lsquic_send_ctl.h revision 04f8f447
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_0rtt_stash,
91                                    sc_lost_packets;
92    struct buf_packet_q             sc_buffered_packets[BPT_OTHER_PRIO + 1];
93    const struct ver_neg           *sc_ver_neg;
94    struct lsquic_conn_public      *sc_conn_pub;
95    struct pacer                    sc_pacer;
96    lsquic_packno_t                 sc_cur_packno;
97    lsquic_packno_t                 sc_largest_sent_at_cutback;
98    lsquic_packno_t                 sc_max_rtt_packno;
99    /* sc_largest_ack2ed is the packet number sent by peer that we acked and
100     * we know that our ACK was received by peer.  This is used to determine
101     * the receive history cutoff point for the purposes of generating ACK
102     * frames in the absense of STOP_WAITING frames.  Used when NSTP option
103     * is set.  (The "ack2ed" is odd enough to not be confused with anything
104     * else and it is not insanely long.)
105     */
106    lsquic_packno_t                 sc_largest_ack2ed[N_PNS];
107    /* sc_largest_acked is the largest packet number in PNS_APP packet number
108     * space sent by peer for which we generated (not necessarily sent) an ACK.
109     * This information is used to drop stale ACK frames from packets in
110     * buffered queues.
111     */
112    lsquic_packno_t                 sc_largest_acked;
113    lsquic_time_t                   sc_loss_to;
114    uint64_t                        sc_ecn_total_acked[N_PNS];
115    uint64_t                        sc_ecn_ce_cnt[N_PNS];
116    struct
117    {
118        lsquic_stream_id_t      stream_id;
119        enum buf_packet_type    packet_type;
120    }                               sc_cached_bpt;
121    unsigned                        sc_next_limit;
122    unsigned                        sc_n_scheduled;
123    enum packno_bits                sc_max_packno_bits;
124#if LSQUIC_SEND_STATS
125    struct {
126        unsigned            n_total_sent,
127                            n_resent,
128                            n_delayed;
129    }                               sc_stats;
130#endif
131    unsigned char                  *sc_token;
132    size_t                          sc_token_sz;
133    unsigned                        sc_retry_count;
134    unsigned                        sc_rt_count;    /* Count round trips */
135    lsquic_packno_t                 sc_cur_rt_end;
136    lsquic_packno_t                 sc_gap;
137    unsigned                        sc_loss_count;  /* Used to set loss bit */
138    unsigned                        sc_square_count;/* Used to set square bit */
139    signed char                     sc_cidlen;      /* For debug purposes */
140} lsquic_send_ctl_t;
141
142void
143lsquic_send_ctl_init (lsquic_send_ctl_t *, struct lsquic_alarmset *,
144          struct lsquic_engine_public *, const struct ver_neg *,
145          struct lsquic_conn_public *, enum send_ctl_flags);
146
147int
148lsquic_send_ctl_sent_packet (lsquic_send_ctl_t *, struct lsquic_packet_out *);
149
150int
151lsquic_send_ctl_got_ack (lsquic_send_ctl_t *, const struct ack_info *,
152                                                lsquic_time_t, lsquic_time_t);
153
154lsquic_packno_t
155lsquic_send_ctl_smallest_unacked (lsquic_send_ctl_t *ctl);
156
157int
158lsquic_send_ctl_have_unacked_stream_frames (const lsquic_send_ctl_t *);
159
