[platform/upstream/libwebsockets.git] / changelog

Changelog
---------

Extension Changes
-----------------

1) There is now a "permessage-deflate" / RFC7692 implementation.  It's very
similar to "deflate-frame" we have offered for a long while; deflate-frame is
now provided as an alias of permessage-deflate.

The main differences are that the new permessage-deflate implementation:

 - properly performs streaming respecting input and output buffer limits.  The
   old deflate-frame implementation could only work on complete deflate input
   and produce complete inflate output for each frame.  The new implementation
   only mallocs buffers at initialization.

 - goes around the event loop after each input package is processed allowing
   interleaved output processing.  The RX flow control api can be used to
   force compressed input processing to match the rate of compressed output
   processing (test--echo shows an example of how to do this).

 - when being "deflate-frame" for compatibility he uses the same default zlib
   settings as the old "deflate-frame", but instead of exponentially increasing
   malloc allocations until the whole output will fit, he observes the default
   input and output chunking buffer sizes of "permessage-deflate", that's
   1024 in and 1024 out at a time.

2) deflate-stream has been disabled for many versions (for over a year) and is
now removed.  Browsers are now standardizing on "permessage-deflate" / RFC7692

3) struct lws_extension is simplified, and lws extensions now have a public
api (their callback) for use in user code to compose extensions and options
the user code wants.  lws_get_internal_exts() is deprecated but kept around
as a NOP.  The changes allow one extension implementation to go by different
names and allows the user client code to control option offers per-ext.

The test client and server are updated to use the new way.  If you use
the old way it should still work, but extensions will be disabled until you
update your code.

Extensions are now responsible for allocating and per-instance private struct
at instance construction time and freeing it when the instance is destroyed.
Not needing to know the size means the extension's struct can be opaque
to user code.


User api additions
------------------

1) The info struct gained two new members

 - max_http_header_data: 0 for default (1024) or set the maximum amount of known
    http header payload that lws can deal with.  Payload in unknown http
    headers is dropped silently.  If for some reason you need to send huge
    cookies or other HTTP-level headers, you can now increase this at context-
    creation time.

 - max_http_header_pool: 0 for default (16) or set the maximum amount of http
     headers that can be tracked by lws in this context.  For the server, if
     the header pool is completely in use then accepts on the listen socket
     are disabled until one becomes free.  For the client, if you simultaneously
     have pending connects for more than this number of client connections,
     additional connects will fail until some of the pending connections timeout
     or complete.

HTTP header processing in lws only exists until just after the first main
callback after the HTTP handshake... for ws connections that is ESTABLISHED and
for HTTP connections the HTTP callback.

So these settings are not related to the maximum number of simultaneous
connections, but the number of HTTP handshakes that may be expected or ongoing,
or have just completed, at one time.  The reason it's useful is it changes the
memory allocation for header processing to be one-time at context creation
instead of every time there is a new connection, and gives you control over
the peak allocation.

Setting max_http_header_pool to 1 is fine it will just queue incoming
connections before the accept as necessary, you can still have as many
simultaneous post-header connections as you like.  Since the http header
processing is completed and the allocation released after ESTABLISHED or the
HTTP callback, even with a pool of 1 many connections can be handled rapidly.

2) There is a new callback that allows the user code to get acccess to the
optional close code + aux data that may have been sent by the peer.

LWS_CALLBACK_WS_PEER_INITIATED_CLOSE:
             The peer has sent an unsolicited Close WS packet.  @in and
             @len are the optional close code (first 2 bytes, network
             order) and the optional additional information which is not
             defined in the standard, and may be a string or non-human-
             readble data.
             If you return 0 lws will echo the close and then close the
             connection.  If you return nonzero lws will just close the
             connection.

As usual not handling it does the right thing, if you're not interested in it
just ignore it.

The test server has "open and close" testing buttons at the bottom, if you
open and close that connection, on close it will send a close code 3000 decimal
and the string "Bye!" as the aux data.

The test server dumb-increment callback handles this callback reason and prints

lwsts[15714]: LWS_CALLBACK_WS_PEER_INITIATED_CLOSE: len 6
lwsts[15714]:  0: 0x0B
lwsts[15714]:  1: 0xB8
lwsts[15714]:  2: 0x42
lwsts[15714]:  3: 0x79
lwsts[15714]:  4: 0x65
lwsts[15714]:  5: 0x21

3) There is a new API to allow the user code to control the content of the
close frame sent when about to return nonzero from the user callback to
indicate the connection should close.

/**
 * lws_close_reason - Set reason and aux data to send with Close packet
 *              If you are going to return nonzero from the callback
 *              requesting the connection to close, you can optionally
 *              call this to set the reason the peer will be told if
 *              possible.
 *
 * @wsi:        The websocket connection to set the close reason on
 * @status:     A valid close status from websocket standard
 * @buf:        NULL or buffer containing up to 124 bytes of auxiliary data
 * @len:        Length of data in @buf to send
 */
LWS_VISIBLE LWS_EXTERN void
lws_close_reason(struct lws *wsi, enum lws_close_status status,
                 unsigned char *buf, size_t len);

An extra button is added to the "open and close" test server page that requests
that the test server close the connection from his end.

The test server code will do so by

                        lws_close_reason(wsi, LWS_CLOSE_STATUS_GOINGAWAY,
                                         (unsigned char *)"seeya", 5);
                        return -1;

The browser shows the close code and reason he received

websocket connection CLOSED, code: 1001, reason: seeya

4) There's a new context creation time option flag

LWS_SERVER_OPTION_VALIDATE_UTF8

if you set it in info->options, then TEXT and CLOSE frames will get checked to
confirm that they contain valid UTF-8.  If they don't, the connection will get
closed by lws.

5) ECDH Certs are now supported.  Enable the CMake option

cmake .. -DLWS_SSL_SERVER_WITH_ECDH_CERT=1 

**and** the info->options flag

LWS_SERVER_OPTION_SSL_ECD

to build in support and select it at runtime.

