xref: /freebsd/sys/netinet/tcp_stacks/tcp_bbr.h (revision cfd6422a5217410fbd66f7a7a8a64d9d85e61229)
1 /*-
2  * Copyright (c) 2016-2020 Netflix, Inc.
3  *
4  * Redistribution and use in source and binary forms, with or without
5  * modification, are permitted provided that the following conditions
6  * are met:
7  * 1. Redistributions of source code must retain the above copyright
8  *    notice, this list of conditions and the following disclaimer.
9  * 2. Redistributions in binary form must reproduce the above copyright
10  *    notice, this list of conditions and the following disclaimer in the
11  *    documentation and/or other materials provided with the distribution.
12  *
13  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
14  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
15  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
16  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
17  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
18  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
19  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
20  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
21  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
22  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
23  * SUCH DAMAGE.
24  *
25  * $FreeBSD$
26  */
27 
28 #ifndef _NETINET_TCP_BBR_H_
29 #define _NETINET_TCP_BBR_H_
30 
31 #define BBR_INITIAL_RTO  1000000	/* 1 second in micro-seconds */
32 /* Send map flags */
33 #define BBR_ACKED	  0x0001	/* The remote endpoint acked this */
34 #define BBR_WAS_RENEGED	  0x0002	/* The peer reneged the ack  */
35 #define BBR_RXT_CLEARED	  0x0004	/* ACK Cleared by the RXT timer  */
36 #define BBR_OVERMAX	  0x0008	/* We have more retran's then we can
37 					 * fit */
38 #define BBR_SACK_PASSED   0x0010	/* A sack was done above this block */
39 #define BBR_WAS_SACKPASS  0x0020	/* We retransmitted due to SACK pass */
40 #define BBR_HAS_FIN	  0x0040	/* segment is sent with fin */
41 #define BBR_TLP	  	  0x0080	/* segment sent as tail-loss-probe */
42 #define BBR_HAS_SYN	  0x0100	/* segment has the syn */
43 #define BBR_MARKED_LOST   0x0200	/*
44 					 * This segments is lost and
45 					 * totaled into bbr->rc_ctl.rc_lost
46 					 */
47 #define BBR_RWND_COLLAPSED 0x0400	/* The peer collapsed the rwnd on the segment */
48 #define BBR_NUM_OF_RETRANS 7
49 
50 /* Defines for socket options to set pacing overheads */
51 #define BBR_INCL_ENET_OH 0x01
52 #define BBR_INCL_IP_OH   0x02
53 #define BBR_INCL_TCP_OH  0x03
54 
55 /*
56  * With the addition of both measurement algorithms
57  * I had to move over the size of a
58  * cache line (unfortunately). For now there is
59  * no way around this. We may be able to cut back
60  * at some point I hope.
61  */
62 struct bbr_sendmap {
63 	TAILQ_ENTRY(bbr_sendmap) r_next;	/* seq number arrayed next */
64 	TAILQ_ENTRY(bbr_sendmap) r_tnext;	/* Time of tmit based next */
65 	uint32_t r_start;	/* Sequence number of the segment */
66 	uint32_t r_end;		/* End seq, this is 1 beyond actually */
67 
68 	uint32_t r_rtr_bytes;	/* How many bytes have been retransmitted */
69 	uint32_t r_delivered;	/* Delivered amount at send */
70 
71 	uint32_t r_del_time;	/* The time of the last delivery update */
72 	uint8_t r_rtr_cnt:4,	/* Retran count, index this -1 to get time
73 				 * sent */
74 		unused_bit:1,
75 	        r_is_drain:1,	/* In a draining cycle */
76 		r_app_limited:1,/* We went app limited */
77 	        r_ts_valid:1;	/* Timestamp field is valid (r_del_ack_ts) */
78 	uint8_t r_dupack;	/* Dup ack count */
79 	uint8_t r_in_tmap:1,	/* Flag to see if its in the r_tnext array */
80 	        r_is_smallmap:1,/* Was logged as a small-map send-map item */
81 		r_is_gain:1,	/* Was in gain cycle */
82 		r_bbr_state:5;  /* The BBR state at send */
83 	uint8_t r_limit_type;	/* is this entry counted against a limit? */
84 
85 	uint16_t r_flags;	/* Flags as defined above */
86 	uint16_t r_spare16;
87 	uint32_t r_del_ack_ts;  /* At send what timestamp of peer was (if r_ts_valid set) */
88 	/****************Cache line*****************/
89 	uint32_t r_tim_lastsent[BBR_NUM_OF_RETRANS];
90 	/*
91 	 * Question, should we instead just grab the sending b/w
92 	 * from the filter with the gain and store it in a
93 	 * uint64_t instead?
