Websocket

// libwebsocketsserver.cpp : Defines the entry point for the console application.
//

#include "stdafx.h"
 #include <stdio.h>
#include <stdlib.h>
#include <string.h>
#ifdef _WIN32
#include <io.h>
#else
#include <unistd.h>
#endif
#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 KMAG "\033[0;35m"
#define KBLU "\033[0;32;34m"
#define KCYN_L "\033[1;36m"
#define RESET "\033[0m"

static int destroy_flag = 0;

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


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

    switch (reason) {
        // http://git.warmcat.com/cgi-bin/cgit/libwebsockets/tree/lib/libwebsockets.h#n260
    case LWS_CALLBACK_CLIENT_WRITEABLE:
        printf("connection established\n");

        // http://git.warmcat.com/cgi-bin/cgit/libwebsockets/tree/lib/libwebsockets.h#n281
    case LWS_CALLBACK_HTTP: {
        char *requested_uri = (char *)in;
        printf("requested URI: %s\n", requested_uri);

        /*if (strcmp(requested_uri, "/") == 0) {
            lws_return_http_status(wsi, 200, "Hello, World!\0");
            // http://git.warmcat.com/cgi-bin/cgit/libwebsockets/tree/lib/libwebsockets.h#n597
            //lws_write(wsi, universal_response,
            //  strlen((const char*)universal_response), LWS_WRITE_HTTP);
            lws_http_transaction_completed(wsi);
            break;

        }
        else {*/
            if (strcmp(requested_uri, "index.html\0") != 0 && strcmp(requested_uri, "/\0") != 0) {
                printf("returning 404\n");
                lws_return_http_status(wsi, 404, "Only index.html is returned");
                lws_http_transaction_completed(wsi);
                break;
            }


            char *resource_path = "./index_cpp.html";
                printf("Returned resource path: %s\n", resource_path);
                char *mime = "text/html";
                // by default non existing resources return code 400
                // for more information how this function handles headers
                // see it's source code
                // http://git.warmcat.com/cgi-bin/cgit/libwebsockets/tree/lib/parsers.c#n1896
                lws_serve_http_file(wsi, resource_path, mime,"",0);
        //}

        // close connection
        lws_http_transaction_completed(wsi);
        break;
    }
    //The following callbacks are ignored due to not being used
    case LWS_CALLBACK_LOCK_POLL:
        /*
        * lock mutex to protect pollfd state
        * called before any other POLL related callback
        * if protecting wsi lifecycle change, len == 1
        */
        break;

    case LWS_CALLBACK_UNLOCK_POLL:
        /*
        * unlock mutex to protect pollfd state when
        * called after any other POLL related callback
        * if protecting wsi lifecycle change, len == 1
        */
        break;
    case LWS_CALLBACK_GET_THREAD_ID:
        break;
    case LWS_CALLBACK_PROTOCOL_INIT:
        break;
    //If something unexpected pops up
    default:
        printf("unhandled callback %d\n ", reason);
        break;
    }



    return 0;
}


char *randstring(int length) {
    static int mySeed = 25011984;
    char *string = "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789,.-#'?!";
    size_t stringLen = strlen(string);
    char *randomString = NULL;

    srand((unsigned int)time(NULL) * length + ++mySeed);

    if (length < 1) {
        length = 1;
    }

    randomString = (char *)malloc(sizeof(char) * (length + 1));

    if (randomString) {
        short key = 0;

        for (int n = 0; n < length; n++) {
            key = rand() % stringLen;
            randomString[n] = string[key];
        }

        randomString[length] = '\0';

        return randomString;
    }
    else {
        printf("No memory");
        exit(1);
    }
}

const int replySize = 30000;

char *reply_string = randstring(replySize);



/* *
* websocket_write_back: write the string data to the destination wsi.
*/
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;
    unsigned char *out = NULL;

    char *write_what = reply_string;

