2 * libwebsockets - small server side websockets and web server implementation
4 * Copyright (C) 2010-2013 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
43 #define getdtablesize() 30000
49 #define LWS_EXTERN extern __declspec(dllexport)
51 #define LWS_EXTERN extern __declspec(dllimport)
63 #define LWS_EXTERN extern
66 #define CONTEXT_PORT_NO_LISTEN 0
67 #define MAX_MUX_RECURSION 2
81 LLL_COUNT = 10 /* set to count of valid flags */
84 LWS_EXTERN void _lws_log(int filter, const char *format, ...);
86 /* notice, warn and log are always compiled in */
87 #define lwsl_notice(...) _lws_log(LLL_NOTICE, __VA_ARGS__)
88 #define lwsl_warn(...) _lws_log(LLL_WARN, __VA_ARGS__)
89 #define lwsl_err(...) _lws_log(LLL_ERR, __VA_ARGS__)
91 * weaker logging can be deselected at configure time using --disable-debug
92 * that gets rid of the overhead of checking while keeping _warn and _err
97 #define lwsl_info(...) _lws_log(LLL_INFO, __VA_ARGS__)
98 #define lwsl_debug(...) _lws_log(LLL_DEBUG, __VA_ARGS__)
99 #define lwsl_parser(...) _lws_log(LLL_PARSER, __VA_ARGS__)
100 #define lwsl_header(...) _lws_log(LLL_HEADER, __VA_ARGS__)
101 #define lwsl_ext(...) _lws_log(LLL_EXT, __VA_ARGS__)
102 #define lwsl_client(...) _lws_log(LLL_CLIENT, __VA_ARGS__)
103 #define lwsl_latency(...) _lws_log(LLL_LATENCY, __VA_ARGS__)
104 LWS_EXTERN void lwsl_hexdump(void *buf, size_t len);
108 #define lwsl_info(...)
109 #define lwsl_debug(...)
110 #define lwsl_parser(...)
111 #define lwsl_header(...)
112 #define lwsl_ext(...)
113 #define lwsl_client(...)
114 #define lwsl_latency(...)
115 #define lwsl_hexdump(a, b)
119 enum libwebsocket_context_options {
120 LWS_SERVER_OPTION_REQUIRE_VALID_OPENSSL_CLIENT_CERT = 2,
121 LWS_SERVER_OPTION_SKIP_SERVER_CANONICAL_NAME = 4,
124 enum libwebsocket_callback_reasons {
125 LWS_CALLBACK_ESTABLISHED,
126 LWS_CALLBACK_CLIENT_CONNECTION_ERROR,
127 LWS_CALLBACK_CLIENT_FILTER_PRE_ESTABLISH,
128 LWS_CALLBACK_CLIENT_ESTABLISHED,
130 LWS_CALLBACK_RECEIVE,
131 LWS_CALLBACK_CLIENT_RECEIVE,
132 LWS_CALLBACK_CLIENT_RECEIVE_PONG,
133 LWS_CALLBACK_CLIENT_WRITEABLE,
134 LWS_CALLBACK_SERVER_WRITEABLE,
136 LWS_CALLBACK_HTTP_FILE_COMPLETION,
137 LWS_CALLBACK_HTTP_WRITEABLE,
138 LWS_CALLBACK_FILTER_NETWORK_CONNECTION,
139 LWS_CALLBACK_FILTER_PROTOCOL_CONNECTION,
140 LWS_CALLBACK_OPENSSL_LOAD_EXTRA_CLIENT_VERIFY_CERTS,
141 LWS_CALLBACK_OPENSSL_LOAD_EXTRA_SERVER_VERIFY_CERTS,
142 LWS_CALLBACK_OPENSSL_PERFORM_CLIENT_CERT_VERIFICATION,
143 LWS_CALLBACK_CLIENT_APPEND_HANDSHAKE_HEADER,
144 LWS_CALLBACK_CONFIRM_EXTENSION_OKAY,
145 LWS_CALLBACK_CLIENT_CONFIRM_EXTENSION_SUPPORTED,
146 LWS_CALLBACK_PROTOCOL_INIT,
147 LWS_CALLBACK_PROTOCOL_DESTROY,
148 /* external poll() management support */
149 LWS_CALLBACK_ADD_POLL_FD,
150 LWS_CALLBACK_DEL_POLL_FD,
151 LWS_CALLBACK_SET_MODE_POLL_FD,
152 LWS_CALLBACK_CLEAR_MODE_POLL_FD,
155 #ifndef LWS_NO_EXTENSIONS
156 enum libwebsocket_extension_callback_reasons {
