2 * libwebsockets - small server side websockets and web server implementation
4 * Copyright (C) 2010 Andy Green <andy@warmcat.com>
6 * This library is free software; you can redistribute it and/or
7 * modify it under the terms of the GNU Lesser General Public
8 * License as published by the Free Software Foundation:
9 * version 2.1 of the License.
11 * This library is distributed in the hope that it will be useful,
12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
14 * Lesser General Public License for more details.
16 * You should have received a copy of the GNU Lesser General Public
17 * License along with this library; if not, write to the Free Software
18 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston,
22 #ifndef __LIBWEBSOCKET_H__
23 #define __LIBWEBSOCKET_H__
32 #ifndef WIN32_LEAN_AND_MEAN
33 #define WIN32_LEAN_AND_MEAN
38 #include "../win32port/win32helpers/websock-w32.h"
40 #include "../win32port/win32helpers/gettimeofday.h"
42 #define strcasecmp stricmp
48 #define LWS_EXTERN extern __declspec(dllexport)
50 #define LWS_EXTERN extern __declspec(dllimport)
59 #define LWS_EXTERN extern
62 #define CONTEXT_PORT_NO_LISTEN 0
63 #define MAX_MUX_RECURSION 2
65 enum libwebsocket_context_options {
66 LWS_SERVER_OPTION_DEFEAT_CLIENT_MASK = 1,
67 LWS_SERVER_OPTION_REQUIRE_VALID_OPENSSL_CLIENT_CERT = 2,
68 LWS_SERVER_OPTION_SKIP_SERVER_CANONICAL_NAME = 4,
71 enum libwebsocket_callback_reasons {
72 LWS_CALLBACK_ESTABLISHED,
73 LWS_CALLBACK_CLIENT_CONNECTION_ERROR,
74 LWS_CALLBACK_CLIENT_ESTABLISHED,
77 LWS_CALLBACK_CLIENT_RECEIVE,
78 LWS_CALLBACK_CLIENT_RECEIVE_PONG,
79 LWS_CALLBACK_CLIENT_WRITEABLE,
80 LWS_CALLBACK_SERVER_WRITEABLE,
82 LWS_CALLBACK_BROADCAST,
83 LWS_CALLBACK_FILTER_NETWORK_CONNECTION,
84 LWS_CALLBACK_FILTER_PROTOCOL_CONNECTION,
85 LWS_CALLBACK_OPENSSL_LOAD_EXTRA_CLIENT_VERIFY_CERTS,
86 LWS_CALLBACK_OPENSSL_LOAD_EXTRA_SERVER_VERIFY_CERTS,
87 LWS_CALLBACK_OPENSSL_PERFORM_CLIENT_CERT_VERIFICATION,
88 LWS_CALLBACK_CLIENT_APPEND_HANDSHAKE_HEADER,
89 LWS_CALLBACK_CONFIRM_EXTENSION_OKAY,
90 LWS_CALLBACK_CLIENT_CONFIRM_EXTENSION_SUPPORTED,
91 /* external poll() management support */
92 LWS_CALLBACK_ADD_POLL_FD,
93 LWS_CALLBACK_DEL_POLL_FD,
94 LWS_CALLBACK_SET_MODE_POLL_FD,
95 LWS_CALLBACK_CLEAR_MODE_POLL_FD,
98 enum libwebsocket_extension_callback_reasons {
99 LWS_EXT_CALLBACK_SERVER_CONTEXT_CONSTRUCT,
100 LWS_EXT_CALLBACK_CLIENT_CONTEXT_CONSTRUCT,
101 LWS_EXT_CALLBACK_SERVER_CONTEXT_DESTRUCT,
102 LWS_EXT_CALLBACK_CLIENT_CONTEXT_DESTRUCT,
103 LWS_EXT_CALLBACK_CONSTRUCT,
104 LWS_EXT_CALLBACK_CLIENT_CONSTRUCT,
105 LWS_EXT_CALLBACK_CHECK_OK_TO_REALLY_CLOSE,
106 LWS_EXT_CALLBACK_CHECK_OK_TO_PROPOSE_EXTENSION,
107 LWS_EXT_CALLBACK_DESTROY,
108 LWS_EXT_CALLBACK_DESTROY_ANY_WSI_CLOSING,
109 LWS_EXT_CALLBACK_ANY_WSI_ESTABLISHED,
110 LWS_EXT_CALLBACK_PACKET_RX_PREPARSE,
111 LWS_EXT_CALLBACK_PACKET_TX_PRESEND,
112 LWS_EXT_CALLBACK_PACKET_TX_DO_SEND,
113 LWS_EXT_CALLBACK_HANDSHAKE_REPLY_TX,
114 LWS_EXT_CALLBACK_FLUSH_PENDING_TX,
115 LWS_EXT_CALLBACK_EXTENDED_PAYLOAD_RX,
116 LWS_EXT_CALLBACK_CAN_PROXY_CLIENT_CONNECTION,
117 LWS_EXT_CALLBACK_1HZ,
118 LWS_EXT_CALLBACK_REQUEST_ON_WRITEABLE,
119 LWS_EXT_CALLBACK_IS_WRITEABLE,
120 LWS_EXT_CALLBACK_PAYLOAD_TX,
121 LWS_EXT_CALLBACK_PAYLOAD_RX,
124 enum libwebsocket_write_protocol {
127 LWS_WRITE_CONTINUATION,
