Using test-server as a quickstart --------------------------------- For a Fedora x86_86 box, the following config line was needed: ./configure --prefix=/usr --libdir=/usr/lib64 --enable-openssl For Apple systems, Christopher Baker reported that this is needed (and I was told separately enabling openssl makes trouble somehow) ./configure CC="gcc -arch i386 -arch x86_64" CXX="g++ -arch i386 -arch x86_64" CPP="gcc -E" CXXCPP="g++ -E" --enable-nofork otherwise if /usr/local/... and /usr/local/lib are OK then... $ ./configure $ make clean $ make $ sudo make install $ libwebsockets-test-server should be enough to get a test server listening on port 7861. There are a couple of other possible configure options --enable-nofork disables the fork into the background API and removes all references to fork() and pr_ctl() from the sources. Use it if your platform doesn't support forking. --enable-libcrypto by default libwebsockets uses its own built-in md5 and sha-1 implementation for simplicity. However the libcrypto ones may be faster, and in a distro context it may be highly desirable to use a common library implementation for ease of security upgrades. Give this configure option to disable the built-in ones and force use of the libcrypto (part of openssl) ones. --with-client-cert-dir=dir tells the client ssl support where to look for trust certificates to validate the remote certificate against. --enable-noping Don't try to build the ping test app It needs some unixy environment that may choke in other build contexts, this lets you cleanly stop it being built --enable-x-google-mux Enable experimental x-google-mux support in the build (see notes later in document) Testing server with a browser ----------------------------- If you point your browser (eg, Chrome) to http://127.0.0.1:7681 It will fetch a script in the form of test.html, and then run the script in there on the browser to open a websocket connection. Incrementing numbers should appear in the browser display. Using SSL on the server side ---------------------------- To test it using SSL/WSS, just run the test server with $ libwebsockets-test-server --ssl and use the URL https://127.0.0.1:7681 The connection will be entirely encrypted using some generated certificates that your browser will not accept, since they are not signed by any real Certificate Authority. Just accept the certificates in the browser and the connection will proceed in first https and then websocket wss, acting exactly the same. test-server.c is all that is needed to use libwebsockets for serving both the script html over http and websockets. Forkless operation ------------------ If your target device does not offer fork(), you can use libwebsockets from your own main loop instead. Use the configure option --nofork and simply call libwebsocket_service() from your own main loop as shown in the test app sources. Testing websocket client support -------------------------------- If you run the test server as described above, you can also connect to it using the test client as well as a browser. $ libwebsockets-test-client localhost will by default connect to the test server on localhost:7681 and print the dumb increment number from the server at the same time as drawing random circles in the mirror protocol; if you connect to the test server using a browser at the same time you will be able to see the circles being drawn. Testing SSL on the client side ------------------------------ To test SSL/WSS client action, just run the client test with $ libwebsockets-test-client localhost --ssl By default the client test applet is set to accept selfsigned certificates used by the test server, this is indicated by the use_ssl var being set to 2. Set it to 1 to reject any server certificate that it doesn't have a trusted CA cert for. Using the websocket ping utility -------------------------------- libwebsockets-test-ping connects as a client to a remote websocket server using 04 protocol and pings it like the normal unix ping utility. $ libwebsockets-test-ping localhost handshake OK for protocol lws-mirror-protocol Websocket PING localhost.localdomain (127.0.0.1) 64 bytes of data. 64 bytes from localhost: req=1 time=0.1ms 64 bytes from localhost: req=2 time=0.1ms 64 bytes from localhost: req=3 time=0.1ms 64 bytes from localhost: req=4 time=0.2ms 64 bytes from localhost: req=5 time=0.1ms 64 bytes from localhost: req=6 time=0.2ms 64 bytes from localhost: req=7 time=0.2ms 64 bytes from localhost: req=8 time=0.1ms ^C --- localhost.localdomain websocket ping