lsquic_stream.h revision 04468d21 
1/* Copyright (c) 2017 - 2018 LiteSpeed Technologies Inc.  See LICENSE. */
2#ifndef LSQUIC_STREAM_H
3#define LSQUIC_STREAM_H
4
5#define LSQUIC_STREAM_HANDSHAKE 1
6#define LSQUIC_STREAM_HEADERS   3
7
8#define LSQUIC_STREAM_DEFAULT_PRIO 16   /* RFC 7540, Section 5.3.5 */
9
10struct lsquic_stream_if;
11struct lsquic_stream_ctx;
12struct lsquic_conn_public;
13struct stream_frame;
14struct uncompressed_headers;
15
16TAILQ_HEAD(lsquic_streams_tailq, lsquic_stream);
17
18#ifndef LSQUIC_KEEP_STREAM_HISTORY
19#   ifdef NDEBUG
20#       define LSQUIC_KEEP_STREAM_HISTORY 0
21#   else
22#       define LSQUIC_KEEP_STREAM_HISTORY 1
23#   endif
24#endif
25
26#if LSQUIC_KEEP_STREAM_HISTORY
27#define SM_HIST_BITS 6
28#define SM_HIST_IDX_MASK ((1 << SM_HIST_BITS) - 1)
29typedef unsigned char sm_hist_idx_t;
30#endif
31
32struct lsquic_stream
33{
34    uint32_t                        id;
35    enum stream_flags {
36        STREAM_WANT_READ    = (1 << 0),
37        STREAM_WANT_WRITE   = (1 << 1),
38        STREAM_FIN_RECVD    = (1 << 2),     /* Received STREAM frame with FIN bit set */
39        STREAM_RST_RECVD    = (1 << 3),     /* Received RST frame */
40        STREAM_SEND_WUF     = (1 << 4),     /* WUF: Window Update Frame */
41        STREAM_LAST_WRITE_OK= (1 << 5),     /* Used to break out of write event dispatch loop */
42        STREAM_SEND_BLOCKED = (1 << 6),
43        STREAM_SEND_RST     = (1 << 7),     /* Error: want to send RST_STREAM */
44        STREAM_U_READ_DONE  = (1 << 8),     /* User is done reading (shutdown was called) */
45        STREAM_U_WRITE_DONE = (1 << 9),     /* User is done writing (shutdown was called) */
46        STREAM_FIN_SENT     = (1 <<10),     /* FIN was written to network */
47        STREAM_RST_SENT     = (1 <<11),     /* RST_STREAM was written to network */
48        STREAM_WANT_FLUSH   = (1 <<12),     /* Flush until sm_flush_to is hit */
49        STREAM_FIN_REACHED  = (1 <<13),     /* User read data up to FIN */
50        STREAM_FINISHED     = (1 <<14),     /* Stream is finished */
51        STREAM_ONCLOSE_DONE = (1 <<15),     /* on_close has been called */
52        STREAM_CALL_ONCLOSE = (1 <<16),
53        STREAM_FREE_STREAM  = (1 <<17),
54        STREAM_USE_HEADERS  = (1 <<18),
55        STREAM_HEADERS_SENT = (1 <<19),
56        STREAM_HAVE_UH      = (1 <<20),     /* Have uncompressed headers */
57        STREAM_CONN_LIMITED = (1 <<21),
58        STREAM_HEAD_IN_FIN  = (1 <<22),     /* Incoming headers has FIN bit set */
59        STREAM_ABORT_CONN   = (1 <<23),     /* Unrecoverable error occurred */
60        STREAM_FRAMES_ELIDED= (1 <<24),
61        STREAM_FORCE_FINISH = (1 <<25),     /* Replaces FIN sent and received */
62        STREAM_ONNEW_DONE   = (1 <<26),     /* on_new_stream has been called */
63        STREAM_AUTOSWITCH   = (1 <<27),
64        STREAM_RW_ONCE      = (1 <<28),     /* When set, read/write events are dispatched once per call */
65        STREAM_ALLOW_OVERLAP= (1 <<29),
66    }                               stream_flags;
67
68    /* There are more than one reason that a stream may be put onto
69     * connections's sending_streams queue.  Note that writing STREAM
70     * frames is done separately.
71     */
72    #define STREAM_SENDING_FLAGS (STREAM_SEND_WUF| \
73                                          STREAM_SEND_RST|STREAM_SEND_BLOCKED)
74
75    #define STREAM_WRITE_Q_FLAGS (STREAM_WANT_FLUSH|STREAM_WANT_WRITE)
76
77    /* Any of these flags will cause user-facing read and write and
78     * shutdown calls to return an error.  They also make the stream
79     * both readable and writeable, as we want the user to collect
80     * the error.
