lsquic_send_ctl.h revision 71eb4000
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    SC_ROUGH_RTT    =  1 << 22,
57#if LSQUIC_DEVEL
58    SC_DYN_PTHRESH  =  1 << 31u,    /* dynamic packet threshold enabled */
59#endif
60};
61
62typedef struct lsquic_send_ctl {
63    /* The first section consists of struct members which are used in the
64     * time-critical lsquic_send_ctl_got_ack() in the approximate order
65     * of usage.
66     */
67    lsquic_senhist_t                sc_senhist;
68    enum send_ctl_flags             sc_flags;
69    enum ecn                        sc_ecn;
70    unsigned                        sc_n_stop_waiting;
71    struct lsquic_packets_tailq     sc_unacked_packets[N_PNS];
72    lsquic_packno_t                 sc_largest_acked_packno;
73    lsquic_time_t                   sc_largest_acked_sent_time;
74    lsquic_time_t                   sc_last_sent_time;
75    lsquic_time_t                   sc_last_rto_time;
76    int                           (*sc_can_send)(struct lsquic_send_ctl *);
77    unsigned                        sc_bytes_unacked_retx;
78    unsigned                        sc_bytes_scheduled;
79    struct adaptive_cc              sc_adaptive_cc;
80    const struct cong_ctl_if       *sc_ci;
81    void                           *sc_cong_ctl;
82    struct lsquic_engine_public    *sc_enpub;
83    unsigned                        sc_bytes_unacked_all;
84    unsigned                        sc_n_in_flight_all;
85    unsigned                        sc_n_in_flight_retx;
86    unsigned                        sc_n_consec_rtos;
87    unsigned                        sc_n_hsk;
88    unsigned                        sc_n_tlp;
89    enum quic_ft_bit                sc_retx_frames;
90    struct lsquic_alarmset         *sc_alset;
91
92    /* Second section: everything else. */
93    struct lsquic_packets_tailq     sc_scheduled_packets,
94                                    sc_0rtt_stash,
95                                    sc_lost_packets;
96    struct buf_packet_q             sc_buffered_packets[BPT_OTHER_PRIO + 1];
97    const struct ver_neg           *sc_ver_neg;
98    struct lsquic_conn_public      *sc_conn_pub;
99    struct pacer                    sc_pacer;
100    lsquic_packno_t                 sc_cur_packno;
101    lsquic_packno_t                 sc_largest_sent_at_cutback;
102    lsquic_packno_t                 sc_max_rtt_packno;
103    /* sc_largest_ack2ed is the packet number sent by peer that we acked and
104     * we know that our ACK was received by peer.  This is used to determine
105     * the receive history cutoff point for the purposes of generating ACK
106     * frames in the absense of STOP_WAITING frames.  Used when NSTP option
107     * is set.  (The "ack2ed" is odd enough to not be confused with anything
108     * else and it is not insanely long.)
109     */
110    lsquic_packno_t                 sc_largest_ack2ed[N_PNS];
111    /* sc_largest_acked is the largest packet number in PNS_APP packet number
112     * space sent by peer for which we generated (not necessarily sent) an ACK.
113     * This information is used to drop stale ACK frames from packets in
114     * buffered queues.
115     */
116    /* XXX We have both sc_largest_acked_packno and sc_largest_acked.  Rename
117     * the latter to make the code more readable.
