mirror of
https://github.com/impact-eintr/netstack.git
synced 2025-10-27 22:41:27 +08:00
wsl code edit
This commit is contained in:
impact-eintr
@@ -1,226 +1,226 @@
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package fdbased
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import (
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"log"
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"netstack/tcpip"
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"netstack/tcpip/buffer"
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"netstack/tcpip/header"
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"netstack/tcpip/link/rawfile"
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"netstack/tcpip/stack"
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"syscall"
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)
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// 从NIC读取数据的多级缓存配置
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var BufConfig = []int{1 << 7, 1 << 8, 1 << 8, 1 << 9, 1 << 10, 1 << 11, 1 << 12, 1 << 13, 1 << 14, 1 << 15}
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// 负责底层网卡的io读写以及数据分发
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type endpoint struct {
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// 发送和接收数据的文件描述符
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fd int
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// 单个帧的最大长度
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mtu uint32
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// 以太网头部长度
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hdrSize int
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// 网卡地址
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addr tcpip.LinkAddress
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// 网卡的能力
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caps stack.LinkEndpointCapabilities
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closed func(*tcpip.Error)
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iovecs []syscall.Iovec
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views []buffer.View
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dispatcher stack.NetworkDispatcher
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// handleLocal指示发往自身的数据包是由内部netstack处理（true）还是转发到FD端点（false）
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handleLocal bool
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}
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type Options struct {
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FD int
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MTU uint32
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ClosedFunc func(*tcpip.Error)
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Address tcpip.LinkAddress
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ResolutionRequired bool
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SaveRestore bool
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ChecksumOffload bool
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DisconnectOk bool
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HandleLocal bool
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TestLossPacket func(data []byte) bool
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}
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// 根据选项参数创建一个链路层的endpoint，并返回该endpoint的id
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func New(opts *Options) tcpip.LinkEndpointID {
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syscall.SetNonblock(opts.FD, true)
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caps := stack.LinkEndpointCapabilities(0) // 初始化
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if opts.ResolutionRequired {
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caps |= stack.CapabilityResolutionRequired
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}
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if opts.ChecksumOffload {
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caps |= stack.CapabilityChecksumOffload
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}
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if opts.SaveRestore {
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caps |= stack.CapabilitySaveRestore
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}
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if opts.DisconnectOk {
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caps |= stack.CapabilityDisconnectOK
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}
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e := &endpoint{
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fd: opts.FD,
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mtu: opts.MTU,
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caps: caps,
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closed: opts.ClosedFunc,
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addr: opts.Address,
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hdrSize: header.EthernetMinimumSize,
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views: make([]buffer.View, len(BufConfig)),
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iovecs: make([]syscall.Iovec, len(BufConfig)),
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handleLocal: opts.HandleLocal,
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}
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// 全局注册链路层设备
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return stack.RegisterLinkEndpoint(e)
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}
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func (e *endpoint) MTU() uint32 {
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return e.mtu
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}
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func (e *endpoint) Capabilities() stack.LinkEndpointCapabilities {
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return e.caps
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}
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// 返回当前以太网头部信息长度
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func (e *endpoint) MaxHeaderLength() uint16 {
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return uint16(e.hdrSize)
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}
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// 返回当前MAC地址
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func (e *endpoint) LinkAddress() tcpip.LinkAddress {
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return e.addr
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}
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// 将上层的报文经过链路层封装，写入网卡中，如果写入失败则丢弃该报文
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func (e *endpoint) WritePacket(r *stack.Route, hdr buffer.Prependable,
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payload buffer.VectorisedView, protocol tcpip.NetworkProtocolNumber) *tcpip.Error {
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// 如果目标地址是设备自己 那么将报文重新返回给协议栈
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if e.handleLocal && r.LocalAddress != "" && r.LocalAddress == r.RemoteAddress {
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views := make([]buffer.View, 1, 1+len(payload.Views()))
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views[0] = hdr.View()
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views = append(views, payload.Views()...)
