1 /*
2     This file is part of libmicrospdy
3     Copyright Copyright (C) 2012 Andrey Uzunov
4 
5     This program is free software: you can redistribute it and/or modify
6     it under the terms of the GNU General Public License as published by
7     the Free Software Foundation, either version 3 of the License, or
8     (at your option) any later version.
9 
10     This program is distributed in the hope that it will be useful,
11     but WITHOUT ANY WARRANTY; without even the implied warranty of
12     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
13     GNU General Public License for more details.
14 
15     You should have received a copy of the GNU General Public License
16     along with this program.  If not, see <http://www.gnu.org/licenses/>.
17 */
18 
19 /**
20  * @file structures.h
21  * @brief  internal and public structures -- most of the structs used by
22  * 			the library are defined here
23  * @author Andrey Uzunov
24  */
25 
26 #ifndef STRUCTURES_H
27 #define STRUCTURES_H
28 
29 #include "platform.h"
30 #include "microspdy.h"
31 #include "io.h"
32 
33 
34 /**
35  * All possible SPDY control frame types. The number is used in the header
36  * of the control frame.
37  */
38 enum SPDY_CONTROL_FRAME_TYPES
39 {
40 	/**
41 	 * The SYN_STREAM control frame allows the sender to asynchronously
42 	 * create a stream between the endpoints.
43 	 */
44 	SPDY_CONTROL_FRAME_TYPES_SYN_STREAM = 1,
45 
46 	/**
47 	 * SYN_REPLY indicates the acceptance of a stream creation by
48 	 * the recipient of a SYN_STREAM frame.
49 	 */
50 	SPDY_CONTROL_FRAME_TYPES_SYN_REPLY = 2,
51 
52 	/**
53 	 * The RST_STREAM frame allows for abnormal termination of a stream.
54 	 * When sent by the creator of a stream, it indicates the creator
55 	 * wishes to cancel the stream. When sent by the recipient of a
56 	 * stream, it indicates an error or that the recipient did not want
57 	 * to accept the stream, so the stream should be closed.
58 	 */
59 	SPDY_CONTROL_FRAME_TYPES_RST_STREAM = 3,
60 
61 	/**
62 	 * A SETTINGS frame contains a set of id/value pairs for
63 	 * communicating configuration data about how the two endpoints may
64 	 * communicate. SETTINGS frames can be sent at any time by either
65 	 * endpoint, are optionally sent, and are fully asynchronous. When
66 	 * the server is the sender, the sender can request that
67 	 * configuration data be persisted by the client across SPDY
68 	 * sessions and returned to the server in future communications.
69 	 */
70 	SPDY_CONTROL_FRAME_TYPES_SETTINGS = 4,
71 
72 	/**
73 	 * The PING control frame is a mechanism for measuring a minimal
74 	 * round-trip time from the sender. It can be sent from the client
75 	 * or the server. Recipients of a PING frame should send an
76 	 * identical frame to the sender as soon as possible (if there is
77 	 * other pending data waiting to be sent, PING should take highest
78 	 * priority). Each ping sent by a sender should use a unique ID.
79 	 */
80 	SPDY_CONTROL_FRAME_TYPES_PING = 6,
81 
82 	/**
83 	 * The GOAWAY control frame is a mechanism to tell the remote side
84 	 * of the connection to stop creating streams on this session. It
85 	 * can be sent from the client or the server.
86 	 */
87 	SPDY_CONTROL_FRAME_TYPES_GOAWAY = 7,
88 
89 	/**
90 	 * The HEADERS frame augments a stream with additional headers. It
91 	 * may be optionally sent on an existing stream at any time.
92 	 * Specific application of the headers in this frame is
93 	 * application-dependent. The name/value header block within this
94 	 * frame is compressed.
95 	 */
96 	SPDY_CONTROL_FRAME_TYPES_HEADERS = 8,
97 
98 	/**
99 	 * The WINDOW_UPDATE control frame is used to implement per stream
100 	 * flow control in SPDY. Flow control in SPDY is per hop, that is,
101 	 * only between the two endpoints of a SPDY connection. If there are
102 	 * one or more intermediaries between the client and the origin
103 	 * server, flow control signals are not explicitly forwarded by the
104 	 * intermediaries.
105 	 */
106 	SPDY_CONTROL_FRAME_TYPES_WINDOW_UPDATE = 9,
107 
108 	/**
109 	 * The CREDENTIAL control frame is used by the client to send
110 	 * additional client certificates to the server. A SPDY client may
111 	 * decide to send requests for resources from different origins on
112 	 * the same SPDY session if it decides that that server handles both
113 	 * origins. For example if the IP address associated with both
114 	 * hostnames matches and the SSL server certificate presented in the
115 	 * initial handshake is valid for both hostnames. However, because
116 	 * the SSL connection can contain at most one client certificate,
117 	 * the client needs a mechanism to send additional client
118 	 * certificates to the server.
119 	 */
120 	SPDY_CONTROL_FRAME_TYPES_CREDENTIAL = 11
121 };
122 
123 
124 /**
125  * SPDY_SESSION_STATUS is used to show the current receiving state
126  * of each session, i.e. what is expected to come now, and how it should
127  * be handled.