81     */
82    #define STREAM_RST_FLAGS (STREAM_RST_RECVD|STREAM_RST_SENT|\
83                                                        STREAM_SEND_RST)
84
85    #define STREAM_SERVICE_FLAGS (STREAM_CALL_ONCLOSE|STREAM_FREE_STREAM|\
86                                                            STREAM_ABORT_CONN)
87
88    const struct lsquic_stream_if  *stream_if;
89    struct lsquic_stream_ctx       *st_ctx;
90    struct lsquic_conn_public      *conn_pub;
91    TAILQ_ENTRY(lsquic_stream)      next_send_stream, next_read_stream,
92                                        next_write_stream, next_service_stream,
93                                        next_prio_stream;
94
95    uint32_t                        error_code;
96    uint64_t                        tosend_off;
97    uint64_t                        max_send_off;
98
99    /* From the network, we get frames, which we keep on a list ordered
100     * by offset.
101     */
102    struct data_in                 *data_in;
103    uint64_t                        read_offset;
104    lsquic_sfcw_t                   fc;
105
106    /** If @ref STREAM_WANT_FLUSH is set, flush until this offset. */
107    uint64_t                        sm_flush_to;
108
109    /* Last offset sent in BLOCKED frame */
110    uint64_t                        blocked_off;
111
112    struct uncompressed_headers    *uh,
113                                   *push_req;
114
115    unsigned char                  *sm_buf;
116    void                           *sm_onnew_arg;
117
118    unsigned                        n_unacked;
119    unsigned short                  sm_n_buffered;  /* Amount of data in sm_buf */
120
121    unsigned char                   sm_priority;  /* 0: high; 255: low */
122#if LSQUIC_KEEP_STREAM_HISTORY
123    sm_hist_idx_t                   sm_hist_idx;
124#endif
125
126#if LSQUIC_KEEP_STREAM_HISTORY
127    /* Stream history: see enum stream_history_event */
128    unsigned char                   sm_hist_buf[ 1 << SM_HIST_BITS ];
129#endif
130};
131
132enum stream_ctor_flags
133{
134    SCF_CALL_ON_NEW   = (1 << 0), /* Call on_new_stream() immediately */
135    SCF_USE_DI_HASH   = (1 << 1), /* Use hash-based data input.  If not set,
136                                   * the nocopy data input is used.
137                                   */
138    SCF_DI_AUTOSWITCH = (1 << 2), /* Automatically switch between nocopy
139                                   * and hash-based to data input for optimal
140                                   * performance.
141                                   */
142    SCF_DISP_RW_ONCE  = (1 << 3),
143    SCF_ALLOW_OVERLAP = (1 << 4), /* Allow STREAM frames to overlap */
144};
145
146lsquic_stream_t *
147lsquic_stream_new_ext (uint32_t id, struct lsquic_conn_public *conn_pub,
148                       const struct lsquic_stream_if *, void *stream_if_ctx,
149                       unsigned initial_sfrw, unsigned initial_send_off,
150                       enum stream_ctor_flags);
151
152#define lsquic_stream_new(id, pub, sm_if, sm_if_ctx, cfcw, send_off)        \
153        lsquic_stream_new_ext(id, pub, sm_if, sm_if_ctx, cfcw, send_off,    \
154                              (SCF_CALL_ON_NEW|SCF_DI_AUTOSWITCH))
155
156void
157lsquic_stream_call_on_new (lsquic_stream_t *);
158
159void
160lsquic_stream_destroy (lsquic_stream_t *);
161
162#define lsquic_stream_is_reset(stream) \
163    (!!((stream)->stream_flags & STREAM_RST_FLAGS))
164
165/* Data that from the network gets inserted into the stream using
166 * lsquic_stream_frame_in() function.  Returns 0 on success, -1 on
167 * failure.  The latter may be caused by flow control violation or
168 * invalid stream frame data, e.g. overlapping segments.
169 *
170 * Note that the caller does gives up control of `frame' no matter
171 * what this function returns.
172 *
173 * This data is read by the user using lsquic_stream_read() function.
174 */
175int
176lsquic_stream_frame_in (lsquic_stream_t *, struct stream_frame *frame);
177
178/* Only one (at least for now) uncompressed header structure is allowed to be
179 * passed in, and only in HTTP mode.