130 /* special 04+ opcodes */
138 LWS_WRITE_NO_FIN = 0x40,
140 * client packet payload goes out on wire unmunged
141 * only useful for security tests since normal servers cannot
142 * decode the content if used
144 LWS_WRITE_CLIENT_IGNORE_XOR_MASK = 0x80
148 * you need these to look at headers that have been parsed if using the
149 * LWS_CALLBACK_FILTER_CONNECTION callback. If a header from the enum
150 * list below is absent, .token = NULL and token_len = 0. Otherwise .token
151 * points to .token_len chars containing that header content.
159 enum lws_token_indexes {
162 WSI_TOKEN_CONNECTION,
177 WSI_TOKEN_EXTENSIONS,
179 /* client receives these */
185 /* always last real token index*/
187 /* parser state additions */
190 WSI_TOKEN_SKIPPING_SAW_CR,
191 WSI_PARSING_COMPLETE,
192 WSI_INIT_TOKEN_MUXURL,
199 1000 indicates a normal closure, meaning that the purpose for
200 which the connection was established has been fulfilled.
204 1001 indicates that an endpoint is "going away", such as a server
205 going down or a browser having navigated away from a page.
209 1002 indicates that an endpoint is terminating the connection due
214 1003 indicates that an endpoint is terminating the connection
215 because it has received a type of data it cannot accept (e.g., an
216 endpoint that understands only text data MAY send this if it
217 receives a binary message).
221 Reserved. The specific meaning might be defined in the future.
225 1005 is a reserved value and MUST NOT be set as a status code in a
226 Close control frame by an endpoint. It is designated for use in
227 applications expecting a status code to indicate that no status
228 code was actually present.
232 1006 is a reserved value and MUST NOT be set as a status code in a
233 Close control frame by an endpoint. It is designated for use in
234 applications expecting a status code to indicate that the
235 connection was closed abnormally, e.g., without sending or
236 receiving a Close control frame.
240 1007 indicates that an endpoint is terminating the connection
241 because it has received data within a message that was not
242 consistent with the type of the message (e.g., non-UTF-8 [RFC3629]
243 data within a text message).
247 1008 indicates that an endpoint is terminating the connection
248 because it has received a message that violates its policy. This
249 is a generic status code that can be returned when there is no
250 other more suitable status code (e.g., 1003 or 1009) or if there
251 is a need to hide specific details about the policy.
255 1009 indicates that an endpoint is terminating the connection
256 because it has received a message that is too big for it to
261 1010 indicates that an endpoint (client) is terminating the
262 connection because it has expected the server to negotiate one or
263 more extension, but the server didn't return them in the response
264 message of the WebSocket handshake. The list of extensions that
265 are needed SHOULD appear in the /reason/ part of the Close frame.
266 Note that this status code is not used by the server, because it
267 can fail the WebSocket handshake instead.
271 1011 indicates that a server is terminating the connection because
272 it encountered an unexpected condition that prevented it from
273 fulfilling the request.
