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Minor fixes

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This commit is contained in:
世界 2026-07-07 15:36:21 +08:00
parent 14c8f75f7a
commit c17af6ee8c
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GPG key ID: CD109927C34A63C4
13 changed files with 357 additions and 181 deletions
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136
stack_system.go
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@ -9,6 +9,7 @@ import (
"syscall"
"time"
"github.com/sagernet/sing-tun/gtcpip"
"github.com/sagernet/sing-tun/gtcpip/checksum"
"github.com/sagernet/sing-tun/gtcpip/header"
"github.com/sagernet/sing/common"
@ -448,36 +449,30 @@ func (s *System) processIPv4TCP(ipHdr header.IPv4, tcpHdr header.TCP) (bool, err
if session == nil {
return false, E.New("ipv4: tcp: session not found: ", destination.Port())
}
ipHdr.SetSourceAddr(session.Destination.Addr())
tcpHdr.SetSourcePort(session.Destination.Port())
ipHdr.SetDestinationAddr(session.Source.Addr())
tcpHdr.SetDestinationPort(session.Source.Port())
rewriteIPv4TCP(ipHdr, tcpHdr, s.txChecksumOffload,
session.Destination.Addr(), session.Destination.Port(), true,
session.Source.Addr(), session.Source.Port(), true)
} else {
var loopback bool
for _, inet4LoopbackAddress := range s.inet4LoopbackAddress {
if destination.Addr() == inet4LoopbackAddress {
ipHdr.SetDestinationAddr(ipHdr.SourceAddr())
ipHdr.SetSourceAddr(inet4LoopbackAddress)
rewriteIPv4TCP(ipHdr, tcpHdr, s.txChecksumOffload,
inet4LoopbackAddress, 0, false,
source.Addr(), 0, false)
loopback = true
break
}
}
if !loopback {
natPort := s.tcpNat.Lookup(source, destination)
ipHdr.SetSourceAddr(s.inet4NextAddress)
tcpHdr.SetSourcePort(natPort)
ipHdr.SetDestinationAddr(s.inet4Address)
tcpHdr.SetDestinationPort(s.tcpPort)
if natPort == 0 {
return false, E.New("ipv4: tcp: NAT port space exhausted")
}
rewriteIPv4TCP(ipHdr, tcpHdr, s.txChecksumOffload,
s.inet4NextAddress, natPort, true,
s.inet4Address, s.tcpPort, true)
}
}
if !s.txChecksumOffload {
tcpHdr.SetChecksum(^checksum.Checksum(tcpHdr.Payload(), tcpHdr.CalculateChecksum(
header.PseudoHeaderChecksum(header.TCPProtocolNumber, ipHdr.SourceAddressSlice(), ipHdr.DestinationAddressSlice(), ipHdr.PayloadLength()),
)))
} else {
tcpHdr.SetChecksum(0)
}
ipHdr.SetChecksum(^ipHdr.CalculateChecksum())
return true, nil
}
@ -491,38 +486,109 @@ func (s *System) processIPv6TCP(ipHdr header.IPv6, tcpHdr header.TCP) (bool, err
if session == nil {
return false, E.New("ipv6: tcp: session not found: ", destination.Port())
}
ipHdr.SetSourceAddr(session.Destination.Addr())
tcpHdr.SetSourcePort(session.Destination.Port())
ipHdr.SetDestinationAddr(session.Source.Addr())
tcpHdr.SetDestinationPort(session.Source.Port())
rewriteIPv6TCP(ipHdr, tcpHdr, s.txChecksumOffload,
session.Destination.Addr(), session.Destination.Port(), true,
session.Source.Addr(), session.Source.Port(), true)
} else {
var loopback bool
for _, inet6LoopbackAddress := range s.inet6LoopbackAddress {
if destination.Addr() == inet6LoopbackAddress {
ipHdr.SetDestinationAddr(ipHdr.SourceAddr())
ipHdr.SetSourceAddr(inet6LoopbackAddress)
rewriteIPv6TCP(ipHdr, tcpHdr, s.txChecksumOffload,
inet6LoopbackAddress, 0, false,
source.Addr(), 0, false)
loopback = true
break
