diff options
Diffstat (limited to 'pkg/tcpip/tcpip.go')
| -rw-r--r-- | pkg/tcpip/tcpip.go | 464 |
1 files changed, 436 insertions, 28 deletions
diff --git a/pkg/tcpip/tcpip.go b/pkg/tcpip/tcpip.go index 2be1c107a..c42bb0991 100644 --- a/pkg/tcpip/tcpip.go +++ b/pkg/tcpip/tcpip.go @@ -43,6 +43,9 @@ import ( "gvisor.dev/gvisor/pkg/waiter" ) +// Using header.IPv4AddressSize would cause an import cycle. +const ipv4AddressSize = 4 + // Error represents an error in the netstack error space. Using a special type // ensures that errors outside of this space are not accidentally introduced. // @@ -192,7 +195,7 @@ func (e ErrSaveRejection) Error() string { return "save rejected due to unsupported networking state: " + e.Err.Error() } -// A Clock provides the current time. +// A Clock provides the current time and schedules work for execution. // // Times returned by a Clock should always be used for application-visible // time. Only monotonic times should be used for netstack internal timekeeping. @@ -203,12 +206,45 @@ type Clock interface { // NowMonotonic returns a monotonic time value. NowMonotonic() int64 + + // AfterFunc waits for the duration to elapse and then calls f in its own + // goroutine. It returns a Timer that can be used to cancel the call using + // its Stop method. + AfterFunc(d time.Duration, f func()) Timer +} + +// Timer represents a single event. A Timer must be created with +// Clock.AfterFunc. +type Timer interface { + // Stop prevents the Timer from firing. It returns true if the call stops the + // timer, false if the timer has already expired or been stopped. + // + // If Stop returns false, then the timer has already expired and the function + // f of Clock.AfterFunc(d, f) has been started in its own goroutine; Stop + // does not wait for f to complete before returning. If the caller needs to + // know whether f is completed, it must coordinate with f explicitly. + Stop() bool + + // Reset changes the timer to expire after duration d. + // + // Reset should be invoked only on stopped or expired timers. If the timer is + // known to have expired, Reset can be used directly. Otherwise, the caller + // must coordinate with the function f of Clock.AfterFunc(d, f). + Reset(d time.Duration) } // Address is a byte slice cast as a string that represents the address of a // network node. Or, in the case of unix endpoints, it may represent a path. type Address string +// WithPrefix returns the address with a prefix that represents a point subnet. +func (a Address) WithPrefix() AddressWithPrefix { + return AddressWithPrefix{ + Address: a, + PrefixLen: len(a) * 8, + } +} + // AddressMask is a bitmask for an address. type AddressMask string @@ -295,6 +331,29 @@ func (s *Subnet) Broadcast() Address { return Address(addr) } +// IsBroadcast returns true if the address is considered a broadcast address. +func (s *Subnet) IsBroadcast(address Address) bool { + // Only IPv4 supports the notion of a broadcast address. + if len(address) != ipv4AddressSize { + return false + } + + // Normally, we would just compare address with the subnet's broadcast + // address but there is an exception where a simple comparison is not + // correct. This exception is for /31 and /32 IPv4 subnets where all + // addresses are considered valid host addresses. + // + // For /31 subnets, the case is easy. RFC 3021 Section 2.1 states that + // both addresses in a /31 subnet "MUST be interpreted as host addresses." + // + // For /32, the case is a bit more vague. RFC 3021 makes no mention of /32 + // subnets. However, the same reasoning applies - if an exception is not + // made, then there do not exist any host addresses in a /32 subnet. RFC + // 4632 Section 3.1 also vaguely implies this interpretation by referring + // to addresses in /32 subnets as "host routes." + return s.Prefix() <= 30 && s.Broadcast() == address +} + // Equal returns true if s equals o. // // Needed to use cmp.Equal on Subnet as its fields are unexported. @@ -316,6 +375,28 @@ const ( ShutdownWrite ) +// PacketType is used to indicate the destination of the packet. +type PacketType uint8 + +const ( + // PacketHost indicates a packet addressed to the local host. + PacketHost PacketType = iota + + // PacketOtherHost indicates an outgoing packet addressed to + // another host caught by a NIC in promiscuous mode. + PacketOtherHost + + // PacketOutgoing for a packet originating from the local host + // that is looped back to a packet socket. + PacketOutgoing + + // PacketBroadcast indicates a link layer broadcast packet. + PacketBroadcast + + // PacketMulticast indicates a link layer multicast packet. + PacketMulticast +) + // FullAddress represents a full transport node address, as required by the // Connect() and Bind() methods. // @@ -488,7 +569,10 @@ type Endpoint interface { // block if no new connections are available. // // The returned Queue is the wait queue for the newly created endpoint. - Accept() (Endpoint, *waiter.Queue, *Error) + // + // If peerAddr is not nil then it is populated with the peer address of the + // returned endpoint. + Accept(peerAddr *FullAddress) (Endpoint, *waiter.Queue, *Error) // Bind binds the endpoint to a specific local address and port. // Specifying a NIC is optional. @@ -505,8 +589,8 @@ type Endpoint interface { // if waiter.EventIn is set, the endpoint is immediately readable. Readiness(mask waiter.EventMask) waiter.EventMask - // SetSockOpt sets a socket option. opt should be one of the *Option types. - SetSockOpt(opt interface{}) *Error + // SetSockOpt sets a socket option. + SetSockOpt(opt SettableSocketOption) *Error // SetSockOptBool sets a socket option, for simple cases where a value // has the bool type. @@ -516,9 +600,8 @@ type Endpoint interface { // has the int type. SetSockOptInt(opt SockOptInt, v int) *Error - // GetSockOpt gets a socket option. opt should be a pointer to one of the - // *Option types. - GetSockOpt(opt interface{}) *Error + // GetSockOpt gets a socket option. + GetSockOpt(opt GettableSocketOption) *Error // GetSockOptBool gets a socket option for simple cases where a return // value has the bool type. @@ -547,6 +630,31 @@ type Endpoint interface { // SetOwner sets the task owner to the endpoint owner. SetOwner(owner PacketOwner) + + // LastError clears and returns the last error reported by the endpoint. + LastError() *Error +} + +// LinkPacketInfo holds Link layer information for a received packet. +// +// +stateify savable +type LinkPacketInfo struct { + // Protocol is the NetworkProtocolNumber for the packet. + Protocol NetworkProtocolNumber + + // PktType is used to indicate the destination of the packet. + PktType PacketType +} + +// PacketEndpoint are additional methods that are only implemented by Packet +// endpoints. +type PacketEndpoint interface { + // ReadPacket reads a datagram/packet from the endpoint and optionally + // returns the sender and additional LinkPacketInfo. + // + // This method does not block if there is no data pending. It will also + // either return an error or data, never both. + ReadPacket(*FullAddress, *LinkPacketInfo) (buffer.View, ControlMessages, *Error) } // EndpointInfo is the interface implemented by each endpoint info struct. @@ -648,6 +756,11 @@ const ( // whether an IPv6 socket is to be restricted to sending and receiving // IPv6 packets only. V6OnlyOption + + // IPHdrIncludedOption is used by SetSockOpt to indicate for a raw + // endpoint that all packets being written have an IP header and the + // endpoint should not attach an IP header. + IPHdrIncludedOption ) // SockOptInt represents socket options which values have the int type. @@ -673,6 +786,13 @@ const ( // TCP_MAXSEG option. MaxSegOption + // MTUDiscoverOption is used to set/get the path MTU discovery setting. + // + // NOTE: Setting this option to any other value than PMTUDiscoveryDont + // is not supported and will fail as such, and getting this option will + // always return PMTUDiscoveryDont. + MTUDiscoverOption + // MulticastTTLOption is used by SetSockOptInt/GetSockOptInt