160void
161lsquic_send_ctl_cleanup (lsquic_send_ctl_t *);
162
163int
164lsquic_send_ctl_can_send (lsquic_send_ctl_t *ctl);
165
166void
167lsquic_send_ctl_scheduled_one (lsquic_send_ctl_t *, struct lsquic_packet_out *);
168
169void
170lsquic_send_ctl_delayed_one (lsquic_send_ctl_t *, struct lsquic_packet_out *);
171
172struct lsquic_packet_out *
173lsquic_send_ctl_next_packet_to_send (struct lsquic_send_ctl *,
174                                                    const struct to_coal *);
175
176int
177lsquic_send_ctl_next_packet_to_send_predict (struct lsquic_send_ctl *);
178
179void
180lsquic_send_ctl_expire_all (lsquic_send_ctl_t *ctl);
181
182#define lsquic_send_ctl_n_in_flight(ctl) (+(ctl)->sc_n_in_flight)
183
184#define lsquic_send_ctl_n_scheduled(ctl) (+(ctl)->sc_n_scheduled)
185
186#define lsquic_send_ctl_largest_ack2ed(ctl, pns) \
187                                            (+(ctl)->sc_largest_ack2ed[pns])
188
189void
190lsquic_send_ctl_do_sanity_check (const struct lsquic_send_ctl *ctl);
191
192#ifndef NDEBUG
193#define lsquic_send_ctl_sanity_check(ctl) do {                      \
194    if ((ctl)->sc_flags & SC_SANITY_CHECK)                          \
195        lsquic_send_ctl_do_sanity_check(ctl);                       \
196} while (0)
197#else
198#define lsquic_send_ctl_sanity_check(ctl)
199#endif
200
201int
202lsquic_send_ctl_have_outgoing_stream_frames (const lsquic_send_ctl_t *);
203
204int
205lsquic_send_ctl_have_outgoing_retx_frames (const lsquic_send_ctl_t *);
206
207struct lsquic_packet_out *
208lsquic_send_ctl_last_scheduled (struct lsquic_send_ctl *, enum packnum_space,
209                                            const struct network_path *, int);
210
211struct lsquic_packet_out *
212lsquic_send_ctl_new_packet_out (lsquic_send_ctl_t *, unsigned,
213                            enum packnum_space, const struct network_path *);
214
215struct lsquic_packet_out *
216lsquic_send_ctl_get_writeable_packet (lsquic_send_ctl_t *, enum packnum_space,
217      unsigned need_at_least, const struct network_path *, int, int *is_err);
218
219struct lsquic_packet_out *
220lsquic_send_ctl_get_packet_for_stream (lsquic_send_ctl_t *,
221                    unsigned need_at_least, const struct network_path *,
222                    const struct lsquic_stream *);
223
224struct lsquic_packet_out *
225lsquic_send_ctl_get_packet_for_crypto (struct lsquic_send_ctl *ctl,
226    unsigned need_at_least, enum packnum_space, const struct network_path *);
227
228unsigned
229lsquic_send_ctl_reschedule_packets (lsquic_send_ctl_t *);
230
231#define lsquic_send_ctl_lost_ack(ctl) \
232    (((ctl)->sc_flags & (SC_LOST_ACK_INIT|SC_LOST_ACK_HSK|SC_LOST_ACK_APP)) \
233                                                        >> SCBIT_LOST_ACK_SHIFT)
234
235#define lsquic_send_ctl_scheduled_ack(ctl, pns, acked) do {         \
236    (ctl)->sc_flags &= ~(SC_LOST_ACK_INIT << pns);                  \
237    if (PNS_APP == pns)                                             \
238        (ctl)->sc_largest_acked = acked;                            \
239} while (0)
240
241void
242lsquic_send_ctl_set_tcid0 (lsquic_send_ctl_t *, int);
243
244#define lsquic_send_ctl_turn_nstp_on(ctl) ((ctl)->sc_flags |= SC_NSTP)
245
246void
247lsquic_send_ctl_elide_stream_frames (lsquic_send_ctl_t *, lsquic_stream_id_t);
248
249int
250lsquic_send_ctl_squeeze_sched (lsquic_send_ctl_t *);
251