157 LWS_EXT_CALLBACK_SERVER_CONTEXT_CONSTRUCT,
158 LWS_EXT_CALLBACK_CLIENT_CONTEXT_CONSTRUCT,
159 LWS_EXT_CALLBACK_SERVER_CONTEXT_DESTRUCT,
160 LWS_EXT_CALLBACK_CLIENT_CONTEXT_DESTRUCT,
161 LWS_EXT_CALLBACK_CONSTRUCT,
162 LWS_EXT_CALLBACK_CLIENT_CONSTRUCT,
163 LWS_EXT_CALLBACK_CHECK_OK_TO_REALLY_CLOSE,
164 LWS_EXT_CALLBACK_CHECK_OK_TO_PROPOSE_EXTENSION,
165 LWS_EXT_CALLBACK_DESTROY,
166 LWS_EXT_CALLBACK_DESTROY_ANY_WSI_CLOSING,
167 LWS_EXT_CALLBACK_ANY_WSI_ESTABLISHED,
168 LWS_EXT_CALLBACK_PACKET_RX_PREPARSE,
169 LWS_EXT_CALLBACK_PACKET_TX_PRESEND,
170 LWS_EXT_CALLBACK_PACKET_TX_DO_SEND,
171 LWS_EXT_CALLBACK_HANDSHAKE_REPLY_TX,
172 LWS_EXT_CALLBACK_FLUSH_PENDING_TX,
173 LWS_EXT_CALLBACK_EXTENDED_PAYLOAD_RX,
174 LWS_EXT_CALLBACK_CAN_PROXY_CLIENT_CONNECTION,
175 LWS_EXT_CALLBACK_1HZ,
176 LWS_EXT_CALLBACK_REQUEST_ON_WRITEABLE,
177 LWS_EXT_CALLBACK_IS_WRITEABLE,
178 LWS_EXT_CALLBACK_PAYLOAD_TX,
179 LWS_EXT_CALLBACK_PAYLOAD_RX,
183 enum libwebsocket_write_protocol {
186 LWS_WRITE_CONTINUATION,
189 /* special 04+ opcodes */
197 LWS_WRITE_NO_FIN = 0x40,
199 * client packet payload goes out on wire unmunged
200 * only useful for security tests since normal servers cannot
201 * decode the content if used
203 LWS_WRITE_CLIENT_IGNORE_XOR_MASK = 0x80
207 * you need these to look at headers that have been parsed if using the
208 * LWS_CALLBACK_FILTER_CONNECTION callback. If a header from the enum
209 * list below is absent, .token = NULL and token_len = 0. Otherwise .token
210 * points to .token_len chars containing that header content.
218 enum lws_token_indexes {
221 WSI_TOKEN_CONNECTION,
236 WSI_TOKEN_EXTENSIONS,
238 /* client receives these */
244 /* use token storage to stash these */
246 _WSI_TOKEN_CLIENT_SENT_PROTOCOLS,
247 _WSI_TOKEN_CLIENT_PEER_ADDRESS,
248 _WSI_TOKEN_CLIENT_URI,
249 _WSI_TOKEN_CLIENT_HOST,
250 _WSI_TOKEN_CLIENT_ORIGIN,
252 /* always last real token index*/
254 /* parser state additions */
257 WSI_TOKEN_SKIPPING_SAW_CR,
258 WSI_PARSING_COMPLETE,
259 WSI_INIT_TOKEN_MUXURL,
266 1000 indicates a normal closure, meaning that the purpose for
267 which the connection was established has been fulfilled.
271 1001 indicates that an endpoint is "going away", such as a server
272 going down or a browser having navigated away from a page.
276 1002 indicates that an endpoint is terminating the connection due
281 1003 indicates that an endpoint is terminating the connection
282 because it has received a type of data it cannot accept (e.g., an
283 endpoint that understands only text data MAY send this if it
284 receives a binary message).
288 Reserved. The specific meaning might be defined in the future.
292 1005 is a reserved value and MUST NOT be set as a status code in a
293 Close control frame by an endpoint. It is designated for use in
294 applications expecting a status code to indicate that no status
295 code was actually present.
