diff options
Diffstat (limited to 'pkg/tcpip/stack/stack.go')
| -rw-r--r-- | pkg/tcpip/stack/stack.go | 162 |
1 files changed, 75 insertions, 87 deletions
diff --git a/pkg/tcpip/stack/stack.go b/pkg/tcpip/stack/stack.go index 1fe21b68e..90c2cf1be 100644 --- a/pkg/tcpip/stack/stack.go +++ b/pkg/tcpip/stack/stack.go @@ -17,18 +17,15 @@ // // For consumers, the only function of interest is New(), everything else is // provided by the tcpip/public package. -// -// For protocol implementers, RegisterTransportProtocolFactory() and -// RegisterNetworkProtocolFactory() are used to register protocol factories with -// the stack, which will then be used to instantiate protocol objects when -// consumers interact with the stack. package stack import ( + "encoding/binary" "sync" "time" "golang.org/x/time/rate" + "gvisor.dev/gvisor/pkg/rand" "gvisor.dev/gvisor/pkg/sleep" "gvisor.dev/gvisor/pkg/tcpip" "gvisor.dev/gvisor/pkg/tcpip/buffer" @@ -351,6 +348,9 @@ type Stack struct { networkProtocols map[tcpip.NetworkProtocolNumber]NetworkProtocol linkAddrResolvers map[tcpip.NetworkProtocolNumber]LinkAddressResolver + // unassociatedFactory creates unassociated endpoints. If nil, raw + // endpoints are disabled. It is set during Stack creation and is + // immutable. unassociatedFactory UnassociatedEndpointFactory demux *transportDemuxer @@ -359,10 +359,6 @@ type Stack struct { linkAddrCache *linkAddrCache - // raw indicates whether raw sockets may be created. It is set during - // Stack creation and is immutable. - raw bool - mu sync.RWMutex nics map[tcpip.NICID]*NIC forwarding bool @@ -394,10 +390,22 @@ type Stack struct { // icmpRateLimiter is a global rate limiter for all ICMP messages generated // by the stack. icmpRateLimiter *ICMPRateLimiter + + // portSeed is a one-time random value initialized at stack startup + // and is used to seed the TCP port picking on active connections + // + // TODO(gvisor.dev/issues/940): S/R this field. + portSeed uint32 } // Options contains optional Stack configuration. type Options struct { + // NetworkProtocols lists the network protocols to enable. + NetworkProtocols []NetworkProtocol + + // TransportProtocols lists the transport protocols to enable. + TransportProtocols []TransportProtocol + // Clock is an optional clock source used for timestampping packets. // // If no Clock is specified, the clock source will be time.Now. @@ -411,8 +419,9 @@ type Options struct { // stack (false). HandleLocal bool - // Raw indicates whether raw sockets may be created. - Raw bool + // UnassociatedFactory produces unassociated endpoints raw endpoints. + // Raw endpoints are enabled only if this is non-nil. + UnassociatedFactory UnassociatedEndpointFactory } // New allocates a new networking stack with only the requested networking and @@ -422,7 +431,7 @@ type Options struct { // SetNetworkProtocolOption/SetTransportProtocolOption methods provided by the // stack. Please refer to individual protocol implementations as to what options // are supported. -func New(network []string, transport []string, opts Options) *Stack { +func New(opts Options) *Stack { clock := opts.Clock if clock == nil { clock = &tcpip.StdClock{} @@ -438,17 +447,12 @@ func New(network []string, transport []string, opts Options) *Stack { clock: clock, stats: opts.Stats.FillIn(), handleLocal: opts.HandleLocal, - raw: opts.Raw, icmpRateLimiter: NewICMPRateLimiter(), + portSeed: generateRandUint32(), } // Add specified network protocols. - for _, name := range network { - netProtoFactory, ok := networkProtocols[name] - if !ok { - continue - } - netProto := netProtoFactory() + for _, netProto := range opts.NetworkProtocols { s.networkProtocols[netProto.Number()] = netProto if r, ok := netProto.