将WebSockets消息发送到服务器

我正在尝试使用一种设备的API，但是它使用的是带有强制执行的Origin标头的WS接口，这给我带来了麻烦。

在Chrome中，我可以在加载具有正确Origin的页面时打开控制台，创建WS连接，并轻松发送/接收消息：请注意，服务器始终会确认发送的消息（绿色）。

作为参考，如果在另一个页面上创建连接会导致Origin标头不匹配（报告为404），则会发生这种情况：

为了避开这个问题，我转向了C语言，因为我的程序的其余部分还是以这种方式编写的。这是我现在拥有的代码，主要基于以下答案：

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <signal.h>
#include <libwebsockets.h>

#define KGRN "\033[0;32;32m"
#define KCYN "\033[0;36m"
#define KRED "\033[0;32;31m"
#define KYEL "\033[1;33m"
#define KBLU "\033[0;32;34m"
#define KCYN_L "\033[1;36m"
#define KBRN "\033[0;33m"
#define RESET "\033[0m"

static int destroy_flag = 0;
static int connection_flag = 0;
static int writeable_flag = 0;

static void INT_HANDLER(int signo) {
    destroy_flag = 1;
}

struct session_data {
    int fd;
};

struct pthread_routine_tool {
    struct lws_context *context;
    struct lws *wsi;
};

static int websocket_write_back(struct lws *wsi_in, char *str, int str_size_in) 
{
    if (str == NULL || wsi_in == NULL)
        return -1;

    int n;
    int len;
    char *out = NULL;

    if (str_size_in < 1) 
        len = strlen(str);
    else
        len = str_size_in;

    out = (char *)malloc(sizeof(char)*(LWS_SEND_BUFFER_PRE_PADDING + len + LWS_SEND_BUFFER_POST_PADDING));
    //* setup the buffer*/
    memcpy (out + LWS_SEND_BUFFER_PRE_PADDING, str, len );
    //* write out*/
    n = lws_write(wsi_in, out + LWS_SEND_BUFFER_PRE_PADDING, len, LWS_WRITE_TEXT);

    printf(KBLU"[websocket_write_back] %s\n"RESET, str);
    //* free the buffer*/
    free(out);

    return n;
}


static int ws_service_callback(
                         struct lws *wsi,
                         enum lws_callback_reasons reason, void *user,
                         void *in, size_t len)
{

    switch (reason) {

        case LWS_CALLBACK_CLIENT_ESTABLISHED:
            printf(KYEL"[Main Service] Connect with server success.\n"RESET);
            connection_flag = 1;
            break;

        case LWS_CALLBACK_CLIENT_CONNECTION_ERROR:
            printf(KRED"[Main Service] Connect with server error.\n"RESET);
            destroy_flag = 1;
            connection_flag = 0;
            break;

        case LWS_CALLBACK_CLOSED:
            printf(KYEL"[Main Service] LWS_CALLBACK_CLOSED\n"RESET);
            destroy_flag = 1;
            connection_flag = 0;
            break;

        case LWS_CALLBACK_CLIENT_RECEIVE:
            printf(KCYN_L"[Main Service] Client recvived:%s\n"RESET, (char *)in);

            if (writeable_flag)
                destroy_flag = 1;

            break;
        case LWS_CALLBACK_CLIENT_WRITEABLE :
            printf(KYEL"[Main Service] On writeable is called. send byebye message\n"RESET);
            websocket_write_back(wsi, "{\"command\":\"subscribe\",\"identifier\":\"{\\\"channel\\\":\\\"DevicesChannel\\\",\\\"share_token\\\":\\\"D0E91\\\"}\"}", -1);
            websocket_write_back(wsi, "{\"command\":\"message\",\"identifier\":\"{\\\"channel\\\":\\\"DevicesChannel\\\",\\\"share_token\\\":\\\"D0E91\\\"}\",\"data\":\"{\\\"value\\\":100,\\\"action\\\":\\\"set_buzz\\\"}\"}", -1);
            writeable_flag = 1;
            break;

        default:
            break;
    }

    return 0;
}

static void *pthread_routine(void *tool_in)
{
    struct pthread_routine_tool *tool = tool_in;

    printf(KBRN"[pthread_routine] Good day. This is pthread_routine.\n"RESET);

    //* waiting for connection with server done.*/
    while(!connection_flag)
        usleep(1000*20);

    //*Send greeting to server*/ 
    lws_callback_on_writable(tool->wsi);

}

int main(void)
{
    //* register the signal SIGINT handler */
    struct sigaction act;
    act.sa_handler = INT_HANDLER;
    act.sa_flags = 0;
    sigemptyset(&act.sa_mask);
    sigaction( SIGINT, &act, 0);


    struct lws_context *context = NULL;
    struct lws_context_creation_info info;
    struct lws *wsi = NULL;
    struct lws_protocols protocol;

    memset(&info, 0, sizeof info);
    info.port = CONTEXT_PORT_NO_LISTEN;
    info.iface = NULL;
    info.protocols = &protocol;
    info.ssl_cert_filepath = NULL;
    info.ssl_private_key_filepath = NULL;
    info.extensions = lws_get_internal_extensions();
    info.gid = -1;
    info.uid = -1;
    info.options = 0;

    protocol.name  = "websockets";
    protocol.callback = &ws_service_callback;
    protocol.per_session_data_size = sizeof(struct session_data);
    protocol.rx_buffer_size = 0;
    protocol.id = 0;
    protocol.user = NULL;

    context = lws_create_context(&info);
    printf(KRED"[Main] context created.\n"RESET);

    if (context == NULL) {
        printf(KRED"[Main] context is NULL.\n"RESET);
        return -1;
    }


    wsi = lws_client_connect(context, "mobu1.herokuapp.com", 443, 1,
        "/cable", "mobu1.herokuapp.com", "link.motorbunny.com",
    if (wsi == NULL) {
        printf(KRED"[Main] wsi create error.\n"RESET);
        return -1;
    }

    printf(KGRN"[Main] wsi create success.\n"RESET);

    struct pthread_routine_tool tool;
    tool.wsi = wsi;
    tool.context = context;

    pthread_t pid;
    pthread_create(&pid, NULL, pthread_routine, &tool);
    pthread_detach(pid);

    while(!destroy_flag)
    {
        lws_service(context, 50);
    }

    lws_context_destroy(context);

    return 0;
}

The result of running the above program is this:

As you can see, the periodic pings from server to my client are being picked up, but the lws_callback_on_writable(wsi); seems to have no effect as the LWS_CALLBACK_CLIENT_WRITEABLE callback never gets called. Additionally, if I call websocket_write_back() directly anywhere else, it doesn't seem to be sending anything to the server, and no acknowledgement is present either.

Is there something obvious I am doing wrong?

EDIT 1: I found this neat wscat, where I can replicate the results from Chrome: Now the question is, how can I interface this with my C program in a way that it can wait for the Welcome message from the server, and then send two messages? And better yet, how to stay connected, so that my program can send multiple commands at different points of time without having to do the handshake all the time?