网卡对象绑定IP地址然后向网卡对象写入数据数据中将包含dst和src

2025-10-06 21:32:59 +08:00 · 2022-11-25 19:25:54 +08:00
parent 4589d971fd
commit 2312813aac
10 changed files with 808 additions and 43 deletions
--- a/ilist/list.go
+++ b/ilist/list.go
@@ -11,10 +11,10 @@ type Element interface {
 	Linker
 }

-type ElementMapper struct {}
+type ElementMapper struct{}

 func (ElementMapper) linkerFor(elem Element) Linker {
-	return elem;
+	return elem
 }

 type List struct {
@@ -31,6 +31,10 @@ func (l *List) Empty() bool {
 	return l.head == nil
 }

+func (l *List) Front() Element {
+	return l.head
+}
+
 func (l *List) Back() Element {
 	return l.tail
 }
--- a/tcpip/header/ipv4.go
+++ b/tcpip/header/ipv4.go
@@ -0,0 +1,30 @@
+package header
+
+import "netstack/tcpip"
+
+type IPv4 []byte
+
+const (
+	// IPv4MinimumSize is the minimum size of a valid IPv4 packet.
+	IPv4MinimumSize = 20
+
+	// IPv4MaximumHeaderSize is the maximum size of an IPv4 header. Given
+	// that there are only 4 bits to represents the header length in 32-bit
+	// units, the header cannot exceed 15*4 = 60 bytes.
+	IPv4MaximumHeaderSize = 60
+
+	// IPv4AddressSize is the size, in bytes, of an IPv4 address.
+	IPv4AddressSize = 4
+
+	// IPv4ProtocolNumber is IPv4's network protocol number.
+	IPv4ProtocolNumber tcpip.NetworkProtocolNumber = 0x0800
+
+	// IPv4Version is the version of the ipv4 protocol.
+	IPv4Version = 4
+
+	// IPv4Broadcast is the broadcast address of the IPv4 procotol.
+	IPv4Broadcast tcpip.Address = "\xff\xff\xff\xff"
+
+	// IPv4Any is the non-routable IPv4 "any" meta address.
+	IPv4Any tcpip.Address = "\x00\x00\x00\x00"
+)
--- a/tcpip/header/ipv6.go
+++ b/tcpip/header/ipv6.go
@@ -0,0 +1,23 @@
+package header
+
+import "netstack/tcpip"
+
+type IPv6 []byte
+
+const (
+	// IPv6MinimumSize is the minimum size of a valid IPv6 packet.
+	IPv6MinimumSize = 40
+
+	// IPv6AddressSize is the size, in bytes, of an IPv6 address.
+	IPv6AddressSize = 16
+
+	// IPv6ProtocolNumber is IPv6's network protocol number.
+	IPv6ProtocolNumber tcpip.NetworkProtocolNumber = 0x86dd
+
+	// IPv6Version is the version of the ipv6 protocol.
+	IPv6Version = 6
+
+	// IPv6MinimumMTU is the minimum MTU required by IPv6, per RFC 2460,
+	// section 5.
+	IPv6MinimumMTU = 1280
+)
--- a/tcpip/stack/nic.go
+++ b/tcpip/stack/nic.go
@@ -5,7 +5,10 @@ import (
 	"netstack/ilist"
 	"netstack/tcpip"
 	"netstack/tcpip/buffer"
+	"netstack/tcpip/header"
+	"strings"
 	"sync"
+	"sync/atomic"
 )

 // PrimaryEndpointBehavior 是端点首要行为的枚举
@@ -44,7 +47,7 @@ type NIC struct {
 	spoofing    bool
 	promiscuous bool // 混杂模式
 	primary     map[tcpip.NetworkProtocolNumber]*ilist.List
-	// 网络层端的记录
+	// 网络层端的记录 IP:网络端实现
 	endpoints map[NetworkEndpointID]*referencedNetworkEndpoint
 	// 子网的记录
 	subnets []tcpip.Subnet
@@ -67,6 +70,22 @@ func (n *NIC) attachLinkEndpoint() {
 	n.linkEP.Attach(n)
 }