299 1006 is a reserved value and MUST NOT be set as a status code in a
300 Close control frame by an endpoint. It is designated for use in
301 applications expecting a status code to indicate that the
302 connection was closed abnormally, e.g., without sending or
303 receiving a Close control frame.
307 1007 indicates that an endpoint is terminating the connection
308 because it has received data within a message that was not
309 consistent with the type of the message (e.g., non-UTF-8 [RFC3629]
310 data within a text message).
314 1008 indicates that an endpoint is terminating the connection
315 because it has received a message that violates its policy. This
316 is a generic status code that can be returned when there is no
317 other more suitable status code (e.g., 1003 or 1009) or if there
318 is a need to hide specific details about the policy.
322 1009 indicates that an endpoint is terminating the connection
323 because it has received a message that is too big for it to
328 1010 indicates that an endpoint (client) is terminating the
329 connection because it has expected the server to negotiate one or
330 more extension, but the server didn't return them in the response
331 message of the WebSocket handshake. The list of extensions that
332 are needed SHOULD appear in the /reason/ part of the Close frame.
333 Note that this status code is not used by the server, because it
334 can fail the WebSocket handshake instead.
338 1011 indicates that a server is terminating the connection because
339 it encountered an unexpected condition that prevented it from
340 fulfilling the request.
344 1015 is a reserved value and MUST NOT be set as a status code in a
345 Close control frame by an endpoint. It is designated for use in
346 applications expecting a status code to indicate that the
347 connection was closed due to a failure to perform a TLS handshake
348 (e.g., the server certificate can't be verified).
351 enum lws_close_status {
352 LWS_CLOSE_STATUS_NOSTATUS = 0,
353 LWS_CLOSE_STATUS_NORMAL = 1000,
354 LWS_CLOSE_STATUS_GOINGAWAY = 1001,
355 LWS_CLOSE_STATUS_PROTOCOL_ERR = 1002,
356 LWS_CLOSE_STATUS_UNACCEPTABLE_OPCODE = 1003,
357 LWS_CLOSE_STATUS_RESERVED = 1004,
358 LWS_CLOSE_STATUS_NO_STATUS = 1005,
359 LWS_CLOSE_STATUS_ABNORMAL_CLOSE = 1006,
360 LWS_CLOSE_STATUS_INVALID_PAYLOAD = 1007,
361 LWS_CLOSE_STATUS_POLICY_VIOLATION = 1008,
362 LWS_CLOSE_STATUS_MESSAGE_TOO_LARGE = 1009,
363 LWS_CLOSE_STATUS_EXTENSION_REQUIRED = 1010,
364 LWS_CLOSE_STATUS_UNEXPECTED_CONDITION = 1011,
365 LWS_CLOSE_STATUS_TLS_FAILURE = 1015,
369 struct libwebsocket_context;
370 /* needed even with extensions disabled for create context */
371 struct libwebsocket_extension;
374 * callback_function() - User server actions
375 * @context: Websockets context
376 * @wsi: Opaque websocket instance pointer
377 * @reason: The reason for the call
378 * @user: Pointer to per-session user data allocated by library
379 * @in: Pointer used for some callback reasons
380 * @len: Length set for some callback reasons
382 * This callback is the way the user controls what is served. All the
383 * protocol detail is hidden and handled by the library.
385 * For each connection / session there is user data allocated that is
386 * pointed to by "user". You set the size of this user data area when
387 * the library is initialized with libwebsocket_create_server.
389 * You get an opportunity to initialize user data when called back with
390 * LWS_CALLBACK_ESTABLISHED reason.
392 * LWS_CALLBACK_ESTABLISHED: after the server completes a handshake with
395 * LWS_CALLBACK_CLIENT_CONNECTION_ERROR: the request client connection has
396 * been unable to complete a handshake with the remote server
398 * LWS_CALLBACK_CLIENT_FILTER_PRE_ESTABLISH: this is the last chance for the
399 * client user code to examine the http headers
400 * and decide to reject the connection. If the
401 * content in the headers is interesting to the
402 * client (url, etc) it needs to copy it out at
403 * this point since it will be destroyed before
404 * the CLIENT_ESTABLISHED call
406 * LWS_CALLBACK_CLIENT_ESTABLISHED: after your client connection completed
407 * a handshake with the remote server
409 * LWS_CALLBACK_CLOSED: when the websocket session ends
411 * LWS_CALLBACK_RECEIVE: data has appeared for this server endpoint from a
412 * remote client, it can be found at *in and is
415 * LWS_CALLBACK_CLIENT_RECEIVE_PONG: if you elected to see PONG packets,
416 * they appear with this callback reason. PONG
417 * packets only exist in 04+ protocol
419 * LWS_CALLBACK_CLIENT_RECEIVE: data has appeared from the server for the
420 * client connection, it can be found at *in and
423 * LWS_CALLBACK_HTTP: an http request has come from a client that is not
424 * asking to upgrade the connection to a websocket
425 * one. This is a chance to serve http content,
426 * for example, to send a script to the client
427 * which will then open the websockets connection.