94 	 */
95 	uint32_t r_first_sent_time; /* Time of first pkt in flight sent */
96 	uint32_t r_pacing_delay;	/* pacing delay of this send */
97 	uint32_t r_flight_at_send;	/* flight at the time of the send */
98 #ifdef _KERNEL
99 }           __aligned(CACHE_LINE_SIZE);
100 #else
101 };
102 #endif
103 #define BBR_LIMIT_TYPE_SPLIT	1
104 
105 TAILQ_HEAD(bbr_head, bbr_sendmap);
106 
107 #define BBR_SEGMENT_TIME_SIZE 1500	/* How many bytes in time_between */
108 
109 #define BBR_MIN_SEG 1460		/* MSS size */
110 #define BBR_MAX_GAIN_VALUE 0xffff
111 
112 #define BBR_TIMER_FUDGE  1500	/* 1.5ms in micro seconds */
113 
114 /* BW twiddle secret codes */
115 #define BBR_RED_BW_CONGSIG  	 0	/* We enter recovery and set using b/w */
116 #define BBR_RED_BW_RATECAL  	 1	/* We are calculating the loss rate */
117 #define BBR_RED_BW_USELRBW       2	/* We are dropping the lower b/w with
118 					 * cDR */
119 #define BBR_RED_BW_SETHIGHLOSS	 3	/* We have set our highloss value at
120 					 * exit from probe-rtt */
121 #define BBR_RED_BW_PE_CLREARLY	 4	/* We have decided to clear the
122 					 * reduction early */
123 #define BBR_RED_BW_PE_CLAFDEL	 5	/* We are clearing it on schedule
124 					 * delayed */
125 #define BBR_RED_BW_REC_ENDCLL	 6	/* Recover exits save high if needed
126 					 * an clear to start measuring */
127 #define BBR_RED_BW_PE_NOEARLY_OUT 7	/* Set pkt epoch judged that we do not
128 					 * get out of jail early */
129 /* For calculating a rate */
130 #define BBR_CALC_BW 	1
131 #define BBR_CALC_LOSS  	2
132 
133 #define BBR_RTT_BY_TIMESTAMP	0
134 #define BBR_RTT_BY_EXACTMATCH	1
135 #define BBR_RTT_BY_EARLIER_RET	2
136 #define BBR_RTT_BY_THIS_RETRAN  3
137 #define BBR_RTT_BY_SOME_RETRAN	4
138 #define BBR_RTT_BY_TSMATCHING	5
139 
140 /* Markers to track where we enter persists from */
141 #define BBR_PERSISTS_FROM_1	1
142 #define BBR_PERSISTS_FROM_2	2
143 #define BBR_PERSISTS_FROM_3	3
144 #define BBR_PERSISTS_FROM_4	4
145 #define BBR_PERSISTS_FROM_5	5
146 
147 /* magic cookies to ask for the RTT */
148 #define BBR_RTT_PROP    0
149 #define BBR_RTT_RACK    1
150 #define BBR_RTT_PKTRTT  2
151 #define BBR_SRTT	3
152 
153 #define BBR_SACKED 0
154 #define BBR_CUM_ACKED  1
155 
156 /* threshold in useconds where we consider we need a higher min cwnd */
157 #define BBR_HIGH_SPEED 1000
158 #define BBR_HIGHSPEED_NUM_MSS 12
159 
160 #define MAX_REDUCE_RXT 3	/* What is the maximum times we are willing to
161 				 * reduce b/w in RTX's. Setting this has a
162 				 * multiplicative effect e.g. if we are
163 				 * reducing by 20% then setting it to 3 means
164 				 * you will have reduced the b/w estimate by >
165 				 * 60% before you stop. */
166 /*
167  * We use the rate sample structure to
168  * assist in single sack/ack rate and rtt
169  * calculation. In the future we will expand
170  * this in BBR to do forward rate sample
171  * b/w estimation.
172  */
173 #define BBR_RS_RTT_EMPTY 0x00000001	/* Nothing yet stored in RTT's */
174 #define BBR_RS_BW_EMPTY  0x00000002	/* Nothing yet stored in cDR */
175 #define BBR_RS_RTT_VALID 0x00000004	/* We have at least one valid RTT */
176 #define BBR_RS_BW_VAILD  0x00000008	/* We have a valid cDR */
177 #define BBR_RS_EMPTY   (BBR_RS_RTT_EMPTY|BBR_RS_BW_EMPTY)
178 struct bbr_rtt_sample {
179 	uint32_t rs_flags;
180 	uint32_t rs_rtt_lowest;
181 	uint32_t rs_rtt_lowest_sendtime;
182 	uint32_t rs_rtt_low_seq_start;
183 
184 	uint32_t rs_rtt_highest;
185 	uint32_t rs_rtt_cnt;
186 
187 	uint64_t rs_rtt_tot;
188 	uint32_t cur_rtt;
189 	uint32_t cur_rtt_bytecnt;
190 
191 	uint32_t cur_rtt_rsmcnt;
192 	uint32_t rc_crtt_set:1,
193 		avail_bits:31;
194 	uint64_t rs_cDR;
195 };
196 
197 /* RTT shrink reasons */
198 #define BBR_RTTS_INIT     0
199 #define BBR_RTTS_NEWRTT   1
200 #define BBR_RTTS_RTTPROBE 2
201 #define BBR_RTTS_WASIDLE  3
202 #define BBR_RTTS_PERSIST  4
203 #define BBR_RTTS_REACHTAR 5
204 #define BBR_RTTS_ENTERPROBE 6
205 #define BBR_RTTS_SHRINK_PG 7
206 #define BBR_RTTS_SHRINK_PG_FINAL 8
207 #define BBR_RTTS_NEW_TARGET 9
208 #define BBR_RTTS_LEAVE_DRAIN 10
209 #define BBR_RTTS_RESETS_VALUES 11
210 