+// setPromiscuousMode enables or disables promiscuous mode.
+// 设备网卡为混杂模式
+func (n *NIC) setPromiscuousMode(enable bool) {
+	n.mu.Lock()
+	n.promiscuous = enable
+	n.mu.Unlock()
+}
+
+// 判断网卡是否开启混杂模式
+func (n *NIC) isPromiscuousMode() bool {
+	n.mu.RLock()
+	rv := n.promiscuous
+	n.mu.RUnlock()
+	return rv
+}
+
 // 在NIC上添加addr地址，注册和初始化网络层协议
 // 相当于给网卡添加ip地址
 func (n *NIC) addAddressLocked(protocol tcpip.NetworkProtocolNumber, addr tcpip.Address,
@@ -76,9 +95,56 @@ func (n *NIC) addAddressLocked(protocol tcpip.NetworkProtocolNumber, addr tcpip.
 		log.Println("添加失败")
 		return nil, tcpip.ErrUnknownProtocol
 	}
-	log.Println(netProto.Number(), "添加ip", addr.String())
-	// TODO 接着这里实现 22/11/24 21:29
-	return nil, nil
+	log.Printf("基于[%d]协议 为 #%d 网卡 添加IP: %s\n", netProto.Number(), n.id, addr.String())
+
+	// 比如netProto是ipv4 会调用ipv4.NewEndpoint 新建一个网络端
+	ep, err := netProto.NewEndpoint(n.id, addr, n.stack, n, n.linkEP)
+	if err != nil {
+		return nil, err
+	}
+
+	// 获取网络层端的id 其实就是ip地址
+	id := *ep.ID()
+	if ref, ok := n.endpoints[id]; ok {
+		// 不是替换 且该id已经存在
+		if !replace {
+			return nil, tcpip.ErrDuplicateAddress
+		}
+		n.removeEndpointLocked(ref) // 这里被调用的时候已经上过锁了 NOTE
+	}
+
+	ref := &referencedNetworkEndpoint{
+		refs:           1,
+		ep:             ep,
+		nic:            n,
+		protocol:       protocol,
+		holdsInsertRef: true,
+	}
+
+	// Set up cache if link address resolution exists for this protocol.
+	if n.linkEP.Capabilities()&CapabilityResolutionRequired != 0 {
+		if _, ok := n.stack.linkAddrResolvers[protocol]; ok {
+			ref.linkCache = n.stack
+		}
+	}
+
+	// 注册该网络端
+	n.endpoints[id] = ref
+
+	l, ok := n.primary[protocol]
+	if !ok {
+		l = &ilist.List{}
+		n.primary[protocol] = l
+	}
+
+	switch peb {
+	case CanBePrimaryEndpoint:
+		l.PushBack(ref) // 目前走这一支
+	case FirstPrimaryEndpoint:
+		l.PushFront(ref)
+	}
+	log.Printf("Network Info: %v \n", ref.ep.ID())
+	return ref, nil
 }

 func (n *NIC) AddAddress(protocol tcpip.NetworkProtocolNumber, addr tcpip.Address) *tcpip.Error {
@@ -94,8 +160,235 @@ func (n *NIC) AddAddressWithOptions(protocol tcpip.NetworkProtocolNumber,
 	return err
 }

