1 /*-
2 *
3 * SPDX-License-Identifier: BSD-3-Clause
4 *
5 * Copyright (c) 2018-2020
6 * Netflix Inc.
7 *
8 * Redistribution and use in source and binary forms, with or without
9 * modification, are permitted provided that the following conditions
10 * are met:
11 * 1. Redistributions of source code must retain the above copyright
12 * notice, this list of conditions and the following disclaimer.
13 * 2. Redistributions in binary form must reproduce the above copyright
14 * notice, this list of conditions and the following disclaimer in the
15 * documentation and/or other materials provided with the distribution.
16 *
17 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
18 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
19 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
20 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
21 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
22 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
23 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
24 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
25 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
26 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
27 * SUCH DAMAGE.
28 *
29 */
30 /**
31 * Author: Randall Stewart <rrs@netflix.com>
32 */
33
34 #include <sys/cdefs.h>
35 #include "opt_inet.h"
36 #include "opt_inet6.h"
37 #include "opt_ipsec.h"
38 #include "opt_ratelimit.h"
39 #include <sys/param.h>
40 #include <sys/kernel.h>
41 #include <sys/malloc.h>
42 #include <sys/mbuf.h>
43 #include <sys/socket.h>
44 #include <sys/socketvar.h>
45 #include <sys/sysctl.h>
46 #include <sys/eventhandler.h>
47 #include <sys/mutex.h>
48 #include <sys/ck.h>
49 #include <net/if.h>
50 #include <net/if_var.h>
51 #include <net/if_private.h>
52 #include <netinet/in.h>
53 #include <netinet/in_pcb.h>
54 #define TCPSTATES /* for logging */
55 #include <netinet/tcp_var.h>
56 #include <netinet/tcp_hpts.h>
57 #include <netinet/tcp_log_buf.h>
58 #include <netinet/tcp_ratelimit.h>
59 #ifndef USECS_IN_SECOND
60 #define USECS_IN_SECOND 1000000
61 #endif
62 /*
63 * For the purposes of each send, what is the size
64 * of an ethernet frame.
65 */
66 MALLOC_DEFINE(M_TCPPACE, "tcp_hwpace", "TCP Hardware pacing memory");
67 #ifdef RATELIMIT
68
69 /*
70 * The following preferred table will seem weird to
71 * the casual viewer. Why do we not have any rates below
72 * 1Mbps? Why do we have a rate at 1.44Mbps called common?
73 * Why do the rates cluster in the 1-100Mbps range more
74 * than others? Why does the table jump around at the beginnign
75 * and then be more consistently raising?
76 *
77 * Let me try to answer those questions. A lot of
78 * this is dependant on the hardware. We have three basic
79 * supporters of rate limiting
80 *
81 * Chelsio - Supporting 16 configurable rates.
82 * Mlx - c4 supporting 13 fixed rates.
83 * Mlx - c5 & c6 supporting 127 configurable rates.
84 *
85 * The c4 is why we have a common rate that is available
86 * in all rate tables. This is a selected rate from the
87 * c4 table and we assure its available in all ratelimit
88 * tables. This way the tcp_ratelimit code has an assured
89 * rate it should always be able to get. This answers a
90 * couple of the questions above.
91 *
92 * So what about the rest, well the table is built to
93 * try to get the most out of a joint hardware/software
94 * pacing system. The software pacer will always pick
95 * a rate higher than the b/w that it is estimating
96 *
97 * on the path. This is done for two reasons.
98 * a) So we can discover more b/w
99 * and
100 * b) So we can send a block of MSS's down and then
101 * have the software timer go off after the previous
102 * send is completely out of the hardware.
103 *
104 * But when we do <b> we don't want to have the delay
105 * between the last packet sent by the hardware be
106 * excessively long (to reach our desired rate).
107 *
108 * So let me give an example for clarity.
109 *
110 * Lets assume that the tcp stack sees that 29,110,000 bps is
111 * what the bw of the path is. The stack would select the
112 * rate 31Mbps. 31Mbps means that each send that is done
113 * by the hardware will cause a 390 micro-second gap between
114 * the packets sent at that rate. For 29,110,000 bps we
115 * would need 416 micro-seconds gap between each send.
116 *
117 * Note that are calculating a complete time for pacing
118 * which includes the ethernet, IP and TCP overhead. So
119 * a full 1514 bytes is used for the above calculations.
120 * My testing has shown that both cards are also using this
121 * as their basis i.e. full payload size of the ethernet frame.
122 * The TCP stack caller needs to be aware of this and make the
123 * appropriate overhead calculations be included in its choices.
124 *
125 * Now, continuing our example, we pick a MSS size based on the
126 * delta between the two rates (416 - 390) divided into the rate
127 * we really wish to send at rounded up. That results in a MSS
128 * send of 17 mss's at once. The hardware then will
129 * run out of data in a single 17MSS send in 6,630 micro-seconds.
130 *
131 * On the other hand the software pacer will send more data
132 * in 7,072 micro-seconds. This means that we will refill
133 * the hardware 52 microseconds after it would have sent
134 * next if it had not ran out of data. This is a win since we are
135 * only sending every 7ms or so and yet all the packets are spaced on
136 * the wire with 94% of what they should be and only
137 * the last packet is delayed extra to make up for the
138 * difference.
139 *
140 * Note that the above formula has two important caveat.
141 * If we are above (b/w wise) over 100Mbps we double the result
142 * of the MSS calculation. The second caveat is if we are 500Mbps
143 * or more we just send the maximum MSS at once i.e. 45MSS. At
144 * the higher b/w's even the cards have limits to what times (timer granularity)
145 * they can insert between packets and start to send more than one
146 * packet at a time on the wire.