428 * @in points to the URI path requested and
429 * libwebsockets_serve_http_file() makes it very
430 * simple to send back a file to the client.
431 * Normally after sending the file you are done
432 * with the http connection, since the rest of the
433 * activity will come by websockets from the script
434 * that was delivered by http, so you will want to
435 * return 1; to close and free up the connection.
436 * That's important because it uses a slot in the
437 * total number of client connections allowed set
440 * LWS_CALLBACK_HTTP_WRITEABLE: you can write more down the http protocol
443 * LWS_CALLBACK_HTTP_FILE_COMPLETION: a file requested to be send down
444 * http link has completed.
446 * LWS_CALLBACK_CLIENT_WRITEABLE:
447 * LWS_CALLBACK_SERVER_WRITEABLE: If you call
448 * libwebsocket_callback_on_writable() on a connection, you will
449 * get one of these callbacks coming when the connection socket
450 * is able to accept another write packet without blocking.
451 * If it already was able to take another packet without blocking,
452 * you'll get this callback at the next call to the service loop
453 * function. Notice that CLIENTs get LWS_CALLBACK_CLIENT_WRITEABLE
454 * and servers get LWS_CALLBACK_SERVER_WRITEABLE.
456 * LWS_CALLBACK_FILTER_NETWORK_CONNECTION: called when a client connects to
457 * the server at network level; the connection is accepted but then
458 * passed to this callback to decide whether to hang up immediately
459 * or not, based on the client IP. @user contains the connection
460 * socket's descriptor. Return non-zero to terminate
461 * the connection before sending or receiving anything.
462 * Because this happens immediately after the network connection
463 * from the client, there's no websocket protocol selected yet so
464 * this callback is issued only to protocol 0.
466 * LWS_CALLBACK_FILTER_PROTOCOL_CONNECTION: called when the handshake has
467 * been received and parsed from the client, but the response is
468 * not sent yet. Return non-zero to disallow the connection.
469 * @user is a pointer to an array of struct lws_tokens, you can
470 * use the header enums lws_token_indexes from libwebsockets.h
471 * to check for and read the supported header presence and
472 * content before deciding to allow the handshake to proceed or
473 * to kill the connection.
475 * LWS_CALLBACK_OPENSSL_LOAD_EXTRA_CLIENT_VERIFY_CERTS: if configured for
476 * including OpenSSL support, this callback allows your user code
477 * to perform extra SSL_CTX_load_verify_locations() or similar
478 * calls to direct OpenSSL where to find certificates the client
479 * can use to confirm the remote server identity. @user is the
482 * LWS_CALLBACK_OPENSSL_LOAD_EXTRA_SERVER_VERIFY_CERTS: if configured for
483 * including OpenSSL support, this callback allows your user code
484 * to load extra certifcates into the server which allow it to
485 * verify the validity of certificates returned by clients. @user
486 * is the server's OpenSSL SSL_CTX*
488 * LWS_CALLBACK_OPENSSL_PERFORM_CLIENT_CERT_VERIFICATION: if the
489 * libwebsockets context was created with the option
490 * LWS_SERVER_OPTION_REQUIRE_VALID_OPENSSL_CLIENT_CERT, then this
491 * callback is generated during OpenSSL verification of the cert
492 * sent from the client. It is sent to protocol[0] callback as
493 * no protocol has been negotiated on the connection yet.
494 * Notice that the libwebsockets context and wsi are both NULL
495 * during this callback. See
496 * http://www.openssl.org/docs/ssl/SSL_CTX_set_verify.html
497 * to understand more detail about the OpenSSL callback that
498 * generates this libwebsockets callback and the meanings of the
499 * arguments passed. In this callback, @user is the x509_ctx,
500 * @in is the ssl pointer and @len is preverify_ok
501 * Notice that this callback maintains libwebsocket return
502 * conventions, return 0 to mean the cert is OK or 1 to fail it.