211 #define BBR_NUM_RATES 5
212 /* Rate flags */
213 #define BBR_RT_FLAG_FREE       0x00	/* Is on the free list */
214 #define BBR_RT_FLAG_INUSE      0x01	/* Has been allocated */
215 #define BBR_RT_FLAG_READY      0x02	/* Ready to initiate a measurement. */
216 #define BBR_RT_FLAG_CAPPED_PRE 0x04	/* Ready to cap if we send the next segment */
217 #define BBR_RT_FLAG_CAPPED     0x08	/* Measurement is capped */
218 #define BBR_RT_FLAG_PASTFA     0x10	/* Past the first ack. */
219 #define BBR_RT_FLAG_LIMITED    0x20	/* Saw application/cwnd or rwnd limited period */
220 #define BBR_RT_SEEN_A_ACK      0x40	/* A ack has been saved */
221 #define BBR_RT_PREV_RTT_SET    0x80	/* There was a RTT set in */
222 #define BBR_RT_PREV_SEND_TIME  0x100	/*
223 					 *There was a RTT send time set that can be used
224 					 * no snd_limits
225 					 */
226 #define BBR_RT_SET_GRADIENT    0x200
227 #define BBR_RT_TS_VALID        0x400
228 
229 struct bbr_log {
230 	union {
231 		struct bbr_sendmap *rsm;	/* For alloc/free */
232 		uint64_t sb_acc;	/* For out/ack or t-o */
233 	};
234 	struct tcpcb *tp;
235 	uint32_t t_flags;
236 	uint32_t th_seq;
237 	uint32_t th_ack;
238 	uint32_t snd_una;
239 	uint32_t snd_nxt;
240 	uint32_t snd_max;
241 	uint32_t snd_cwnd;
242 	uint32_t snd_wnd;
243 	uint32_t rc_lost;
244 	uint32_t target_cwnd;	/* UU */
245 	uint32_t inflight;	/* UU */
246 	uint32_t applimited;	/* UU */
247 	/* Things for BBR */
248 	uint32_t delivered;	/* UU */
249 	uint64_t cur_del_rate;	/* UU */
250 	uint64_t delRate;	/* UU */
251 	uint64_t rttProp;	/* UU */
252 	uint64_t lt_bw;		/* UU */
253 	uint32_t timeStamp;
254 	uint32_t time;
255 	uint32_t slot;		/* UU */
256 	uint32_t delayed_by;
257 	uint32_t exp_del;
258 	uint32_t pkts_out;
259 	uint32_t new_win;
260 	uint32_t hptsi_gain;	/* UU */
261 	uint32_t cwnd_gain;	/* UU */
262 	uint32_t epoch;		/* UU */
263 	uint32_t lt_epoch;	/* UU */
264 	/* Sack fun */
265 	uint32_t blk_start[4];	/* xx */
266 	uint32_t blk_end[4];
267 	uint32_t len;		/* Timeout T3=1, TLP=2, RACK=3 */
268 	uint8_t type;
269 	uint8_t n_sackblks;
270 	uint8_t applied;	/* UU */
271 	uint8_t inhpts;		/* UU */
272 	uint8_t ininput;	/* UU */
273 	uint8_t use_lt_bw;	/* UU */
274 };
275 
276 struct bbr_log_sysctl_out {
277 	uint32_t bbr_log_at;
278 	uint32_t bbr_log_max;
279 	struct bbr_log entries[0];
280 };
281 
282 /*
283  * Magic numbers for logging timeout events if the
284  * logging is enabled.
285  */
286 #define BBR_TO_FRM_TMR  1
287 #define BBR_TO_FRM_TLP  2
288 #define BBR_TO_FRM_RACK 3
289 #define BBR_TO_FRM_KEEP 4
290 #define BBR_TO_FRM_PERSIST 5
291 #define BBR_TO_FRM_DELACK 6
292 
293 #define BBR_SEES_STRETCH_ACK 1
294 #define BBR_SEES_COMPRESSED_ACKS 2
295 
296 /*
297  * As we get each SACK we wade through the
298  * rc_map and mark off what is acked.
299  * We also increment rc_sacked as well.
300  *
301  * We also pay attention to missing entries
302  * based on the time and possibly mark them
303  * for retransmit. If we do and we are not already
304  * in recovery we enter recovery. In doing
305  * so we claer prr_delivered/holes_rxt and prr_sent_dur_rec.
306  * We also setup rc_next/rc_snd_nxt/rc_send_end so
307  * we will know where to send from. When not in
308  * recovery rc_next will be NULL and rc_snd_nxt should
309  * equal snd_max.
310  *
311  * Whenever we retransmit from recovery we increment
312  * rc_holes_rxt as we retran a block and mark it as retransmitted
313  * with the time it was sent. During non-recovery sending we
314  * add to our map and note the time down of any send expanding
315  * the rc_map at the tail and moving rc_snd_nxt up with snd_max.
316  *
317  * In recovery during SACK/ACK processing if a chunk has
318  * been retransmitted and it is now acked, we decrement rc_holes_rxt.
319  * When we retransmit from the scoreboard we use
320  * rc_next and rc_snd_nxt/rc_send_end to help us
321  * find what needs to be retran.
322  *
323  * To calculate pipe we simply take (snd_max - snd_una) + rc_holes_rxt
324  * This gets us the effect of RFC6675 pipe, counting twice for
325  * bytes retransmitted.
