3 Libwebsockets can be built using two different build systems
4 autoconf or CMake. autoconf only works on Unix systems, or mingw/cygwin
5 on Windows. CMake works differently and can generate platform specific
6 project files for most popular IDEs and build systems.
8 ################################### Autoconf ###################################
10 Building the library and test apps
11 ----------------------------------
13 You need to regenerate the autotools and libtoolize stuff for your system
21 ./configure --prefix=/usr --libdir=/usr/lib64 --enable-openssl
25 Christopher Baker reported that this is needed
27 ./configure CC="gcc -arch i386 -arch x86_64" CXX="g++ -arch i386 -arch
28 x86_64" CPP="gcc -E" CXXCPP="g++ -E" --enable-nofork
32 I did the following to get working build, ping test is disabled when
35 1) install mingw64_w32 compiler packages from Fedora
36 2) additionally install mingw64-zlib package
37 3) ./configure --prefix=/usr --enable-mingw --host=x86_64-w64-mingw32
40 ------MIPS cross-build using OpenWRT
42 ./configure --prefix=/usr --without-extensions --host mips-openwrt-linux
44 I did not try building the extensions since they need cross-zlib, but it
45 should also be workable.
49 you may need --enable-builtin-getifaddrs if your toolchain
50 doesn't have it - openWRT uclibc has it so you don't need this option.
54 ./configure --prefix=/usr --host=arm-linux-gnueabi --without-client --without-extensions
56 you can build cross with client and extensions perfectly well, but
57 apart from the size shrink this has the nice characteristic that no
58 non-toolchain libraries are needed to build it.
61 otherwise if /usr/local/... and /usr/local/lib are OK then...
65 $ make && sudo make install
66 $ libwebsockets-test-server
68 should be enough to get a test server listening on port 7861.
71 Configure script options
72 ------------------------
74 There are several other possible configure options
76 --enable-openssl Builds in the SSL support
78 --with-cyassl Use cyassl instead of OpenSSL... you will need CyaSSL
79 to have been configured with --enable-opensslExtra
82 --enable-libcrypto by default libwebsockets uses its own
83 built-in md5 and sha-1 implementation for
84 simplicity. However the libcrypto ones
85 may be faster, and in a distro context it
86 may be highly desirable to use a common
87 library implementation for ease of security
88 upgrades. Give this configure option
89 to disable the built-in ones and force use
90 of the libcrypto (part of openssl) ones.
92 --with-client-cert-dir=dir tells the client ssl support where to
93 look for trust certificates to validate
94 the remote certificate against.
96 --enable-noping Don't try to build the ping test app
97 It needs some unixy environment that
98 may choke in other build contexts, this
99 lets you cleanly stop it being built
101 --enable-builtin-getifaddrs if your libc lacks getifaddrs, you can build an
102 implementation into the library. By default your libc
105 --without-testapps Just build the library not the test apps
107 --without-client Don't build the client part of the library nor the
108 test apps that need the client part. Useful to
109 minimize library footprint for embedded server-only
112 --without-server Don't build the server part of the library nor the
113 test apps that need the server part. Useful to
114 minimize library footprint for embedded client-only
117 --without-daemonize Don't build daemonize.c / lws_daemonize
119 --disable-debug Remove all debug logging below lwsl_notice in severity
120 from the code -- it's not just defeated from logging
121 but removed from compilation
123 --without-extensions Remove all code and data around protocol extensions.
124 This reduces the code footprint considerably but
125 you will lose extension features like compression.
126 However that may be irrelevant for embedded use and
127 the code / data size / speed improvements may be
130 --with-latency Builds the latency-tracking code into the library...
131 this slows your library down a bit but is very useful
132 to find the cause of unexpected latencies occurring
133 inside the library. See README.test-apps for more
137 Externally configurable important constants
138 -------------------------------------------
140 You can control these from configure by just setting them as commandline
141 args throgh CFLAGS, eg
143 ./configure CFLAGS="-DLWS_MAX_ZLIB_CONN_BUFFER=8192"
146 They all have reasonable defaults usable for all use-cases except resource-
147 constrained, so you only need to take care about them if you want to tune them
148 to the amount of memory available.
150 - LWS_MAX_HEADER_NAME_LENGTH default 64: max characters in an HTTP header
151 name that libwebsockets can cope with, if a header arrives bigger than this
152 it's ignored until the next header is seen
154 - LWS_MAX_HEADER_LEN default 1024: allocated area to copy http headers that
155 libwebsockets knows about into. You only need to think about increasing this
156 if your application might have monster length URLs for example, or some other
157 header that lws cares about will be abnormally large (headers it does not
158 know about are skipped).
