1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
|
/*
* libwebsockets-test-client - libwebsockets test implementation
*
* Copyright (C) 2011 Andy Green <andy@warmcat.com>
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation:
* version 2.1 of the License.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston,
* MA 02110-1301 USA
*/
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <getopt.h>
#include <string.h>
#include "../lib/libwebsockets.h"
#include <poll.h>
/*
* This demo shows how to connect multiple websockets simultaneously to a
* websocket server (there is no restriction on their having to be the same
* server just it simplifies the demo).
*
* dumb-increment-protocol: we connect to the server and print the number
* we are given
*
* lws-mirror-protocol: draws random circles, which are mirrored on to every
* client (see them being drawn in every browser
* session also using the test server)
*/
enum demo_protocols {
PROTOCOL_DUMB_INCREMENT,
PROTOCOL_LWS_MIRROR,
/* always last */
DEMO_PROTOCOL_COUNT
};
/* dumb_increment protocol */
static int
callback_dumb_increment(struct libwebsocket *wsi,
enum libwebsocket_callback_reasons reason,
void *user, void *in, size_t len)
{
switch (reason) {
case LWS_CALLBACK_CLIENT_RECEIVE:
((char *)in)[len] = '\0';
fprintf(stderr, "rx %d '%s'\n", (int)len, (char *)in);
break;
default:
break;
}
return 0;
}
/* lws-mirror_protocol */
static int
callback_lws_mirror(struct libwebsocket *wsi,
enum libwebsocket_callback_reasons reason,
void *user, void *in, size_t len)
{
unsigned char buf[LWS_SEND_BUFFER_PRE_PADDING + 4096 +
LWS_SEND_BUFFER_POST_PADDING];
int l;
switch (reason) {
case LWS_CALLBACK_CLIENT_ESTABLISHED:
/*
* start the ball rolling,
* LWS_CALLBACK_CLIENT_WRITEABLE will come next service
*/
libwebsocket_callback_on_writable(wsi);
break;
case LWS_CALLBACK_CLIENT_RECEIVE:
/* fprintf(stderr, "rx %d '%s'\n", (int)len, (char *)in); */
break;
case LWS_CALLBACK_CLIENT_WRITEABLE:
l = sprintf((char *)&buf[LWS_SEND_BUFFER_PRE_PADDING],
"c #%06X %d %d %d;",
(int)random() & 0xffffff,
(int)random() % 500,
(int)random() % 250,
(int)random() % 24);
libwebsocket_write(wsi,
&buf[LWS_SEND_BUFFER_PRE_PADDING], l, LWS_WRITE_TEXT);
/* get notified as soon as we can write again */
libwebsocket_callback_on_writable(wsi);
/*
* without at least this delay, we choke the browser
* and the connection stalls, despite we now take care about
* flow control
*/
usleep(200);
break;
default:
break;
}
return 0;
}
/* list of supported protocols and callbacks */
static struct libwebsocket_protocols protocols[] = {
[PROTOCOL_DUMB_INCREMENT] = {
.name = "dumb-increment-protocol",
.callback = callback_dumb_increment,
},
[PROTOCOL_LWS_MIRROR] = {
.name = "lws-mirror-protocol",
.callback = callback_lws_mirror,
},
[DEMO_PROTOCOL_COUNT] = { /* end of list */
.callback = NULL
}
};
static struct option options[] = {
{ "help", no_argument, NULL, 'h' },
{ "port", required_argument, NULL, 'p' },
{ "ssl", no_argument, NULL, 's' },
{ NULL, 0, 0, 0 }
};
int main(int argc, char **argv)
{
int n = 0;
int port = 7681;
int use_ssl = 0;
struct libwebsocket_context *context;
const char *address = argv[1];
struct libwebsocket *wsi_dumb;
struct libwebsocket *wsi_mirror;
fprintf(stderr, "libwebsockets test client\n"
"(C) Copyright 2010 Andy Green <andy@warmcat.com> "
"licensed under LGPL2.1\n");
if (argc < 2)
goto usage;
optind++;
while (n >= 0) {
n = getopt_long(argc, argv, "hsp:", options, NULL);
if (n < 0)
continue;
switch (n) {
case 's':
use_ssl = 2; /* 2 = allow selfsigned */
break;
case 'p':
port = atoi(optarg);
break;
case 'h':
goto usage;
}
}
/*
* create the websockets context. This tracks open connections and
* knows how to route any traffic and which protocol version to use,
* and if each connection is client or server side.
*
* For this client-only demo, we tell it to not listen on any port.
*/
context = libwebsocket_create_context(CONTEXT_PORT_NO_LISTEN,
protocols, NULL, NULL, -1, -1);
if (context == NULL) {
fprintf(stderr, "Creating libwebsocket context failed\n");
return 1;
}
/* create a client websocket using dumb increment protocol */
wsi_dumb = libwebsocket_client_connect(context, address, port, use_ssl,
"/", libwebsocket_canonical_hostname(context), "origin",
protocols[PROTOCOL_DUMB_INCREMENT].name);
if (wsi_dumb == NULL) {
fprintf(stderr, "libwebsocket dumb connect failed\n");
return -1;
}
/* create a client websocket using mirror protocol */
wsi_mirror = libwebsocket_client_connect(context, address, port,
use_ssl, "/", libwebsocket_canonical_hostname(context), "origin",
protocols[PROTOCOL_LWS_MIRROR].name);
if (wsi_mirror == NULL) {
fprintf(stderr, "libwebsocket dumb connect failed\n");
return -1;
}
fprintf(stderr, "Websocket connections opened\n");
/*
* sit there servicing the websocket context to handle incoming
* packets, and drawing random circles on the mirror protocol websocket
*/
n = 0;
while (n >= 0)
n = libwebsocket_service(context, 1000);
libwebsocket_context_destroy(context);
return 0;
usage:
fprintf(stderr, "Usage: libwebsockets-test-client "
"<server address> [--port=<p>] "
"[--ssl]\n");
return 1;
}
|