statistics --- 8 packets transmitted, 8 received, 0% packet loss, time 7458ms rtt min/avg/max = 0.110/0.185/0.218 ms $ By default it sends 64 byte payload packets using the 04 PING packet opcode type. You can change the payload size using the -s= flag, up to a maximum of 125 mandated by the 04 standard. Using the lws-mirror protocol that is provided by the test server, libwebsockets-test-ping can also use larger payload sizes up to 4096 is BINARY packets; lws-mirror will copy them back to the client and they appear as a PONG. Use the -m flag to select this operation. The default interval between pings is 1s, you can use the -i= flag to set this, including fractions like -i=0.01 for 10ms interval. Before you can even use the PING opcode that is part of the standard, you must complete a handshake with a specified protocol. By default lws-mirror-protocol is used which is supported by the test server. But if you are using it on another server, you can specify the protcol to handshake with by --protocol=protocolname Fraggle test app ---------------- By default it runs in server mode $ libwebsockets-test-fraggle libwebsockets test fraggle (C) Copyright 2010-2011 Andy Green licensed under LGPL2.1 Compiled with SSL support, not using it Listening on port 7681 server sees client connect accepted v06 connection Spamming 360 random fragments Spamming session over, len = 371913. sum = 0x2D3C0AE Spamming 895 random fragments Spamming session over, len = 875970. sum = 0x6A74DA1 ... You need to run a second session in client mode, you have to give the -c switch and the server address at least: $ libwebsockets-test-fraggle -c localhost libwebsockets test fraggle (C) Copyright 2010-2011 Andy Green licensed under LGPL2.1 Client mode Connecting to localhost:7681 denied deflate-stream extension handshake OK for protocol fraggle-protocol client connects to server EOM received 371913 correctly from 360 fragments EOM received 875970 correctly from 895 fragments EOM received 247140 correctly from 258 fragments EOM received 695451 correctly from 692 fragments ... The fraggle test sends a random number up to 1024 fragmented websocket frames each of a random size between 1 and 2001 bytes in a single message, then sends a checksum and starts sending a new randomly sized and fragmented message. The fraggle test client receives the same message fragments and computes the same checksum using websocket framing to see when the message has ended. It then accepts the server checksum message and compares that to its checksum. proxy support ------------- The http_proxy environment variable is respected by the client connection code for both ws:// and wss://. It doesn't support authentication yet. You use it like this export http_proxy=myproxy.com:3128 libwebsockets-test-client someserver.com Websocket version supported --------------------------- The websocket client code is 04 and 05 version, the server supports 00/76 in text mode and 04 and 05 dynamically per-connection depending on the version of the client / browser. External Polling Loop support ----------------------------- libwebsockets maintains an internal poll() array for all of its sockets, but you can instead integrate the sockets into an external polling array. That's needed if libwebsockets will cooperate with an existing poll array maintained by another server. Four callbacks LWS_CALLBACK_ADD_POLL_FD, LWS_CALLBACK_DEL_POLL_FD, LWS_CALLBACK_SET_MODE_POLL_FD and LWS_CALLBACK_CLEAR_MODE_POLL_FD appear in the callback for protocol 0 and allow interface code to manage socket descriptors in other poll loops. x-google-mux support -------------------- Experimental and super-preliminary x-google-mux support is available if enabled in ./configure with --enable-x-google-mux. Note that when changing configurations, you will need to do a make distclean before, then the new configure and then make ; make install. Don't forget the necessary other flags for your platform as described at the top of the readme. It has the following notes: 1) To enable it, reconfigure with --enable-x-google-mux 2) It deviates from the google standard by sending full headers in the addchannel subcommand rather than just changed ones from original connect 3) Quota is not implemented yet However despite those caveats, in fact it can run the test client reliably over one socket (both dumb-increment and lws-mirror-protocol), you can open a browser on the same test server too and see the circles, etc. It also works compatibly with deflate-stream automatically. 2011-05-28 Andy Green