github.com/inazumav/sing-box@v0.0.0-20230926072359-ab51429a14f1/adapter/upstream.go (about)

     1  package adapter
     2  
     3  import (
     4  	"context"
     5  	"net"
     6  
     7  	E "github.com/sagernet/sing/common/exceptions"
     8  	M "github.com/sagernet/sing/common/metadata"
     9  	N "github.com/sagernet/sing/common/network"
    10  )
    11  
    12  type (
    13  	ConnectionHandlerFunc       = func(ctx context.Context, conn net.Conn, metadata InboundContext) error
    14  	PacketConnectionHandlerFunc = func(ctx context.Context, conn N.PacketConn, metadata InboundContext) error
    15  )
    16  
    17  func NewUpstreamHandler(
    18  	metadata InboundContext,
    19  	connectionHandler ConnectionHandlerFunc,
    20  	packetHandler PacketConnectionHandlerFunc,
    21  	errorHandler E.Handler,
    22  ) UpstreamHandlerAdapter {
    23  	return &myUpstreamHandlerWrapper{
    24  		metadata:          metadata,
    25  		connectionHandler: connectionHandler,
    26  		packetHandler:     packetHandler,
    27  		errorHandler:      errorHandler,
    28  	}
    29  }
    30  
    31  var _ UpstreamHandlerAdapter = (*myUpstreamHandlerWrapper)(nil)
    32  
    33  type myUpstreamHandlerWrapper struct {
    34  	metadata          InboundContext
    35  	connectionHandler ConnectionHandlerFunc
    36  	packetHandler     PacketConnectionHandlerFunc
    37  	errorHandler      E.Handler
    38  }
    39  
    40  func (w *myUpstreamHandlerWrapper) NewConnection(ctx context.Context, conn net.Conn, metadata M.Metadata) error {
    41  	myMetadata := w.metadata
    42  	if metadata.Source.IsValid() {
    43  		myMetadata.Source = metadata.Source
    44  	}
    45  	if metadata.Destination.IsValid() {
    46  		myMetadata.Destination = metadata.Destination
    47  	}
    48  	return w.connectionHandler(ctx, conn, myMetadata)
    49  }
    50  
    51  func (w *myUpstreamHandlerWrapper) NewPacketConnection(ctx context.Context, conn N.PacketConn, metadata M.Metadata) error {
    52  	myMetadata := w.metadata
    53  	if metadata.Source.IsValid() {
    54  		myMetadata.Source = metadata.Source
    55  	}
    56  	if metadata.Destination.IsValid() {
    57  		myMetadata.Destination = metadata.Destination
    58  	}
    59  	return w.packetHandler(ctx, conn, myMetadata)
    60  }
    61  
    62  func (w *myUpstreamHandlerWrapper) NewError(ctx context.Context, err error) {
    63  	w.errorHandler.NewError(ctx, err)
    64  }
    65  
    66  func UpstreamMetadata(metadata InboundContext) M.Metadata {
    67  	return M.Metadata{
    68  		Source:      metadata.Source,
    69  		Destination: metadata.Destination,
    70  	}
    71  }
    72  
    73  type myUpstreamContextHandlerWrapper struct {
    74  	connectionHandler ConnectionHandlerFunc
    75  	packetHandler     PacketConnectionHandlerFunc
    76  	errorHandler      E.Handler
    77  }
    78  
    79  func NewUpstreamContextHandler(
    80  	connectionHandler ConnectionHandlerFunc,
    81  	packetHandler PacketConnectionHandlerFunc,
    82  	errorHandler E.Handler,
    83  ) UpstreamHandlerAdapter {
    84  	return &myUpstreamContextHandlerWrapper{
    85  		connectionHandler: connectionHandler,
    86  		packetHandler:     packetHandler,
    87  		errorHandler:      errorHandler,
    88  	}
    89  }
    90  
    91  func (w *myUpstreamContextHandlerWrapper) NewConnection(ctx context.Context, conn net.Conn, metadata M.Metadata) error {
    92  	myMetadata := ContextFrom(ctx)
    93  	if metadata.Source.IsValid() {
    94  		myMetadata.Source = metadata.Source
    95  	}
    96  	if metadata.Destination.IsValid() {
    97  		myMetadata.Destination = metadata.Destination
    98  	}
    99  	return w.connectionHandler(ctx, conn, *myMetadata)
   100  }
   101  
   102  func (w *myUpstreamContextHandlerWrapper) NewPacketConnection(ctx context.Context, conn N.PacketConn, metadata M.Metadata) error {
   103  	myMetadata := ContextFrom(ctx)
   104  	if metadata.Source.IsValid() {
   105  		myMetadata.Source = metadata.Source
   106  	}
   107  	if metadata.Destination.IsValid() {
   108  		myMetadata.Destination = metadata.Destination
   109  	}
   110  	return w.packetHandler(ctx, conn, *myMetadata)
   111  }
   112  
   113  func (w *myUpstreamContextHandlerWrapper) NewError(ctx context.Context, err error) {
   114  	w.errorHandler.NewError(ctx, err)
   115  }