147 *
148 */
149 #define COMMON_RATE 180500
150 const uint64_t desired_rates[] = {
151 122500, /* 1Mbps - rate 1 */
152 180500, /* 1.44Mpbs - rate 2 common rate */
153 375000, /* 3Mbps - rate 3 */
154 625000, /* 5Mbps - rate 4 */
155 1250000, /* 10Mbps - rate 5 */
156 1875000, /* 15Mbps - rate 6 */
157 2500000, /* 20Mbps - rate 7 */
158 3125000, /* 25Mbps - rate 8 */
159 3750000, /* 30Mbps - rate 9 */
160 4375000, /* 35Mbps - rate 10 */
161 5000000, /* 40Meg - rate 11 */
162 6250000, /* 50Mbps - rate 12 */
163 12500000, /* 100Mbps - rate 13 */
164 25000000, /* 200Mbps - rate 14 */
165 50000000, /* 400Mbps - rate 15 */
166 100000000, /* 800Mbps - rate 16 */
167 5625000, /* 45Mbps - rate 17 */
168 6875000, /* 55Mbps - rate 19 */
169 7500000, /* 60Mbps - rate 20 */
170 8125000, /* 65Mbps - rate 21 */
171 8750000, /* 70Mbps - rate 22 */
172 9375000, /* 75Mbps - rate 23 */
173 10000000, /* 80Mbps - rate 24 */
174 10625000, /* 85Mbps - rate 25 */
175 11250000, /* 90Mbps - rate 26 */
176 11875000, /* 95Mbps - rate 27 */
177 12500000, /* 100Mbps - rate 28 */
178 13750000, /* 110Mbps - rate 29 */
179 15000000, /* 120Mbps - rate 30 */
180 16250000, /* 130Mbps - rate 31 */
181 17500000, /* 140Mbps - rate 32 */
182 18750000, /* 150Mbps - rate 33 */
183 20000000, /* 160Mbps - rate 34 */
184 21250000, /* 170Mbps - rate 35 */
185 22500000, /* 180Mbps - rate 36 */
186 23750000, /* 190Mbps - rate 37 */
187 26250000, /* 210Mbps - rate 38 */
188 27500000, /* 220Mbps - rate 39 */
189 28750000, /* 230Mbps - rate 40 */
190 30000000, /* 240Mbps - rate 41 */
191 31250000, /* 250Mbps - rate 42 */
192 34375000, /* 275Mbps - rate 43 */
193 37500000, /* 300Mbps - rate 44 */
194 40625000, /* 325Mbps - rate 45 */
195 43750000, /* 350Mbps - rate 46 */
196 46875000, /* 375Mbps - rate 47 */
197 53125000, /* 425Mbps - rate 48 */
198 56250000, /* 450Mbps - rate 49 */
199 59375000, /* 475Mbps - rate 50 */
200 62500000, /* 500Mbps - rate 51 */
201 68750000, /* 550Mbps - rate 52 */
202 75000000, /* 600Mbps - rate 53 */
203 81250000, /* 650Mbps - rate 54 */
204 87500000, /* 700Mbps - rate 55 */
205 93750000, /* 750Mbps - rate 56 */
206 106250000, /* 850Mbps - rate 57 */
207 112500000, /* 900Mbps - rate 58 */
208 125000000, /* 1Gbps - rate 59 */
209 156250000, /* 1.25Gps - rate 60 */
210 187500000, /* 1.5Gps - rate 61 */
211 218750000, /* 1.75Gps - rate 62 */
212 250000000, /* 2Gbps - rate 63 */
213 281250000, /* 2.25Gps - rate 64 */
214 312500000, /* 2.5Gbps - rate 65 */
215 343750000, /* 2.75Gbps - rate 66 */
216 375000000, /* 3Gbps - rate 67 */
217 500000000, /* 4Gbps - rate 68 */
218 625000000, /* 5Gbps - rate 69 */
219 750000000, /* 6Gbps - rate 70 */
220 875000000, /* 7Gbps - rate 71 */
221 1000000000, /* 8Gbps - rate 72 */
222 1125000000, /* 9Gbps - rate 73 */
223 1250000000, /* 10Gbps - rate 74 */
224 1875000000, /* 15Gbps - rate 75 */
225 2500000000 /* 20Gbps - rate 76 */
226 };
227
228 #define MAX_HDWR_RATES (sizeof(desired_rates)/sizeof(uint64_t))
229 #define RS_ORDERED_COUNT 16 /*
230 * Number that are in order
231 * at the beginning of the table,
232 * over this a sort is required.
233 */
234 #define RS_NEXT_ORDER_GROUP 16 /*
235 * The point in our table where
236 * we come fill in a second ordered
237 * group (index wise means -1).
238 */
239 #define ALL_HARDWARE_RATES 1004 /*
240 * 1Meg - 1Gig in 1 Meg steps
241 * plus 100, 200k and 500k and
242 * 10Gig
243 */
244
245 #define RS_ONE_MEGABIT_PERSEC 1000000
246 #define RS_ONE_GIGABIT_PERSEC 1000000000
247 #define RS_TEN_GIGABIT_PERSEC 10000000000
248
249 static struct head_tcp_rate_set int_rs;
250 static struct mtx rs_mtx;
251 uint32_t rs_number_alive;
252 uint32_t rs_number_dead;
253 static uint32_t rs_floor_mss = 0;
254 static uint32_t wait_time_floor = 8000; /* 8 ms */
255 static uint32_t rs_hw_floor_mss = 16;
256 static uint32_t num_of_waits_allowed = 1; /* How many time blocks are we willing to wait */
257
258 static uint32_t mss_divisor = RL_DEFAULT_DIVISOR;
259 static uint32_t even_num_segs = 1;
260 static uint32_t even_threshold = 4;
261
262 SYSCTL_NODE(_net_inet_tcp, OID_AUTO, rl, CTLFLAG_RW | CTLFLAG_MPSAFE, 0,
263 "TCP Ratelimit stats");
264 SYSCTL_UINT(_net_inet_tcp_rl, OID_AUTO, alive, CTLFLAG_RW,
265 &rs_number_alive, 0,
266 "Number of interfaces initialized for ratelimiting");
267 SYSCTL_UINT(_net_inet_tcp_rl, OID_AUTO, dead, CTLFLAG_RW,
268 &rs_number_dead, 0,
269 "Number of interfaces departing from ratelimiting");
270 SYSCTL_UINT(_net_inet_tcp_rl, OID_AUTO, floor_mss, CTLFLAG_RW,
271 &rs_floor_mss, 0,
272 "Number of MSS that will override the normal minimums (0 means don't enforce)");
273 SYSCTL_UINT(_net_inet_tcp_rl, OID_AUTO, wait_floor, CTLFLAG_RW,
274 &wait_time_floor, 2000,
275 "Has b/w increases what is the wait floor we are willing to wait at the end?");
276 SYSCTL_UINT(_net_inet_tcp_rl, OID_AUTO, time_blocks, CTLFLAG_RW,
277 &num_of_waits_allowed, 1,
278 "How many time blocks on the end should software pacing be willing to wait?");
279
280 SYSCTL_UINT(_net_inet_tcp_rl, OID_AUTO, hw_floor_mss, CTLFLAG_RW,
281 &rs_hw_floor_mss, 16,
282 "Number of mss that are a minum for hardware pacing?");
283
284 SYSCTL_INT(_net_inet_tcp_rl, OID_AUTO, divisor, CTLFLAG_RW,
285 &mss_divisor, RL_DEFAULT_DIVISOR,
286 "The value divided into bytes per second to help establish mss size");
287 SYSCTL_INT(_net_inet_tcp_rl, OID_AUTO, even, CTLFLAG_RW,
288 &even_num_segs, 1,
289 "Do we round mss size up to an even number of segments for delayed ack");
290 SYSCTL_INT(_net_inet_tcp_rl, OID_AUTO, eventhresh, CTLFLAG_RW,
291 &even_threshold, 4,
292 "At what number of mss do we start rounding up to an even number of mss?");
293
294 static void
rl_add_syctl_entries(struct sysctl_oid * rl_sysctl_root,struct tcp_rate_set * rs)295 rl_add_syctl_entries(struct sysctl_oid *rl_sysctl_root, struct tcp_rate_set *rs)
296 {
297 /*
298 * Add sysctl entries for thus interface.