6) There's a new api lws_parse_uri() that simplies chopping up
https://xxx:yyy/zzz uris into parts nicely.  The test client now uses this
to allow proper uris as well as the old address style.

7) SMP support is integrated into LWS without any internal threading.  It's
very simple to use, libwebsockets-test-server-pthread shows how to do it,
use -j <n> argument there to control the number of service threads up to 32.

Two new members are added to the info struct

        unsigned int count_threads;
        unsigned int fd_limit_per_thread;
        
leave them at the default 0 to get the normal singlethreaded service loop.

Set count_threads to n to tell lws you will have n simultaneous service threads
operating on the context.

There is still a single listen socket on one port, no matter how many
service threads.

When a connection is made, it is accepted by the service thread with the least
connections active to perform load balancing.

The user code is responsible for spawning n threads running the service loop
associated to a specific tsi (Thread Service Index, 0 .. n - 1).  See
the libwebsockets-test-server-pthread for how to do.

If you leave fd_limit_per_thread at 0, then the process limit of fds is shared
between the service threads; if you process was allowed 1024 fds overall then
each thread is limited to 1024 / n.

You can set fd_limit_per_thread to a nonzero number to control this manually, eg
the overall supported fd limit is less than the process allowance.

You can control the context basic data allocation for multithreading from Cmake
using -DLWS_MAX_SMP=, if not given it's set to 32.  The serv_buf allocation
for the threads (currently 4096) is made at runtime only for active threads.

Because lws will limit the requested number of actual threads supported
according to LWS_MAX_SMP, there is an api lws_get_count_threads(context) to
discover how many threads were actually allowed when the context was created.

It's required to implement locking in the user code in the same way that
libwebsockets-test-server-pthread does it, for the FD locking callbacks.

If LWS_MAX_SMP=1, then there is no code related to pthreads compiled in the
library.  If more than 1, a small amount of pthread mutex code is built into
the library.

8) New API

LWS_VISIBLE struct lws *
lws_adopt_socket(struct lws_context *context, lws_sockfd_type accept_fd)

allows foreign sockets accepted by non-lws code to be adopted by lws as if they
had just been accepted by lws' own listen socket.

9) X-Real-IP: header has been added as WSI_TOKEN_HTTP_X_REAL_IP

10) Libuv support is added, there are new related user apis

typedef void (lws_uv_signal_cb_t)(uv_loop_t *l, uv_signal_t *w, int revents);

LWS_VISIBLE LWS_EXTERN int
lws_uv_sigint_cfg(struct lws_context *context, int use_uv_sigint,
                  lws_uv_signal_cb_t *cb);

LWS_VISIBLE LWS_EXTERN int
lws_uv_initloop(struct lws_context *context, uv_loop_t *loop, int tsi);

LWS_VISIBLE void
lws_uv_sigint_cb(uv_loop_t *loop, uv_signal_t *watcher, int revents);

and CMAKE option

LWS_WITH_LIBUV


User api changes
----------------

1) LWS_SEND_BUFFER_POST_PADDING is now 0 and deprecated.  You can remove it; if
you still use it, obviously it does nothing.  Old binary code with nonzero
LWS_SEND_BUFFER_POST_PADDING is perfectly compatible, the old code just
allocated a buffer bigger than the library is going to use.

The example apps no longer use LWS_SEND_BUFFER_POST_PADDING.

The only path who made use of it was sending with LWS_WRITE_CLOSE --->

2) Because of lws_close_reason() formalizing handling close frames,
LWS_WRITE_CLOSE is removed from libwebsockets.h.  It was only of use to send
close frames...close frame content should be managed using lws_close_reason()
now.

3) We check for invalid CLOSE codes and complain about protocol violation in
our close code.  But it changes little since we were in the middle of closing
anyway.

4) zero-length RX frames and zero length TX frames are now allowed.

5) Pings and close used to be limited to 124 bytes, the correct limit is 125
so that is now also allowed.

6) LWS_PRE is provided as a synonym for LWS_SEND_BUFFER_PRE_PADDING, either is
valid to use now.

7) There's generic support for RFC7462 style extension options built into the
library now.  As a consequence, a field "options" is added to lws_extension.
It can be NULL if there are no options on the extension.  Extension internal
info is part of the public abi because extensions may be implemented outside
the library.

8) WSI_TOKEN_PROXY enum was accidentally defined to collide with another token
of value 73.  That's now corrected and WSI_TOKEN_PROXY moved to his own place at
77.

9) With the addition of libuv support, libev is not the only event loop
library in town and his api names must be elaborated with _ev_

  Callback typedef: lws_signal_cb ---> lws_ev_signal_cb_t
  lws_sigint_cfg --> lws_ev_sigint_cfg
  lws_initloop --> lws_ev_initloop
  lws_sigint_cb --> lws_ev_sigint_cb

10) Libev support is made compatible with multithreaded service,
lws_ev_initloop (was lws_initloop) gets an extra argument for the
thread service index (use 0 if you will just have 1 service thread).

LWS_VISIBLE LWS_EXTERN int
lws_uv_initloop(struct lws_context *context, uv_loop_t *loop, int tsi);


v1.6.0-chrome48-firefox42
=======================

Major API improvements
----------------------

v1.6.0 has many cleanups and improvements in the API.  Although at first it
looks pretty drastic, user code will only need four actions to update it.

 - Do the three search/replaces in your user code, /libwebsocket_/lws_/,
   /libwebsockets_/lws_/, and /struct\ libwebsocket/struct\ lws/

 - Remove the context parameter from your user callbacks

 - Remove context as the first parameter from the "Eleven APIS" listed in the
   User Api Changes section

 - Add lws_get_context(wsi) as the first parameter on the "Three APIS" listed
   in the User Api Changes section, and anywhere else you still need context

That's it... generally only a handful of the 14 affected APIs are actually in
use in your user code and you can find them quickest by compiling and visiting
the errors each in turn.  And the end results are much cleaner, more
predictable and maintainable.