to control // the default TTL value for multicast messages. The default is 1. MulticastTTLOption @@ -714,14 +834,152 @@ const ( TCPWindowClampOption ) -// ErrorOption is used in GetSockOpt to specify that the last error reported by -// the endpoint should be cleared and returned. -type ErrorOption struct{} +const ( + // PMTUDiscoveryWant is a setting of the MTUDiscoverOption to use + // per-route settings. + PMTUDiscoveryWant int = iota + + // PMTUDiscoveryDont is a setting of the MTUDiscoverOption to disable + // path MTU discovery. + PMTUDiscoveryDont + + // PMTUDiscoveryDo is a setting of the MTUDiscoverOption to always do + // path MTU discovery. + PMTUDiscoveryDo + + // PMTUDiscoveryProbe is a setting of the MTUDiscoverOption to set DF + // but ignore path MTU. + PMTUDiscoveryProbe +) + +// GettableNetworkProtocolOption is a marker interface for network protocol +// options that may be queried. +type GettableNetworkProtocolOption interface { + isGettableNetworkProtocolOption() +} + +// SettableNetworkProtocolOption is a marker interface for network protocol +// options that may be set. +type SettableNetworkProtocolOption interface { + isSettableNetworkProtocolOption() +} + +// DefaultTTLOption is used by stack.(*Stack).NetworkProtocolOption to specify +// a default TTL. +type DefaultTTLOption uint8 + +func (*DefaultTTLOption) isGettableNetworkProtocolOption() {} + +func (*DefaultTTLOption) isSettableNetworkProtocolOption() {} + +// GettableTransportProtocolOption is a marker interface for transport protocol +// options that may be queried. +type GettableTransportProtocolOption interface { + isGettableTransportProtocolOption() +} + +// SettableTransportProtocolOption is a marker interface for transport protocol +// options that may be set. +type SettableTransportProtocolOption interface { + isSettableTransportProtocolOption() +} + +// TCPSACKEnabled the SACK option for TCP. +// +// See: https://tools.ietf.org/html/rfc2018. +type TCPSACKEnabled bool + +func (*TCPSACKEnabled) isGettableTransportProtocolOption() {} + +func (*TCPSACKEnabled) isSettableTransportProtocolOption() {} + +// TCPRecovery is the loss deteoction algorithm used by TCP. +type TCPRecovery int32 + +func (*TCPRecovery) isGettableTransportProtocolOption() {} + +func (*TCPRecovery) isSettableTransportProtocolOption() {} + +const ( + // TCPRACKLossDetection indicates RACK is used for loss detection and + // recovery. + TCPRACKLossDetection TCPRecovery = 1 << iota + + // TCPRACKStaticReoWnd indicates the reordering window should not be + // adjusted when DSACK is received. + TCPRACKStaticReoWnd + + // TCPRACKNoDupTh indicates RACK should not consider the classic three + // duplicate acknowledgements rule to mark the segments as lost. This + // is used when reordering is not detected. + TCPRACKNoDupTh +) + +// TCPDelayEnabled enables/disables Nagle's algorithm in TCP. +type TCPDelayEnabled bool + +func (*TCPDelayEnabled) isGettableTransportProtocolOption() {} + +func (*TCPDelayEnabled) isSettableTransportProtocolOption() {} + +// TCPSendBufferSizeRangeOption is the send buffer size range for TCP. +type TCPSendBufferSizeRangeOption struct { + Min int + Default int + Max int +} + +func (*TCPSendBufferSizeRangeOption) isGettableTransportProtocolOption() {} + +func (*TCPSendBufferSizeRangeOption) isSettableTransportProtocolOption() {} + +// TCPReceiveBufferSizeRangeOption is the receive buffer size range for TCP. +type TCPReceiveBufferSizeRangeOption struct { + Min int + Default int + Max int +} + +func (*TCPReceiveBufferSizeRangeOption) isGettableTransportProtocolOption() {} + +func (*TCPReceiveBufferSizeRangeOption) isSettableTransportProtocolOption() {} + +// TCPAvailableCongestionControlOption is the supported congestion control +// algorithms for TCP +type TCPAvailableCongestionControlOption string + +func (*TCPAvailableCongestionControlOption) isGettableTransportProtocolOption() {} + +func (*TCPAvailableCongestionControlOption) isSettableTransportProtocolOption() {} + +// TCPModerateReceiveBufferOption