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/***************************************************************************
* _ _ ____ _
* Project ___| | | | _ \| |
* / __| | | | |_) | |
* | (__| |_| | _ <| |___
* \___|\___/|_| \_\_____|
*
* Copyright (C) Daniel Stenberg, <daniel@haxx.se>, et al.
*
* This software is licensed as described in the file COPYING, which
* you should have received as part of this distribution. The terms
* are also available at https://curl.se/docs/copyright.html.
*
* You may opt to use, copy, modify, merge, publish, distribute and/or sell
* copies of the Software, and permit persons to whom the Software is
* furnished to do so, under the terms of the COPYING file.
*
* This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
* KIND, either express or implied.
*
* SPDX-License-Identifier: curl
*
***************************************************************************/
/* <DESC>
* WebSocket using CONNECT_ONLY
* </DESC>
*/
#include <stdio.h>
#include <string.h>
#ifdef _WIN32
#include <winsock2.h>
#include <windows.h>
#define sleep(s) Sleep((DWORD)(s))
#else
#include <unistd.h>
#endif
#include <curl/curl.h>
static CURLcode ping(CURL *curl, const char *send_payload)
{
CURLcode result = CURLE_OK;
const char *buf = send_payload;
size_t sent, blen = strlen(send_payload);
while(blen) {
result = curl_ws_send(curl, buf, blen, &sent, 0, CURLWS_PING);
if(!result) {
buf += sent; /* deduct what was sent */
blen -= sent;
}
else if(result == CURLE_AGAIN) { /* blocked on sending */
fprintf(stderr, "ws: sent PING blocked, waiting a second\n");
sleep(1); /* either select() on socket or max timeout would
be good here. */
}
else /* real error sending */
break;
}
if(!result)
fprintf(stderr, "ws: sent PING with payload\n");
return result;
}
static CURLcode recv_pong(CURL *curl, const char *expected_payload)
{
size_t rlen = 0;
const struct curl_ws_frame *meta;
char buffer[256];
CURLcode result;
retry:
result = curl_ws_recv(curl, buffer, sizeof(buffer), &rlen, &meta);
if(!result) {
/* on small PING content, this example assumes the complete
* PONG content arrives in one go. Larger frames will arrive
* in chunks, however. */
if(meta->flags & CURLWS_PONG) {
int same = 0;
if(rlen == strlen(expected_payload)) {
if(!memcmp(expected_payload, buffer, rlen))
same = 1;
}
fprintf(stderr, "ws: received PONG with %s payload back\n",
same ? "same" : "different");
}
else if(meta->flags & CURLWS_TEXT) {
fprintf(stderr, "ws: received TEXT frame '%.*s'\n", (int)rlen, buffer);
}
else if(meta->flags & CURLWS_BINARY) {
fprintf(stderr, "ws: received BINARY frame of %u bytes\n",
(unsigned int)rlen);
}
else {
/* some other frame arrived. */
fprintf(stderr, "ws: received frame of %u bytes rflags %x\n",
(unsigned int)rlen, meta->flags);
goto retry;
}
}
else if(result == CURLE_AGAIN) { /* blocked on receiving */
fprintf(stderr, "ws: PONG not there yet, waiting a second\n");
sleep(1); /* either select() on socket or max timeout would
be good here. */
goto retry;
}
if(result)
fprintf(stderr, "ws: curl_ws_recv returned %u, received %u\n",
(unsigned int)result, (unsigned int)rlen);
return result;
}
/* close the connection */
static void websocket_close(CURL *curl)
{
size_t sent;
(void)curl_ws_send(curl, "", 0, &sent, 0, CURLWS_CLOSE);
}
static CURLcode websocket(CURL *curl)
{
CURLcode result;
int i = 0;
do {
result = ping(curl, "foobar");
if(result)
break;
result = recv_pong(curl, "foobar");
if(result)
break;
sleep(1);
} while(i++ < 10);
websocket_close(curl);
return result;
}
int main(int argc, const char *argv[])
{
CURL *curl;
CURLcode result = curl_global_init(CURL_GLOBAL_ALL);
if(result)
return (int)result;
curl = curl_easy_init();
if(curl) {
if(argc == 2)
curl_easy_setopt(curl, CURLOPT_URL, argv[1]);
else
curl_easy_setopt(curl, CURLOPT_URL, "wss://example.com");
curl_easy_setopt(curl, CURLOPT_CONNECT_ONLY, 2L); /* websocket style */
/* Perform the request, result gets the return code */
result = curl_easy_perform(curl);
/* Check for errors */
if(result != CURLE_OK)
fprintf(stderr, "curl_easy_perform() failed: %s\n",
curl_easy_strerror(result));
else {
/* connected and ready */
result = websocket(curl);
}
/* always cleanup */
curl_easy_cleanup(curl);
}
curl_global_cleanup();
return (int)result;
}
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