Remote media server support

Closes #1

content.go

@@ -50,7 +50,8 @@ type contentConn struct {
 
 	nodeDefs []mt.NodeDef
 
-	media []mediaFile
+	media   []mediaFile
+	remotes []string
 }
 
 func (cc *contentConn) state() clientState {
@@ -173,7 +174,9 @@ func handleContent(cc *contentConn) {
 					NoSHA1: true,
 				})
 			case mt.FirstSRP:
-				salt, verifier, err := srp.NewClient([]byte(cc.userName), []byte{})
+				id := strings.ToLower(cc.userName)
+
+				salt, verifier, err := srp.NewClient([]byte(id), []byte{})
 				if err != nil {
 					cc.log("->", err)
 					break
@@ -194,7 +197,9 @@ func handleContent(cc *contentConn) {
 				break
 			}
 
-			cc.auth.srpK, err = srp.CompleteHandshake(cc.auth.srpA, cc.auth.a, []byte(cc.userName), []byte{}, cmd.Salt, cmd.B)
+			id := strings.ToLower(cc.userName)
+
+			cc.auth.srpK, err = srp.CompleteHandshake(cc.auth.srpA, cc.auth.a, []byte(id), []byte{}, cmd.Salt, cmd.B)
 			if err != nil {
 				cc.log("->", err)
 				break
@@ -247,6 +252,11 @@ func handleContent(cc *contentConn) {
 				})
 			}
 
+			cc.remotes = strings.Split(cmd.URL, ",")
+			for k, v := range cc.remotes {
+				cc.remotes[k] = strings.TrimSpace(v)
+			}
+
 			cc.SendCmd(&mt.ToSrvReqMedia{Filenames: filenames})
 		case *mt.ToCltMedia:
 			for _, f := range cmd.Files {
@@ -464,7 +474,25 @@ func muxMedia(conns []*contentConn) []mediaFile {
 	return media
 }
 
-func muxContent(userName string) (itemDefs []mt.ItemDef, aliases []struct{ Alias, Orig string }, nodeDefs []mt.NodeDef, p0Map param0Map, p0SrvMap param0SrvMap, media []mediaFile, err error) {
+func muxRemotes(conns []*contentConn) []string {
+	remotes := make(map[string]struct{})
+
+	for _, cc := range conns {
+		<-cc.done()
+		for _, v := range cc.remotes {
+			remotes[v] = struct{}{}
+		}
+	}
+
+	urls := make([]string, 0, len(remotes))
+	for remote := range remotes {
+		urls = append(urls, remote)
+	}
+
+	return urls
+}
+
+func muxContent(userName string) (itemDefs []mt.ItemDef, aliases []struct{ Alias, Orig string }, nodeDefs []mt.NodeDef, p0Map param0Map, p0SrvMap param0SrvMap, media []mediaFile, remotes []string, err error) {
 	var conns []*contentConn
 	for _, srv := range Conf().Servers {
 		var addr *net.UDPAddr
@@ -492,6 +520,7 @@ func muxContent(userName string) (itemDefs []mt.ItemDef, aliases []struct{ Alias
 	itemDefs, aliases = muxItemDefs(conns)
 	nodeDefs, p0Map, p0SrvMap = muxNodeDefs(conns)
 	media = muxMedia(conns)
+	remotes = muxRemotes(conns)
 	return
 }
 

process.go

@@ -349,8 +349,9 @@ func (cc *ClientConn) process(pkt mt.Pkt) {
 
 		return
 	case *mt.ToSrvInit2:
+		var remotes []string
 		var err error
-		cc.itemDefs, cc.aliases, cc.nodeDefs, cc.p0Map, cc.p0SrvMap, cc.media, err = muxContent(cc.Name())
+		cc.itemDefs, cc.aliases, cc.nodeDefs, cc.p0Map, cc.p0SrvMap, cc.media, remotes, err = muxContent(cc.Name())
 		if err != nil {
 			cc.Log("<-", err.Error())
 			cc.Kick("Content multiplexing failed.")
@@ -374,7 +375,10 @@ func (cc *ClientConn) process(pkt mt.Pkt) {
 			})
 		}
 
-		cc.SendCmd(&mt.ToCltAnnounceMedia{Files: files})
+		cc.SendCmd(&mt.ToCltAnnounceMedia{
+			Files: files,
+			URL:   strings.Join(remotes, ","),
+		})
 		cc.lang = cmd.Lang
 
 		var csmrf mt.CSMRestrictionFlags
@@ -487,7 +491,9 @@ func (sc *ServerConn) process(pkt mt.Pkt) {
 				NoSHA1: true,
 			})
 		case mt.FirstSRP:
-			salt, verifier, err := srp.NewClient([]byte(clt.name), []byte{})
+			id := strings.ToLower(clt.Name())
+
+			salt, verifier, err := srp.NewClient([]byte(id), []byte{})
 			if err != nil {
 				sc.Log("->", err)
 				return
@@ -510,14 +516,16 @@ func (sc *ServerConn) process(pkt mt.Pkt) {
 			return
 		}
 
+		id := strings.ToLower(clt.Name())
+
 		var err error
-		sc.auth.srpK, err = srp.CompleteHandshake(sc.auth.srpA, sc.auth.a, []byte(clt.name), []byte{}, cmd.Salt, cmd.B)
+		sc.auth.srpK, err = srp.CompleteHandshake(sc.auth.srpA, sc.auth.a, []byte(id), []byte{}, cmd.Salt, cmd.B)
 		if err != nil {
 			sc.Log("->", err)
 			return
 		}
 
-		M := srp.ClientProof([]byte(clt.name), cmd.Salt, sc.auth.srpA, cmd.B, sc.auth.srpK)
+		M := srp.ClientProof([]byte(clt.Name()), cmd.Salt, sc.auth.srpA, cmd.B, sc.auth.srpK)
 		if M == nil {
 			sc.Log("<-", "SRP safety check fail")
 			return