252#define lsquic_send_ctl_maybe_squeeze_sched(ctl) (                  \
253    (ctl)->sc_n_scheduled && lsquic_send_ctl_squeeze_sched(ctl)     \
254)
255
256/* Same return value as for squeezing, but without actual squeezing. */
257int
258lsquic_send_ctl_have_delayed_packets (const lsquic_send_ctl_t *ctl);
259
260void
261lsquic_send_ctl_reset_packnos (lsquic_send_ctl_t *);
262
263void
264lsquic_send_ctl_ack_to_front (struct lsquic_send_ctl *, unsigned n_acks);
265
266#define lsquic_send_ctl_n_stop_waiting(ctl) \
267                                    (+(ctl)->sc_n_stop_waiting)
268
269#define lsquic_send_ctl_n_stop_waiting_reset(ctl) do {      \
270    (ctl)->sc_n_stop_waiting = 0;                           \
271} while (0)
272
273void
274lsquic_send_ctl_drop_scheduled (lsquic_send_ctl_t *);
275
276#define lsquic_send_ctl_tick_in(ctl, now) do {              \
277    if ((ctl)->sc_flags & SC_PACE)                          \
278    {                                                       \
279        (ctl)->sc_flags |= SC_SCHED_TICK;                   \
280        lsquic_pacer_tick_in(&(ctl)->sc_pacer, now);        \
281    }                                                       \
282    (ctl)->sc_flags &= ~SC_APP_LIMITED;                     \
283} while (0)
284
285#define lsquic_send_ctl_tick_out(ctl) do {                  \
286    if ((ctl)->sc_flags & SC_PACE)                          \
287        lsquic_pacer_tick_out(&(ctl)->sc_pacer);            \
288} while (0)
289
290#define lsquic_send_ctl_next_pacer_time(ctl) (              \
291    ((ctl)->sc_flags & SC_PACE)                             \
292        && lsquic_pacer_delayed(&(ctl)->sc_pacer)           \
293        ? lsquic_pacer_next_sched(&(ctl)->sc_pacer)         \
294        : 0 )
295
296enum packno_bits
297lsquic_send_ctl_packno_bits (struct lsquic_send_ctl *, enum packnum_space);
298
299int
300lsquic_send_ctl_schedule_buffered (lsquic_send_ctl_t *, enum buf_packet_type);
301
302#define lsquic_send_ctl_has_buffered(ctl) (                                 \
303    TAILQ_FIRST(&(ctl)->sc_buffered_packets[BPT_HIGHEST_PRIO].bpq_packets)  \
304 || TAILQ_FIRST(&(ctl)->sc_buffered_packets[BPT_OTHER_PRIO].bpq_packets  ))
305
306#define lsquic_send_ctl_has_buffered_high(ctl) (                            \
307    !TAILQ_EMPTY(&(ctl)->sc_buffered_packets[BPT_HIGHEST_PRIO].bpq_packets))
308
309#define lsquic_send_ctl_invalidate_bpt_cache(ctl) do {      \
310    (ctl)->sc_cached_bpt.stream_id = UINT64_MAX;            \
311} while (0)
312
313#ifndef NDEBUG
314enum packno_bits
315lsquic_send_ctl_guess_packno_bits (struct lsquic_send_ctl *);
316
317int
318lsquic_send_ctl_schedule_stream_packets_immediately (struct lsquic_send_ctl *);
319
320enum buf_packet_type
321lsquic_send_ctl_determine_bpt (struct lsquic_send_ctl *,
322                                            const struct lsquic_stream *);
323
324enum packno_bits
325lsquic_send_ctl_calc_packno_bits (struct lsquic_send_ctl *);
326
327void
328lsquic_send_ctl_set_max_bpq_count (unsigned);
329#endif
330
331size_t
332lsquic_send_ctl_mem_used (const struct lsquic_send_ctl *);
333
334#define lsquic_send_ctl_set_buffer_stream_packets(ctl, b) do {  \
335    (ctl)->sc_flags &= ~SC_BUFFER_STREAM;                       \
336    (ctl)->sc_flags |= -!!(b) & SC_BUFFER_STREAM;               \
337} while (0)
338
339int
340lsquic_send_ctl_turn_on_fin (struct lsquic_send_ctl *,