-func (n *NIC) DeliverNetworkPacket(linkEP LinkEndpoint, dstLinkAddr, srcLinkAddr tcpip.LinkAddress,
+// 删除一个网络端
+func (n *NIC) removeEndpointLocked(r *referencedNetworkEndpoint) {
+	id := *r.ep.ID()
+
+	// Nothing to do if the reference has already been replaced with a
+	// different one.
+	if n.endpoints[id] != r {
+		return
+	}
+
+	if r.holdsInsertRef {
+		panic("Reference count dropped to zero before being removed")
+	}
+
+	delete(n.endpoints, id)
+	wasInList := r.Next() != nil || r.Prev() != nil || r == n.primary[r.protocol].Front()
+	if wasInList {
+		n.primary[r.protocol].Remove(r)
+	}
+
+	r.ep.Close()
+}
+
+func (n *NIC) removeEndpoint(r *referencedNetworkEndpoint) {
+	n.mu.Lock()
+	n.removeEndpointLocked(r)
+	n.mu.Unlock()
+}
+
+// 根据address参数找到对应的网络层端
+func (n *NIC) findEndpoint(protocol tcpip.NetworkProtocolNumber, address tcpip.Address,
+	peb PrimaryEndpointBehavior) *referencedNetworkEndpoint {
+	id := NetworkEndpointID{address}
+
+	n.mu.RLock()
+	ref := n.endpoints[id]
+	if ref != nil && !ref.tryIncRef() {
+		ref = nil
+	}
+	spoofing := n.spoofing
+	n.mu.RUnlock()
+
+	if ref != nil || !spoofing {
+		return ref
+	}
+
+	// Try again with the lock in exclusive mode. If we still can't get the
+	// endpoint, create a new "temporary" endpoint. It will only exist while
+	// there's a route through it.
+	n.mu.Lock()
+	ref = n.endpoints[id]
+	if ref == nil || !ref.tryIncRef() {
+		ref, _ = n.addAddressLocked(protocol, address, peb, true)
+		if ref != nil {
+			ref.holdsInsertRef = false
+		}
+	}
+	n.mu.Unlock()
+	return ref
+}
+
+// AddSubnet adds a new subnet to n, so that it starts accepting packets
+// targeted at the given address and network protocol.
+// AddSubnet向n添加一个新子网，以便它开始接受针对给定地址和网络协议的数据包。
+func (n *NIC) AddSubnet(protocol tcpip.NetworkProtocolNumber, subnet tcpip.Subnet) {
+	n.mu.Lock()
+	n.subnets = append(n.subnets, subnet)
+	n.mu.Unlock()
+}
+
+// RemoveSubnet removes the given subnet from n.
+// 从n中删除一个子网
+func (n *NIC) RemoveSubnet(subnet tcpip.Subnet) {
+	n.mu.Lock()
+
+	// Use the same underlying array.
+	tmp := n.subnets[:0]
+	for _, sub := range n.subnets {
+		if sub != subnet {
+			tmp = append(tmp, sub)
+		}
+	}
+	n.subnets = tmp
+
+	n.mu.Unlock()
+}
+
+// ContainsSubnet reports whether this NIC contains the given subnet.
+// 判断 subnet 这个子网是否在该网卡下
+func (n *NIC) ContainsSubnet(subnet tcpip.Subnet) bool {
+	for _, s := range n.Subnets() {
+		if s == subnet {
+			return true
+		}
+	}
+	return false
+}
+
+// Subnets returns the Subnets associated with this NIC.
+// 获取该网卡的所有子网
+func (n *NIC) Subnets() []tcpip.Subnet {
+	n.mu.RLock()
+	defer n.mu.RUnlock()
+	sns := make([]tcpip.Subnet, 0, len(n.subnets)+len(n.endpoints))
+	for nid := range n.endpoints {
+		sn, err := tcpip.NewSubnet(nid.LocalAddress, tcpip.AddressMask(strings.Repeat("\xff", len(nid.LocalAddress))))
+		if err != nil {
+			// This should never happen as the mask has been carefully crafted to
+			// match the address.
+			panic("Invalid endpoint subnet: " + err.Error())
+		}
+		sns = append(sns, sn)
+	}
+	return append(sns, n.subnets...)
+}
+
+// 根据协议类型和目标地址，找出关联的Endpoint
+func (n *NIC) getRef(protocol tcpip.NetworkProtocolNumber, dst tcpip.Address) *referencedNetworkEndpoint {
+	id := NetworkEndpointID{dst}
+
+	n.mu.RLock()
+	if ref, ok := n.endpoints[id]; ok && ref.tryIncRef() {
+		log.Println("找到了目标地址: ", id)
+		n.mu.RUnlock()
+		return ref
+	}
+
+	promiscuous := n.promiscuous
+	// Check if the packet is for a subnet this NIC cares about.
+	if !promiscuous {
+		for _, sn := range n.subnets {
+			if sn.Contains(dst) {
+				promiscuous = true
+				break
+			}
+		}
+	}
+	n.mu.RUnlock()
+	if promiscuous {
+		// Try again with the lock in exclusive mode. If we still can't
+		// get the endpoint, create a new "temporary" one. It will only
+		// exist while there's a route through it.
+		n.mu.Lock()
+		if ref, ok := n.endpoints[id]; ok && ref.tryIncRef() {
+			n.mu.Unlock()
+			return ref
+		}
+		ref, err := n.addAddressLocked(protocol, dst, CanBePrimaryEndpoint, true)
+		n.mu.Unlock()
+		if err == nil {
+			ref.holdsInsertRef = false
+			return ref
+		}
+	}
+
+	return nil
+}
+
+func (n *NIC) DeliverNetworkPacket(linkEP LinkEndpoint, remoteLinkAddr, localLinkAddr tcpip.LinkAddress,
 	protocol tcpip.NetworkProtocolNumber, vv buffer.VectorisedView) {
 	// TODO 需要完成逻辑
-	log.Println(vv.ToView())
+	netProto, ok := n.stack.networkProtocols[protocol]
+	if !ok {
+		n.stack.stats.UnknownProtocolRcvdPackets.Increment()
+		return
+	}
+
+	if netProto.Number() == header.IPv4ProtocolNumber || netProto.Number() == header.IPv6ProtocolNumber {
+		n.stack.stats.IP.PacketsReceived.Increment()
+	}
+
+	if len(vv.First()) < netProto.MinimumPacketSize() {
+		n.stack.stats.MalformedRcvdPackets.Increment()
+		return
+	}
+	src, dst := netProto.ParseAddresses(vv.First())
+	log.Printf("设备[%s]准备从 [%s] 向 [%s] 分发数据: %v\n", linkEP.LinkAddress(), src, dst, vv.ToView())
+	// 根据网络协议和数据包的目的地址，找到网络端
+	// 然后将数据包分发给网络层
+	if ref := n.getRef(protocol, dst); ref != nil {
+		r := makeRoute(protocol, dst, src, linkEP.LinkAddress(), ref)
+		r.RemoteLinkAddress = remoteLinkAddr
+		ref.ep.HandlePacket(&r, vv)
+		ref.decRef()
+
+		return
+	}
+	n.stack.stats.IP.InvalidAddressesReceived.Increment()
+}
+
+// 网络端引用
+type referencedNetworkEndpoint struct {
+	ilist.Entry
+	refs     int32           // 引用计数
+	ep       NetworkEndpoint // 网络端实现
+	nic      *NIC
+	protocol tcpip.NetworkProtocolNumber
+
+	// linkCache is set if link address resolution is enabled for this
+	// protocol. Set to nil otherwise.
+	linkCache LinkAddressCache
+	linkAddrCache
+
+	// holdsInsertRef is protected by the NIC's mutex. It indicates whether
+	// the reference count is biased by 1 due to the insertion of the
+	// endpoint. It is reset to false when RemoveAddress is called on the
+	// NIC.
+	holdsInsertRef bool
+}
+
+func (r *referencedNetworkEndpoint) decRef() {
+	if atomic.AddInt32(&r.refs, -1) == 0 {
+		r.nic.removeEndpoint(r)
+	}
+}
+
+func (r *referencedNetworkEndpoint) incRef() {
+	atomic.AddInt32(&r.refs, 1)
+}
+
+func (r *referencedNetworkEndpoint) tryIncRef() bool {
+	for {
+		v := atomic.LoadInt32(&r.refs)
+		if v == 0 {
+			return false
+		}
+
+		if atomic.CompareAndSwapInt32(&r.refs, v, v+1) {
+			return true
+		}
+	}
 }
--- a/tcpip/stack/registration.go
+++ b/tcpip/stack/registration.go
@@ -1,8 +1,6 @@
 package stack