277 1015 is a reserved value and MUST NOT be set as a status code in a
278 Close control frame by an endpoint. It is designated for use in
279 applications expecting a status code to indicate that the
280 connection was closed due to a failure to perform a TLS handshake
281 (e.g., the server certificate can't be verified).
284 enum lws_close_status {
285 LWS_CLOSE_STATUS_NOSTATUS = 0,
286 LWS_CLOSE_STATUS_NORMAL = 1000,
287 LWS_CLOSE_STATUS_GOINGAWAY = 1001,
288 LWS_CLOSE_STATUS_PROTOCOL_ERR = 1002,
289 LWS_CLOSE_STATUS_UNACCEPTABLE_OPCODE = 1003,
290 LWS_CLOSE_STATUS_RESERVED = 1004,
291 LWS_CLOSE_STATUS_NO_STATUS = 1005,
292 LWS_CLOSE_STATUS_ABNORMAL_CLOSE = 1006,
293 LWS_CLOSE_STATUS_INVALID_PAYLOAD = 1007,
294 LWS_CLOSE_STATUS_POLICY_VIOLATION = 1008,
295 LWS_CLOSE_STATUS_MESSAGE_TOO_LARGE = 1009,
296 LWS_CLOSE_STATUS_EXTENSION_REQUIRED = 1010,
297 LWS_CLOSE_STATUS_UNEXPECTED_CONDITION = 1011,
298 LWS_CLOSE_STATUS_TLS_FAILURE = 1015,
302 struct libwebsocket_context;
303 struct libwebsocket_extension;
306 * callback_function() - User server actions
307 * @context: Websockets context
308 * @wsi: Opaque websocket instance pointer
309 * @reason: The reason for the call
310 * @user: Pointer to per-session user data allocated by library
311 * @in: Pointer used for some callback reasons
312 * @len: Length set for some callback reasons
314 * This callback is the way the user controls what is served. All the
315 * protocol detail is hidden and handled by the library.
317 * For each connection / session there is user data allocated that is
318 * pointed to by "user". You set the size of this user data area when
319 * the library is initialized with libwebsocket_create_server.
321 * You get an opportunity to initialize user data when called back with
322 * LWS_CALLBACK_ESTABLISHED reason.
324 * LWS_CALLBACK_ESTABLISHED: after the server completes a handshake with
327 * LWS_CALLBACK_CLIENT_CONNECTION_ERROR: the request client connection has
328 * been unable to complete a handshake with the remote server
330 * LWS_CALLBACK_CLIENT_ESTABLISHED: after your client connection completed
331 * a handshake with the remote server
333 * LWS_CALLBACK_CLOSED: when the websocket session ends
335 * LWS_CALLBACK_BROADCAST: signal to send to client (you would use
336 * libwebsocket_write() taking care about the
337 * special buffer requirements
339 * LWS_CALLBACK_RECEIVE: data has appeared for this server endpoint from a
340 * remote client, it can be found at *in and is
343 * LWS_CALLBACK_CLIENT_RECEIVE_PONG: if you elected to see PONG packets,
344 * they appear with this callback reason. PONG
345 * packets only exist in 04+ protocol
347 * LWS_CALLBACK_CLIENT_RECEIVE: data has appeared from the server for the
348 * client connection, it can be found at *in and
351 * LWS_CALLBACK_HTTP: an http request has come from a client that is not
352 * asking to upgrade the connection to a websocket
353 * one. This is a chance to serve http content,
354 * for example, to send a script to the client
355 * which will then open the websockets connection.
356 * @in points to the URI path requested and
357 * libwebsockets_serve_http_file() makes it very
358 * simple to send back a file to the client.
360 * LWS_CALLBACK_CLIENT_WRITEABLE:
361 * LWS_CALLBACK_SERVER_WRITEABLE: If you call
362 * libwebsocket_callback_on_writable() on a connection, you will
363 * get one of these callbacks coming when the connection socket
364 * is able to accept another write packet without blocking.
365 * If it already was able to take another packet without blocking,
366 * you'll get this callback at the next call to the service loop
367 * function. Notice that CLIENTs get LWS_CALLBACK_CLIENT_WRITEABLE
368 * and servers get LWS_CALLBACK_SERVER_WRITEABLE.