128  */
129 enum SPDY_SESSION_STATUS
130 {
131 	/**
132 	 * The session is in closing state, do not read read anything from
133 	 * it. Do not write anything to it.
134 	 */
135 	SPDY_SESSION_STATUS_CLOSING = 0,
136 
137 	/**
138 	 * Wait for new SPDY frame to come.
139 	 */
140 	SPDY_SESSION_STATUS_WAIT_FOR_HEADER = 1,
141 
142 	/**
143 	 * The standard 8 byte header of the SPDY frame was received and
144 	 * handled. Wait for the specific (sub)headers according to the
145 	 * frame type.
146 	 */
147 	SPDY_SESSION_STATUS_WAIT_FOR_SUBHEADER = 2,
148 
149 	/**
150 	 * The specific (sub)headers were received and handled. Wait for the
151 	 * "body", i.e. wait for the name/value pairs compressed by zlib.
152 	 */
153 	SPDY_SESSION_STATUS_WAIT_FOR_BODY = 3,
154 
155 	/**
156 	 * Ignore all the bytes read from the socket, e.g. larger frames.
157 	 */
158 	SPDY_SESSION_STATUS_IGNORE_BYTES= 4,
159 
160 	/**
161 	 * The session is in pre-closing state, do not read read anything
162 	 * from it. In this state the output queue will be written to the
163 	 * socket.
164 	 */
165 	SPDY_SESSION_STATUS_FLUSHING = 5,
166 };
167 
168 
169 /**
170  * Specific flags for the SYN_STREAM control frame.
171  */
172 enum SPDY_SYN_STREAM_FLAG
173 {
174 	/**
175 	 * The sender won't send any more frames on this stream.
176 	 */
177 	SPDY_SYN_STREAM_FLAG_FIN = 1,
178 
179 	/**
180 	 * The sender creates this stream as unidirectional.
181 	 */
182 	SPDY_SYN_STREAM_FLAG_UNIDIRECTIONAL = 2
183 };
184 
185 
186 /**
187  * Specific flags for the SYN_REPLY control frame.
188  */
189 enum SPDY_SYN_REPLY_FLAG
190 {
191 	/**
192 	 * The sender won't send any more frames on this stream.
193 	 */
194 	SPDY_SYN_REPLY_FLAG_FIN = 1
195 };
196 
197 
198 /**
199  * Specific flags for the data frame.
200  */
201 enum SPDY_DATA_FLAG
202 {
203 	/**
204 	 * The sender won't send any more frames on this stream.
205 	 */
206 	SPDY_DATA_FLAG_FIN = 1,
207 
208 	/**
209 	 * The data in the frame is compressed.
210 	 * This flag appears only in the draft on ietf.org but not on
211 	 * chromium.org.
212 	 */
213 	SPDY_DATA_FLAG_COMPRESS = 2
214 };
215 
216 /**
217  * Status code within RST_STREAM control frame.
218  */
219 enum SPDY_RST_STREAM_STATUS
220 {
221 	/**
222 	 * This is a generic error, and should only be used if a more
223 	 * specific error is not available.
224 	 */
225 	SPDY_RST_STREAM_STATUS_PROTOCOL_ERROR = 1,
226 
227 	/**
228 	 * This is returned when a frame is received for a stream which is
229 	 * not active.
230 	 */
231 	SPDY_RST_STREAM_STATUS_INVALID_STREAM = 2,
232 
233 	/**
234 	 * Indicates that the stream was refused before any processing has
235 	 * been done on the stream.
236 	 */
237 	SPDY_RST_STREAM_STATUS_REFUSED_STREAM = 3,
238 
239 	/**
240 	 * Indicates that the recipient of a stream does not support the
241 	 * SPDY version requested.
242 	 */
243 	SPDY_RST_STREAM_STATUS_UNSUPPORTED_VERSION = 4,
244 
245 	/**
246 	 * Used by the creator of a stream to indicate that the stream is
247 	 * no longer needed.
248 	 */
249 	SPDY_RST_STREAM_STATUS_CANCEL = 5,
250 
251 	/**
252 	 * This is a generic error which can be used when the implementation
253 	 * has internally failed, not due to anything in the protocol.
254 	 */
255 	SPDY_RST_STREAM_STATUS_INTERNAL_ERROR = 6,
256 
257 	/**
258 	 * The endpoint detected that its peer violated the flow control
259 	 * protocol.
260 	 */
261 	SPDY_RST_STREAM_STATUS_FLOW_CONTROL_ERROR = 7,
262 
263 	/**
264 	 * The endpoint received a SYN_REPLY for a stream already open.
265 	 */
266 	SPDY_RST_STREAM_STATUS_STREAM_IN_USE = 8,
267 
268 	/**
269 	 * The endpoint received a data or SYN_REPLY frame for a stream
270 	 * which is half closed.
