diff options
Diffstat (limited to 'pkg/tcpip/transport/tcp/testing')
| -rw-r--r-- | pkg/tcpip/transport/tcp/testing/context/BUILD | 26 | ||||
| -rw-r--r-- | pkg/tcpip/transport/tcp/testing/context/context.go | 1271 |
2 files changed, 0 insertions, 1297 deletions
diff --git a/pkg/tcpip/transport/tcp/testing/context/BUILD b/pkg/tcpip/transport/tcp/testing/context/BUILD deleted file mode 100644 index ce6a2c31d..000000000 --- a/pkg/tcpip/transport/tcp/testing/context/BUILD +++ /dev/null @@ -1,26 +0,0 @@ -load("//tools:defs.bzl", "go_library") - -package(licenses = ["notice"]) - -go_library( - name = "context", - testonly = 1, - srcs = ["context.go"], - visibility = [ - "//visibility:public", - ], - deps = [ - "//pkg/tcpip", - "//pkg/tcpip/buffer", - "//pkg/tcpip/checker", - "//pkg/tcpip/header", - "//pkg/tcpip/link/channel", - "//pkg/tcpip/link/sniffer", - "//pkg/tcpip/network/ipv4", - "//pkg/tcpip/network/ipv6", - "//pkg/tcpip/seqnum", - "//pkg/tcpip/stack", - "//pkg/tcpip/transport/tcp", - "//pkg/waiter", - ], -) diff --git a/pkg/tcpip/transport/tcp/testing/context/context.go b/pkg/tcpip/transport/tcp/testing/context/context.go deleted file mode 100644 index fd0eca4bd..000000000 --- a/pkg/tcpip/transport/tcp/testing/context/context.go +++ /dev/null @@ -1,1271 +0,0 @@ -// Copyright 2018 The gVisor Authors. -// -// Licensed under the Apache License, Version 2.0 (the "License"); -// you may not use this file except in compliance with the License. -// You may obtain a copy of the License at -// -// http://www.apache.org/licenses/LICENSE-2.0 -// -// Unless required by applicable law or agreed to in writing, software -// distributed under the License is distributed on an "AS IS" BASIS, -// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. -// See the License for the specific language governing permissions and -// limitations under the License. - -// Package context provides a test context for use in tcp tests. It also -// provides helper methods to assert/check certain behaviours. -package context - -import ( - "bytes" - "context" - "testing" - "time" - - "gvisor.dev/gvisor/pkg/tcpip" - "gvisor.dev/gvisor/pkg/tcpip/buffer" - "gvisor.dev/gvisor/pkg/tcpip/checker" - "gvisor.dev/gvisor/pkg/tcpip/header" - "gvisor.dev/gvisor/pkg/tcpip/link/channel" - "gvisor.dev/gvisor/pkg/tcpip/link/sniffer" - "gvisor.dev/gvisor/pkg/tcpip/network/ipv4" - "gvisor.dev/gvisor/pkg/tcpip/network/ipv6" - "gvisor.dev/gvisor/pkg/tcpip/seqnum" - "gvisor.dev/gvisor/pkg/tcpip/stack" - "gvisor.dev/gvisor/pkg/tcpip/transport/tcp" - "gvisor.dev/gvisor/pkg/waiter" -) - -const ( - // StackAddr is the IPv4 address assigned to the stack. - StackAddr = "\x0a\x00\x00\x01" - - // StackPort is used as the listening port in tests for passive - // connects. - StackPort = 1234 - - // TestAddr is the source address for packets sent to the stack via the - // link layer endpoint. - TestAddr = "\x0a\x00\x00\x02" - - // TestPort is the TCP port used for packets sent to the stack - // via the link layer endpoint. - TestPort = 4096 - - // StackV6Addr is the IPv6 address assigned to the stack. - StackV6Addr = "\x0a\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x01" - - // TestV6Addr is the source address for packets sent to the stack via - // the link layer endpoint. - TestV6Addr = "\x0a\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x02" - - // StackV4MappedAddr is StackAddr as a mapped v6 address. - StackV4MappedAddr = "\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\xff\xff" + StackAddr - - // TestV4MappedAddr is TestAddr as a mapped v6 address. - TestV4MappedAddr = "\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\xff\xff" + TestAddr - - // V4MappedWildcardAddr is the mapped v6 representation of 0.0.0.0. - V4MappedWildcardAddr = "\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\xff\xff\x00\x00\x00\x00" - - // TestInitialSequenceNumber is the initial sequence number sent in packets that - // are sent in response to a SYN or in the initial SYN sent to the stack. - TestInitialSequenceNumber = 789 -) - -// StackAddrWithPrefix is StackAddr with its associated prefix length. -var StackAddrWithPrefix = tcpip.AddressWithPrefix{ - Address: StackAddr, - PrefixLen: 24, -} - -// StackV6AddrWithPrefix is StackV6Addr with its associated prefix length. -var StackV6AddrWithPrefix = tcpip.AddressWithPrefix{ - Address: StackV6Addr, - PrefixLen: header.IIDOffsetInIPv6Address * 8, -} - -// Headers is used to represent the TCP header fields when building a -// new packet. -type Headers struct { - // SrcPort holds the src port value to be used in the packet. - SrcPort uint16 - - // DstPort holds the destination port value to be used in the packet. - DstPort uint16 - - // SeqNum is the value of the sequence number field in the TCP header. - SeqNum seqnum.Value - - // AckNum represents the acknowledgement number field in the TCP header. - AckNum seqnum.Value - - // Flags are the TCP flags in the TCP header. - Flags header.TCPFlags - - // RcvWnd is the window to be advertised in the ReceiveWindow field of - // the TCP header. - RcvWnd seqnum.Size - - // TCPOpts holds the options to be sent in the option field of the TCP - // header. - TCPOpts []byte -} - -// Options contains options for creating a new test context. -type Options struct { - // EnableV4 indicates whether IPv4 should be enabled. - EnableV4 bool - - // EnableV6 indicates whether IPv4 should be enabled. - EnableV6 bool - - // MTU indicates the maximum transmission unit on the link layer. - MTU