370 * LWS_CALLBACK_FILTER_NETWORK_CONNECTION: called when a client connects to
371 * the server at network level; the connection is accepted but then
372 * passed to this callback to decide whether to hang up immediately
373 * or not, based on the client IP. @user contains the connection
374 * socket's descriptor. Return non-zero to terminate
375 * the connection before sending or receiving anything.
376 * Because this happens immediately after the network connection
377 * from the client, there's no websocket protocol selected yet so
378 * this callback is issued only to protocol 0.
380 * LWS_CALLBACK_FILTER_PROTOCOL_CONNECTION: called when the handshake has
381 * been received and parsed from the client, but the response is
382 * not sent yet. Return non-zero to disallow the connection.
383 * @user is a pointer to an array of struct lws_tokens, you can
384 * use the header enums lws_token_indexes from libwebsockets.h
385 * to check for and read the supported header presence and
386 * content before deciding to allow the handshake to proceed or
387 * to kill the connection.
389 * LWS_CALLBACK_OPENSSL_LOAD_EXTRA_CLIENT_VERIFY_CERTS: if configured for
390 * including OpenSSL support, this callback allows your user code
391 * to perform extra SSL_CTX_load_verify_locations() or similar
392 * calls to direct OpenSSL where to find certificates the client
393 * can use to confirm the remote server identity. @user is the
396 * LWS_CALLBACK_OPENSSL_LOAD_EXTRA_SERVER_VERIFY_CERTS: if configured for
397 * including OpenSSL support, this callback allows your user code
398 * to load extra certifcates into the server which allow it to
399 * verify the validity of certificates returned by clients. @user
400 * is the server's OpenSSL SSL_CTX*
402 * LWS_CALLBACK_OPENSSL_PERFORM_CLIENT_CERT_VERIFICATION: if the
403 * libwebsockets context was created with the option
404 * LWS_SERVER_OPTION_REQUIRE_VALID_OPENSSL_CLIENT_CERT, then this
405 * callback is generated during OpenSSL verification of the cert
406 * sent from the client. It is sent to protocol[0] callback as
407 * no protocol has been negotiated on the connection yet.
408 * Notice that the libwebsockets context and wsi are both NULL
409 * during this callback. See
410 * http://www.openssl.org/docs/ssl/SSL_CTX_set_verify.html
411 * to understand more detail about the OpenSSL callback that
412 * generates this libwebsockets callback and the meanings of the
413 * arguments passed. In this callback, @user is the x509_ctx,
414 * @in is the ssl pointer and @len is preverify_ok
415 * Notice that this callback maintains libwebsocket return
416 * conventions, return 0 to mean the cert is OK or 1 to fail it.
417 * This also means that if you don't handle this callback then
418 * the default callback action of returning 0 allows the client
421 * LWS_CALLBACK_CLIENT_APPEND_HANDSHAKE_HEADER: this callback happens
422 * when a client handshake is being compiled. @user is NULL,
423 * @in is a char **, it's pointing to a char * which holds the
424 * next location in the header buffer where you can add
425 * headers, and @len is the remaining space in the header buffer,
426 * which is typically some hundreds of bytes. So, to add a canned
427 * cookie, your handler code might look similar to:
429 * char **p = (char **)in;
434 * *p += sprintf(*p, "Cookie: a=b\x0d\x0a");
438 * Notice if you add anything, you just have to take care about
439 * the CRLF on the line you added. Obviously this callback is
440 * optional, if you don't handle it everything is fine.
442 * Notice the callback is coming to protocols[0] all the time,
443 * because there is no specific protocol handshook yet.
445 * LWS_CALLBACK_CONFIRM_EXTENSION_OKAY: When the server handshake code
446 * sees that it does support a requested extension, before
447 * accepting the extension by additing to the list sent back to
448 * the client it gives this callback just to check that it's okay
449 * to use that extension. It calls back to the requested protocol
450 * and with @in being the extension name, @len is 0 and @user is
451 * valid. Note though at this time the ESTABLISHED callback hasn't
452 * happened yet so if you initialize @user content there, @user
453 * content during this callback might not be useful for anything.
454 * Notice this callback comes to protocols[0].