299 */
300 if (rs->rs_flags & RS_INTF_NO_SUP) {
301 SYSCTL_ADD_S32(&rs->sysctl_ctx,
302 SYSCTL_CHILDREN(rl_sysctl_root),
303 OID_AUTO, "disable", CTLFLAG_RD,
304 &rs->rs_disable, 0,
305 "Disable this interface from new hdwr limiting?");
306 } else {
307 SYSCTL_ADD_S32(&rs->sysctl_ctx,
308 SYSCTL_CHILDREN(rl_sysctl_root),
309 OID_AUTO, "disable", CTLFLAG_RW,
310 &rs->rs_disable, 0,
311 "Disable this interface from new hdwr limiting?");
312 }
313 SYSCTL_ADD_S32(&rs->sysctl_ctx,
314 SYSCTL_CHILDREN(rl_sysctl_root),
315 OID_AUTO, "minseg", CTLFLAG_RW,
316 &rs->rs_min_seg, 0,
317 "What is the minimum we need to send on this interface?");
318 SYSCTL_ADD_U64(&rs->sysctl_ctx,
319 SYSCTL_CHILDREN(rl_sysctl_root),
320 OID_AUTO, "flow_limit", CTLFLAG_RW,
321 &rs->rs_flow_limit, 0,
322 "What is the limit for number of flows (0=unlimited)?");
323 SYSCTL_ADD_S32(&rs->sysctl_ctx,
324 SYSCTL_CHILDREN(rl_sysctl_root),
325 OID_AUTO, "highest", CTLFLAG_RD,
326 &rs->rs_highest_valid, 0,
327 "Highest valid rate");
328 SYSCTL_ADD_S32(&rs->sysctl_ctx,
329 SYSCTL_CHILDREN(rl_sysctl_root),
330 OID_AUTO, "lowest", CTLFLAG_RD,
331 &rs->rs_lowest_valid, 0,
332 "Lowest valid rate");
333 SYSCTL_ADD_S32(&rs->sysctl_ctx,
334 SYSCTL_CHILDREN(rl_sysctl_root),
335 OID_AUTO, "flags", CTLFLAG_RD,
336 &rs->rs_flags, 0,
337 "What lags are on the entry?");
338 SYSCTL_ADD_S32(&rs->sysctl_ctx,
339 SYSCTL_CHILDREN(rl_sysctl_root),
340 OID_AUTO, "numrates", CTLFLAG_RD,
341 &rs->rs_rate_cnt, 0,
342 "How many rates re there?");
343 SYSCTL_ADD_U64(&rs->sysctl_ctx,
344 SYSCTL_CHILDREN(rl_sysctl_root),
345 OID_AUTO, "flows_using", CTLFLAG_RD,
346 &rs->rs_flows_using, 0,
347 "How many flows are using this interface now?");
348 #ifdef DETAILED_RATELIMIT_SYSCTL
349 if (rs->rs_rlt && rs->rs_rate_cnt > 0) {
350 /* Lets display the rates */
351 int i;
352 struct sysctl_oid *rl_rates;
353 struct sysctl_oid *rl_rate_num;
354 char rate_num[16];
355 rl_rates = SYSCTL_ADD_NODE(&rs->sysctl_ctx,
356 SYSCTL_CHILDREN(rl_sysctl_root),
357 OID_AUTO,
358 "rate",
359 CTLFLAG_RW | CTLFLAG_MPSAFE, 0,
360 "Ratelist");
361 for( i = 0; i < rs->rs_rate_cnt; i++) {
362 sprintf(rate_num, "%d", i);
363 rl_rate_num = SYSCTL_ADD_NODE(&rs->sysctl_ctx,
364 SYSCTL_CHILDREN(rl_rates),
365 OID_AUTO,
366 rate_num,
367 CTLFLAG_RW | CTLFLAG_MPSAFE, 0,
368 "Individual Rate");
369 SYSCTL_ADD_U32(&rs->sysctl_ctx,
370 SYSCTL_CHILDREN(rl_rate_num),
371 OID_AUTO, "flags", CTLFLAG_RD,
372 &rs->rs_rlt[i].flags, 0,
373 "Flags on this rate");
374 SYSCTL_ADD_U32(&rs->sysctl_ctx,
375 SYSCTL_CHILDREN(rl_rate_num),
376 OID_AUTO, "pacetime", CTLFLAG_RD,
377 &rs->rs_rlt[i].time_between, 0,
378 "Time hardware inserts between 1500 byte sends");
379 SYSCTL_ADD_LONG(&rs->sysctl_ctx,
380 SYSCTL_CHILDREN(rl_rate_num),
381 OID_AUTO, "rate", CTLFLAG_RD,
382 &rs->rs_rlt[i].rate,
383 "Rate in bytes per second");
384 SYSCTL_ADD_LONG(&rs->sysctl_ctx,
385 SYSCTL_CHILDREN(rl_rate_num),
386 OID_AUTO, "using", CTLFLAG_RD,
387 &rs->rs_rlt[i].using,
388 "Number of flows using");
389 SYSCTL_ADD_LONG(&rs->sysctl_ctx,
390 SYSCTL_CHILDREN(rl_rate_num),
391 OID_AUTO, "enobufs", CTLFLAG_RD,
392 &rs->rs_rlt[i].rs_num_enobufs,
393 "Number of enobufs logged on this rate");
394
395 }
396 }
397 #endif
398 }
399
400 static void
rs_destroy(epoch_context_t ctx)401 rs_destroy(epoch_context_t ctx)
402 {
403 struct tcp_rate_set *rs;
404 bool do_free_rs;
405
406 rs = __containerof(ctx, struct tcp_rate_set, rs_epoch_ctx);
407
408 mtx_lock(&rs_mtx);
409 rs->rs_flags &= ~RS_FUNERAL_SCHD;
410 /*
411 * In theory its possible (but unlikely)
412 * that while the delete was occuring
413 * and we were applying the DEAD flag
414 * someone slipped in and found the
415 * interface in a lookup. While we
416 * decided rs_flows_using were 0 and
417 * scheduling the epoch_call, the other
418 * thread incremented rs_flow_using. This
419 * is because users have a pointer and
420 * we only use the rs_flows_using in an
421 * atomic fashion, i.e. the other entities
422 * are not protected. To assure this did
423 * not occur, we check rs_flows_using here
424 * before deleting.