341                             const struct lsquic_stream *);
342
343int
344lsquic_send_ctl_pacer_blocked (struct lsquic_send_ctl *);
345
346#define lsquic_send_ctl_incr_pack_sz(ctl, packet, delta) do {   \
347    (packet)->po_data_sz += (delta);                            \
348    if ((packet)->po_flags & PO_SCHED)                          \
349        (ctl)->sc_bytes_scheduled += (delta);                   \
350    lsquic_send_ctl_sanity_check(ctl);                          \
351} while (0)
352
353int
354lsquic_send_ctl_sched_is_blocked (struct lsquic_send_ctl *);
355
356void
357lsquic_send_ctl_verneg_done (struct lsquic_send_ctl *);
358
359int
360lsquic_send_ctl_retry (struct lsquic_send_ctl *, const unsigned char *, size_t);
361
362int
363lsquic_send_ctl_set_token (struct lsquic_send_ctl *,
364                const unsigned char *token, size_t token_sz);
365
366void
367lsquic_send_ctl_empty_pns (struct lsquic_send_ctl *, enum packnum_space);
368
369void
370lsquic_send_ctl_repath (struct lsquic_send_ctl *ctl,
371    const struct network_path *old, const struct network_path *new,
372    int keep_path_properties);
373
374void
375lsquic_send_ctl_resize (struct lsquic_send_ctl *);
376
377void
378lsquic_send_ctl_return_enc_data (struct lsquic_send_ctl *);
379
380#define lsquic_send_ctl_1rtt_acked(ctl) ((ctl)->sc_flags & SC_1RTT_ACKED)
381
382void
383lsquic_send_ctl_maybe_app_limited (struct lsquic_send_ctl *,
384                                            const struct network_path *);
385
386#define lsquic_send_ctl_do_ql_bits(ctl) do {                       \
387    (ctl)->sc_flags |= SC_QL_BITS;                                 \
388} while (0)
389
390void
391lsquic_send_ctl_cidlen_change (struct lsquic_send_ctl *,
392                                unsigned orig_cid_len, unsigned new_cid_len);
393
394void
395lsquic_send_ctl_begin_optack_detection (struct lsquic_send_ctl *);
396
397#define lsquic_send_ctl_n_unacked(ctl_) ((ctl_)->sc_n_in_flight_retx)
398
399void
400lsquic_send_ctl_path_validated (struct lsquic_send_ctl *);
401
402/* Has immediately sendable packets */
403#define lsquic_send_ctl_has_sendable(ctl_) \
404    (lsquic_send_ctl_n_scheduled(ctl_) > 0 \
405                && lsquic_send_ctl_next_packet_to_send_predict(ctl_))
406
407#define lsquic_send_ctl_in_recovery(ctl_) ((ctl_)->sc_largest_acked_packno \
408    && (ctl_)->sc_largest_acked_packno <= (ctl_)->sc_largest_sent_at_cutback)
409
410#define send_ctl_in_recovery lsquic_send_ctl_in_recovery
411
412int
413lsquic_send_ctl_can_send_probe (const struct lsquic_send_ctl *,
414                                            const struct network_path *);
415
416#define lsquic_send_ctl_ecn_turned_on(ctl_) ((ctl_)->sc_ecn != ECN_NOT_ECT)
417
418void
419lsquic_send_ctl_disable_ecn (struct lsquic_send_ctl *);
420
421struct send_ctl_state
422{
423    struct pacer        pacer;
424    struct ack_state    ack_state;
425    unsigned            buf_counts[BPT_OTHER_PRIO + 1];
426};
427
428void
429lsquic_send_ctl_snapshot (struct lsquic_send_ctl *, struct send_ctl_state *);
430
431void
432lsquic_send_ctl_rollback (struct lsquic_send_ctl *, struct send_ctl_state *,
433                                                const struct iovec *, size_t);
434
435void
436lsquic_send_ctl_0rtt_to_1rtt (struct lsquic_send_ctl *);
437
438void
439lsquic_send_ctl_stash_0rtt_packets (struct lsquic_send_ctl *);
440
441#endif
442