lsquic_send_ctl.h revision 662de5e1
1/* Copyright (c) 2017 - 2019 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;
23
24enum buf_packet_type { BPT_HIGHEST_PRIO, BPT_OTHER_PRIO, };
25
26struct buf_packet_q
27{
28    struct lsquic_packets_tailq     bpq_packets;
29    unsigned                        bpq_count;
30};
31
32enum send_ctl_flags {
33    SC_TCID0        = (1 << 0),
34    SC_NSTP         = (1 << 2),
35    SC_PACE         = (1 << 3),
36    SC_SCHED_TICK   = (1 << 4),
37    SC_BUFFER_STREAM= (1 << 5),
38    SC_WAS_QUIET    = (1 << 6),
39    SC_IETF         = (1 << 7),
40#define SCBIT_LOST_ACK_SHIFT 8
41    SC_LOST_ACK_INIT=  1 << 8,
42    SC_LOST_ACK_HSK = SC_LOST_ACK_INIT << PNS_HSK,
43    SC_LOST_ACK_APP = SC_LOST_ACK_INIT << PNS_APP,
44    SC_1RTT_ACKED   =  1 << 11,
45    SC_APP_LIMITED  =  1 << 12,
46    SC_ECN          =  1 << 13,
47};
48
49typedef struct lsquic_send_ctl {
50    /* The first section consists of struct members which are used in the
51     * time-critical lsquic_send_ctl_got_ack() in the approximate order
52     * of usage.
53     */
54    lsquic_senhist_t                sc_senhist;
55    enum send_ctl_flags             sc_flags;
56    enum ecn                        sc_ecn;
57    unsigned                        sc_n_stop_waiting;
58    struct lsquic_packets_tailq     sc_unacked_packets[N_PNS];
59    lsquic_packno_t                 sc_largest_acked_packno;
60    lsquic_time_t                   sc_largest_acked_sent_time;
61    lsquic_time_t                   sc_last_sent_time;
62    lsquic_time_t                   sc_last_rto_time;
63    unsigned                        sc_bytes_unacked_retx;
64    unsigned                        sc_bytes_scheduled;
65    union {
66        struct lsquic_cubic         cubic;
67        struct lsquic_bbr           bbr;
68    }                               sc_cong_u;
69    const struct cong_ctl_if       *sc_ci;
70    struct lsquic_engine_public    *sc_enpub;
71    unsigned                        sc_bytes_unacked_all;
72    unsigned                        sc_n_in_flight_all;
73    unsigned                        sc_n_in_flight_retx;
74    unsigned                        sc_n_consec_rtos;
75    unsigned                        sc_n_hsk;
76    unsigned                        sc_n_tlp;
77    enum quic_ft_bit                sc_retx_frames;
78    struct lsquic_alarmset         *sc_alset;
79
80    /* Second section: everything else. */
81    struct lsquic_packets_tailq     sc_scheduled_packets,
82                                    sc_lost_packets;
83    struct buf_packet_q             sc_buffered_packets[BPT_OTHER_PRIO + 1];
84    const struct ver_neg           *sc_ver_neg;
85    struct lsquic_conn_public      *sc_conn_pub;
86    struct pacer                    sc_pacer;
87    lsquic_packno_t                 sc_cur_packno;
88    lsquic_packno_t                 sc_largest_sent_at_cutback;
89    lsquic_packno_t                 sc_max_rtt_packno;
90    /* sc_largest_ack2ed is the packet number sent by peer that we acked and
91     * we know that our ACK was received by peer.  This is used to determine
92     * the receive history cutoff point for the purposes of generating ACK
93     * frames in the absense of STOP_WAITING frames.  Used when NSTP option
94     * is set.  (The "ack2ed" is odd enough to not be confused with anything
95     * else and it is not insanely long.)
96     */
97    lsquic_packno_t                 sc_largest_ack2ed[N_PNS];
98    /* sc_largest_acked is the largest packet number in PNS_APP packet number
99     * space sent by peer for which we generated (not necessarily sent) an ACK.
100     * This information is used to drop stale ACK frames from packets in
101     * buffered queues.