(LinkAddressResolver); ok { s.linkAddrResolvers[r.LinkAddressProtocol()] = r @@ -456,18 +460,14 @@ func New(network []string, transport []string, opts Options) *Stack { } // Add specified transport protocols. - for _, name := range transport { - transProtoFactory, ok := transportProtocols[name] - if !ok { - continue - } - transProto := transProtoFactory() + for _, transProto := range opts.TransportProtocols { s.transportProtocols[transProto.Number()] = &transportProtocolState{ proto: transProto, } } - s.unassociatedFactory = unassociatedFactory + // Add the factory for unassociated endpoints, if present. + s.unassociatedFactory = opts.UnassociatedFactory // Create the global transport demuxer. s.demux = newTransportDemuxer(s) @@ -602,7 +602,7 @@ func (s *Stack) NewEndpoint(transport tcpip.TransportProtocolNumber, network tcp // protocol. Raw endpoints receive all traffic for a given protocol regardless // of address. func (s *Stack) NewRawEndpoint(transport tcpip.TransportProtocolNumber, network tcpip.NetworkProtocolNumber, waiterQueue *waiter.Queue, associated bool) (tcpip.Endpoint, *tcpip.Error) { - if !s.raw { + if s.unassociatedFactory == nil { return nil, tcpip.ErrNotPermitted } @@ -738,7 +738,7 @@ func (s *Stack) NICInfo() map[tcpip.NICID]NICInfo { nics[id] = NICInfo{ Name: nic.name, LinkAddress: nic.linkEP.LinkAddress(), - ProtocolAddresses: nic.Addresses(), + ProtocolAddresses: nic.PrimaryAddresses(), Flags: flags, MTU: nic.linkEP.MTU(), Stats: nic.stats, @@ -845,19 +845,37 @@ func (s *Stack) RemoveAddress(id tcpip.NICID, addr tcpip.Address) *tcpip.Error { return tcpip.ErrUnknownNICID } -// GetMainNICAddress returns the first primary address (and the subnet that -// contains it) for the given NIC and protocol. Returns an arbitrary endpoint's -// address if no primary addresses exist. Returns an error if the NIC doesn't -// exist or has no endpoints. +// AllAddresses returns a map of NICIDs to their protocol addresses (primary +// and non-primary). +func (s *Stack) AllAddresses() map[tcpip.NICID][]tcpip.ProtocolAddress { + s.mu.RLock() + defer s.mu.RUnlock() + + nics := make(map[tcpip.NICID][]tcpip.ProtocolAddress) + for id, nic := range s.nics { + nics[id] = nic.AllAddresses() + } + return nics +} + +// GetMainNICAddress returns the first primary address and prefix for the given +// NIC and protocol. Returns an error if the NIC doesn't exist and an empty +// value if the NIC doesn't have a primary address for the given protocol. func (s *Stack) GetMainNICAddress(id tcpip.NICID, protocol tcpip.NetworkProtocolNumber) (tcpip.AddressWithPrefix, *tcpip.Error) { s.mu.RLock() defer s.mu.RUnlock() - if nic, ok := s.nics[id]; ok { - return nic.getMainNICAddress(protocol) + nic, ok := s.nics[id] + if !ok { + return tcpip.AddressWithPrefix{}, tcpip.ErrUnknownNICID } - return tcpip.AddressWithPrefix{}, tcpip.ErrUnknownNICID + for _, a := range nic.PrimaryAddresses() { + if a.Protocol == protocol { + return a.AddressWithPrefix, nil + } + } + return tcpip.AddressWithPrefix{}, nil } func (s *Stack) getRefEP(nic *NIC, localAddr tcpip.Address, netProto tcpip.NetworkProtocolNumber) (ref *referencedNetworkEndpoint) { @@ -1024,73 +1042,27 @@ func (s *Stack) RemoveWaker(nicid tcpip.NICID, addr tcpip.Address, waker *sleep. // transport dispatcher. Received packets that match the provided id will be // delivered to the given endpoint; specifying a nic is optional, but // nic-specific IDs have precedence over global ones. -func (s *Stack) RegisterTransportEndpoint(nicID tcpip.NICID, netProtos []tcpip.NetworkProtocolNumber, protocol tcpip.TransportProtocolNumber, id TransportEndpointID, ep TransportEndpoint, reusePort bool) *tcpip.Error { - if nicID == 0 { - return s.demux.registerEndpoint(netProtos, protocol, id, ep, reusePort) - } - - s.mu.RLock() - defer s.mu.RUnlock() - - nic := s.nics[nicID] - if nic == nil { - return tcpip.ErrUnknownNICID - } - - return nic.demux.registerEndpoint(netProtos, protocol, id, ep, reusePort) +func (s *Stack) RegisterTransportEndpoint(nicID tcpip.NICID, netProtos []tcpip.NetworkProtocolNumber, protocol tcpip.TransportProtocolNumber, id TransportEndpointID, ep TransportEndpoint, reusePort bool, bindToDevice tcpip.NICID) *tcpip.Error { + return s.demux.registerEndpoint(netProtos, protocol, id, ep, reusePort, bindToDevice) } // UnregisterTransportEndpoint removes the endpoint with the given id from the // stack transport dispatcher. -func (s *Stack) UnregisterTransportEndpoint(nicID tcpip.NICID, netProtos []tcpip.NetworkProtocolNumber, protocol tcpip.TransportProtocolNumber, id TransportEndpointID, ep TransportEndpoint) { - if nicID == 0 { - s.demux.unregisterEndpoint(netProtos, protocol, id, ep) - return - } - - s.mu.RLock() - defer s.mu.RUnlock() - - nic := s.nics[nicID] - if nic != nil { - nic.demux.unregisterEndpoint(netProtos, protocol, id, ep) - } +func (s *Stack) UnregisterTransportEndpoint(nicID tcpip.NICID, netProtos []tcpip.NetworkProtocolNumber, protocol tcpip.TransportProtocolNumber, id TransportEndpointID, ep TransportEndpoint, bindToDevice tcpip.NICID) { + s.demux.unregisterEndpoint(netProtos, protocol, id, ep, bindToDevice) } // RegisterRawTransportEndpoint registers the given endpoint with the stack // transport dispatcher. Received packets that match the provided transport // protocol will be delivered to the given endpoint. func (s *Stack) RegisterRawTransportEndpoint(nicID tcpip.NICID, netProto tcpip.NetworkProtocolNumber, transProto tcpip.TransportProtocolNumber, ep RawTransportEndpoint) *tcpip.Error { - if nicID == 0 { - return s.demux.registerRawEndpoint(netProto, transProto, ep) - } - - s.mu.RLock() - defer s.mu.RUnlock() - - nic := s.nics[nicID] - if nic == nil { - return tcpip.ErrUnknownNICID - } - - return nic.demux.registerRawEndpoint(netProto, transProto, ep) + return s.demux.registerRawEndpoint(netProto, transProto, ep) } // UnregisterRawTransportEndpoint removes the endpoint for the transport // protocol from the stack transport dispatcher. func (s *Stack) UnregisterRawTransportEndpoint(nicID tcpip.NICID, netProto tcpip.NetworkProtocolNumber, transProto tcpip.TransportProtocolNumber, ep RawTransportEndpoint) { - if nicID == 0 { - s.demux.unregisterRawEndpoint(netProto, transProto, ep) - return - } - - s.mu.RLock() - defer s.mu.RUnlock() - - nic := s.nics[nicID] - if nic != nil { - nic.demux.unregisterRawEndpoint(netProto, transProto, ep) - } + s.demux.unregisterRawEndpoint(netProto, transProto, ep) } // RegisterRestoredEndpoint records e as an endpoint that has been restored on @@ -1234,3 +1206,19 @@ func (s *Stack) SetICMPBurst(burst int) { func (s *Stack) AllowICMPMessage() bool { return s.icmpRateLimiter.Allow() } + +// PortSeed returns a 32 bit value that can be used as a seed value for port +// picking. +// +// NOTE: The seed is generated once during stack initialization only. +func (s *Stack) PortSeed() uint32 { + return s.portSeed +} + +func generateRandUint32() uint32 { + b := make([]byte, 4) + if _, err := rand.Read(b); err != nil { + panic(err) + } + return binary.LittleEndian.Uint32(b) +} |