503 * This also means that if you don't handle this callback then
504 * the default callback action of returning 0 allows the client
507 * LWS_CALLBACK_CLIENT_APPEND_HANDSHAKE_HEADER: this callback happens
508 * when a client handshake is being compiled. @user is NULL,
509 * @in is a char **, it's pointing to a char * which holds the
510 * next location in the header buffer where you can add
511 * headers, and @len is the remaining space in the header buffer,
512 * which is typically some hundreds of bytes. So, to add a canned
513 * cookie, your handler code might look similar to:
515 * char **p = (char **)in;
520 * *p += sprintf(*p, "Cookie: a=b\x0d\x0a");
524 * Notice if you add anything, you just have to take care about
525 * the CRLF on the line you added. Obviously this callback is
526 * optional, if you don't handle it everything is fine.
528 * Notice the callback is coming to protocols[0] all the time,
529 * because there is no specific protocol handshook yet.
531 * LWS_CALLBACK_CONFIRM_EXTENSION_OKAY: When the server handshake code
532 * sees that it does support a requested extension, before
533 * accepting the extension by additing to the list sent back to
534 * the client it gives this callback just to check that it's okay
535 * to use that extension. It calls back to the requested protocol
536 * and with @in being the extension name, @len is 0 and @user is
537 * valid. Note though at this time the ESTABLISHED callback hasn't
538 * happened yet so if you initialize @user content there, @user
539 * content during this callback might not be useful for anything.
540 * Notice this callback comes to protocols[0].
542 * LWS_CALLBACK_CLIENT_CONFIRM_EXTENSION_SUPPORTED: When a client
543 * connection is being prepared to start a handshake to a server,
544 * each supported extension is checked with protocols[0] callback
545 * with this reason, giving the user code a chance to suppress the
546 * claim to support that extension by returning non-zero. If
547 * unhandled, by default 0 will be returned and the extension
548 * support included in the header to the server. Notice this
549 * callback comes to protocols[0].
551 * LWS_CALLBACK_PROTOCOL_INIT: One-time call per protocol so it can
552 * do initial setup / allocations etc
554 * LWS_CALLBACK_PROTOCOL_DESTROY: One-time call per protocol indicating
555 * this protocol won't get used at all after this callback, the
556 * context is getting destroyed. Take the opportunity to
557 * deallocate everything that was allocated by the protocol.
559 * The next four reasons are optional and only need taking care of if you
560 * will be integrating libwebsockets sockets into an external polling
563 * LWS_CALLBACK_ADD_POLL_FD: libwebsocket deals with its poll() loop
564 * internally, but in the case you are integrating with another
565 * server you will need to have libwebsocket sockets share a
566 * polling array with the other server. This and the other
567 * POLL_FD related callbacks let you put your specialized
568 * poll array interface code in the callback for protocol 0, the
569 * first protocol you support, usually the HTTP protocol in the
570 * serving case. This callback happens when a socket needs to be
571 * added to the polling loop: @user contains the fd, and
572 * @len is the events bitmap (like, POLLIN). If you are using the
573 * internal polling loop (the "service" callback), you can just
574 * ignore these callbacks.
576 * LWS_CALLBACK_DEL_POLL_FD: This callback happens when a socket descriptor
577 * needs to be removed from an external polling array. @user is
578 * the socket desricptor. If you are using the internal polling
579 * loop, you can just ignore it.
581 * LWS_CALLBACK_SET_MODE_POLL_FD: This callback happens when libwebsockets
582 * wants to modify the events for the socket descriptor in @user.
583 * The handler should OR @len on to the events member of the pollfd
584 * struct for this socket descriptor. If you are using the
585 * internal polling loop, you can just ignore it.
587 * LWS_CALLBACK_CLEAR_MODE_POLL_FD: This callback occurs when libwebsockets
588 * wants to modify the events for the socket descriptor in @user.
589 * The handler should AND ~@len on to the events member of the
590 * pollfd struct for this socket descriptor. If you are using the
591 * internal polling loop, you can just ignore it.
