diff options
-rw-r--r-- | pkg/tcpip/network/internal/ip/duplicate_address_detection.go | 2 | ||||
-rw-r--r-- | pkg/tcpip/network/ipv4/ipv4.go | 76 | ||||
-rw-r--r-- | pkg/tcpip/network/ipv6/icmp.go | 6 | ||||
-rw-r--r-- | pkg/tcpip/network/ipv6/ipv6.go | 82 | ||||
-rw-r--r-- | pkg/tcpip/network/ipv6/ndp.go | 4 | ||||
-rw-r--r-- | pkg/tcpip/stack/nic.go | 29 | ||||
-rw-r--r-- | pkg/tcpip/stack/registration.go | 6 | ||||
-rw-r--r-- | pkg/tcpip/stack/route.go | 2 | ||||
-rw-r--r-- | pkg/tcpip/stack/stack.go | 145 |
9 files changed, 216 insertions, 136 deletions
diff --git a/pkg/tcpip/network/internal/ip/duplicate_address_detection.go b/pkg/tcpip/network/internal/ip/duplicate_address_detection.go index eed49f5d2..5123b7d6a 100644 --- a/pkg/tcpip/network/internal/ip/duplicate_address_detection.go +++ b/pkg/tcpip/network/internal/ip/duplicate_address_detection.go @@ -83,6 +83,8 @@ func (d *DAD) Init(protocolMU sync.Locker, configs stack.DADConfigurations, opts panic(fmt.Sprintf("given a non-zero value for NonceSize (%d) but zero for ExtendDADTransmits", opts.NonceSize)) } + configs.Validate() + *d = DAD{ opts: opts, configs: configs, diff --git a/pkg/tcpip/network/ipv4/ipv4.go b/pkg/tcpip/network/ipv4/ipv4.go index 049811cbb..23178277a 100644 --- a/pkg/tcpip/network/ipv4/ipv4.go +++ b/pkg/tcpip/network/ipv4/ipv4.go @@ -63,9 +63,15 @@ const ( fragmentblockSize = 8 ) +const ( + forwardingDisabled = 0 + forwardingEnabled = 1 +) + var ipv4BroadcastAddr = header.IPv4Broadcast.WithPrefix() var _ stack.LinkResolvableNetworkEndpoint = (*endpoint)(nil) +var _ stack.ForwardingNetworkEndpoint = (*endpoint)(nil) var _ stack.GroupAddressableEndpoint = (*endpoint)(nil) var _ stack.AddressableEndpoint = (*endpoint)(nil) var _ stack.NetworkEndpoint = (*endpoint)(nil) @@ -82,6 +88,12 @@ type endpoint struct { // Must be accessed using atomic operations. enabled uint32 + // forwarding is set to forwardingEnabled when the endpoint has forwarding + // enabled and forwardingDisabled when it is disabled. + // + // Must be accessed using atomic operations. + forwarding uint32 + mu struct { sync.RWMutex @@ -151,14 +163,32 @@ func (p *protocol) forgetEndpoint(nicID tcpip.NICID) { delete(p.mu.eps, nicID) } -// transitionForwarding transitions the endpoint's forwarding status to -// forwarding. +// Forwarding implements stack.ForwardingNetworkEndpoint. +func (e *endpoint) Forwarding() bool { + return atomic.LoadUint32(&e.forwarding) == forwardingEnabled +} + +// setForwarding sets the forwarding status for the endpoint. // -// Must only be called when the forwarding status changes. -func (e *endpoint) transitionForwarding(forwarding bool) { +// Returns true if the forwarding status was updated. +func (e *endpoint) setForwarding(v bool) bool { + forwarding := uint32(forwardingDisabled) + if v { + forwarding = forwardingEnabled + } + + return atomic.SwapUint32(&e.forwarding, forwarding) != forwarding +} + +// SetForwarding implements stack.ForwardingNetworkEndpoint. +func (e *endpoint) SetForwarding(forwarding bool) { e.mu.Lock() defer e.mu.Unlock() + if !e.setForwarding(forwarding) { + return + } + if forwarding { // There does not seem to be an RFC requirement for a node to join the all // routers multicast address but @@ -852,7 +882,7 @@ func (e *endpoint) handleValidatedPacket(h header.IPv4, pkt *stack.PacketBuffer) addressEndpoint.DecRef() pkt.NetworkPacketInfo.LocalAddressBroadcast = subnet.IsBroadcast(dstAddr) || dstAddr == header.IPv4Broadcast } else if !e.IsInGroup(dstAddr) { - if !e.protocol.Forwarding() { + if !e.Forwarding() { stats.ip.InvalidDestinationAddressesReceived.Increment() return } @@ -1144,7 +1174,6 @@ func (e *endpoint) Stats() stack.NetworkEndpointStats { return &e.stats.localStats } -var _ stack.ForwardingNetworkProtocol = (*protocol)(nil) var _ stack.NetworkProtocol = (*protocol)(nil) var _ fragmentation.TimeoutHandler = (*protocol)(nil) @@ -1165,12 +1194,6 @@ type protocol struct { // Must be accessed using atomic operations. defaultTTL uint32 - // forwarding is set to 1 when the protocol has forwarding enabled and 0 - // when it is disabled. - // - // Must be accessed using atomic operations. - forwarding uint32 - ids []uint32 hashIV uint32 @@ -1283,35 +1306,6 @@ func (*protocol) Parse(pkt *stack.PacketBuffer) (proto tcpip.TransportProtocolNu return ipHdr.TransportProtocol(), !ipHdr.More() && ipHdr.FragmentOffset() == 0, true } -// Forwarding implements stack.ForwardingNetworkProtocol. -func (p *protocol) Forwarding() bool { - return uint8(atomic.LoadUint32(&p.forwarding)) == 1 -} - -// setForwarding sets the forwarding status for the protocol. -// -// Returns true if the forwarding status was updated. -func (p *protocol) setForwarding(v bool) bool { - if v { - return atomic.CompareAndSwapUint32(&p.forwarding, 0 /* old */, 1 /* new */) - } - return atomic.CompareAndSwapUint32(&p.forwarding, 1 /* old */, 0 /* new */) -} - -// SetForwarding implements stack.ForwardingNetworkProtocol. -func (p *protocol) SetForwarding(v bool) { - p.mu.Lock() - defer p.mu.Unlock() - - if !p.setForwarding(v) { - return - } - - for _, ep := range p.mu.eps { - ep.transitionForwarding(v) - } -} - // calculateNetworkMTU calculates the network-layer payload MTU based on the // link-layer payload mtu. func calculateNetworkMTU(linkMTU, networkHeaderSize uint32) (uint32, tcpip.Error) { diff --git a/pkg/tcpip/network/ipv6/icmp.go b/pkg/tcpip/network/ipv6/icmp.go index 4051fda07..307e1972d 100644 --- a/pkg/tcpip/network/ipv6/icmp.go +++ b/pkg/tcpip/network/ipv6/icmp.go @@ -745,11 +745,7 @@ func (e *endpoint) handleICMP(pkt *stack.PacketBuffer, hasFragmentHeader bool, r return } - stack := e.protocol.stack - - // Is the networking stack operating as a router? - if !stack.Forwarding(ProtocolNumber) { - // ... No, silently drop the packet. + if !e.Forwarding() { received.routerOnlyPacketsDroppedByHost.Increment() return } diff --git a/pkg/tcpip/network/ipv6/ipv6.go b/pkg/tcpip/network/ipv6/ipv6.go index f0e06f86b..95e11ac51 100644 --- a/pkg/tcpip/network/ipv6/ipv6.go +++ b/pkg/tcpip/network/ipv6/ipv6.go @@ -63,6 +63,11 @@ const ( buckets = 2048 ) +const ( + forwardingDisabled = 0 + forwardingEnabled = 1 +) + // policyTable is the default policy table defined in RFC 6724 section 2.1. // // A more human-readable version: @@ -168,6 +173,7 @@ func getLabel(addr tcpip.Address) uint8 { var _ stack.DuplicateAddressDetector = (*endpoint)(nil) var _ stack.LinkAddressResolver = (*endpoint)(nil) var _ stack.LinkResolvableNetworkEndpoint = (*endpoint)(nil) +var _ stack.ForwardingNetworkEndpoint = (*endpoint)(nil) var _ stack.GroupAddressableEndpoint = (*endpoint)(nil) var _ stack.AddressableEndpoint = (*endpoint)(nil) var _ stack.NetworkEndpoint = (*endpoint)(nil) @@ -187,6 +193,12 @@ type endpoint struct { // Must be accessed using atomic operations. enabled uint32 + // forwarding is set to forwardingEnabled when the endpoint has forwarding + // enabled and forwardingDisabled when it is disabled. + // + // Must be accessed using atomic operations. + forwarding uint32 + mu struct { sync.RWMutex @@ -405,20 +417,38 @@ func (e *endpoint) dupTentativeAddrDetected(addr tcpip.Address, holderLinkAddr t } } -// transitionForwarding transitions