diff options
Diffstat (limited to 'pkg/tcpip/stack/route.go')
| -rw-r--r-- | pkg/tcpip/stack/route.go | 100 |
1 files changed, 74 insertions, 26 deletions
diff --git a/pkg/tcpip/stack/route.go b/pkg/tcpip/stack/route.go index f0b256507..8cb7c5dd8 100644 --- a/pkg/tcpip/stack/route.go +++ b/pkg/tcpip/stack/route.go @@ -18,11 +18,18 @@ import ( "fmt" "gvisor.dev/gvisor/pkg/sleep" + "gvisor.dev/gvisor/pkg/sync" "gvisor.dev/gvisor/pkg/tcpip" "gvisor.dev/gvisor/pkg/tcpip/header" ) // Route represents a route through the networking stack to a given destination. +// +// It is safe to call Route's methods from multiple goroutines. +// +// The exported fields are immutable. +// +// TODO(gvisor.dev/issue/4902): Unexpose immutable fields. type Route struct { // RemoteAddress is the final destination of the route. RemoteAddress tcpip.Address @@ -52,8 +59,12 @@ type Route struct { // address's assigned status without the NIC. localAddressNIC *NIC - // localAddressEndpoint is the local address this route is associated with. - localAddressEndpoint AssignableAddressEndpoint + mu struct { + sync.RWMutex + + // localAddressEndpoint is the local address this route is associated with. + localAddressEndpoint AssignableAddressEndpoint + } // outgoingNIC is the interface this route uses to write packets. outgoingNIC *NIC @@ -71,14 +82,14 @@ type Route struct { // ownership of the provided local address. // // Returns an empty route if validation fails. -func constructAndValidateRoute(netProto tcpip.NetworkProtocolNumber, addressEndpoint AssignableAddressEndpoint, localAddressNIC, outgoingNIC *NIC, gateway, localAddr, remoteAddr tcpip.Address, handleLocal, multicastLoop bool) Route { +func constructAndValidateRoute(netProto tcpip.NetworkProtocolNumber, addressEndpoint AssignableAddressEndpoint, localAddressNIC, outgoingNIC *NIC, gateway, localAddr, remoteAddr tcpip.Address, handleLocal, multicastLoop bool) *Route { if len(localAddr) == 0 { localAddr = addressEndpoint.AddressWithPrefix().Address } if localAddressNIC != outgoingNIC && header.IsV6LinkLocalAddress(localAddr) { addressEndpoint.DecRef() - return Route{} + return nil } // If no remote address is provided, use the local address. @@ -110,7 +121,7 @@ func constructAndValidateRoute(netProto tcpip.NetworkProtocolNumber, addressEndp // makeRoute initializes a new route. It takes ownership of the provided // AssignableAddressEndpoint. -func makeRoute(netProto tcpip.NetworkProtocolNumber, localAddr, remoteAddr tcpip.Address, outgoingNIC, localAddressNIC *NIC, localAddressEndpoint AssignableAddressEndpoint, handleLocal, multicastLoop bool) Route { +func makeRoute(netProto tcpip.NetworkProtocolNumber, localAddr, remoteAddr tcpip.Address, outgoingNIC, localAddressNIC *NIC, localAddressEndpoint AssignableAddressEndpoint, handleLocal, multicastLoop bool) *Route { if localAddressNIC.stack != outgoingNIC.stack { panic(fmt.Sprintf("cannot create a route with NICs from different stacks")) } @@ -139,18 +150,21 @@ func makeRoute(netProto tcpip.NetworkProtocolNumber, localAddr, remoteAddr tcpip return makeRouteInner(netProto, localAddr, remoteAddr, outgoingNIC, localAddressNIC, localAddressEndpoint, loop) } -func makeRouteInner(netProto tcpip.NetworkProtocolNumber, localAddr, remoteAddr tcpip.Address, outgoingNIC, localAddressNIC *NIC, localAddressEndpoint AssignableAddressEndpoint, loop PacketLooping) Route { - r := Route{ - NetProto: netProto, - LocalAddress: localAddr, - LocalLinkAddress: outgoingNIC.LinkEndpoint.LinkAddress(), - RemoteAddress: remoteAddr, - localAddressNIC: localAddressNIC, - localAddressEndpoint: localAddressEndpoint, - outgoingNIC: outgoingNIC, - Loop: loop, +func makeRouteInner(netProto tcpip.NetworkProtocolNumber, localAddr, remoteAddr tcpip.Address, outgoingNIC, localAddressNIC *NIC, localAddressEndpoint AssignableAddressEndpoint, loop PacketLooping) *Route { + r := &Route{ + NetProto: netProto, + LocalAddress: localAddr, + LocalLinkAddress: outgoingNIC.LinkEndpoint.LinkAddress(), + RemoteAddress: remoteAddr, + localAddressNIC: localAddressNIC, + outgoingNIC: outgoingNIC, + Loop: loop, } + r.mu.Lock() + r.mu.localAddressEndpoint = localAddressEndpoint + r.mu.Unlock() + if r.outgoingNIC.LinkEndpoint.Capabilities()&CapabilityResolutionRequired != 0 { if linkRes, ok := r.outgoingNIC.stack.linkAddrResolvers[r.NetProto]; ok { r.linkRes = linkRes @@ -165,7 +179,7 @@ func makeRouteInner(netProto tcpip.NetworkProtocolNumber, localAddr, remoteAddr // provided AssignableAddressEndpoint. // // A local route is a route to a destination that is local to the stack. -func makeLocalRoute(netProto tcpip.NetworkProtocolNumber, localAddr, remoteAddr tcpip.Address, outgoingNIC, localAddressNIC *NIC, localAddressEndpoint AssignableAddressEndpoint) Route { +func makeLocalRoute(netProto tcpip.NetworkProtocolNumber, localAddr, remoteAddr tcpip.Address, outgoingNIC, localAddressNIC *NIC, localAddressEndpoint AssignableAddressEndpoint) *Route { loop := PacketLoop // TODO(gvisor.dev/issue/4689): Loopback interface loops back packets at the // link endpoint level. We can remove this check once loopback interfaces @@ -327,7 +341,10 @@ func (r *Route) isValidForOutgoing() bool { return false } - if !r.localAddressNIC.isValidForOutgoing(r.localAddressEndpoint) { + r.mu.RLock() + localAddressEndpoint := r.mu.localAddressEndpoint + r.mu.RUnlock() + if localAddressEndpoint == nil || !r.localAddressNIC.isValidForOutgoing(localAddressEndpoint) { return false } @@ -381,20 +398,44 @@ func (r *Route) MTU() uint32 { // Release frees all resources associated with the route. func (r *Route) Release() { - if r.localAddressEndpoint != nil { - r.localAddressEndpoint.DecRef() - r.localAddressEndpoint = nil + r.mu.Lock() + defer r.mu.Unlock() + + if r.mu.localAddressEndpoint != nil { + r.mu.localAddressEndpoint.DecRef() + r.mu.localAddressEndpoint = nil } } // Clone clones the route. -func (r *Route) Clone() Route { - if r.localAddressEndpoint != nil { - if !r.localAddressEndpoint.IncRef() { - panic(fmt.Sprintf("failed to increment reference count for local address endpoint = %s", r.LocalAddress)) +func (r *Route) Clone() *Route { + r.mu.RLock() + defer r.mu.RUnlock() + + newRoute := &Route{ + RemoteAddress: r.RemoteAddress, + RemoteLinkAddress: r.RemoteLinkAddress, + LocalAddress: r.LocalAddress, + LocalLinkAddress: r.LocalLinkAddress, + NextHop: r.NextHop, + NetProto: r.NetProto, + Loop: r.Loop, + localAddressNIC: r.localAddressNIC, + outgoingNIC: r.outgoingNIC, + linkCache: r.linkCache, + linkRes: r.linkRes, + } + + newRoute.mu.Lock() + defer newRoute.mu.Unlock() + newRoute.mu.localAddressEndpoint = r.mu.localAddressEndpoint + if newRoute.mu.localAddressEndpoint != nil { + if !newRoute.mu.localAddressEndpoint.IncRef() { + panic(fmt.Sprintf("failed to increment reference count for local address endpoint = %s", newRoute.LocalAddress)) } } - return *r + + return newRoute } // Stack returns the instance of the Stack that owns this route. @@ -407,7 +448,14 @@ func (r *Route) isV4Broadcast(addr tcpip.Address) bool { return true } - subnet := r.localAddressEndpoint.Subnet() + r.mu.RLock() + localAddressEndpoint := r.mu.localAddressEndpoint + r.mu.RUnlock() + if localAddressEndpoint == nil { + return false + } + + subnet := localAddressEndpoint.Subnet() return subnet.IsBroadcast(addr) } |