User api additions
------------------

1) lws now exposes his internal platform file abstraction in a way that can be
both used by user code to make it platform-agnostic, and be overridden or
subclassed by user code.  This allows things like handling the URI "directory
space" as a virtual filesystem that may or may not be backed by a regular
filesystem.  One example use is serving files from inside large compressed
archive storage without having to unpack anything except the file being
requested.

The test server shows how to use it, basically the platform-specific part of
lws prepares a file operations structure that lives in the lws context.

Helpers are provided to also leverage these platform-independent file handling
apis

static inline lws_filefd_type
lws_plat_file_open(struct lws *wsi, const char *filename,
                   unsigned long *filelen, int flags)
static inline int
lws_plat_file_close(struct lws *wsi, lws_filefd_type fd)

static inline unsigned long
lws_plat_file_seek_cur(struct lws *wsi, lws_filefd_type fd, long offset)

static inline int
lws_plat_file_read(struct lws *wsi, lws_filefd_type fd, unsigned long *amount,
                   unsigned char *buf, unsigned long len)

static inline int
lws_plat_file_write(struct lws *wsi, lws_filefd_type fd, unsigned long *amount,
                    unsigned char *buf, unsigned long len)
                    
The user code can also override or subclass the file operations, to either
wrap or replace them.  An example is shown in test server.

A wsi can be associated with the file activity, allowing per-connection
authentication and state to be used when interpreting the file request.

2) A new API void * lws_wsi_user(struct lws *wsi) lets you get the pointer to
the user data associated with the wsi, just from the wsi.

3) URI argument handling.  Libwebsockets parses and protects URI arguments
like test.html?arg1=1&arg2=2, it decodes %xx uriencoding format and reduces
path attacks like ../.../../etc/passwd so they cannot go behind the web
server's /.  There is a list of confirmed attacks we're proof against in
./test-server/attack.sh.

There is a new API lws_hdr_copy_fragment that should be used now to access
the URI arguments (it returns the fragments length)

               while (lws_hdr_copy_fragment(wsi, buf, sizeof(buf),
                                            WSI_TOKEN_HTTP_URI_ARGS, n) > 0) {
                       lwsl_info("URI Arg %d: %s\n", ++n, buf);
               }

For the example above, calling with n=0 will return "arg1=1" and n=1 "arg2=2".
All legal uriencodings will have been reduced in those strings.

lws_hdr_copy_fragment() returns the length of the x=y fragment, so it's also
possible to deal with arguments containing %00.  If you don't care about that,
the returned string has '\0' appended to simplify processing.


User api changes
----------------

1) Three APIS

 - lws_callback_on_writable_all_protocol(const struct lws_protocols *protocol)
 - lws_callback_all_protocol(const struct lws_protocols *protocol)
 - lws_rx_flow_allow_all_protocol(lws_rx_flow_allow_all_protocol)

Now take an additional pointer to the lws_context in their first argument.

The reason for this change is struct lws_protocols has been changed to remove
members that lws used for private storage: so the protocols struct in now
truly const and may be reused serially or simultaneously by different contexts.

2) Eleven APIs

LWS_VISIBLE LWS_EXTERN int
lws_add_http_header_by_name(struct lws_context *context,
                struct lws *wsi,
                const unsigned char *name,
                const unsigned char *value,
                int length,
                unsigned char **p,
                unsigned char *end);
LWS_VISIBLE LWS_EXTERN int
lws_finalize_http_header(struct lws_context *context,
             struct lws *wsi,
             unsigned char **p,
             unsigned char *end);
LWS_VISIBLE LWS_EXTERN int
lws_add_http_header_by_token(struct lws_context *context,
                 struct lws *wsi,
                 enum lws_token_indexes token,
                 const unsigned char *value,
                 int length,
                 unsigned char **p,
                 unsigned char *end);
LWS_VISIBLE LWS_EXTERN int
lws_add_http_header_content_length(struct lws_context *context,
                   struct lws *wsi,
                   unsigned long content_length,
                   unsigned char **p,
                   unsigned char *end);
LWS_VISIBLE LWS_EXTERN int
lws_add_http_header_status(struct lws_context *context, struct lws *wsi,
               unsigned int code, unsigned char **p,
               unsigned char *end);

LWS_VISIBLE LWS_EXTERN int
lws_serve_http_file(struct lws_context *context, struct lws *wsi,
            const char *file, const char *content_type,
            const char *other_headers, int other_headers_len);
LWS_VISIBLE LWS_EXTERN int
lws_serve_http_file_fragment(struct lws_context *context, struct lws *wsi);

LWS_VISIBLE LWS_EXTERN int
lws_return_http_status(struct lws_context *context, struct lws *wsi,
               unsigned int code, const char *html_body);

LWS_VISIBLE LWS_EXTERN int
lws_callback_on_writable(const struct lws_context *context, struct lws *wsi);

LWS_VISIBLE LWS_EXTERN void
lws_get_peer_addresses(struct lws_context *context, struct lws *wsi,
               lws_sockfd_type fd, char *name, int name_len,
               char *rip, int rip_len);

LWS_VISIBLE LWS_EXTERN int
lws_read(struct lws_context *context, struct lws *wsi,
     unsigned char *buf, size_t len); 

no longer require their initial struct lws_context * parameter.

3) Several older apis start with libwebsocket_ or libwebsockets_ while newer ones
all begin lws_.  These apis have been changed to all begin with lws_.

To convert, search-replace

 - libwebsockets_/lws_
 - libwebsocket_/lws_
 - struct\ libwebsocket/struct\ lws
 
4) context parameter removed from user callback.

Since almost all apis no longer need the context as a parameter, it's no longer
provided at the user callback directly.

However if you need it, for ALL callbacks wsi is valid and has a valid context
pointer you can recover using lws_get_context(wsi).


v1.5-chrome47-firefox41
=======================

User api changes
----------------

LWS_CALLBACK_CLIENT_CONNECTION_ERROR may provide an error string if in is
non-NULL.  If so, the string has length len.

