quickjs-tart

quickjs-based runtime for wallet-core logic
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websocket.c (4687B)

      1 /***************************************************************************
      2  *                                  _   _ ____  _
      3  *  Project                     ___| | | |  _ \| |
      4  *                             / __| | | | |_) | |
      5  *                            | (__| |_| |  _ <| |___
      6  *                             \___|\___/|_| \_\_____|
      7  *
      8  * Copyright (C) Daniel Stenberg, <daniel@haxx.se>, et al.
      9  *
     10  * This software is licensed as described in the file COPYING, which
     11  * you should have received as part of this distribution. The terms
     12  * are also available at https://curl.se/docs/copyright.html.
     13  *
     14  * You may opt to use, copy, modify, merge, publish, distribute and/or sell
     15  * copies of the Software, and permit persons to whom the Software is
     16  * furnished to do so, under the terms of the COPYING file.
     17  *
     18  * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
     19  * KIND, either express or implied.
     20  *
     21  * SPDX-License-Identifier: curl
     22  *
     23  ***************************************************************************/
     24 /* <DESC>
     25  * WebSocket using CONNECT_ONLY
     26  * </DESC>
     27  */
     28 #include <stdio.h>
     29 #include <string.h>
     30 #ifdef _WIN32
     31 #include <winsock2.h>
     32 #include <windows.h>
     33 #define sleep(s) Sleep((DWORD)(s))
     34 #else
     35 #include <unistd.h>
     36 #endif
     37 
     38 #include <curl/curl.h>
     39 
     40 static CURLcode ping(CURL *curl, const char *send_payload)
     41 {
     42   CURLcode res = CURLE_OK;
     43   const char *buf = send_payload;
     44   size_t sent, blen = strlen(send_payload);
     45 
     46   while(blen) {
     47     res = curl_ws_send(curl, buf, blen, &sent, 0, CURLWS_PING);
     48     if(!res) {
     49       buf += sent; /* deduct what was sent */
     50       blen -= sent;
     51     }
     52     else if(res == CURLE_AGAIN) {  /* blocked on sending */
     53       fprintf(stderr, "ws: sent PING blocked, waiting a second\n");
     54       sleep(1);  /* either select() on socket or max timeout would
     55                     be good here. */
     56     }
     57     else /* real error sending */
     58       break;
     59   }
     60   if(!res)
     61     fprintf(stderr, "ws: sent PING with payload\n");
     62   return res;
     63 }
     64 
     65 static CURLcode recv_pong(CURL *curl, const char *expected_payload)
     66 {
     67   size_t rlen;
     68   const struct curl_ws_frame *meta;
     69   char buffer[256];
     70   CURLcode res;
     71 
     72 retry:
     73   res = curl_ws_recv(curl, buffer, sizeof(buffer), &rlen, &meta);
     74   if(!res) {
     75     /* on small PING content, this example assumes the complete
     76      * PONG content arrives in one go. Larger frames will arrive
     77      * in chunks, however. */
     78     if(meta->flags & CURLWS_PONG) {
     79       int same = 0;
     80       if(rlen == strlen(expected_payload)) {
     81         if(!memcmp(expected_payload, buffer, rlen))
     82           same = 1;
     83       }
     84       fprintf(stderr, "ws: received PONG with %s payload back\n",
     85               same ? "same" : "different");
     86     }
     87     else if(meta->flags & CURLWS_TEXT) {
     88       fprintf(stderr, "ws: received TEXT frame '%.*s'\n", (int)rlen,
     89               buffer);
     90     }
     91     else if(meta->flags & CURLWS_BINARY) {
     92       fprintf(stderr, "ws: received BINARY frame of %u bytes\n", (int)rlen);
     93     }
     94     else {
     95       /* some other frame arrived. */
     96       fprintf(stderr, "ws: received frame of %u bytes rflags %x\n", (int)rlen,
     97               meta->flags);
     98       goto retry;
     99     }
    100   }
    101   else if(res == CURLE_AGAIN) {  /* blocked on receiving */
    102     fprintf(stderr, "ws: PONG not there yet, waiting a second\n");
    103     sleep(1);  /* either select() on socket or max timeout would
    104                   be good here. */
    105     goto retry;
    106   }
    107   if(res)
    108     fprintf(stderr, "ws: curl_ws_recv returned %u, received %u\n",
    109             (unsigned int)res, (unsigned int)rlen);
    110   return res;
    111 }
    112 
    113 /* close the connection */
    114 static void websocket_close(CURL *curl)
    115 {
    116   size_t sent;
    117   (void)curl_ws_send(curl, "", 0, &sent, 0, CURLWS_CLOSE);
    118 }
    119 
    120 static CURLcode websocket(CURL *curl)
    121 {
    122   CURLcode res;
    123   int i = 0;
    124   do {
    125     res = ping(curl, "foobar");
    126     if(res)
    127       break;
    128     res = recv_pong(curl, "foobar");
    129     if(res)
    130       break;
    131     sleep(1);
    132   } while(i++ < 10);
    133   websocket_close(curl);
    134   return res;
    135 }
    136 
    137 int main(int argc, const char *argv[])
    138 {
    139   CURL *curl;
    140   CURLcode res;
    141 
    142   curl = curl_easy_init();
    143   if(!curl) {
    144     return 1; /* memory failure */
    145   }
    146   if(argc == 2)
    147     curl_easy_setopt(curl, CURLOPT_URL, argv[1]);
    148   else
    149     curl_easy_setopt(curl, CURLOPT_URL, "wss://example.com");
    150 
    151   curl_easy_setopt(curl, CURLOPT_CONNECT_ONLY, 2L); /* websocket style */
    152 
    153   /* Perform the request, res gets the return code */
    154   res = curl_easy_perform(curl);
    155   /* Check for errors */
    156   if(res != CURLE_OK)
    157     fprintf(stderr, "curl_easy_perform() failed: %s\n",
    158             curl_easy_strerror(res));
    159   else {
    160     /* connected and ready */
    161     res = websocket(curl);
    162   }
    163 
    164   /* always cleanup */
    165   curl_easy_cleanup(curl);
    166   return (int)res;
    167 }