[app/proxyman] DomainStrategy support for all outbounds

app/proxyman/config.proto

@@ -86,11 +86,19 @@ message InboundHandlerConfig {
 message OutboundConfig {}
 
 message SenderConfig {
+  enum DomainStrategy {
+    AS_IS = 0;
+    USE_IP = 1;
+    USE_IP4 = 2;
+    USE_IP6 = 3;
+  }
+
   // Send traffic through the given IP. Only IP is allowed.
   v2ray.core.common.net.IPOrDomain via = 1;
   v2ray.core.transport.internet.StreamConfig stream_settings = 2;
   v2ray.core.transport.internet.ProxyConfig proxy_settings = 3;
   MultiplexingConfig multiplex_settings = 4;
+  DomainStrategy domain_strategy = 5;
 }
 
 message MultiplexingConfig {

app/proxyman/outbound/handler.go

@@ -6,11 +6,13 @@ import (
 	core "github.com/v2fly/v2ray-core/v5"
 	"github.com/v2fly/v2ray-core/v5/app/proxyman"
 	"github.com/v2fly/v2ray-core/v5/common"
+	"github.com/v2fly/v2ray-core/v5/common/dice"
 	"github.com/v2fly/v2ray-core/v5/common/mux"
 	"github.com/v2fly/v2ray-core/v5/common/net"
 	"github.com/v2fly/v2ray-core/v5/common/net/packetaddr"
 	"github.com/v2fly/v2ray-core/v5/common/serial"
 	"github.com/v2fly/v2ray-core/v5/common/session"
+	"github.com/v2fly/v2ray-core/v5/features/dns"
 	"github.com/v2fly/v2ray-core/v5/features/outbound"
 	"github.com/v2fly/v2ray-core/v5/features/policy"
 	"github.com/v2fly/v2ray-core/v5/features/stats"
@@ -56,6 +58,7 @@ type Handler struct {
 	mux             *mux.ClientManager
 	uplinkCounter   stats.Counter
 	downlinkCounter stats.Counter
+	dns             dns.Client
 }
 
 // NewHandler create a new Handler based on the given configuration.
@@ -123,6 +126,16 @@ func NewHandler(ctx context.Context, config *core.OutboundHandlerConfig) (outbou
 		}
 	}
 
+	if h.senderSettings != nil && h.senderSettings.DomainStrategy != proxyman.SenderConfig_AS_IS {
+		err := core.RequireFeatures(ctx, func(d dns.Client) error {
+			h.dns = d
+			return nil
+		})
+		if err != nil {
+			return nil, err
+		}
+	}
+
 	h.proxy = proxyHandler
 	return h, nil
 }
@@ -208,7 +221,19 @@ func (h *Handler) Dial(ctx context.Context, dest net.Destination) (internet.Conn
 			}
 			outbound.Gateway = h.senderSettings.Via.AsAddress()
 		}
+
+		if h.senderSettings.DomainStrategy != proxyman.SenderConfig_AS_IS {
+			outbound := session.OutboundFromContext(ctx)
+			if outbound == nil {
+				outbound = new(session.Outbound)
+				ctx = session.ContextWithOutbound(ctx, outbound)
+			}
+			outbound.Resolver = func(ctx context.Context, domain string) net.Address {
+				return h.resolveIP(ctx, domain, h.Address())
+			}
+		}
 	}
+
 	enablePacketAddrCapture := true
 	if h.senderSettings != nil && h.senderSettings.ProxySettings != nil && h.senderSettings.ProxySettings.HasTag() && h.senderSettings.ProxySettings.TransportLayerProxy {
 		tag := h.senderSettings.ProxySettings.Tag
@@ -230,6 +255,22 @@ func (h *Handler) Dial(ctx context.Context, dest net.Destination) (internet.Conn
 	return h.getStatCouterConnection(conn), err
 }
 
