lsquic_send_ctl.h revision fbc6cc04
1/* Copyright (c) 2017 - 2020 LiteSpeed Technologies Inc.  See LICENSE. */
2#ifndef LSQUIC_SEND_CTL_H
3#define LSQUIC_SEND_CTL_H 1
4
5#include <sys/queue.h>
6
7#include "lsquic_types.h"
8
9#ifndef LSQUIC_SEND_STATS
10#   define LSQUIC_SEND_STATS 1
11#endif
12
13TAILQ_HEAD(lsquic_packets_tailq, lsquic_packet_out);
14
15struct lsquic_packet_out;
16struct ack_info;
17struct lsquic_alarmset;
18struct lsquic_engine_public;
19struct lsquic_conn_public;
20struct network_path;
21struct ver_neg;
22enum pns;
23struct to_coal;
24
25enum buf_packet_type { BPT_HIGHEST_PRIO, BPT_OTHER_PRIO, };
26
27struct buf_packet_q
28{
29    struct lsquic_packets_tailq     bpq_packets;
30    unsigned                        bpq_count;
31};
32
33enum send_ctl_flags {
34    SC_TCID0        = (1 << 0),
35    SC_NSTP         = (1 << 2),
36    SC_PACE         = (1 << 3),
37    SC_SCHED_TICK   = (1 << 4),
38    SC_BUFFER_STREAM= (1 << 5),
39    SC_WAS_QUIET    = (1 << 6),
40    SC_IETF         = (1 << 7),
41#define SCBIT_LOST_ACK_SHIFT 8
42    SC_LOST_ACK_INIT=  1 << 8,
43    SC_LOST_ACK_HSK = SC_LOST_ACK_INIT << PNS_HSK,
44    SC_LOST_ACK_APP = SC_LOST_ACK_INIT << PNS_APP,
45    SC_1RTT_ACKED   =  1 << 11,
46    SC_APP_LIMITED  =  1 << 12,
47    SC_ECN          =  1 << 13,
48    SC_QL_BITS      =  1 << 14,
49    SC_SANITY_CHECK =  1 << 15,
50    SC_CIDLEN       =  1 << 16,     /* sc_cidlen is set */
51    SC_POISON       =  1 << 17,     /* poisoned packet exists */
52    SC_CLEANUP_BBR  =  1 << 18,
53    SC_ACK_RECV_INIT=  1 << 19,
54    SC_ACK_RECV_HSK =  SC_ACK_RECV_INIT << PNS_HSK,
55    SC_ACK_RECV_APP =  SC_ACK_RECV_INIT << PNS_APP,
56};
57
58typedef struct lsquic_send_ctl {
59    /* The first section consists of struct members which are used in the
60     * time-critical lsquic_send_ctl_got_ack() in the approximate order
61     * of usage.
62     */
63    lsquic_senhist_t                sc_senhist;
64    enum send_ctl_flags             sc_flags;
65    enum ecn                        sc_ecn;
66    unsigned                        sc_n_stop_waiting;
67    struct lsquic_packets_tailq     sc_unacked_packets[N_PNS];
68    lsquic_packno_t                 sc_largest_acked_packno;
69    lsquic_time_t                   sc_largest_acked_sent_time;
70    lsquic_time_t                   sc_last_sent_time;
71    lsquic_time_t                   sc_last_rto_time;
72    int                           (*sc_can_send)(struct lsquic_send_ctl *);
73    unsigned                        sc_bytes_unacked_retx;
74    unsigned                        sc_bytes_scheduled;
75    struct adaptive_cc              sc_adaptive_cc;
76    const struct cong_ctl_if       *sc_ci;
77    void                           *sc_cong_ctl;
78    struct lsquic_engine_public    *sc_enpub;
79    unsigned                        sc_bytes_unacked_all;
80    unsigned                        sc_n_in_flight_all;
81    unsigned                        sc_n_in_flight_retx;
82    unsigned                        sc_n_consec_rtos;
83    unsigned                        sc_n_hsk;
84    unsigned                        sc_n_tlp;
85    enum quic_ft_bit                sc_retx_frames;
86    struct lsquic_alarmset         *sc_alset;
87
88    /* Second section: everything else. */
89    struct lsquic_packets_tailq     sc_scheduled_packets,
90                                    sc_lost_packets;
91    struct buf_packet_q             sc_buffered_packets[BPT_OTHER_PRIO + 1];
92    const struct ver_neg           *sc_ver_neg;
93    struct lsquic_conn_public      *sc_conn_pub;
94    struct pacer                    sc_pacer;
95    lsquic_packno_t                 sc_cur_packno;
96    lsquic_packno_t                 sc_largest_sent_at_cutback;
97    lsquic_packno_t                 sc_max_rtt_packno;
98    /* sc_largest_ack2ed is the packet number sent by peer that we acked and
99     * we know that our ACK was received by peer.  This is used to determine
100     * the receive history cutoff point for the purposes of generating ACK
101     * frames in the absense of STOP_WAITING frames.  Used when NSTP option
102     * is set.  (The "ack2ed" is odd enough to not be confused with anything
103     * else and it is not insanely long.)