456 * LWS_CALLBACK_CLIENT_CONFIRM_EXTENSION_SUPPORTED: When a client
457 * connection is being prepared to start a handshake to a server,
458 * each supported extension is checked with protocols[0] callback
459 * with this reason, giving the user code a chance to suppress the
460 * claim to support that extension by returning non-zero. If
461 * unhandled, by default 0 will be returned and the extension
462 * support included in the header to the server. Notice this
463 * callback comes to protocols[0].
465 * The next four reasons are optional and only need taking care of if you
466 * will be integrating libwebsockets sockets into an external polling
469 * LWS_CALLBACK_ADD_POLL_FD: libwebsocket deals with its poll() loop
470 * internally, but in the case you are integrating with another
471 * server you will need to have libwebsocket sockets share a
472 * polling array with the other server. This and the other
473 * POLL_FD related callbacks let you put your specialized
474 * poll array interface code in the callback for protocol 0, the
475 * first protocol you support, usually the HTTP protocol in the
476 * serving case. This callback happens when a socket needs to be
477 * added to the polling loop: @user contains the fd, and
478 * @len is the events bitmap (like, POLLIN). If you are using the
479 * internal polling loop (the "service" callback), you can just
480 * ignore these callbacks.
482 * LWS_CALLBACK_DEL_POLL_FD: This callback happens when a socket descriptor
483 * needs to be removed from an external polling array. @user is
484 * the socket desricptor. If you are using the internal polling
485 * loop, you can just ignore it.
487 * LWS_CALLBACK_SET_MODE_POLL_FD: This callback happens when libwebsockets
488 * wants to modify the events for the socket descriptor in @user.
489 * The handler should OR @len on to the events member of the pollfd
490 * struct for this socket descriptor. If you are using the
491 * internal polling loop, you can just ignore it.
493 * LWS_CALLBACK_CLEAR_MODE_POLL_FD: This callback occurs when libwebsockets
494 * wants to modify the events for the socket descriptor in @user.
495 * The handler should AND ~@len on to the events member of the
496 * pollfd struct for this socket descriptor. If you are using the
497 * internal polling loop, you can just ignore it.
499 LWS_EXTERN int callback(struct libwebsocket_context * context,
500 struct libwebsocket *wsi,
501 enum libwebsocket_callback_reasons reason, void *user,
502 void *in, size_t len);
504 typedef int (callback_function)(struct libwebsocket_context * context,
505 struct libwebsocket *wsi,
506 enum libwebsocket_callback_reasons reason, void *user,
507 void *in, size_t len);
511 * extension_callback_function() - Hooks to allow extensions to operate
512 * @context: Websockets context
513 * @ext: This extension
514 * @wsi: Opaque websocket instance pointer
515 * @reason: The reason for the call
516 * @user: Pointer to per-session user data allocated by library
517 * @in: Pointer used for some callback reasons
518 * @len: Length set for some callback reasons
520 * Each extension that is active on a particular connection receives
521 * callbacks during the connection lifetime to allow the extension to
522 * operate on websocket data and manage itself.
524 * Libwebsockets takes care of allocating and freeing "user" memory for
525 * each active extension on each connection. That is what is pointed to
526 * by the @user parameter.
528 * LWS_EXT_CALLBACK_CONSTRUCT: called when the server has decided to
529 * select this extension from the list provided by the client,
530 * just before the server will send back the handshake accepting
531 * the connection with this extension active. This gives the
532 * extension a chance to initialize its connection context found
535 * LWS_EXT_CALLBACK_CLIENT_CONSTRUCT: same as LWS_EXT_CALLBACK_CONSTRUCT
536 * but called when client is instantiating this extension. Some
537 * extensions will work the same on client and server side and then
538 * you can just merge handlers for both CONSTRUCTS.
540 * LWS_EXT_CALLBACK_DESTROY: called when the connection the extension was
541 * being used on is about to be closed and deallocated. It's the
542 * last chance for the extension to deallocate anything it has
543 * allocated in the user data (pointed to by @user) before the
544 * user data is deleted. This same callback is used whether you
545 * are in client or server instantiation context.
547 * LWS_EXT_CALLBACK_PACKET_RX_PREPARSE: when this extension was active on
548 * a connection, and a packet of data arrived at the connection,
549 * it is passed to this callback to give the extension a chance to
550 * change the data, eg, decompress it. @user is pointing to the
551 * extension's private connection context data, @in is pointing
552 * to an lws_tokens struct, it consists of a char * pointer called
553 * token, and an int called token_len. At entry, these are
554 * set to point to the received buffer and set to the content
555 * length. If the extension will grow the content, it should use
556 * a new buffer allocated in its private user context data and
557 * set the pointed-to lws_tokens members to point to its buffer.
