1 Overview of lws test apps
2 =========================
4 Are you building a client? You just need to look at the test client
5 [libwebsockets-test-client](test-server/test-client.c).
7 If you are building a standalone server, there are three choices, in order of
10 1) lwsws + protocol plugins
12 Lws provides a generic web server app that can be configured with JSON
13 config files. https://libwebsockets.org itself uses this method.
15 With lwsws handling the serving part, you only need to write an lws protocol
16 plugin. See [plugin-standalone](plugin-standalone) for an example of how
17 to do that outside lws itself, using lws public apis.
19 $ cmake .. -DLWS_WITH_LWSWS=1
21 See [README.lwsws.md](README.lwsws.md) for information on how to configure
24 NOTE this method implies libuv is used by lws, to provide crossplatform
25 implementations of timers, dynamic lib loading etc for plugins and lwsws.
29 This method lets you configure web serving in code, instead of using lwsws.
31 Plugins are still used, which implies libuv needed.
33 $ cmake .. -DLWS_WITH_PLUGINS=1
35 See [test-server-v2.0.c](test-server/test-server-v2.0.c)
37 3) protocols in the server app
39 This is the original way lws implemented servers, plugins and libuv are not
40 required, but without plugins separating the protocol code directly, the
41 combined code is all squidged together and is much less maintainable.
43 This method is still supported in lws but all ongoing and future work is
44 being done in protocol plugins only.
47 Notes about lws test apps
48 =========================
50 @section tsb Testing server with a browser
52 If you run [libwebsockets-test-server](test-server/test-server.c) and point your browser
57 It will fetch a script in the form of `test.html`, and then run the
58 script in there on the browser to open a websocket connection.
59 Incrementing numbers should appear in the browser display.
61 By default the test server logs to both stderr and syslog, you can control
62 what is logged using `-d <log level>`, see later.
65 @section tsd Running test server as a Daemon
67 You can use the -D option on the test server to have it fork into the
68 background and return immediately. In this daemonized mode all stderr is
69 disabled and logging goes only to syslog, eg, `/var/log/messages` or similar.
71 The server maintains a lockfile at `/tmp/.lwsts-lock` that contains the pid
72 of the master process, and deletes this file when the master process
75 To stop the daemon, do
77 $ kill cat /tmp/.lwsts-lock
79 If it finds a stale lock (the pid mentioned in the file does not exist
80 any more) it will delete the lock and create a new one during startup.
82 If the lock is valid, the daemon will exit with a note on stderr that
83 it was already running.
86 @section sssl Using SSL on the server side
88 To test it using SSL/WSS, just run the test server with
90 $ libwebsockets-test-server --ssl
94 https://127.0.0.1:7681
96 The connection will be entirely encrypted using some generated
97 certificates that your browser will not accept, since they are
98 not signed by any real Certificate Authority. Just accept the
99 certificates in the browser and the connection will proceed
100 in first https and then websocket wss, acting exactly the
103 [test-server.c](test-server/test-server.c) is all that is needed to use libwebsockets for
104 serving both the script html over http and websockets.
107 @section wscl Testing websocket client support
109 If you run the test server as described above, you can also
110 connect to it using the test client as well as a browser.
113 $ libwebsockets-test-client localhost
116 will by default connect to the test server on localhost:7681
117 and print the dumb increment number from the server at the
118 same time as drawing random circles in the mirror protocol;
119 if you connect to the test server using a browser at the
120 same time you will be able to see the circles being drawn.
122 The test client supports SSL too, use
125 $ libwebsockets-test-client localhost --ssl -s
128 the -s tells it to accept the default self-signed cert from the server,
129 otherwise it will strictly fail the connection if there is no CA cert to
130 validate the server's certificate.
133 @section choosingts Choosing between test server variations
135 If you will be doing standalone serving with lws, ideally you should avoid
136 making your own server at all, and use lwsws with your own protocol plugins.
138 The second best option is follow test-server-v2.0.c, which uses a mount to
139 autoserve a directory, and lws protocol plugins for ws, without needing any
140 user callback code (other than what's needed in the protocol plugin).