271 	 */
272 	SPDY_RST_STREAM_STATUS_STREAM_ALREADY_CLOSED = 9,
273 
274 	/**
275 	 * The server received a request for a resource whose origin does
276 	 * not have valid credentials in the client certificate vector.
277 	 */
278 	SPDY_RST_STREAM_STATUS_INVALID_CREDENTIALS = 10,
279 
280 	/**
281 	 * The endpoint received a frame which this implementation could not
282 	 * support. If FRAME_TOO_LARGE is sent for a SYN_STREAM, HEADERS,
283 	 * or SYN_REPLY frame without fully processing the compressed
284 	 * portion of those frames, then the compression state will be
285 	 * out-of-sync with the other endpoint. In this case, senders of
286 	 * FRAME_TOO_LARGE MUST close the session.
287 	 */
288 	SPDY_RST_STREAM_STATUS_FRAME_TOO_LARGE = 11
289 };
290 
291 
292 /**
293  * Status code within GOAWAY control frame.
294  */
295 enum SPDY_GOAWAY_STATUS
296 {
297 	/**
298 	 * This is a normal session teardown.
299 	 */
300 	SPDY_GOAWAY_STATUS_OK = 0,
301 
302 	/**
303 	 * This is a generic error, and should only be used if a more
304 	 * specific error is not available.
305 	 */
306 	SPDY_GOAWAY_STATUS_PROTOCOL_ERROR = 1,
307 
308 	/**
309 	 * This is a generic error which can be used when the implementation
310 	 * has internally failed, not due to anything in the protocol.
311 	 */
312 	SPDY_GOAWAY_STATUS_INTERNAL_ERROR = 11
313 };
314 
315 
316 struct SPDYF_Stream;
317 
318 struct SPDYF_Response_Queue;
319 
320 
321 /**
322  * Callback for received new data chunk.
323  *
324  * @param cls client-defined closure
325  * @param stream handler
326  * @param buf data chunk from the data
327  * @param size the size of the data chunk 'buf' in bytes
328  * @param more false if this is the last frame received on this stream. Note:
329  *             true does not mean that more data will come, exceptional
330  *             situation is possible
331  * @return SPDY_YES to continue calling the function,
332  *         SPDY_NO to stop calling the function for this stream
333  */
334 typedef int
335 (*SPDYF_NewDataCallback) (void * cls,
336 					 struct SPDYF_Stream *stream,
337 					 const void * buf,
338 					 size_t size,
339 					 bool more);
340 
341 
342 /**
343  * Callback for new stream. To be used in the application layer of the
344  * lib.
345  *
346  * @param cls
347  * @param stream the new stream
348  * @return SPDY_YES on success,
349  *         SPDY_NO if error occurs
350  */
351 typedef int
352 (*SPDYF_NewStreamCallback) (void *cls,
353 						struct SPDYF_Stream * stream);
354 
355 
356 /**
357  * Callback to be called when the response queue object was handled and
358  * the data was already sent.
359  *
360  * @param cls
361  * @param response_queue the SPDYF_Response_Queue structure which will
362  * 			be cleaned very soon
363  * @param status shows if actually the response was sent or it was
364  * 			discarded by the lib for any reason (e.g., closing session,
365  * 			closing stream, stopping daemon, etc.). It is possible that
366  * 			status indicates an error but part of the response (in one
367  * 			or several frames) was sent to the client.
368  */
369 typedef void
370 (*SPDYF_ResponseQueueResultCallback) (void * cls,
371 								struct SPDYF_Response_Queue *response_queue,
372 								enum SPDY_RESPONSE_RESULT status);
373 
374 
375 /**
376  * Representation of the control frame's headers, which are common for
377  * all types.
378  */
379 struct __attribute__((__packed__)) SPDYF_Control_Frame
380 {
381 	uint16_t version : 15;
382 	uint16_t control_bit : 1; /* always 1 for control frames */
383 	uint16_t type;
384 	uint32_t flags : 8;
385 	uint32_t length : 24;
386 };
387 
388 
389 /**
390  * Representation of the data frame's headers.
391  */
392 struct __attribute__((__packed__)) SPDYF_Data_Frame
393 {
394 	uint32_t stream_id : 31;
395 	uint32_t control_bit : 1; /* always 0 for data frames */
396 	uint32_t flags : 8;
397 	uint32_t length : 24;
398 };
399 
400 
401 /**
402  * Queue of the responses, to be handled (e.g. compressed) and sent later.
403  */
404 struct SPDYF_Response_Queue
405 {
406 	/**
407 	 * This is a doubly-linked list.
408 	 */
409 	struct SPDYF_Response_Queue *next;
410 
411 	/**
412 	 * This is a doubly-linked list.
413 	 */
414 	struct SPDYF_Response_Queue *prev;
415 
416 	/**
417 	 * Stream (Request) for which is the response.
418 	 */
419 	struct SPDYF_Stream *stream;
420 
421 	/**
422 	 * Response structure with all the data (uncompressed headers) to be sent.
423 	 */
424 	struct SPDY_Response *response;
425 
426 	/**
427 	 * Control frame. The length field should be set after compressing
428 	 * the headers!