326  */
327 
328 #define TT_BBR_FR_TMR	0x2001
329 
330 #define BBR_SCALE 8
331 #define BBR_UNIT (1 << BBR_SCALE)
332 
333 #define BBR_NUM_RTTS_FOR_DEL_LIMIT 8	/* How many pkt-rtts do we keep
334 					 * Delivery rate for */
335 #define BBR_NUM_RTTS_FOR_GOOG_DEL_LIMIT 10	/* How many pkt-rtts do we keep
336 						 * Delivery rate for google */
337 
338 #define BBR_SECONDS_NO_RTT 10	/* 10 seconds with no RTT shrinkage */
339 #define BBR_PROBERTT_MAX 200	/* 200ms */
340 #define BBR_PROBERTT_NUM_MSS 4
341 #define BBR_STARTUP_EPOCHS 3
342 #define USECS_IN_MSEC 1000
343 #define BBR_TIME_TO_SECONDS(a) (a / USECS_IN_SECOND)
344 #define BBR_TIME_TO_MILLI(a) (a / MS_IN_USEC)
345 
346 /* BBR keeps time in usec's so we divide by 1000 and round up */
347 #define BBR_TS_TO_MS(t)  ((t+999)/MS_IN_USEC)
348 
349 /*
350  * Locking for the rack control block.
351  * a) Locked by INP_WLOCK
352  * b) Locked by the hpts-mutex
353  *
354  */
355 #define BBR_STATE_STARTUP   0x01
356 #define BBR_STATE_DRAIN     0x02
357 #define BBR_STATE_PROBE_BW  0x03
358 #define BBR_STATE_PROBE_RTT 0x04
359 #define BBR_STATE_IDLE_EXIT 0x05
360 
361 /* Substate defines for STATE == PROBE_BW */
362 #define BBR_SUB_GAIN  0		/* State 0 where we are 5/4 BBR_UNIT */
363 #define BBR_SUB_DRAIN 1		/* State 1 where we are at 3/4 BBR_UNIT */
364 #define BBR_SUB_LEVEL1 2	/* State 1 first BBR_UNIT */
365 #define BBR_SUB_LEVEL2 3	/* State 2nd BBR_UNIT */
366 #define BBR_SUB_LEVEL3 4	/* State 3rd BBR_UNIT */
367 #define BBR_SUB_LEVEL4 5	/* State 4th BBR_UNIT */
368 #define BBR_SUB_LEVEL5 6	/* State 5th BBR_UNIT */
369 #define BBR_SUB_LEVEL6 7	/* State last BBR_UNIT */
370 #define BBR_SUBSTATE_COUNT 8
371 
372 /* Single remaining reduce log */
373 #define BBR_REDUCE_AT_FR 5
374 
375 #define BBR_BIG_LOG_SIZE 300000
376 
377 struct bbr_stats {
378 	uint64_t bbr_badfr;		/* 0 */
379 	uint64_t bbr_badfr_bytes;	/* 1 */
380 	uint64_t bbr_saw_oerr;		/* 2 */
381 	uint64_t bbr_saw_emsgsiz;	/* 3 */
382 	uint64_t bbr_reorder_seen;	/* 4 */
383 	uint64_t bbr_tlp_tot;		/* 5 */
384 	uint64_t bbr_tlp_newdata;	/* 6 */
385 	uint64_t bbr_offset_recovery;	/* 7 */
386 	uint64_t bbr_tlp_retran_fail;	/* 8 */
387 	uint64_t bbr_to_tot;		/* 9 */
388 	uint64_t bbr_to_arm_rack;	/* 10 */
389 	uint64_t bbr_enter_probertt;	/* 11 */
390 	uint64_t bbr_tlp_set;		/* 12 */
391 	uint64_t bbr_resends_set;	/* 13 */
392 	uint64_t bbr_force_output;	/* 14 */
393 	uint64_t bbr_to_arm_tlp;	/* 15 */
394 	uint64_t bbr_paced_segments;	/* 16 */
395 	uint64_t bbr_saw_enobuf;	/* 17 */
396 	uint64_t bbr_to_alloc_failed;	/* 18 */
397 	uint64_t bbr_to_alloc_emerg;	/* 19 */
398 	uint64_t bbr_sack_proc_all;	/* 20 */
399 	uint64_t bbr_sack_proc_short;	/* 21 */
400 	uint64_t bbr_sack_proc_restart;	/* 22 */
401 	uint64_t bbr_to_alloc;		/* 23 */
402 	uint64_t bbr_offset_drop;	/* 24 */
403 	uint64_t bbr_runt_sacks;	/* 25 */
404 	uint64_t bbr_sack_passed;	/* 26 */
405 	uint64_t bbr_rlock_left_ret0;	/* 27 */
406 	uint64_t bbr_rlock_left_ret1;	/* 28 */
407 	uint64_t bbr_dynamic_rwnd;	/* 29 */
408 	uint64_t bbr_static_rwnd;	/* 30 */
409 	uint64_t bbr_sack_blocks;	/* 31 */
410 	uint64_t bbr_sack_blocks_skip;	/* 32 */
411 	uint64_t bbr_sack_search_both;	/* 33 */
412 	uint64_t bbr_sack_search_fwd;	/* 34 */
413 	uint64_t bbr_sack_search_back;	/* 35 */
414 	uint64_t bbr_plain_acks;	/* 36 */
415 	uint64_t bbr_acks_with_sacks;	/* 37 */
416 	uint64_t bbr_progress_drops;	/* 38 */
417 	uint64_t bbr_early;		/* 39 */
418 	uint64_t bbr_reneges_seen;	/* 40 */
419 	uint64_t bbr_persist_reneg;	/* 41 */
420 	uint64_t bbr_dropped_af_data;	/* 42 */
421 	uint64_t bbr_failed_mbuf_aloc;	/* 43 */
422 	uint64_t bbr_cwnd_limited;	/* 44 */
423 	uint64_t bbr_rwnd_limited;	/* 45 */
424 	uint64_t bbr_app_limited;	/* 46 */
425 	uint64_t bbr_force_timer_start;	/* 47 */
426 	uint64_t bbr_hpts_min_time;	/* 48 */
427 	uint64_t bbr_meets_tso_thresh;  /* 49 */
428 	uint64_t bbr_miss_tso_rwnd;	/* 50 */
429 	uint64_t bbr_miss_tso_cwnd;	/* 51 */
430 	uint64_t bbr_miss_tso_app;	/* 52 */
431 	uint64_t bbr_miss_retran;	/* 53 */
432 	uint64_t bbr_miss_tlp;		/* 54 */
433 	uint64_t bbr_miss_unknown;	/* 55 */
434 	uint64_t bbr_hdwr_rl_add_ok;	/* 56 */
435 	uint64_t bbr_hdwr_rl_add_fail;	/* 57 */
436 	uint64_t bbr_hdwr_rl_mod_ok;	/* 58 */
437 	uint64_t bbr_hdwr_rl_mod_fail;	/* 59 */
438 	uint64_t bbr_collapsed_win;     /* 60 */
439 	uint64_t bbr_alloc_limited;	/* 61 */
440 	uint64_t bbr_alloc_limited_conns; /* 62 */
441 	uint64_t bbr_split_limited;	/* 63 */
442 };
443 
444 /*
445  * The structure bbr_opt_stats is a simple
446  * way to see how many options are being
447  * changed in the stack.
