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 lws *wsi, enum lws_callback_reasons reason,
  37                     void *user, void *in, size_t len)
  38 {
  39         struct per_session_data__lws_mirror *pss =
  40                         (struct per_session_data__lws_mirror *)user;
  41         int n;
  42
  43         switch (reason) {
  44
  45         case LWS_CALLBACK_ESTABLISHED:
  46                 lwsl_info("%s: LWS_CALLBACK_ESTABLISHED\n", __func__);
  47                 pss->ringbuffer_tail = ringbuffer_head;
  48                 pss->wsi = wsi;
  49                 break;
  50
  51         case LWS_CALLBACK_PROTOCOL_DESTROY:
  52                 lwsl_notice("%s: mirror protocol cleaning up\n", __func__);
  53                 for (n = 0; n < sizeof ringbuffer / sizeof ringbuffer[0]; n++)
  54                         if (ringbuffer[n].payload)
  55                                 free(ringbuffer[n].payload);
  56                 break;
  57
  58         case LWS_CALLBACK_SERVER_WRITEABLE:
  59                 if (close_testing)
  60                         break;
  61                 while (pss->ringbuffer_tail != ringbuffer_head) {
  62
  63                         n = lws_write(wsi, (unsigned char *)
  64                                    ringbuffer[pss->ringbuffer_tail].payload +
  65                                    LWS_SEND_BUFFER_PRE_PADDING,
  66                                    ringbuffer[pss->ringbuffer_tail].len,
  67                                                                 LWS_WRITE_TEXT);
  68                         if (n < 0) {
  69                                 lwsl_err("ERROR %d writing to mirror socket\n", n);
  70                                 return -1;
  71                         }
  72                         if (n < (int)ringbuffer[pss->ringbuffer_tail].len)
  73                                 lwsl_err("mirror partial write %d vs %d\n",
  74                                        n, ringbuffer[pss->ringbuffer_tail].len);
  75
  76                         if (pss->ringbuffer_tail == (MAX_MESSAGE_QUEUE - 1))
  77                                 pss->ringbuffer_tail = 0;
  78                         else
  79                                 pss->ringbuffer_tail++;
  80
  81                         if (((ringbuffer_head - pss->ringbuffer_tail) &
  82                                   (MAX_MESSAGE_QUEUE - 1)) == (MAX_MESSAGE_QUEUE - 15))
  83                                 lws_rx_flow_allow_all_protocol(lws_get_ctx(wsi),
  84                                                lws_get_protocol(wsi));
  85
  86                         if (lws_partial_buffered(wsi) || lws_send_pipe_choked(wsi)) {
  87                                 lws_callback_on_writable(wsi);
  88                                 break;
  89                         }
  90                 }
  91                 break;
  92
  93         case LWS_CALLBACK_RECEIVE:
  94                 if (((ringbuffer_head - pss->ringbuffer_tail) &
  95                     (MAX_MESSAGE_QUEUE - 1)) == (MAX_MESSAGE_QUEUE - 1)) {
  96                         lwsl_err("dropping!\n");
  97                         goto choke;
  98                 }
  99
 100                 if (ringbuffer[ringbuffer_head].payload)
 101                         free(ringbuffer[ringbuffer_head].payload);
 102
 103                 ringbuffer[ringbuffer_head].payload =
 104                                 malloc(LWS_SEND_BUFFER_PRE_PADDING + len +
 105                                                   LWS_SEND_BUFFER_POST_PADDING);
 106                 ringbuffer[ringbuffer_head].len = len;
 107                 memcpy((char *)ringbuffer[ringbuffer_head].payload +
 108                                           LWS_SEND_BUFFER_PRE_PADDING, in, len);
 109                 if (ringbuffer_head == (MAX_MESSAGE_QUEUE - 1))
 110                         ringbuffer_head = 0;
 111                 else
 112                         ringbuffer_head++;
 113
 114                 if (((ringbuffer_head - pss->ringbuffer_tail) &
 115                     (MAX_MESSAGE_QUEUE - 1)) != (MAX_MESSAGE_QUEUE - 2))
 116                         goto done;
 117
 118 choke:
 119                 lwsl_debug("LWS_CALLBACK_RECEIVE: throttling %p\n", wsi);
 120                 lws_rx_flow_control(wsi, 0);
 121
 122 done:
 123                 lws_callback_on_writable_all_protocol(lws_get_ctx(wsi),
 124                                                lws_get_protocol(wsi));
 125                 break;
 126
 127         /*
 128          * this just demonstrates how to use the protocol filter. If you won't
 129          * study and reject connections based on header content, you don't need
 130          * to handle this callback
 131          */
 132
 133         case LWS_CALLBACK_FILTER_PROTOCOL_CONNECTION:
 134                 dump_handshake_info(wsi);
 135                 /* you could return non-zero here and kill the connection */
 136                 break;
 137
 138         default:
 139                 break;
 140         }
 141
 142         return 0;
 143 }