 import (
-	"log"
-	"netstack/ilist"
 	"netstack/sleep"
 	"netstack/tcpip"
 	"netstack/tcpip/buffer"
@@ -108,13 +106,70 @@ var (

 // ==============================网络层相关==============================
 type NetworkProtocol interface {
+	// 网络协议版本号
 	Number() tcpip.NetworkProtocolNumber
-	// todo 需要添加
+
+	// MinimumPacketSize returns the minimum valid packet size of this
+	// network protocol. The stack automatically drops any packets smaller
+	// than this targeted at this protocol.
+	MinimumPacketSize() int
+
+	// ParsePorts returns the source and destination addresses stored in a
+	// packet of this protocol.
+	ParseAddresses(v buffer.View) (src, dst tcpip.Address)
+
+	// 新建一个网络终端 比如 ipv4 或者 ipv6 的一个实现
+	NewEndpoint(nicid tcpip.NICID, addr tcpip.Address, linkAddrCache LinkAddressCache,
+		dispatcher TransportDispatcher, sender LinkEndpoint) (NetworkEndpoint, *tcpip.Error)
+
+	// SetOption allows enabling/disabling protocol specific features.
+	// SetOption returns an error if the option is not supported or the
+	// provided option value is invalid.
+	SetOption(option interface{}) *tcpip.Error
+
+	// Option allows retrieving protocol specific option values.
+	// Option returns an error if the option is not supported or the
+	// provided option value is invalid.
+	Option(option interface{}) *tcpip.Error
 }

 // NetworkEndpoint是需要由网络层协议（例如，ipv4，ipv6）的端点实现的接口
 type NetworkEndpoint interface {
-	// TODO 需要添加
+	// DefaultTTL is the default time-to-live value (or hop limit, in ipv6)
+	// for this endpoint.
+	DefaultTTL() uint8
+
+	// MTU is the maximum transmission unit for this endpoint. This is
+	// generally calculated as the MTU of the underlying data link endpoint
+	// minus the network endpoint max header length.
+	MTU() uint32
+
+	// Capabilities returns the set of capabilities supported by the
+	// underlying link-layer endpoint.
+	Capabilities() LinkEndpointCapabilities
+
+	// MaxHeaderLength returns the maximum size the network (and lower
+	// level layers combined) headers can have. Higher levels use this
+	// information to reserve space in the front of the packets they're
+	// building.
+	MaxHeaderLength() uint16
+
+	// WritePacket writes a packet to the given destination address and
+	// protocol.
+	WritePacket(r *Route, hdr buffer.Prependable, payload buffer.VectorisedView, protocol tcpip.TransportProtocolNumber, ttl uint8) *tcpip.Error
+
+	// ID returns the network protocol endpoint ID.
+	ID() *NetworkEndpointID
+
+	// 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)
+
+	// Close is called when the endpoint is reomved from a stack.
+	Close()
 }

 type NetworkEndpointID struct {
@@ -137,29 +192,16 @@ type TransportEndpoint interface {
 }