LWS_SERVER_OPTION_PEER_CERT_NOT_REQUIRED is available to relax the requirement
for peer certs if you are using the option to require client certs.

LWS_WITHOUT_BUILTIN_SHA1 cmake option forces lws to use SHA1() defined
externally, eg, byOpenSSL, and disables build of libwebsockets_SHA1()


v1.4-chrome43-firefox36
=======================

User api additions
------------------

There's a new member in the info struct used to control context creation,
ssl_private_key_password, which allows passing into lws the passphrase on
an SSL cetificate

There's a new member in struct protocols, id, which is ignored by lws but can
be used by the user code to mark the selected protocol by user-defined version
or capabliity flag information, for the case multiple versions of a protocol are
supported.

int lws_is_ssl(wsi) added to allow user code to know if the connection was made
over ssl or not.  If LWS_SERVER_OPTION_ALLOW_NON_SSL_ON_SSL_PORT is used, both
ssl and non-ssl connections are possible and may need to be treated differently
in the user code.

int lws_partial_buffered(wsi) added... should be checked after any
libwebsocket_write that will be followed by another libwebsocket_write inside
the same writeable callback.  If set, you can't do any more writes until the
writeable callback is called again.  If you only do one write per writeable callback,
you can ignore this.

HTTP2-related: HTTP2 changes how headers are handled, lws now has new version-
agnositic header creation APIs.  These do the right thing depending on each
connection's HTTP version without the user code having to know or care, except
to make sure to use the new APIs for headers (test-server is updated to use
them already, so look there for examples)

The APIs "render" the headers into a user-provided buffer and bump *p as it
is used.  If *p reaches end, then the APIs return nonzero for error.

LWS_VISIBLE LWS_EXTERN int
lws_add_http_header_status(struct libwebsocket_context *context,
                            struct libwebsocket *wsi,
                            unsigned int code,
                            unsigned char **p,
                            unsigned char *end);

Start a response header reporting status like 200, 500, etc

LWS_VISIBLE LWS_EXTERN int
lws_add_http_header_by_name(struct libwebsocket_context *context,
                            struct libwebsocket *wsi,
                            const unsigned char *name,
                            const unsigned char *value,
                            int length,
                            unsigned char **p,
                            unsigned char *end);

Add a header like name: value in HTTP1.x

LWS_VISIBLE LWS_EXTERN int 
lws_finalize_http_header(struct libwebsocket_context *context,
                            struct libwebsocket *wsi,
                            unsigned char **p,
                            unsigned char *end);

Finish off the headers, like add the extra \r\n in HTTP1.x

LWS_VISIBLE LWS_EXTERN int
lws_add_http_header_by_token(struct libwebsocket_context *context,
                            struct libwebsocket *wsi,
                            enum lws_token_indexes token,
                            const unsigned char *value,
                            int length,
                            unsigned char **p,
                            unsigned char *end);

Add a header by using a lws token as the name part.  In HTTP2, this can be
compressed to one or two bytes.


User api removal
----------------

protocols struct member no_buffer_all_partial_tx is removed.  Under some
conditions like rewriting extension such as compression in use, the built-in
partial send buffering is the only way to deal with the problem, so turning
it off is deprecated.


User api changes
----------------

HTTP2-related: API libwebsockets_serve_http_file() takes an extra parameter at
the end now

int other_headers_len)

If you are providing other headers, they must be generated using the new
HTTP-version-agnostic APIs, and you must provide the length of them using this
additional parameter.

struct lws_context_creation_info now has an additional member
SSL_CTX *provided_client_ssl_ctx you may set to an externally-initialized
SSL_CTX managed outside lws.  Defaulting to zero keeps the existing behaviour of
lws managing the context, if you memset the struct to 0 or have as a filescope
initialized struct in bss, no need to change anything.


v1.3-chrome37-firefox30
=======================

 .gitignore                                               |    1 -
 CMakeLists.txt                                           |  447 +++--
 README.build                                             |   35 +-
 README.coding                                            |   14 +
 changelog                                                |   66 +
 cmake/LibwebsocketsConfig.cmake.in                       |   17 +
 cmake/LibwebsocketsConfigVersion.cmake.in                |   11 +
 config.h.cmake                                           |   18 +
 cross-ming.cmake                                         |   31 +
 cross-openwrt-makefile                                   |   91 +
 lib/client-handshake.c                                   |  205 ++-
 lib/client-parser.c                                      |   58 +-
 lib/client.c                                             |  158 +-
 lib/context.c                                            |  341 ++++
 lib/extension-deflate-frame.c                            |    2 +-
 lib/extension.c                                          |  178 ++
 lib/handshake.c                                          |  287 +---
 lib/lextable.h                                           |  338 ++++
 lib/libev.c                                              |  175 ++
 lib/libwebsockets.c                                      | 2089 +++--------------------
 lib/libwebsockets.h                                      |  253 ++-
 lib/lws-plat-unix.c                                      |  404 +++++
 lib/lws-plat-win.c                                       |  358 ++++
 lib/minilex.c                                            |  530 +++---
 lib/output.c                                             |  445 ++---
 lib/parsers.c                                            |  682 ++++----
 lib/pollfd.c                                             |  239 +++
 lib/private-libwebsockets.h                              |  501 +++++-
 lib/server-handshake.c                                   |  274 +--
 lib/server.c                                             |  858 ++++++++--
 lib/service.c                                            |  517 ++++++
 lib/sha-1.c                                              |   38 +-
 lib/ssl-http2.c                                          |   78 +
 lib/ssl.c                                                |  571 +++++++
 test-server/attack.sh                                    |  101 +-
 test-server/test-client.c                                |    9 +-
 test-server/test-echo.c                                  |   17 +-
 test-server/test-fraggle.c                               |    7 -
 test-server/test-ping.c                                  |   12 +-
 test-server/test-server.c                                |  330 ++--
 test-server/test.html                                    |    4 +-
 win32port/client/client.vcxproj                          |  259 ---
 win32port/client/client.vcxproj.filters                  |   39 -
 .../libwebsocketswin32.vcxproj.filters                   |   93 -
 win32port/server/server.vcxproj                          |  276 ---
 win32port/server/server.vcxproj.filters                  |   51 -
 win32port/win32helpers/gettimeofday.h                    |   59 +-
 win32port/win32helpers/netdb.h                           |    1 -
 win32port/win32helpers/strings.h                         |    0
 win32port/win32helpers/sys/time.h                        |    1 -
 win32port/win32helpers/unistd.h                          |    0
 win32port/win32helpers/websock-w32.c                     |  104 --
 win32port/win32helpers/websock-w32.h                     |   62 -
 win32port/win32port.sln                                  |  100 --
 win32port/zlib/gzio.c                                    |    3 +-
 55 files changed, 6779 insertions(+), 5059 deletions(-)