uint32 - - // Clock that is used by Stack. - Clock tcpip.Clock -} - -// Context provides an initialized Network stack and a link layer endpoint -// for use in TCP tests. -type Context struct { - t *testing.T - linkEP *channel.Endpoint - s *stack.Stack - - // IRS holds the initial sequence number in the SYN sent by endpoint in - // case of an active connect or the sequence number sent by the endpoint - // in the SYN-ACK sent in response to a SYN when listening in passive - // mode. - IRS seqnum.Value - - // Port holds the port bound by EP below in case of an active connect or - // the listening port number in case of a passive connect. - Port uint16 - - // EP is the test endpoint in the stack owned by this context. This endpoint - // is used in various tests to either initiate an active connect or is used - // as a passive listening endpoint to accept inbound connections. - EP tcpip.Endpoint - - // Wq is the wait queue associated with EP and is used to block for events - // on EP. - WQ waiter.Queue - - // TimeStampEnabled is true if ep is connected with the timestamp option - // enabled. - TimeStampEnabled bool - - // WindowScale is the expected window scale in SYN packets sent by - // the stack. - WindowScale uint8 - - // RcvdWindowScale is the actual window scale sent by the stack in - // SYN/SYN-ACK. - RcvdWindowScale uint8 -} - -// New allocates and initializes a test context containing a new -// stack and a link-layer endpoint. -func New(t *testing.T, mtu uint32) *Context { - return NewWithOpts(t, Options{ - EnableV4: true, - EnableV6: true, - MTU: mtu, - }) -} - -// NewWithOpts allocates and initializes a test context containing a new -// stack and a link-layer endpoint with specific options. -func NewWithOpts(t *testing.T, opts Options) *Context { - if opts.MTU == 0 { - panic("MTU must be greater than 0") - } - - stackOpts := stack.Options{ - TransportProtocols: []stack.TransportProtocolFactory{tcp.NewProtocol}, - Clock: opts.Clock, - } - if opts.EnableV4 { - stackOpts.NetworkProtocols = append(stackOpts.NetworkProtocols, ipv4.NewProtocol) - } - if opts.EnableV6 { - stackOpts.NetworkProtocols = append(stackOpts.NetworkProtocols, ipv6.NewProtocol) - } - s := stack.New(stackOpts) - - const sendBufferSize = 1 << 20 // 1 MiB - const recvBufferSize = 1 << 20 // 1 MiB - // Allow minimum send/receive buffer sizes to be 1 during tests. - sendBufOpt := tcpip.TCPSendBufferSizeRangeOption{Min: 1, Default: sendBufferSize, Max: 10 * sendBufferSize} - if err := s.SetTransportProtocolOption(tcp.ProtocolNumber, &sendBufOpt); err != nil { - t.Fatalf("SetTransportProtocolOption(%d, &%#v) failed: %s", tcp.ProtocolNumber, sendBufOpt, err) - } - - rcvBufOpt := tcpip.TCPReceiveBufferSizeRangeOption{Min: 1, Default: recvBufferSize, Max: 10 * recvBufferSize} - if err := s.SetTransportProtocolOption(tcp.ProtocolNumber, &rcvBufOpt); err != nil { - t.Fatalf("SetTransportProtocolOption(%d, &%#v) failed: %s", tcp.ProtocolNumber, rcvBufOpt, err) - } - - // Increase minimum RTO in tests to avoid test flakes due to early - // retransmit in case the test executors are overloaded and cause timers - // to fire earlier than expected. - minRTOOpt := tcpip.TCPMinRTOOption(3 * time.Second) - if err := s.SetTransportProtocolOption(tcp.ProtocolNumber, &minRTOOpt); err != nil { - t.Fatalf("s.SetTransportProtocolOption(%d, &%T(%d)): %s", tcp.ProtocolNumber, minRTOOpt, minRTOOpt, err) - } - - // Some of the congestion control tests send up to 640 packets, we so - // set the channel size to 1000. - ep := channel.New(1000, opts.MTU, "") - wep := stack.LinkEndpoint(ep) - if testing.Verbose() { - wep = sniffer.New(ep) - } - nicOpts := stack.NICOptions{Name: "nic1"} - if err := s.CreateNICWithOptions(1, wep, nicOpts); err != nil { - t.Fatalf("CreateNICWithOptions(_, _, %+v) failed: %v", opts, err) - } - wep2 := stack.LinkEndpoint(channel.New(1000, opts.MTU, "")) - if testing.Verbose() { - wep2 = sniffer.New(channel.New(1000, opts.MTU, "")) - } - opts2 := stack.NICOptions{Name: "nic2"} - if err := s.CreateNICWithOptions(2, wep2, opts2); err != nil { - t.Fatalf("CreateNICWithOptions(_, _, %+v) failed: %v", opts2, err) - } - - var routeTable []tcpip.Route - - if opts.EnableV4 { - v4ProtocolAddr := tcpip.ProtocolAddress{ - Protocol: ipv4.ProtocolNumber, - AddressWithPrefix: StackAddrWithPrefix, - } - if err := s.AddProtocolAddress(1, v4ProtocolAddr, stack.AddressProperties{}); err != nil { - t.Fatalf("AddProtocolAddress(1, %+v, {}): %s", v4ProtocolAddr, err) - } - routeTable = append(routeTable, tcpip.Route{ - Destination: header.IPv4EmptySubnet, - NIC: 1, - }) - } - - if opts.EnableV6 { - v6ProtocolAddr := tcpip.ProtocolAddress{ - Protocol: ipv6.ProtocolNumber, - AddressWithPrefix: StackV6AddrWithPrefix, - } - if err := s.AddProtocolAddress(1, v6ProtocolAddr, stack.AddressProperties{}); err != nil { - t.Fatalf("AddProtocolAddress(1, %+v, {}): %s", v6ProtocolAddr, err) - } - routeTable = append(routeTable, tcpip.Route{ - Destination: header.IPv6EmptySubnet, - NIC: 1, - }) - } - - s.SetRouteTable(routeTable) - - return &Context{ - t: t, - s: s, - linkEP: ep, - WindowScale: uint8(tcp.FindWndScale(recvBufferSize)), - } -} - -// Cleanup closes the context endpoint if required. -func (c *Context) Cleanup() { - if c.EP != nil { - c.EP.Close() - } - c.Stack().Close() -} - -// Stack returns a reference to the stack in the Context. -func (c *Context) Stack() *stack.Stack { - return c.s -} - -// CheckNoPacketTimeout verifies that no packet is received