+func (h *Handler) resolveIP(ctx context.Context, domain string, localAddr net.Address) net.Address {
+	strategy := h.senderSettings.DomainStrategy
+	ips, err := dns.LookupIPWithOption(h.dns, domain, dns.IPOption{
+		IPv4Enable: strategy == proxyman.SenderConfig_USE_IP || strategy == proxyman.SenderConfig_USE_IP4 || (localAddr != nil && localAddr.Family().IsIPv4()),
+		IPv6Enable: strategy == proxyman.SenderConfig_USE_IP || strategy == proxyman.SenderConfig_USE_IP6 || (localAddr != nil && localAddr.Family().IsIPv6()),
+		FakeEnable: false,
+	})
+	if err != nil {
+		newError("failed to get IP address for domain ", domain).Base(err).WriteToLog(session.ExportIDToError(ctx))
+	}
+	if len(ips) == 0 {
+		return nil
+	}
+	return net.IPAddress(ips[dice.Roll(len(ips))])
+}
+
 func (h *Handler) getStatCouterConnection(conn internet.Connection) internet.Connection {
 	if h.uplinkCounter != nil || h.downlinkCounter != nil {
 		return &internet.StatCouterConnection{

common/buf/buffer.go

@@ -13,14 +13,23 @@ const (
 
 var pool = bytespool.GetPool(Size)
 
+// ownership represents the data owner of the buffer.
+type ownership uint8
+
+const (
+	managed    ownership = 0
+	unmanaged  ownership = 1
+	bytespools ownership = 2
+)
+
 // Buffer is a recyclable allocation of a byte array. Buffer.Release() recycles
 // the buffer into an internal buffer pool, in order to recreate a buffer more
 // quickly.
 type Buffer struct {
 	v         []byte
 	start     int32
 	end       int32
-	unmanaged bool
+	ownership ownership
 }
 
 // New creates a Buffer with 0 length and 2K capacity.
@@ -30,12 +39,20 @@ func New() *Buffer {
 	}
 }
 
+// NewWithSize creates a Buffer with 0 length and capacity with at least the given size.
+func NewWithSize(size int32) *Buffer {
+	return &Buffer{
+		v:         bytespool.Alloc(size),
+		ownership: bytespools,
+	}
+}
+
 // FromBytes creates a Buffer with an existed bytearray
 func FromBytes(data []byte) *Buffer {
 	return &Buffer{
 		v:         data,
 		end:       int32(len(data)),
-		unmanaged: true,
+		ownership: unmanaged,
 	}
 }
 
@@ -49,14 +66,19 @@ func StackNew() Buffer {
 
 // Release recycles the buffer into an internal buffer pool.
 func (b *Buffer) Release() {
-	if b == nil || b.v == nil || b.unmanaged {
+	if b == nil || b.v == nil || b.ownership == unmanaged {
 		return
 	}
 
 	p := b.v
 	b.v = nil
 	b.Clear()
-	pool.Put(p) // nolint: staticcheck
+	switch b.ownership {
+	case managed:
+		pool.Put(p) // nolint: staticcheck
+	case bytespools:
+		bytespool.Free(p) // nolint: staticcheck
+	}
 }
 
 // Clear clears the content of the buffer, results an empty buffer with
@@ -151,6 +173,14 @@ func (b *Buffer) Len() int32 {
 	return b.end - b.start
 }
 
+// Cap returns the capacity of the buffer content.
+func (b *Buffer) Cap() int32 {
+	if b == nil {
+		return 0
+	}
+	return int32(len(b.v))
+}
+
 // IsEmpty returns true if the buffer is empty.
 func (b *Buffer) IsEmpty() bool {
 	return b.Len() == 0

common/session/session.go

@@ -51,6 +51,8 @@ type Outbound struct {
 	Target net.Destination
 	// Gateway address
 	Gateway net.Address
+	// Domain resolver to use when dialing
+	Resolver func(ctx context.Context, domain string) net.Address
 }
 
 // SniffingRequest controls the behavior of content sniffing.

infra/conf/v4/v2ray.go

@@ -203,13 +203,14 @@ func (c *InboundDetourConfig) Build() (*core.InboundHandlerConfig, error) {
 }
 
 type OutboundDetourConfig struct {
-	Protocol      string                `json:"protocol"`
-	SendThrough   *cfgcommon.Address    `json:"sendThrough"`
-	Tag           string                `json:"tag"`
-	Settings      *json.RawMessage      `json:"settings"`
-	StreamSetting *StreamConfig         `json:"streamSettings"`
-	ProxySettings *proxycfg.ProxyConfig `json:"proxySettings"`
-	MuxSettings   *muxcfg.MuxConfig     `json:"mux"`
+	Protocol       string                `json:"protocol"`
+	SendThrough    *cfgcommon.Address    `json:"sendThrough"`
+	Tag            string                `json:"tag"`
+	Settings       *json.RawMessage      `json:"settings"`
+	StreamSetting  *StreamConfig         `json:"streamSettings"`
+	ProxySettings  *proxycfg.ProxyConfig `json:"proxySettings"`
+	MuxSettings    *muxcfg.MuxConfig     `json:"mux"`
+	DomainStrategy string                `json:"domainStrategy"`
 }
 
