sing-box/adapter/upstream.go
2022-07-05 13:23:47 +08:00

115 lines
3.3 KiB
Go

package adapter
import (
"context"
"net"
E "github.com/sagernet/sing/common/exceptions"
M "github.com/sagernet/sing/common/metadata"
N "github.com/sagernet/sing/common/network"
)
type (
ConnectionHandlerFunc = func(ctx context.Context, conn net.Conn, metadata InboundContext) error
PacketConnectionHandlerFunc = func(ctx context.Context, conn N.PacketConn, metadata InboundContext) error
)
func NewUpstreamHandler(
metadata InboundContext,
connectionHandler ConnectionHandlerFunc,
packetHandler PacketConnectionHandlerFunc,
errorHandler E.Handler,
) UpstreamHandlerAdapter {
return &myUpstreamHandlerWrapper{
metadata: metadata,
connectionHandler: connectionHandler,
packetHandler: packetHandler,
errorHandler: errorHandler,
}
}
var _ UpstreamHandlerAdapter = (*myUpstreamHandlerWrapper)(nil)
type myUpstreamHandlerWrapper struct {
metadata InboundContext
connectionHandler ConnectionHandlerFunc
packetHandler PacketConnectionHandlerFunc
errorHandler E.Handler
}
func (w *myUpstreamHandlerWrapper) NewConnection(ctx context.Context, conn net.Conn, metadata M.Metadata) error {
w.metadata.Destination = metadata.Destination
return w.connectionHandler(ctx, conn, w.metadata)
}
func (w *myUpstreamHandlerWrapper) NewPacketConnection(ctx context.Context, conn N.PacketConn, metadata M.Metadata) error {
w.metadata.Destination = metadata.Destination
return w.packetHandler(ctx, conn, w.metadata)
}
func (w *myUpstreamHandlerWrapper) NewError(ctx context.Context, err error) {
w.errorHandler.NewError(ctx, err)
}
var myContextType = (*MetadataContext)(nil)
type MetadataContext struct {
context.Context
Metadata InboundContext
}
func (c *MetadataContext) Value(key any) any {
if key == myContextType {
return c
}
return c.Context.Value(key)
}
func ContextWithMetadata(ctx context.Context, metadata InboundContext) context.Context {
return &MetadataContext{
Context: ctx,
Metadata: metadata,
}
}
func UpstreamMetadata(metadata InboundContext) M.Metadata {
return M.Metadata{
Source: metadata.Source,
Destination: metadata.Destination,
}
}
type myUpstreamContextHandlerWrapper struct {
connectionHandler ConnectionHandlerFunc
packetHandler PacketConnectionHandlerFunc
errorHandler E.Handler
}
func NewUpstreamContextHandler(
connectionHandler ConnectionHandlerFunc,
packetHandler PacketConnectionHandlerFunc,
errorHandler E.Handler,
) UpstreamHandlerAdapter {
return &myUpstreamContextHandlerWrapper{
connectionHandler: connectionHandler,
packetHandler: packetHandler,
errorHandler: errorHandler,
}
}
func (w *myUpstreamContextHandlerWrapper) NewConnection(ctx context.Context, conn net.Conn, metadata M.Metadata) error {
myCtx := ctx.Value(myContextType).(*MetadataContext)
myCtx.Metadata.Destination = metadata.Destination
return w.connectionHandler(ctx, conn, myCtx.Metadata)
}
func (w *myUpstreamContextHandlerWrapper) NewPacketConnection(ctx context.Context, conn N.PacketConn, metadata M.Metadata) error {
myCtx := ctx.Value(myContextType).(*MetadataContext)
myCtx.Metadata.Destination = metadata.Destination
return w.packetHandler(ctx, conn, myCtx.Metadata)
}
func (w *myUpstreamContextHandlerWrapper) NewError(ctx context.Context, err error) {
w.errorHandler.NewError(ctx, err)
}