118     */
119    lsquic_packno_t                 sc_largest_acked;
120    lsquic_time_t                   sc_loss_to;
121    uint64_t                        sc_ecn_total_acked[N_PNS];
122    uint64_t                        sc_ecn_ce_cnt[N_PNS];
123    struct
124    {
125        lsquic_stream_id_t      stream_id;
126        enum buf_packet_type    packet_type;
127    }                               sc_cached_bpt;
128    unsigned                        sc_next_limit;
129    unsigned                        sc_n_scheduled;
130    enum packno_bits                sc_max_packno_bits;
131#if LSQUIC_SEND_STATS
132    struct {
133        unsigned            n_total_sent,
134                            n_resent,
135                            n_delayed;
136    }                               sc_stats;
137#endif
138    unsigned char                  *sc_token;
139    size_t                          sc_token_sz;
140    unsigned                        sc_retry_count;
141    unsigned                        sc_rt_count;    /* Count round trips */
142    lsquic_packno_t                 sc_cur_rt_end;
143    lsquic_packno_t                 sc_gap;
144    unsigned                        sc_loss_count;  /* Used to set loss bit */
145    unsigned                        sc_square_count;/* Used to set square bit */
146    unsigned                        sc_reord_thresh;
147    signed char                     sc_cidlen;      /* For debug purposes */
148} lsquic_send_ctl_t;
149
150void
151lsquic_send_ctl_init (lsquic_send_ctl_t *, struct lsquic_alarmset *,
152          struct lsquic_engine_public *, const struct ver_neg *,
153          struct lsquic_conn_public *, enum send_ctl_flags);
154
155int
156lsquic_send_ctl_sent_packet (lsquic_send_ctl_t *, struct lsquic_packet_out *);
157
158int
159lsquic_send_ctl_got_ack (lsquic_send_ctl_t *, const struct ack_info *,
160                                                lsquic_time_t, lsquic_time_t);
161
162lsquic_packno_t
163lsquic_send_ctl_smallest_unacked (lsquic_send_ctl_t *ctl);
164
165int
166lsquic_send_ctl_have_unacked_stream_frames (const lsquic_send_ctl_t *);
167
168int
169lsquic_send_ctl_have_unacked_retx_data (const struct lsquic_send_ctl *);
170
171void
172lsquic_send_ctl_cleanup (lsquic_send_ctl_t *);
173
174int
175lsquic_send_ctl_can_send (lsquic_send_ctl_t *ctl);
176
177void
178lsquic_send_ctl_scheduled_one (lsquic_send_ctl_t *, struct lsquic_packet_out *);
179
180void
181lsquic_send_ctl_delayed_one (lsquic_send_ctl_t *, struct lsquic_packet_out *);
182
183struct lsquic_packet_out *
184lsquic_send_ctl_next_packet_to_send (struct lsquic_send_ctl *,
185                                                    const struct to_coal *);
186
187int
188lsquic_send_ctl_next_packet_to_send_predict (struct lsquic_send_ctl *);
189
190void
191lsquic_send_ctl_expire_all (lsquic_send_ctl_t *ctl);
192
193#define lsquic_send_ctl_n_in_flight(ctl) (+(ctl)->sc_n_in_flight)
194
195#define lsquic_send_ctl_n_scheduled(ctl) (+(ctl)->sc_n_scheduled)
196
197#define lsquic_send_ctl_largest_ack2ed(ctl, pns) \
198                                            (+(ctl)->sc_largest_ack2ed[pns])
199
200void
201lsquic_send_ctl_do_sanity_check (const struct lsquic_send_ctl *ctl);
202
203#ifndef NDEBUG
204#define lsquic_send_ctl_sanity_check(ctl) do {                      \
205    if ((ctl)->sc_flags & SC_SANITY_CHECK)                          \
206        lsquic_send_ctl_do_sanity_check(ctl);                       \
207} while (0)
208#else
209#define lsquic_send_ctl_sanity_check(ctl)
210#endif
211
212int
213lsquic_send_ctl_have_outgoing_stream_frames (const lsquic_send_ctl_t *);
214
215int
216lsquic_send_ctl_have_outgoing_retx_frames (const lsquic_send_ctl_t *);
217
218struct lsquic_packet_out *
219lsquic_send_ctl_last_scheduled (struct lsquic_send_ctl *, enum packnum_space,
220                                            const struct network_path *, int);
221
222struct lsquic_packet_out *
223lsquic_send_ctl_new_packet_out (lsquic_send_ctl_t *, unsigned,
224                            enum packnum_space, const struct network_path *);
225
226struct lsquic_packet_out *
227lsquic_send_ctl_get_writeable_packet (lsquic_send_ctl_t *, enum packnum_space,