during the time -// specified by wait. -func (c *Context) CheckNoPacketTimeout(errMsg string, wait time.Duration) { - c.t.Helper() - - ctx, cancel := context.WithTimeout(context.Background(), wait) - defer cancel() - if _, ok := c.linkEP.ReadContext(ctx); ok { - c.t.Fatal(errMsg) - } -} - -// CheckNoPacket verifies that no packet is received for 1 second. -func (c *Context) CheckNoPacket(errMsg string) { - c.CheckNoPacketTimeout(errMsg, 1*time.Second) -} - -// GetPacketWithTimeout reads a packet from the link layer endpoint and verifies -// that it is an IPv4 packet with the expected source and destination -// addresses. If no packet is received in the specified timeout it will return -// nil. -func (c *Context) GetPacketWithTimeout(timeout time.Duration) []byte { - c.t.Helper() - - ctx, cancel := context.WithTimeout(context.Background(), timeout) - defer cancel() - p, ok := c.linkEP.ReadContext(ctx) - if !ok { - return nil - } - - if p.Proto != ipv4.ProtocolNumber { - c.t.Fatalf("Bad network protocol: got %v, wanted %v", p.Proto, ipv4.ProtocolNumber) - } - - // Just check that the stack set the transport protocol number for outbound - // TCP messages. - // TODO(gvisor.dev/issues/3810): Remove when protocol numbers are part - // of the headerinfo. - if p.Pkt.TransportProtocolNumber != tcp.ProtocolNumber { - c.t.Fatalf("got p.Pkt.TransportProtocolNumber = %d, want = %d", p.Pkt.TransportProtocolNumber, tcp.ProtocolNumber) - } - - vv := buffer.NewVectorisedView(p.Pkt.Size(), p.Pkt.Views()) - b := vv.ToView() - - if p.Pkt.GSOOptions.Type != stack.GSONone && p.Pkt.GSOOptions.L3HdrLen != header.IPv4MinimumSize { - c.t.Errorf("got L3HdrLen = %d, want = %d", p.Pkt.GSOOptions.L3HdrLen, header.IPv4MinimumSize) - } - - checker.IPv4(c.t, b, checker.SrcAddr(StackAddr), checker.DstAddr(TestAddr)) - return b -} - -// GetPacket reads a packet from the link layer endpoint and verifies -// that it is an IPv4 packet with the expected source and destination -// addresses. -func (c *Context) GetPacket() []byte { - c.t.Helper() - - p := c.GetPacketWithTimeout(5 * time.Second) - if p == nil { - c.t.Fatalf("Packet wasn't written out") - return nil - } - - return p -} - -// GetPacketNonBlocking reads a packet from the link layer endpoint -// and verifies that it is an IPv4 packet with the expected source -// and destination address. If no packet is available it will return -// nil immediately. -func (c *Context) GetPacketNonBlocking() []byte { - c.t.Helper() - - p, ok := c.linkEP.Read() - if !ok { - return nil - } - - if p.Proto != ipv4.ProtocolNumber { - c.t.Fatalf("Bad network protocol: got %v, wanted %v", p.Proto, ipv4.ProtocolNumber) - } - - // Just check that the stack set the transport protocol number for outbound - // TCP messages. - // TODO(gvisor.dev/issues/3810): Remove when protocol numbers are part - // of the headerinfo. - if p.Pkt.TransportProtocolNumber != tcp.ProtocolNumber { - c.t.Fatalf("got p.Pkt.TransportProtocolNumber = %d, want = %d", p.Pkt.TransportProtocolNumber, tcp.ProtocolNumber) - } - - vv := buffer.NewVectorisedView(p.Pkt.Size(), p.Pkt.Views()) - b := vv.ToView() - - checker.IPv4(c.t, b, checker.SrcAddr(StackAddr), checker.DstAddr(TestAddr)) - return b -} - -// SendICMPPacket builds and sends an ICMPv4 packet via the link layer endpoint. -func (c *Context) SendICMPPacket(typ header.ICMPv4Type, code header.ICMPv4Code, p1, p2 []byte, maxTotalSize int) { - // Allocate a buffer data and headers. - buf := buffer.NewView(header.IPv4MinimumSize + header.ICMPv4PayloadOffset + len(p2)) - if len(buf) > maxTotalSize { - buf = buf[:maxTotalSize] - } - - ip := header.IPv4(buf) - ip.Encode(&header.IPv4Fields{ - TotalLength: uint16(len(buf)), - TTL: 65, - Protocol: uint8(header.ICMPv4ProtocolNumber), - SrcAddr: TestAddr, - DstAddr: StackAddr, - }) - ip.SetChecksum(^ip.CalculateChecksum()) - - icmp := header.ICMPv4(buf[header.IPv4MinimumSize:]) - icmp.SetType(typ) - icmp.SetCode(code) - const icmpv4VariableHeaderOffset = 4 - copy(icmp[icmpv4VariableHeaderOffset:], p1) - copy(icmp[header.ICMPv4PayloadOffset:], p2) - icmp.SetChecksum(0) - checksum := ^header.Checksum(icmp, 0 /* initial */) - icmp.SetChecksum(checksum) - - // Inject packet. - pkt := stack.NewPacketBuffer(stack.PacketBufferOptions{ - Data: buf.ToVectorisedView(), - }) - defer pkt.DecRef() - c.linkEP.InjectInbound(ipv4.ProtocolNumber, pkt) -} - -// BuildSegment builds a TCP segment based on the given Headers and payload. -func (c *Context) BuildSegment(payload []byte, h *Headers) buffer.VectorisedView { - return c.BuildSegmentWithAddrs(payload, h, TestAddr, StackAddr) -} - -// BuildSegmentWithAddrs builds a TCP segment based on the given Headers, -// payload and source and destination IPv4 addresses. -func (c *Context) BuildSegmentWithAddrs(payload []byte, h *Headers, src, dst tcpip.Address) buffer.VectorisedView { - // Allocate a buffer for data and headers. - buf := buffer.NewView(header.TCPMinimumSize + header.IPv4MinimumSize + len(h.TCPOpts) + len(payload)) - copy(buf[len(buf)-len(payload):], payload) - copy(buf[len(buf)-len(payload)-len(h.TCPOpts):], h.TCPOpts) - - // Initialize the IP header. - ip := header.IPv4(buf) - ip.Encode(&header.IPv4Fields{ - TotalLength: uint16(len(buf)), - TTL: 65, - Protocol: uint8(tcp.ProtocolNumber), - SrcAddr: src, - DstAddr: dst, - }) - ip.SetChecksum(^ip.CalculateChecksum()) - - // Initialize the TCP header. - t := header.TCP(buf[header.IPv4MinimumSize:]) - t.Encode(&header.TCPFields{ - SrcPort: h.SrcPort, - DstPort: h.DstPort, - SeqNum: uint32(h.SeqNum), - AckNum: uint32(h.AckNum), - DataOffset: uint8(header.TCPMinimumSize + len(h.TCPOpts)), - Flags: h.Flags, - WindowSize: uint16(h.RcvWnd), - }) - - // Calculate the TCP pseudo-header checksum. - xsum := header.PseudoHeaderChecksum(tcp.ProtocolNumber, src, dst, uint16(len(t))) - - // Calculate the TCP checksum and set it. - xsum = header.Checksum(payload, xsum) - t.SetChecksum(^t.CalculateChecksum(xsum)) - - // Inject packet. - return buf.ToVectorisedView() -} - -// SendSegment sends a TCP segment that has already been built and written to a -// buffer.VectorisedView. -func (c *Context) SendSegment(s buffer.VectorisedView) { - pkt := stack.NewPacketBuffer(stack.PacketBufferOptions{ - Data: s, - }) - defer pkt.DecRef() - c.linkEP.InjectInbound(ipv4.ProtocolNumber, pkt) -} - -// SendPacket builds and sends a TCP segment(with the provided payload & TCP -// headers) in an IPv4 packet via the link layer endpoint. -func (c *Context) SendPacket(payload []byte, h *Headers) { - pkt := stack.NewPacketBuffer(stack.PacketBufferOptions{ - Data: c.BuildSegment(payload, h), - }) - defer pkt.DecRef() - c.linkEP.InjectInbound(ipv4.ProtocolNumber, pkt) -} - -// SendPacketWithAddrs builds and sends a TCP segment(with the provided payload -// & TCPheaders) in an IPv4 packet via the link layer endpoint using the -// provided source and destination IPv4 addresses. -func (c *Context) SendPacketWithAddrs(payload []byte, h *Headers, src, dst tcpip.Address) { - pkt := stack.NewPacketBuffer(stack.PacketBufferOptions{ - Data: c.BuildSegmentWithAddrs(payload, h, src, dst), - }) - c.linkEP.InjectInbound(ipv4.ProtocolNumber, pkt) -} - -// SendAck sends an ACK packet. -func (c *Context) SendAck(seq seqnum.Value, bytesReceived int) { - c.SendAckWithSACK(seq, bytesReceived, nil) -} - -// SendAckWithSACK sends an ACK packet which includes the sackBlocks specified. -func (c *Context) SendAckWithSACK(seq seqnum.Value, bytesReceived int, sackBlocks []header.SACKBlock) { - options := make([]byte, 40) - offset := 0 - if len(sackBlocks) > 0 { - offset += header.EncodeNOP(options[offset:]) - offset += header.EncodeNOP(options[offset:]) - offset += header.EncodeSACKBlocks(sackBlocks, options[offset:]) - } - - c.SendPacket(nil, &Headers{ - SrcPort: TestPort, - DstPort: c.Port, - Flags: header.TCPFlagAck, - SeqNum: seq, - AckNum: c.IRS.Add(1 + seqnum.Size(bytesReceived)), - RcvWnd: 30000, - TCPOpts: options[:offset], - }) -} - -// ReceiveAndCheckPacket reads a packet from the link layer endpoint and -// verifies that the packet packet payload of packet matches the slice -// of data indicated by offset & size. -func (c *Context) ReceiveAndCheckPacket(data []byte, offset, size int) { - c.t.Helper() - - c.ReceiveAndCheckPacketWithOptions(data, offset, size, 0) -} - -// ReceiveAndCheckPacketWithOptions reads a packet from the link layer endpoint -// and verifies that the packet packet payload of packet matches the slice of -// data indicated by offset & size and skips optlen bytes in addition to the IP -// TCP headers when comparing the data. -func (c *Context) ReceiveAndCheckPacketWithOptions(data []byte, offset, size, optlen int) { - c.t.Helper() - - b := c.GetPacket() - checker.IPv4(c.t, b, - checker.PayloadLen(size+header.TCPMinimumSize+optlen), - checker.TCP( - checker.DstPort(TestPort), - checker.TCPSeqNum(uint32(c.IRS.Add(seqnum.Size(1+offset)))), - checker.TCPAckNum(uint32(seqnum.Value(TestInitialSequenceNumber).Add(1))), - checker.TCPFlagsMatch(header.TCPFlagAck, ^header.TCPFlagPsh), - ), - ) - - pdata := data[offset:][:size] - if p := b[header.IPv4MinimumSize+header.TCPMinimumSize+optlen:]; bytes.Compare(pdata, p) != 0 { - c.t.Fatalf("Data is different: expected %v, got %v", pdata, p) - } -} - -// ReceiveNonBlockingAndCheckPacket reads a packet from the link layer endpoint -// and verifies that the packet packet payload of packet matches the slice of -// data indicated by offset & size. It returns true if a packet was received and -// processed. -func (c *Context) ReceiveNonBlockingAndCheckPacket(data []byte, offset, size int) bool { - c.t.Helper() - - b := c.GetPacketNonBlocking() - if b == nil { - return false - } - checker.IPv4(c.t, b, - checker.PayloadLen(size+header.TCPMinimumSize), - checker.TCP( - checker.DstPort(TestPort), - checker.TCPSeqNum(uint32(c.IRS.Add(seqnum.Size(1+offset)))), - checker.TCPAckNum(uint32(seqnum.Value(TestInitialSequenceNumber).Add(1))), - checker.TCPFlagsMatch(header.TCPFlagAck, ^header.TCPFlagPsh), - ), - ) - - pdata := data[offset:][:size] - if p := b[header.IPv4MinimumSize+header.TCPMinimumSize:]; bytes.Compare(pdata, p) != 0 { - c.t.Fatalf("Data is different: expected %v, got %v", pdata, p) - } - return true -} - -// CreateV6Endpoint creates and initializes c.ep as a IPv6 Endpoint. If v6Only -// is true then it sets the IP_V6ONLY option on the socket to make it a IPv6 -// only endpoint instead of a default dual stack socket. -func (c *Context) CreateV6Endpoint(v6only bool) { - var err tcpip.Error - c.EP, err = c.s.NewEndpoint(tcp.ProtocolNumber, ipv6.ProtocolNumber, &c.WQ) - if err != nil { - c.t.Fatalf("NewEndpoint failed: %v", err) - } - - c.EP.SocketOptions().SetV6Only(v6only) -} - -// GetV6Packet reads a single packet from the link layer endpoint of the context -// and asserts that it is an IPv6 Packet with the expected src/dest addresses. -func (c *Context) GetV6Packet() []byte { - c.t.Helper() - - ctx, cancel := context.WithTimeout(context.Background(), 2*time.Second) - defer