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Add loopback address support

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世界 2025-06-09 18:51:17 +08:00
parent f57754918d
commit 5e343c4b66
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GPG key ID: CD109927C34A63C4
7 changed files with 524 additions and 183 deletions
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138
stack_system.go
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@ -23,30 +23,32 @@ import (
var ErrIncludeAllNetworks = E.New("`system` and `mixed` stack are not available when `includeAllNetworks` is enabled. See https://github.com/SagerNet/sing-tun/issues/25")
type System struct {
ctx context.Context
tun Tun
tunName string
mtu int
handler Handler
logger logger.Logger
inet4Prefixes []netip.Prefix
inet6Prefixes []netip.Prefix
inet4ServerAddress netip.Addr
inet4Address netip.Addr
inet6ServerAddress netip.Addr
inet6Address netip.Addr
broadcastAddr netip.Addr
udpTimeout time.Duration
tcpListener net.Listener
tcpListener6 net.Listener
tcpPort uint16
tcpPort6 uint16
tcpNat *TCPNat
udpNat *udpnat.Service
bindInterface bool
interfaceFinder control.InterfaceFinder
frontHeadroom int
txChecksumOffload bool
ctx context.Context
tun Tun
tunName string
mtu int
handler Handler
logger logger.Logger
inet4Prefixes []netip.Prefix
inet6Prefixes []netip.Prefix
inet4ServerAddress netip.Addr
inet4Address netip.Addr
inet6ServerAddress netip.Addr
inet6Address netip.Addr
broadcastAddr netip.Addr
inet4LoopbackAddress []netip.Addr
inet6LoopbackAddress []netip.Addr
udpTimeout time.Duration
tcpListener net.Listener
tcpListener6 net.Listener
tcpPort uint16
tcpPort6 uint16
tcpNat *TCPNat
udpNat *udpnat.Service
bindInterface bool
interfaceFinder control.InterfaceFinder
frontHeadroom int
txChecksumOffload bool
}
type Session struct {
@ -58,18 +60,20 @@ type Session struct {
func NewSystem(options StackOptions) (Stack, error) {
stack := &System{
ctx: options.Context,
tun: options.Tun,
tunName: options.TunOptions.Name,
mtu: int(options.TunOptions.MTU),
udpTimeout: options.UDPTimeout,
handler: options.Handler,
logger: options.Logger,
inet4Prefixes: options.TunOptions.Inet4Address,
inet6Prefixes: options.TunOptions.Inet6Address,
broadcastAddr: BroadcastAddr(options.TunOptions.Inet4Address),
bindInterface: options.ForwarderBindInterface,
interfaceFinder: options.InterfaceFinder,
ctx: options.Context,
tun: options.Tun,
tunName: options.TunOptions.Name,
mtu: int(options.TunOptions.MTU),
inet4LoopbackAddress: options.TunOptions.Inet4LoopbackAddress,
inet6LoopbackAddress: options.TunOptions.Inet6LoopbackAddress,
udpTimeout: options.UDPTimeout,
handler: options.Handler,
logger: options.Logger,
inet4Prefixes: options.TunOptions.Inet4Address,
inet6Prefixes: options.TunOptions.Inet6Address,
broadcastAddr: BroadcastAddr(options.TunOptions.Inet4Address),
bindInterface: options.ForwarderBindInterface,
interfaceFinder: options.InterfaceFinder,
}
if len(options.TunOptions.Inet4Address) > 0 {
if !HasNextAddress(options.TunOptions.Inet4Address[0], 1) {
@ -353,18 +357,29 @@ func (s *System) processIPv4TCP(ipHdr header.IPv4, tcpHdr header.TCP) (bool, err
ipHdr.SetDestinationAddr(session.Source.Addr())
tcpHdr.SetDestinationPort(session.Source.Port())
} else {
natPort, err := s.tcpNat.Lookup(source, destination, s.handler)
if err != nil {
if errors.Is(err, ErrDrop) {
return false, nil
} else {
return false, s.resetIPv4TCP(ipHdr, tcpHdr)
var loopback bool
for _, inet4LoopbackAddress := range s.inet4LoopbackAddress {
if destination.Addr() == inet4LoopbackAddress {
ipHdr.SetDestinationAddr(ipHdr.SourceAddr())
ipHdr.SetSourceAddr(inet4LoopbackAddress)
loopback = true
break
}
}
ipHdr.SetSourceAddr(s.inet4Address)
tcpHdr.SetSourcePort(natPort)
ipHdr.SetDestinationAddr(s.inet4ServerAddress)
tcpHdr.SetDestinationPort(s.tcpPort)
if !loopback {
natPort, err := s.tcpNat.Lookup(source, destination, s.handler)
if err != nil {
if errors.Is(err, ErrDrop) {
return false, nil
} else {
return false, s.resetIPv4TCP(ipHdr, tcpHdr)
}
}
ipHdr.SetSourceAddr(s.inet4Address)
tcpHdr.SetSourcePort(natPort)
ipHdr.SetDestinationAddr(s.inet4ServerAddress)
tcpHdr.SetDestinationPort(s.tcpPort)
}
}
if !s.txChecksumOffload {
tcpHdr.SetChecksum(0)
@ -440,18 +455,29 @@ func (s *System) processIPv6TCP(ipHdr header.IPv6, tcpHdr header.TCP) (bool, err
ipHdr.SetDestinationAddr(session.Source.Addr())
tcpHdr.SetDestinationPort(session.Source.Port())
} else {
natPort, err := s.tcpNat.Lookup(source, destination, s.handler)
if err != nil {
if errors.Is(err, ErrDrop) {
return false, nil
} else {
return false, s.resetIPv6TCP(ipHdr, tcpHdr)
var loopback bool
for _, inet6LoopbackAddress := range s.inet6LoopbackAddress {
if destination.Addr() == inet6LoopbackAddress {
ipHdr.SetDestinationAddr(ipHdr.SourceAddr())
ipHdr.SetSourceAddr(inet6LoopbackAddress)
loopback = true
break
}
}
ipHdr.SetSourceAddr(s.inet6Address)
tcpHdr.SetSourcePort(natPort)
ipHdr.SetDestinationAddr(s.inet6ServerAddress)
tcpHdr.SetDestinationPort(s.tcpPort6)
if !loopback {
natPort, err := s.tcpNat.Lookup(source, destination, s.handler)
if err != nil {
if errors.Is(err, ErrDrop) {
return false, nil
} else {
return false, s.resetIPv6TCP(ipHdr, tcpHdr)
}
}
ipHdr.SetSourceAddr(s.inet6Address)
tcpHdr.SetSourcePort(natPort)
ipHdr.SetDestinationAddr(s.inet6ServerAddress)
tcpHdr.SetDestinationPort(s.tcpPort6)
}
}
if !s.txChecksumOffload {
tcpHdr.SetChecksum(0)