websocket - 如何终止 Websocket 连接？

Question

如何终止 Websocket 连接？我不是在谈论在任何一端关闭连接，而是在“中间”中断它。我需要测试一些必须在重新连接时发生的应用程序逻辑(通过 SocketIO 处理)。

不，拔掉网线不算数，因为我无法在单元测试中真正实现自动化:-) 此外，我希望只杀死一个特定的连接，而不是所有的连接。

Answer 1

这很痛苦，但这是可能的。你可以找到解释here .代码如下:

using System;
using System.Collections;
using System.Runtime.InteropServices;
/// <summary>
/// This is a class for disconnecting TCP connections.
/// You can get a list of all connections and close by a connection, localIP, 
///  remoteIP, localPort and remotePort.
/// </summary>
public class Disconnecter {
        //Enumeration of the states
        public enum State{
                All=0,
                Closed=1,
                Listen=2,
                Syn_Sent=3,
                Syn_Rcvd=4,
                Established=5,
                Fin_Wait1=6,
                Fin_Wait2=7,
                Close_Wait=8,
                Closing=9,
                Last_Ack=10,
                Time_Wait=11,
                Delete_TCB=12
        }
        //Connection info
        private struct MIB_TCPROW{
                public int dwState;
                public int dwLocalAddr;
                public int dwLocalPort;
                public int dwRemoteAddr;
                public int dwRemotePort;
        }
        //API to get list of connections
        [DllImport("iphlpapi.dll")]
        private static extern int GetTcpTable(IntPtr pTcpTable,ref int pdwSize,bool bOrder);
        //API to change status of connection
        [DllImport("iphlpapi.dll")]
                //private static extern int SetTcpEntry(MIB_TCPROW tcprow);
        private static extern int SetTcpEntry(IntPtr pTcprow);
        //Convert 16-bit value from network to host byte order
        [DllImport("wsock32.dll")]
        private static extern int ntohs(int netshort);
        //Convert 16-bit value back again
        [DllImport("wsock32.dll")]
        private static extern int htons(int netshort);

        //Close all connection to the remote IP
        public static void CloseRemoteIP(string IP){
                MIB_TCPROW[] rows = getTcpTable();
                for(int i=0; i<rows.Length; i++){
                        if(rows[i].dwRemoteAddr==IPStringToInt(IP)){
                                rows[i].dwState = (int) State.Delete_TCB;
                                IntPtr ptr = GetPtrToNewObject(rows[i]);
                                int ret = SetTcpEntry(ptr);
                        }
                }
        }

        //Close all connections at current local IP
        public static void CloseLocalIP(string IP){
                MIB_TCPROW[] rows = getTcpTable();
                for(int i=0; i<rows.Length; i++){
                        if(rows[i].dwLocalAddr==IPStringToInt(IP)){
                                rows[i].dwState = (int) State.Delete_TCB;
                                IntPtr ptr = GetPtrToNewObject(rows[i]);
                                int ret = SetTcpEntry(ptr);
                        }
                }
        }
        //Closes all connections to the remote port
        public static void CloseRemotePort(int port){
                MIB_TCPROW[] rows = getTcpTable();
                for(int i=0; i<rows.Length; i++){
                        if(port==ntohs(rows[i].dwRemotePort)){
                                rows[i].dwState = (int) State.Delete_TCB;
                                IntPtr ptr = GetPtrToNewObject(rows[i]);
                                int ret = SetTcpEntry(ptr);
                        }
                }
        }
        //Closes all connections to the local port
        public static void CloseLocalPort(int port){
                MIB_TCPROW[] rows = getTcpTable();
                for(int i=0; i<rows.Length; i++){
                        if(port==ntohs(rows[i].dwLocalPort)){
                                rows[i].dwState = (int) State.Delete_TCB;
                                IntPtr ptr = GetPtrToNewObject(rows[i]);
                                int ret = SetTcpEntry(ptr);
                        }
                }
        }
        //Close a connection by returning the connectionstring
        public static void CloseConnection(string connectionstring){
                try{
                        //Split the string to its subparts
                        string[] parts = connectionstring.Split('-');
                        if(parts.Length!=4) throw new Exception("Invalid connectionstring - use the one provided by Connections.");
                        string[] loc = parts[0].Split(':');
                        string[] rem = parts[1].Split(':');
                        string[] locaddr = loc[0].Split('.');
                        string[] remaddr = rem[0].Split('.');
                        //Fill structure with data
                        MIB_TCPROW row = new MIB_TCPROW();
                        row.dwState = 12;
                        byte[] bLocAddr = new byte[]{byte.Parse(locaddr[0]),byte.Parse(locaddr[1]),byte.Parse(locaddr[2]),byte.Parse(locaddr[3])};
                        byte[] bRemAddr = new byte[]{byte.Parse(remaddr[0]),byte.Parse(remaddr[1]),byte.Parse(remaddr[2]),byte.Parse(remaddr[3])};
                        row.dwLocalAddr = BitConverter.ToInt32(bLocAddr,0);
                        row.dwRemoteAddr = BitConverter.ToInt32(bRemAddr,0);
                        row.dwLocalPort = htons(int.Parse(loc[1]));
                        row.dwRemotePort = htons(int.Parse(rem[1]));
                        //Make copy of the structure into memory and use the pointer to call SetTcpEntry
                        IntPtr ptr = GetPtrToNewObject(row);
                        int ret = SetTcpEntry(ptr);
                        if(ret==-1) throw new Exception("Unsuccessful");
                        if(ret==65) throw new Exception("User has no sufficient privilege to execute this API successfully");
                        if(ret==87) throw new Exception("Specified port is not in state to be closed down");
                        if(ret!=0) throw new Exception("Unknown error ("+ret+")");
                }catch(Exception ex){
                        throw new Exception("CloseConnection failed ("+connectionstring+")! ["+ex.GetType().ToString()+","+ex.Message+"]");
                }
        }
        //Gets all connections
        public static string[] Connections(){
                return Connections(State.All);
        }
        //Gets a connection list of connections with a defined state
        public static string[] Connections(State state){
                MIB_TCPROW[] rows = getTcpTable();