160 - LWS_MAX_PROTOCOLS default 5: largest amount of different protocols the
163 - LWS_MAX_EXTENSIONS_ACTIVE default 3: largest amount of extensions we can
164 choose to have active on one connection
166 - SPEC_LATEST_SUPPORTED default 13: only change if you want to remove support
167 for later protocol versions... unlikely
169 - AWAITING_TIMEOUT default 5: after this many seconds without a response, the
170 server will hang up on the client
172 - CIPHERS_LIST_STRING default "DEFAULT": SSL Cipher selection. It's advisable
173 to tweak the ciphers allowed to be negotiated on secure connections for
174 performance reasons, otherwise a slow algorithm may be selected by the two
175 endpoints and the server could expend most of its time just encrypting and
176 decrypting data, severely limiting the amount of messages it will be able to
177 handle per second. For example::
179 "RC4-MD5:RC4-SHA:AES128-SHA:AES256-SHA:HIGH:!DSS:!aNULL"
181 - SYSTEM_RANDOM_FILEPATH default "/dev/urandom": if your random device differs
184 - LWS_MAX_ZLIB_CONN_BUFFER maximum size a compression buffer is allowed to
185 grow to before closing the connection. Some limit is needed or any connecton
186 can exhaust all server memory by sending it 4G buffers full of zeros which the
187 server is expect to expand atomically. Default is 64KBytes.
189 - LWS_SOMAXCONN maximum number of pending connect requests the listening
190 socket can cope with. Default is SOMAXCONN. If you need to use synthetic
191 tests that just spam hundreds of connect requests at once without dropping
192 any, you can try messing with these as well as ulimit (see later)
193 (courtesy Edwin van der Oetelaar)
195 echo "2048 64512" > /proc/sys/net/ipv4/ip_local_port_range
196 echo "1" > /proc/sys/net/ipv4/tcp_tw_recycle
197 echo "1" > /proc/sys/net/ipv4/tcp_tw_reuse
198 echo "10" > /proc/sys/net/ipv4/tcp_fin_timeout
199 echo "65536" > /proc/sys/net/core/somaxconn
200 echo "65536" > /proc/sys/net/ipv4/tcp_max_syn_backlog
201 echo "262144" > /proc/sys/net/netfilter/nf_conntrack_max
207 Embedded server-only configuration without extensions (ie, no compression
208 on websocket connections), but with full v13 websocket features and http
209 server, built on ARM Cortex-A9:
211 Update at 224149ai (2013-02-11)
213 ./configure --without-client --without-extensions --disable-debug --without-daemonize
215 Context Creation, 1024 fd limit[2]: 17444 (incl. 12 bytes per fd)
216 Per-connection [3]: 112 bytes, additional 1328 bytes only during headers
218 .text .rodata .data .bss
222 Update at 35f332bb46464feb87eb
224 ./configure --without-client --without-extensions --disable-debug --enable-nofork --without-daemonize
226 .text .rodata .data .bss
229 Context Creation, 1024 fd limit[2]: 12288 (12 bytes per fd)
230 Per-connection [3]: 4400 bytes
233 This shows the impact of the major configuration with/without options at
234 13ba5bbc633ea962d46d using Ubuntu ARM on a PandaBoard ES.
236 These are accounting for static allocations from the library elf, there are
237 additional dynamic allocations via malloc
239 Static allocations, ARM9
240 .text .rodata .data .bss
241 All (no without) 35024 9940 336 4104
242 without client 25684 7144 336 4104
243 without client, exts 21652 6288 288 4104
244 without client, exts, debug[1] 19756 3768 288 4104
245 without server 30304 8160 336 4104
246 without server, exts 25382 7204 288 4104
247 without server, exts, debug[1] 23712 4256 288 4104
249 Dynamic allocations: ARM9 (32 bit)
251 Context Creation, 1024 fd limit[2] in ulimit: 12288 (12 bytes per fd)
252 Per-connection (excluding headers[3]): 8740
254 Dynamic allocations: x86_64 (64 bit)
256 Context Creation, 1024 fd limit[2] in ulimit: 16384 (16 bytes per fd)
257 Per-connection (excluding headers[3]): 9224
259 [1] --disable-debug only removes messages below lwsl_notice. Since that is
260 the default logging level the impact is not noticable, error, warn and notice
261 logs are all still there.
263 [2] 1024 fd per process is the default limit (set by ulimit) in at least Fedora
266 [3] known headers are retained via additional mallocs for the lifetime of the
270 #################################### CMake ####################################
272 CMake is a multi-platform build tool that can generate build files for many
273 different target platforms. See more info at http://www.cmake.org
275 CMake also allows/recommends you to do "out of source"-builds, that is,
276 the build files are separated from your sources, so there is no need to
277 create elaborate clean scripts to get a clean source tree, instead you
278 simply remove your build directory.
