Freedom: Cache UDP resolve result (#4804)

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风扇滑翔翼 2025-07-23 18:02:27 +08:00 committed by GitHub
parent 7f23a1cb65
commit 3b47d0846e
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GPG key ID: B5690EEEBB952194
2 changed files with 157 additions and 5 deletions

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@ -18,6 +18,7 @@ import (
"github.com/xtls/xray-core/common/session"
"github.com/xtls/xray-core/common/signal"
"github.com/xtls/xray-core/common/task"
"github.com/xtls/xray-core/common/utils"
"github.com/xtls/xray-core/core"
"github.com/xtls/xray-core/features/dns"
"github.com/xtls/xray-core/features/policy"
@ -202,7 +203,7 @@ func (h *Handler) Process(ctx context.Context, link *transport.Link, dialer inte
writer = buf.NewWriter(conn)
}
} else {
writer = NewPacketWriter(conn, h, ctx, UDPOverride)
writer = NewPacketWriter(conn, h, ctx, UDPOverride, destination)
if h.config.Noises != nil {
errors.LogDebug(ctx, "NOISE", h.config.Noises)
writer = &NoisePacketWriter{
@ -317,7 +318,8 @@ func (r *PacketReader) ReadMultiBuffer() (buf.MultiBuffer, error) {
return buf.MultiBuffer{b}, nil
}
func NewPacketWriter(conn net.Conn, h *Handler, ctx context.Context, UDPOverride net.Destination) buf.Writer {
// DialDest means the dial target used in the dialer when creating conn
func NewPacketWriter(conn net.Conn, h *Handler, ctx context.Context, UDPOverride net.Destination, DialDest net.Destination) buf.Writer {
iConn := conn
statConn, ok := iConn.(*stat.CounterConnection)
if ok {
@ -328,12 +330,20 @@ func NewPacketWriter(conn net.Conn, h *Handler, ctx context.Context, UDPOverride
counter = statConn.WriteCounter
}
if c, ok := iConn.(*internet.PacketConnWrapper); ok {
// If DialDest is a domain, it will be resolved in dialer
// check this behavior and add it to map
resolvedUDPAddr := utils.NewTypedSyncMap[string, net.Address]()
if DialDest.Address.Family().IsDomain() {
RemoteAddress, _, _ := net.SplitHostPort(conn.RemoteAddr().String())
resolvedUDPAddr.Store(DialDest.Address.String(), net.ParseAddress(RemoteAddress))
}
return &PacketWriter{
PacketConnWrapper: c,
Counter: counter,
Handler: h,
Context: ctx,
UDPOverride: UDPOverride,
resolvedUDPAddr: resolvedUDPAddr,
}
}
@ -346,6 +356,12 @@ type PacketWriter struct {
*Handler
context.Context
UDPOverride net.Destination
// Dest of udp packets might be a domain, we will resolve them to IP
// But resolver will return a random one if the domain has many IPs
// Resulting in these packets being sent to many different IPs randomly
// So, cache and keep the resolve result
resolvedUDPAddr *utils.TypedSyncMap[string, net.Address]
}
func (w *PacketWriter) WriteMultiBuffer(mb buf.MultiBuffer) error {
@ -364,10 +380,34 @@ func (w *PacketWriter) WriteMultiBuffer(mb buf.MultiBuffer) error {
if w.UDPOverride.Port != 0 {
b.UDP.Port = w.UDPOverride.Port
}
if w.Handler.config.hasStrategy() && b.UDP.Address.Family().IsDomain() {
ip := w.Handler.resolveIP(w.Context, b.UDP.Address.Domain(), nil)
if ip != nil {
if b.UDP.Address.Family().IsDomain() {
if ip, ok := w.resolvedUDPAddr.Load(b.UDP.Address.Domain()); ok {
b.UDP.Address = ip
} else {
ShouldUseSystemResolver := true
if w.Handler.config.hasStrategy() {
ip = w.Handler.resolveIP(w.Context, b.UDP.Address.Domain(), nil)
if ip != nil {
ShouldUseSystemResolver = false
}
// drop packet if resolve failed when forceIP
if ip == nil && w.Handler.config.forceIP() {
b.Release()
continue
}
}
if ShouldUseSystemResolver {
udpAddr, err := net.ResolveUDPAddr("udp", b.UDP.NetAddr())
if err != nil {
b.Release()
continue
} else {
ip = net.IPAddress(udpAddr.IP)
}
}
if ip != nil {
b.UDP.Address, _ = w.resolvedUDPAddr.LoadOrStore(b.UDP.Address.Domain(), ip)
}
}
}
destAddr, _ := net.ResolveUDPAddr("udp", b.UDP.NetAddr())