142 For those two options libuv is needed to support the protocol plugins, if
143 that's not possible then the other variations with their own protocol code
144 should be considered.
147 @section echo Testing simple echo
149 You can test against `echo.websockets.org` as a sanity test like
150 this (the client connects to port `80` by default):
153 $ libwebsockets-test-echo --client echo.websocket.org
156 This echo test is of limited use though because it doesn't
157 negotiate any protocol. You can run the same test app as a
158 local server, by default on localhost:7681
160 $ libwebsockets-test-echo
162 and do the echo test against the local echo server
164 $ libwebsockets-test-echo --client localhost --port 7681
166 If you add the `--ssl` switch to both the client and server, you can also test
167 with an encrypted link.
170 @section tassl Testing SSL on the client side
172 To test SSL/WSS client action, just run the client test with
174 $ libwebsockets-test-client localhost --ssl
176 By default the client test applet is set to accept self-signed
177 certificates used by the test server, this is indicated by the
178 `use_ssl` var being set to `2`. Set it to `1` to reject any server
179 certificate that it doesn't have a trusted CA cert for.
182 @section taping Using the websocket ping utility
184 libwebsockets-test-ping connects as a client to a remote
185 websocket server and pings it like the
186 normal unix ping utility.
188 $ libwebsockets-test-ping localhost
189 handshake OK for protocol lws-mirror-protocol
190 Websocket PING localhost.localdomain (127.0.0.1) 64 bytes of data.
191 64 bytes from localhost: req=1 time=0.1ms
192 64 bytes from localhost: req=2 time=0.1ms
193 64 bytes from localhost: req=3 time=0.1ms
194 64 bytes from localhost: req=4 time=0.2ms
195 64 bytes from localhost: req=5 time=0.1ms
196 64 bytes from localhost: req=6 time=0.2ms
197 64 bytes from localhost: req=7 time=0.2ms
198 64 bytes from localhost: req=8 time=0.1ms
200 --- localhost.localdomain websocket ping statistics ---
201 8 packets transmitted, 8 received, 0% packet loss, time 7458ms
202 rtt min/avg/max = 0.110/0.185/0.218 ms
205 By default it sends 64 byte payload packets using the 04
206 PING packet opcode type. You can change the payload size
207 using the `-s=` flag, up to a maximum of 125 mandated by the
210 Using the lws-mirror protocol that is provided by the test
211 server, libwebsockets-test-ping can also use larger payload
212 sizes up to 4096 is BINARY packets; lws-mirror will copy
213 them back to the client and they appear as a PONG. Use the
214 `-m` flag to select this operation.
216 The default interval between pings is 1s, you can use the -i=
217 flag to set this, including fractions like `-i=0.01` for 10ms
220 Before you can even use the PING opcode that is part of the
221 standard, you must complete a handshake with a specified
222 protocol. By default lws-mirror-protocol is used which is
223 supported by the test server. But if you are using it on
224 another server, you can specify the protocol to handshake with
225 by `--protocol=protocolname`
228 @section ta fraggle Fraggle test app
230 By default it runs in server mode
232 $ libwebsockets-test-fraggle
233 libwebsockets test fraggle
234 (C) Copyright 2010-2011 Andy Green <andy@warmcat.com> licensed under LGPL2.1
235 Compiled with SSL support, not using it
236 Listening on port 7681
237 server sees client connect
238 accepted v06 connection
239 Spamming 360 random fragments
240 Spamming session over, len = 371913. sum = 0x2D3C0AE
241 Spamming 895 random fragments
242 Spamming session over, len = 875970. sum = 0x6A74DA1
245 You need to run a second session in client mode, you have to
246 give the `-c` switch and the server address at least:
248 $ libwebsockets-test-fraggle -c localhost
249 libwebsockets test fraggle
250 (C) Copyright 2010-2011 Andy Green <andy@warmcat.com> licensed under LGPL2.1
252 Connecting to localhost:7681
253 denied deflate-stream extension
254 handshake OK for protocol fraggle-protocol
255 client connects to server
256 EOM received 371913 correctly from 360 fragments
257 EOM received 875970 correctly from 895 fragments
258 EOM received 247140 correctly from 258 fragments
259 EOM received 695451 correctly from 692 fragments
262 The fraggle test sends a random number up to 1024 fragmented websocket frames
263 each of a random size between 1 and 2001 bytes in a single message, then sends
264 a checksum and starts sending a new randomly sized and fragmented message.