the endpoint's forwarding status to -// forwarding. +// Forwarding implements stack.ForwardingNetworkEndpoint. +func (e *endpoint) Forwarding() bool { + return atomic.LoadUint32(&e.forwarding) == forwardingEnabled +} + +// setForwarding sets the forwarding status for the endpoint. // -// Must only be called when the forwarding status changes. -func (e *endpoint) transitionForwarding(forwarding bool) { +// Returns true if the forwarding status was updated. +func (e *endpoint) setForwarding(v bool) bool { + forwarding := uint32(forwardingDisabled) + if v { + forwarding = forwardingEnabled + } + + return atomic.SwapUint32(&e.forwarding, forwarding) != forwarding +} + +// SetForwarding implements stack.ForwardingNetworkEndpoint. +func (e *endpoint) SetForwarding(forwarding bool) { + e.mu.Lock() + defer e.mu.Unlock() + + if !e.setForwarding(forwarding) { + return + } + allRoutersGroups := [...]tcpip.Address{ header.IPv6AllRoutersInterfaceLocalMulticastAddress, header.IPv6AllRoutersLinkLocalMulticastAddress, header.IPv6AllRoutersSiteLocalMulticastAddress, } - e.mu.Lock() - defer e.mu.Unlock() - if forwarding { // As per RFC 4291 section 2.8: // @@ -1109,7 +1139,7 @@ func (e *endpoint) handleValidatedPacket(h header.IPv6, pkt *stack.PacketBuffer) if addressEndpoint := e.AcquireAssignedAddress(dstAddr, e.nic.Promiscuous(), stack.CanBePrimaryEndpoint); addressEndpoint != nil { addressEndpoint.DecRef() } else if !e.IsInGroup(dstAddr) { - if !e.protocol.Forwarding() { + if !e.Forwarding() { stats.InvalidDestinationAddressesReceived.Increment() return } @@ -1932,7 +1962,6 @@ func (e *endpoint) Stats() stack.NetworkEndpointStats { return &e.stats.localStats } -var _ stack.ForwardingNetworkProtocol = (*protocol)(nil) var _ stack.NetworkProtocol = (*protocol)(nil) var _ fragmentation.TimeoutHandler = (*protocol)(nil) @@ -1957,12 +1986,6 @@ type protocol struct { // Must be accessed using atomic operations. defaultTTL uint32 - // forwarding is set to 1 when the protocol has forwarding enabled and 0 - // when it is disabled. - // - // Must be accessed using atomic operations. - forwarding uint32 - fragmentation *fragmentation.Fragmentation } @@ -2137,35 +2160,6 @@ func (*protocol) Parse(pkt *stack.PacketBuffer) (proto tcpip.TransportProtocolNu return proto, !fragMore && fragOffset == 0, true } -// Forwarding implements stack.ForwardingNetworkProtocol. -func (p *protocol) Forwarding() bool { - return uint8(atomic.LoadUint32(&p.forwarding)) == 1 -} - -// setForwarding sets the forwarding status for the protocol. -// -// Returns true if the forwarding status was updated. -func (p *protocol) setForwarding(v bool) bool { - if v { - return atomic.CompareAndSwapUint32(&p.forwarding, 0 /* old */, 1 /* new */) - } - return atomic.CompareAndSwapUint32(&p.forwarding, 1 /* old */, 0 /* new */) -} - -// SetForwarding implements stack.ForwardingNetworkProtocol. -func (p *protocol) SetForwarding(v bool) { - p.mu.Lock() - defer p.mu.Unlock() - - if !p.setForwarding(v) { - return - } - - for _, ep := range p.mu.eps { - ep.transitionForwarding(v) - } -} - // calculateNetworkMTU calculates the network-layer payload MTU based on the // link-layer payload MTU and the length of every IPv6 header. // Note that this is different than the Payload Length field of the IPv6 header, diff --git a/pkg/tcpip/network/ipv6/ndp.go b/pkg/tcpip/network/ipv6/ndp.go index b29fed347..f0ff111c5 100644 --- a/pkg/tcpip/network/ipv6/ndp.go +++ b/pkg/tcpip/network/ipv6/ndp.go @@ -705,7 +705,7 @@ func (ndp *ndpState) handleRA(ip tcpip.Address, ra header.NDPRouterAdvert) { // per-interface basis; it is a