104     */
105    lsquic_packno_t                 sc_largest_ack2ed[N_PNS];
106    /* sc_largest_acked is the largest packet number in PNS_APP packet number
107     * space sent by peer for which we generated (not necessarily sent) an ACK.
108     * This information is used to drop stale ACK frames from packets in
109     * buffered queues.
110     */
111    lsquic_packno_t                 sc_largest_acked;
112    lsquic_time_t                   sc_loss_to;
113    uint64_t                        sc_ecn_total_acked[N_PNS];
114    uint64_t                        sc_ecn_ce_cnt[N_PNS];
115    struct
116    {
117        lsquic_stream_id_t      stream_id;
118        enum buf_packet_type    packet_type;
119    }                               sc_cached_bpt;
120    unsigned                        sc_next_limit;
121    unsigned                        sc_n_scheduled;
122    enum packno_bits                sc_max_packno_bits;
123#if LSQUIC_SEND_STATS
124    struct {
125        unsigned            n_total_sent,
126                            n_resent,
127                            n_delayed;
128    }                               sc_stats;
129#endif
130    unsigned char                  *sc_token;
131    size_t                          sc_token_sz;
132    unsigned                        sc_retry_count;
133    unsigned                        sc_rt_count;    /* Count round trips */
134    lsquic_packno_t                 sc_cur_rt_end;
135    lsquic_packno_t                 sc_gap;
136    unsigned                        sc_loss_count;  /* Used to set loss bit */
137    unsigned                        sc_square_count;/* Used to set square bit */
138    signed char                     sc_cidlen;      /* For debug purposes */
139} lsquic_send_ctl_t;
140
141void
142lsquic_send_ctl_init (lsquic_send_ctl_t *, struct lsquic_alarmset *,
143          struct lsquic_engine_public *, const struct ver_neg *,
144          struct lsquic_conn_public *, enum send_ctl_flags);
145
146int
147lsquic_send_ctl_sent_packet (lsquic_send_ctl_t *, struct lsquic_packet_out *);
148
149int
150lsquic_send_ctl_got_ack (lsquic_send_ctl_t *, const struct ack_info *,
151                                                lsquic_time_t, lsquic_time_t);
152
153lsquic_packno_t
154lsquic_send_ctl_smallest_unacked (lsquic_send_ctl_t *ctl);
155
156int
157lsquic_send_ctl_have_unacked_stream_frames (const lsquic_send_ctl_t *);
158
159void
160lsquic_send_ctl_cleanup (lsquic_send_ctl_t *);
161
162int
163lsquic_send_ctl_can_send (lsquic_send_ctl_t *ctl);
164
165void
166lsquic_send_ctl_scheduled_one (lsquic_send_ctl_t *, struct lsquic_packet_out *);
167
168void
169lsquic_send_ctl_delayed_one (lsquic_send_ctl_t *, struct lsquic_packet_out *);
170
171struct lsquic_packet_out *
172lsquic_send_ctl_next_packet_to_send (struct lsquic_send_ctl *,
173                                                    const struct to_coal *);
174
175int
176lsquic_send_ctl_next_packet_to_send_predict (struct lsquic_send_ctl *);
177
178void
179lsquic_send_ctl_expire_all (lsquic_send_ctl_t *ctl);
180
181#define lsquic_send_ctl_n_in_flight(ctl) (+(ctl)->sc_n_in_flight)