User api additions
------------------

POST method is supported

The protocol 0 / HTTP callback can now get two new kinds of callback,
LWS_CALLBACK_HTTP_BODY (in and len are a chunk of the body of the HTTP request)
and LWS_CALLBACK_HTTP_BODY_COMPLETION (the expected amount of body has arrived
and been passed to the user code already).  These callbacks are used with the
post method (see the test server for details).

The period between the HTTP header completion and the completion of the body
processing is protected by a 5s timeout.

The chunks are stored in a malloc'd buffer of size protocols[0].rx_buffer_size.


New server option you can enable from user code
LWS_SERVER_OPTION_ALLOW_NON_SSL_ON_SSL_PORT allows non-SSL connections to
also be accepted on an SSL listening port.  It's disabled unless you enable
it explicitly.


Two new callbacks are added in protocols[0] that are optional for allowing
limited thread access to libwebsockets, LWS_CALLBACK_LOCK_POLL and
LWS_CALLBACK_UNLOCK_POLL.

If you use them, they protect internal and external poll list changes, but if
you want to use external thread access to libwebsocket_callback_on_writable()
you have to implement your locking here even if you don't use external
poll support.

If you will use another thread for this, take a lot of care about managing
your list of live wsi by doing it from ESTABLISHED and CLOSED callbacks
(with your own locking).

If you configure cmake with -DLWS_WITH_LIBEV=1 then the code allowing the libev
eventloop instead of the default poll() one will also be compiled in.  But to
use it, you must also set the LWS_SERVER_OPTION_LIBEV flag on the context
creation info struct options member.

IPV6 is supported and enabled by default except for Windows, you can disable
the support at build-time by giving -DLWS_IPV6=, and disable use of it even if
compiled in by making sure the flag LWS_SERVER_OPTION_DISABLE_IPV6 is set on
the context creation info struct options member.

You can give LWS_SERVER_OPTION_DISABLE_OS_CA_CERTS option flag to
guarantee the OS CAs will not be used, even if that support was selected at
build-time.

Optional "token limits" may be enforced by setting the member "token_limits"
in struct lws_context_creation_info to point to a struct lws_token_limits.
NULL means no token limits used for compatibility.


User api changes
----------------

Extra optional argument to libwebsockets_serve_http_file() allows injecion
of HTTP headers into the canned response.  Eg, cookies may be added like
that without getting involved in having to send the header by hand.

A new info member http_proxy_address may be used at context creation time to
set the http proxy.  If non-NULL, it overrides http_proxy environment var.

Cmake supports LWS_SSL_CLIENT_USE_OS_CA_CERTS defaulting to on, which gets
the client to use the OS CA Roots.  If you're worried somebody with the
ability to forge for force creation of a client cert from the root CA in
your OS, you should disable this since your selfsigned $0 cert is a lot safer
then...


v1.23-chrome32-firefox24
========================

 Android.mk                            |   29 +
 CMakeLists.txt                        |  573 ++++++++----
 COPYING                               |  503 -----------
 INSTALL                               |  365 --------
 Makefile.am                           |   13 -
 README.build                          |  371 ++------
 README.coding                         |   63 ++
 autogen.sh                            | 1578 ---------------------------------
 changelog                             |   69 ++
 cmake/FindGit.cmake                   |  163 ++++
 cmake/FindOpenSSLbins.cmake           |   15 +-
 cmake/UseRPMTools.cmake               |  176 ++++
 config.h.cmake                        |   25 +-
 configure.ac                          |  226 -----
 cross-arm-linux-gnueabihf.cmake       |   28 +
 lib/Makefile.am                       |   89 --
 lib/base64-decode.c                   |   98 +-
 lib/client-handshake.c                |  123 ++-
 lib/client-parser.c                   |   19 +-
 lib/client.c                          |  145 ++-
 lib/daemonize.c                       |    4 +-
 lib/extension.c                       |    2 +-
 lib/getifaddrs.h                      |    4 +-
 lib/handshake.c                       |   76 +-
 lib/libwebsockets.c                   |  491 ++++++----
 lib/libwebsockets.h                   |  164 ++--
 lib/output.c                          |  214 ++++-
 lib/parsers.c                         |  102 +--
 lib/private-libwebsockets.h           |   66 +-
 lib/server-handshake.c                |    5 +-
 lib/server.c                          |   29 +-
 lib/sha-1.c                           |    2 +-
 libwebsockets-api-doc.html            |  249 +++---
 libwebsockets.pc.in                   |   11 -
 libwebsockets.spec                    |   14 +-
 m4/ignore-me                          |    2 -
 scripts/FindLibWebSockets.cmake       |   33 +
 scripts/kernel-doc                    |    1 +
 test-server/Makefile.am               |  131 ---
 test-server/leaf.jpg                  |  Bin 0 -> 2477518 bytes
 test-server/test-client.c             |   78 +-
 test-server/test-echo.c               |   33 +-
 test-server/test-fraggle.c            |   26 +-
 test-server/test-ping.c               |   15 +-
 test-server/test-server.c             |  197 +++-
 test-server/test.html                 |    5 +-
 win32port/win32helpers/gettimeofday.c |   74 +-
 win32port/win32helpers/websock-w32.h  |    6 +-
 48 files changed, 2493 insertions(+), 4212 deletions(-)


User api additions
------------------

 - You can now call libwebsocket_callback_on_writable() on http connectons,
        and get a LWS_CALLBACK_HTTP_WRITEABLE callback, the same way you can
        regulate writes with a websocket protocol connection.