429 	 */
430 	struct SPDYF_Control_Frame *control_frame;
431 
432 	/**
433 	 * Data frame. The length field should be set after compressing
434 	 * the body!
435 	 */
436 	struct SPDYF_Data_Frame *data_frame;
437 
438 	/**
439 	 * Data to be sent: name/value pairs in control frames or body in data frames.
440 	 */
441 	void *data;
442 
443 	/**
444 	 * Specific handler for different frame types.
445 	 */
446 	int (* process_response_handler)(struct SPDY_Session *session);
447 
448 	/**
449 	 * Callback to be called when the last bytes from the response was sent
450 	 * to the client.
451 	 */
452 	SPDYF_ResponseQueueResultCallback frqcb;
453 
454 	/**
455 	 * Closure for frqcb.
456 	 */
457 	void *frqcb_cls;
458 
459 	/**
460 	 * Callback to be used by the application layer.
461 	 */
462 	SPDY_ResponseResultCallback rrcb;
463 
464 	/**
465 	 * Closure for rcb.
466 	 */
467 	void *rrcb_cls;
468 
469 	/**
470 	 * Data size.
471 	 */
472 	size_t data_size;
473 
474 	/**
475 	 * True if data frame should be sent. False if control frame should
476 	 * be sent.
477 	 */
478 	bool is_data;
479 };
480 
481 
482 
483 /**
484  * Collection of HTTP headers used in requests and responses.
485  */
486 struct SPDY_NameValue
487 {
488 	/**
489 	* This is a doubly-linked list.
490 	*/
491 	struct SPDY_NameValue *next;
492 
493 	/**
494 	* This is a doubly-linked list.
495 	*/
496 	struct SPDY_NameValue *prev;
497 
498 	/**
499 	* Null terminated string for name.
500 	*/
501     char *name;
502 
503 	/**
504 	* Array of Null terminated strings for value. num_values is the
505 	* length of the array.
506 	*/
507 	char **value;
508 
509 	/**
510 	* Number of values, this is >= 0.
511 	*/
512 	unsigned int num_values;
513 };
514 
515 
516 /**
517  * Represents a SPDY stream
518  */
519 struct SPDYF_Stream
520 {
521 	/**
522 	 * This is a doubly-linked list.
523 	 */
524 	struct SPDYF_Stream *next;
525 
526 	/**
527 	 * This is a doubly-linked list.
528 	 */
529 	struct SPDYF_Stream *prev;
530 
531 	/**
532 	 * Reference to the SPDY_Session struct.
533 	 */
534 	struct SPDY_Session *session;
535 
536 	/**
537 	 * Name value pairs, sent within the frame which created the stream.
538 	 */
539 	struct SPDY_NameValue *headers;
540 
541 	/**
542 	 * Any object to be used by the application layer.
543 	 */
544 	void *cls;
545 
546 	/**
547 	 * This stream's ID.
548 	 */
549 	uint32_t stream_id;
550 
551 	/**
552 	 * Stream to which this one is associated.
553 	 */
554 	uint32_t assoc_stream_id;
555 
556 	/**
557 	 * The window of the data within data frames.
558 	 */
559 	uint32_t window_size;
560 
561 	/**
562 	 * Stream priority. 0 is the highest, 7 is the lowest.
563 	 */
564 	uint8_t priority;
565 
566 	/**
567 	 * Integer specifying the index in the server's CREDENTIAL vector of
568 	 * the client certificate to be used for this request The value 0
569 	 * means no client certificate should be associated with this stream.
570 	 */
571 	uint8_t slot;
572 
573 	/**
574 	 * If initially the stream was created as unidirectional.
575 	 */
576 	bool flag_unidirectional;
577 
578 	/**
579 	 * If the stream won't be used for receiving frames anymore. The
580 	 * client has sent FLAG_FIN or the stream was terminated with
581 	 * RST_STREAM.
582 	 */
583 	bool is_in_closed;
584 
585 	/**
586 	 * If the stream won't be used for sending out frames anymore. The
587 	 * server has sent FLAG_FIN or the stream was terminated with
588 	 * RST_STREAM.
589 	 */
590 	bool is_out_closed;
591 
592 	/**
593 	 * Which entity (server/client) has created the stream.
594 	 */
595 	bool is_server_initiator;
596 };
597 
598 
599 /**
600  * Represents a SPDY session which is just a TCP connection
601  */
602 struct SPDY_Session
603 {
604 	/**
605 	 * zlib stream for decompressing all the name/pair values from the
606 	 * received frames. All the received compressed data must be
607 	 * decompressed within one context: this stream. Thus, it should be
608 	 * unique for the session and initialized at its creation.
609 	 */
610 	z_stream zlib_recv_stream;
611 
612 	/**
613 	 * zlib stream for compressing all the name/pair values from the
614 	 * frames to be sent. All the sent compressed data must be
615 	 * compressed within one context: this stream. Thus, it should be
616 	 * unique for the session and initialized at its creation.
617 	 */
618 	z_stream zlib_send_stream;
619 
620 	/**
621 	 * This is a doubly-linked list.