}
}
if !loopback {
natPort := s.tcpNat.Lookup(source, destination)
ipHdr.SetSourceAddr(s.inet6NextAddress)
tcpHdr.SetSourcePort(natPort)
ipHdr.SetDestinationAddr(s.inet6Address)
tcpHdr.SetDestinationPort(s.tcpPort6)
if natPort == 0 {
return false, E.New("ipv6: tcp: NAT port space exhausted")
}
rewriteIPv6TCP(ipHdr, tcpHdr, s.txChecksumOffload,
s.inet6NextAddress, natPort, true,
s.inet6Address, s.tcpPort6, true)
}
}
if !s.txChecksumOffload {
tcpHdr.SetChecksum(^checksum.Checksum(tcpHdr.Payload(), tcpHdr.CalculateChecksum(
header.PseudoHeaderChecksum(header.TCPProtocolNumber, ipHdr.SourceAddressSlice(), ipHdr.DestinationAddressSlice(), ipHdr.PayloadLength()),
)))
} else {
tcpHdr.SetChecksum(0)
}
return true, nil
}
func rewriteIPv4TCP(ipHdr header.IPv4, tcpHdr header.TCP, txChecksumOffload bool,
newSource netip.Addr, newSourcePort uint16, rewriteSourcePort bool,
newDestination netip.Addr, newDestinationPort uint16, rewriteDestinationPort bool,
) {
oldSource := ipHdr.SourceAddress()
oldDestination := ipHdr.DestinationAddress()
newSourceAddr := tcpip.AddrFrom4(newSource.As4())
newDestinationAddr := tcpip.AddrFrom4(newDestination.As4())
if newSourceAddr != oldSource {
ipHdr.SetSourceAddressWithChecksumUpdate(newSourceAddr)
if !txChecksumOffload {
tcpHdr.UpdateChecksumPseudoHeaderAddress(oldSource, newSourceAddr, true)
}
}
if newDestinationAddr != oldDestination {
ipHdr.SetDestinationAddressWithChecksumUpdate(newDestinationAddr)
if !txChecksumOffload {
tcpHdr.UpdateChecksumPseudoHeaderAddress(oldDestination, newDestinationAddr, true)
}
}
if txChecksumOffload {
if rewriteSourcePort {
tcpHdr.SetSourcePort(newSourcePort)
}
if rewriteDestinationPort {
tcpHdr.SetDestinationPort(newDestinationPort)
}
tcpHdr.SetChecksum(0)
} else {
if rewriteSourcePort {
tcpHdr.SetSourcePortWithChecksumUpdate(newSourcePort)
}
if rewriteDestinationPort {
tcpHdr.SetDestinationPortWithChecksumUpdate(newDestinationPort)
}
}
}
func rewriteIPv6TCP(ipHdr header.IPv6, tcpHdr header.TCP, txChecksumOffload bool,
newSource netip.Addr, newSourcePort uint16, rewriteSourcePort bool,
newDestination netip.Addr, newDestinationPort uint16, rewriteDestinationPort bool,
) {
oldSource := ipHdr.SourceAddress()
oldDestination := ipHdr.DestinationAddress()
newSourceAddr := tcpip.AddrFrom16(newSource.As16())
newDestinationAddr := tcpip.AddrFrom16(newDestination.As16())
if newSourceAddr != oldSource {
ipHdr.SetSourceAddress(newSourceAddr)
if !txChecksumOffload {
tcpHdr.UpdateChecksumPseudoHeaderAddress(oldSource, newSourceAddr, true)
}
}
if newDestinationAddr != oldDestination {
ipHdr.SetDestinationAddress(newDestinationAddr)
if !txChecksumOffload {
tcpHdr.UpdateChecksumPseudoHeaderAddress(oldDestination, newDestinationAddr, true)
}
}
if txChecksumOffload {
if rewriteSourcePort {
tcpHdr.SetSourcePort(newSourcePort)
}
if rewriteDestinationPort {
tcpHdr.SetDestinationPort(newDestinationPort)
}
tcpHdr.SetChecksum(0)
} else {
if rewriteSourcePort {
tcpHdr.SetSourcePortWithChecksumUpdate(newSourcePort)
}
if rewriteDestinationPort {
tcpHdr.SetDestinationPortWithChecksumUpdate(newDestinationPort)
}
}
}
func (s *System) processIPv4UDP(ipHdr header.IPv4, udpHdr header.UDP) error {
if ipHdr.Flags()&header.IPv4FlagMoreFragments != 0 {
return E.New("ipv4: fragment dropped")