lsquic_stream.h revision 02b6086d
1/* Copyright (c) 2017 - 2019 LiteSpeed Technologies Inc.  See LICENSE. */
2#ifndef LSQUIC_STREAM_H
3#define LSQUIC_STREAM_H
4
5#define LSQUIC_GQUIC_STREAM_HANDSHAKE 1
6#define LSQUIC_GQUIC_STREAM_HEADERS   3
7
8#define LSQUIC_STREAM_DEFAULT_PRIO 16   /* RFC 7540, Section 5.3.5 */
9
10
11struct lsquic_stream_if;
12struct lsquic_stream_ctx;
13struct lsquic_conn_public;
14struct stream_frame;
15struct uncompressed_headers;
16enum enc_level;
17enum swtp_status;
18struct frame_gen_ctx;
19struct data_frame;
20enum quic_frame_type;
21struct push_promise;
22
23TAILQ_HEAD(lsquic_streams_tailq, lsquic_stream);
24
25
26#ifndef LSQUIC_KEEP_STREAM_HISTORY
27#   ifdef NDEBUG
28#       define LSQUIC_KEEP_STREAM_HISTORY 0
29#   else
30#       define LSQUIC_KEEP_STREAM_HISTORY 1
31#   endif
32#endif
33
34
35#if LSQUIC_KEEP_STREAM_HISTORY
36#define SM_HIST_BITS 6
37#define SM_HIST_IDX_MASK ((1 << SM_HIST_BITS) - 1)
38typedef unsigned char sm_hist_idx_t;
39#endif
40
41
42/*
43 *  +----------+----------------------------------+
44 *  | Low Bits | Stream Type                      |
45 *  +----------+----------------------------------+
46 *  | 0x0      | Client-Initiated, Bidirectional  |
47 *  |          |                                  |
48 *  | 0x1      | Server-Initiated, Bidirectional  |
49 *  |          |                                  |
50 *  | 0x2      | Client-Initiated, Unidirectional |
51 *  |          |                                  |
52 *  | 0x3      | Server-Initiated, Unidirectional |
53 *  +----------+----------------------------------+
54 */
55
56enum stream_id_type
57{
58    SIT_BIDI_CLIENT,
59    SIT_BIDI_SERVER,
60    SIT_UNI_CLIENT,
61    SIT_UNI_SERVER,
62    N_SITS
63};
64
65#define SIT_MASK (N_SITS - 1)
66
67#define SIT_SHIFT 2
68#define SD_SHIFT 1
69
70enum stream_dir { SD_BIDI, SD_UNI, N_SDS };
71
72
73struct stream_hq_frame
74{
75    STAILQ_ENTRY(stream_hq_frame)
76                        shf_next;
77    /* At which point in the stream (sm_payload) to insert the HQ frame. */
78    uint64_t            shf_off;
79    union {
80        /* Points to the frame if SHF_FIXED_SIZE is not set */
81        unsigned char  *frame_ptr;
82        /* If SHF_FIXED_SIZE is set, the size of the frame to follow.
83         * Non-fixed frame size gets calculated using sm_payload when they
84         * are closed.
