		verificationKeys:        make(map[string]net.Conn),
 		denyIPMatch:             make(map[ipPair]time.Time),
 		pools:                   make(map[int]*Pool),
@@ -78,7 +79,7 @@ func NewTracker(poolSize int, shufflePort int, shuffleWebSocketPort int, torShuf
 }
 
 // add adds a connection to the tracker.
-func (t *Tracker) add(p *playerData) {
+func (t *Tracker) add(p *PlayerData) {
 	t.mutex.Lock()
 	defer t.mutex.Unlock()
 
@@ -217,7 +218,7 @@ func (t *Tracker) cleanupBan(ip string) {
 }
 
 // playerByVerificationKey gets the player for a verification key.
-func (t *Tracker) playerByVerificationKey(key string) *playerData {
+func (t *Tracker) playerByVerificationKey(key string) *PlayerData {
 	t.mutex.RLock()
 	defer t.mutex.RUnlock()
 
@@ -229,7 +230,7 @@ func (t *Tracker) playerByVerificationKey(key string) *playerData {
 }
 
 // playerByConnection gets the player for a connection.
-func (t *Tracker) playerByConnection(c net.Conn) *playerData {
+func (t *Tracker) playerByConnection(c net.Conn) *PlayerData {
 	t.mutex.RLock()
 	defer t.mutex.RUnlock()
 
@@ -246,7 +247,7 @@ func (t *Tracker) generateSessionID() []byte {
 
 // assignPool assigns a user to a pool.
 // This method assumes the caller is holding the mutex.
-func (t *Tracker) assignPool(p *playerData) {
+func (t *Tracker) assignPool(p *PlayerData) {
 	pool := t.assignExistingPool(p)
 	if pool == nil {
 		t.assignNewPool(p)
@@ -256,7 +257,7 @@ func (t *Tracker) assignPool(p *playerData) {
 // assignExistingPool finds an existing pool and places the player or returns
 // nil if there is not an available slot
 // This method assumes the caller is holding the mutex.
-func (t *Tracker) assignExistingPool(p *playerData) *Pool {
+func (t *Tracker) assignExistingPool(p *PlayerData) *Pool {
 	for _, pool := range t.pools {
 		if t.deniedByIPMatch(p.conn, pool) {
 			continue
@@ -271,7 +272,7 @@ func (t *Tracker) assignExistingPool(p *playerData) *Pool {
 
 // assignNewPool assigns player to the lowest empty pool number >=1
 // This method assumes the caller is holding the mutex.
-func (t *Tracker) assignNewPool(player *playerData) {
+func (t *Tracker) assignNewPool(player *PlayerData) {
 	num := firstPoolNum
 	for {
 		if _, ok := t.pools[num]; !ok {
@@ -285,13 +286,16 @@ func (t *Tracker) assignNewPool(player *playerData) {
 
 // unassignPool removes a user from a pool.
 // This method assumes the caller is holding the mutex.
-func (t *Tracker) unassignPool(p *playerData) {
+func (t *Tracker) unassignPool(p *PlayerData) {
 	// A passive player gets ban score and p2p ban because they never
 	// attempted to announce their verification key,
 	// are unblameable by other players,
 	// and probably caused the failure of a shuffle.
 	if p.isPassive {
 		t.increaseBanScore(p.conn, true)
+		if debugMode {
+			fmt.Printf("[DenyIP] Passive user disconnected: %s\n", p.verificationKey)
+		}
 		t.addDenyIPMatch(p.conn, p.pool, true)
 	}