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vv := buffer.NewVectorisedView(len(views[0])+payload.Size(), views) // 添加报文头
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e.dispatcher.DeliverNetworkPacket(e, r.RemoteLinkAddress, r.LocalLinkAddress,
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protocol, vv) // 分发数据报
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return nil
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}
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// 封装增加以太网头部
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eth := header.Ethernet(hdr.Prepend(header.EthernetMinimumSize)) // 分配14B的内存
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ethHdr := &header.EthernetFields{ // 配置以太帧信息
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DstAddr: r.RemoteLinkAddress,
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Type: protocol,
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}
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// 如果路由信息中有配置源MAC地址，那么使用该地址
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// 如果没有，则使用本网卡的地址
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if r.LocalLinkAddress != "" {
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ethHdr.SrcAddr = r.LocalLinkAddress // 源网卡地址 说明这是一个转发报文
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} else {
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ethHdr.SrcAddr = e.addr // 说明这是一个原始报文
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}
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eth.Encode(ethHdr) // 将以太帧信息作为报文头编入
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log.Println("链路层写回报文")
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// 写入网卡中
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if payload.Size() == 0 {
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return rawfile.NonBlockingWrite(e.fd, hdr.View())
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}
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return rawfile.NonBlockingWrite2(e.fd, hdr.View(), payload.ToView())
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}
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// Attach 启动从文件描述符中读取数据包的goroutine,并通过提供的分发函数来分发数据报
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func (e *endpoint) Attach(dispatcher stack.NetworkDispatcher) {
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e.dispatcher = dispatcher
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// 链接端点不可靠。保存传输端点后，它们将停止发送传出数据包，并拒绝所有传入数据包。
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go e.dispatchLoop()
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}
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func (e *endpoint) IsAttached() bool {
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return e.dispatcher != nil
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}
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// 截取需要的内容
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func (e *endpoint) capViews(n int, buffers []int) int {
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c := 0
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for i, s := range buffers {
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c += s
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if c >= n {
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e.views[i].CapLength(s - (c - n))
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return i + 1
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}
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}
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return len(buffers)
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}
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// 按照bufConfig的长度分配内存大小
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// 注意e.views 和 e.iovecs共用相同的内存块
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func (e *endpoint) allocateViews(bufConfig []int) {
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for i, v := range e.views {
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if v != nil {
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break
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}
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b := buffer.NewView(bufConfig[i]) // 分配内存
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e.views[i] = b
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e.iovecs[i] = syscall.Iovec{
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Base: &b[0],
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Len: uint64(len(b)),
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}
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}
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}
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func (e *endpoint) dispatch() (bool, *tcpip.Error) {
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// 读取数据缓存的分配
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e.allocateViews(BufConfig)
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// 从网卡读取数据
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n, err := rawfile.BlockingReadv(e.fd, e.iovecs) // 读到ioves中相当于读到views中
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if err != nil {
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return false, err
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}
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if n <= e.hdrSize {
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return false, nil // 读到的数据比头部还小 直接丢弃
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}
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var (
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p tcpip.NetworkProtocolNumber
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remoteLinkAddr, localLinkAddr tcpip.LinkAddress // 目标MAC 源MAC
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)
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// 获取以太网头部信息
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eth := header.Ethernet(e.views[0])
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p = eth.Type()
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remoteLinkAddr = eth.SourceAddress()
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localLinkAddr = eth.DestinationAddress()
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used := e.capViews(n, BufConfig) // 从缓存中截有效的内容
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vv := buffer.NewVectorisedView(n, e.views[:used]) // 用这些有效的内容构建vv
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vv.TrimFront(e.hdrSize) // 将数据内容删除以太网头部信息 将网络层作为数据头
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e.dispatcher.DeliverNetworkPacket(e, remoteLinkAddr, localLinkAddr, p, vv)
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// 将分发后的数据无效化(设置nil可以让gc回收这些内存)
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for i := 0; i < used; i++ {
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e.views[i] = nil
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}
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return true, nil
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}
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// 循环地从fd中读取数据 然后将数据报分发给协议栈
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func (e *endpoint) dispatchLoop() *tcpip.Error {
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for {
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cont, err := e.dispatch()
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if err != nil || !cont {