 // TODO 需要解读
-type referencedNetworkEndpoint struct {
-	ilist.Entry
-	refs     int32
-	ep       NetworkEndpoint
-	nic      *NIC
-	protocol tcpip.NetworkProtocolNumber
+type TransportProtocol interface {
+}

-	// linkCache is set if link address resolution is enabled for this
-	// protocol. Set to nil otherwise.
-	linkCache LinkAddressCache
-	linkAddrCache
-
-	// holdsInsertRef is protected by the NIC's mutex. It indicates whether
-	// the reference count is biased by 1 due to the insertion of the
-	// endpoint. It is reset to false when RemoveAddress is called on the
-	// NIC.
-	holdsInsertRef bool
+// TODO 需要解读
+type TransportDispatcher interface {
 }

 // 注册一个新的网络协议工厂
 func RegisterNetworkProtocolFactory(name string, p NetworkProtocolFactory) {
 	networkProtocols[name] = p
-	log.Println(networkProtocols)
 }

 // 注册一个链路层设备
--- a/tcpip/stack/route.go
+++ b/tcpip/stack/route.go
@@ -25,3 +25,15 @@ type Route struct {
 	// 相关的网络终端
 	ref *referencedNetworkEndpoint
 }
+
+// 根据参数新建一个路由，并关联一个网络层端
+func makeRoute(netProto tcpip.NetworkProtocolNumber, localAddr, remoteAddr tcpip.Address,
+	localLinkAddr tcpip.LinkAddress, ref *referencedNetworkEndpoint) Route {
+	return Route{
+		NetProto:         netProto,
+		LocalAddress:     localAddr,
+		LocalLinkAddress: localLinkAddr,
+		RemoteAddress:    remoteAddr,
+		ref:              ref,
+	}
+}
--- a/tcpip/stack/stack.go
+++ b/tcpip/stack/stack.go
@@ -1,7 +1,7 @@
 package stack

 import (
-	"log"
+	"netstack/sleep"
 	"netstack/tcpip"
 	"netstack/tcpip/ports"
 	"sync"
@@ -49,12 +49,32 @@ type Stack struct {
 	clock tcpip.Clock
 }

-func New(network []string) *Stack {
+// Options contains optional Stack configuration.
+type Options struct {
+	// Clock is an optional clock source used for timestampping packets.
+	//
+	// If no Clock is specified, the clock source will be time.Now.
+	Clock tcpip.Clock
+
+	// Stats are optional statistic counters.
+	Stats tcpip.Stats
+}
+
+func New(network []string, transport []string, opts Options) *Stack {
+	clock := opts.Clock
+	if clock == nil {
+		clock = &tcpip.StdClock{}
+	}
+
 	s := &Stack{
 		transportProtocols: make(map[tcpip.TransportProtocolNumber]*transportProtocolState),
 		networkProtocols:   make(map[tcpip.NetworkProtocolNumber]NetworkProtocol),
 		linkAddrResolvers:  make(map[tcpip.NetworkProtocolNumber]LinkAddressResolver),
 		nics:               make(map[tcpip.NICID]*NIC),
+		//linkAddrCache:      newLinkAddrCache(ageLimit, resolutionTimeout, resolutionAttempts),
+		//PortManager:        ports.NewPortManager(),
+		clock: clock,
+		stats: opts.Stats.FillIn(),
 	}

 	// 添加指定的网络端协议 必须已经在init中注册过
@@ -62,7 +82,6 @@ func New(network []string) *Stack {
 		// 先检查这个网络协议是否注册过工厂方法
 		netProtoFactory, ok := networkProtocols[name]
 		if !ok {
-			log.Println(name)
 			continue // 没有就略过
 		}
 		netProto := netProtoFactory()                    // 制造一个该型号协议的示实例
@@ -119,3 +138,59 @@ func (s *Stack) AddAddressWithOptions(id tcpip.NICID, protocol tcpip.NetworkProt