enables/disables receive buffer moderation +// for TCP. +type TCPModerateReceiveBufferOption bool + +func (*TCPModerateReceiveBufferOption) isGettableTransportProtocolOption() {} + +func (*TCPModerateReceiveBufferOption) isSettableTransportProtocolOption() {} + +// GettableSocketOption is a marker interface for socket options that may be +// queried. +type GettableSocketOption interface { + isGettableSocketOption() +} + +// SettableSocketOption is a marker interface for socket options that may be +// configured. +type SettableSocketOption interface { + isSettableSocketOption() +} // BindToDeviceOption is used by SetSockOpt/GetSockOpt to specify that sockets // should bind only on a specific NIC. type BindToDeviceOption NICID +func (*BindToDeviceOption) isGettableSocketOption() {} + +func (*BindToDeviceOption) isSettableSocketOption() {} + // TCPInfoOption is used by GetSockOpt to expose TCP statistics. // // TODO(b/64800844): Add and populate stat fields. @@ -730,68 +988,143 @@ type TCPInfoOption struct { RTTVar time.Duration } +func (*TCPInfoOption) isGettableSocketOption() {} + // KeepaliveIdleOption is used by SetSockOpt/GetSockOpt to specify the time a // connection must remain idle before the first TCP keepalive packet is sent. // Once this time is reached, KeepaliveIntervalOption is used instead. type KeepaliveIdleOption time.Duration +func (*KeepaliveIdleOption) isGettableSocketOption() {} + +func (*KeepaliveIdleOption) isSettableSocketOption() {} + // KeepaliveIntervalOption is used by SetSockOpt/GetSockOpt to specify the // interval between sending TCP keepalive packets. type KeepaliveIntervalOption time.Duration +func (*KeepaliveIntervalOption) isGettableSocketOption() {} + +func (*KeepaliveIntervalOption) isSettableSocketOption() {} + // TCPUserTimeoutOption is used by SetSockOpt/GetSockOpt to specify a user // specified timeout for a given TCP connection. // See: RFC5482 for details. type TCPUserTimeoutOption time.Duration +func (*TCPUserTimeoutOption) isGettableSocketOption() {} + +func (*TCPUserTimeoutOption) isSettableSocketOption() {} + // CongestionControlOption is used by SetSockOpt/GetSockOpt to set/get // the current congestion control algorithm. type CongestionControlOption string -// AvailableCongestionControlOption is used to query the supported congestion -// control algorithms. -type AvailableCongestionControlOption string +func (*CongestionControlOption) isGettableSocketOption() {} + +func (*CongestionControlOption) isSettableSocketOption() {} -// buffer moderation. -type ModerateReceiveBufferOption bool +func (*CongestionControlOption) isGettableTransportProtocolOption() {} + +func (*CongestionControlOption) isSettableTransportProtocolOption() {} // TCPLingerTimeoutOption is used by SetSockOpt/GetSockOpt to set/get the // maximum duration for which a socket lingers in the TCP_FIN_WAIT_2 state // before being marked closed. type TCPLingerTimeoutOption time.Duration +func (*TCPLingerTimeoutOption) isGettableSocketOption() {} + +func (*TCPLingerTimeoutOption) isSettableSocketOption() {} + +func (*TCPLingerTimeoutOption) isGettableTransportProtocolOption() {} + +func (*TCPLingerTimeoutOption) isSettableTransportProtocolOption() {} + // TCPTimeWaitTimeoutOption is used by SetSockOpt/GetSockOpt to set/get the // maximum duration for which a socket lingers in the TIME_WAIT state // before being marked closed. type TCPTimeWaitTimeoutOption time.Duration +func (*TCPTimeWaitTimeoutOption) isGettableSocketOption() {} + +func (*TCPTimeWaitTimeoutOption) isSettableSocketOption() {} + +func (*TCPTimeWaitTimeoutOption) isGettableTransportProtocolOption() {} + +func (*TCPTimeWaitTimeoutOption) isSettableTransportProtocolOption() {} + // TCPDeferAcceptOption is used by SetSockOpt/GetSockOpt to allow a // accept to return a completed connection only when there is data to be // read. This usually means the listening socket will drop the final ACK // for a handshake till the specified timeout until a segment with data