feat: rework config parsing to use viper unmarshal

app/cmd/client.go

@@ -6,6 +6,7 @@ import (
 	"net"
 	"os"
 	"sync"
+	"time"
 
 	"github.com/spf13/cobra"
 	"github.com/spf13/viper"
@@ -22,154 +23,174 @@ var clientCmd = &cobra.Command{
 	Run:   runClient,
 }
 
-type modeFunc func(*viper.Viper, client.Client) error
-
-var modeMap = map[string]modeFunc{
-	"socks5": clientSOCKS5,
-	"http":   clientHTTP,
-}
-
 func init() {
 	rootCmd.AddCommand(clientCmd)
 }
 
+type clientConfig struct {
+	Server string `mapstructure:"server"`
+	Auth   string `mapstructure:"auth"`
+	TLS    struct {
+		SNI      string `mapstructure:"sni"`
+		Insecure bool   `mapstructure:"insecure"`
+		CA       string `mapstructure:"ca"`
+	} `mapstructure:"tls"`
+	QUIC struct {
+		InitStreamReceiveWindow     uint64        `mapstructure:"initStreamReceiveWindow"`
+		MaxStreamReceiveWindow      uint64        `mapstructure:"maxStreamReceiveWindow"`
+		InitConnectionReceiveWindow uint64        `mapstructure:"initConnReceiveWindow"`
+		MaxConnectionReceiveWindow  uint64        `mapstructure:"maxConnReceiveWindow"`
+		MaxIdleTimeout              time.Duration `mapstructure:"maxIdleTimeout"`
+		KeepAlivePeriod             time.Duration `mapstructure:"keepAlivePeriod"`
+		DisablePathMTUDiscovery     bool          `mapstructure:"disablePathMTUDiscovery"`
+	} `mapstructure:"quic"`
+	Bandwidth struct {
+		Up   string `mapstructure:"up"`
+		Down string `mapstructure:"down"`
+	} `mapstructure:"bandwidth"`
+	FastOpen bool          `mapstructure:"fastOpen"`
+	SOCKS5   *socks5Config `mapstructure:"socks5"`
+	HTTP     *httpConfig   `mapstructure:"http"`
+}
+
+type socks5Config struct {
+	Listen     string `mapstructure:"listen"`
+	Username   string `mapstructure:"username"`
+	Password   string `mapstructure:"password"`
+	DisableUDP bool   `mapstructure:"disableUDP"`
+}
+
+type httpConfig struct {
+	Listen   string `mapstructure:"listen"`
+	Username string `mapstructure:"username"`
+	Password string `mapstructure:"password"`
+	Realm    string `mapstructure:"realm"`
+}
+
+// Config validates the fields and returns a ready-to-use Hysteria client config
+func (c *clientConfig) Config() (*client.Config, error) {
+	hyConfig := &client.Config{}
+	// ServerAddr
+	if c.Server == "" {
+		return nil, configError{Field: "server", Err: errors.New("server address is empty")}
+	}
+	host, hostPort := parseServerAddrString(c.Server)
+	addr, err := net.ResolveUDPAddr("udp", hostPort)
+	if err != nil {
+		return nil, configError{Field: "server", Err: err}
+	}
+	hyConfig.ServerAddr = addr
+	// Auth
+	hyConfig.Auth = c.Auth
+	// TLSConfig
+	if c.TLS.SNI == "" {
+		// Use server hostname as SNI
+		hyConfig.TLSConfig.ServerName = host
+	} else {
+		hyConfig.TLSConfig.ServerName = c.TLS.SNI
+	}
+	hyConfig.TLSConfig.InsecureSkipVerify = c.TLS.Insecure
+	if c.TLS.CA != "" {
+		ca, err := os.ReadFile(c.TLS.CA)
+		if err != nil {
+			return nil, configError{Field: "tls.ca", Err: err}
+		}
+		cPool := x509.NewCertPool()
+		if !cPool.AppendCertsFromPEM(ca) {
+			return nil, configError{Field: "tls.ca", Err: errors.New("failed to parse CA certificate")}
+		}
+		hyConfig.TLSConfig.RootCAs = cPool
+	}
+	// QUICConfig
+	hyConfig.QUICConfig = client.QUICConfig{
+		InitialStreamReceiveWindow:     c.QUIC.InitStreamReceiveWindow,
+		MaxStreamReceiveWindow:         c.QUIC.MaxStreamReceiveWindow,
+		InitialConnectionReceiveWindow: c.QUIC.InitConnectionReceiveWindow,
+		MaxConnectionReceiveWindow:     c.QUIC.MaxConnectionReceiveWindow,
+		MaxIdleTimeout:                 c.QUIC.MaxIdleTimeout,
+		KeepAlivePeriod:                c.QUIC.KeepAlivePeriod,
+		DisablePathMTUDiscovery:        c.QUIC.DisablePathMTUDiscovery,
+	}
+	// BandwidthConfig
+	if c.Bandwidth.Up == "" || c.Bandwidth.Down == "" {
+		return nil, configError{Field: "bandwidth", Err: errors.New("both up and down bandwidth must be set")}
+	}
+	hyConfig.BandwidthConfig.MaxTx, err = convBandwidth(c.Bandwidth.Up)
+	if err != nil {
+		return nil, configError{Field: "bandwidth.up", Err: err}
+	}
+	hyConfig.BandwidthConfig.MaxRx, err = convBandwidth(c.Bandwidth.Down)
+	if err != nil {
+		return nil, configError{Field: "bandwidth.down", Err: err}
+	}
+	// FastOpen
+	hyConfig.FastOpen = c.FastOpen
+
+	return hyConfig, nil
+}
+
 func runClient(cmd *cobra.Command, args []string) {
 	logger.Info("client mode")
 
