Fix race conditions (#36)

4 files changed, 81 insertions, 30 deletions

diff --git a/client_conn.go b/client_conn.go
index 8eb5dcd..9b0309f 100644
--- a/client_conn.go
+++ b/client_conn.go
@@ -26,11 +26,13 @@ const (
 type clientConn struct {
 	mt.Peer
 	srv *serverConn
+	mu  sync.RWMutex
 
-	state  clientState
-	name   string
-	initCh chan struct{}
-	hopMu  sync.Mutex
+	cstate   clientState
+	cstateMu sync.RWMutex
+	name     string
+	initCh   chan struct{}
+	hopMu    sync.Mutex
 
 	auth struct {
 		method                       mt.AuthMethods
@@ -58,7 +60,26 @@ type clientConn struct {
 	modChs map[string]struct{}
 }
 
-func (cc *clientConn) server() *serverConn { return cc.srv }
+func (cc *clientConn) server() *serverConn {
+	cc.mu.RLock()
+	defer cc.mu.RUnlock()
+
+	return cc.srv
+}
+
+func (cc *clientConn) state() clientState {
+	cc.cstateMu.RLock()
+	defer cc.cstateMu.RUnlock()
+
+	return cc.cstate
+}
+
+func (cc *clientConn) setState(state clientState) {
+	cc.cstateMu.Lock()
+	defer cc.cstateMu.Unlock()
+
+	cc.cstate = state
+}
 
 func (cc *clientConn) init() <-chan struct{} { return cc.initCh }
 
@@ -102,13 +123,12 @@ func handleClt(cc *clientConn) {
 
 		switch cmd := pkt.Cmd.(type) {
 		case *mt.ToSrvInit:
-			if cc.state > csCreated {
+			if cc.state() > csCreated {
 				cc.log("-->", "duplicate init")
 				break
 			}
 
-			cc.state = csInit
-
+			cc.setState(csInit)
 			if cmd.SerializeVer != latestSerializeVer {
 				cc.log("<--", "invalid serializeVer")
 				ack, _ := cc.SendCmd(&mt.ToCltDisco{Reason: mt.UnsupportedVer})
@@ -223,7 +243,7 @@ func handleClt(cc *clientConn) {
 				Username:     cc.name,
 			})
 		case *mt.ToSrvFirstSRP:
-			if cc.state == csInit {
+			if cc.state() == csInit {
 				if cc.auth.method != mt.FirstSRP {
 					cc.log("-->", "unauthorized password change")
 					ack, _ := cc.SendCmd(&mt.ToCltDisco{Reason: mt.UnexpectedData})
@@ -276,13 +296,12 @@ func handleClt(cc *clientConn) {
 					SudoAuthMethods: mt.SRP,
 				})
 			} else {
-				if cc.state < csSudo {
+				if cc.state() < csSudo {
 					cc.log("-->", "unauthorized sudo action")
 					break
 				}
 
-				cc.state--
-
+				cc.setState(cc.state() - 1)
 				if err := authIface.SetPasswd(cc.name, cmd.Salt, cmd.Verifier); err != nil {
 					cc.log("<--", "change password fail")
 					cc.SendCmd(&mt.ToCltChatMsg{
@@ -301,9 +320,9 @@ func handleClt(cc *clientConn) {
 				})
 			}
 		case *mt.ToSrvSRPBytesA:
-			wantSudo := cc.state == csActive
+			wantSudo := cc.state() == csActive
 
-			if cc.state != csInit && cc.state != csActive {
+			if cc.state() != csInit && cc.state() != csActive {
 				cc.log("-->", "unexpected authentication")
 				break
 			}
@@ -368,9 +387,9 @@ func handleClt(cc *clientConn) {
 				B:    cc.auth.srpB,
 			})
 		case *mt.ToSrvSRPBytesM:
-			wantSudo := cc.state == csActive
+			wantSudo := cc.state() == csActive
 
-			if cc.state != csInit && cc.state != csActive {
+			if cc.state() != csInit && cc.state() != csActive {
 				cc.log("-->", "unexpected authentication")
 				break
 			}
@@ -401,7 +420,7 @@ func handleClt(cc *clientConn) {
 				}{}
 
 				if wantSudo {
-					cc.state++
+					cc.setState(cc.state() + 1)
 					cc.SendCmd(&mt.ToCltAcceptSudoMode{})
 				} else {
 					cc.SendCmd(&mt.ToCltAcceptAuth{
@@ -485,7 +504,7 @@ func handleClt(cc *clientConn) {
 			cc.versionStr = cmd.Version
 			cc.formspecVer = cmd.Formspec
 
