sing-box/route/dns.go
2024-11-09 18:41:11 +08:00

92 lines
2.8 KiB
Go

package route
import (
"context"
"net"
"time"
"github.com/sagernet/sing-box/adapter"
C "github.com/sagernet/sing-box/constant"
dnsOutbound "github.com/sagernet/sing-box/protocol/dns"
"github.com/sagernet/sing-dns"
"github.com/sagernet/sing/common/buf"
E "github.com/sagernet/sing/common/exceptions"
M "github.com/sagernet/sing/common/metadata"
N "github.com/sagernet/sing/common/network"
"github.com/sagernet/sing/common/udpnat2"
mDNS "github.com/miekg/dns"
)
func (r *Router) hijackDNSStream(ctx context.Context, conn net.Conn, metadata adapter.InboundContext) error {
metadata.Destination = M.Socksaddr{}
for {
conn.SetReadDeadline(time.Now().Add(C.DNSTimeout))
err := dnsOutbound.HandleStreamDNSRequest(ctx, r, conn, metadata)
if err != nil {
return err
}
}
}
func (r *Router) hijackDNSPacket(ctx context.Context, conn N.PacketConn, packetBuffers []*N.PacketBuffer, metadata adapter.InboundContext) {
if uConn, isUDPNAT2 := conn.(*udpnat.Conn); isUDPNAT2 {
metadata.Destination = M.Socksaddr{}
for _, packet := range packetBuffers {
buffer := packet.Buffer
destination := packet.Destination
N.PutPacketBuffer(packet)
go ExchangeDNSPacket(ctx, r, uConn, buffer, metadata, destination)
}
uConn.SetHandler(&dnsHijacker{
router: r,
conn: conn,
ctx: ctx,
metadata: metadata,
})
return
}
err := dnsOutbound.NewDNSPacketConnection(ctx, r, conn, packetBuffers, metadata)
if err != nil && !E.IsClosedOrCanceled(err) {
r.dnsLogger.ErrorContext(ctx, E.Cause(err, "process packet connection"))
}
}
func ExchangeDNSPacket(ctx context.Context, router *Router, conn N.PacketConn, buffer *buf.Buffer, metadata adapter.InboundContext, destination M.Socksaddr) {
err := exchangeDNSPacket(ctx, router, conn, buffer, metadata, destination)
if err != nil && !E.IsClosedOrCanceled(err) {
router.dnsLogger.ErrorContext(ctx, E.Cause(err, "process packet connection"))
}
}
func exchangeDNSPacket(ctx context.Context, router *Router, conn N.PacketConn, buffer *buf.Buffer, metadata adapter.InboundContext, destination M.Socksaddr) error {
var message mDNS.Msg
err := message.Unpack(buffer.Bytes())
buffer.Release()
if err != nil {
return E.Cause(err, "unpack request")
}
response, err := router.Exchange(adapter.WithContext(ctx, &metadata), &message)
if err != nil {
return err
}
responseBuffer, err := dns.TruncateDNSMessage(&message, response, 1024)
if err != nil {
return err
}
err = conn.WritePacket(responseBuffer, destination)
responseBuffer.Release()
return err
}
type dnsHijacker struct {
router *Router
conn N.PacketConn
ctx context.Context
metadata adapter.InboundContext
}
func (h *dnsHijacker) NewPacketEx(buffer *buf.Buffer, destination M.Socksaddr) {
go ExchangeDNSPacket(h.ctx, h.router, h.conn, buffer, h.metadata, destination)
}