425 */
426 do_free_rs = (rs->rs_flows_using == 0);
427 rs_number_dead--;
428 mtx_unlock(&rs_mtx);
429
430 if (do_free_rs) {
431 sysctl_ctx_free(&rs->sysctl_ctx);
432 free(rs->rs_rlt, M_TCPPACE);
433 free(rs, M_TCPPACE);
434 }
435 }
436
437 static void
rs_defer_destroy(struct tcp_rate_set * rs)438 rs_defer_destroy(struct tcp_rate_set *rs)
439 {
440
441 mtx_assert(&rs_mtx, MA_OWNED);
442
443 /* Check if already pending. */
444 if (rs->rs_flags & RS_FUNERAL_SCHD)
445 return;
446
447 rs_number_dead++;
448
449 /* Set flag to only defer once. */
450 rs->rs_flags |= RS_FUNERAL_SCHD;
451 NET_EPOCH_CALL(rs_destroy, &rs->rs_epoch_ctx);
452 }
453
454 #ifdef INET
455 extern counter_u64_t rate_limit_new;
456 extern counter_u64_t rate_limit_chg;
457 extern counter_u64_t rate_limit_set_ok;
458 extern counter_u64_t rate_limit_active;
459 extern counter_u64_t rate_limit_alloc_fail;
460 #endif
461
462 static int
rl_attach_txrtlmt(struct ifnet * ifp,uint32_t flowtype,int flowid,uint64_t cfg_rate,struct m_snd_tag ** tag)463 rl_attach_txrtlmt(struct ifnet *ifp,
464 uint32_t flowtype,
465 int flowid,
466 uint64_t cfg_rate,
467 struct m_snd_tag **tag)
468 {
469 int error;
470 union if_snd_tag_alloc_params params = {
471 .rate_limit.hdr.type = IF_SND_TAG_TYPE_RATE_LIMIT,
472 .rate_limit.hdr.flowid = flowid,
473 .rate_limit.hdr.flowtype = flowtype,
474 .rate_limit.max_rate = cfg_rate,
475 .rate_limit.flags = M_NOWAIT,
476 };
477
478 error = m_snd_tag_alloc(ifp, ¶ms, tag);
479 #ifdef INET
480 if (error == 0) {
481 counter_u64_add(rate_limit_set_ok, 1);
482 counter_u64_add(rate_limit_active, 1);
483 } else if (error != EOPNOTSUPP)
484 counter_u64_add(rate_limit_alloc_fail, 1);
485 #endif
486 return (error);
487 }
488
489 static void
populate_canned_table(struct tcp_rate_set * rs,const uint64_t * rate_table_act)490 populate_canned_table(struct tcp_rate_set *rs, const uint64_t *rate_table_act)
491 {
492 /*
493 * The internal table is "special", it
494 * is two seperate ordered tables that
495 * must be merged. We get here when the
496 * adapter specifies a number of rates that
497 * covers both ranges in the table in some
498 * form.
499 */
500 int i, at_low, at_high;
501 uint8_t low_disabled = 0, high_disabled = 0;
502
503 for(i = 0, at_low = 0, at_high = RS_NEXT_ORDER_GROUP; i < rs->rs_rate_cnt; i++) {
504 rs->rs_rlt[i].flags = 0;
505 rs->rs_rlt[i].time_between = 0;
506 if ((low_disabled == 0) &&
507 (high_disabled ||
508 (rate_table_act[at_low] < rate_table_act[at_high]))) {
509 rs->rs_rlt[i].rate = rate_table_act[at_low];
510 at_low++;
511 if (at_low == RS_NEXT_ORDER_GROUP)
512 low_disabled = 1;
513 } else if (high_disabled == 0) {
514 rs->rs_rlt[i].rate = rate_table_act[at_high];
515 at_high++;
516 if (at_high == MAX_HDWR_RATES)
517 high_disabled = 1;
518 }
519 }
520 }
521
522 static struct tcp_rate_set *
rt_setup_new_rs(struct ifnet * ifp,int * error)523 rt_setup_new_rs(struct ifnet *ifp, int *error)
524 {
525 struct tcp_rate_set *rs;
526 const uint64_t *rate_table_act;
527 uint64_t lentim, res;
528 size_t sz;
529 uint32_t hash_type;
530 int i;
531 struct if_ratelimit_query_results rl;
532 struct sysctl_oid *rl_sysctl_root;
533 struct epoch_tracker et;
534 /*
535 * We expect to enter with the
536 * mutex locked.
537 */
538
539 if (ifp->if_ratelimit_query == NULL) {
540 /*
541 * We can do nothing if we cannot
542 * get a query back from the driver.
543 */
544 printf("Warning:No query functions for %s:%d-- failed\n",
545 ifp->if_dname, ifp->if_dunit);
546 return (NULL);
547 }
548 rs = malloc(sizeof(struct tcp_rate_set), M_TCPPACE, M_NOWAIT | M_ZERO);
549 if (rs == NULL) {
550 if (error)
551 *error = ENOMEM;
552 printf("Warning:No memory for malloc of tcp_rate_set\n");
553 return (NULL);
554 }
555 memset(&rl, 0, sizeof(rl));
556 rl.flags = RT_NOSUPPORT;
557 ifp->if_ratelimit_query(ifp, &rl);
558 if (rl.flags & RT_IS_UNUSABLE) {
559 /*
560 * The interface does not really support
561 * the rate-limiting.