 	return nic.AddAddressWithOptions(protocol, addr, peb)
 }
+
+// AddSubnet adds a subnet range to the specified NIC.
+func (s *Stack) AddSubnet(id tcpip.NICID, protocol tcpip.NetworkProtocolNumber, subnet tcpip.Subnet) *tcpip.Error {
+	s.mu.RLock()
+	defer s.mu.RUnlock()
+
+	if nic, ok := s.nics[id]; ok {
+		nic.AddSubnet(protocol, subnet)
+		return nil
+	}
+
+	return tcpip.ErrUnknownNICID
+}
+
+// RemoveSubnet removes the subnet range from the specified NIC.
+func (s *Stack) RemoveSubnet(id tcpip.NICID, subnet tcpip.Subnet) *tcpip.Error {
+	s.mu.RLock()
+	defer s.mu.RUnlock()
+
+	if nic, ok := s.nics[id]; ok {
+		nic.RemoveSubnet(subnet)
+		return nil
+	}
+
+	return tcpip.ErrUnknownNICID
+}
+
+// ContainsSubnet reports whether the specified NIC contains the specified
+// subnet.
+func (s *Stack) ContainsSubnet(id tcpip.NICID, subnet tcpip.Subnet) (bool, *tcpip.Error) {
+	s.mu.RLock()
+	defer s.mu.RUnlock()
+
+	if nic, ok := s.nics[id]; ok {
+		return nic.ContainsSubnet(subnet), nil
+	}
+
+	return false, tcpip.ErrUnknownNICID
+}
+
+func (s *Stack) CheckLocalAddress(nicid tcpip.NICID, protocol tcpip.NetworkProtocolNumber, addr tcpip.Address) tcpip.NICID {
+	return 0
+}
+
+func (s *Stack) AddLinkAddress(nicid tcpip.NICID, addr tcpip.Address, linkAddr tcpip.LinkAddress) {
+
+}
+
+func (s *Stack) GetLinkAddress(nicid tcpip.NICID, addr, localAddr tcpip.Address,
+	protocol tcpip.NetworkProtocolNumber, w *sleep.Waker) (tcpip.LinkAddress, <-chan struct{}, *tcpip.Error) {
+	return "", nil, nil
+}
+
+func (s *Stack) RemoveWaker(nicid tcpip.NICID, addr tcpip.Address, waker *sleep.Waker) {
+
+}
--- a/tcpip/stack/stack_test.go
+++ b/tcpip/stack/stack_test.go
@@ -10,16 +10,86 @@ import (
 )

 const (
+	fakeNetHeaderLen = 12
 	defaultMTU       = 65536
 )

-type fakeNetworkProtocol struct {
+type fakeNetworkEndpoint struct {
+	nicid      tcpip.NICID
+	id         stack.NetworkEndpointID
+	proto      *fakeNetworkProtocol
+	dispatcher stack.TransportDispatcher
+	linkEP     stack.LinkEndpoint
 }

+func (f *fakeNetworkEndpoint) DefaultTTL() uint8 {
+	return 123
+}
+
+func (f *fakeNetworkEndpoint) MTU() uint32 {
+	return f.linkEP.MTU() - uint32(f.MaxHeaderLength())
+}
+
+func (f *fakeNetworkEndpoint) Capabilities() stack.LinkEndpointCapabilities {
+	return f.linkEP.Capabilities()
+}
+
+func (f *fakeNetworkEndpoint) MaxHeaderLength() uint16 {
+	return f.linkEP.MaxHeaderLength() + fakeNetHeaderLen
+}
+func (f *fakeNetworkEndpoint) WritePacket(r *stack.Route, hdr buffer.Prependable, payload buffer.VectorisedView,
+	protocol tcpip.TransportProtocolNumber, ttl uint8) *tcpip.Error {
+	return nil
+}
+
+func (f *fakeNetworkEndpoint) ID() *stack.NetworkEndpointID {
+	return &f.id
+}
+
+func (f *fakeNetworkEndpoint) NICID() tcpip.NICID {
+	return f.nicid
+}
+
+func (f *fakeNetworkEndpoint) HandlePacket(r *stack.Route, vv buffer.VectorisedView) {
+	log.Println("执行这个函数 接下来它会去向传输层分发数据")
+}
+
+func (f *fakeNetworkEndpoint) Close() {}
+
+// dst|src|payload
+type fakeNetworkProtocol struct{}
+
 func (f *fakeNetworkProtocol) Number() tcpip.NetworkProtocolNumber {
 	return 114514
 }

+func (f *fakeNetworkProtocol) NewEndpoint(nicid tcpip.NICID, addr tcpip.Address, linkAddrCache stack.LinkAddressCache,
+	dispatcher stack.TransportDispatcher, linkEP stack.LinkEndpoint) (stack.NetworkEndpoint, *tcpip.Error) {
+	return &fakeNetworkEndpoint{
+		nicid:      nicid,
+		id:         stack.NetworkEndpointID{addr},
+		proto:      f,
+		dispatcher: dispatcher,
+		linkEP:     linkEP,
+	}, nil
+}
+
+func (f *fakeNetworkProtocol) MinimumPacketSize() int {
+	return fakeNetHeaderLen
+}
+
+func (f *fakeNetworkProtocol) ParseAddresses(v buffer.View) (src, dst tcpip.Address) {
+	return tcpip.Address(v[4:8]), tcpip.Address(v[0:4])
+}
+
+func (f *fakeNetworkProtocol) SetOption(option interface{}) *tcpip.Error {
+	return nil
+}
+
+func (f *fakeNetworkProtocol) Option(option interface{}) *tcpip.Error {
+	return nil
+}
+
 func init() {
 	stack.RegisterNetworkProtocolFactory("fakeNet", func() stack.NetworkProtocol {
 		return &fakeNetworkProtocol{}
@@ -28,18 +98,34 @@ func init() {