    //if (str_size_in < 1)
        len = strlen(write_what);
    //else
        //len = str_size_in;

    out = (unsigned 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, write_what, 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, write_what);
    //* 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)
{

    printf("Got a ws request %d\n", reason);

    switch (reason) {

    case LWS_CALLBACK_ESTABLISHED:
        printf(KYEL"[Main Service] Connection established\n"RESET);
        break;

        //* If receive a data from client*/
    case LWS_CALLBACK_RECEIVE:
        printf(KCYN_L"[Main Service] Server recvived:\n"RESET/*, (char *)in*/);

        //* echo back to client*/
        websocket_write_back(wsi, (char *)in, -1);

        break;
    case LWS_CALLBACK_CLOSED:
        printf(KYEL"[Main Service] Client close.\n"RESET);
        break;

    default:
        break;
    }

    return 0;
}

struct per_session_data {
    int fd;
};

bool got_sighup = false;
bool got_sigint = false;

void handle_signal(int signal) {
    switch (signal) {
#ifdef _WIN32
    case SIGTERM:
    case SIGABRT:
    case SIGBREAK:
#else
    case SIGHUP:
#endif
        got_sighup = true;
        break;
    case SIGINT:
        got_sigint = true;
        break;
    }
}
#ifdef _WIN32

void usleep(__int64 usec)
{
    HANDLE timer;
    LARGE_INTEGER ft;

    ft.QuadPart = -(10 * usec); // Convert to 100 nanosecond interval, negative value indicates relative time

    timer = CreateWaitableTimer(NULL, TRUE, NULL);
    SetWaitableTimer(timer, &ft, 0, NULL, NULL, 0);
    WaitForSingleObject(timer, INFINITE);
    CloseHandle(timer);
}
#endif

struct per_session_data__http {
    lws_filefd_type fd;
    char post_string[256];
#ifdef LWS_WITH_CGI
    struct lws_cgi_args args;
#endif
#if defined(LWS_WITH_CGI) || !defined(LWS_NO_CLIENT)
    int reason_bf;
#endif
    unsigned int client_finished : 1;
};


static struct lws_protocols protocols[] = {
    /* first protocol must always be HTTP handler */

    {
        "http-only",        /* name */
        callback_http,      /* callback */
        sizeof(struct per_session_data__http),  /* per_session_data_size */
        0,          /* max frame size / rx buffer */
    },
    {
        "tspp",
        ws_service_callback,
        sizeof(struct per_session_data),
        0, /* rx buf size must be >= permessage-deflate rx size */
    },
    { NULL, NULL, 0, 0 } /* terminator */
};


int _tmain(int argc, _TCHAR* argv[])
{
    // server url will usd port 5000
    int port = 5000;
    const char *interface = NULL;
    struct lws_context_creation_info info;
    struct lws_context *context;
    // Not using ssl
    const char *cert_path = NULL;
    const char *key_path = NULL;
    // no special options
    int opts = 0;

#ifdef _WIN32
    signal(SIGINT, handle_signal);
    signal(SIGTERM, handle_signal);
    signal(SIGABRT, handle_signal);
#else

    //* 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);
#endif

    //* setup websocket protocol */

    //* setup websocket context info*/
    memset(&info, 0, sizeof info);
    info.port = port;
    info.iface = interface;
    info.protocols = protocols;

    info.extensions = lws_get_internal_extensions();
    info.ssl_cert_filepath = cert_path;
    info.ssl_private_key_filepath = key_path;
    info.gid = -1;
    info.uid = -1;
    info.options = opts;

    //* create libwebsocket context. */
    context = lws_create_context(&info);
    if (context == NULL) {
        printf(KRED"[Main] Websocket context create error.\n"RESET);
        return -1;
    }

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

    //* websocket service */
    while (!destroy_flag) {
        lws_service(context, 0);
    }
    usleep(10);
    lws_context_destroy(context);

    return 0;
    return 0;
}