-			cc.state++
+			cc.setState(cc.state() + 1)
 			close(cc.initCh)
 		case *mt.ToSrvInteract:
 			if cc.server() == nil {
diff --git a/connect.go b/connect.go
index 9ad3a1e..03f9243 100644
--- a/connect.go
+++ b/connect.go
@@ -19,7 +19,10 @@ func connect(conn net.Conn, name string, cc *clientConn) *serverConn {
 		playerList:       make(map[string]struct{}),
 	}
 	sc.log("-->", "connect")
+
+	cc.mu.Lock()
 	cc.srv = sc
+	cc.mu.Unlock()
 
 	go handleSrv(sc)
 	return sc
diff --git a/content.go b/content.go
index a8a9381..079739e 100644
--- a/content.go
+++ b/content.go
@@ -24,7 +24,8 @@ type mediaFile struct {
 type contentConn struct {
 	mt.Peer
 
-	state          clientState
+	cstate         clientState
+	cstateMu       sync.RWMutex
 	name, userName string
 	doneCh         chan struct{}
 
@@ -41,6 +42,20 @@ type contentConn struct {
 	media []mediaFile
 }
 
+func (cc *contentConn) state() clientState {
+	cc.cstateMu.RLock()
+	defer cc.cstateMu.RUnlock()
+
+	return cc.cstate
+}
+
+func (cc *contentConn) setState(state clientState) {
+	cc.cstateMu.Lock()
+	defer cc.cstateMu.Unlock()
+
+	cc.cstate = state
+}
+
 func (cc *contentConn) done() <-chan struct{} { return cc.doneCh }
 
 func (cc *contentConn) log(dir, msg string) {
@@ -51,7 +66,7 @@ func handleContent(cc *contentConn) {
 	defer close(cc.doneCh)
 
 	go func() {
-		for cc.state == csCreated {
+		for cc.state() == csCreated {
 			cc.SendCmd(&mt.ToSrvInit{
 				SerializeVer: latestSerializeVer,
 				MinProtoVer:  latestProtoVer,
@@ -84,8 +99,7 @@ func handleContent(cc *contentConn) {
 				break
 			}
 
-			cc.state++
-
+			cc.setState(cc.state() + 1)
 			if cmd.AuthMethods&mt.FirstSRP != 0 {
 				cc.auth.method = mt.FirstSRP
 			} else {
diff --git a/server_conn.go b/server_conn.go
index 45e11fa..3e0bac5 100644
--- a/server_conn.go
+++ b/server_conn.go
@@ -6,6 +6,7 @@ import (
 	"log"
 	"net"
 	"strings"
+	"sync"
 	"time"
 
 	"github.com/HimbeerserverDE/srp"
@@ -17,9 +18,10 @@ type serverConn struct {
 	mt.Peer
 	clt *clientConn
 
-	state  clientState
-	name   string
-	initCh chan struct{}
+	cstate   clientState
+	cstateMu sync.RWMutex
+	name     string
+	initCh   chan struct{}
 
 	auth struct {
 		method              mt.AuthMethods
@@ -41,6 +43,20 @@ type serverConn struct {
 
 func (sc *serverConn) client() *clientConn { return sc.clt }
 
+func (sc *serverConn) state() clientState {
+	sc.cstateMu.RLock()
+	defer sc.cstateMu.RUnlock()
+
+	return sc.cstate
+}
+
+func (sc *serverConn) setState(state clientState) {
+	sc.cstateMu.Lock()
+	defer sc.cstateMu.Unlock()
+
+	sc.cstate = state
+}
+
 func (sc *serverConn) init() <-chan struct{} { return sc.initCh }
 
 func (sc *serverConn) log(dir, msg string) {
@@ -57,7 +73,7 @@ func handleSrv(sc *serverConn) {
 	}
 
 	go func() {
-		for sc.state == csCreated && sc.client() != nil {
+		for sc.state() == csCreated && sc.client() != nil {
 			sc.SendCmd(&mt.ToSrvInit{
 				SerializeVer: latestSerializeVer,
 				MinProtoVer:  latestProtoVer,
@@ -108,8 +124,7 @@ func handleSrv(sc *serverConn) {
 				break
 			}
 
-			sc.state++
-
+			sc.setState(sc.state() + 1)
 			if cmd.AuthMethods&mt.FirstSRP != 0 {
 				sc.auth.method = mt.FirstSRP
 			} else {
@@ -190,7 +205,7 @@ func handleSrv(sc *serverConn) {
 			sc.log("<--", "deny sudo")
 		case *mt.ToCltAcceptSudoMode:
 			sc.log("<--", "accept sudo")
-			sc.state++
+			sc.setState(sc.state() + 1)
 		case *mt.ToCltAnnounceMedia:
 			sc.SendCmd(&mt.ToSrvReqMedia{})
 
@@ -204,7 +219,7 @@ func handleSrv(sc *serverConn) {
 			})
 
 			sc.log("<->", "handshake completed")
-			sc.state++
+			sc.setState(sc.state() + 1)
 			close(sc.initCh)
 		case *mt.ToCltInv:
 			var oldInv mt.Inv