280 Libwebsockets has been tested to build successfully on the following platforms
281 with SSL support (both OpenSSL/CyaSSL):
284 - Linux (x86 and ARM)
288 Building the library and test apps
289 ----------------------------------
291 The project settings used by CMake to generate the platform specific build
292 files is called CMakeLists.txt. CMake then uses one of its "Generators" to
293 output a Visual Studio project or Make file for instance. To see a list of
294 the available generators for your platform, simply run the "cmake" command.
296 Note that by default OpenSSL will be linked, if you don't want SSL support
297 see below on how to toggle compile options.
302 1. Install CMake 2.6 or greater: http://cmake.org/cmake/resources/software.html
303 (Most Unix distributions comes with a packaged version also)
307 3. Generate the build files (default is Make files):
314 (NOTE: The build/ directory can have any name and be located anywhere
315 on your filesystem, and that the argument ".." given to cmake is simply
316 the source directory of libwebsockets containing the CMakeLists.txt project
317 file. All examples in this file assumes you use "..")
319 4. Finally you can build using the generated Makefile:
323 Building on Windows (Visual Studio)
324 -----------------------------------
325 1. Install CMake 2.6 or greater: http://cmake.org/cmake/resources/software.html
327 2. Install OpenSSL binaries. http://www.openssl.org/related/binaries.html
328 (Preferably in the default location to make it easier for CMake to find them)
330 3. Generate the Visual studio project by opening the Visual Studio cmd prompt:
335 cmake -G "Visual Studio 10" ..
337 (NOTE: There is also a cmake-gui available on Windows if you prefer that)
339 4. Now you should have a generated Visual Studio Solution in your
340 <path to src>/build directory, which can be used to build.
342 Setting compile options
343 -----------------------
345 To set compile time flags you can either use one of the CMake gui applications
346 or do it via command line.
350 To list avaialable options (ommit the H if you don't want the help text):
354 Then to set an option and build (for example turn off SSL support):
356 cmake -DWITH_SSL=0 ..
358 cmake -DWITH_SSL:BOOL=OFF ..
362 If you have a curses enabled build you simply type:
363 (not all packages include this, my debian install does not for example).
369 On windows CMake comes with a gui application:
370 Start -> Programs -> CMake -> CMake (cmake-gui)
372 CyaSSL replacement for OpenSSL
373 ------------------------------
374 CyaSSL is a lightweight SSL library targeted at embedded system:
375 http://www.yassl.com/yaSSL/Products-cyassl.html
377 It contains a OpenSSL compatability layer which makes it possible to pretty
378 much link to it instead of OpenSSL, giving a much smaller footprint.
380 NOTE: At the time of writing this the current release of CyaSSL contains a
381 crash bug due to some APIs libwebsocket uses. To be able to use this you will
382 need to use the current HEAD in their official repository:
383 https://github.com/cyassl/cyassl
385 NOTE: cyassl needs to be compiled using the --enable-opensslExtra flag for
388 Compiling libwebsockets with CyaSSL
389 -----------------------------------
392 -DCYASSL_INCLUDE_DIRS=/path/to/cyassl
393 -DCYASSL_LIB=/path/to/cyassl/cyassl.a ..
395 NOTE: On windows use the .lib file extension for CYASSL_LIB instead.
399 To enable cross compiling libwebsockets using CMake you need to create
400 a "Toolchain file" that you supply to CMake when generating your build files.
401 CMake will then use the cross compilers and build paths specified in this file
402 to look for dependencies and such.
404 Below is an example of how one of these files might look like:
407 # CMake Toolchain file for crosscompiling on ARM.
409 # This can be used when running cmake in the following way:
411 # cmake .. -DCMAKE_TOOLCHAIN_FILE=/path/to/this/file/TC_arm-linux-gcc.cmake
414 set(CROSS_PATH /path/to/cross_environment/uClibc)
416 # Target operating system name.
417 set(CMAKE_SYSTEM_NAME Linux)
419 # Name of C compiler.
420 set(CMAKE_C_COMPILER "${CROSS_PATH}/bin/arm-linux-uclibc-gcc")
421 set(CMAKE_CXX_COMPILER "${CROSS_PATH}/bin/arm-linux-uclibc-g++")
423 # Where to look for the target environment. (More paths can be added here)
424 set(CMAKE_FIND_ROOT_PATH "${CROSS_PATH}")
426 # Adjust the default behavior of the FIND_XXX() commands:
427 # search programs in the host environment only.
428 set(CMAKE_FIND_ROOT_PATH_MODE_PROGRAM NEVER)
430 # Search headers and libraries in the target environment only.
431 set(CMAKE_FIND_ROOT_PATH_MODE_LIBRARY ONLY)
432 set(CMAKE_FIND_ROOT_PATH_MODE_INCLUDE ONLY)
434 Additional information on cross compilation with CMake:
435 http://www.vtk.org/Wiki/CMake_Cross_Compiling