102     */
103    lsquic_packno_t                 sc_largest_acked;
104    lsquic_time_t                   sc_loss_to;
105    uint64_t                        sc_ecn_total_acked[N_PNS];
106    uint64_t                        sc_ecn_ce_cnt[N_PNS];
107    struct
108    {
109        lsquic_stream_id_t      stream_id;
110        enum buf_packet_type    packet_type;
111    }                               sc_cached_bpt;
112    unsigned                        sc_next_limit;
113    unsigned                        sc_n_scheduled;
114    enum packno_bits                sc_max_packno_bits;
115#if LSQUIC_SEND_STATS
116    struct {
117        unsigned            n_total_sent,
118                            n_resent,
119                            n_delayed;
120    }                               sc_stats;
121#endif
122    unsigned char                  *sc_token;
123    size_t                          sc_token_sz;
124    unsigned                        sc_retry_count;
125    unsigned                        sc_rt_count;    /* Count round trips */
126    lsquic_packno_t                 sc_cur_rt_end;
127} lsquic_send_ctl_t;
128
129void
130lsquic_send_ctl_init (lsquic_send_ctl_t *, struct lsquic_alarmset *,
131          struct lsquic_engine_public *, const struct ver_neg *,
132          struct lsquic_conn_public *, enum send_ctl_flags);
133
134int
135lsquic_send_ctl_sent_packet (lsquic_send_ctl_t *, struct lsquic_packet_out *);
136
137int
138lsquic_send_ctl_got_ack (lsquic_send_ctl_t *, const struct ack_info *,
139                                                lsquic_time_t, lsquic_time_t);
140
141lsquic_packno_t
142lsquic_send_ctl_smallest_unacked (lsquic_send_ctl_t *ctl);
143
144int
145lsquic_send_ctl_have_unacked_stream_frames (const lsquic_send_ctl_t *);
146
147void
148lsquic_send_ctl_cleanup (lsquic_send_ctl_t *);
149
150int
151lsquic_send_ctl_can_send (lsquic_send_ctl_t *ctl);
152
153void
154lsquic_send_ctl_scheduled_one (lsquic_send_ctl_t *, struct lsquic_packet_out *);
155
156void
157lsquic_send_ctl_delayed_one (lsquic_send_ctl_t *, struct lsquic_packet_out *);
158
159struct lsquic_packet_out *
160lsquic_send_ctl_next_packet_to_send (struct lsquic_send_ctl *, size_t);
161
162void
163lsquic_send_ctl_expire_all (lsquic_send_ctl_t *ctl);
164
165#define lsquic_send_ctl_n_in_flight(ctl) (+(ctl)->sc_n_in_flight)
166
167#define lsquic_send_ctl_n_scheduled(ctl) (+(ctl)->sc_n_scheduled)
168
169#define lsquic_send_ctl_largest_ack2ed(ctl, pns) \
170                                            (+(ctl)->sc_largest_ack2ed[pns])
171
172#if LSQUIC_EXTRA_CHECKS
173void
174lsquic_send_ctl_sanity_check (const lsquic_send_ctl_t *ctl);
175#else
176#   define lsquic_send_ctl_sanity_check(ctl)
177#endif
178
179int
180lsquic_send_ctl_have_outgoing_stream_frames (const lsquic_send_ctl_t *);
181
182int
183lsquic_send_ctl_have_outgoing_retx_frames (const lsquic_send_ctl_t *);
184
185struct lsquic_packet_out *
186lsquic_send_ctl_last_scheduled (struct lsquic_send_ctl *, enum packnum_space,
187                                            const struct network_path *, int);
188
189struct lsquic_packet_out *
190lsquic_send_ctl_new_packet_out (lsquic_send_ctl_t *, unsigned,
191                            enum packnum_space, const struct network_path *);
192
193struct lsquic_packet_out *
194lsquic_send_ctl_get_writeable_packet (lsquic_send_ctl_t *, enum packnum_space,
195      unsigned need_at_least, const struct network_path *, int, int *is_err);
196
197struct lsquic_packet_out *
198lsquic_send_ctl_get_packet_for_stream (lsquic_send_ctl_t *,
199                    unsigned need_at_least, const struct network_path *,
200                    const struct lsquic_stream *);
201
202struct lsquic_packet_out *
203lsquic_send_ctl_get_packet_for_crypto (struct lsquic_send_ctl *ctl,
204    unsigned need_at_least, enum packnum_space, const struct network_path *);
205
206unsigned
207lsquic_send_ctl_reschedule_packets (lsquic_send_ctl_t *);
208
209#define lsquic_send_ctl_lost_ack(ctl) \
210    (((ctl)->sc_flags & (SC_LOST_ACK_INIT|SC_LOST_ACK_HSK|SC_LOST_ACK_APP)) \
211                                                        >> SCBIT_LOST_ACK_SHIFT)
212
213#define lsquic_send_ctl_scheduled_ack(ctl, pns, acked) do {         \
214    (ctl)->sc_flags &= ~(SC_LOST_ACK_INIT << pns);                  \
215    if (PNS_APP == pns)                                             \
216        (ctl)->sc_largest_acked = acked;                            \
217} while (0)
218
219void
220lsquic_send_ctl_set_tcid0 (lsquic_send_ctl_t *, int);
221
222#define lsquic_send_ctl_turn_nstp_on(ctl) ((ctl)->sc_flags |= SC_NSTP)
223
224void
225lsquic_send_ctl_elide_stream_frames (lsquic_send_ctl_t *, lsquic_stream_id_t);
226
227int
228lsquic_send_ctl_squeeze_sched (lsquic_send_ctl_t *);