85         */
86        size_t          frame_size;
87    }                   shf_u;
88#define shf_frame_ptr shf_u.frame_ptr
89#define shf_frame_size shf_u.frame_size
90    enum hq_frame_type  shf_frame_type:8;
91    enum shf_flags {
92        SHF_TWO_BYTES   = 1 << 0,   /* Use two byte to encode frame length */
93        SHF_FIXED_SIZE  = 1 << 1,   /* Payload size guaranteed */
94        SHF_ACTIVE      = 1 << 2,   /* On sm_hq_frames list */
95        SHF_WRITTEN     = 1 << 3,   /* Framing bytes have been packetized */
96        SHF_CC_PAID     = 1 << 4,   /* Paid connection cap */
97        SHF_PHANTOM     = 1 << 5,   /* Phantom frame headers are not written */
98    }                   shf_flags:8;
99};
100
101
102struct hq_filter
103{
104    struct varint_read2_state   hqfi_vint2_state;
105    /* No need to copy the values: use it directly */
106#define hqfi_left hqfi_vint2_state.vr2s_two
107#define hqfi_type hqfi_vint2_state.vr2s_one
108    struct varint_read_state    hqfi_vint1_state;
109#define hqfi_push_id hqfi_vint1_state.value
110    enum {
111        HQFI_FLAG_UNUSED_0      = 1 << 0,
112        HQFI_FLAG_ERROR         = 1 << 1,
113        HQFI_FLAG_BEGIN         = 1 << 2,
114        HQFI_FLAG_BLOCKED       = 1 << 3,
115    }                           hqfi_flags:8;
116    enum {
117        HQFI_STATE_FRAME_HEADER_BEGIN,
118        HQFI_STATE_FRAME_HEADER_CONTINUE,
119        HQFI_STATE_READING_PAYLOAD,
120        HQFI_STATE_PUSH_ID_BEGIN,
121        HQFI_STATE_PUSH_ID_CONTINUE,
122    }                           hqfi_state:8;
123    unsigned char               hqfi_hist_idx;
124#define MAX_HQFI_ENTRIES (sizeof(unsigned) * 8 / 3)
125    unsigned                    hqfi_hist_buf;
126};
127
128
129struct stream_filter_if
130{
131    int         (*sfi_readable)(struct lsquic_stream *);
132    size_t      (*sfi_filter_df)(struct lsquic_stream *, struct data_frame *);
133    void        (*sfi_decr_left)(struct lsquic_stream *, size_t);
134};
135
136
137/* These flags indicate which queues -- or other entities -- currently
138 * reference the stream.
139 */
140enum stream_q_flags
141{
142    /* read_streams: */
143    SMQF_WANT_READ    = 1 << 0,
144
145    /* write_streams: */
146#define SMQF_WRITE_Q_FLAGS (SMQF_WANT_FLUSH|SMQF_WANT_WRITE)
147    SMQF_WANT_WRITE   = 1 << 1,
148    SMQF_WANT_FLUSH   = 1 << 2,     /* Flush until sm_flush_to is hit */
149
150    /* There are more than one reason that a stream may be put onto
151     * connections's sending_streams queue.  Note that writing STREAM
152     * frames is done separately.
153     */
154#define SMQF_SENDING_FLAGS (SMQF_SEND_WUF|SMQF_SEND_RST|SMQF_SEND_BLOCKED)
155    /* sending_streams: */
156    SMQF_SEND_WUF     = 1 << 3,     /* WUF: Window Update Frame */
157    SMQF_SEND_BLOCKED = 1 << 4,
158    SMQF_SEND_RST     = 1 << 5,     /* Error: want to send RST_STREAM */
159
160    /* The equivalent of WINDOW_UPDATE frame for streams in IETF QUIC is
161     * the MAX_STREAM_DATA frame.  Define an alias for use in the IETF
162     * QUIC code:
163     */
164#define SMQF_SEND_MAX_STREAM_DATA SMQF_SEND_WUF
165
166#define SMQF_SERVICE_FLAGS (SMQF_CALL_ONCLOSE|SMQF_FREE_STREAM|SMQF_ABORT_CONN)
167    SMQF_CALL_ONCLOSE = 1 << 6,
168    SMQF_FREE_STREAM  = 1 << 7,
169    SMQF_ABORT_CONN   = 1 << 8,     /* Unrecoverable error occurred */
170
171    SMQF_QPACK_DEC    = 1 << 9,     /* QPACK decoder is holding a reference to this stream */
172};
173
174
175/* Stream behavior flags */
176enum stream_b_flags
177{
178    SMBF_SERVER       = 1 << 0,
179    SMBF_IETF         = 1 << 1,
180    SMBF_USE_HEADERS  = 1 << 2,
181    SMBF_CRYPTO       = 1 << 3,
182    SMBF_CRITICAL     = 1 << 4,  /* This is a critical stream */
183    SMBF_AUTOSWITCH   = 1 << 5,
184    SMBF_RW_ONCE      = 1 << 6,  /* When set, read/write events are dispatched once per call */
185    SMBF_CONN_LIMITED = 1 << 7,