 - A new member in the context creation parameter struct "ssl_cipher_list" is
        added, replacing CIPHERS_LIST_STRING.  NULL means use the ssl library
        default list of ciphers.

 - Not really an api addition, but libwebsocket_service_fd() will now zero
        the revents field of the pollfd it was called with if it handled the
        descriptor.  So you can tell if it is a non-lws fd by checking revents
        after the service call... if it's still nonzero, the descriptor
        belongs to you and you need to take care of it.

 - libwebsocket_rx_flow_allow_all_protocol(protocol) will unthrottle all
        connections with the established protocol.  It's designed to be
        called from user server code when it sees it can accept more input
        and may have throttled connections using the server rx flow apis
        while it was unable to accept any other input  The user server code
        then does not have to try to track while connections it choked, this
        will free up all of them in one call.

 - there's a new, optional callback LWS_CALLBACK_CLOSED_HTTP which gets
        called when an HTTP protocol socket closes

 - for LWS_CALLBACK_FILTER_PROTOCOL_CONNECTION callback, the user_space alloc
        has already been done before the callback happens.  That means we can
        use the user parameter to the callback to contain the user pointer, and
        move the protocol name to the "in" parameter.  The docs for this
        callback are also updated to reflect how to check headers in there.

 - libwebsocket_client_connect() is now properly nonblocking and async.  See
        README.coding and test-client.c for information on the callbacks you
        can rely on controlling the async connection period with.

 - if your OS does not support the http_proxy environment variable convention
        (eg, reportedly OSX), you can use a new api libwebsocket_set_proxy()
        to set the proxy details in between context creation and the connection
        action.  For OSes that support http_proxy, that's used automatically.

User api changes
----------------

 - the external poll callbacks now get the socket descriptor coming from the
        "in" parameter.  The user parameter provides the user_space for the
        wsi as it normally does on the other callbacks.
        LWS_CALLBACK_FILTER_NETWORK_CONNECTION also has the socket descriptor
        delivered by @in now instead of @user.

 - libwebsocket_write() now returns -1 for error, or the amount of data
        actually accepted for send.  Under load, the OS may signal it is
        ready to send new data on the socket, but have only a restricted
        amount of memory to buffer the packet compared to usual.


User api removal
----------------

 - libwebsocket_ensure_user_space() is removed from the public api, if you
        were using it to get user_space, you need to adapt your code to only
        use user_space inside the user callback.

 - CIPHERS_LIST_STRING is removed

 - autotools build has been removed.  See README.build for info on how to
        use CMake for your platform


v1.21-chrome26-firefox18
========================

 - Fixes buffer overflow bug in max frame size handling if you used the
        default protocol buffer size.  If you declared rx_buffer_size in your
        protocol, which is recommended anyway, your code was unaffected.

v1.2-chrome26-firefox18
=======================

Diffstat
--------

 .gitignore                                                      |  16 +++
 CMakeLists.txt                                                  | 544 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 LICENSE                                                         | 526 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 Makefile.am                                                     |   1 +
 README                                                          |  20 +++
 README.build                                                    | 258 ++++++++++++++++++++++++++++++++-----
 README.coding                                                   |  52 ++++++++
 changelog                                                       | 136 ++++++++++++++++++++
 cmake/FindOpenSSLbins.cmake                                     |  33 +++++
 config.h.cmake                                                  | 173 +++++++++++++++++++++++++
 configure.ac                                                    |  22 +++-
 lib/Makefile.am                                                 |  20 ++-
 lib/base64-decode.c                                             |   2 +-
 lib/client-handshake.c                                          | 190 +++++++++++-----------------
 lib/client-parser.c                                             |  88 +++++++------
 lib/client.c                                                    | 384 ++++++++++++++++++++++++++++++-------------------------
 lib/daemonize.c                                                 |  32 +++--
 lib/extension-deflate-frame.c                                   |  58 +++++----
 lib/extension-deflate-stream.c                                  |  19 ++-
 lib/extension-deflate-stream.h                                  |   4 +-
 lib/extension.c                                                 |  11 +-
 lib/getifaddrs.c                                                | 315 +++++++++++++++++++++++-----------------------
 lib/getifaddrs.h                                                |  30 ++---
 lib/handshake.c                                                 | 124 +++++++++++-------
 lib/libwebsockets.c                                             | 736 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++--------------------------------------
 lib/libwebsockets.h                                             | 237 ++++++++++++++++++++++------------
 lib/output.c                                                    | 192 +++++++++++-----------------
 lib/parsers.c                                                   | 966 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++----------------------------------------------------------------
 lib/private-libwebsockets.h                                     | 225 +++++++++++++++++++++------------
 lib/server-handshake.c                                          |  82 ++++++------
 lib/server.c                                                    |  96 +++++++-------
 libwebsockets-api-doc.html                                      | 189 ++++++++++++++++++----------
 libwebsockets.spec                                              |  17 +--
 test-server/attack.sh                                           | 148 ++++++++++++++++++++++
 test-server/test-client.c                                       | 125 +++++++++---------
 test-server/test-echo.c                                         |  31 +++--
 test-server/test-fraggle.c                                      |  32 ++---
 test-server/test-ping.c                                         |  52 ++++----
 test-server/test-server.c                                       | 129 ++++++++++++-------
 win32port/libwebsocketswin32/libwebsocketswin32.vcxproj         | 279 ----------------------------------------
 win32port/libwebsocketswin32/libwebsocketswin32.vcxproj.filters |  23 +++-
 41 files changed, 4398 insertions(+), 2219 deletions(-)


User api additions
------------------

 - lws_get_library_version() returns a const char * with a string like
         "1.1 9e7f737", representing the library version from configure.ac
         and the git HEAD hash the library was built from

 - TCP Keepalive can now optionally be applied to all lws sockets, on Linux
        also with controllable timeout, number of probes and probe interval.
        (On BSD type OS, you can only use system default settings for the
        timing and retries, although enabling it is supported by setting
        ka_time to nonzero, the exact value has no meaning.)
        This enables detection of idle connections which are logically okay,
        but are in fact dead, due to network connectivity issues at the server,
        client, or any intermediary.  By default it's not enabled, but you
        can enable it by setting a non-zero timeout (in seconds) at the new
        ka_time member at context creation time.