182
183#define lsquic_send_ctl_n_scheduled(ctl) (+(ctl)->sc_n_scheduled)
184
185#define lsquic_send_ctl_largest_ack2ed(ctl, pns) \
186                                            (+(ctl)->sc_largest_ack2ed[pns])
187
188void
189lsquic_send_ctl_do_sanity_check (const struct lsquic_send_ctl *ctl);
190
191#ifndef NDEBUG
192#define lsquic_send_ctl_sanity_check(ctl) do {                      \
193    if ((ctl)->sc_flags & SC_SANITY_CHECK)                          \
194        lsquic_send_ctl_do_sanity_check(ctl);                       \
195} while (0)
196#else
197#define lsquic_send_ctl_sanity_check(ctl)
198#endif
199
200int
201lsquic_send_ctl_have_outgoing_stream_frames (const lsquic_send_ctl_t *);
202
203int
204lsquic_send_ctl_have_outgoing_retx_frames (const lsquic_send_ctl_t *);
205
206struct lsquic_packet_out *
207lsquic_send_ctl_last_scheduled (struct lsquic_send_ctl *, enum packnum_space,
208                                            const struct network_path *, int);
209
210struct lsquic_packet_out *
211lsquic_send_ctl_new_packet_out (lsquic_send_ctl_t *, unsigned,
212                            enum packnum_space, const struct network_path *);
213
214struct lsquic_packet_out *
215lsquic_send_ctl_get_writeable_packet (lsquic_send_ctl_t *, enum packnum_space,
216      unsigned need_at_least, const struct network_path *, int, int *is_err);
217
218struct lsquic_packet_out *
219lsquic_send_ctl_get_packet_for_stream (lsquic_send_ctl_t *,
220                    unsigned need_at_least, const struct network_path *,
221                    const struct lsquic_stream *);
222
223struct lsquic_packet_out *
224lsquic_send_ctl_get_packet_for_crypto (struct lsquic_send_ctl *ctl,
225    unsigned need_at_least, enum packnum_space, const struct network_path *);
226
227unsigned
228lsquic_send_ctl_reschedule_packets (lsquic_send_ctl_t *);
229
230#define lsquic_send_ctl_lost_ack(ctl) \
231    (((ctl)->sc_flags & (SC_LOST_ACK_INIT|SC_LOST_ACK_HSK|SC_LOST_ACK_APP)) \
232                                                        >> SCBIT_LOST_ACK_SHIFT)
233
234#define lsquic_send_ctl_scheduled_ack(ctl, pns, acked) do {         \
235    (ctl)->sc_flags &= ~(SC_LOST_ACK_INIT << pns);                  \
236    if (PNS_APP == pns)                                             \
237        (ctl)->sc_largest_acked = acked;                            \
238} while (0)
239
240void
241lsquic_send_ctl_set_tcid0 (lsquic_send_ctl_t *, int);
242
243#define lsquic_send_ctl_turn_nstp_on(ctl) ((ctl)->sc_flags |= SC_NSTP)
244
245void
246lsquic_send_ctl_elide_stream_frames (lsquic_send_ctl_t *, lsquic_stream_id_t);
247
248int
249lsquic_send_ctl_squeeze_sched (lsquic_send_ctl_t *);
250
251#define lsquic_send_ctl_maybe_squeeze_sched(ctl) (                  \
252    (ctl)->sc_n_scheduled && lsquic_send_ctl_squeeze_sched(ctl)     \
253)
254
255/* Same return value as for squeezing, but without actual squeezing. */
256int
257lsquic_send_ctl_have_delayed_packets (const lsquic_send_ctl_t *ctl);
258
259void
260lsquic_send_ctl_reset_packnos (lsquic_send_ctl_t *);
261
262void
263lsquic_send_ctl_ack_to_front (struct lsquic_send_ctl *, unsigned n_acks);