562 */
563 memset(rs, 0, sizeof(struct tcp_rate_set));
564 rs->rs_ifp = ifp;
565 rs->rs_if_dunit = ifp->if_dunit;
566 rs->rs_flags = RS_INTF_NO_SUP;
567 rs->rs_disable = 1;
568 rs_number_alive++;
569 sysctl_ctx_init(&rs->sysctl_ctx);
570 rl_sysctl_root = SYSCTL_ADD_NODE(&rs->sysctl_ctx,
571 SYSCTL_STATIC_CHILDREN(_net_inet_tcp_rl),
572 OID_AUTO,
573 rs->rs_ifp->if_xname,
574 CTLFLAG_RW | CTLFLAG_MPSAFE, 0,
575 "");
576 rl_add_syctl_entries(rl_sysctl_root, rs);
577 NET_EPOCH_ENTER(et);
578 mtx_lock(&rs_mtx);
579 CK_LIST_INSERT_HEAD(&int_rs, rs, next);
580 mtx_unlock(&rs_mtx);
581 NET_EPOCH_EXIT(et);
582 return (rs);
583 } else if ((rl.flags & RT_IS_INDIRECT) == RT_IS_INDIRECT) {
584 memset(rs, 0, sizeof(struct tcp_rate_set));
585 rs->rs_ifp = ifp;
586 rs->rs_if_dunit = ifp->if_dunit;
587 rs->rs_flags = RS_IS_DEFF;
588 rs_number_alive++;
589 sysctl_ctx_init(&rs->sysctl_ctx);
590 rl_sysctl_root = SYSCTL_ADD_NODE(&rs->sysctl_ctx,
591 SYSCTL_STATIC_CHILDREN(_net_inet_tcp_rl),
592 OID_AUTO,
593 rs->rs_ifp->if_xname,
594 CTLFLAG_RW | CTLFLAG_MPSAFE, 0,
595 "");
596 rl_add_syctl_entries(rl_sysctl_root, rs);
597 NET_EPOCH_ENTER(et);
598 mtx_lock(&rs_mtx);
599 CK_LIST_INSERT_HEAD(&int_rs, rs, next);
600 mtx_unlock(&rs_mtx);
601 NET_EPOCH_EXIT(et);
602 return (rs);
603 } else if ((rl.flags & RT_IS_FIXED_TABLE) == RT_IS_FIXED_TABLE) {
604 /* Mellanox C4 likely */
605 rs->rs_ifp = ifp;
606 rs->rs_if_dunit = ifp->if_dunit;
607 rs->rs_rate_cnt = rl.number_of_rates;
608 rs->rs_min_seg = rl.min_segment_burst;
609 rs->rs_highest_valid = 0;
610 rs->rs_flow_limit = rl.max_flows;
611 rs->rs_flags = RS_IS_INTF | RS_NO_PRE;
612 rs->rs_disable = 0;
613 rate_table_act = rl.rate_table;
614 } else if ((rl.flags & RT_IS_SELECTABLE) == RT_IS_SELECTABLE) {
615 /* Chelsio, C5 and C6 of Mellanox? */
616 rs->rs_ifp = ifp;
617 rs->rs_if_dunit = ifp->if_dunit;
618 rs->rs_rate_cnt = rl.number_of_rates;
619 rs->rs_min_seg = rl.min_segment_burst;
620 rs->rs_disable = 0;
621 rs->rs_flow_limit = rl.max_flows;
622 rate_table_act = desired_rates;
623 if ((rs->rs_rate_cnt > MAX_HDWR_RATES) &&
624 (rs->rs_rate_cnt < ALL_HARDWARE_RATES)) {
625 /*
626 * Our desired table is not big
627 * enough, do what we can.
628 */
629 rs->rs_rate_cnt = MAX_HDWR_RATES;
630 }
631 if (rs->rs_rate_cnt <= RS_ORDERED_COUNT)
632 rs->rs_flags = RS_IS_INTF;
633 else
634 rs->rs_flags = RS_IS_INTF | RS_INT_TBL;
635 if (rs->rs_rate_cnt >= ALL_HARDWARE_RATES)
636 rs->rs_rate_cnt = ALL_HARDWARE_RATES;
637 } else {
638 free(rs, M_TCPPACE);
639 return (NULL);
640 }
641 sz = sizeof(struct tcp_hwrate_limit_table) * rs->rs_rate_cnt;
642 rs->rs_rlt = malloc(sz, M_TCPPACE, M_NOWAIT);
643 if (rs->rs_rlt == NULL) {
644 if (error)
645 *error = ENOMEM;
646 bail:
647 free(rs, M_TCPPACE);
648 return (NULL);
649 }
650 if (rs->rs_rate_cnt >= ALL_HARDWARE_RATES) {
651 /*
652 * The interface supports all
653 * the rates we could possibly want.
654 */
655 uint64_t rat;
656
657 rs->rs_rlt[0].rate = 12500; /* 100k */
658 rs->rs_rlt[1].rate = 25000; /* 200k */
659 rs->rs_rlt[2].rate = 62500; /* 500k */
660 /* Note 125000 == 1Megabit
661 * populate 1Meg - 1000meg.
662 */
663 for(i = 3, rat = 125000; i< (ALL_HARDWARE_RATES-1); i++) {
664 rs->rs_rlt[i].rate = rat;
665 rat += 125000;
666 }
667 rs->rs_rlt[(ALL_HARDWARE_RATES-1)].rate = 1250000000;
668 } else if (rs->rs_flags & RS_INT_TBL) {
669 /* We populate this in a special way */
670 populate_canned_table(rs, rate_table_act);
671 } else {
672 /*
673 * Just copy in the rates from
674 * the table, it is in order.
675 */
676 for (i=0; i<rs->rs_rate_cnt; i++) {
677 rs->rs_rlt[i].rate = rate_table_act[i];
678 rs->rs_rlt[i].time_between = 0;
679 rs->rs_rlt[i].flags = 0;
680 }
681 }
682 for (i = (rs->rs_rate_cnt - 1); i >= 0; i--) {
683 /*
684 * We go backwards through the list so that if we can't get
685 * a rate and fail to init one, we have at least a chance of
686 * getting the highest one.
687 */
688 rs->rs_rlt[i].ptbl = rs;
689 rs->rs_rlt[i].tag = NULL;
690 rs->rs_rlt[i].using = 0;
691 rs->rs_rlt[i].rs_num_enobufs = 0;
692 /*
693 * Calculate the time between.
694 */
695 lentim = ETHERNET_SEGMENT_SIZE * USECS_IN_SECOND;
696 res = lentim / rs->rs_rlt[i].rate;
697 if (res > 0)
698 rs->rs_rlt[i].time_between = res;
699 else
700 rs->rs_rlt[i].time_between = 1;
701 if (rs->rs_flags & RS_NO_PRE) {
702 rs->rs_rlt[i].flags = HDWRPACE_INITED;
703 rs->rs_lowest_valid = i;
704 } else {
705 int err;
706
707 if ((rl.flags & RT_IS_SETUP_REQ) &&
708 (ifp->if_ratelimit_query)) {
709 err = ifp->if_ratelimit_setup(ifp,
710 rs->rs_rlt[i].rate, i);
711 if (err)
712 goto handle_err;
713 }
714 #ifdef RSS
715 hash_type = M_HASHTYPE_RSS_TCP_IPV4;
716 #else
717 hash_type = M_HASHTYPE_OPAQUE_HASH;
718 #endif
719 err = rl_attach_txrtlmt(ifp,
720 hash_type,
721 (i + 1),
722 rs->rs_rlt[i].rate,
723 &rs->rs_rlt[i].tag);
724 if (err) {
725 handle_err:
726 if (i == (rs->rs_rate_cnt - 1)) {
727 /*
728 * Huh - first rate and we can't get
729 * it?