448  */
449 struct bbr_opts_stats {
450 	uint64_t tcp_bbr_pace_per_sec;
451 	uint64_t tcp_bbr_pace_del_tar;
452 	uint64_t tcp_bbr_pace_seg_max;
453 	uint64_t tcp_bbr_pace_seg_min;
454 	uint64_t tcp_bbr_pace_cross;
455 	uint64_t tcp_bbr_drain_inc_extra;
456 	uint64_t tcp_bbr_unlimited;
457 	uint64_t tcp_bbr_iwintso;
458 	uint64_t tcp_bbr_rec_over_hpts;
459 	uint64_t tcp_bbr_recforce;
460 	uint64_t tcp_bbr_startup_pg;
461 	uint64_t tcp_bbr_drain_pg;
462 	uint64_t tcp_bbr_rwnd_is_app;
463 	uint64_t tcp_bbr_probe_rtt_int;
464 	uint64_t tcp_bbr_one_retran;
465 	uint64_t tcp_bbr_startup_loss_exit;
466 	uint64_t tcp_bbr_use_lowgain;
467 	uint64_t tcp_bbr_lowgain_thresh;
468 	uint64_t tcp_bbr_lowgain_half;
469 	uint64_t tcp_bbr_lowgain_fd;
470 	uint64_t tcp_bbr_usedel_rate;
471 	uint64_t tcp_bbr_min_rto;
472 	uint64_t tcp_bbr_max_rto;
473 	uint64_t tcp_rack_pace_max_seg;
474 	uint64_t tcp_rack_min_to;
475 	uint64_t tcp_rack_reord_thresh;
476 	uint64_t tcp_rack_reord_fade;
477 	uint64_t tcp_rack_tlp_thresh;
478 	uint64_t tcp_rack_pkt_delay;
479 	uint64_t tcp_bbr_startup_exit_epoch;
480 	uint64_t tcp_bbr_ack_comp_alg;
481 	uint64_t tcp_rack_cheat;
482 	uint64_t tcp_iwnd_tso;
483 	uint64_t tcp_utter_max_tso;
484 	uint64_t tcp_hdwr_pacing;
485 	uint64_t tcp_extra_state;
486 	uint64_t tcp_floor_min_tso;
487 	/* New */
488 	uint64_t tcp_bbr_algorithm;
489 	uint64_t tcp_bbr_tslimits;
490 	uint64_t tcp_bbr_probertt_len;
491 	uint64_t tcp_bbr_probertt_gain;
492 	uint64_t tcp_bbr_topaceout;
493 	uint64_t tcp_use_rackcheat;
494 	uint64_t tcp_delack;
495 	uint64_t tcp_maxpeak;
496 	uint64_t tcp_retran_wtso;
497 	uint64_t tcp_data_ac;
498 	uint64_t tcp_ts_raises;
499 	uint64_t tcp_pacing_oh_tmr;
500 	uint64_t tcp_pacing_oh;
501 	uint64_t tcp_policer_det;
502 };
503 
504 #ifdef _KERNEL
505 #define BBR_STAT_SIZE (sizeof(struct bbr_stats)/sizeof(uint64_t))
506 extern counter_u64_t bbr_stat_arry[BBR_STAT_SIZE];
507 #define BBR_STAT_ADD(name, amm) counter_u64_add(bbr_stat_arry[(offsetof(struct bbr_stats, name)/sizeof(uint64_t))], (amm))
508 #define BBR_STAT_INC(name) BBR_STAT_ADD(name, 1)
509 #define BBR_OPTS_SIZE (sizeof(struct bbr_stats)/sizeof(uint64_t))
510 extern counter_u64_t bbr_opts_arry[BBR_OPTS_SIZE];
511 #define BBR_OPTS_ADD(name, amm) counter_u64_add(bbr_opts_arry[(offsetof(struct bbr_opts_stats, name)/sizeof(uint64_t))], (amm))
512 #define BBR_OPTS_INC(name) BBR_OPTS_ADD(name, 1)
513 #endif
514 
515 #define BBR_NUM_LOSS_RATES 3
516 #define BBR_NUM_BW_RATES 3
517 
518 #define BBR_RECOVERY_LOWRTT 1
519 #define BBR_RECOVERY_MEDRTT 2
520 #define BBR_RECOVERY_HIGHRTT 3
521 #define BBR_RECOVERY_EXTREMERTT 4
522 
523 struct bbr_control {
524 	/*******************************/
525 	/* Cache line 2 from bbr start */
526 	/*******************************/
527 	struct bbr_head rc_map;	/* List of all segments Lock(a) */
528 	struct bbr_head rc_tmap;	/* List in transmit order Lock(a) */
529 	struct bbr_sendmap *rc_resend;	/* something we have been asked to
530 					 * resend */
531 	uint32_t rc_last_delay_val;	/* How much we expect to delay Lock(a) */
532 	uint32_t rc_bbr_hptsi_gain:16,	/* Current hptsi gain Lock(a) */
533 	         rc_hpts_flags:16;	/* flags on whats on the pacer wheel */
534 
535 	uint32_t rc_delivered;	/* BRR delivered amount Lock(a) */
536 	uint32_t rc_hptsi_agg_delay;	/* How much time are we behind */
537 
538 	uint32_t rc_flight_at_input;
539 	uint32_t rc_lost_bytes;		/* Total bytes currently marked lost */
540 	/*******************************/
541 	/* Cache line 3 from bbr start */
542 	/*******************************/
543 	struct time_filter rc_delrate;
544 	/*******************************/
545 	/* Cache line 4 from bbr start */
546 	/*******************************/