622 	 */
623 	struct SPDY_Session *next;
624 
625 	/**
626 	 * This is a doubly-linked list.
627 	 */
628 	struct SPDY_Session *prev;
629 
630 	/**
631 	 * Reference to the SPDY_Daemon struct.
632 	 */
633 	struct SPDY_Daemon *daemon;
634 
635 	/**
636 	 * Foreign address (of length addr_len).
637 	 */
638 	struct sockaddr *addr;
639 
640 	/**
641 	 * Head of doubly-linked list of the SPDY streams belonging to the
642 	 * session.
643 	 */
644 	struct SPDYF_Stream *streams_head;
645 
646 	/**
647 	 * Tail of doubly-linked list of the streams.
648 	 */
649 	struct SPDYF_Stream *streams_tail;
650 
651 	/**
652 	 * Unique IO context for the session. Initialized on each creation
653 	 * (actually when the TCP connection is established).
654 	 */
655 	void *io_context;
656 
657 	/**
658 	 * Head of doubly-linked list of the responses.
659 	 */
660 	struct SPDYF_Response_Queue *response_queue_head;
661 
662 	/**
663 	 * Tail of doubly-linked list of the responses.
664 	 */
665 	struct SPDYF_Response_Queue *response_queue_tail;
666 
667 	/**
668 	 * Buffer for reading requests.
669 	 */
670 	void *read_buffer;
671 
672 	/**
673 	 * Buffer for writing responses.
674 	 */
675 	void *write_buffer;
676 
677 	/**
678 	 * Specific handler for the frame that is currently being received.
679 	 */
680 	void (*frame_handler) (struct SPDY_Session * session);
681 
682 	/**
683 	 * Closure for frame_handler.
684 	 */
685 	void *frame_handler_cls;
686 
687 	/**
688 	 * Extra field to be used by the user with set/get func for whatever
689 	 * purpose he wants.
690 	 */
691 	void *user_cls;
692 
693 	/**
694 	 * Function to initialize the IO context for a new session.
695 	 */
696 	SPDYF_IONewSession fio_new_session;
697 
698 	/**
699 	 * Function to deinitialize the IO context for a session.
700 	 */
701 	SPDYF_IOCloseSession fio_close_session;
702 
703 	/**
704 	 * Function to read data from socket.
705 	 */
706 	SPDYF_IORecv fio_recv;
707 
708 	/**
709 	 * Function to write data to socket.
710 	 */
711 	SPDYF_IOSend fio_send;
712 
713 	/**
714 	 * Function to check for pending data in IO buffers.
715 	 */
716 	SPDYF_IOIsPending fio_is_pending;
717 
718 	/**
719 	 * Function to call before writing set of frames.
720 	 */
721 	SPDYF_IOBeforeWrite fio_before_write;
722 
723 	/**
724 	 * Function to call after writing set of frames.
725 	 */
726 	SPDYF_IOAfterWrite fio_after_write;
727 
728 	/**
729 	 * Number of bytes that the lib must ignore immediately after they
730 	 * are read from the TLS socket without adding them to the read buf.
731 	 * This is needed, for instance, when receiving frame bigger than
732 	 * the buffer to avoid deadlock situations.
733 	 */
734 	size_t read_ignore_bytes;
735 
736 	/**
737 	 * Size of read_buffer (in bytes).  This value indicates
738 	 * how many bytes we're willing to read into the buffer;
739 	 * the real buffer is one byte longer to allow for
740 	 * adding zero-termination (when needed).
741 	 */
742 	size_t read_buffer_size;
743 
744 	/**
745 	 * Position where we currently append data in
746 	 * read_buffer (last valid position).
747 	 */
748 	size_t read_buffer_offset;
749 
750 	/**
751 	 * Position until where everything was already read
752 	 */
753 	size_t read_buffer_beginning;
754 
755 	/**
756 	 * Size of write_buffer (in bytes).  This value indicates
757 	 * how many bytes we're willing to prepare for writing.
758 	 */
759 	size_t write_buffer_size;
760 
761 	/**
762 	 * Position where we currently append data in
763 	 * write_buffer (last valid position).
764 	 */
765 	size_t write_buffer_offset;
766 
767 	/**
768 	 * Position until where everything was already written to the socket
769 	 */
770 	size_t write_buffer_beginning;
771 
772 	/**
773 	 * Last time this connection had any activity
774 	 * (reading or writing). In milliseconds.
775 	 */
776 	unsigned long long last_activity;
777 
778 	/**
779 	 * Socket for this connection.  Set to -1 if
780 	 * this connection has died (daemon should clean
781 	 * up in that case).
782 	 */
783 	int socket_fd;
784 
785 	/**
786 	 * Length of the foreign address.
787 	 */
788 	socklen_t addr_len;
789 
790 	/**
791 	 * The biggest stream ID for this session for streams initiated
792 	 * by the client.
793 	 */
794 	uint32_t last_in_stream_id;
795 
796 	/**
797 	 * The biggest stream ID for this session for streams initiated
798 	 * by the server.