186#define N_SMBF_FLAGS 8
187};
188
189
190enum stream_flags {
191    STREAM_FIN_RECVD    = 1 << 0,   /* Received STREAM frame with FIN bit set */
192    STREAM_RST_RECVD    = 1 << 1,   /* Received RST frame */
193    STREAM_LAST_WRITE_OK= 1 << 2,   /* Used to break out of write event dispatch loop */
194    STREAM_U_READ_DONE  = 1 << 3,   /* User is done reading (shutdown was called) */
195    STREAM_U_WRITE_DONE = 1 << 4,   /* User is done writing (shutdown was called) */
196    STREAM_FIN_SENT     = 1 << 5,   /* FIN was written to network */
197    STREAM_RST_SENT     = 1 << 6,   /* RST_STREAM was written to network */
198    STREAM_FIN_REACHED  = 1 << 7,   /* User read data up to FIN */
199    STREAM_FINISHED     = 1 << 8,   /* Stream is finished */
200    STREAM_ONCLOSE_DONE = 1 << 9,   /* on_close has been called */
201    STREAM_CACHED_FRAME = 1 << 10,  /* If set, sm_has_frame can be used */
202    STREAM_HEADERS_SENT = 1 << 11,
203    STREAM_HAVE_UH      = 1 << 12,  /* Have uncompressed headers */
204    STREAM_ENCODER_DEP  = 1 << 13,  /* Encoder dependency: flush (IETF only) */
205    STREAM_HEAD_IN_FIN  = 1 << 14,  /* Incoming headers has FIN bit set */
206    STREAM_FRAMES_ELIDED= 1 << 15,
207    STREAM_FORCE_FINISH = 1 << 16,  /* Replaces FIN sent and received */
208    STREAM_ONNEW_DONE   = 1 << 17,  /* on_new_stream has been called */
209    STREAM_PUSHING      = 1 << 18,
210    STREAM_NOPUSH       = 1 << 19,  /* Disallow further push promises */
211    STREAM_UNUSED20     = 1 << 20,  /* Unused */
212    STREAM_UNUSED21     = 1 << 21,  /* Unused */
213    STREAM_RST_ACKED    = 1 << 22,  /* Packet containing RST has been acked */
214    STREAM_BLOCKED_SENT = 1 << 23,  /* Stays set once a STREAM_BLOCKED frame is sent */
215    STREAM_RST_READ     = 1 << 24,  /* User code collected the error */
216    STREAM_DATA_RECVD   = 1 << 25,  /* Cache stream state calculation */
217    STREAM_UNUSED26     = 1 << 26,  /* Unused */
218    STREAM_HDRS_FLUSHED = 1 << 27,  /* Only used in buffered packets mode */
219    STREAM_SS_RECVD     = 1 << 28,  /* Received STOP_SENDING frame */
220    STREAM_DELAYED_SW   = 1 << 29,  /* Delayed shutdown_write call */
221};
222
223
224/* By keeping this number low, we make sure that the code to allocate HQ
225 * frames dynamically gets exercised whenever push promises are sent.
226 */
227#define NUM_ALLOCED_HQ_FRAMES 2
228
229
230struct lsquic_stream
231{
232    struct lsquic_hash_elem         sm_hash_el;
233    lsquic_stream_id_t              id;
234    enum stream_flags               stream_flags;
235    enum stream_b_flags             sm_bflags;
236    enum stream_q_flags             sm_qflags;
237    unsigned                        n_unacked;
238
239    const struct lsquic_stream_if  *stream_if;
240    struct lsquic_stream_ctx       *st_ctx;
241    struct lsquic_conn_public      *conn_pub;
242    TAILQ_ENTRY(lsquic_stream)      next_send_stream, next_read_stream,
243                                        next_write_stream, next_service_stream,
244                                        next_prio_stream;
245
246    uint64_t                        tosend_off;
247    uint64_t                        sm_payload;     /* Not counting HQ frames */
248    uint64_t                        max_send_off;
249    uint64_t                        sm_last_recv_off;
250    uint64_t                        error_code;
251
252    /* From the network, we get frames, which we keep on a list ordered
253     * by offset.
254     */
255    struct data_in                 *data_in;
256    uint64_t                        read_offset;
257    lsquic_sfcw_t                   fc;
258
259    /* List of active HQ frames */
260    STAILQ_HEAD(, stream_hq_frame)  sm_hq_frames;
261
262    /* For efficiency, several frames are allocated as part of the stream
263     * itself.  If more frames are needed, they are allocated.