547 	struct bbr_head rc_free;	/* List of Free map entries Lock(a) */
548 	struct bbr_sendmap *rc_tlp_send;	/* something we have been
549 						 * asked to resend */
550 	uint32_t rc_del_time;
551 	uint32_t rc_target_at_state;	/* Target for a state */
552 
553 	uint16_t rc_free_cnt;	/* Number of free entries on the rc_free list
554 				 * Lock(a) */
555 	uint16_t rc_startup_pg;
556 
557 	uint32_t cur_rtt;	/* Last RTT from ack */
558 
559 	uint32_t rc_went_idle_time;	/* Used for persits to see if its
560 					 * probe-rtt qualified */
561 	uint32_t rc_pace_max_segs:17,	/* How much in any single TSO we send Lock(a) */
562 		 rc_pace_min_segs:15;	/* The minimum single segment size before we enter persists */
563 
564 	uint32_t rc_rtt_shrinks;	/* Time of last rtt shrinkage Lock(a) */
565 	uint32_t r_app_limited_until;
566 	uint32_t rc_timer_exp;	/* If a timer ticks of expiry */
567 	uint32_t rc_rcv_epoch_start;	/* Start time of the Epoch Lock(a) */
568 
569 	/*******************************/
570 	/* Cache line 5 from bbr start */
571 	/*******************************/
572 
573 	uint32_t rc_lost_at_pktepoch;	/* what the lost value was at the last
574 					 * pkt-epoch */
575 	uint32_t r_measurement_count;	/* count of measurement applied lock(a) */
576 
577 	uint32_t rc_last_tlp_seq;	/* Last tlp sequence Lock(a) */
578 	uint16_t rc_reorder_shift;	/* Socket option value Lock(a) */
579 	uint16_t rc_pkt_delay;	/* Socket option value Lock(a) */
580 
581 	struct bbr_sendmap *rc_sacklast;	/* sack remembered place
582 						 * Lock(a) */
583 	struct bbr_sendmap *rc_next;	/* remembered place where we next
584 					 * retransmit at Lock(a) */
585 
586 	uint32_t rc_sacked;	/* Tot sacked on scoreboard Lock(a) */
587 	uint32_t rc_holes_rxt;	/* Tot retraned from scoreboard Lock(a) */
588 
589 	uint32_t rc_reorder_ts;	/* Last time we saw reordering Lock(a) */
590 	uint32_t rc_init_rwnd;	/* Initial rwnd when we transitioned */
591                                 /*- ---
592 				 * used only initial and close
593                                  */
594 	uint32_t rc_high_rwnd;	/* Highest rwnd seen */
595 	uint32_t rc_lowest_rtt;	/* Smallest RTT we have seen */
596 
597 	uint32_t rc_last_rtt;	/* Last valid measured RTT that ack'd data */
598 	uint32_t bbr_cross_over;
599 
600 	/*******************************/
601 	/* Cache line 6 from bbr start */
602 	/*******************************/
603 	struct sack_filter bbr_sf;
604 
605 	/*******************************/
606 	/* Cache line 7 from bbr start */
607 	/*******************************/
608 	struct time_filter_small rc_rttprop;
609 	uint32_t last_inbound_ts;	/* Peers last timestamp */
610 
611 	uint32_t rc_inc_tcp_oh: 1,
612 		 rc_inc_ip_oh: 1,
613 		 rc_inc_enet_oh:1,
614 		 rc_incr_tmrs:1,
615 		 restrict_growth:28;
616 	uint32_t rc_lt_epoch_use;	/* When we started lt-bw use Lock(a) */
617 
618 	uint32_t rc_recovery_start;	/* Time we start recovery Lock(a) */
619 	uint32_t rc_lt_del;	/* Delivered at lt bw sampling start Lock(a) */
620 
621 	uint64_t rc_bbr_cur_del_rate;	/* Current measured delivery rate
622 					 * Lock(a) */
623 
624 	/*******************************/
625 	/* Cache line 8 from bbr start */
626 	/*******************************/
627 	uint32_t rc_cwnd_on_ent;	/* On entry to recovery the cwnd
628 					 * Lock(a) */
629 	uint32_t rc_agg_early;	/* aggregate amount early */
630 
631 	uint32_t rc_rcvtime;	/* When we last received data Lock(a) */
632 	uint32_t rc_pkt_epoch_del;	/* seq num that we need for RTT epoch */
633 
634 	uint32_t rc_pkt_epoch;	/* Epoch based on packet RTTs */
635 	uint32_t rc_pkt_epoch_time;	/* Time we started the pkt epoch */
636 
637 	uint32_t rc_pkt_epoch_rtt;	/* RTT using the packet epoch */
638 	uint32_t rc_rtt_epoch;	/* Current RTT epoch, it ticks every rttProp