593 LWS_EXTERN int callback(struct libwebsocket_context *context,
594 struct libwebsocket *wsi,
595 enum libwebsocket_callback_reasons reason, void *user,
596 void *in, size_t len);
598 typedef int (callback_function)(struct libwebsocket_context *context,
599 struct libwebsocket *wsi,
600 enum libwebsocket_callback_reasons reason, void *user,
601 void *in, size_t len);
603 #ifndef LWS_NO_EXTENSIONS
605 * extension_callback_function() - Hooks to allow extensions to operate
606 * @context: Websockets context
607 * @ext: This extension
608 * @wsi: Opaque websocket instance pointer
609 * @reason: The reason for the call
610 * @user: Pointer to per-session user data allocated by library
611 * @in: Pointer used for some callback reasons
612 * @len: Length set for some callback reasons
614 * Each extension that is active on a particular connection receives
615 * callbacks during the connection lifetime to allow the extension to
616 * operate on websocket data and manage itself.
618 * Libwebsockets takes care of allocating and freeing "user" memory for
619 * each active extension on each connection. That is what is pointed to
620 * by the @user parameter.
622 * LWS_EXT_CALLBACK_CONSTRUCT: called when the server has decided to
623 * select this extension from the list provided by the client,
624 * just before the server will send back the handshake accepting
625 * the connection with this extension active. This gives the
626 * extension a chance to initialize its connection context found
629 * LWS_EXT_CALLBACK_CLIENT_CONSTRUCT: same as LWS_EXT_CALLBACK_CONSTRUCT
630 * but called when client is instantiating this extension. Some
631 * extensions will work the same on client and server side and then
632 * you can just merge handlers for both CONSTRUCTS.
634 * LWS_EXT_CALLBACK_DESTROY: called when the connection the extension was
635 * being used on is about to be closed and deallocated. It's the
636 * last chance for the extension to deallocate anything it has
637 * allocated in the user data (pointed to by @user) before the
638 * user data is deleted. This same callback is used whether you
639 * are in client or server instantiation context.
641 * LWS_EXT_CALLBACK_PACKET_RX_PREPARSE: when this extension was active on
642 * a connection, and a packet of data arrived at the connection,
643 * it is passed to this callback to give the extension a chance to
644 * change the data, eg, decompress it. @user is pointing to the
645 * extension's private connection context data, @in is pointing
646 * to an lws_tokens struct, it consists of a char * pointer called
647 * token, and an int called token_len. At entry, these are
648 * set to point to the received buffer and set to the content
649 * length. If the extension will grow the content, it should use
650 * a new buffer allocated in its private user context data and
651 * set the pointed-to lws_tokens members to point to its buffer.
653 * LWS_EXT_CALLBACK_PACKET_TX_PRESEND: this works the same way as
654 * LWS_EXT_CALLBACK_PACKET_RX_PREPARSE above, except it gives the
655 * extension a chance to change websocket data just before it will
656 * be sent out. Using the same lws_token pointer scheme in @in,
657 * the extension can change the buffer and the length to be
658 * transmitted how it likes. Again if it wants to grow the
659 * buffer safely, it should copy the data into its own buffer and
660 * set the lws_tokens token pointer to it.
662 LWS_EXTERN int extension_callback(struct libwebsocket_context *context,
663 struct libwebsocket_extension *ext,
664 struct libwebsocket *wsi,
665 enum libwebsocket_extension_callback_reasons reason,
666 void *user, void *in, size_t len);
668 typedef int (extension_callback_function)(struct libwebsocket_context *context,
669 struct libwebsocket_extension *ext,
670 struct libwebsocket *wsi,
671 enum libwebsocket_extension_callback_reasons reason,
672 void *user, void *in, size_t len);
676 * struct libwebsocket_protocols - List of protocols and handlers server
678 * @name: Protocol name that must match the one given in the client
679 * Javascript new WebSocket(url, 'protocol') name
680 * @callback: The service callback used for this protocol. It allows the
681 * service action for an entire protocol to be encapsulated in
682 * the protocol-specific callback
683 * @per_session_data_size: Each new connection using this protocol gets
684 * this much memory allocated on connection establishment and
685 * freed on connection takedown. A pointer to this per-connection
686 * allocation is passed into the callback in the 'user' parameter
687 * @rx_buffer_size: if you want atomic frames delivered to the callback, you
688 * should set this to the size of the biggest legal frame that
689 * you support. If the frame size is exceeded, there is no
690 * error, but the buffer will spill to the user callback when
691 * full, which you can detect by using
692 * libwebsockets_remaining_packet_payload(). Notice that you
693 * just talk about frame size here, the LWS_SEND_BUFFER_PRE_PADDING
694 * and post-padding are automatically also allocated on top.