180 */
181int
182lsquic_stream_uh_in (lsquic_stream_t *, struct uncompressed_headers *);
183
184void
185lsquic_stream_push_req (lsquic_stream_t *,
186                        struct uncompressed_headers *push_req);
187
188int
189lsquic_stream_rst_in (lsquic_stream_t *, uint64_t offset, uint32_t error_code);
190
191ssize_t
192lsquic_stream_read (lsquic_stream_t *stream, void *buf, size_t len);
193
194uint64_t
195lsquic_stream_read_offset (const lsquic_stream_t *stream);
196
197/* Return true if we sent all available data to the network and write
198 * end of the stream was closed.
199 */
200int
201lsquic_stream_tosend_fin (const lsquic_stream_t *stream);
202
203/* Data to be sent out to the network is written using lsquic_stream_write().
204 */
205ssize_t
206lsquic_stream_write (lsquic_stream_t *stream, const void *buf, size_t len);
207
208void
209lsquic_stream_window_update (lsquic_stream_t *stream, uint64_t offset);
210
211int
212lsquic_stream_set_max_send_off (lsquic_stream_t *stream, unsigned offset);
213
214/* The caller should only call this function if STREAM_SEND_WUF is set and
215 * it must generate a window update frame using this value.
216 */
217uint64_t
218lsquic_stream_fc_recv_off (lsquic_stream_t *stream);
219
220void
221lsquic_stream_dispatch_read_events (lsquic_stream_t *);
222
223void
224lsquic_stream_dispatch_write_events (lsquic_stream_t *);
225
226void
227lsquic_stream_blocked_frame_sent (lsquic_stream_t *);
228
229void
230lsquic_stream_rst_frame_sent (lsquic_stream_t *);
231
232void
233lsquic_stream_stream_frame_sent (lsquic_stream_t *);
234
235void
236lsquic_stream_reset (lsquic_stream_t *, uint32_t error_code);
237
238void
239lsquic_stream_reset_ext (lsquic_stream_t *, uint32_t error_code, int close);
240
241void
242lsquic_stream_call_on_close (lsquic_stream_t *);
243
244void
245lsquic_stream_shutdown_internal (lsquic_stream_t *);
246
247void
248lsquic_stream_received_goaway (lsquic_stream_t *);
249
250void
251lsquic_stream_acked (lsquic_stream_t *);
252
253#define lsquic_stream_is_closed(s)                                          \
254    (((s)->stream_flags & (STREAM_U_READ_DONE|STREAM_U_WRITE_DONE))         \
255                            == (STREAM_U_READ_DONE|STREAM_U_WRITE_DONE))
256int
257lsquic_stream_update_sfcw (lsquic_stream_t *, uint64_t max_off);
258
259int
260lsquic_stream_set_priority_internal (lsquic_stream_t *, unsigned priority);
261
262/* The following flags are checked to see whether progress was made: */
263#define STREAM_RW_PROG_FLAGS (                                              \
264    STREAM_U_READ_DONE  /* User closed read side of the stream */           \
265   |STREAM_FIN_REACHED  /* User reached FIN.  We check this because it */   \
266                        /*   may have been a result of zero-byte read. */   \
267)
268
269/* Stream progress status is used to judge whether a connection made progress
270 * during Pending RW Queue processing.  We only check for stream read progress,
271 * as the write progress is defined as any new data packetized for sending.
272 */
273struct stream_read_prog_status
274{
275    uint64_t                srps_read_offset;
276    enum stream_flags       srps_flags;
277};
278
279#define lsquic_stream_is_critical(stream) (                                 \
280    (stream)->id == LSQUIC_STREAM_HANDSHAKE ||                              \
281    ((stream)->id == LSQUIC_STREAM_HEADERS &&                               \
282        (stream)->stream_flags & STREAM_USE_HEADERS))
283
284size_t
285lsquic_stream_mem_used (const struct lsquic_stream *);
286
287lsquic_cid_t
288lsquic_stream_cid (const struct lsquic_stream *);
289
290#define lsquic_stream_has_data_to_flush(stream) ((stream)->sm_n_buffered > 0)
291
292int
293lsquic_stream_readable (const lsquic_stream_t *);
294
295size_t
296lsquic_stream_write_avail (const struct lsquic_stream *);
297
298#ifndef NDEBUG
299size_t
300lsquic_stream_flush_threshold (const struct lsquic_stream *);
301#endif
302
303#endif
304