curl/docs/examples/websocket.c
2023-09-03 18:01:58 +02:00

132 lines
3.4 KiB
C

/***************************************************************************
* _ _ ____ _
* 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>
#include <unistd.h>
#include <curl/curl.h>
static int ping(CURL *curl, const char *send_payload)
{
size_t sent;
CURLcode result =
curl_ws_send(curl, send_payload, strlen(send_payload), &sent, 0,
CURLWS_PING);
return (int)result;
}
static int recv_pong(CURL *curl, const char *expected_payload)
{
size_t rlen;
const struct curl_ws_frame *meta;
char buffer[256];
CURLcode result = curl_ws_recv(curl, buffer, sizeof(buffer), &rlen, &meta);
if(!result) {
if(meta->flags & CURLWS_PONG) {
int same = 0;
fprintf(stderr, "ws: got PONG back\n");
if(rlen == strlen(expected_payload)) {
if(!memcmp(expected_payload, buffer, rlen)) {
fprintf(stderr, "ws: got the same payload back\n");
same = 1;
}
}
if(!same)
fprintf(stderr, "ws: did NOT get the same payload back\n");
}
else {
fprintf(stderr, "recv_pong: got %u bytes rflags %x\n", (int)rlen,
meta->flags);
}
}
fprintf(stderr, "ws: curl_ws_recv returned %u, received %u\n",
(unsigned int)result, (unsigned int)rlen);
return (int)result;
}
static int recv_any(CURL *curl)
{
size_t rlen;
const struct curl_ws_frame *meta;
char buffer[256];
CURLcode result = curl_ws_recv(curl, buffer, sizeof(buffer), &rlen, &meta);
if(result)
return result;
return 0;
}
/* close the connection */
static void websocket_close(CURL *curl)
{
size_t sent;
(void)curl_ws_send(curl, "", 0, &sent, 0, CURLWS_CLOSE);
}
static void websocket(CURL *curl)
{
int i = 0;
do {
recv_any(curl);
if(ping(curl, "foobar"))
return;
if(recv_pong(curl, "foobar")) {
return;
}
sleep(2);
} while(i++ < 10);
websocket_close(curl);
}
int main(void)
{
CURL *curl;
CURLcode res;
curl = curl_easy_init();
if(curl) {
curl_easy_setopt(curl, CURLOPT_URL, "wss://example.com");
curl_easy_setopt(curl, CURLOPT_CONNECT_ONLY, 2L); /* websocket style */
/* Perform the request, res will get the return code */
res = curl_easy_perform(curl);
/* Check for errors */
if(res != CURLE_OK)
fprintf(stderr, "curl_easy_perform() failed: %s\n",
curl_easy_strerror(res));
else {
/* connected and ready */
websocket(curl);
}
/* always cleanup */
curl_easy_cleanup(curl);
}
return 0;
}