cancel() - p, ok := c.linkEP.ReadContext(ctx) - if !ok { - c.t.Fatalf("Packet wasn't written out") - return nil - } - - if p.Proto != ipv6.ProtocolNumber { - c.t.Fatalf("Bad network protocol: got %v, wanted %v", p.Proto, ipv6.ProtocolNumber) - } - vv := buffer.NewVectorisedView(p.Pkt.Size(), p.Pkt.Views()) - b := vv.ToView() - - checker.IPv6(c.t, b, checker.SrcAddr(StackV6Addr), checker.DstAddr(TestV6Addr)) - return b -} - -// SendV6Packet builds and sends an IPv6 Packet via the link layer endpoint of -// the context. -func (c *Context) SendV6Packet(payload []byte, h *Headers) { - c.SendV6PacketWithAddrs(payload, h, TestV6Addr, StackV6Addr) -} - -// SendV6PacketWithAddrs builds and sends an IPv6 Packet via the link layer -// endpoint of the context using the provided source and destination IPv6 -// addresses. -func (c *Context) SendV6PacketWithAddrs(payload []byte, h *Headers, src, dst tcpip.Address) { - // Allocate a buffer for data and headers. - buf := buffer.NewView(header.TCPMinimumSize + header.IPv6MinimumSize + len(payload)) - copy(buf[len(buf)-len(payload):], payload) - - // Initialize the IP header. - ip := header.IPv6(buf) - ip.Encode(&header.IPv6Fields{ - PayloadLength: uint16(header.TCPMinimumSize + len(payload)), - TransportProtocol: tcp.ProtocolNumber, - HopLimit: 65, - SrcAddr: src, - DstAddr: dst, - }) - - // Initialize the TCP header. - t := header.TCP(buf[header.IPv6MinimumSize:]) - t.Encode(&header.TCPFields{ - SrcPort: h.SrcPort, - DstPort: h.DstPort, - SeqNum: uint32(h.SeqNum), - AckNum: uint32(h.AckNum), - DataOffset: header.TCPMinimumSize, - Flags: h.Flags, - WindowSize: uint16(h.RcvWnd), - }) - - // Calculate the TCP pseudo-header checksum. - xsum := header.PseudoHeaderChecksum(tcp.ProtocolNumber, src, dst, uint16(len(t))) - - // Calculate the TCP checksum and set it. - xsum = header.Checksum(payload, xsum) - t.SetChecksum(^t.CalculateChecksum(xsum)) - - // Inject packet. - pkt := stack.NewPacketBuffer(stack.PacketBufferOptions{ - Data: buf.ToVectorisedView(), - }) - c.linkEP.InjectInbound(ipv6.ProtocolNumber, pkt) -} - -// CreateConnected creates a connected TCP endpoint. -func (c *Context) CreateConnected(iss seqnum.Value, rcvWnd seqnum.Size, epRcvBuf int) { - c.CreateConnectedWithRawOptions(iss, rcvWnd, epRcvBuf, nil) -} - -// Connect performs the 3-way handshake for c.EP with the provided Initial -// Sequence Number (iss) and receive window(rcvWnd) and any options if -// specified. -// -// It also sets the receive buffer for the endpoint to the specified -// value in epRcvBuf. -// -// PreCondition: c.EP must already be created. -func (c *Context) Connect(iss seqnum.Value, rcvWnd seqnum.Size, options []byte) { - c.t.Helper() - - // Start connection attempt. - waitEntry, notifyCh := waiter.NewChannelEntry(nil) - c.WQ.EventRegister(&waitEntry, waiter.WritableEvents) - defer c.WQ.EventUnregister(&waitEntry) - - err := c.EP.Connect(tcpip.FullAddress{Addr: TestAddr, Port: TestPort}) - if _, ok := err.(*tcpip.ErrConnectStarted); !ok { - c.t.Fatalf("Unexpected return value from Connect: %v", err) - } - - // Receive SYN packet. - b := c.GetPacket() - checker.IPv4(c.t, b, - checker.TCP( - checker.DstPort(TestPort), - checker.TCPFlags(header.TCPFlagSyn), - ), - ) - if got, want := tcp.EndpointState(c.EP.State()), tcp.StateSynSent; got != want { - c.t.Fatalf("Unexpected endpoint state: want %v, got %v", want, got) - } - - tcpHdr := header.TCP(header.IPv4(b).Payload()) - synOpts := header.ParseSynOptions(tcpHdr.Options(), false /* isAck */) - c.IRS = seqnum.Value(tcpHdr.SequenceNumber()) - - c.SendPacket(nil, &Headers{ - SrcPort: tcpHdr.DestinationPort(), - DstPort: tcpHdr.SourcePort(), - Flags: header.TCPFlagSyn | header.TCPFlagAck, - SeqNum: iss, - AckNum: c.IRS.Add(1), - RcvWnd: rcvWnd, - TCPOpts: options, - }) - - // Receive ACK packet. - checker.IPv4(c.t, c.GetPacket(), - checker.TCP( - checker.DstPort(TestPort), - checker.TCPFlags(header.TCPFlagAck), - checker.TCPSeqNum(uint32(c.IRS)+1), - checker.TCPAckNum(uint32(iss)+1), - ), - ) - - // Wait for connection to be established. - select { - case <-notifyCh: - if err := c.EP.LastError(); err != nil { - c.t.Fatalf("Unexpected error when connecting: %v", err) - } - case <-time.After(1 * time.Second): - c.t.Fatalf("Timed out waiting for connection") - } - if got, want := tcp.EndpointState(c.EP.State()), tcp.StateEstablished; got != want { - c.t.Fatalf("Unexpected endpoint state: want %v, got %v", want, got) - } - - c.RcvdWindowScale = uint8(synOpts.WS) - c.Port = tcpHdr.SourcePort() -} - -// Create creates a TCP endpoint. -func (c *Context) Create(epRcvBuf int) { - // Create TCP endpoint. - var err tcpip.Error - c.EP, err = c.s.NewEndpoint(tcp.ProtocolNumber, ipv4.ProtocolNumber, &c.WQ) - if err != nil { - c.t.Fatalf("NewEndpoint failed: %v", err) - } - - if epRcvBuf != -1 { - c.EP.SocketOptions().SetReceiveBufferSize(int64(epRcvBuf)*2, true /* notify */) - } -} - -// CreateConnectedWithRawOptions creates a connected TCP endpoint and sends -// the specified option bytes as the Option field in the initial SYN packet. -// -// It also sets the receive buffer for the endpoint to the specified -// value in epRcvBuf. -func (c *Context) CreateConnectedWithRawOptions(iss seqnum.Value, rcvWnd seqnum.Size, epRcvBuf int, options []byte) { - c.Create(epRcvBuf) - c.Connect(iss, rcvWnd, options) -} - -// RawEndpoint is just a small wrapper around a TCP endpoint's state to make -// sending data and ACK packets easy while being able to manipulate