799 	 */
800 	uint32_t last_out_stream_id;
801 
802 	/**
803 	 * This value is updated whenever SYN_REPLY or RST_STREAM are sent
804 	 * and is used later in GOAWAY frame.
805 	 * TODO it is not clear in the draft what happens when streams are
806 	 * not answered in the order of their IDs. Moreover, why should we
807 	 * send GOAWAY with the ID of received bogus SYN_STREAM with huge ID?
808 	 */
809 	uint32_t last_replied_to_stream_id;
810 
811 	/**
812 	 * Shows the stream id of the currently handled frame. This value is
813 	 * to be used when sending RST_STREAM in answer to a problematic
814 	 * frame, e.g. larger than supported.
815 	 */
816 	uint32_t current_stream_id;
817 
818 	/**
819 	 * Maximum number of frames to be written to the socket at once. The
820    * library tries to send max_num_frames in a single call to SPDY_run
821    * for a single session. This means no requests can be received nor
822    * other sessions can send data as long the current one has enough
823    * frames to send and there is no error on writing.
824 	 */
825 	uint32_t max_num_frames;
826 
827 	/**
828 	 * Shows the current receiving state the session, i.e. what is
829 	 * expected to come now, and how it shold be handled.
830 	 */
831 	enum SPDY_SESSION_STATUS status;
832 
833 	/**
834 	 * Has this socket been closed for reading (i.e.
835 	 * other side closed the connection)?  If so,
836 	 * we must completely close the connection once
837 	 * we are done sending our response (and stop
838 	 * trying to read from this socket).
839 	 */
840 	bool read_closed;
841 
842 	/**
843 	 * If the server sends GOAWAY, it must ignore all SYN_STREAMS for
844 	 * this session. Normally the server will soon close the TCP session.
845 	 */
846 	bool is_goaway_sent;
847 
848 	/**
849 	 * If the server receives GOAWAY, it must not send new SYN_STREAMS
850 	 * on this session. Normally the client will soon close the TCP
851 	 * session.
852 	 */
853 	bool is_goaway_received;
854 };
855 
856 
857 /**
858  * State and settings kept for each SPDY daemon.
859  */
860 struct SPDY_Daemon
861 {
862 
863 	/**
864 	 * Tail of doubly-linked list of our current, active sessions.
865 	 */
866 	struct SPDY_Session *sessions_head;
867 
868 	/**
869 	 * Tail of doubly-linked list of our current, active sessions.
870 	 */
871 	struct SPDY_Session *sessions_tail;
872 
873 	/**
874 	 * Tail of doubly-linked list of connections to clean up.
875 	 */
876 	struct SPDY_Session *cleanup_head;
877 
878 	/**
879 	 * Tail of doubly-linked list of connections to clean up.
880 	 */
881 	struct SPDY_Session *cleanup_tail;
882 
883 	/**
884 	 * Unique IO context for the daemon. Initialized on daemon start.
885 	 */
886 	void *io_context;
887 
888 	/**
889 	 * Certificate file of the server. File path is kept here.
890 	 */
891 	char *certfile;
892 
893 	/**
894 	 * Key file for the certificate of the server. File path is
895 	 * kept here.
896 	 */
897 	char *keyfile;
898 
899 
900 	/**
901 	 * The address to which the listening socket is bound.
902 	 */
903 	struct sockaddr *address;
904 
905 	/**
906 	 * Callback called when a new SPDY session is
907 	 * established by a client
908 	 */
909 	SPDY_NewSessionCallback new_session_cb;
910 
911 	/**
912 	 * Callback called when a client closes the session
913 	 */
914 	SPDY_SessionClosedCallback session_closed_cb;
915 
916 	/**
917 	 * Callback called when a client sends request
918 	 */
919 	SPDY_NewRequestCallback new_request_cb;
920 
921 	/**
922 	* Callback called when HTTP POST params are received
923 	* after request. To be used by the application layer
924 	*/
925 	SPDY_NewDataCallback received_data_cb;
926 
927 	/**
928 	* Callback called when DATA frame is received.
929 	*/
930 	SPDYF_NewDataCallback freceived_data_cb;
931 
932 	/**
933 	 * Closure argument for all the callbacks that can be used by the client.
934 	 */
935 	void *cls;
936 
937 	/**
938 	 * Callback called when new stream is created.
939 	 */
940 	SPDYF_NewStreamCallback fnew_stream_cb;
941 
942 	/**
943 	 * Closure argument for all the callbacks defined in the framing layer.
944 	 */
945 	void *fcls;
946 
947 	/**
948 	 * Function to initialize the IO context for the daemon.
949 	 */
950 	SPDYF_IOInit fio_init;
951 
952 	/**
953 	 * Function to deinitialize the IO context for the daemon.
954 	 */
955 	SPDYF_IODeinit fio_deinit;
956 
957 	/**
958 	 * After how many milliseconds of inactivity should
959 	 * connections time out? Zero for no timeout.
960 	 */
961 	unsigned long long session_timeout;
962 
963 	/**
964 	 * Listen socket.