730 */
731 free(rs->rs_rlt, M_TCPPACE);
732 if (error)
733 *error = err;
734 goto bail;
735 } else {
736 if (error)
737 *error = err;
738 }
739 break;
740 } else {
741 rs->rs_rlt[i].flags = HDWRPACE_INITED | HDWRPACE_TAGPRESENT;
742 rs->rs_lowest_valid = i;
743 }
744 }
745 }
746 /* Did we get at least 1 rate? */
747 if (rs->rs_rlt[(rs->rs_rate_cnt - 1)].flags & HDWRPACE_INITED)
748 rs->rs_highest_valid = rs->rs_rate_cnt - 1;
749 else {
750 free(rs->rs_rlt, M_TCPPACE);
751 goto bail;
752 }
753 rs_number_alive++;
754 sysctl_ctx_init(&rs->sysctl_ctx);
755 rl_sysctl_root = SYSCTL_ADD_NODE(&rs->sysctl_ctx,
756 SYSCTL_STATIC_CHILDREN(_net_inet_tcp_rl),
757 OID_AUTO,
758 rs->rs_ifp->if_xname,
759 CTLFLAG_RW | CTLFLAG_MPSAFE, 0,
760 "");
761 rl_add_syctl_entries(rl_sysctl_root, rs);
762 NET_EPOCH_ENTER(et);
763 mtx_lock(&rs_mtx);
764 CK_LIST_INSERT_HEAD(&int_rs, rs, next);
765 mtx_unlock(&rs_mtx);
766 NET_EPOCH_EXIT(et);
767 return (rs);
768 }
769
770 /*
771 * For an explanation of why the argument is volatile please
772 * look at the comments around rt_setup_rate().
773 */
774 static const struct tcp_hwrate_limit_table *
tcp_int_find_suitable_rate(const volatile struct tcp_rate_set * rs,uint64_t bytes_per_sec,uint32_t flags,uint64_t * lower_rate)775 tcp_int_find_suitable_rate(const volatile struct tcp_rate_set *rs,
776 uint64_t bytes_per_sec, uint32_t flags, uint64_t *lower_rate)
777 {
778 struct tcp_hwrate_limit_table *arte = NULL, *rte = NULL;
779 uint64_t mbits_per_sec, ind_calc, previous_rate = 0;
780 int i;
781
782 mbits_per_sec = (bytes_per_sec * 8);
783 if (flags & RS_PACING_LT) {
784 if ((mbits_per_sec < RS_ONE_MEGABIT_PERSEC) &&
785 (rs->rs_lowest_valid <= 2)){
786 /*
787 * Smaller than 1Meg, only
788 * 3 entries can match it.
789 */
790 previous_rate = 0;
791 for(i = rs->rs_lowest_valid; i < 3; i++) {
792 if (bytes_per_sec <= rs->rs_rlt[i].rate) {
793 rte = &rs->rs_rlt[i];
794 break;
795 } else if (rs->rs_rlt[i].flags & HDWRPACE_INITED) {
796 arte = &rs->rs_rlt[i];
797 }
798 previous_rate = rs->rs_rlt[i].rate;
799 }
800 goto done;
801 } else if ((mbits_per_sec > RS_ONE_GIGABIT_PERSEC) &&
802 (rs->rs_rlt[(ALL_HARDWARE_RATES-1)].flags & HDWRPACE_INITED)){
803 /*
804 * Larger than 1G (the majority of
805 * our table.
806 */
807 if (mbits_per_sec < RS_TEN_GIGABIT_PERSEC)
808 rte = &rs->rs_rlt[(ALL_HARDWARE_RATES-1)];
809 else
810 arte = &rs->rs_rlt[(ALL_HARDWARE_RATES-1)];
811 previous_rate = rs->rs_rlt[(ALL_HARDWARE_RATES-2)].rate;
812 goto done;
813 }
814 /*
815 * If we reach here its in our table (between 1Meg - 1000Meg),
816 * just take the rounded down mbits per second, and add
817 * 1Megabit to it, from this we can calculate
818 * the index in the table.
819 */
820 ind_calc = mbits_per_sec/RS_ONE_MEGABIT_PERSEC;
821 if ((ind_calc * RS_ONE_MEGABIT_PERSEC) != mbits_per_sec)
822 ind_calc++;
823 /* our table is offset by 3, we add 2 */
824 ind_calc += 2;
825 if (ind_calc > (ALL_HARDWARE_RATES-1)) {
826 /* This should not happen */
827 ind_calc = ALL_HARDWARE_RATES-1;
828 }
829 if ((ind_calc >= rs->rs_lowest_valid) &&
830 (ind_calc <= rs->rs_highest_valid)) {
831 rte = &rs->rs_rlt[ind_calc];
832 if (ind_calc >= 1)
833 previous_rate = rs->rs_rlt[(ind_calc-1)].rate;
834 }
835 } else if (flags & RS_PACING_EXACT_MATCH) {
836 if ((mbits_per_sec < RS_ONE_MEGABIT_PERSEC) &&
837 (rs->rs_lowest_valid <= 2)){
838 for(i = rs->rs_lowest_valid; i < 3; i++) {
839 if (bytes_per_sec == rs->rs_rlt[i].rate) {
840 rte = &rs->rs_rlt[i];
841 break;
842 }
843 }
844 } else if ((mbits_per_sec > RS_ONE_GIGABIT_PERSEC) &&
845 (rs->rs_rlt[(ALL_HARDWARE_RATES-1)].flags & HDWRPACE_INITED)) {
846 /* > 1Gbps only one rate */
847 if (bytes_per_sec == rs->rs_rlt[(ALL_HARDWARE_RATES-1)].rate) {
848 /* Its 10G wow */
849 rte = &rs->rs_rlt[(ALL_HARDWARE_RATES-1)];
850 }
851 } else {
852 /* Ok it must be a exact meg (its between 1G and 1Meg) */
853 ind_calc = mbits_per_sec/RS_ONE_MEGABIT_PERSEC;
854 if ((ind_calc * RS_ONE_MEGABIT_PERSEC) == mbits_per_sec) {
855 /* its an exact Mbps */
856 ind_calc += 2;
857 if (ind_calc > (ALL_HARDWARE_RATES-1)) {
858 /* This should not happen */
859 ind_calc = ALL_HARDWARE_RATES-1;
860 }
861 if (rs->rs_rlt[ind_calc].flags & HDWRPACE_INITED)
862 rte = &rs->rs_rlt[ind_calc];
863 }
864 }
865 } else {
866 /* we want greater than the requested rate */
867 if ((mbits_per_sec < RS_ONE_MEGABIT_PERSEC) &&
868 (rs->rs_lowest_valid <= 2)){
869 arte = &rs->rs_rlt[3]; /* set alternate to 1Meg */
870 for (i=2; i>=rs->rs_lowest_valid; i--) {
871 if (bytes_per_sec < rs->rs_rlt[i].rate) {
872 rte = &rs->rs_rlt[i];
873 if (i >= 1) {
874 previous_rate = rs->rs_rlt[(i-1)].rate;