264     */
265    struct stream_hq_frame          sm_hq_frame_arr[NUM_ALLOCED_HQ_FRAMES];
266
267    struct hq_filter                sm_hq_filter;
268
269    /* We can safely use sm_hq_filter */
270#define sm_uni_type_state sm_hq_filter.hqfi_vint2_state.vr2s_varint_state
271
272    /** If @ref SMQF_WANT_FLUSH is set, flush until this offset. */
273    uint64_t                        sm_flush_to;
274
275    /**
276     * If @ref SMQF_WANT_FLUSH is set, this indicates payload offset
277     * to flush to.  Used to adjust @ref sm_flush_to when H3 frame
278     * size grows.
279     */
280    uint64_t                        sm_flush_to_payload;
281
282    /* Last offset sent in BLOCKED frame */
283    uint64_t                        blocked_off;
284
285    struct uncompressed_headers    *uh,
286                                   *push_req;
287
288    unsigned char                  *sm_buf;
289    void                           *sm_onnew_arg;
290
291    unsigned char                  *sm_header_block;
292    uint64_t                        sm_hb_compl;
293
294    /* Valid if STREAM_FIN_RECVD is set: */
295    uint64_t                        sm_fin_off;
296
297    /* A stream may be generating STREAM or CRYPTO frames */
298    size_t                        (*sm_frame_header_sz)(
299                                        const struct lsquic_stream *, unsigned);
300    enum swtp_status              (*sm_write_to_packet)(struct frame_gen_ctx *,
301                                                const size_t);
302    size_t                        (*sm_write_avail)(struct lsquic_stream *);
303    int                           (*sm_readable)(struct lsquic_stream *);
304
305    /* This element is optional */
306    const struct stream_filter_if  *sm_sfi;
307
308    /* sm_promise and sm_promises are never used at the same time and can
309     * be combined into a union should space in this struct become tight.
310     */
311    /* Push promise that engendered this push stream */
312    struct push_promise            *sm_promise;
313
314    /* Push promises sent on this stream */
315    SLIST_HEAD(, push_promise)      sm_promises;
316
317    uint64_t                        sm_last_frame_off;
318
319    /* How much data there is in sm_header_block and how much of it has been
320     * sent:
321     */
322    unsigned                        sm_hblock_sz,
323                                    sm_hblock_off;
324
325    unsigned short                  sm_n_buffered;  /* Amount of data in sm_buf */
326    unsigned short                  sm_n_allocated;  /* Size of sm_buf */
327
328    unsigned char                   sm_priority;  /* 0: high; 255: low */
329    unsigned char                   sm_enc_level;
330    enum {
331        SSHS_BEGIN,         /* Nothing has happened yet */
332        SSHS_ENC_SENDING,   /* Sending encoder stream data */
333        SSHS_HBLOCK_SENDING,/* Sending header block data */
334    }                               sm_send_headers_state:8;
335    signed char                     sm_saved_want_write;
336    signed char                     sm_has_frame;
337
338    unsigned char                   sm_dup_push_off;
339    unsigned char                   sm_dup_push_len;
340    unsigned char                   sm_dup_push_buf[8];
341
342#if LSQUIC_KEEP_STREAM_HISTORY
343    sm_hist_idx_t                   sm_hist_idx;
344#endif
345
346#if LSQUIC_KEEP_STREAM_HISTORY
347    /* Stream history: see enum stream_history_event */
348    unsigned char                   sm_hist_buf[ 1 << SM_HIST_BITS ];
349#endif
350};
351
352
353enum stream_ctor_flags
354{
355    SCF_CALL_ON_NEW   = (1 << (N_SMBF_FLAGS + 0)), /* Call on_new_stream() immediately */
356    SCF_USE_DI_HASH   = (1 << (N_SMBF_FLAGS + 1)), /* Use hash-based data input.  If not set,
357                                   * the nocopy data input is used.
358                                   */
359    SCF_DI_AUTOSWITCH = SMBF_AUTOSWITCH, /* Automatically switch between nocopy
360                                   * and hash-based to data input for optimal
361                                   * performance.