228      unsigned need_at_least, const struct network_path *, int, int *is_err);
229
230struct lsquic_packet_out *
231lsquic_send_ctl_get_packet_for_stream (lsquic_send_ctl_t *,
232                    unsigned need_at_least, const struct network_path *,
233                    const struct lsquic_stream *);
234
235struct lsquic_packet_out *
236lsquic_send_ctl_get_packet_for_crypto (struct lsquic_send_ctl *ctl,
237    unsigned need_at_least, enum packnum_space, const struct network_path *);
238
239unsigned
240lsquic_send_ctl_reschedule_packets (lsquic_send_ctl_t *);
241
242#define lsquic_send_ctl_lost_ack(ctl) \
243    (((ctl)->sc_flags & (SC_LOST_ACK_INIT|SC_LOST_ACK_HSK|SC_LOST_ACK_APP)) \
244                                                        >> SCBIT_LOST_ACK_SHIFT)
245
246#define lsquic_send_ctl_scheduled_ack(ctl, pns, acked) do {         \
247    (ctl)->sc_flags &= ~(SC_LOST_ACK_INIT << pns);                  \
248    if (PNS_APP == pns)                                             \
249        (ctl)->sc_largest_acked = acked;                            \
250} while (0)
251
252void
253lsquic_send_ctl_set_tcid0 (lsquic_send_ctl_t *, int);
254
255#define lsquic_send_ctl_turn_nstp_on(ctl) ((ctl)->sc_flags |= SC_NSTP)
256
257void
258lsquic_send_ctl_elide_stream_frames (lsquic_send_ctl_t *, lsquic_stream_id_t);
259
260int
261lsquic_send_ctl_squeeze_sched (lsquic_send_ctl_t *);
262
263#define lsquic_send_ctl_maybe_squeeze_sched(ctl) (                  \
264    (ctl)->sc_n_scheduled && lsquic_send_ctl_squeeze_sched(ctl)     \
265)
266
267/* Same return value as for squeezing, but without actual squeezing. */
268int
269lsquic_send_ctl_have_delayed_packets (const lsquic_send_ctl_t *ctl);
270
271void
272lsquic_send_ctl_reset_packnos (lsquic_send_ctl_t *);
273
274void
275lsquic_send_ctl_ack_to_front (struct lsquic_send_ctl *, unsigned n_acks);
276
277#define lsquic_send_ctl_n_stop_waiting(ctl) \
278                                    (+(ctl)->sc_n_stop_waiting)
279
280#define lsquic_send_ctl_n_stop_waiting_reset(ctl) do {      \
281    (ctl)->sc_n_stop_waiting = 0;                           \
282} while (0)
283
284void
285lsquic_send_ctl_drop_scheduled (lsquic_send_ctl_t *);
286
287#define lsquic_send_ctl_tick_in(ctl, now) do {              \
288    if ((ctl)->sc_flags & SC_PACE)                          \
289    {                                                       \
290        (ctl)->sc_flags |= SC_SCHED_TICK;                   \
291        lsquic_pacer_tick_in(&(ctl)->sc_pacer, now);        \
292    }                                                       \
293    (ctl)->sc_flags &= ~SC_APP_LIMITED;                     \
294} while (0)
295
296#define lsquic_send_ctl_tick_out(ctl) do {                  \
297    if ((ctl)->sc_flags & SC_PACE)                          \
298        lsquic_pacer_tick_out(&(ctl)->sc_pacer);            \
299} while (0)
300
301#define lsquic_send_ctl_next_pacer_time(ctl) (              \
302    ((ctl)->sc_flags & SC_PACE)                             \
303        && lsquic_pacer_delayed(&(ctl)->sc_pacer)           \
304        ? lsquic_pacer_next_sched(&(ctl)->sc_pacer)         \
305        : 0 )
306
307enum packno_bits
308lsquic_send_ctl_packno_bits (struct lsquic_send_ctl *, enum packnum_space);
309
310int
311lsquic_send_ctl_schedule_buffered (lsquic_send_ctl_t *, enum buf_packet_type);
312
313#define lsquic_send_ctl_has_buffered(ctl) (                                 \
314    TAILQ_FIRST(&(ctl)->sc_buffered_packets[BPT_HIGHEST_PRIO].bpq_packets)  \
315 || TAILQ_FIRST(&(ctl)->sc_buffered_packets[BPT_OTHER_PRIO].bpq_packets  ))
316
317#define lsquic_send_ctl_has_buffered_high(ctl) (                            \
318    !TAILQ_EMPTY(&(ctl)->sc_buffered_packets[BPT_HIGHEST_PRIO].bpq_packets))
319
320#define lsquic_send_ctl_invalidate_bpt_cache(ctl) do {      \
321    (ctl)->sc_cached_bpt.stream_id = UINT64_MAX;            \
322} while (0)
323
324#ifndef NDEBUG
325enum packno_bits
326lsquic_send_ctl_guess_packno_bits (struct lsquic_send_ctl *);
327
328int
329lsquic_send_ctl_schedule_stream_packets_immediately (struct lsquic_send_ctl *);
330
331enum buf_packet_type
332lsquic_send_ctl_determine_bpt (struct lsquic_send_ctl *,