695 * @owning_server: the server init call fills in this opaque pointer when
696 * registering this protocol with the server.
697 * @protocol_index: which protocol we are starting from zero
699 * This structure represents one protocol supported by the server. An
700 * array of these structures is passed to libwebsocket_create_server()
701 * allows as many protocols as you like to be handled by one server.
704 struct libwebsocket_protocols {
706 callback_function *callback;
707 size_t per_session_data_size;
708 size_t rx_buffer_size;
711 * below are filled in on server init and can be left uninitialized,
712 * no need for user to use them directly either
715 struct libwebsocket_context *owning_server;
719 #ifndef LWS_NO_EXTENSIONS
721 * struct libwebsocket_extension - An extension we know how to cope with
723 * @name: Formal extension name, eg, "deflate-stream"
724 * @callback: Service callback
725 * @per_session_data_size: Libwebsockets will auto-malloc this much
726 * memory for the use of the extension, a pointer
727 * to it comes in the @user callback parameter
728 * @per_context_private_data: Optional storage for this extension that
729 * is per-context, so it can track stuff across
730 * all sessions, etc, if it wants
733 struct libwebsocket_extension {
735 extension_callback_function *callback;
736 size_t per_session_data_size;
737 void *per_context_private_data;
742 * struct lws_context_creation_info: parameters to create context with
744 * @port: Port to listen on... you can use 0 to suppress listening on
745 * any port, that's what you want if you are not running a
746 * websocket server at all but just using it as a client
747 * @iface: NULL to bind the listen socket to all interfaces, or the
748 * interface name, eg, "eth2"
749 * @protocols: Array of structures listing supported protocols and a protocol-
750 * specific callback for each one. The list is ended with an
751 * entry that has a NULL callback pointer.
752 * It's not const because we write the owning_server member
753 * @extensions: NULL or array of libwebsocket_extension structs listing the
754 * extensions this context supports. If you configured with
755 * --without-extensions, you should give NULL here.
756 * @ssl_cert_filepath: If libwebsockets was compiled to use ssl, and you want
757 * to listen using SSL, set to the filepath to fetch the
758 * server cert from, otherwise NULL for unencrypted
759 * @ssl_private_key_filepath: filepath to private key if wanting SSL mode,
761 * @ssl_ca_filepath: CA certificate filepath or NULL
762 * @gid: group id to change to after setting listen socket, or -1.
763 * @uid: user id to change to after setting listen socket, or -1.
764 * @options: 0, or LWS_SERVER_OPTION_DEFEAT_CLIENT_MASK
765 * @user: optional user pointer that can be recovered via the context
766 * pointer using libwebsocket_context_user
767 * @ka_time: 0 for no keepalive, otherwise apply this keepalive timeout to
768 * all libwebsocket sockets, client or server
769 * @ka_probes: if ka_time was nonzero, after the timeout expires how many
770 * times to try to get a response from the peer before giving up
771 * and killing the connection
772 * @ka_interval: if ka_time was nonzero, how long to wait before each ka_probes
776 struct lws_context_creation_info {
779 struct libwebsocket_protocols *protocols;
780 struct libwebsocket_extension *extensions;
781 const char *ssl_cert_filepath;
782 const char *ssl_private_key_filepath;
783 const char *ssl_ca_filepath;
786 unsigned int options;
795 void lws_set_log_level(int level,
796 void (*log_emit_function)(int level, const char *line));
799 lwsl_emit_syslog(int level, const char *line);
801 LWS_EXTERN struct libwebsocket_context *
802 libwebsocket_create_context(struct lws_context_creation_info *info);
805 libwebsocket_context_destroy(struct libwebsocket_context *context);
808 libwebsocket_service(struct libwebsocket_context *context, int timeout_ms);
811 libwebsocket_service_fd(struct libwebsocket_context *context,
812 struct pollfd *pollfd);
815 libwebsocket_context_user(struct libwebsocket_context *context);
820 * When sending with websocket protocol (LWS_WRITE_TEXT or LWS_WRITE_BINARY)
821 * the send buffer has to have LWS_SEND_BUFFER_PRE_PADDING bytes valid BEFORE
822 * buf, and LWS_SEND_BUFFER_POST_PADDING bytes valid AFTER (buf + len).
824 * This allows us to add protocol info before and after the data, and send as
825 * one packet on the network without payload copying, for maximum efficiency.