264
265#define lsquic_send_ctl_n_stop_waiting(ctl) \
266                                    (+(ctl)->sc_n_stop_waiting)
267
268#define lsquic_send_ctl_n_stop_waiting_reset(ctl) do {      \
269    (ctl)->sc_n_stop_waiting = 0;                           \
270} while (0)
271
272void
273lsquic_send_ctl_drop_scheduled (lsquic_send_ctl_t *);
274
275#define lsquic_send_ctl_tick_in(ctl, now) do {              \
276    if ((ctl)->sc_flags & SC_PACE)                          \
277    {                                                       \
278        (ctl)->sc_flags |= SC_SCHED_TICK;                   \
279        lsquic_pacer_tick_in(&(ctl)->sc_pacer, now);        \
280    }                                                       \
281    (ctl)->sc_flags &= ~SC_APP_LIMITED;                     \
282} while (0)
283
284#define lsquic_send_ctl_tick_out(ctl) do {                  \
285    if ((ctl)->sc_flags & SC_PACE)                          \
286        lsquic_pacer_tick_out(&(ctl)->sc_pacer);            \
287} while (0)
288
289#define lsquic_send_ctl_next_pacer_time(ctl) (              \
290    ((ctl)->sc_flags & SC_PACE)                             \
291        && lsquic_pacer_delayed(&(ctl)->sc_pacer)           \
292        ? lsquic_pacer_next_sched(&(ctl)->sc_pacer)         \
293        : 0 )
294
295enum packno_bits
296lsquic_send_ctl_packno_bits (struct lsquic_send_ctl *, enum packnum_space);
297
298int
299lsquic_send_ctl_schedule_buffered (lsquic_send_ctl_t *, enum buf_packet_type);
300
301#define lsquic_send_ctl_has_buffered(ctl) (                                 \
302    TAILQ_FIRST(&(ctl)->sc_buffered_packets[BPT_HIGHEST_PRIO].bpq_packets)  \
303 || TAILQ_FIRST(&(ctl)->sc_buffered_packets[BPT_OTHER_PRIO].bpq_packets  ))
304
305#define lsquic_send_ctl_has_buffered_high(ctl) (                            \
306    !TAILQ_EMPTY(&(ctl)->sc_buffered_packets[BPT_HIGHEST_PRIO].bpq_packets))
307
308#define lsquic_send_ctl_invalidate_bpt_cache(ctl) do {      \
309    (ctl)->sc_cached_bpt.stream_id = UINT64_MAX;            \
310} while (0)
311
312#ifndef NDEBUG
313enum packno_bits
314lsquic_send_ctl_guess_packno_bits (struct lsquic_send_ctl *);
315
316int
317lsquic_send_ctl_schedule_stream_packets_immediately (struct lsquic_send_ctl *);
318
319enum buf_packet_type
320lsquic_send_ctl_determine_bpt (struct lsquic_send_ctl *,
321                                            const struct lsquic_stream *);
322
323enum packno_bits
324lsquic_send_ctl_calc_packno_bits (struct lsquic_send_ctl *);
325
326void
327lsquic_send_ctl_set_max_bpq_count (unsigned);
328#endif
329
330size_t
331lsquic_send_ctl_mem_used (const struct lsquic_send_ctl *);
332
333#define lsquic_send_ctl_set_buffer_stream_packets(ctl, b) do {  \
334    (ctl)->sc_flags &= ~SC_BUFFER_STREAM;                       \
335    (ctl)->sc_flags |= -!!(b) & SC_BUFFER_STREAM;               \
336} while (0)
337
338int
339lsquic_send_ctl_turn_on_fin (struct lsquic_send_ctl *,
340                             const struct lsquic_stream *);
341
342int
343lsquic_send_ctl_pacer_blocked (struct lsquic_send_ctl *);
344