266 The fraggle test client receives the same message fragments and computes the
267 same checksum using websocket framing to see when the message has ended. It
268 then accepts the server checksum message and compares that to its checksum.
271 @section taproxy proxy support
273 The http_proxy environment variable is respected by the client
274 connection code for both `ws://` and `wss://`. It doesn't support
279 $ export http_proxy=myproxy.com:3128
280 $ libwebsockets-test-client someserver.com
283 @section talog debug logging
285 By default logging of severity "notice", "warn" or "err" is enabled to stderr.
287 Again by default other logging is compiled in but disabled from printing.
289 By default debug logs below "notice" in severity are not compiled in. To get
290 them included, add this option in CMAKE
293 $ cmake .. -DCMAKE_BUILD_TYPE=DEBUG
296 If you want to see more detailed debug logs, you can control a bitfield to
297 select which logs types may print using the `lws_set_log_level()` api, in the
298 test apps you can use `-d <number>` to control this. The types of logging
299 available are (OR together the numbers to select multiple)
313 @section ws13 Websocket version supported
315 The final IETF standard is supported for both client and server, protocol
319 @section latency Latency Tracking
321 Since libwebsockets runs using `poll()` and a single threaded approach, any
322 unexpected latency coming from system calls would be bad news. There's now
323 a latency tracking scheme that can be built in with `--with-latency` at
324 configure-time, logging the time taken for system calls to complete and if
325 the whole action did complete that time or was deferred.
327 You can see the detailed data by enabling logging level 512 (eg, `-d 519` on
328 the test server to see that and the usual logs), however even without that
329 the "worst" latency is kept and reported to the logs with NOTICE severity
330 when the context is destroyed.
332 Some care is needed interpreting them, if the action completed the first figure
333 (in us) is the time taken for the whole action, which may have retried through
334 the poll loop many times and will depend on network roundtrip times. High
335 figures here don't indicate a problem. The figure in us reported after "lat"
336 in the logging is the time taken by this particular attempt. High figures
337 here may indicate a problem, or if you system is loaded with another app at
338 that time, such as the browser, it may simply indicate the OS gave preferential
339 treatment to the other app during that call.
342 @section autobahn Autobahn Test Suite
344 Lws can be tested against the autobahn websocket fuzzer.
346 1) pip install autobahntestsuite
348 2) wstest -m fuzzingserver
350 3) Run tests like this
352 libwebsockets-test-echo --client localhost --port 9001 -u "/runCase?case=20&agent=libwebsockets" -v -d 65535 -n 1
356 4) In a browser, go here
358 http://localhost:8080/test_browser.html
360 fill in "libwebsockets" in "User Agent Identifier" and press "Update Reports (Manual)"
362 5) In a browser go to the directory you ran wstest in (eg, /projects/libwebsockets)
364 file:///projects/libwebsockets/reports/clients/index.html
369 @section autobahnnotes Autobahn Test Notes
371 1) Autobahn tests the user code + lws implementation. So to get the same
372 results, you need to follow test-echo.c in terms of user implementation.
374 2) Two of the tests make no sense for Libwebsockets to support and we fail them.
376 - Tests 2.10 + 2.11: sends multiple pings on one connection. Lws policy is to
377 only allow one active ping in flight on each connection, the rest are dropped.
378 The autobahn test itself admits this is not part of the standard, just someone's
379 random opinion about how they think a ws server should act. So we will fail
380 this by design and it is no problem about RFC6455 compliance.