 func TestStackBase(t *testing.T) {

-	myStack := stack.New([]string{"fakeNet"})
-	id, ep := channel.New(10, defaultMTU, "") // 这是一个物理设备
-	log.Println(id)
+	myStack := stack.New([]string{"fakeNet"}, nil, stack.Options{})
+	id1, ep1 := channel.New(10, defaultMTU, "00:15:5d:26:d7:a1") // 这是一个物理设备

-	if err := myStack.CreateNIC(1, id); err != nil { // 将上面的物理设备抽象成我们的网卡对象
+	if err := myStack.CreateNIC(1, id1); err != nil { // 将上面的物理设备抽象成我们的网卡对象
 		panic(err)
 	}
-	myStack.AddAddress(1, 114514, "\x01") // 给网卡对象绑定一个IP地址 可以绑定多个
+	myStack.AddAddress(1, 114514, "\x0a\xff\x01\x01") // 给网卡对象绑定一个IP地址 可以绑定多个
+
+	id2, _ := channel.New(10, defaultMTU, "50:5B:C2:D0:96:57") // 这是一个物理设备
+	if err := myStack.CreateNIC(2, id2); err != nil {          // 将上面的物理设备抽象成我们的网卡对象
+		panic(err)
+	}
+	myStack.AddAddress(1, 114514, "\x0a\xff\x01\x02") // 给网卡对象绑定一个IP地址 可以绑定多个

 	buf := buffer.NewView(30)
 	for i := range buf {
-		buf[i] = 1
+		buf[i] = 0
 	}
-	ep.Inject(114514, buf.ToVectoriseView())
+	// dst 10.255.1.2
+	buf[0] = '\x0a'
+	buf[1] = '\xff'
+	buf[2] = '\x01'
+	buf[3] = '\x02'
+	// src 10.255.1.1
+	buf[4] = '\x0a'
+	buf[5] = '\xff'
+	buf[6] = '\x01'
+	buf[7] = '\x01'
+
+	ep1.Inject(114514, buf.ToVectoriseView())
 }
--- a/tcpip/tcpip.go
+++ b/tcpip/tcpip.go
@@ -1,8 +1,11 @@
 package tcpip

 import (
+	"errors"
 	"fmt"
+	"reflect"
 	"strings"
+	"sync/atomic"
 )

 type Error struct {
@@ -55,6 +58,12 @@ var (
 	ErrNoBufferSpace         = &Error{msg: "no buffer space available"}
 )

+// Errors related to Subnet
+var (
+	errSubnetLengthMismatch = errors.New("subnet length of address and mask differ")
+	errSubnetAddressMasked  = errors.New("subnet address has bits set outside the mask")
+)
+
 // Clock 提供当前的时间戳
 type Clock interface {
 	NowNanoseconds() int64
@@ -83,6 +92,70 @@ type Subnet struct {
 	mask    AddressMask
 }

+// NewSubnet creates a new Subnet, checking that the address and mask are the same length.
+func NewSubnet(a Address, m AddressMask) (Subnet, error) {
+	if len(a) != len(m) {
+		return Subnet{}, errSubnetLengthMismatch
+	}
+	for i := 0; i < len(a); i++ {
+		if a[i]&^m[i] != 0 {
+			return Subnet{}, errSubnetAddressMasked
+		}
+	}
+	return Subnet{a, m}, nil
+}
+
+// Contains returns true iff the address is of the same length and matches the
+// subnet address and mask.
+func (s *Subnet) Contains(a Address) bool {
+	if len(a) != len(s.address) {
+		return false
+	}
+	for i := 0; i < len(a); i++ {
+		if a[i]&s.mask[i] != s.address[i] {
+			return false
+		}
+	}
+	return true
+}
+
+// ID returns the subnet ID.
+func (s *Subnet) ID() Address {
+	return s.address
+}
+
+// Bits returns the number of ones (network bits) and zeros (host bits) in the
+// subnet mask.
+func (s *Subnet) Bits() (ones int, zeros int) {
+	for _, b := range []byte(s.mask) {
+		for i := uint(0); i < 8; i++ {
+			if b&(1<<i) == 0 {
+				zeros++
+			} else {
+				ones++
+			}
+		}
+	}
+	return
+}
+
+// Prefix returns the number of bits before the first host bit.
+func (s *Subnet) Prefix() int {
+	for i, b := range []byte(s.mask) {
+		for j := 7; j >= 0; j-- {
+			if b&(1<<uint(j)) == 0 {
+				return i*8 + 7 - j
+			}
+		}
+	}
+	return len(s.mask) * 8
+}
+
+// Mask returns the subnet mask.
+func (s *Subnet) Mask() AddressMask {
+	return s.mask
+}
+
 // LinkAddress 是一个字节切片，转换为表示链接地址的字符串。
 // 它通常是一个 6 字节的 MAC 地址。
 type LinkAddress string // MAC地址
@@ -104,11 +177,96 @@ type Route struct {