559 * LWS_EXT_CALLBACK_PACKET_TX_PRESEND: this works the same way as
560 * LWS_EXT_CALLBACK_PACKET_RX_PREPARSE above, except it gives the
561 * extension a chance to change websocket data just before it will
562 * be sent out. Using the same lws_token pointer scheme in @in,
563 * the extension can change the buffer and the length to be
564 * transmitted how it likes. Again if it wants to grow the
565 * buffer safely, it should copy the data into its own buffer and
566 * set the lws_tokens token pointer to it.
568 LWS_EXTERN int extension_callback(struct libwebsocket_context * context,
569 struct libwebsocket_extension *ext,
570 struct libwebsocket *wsi,
571 enum libwebsocket_extension_callback_reasons reason, void *user,
572 void *in, size_t len);
574 typedef int (extension_callback_function)(struct libwebsocket_context * context,
575 struct libwebsocket_extension *ext,
576 struct libwebsocket *wsi,
577 enum libwebsocket_extension_callback_reasons reason, void *user,
578 void *in, size_t len);
581 * struct libwebsocket_protocols - List of protocols and handlers server
583 * @name: Protocol name that must match the one given in the client
584 * Javascript new WebSocket(url, 'protocol') name
585 * @callback: The service callback used for this protocol. It allows the
586 * service action for an entire protocol to be encapsulated in
587 * the protocol-specific callback
588 * @per_session_data_size: Each new connection using this protocol gets
589 * this much memory allocated on connection establishment and
590 * freed on connection takedown. A pointer to this per-connection
591 * allocation is passed into the callback in the 'user' parameter
592 * @owning_server: the server init call fills in this opaque pointer when
593 * registering this protocol with the server.
594 * @broadcast_socket_port: the server init call fills this in with the
595 * localhost port number used to forward broadcasts for this
597 * @broadcast_socket_user_fd: the server init call fills this in ... the main()
598 * process context can write to this socket to perform broadcasts
599 * (use the libwebsockets_broadcast() api to do this instead,
600 * it works from any process context)
601 * @protocol_index: which protocol we are starting from zero
603 * This structure represents one protocol supported by the server. An
604 * array of these structures is passed to libwebsocket_create_server()
605 * allows as many protocols as you like to be handled by one server.
608 struct libwebsocket_protocols {
610 callback_function *callback;
611 size_t per_session_data_size;
614 * below are filled in on server init and can be left uninitialized,
615 * no need for user to use them directly either
618 struct libwebsocket_context *owning_server;
619 int broadcast_socket_port;
620 int broadcast_socket_user_fd;
625 * struct libwebsocket_extension - An extension we know how to cope with
627 * @name: Formal extension name, eg, "deflate-stream"
628 * @callback: Service callback
629 * @per_session_data_size: Libwebsockets will auto-malloc this much
630 * memory for the use of the extension, a pointer
631 * to it comes in the @user callback parameter
632 * @per_context_private_data: Optional storage for this externsion that
633 * is per-context, so it can track stuff across
634 * all sessions, etc, if it wants
637 struct libwebsocket_extension {
639 extension_callback_function *callback;
640 size_t per_session_data_size;
641 void * per_context_private_data;
646 LWS_EXTERN struct libwebsocket_context *
647 libwebsocket_create_context(int port, const char * interf,
648 struct libwebsocket_protocols *protocols,
649 struct libwebsocket_extension *extensions,
650 const char *ssl_cert_filepath,
651 const char *ssl_private_key_filepath,
652 const char *ssl_ca_filepath,
654 unsigned int options, void *user);
657 libwebsocket_context_destroy(struct libwebsocket_context *context);
660 libwebsockets_fork_service_loop(struct libwebsocket_context *context);
663 libwebsocket_service(struct libwebsocket_context *context, int timeout_ms);
666 libwebsocket_service_fd(struct libwebsocket_context *context,
667 struct pollfd *pollfd);
670 libwebsocket_context_user(struct libwebsocket_context *context);
675 * When sending with websocket protocol (LWS_WRITE_TEXT or LWS_WRITE_BINARY)
676 * the send buffer has to have LWS_SEND_BUFFER_PRE_PADDING bytes valid BEFORE
677 * buf, and LWS_SEND_BUFFER_POST_PADDING bytes valid AFTER (buf + len).