229
230#define lsquic_send_ctl_maybe_squeeze_sched(ctl) (                  \
231    (ctl)->sc_n_scheduled && lsquic_send_ctl_squeeze_sched(ctl)     \
232)
233
234/* Same return value as for squeezing, but without actual squeezing. */
235int
236lsquic_send_ctl_have_delayed_packets (const lsquic_send_ctl_t *ctl);
237
238void
239lsquic_send_ctl_reset_packnos (lsquic_send_ctl_t *);
240
241void
242lsquic_send_ctl_ack_to_front (struct lsquic_send_ctl *, unsigned n_acks);
243
244#define lsquic_send_ctl_n_stop_waiting(ctl) \
245                                    (+(ctl)->sc_n_stop_waiting)
246
247#define lsquic_send_ctl_n_stop_waiting_reset(ctl) do {      \
248    (ctl)->sc_n_stop_waiting = 0;                           \
249} while (0)
250
251void
252lsquic_send_ctl_drop_scheduled (lsquic_send_ctl_t *);
253
254#define lsquic_send_ctl_tick_in(ctl, now) do {              \
255    if ((ctl)->sc_flags & SC_PACE)                          \
256    {                                                       \
257        (ctl)->sc_flags |= SC_SCHED_TICK;                   \
258        pacer_tick_in(&(ctl)->sc_pacer, now);               \
259    }                                                       \
260    (ctl)->sc_flags &= ~SC_APP_LIMITED;                     \
261} while (0)
262
263#define lsquic_send_ctl_tick_out(ctl) do {                  \
264    if ((ctl)->sc_flags & SC_PACE)                          \
265        pacer_tick_out(&(ctl)->sc_pacer);                   \
266} while (0)
267
268#define lsquic_send_ctl_next_pacer_time(ctl) (              \
269    ((ctl)->sc_flags & SC_PACE)                             \
270        && pacer_delayed(&(ctl)->sc_pacer)                  \
271        ? pacer_next_sched(&(ctl)->sc_pacer)                \
272        : 0 )
273
274enum packno_bits
275lsquic_send_ctl_packno_bits (lsquic_send_ctl_t *);
276
277int
278lsquic_send_ctl_schedule_buffered (lsquic_send_ctl_t *, enum buf_packet_type);
279
280#define lsquic_send_ctl_has_buffered(ctl) (                                 \
281    TAILQ_FIRST(&(ctl)->sc_buffered_packets[BPT_HIGHEST_PRIO].bpq_packets)  \
282 || TAILQ_FIRST(&(ctl)->sc_buffered_packets[BPT_OTHER_PRIO].bpq_packets  ))
283
284#define lsquic_send_ctl_invalidate_bpt_cache(ctl) do {      \
285    (ctl)->sc_cached_bpt.stream_id = UINT64_MAX;            \
286} while (0)
287
288#ifndef NDEBUG
289enum packno_bits
290lsquic_send_ctl_guess_packno_bits (struct lsquic_send_ctl *);
291
292int
293lsquic_send_ctl_schedule_stream_packets_immediately (struct lsquic_send_ctl *);
294
295enum buf_packet_type
296lsquic_send_ctl_determine_bpt (struct lsquic_send_ctl *,
297                                            const struct lsquic_stream *);
298
299enum packno_bits
300lsquic_send_ctl_calc_packno_bits (struct lsquic_send_ctl *);
301
302void
303lsquic_send_ctl_set_max_bpq_count (unsigned);
304#endif
305
306size_t
307lsquic_send_ctl_mem_used (const struct lsquic_send_ctl *);
308
309#define lsquic_send_ctl_set_buffer_stream_packets(ctl, b) do {  \
310    (ctl)->sc_flags &= ~SC_BUFFER_STREAM;                       \
311    (ctl)->sc_flags |= -!!(b) & SC_BUFFER_STREAM;               \
312} while (0)
313
314int
315lsquic_send_ctl_turn_on_fin (struct lsquic_send_ctl *,
316                             const struct lsquic_stream *);
317
318int
319lsquic_send_ctl_pacer_blocked (struct lsquic_send_ctl *);
320
321#define lsquic_send_ctl_incr_pack_sz(ctl, packet, delta) do {   \
322    (packet)->po_data_sz += (delta);                            \
323    if ((packet)->po_flags & PO_SCHED)                          \
324        (ctl)->sc_bytes_scheduled += (delta);                   \
325    lsquic_send_ctl_sanity_check(ctl);                          \
326} while (0)
327
328int
329lsquic_send_ctl_sched_is_blocked (struct lsquic_send_ctl *);
330
331void
332lsquic_send_ctl_verneg_done (struct lsquic_send_ctl *);
333
334int
335lsquic_send_ctl_retry (struct lsquic_send_ctl *, const unsigned char *,
336                                                                size_t, int);
337
338int
339lsquic_send_ctl_set_token (struct lsquic_send_ctl *,
340                const unsigned char *token, size_t token_sz);
341
342void
343lsquic_send_ctl_empty_pns (struct lsquic_send_ctl *, enum packnum_space);
344
345void
346lsquic_send_ctl_repath (struct lsquic_send_ctl *, struct network_path *old,
347                                struct network_path *new);
348
349void
350lsquic_send_ctl_return_enc_data (struct lsquic_send_ctl *);
351
352#define lsquic_send_ctl_1rtt_acked(ctl) ((ctl)->sc_flags & SC_1RTT_ACKED)
353
354void
355lsquic_send_ctl_maybe_app_limited (struct lsquic_send_ctl *,
356                                            const struct network_path *);
357
358#endif
359