trex-emu中的plugin是各个协议处理rpc请求及相应协议数据的模块

• trex-emu server 架构图

每个TRex emulation的Thread包含多个Namespaces，而每个Namespaces只能对应到一个Thread上

每个Namespaces必须有独一无二的tuple key，其由{physical-port, dot1q, QinQ}组成

每个Client绑定到一个Namespaces上，绑定到同一个Namespaces上的客户端能共享信息

以arp协议plugin为例

• ARP plugin Emulation Server

func init() {

	/* register of plugins callbacks for ns,c level  */
	core.PluginRegister(ARP_PLUG,
		core.PluginRegisterData{Client: PluginArpCReg{},
			Ns:     PluginArpNsReg{},
			Thread: nil}) /* no need for thread context for now */

	/* The format of the RPC commands xxx_yy_zz_aa
	  xxx - the plugin name
	  yy  - ns - namespace
			c  - client
			t   -thread
	  zz  - cmd  command like ping etc
			set  set configuration
			get  get configuration/counters
	  aa - misc
	*/
	core.RegisterCB("arp_ns_set_cfg", ApiArpNsSetCfgHandler{}, true)
	core.RegisterCB("arp_ns_get_cfg", ApiArpNsGetCfgHandler{}, true)
	core.RegisterCB("arp_ns_cnt", ApiArpNsCntHandler{}, true)
	core.RegisterCB("arp_c_cmd_query", ApiArpCCmdQueryHandler{}, true)
	core.RegisterCB("arp_ns_iter", ApiArpNsIterHandler{}, true)

	/* register callback for rx side*/
	core.ParserRegister("arp", HandleRxArpPacket)
}

func Register(ctx *core.CThreadCtx) {
	ctx.RegisterParserCb("arp")
}

以上是arp plugin的入口，其先注册了PluginArpCReg对象和PluginArpNsReg对象

/* read only map, init */
var pluginregister pluginRegister

type PluginRegisterData struct {
	Client IPluginRegister
	Ns     IPluginRegister
	Thread IPluginRegister
}

type pluginRegister struct {
	M map[string]PluginRegisterData
}

func init() {
	if runtime.NumGoroutine() != 1 {
		panic(" NumGoroutine() should be 1 on init time, require lock  ")
	}
	pluginregister.M = make(map[string]PluginRegisterData)
}

PluginRegister负责注册各个协议插件，以arp协议为例：

/* register of plugins callbacks for ns,c level  */
core.PluginRegister(ARP_PLUG,
	core.PluginRegisterData{Client: PluginArpCReg{},
		Ns:     PluginArpNsReg{},
		Thread: nil}) /* no need for thread context for now */

// core.PluginRegister
// PluginRegister register per plugin 3 level information
func PluginRegister(pi string, pr PluginRegisterData) {
	...
	fmt.Sprintf(" register plugin %s ", pi)
	pluginregister.M[pi] = pr
}

RegisterCB负责将具体的功能函数注册到rpc处理框架中, 如以arp协议为例core.RegisterCB("arp_ns_set_cfg", ApiArpNsSetCfgHandler{}, true)

func RegisterCB(method string, h jsonrpc.Handler, noApi bool) {
   method_repo = append(method_repo, cRpcMethodRec{method, h, noApi})
}

// NewZmqRpc create a zmq server in port
func (o *CZmqJsonRPC2) NewZmqRpc(serverPort uint16, simulation bool) {

   ...
   
   mr := jsonrpc.NewMethodRepository()
   o.mr = mr
   o.mr.Verbose = false

   for _, rec := range method_repo {
   	...
   	if err := mr.RegisterMethod(rec.method, rec.h, noApi); err != nil {
   		log.Fatalln(err)
   	}
   }
}

ParserRegister注册处理协议相关数据的函数，以arp协议为例，当收到arp数据包时，调用函数HandleRxArpPacket处理相应数据报文

/* register callback for rx side*/
core.ParserRegister("arp", HandleRxArpPacket)

type parserProtocols struct {
   M map[string]ParserCb
}

var parserDb parserProtocols

func getProto(proto string) ParserCb {
   ...
   return parserDb.M[proto]
}

func ParserRegister(proto string, cb ParserCb) {
   ...
   fmt.Sprintf(" register protocol %s ", proto)
   parserDb.M[proto] = cb
}

协议Register函数将各个协议通过ParserRegister注册的处理函数，通过RegisterParserCb函数将协议处理函数对应到Parser对象中的各个协议处理函数;

以arp协议为例

func RegisterPlugins(tctx *core.CThreadCtx) {
   // These are ordered alphabetically, just like in the imports.
   appsim.Register(tctx)
   arp.Register(tctx)
   ...
}

// arp.Register
func Register(ctx *core.CThreadCtx) {
   ctx.RegisterParserCb("arp")
}

func (o *CThreadCtx) RegisterParserCb(protocol string) {
   o.parser.Register(protocol)
}

/* counters */
type Parser struct {
   tctx *CThreadCtx

   stats ParserStats
   /* call backs */
   arp     ParserCb
   ....
}

func (o *Parser) Register(protocol string) {
   if protocol == "arp" {
   	o.arp = getProto("arp")
   }
   ...
}