Feature: add inbounds for flexible binding inbound (#2818)

constant/listener.go

@@ -1,7 +1,92 @@
 package constant
 
+import (
+	"fmt"
+	"net"
+	"net/url"
+	"strconv"
+)
+
 type Listener interface {
 	RawAddress() string
 	Address() string
 	Close() error
 }
+
+type InboundType string
+
+const (
+	InboundTypeSocks  InboundType = "socks"
+	InboundTypeRedir  InboundType = "redir"
+	InboundTypeTproxy InboundType = "tproxy"
+	InboundTypeHTTP   InboundType = "http"
+	InboundTypeMixed  InboundType = "mixed"
+)
+
+var supportInboundTypes = map[InboundType]bool{
+	InboundTypeSocks:  true,
+	InboundTypeRedir:  true,
+	InboundTypeTproxy: true,
+	InboundTypeHTTP:   true,
+	InboundTypeMixed:  true,
+}
+
+type inbound struct {
+	Type          InboundType `json:"type" yaml:"type"`
+	BindAddress   string      `json:"bind-address" yaml:"bind-address"`
+	IsFromPortCfg bool        `json:"-" yaml:"-"`
+}
+
+// Inbound
+type Inbound inbound
+
+// UnmarshalYAML implements yaml.Unmarshaler
+func (i *Inbound) UnmarshalYAML(unmarshal func(any) error) error {
+	var tp string
+	if err := unmarshal(&tp); err != nil {
+		var inner inbound
+		if err := unmarshal(&inner); err != nil {
+			return err
+		}
+
+		*i = Inbound(inner)
+		return nil
+	}
+
+	inner, err := parseInbound(tp)
+	if err != nil {
+		return err
+	}
+	*i = Inbound(*inner)
+	if !supportInboundTypes[i.Type] {
+		return fmt.Errorf("not support inbound type: %s", i.Type)
+	}
+	_, portStr, err := net.SplitHostPort(i.BindAddress)
+	if err != nil {
+		return fmt.Errorf("bind address parse error. addr:%s, err:%v", i.BindAddress, err)
+	}
+	port, err := strconv.Atoi(portStr)
+	if err != nil {
+		return fmt.Errorf("port not a number. addr:%s", i.BindAddress)
+	}
+	if port == 0 {
+		return fmt.Errorf("invalid bind port. addr:%s", i.BindAddress)
+	}
+	return nil
+}
+
+func parseInbound(alias string) (*inbound, error) {
+	u, err := url.Parse(alias)
+	if err != nil {
+		return nil, err
+	}
+	listenerType := InboundType(u.Scheme)
+	return &inbound{
+		Type:        listenerType,
+		BindAddress: u.Host,
+	}, nil
+}
+
+func (i *Inbound) ToAlias() string {
+	return string(i.Type) + "://" + i.BindAddress
+}