 // Build implements Buildable.
@@ -244,6 +245,16 @@ func (c *OutboundDetourConfig) Build() (*core.OutboundHandlerConfig, error) {
 		senderSettings.MultiplexSettings = c.MuxSettings.Build()
 	}
 
+	senderSettings.DomainStrategy = proxyman.SenderConfig_AS_IS
+	switch strings.ToLower(c.DomainStrategy) {
+	case "useip", "use_ip", "use-ip":
+		senderSettings.DomainStrategy = proxyman.SenderConfig_USE_IP
+	case "useip4", "useipv4", "use_ip4", "use_ipv4", "use_ip_v4", "use-ip4", "use-ipv4", "use-ip-v4":
+		senderSettings.DomainStrategy = proxyman.SenderConfig_USE_IP4
+	case "useip6", "useipv6", "use_ip6", "use_ipv6", "use_ip_v6", "use-ip6", "use-ipv6", "use-ip-v6":
+		senderSettings.DomainStrategy = proxyman.SenderConfig_USE_IP6
+	}
+
 	settings := []byte("{}")
 	if c.Settings != nil {
 		settings = ([]byte)(*c.Settings)

proxy/freedom/freedom.go

@@ -104,27 +104,19 @@ func (h *Handler) Process(ctx context.Context, link *transport.Link, dialer inte
 			destination.Port = net.Port(server.Port)
 		}
 	}
+	if h.config.useIP() {
+		outbound.Resolver = func(ctx context.Context, domain string) net.Address {
+			return h.resolveIP(ctx, domain, dialer.Address())
+		}
+	}
 	newError("opening connection to ", destination).WriteToLog(session.ExportIDToError(ctx))
 
 	input := link.Reader
 	output := link.Writer
 
 	var conn internet.Connection
 	err := retry.ExponentialBackoff(5, 100).On(func() error {
-		dialDest := destination
-		if h.config.useIP() && dialDest.Address.Family().IsDomain() {
-			ip := h.resolveIP(ctx, dialDest.Address.Domain(), dialer.Address())
-			if ip != nil {
-				dialDest = net.Destination{
-					Network: dialDest.Network,
-					Address: ip,
-					Port:    dialDest.Port,
-				}
-				newError("dialing to ", dialDest).WriteToLog(session.ExportIDToError(ctx))
-			}
-		}
-
-		rawConn, err := dialer.Dial(ctx, dialDest)
+		rawConn, err := dialer.Dial(ctx, destination)
 		if err != nil {
 			return err
 		}

transport/internet/dialer.go

@@ -68,15 +68,33 @@ func Dial(ctx context.Context, dest net.Destination, streamSettings *MemoryStrea
 
 // DialSystem calls system dialer to create a network connection.
 func DialSystem(ctx context.Context, dest net.Destination, sockopt *SocketConfig) (net.Conn, error) {
+	outbound := session.OutboundFromContext(ctx)
+
 	var src net.Address
-	if outbound := session.OutboundFromContext(ctx); outbound != nil {
+	if outbound != nil {
 		src = outbound.Gateway
 	}
 
 	if transportLayerOutgoingTag := session.GetTransportLayerProxyTagFromContext(ctx); transportLayerOutgoingTag != "" {
 		return DialTaggedOutbound(ctx, dest, transportLayerOutgoingTag)
 	}
 
+	originalAddr := dest.Address
+	if outbound != nil && outbound.Resolver != nil && dest.Address.Family().IsDomain() {
+		if addr := outbound.Resolver(ctx, dest.Address.Domain()); addr != nil {
+			dest.Address = addr
+		}
+	}
+
+	switch {
+	case src != nil && dest.Address != originalAddr:
+		newError("dialing to ", dest, " resolved from ", originalAddr, " via ", src).WriteToLog(session.ExportIDToError(ctx))
+	case src != nil:
+		newError("dialing to ", dest, " via ", src).WriteToLog(session.ExportIDToError(ctx))
+	case dest.Address != originalAddr:
+		newError("dialing to ", dest, " resolved from ", originalAddr).WriteToLog(session.ExportIDToError(ctx))
+	}
+
 	return effectiveSystemDialer.Dial(ctx, src, dest, sockopt)
 }