362                                   */
363    SCF_DISP_RW_ONCE  = SMBF_RW_ONCE,
364    SCF_CRITICAL      = SMBF_CRITICAL, /* This is a critical stream */
365    SCF_IETF          = SMBF_IETF,
366    SCF_HTTP          = SMBF_USE_HEADERS,
367};
368
369
370lsquic_stream_t *
371lsquic_stream_new (lsquic_stream_id_t id, struct lsquic_conn_public *,
372                   const struct lsquic_stream_if *, void *stream_if_ctx,
373                   unsigned initial_sfrw, uint64_t initial_send_off,
374                   enum stream_ctor_flags);
375
376struct lsquic_stream *
377lsquic_stream_new_crypto (enum enc_level,
378        struct lsquic_conn_public *conn_pub,
379        const struct lsquic_stream_if *stream_if, void *stream_if_ctx,
380        enum stream_ctor_flags ctor_flags);
381
382void
383lsquic_stream_call_on_new (lsquic_stream_t *);
384
385void
386lsquic_stream_destroy (lsquic_stream_t *);
387
388/* Any of these flags will cause user-facing read and write and
389 * shutdown calls to return an error.  They also make the stream
390 * both readable and writeable, as we want the user to collect
391 * the error.
392 */
393#define lsquic_stream_is_reset(stream) \
394    (((stream)->stream_flags & \
395                    (STREAM_RST_RECVD|STREAM_RST_SENT|STREAM_SS_RECVD)) \
396        || ((stream)->sm_qflags & SMQF_SEND_RST))
397
398/* Data that from the network gets inserted into the stream using
399 * lsquic_stream_frame_in() function.  Returns 0 on success, -1 on
400 * failure.  The latter may be caused by flow control violation or
401 * invalid stream frame data, e.g. overlapping segments.
402 *
403 * Note that the caller does gives up control of `frame' no matter
404 * what this function returns.
405 *
406 * This data is read by the user using lsquic_stream_read() function.
407 */
408int
409lsquic_stream_frame_in (lsquic_stream_t *, struct stream_frame *frame);
410
411/* Only one (at least for now) uncompressed header structure is allowed to be
412 * passed in, and only in HTTP mode.
413 */
414int
415lsquic_stream_uh_in (lsquic_stream_t *, struct uncompressed_headers *);
416
417void
418lsquic_stream_push_req (lsquic_stream_t *,
419                        struct uncompressed_headers *push_req);
420
421int
422lsquic_stream_rst_in (lsquic_stream_t *, uint64_t offset, uint64_t error_code);
423
424void
425lsquic_stream_stop_sending_in (struct lsquic_stream *, uint64_t error_code);
426
427ssize_t
428lsquic_stream_read (lsquic_stream_t *stream, void *buf, size_t len);
429
430uint64_t
431lsquic_stream_read_offset (const lsquic_stream_t *stream);
432
433/* Return true if we sent all available data to the network and write
434 * end of the stream was closed.
435 */
436int
437lsquic_stream_tosend_fin (const lsquic_stream_t *stream);
438
439/* Data to be sent out to the network is written using lsquic_stream_write().
440 */
441ssize_t
442lsquic_stream_write (lsquic_stream_t *stream, const void *buf, size_t len);
443
444void
445lsquic_stream_window_update (lsquic_stream_t *stream, uint64_t offset);
446
447int
448lsquic_stream_set_max_send_off (lsquic_stream_t *stream, uint64_t offset);
449
450/* The caller should only call this function if SMQF_SEND_WUF is set and
451 * it must generate a window update frame using this value.