protocol-wide configuration, so we check the // protocol's forwarding flag to determine if the IPv6 endpoint is forwarding // packets. - if !ndp.configs.HandleRAs.enabled(ndp.ep.protocol.Forwarding()) { + if !ndp.configs.HandleRAs.enabled(ndp.ep.Forwarding()) { ndp.ep.stats.localStats.UnhandledRouterAdvertisements.Increment() return } @@ -1710,7 +1710,7 @@ func (ndp *ndpState) startSolicitingRouters() { return } - if !ndp.configs.HandleRAs.enabled(ndp.ep.protocol.Forwarding()) { + if !ndp.configs.HandleRAs.enabled(ndp.ep.Forwarding()) { return } diff --git a/pkg/tcpip/stack/nic.go b/pkg/tcpip/stack/nic.go index 8d615500f..dbba2c79f 100644 --- a/pkg/tcpip/stack/nic.go +++ b/pkg/tcpip/stack/nic.go @@ -1000,3 +1000,32 @@ func (n *nic) checkDuplicateAddress(protocol tcpip.NetworkProtocolNumber, addr t return d.CheckDuplicateAddress(addr, h), nil } + +func (n *nic) setForwarding(protocol tcpip.NetworkProtocolNumber, enable bool) tcpip.Error { + ep := n.getNetworkEndpoint(protocol) + if ep == nil { + return &tcpip.ErrUnknownProtocol{} + } + + forwardingEP, ok := ep.(ForwardingNetworkEndpoint) + if !ok { + return &tcpip.ErrNotSupported{} + } + + forwardingEP.SetForwarding(enable) + return nil +} + +func (n *nic) forwarding(protocol tcpip.NetworkProtocolNumber) (bool, tcpip.Error) { + ep := n.getNetworkEndpoint(protocol) + if ep == nil { + return false, &tcpip.ErrUnknownProtocol{} + } + + forwardingEP, ok := ep.(ForwardingNetworkEndpoint) + if !ok { + return false, &tcpip.ErrNotSupported{} + } + + return forwardingEP.Forwarding(), nil +} diff --git a/pkg/tcpip/stack/registration.go b/pkg/tcpip/stack/registration.go index a82c807b4..85bb87b4b 100644 --- a/pkg/tcpip/stack/registration.go +++ b/pkg/tcpip/stack/registration.go @@ -658,9 +658,9 @@ type IPNetworkEndpointStats interface { IPStats() *tcpip.IPStats } -// ForwardingNetworkProtocol is a NetworkProtocol that may forward packets. -type ForwardingNetworkProtocol interface { - NetworkProtocol +// ForwardingNetworkEndpoint is a network endpoint that may forward packets. +type ForwardingNetworkEndpoint interface { + NetworkEndpoint // Forwarding returns the forwarding configuration. Forwarding() bool diff --git a/pkg/tcpip/stack/route.go b/pkg/tcpip/stack/route.go index 8a044c073..f17c04277 100644 --- a/pkg/tcpip/stack/route.go +++ b/pkg/tcpip/stack/route.go @@ -446,7 +446,7 @@ func (r *Route) isValidForOutgoingRLocked() bool { // If the source NIC and outgoing NIC are different, make sure the stack has // forwarding enabled, or the packet will be handled locally. - if r.outgoingNIC != r.localAddressNIC && !r.outgoingNIC.stack.Forwarding(r.NetProto()) && (!r.outgoingNIC.stack.handleLocal || !r.outgoingNIC.hasAddress(r.NetProto(), r.RemoteAddress())) { + if r.outgoingNIC != r.localAddressNIC && !isNICForwarding(r.localAddressNIC, r.NetProto()) && (!r.outgoingNIC.stack.handleLocal || !r.outgoingNIC.hasAddress(r.NetProto(), r.RemoteAddress())) { return false } diff --git a/pkg/tcpip/stack/stack.go b/pkg/tcpip/stack/stack.go index 483a960c8..8814f45a6 100644 --- a/pkg/tcpip/stack/stack.go +++ b/pkg/tcpip/stack/stack.go @@ -95,8 +95,9 @@ type Stack struct { } } - mu sync.RWMutex - nics map[tcpip.NICID]*nic + mu sync.RWMutex + nics map[tcpip.NICID]*nic + defaultForwardingEnabled map[tcpip.NetworkProtocolNumber]struct{} // cleanupEndpointsMu protects cleanupEndpoints. cleanupEndpointsMu sync.Mutex @@ -348,22 +349,23 @@ func New(opts Options) *Stack { } s := &Stack{ - transportProtocols: make(map[tcpip.TransportProtocolNumber]*transportProtocolState), - networkProtocols: make(map[tcpip.NetworkProtocolNumber]NetworkProtocol), - nics: make(map[tcpip.NICID]*nic), - cleanupEndpoints: make(map[TransportEndpoint]struct{}), - PortManager: ports.NewPortManager(), - clock: clock, - stats: opts.Stats.FillIn(), - handleLocal: opts.HandleLocal, - tables: opts.IPTables, - icmpRateLimiter: NewICMPRateLimiter(), - seed: generateRandUint32(), - nudConfigs: opts.NUDConfigs, - uniqueIDGenerator: opts.UniqueID, - nudDisp: opts.NUDDisp, - randomGenerator: mathrand.New(randSrc), - secureRNG: opts.SecureRNG, + transportProtocols: make(map[tcpip.TransportProtocolNumber]*transportProtocolState), + networkProtocols: make(map[tcpip.NetworkProtocolNumber]NetworkProtocol), + nics: make(map[tcpip.NICID]*nic), + defaultForwardingEnabled: make(map[tcpip.NetworkProtocolNumber]struct{}), + cleanupEndpoints: make(map[TransportEndpoint]struct{}), + PortManager: ports.NewPortManager(), + clock: clock, + stats: opts.Stats.FillIn(), + handleLocal: opts.HandleLocal, + tables: opts.IPTables, + icmpRateLimiter: NewICMPRateLimiter(), + seed: generateRandUint32(), + nudConfigs: opts.NUDConfigs, + uniqueIDGenerator: opts.UniqueID, + nudDisp: opts.NUDDisp, + randomGenerator: mathrand.New(randSrc), + secureRNG: opts.SecureRNG, sendBufferSize: tcpip.SendBufferSizeOption{ Min: MinBufferSize, Default: DefaultBufferSize, @@ -492,37 +494,61 @@ func (s *Stack) Stats() tcpip.Stats { return s.stats } -// SetForwardingDefaultAndAllNICs sets packet forwarding for all NICs for the -// passed protocol and sets the default setting for newly created NICs. -func (s *Stack) SetForwardingDefaultAndAllNICs(protocolNum tcpip.NetworkProtocolNumber, enable bool) tcpip.Error { - protocol, ok := s.networkProtocols[protocolNum] +// SetNICForwarding enables or disables packet forwarding on the specified NIC +// for the passed protocol. +func (s *Stack) SetNICForwarding(id tcpip.NICID, protocol tcpip.NetworkProtocolNumber, enable bool) tcpip.Error { + s.mu.RLock() + defer s.mu.RUnlock() + + nic, ok := s.nics[id] if !ok { - return &tcpip.ErrUnknownProtocol{} + return &tcpip.ErrUnknownNICID{} } - forwardingProtocol, ok := protocol.(ForwardingNetworkProtocol) + return nic.setForwarding(protocol, enable) +} + +// NICForwarding returns the forwarding configuration for the specified NIC. +func (s *Stack) NICForwarding(id tcpip.NICID, protocol tcpip.NetworkProtocolNumber) (bool, tcpip.Error) { + s.mu.RLock() + defer s.mu.RUnlock() + + nic, ok := s.nics[id] if !ok { - return &tcpip.ErrNotSupported{} + return false, &tcpip.ErrUnknownNICID{} } - forwardingProtocol.SetForwarding(enable) - return nil + return nic.forwarding(protocol) } -// Forwarding returns true if packet forwarding between NICs is enabled for the -// passed protocol. -func (s *Stack) Forwarding(protocolNum tcpip.NetworkProtocolNumber) bool { - protocol, ok := s.networkProtocols[protocolNum] - if !ok { - return false +// SetForwardingDefaultAndAllNICs sets packet forwarding for all NICs for the +// passed protocol and sets the default setting for newly created NICs. +func (s *Stack) SetForwardingDefaultAndAllNICs(protocol tcpip.NetworkProtocolNumber, enable bool) tcpip.Error { + s.mu.Lock() + defer s.mu.Unlock() + + doneOnce := false + for id, nic := range s.nics { + if err := nic.setForwarding(protocol, enable); err != nil { + // Expect forwarding to be settable on all interfaces if it was set on + // one. + if doneOnce { + panic(fmt.Sprintf("nic(id=%d).setForwarding(%d, %t): %s", id, protocol, enable, err)) + } + + return err + } + + doneOnce = true } - forwardingProtocol, ok := protocol.