diff options
Diffstat (limited to 'pkg/tcpip/stack/registration.go')
| -rw-r--r-- | pkg/tcpip/stack/registration.go | 197 |
1 files changed, 148 insertions, 49 deletions
diff --git a/pkg/tcpip/stack/registration.go b/pkg/tcpip/stack/registration.go index 0869fb084..aca2f77f8 100644 --- a/pkg/tcpip/stack/registration.go +++ b/pkg/tcpip/stack/registration.go @@ -18,6 +18,7 @@ import ( "gvisor.dev/gvisor/pkg/sleep" "gvisor.dev/gvisor/pkg/tcpip" "gvisor.dev/gvisor/pkg/tcpip/buffer" + "gvisor.dev/gvisor/pkg/tcpip/header" "gvisor.dev/gvisor/pkg/waiter" ) @@ -51,8 +52,11 @@ type TransportEndpointID struct { type ControlType int // The following are the allowed values for ControlType values. +// TODO(http://gvisor.dev/issue/3210): Support time exceeded messages. const ( - ControlPacketTooBig ControlType = iota + ControlNetworkUnreachable ControlType = iota + ControlNoRoute + ControlPacketTooBig ControlPortUnreachable ControlUnknown ) @@ -60,13 +64,34 @@ const ( // TransportEndpoint is the interface that needs to be implemented by transport // protocol (e.g., tcp, udp) endpoints that can handle packets. type TransportEndpoint interface { + // UniqueID returns an unique ID for this transport endpoint. + UniqueID() uint64 + // HandlePacket is called by the stack when new packets arrive to - // this transport endpoint. - HandlePacket(r *Route, id TransportEndpointID, vv buffer.VectorisedView) + // this transport endpoint. It sets pkt.TransportHeader. + // + // HandlePacket takes ownership of pkt. + HandlePacket(r *Route, id TransportEndpointID, pkt *PacketBuffer) - // HandleControlPacket is called by the stack when new control (e.g., + // HandleControlPacket is called by the stack when new control (e.g. // ICMP) packets arrive to this transport endpoint. - HandleControlPacket(id TransportEndpointID, typ ControlType, extra uint32, vv buffer.VectorisedView) + // HandleControlPacket takes ownership of pkt. + HandleControlPacket(id TransportEndpointID, typ ControlType, extra uint32, pkt *PacketBuffer) + + // Abort initiates an expedited endpoint teardown. It puts the endpoint + // in a closed state and frees all resources associated with it. This + // cleanup may happen asynchronously. Wait can be used to block on this + // asynchronous cleanup. + Abort() + + // Wait waits for any worker goroutines owned by the endpoint to stop. + // + // An endpoint can be requested to stop its worker goroutines by calling + // its Close method. + // + // Wait will not block if the endpoint hasn't started any goroutines + // yet, even if it might later. + Wait() } // RawTransportEndpoint is the interface that needs to be implemented by raw @@ -77,7 +102,9 @@ type RawTransportEndpoint interface { // HandlePacket is called by the stack when new packets arrive to // this transport endpoint. The packet contains all data from the link // layer up. - HandlePacket(r *Route, netHeader buffer.View, packet buffer.VectorisedView) + // + // HandlePacket takes ownership of pkt. + HandlePacket(r *Route, pkt *PacketBuffer) } // PacketEndpoint is the interface that needs to be implemented by packet @@ -93,7 +120,9 @@ type PacketEndpoint interface { // // linkHeader may have a length of 0, in which case the PacketEndpoint // should construct its own ethernet header for applications. - HandlePacket(nicid tcpip.NICID, addr tcpip.LinkAddress, netProto tcpip.NetworkProtocolNumber, packet buffer.VectorisedView, linkHeader buffer.View) + // + // HandlePacket takes ownership of pkt. + HandlePacket(nicID tcpip.NICID, addr tcpip.LinkAddress, netProto tcpip.NetworkProtocolNumber, pkt *PacketBuffer) } // TransportProtocol is the interface that needs to be implemented by transport @@ -123,7 +152,9 @@ type TransportProtocol interface { // // The return value indicates whether the packet was well-formed (for // stats purposes only). - HandleUnknownDestinationPacket(r *Route, id TransportEndpointID, netHeader buffer.View, vv buffer.VectorisedView) bool + // + // HandleUnknownDestinationPacket takes ownership of pkt. + HandleUnknownDestinationPacket(r *Route, id TransportEndpointID, pkt *PacketBuffer) bool // SetOption allows enabling/disabling protocol specific features. // SetOption returns an error if the option is not supported or the @@ -134,6 +165,18 @@ type TransportProtocol interface { // Option returns an error if the option is not supported or the // provided option value is invalid. Option(option interface{}) *tcpip.Error + + // Close requests that any worker goroutines owned by the protocol + // stop. + Close() + + // Wait waits for any worker goroutines owned by the protocol to stop. + Wait() + + // Parse sets pkt.TransportHeader and trims pkt.Data appropriately. It does + // neither and returns false if pkt.Data is too small, i.e. pkt.Data.Size() < + // MinimumPacketSize() + Parse(pkt *PacketBuffer) (ok bool) } // TransportDispatcher contains the methods used by the network stack to deliver @@ -141,13 +184,21 @@ type TransportProtocol interface { // the network layer. type TransportDispatcher interface { // DeliverTransportPacket delivers packets to the appropriate - // transport protocol endpoint. It also returns the network layer - // header for the enpoint to inspect or pass up the stack. - DeliverTransportPacket(r *Route, protocol tcpip.TransportProtocolNumber, netHeader buffer.View, vv buffer.VectorisedView) + // transport protocol endpoint. + // + // pkt.NetworkHeader must be set before calling DeliverTransportPacket. + // + // DeliverTransportPacket takes ownership of pkt. + DeliverTransportPacket(r *Route, protocol tcpip.TransportProtocolNumber, pkt *PacketBuffer) // DeliverTransportControlPacket delivers control packets to the // appropriate transport protocol endpoint. - DeliverTransportControlPacket(local, remote tcpip.Address, net tcpip.NetworkProtocolNumber, trans tcpip.TransportProtocolNumber, typ ControlType, extra uint32, vv buffer.VectorisedView) + // + // pkt.NetworkHeader must be set before calling + // DeliverTransportControlPacket. + // + // DeliverTransportControlPacket takes ownership of pkt. + DeliverTransportControlPacket(local, remote tcpip.Address, net tcpip.NetworkProtocolNumber, trans tcpip.TransportProtocolNumber, typ ControlType, extra uint32, pkt *PacketBuffer) } // PacketLooping specifies where an outbound packet should be sent. @@ -198,32 +249,34 @@ type NetworkEndpoint interface { MaxHeaderLength() uint16 // WritePacket writes a packet to the given destination address and - // protocol. - WritePacket(r *Route, gso *GSO, hdr buffer.Prependable, payload buffer.VectorisedView, params NetworkHeaderParams, loop PacketLooping) *tcpip.Error + // protocol. It takes ownership of pkt. pkt.TransportHeader must have + // already been set. + WritePacket(r *Route, gso *GSO, params NetworkHeaderParams, pkt *PacketBuffer) *tcpip.Error // WritePackets writes packets to the given destination address and - // protocol. - WritePackets(r *Route, gso *GSO, hdrs []PacketDescriptor, payload buffer.VectorisedView, params NetworkHeaderParams, loop PacketLooping) (int, *tcpip.Error) + // protocol. pkts must not be zero length. It takes ownership of pkts and + // underlying packets. + WritePackets(r *Route, gso *GSO, pkts PacketBufferList, params NetworkHeaderParams) (int, *tcpip.Error) // WriteHeaderIncludedPacket writes a packet that includes a network - // header to the given destination address. - WriteHeaderIncludedPacket(r *Route, payload buffer.VectorisedView, loop PacketLooping) *tcpip.Error - - // ID returns the network protocol endpoint ID. - ID() *NetworkEndpointID - - // PrefixLen returns the network endpoint's subnet prefix length in bits. - PrefixLen() int + // header to the given destination address. It takes ownership of pkt. + WriteHeaderIncludedPacket(r *Route, pkt *PacketBuffer) *tcpip.Error // NICID returns the id of the NIC this endpoint belongs to. NICID() tcpip.NICID // HandlePacket is called by the link layer when new packets arrive to - // this network endpoint. - HandlePacket(r *Route, vv buffer.VectorisedView) + // this network endpoint. It sets pkt.NetworkHeader. + // + // HandlePacket takes ownership of pkt. + HandlePacket(r *Route, pkt *PacketBuffer) // Close is called when the endpoint is reomved from a stack. Close() + + // NetworkProtocolNumber returns the tcpip.NetworkProtocolNumber for + // this endpoint. + NetworkProtocolNumber() tcpip.NetworkProtocolNumber } // NetworkProtocol is the interface that needs to be implemented by network @@ -240,12 +293,12 @@ type NetworkProtocol interface { // DefaultPrefixLen returns the protocol's default prefix length. DefaultPrefixLen() int - // ParsePorts returns the source and destination addresses stored in a + // ParseAddresses returns the source and destination addresses stored in a // packet of this protocol. ParseAddresses(v buffer.View) (src, dst tcpip.Address) // NewEndpoint creates a new endpoint of this protocol. - NewEndpoint(nicid tcpip.NICID, addrWithPrefix tcpip.AddressWithPrefix, linkAddrCache LinkAddressCache, dispatcher TransportDispatcher, sender