test-server/test-server-mirror.c

   1 /*
   2  * libwebsockets-test-server - libwebsockets test implementation
   3  *
   4  * Copyright (C) 2010-2015 Andy Green <andy@warmcat.com>
   5  *
   6  *  This library is free software; you can redistribute it and/or
   7  *  modify it under the terms of the GNU Lesser General Public
   8  *  License as published by the Free Software Foundation:
   9  *  version 2.1 of the License.
  10  *
  11  *  This library is distributed in the hope that it will be useful,
  12  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  14  *  Lesser General Public License for more details.
  15  *
  16  *  You should have received a copy of the GNU Lesser General Public
  17  *  License along with this library; if not, write to the Free Software
  18  *  Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston,
  19  *  MA  02110-1301  USA
  20  */
  21 #include "test-server.h"
  22
  23 /* lws-mirror_protocol */
  24
  25 #define MAX_MESSAGE_QUEUE 32
  26
  27 struct a_message {
  28         void *payload;
  29         size_t len;
  30 };
  31
  32 static struct a_message ringbuffer[MAX_MESSAGE_QUEUE];
  33 static int ringbuffer_head;
  34
  35 int
  36 callback_lws_mirror(struct libwebsocket_context *context,
  37                     struct libwebsocket *wsi,
  38                     enum libwebsocket_callback_reasons reason,
  39                     void *user, void *in, size_t len)
  40 {
  41         struct per_session_data__lws_mirror *pss =
  42                         (struct per_session_data__lws_mirror *)user;
  43         int n;
  44
  45         switch (reason) {
  46
  47         case LWS_CALLBACK_ESTABLISHED:
  48                 lwsl_info("%s: LWS_CALLBACK_ESTABLISHED\n", __func__);
  49                 pss->ringbuffer_tail = ringbuffer_head;
  50                 pss->wsi = wsi;
  51                 break;
  52
  53         case LWS_CALLBACK_PROTOCOL_DESTROY:
  54                 lwsl_notice("%s: mirror protocol cleaning up\n", __func__);
  55                 for (n = 0; n < sizeof ringbuffer / sizeof ringbuffer[0]; n++)
  56                         if (ringbuffer[n].payload)
  57                                 free(ringbuffer[n].payload);
  58                 break;
  59
  60         case LWS_CALLBACK_SERVER_WRITEABLE:
  61                 if (close_testing)
  62                         break;
  63                 while (pss->ringbuffer_tail != ringbuffer_head) {
  64
  65                         n = libwebsocket_write(wsi, (unsigned char *)
  66                                    ringbuffer[pss->ringbuffer_tail].payload +
  67                                    LWS_SEND_BUFFER_PRE_PADDING,
  68                                    ringbuffer[pss->ringbuffer_tail].len,
  69                                                                 LWS_WRITE_TEXT);
  70                         if (n < 0) {
  71                                 lwsl_err("ERROR %d writing to mirror socket\n", n);
  72                                 return -1;
  73                         }
  74                         if (n < ringbuffer[pss->ringbuffer_tail].len)
  75                                 lwsl_err("mirror partial write %d vs %d\n",
  76                                        n, ringbuffer[pss->ringbuffer_tail].len);
  77
  78                         if (pss->ringbuffer_tail == (MAX_MESSAGE_QUEUE - 1))
  79                                 pss->ringbuffer_tail = 0;
  80                         else
  81                                 pss->ringbuffer_tail++;
  82
  83                         if (((ringbuffer_head - pss->ringbuffer_tail) &
  84                                   (MAX_MESSAGE_QUEUE - 1)) == (MAX_MESSAGE_QUEUE - 15))
  85                                 libwebsocket_rx_flow_allow_all_protocol(
  86                                                libwebsockets_get_protocol(wsi));
  87
  88                         if (lws_partial_buffered(wsi) || lws_send_pipe_choked(wsi)) {
  89                                 libwebsocket_callback_on_writable(context, wsi);
  90                                 break;
  91                         }
  92                         /*
  93                          * for tests with chrome on same machine as client and
  94                          * server, this is needed to stop chrome choking
  95                          */
  96 #ifdef _WIN32
  97                         Sleep(1);
  98 #else
  99                         usleep(1);
 100 #endif
 101                 }
 102                 break;
 103
 104         case LWS_CALLBACK_RECEIVE:
 105                 if (((ringbuffer_head - pss->ringbuffer_tail) &
 106                     (MAX_MESSAGE_QUEUE - 1)) == (MAX_MESSAGE_QUEUE - 1)) {
 107                         lwsl_err("dropping!\n");
 108                         goto choke;
 109                 }
 110
 111                 if (ringbuffer[ringbuffer_head].payload)
 112                         free(ringbuffer[ringbuffer_head].payload);
 113
 114                 ringbuffer[ringbuffer_head].payload =
 115                                 malloc(LWS_SEND_BUFFER_PRE_PADDING + len +
 116                                                   LWS_SEND_BUFFER_POST_PADDING);
 117                 ringbuffer[ringbuffer_head].len = len;
 118                 memcpy((char *)ringbuffer[ringbuffer_head].payload +
 119                                           LWS_SEND_BUFFER_PRE_PADDING, in, len);
 120                 if (ringbuffer_head == (MAX_MESSAGE_QUEUE - 1))
 121                         ringbuffer_head = 0;
 122                 else
 123                         ringbuffer_head++;
 124
 125                 if (((ringbuffer_head - pss->ringbuffer_tail) &
 126                     (MAX_MESSAGE_QUEUE - 1)) != (MAX_MESSAGE_QUEUE - 2))
 127                         goto done;
 128
 129 choke:
 130                 lwsl_debug("LWS_CALLBACK_RECEIVE: throttling %p\n", wsi);
 131                 libwebsocket_rx_flow_control(wsi, 0);
 132
 133 done:
 134                 libwebsocket_callback_on_writable_all_protocol(
 135                                                libwebsockets_get_protocol(wsi));
 136                 break;
 137
 138         /*
 139          * this just demonstrates how to use the protocol filter. If you won't
 140          * study and reject connections based on header content, you don't need
 141          * to handle this callback
 142          */
 143
 144         case LWS_CALLBACK_FILTER_PROTOCOL_CONNECTION:
 145                 dump_handshake_info(wsi);
 146                 /* you could return non-zero here and kill the connection */
 147                 break;
 148
 149         default:
 150                 break;
 151         }
 152
 153         return 0;
 154 }