                ArrayList arr = new ArrayList();

                foreach(MIB_TCPROW row in rows){
                        if(state == State.All || state == (State)row.dwState){
                                string localaddress = IPIntToString(row.dwLocalAddr) +":"+ ntohs(row.dwLocalPort);
                                string remoteaddress = IPIntToString(row.dwRemoteAddr) + ":" + ntohs(row.dwRemotePort);
                                arr.Add(localaddress + "-" + remoteaddress + "-" + ((State)row.dwState).ToString() + "-" + row.dwState);
                        }
                }

                return (string[])arr.ToArray(typeof(System.String));
        }
        //The function that fills the MIB_TCPROW array with connectioninfos
        private static MIB_TCPROW[] getTcpTable(){
                IntPtr buffer = IntPtr.Zero; bool allocated=false;
                try{
                        int iBytes=0;
                        GetTcpTable(IntPtr.Zero, ref iBytes, false); //Getting size of return data
                        buffer=Marshal.AllocCoTaskMem(iBytes); //allocating the datasize

                        allocated=true;
                        GetTcpTable(buffer, ref iBytes, false); //Run it again to fill the memory with the data
                        int structCount=Marshal.ReadInt32(buffer); // Get the number of structures
                        IntPtr buffSubPointer = buffer; //Making a pointer that will point into the buffer
                        buffSubPointer = (IntPtr)((int)buffer + 4); //Move to the first data (ignoring dwNumEntries from the original MIB_TCPTABLE struct)
                        MIB_TCPROW[] tcpRows = new MIB_TCPROW[structCount]; //Declaring the array
                        //Get the struct size
                        MIB_TCPROW tmp = new MIB_TCPROW();
                        int sizeOfTCPROW = Marshal.SizeOf(tmp);
                        //Fill the array 1 by 1
                        for(int i=0; i<structCount; i++){
                                tcpRows[i] = (MIB_TCPROW)Marshal.PtrToStructure(buffSubPointer, typeof(MIB_TCPROW)); //copy struct data
                                buffSubPointer = (IntPtr)((int)buffSubPointer + sizeOfTCPROW ); //move to next structdata
                        }

                        return tcpRows;
                }catch(Exception ex){
                        throw new Exception("getTcpTable failed! ["+ex.GetType().ToString()+","+ex.Message+"]");
                }finally{
                        if(allocated) Marshal.FreeCoTaskMem(buffer); //Free the allocated memory
                }
        }
        private static IntPtr GetPtrToNewObject(object obj){
                IntPtr ptr = Marshal.AllocCoTaskMem(Marshal.SizeOf(obj));
                Marshal.StructureToPtr(obj,ptr,false);
                return ptr;
        }
        //Convert an IP string to the INT value
        private static int IPStringToInt(string IP){
                if(IP.IndexOf(".")<0) throw new Exception("Invalid IP address");
                string[] addr = IP.Split('.');
                if(addr.Length!=4) throw new Exception("Invalid IP address");
                byte[] bytes = new byte[]{byte.Parse(addr[0]),byte.Parse(addr[1]),byte.Parse(addr[2]),byte.Parse(addr[3])};
                return BitConverter.ToInt32(bytes,0);
        }
        //Convert an IP integer to IP string
        private static string IPIntToString(int IP){
                byte[] addr = System.BitConverter.GetBytes(IP);
                return addr[0] +"."+addr[1] +"."+addr[2] +"."+addr[3];
        }
}