LinkEndpoint) (NetworkEndpoint, *tcpip.Error) + NewEndpoint(nicID tcpip.NICID, linkAddrCache LinkAddressCache, dispatcher TransportDispatcher, sender LinkEndpoint, st *Stack) NetworkEndpoint // SetOption allows enabling/disabling protocol specific features. // SetOption returns an error if the option is not supported or the @@ -256,16 +309,45 @@ type NetworkProtocol interface { // Option returns an error if the option is not supported or the // provided option value is invalid. Option(option interface{}) *tcpip.Error + + // Close requests that any worker goroutines owned by the protocol + // stop. + Close() + + // Wait waits for any worker goroutines owned by the protocol to stop. + Wait() + + // Parse sets pkt.NetworkHeader and trims pkt.Data appropriately. It + // returns: + // - The encapsulated protocol, if present. + // - Whether there is an encapsulated transport protocol payload (e.g. ARP + // does not encapsulate anything). + // - Whether pkt.Data was large enough to parse and set pkt.NetworkHeader. + Parse(pkt *PacketBuffer) (proto tcpip.TransportProtocolNumber, hasTransportHdr bool, ok bool) } // NetworkDispatcher contains the methods used by the network stack to deliver -// packets to the appropriate network endpoint after it has been handled by -// the data link layer. +// inbound/outbound packets to the appropriate network/packet(if any) endpoints. type NetworkDispatcher interface { // DeliverNetworkPacket finds the appropriate network protocol endpoint - // and hands the packet over for further processing. linkHeader may have - // length 0 when the caller does not have ethernet data. - DeliverNetworkPacket(linkEP LinkEndpoint, remote, local tcpip.LinkAddress, protocol tcpip.NetworkProtocolNumber, vv buffer.VectorisedView, linkHeader buffer.View) + // and hands the packet over for further processing. + // + // pkt.LinkHeader may or may not be set before calling + // DeliverNetworkPacket. Some packets do not have link headers (e.g. + // packets sent via loopback), and won't have the field set. + // + // DeliverNetworkPacket takes ownership of pkt. + DeliverNetworkPacket(remote, local tcpip.LinkAddress, protocol tcpip.NetworkProtocolNumber, pkt *PacketBuffer) + + // DeliverOutboundPacket is called by link layer when a packet is being + // sent out. + // + // pkt.LinkHeader may or may not be set before calling + // DeliverOutboundPacket. Some packets do not have link headers (e.g. + // packets sent via loopback), and won't have the field set. + // + // DeliverOutboundPacket takes ownership of pkt. + DeliverOutboundPacket(remote, local tcpip.LinkAddress, protocol tcpip.NetworkProtocolNumber, pkt *PacketBuffer) } // LinkEndpointCapabilities is the type associated with the capabilities @@ -296,7 +378,9 @@ const ( // LinkEndpoint is the interface implemented by data link layer protocols (e.g., // ethernet, loopback, raw) and used by network layer protocols to send packets -// out through the implementer's data link endpoint. +// out through the implementer's data link endpoint. When a link header exists, +// it sets each PacketBuffer's LinkHeader field before passing it up the +// stack. type LinkEndpoint interface { // MTU is the maximum transmission unit for this endpoint. This is // usually dictated by the backing physical network; when such a @@ -318,28 +402,33 @@ type LinkEndpoint interface { // link endpoint. LinkAddress() tcpip.LinkAddress - // WritePacket writes a packet with the given protocol through the given - // route. + // WritePacket writes a packet with the given protocol through the + // given route. It takes ownership of pkt. pkt.NetworkHeader and + // pkt.TransportHeader must have already been set. // // To participate in transparent bridging, a LinkEndpoint implementation // should call eth.Encode with header.EthernetFields.SrcAddr set to // r.LocalLinkAddress if it is provided. - WritePacket(r *Route, gso *GSO, hdr buffer.Prependable, payload buffer.VectorisedView, protocol tcpip.NetworkProtocolNumber) *tcpip.Error + WritePacket(r *Route, gso *GSO, protocol tcpip.NetworkProtocolNumber, pkt *PacketBuffer) *tcpip.Error // WritePackets writes packets with the given protocol through the - // given route. + // given route. pkts must not be zero length. It takes ownership of pkts and + // underlying packets. // // Right now, WritePackets is used only when the software segmentation // offload is enabled. If it will be used for something else, it may // require to change syscall filters. - WritePackets(r *Route, gso *GSO, hdrs []PacketDescriptor, payload buffer.VectorisedView, protocol tcpip.NetworkProtocolNumber) (int, *tcpip.Error) + WritePackets(r *Route, gso *GSO, pkts PacketBufferList, protocol tcpip.NetworkProtocolNumber) (int, *tcpip.Error) // WriteRawPacket writes a packet directly to the link. The packet - // should already have an ethernet header. - WriteRawPacket(packet buffer.VectorisedView) *tcpip.Error + // should already have an ethernet header. It takes ownership of vv. + WriteRawPacket(vv buffer.VectorisedView) *tcpip.Error // Attach attaches the data link layer endpoint to the network-layer // dispatcher of the stack. + // + // Attach will be called with a nil dispatcher if the receiver's associated + // NIC is being removed. Attach(dispatcher NetworkDispatcher) // IsAttached returns whether a NetworkDispatcher is attached to the @@ -354,6 +443,15 @@ type LinkEndpoint interface { // Wait will not block if the endpoint hasn't started any goroutines // yet, even if it might later. Wait() + + // ARPHardwareType returns the ARPHRD_TYPE of the link endpoint. + // + // See: + // https://github.com/torvalds/linux/blob/aa0c9086b40c17a7ad94425b3b70dd1fdd7497bf/include/uapi/linux/if_arp.h#L30 + ARPHardwareType() header.ARPHardwareType + + // AddHeader adds a link layer header to pkt if required. + AddHeader(local, remote tcpip.LinkAddress, protocol tcpip.NetworkProtocolNumber, pkt *PacketBuffer) } // InjectableLinkEndpoint is a LinkEndpoint where inbound packets are @@ -362,7 +460,7 @@ type InjectableLinkEndpoint interface { LinkEndpoint // InjectInbound injects an inbound packet. - InjectInbound(protocol tcpip.NetworkProtocolNumber, vv buffer.VectorisedView) + InjectInbound(protocol tcpip.NetworkProtocolNumber, pkt *PacketBuffer) // InjectOutbound writes a fully formed outbound packet directly to the // link. @@ -374,12 +472,13 @@ type InjectableLinkEndpoint interface { // A LinkAddressResolver is an extension to a NetworkProtocol that // can resolve link addresses. type LinkAddressResolver interface { - // LinkAddressRequest sends a request for the LinkAddress of addr. - // The request is sent on linkEP with localAddr as the source. + // LinkAddressRequest sends a request for the LinkAddress of addr. Broadcasts + // the request on the local network if remoteLinkAddr is the zero value. The + // request is sent on linkEP with localAddr as the source. // // A valid response will cause the discovery protocol's network // endpoint to call AddLinkAddress. - LinkAddressRequest(addr, localAddr tcpip.Address, linkEP LinkEndpoint) *tcpip.Error + LinkAddressRequest(addr, localAddr tcpip.Address, remoteLinkAddr tcpip.LinkAddress, linkEP LinkEndpoint) *tcpip.Error // ResolveStaticAddress attempts to resolve address without sending // requests. It either resolves the name immediately or returns the @@ -397,10 +496,10 @@ type LinkAddressResolver interface { type LinkAddressCache interface { // CheckLocalAddress determines if the given local address exists, and if it // does not exist. - CheckLocalAddress(nicid tcpip.NICID, protocol tcpip.NetworkProtocolNumber, addr tcpip.Address) tcpip.NICID + CheckLocalAddress(nicID tcpip.NICID, protocol tcpip.NetworkProtocolNumber, addr tcpip.Address) tcpip.NICID // AddLinkAddress adds a link address to the cache. - AddLinkAddress(nicid tcpip.NICID, addr tcpip.Address, linkAddr tcpip.LinkAddress) + AddLinkAddress(nicID tcpip.NICID, addr tcpip.Address, linkAddr tcpip.LinkAddress) // GetLinkAddress looks up the cache to translate address to link address (e.g. IP -> MAC). // If the LinkEndpoint requests address resolution and there is a LinkAddressResolver @@ -411,10 +510,10 @@ type LinkAddressCache interface { // If address resolution is required, ErrNoLinkAddress and a notification channel is // returned for the top level caller to block. Channel is closed once address resolution // is complete (success or not). - GetLinkAddress(nicid tcpip.NICID, addr, localAddr tcpip.Address, protocol tcpip.NetworkProtocolNumber, w *sleep.Waker) (tcpip.LinkAddress, <-chan struct{}, *tcpip.Error) + GetLinkAddress(nicID tcpip.NICID, addr, localAddr tcpip.Address, protocol tcpip.NetworkProtocolNumber, w *sleep.Waker) (tcpip.LinkAddress, <-chan struct{}, *tcpip.Error) // RemoveWaker removes a waker that has been added in GetLinkAddress(). - RemoveWaker(nicid tcpip.NICID, addr tcpip.Address, waker *sleep.Waker) + RemoveWaker(nicID tcpip.NICID, addr tcpip.Address, waker *sleep.Waker) } // RawFactory produces endpoints for writing various types of raw packets. |