56 lines
1.3 KiB
Go
56 lines
1.3 KiB
Go
package fakeip
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import (
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"github.com/sagernet/sing/common/buf"
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M "github.com/sagernet/sing/common/metadata"
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N "github.com/sagernet/sing/common/network"
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)
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var _ N.PacketConn = (*NATPacketConn)(nil)
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type NATPacketConn struct {
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N.PacketConn
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origin M.Socksaddr
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destination M.Socksaddr
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}
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func NewNATPacketConn(conn N.PacketConn, origin M.Socksaddr, destination M.Socksaddr) *NATPacketConn {
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return &NATPacketConn{
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PacketConn: conn,
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origin: socksaddrWithoutPort(origin),
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destination: socksaddrWithoutPort(destination),
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}
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}
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func (c *NATPacketConn) ReadPacket(buffer *buf.Buffer) (destination M.Socksaddr, err error) {
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destination, err = c.PacketConn.ReadPacket(buffer)
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if socksaddrWithoutPort(destination) == c.origin {
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destination = M.Socksaddr{
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Addr: c.destination.Addr,
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Fqdn: c.destination.Fqdn,
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Port: destination.Port,
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}
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}
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return
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}
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func (c *NATPacketConn) WritePacket(buffer *buf.Buffer, destination M.Socksaddr) error {
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if socksaddrWithoutPort(destination) == c.destination {
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destination = M.Socksaddr{
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Addr: c.origin.Addr,
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Fqdn: c.origin.Fqdn,
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Port: destination.Port,
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}
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}
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return c.PacketConn.WritePacket(buffer, destination)
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}
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func (c *NATPacketConn) Upstream() any {
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return c.PacketConn
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}
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func socksaddrWithoutPort(destination M.Socksaddr) M.Socksaddr {
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destination.Port = 0
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return destination
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}
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