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if e.closed != nil {
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e.closed(err) // 阻塞中
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}
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return err
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}
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}
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}
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package fdbased
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import (
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"log"
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"netstack/tcpip"
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"netstack/tcpip/buffer"
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"netstack/tcpip/header"
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"netstack/tcpip/link/rawfile"
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"netstack/tcpip/stack"
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"syscall"
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)
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// 从NIC读取数据的多级缓存配置
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var BufConfig = []int{1 << 7, 1 << 8, 1 << 8, 1 << 9, 1 << 10, 1 << 11, 1 << 12, 1 << 13, 1 << 14, 1 << 15}
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|
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// 负责底层网卡的io读写以及数据分发
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type endpoint struct {
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// 发送和接收数据的文件描述符
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fd int
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// 单个帧的最大长度
|
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mtu uint32
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// 以太网头部长度
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hdrSize int
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// 网卡地址
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addr tcpip.LinkAddress
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// 网卡的能力
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caps stack.LinkEndpointCapabilities
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closed func(*tcpip.Error)
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iovecs []syscall.Iovec
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views []buffer.View
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dispatcher stack.NetworkDispatcher
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// handleLocal指示发往自身的数据包是由内部netstack处理（true）还是转发到FD端点（false）
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handleLocal bool
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}
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type Options struct {
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FD int
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MTU uint32
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ClosedFunc func(*tcpip.Error)
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Address tcpip.LinkAddress
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ResolutionRequired bool
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SaveRestore bool
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ChecksumOffload bool
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DisconnectOk bool
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HandleLocal bool
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TestLossPacket func(data []byte) bool
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}
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// 根据选项参数创建一个链路层的endpoint，并返回该endpoint的id
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func New(opts *Options) tcpip.LinkEndpointID {
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syscall.SetNonblock(opts.FD, true)
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caps := stack.LinkEndpointCapabilities(0) // 初始化
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if opts.ResolutionRequired {
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caps |= stack.CapabilityResolutionRequired
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}
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if opts.ChecksumOffload {
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caps |= stack.CapabilityChecksumOffload
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}
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if opts.SaveRestore {
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caps |= stack.CapabilitySaveRestore
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}
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if opts.DisconnectOk {
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caps |= stack.CapabilityDisconnectOK
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}
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e := &endpoint{
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fd: opts.FD,
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mtu: opts.MTU,
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caps: caps,
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closed: opts.ClosedFunc,
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addr: opts.Address,
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hdrSize: header.EthernetMinimumSize,
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views: make([]buffer.View, len(BufConfig)),
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iovecs: make([]syscall.Iovec, len(BufConfig)),
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handleLocal: opts.HandleLocal,
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}
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// 全局注册链路层设备
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return stack.RegisterLinkEndpoint(e)
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}
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func (e *endpoint) MTU() uint32 {
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return e.mtu
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}
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func (e *endpoint) Capabilities() stack.LinkEndpointCapabilities {
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return e.caps
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}
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|
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// 返回当前以太网头部信息长度
|
||||
func (e *endpoint) MaxHeaderLength() uint16 {
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return uint16(e.hdrSize)
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}
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// 返回当前MAC地址
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func (e *endpoint) LinkAddress() tcpip.LinkAddress {
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return e.addr
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}
|
||||
|
||||
// 将上层的报文经过链路层封装，写入网卡中，如果写入失败则丢弃该报文
|
||||
func (e *endpoint) WritePacket(r *stack.Route, hdr buffer.Prependable,
|
||||
payload buffer.VectorisedView, protocol tcpip.NetworkProtocolNumber) *tcpip.Error {
|
||||
// 如果目标地址是设备自己 那么将报文重新返回给协议栈
|
||||
if e.handleLocal && r.LocalAddress != "" && r.LocalAddress == r.RemoteAddress {
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views := make([]buffer.View, 1, 1+len(payload.Views()))
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views[0] = hdr.View()
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||||
views = append(views, payload.Views()...)