the sequence -// numbers and timestamp values as needed. -type RawEndpoint struct { - C *Context - SrcPort uint16 - DstPort uint16 - Flags header.TCPFlags - NextSeqNum seqnum.Value - AckNum seqnum.Value - WndSize seqnum.Size - RecentTS uint32 // Stores the latest timestamp to echo back. - TSVal uint32 // TSVal stores the last timestamp sent by this endpoint. - - // SackPermitted is true if SACKPermitted option was negotiated for this endpoint. - SACKPermitted bool -} - -// SendPacketWithTS embeds the provided tsVal in the Timestamp option -// for the packet to be sent out. -func (r *RawEndpoint) SendPacketWithTS(payload []byte, tsVal uint32) { - r.TSVal = tsVal - tsOpt := [12]byte{header.TCPOptionNOP, header.TCPOptionNOP} - header.EncodeTSOption(r.TSVal, r.RecentTS, tsOpt[2:]) - r.SendPacket(payload, tsOpt[:]) -} - -// SendPacket is a small wrapper function to build and send packets. -func (r *RawEndpoint) SendPacket(payload []byte, opts []byte) { - packetHeaders := &Headers{ - SrcPort: r.SrcPort, - DstPort: r.DstPort, - Flags: r.Flags, - SeqNum: r.NextSeqNum, - AckNum: r.AckNum, - RcvWnd: r.WndSize, - TCPOpts: opts, - } - r.C.SendPacket(payload, packetHeaders) - r.NextSeqNum = r.NextSeqNum.Add(seqnum.Size(len(payload))) -} - -// VerifyAndReturnACKWithTS verifies that the tsEcr field int he ACK matches -// the provided tsVal as well as returns the original packet. -func (r *RawEndpoint) VerifyAndReturnACKWithTS(tsVal uint32) []byte { - r.C.t.Helper() - // Read ACK and verify that tsEcr of ACK packet is [1,2,3,4] - ackPacket := r.C.GetPacket() - checker.IPv4(r.C.t, ackPacket, - checker.TCP( - checker.DstPort(r.SrcPort), - checker.TCPFlags(header.TCPFlagAck), - checker.TCPSeqNum(uint32(r.AckNum)), - checker.TCPAckNum(uint32(r.NextSeqNum)), - checker.TCPTimestampChecker(true, 0, tsVal), - ), - ) - // Store the parsed TSVal from the ack as recentTS. - tcpSeg := header.TCP(header.IPv4(ackPacket).Payload()) - opts := tcpSeg.ParsedOptions() - r.RecentTS = opts.TSVal - return ackPacket -} - -// VerifyACKWithTS verifies that the tsEcr field in the ack matches the provided -// tsVal. -func (r *RawEndpoint) VerifyACKWithTS(tsVal uint32) { - r.C.t.Helper() - _ = r.VerifyAndReturnACKWithTS(tsVal) -} - -// VerifyACKRcvWnd verifies that the window advertised by the incoming ACK -// matches the provided rcvWnd. -func (r *RawEndpoint) VerifyACKRcvWnd(rcvWnd uint16) { - r.C.t.Helper() - ackPacket := r.C.GetPacket() - checker.IPv4(r.C.t, ackPacket, - checker.TCP( - checker.DstPort(r.SrcPort), - checker.TCPFlags(header.TCPFlagAck), - checker.TCPSeqNum(uint32(r.AckNum)), - checker.TCPAckNum(uint32(r.NextSeqNum)), - checker.TCPWindow(rcvWnd), - ), - ) -} - -// VerifyACKNoSACK verifies that the ACK does not contain a SACK block. -func (r *RawEndpoint) VerifyACKNoSACK() { - r.VerifyACKHasSACK(nil) -} - -// VerifyACKHasSACK verifies that the ACK contains the specified SACKBlocks. -func (r *RawEndpoint) VerifyACKHasSACK(sackBlocks []header.SACKBlock) { - // Read ACK and verify that the TCP options in the segment do - // not contain a SACK block. - ackPacket := r.C.GetPacket() - checker.IPv4(r.C.t, ackPacket, - checker.TCP( - checker.DstPort(r.SrcPort), - checker.TCPFlags(header.TCPFlagAck), - checker.TCPSeqNum(uint32(r.AckNum)), - checker.TCPAckNum(uint32(r.NextSeqNum)), - checker.TCPSACKBlockChecker(sackBlocks), - ), - ) -} - -// CreateConnectedWithOptionsNoDelay just calls CreateConnectedWithOptions -// without delay. -func (c *Context) CreateConnectedWithOptionsNoDelay(wantOptions header.TCPSynOptions) *RawEndpoint { - return c.CreateConnectedWithOptions(wantOptions, 0 /* delay */) -} - -// CreateConnectedWithOptions creates and connects c.ep with the specified TCP -// options enabled and returns a RawEndpoint which represents the other end of -// the connection. It delays before a SYNACK is sent. This makes c.EP have a -// higher RTT estimate so that spurious TLPs aren't sent in tests, which helps -// reduce flakiness. -// -// It also verifies where required(eg.Timestamp) that the ACK to the SYN-ACK -// does not carry an option that was not requested. -func (c *Context) CreateConnectedWithOptions(wantOptions header.TCPSynOptions, delay time.Duration) *RawEndpoint { - var err tcpip.Error - c.EP, err = c.s.NewEndpoint(tcp.ProtocolNumber, ipv4.ProtocolNumber, &c.WQ) - if err != nil { - c.t.Fatalf("c.s.NewEndpoint(tcp, ipv4...) = %v", err) - } - if got, want := tcp.EndpointState(c.EP.State()), tcp.StateInitial; got != want { - c.t.Fatalf("Unexpected endpoint state: want %v, got %v", want, got) - } - - // Start connection attempt. - waitEntry, notifyCh := waiter.NewChannelEntry(nil) - c.WQ.EventRegister(&waitEntry, waiter.WritableEvents) - defer c.WQ.EventUnregister(&waitEntry) - - testFullAddr := tcpip.FullAddress{Addr: TestAddr, Port: TestPort} - err = c.EP.Connect(testFullAddr) - if _, ok := err.