965 	 */
966 	int socket_fd;
967 
968 	/**
969    * This value is inherited by all sessions of the daemon.
970 	 * Maximum number of frames to be written to the socket at once. The
971    * library tries to send max_num_frames in a single call to SPDY_run
972    * for a single session. This means no requests can be received nor
973    * other sessions can send data as long the current one has enough
974    * frames to send and there is no error on writing.
975 	 */
976 	uint32_t max_num_frames;
977 
978 	/**
979 	 * Daemon's options.
980 	 */
981 	enum SPDY_DAEMON_OPTION options;
982 
983 	/**
984 	 * Daemon's flags.
985 	 */
986 	enum SPDY_DAEMON_FLAG flags;
987 
988 	/**
989 	 * IO subsystem type used by daemon and all its sessions.
990 	 */
991 	enum SPDY_IO_SUBSYSTEM io_subsystem;
992 
993 	/**
994 	 * Listen port.
995 	 */
996 	uint16_t port;
997 };
998 
999 
1000 /**
1001  * Represents a SPDY response.
1002  */
1003 struct SPDY_Response
1004 {
1005 	/**
1006 	 * Raw uncompressed stream of the name/value pairs in SPDY frame
1007 	 * used for the HTTP headers.
1008 	 */
1009     void *headers;
1010 
1011 	/**
1012 	 * Raw stream of the data to be sent. Equivalent to the body in HTTP
1013 	 * response.
1014 	 */
1015 	void *data;
1016 
1017 	/**
1018 	 * Callback function to be used when the response data is provided
1019 	 * with callbacks. In this case data must be NULL and data_size must
1020 	 * be 0.
1021 	 */
1022 	SPDY_ResponseCallback rcb;
1023 
1024 	/**
1025 	 * Extra argument to rcb.
1026 	 */
1027 	void *rcb_cls;
1028 
1029 	/**
1030 	 * Length of headers.
1031 	 */
1032 	size_t headers_size;
1033 
1034 	/**
1035 	 * Length of data.
1036 	 */
1037 	size_t data_size;
1038 
1039 	/**
1040 	 * The callback func will be called to get that amount of bytes to
1041 	 * put them into a DATA frame. It is either user preffered or
1042 	 * the maximum supported by the lib value.
1043 	 */
1044 	uint32_t rcb_block_size;
1045 };
1046 
1047 
1048 /* Macros for handling data and structures */
1049 
1050 
1051 /**
1052  * Insert an element at the head of a DLL. Assumes that head, tail and
1053  * element are structs with prev and next fields.
1054  *
1055  * @param head pointer to the head of the DLL (struct ? *)
1056  * @param tail pointer to the tail of the DLL (struct ? *)
1057  * @param element element to insert (struct ? *)
1058  */
1059 #define DLL_insert(head,tail,element) do { \
1060 	(element)->next = (head); \
1061 	(element)->prev = NULL; \
1062 	if ((tail) == NULL) \
1063 		(tail) = element; \
1064 	else \
1065 		(head)->prev = element; \
1066 	(head) = (element); } while (0)
1067 
1068 
1069 /**
1070  * Remove an element from a DLL. Assumes
1071  * that head, tail and element are structs
1072  * with prev and next fields.
1073  *
1074  * @param head pointer to the head of the DLL (struct ? *)
1075  * @param tail pointer to the tail of the DLL (struct ? *)
1076  * @param element element to remove (struct ? *)
1077  */
1078 #define DLL_remove(head,tail,element) do { \
1079 	if ((element)->prev == NULL) \
1080 		(head) = (element)->next;  \
1081 	else \
1082 		(element)->prev->next = (element)->next; \
1083 	if ((element)->next == NULL) \
1084 		(tail) = (element)->prev;  \
1085 	else \
1086 		(element)->next->prev = (element)->prev; \
1087 	(element)->next = NULL; \
1088 	(element)->prev = NULL; } while (0)
1089 
1090 
1091 /**
1092  * Convert all integers in a SPDY control frame headers structure from
1093  * host byte order to network byte order.
1094  *
1095  * @param frame input and output structure (struct SPDY_Control_Frame *)
1096  */
1097 #if HAVE_BIG_ENDIAN
1098 #define SPDYF_CONTROL_FRAME_HTON(frame)
1099 #else
1100 #define SPDYF_CONTROL_FRAME_HTON(frame) do { \
1101 	(*((uint16_t *) frame  )) = (*((uint8_t *) (frame) +1 )) | ((*((uint8_t *) frame  ))<<8);\
1102 	(frame)->type = htons((frame)->type); \
1103 	(frame)->length = HTON24((frame)->length); \
1104 	} while (0)
1105 #endif
1106 
1107 
1108 /**
1109  * Convert all integers in a SPDY control frame headers structure from
1110  * network byte order to host byte order.