827 * So for example you need this kind of code to use libwebsocket_write with a
830 * char buf[LWS_SEND_BUFFER_PRE_PADDING + 128 + LWS_SEND_BUFFER_POST_PADDING];
832 * // fill your part of the buffer... for example here it's all zeros
833 * memset(&buf[LWS_SEND_BUFFER_PRE_PADDING], 0, 128);
835 * libwebsocket_write(wsi, &buf[LWS_SEND_BUFFER_PRE_PADDING], 128);
837 * When sending LWS_WRITE_HTTP, there is no protocol addition and you can just
838 * use the whole buffer without taking care of the above.
842 * this is the frame nonce plus two header plus 8 length
843 * there's an additional two for mux extension per mux nesting level
844 * 2 byte prepend on close will already fit because control frames cannot use
845 * the big length style
848 #define LWS_SEND_BUFFER_PRE_PADDING (4 + 10 + (2 * MAX_MUX_RECURSION))
849 #define LWS_SEND_BUFFER_POST_PADDING 4
852 libwebsocket_write(struct libwebsocket *wsi, unsigned char *buf, size_t len,
853 enum libwebsocket_write_protocol protocol);
856 libwebsockets_serve_http_file(struct libwebsocket_context *context,
857 struct libwebsocket *wsi, const char *file,
858 const char *content_type);
860 libwebsockets_serve_http_file_fragment(struct libwebsocket_context *context,
861 struct libwebsocket *wsi);
863 LWS_EXTERN const struct libwebsocket_protocols *
864 libwebsockets_get_protocol(struct libwebsocket *wsi);
867 libwebsocket_callback_on_writable(struct libwebsocket_context *context,
868 struct libwebsocket *wsi);
871 libwebsocket_callback_on_writable_all_protocol(
872 const struct libwebsocket_protocols *protocol);
875 libwebsocket_get_socket_fd(struct libwebsocket *wsi);
878 libwebsocket_is_final_fragment(struct libwebsocket *wsi);
880 LWS_EXTERN unsigned char
881 libwebsocket_get_reserved_bits(struct libwebsocket *wsi);
884 libwebsocket_ensure_user_space(struct libwebsocket *wsi);
887 libwebsocket_rx_flow_control(struct libwebsocket *wsi, int enable);
890 libwebsockets_remaining_packet_payload(struct libwebsocket *wsi);
892 LWS_EXTERN struct libwebsocket *
893 libwebsocket_client_connect(struct libwebsocket_context *clients,
900 const char *protocol,
901 int ietf_version_or_minus_one);
903 LWS_EXTERN struct libwebsocket *
904 libwebsocket_client_connect_extended(struct libwebsocket_context *clients,
911 const char *protocol,
912 int ietf_version_or_minus_one,
915 LWS_EXTERN const char *
916 libwebsocket_canonical_hostname(struct libwebsocket_context *context);
920 libwebsockets_get_peer_addresses(struct libwebsocket_context *context,
921 struct libwebsocket *wsi, int fd, char *name, int name_len,
922 char *rip, int rip_len);
925 libwebsockets_get_random(struct libwebsocket_context *context,
929 lws_daemonize(const char *_lock_path);
932 lws_send_pipe_choked(struct libwebsocket *wsi);
935 lws_frame_is_binary(struct libwebsocket *wsi);
937 LWS_EXTERN unsigned char *
938 libwebsockets_SHA1(const unsigned char *d, size_t n, unsigned char *md);
941 lws_b64_encode_string(const char *in, int in_len, char *out, int out_size);
944 lws_b64_decode_string(const char *in, char *out, int out_size);
946 LWS_EXTERN const char *
947 lws_get_library_version(void);
949 /* access to headers... only valid while headers valid */
952 lws_hdr_total_length(struct libwebsocket *wsi, enum lws_token_indexes h);
955 lws_hdr_copy(struct libwebsocket *wsi, char *dest, int len,
956 enum lws_token_indexes h);
959 * Note: this is not normally needed as a user api. It's provided in case it is
960 * useful when integrating with other app poll loop service code.
964 libwebsocket_read(struct libwebsocket_context *context,
965 struct libwebsocket *wsi,
966 unsigned char *buf, size_t len);
968 #ifndef LWS_NO_EXTENSIONS
969 LWS_EXTERN struct libwebsocket_extension *libwebsocket_get_internal_extensions();