testsAndMisc/C/websocketServer/main.c

#include <libwebsockets.h>
#include <signal.h>
#include <string.h>

static int                 interrupted;
static struct lws_context *context;

// Callback for WebSocket communication
static int callback_function(struct lws *wsi, enum lws_callback_reasons reason, void *user,
                             void *in, size_t len)
{
    switch (reason)
    {
    case LWS_CALLBACK_CLIENT_ESTABLISHED:
        printf("WebSocket connection established\n");
        break;

    case LWS_CALLBACK_CLIENT_RECEIVE:
        printf("Received data: %s\n", (char *)in);
        break;

    case LWS_CALLBACK_CLIENT_WRITEABLE:
    {
        const char   *msg = "Hello, WebSocket server!";
        unsigned char buf[LWS_PRE + 512];
        size_t        msg_len = strlen(msg);
        memcpy(&buf[LWS_PRE], msg, msg_len);
        lws_write(wsi, &buf[LWS_PRE], msg_len, LWS_WRITE_TEXT);
        break;
    }

    case LWS_CALLBACK_CLOSED:
        printf("WebSocket connection closed\n");
        interrupted = 1;
        break;

    default:
        break;
    }
    return 0;
}

// Signal handler for clean exit
static void sigint_handler(int sig)
{
    interrupted = 1;
    lws_cancel_service(context);
}

int main(void)
{
    struct lws_protocols protocols[] = {
        {
            "ws-protocol",     // Protocol name
            callback_function, // Callback function
            0,                 // Per-session data size
            0,
        },
        {NULL, NULL, 0, 0} // End of list
    };

    struct lws_client_connect_info   ccinfo = {0};
    struct lws_context_creation_info info   = {0};
    info.port                               = CONTEXT_PORT_NO_LISTEN;
    info.protocols                          = protocols;
    info.options                            = LWS_SERVER_OPTION_DO_SSL_GLOBAL_INIT;

    // Create WebSocket context
    context = lws_create_context(&info);
    if (!context)
    {
        fprintf(stderr, "Failed to create context\n");
        return -1;
    }

    signal(SIGINT, sigint_handler);

    // Configure connection details
    ccinfo.context        = context;
    ccinfo.address        = "echo.websocket.org"; // WebSocket server address
    ccinfo.port           = 443;                  // Port (for WSS use 443)
    ccinfo.path           = "/";                  // Path on the server
    ccinfo.host           = lws_canonical_hostname(context);
    ccinfo.origin         = "origin";
    ccinfo.protocol       = protocols[0].name;
    ccinfo.ssl_connection = LCCSCF_USE_SSL; // Use SSL for secure WebSocket

    // Initiate the WebSocket connection
    struct lws *wsi = lws_client_connect_via_info(&ccinfo);
    if (!wsi)
    {
        fprintf(stderr, "Failed to initiate WebSocket connection\n");
        lws_context_destroy(context);
        return -1;
    }

    // Event loop
    while (!interrupted)
    {
        lws_service(context, 1000);
    }

    // Cleanup
    lws_context_destroy(context);
    printf("Exiting...\n");
    return 0;
}