639 				 * Lock(a) */
640 	uint32_t lowest_rtt;
641 	uint32_t bbr_smallest_srtt_this_state;
642 
643 	uint32_t rc_lt_epoch;	/* LT epoch start of bw_sampling */
644 	uint32_t rc_lost_at_startup;
645 
646 	uint32_t rc_bbr_state_atflight;
647 	uint32_t rc_bbr_last_startup_epoch;	/* Last startup epoch where we
648 						 * increased 20% */
649 	uint32_t rc_bbr_enters_probertt;	/* Timestamp we entered
650 						 * probertt Lock(a) */
651 	uint32_t rc_lt_time;	/* Time of lt sampling start Lock(a) */
652 
653 	/*******************************/
654 	/* Cache line 9 from bbr start */
655 	/*******************************/
656 	uint64_t rc_lt_bw;	/* LT bw calculated Lock(a) */
657 	uint64_t rc_bbr_lastbtlbw;	/* For startup, what was last btlbw I
658 					 * saw to check the 20% gain Lock(a) */
659 
660 	uint32_t rc_bbr_cwnd_gain;	/* Current cwnd gain Lock(a) */
661 	uint32_t rc_pkt_epoch_loss_rate;	/* pkt-epoch loss rate */
662 
663 	uint32_t rc_saved_cwnd;	/* Saved cwnd during Probe-rtt drain Lock(a) */
664 	uint32_t substate_pe;
665 
666 	uint32_t rc_lost;	/* Number of bytes lost Lock(a) */
667 	uint32_t rc_exta_time_gd; /* How much extra time we got in d/g */
668 
669 	uint32_t rc_lt_lost;	/* Number of lt bytes lost at sampling start
670 				 * Lock(a) */
671 	uint32_t rc_bbr_state_time;
672 
673 	uint32_t rc_min_to;	/* Socket option value Lock(a) */
674 	uint32_t rc_initial_hptsi_bw;	/* Our initial startup bw Lock(a) */
675 
676 	uint32_t bbr_lost_at_state;	/* Temp counter debug lost value as we
677 					 * enter a state */
678 	/*******************************/
679 	/* Cache line 10 from bbr start */
680 	/*******************************/
681 	uint32_t rc_level_state_extra;
682 	uint32_t rc_red_cwnd_pe;
683 	const struct tcp_hwrate_limit_table *crte;
684 	uint64_t red_bw;
685 
686 	uint32_t rc_probertt_int;
687 	uint32_t rc_probertt_srttchktim;	/* Time we last did a srtt
688 						 * check  */
689 	uint32_t gain_epoch;	/* Epoch we should be out of gain */
690 	uint32_t rc_min_rto_ms;
691 
692 	uint32_t rc_reorder_fade;	/* Socket option value Lock(a) */
693 	uint32_t last_startup_measure;
694 
695 	int32_t bbr_hptsi_per_second;
696 	int32_t bbr_hptsi_segments_delay_tar;
697 
698 	int32_t bbr_hptsi_segments_max;
699 	uint32_t bbr_rttprobe_gain_val;
700 	/*******************************/
701 	/* Cache line 11 from bbr start */
702 	/*******************************/
703 	uint32_t cur_rtt_send_time;	/* Time we sent our rtt measured packet */
704 	uint32_t bbr_peer_tsratio;	/* Our calculated ts ratio to multply */
705 	uint32_t bbr_ts_check_tstmp;	/* When we filled it the TS that came on the ack */
706 	uint32_t bbr_ts_check_our_cts;	/* When we filled it the cts of the send */
707 	uint32_t rc_tlp_rxt_last_time;
708 	uint32_t bbr_smallest_srtt_state2;
709 	uint32_t bbr_hdwr_cnt_noset_snt;	/* count of hw pacing sends during delay */
710 	uint32_t startup_last_srtt;
711 	uint32_t rc_ack_hdwr_delay;
712 	uint32_t highest_hdwr_delay;		/* Largest delay we have seen from hardware */
713 	uint32_t non_gain_extra;
714 	uint32_t recovery_lr;			/* The sum of the loss rate from the pe's during recovery */
715 	uint32_t last_in_probertt;
716 	uint32_t flightsize_at_drain;		/* In draining what was the last marked flight size */
717 	uint32_t rc_pe_of_prtt;			/* PE we went into probe-rtt */
718 	uint32_t ts_in;				/* ts that went with the last rtt */
719 
720 	uint16_t rc_tlp_seg_send_cnt;	/* Number of times we have TLP sent
721 					 * rc_last_tlp_seq Lock(a) */
722 	uint16_t rc_drain_pg;
723 	uint32_t rc_num_maps_alloced;		/* num send map entries allocated */
724 	uint32_t rc_num_split_allocs;		/* num split map entries allocated */
725 	uint16_t rc_num_small_maps_alloced;	/* Number of sack blocks
726 						 * allocated */