345#define lsquic_send_ctl_incr_pack_sz(ctl, packet, delta) do {   \
346    (packet)->po_data_sz += (delta);                            \
347    if ((packet)->po_flags & PO_SCHED)                          \
348        (ctl)->sc_bytes_scheduled += (delta);                   \
349    lsquic_send_ctl_sanity_check(ctl);                          \
350} while (0)
351
352int
353lsquic_send_ctl_sched_is_blocked (struct lsquic_send_ctl *);
354
355void
356lsquic_send_ctl_verneg_done (struct lsquic_send_ctl *);
357
358int
359lsquic_send_ctl_retry (struct lsquic_send_ctl *, const unsigned char *, size_t);
360
361int
362lsquic_send_ctl_set_token (struct lsquic_send_ctl *,
363                const unsigned char *token, size_t token_sz);
364
365void
366lsquic_send_ctl_empty_pns (struct lsquic_send_ctl *, enum packnum_space);
367
368void
369lsquic_send_ctl_repath (struct lsquic_send_ctl *ctl,
370    const struct network_path *old, const struct network_path *new,
371    int keep_path_properties);
372
373void
374lsquic_send_ctl_resize (struct lsquic_send_ctl *);
375
376void
377lsquic_send_ctl_return_enc_data (struct lsquic_send_ctl *);
378
379#define lsquic_send_ctl_1rtt_acked(ctl) ((ctl)->sc_flags & SC_1RTT_ACKED)
380
381void
382lsquic_send_ctl_maybe_app_limited (struct lsquic_send_ctl *,
383                                            const struct network_path *);
384
385#define lsquic_send_ctl_do_ql_bits(ctl) do {                       \
386    (ctl)->sc_flags |= SC_QL_BITS;                                 \
387} while (0)
388
389void
390lsquic_send_ctl_cidlen_change (struct lsquic_send_ctl *,
391                                unsigned orig_cid_len, unsigned new_cid_len);
392
393void
394lsquic_send_ctl_begin_optack_detection (struct lsquic_send_ctl *);
395
396#define lsquic_send_ctl_n_unacked(ctl_) ((ctl_)->sc_n_in_flight_retx)
397
398void
399lsquic_send_ctl_path_validated (struct lsquic_send_ctl *);
400
401/* Has immediately sendable packets */
402#define lsquic_send_ctl_has_sendable(ctl_) \
403    (lsquic_send_ctl_n_scheduled(ctl_) > 0 \
404                && lsquic_send_ctl_next_packet_to_send_predict(ctl_))
405
406#define lsquic_send_ctl_in_recovery(ctl_) ((ctl_)->sc_largest_acked_packno \
407    && (ctl_)->sc_largest_acked_packno <= (ctl_)->sc_largest_sent_at_cutback)
408
409#define send_ctl_in_recovery lsquic_send_ctl_in_recovery
410
411int
412lsquic_send_ctl_can_send_probe (const struct lsquic_send_ctl *,
413                                            const struct network_path *);
414
415#define lsquic_send_ctl_ecn_turned_on(ctl_) ((ctl_)->sc_ecn != ECN_NOT_ECT)
416
417void
418lsquic_send_ctl_disable_ecn (struct lsquic_send_ctl *);
419
420struct send_ctl_state
421{
422    struct pacer        pacer;
423    struct ack_state    ack_state;
424    unsigned            buf_counts[BPT_OTHER_PRIO + 1];
425};
426
427void
428lsquic_send_ctl_snapshot (struct lsquic_send_ctl *, struct send_ctl_state *);
429
430void
431lsquic_send_ctl_rollback (struct lsquic_send_ctl *, struct send_ctl_state *,
432                                                const struct iovec *, size_t);
433
434#endif
435