arrives. type TCPDeferAcceptOption time.Duration +func (*TCPDeferAcceptOption) isGettableSocketOption() {} + +func (*TCPDeferAcceptOption) isSettableSocketOption() {} + // TCPMinRTOOption is use by SetSockOpt/GetSockOpt to allow overriding // default MinRTO used by the Stack. type TCPMinRTOOption time.Duration +func (*TCPMinRTOOption) isGettableSocketOption() {} + +func (*TCPMinRTOOption) isSettableSocketOption() {} + +func (*TCPMinRTOOption) isGettableTransportProtocolOption() {} + +func (*TCPMinRTOOption) isSettableTransportProtocolOption() {} + // TCPMaxRTOOption is use by SetSockOpt/GetSockOpt to allow overriding // default MaxRTO used by the Stack. type TCPMaxRTOOption time.Duration +func (*TCPMaxRTOOption) isGettableSocketOption() {} + +func (*TCPMaxRTOOption) isSettableSocketOption() {} + +func (*TCPMaxRTOOption) isGettableTransportProtocolOption() {} + +func (*TCPMaxRTOOption) isSettableTransportProtocolOption() {} + // TCPMaxRetriesOption is used by SetSockOpt/GetSockOpt to set/get the // maximum number of retransmits after which we time out the connection. type TCPMaxRetriesOption uint64 +func (*TCPMaxRetriesOption) isGettableSocketOption() {} + +func (*TCPMaxRetriesOption) isSettableSocketOption() {} + +func (*TCPMaxRetriesOption) isGettableTransportProtocolOption() {} + +func (*TCPMaxRetriesOption) isSettableTransportProtocolOption() {} + // TCPSynRcvdCountThresholdOption is used by SetSockOpt/GetSockOpt to specify // the number of endpoints that can be in SYN-RCVD state before the stack // switches to using SYN cookies. type TCPSynRcvdCountThresholdOption uint64 +func (*TCPSynRcvdCountThresholdOption) isGettableSocketOption() {} + +func (*TCPSynRcvdCountThresholdOption) isSettableSocketOption() {} + +func (*TCPSynRcvdCountThresholdOption) isGettableTransportProtocolOption() {} + +func (*TCPSynRcvdCountThresholdOption) isSettableTransportProtocolOption() {} + // TCPSynRetriesOption is used by SetSockOpt/GetSockOpt to specify stack-wide // default for number of times SYN is retransmitted before aborting a connect. type TCPSynRetriesOption uint8 +func (*TCPSynRetriesOption) isGettableSocketOption() {} + +func (*TCPSynRetriesOption) isSettableSocketOption() {} + +func (*TCPSynRetriesOption) isGettableTransportProtocolOption() {} + +func (*TCPSynRetriesOption) isSettableTransportProtocolOption() {} + // MulticastInterfaceOption is used by SetSockOpt/GetSockOpt to specify a // default interface for multicast. type MulticastInterfaceOption struct { @@ -799,33 +1132,89 @@ type MulticastInterfaceOption struct { InterfaceAddr Address } -// MembershipOption is used by SetSockOpt/GetSockOpt as an argument to -// AddMembershipOption and RemoveMembershipOption. +func (*MulticastInterfaceOption) isGettableSocketOption() {} + +func (*MulticastInterfaceOption) isSettableSocketOption() {} + +// MembershipOption is used to identify a multicast membership on an interface. type MembershipOption struct { NIC NICID InterfaceAddr Address MulticastAddr Address } -// AddMembershipOption is used by SetSockOpt/GetSockOpt to join a multicast -// group identified by the given multicast address, on the interface matching -// the given interface address. +// AddMembershipOption identifies a multicast group to join on some interface. type AddMembershipOption MembershipOption -// RemoveMembershipOption is used by SetSockOpt/GetSockOpt to leave a multicast -// group identified by the given multicast address, on the interface matching -// the given interface address. +func (*AddMembershipOption) isSettableSocketOption() {} + +// RemoveMembershipOption identifies a multicast group to leave on some +// interface. type RemoveMembershipOption MembershipOption +func (*RemoveMembershipOption) isSettableSocketOption() {} + // OutOfBandInlineOption is used by SetSockOpt/GetSockOpt to specify whether // TCP out-of-band data is delivered along with the normal in-band data. type OutOfBandInlineOption int -// DefaultTTLOption is used by stack.