 	if err := viper.ReadInConfig(); err != nil {
 		logger.Fatal("failed to read client config", zap.Error(err))
 	}
-	config, err := viperToClientConfig()
-	if err != nil {
+	var config clientConfig
+	if err := viper.Unmarshal(&config); err != nil {
 		logger.Fatal("failed to parse client config", zap.Error(err))
 	}
+	hyConfig, err := config.Config()
+	if err != nil {
+		logger.Fatal("failed to validate client config", zap.Error(err))
+	}
 
-	c, err := client.NewClient(config)
+	c, err := client.NewClient(hyConfig)
 	if err != nil {
 		logger.Fatal("failed to initialize client", zap.Error(err))
 	}
 	defer c.Close()
 
+	// Modes
 	var wg sync.WaitGroup
 	hasMode := false
-	for mode, fn := range modeMap {
-		v := viper.Sub(mode)
-		if v != nil {
-			hasMode = true
-			wg.Add(1)
-			go func(mode string, fn modeFunc) {
-				defer wg.Done()
-				if err := fn(v, c); err != nil {
-					logger.Fatal("failed to run mode", zap.String("mode", mode), zap.Error(err))
-				}
-			}(mode, fn)
-		}
+
+	if config.SOCKS5 != nil {
+		hasMode = true
+		wg.Add(1)
+		go func() {
+			defer wg.Done()
+			if err := clientSOCKS5(*config.SOCKS5, c); err != nil {
+				logger.Fatal("failed to run SOCKS5 server", zap.Error(err))
+			}
+		}()
 	}
+	if config.HTTP != nil {
+		hasMode = true
+		wg.Add(1)
+		go func() {
+			defer wg.Done()
+			if err := clientHTTP(*config.HTTP, c); err != nil {
+				logger.Fatal("failed to run HTTP proxy server", zap.Error(err))
+			}
+		}()
+	}
+
 	if !hasMode {
 		logger.Fatal("no mode specified")
 	}
 	wg.Wait()
 }
 