333                                            const struct lsquic_stream *);
334
335enum packno_bits
336lsquic_send_ctl_calc_packno_bits (struct lsquic_send_ctl *);
337
338void
339lsquic_send_ctl_set_max_bpq_count (unsigned);
340#endif
341
342size_t
343lsquic_send_ctl_mem_used (const struct lsquic_send_ctl *);
344
345#define lsquic_send_ctl_set_buffer_stream_packets(ctl, b) do {  \
346    (ctl)->sc_flags &= ~SC_BUFFER_STREAM;                       \
347    (ctl)->sc_flags |= -!!(b) & SC_BUFFER_STREAM;               \
348} while (0)
349
350int
351lsquic_send_ctl_turn_on_fin (struct lsquic_send_ctl *,
352                             const struct lsquic_stream *);
353
354int
355lsquic_send_ctl_pacer_blocked (struct lsquic_send_ctl *);
356
357#define lsquic_send_ctl_incr_pack_sz(ctl, packet, delta) do {   \
358    (packet)->po_data_sz += (delta);                            \
359    if ((packet)->po_flags & PO_SCHED)                          \
360        (ctl)->sc_bytes_scheduled += (delta);                   \
361    lsquic_send_ctl_sanity_check(ctl);                          \
362} while (0)
363
364int
365lsquic_send_ctl_sched_is_blocked (struct lsquic_send_ctl *);
366
367void
368lsquic_send_ctl_verneg_done (struct lsquic_send_ctl *);
369
370int
371lsquic_send_ctl_retry (struct lsquic_send_ctl *, const unsigned char *, size_t);
372
373int
374lsquic_send_ctl_set_token (struct lsquic_send_ctl *,
375                const unsigned char *token, size_t token_sz);
376
377void
378lsquic_send_ctl_empty_pns (struct lsquic_send_ctl *, enum packnum_space);
379
380void
381lsquic_send_ctl_maybe_calc_rough_rtt (struct lsquic_send_ctl *,
382                                                        enum packnum_space);
383
384void
385lsquic_send_ctl_repath (struct lsquic_send_ctl *ctl,
386    const struct network_path *old, const struct network_path *new,
387    int keep_path_properties);
388
389void
390lsquic_send_ctl_cancel_chals (struct lsquic_send_ctl *,
391                                                const struct network_path *);
392
393void
394lsquic_send_ctl_resize (struct lsquic_send_ctl *);
395
396void
397lsquic_send_ctl_return_enc_data (struct lsquic_send_ctl *);
398
399#define lsquic_send_ctl_1rtt_acked(ctl) ((ctl)->sc_flags & SC_1RTT_ACKED)
400
401void
402lsquic_send_ctl_maybe_app_limited (struct lsquic_send_ctl *,
403                                            const struct network_path *);
404
405#define lsquic_send_ctl_do_ql_bits(ctl) do {                       \
406    (ctl)->sc_flags |= SC_QL_BITS;                                 \
407} while (0)
408
409void
410lsquic_send_ctl_cidlen_change (struct lsquic_send_ctl *,
411                                unsigned orig_cid_len, unsigned new_cid_len);
412
413void
414lsquic_send_ctl_begin_optack_detection (struct lsquic_send_ctl *);
415
416void
417lsquic_send_ctl_path_validated (struct lsquic_send_ctl *);
418
419/* Has immediately sendable packets */
420#define lsquic_send_ctl_has_sendable(ctl_) \
421    (lsquic_send_ctl_n_scheduled(ctl_) > 0 \
422                && lsquic_send_ctl_next_packet_to_send_predict(ctl_))
423
424#define lsquic_send_ctl_in_recovery(ctl_) ((ctl_)->sc_largest_acked_packno \
425    && (ctl_)->sc_largest_acked_packno <= (ctl_)->sc_largest_sent_at_cutback)
426
427#define send_ctl_in_recovery lsquic_send_ctl_in_recovery
428
429int
430lsquic_send_ctl_can_send_probe (const struct lsquic_send_ctl *,
431                                            const struct network_path *);
432
433#define lsquic_send_ctl_ecn_turned_on(ctl_) ((ctl_)->sc_ecn != ECN_NOT_ECT)
434
435void
436lsquic_send_ctl_disable_ecn (struct lsquic_send_ctl *);
437
438struct send_ctl_state
439{
440    struct pacer        pacer;
441    struct ack_state    ack_state;
442    unsigned            buf_counts[BPT_OTHER_PRIO + 1];
443};
444
445void
446lsquic_send_ctl_snapshot (struct lsquic_send_ctl *, struct send_ctl_state *);
447
448void
449lsquic_send_ctl_rollback (struct lsquic_send_ctl *, struct send_ctl_state *,
450                                                const struct iovec *, size_t);
451
452void
453lsquic_send_ctl_0rtt_to_1rtt (struct lsquic_send_ctl *);
454
455void
456lsquic_send_ctl_stash_0rtt_packets (struct lsquic_send_ctl *);
457
458#endif
459