1111  *
1112  * @param frame input and output structure (struct SPDY_Control_Frame *)
1113  */
1114 #if HAVE_BIG_ENDIAN
1115 #define SPDYF_CONTROL_FRAME_NTOH(frame)
1116 #else
1117 #define SPDYF_CONTROL_FRAME_NTOH(frame) do { \
1118 	(*((uint16_t *) frame  )) = (*((uint8_t *) (frame) +1 )) | ((*((uint8_t *) frame  ))<<8);\
1119 	(frame)->type = ntohs((frame)->type); \
1120 	(frame)->length = NTOH24((frame)->length); \
1121 	} while (0)
1122 #endif
1123 
1124 
1125 /**
1126  * Convert all integers in a SPDY data frame headers structure from
1127  * host byte order to network byte order.
1128  *
1129  * @param frame input and output structure (struct SPDY_Data_Frame *)
1130  */
1131 #if HAVE_BIG_ENDIAN
1132 #define SPDYF_DATA_FRAME_HTON(frame)
1133 #else
1134 #define SPDYF_DATA_FRAME_HTON(frame) do { \
1135 	*((uint32_t *) frame  ) = htonl(*((uint32_t *) frame  ));\
1136 	(frame)->length = HTON24((frame)->length); \
1137 	} while (0)
1138 #endif
1139 
1140 
1141 /**
1142  * Convert all integers in a SPDY data frame headers structure from
1143  * network byte order to host byte order.
1144  *
1145  * @param frame input and output structure (struct SPDY_Data_Frame *)
1146  */
1147 #if HAVE_BIG_ENDIAN
1148 #define SPDYF_DATA_FRAME_NTOH(frame)
1149 #else
1150 #define SPDYF_DATA_FRAME_NTOH(frame) do { \
1151 	*((uint32_t *) frame  ) = ntohl(*((uint32_t *) frame  ));\
1152 	(frame)->length = NTOH24((frame)->length); \
1153 	} while (0)
1154 #endif
1155 
1156 
1157 /**
1158  * Creates one or more new SPDYF_Response_Queue object to be put on the
1159  * response queue.
1160  *
1161  * @param is_data whether new data frame or new control frame will be
1162  *                crerated
1163  * @param data the row stream which will be used as the body of the frame
1164  * @param data_size length of data
1165  * @param response object, part of which is the frame
1166  * @param stream on which data is to be sent
1167  * @param closestream TRUE if the frame must close the stream (with flag)
1168  * @param frqcb callback to notify application layer when the frame
1169  *              has been sent or discarded
1170  * @param frqcb_cls closure for frqcb
1171  * @param rrcb callback used by the application layer to notify the
1172  *             application when the frame has been sent or discarded.
1173  *             frqcb will call it
1174  * @param rrcb_cls closure for rrcb
1175  * @return double linked list of SPDYF_Response_Queue structures: one or
1176  *         more frames are returned based on the size of the data
1177  */
1178 struct SPDYF_Response_Queue *
1179 SPDYF_response_queue_create(bool is_data,
1180 						void *data,
1181 						size_t data_size,
1182 						struct SPDY_Response *response,
1183 						struct SPDYF_Stream *stream,
1184 						bool closestream,
1185 						SPDYF_ResponseQueueResultCallback frqcb,
1186 						void *frqcb_cls,
1187 						SPDY_ResponseResultCallback rrcb,
1188 						void *rrcb_cls);
1189 
1190 
1191 /**
1192  * Destroys SPDYF_Response_Queue structure and whatever is in it.
1193  *
1194  * @param response_queue to destroy
1195  */
1196 void
1197 SPDYF_response_queue_destroy(struct SPDYF_Response_Queue *response_queue);
1198 
1199 
1200 /**
1201  * Checks if the container is empty, i.e. created but no values were
1202  * added to it.
1203  *
1204  * @param container
1205  * @return SPDY_YES if empty
1206  *         SPDY_NO if not
1207  */
1208 int
1209 SPDYF_name_value_is_empty(struct SPDY_NameValue *container);
1210 
1211 
1212 /**
1213  * Transforms raw binary decomressed stream of headers
1214  * into SPDY_NameValue, containing all of the headers and values.
1215  *
1216  * @param stream that is to be transformed
1217  * @param size length of the stream
1218  * @param container will contain the newly created SPDY_NameValue
1219  *        container. Should point to NULL.
1220  * @return SPDY_YES on success
1221  *         SPDY_NO on memory error
1222  *         SPDY_INPUT_ERROR if the provided stream is not valid
1223  */
1224 int
1225 SPDYF_name_value_from_stream(void *stream,
1226 							size_t size,
1227 							struct SPDY_NameValue ** container);
1228 
1229 
1230 /**
1231  * Transforms array of objects of name/values tuples, containing HTTP
1232  * headers, into raw binary stream. The resulting stream is ready to
1233  * be compressed and sent.
1234  *
1235  * @param container one or more SPDY_NameValue objects. Each object
1236  *        contains multiple number of name/value tuples.
1237  * @param num_containers length of the array
1238  * @param stream will contain the resulting stream. Should point to NULL.
1239  * @return length of stream or value less than 0 indicating error
1240  */
1241 ssize_t
1242 SPDYF_name_value_to_stream(struct SPDY_NameValue * container[],
1243 							int num_containers,
1244 							void **stream);
1245 
1246 #endif
1247