727 	uint16_t bbr_hptsi_bytes_min;
728 
729 	uint16_t bbr_hptsi_segments_floor;
730 	uint16_t bbr_utter_max;
731 	uint16_t bbr_google_discount;
732 
733 };
734 
735 struct socket;
736 struct tcp_bbr {
737 	/* First cache line 0x00 */
738 	int32_t(*r_substate) (struct mbuf *, struct tcphdr *,
739 	    struct socket *, struct tcpcb *, struct tcpopt *,
740 	    int32_t, int32_t, uint32_t, int32_t, int32_t, uint8_t);	/* Lock(a) */
741 	struct tcpcb *rc_tp;	/* The tcpcb Lock(a) */
742 	struct inpcb *rc_inp;	/* The inpcb Lock(a) */
743 	struct timeval rc_tv;
744 	uint32_t rc_pacer_started;  /* Time we started the pacer */
745 	uint16_t no_pacing_until:8, /* No pacing until N packet epochs */
746 		 ts_can_raise:1,/* TS b/w calculations can raise the bw higher */
747 		 skip_gain:1,	/* Skip the gain cycle (hardware pacing) */
748 		 gain_is_limited:1,	/* With hardware pacing we are limiting gain */
749 		 output_error_seen:1,
750 		 oerror_cnt:4,
751 		hw_pacing_set:1;	/* long enough has passed for us to start pacing */
752 	uint16_t xxx_r_ack_count;	/* During recovery count of ack's received
753 				 * that added data since output */
754 	uint16_t bbr_segs_rcvd;	/* In Segment count since we sent a ack */
755 
756 	uint8_t bbr_timer_src:4,	/* Used for debugging Lock(a) */
757 		bbr_use_rack_cheat:1,   /* Use the rack cheat */
758 		bbr_init_win_cheat:1,	/* Send full IW for TSO */
759 		bbr_attempt_hdwr_pace:1,/* Try to do hardware pacing */
760 		bbr_hdrw_pacing:1;	/* Hardware pacing is available */
761 	uint8_t bbr_hdw_pace_ena:1,	/* Does the connection allow hardware pacing to be attempted */
762 		bbr_prev_in_rec:1,	/* We were previously in recovery */
763 		pkt_conservation:1,
764 		use_policer_detection:1,
765 		xxx_bbr_hdw_pace_idx:4;	/* If hardware pacing is on, index to slot in pace tbl */
766 	uint16_t r_wanted_output:1,
767 		 rtt_valid:1,
768 		 rc_timer_first:1,
769 		 rc_output_starts_timer:1,
770 		 rc_resends_use_tso:1,
771 		 rc_all_timers_stopped:1,
772 		 rc_loss_exit:1,
773 		 rc_ack_was_delayed:1,
774 		 rc_lt_is_sampling:1,
775 		 rc_filled_pipe:1,
776 		 rc_tlp_new_data:1,
777 		 rc_hit_state_1:1,
778 		 rc_ts_valid:1,
779 		 rc_prtt_set_ts:1,
780 		 rc_is_pkt_epoch_now:1,
781 		 rc_has_collapsed:1;
782 
783 	uint8_t r_state:4,	/* Current bbr state Lock(a) */
784 	        r_agg_early_set:1,	/* Did we get called early */
785 		r_init_rtt:1,
786 		r_use_policer:1,	/* For google mode only */
787 		r_recovery_bw:1;
788 	uint8_t r_timer_override:1,	/* pacer override Lock(a)  0/1 */
789 	        rc_in_persist:1,
790 		rc_lt_use_bw:1,
791 		rc_allow_data_af_clo:1,
792 		rc_tlp_rtx_out:1,	/* A TLP is in flight  */
793 	        rc_tlp_in_progress:1,	/* a TLP timer is running needed? */
794 	        rc_use_idle_restart:1;   /* Do we restart fast after idle (persist or applim) */
795 	uint8_t rc_bbr_state:3,	/* What is the major BBR state */
796 	        rc_bbr_substate:3,	/* For probeBW state */
797 	        r_is_v6:1,
798 		rc_past_init_win:1;
799 	uint8_t rc_last_options;
800 	uint8_t rc_tlp_threshold;	/* Socket option value Lock(a) */
801 	uint8_t rc_max_rto_sec;
802 	uint8_t rc_cwnd_limited:1,	/* We are cwnd limited */
803 		rc_tmr_stopped:7;	/* What timers have been stopped  */
804 	uint8_t rc_use_google:1,
805 		rc_use_ts_limit:1,
806 		rc_ts_data_set:1,	/* We have filled a set point to determine */
807 		rc_ts_clock_set:1, 	/* We have determined the ts type */
808 		rc_ts_cant_be_used:1,	/* We determined we can't use ts values */
809 		rc_ack_is_cumack:1,
810 		rc_no_pacing:1,
811 		alloc_limit_reported:1;
812 	uint8_t rc_init_win;
813 	/* Cache line 2 0x40 */
814 	struct bbr_control r_ctl;
815 #ifdef _KERNEL
816 }       __aligned(CACHE_LINE_SIZE);
817 #else
818 };
819 #endif
820 
821 #endif
822