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||||
vv := buffer.NewVectorisedView(len(views[0])+payload.Size(), views) // 添加报文头
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e.dispatcher.DeliverNetworkPacket(e, r.RemoteLinkAddress, r.LocalLinkAddress,
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protocol, vv) // 分发数据报
|
||||
return nil
|
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}
|
||||
// 封装增加以太网头部
|
||||
eth := header.Ethernet(hdr.Prepend(header.EthernetMinimumSize)) // 分配14B的内存
|
||||
ethHdr := &header.EthernetFields{ // 配置以太帧信息
|
||||
DstAddr: r.RemoteLinkAddress,
|
||||
Type: protocol,
|
||||
}
|
||||
// 如果路由信息中有配置源MAC地址，那么使用该地址
|
||||
// 如果没有，则使用本网卡的地址
|
||||
if r.LocalLinkAddress != "" {
|
||||
ethHdr.SrcAddr = r.LocalLinkAddress // 源网卡地址 说明这是一个转发报文
|
||||
} else {
|
||||
ethHdr.SrcAddr = e.addr // 说明这是一个原始报文
|
||||
}
|
||||
eth.Encode(ethHdr) // 将以太帧信息作为报文头编入
|
||||
log.Println("链路层写回报文")
|
||||
// 写入网卡中
|
||||
if payload.Size() == 0 {
|
||||
return rawfile.NonBlockingWrite(e.fd, hdr.View())
|
||||
}
|
||||
return rawfile.NonBlockingWrite2(e.fd, hdr.View(), payload.ToView())
|
||||
}
|
||||
|
||||
// Attach 启动从文件描述符中读取数据包的goroutine,并通过提供的分发函数来分发数据报
|
||||
func (e *endpoint) Attach(dispatcher stack.NetworkDispatcher) {
|
||||
e.dispatcher = dispatcher
|
||||
// 链接端点不可靠。保存传输端点后，它们将停止发送传出数据包，并拒绝所有传入数据包。
|
||||
go e.dispatchLoop()
|
||||
}
|
||||
|
||||
func (e *endpoint) IsAttached() bool {
|
||||
return e.dispatcher != nil
|
||||
}
|
||||
|
||||
// 截取需要的内容
|
||||
func (e *endpoint) capViews(n int, buffers []int) int {
|
||||
c := 0
|
||||
for i, s := range buffers {
|
||||
c += s
|
||||
if c >= n {
|
||||
e.views[i].CapLength(s - (c - n))
|
||||
return i + 1
|
||||
}
|
||||
}
|
||||
return len(buffers)
|
||||
}
|
||||
|
||||
// 按照bufConfig的长度分配内存大小
|
||||
// 注意e.views 和 e.iovecs共用相同的内存块
|
||||
func (e *endpoint) allocateViews(bufConfig []int) {
|
||||
for i, v := range e.views {
|
||||
if v != nil {
|
||||
break
|
||||
}
|
||||
b := buffer.NewView(bufConfig[i]) // 分配内存
|
||||
e.views[i] = b
|
||||
e.iovecs[i] = syscall.Iovec{
|
||||
Base: &b[0],
|
||||
Len: uint64(len(b)),
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
func (e *endpoint) dispatch() (bool, *tcpip.Error) {
|
||||
// 读取数据缓存的分配
|
||||
e.allocateViews(BufConfig)
|
||||
|
||||
// 从网卡读取数据
|
||||
n, err := rawfile.BlockingReadv(e.fd, e.iovecs) // 读到ioves中相当于读到views中
|
||||
if err != nil {
|
||||
return false, err
|
||||
}
|
||||
if n <= e.hdrSize {
|
||||
return false, nil // 读到的数据比头部还小 直接丢弃
|
||||
}
|
||||
|
||||
var (
|
||||
p tcpip.NetworkProtocolNumber
|
||||
remoteLinkAddr, localLinkAddr tcpip.LinkAddress // 目标MAC 源MAC
|
||||
)
|
||||
// 获取以太网头部信息
|
||||
eth := header.Ethernet(e.views[0])
|
||||
p = eth.Type()
|
||||
remoteLinkAddr = eth.SourceAddress()
|
||||
localLinkAddr = eth.DestinationAddress()
|
||||
|
||||
used := e.capViews(n, BufConfig) // 从缓存中截有效的内容
|
||||
vv := buffer.NewVectorisedView(n, e.views[:used]) // 用这些有效的内容构建vv
|
||||
vv.TrimFront(e.hdrSize) // 将数据内容删除以太网头部信息 将网络层作为数据头
|
||||
|
||||
e.dispatcher.DeliverNetworkPacket(e, remoteLinkAddr, localLinkAddr, p, vv)
|
||||
|
||||
// 将分发后的数据无效化(设置nil可以让gc回收这些内存)
|
||||
for i := 0; i < used; i++ {
|
||||
e.views[i] = nil
|
||||
}
|
||||
|
||||
return true, nil
|
||||
}
|
||||
|
||||
// 循环地从fd中读取数据 然后将数据报分发给协议栈
|
||||
func (e *endpoint) dispatchLoop() *tcpip.Error {
|
||||
for {
|
||||
cont, err := e.dispatch()
|
||||
if err != nil || !cont {
|
||||
if e.closed != nil {
|
||||
e.closed(err) // 阻塞中
|
||||
}
|
||||
return err
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
Reference in New Issue
Block a user