(ForwardingNetworkProtocol) - if !ok { - return false + if enable { + s.defaultForwardingEnabled[protocol] = struct{}{} + } else { + delete(s.defaultForwardingEnabled, protocol) } - return forwardingProtocol.Forwarding() + return nil } // PortRange returns the UDP and TCP inclusive range of ephemeral ports used in @@ -659,6 +685,11 @@ func (s *Stack) CreateNICWithOptions(id tcpip.NICID, ep LinkEndpoint, opts NICOp } n := newNIC(s, id, opts.Name, ep, opts.Context) + for proto := range s.defaultForwardingEnabled { + if err := n.setForwarding(proto, true); err != nil { + panic(fmt.Sprintf("newNIC(%d, ...).setForwarding(%d, true): %s", id, proto, err)) + } + } s.nics[id] = n if !opts.Disabled { return n.enable() @@ -786,6 +817,10 @@ type NICInfo struct { // value sent in haType field of an ARP Request sent by this NIC and the // value expected in the haType field of an ARP response. ARPHardwareType header.ARPHardwareType + + // Forwarding holds the forwarding status for each network endpoint that + // supports forwarding. + Forwarding map[tcpip.NetworkProtocolNumber]bool } // HasNIC returns true if the NICID is defined in the stack. @@ -815,7 +850,7 @@ func (s *Stack) NICInfo() map[tcpip.NICID]NICInfo { netStats[proto] = netEP.Stats() } - nics[id] = NICInfo{ + info := NICInfo{ Name: nic.name, LinkAddress: nic.LinkEndpoint.LinkAddress(), ProtocolAddresses: nic.primaryAddresses(), @@ -825,7 +860,23 @@ func (s *Stack) NICInfo() map[tcpip.NICID]NICInfo { NetworkStats: netStats, Context: nic.context, ARPHardwareType: nic.LinkEndpoint.ARPHardwareType(), + Forwarding: make(map[tcpip.NetworkProtocolNumber]bool), } + + for proto := range s.networkProtocols { + switch forwarding, err := nic.forwarding(proto); err.(type) { + case nil: + info.Forwarding[proto] = forwarding + case *tcpip.ErrUnknownProtocol: + panic(fmt.Sprintf("expected network protocol %d to be available on NIC %d", proto, nic.ID())) + case *tcpip.ErrNotSupported: + // Not all network protocols support forwarding. + default: + panic(fmt.Sprintf("nic(id=%d).forwarding(%d): %s", nic.ID(), proto, err)) + } + } + + nics[id] = info } return nics } @@ -1029,6 +1080,20 @@ func (s *Stack) HandleLocal() bool { return s.handleLocal } +func isNICForwarding(nic *nic, proto tcpip.NetworkProtocolNumber) bool { + switch forwarding, err := nic.forwarding(proto); err.(type) { + case nil: + return forwarding + case *tcpip.ErrUnknownProtocol: + panic(fmt.Sprintf("expected network protocol %d to be available on NIC %d", proto, nic.ID())) + case *tcpip.ErrNotSupported: + // Not all network protocols support forwarding. + return false + default: + panic(fmt.Sprintf("nic(id=%d).forwarding(%d): %s", nic.ID(), proto, err)) + } +} + // FindRoute creates a route to the given destination address, leaving through // the given NIC and local address (if provided). // @@ -1081,7 +1146,7 @@ func (s *Stack) FindRoute(id tcpip.NICID, localAddr, remoteAddr tcpip.Address, n return nil, &tcpip.ErrNetworkUnreachable{} } - canForward := s.Forwarding(netProto) && !header.IsV6LinkLocalUnicastAddress(localAddr) && !isLinkLocal + onlyGlobalAddresses := !header.IsV6LinkLocalUnicastAddress(localAddr) && !isLinkLocal // Find a route to the remote with the route table. var chosenRoute tcpip.Route @@ -1120,7 +1185,7 @@ func (s *Stack) FindRoute(id tcpip.NICID, localAddr, remoteAddr tcpip.Address, n // requirement to do this from any RFC but simply a choice made to better // follow a strong host model which the netstack follows at the time of // writing. - if canForward && chosenRoute == (tcpip.Route{}) { + if onlyGlobalAddresses && chosenRoute == (tcpip.Route{}) && isNICForwarding(nic, netProto) { chosenRoute = route } } |