 // Stats 包含了网络栈的统计信息
 type Stats struct {
-	// TODO 需要添加
+	// TODO 需要解读
+	// UnknownProtocolRcvdPackets is the number of packets received by the
+	// stack that were for an unknown or unsupported protocol.
+	UnknownProtocolRcvdPackets *StatCounter
+
+	// MalformedRcvPackets is the number of packets received by the stack
+	// that were deemed malformed.
+	MalformedRcvdPackets *StatCounter
+
+	// DroppedPackets is the number of packets dropped due to full queues.
+	DroppedPackets *StatCounter
+
+	// IP breaks out IP-specific stats (both v4 and v6).
+	IP IPStats
+
+	// TCP breaks out TCP-specific stats.
+	TCP TCPStats
+
+	// UDP breaks out UDP-specific stats.
+	UDP UDPStats
+}
+
+// A StatCounter keeps track of a statistic.
+type StatCounter struct {
+	count uint64
+}
+
+// Increment adds one to the counter.
+func (s *StatCounter) Increment() {
+	s.IncrementBy(1)
+}
+
+// Value returns the current value of the counter.
+func (s *StatCounter) Value() uint64 {
+	return atomic.LoadUint64(&s.count)
+}
+
+// IncrementBy increments the counter by v.
+func (s *StatCounter) IncrementBy(v uint64) {
+	atomic.AddUint64(&s.count, v)
+}
+
+type IPStats struct {
+	// PacketsReceived is the total number of IP packets received from the link
+	// layer in nic.DeliverNetworkPacket.
+	PacketsReceived *StatCounter
+
+	// InvalidAddressesReceived is the total number of IP packets received
+	// with an unknown or invalid destination address.
+	InvalidAddressesReceived *StatCounter
+
+	// PacketsDelivered is the total number of incoming IP packets that
+	// are successfully delivered to the transport layer via HandlePacket.
+	PacketsDelivered *StatCounter
+
+	// PacketsSent is the total number of IP packets sent via WritePacket.
+	PacketsSent *StatCounter
+
+	// OutgoingPacketErrors is the total number of IP packets which failed
+	// to write to a link-layer endpoint.
+	OutgoingPacketErrors *StatCounter
+}
+
+type TCPStats struct{}
+
+type UDPStats struct{}
+
+func fillIn(v reflect.Value) {
+	for i := 0; i < v.NumField(); i++ {
+		v := v.Field(i)
+		switch v.Kind() {
+		case reflect.Ptr:
+			if s, ok := v.Addr().Interface().(**StatCounter); ok {
+				if *s == nil {
+					*s = &StatCounter{}
+				}
+			}
+		case reflect.Struct:
+			fillIn(v)
+		}
+	}
+}
+
+// FillIn returns a copy of s with nil fields initialized to new StatCounters.
+func (s Stats) FillIn() Stats {
+	fillIn(reflect.ValueOf(&s).Elem())
+	return s
 }

 func (a Address) String() string {
-	fmt.Println(string(a), len(a))
 	switch len(a) {
 	case 4:
 		return fmt.Sprintf("%d.%d.%d.%d", int(a[0]), int(a[1]), int(a[2]), int(a[3]))
--- a/tcpip/time_unsafe.go
+++ b/tcpip/time_unsafe.go
@@ -0,0 +1,42 @@
+// Copyright 2018 Google LLC
+//
+// 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.
+
+// +build go1.9
+
+package tcpip
+
+import (
+	_ "time"   // Used with go:linkname.
+	_ "unsafe" // Required for go:linkname.
+)
+
+// StdClock implements Clock with the time package.
+type StdClock struct{}
+
+var _ Clock = (*StdClock)(nil)
+
+//go:linkname now time.now
+func now() (sec int64, nsec int32, mono int64)
+
+// NowNanoseconds implements Clock.NowNanoseconds.
+func (*StdClock) NowNanoseconds() int64 {
+	sec, nsec, _ := now()
+	return sec*1e9 + int64(nsec)
+}
+
+// NowMonotonic implements Clock.NowMonotonic.
+func (*StdClock) NowMonotonic() int64 {
+	_, _, mono := now()
+	return mono
+}