-func viperToClientConfig() (*client.Config, error) {
-	// Conn and address
-	addrStr := viper.GetString("server")
-	if addrStr == "" {
-		return nil, configError{Field: "server", Err: errors.New("server address is empty")}
-	}
-	host, hostPort := parseServerAddrString(addrStr)
-	addr, err := net.ResolveUDPAddr("udp", hostPort)
-	if err != nil {
-		return nil, configError{Field: "server", Err: err}
-	}
-	// TLS
-	tlsConfig, err := viperToClientTLSConfig(host)
-	if err != nil {
-		return nil, err
-	}
-	// QUIC
-	quicConfig := viperToClientQUICConfig()
-	// Bandwidth
-	bwConfig, err := viperToClientBandwidthConfig()
-	if err != nil {
-		return nil, err
-	}
-	return &client.Config{
-		ConnFactory:     nil, // TODO
-		ServerAddr:      addr,
-		Auth:            viper.GetString("auth"),
-		TLSConfig:       tlsConfig,
-		QUICConfig:      quicConfig,
-		BandwidthConfig: bwConfig,
-		FastOpen:        viper.GetBool("fastOpen"),
-	}, nil
-}
-
-func viperToClientTLSConfig(host string) (client.TLSConfig, error) {
-	config := client.TLSConfig{
-		ServerName:         viper.GetString("tls.sni"),
-		InsecureSkipVerify: viper.GetBool("tls.insecure"),
-	}
-	if config.ServerName == "" {
-		// The user didn't specify a server name, fallback to the host part of the server address
-		config.ServerName = host
-	}
-	caPath := viper.GetString("tls.ca")
-	if caPath != "" {
-		ca, err := os.ReadFile(caPath)
-		if err != nil {
-			return client.TLSConfig{}, configError{Field: "tls.ca", Err: err}
-		}
-		pool := x509.NewCertPool()
-		if !pool.AppendCertsFromPEM(ca) {
-			return client.TLSConfig{}, configError{Field: "tls.ca", Err: errors.New("failed to parse CA certificate")}
-		}
-		config.RootCAs = pool
-	}
-	return config, nil
-}
-
-func viperToClientQUICConfig() client.QUICConfig {
-	return client.QUICConfig{
-		InitialStreamReceiveWindow:     viper.GetUint64("quic.initStreamReceiveWindow"),
-		MaxStreamReceiveWindow:         viper.GetUint64("quic.maxStreamReceiveWindow"),
-		InitialConnectionReceiveWindow: viper.GetUint64("quic.initConnReceiveWindow"),
-		MaxConnectionReceiveWindow:     viper.GetUint64("quic.maxConnReceiveWindow"),
-		MaxIdleTimeout:                 viper.GetDuration("quic.maxIdleTimeout"),
-		KeepAlivePeriod:                viper.GetDuration("quic.keepAlivePeriod"),
-		DisablePathMTUDiscovery:        viper.GetBool("quic.disablePathMTUDiscovery"),
-	}
-}
-
-func viperToClientBandwidthConfig() (client.BandwidthConfig, error) {
-	bw := client.BandwidthConfig{}
-	upStr, downStr := viper.GetString("bandwidth.up"), viper.GetString("bandwidth.down")
-	if upStr == "" || downStr == "" {
-		return client.BandwidthConfig{}, configError{Field: "bandwidth", Err: errors.New("bandwidth.up and bandwidth.down must be set")}
-	}
-	up, err := convBandwidth(upStr)
-	if err != nil {
-		return client.BandwidthConfig{}, configError{Field: "bandwidth.up", Err: err}
-	}
-	down, err := convBandwidth(downStr)
-	if err != nil {
-		return client.BandwidthConfig{}, configError{Field: "bandwidth.down", Err: err}
-	}
-	bw.MaxTx, bw.MaxRx = up, down
-	return bw, nil
-}
-
-func clientSOCKS5(v *viper.Viper, c client.Client) error {
-	listenAddr := v.GetString("listen")
-	if listenAddr == "" {
+func clientSOCKS5(config socks5Config, c client.Client) error {
+	if config.Listen == "" {
 		return configError{Field: "listen", Err: errors.New("listen address is empty")}
 	}
-	l, err := net.Listen("tcp", listenAddr)
+	l, err := net.Listen("tcp", config.Listen)
 	if err != nil {
 		return configError{Field: "listen", Err: err}
 	}
 	var authFunc func(username, password string) bool
-	username, password := v.GetString("username"), v.GetString("password")
+	username, password := config.Username, config.Password
 	if username != "" && password != "" {
 		authFunc = func(u, p string) bool {
 			return u == username && p == password
@@ -178,47 +199,46 @@ func clientSOCKS5(v *viper.Viper, c client.Client) error {
 	s := socks5.Server{
 		HyClient:    c,
 		AuthFunc:    authFunc,
-		DisableUDP:  viper.GetBool("disableUDP"),
+		DisableUDP:  config.DisableUDP,
 		EventLogger: &socks5Logger{},
 	}
-	logger.Info("SOCKS5 server listening", zap.String("addr", listenAddr))
+	logger.Info("SOCKS5 server listening", zap.String("addr", config.Listen))
 	return s.Serve(l)
 }
 
-func clientHTTP(v *viper.Viper, c client.Client) error {
-	listenAddr := v.GetString("listen")
-	if listenAddr == "" {
+func clientHTTP(config httpConfig, c client.Client) error {
+	if config.Listen == "" {
 		return configError{Field: "listen", Err: errors.New("listen address is empty")}
 	}
-	l, err := net.Listen("tcp", listenAddr)
+	l, err := net.Listen("tcp", config.Listen)
 	if err != nil {
 		return configError{Field: "listen", Err: err}
 	}
 	var authFunc func(username, password string) bool
-	username, password := v.GetString("username"), v.GetString("password")
+	username, password := config.Username, config.Password
 	if username != "" && password != "" {
 		authFunc = func(u, p string) bool {
 			return u == username && p == password
 		}
 	}
-	realm := v.GetString("realm")
-	if realm == "" {
-		realm = "Hysteria"
+	if config.Realm == "" {
+		config.Realm = "Hysteria"
 	}
 	h := http.Server{
 		HyClient:    c,
 		AuthFunc:    authFunc,
-		AuthRealm:   realm,
+		AuthRealm:   config.Realm,
 		EventLogger: &httpLogger{},
 	}
-	logger.Info("HTTP proxy server listening", zap.String("addr", listenAddr))
+	logger.Info("HTTP proxy server listening", zap.String("addr", config.Listen))
 	return h.Serve(l)
 }
 
+// parseServerAddrString parses server address string.
+// Server address can be in either "host:port" or "host" format (in which case we assume port 443).
 func parseServerAddrString(addrStr string) (host, hostPort string) {
 	h, _, err := net.SplitHostPort(addrStr)
 	if err != nil {
-		// No port provided, use default HTTPS port
 		return addrStr, net.JoinHostPort(addrStr, "443")
 	}
 	return h, addrStr