(*tcpip.ErrConnectStarted); !ok { - c.t.Fatalf("c.ep.Connect(%v) = %v", testFullAddr, err) - } - // Receive SYN packet. - b := c.GetPacket() - // Validate that the syn has the timestamp option and a valid - // TS value. - mss := uint16(c.linkEP.MTU() - header.IPv4MinimumSize - header.TCPMinimumSize) - - synChecker := checker.TCP( - checker.DstPort(TestPort), - checker.TCPFlags(header.TCPFlagSyn), - checker.TCPSynOptions(header.TCPSynOptions{ - MSS: mss, - TS: true, - WS: int(c.WindowScale), - SACKPermitted: c.SACKEnabled(), - }), - ) - checker.IPv4(c.t, b, synChecker) - if got, want := tcp.EndpointState(c.EP.State()), tcp.StateSynSent; got != want { - c.t.Fatalf("Unexpected endpoint state: want %v, got %v", want, got) - } - - tcpSeg := header.TCP(header.IPv4(b).Payload()) - synOptions := header.ParseSynOptions(tcpSeg.Options(), false) - - // Build options w/ tsVal to be sent in the SYN-ACK. - synAckOptions := make([]byte, header.TCPOptionsMaximumSize) - offset := 0 - if wantOptions.WS != -1 { - offset += header.EncodeWSOption(wantOptions.WS, synAckOptions[offset:]) - } - if wantOptions.TS { - offset += header.EncodeTSOption(wantOptions.TSVal, synOptions.TSVal, synAckOptions[offset:]) - } - if wantOptions.SACKPermitted { - offset += header.EncodeSACKPermittedOption(synAckOptions[offset:]) - } - - offset += header.AddTCPOptionPadding(synAckOptions, offset) - - // Build SYN-ACK. - c.IRS = seqnum.Value(tcpSeg.SequenceNumber()) - iss := seqnum.Value(TestInitialSequenceNumber) - if delay > 0 { - // Sleep so that RTT is increased. - time.Sleep(delay) - } - c.SendPacket(nil, &Headers{ - SrcPort: tcpSeg.DestinationPort(), - DstPort: tcpSeg.SourcePort(), - Flags: header.TCPFlagSyn | header.TCPFlagAck, - SeqNum: iss, - AckNum: c.IRS.Add(1), - RcvWnd: 30000, - TCPOpts: synAckOptions[:offset], - }) - - // Read ACK. - var ackPacket []byte - // Ignore retransimitted SYN packets. - for { - packet := c.GetPacket() - if header.TCP(header.IPv4(packet).Payload()).Flags()&header.TCPFlagSyn != 0 { - checker.IPv4(c.t, packet, synChecker) - } else { - ackPacket = packet - break - } - } - - // Verify TCP header fields. - tcpCheckers := []checker.TransportChecker{ - checker.DstPort(TestPort), - checker.TCPFlags(header.TCPFlagAck), - checker.TCPSeqNum(uint32(c.IRS) + 1), - checker.TCPAckNum(uint32(iss) + 1), - } - - // Verify that tsEcr of ACK packet is wantOptions.TSVal if the - // timestamp option was enabled, if not then we verify that - // there is no timestamp in the ACK packet. - if wantOptions.TS { - tcpCheckers = append(tcpCheckers, checker.TCPTimestampChecker(true, 0, wantOptions.TSVal)) - } else { - tcpCheckers = append(tcpCheckers, checker.TCPTimestampChecker(false, 0, 0)) - } - - checker.IPv4(c.t, ackPacket, checker.TCP(tcpCheckers...)) - - ackSeg := header.TCP(header.IPv4(ackPacket).Payload()) - ackOptions := ackSeg.ParsedOptions() - - // Wait for connection to be established. - select { - case <-notifyCh: - if err := c.EP.LastError(); err != nil { - c.t.Fatalf("Unexpected error when connecting: %v", err) - } - case <-time.After(1 * time.Second): - c.t.Fatalf("Timed out waiting for connection") - } - if got, want := tcp.EndpointState(c.EP.State()), tcp.StateEstablished; got != want { - c.t.Fatalf("Unexpected endpoint state: want %v, got %v", want, got) - } - - // Store the source port in use by the endpoint. - c.Port = tcpSeg.SourcePort() - - // Mark in context that timestamp option is enabled for this endpoint. - c.TimeStampEnabled = true - c.RcvdWindowScale = uint8(synOptions.WS) - return &RawEndpoint{ - C: c, - SrcPort: tcpSeg.DestinationPort(), - DstPort: tcpSeg.SourcePort(), - Flags: header.TCPFlagAck | header.TCPFlagPsh, - NextSeqNum: iss + 1, - AckNum: c.IRS.Add(1), - WndSize: 30000, - RecentTS: ackOptions.TSVal, - TSVal: wantOptions.TSVal, - SACKPermitted: wantOptions.SACKPermitted, - } -} - -// AcceptWithOptionsNoDelay delegates call to AcceptWithOptions without delay. -func (c *Context) AcceptWithOptionsNoDelay(wndScale int, synOptions header.TCPSynOptions) *RawEndpoint { - return c.AcceptWithOptions(wndScale, synOptions, 0 /* delay */) -} - -// AcceptWithOptions initializes a listening endpoint and connects to it with -// the provided options enabled. It delays before the final ACK of the 3WHS is -// sent. It also verifies that the SYN-ACK has the expected values for the -// provided options. -// -// The function returns a RawEndpoint representing the other end of the accepted -// endpoint. -func (c *Context) AcceptWithOptions(wndScale int, synOptions header.TCPSynOptions, delay time.Duration) *RawEndpoint { - // Create EP and start listening. - wq := &waiter.Queue{} - ep, err := c.s.NewEndpoint(tcp.ProtocolNumber, ipv4.ProtocolNumber, wq) - if err != nil { - c.t.Fatalf("NewEndpoint failed: %v", err) - } - defer ep.Close() - - if err := ep.Bind(tcpip.FullAddress{Port: StackPort}); err != nil { - c.t.Fatalf("Bind failed: %v", err) - } - if got, want := tcp.EndpointState(ep.State()), tcp.StateBound; got != want { - c.t.Errorf("Unexpected endpoint state: want %v, got %v", want, got) - } - - if err := ep.Listen(10); err != nil { - c.t.Fatalf("Listen failed: %v", err) - } - if got, want := tcp.EndpointState(ep.State()), tcp.StateListen; got != want { - c.t.Errorf("Unexpected endpoint state: want %v, got %v", want, got) - } - - rep := c.PassiveConnectWithOptions(100, wndScale, synOptions, delay) - - // Try to accept the connection. - we, ch := waiter.NewChannelEntry(nil) - wq.EventRegister(&we, waiter.ReadableEvents) - defer wq.EventUnregister(&we) - - c.EP, _, err = ep.Accept(nil) - if _, ok := err.