 - Two new optional user callbacks added, LWS_CALLBACK_PROTOCOL_DESTROY which
        is called one-time per protocol as the context is being destroyed, and
        LWS_CALLBACK_PROTOCOL_INIT which is called when the context is created
        and the protocols are added, again it's a one-time affair.
        This lets you manage per-protocol allocations properly including
        cleaning up after yourself when the server goes down.

User api changes
----------------

 - libwebsocket_create_context() has changed from taking a ton of parameters
        to just taking a pointer to a struct containing the parameters.  The
        struct lws_context_creation_info is in libwebsockets.h, the members
        are in the same order as when they were parameters to the call
        previously.  The test apps are all updated accordingly so you can
        see example code there.

 - Header tokens are now deleted after the websocket connection is
        established.  Not just the header data is saved, but the pointer and
        length array is also removed from (union) scope saving several hundred
        bytes per connection once it is established

 - struct libwebsocket_protocols has a new member rx_buffer_size, this
        controls rx buffer size per connection of that protocol now.  Sources
        for apps built against older versions of the library won't declare
        this in their protocols, defaulting it to 0.  Zero buffer is legal,
        it causes a default buffer to be allocated (currently 4096)

        If you want to receive only atomic frames in your user callback, you
        should set this to greater than your largest frame size.  If a frame
        comes that exceeds that, no error occurs but the callback happens as
        soon as the buffer limit is reached, and again if it is reached again
        or the frame completes.  You can detect that has happened by seeing
        there is still frame content pending using
        libwebsockets_remaining_packet_payload()

        By correctly setting this, you can save a lot of memory when your
        protocol has small frames (see the test server and client sources).

 - LWS_MAX_HEADER_LEN now defaults to 1024 and is the total amount of known
        header payload lws can cope with, that includes the GET URL, origin
        etc.  Headers not understood by lws are ignored and their payload
        not included in this.


User api removals
-----------------

 - The configuration-time option MAX_USER_RX_BUFFER has been replaced by a
        buffer size chosen per-protocol.  For compatibility, there's a default
        of 4096 rx buffer, but user code should set the appropriate size for
        the protocol frames.

 - LWS_INITIAL_HDR_ALLOC and LWS_ADDITIONAL_HDR_ALLOC are no longer needed
        and have been removed.  There's a new header management scheme that
        handles them in a much more compact way.

 - libwebsockets_hangup_on_client() is removed.  If you want to close the
        connection you must do so from the user callback and by returning
        -1 from there.

 - libwebsocket_close_and_free_session() is now private to the library code
        only and not exposed for user code.  If you want to close the
        connection, you must do so from the user callback by returning -1
        from there.


New features
------------

 - Cmake project file added, aimed initially at Windows support: this replaces
        the visual studio project files that were in the tree until now.

 - CyaSSL now supported in place of OpenSSL (--use-cyassl on configure)

 - PATH_MAX or MAX_PATH no longer needed

 - cutomizable frame rx buffer size by protocol

 - optional TCP keepalive so dead peers can be detected, can be enabled at
        context-creation time

 - valgrind-clean: no SSL or CyaSSL: completely clean.  With OpenSSL, 88 bytes
        lost at OpenSSL library init and symptomless reports of uninitialized
        memory usage... seems to be a known and ignored problem at OpenSSL

 - By default debug is enabled and the library is built for -O0 -g to faclitate
        that.  Use --disable-debug configure option to build instead with -O4
        and no -g (debug info), obviously providing best performance and
        reduced binary size.

 - 1.0 introduced some code to try to not deflate small frames, however this
        seems to break when confronted with a mixture of frames above and
        below the threshold, so it's removed.  Veto the compression extension
        in your user callback if you will typically have very small frames.

 - There are many memory usage improvements, both a reduction in malloc/
        realloc and architectural changes.  A websocket connection now
        consumes only 296 bytes with SSL or 272 bytes without on x86_64,
        during header processing an additional 1262 bytes is allocated in a
        single malloc, but is freed when the websocket connection starts.
        The RX frame buffer defined by the protocol in user
        code is also allocated per connection, this represents the largest
        frame you can receive atomically in that protocol.

 - On ARM9 build, just http+ws server no extensions or ssl, <12Kbytes .text
        and 112 bytes per connection (+1328 only during header processing)