875 }
876 break;
877 } else if ((flags & RS_PACING_GEQ) &&
878 (bytes_per_sec == rs->rs_rlt[i].rate)) {
879 rte = &rs->rs_rlt[i];
880 if (i >= 1) {
881 previous_rate = rs->rs_rlt[(i-1)].rate;
882 }
883 break;
884 } else {
885 arte = &rs->rs_rlt[i]; /* new alternate */
886 }
887 }
888 } else if (mbits_per_sec > RS_ONE_GIGABIT_PERSEC) {
889 if ((bytes_per_sec < rs->rs_rlt[(ALL_HARDWARE_RATES-1)].rate) &&
890 (rs->rs_rlt[(ALL_HARDWARE_RATES-1)].flags & HDWRPACE_INITED)){
891 /* Our top rate is larger than the request */
892 rte = &rs->rs_rlt[(ALL_HARDWARE_RATES-1)];
893 } else if ((flags & RS_PACING_GEQ) &&
894 (bytes_per_sec == rs->rs_rlt[(ALL_HARDWARE_RATES-1)].rate) &&
895 (rs->rs_rlt[(ALL_HARDWARE_RATES-1)].flags & HDWRPACE_INITED)) {
896 /* It matches our top rate */
897 rte = &rs->rs_rlt[(ALL_HARDWARE_RATES-1)];
898 } else if (rs->rs_rlt[(ALL_HARDWARE_RATES-1)].flags & HDWRPACE_INITED) {
899 /* The top rate is an alternative */
900 arte = &rs->rs_rlt[(ALL_HARDWARE_RATES-1)];
901 }
902 previous_rate = rs->rs_rlt[(ALL_HARDWARE_RATES-2)].rate;
903 } else {
904 /* Its in our range 1Meg - 1Gig */
905 if (flags & RS_PACING_GEQ) {
906 ind_calc = mbits_per_sec/RS_ONE_MEGABIT_PERSEC;
907 if ((ind_calc * RS_ONE_MEGABIT_PERSEC) == mbits_per_sec) {
908 if (ind_calc > (ALL_HARDWARE_RATES-1)) {
909 /* This should not happen */
910 ind_calc = (ALL_HARDWARE_RATES-1);
911 }
912 rte = &rs->rs_rlt[ind_calc];
913 if (ind_calc >= 1)
914 previous_rate = rs->rs_rlt[(ind_calc-1)].rate;
915 }
916 goto done;
917 }
918 ind_calc = (mbits_per_sec + (RS_ONE_MEGABIT_PERSEC-1))/RS_ONE_MEGABIT_PERSEC;
919 ind_calc += 2;
920 if (ind_calc > (ALL_HARDWARE_RATES-1)) {
921 /* This should not happen */
922 ind_calc = ALL_HARDWARE_RATES-1;
923 }
924 if (rs->rs_rlt[ind_calc].flags & HDWRPACE_INITED) {
925 rte = &rs->rs_rlt[ind_calc];
926 if (ind_calc >= 1)
927 previous_rate = rs->rs_rlt[(ind_calc-1)].rate;
928 }
929 }
930 }
931 done:
932 if ((rte == NULL) &&
933 (arte != NULL) &&
934 (flags & RS_PACING_SUB_OK)) {
935 /* We can use the substitute */
936 rte = arte;
937 }
938 if (lower_rate)
939 *lower_rate = previous_rate;
940 return (rte);
941 }
942
943 /*
944 * For an explanation of why the argument is volatile please
945 * look at the comments around rt_setup_rate().
946 */
947 static const struct tcp_hwrate_limit_table *
tcp_find_suitable_rate(const volatile struct tcp_rate_set * rs,uint64_t bytes_per_sec,uint32_t flags,uint64_t * lower_rate)948 tcp_find_suitable_rate(const volatile struct tcp_rate_set *rs, uint64_t bytes_per_sec, uint32_t flags, uint64_t *lower_rate)
949 {
950 /**
951 * Hunt the rate table with the restrictions in flags and find a
952 * suitable rate if possible.
953 * RS_PACING_EXACT_MATCH - look for an exact match to rate.
954 * RS_PACING_GT - must be greater than.
955 * RS_PACING_GEQ - must be greater than or equal.
956 * RS_PACING_LT - must be less than.
957 * RS_PACING_SUB_OK - If we don't meet criteria a
958 * substitute is ok.
959 */
960 int i, matched;
961 struct tcp_hwrate_limit_table *rte = NULL;
962 uint64_t previous_rate = 0;
963
964 if ((rs->rs_flags & RS_INT_TBL) &&
965 (rs->rs_rate_cnt >= ALL_HARDWARE_RATES)) {
966 /*
967 * Here we don't want to paw thru
968 * a big table, we have everything
969 * from 1Meg - 1000Meg in 1Meg increments.
970 * Use an alternate method to "lookup".
971 */
972 return (tcp_int_find_suitable_rate(rs, bytes_per_sec, flags, lower_rate));
973 }
974 if ((flags & RS_PACING_LT) ||
975 (flags & RS_PACING_EXACT_MATCH)) {
976 /*
977 * For exact and less than we go forward through the table.
978 * This way when we find one larger we stop (exact was a
979 * toss up).
980 */
981 for (i = rs->rs_lowest_valid, matched = 0; i <= rs->rs_highest_valid; i++) {
982 if ((flags & RS_PACING_EXACT_MATCH) &&
983 (bytes_per_sec == rs->rs_rlt[i].rate)) {
984 rte = &rs->rs_rlt[i];
985 matched = 1;
986 if (lower_rate != NULL)
987 *lower_rate = previous_rate;
988 break;
989 } else if ((flags & RS_PACING_LT) &&
990 (bytes_per_sec <= rs->rs_rlt[i].rate)) {
991 rte = &rs->rs_rlt[i];
992 matched = 1;
993 if (lower_rate != NULL)
994 *lower_rate = previous_rate;
995 break;
996 }
997 previous_rate = rs->rs_rlt[i].rate;
998 if (bytes_per_sec > rs->rs_rlt[i].rate)
999 break;
1000 }
1001 if ((matched == 0) &&
1002 (flags & RS_PACING_LT) &&
1003 (flags & RS_PACING_SUB_OK)) {
1004 /* Kick in a substitute (the lowest) */
1005 rte = &rs->rs_rlt[rs->rs_lowest_valid];
1006 }
1007 } else {
1008 /*
1009 * Here we go backward through the table so that we can find
1010 * the one greater in theory faster (but its probably a
1011 * wash).
