网站可以在这里找到：http://libwebsockets.org/trac/libwebsockets

我的问题是,如果我为libwebsocket_client_connect()函数的ssl_connection参数传入1或2,我会得到一个段错误.

我的代码用c写的.

想要找出它发生的位置,我在gdb中运行了我的代码(在添加了-g标志之后).在segfault之后,我跑了回溯.这就是我得到的：

来自/lib/x86_64-linux-gnu/libssl.so.1.0.0的SSL_ctrl()中的0x00007ffff7748c43
(gdb)回溯

来自/lib/x86_64-linux-gnu/libssl.so.1.0.0的SSL_ctrl()中的0 0x00007ffff7748c43

来自/usr/local/lib/libwebsockets.so.5.0.0的lws_client_socket_service()中的1 0x00007ffff7503aa2

来自/usr/local/lib/libwebsockets.so.5.0.0的libwebsocket_service_fd()中的2 0x00007ffff74fe606

来自/usr/local/lib/libwebsockets.so.5.0.0的libwebsocket_client_connect_2()中的3 0x00007ffff7504029

来自/usr/local/lib/libwebsockets.so.5.0.0的lws_client_socket_service()中的4 0x00007ffff75037d5

来自/usr/local/lib/libwebsockets.so.5.0.0的libwebsocket_service_fd()中的5 0x00007ffff74fe606

来自/usr/local/lib/libwebsockets.so.5.0.0的lws_plat_service()中的6 0x00007ffff7505980

还有更多,但相关信息高于……

如上所示,segfault发生在SSL_ctrl()函数中.

如果有人从libwebsockets SSL_ctrl()函数获得了段错误并解决了它,请告诉我.

如果有人可以告诉我如何使用调试标志构建libwebsockets(使用make,cmake或其他方式)和/或使它以冗长的方式写入某个日志文件和/或使其成为可能,我可以使用gdb进入函数,我非常感谢！

请确保删除所有早期版本的libwebsockets.h(使用-DCMAKE_BUILD_TYPE = DEBUG选项构建)并使用-DCMAKE_BUILD_TYPE = DEBUG参数进行干净构建.

在此之后启用调试时执行使用-d选项设置为日志级别

如果我的可执行文件是sock,那么在运行use时启用调试日志
     ./sock 127.0.0.1 -p 9000 -d 65535

这将产生类似的输出

[1449754712:6654] CLIENT: lws_client_connect: direct conn
    [1449754712:6654] CLIENT: lws_client_connect_2
    [1449754712:6654] CLIENT: lws_client_connect_2: address 127.0.0.1
    Reason :35
    Reason :32
    Reason :36
    [1449754712:6655] CLIENT: nonblocking connect retry

using System;
using WebSocketSharp;


namespace WebsocketTest
{
    class Program
    {
        public static void Main(string[] args)
        {
            try
            { 
            using (var ws = new WebSocketSharp.WebSocket("ws://192.168.18.186:7884"))
            {
               Console.WriteLine("started");
                ws.Connect();
                ws.Send("START");
                Console.ReadLine();
                }
            }catch(Exception ex)
            {
                Console.WriteLine(ex.Message);
                Console.ReadLine();
            }

        }
    }
}

但是我无法创建与在另一台机器上运行的websocket服务器的连接.我收到这样的错误信息

09-05-2017 16:20:41|Fatal|WebSocket.connect:0|System.Net.sockets.socketException (0x80004005): No connection Could be made because the target machine actively refused it 192.168.18.186:7884
                             at System.Net.sockets.TcpClient..ctor(String hostname,Int32 port)
                             at WebSocketSharp.WebSocket.setClientStream()
                             at WebSocketSharp.WebSocket.doHandshake()
                             at WebSocketSharp.WebSocket.connect()

与我的代码有关的问题是什么？有什么好的websocket库可用吗？

如果telnet可以连接,则客户端lib可能存在问题.实际上有一个内置于.NET中的Web套接字客户端,您应该可以使用它(ClientWebSocket)

截至目前,我只是尝试这个Sample Code(简单地回复了调用者所说的内容),并按照“文档”Here通过Nexmo连接到这个websocket.

我成功地向nexmo发送了一个动作“connect”.在调用Nexmo购买的号码时,它正确地重定向到端点(api / nexmo / socket),如使用断点时所示,但是当它在Echo方法中到达webSocket.ReceiveAsync时它会挂起.

using System;
    using System.Net.WebSockets;
    using System.Threading;
    using System.Threading.Tasks;
    using Microsoft.AspNetCore.Http;
    using Microsoft.AspNetCore.Mvc;
    using Newtonsoft.Json.Linq;

    namespace MyProject.Web.Controllers
    {
        [Route("api/[controller]")]
        [ApiController]
        public class NexmoController : ControllerBase
        {
            private WebSocket _webSocket;

            [HttpGet("answer")]
            public IActionResult AnswerHandler()
            {
                const string host = "MY_NGROK_URL";
                const string locale = "fr-FR";

                var nccos = new JArray();
                var nccoConnect = new JObject()
                {
                    { "action","connect" },{ "endpoint",new JArray(new JObject{
                            { "type","websocket" },{ "uri",$"wss://{host}/api/nexmo/socket"},{ "content-type","audio/l16;rate=16000"},{ "headers",new JObject {
                                    { "language",locale },{ "callerID","MY_NUMBER_HARDCODED_WHILE_TESTING" }
                                }
                            }
                        })
                    }
                };
                nccos.Add(nccoConnect);
                return Content(nccos.ToString(),"application/json");
            }