679 * This allows us to add protocol info before and after the data, and send as
680 * one packet on the network without payload copying, for maximum efficiency.
682 * So for example you need this kind of code to use libwebsocket_write with a
685 * char buf[LWS_SEND_BUFFER_PRE_PADDING + 128 + LWS_SEND_BUFFER_POST_PADDING];
687 * // fill your part of the buffer... for example here it's all zeros
688 * memset(&buf[LWS_SEND_BUFFER_PRE_PADDING], 0, 128);
690 * libwebsocket_write(wsi, &buf[LWS_SEND_BUFFER_PRE_PADDING], 128);
692 * When sending LWS_WRITE_HTTP, there is no protocol addition and you can just
693 * use the whole buffer without taking care of the above.
697 * this is the frame nonce plus two header plus 8 length
698 * there's an additional two for mux extension per mux nesting level
699 * 2 byte prepend on close will already fit because control frames cannot use
700 * the big length style
703 #define LWS_SEND_BUFFER_PRE_PADDING (4 + 10 + (2 * MAX_MUX_RECURSION))
704 #define LWS_SEND_BUFFER_POST_PADDING 4
707 libwebsocket_write(struct libwebsocket *wsi, unsigned char *buf, size_t len,
708 enum libwebsocket_write_protocol protocol);
711 libwebsockets_serve_http_file(struct libwebsocket *wsi, const char *file,
712 const char *content_type);
714 /* notice - you need the pre- and post- padding allocation for buf below */
717 libwebsockets_broadcast(const struct libwebsocket_protocols *protocol,
718 unsigned char *buf, size_t len);
720 LWS_EXTERN const struct libwebsocket_protocols *
721 libwebsockets_get_protocol(struct libwebsocket *wsi);
724 libwebsocket_callback_on_writable(struct libwebsocket_context *context,
725 struct libwebsocket *wsi);
728 libwebsocket_callback_on_writable_all_protocol(
729 const struct libwebsocket_protocols *protocol);
732 libwebsocket_get_socket_fd(struct libwebsocket *wsi);
735 libwebsocket_is_final_fragment(struct libwebsocket *wsi);
737 LWS_EXTERN unsigned char
738 libwebsocket_get_reserved_bits(struct libwebsocket *wsi);
741 libwebsocket_ensure_user_space(struct libwebsocket *wsi);
744 libwebsocket_rx_flow_control(struct libwebsocket *wsi, int enable);
747 libwebsockets_remaining_packet_payload(struct libwebsocket *wsi);
749 LWS_EXTERN struct libwebsocket *
750 libwebsocket_client_connect(struct libwebsocket_context *clients,
757 const char *protocol,
758 int ietf_version_or_minus_one);
760 LWS_EXTERN struct libwebsocket *
761 libwebsocket_client_connect_extended(struct libwebsocket_context *clients,
768 const char *protocol,
769 int ietf_version_or_minus_one,
772 LWS_EXTERN const char *
773 libwebsocket_canonical_hostname(struct libwebsocket_context *context);
777 libwebsockets_get_peer_addresses(int fd, char *name, int name_len,
778 char *rip, int rip_len);
781 libwebsockets_hangup_on_client(struct libwebsocket_context *context, int fd);
784 libwebsocket_close_and_free_session(struct libwebsocket_context *context,
785 struct libwebsocket *wsi, enum lws_close_status);
788 libwebsockets_get_random(struct libwebsocket_context *context,
792 lws_send_pipe_choked(struct libwebsocket *wsi);
794 LWS_EXTERN unsigned char *
795 libwebsockets_SHA1(const unsigned char *d, size_t n, unsigned char *md);
798 lws_b64_encode_string(const char *in, int in_len, char *out, int out_size);
801 lws_b64_decode_string(const char *in, char *out, int out_size);
803 LWS_EXTERN struct libwebsocket_extension libwebsocket_internal_extensions[];