Add dial parallel for outbound dialer

option/outbound.go

@@ -67,19 +67,20 @@ func (h *Outbound) UnmarshalJSON(bytes []byte) error {
 }
 
 type DialerOptions struct {
-	Detour         string `json:"detour,omitempty"`
-	BindInterface  string `json:"bind_interface,omitempty"`
-	ProtectPath    string `json:"protect_path,omitempty"`
-	RoutingMark    int    `json:"routing_mark,omitempty"`
-	ReuseAddr      bool   `json:"reuse_addr,omitempty"`
-	ConnectTimeout int    `json:"connect_timeout,omitempty"`
-	TCPFastOpen    bool   `json:"tcp_fast_open,omitempty"`
+	Detour         string   `json:"detour,omitempty"`
+	BindInterface  string   `json:"bind_interface,omitempty"`
+	ProtectPath    string   `json:"protect_path,omitempty"`
+	RoutingMark    int      `json:"routing_mark,omitempty"`
+	ReuseAddr      bool     `json:"reuse_addr,omitempty"`
+	ConnectTimeout Duration `json:"connect_timeout,omitempty"`
+	TCPFastOpen    bool     `json:"tcp_fast_open,omitempty"`
 }
 
 type OutboundDialerOptions struct {
 	DialerOptions
 	OverrideOptions *OverrideStreamOptions `json:"override,omitempty"`
 	DomainStrategy  DomainStrategy         `json:"domain_strategy,omitempty"`
+	FallbackDelay   Duration               `json:"fallback_delay,omitempty"`
 }
 
 type OverrideStreamOptions struct {

option/types.go

@@ -3,6 +3,7 @@ package option
 import (
 	"net/netip"
 	"strings"
+	"time"
 
 	E "github.com/sagernet/sing/common/exceptions"
 
@@ -135,3 +136,23 @@ func (s *DomainStrategy) UnmarshalJSON(bytes []byte) error {
 	}
 	return nil
 }
+
+type Duration time.Duration
+
+func (d Duration) MarshalJSON() ([]byte, error) {
+	return json.Marshal((time.Duration)(d).String())
+}
+
+func (d *Duration) UnmarshalJSON(bytes []byte) error {
+	var value string
+	err := json.Unmarshal(bytes, &value)
+	if err != nil {
+		return err
+	}
+	duration, err := time.ParseDuration(value)
+	if err != nil {
+		return err
+	}
+	*d = Duration(duration)
+	return nil
+}