            [HttpPost("event")]
            public IActionResult EventHandler()
            {
                return Ok();
            }

            [HttpGet("socket")]
            public async Task GetAudio()
            {
                if (HttpContext.WebSockets.IsWebSocketRequest)
                {
                    _webSocket = await HttpContext.WebSockets.AcceptWebSocketAsync();
                    await Echo(HttpContext,_webSocket);
                }
                else
                {
                    HttpContext.Response.StatusCode = 400;
                }
            }

            //copy Paste from the Sample Code
            private async Task Echo(HttpContext context,WebSocket webSocket)
            {
                var buffer = new byte[1024 * 4];
                //Breakpoint : ReceiveAsync generates an exception
                WebSocketReceiveResult result = await webSocket.ReceiveAsync(new ArraySegment<byte>(buffer),CancellationToken.None);
                while (!result.CloseStatus.HasValue)
                {
                    await webSocket.SendAsync(new ArraySegment<byte>(buffer,result.Count),result.MessageType,result.EndOfMessage,CancellationToken.None);

                    result = await webSocket.ReceiveAsync(new ArraySegment<byte>(buffer),CancellationToken.None);
                }
                await webSocket.CloseAsync(result.CloseStatus.Value,result.CloseStatusDescription,CancellationToken.None);
            }
        }
    }

这里捕到的异常：

System.Net.WebSockets.WebSocketException (0x80004005): The remote
party closed the WebSocket connection without completing the close
handshake. —> System.Net.WebSockets.WebSocketException (0x80004005):
The remote party closed the WebSocket connection without completing
the close handshake.

更多例外：

at System.Net.WebSockets.ManagedWebSocket.ThrowIfEOFUnexpected(Boolean
throwOnPrematureClosure)
at System.Net.WebSockets.ManagedWebSocket.EnsureBufferContainsAsync(Int32
minimumrequiredBytes,CancellationToken cancellationToken,Boolean
throwOnPrematureClosure)
at System.Net.WebSockets.ManagedWebSocket.ReceiveAsyncPrivate[TWebSocketReceiveResultGetter,TWebSocketReceiveResult](Memory`1
payloadBuffer,
TWebSocketReceiveResultGetter resultGetter) at
System.Net.WebSockets.ManagedWebSocket.ReceiveAsyncPrivate[TWebSocketReceiveResultGetter,
TWebSocketReceiveResultGetter resultGetter) at
….Controllers.NexmoController.Echo(HttpContext context,
WebSocket webSocket) in
C:…\Controllers\NexmoController.cs:line
97 at ….Controllers.NexmoController.GetAudio() in
C:…\Controllers\NexmoController.cs:line
68 at lambda_method(Closure,Object ) at
Microsoft.Extensions.Internal.ObjectMethodExecutorAwaitable.Awaiter.GetResult()
at
Microsoft.AspNetCore.Mvc.Internal.ActionMethodExecutor.AwaitableResultExecutor.Execute(IActionResultTypeMapper
mapper,ObjectMethodExecutor executor,Object controller,Object[]
arguments) at System.Threading.Tasks.ValueTask`1.get_Result() at
Microsoft.AspNetCore.Mvc.Internal.ControllerActionInvoker.InvokeActionMethodAsync()
at
Microsoft.AspNetCore.Mvc.Internal.ControllerActionInvoker.InvokeNextActionFilterasync()
at
Microsoft.AspNetCore.Mvc.Internal.ControllerActionInvoker.Rethrow(ActionExecutedContext
context) at
Microsoft.AspNetCore.Mvc.Internal.ControllerActionInvoker.Next(State&
next,Scope& scope,Object& state,Boolean& isCompleted) at
Microsoft.AspNetCore.Mvc.Internal.ControllerActionInvoker.InvokeInnerFilterasync()
at
Microsoft.AspNetCore.Mvc.Internal.ResourceInvoker.InvokeNextResourceFilter()
at
Microsoft.AspNetCore.Mvc.Internal.ResourceInvoker.Rethrow(ResourceExecutedContext
context) at
Microsoft.AspNetCore.Mvc.Internal.ResourceInvoker.Next(State& next,
Scope& scope,Boolean& isCompleted) at
Microsoft.AspNetCore.Mvc.Internal.ResourceInvoker.InvokeFilterPipelineAsync()
at Microsoft.AspNetCore.Mvc.Internal.ResourceInvoker.InvokeAsync()
at Microsoft.AspNetCore.Routing.EndpointMiddleware.Invoke(HttpContext
httpContext) at
Microsoft.AspNetCore.Routing.EndpointRoutingMiddleware.Invoke(HttpContext
httpContext) at
Microsoft.AspNetCore.StaticFiles.StaticFileMiddleware.Invoke(HttpContext
context) at
Microsoft.AspNetCore.Diagnostics.DeveloperExceptionPageMiddleware.Invoke(HttpContext
context)

什么想法发生了什么？或者我如何解决这个问题？
我真的不明白这里的问题是什么.

我还尝试检查Websocket的WebSocketState,并将其设置为“Open”.
有关信息,我自己测试了示例代码(websocket回应用户的输入)并且它可以工作.

> ngrock不支持websockets(不是免费),所以我们在azure上发布了我们的应用程序.
>我们需要实例化websocket
StartUp而不是我们的控制器(如sample code
listed in the original post).我们已经采用了“Echo”方法
另一个类(更多是为了保持良好的结构)并设置它
静态的.

现在一切正常:)

澄清：ngrock不适用于安全的websockets(wss)