(*tcpip.ErrWouldBlock); ok { - // Wait for connection to be established. - select { - case <-ch: - c.EP, _, err = ep.Accept(nil) - if err != nil { - c.t.Fatalf("Accept failed: %v", err) - } - - case <-time.After(1 * time.Second): - c.t.Fatalf("Timed out waiting for accept") - } - } - if got, want := tcp.EndpointState(c.EP.State()), tcp.StateEstablished; got != want { - c.t.Errorf("Unexpected endpoint state: want %v, got %v", want, got) - } - - return rep -} - -// PassiveConnect just disables WindowScaling and delegates the call to -// PassiveConnectWithOptions. -func (c *Context) PassiveConnect(maxPayload, wndScale int, synOptions header.TCPSynOptions) { - synOptions.WS = -1 - c.PassiveConnectWithOptions(maxPayload, wndScale, synOptions, 0 /* delay */) -} - -// PassiveConnectWithOptions initiates a new connection (with the specified TCP -// options enabled) to the port on which the Context.ep is listening for new -// connections. It also validates that the SYN-ACK has the expected values for -// the enabled options. The final ACK of the handshake is delayed by specified -// duration. -// -// NOTE: MSS is not a negotiated option and it can be asymmetric -// in each direction. This function uses the maxPayload to set the MSS to be -// sent to the peer on a connect and validates that the MSS in the SYN-ACK -// response is equal to the MTU - (tcphdr len + iphdr len). -// -// wndScale is the expected window scale in the SYN-ACK and synOptions.WS is the -// value of the window scaling option to be sent in the SYN. If synOptions.WS > -// 0 then we send the WindowScale option. -func (c *Context) PassiveConnectWithOptions(maxPayload, wndScale int, synOptions header.TCPSynOptions, delay time.Duration) *RawEndpoint { - c.t.Helper() - opts := make([]byte, header.TCPOptionsMaximumSize) - offset := 0 - offset += header.EncodeMSSOption(uint32(maxPayload), opts) - - if synOptions.WS >= 0 { - offset += header.EncodeWSOption(3, opts[offset:]) - } - if synOptions.TS { - offset += header.EncodeTSOption(synOptions.TSVal, synOptions.TSEcr, opts[offset:]) - } - - if synOptions.SACKPermitted { - offset += header.EncodeSACKPermittedOption(opts[offset:]) - } - - paddingToAdd := 4 - offset%4 - // Now add any padding bytes that might be required to quad align the - // options. - for i := offset; i < offset+paddingToAdd; i++ { - opts[i] = header.TCPOptionNOP - } - offset += paddingToAdd - - // Send a SYN request. - iss := seqnum.Value(TestInitialSequenceNumber) - c.SendPacket(nil, &Headers{ - SrcPort: TestPort, - DstPort: StackPort, - Flags: header.TCPFlagSyn, - SeqNum: iss, - RcvWnd: 30000, - TCPOpts: opts[:offset], - }) - - // Receive the SYN-ACK reply. Make sure MSS and other expected options - // are present. - b := c.GetPacket() - tcp := header.TCP(header.IPv4(b).Payload()) - rcvdSynOptions := header.ParseSynOptions(tcp.Options(), true /* isAck */) - c.IRS = seqnum.Value(tcp.SequenceNumber()) - - tcpCheckers := []checker.TransportChecker{ - checker.SrcPort(StackPort), - checker.DstPort(TestPort), - checker.TCPFlags(header.TCPFlagAck | header.TCPFlagSyn), - checker.TCPAckNum(uint32(iss) + 1), - checker.TCPSynOptions(header.TCPSynOptions{MSS: synOptions.MSS, WS: wndScale, SACKPermitted: synOptions.SACKPermitted && c.SACKEnabled()}), - } - - // If TS option was enabled in the original SYN then add a checker to - // validate the Timestamp option in the SYN-ACK. - if synOptions.TS { - tcpCheckers = append(tcpCheckers, checker.TCPTimestampChecker(synOptions.TS, 0, synOptions.TSVal)) - } else { - tcpCheckers = append(tcpCheckers, checker.TCPTimestampChecker(false, 0, 0)) - } - - checker.IPv4(c.t, b, checker.TCP(tcpCheckers...)) - rcvWnd := seqnum.Size(30000) - ackHeaders := &Headers{ - SrcPort: TestPort, - DstPort: StackPort, - Flags: header.TCPFlagAck, - SeqNum: iss + 1, - AckNum: c.IRS + 1, - RcvWnd: rcvWnd, - } - - // If WS was expected to be in effect then scale the advertised window - // correspondingly. - if synOptions.WS > 0 { - ackHeaders.RcvWnd = rcvWnd >> byte(synOptions.WS) - } - - parsedOpts := tcp.ParsedOptions() - if synOptions.TS { - // Echo the tsVal back to the peer in the tsEcr field of the - // timestamp option. - // Increment TSVal by 1 from the value sent in the SYN and echo - // the TSVal in the SYN-ACK in the TSEcr field. - opts := [12]byte{header.TCPOptionNOP, header.TCPOptionNOP} - header.EncodeTSOption(synOptions.TSVal+1, parsedOpts.TSVal, opts[2:]) - ackHeaders.TCPOpts = opts[:] - } - - // Send ACK, delay if needed. - if delay > 0 { - time.Sleep(delay) - } - c.SendPacket(nil, ackHeaders) - - c.RcvdWindowScale = uint8(rcvdSynOptions.WS) - c.Port = StackPort - - return &RawEndpoint{ - C: c, - SrcPort: TestPort, - DstPort: StackPort, - Flags: header.TCPFlagPsh | header.TCPFlagAck, - NextSeqNum: iss + 1, - AckNum: c.IRS + 1, - WndSize: rcvWnd, - SACKPermitted: synOptions.SACKPermitted && c.SACKEnabled(), - RecentTS: parsedOpts.TSVal, - TSVal: synOptions.TSVal + 1, - } -} - -// SACKEnabled returns true if the TCP Protocol option SACKEnabled is set to true -// for the Stack in the context. -func (c *Context) SACKEnabled() bool { - var v tcpip.TCPSACKEnabled - if err := c.Stack().TransportProtocolOption(tcp.ProtocolNumber, &v); err != nil { - // Stack doesn't support SACK. So just return. - return false - } - return bool(v) -} - -// SetGSOEnabled enables or disables generic segmentation offload. -func (c *Context) SetGSOEnabled(enable bool) { - if enable { - c.linkEP.SupportedGSOKind = stack.HWGSOSupported - } else { - c.linkEP.SupportedGSOKind = stack.GSONotSupported - } -} - -// MSSWithoutOptions returns the value for the MSS used by the stack when no -// options are in use. -func (c *Context) MSSWithoutOptions() uint16 { - return uint16(c.linkEP.MTU() - header.IPv4MinimumSize - header.TCPMinimumSize) -} - -// MSSWithoutOptionsV6 returns the value for the MSS used by the stack when no -// options are in use for IPv6 packets. -func (c *Context) MSSWithoutOptionsV6() uint16 { - return uint16(c.linkEP.MTU() - header.IPv6MinimumSize - header.TCPMinimumSize) -} |