(*Stack).NetworkProtocolOption to specify -// a default TTL. -type DefaultTTLOption uint8 +func (*OutOfBandInlineOption) isGettableSocketOption() {} + +func (*OutOfBandInlineOption) isSettableSocketOption() {} + +// SocketDetachFilterOption is used by SetSockOpt to detach a previously attached +// classic BPF filter on a given endpoint. +type SocketDetachFilterOption int + +func (*SocketDetachFilterOption) isSettableSocketOption() {} +// OriginalDestinationOption is used to get the original destination address +// and port of a redirected packet. +type OriginalDestinationOption FullAddress + +func (*OriginalDestinationOption) isGettableSocketOption() {} + +// TCPTimeWaitReuseOption is used stack.(*Stack).TransportProtocolOption to +// specify if the stack can reuse the port bound by an endpoint in TIME-WAIT for +// new connections when it is safe from protocol viewpoint. +type TCPTimeWaitReuseOption uint8 + +func (*TCPTimeWaitReuseOption) isGettableSocketOption() {} + +func (*TCPTimeWaitReuseOption) isSettableSocketOption() {} + +func (*TCPTimeWaitReuseOption) isGettableTransportProtocolOption() {} + +func (*TCPTimeWaitReuseOption) isSettableTransportProtocolOption() {} + +const ( + // TCPTimeWaitReuseDisabled indicates reuse of port bound by endponts in TIME-WAIT cannot + // be reused for new connections. + TCPTimeWaitReuseDisabled TCPTimeWaitReuseOption = iota + + // TCPTimeWaitReuseGlobal indicates reuse of port bound by endponts in TIME-WAIT can + // be reused for new connections irrespective of the src/dest addresses. + TCPTimeWaitReuseGlobal + + // TCPTimeWaitReuseLoopbackOnly indicates reuse of port bound by endpoint in TIME-WAIT can + // only be reused if the connection was a connection over loopback. i.e src/dest adddresses + // are loopback addresses. + TCPTimeWaitReuseLoopbackOnly +) + +// LingerOption is used by SetSockOpt/GetSockOpt to set/get the +// duration for which a socket lingers before returning from Close. // +// +stateify savable +type LingerOption struct { + Enabled bool + Timeout time.Duration +} + +func (*LingerOption) isGettableSocketOption() {} + +func (*LingerOption) isSettableSocketOption() {} + // IPPacketInfo is the message structure for IP_PKTINFO. // // +stateify savable @@ -836,7 +1225,7 @@ type IPPacketInfo struct { // LocalAddr is the local address. LocalAddr Address - // DestinationAddr is the destination address. + // DestinationAddr is the destination address found in the IP header. DestinationAddr Address } @@ -868,7 +1257,10 @@ func (r Route) String() string { // TransportProtocolNumber is the number of a transport protocol. type TransportProtocolNumber uint32 -// NetworkProtocolNumber is the number of a network protocol. +// NetworkProtocolNumber is the EtherType of a network protocol in an Ethernet +// frame. +// +// See: https://www.iana.org/assignments/ieee-802-numbers/ieee-802-numbers.xhtml type NetworkProtocolNumber uint32 // A StatCounter keeps track of a statistic. @@ -1031,6 +1423,10 @@ type ICMPv6ReceivedPacketStats struct { // Invalid is the total number of ICMPv6 packets received that the // transport layer could not parse. Invalid *StatCounter + + // RouterOnlyPacketsDroppedByHost is the total number of ICMPv6 packets + // dropped due to being router-specific packets. + RouterOnlyPacketsDroppedByHost *StatCounter } // ICMPStats collects ICMP-specific stats (both v4 and v6). @@ -1086,6 +1482,18 @@ type IPStats struct { // MalformedFragmentsReceived is the total number of IP Fragments that were // dropped due to the fragment failing validation checks. MalformedFragmentsReceived *StatCounter + + // IPTablesPreroutingDropped is the total number of IP packets dropped + // in the Prerouting chain. + IPTablesPreroutingDropped *StatCounter + + // IPTablesInputDropped is the total number of IP packets dropped in + // the Input chain. + IPTablesInputDropped *StatCounter + + // IPTablesOutputDropped is the total number of IP packets dropped in + // the Output chain. + IPTablesOutputDropped *StatCounter } // TCPStats collects TCP-specific stats. |