v1.1-chrome26-firefox18
=======================

Diffstat
--------

 Makefile.am                            |    4 +
 README-test-server                     |  291 ---
 README.build                           |  239 ++
 README.coding                          |  138 ++
 README.rst                             |   72 -
 README.test-apps                       |  272 +++
 configure.ac                           |  116 +-
 lib/Makefile.am                        |   55 +-
 lib/base64-decode.c                    |    5 +-
 lib/client-handshake.c                 |  121 +-
 lib/client-parser.c                    |  394 ++++
 lib/client.c                           |  807 +++++++
 lib/daemonize.c                        |  212 ++
 lib/extension-deflate-frame.c          |  132 +-
 lib/extension-deflate-stream.c         |   12 +-
 lib/extension-x-google-mux.c           | 1223 ----------
 lib/extension-x-google-mux.h           |   96 -
 lib/extension.c                        |    8 -
 lib/getifaddrs.c                       |  271 +++
 lib/getifaddrs.h                       |   76 +
 lib/handshake.c                        |  582 +----
 lib/libwebsockets.c                    | 2493 ++++++---------------
 lib/libwebsockets.h                    |  115 +-
 lib/md5.c                              |  217 --
 lib/minilex.c                          |  440 ++++
 lib/output.c                           |  628 ++++++
 lib/parsers.c                          | 2016 +++++------------
 lib/private-libwebsockets.h            |  284 +--
 lib/server-handshake.c                 |  275 +++
 lib/server.c                           |  377 ++++
 libwebsockets-api-doc.html             |  300 +--
 m4/ignore-me                           |    2 +
 test-server/Makefile.am                |  111 +-
 test-server/libwebsockets.org-logo.png |  Bin 0 -> 7029 bytes
 test-server/test-client.c              |   45 +-
 test-server/test-echo.c                |  330 +++
 test-server/test-fraggle.c             |   20 +-
 test-server/test-ping.c                |   22 +-
 test-server/test-server-extpoll.c      |  554 -----
 test-server/test-server.c              |  349 ++-
 test-server/test.html                  |    3 +-
 win32port/zlib/ZLib.vcxproj            |  749 ++++---
 win32port/zlib/ZLib.vcxproj.filters    |  188 +-
 win32port/zlib/adler32.c               |  348 ++-
 win32port/zlib/compress.c              |  160 +-
 win32port/zlib/crc32.c                 |  867 ++++----
 win32port/zlib/crc32.h                 |  882 ++++----
 win32port/zlib/deflate.c               | 3799 +++++++++++++++-----------------
 win32port/zlib/deflate.h               |  688 +++---
 win32port/zlib/gzclose.c               |   50 +-
 win32port/zlib/gzguts.h                |  325 ++-
 win32port/zlib/gzlib.c                 | 1157 +++++-----
 win32port/zlib/gzread.c                | 1242 ++++++-----
 win32port/zlib/gzwrite.c               | 1096 +++++----
 win32port/zlib/infback.c               | 1272 ++++++-----
 win32port/zlib/inffast.c               |  680 +++---
 win32port/zlib/inffast.h               |   22 +-
 win32port/zlib/inffixed.h              |  188 +-
 win32port/zlib/inflate.c               | 2976 +++++++++++++------------
 win32port/zlib/inflate.h               |  244 +-
 win32port/zlib/inftrees.c              |  636 +++---
 win32port/zlib/inftrees.h              |  124 +-
 win32port/zlib/trees.c                 | 2468 +++++++++++----------
 win32port/zlib/trees.h                 |  256 +--
 win32port/zlib/uncompr.c               |  118 +-
 win32port/zlib/zconf.h                 |  934 ++++----
 win32port/zlib/zlib.h                  | 3357 ++++++++++++++--------------
 win32port/zlib/zutil.c                 |  642 +++---
 win32port/zlib/zutil.h                 |  526 ++---
 69 files changed, 19556 insertions(+), 20145 deletions(-)

user api changes
----------------

 - libwebsockets_serve_http_file() now takes a context as first argument

 - libwebsockets_get_peer_addresses() now takes a context and wsi as first
        two arguments


user api additions
------------------

 - lwsl_...() logging apis, default to stderr but retargetable by user code;
        may be used also by user code

 - lws_set_log_level() set which logging apis are able to emit (defaults to
        notice, warn, err severities), optionally set the emit callback

 - lwsl_emit_syslog() helper callback emits to syslog

 - lws_daemonize() helper code that forks the app into a headless daemon
        properly, maintains a lock file with pid in suitable for sysvinit etc to
        control lifecycle

 - LWS_CALLBACK_HTTP_FILE_COMPLETION callback added since http file
        transfer is now asynchronous (see test server code)

 - lws_frame_is_binary() from a wsi pointer, let you know if the received
        data was sent in BINARY mode


user api removals
-----------------

 - libwebsockets_fork_service_loop() - no longer supported (had intractable problems)
        arrange your code to act from the user callback instead from same
        process context as the service loop

 - libwebsockets_broadcast() - use libwebsocket_callback_on_writable[_all_protocol]()
        instead from same process context as the service loop.  See the test apps
        for examples.

 - x-google-mux() removed until someone wants it

 - pre -v13 (ancient) protocol support removed


New features
------------

 - echo test server and client compatible with echo.websocket.org added

 - many new configure options (see README.build) to reduce footprint of the
        library to what you actually need, eg, --without-client and
        --without-server

 - http + websocket server can build to as little as 12K .text for ARM

 - no more MAX_CLIENTS limitation; adapts to support the max number of fds
        allowed to the process by ulimit, defaults to 1024 on Fedora and
        Ubuntu.  Use ulimit to control this without needing to configure
        the library.  Code here is smaller and faster.

 - adaptive ratio of listen socket to connection socket service allows
        good behaviour under Apache ab test load.  Tested with thousands
        of simultaneous connections

 - reduction in per-connection memory footprint by moving to a union to hold
        mutually-exclusive state for the connection

 - robustness: Out of Memory taken care of for all allocation code now

 - internal getifaddrs option if your toolchain lacks it (some uclibc)

 - configurable memory limit for deflate operations

 - improvements in SSL code nonblocking operation, possible hang solved,
        some SSL operations broken down into pollable states so there is
        no library blocking, timeout coverage for SSL_connect

 - extpoll test server merged into single test server source

 - robustness: library should deal with all recoverable socket conditions

 - rx flowcontrol for backpressure notification fixed and implmeneted
        correctly in the test server

 - optimal lexical parser added for header processing; all headers in a
        single 276-byte state table

 - latency tracking api added (configure --with-latency)

 - Improved in-tree documentation, REAME.build, README.coding,
        README.test-apps, changelog

 - Many small fixes


v1.0-chrome25-firefox17 (6cd1ea9b005933f)