452 */
453uint64_t
454lsquic_stream_fc_recv_off (lsquic_stream_t *stream);
455
456void
457lsquic_stream_peer_blocked (struct lsquic_stream *, uint64_t);
458
459void
460lsquic_stream_peer_blocked_gquic (struct lsquic_stream *);
461
462void
463lsquic_stream_dispatch_read_events (lsquic_stream_t *);
464
465void
466lsquic_stream_dispatch_write_events (lsquic_stream_t *);
467
468void
469lsquic_stream_blocked_frame_sent (lsquic_stream_t *);
470
471void
472lsquic_stream_rst_frame_sent (lsquic_stream_t *);
473
474void
475lsquic_stream_stream_frame_sent (lsquic_stream_t *);
476
477void
478lsquic_stream_reset (lsquic_stream_t *, uint64_t error_code);
479
480void
481lsquic_stream_reset_ext (lsquic_stream_t *, uint64_t error_code, int close);
482
483void
484lsquic_stream_call_on_close (lsquic_stream_t *);
485
486void
487lsquic_stream_shutdown_internal (lsquic_stream_t *);
488
489void
490lsquic_stream_received_goaway (lsquic_stream_t *);
491
492void
493lsquic_stream_acked (struct lsquic_stream *, enum quic_frame_type);
494
495#define lsquic_stream_is_closed(s)                                          \
496    (((s)->stream_flags & (STREAM_U_READ_DONE|STREAM_U_WRITE_DONE))         \
497                            == (STREAM_U_READ_DONE|STREAM_U_WRITE_DONE))
498int
499lsquic_stream_update_sfcw (lsquic_stream_t *, uint64_t max_off);
500
501int
502lsquic_stream_set_priority_internal (lsquic_stream_t *, unsigned priority);
503
504int
505lsquic_stream_id_is_critical (int use_http, lsquic_stream_id_t);
506
507int
508lsquic_stream_is_critical (const struct lsquic_stream *);
509
510size_t
511lsquic_stream_mem_used (const struct lsquic_stream *);
512
513const lsquic_cid_t *
514lsquic_stream_cid (const struct lsquic_stream *);
515
516#define lsquic_stream_has_data_to_flush(stream) ((stream)->sm_n_buffered > 0)
517
518int
519lsquic_stream_readable (struct lsquic_stream *);
520
521size_t
522lsquic_stream_write_avail (struct lsquic_stream *);
523
524void
525lsquic_stream_dump_state (const struct lsquic_stream *);
526
527#ifndef NDEBUG
528size_t
529lsquic_stream_flush_threshold (const struct lsquic_stream *, unsigned);
530#endif
531
532#define crypto_level(stream) (~0ULL - (stream)->id)
533
534void
535lsquic_stream_set_stream_if (struct lsquic_stream *,
536                   const struct lsquic_stream_if *, void *stream_if_ctx);
537
538struct qpack_dec_hdl *
539lsquic_stream_get_qdh (const struct lsquic_stream *);
540
541uint64_t
542lsquic_stream_combined_send_off (const struct lsquic_stream *);
543
544/* [draft-ietf-quic-transport-16] Section 3.1 */
545enum stream_state_sending
546{
547    SSS_READY,
548    SSS_SEND,
549    SSS_DATA_SENT,
550    SSS_RESET_SENT,
551    SSS_DATA_RECVD,
552    SSS_RESET_RECVD,
553};
554
555extern const char *const lsquic_sss2str[];
556
557enum stream_state_sending
558lsquic_stream_sending_state (const struct lsquic_stream *);
559
560/* [draft-ietf-quic-transport-16] Section 3.2 */
561enum stream_state_receiving
562{
563    SSR_RECV,
564    SSR_SIZE_KNOWN,
565    SSR_DATA_RECVD,
566    SSR_RESET_RECVD,
567    SSR_DATA_READ,
568    SSR_RESET_READ,
569};
570
571extern const char *const lsquic_ssr2str[];
572
573enum stream_state_receiving
574lsquic_stream_receiving_state (struct lsquic_stream *);
575
576uint64_t
577lsquic_stream_fc_recv_off_const (const struct lsquic_stream *);
578
579void
580lsquic_stream_max_stream_data_sent (struct lsquic_stream *);
581
582void
583lsquic_stream_qdec_unblocked (struct lsquic_stream *);
584
585int
586lsquic_stream_can_push (const struct lsquic_stream *);
587
588int
589lsquic_stream_duplicate_push (struct lsquic_stream *, uint64_t push_id);
590
591int
592lsquic_stream_push_promise (struct lsquic_stream *, struct push_promise *);
593
594void
595lsquic_stream_force_finish (struct lsquic_stream *);
596
597int
598lsquic_stream_header_is_pp (const struct lsquic_stream *);
599
600int
601lsquic_stream_header_is_trailer (const struct lsquic_stream *);
602
603#endif
604