1012 */
1013 for (i = rs->rs_highest_valid, matched = 0; i >= rs->rs_lowest_valid; i--) {
1014 if (rs->rs_rlt[i].rate > bytes_per_sec) {
1015 /* A possible candidate */
1016 rte = &rs->rs_rlt[i];
1017 }
1018 if ((flags & RS_PACING_GEQ) &&
1019 (bytes_per_sec == rs->rs_rlt[i].rate)) {
1020 /* An exact match and we want equal */
1021 matched = 1;
1022 rte = &rs->rs_rlt[i];
1023 break;
1024 } else if (rte) {
1025 /*
1026 * Found one that is larger than but don't
1027 * stop, there may be a more closer match.
1028 */
1029 matched = 1;
1030 }
1031 if (rs->rs_rlt[i].rate < bytes_per_sec) {
1032 /*
1033 * We found a table entry that is smaller,
1034 * stop there will be none greater or equal.
1035 */
1036 if (lower_rate != NULL)
1037 *lower_rate = rs->rs_rlt[i].rate;
1038 break;
1039 }
1040 }
1041 if ((matched == 0) &&
1042 (flags & RS_PACING_SUB_OK)) {
1043 /* Kick in a substitute (the highest) */
1044 rte = &rs->rs_rlt[rs->rs_highest_valid];
1045 }
1046 }
1047 return (rte);
1048 }
1049
1050 static struct ifnet *
rt_find_real_interface(struct ifnet * ifp,struct inpcb * inp,int * error)1051 rt_find_real_interface(struct ifnet *ifp, struct inpcb *inp, int *error)
1052 {
1053 struct ifnet *tifp;
1054 struct m_snd_tag *tag, *ntag;
1055 union if_snd_tag_alloc_params params = {
1056 .rate_limit.hdr.type = IF_SND_TAG_TYPE_RATE_LIMIT,
1057 .rate_limit.hdr.flowid = inp->inp_flowid,
1058 .rate_limit.hdr.numa_domain = inp->inp_numa_domain,
1059 .rate_limit.max_rate = COMMON_RATE,
1060 .rate_limit.flags = M_NOWAIT,
1061 };
1062 int err;
1063 #ifdef RSS
1064 params.rate_limit.hdr.flowtype = ((inp->inp_vflag & INP_IPV6) ?
1065 M_HASHTYPE_RSS_TCP_IPV6 : M_HASHTYPE_RSS_TCP_IPV4);
1066 #else
1067 params.rate_limit.hdr.flowtype = M_HASHTYPE_OPAQUE_HASH;
1068 #endif
1069 err = m_snd_tag_alloc(ifp, ¶ms, &tag);
1070 if (err) {
1071 /* Failed to setup a tag? */
1072 if (error)
1073 *error = err;
1074 return (NULL);
1075 }
1076 ntag = tag;
1077 while (ntag->sw->next_snd_tag != NULL) {
1078 ntag = ntag->sw->next_snd_tag(ntag);
1079 }
1080 tifp = ntag->ifp;
1081 m_snd_tag_rele(tag);
1082 return (tifp);
1083 }
1084
1085 static void
rl_increment_using(const struct tcp_hwrate_limit_table * rte)1086 rl_increment_using(const struct tcp_hwrate_limit_table *rte)
1087 {
1088 struct tcp_hwrate_limit_table *decon_rte;
1089
1090 decon_rte = __DECONST(struct tcp_hwrate_limit_table *, rte);
1091 atomic_add_long(&decon_rte->using, 1);
1092 }
1093
1094 static void
rl_decrement_using(const struct tcp_hwrate_limit_table * rte)1095 rl_decrement_using(const struct tcp_hwrate_limit_table *rte)
1096 {
1097 struct tcp_hwrate_limit_table *decon_rte;
1098
1099 decon_rte = __DECONST(struct tcp_hwrate_limit_table *, rte);
1100 atomic_subtract_long(&decon_rte->using, 1);
1101 }
1102
1103 void
tcp_rl_log_enobuf(const struct tcp_hwrate_limit_table * rte)1104 tcp_rl_log_enobuf(const struct tcp_hwrate_limit_table *rte)
1105 {
1106 struct tcp_hwrate_limit_table *decon_rte;
1107
1108 decon_rte = __DECONST(struct tcp_hwrate_limit_table *, rte);
1109 atomic_add_long(&decon_rte->rs_num_enobufs, 1);
1110 }
1111
1112 /*
1113 * Do NOT take the __noinline out of the
1114 * find_rs_for_ifp() function. If you do the inline
1115 * of it for the rt_setup_rate() will show you a
1116 * compiler bug. For some reason the compiler thinks
1117 * the list can never be empty. The consequence of
1118 * this will be a crash when we dereference NULL
1119 * if an ifp is removed just has a hw rate limit
1120 * is attempted. If you are working on the compiler
1121 * and want to "test" this go ahead and take the noinline
1122 * out otherwise let sleeping dogs ly until such time
1123 * as we get a compiler fix 10/2/20 -- RRS
1124 */
1125 static __noinline struct tcp_rate_set *
find_rs_for_ifp(struct ifnet * ifp)1126 find_rs_for_ifp(struct ifnet *ifp)
1127 {
1128 struct tcp_rate_set *rs;
1129
1130 CK_LIST_FOREACH(rs, &int_rs, next) {
1131 if ((rs->rs_ifp == ifp) &&
1132 (rs->rs_if_dunit == ifp->if_dunit)) {
1133 /* Ok we found it */
1134 return (rs);
1135 }
1136 }
1137 return (NULL);
1138 }
1139
1140
1141 static const struct tcp_hwrate_limit_table *
rt_setup_rate(struct inpcb * inp,struct ifnet * ifp,uint64_t bytes_per_sec,uint32_t flags,int * error,uint64_t * lower_rate)1142 rt_setup_rate(struct inpcb *inp, struct ifnet *ifp, uint64_t bytes_per_sec,
1143 uint32_t flags, int *error, uint64_t *lower_rate)
1144 {
1145 /* First lets find the interface if it exists */
1146 const struct tcp_hwrate_limit_table *rte;
1147 /*
1148 * So why is rs volatile? This is to defeat a
1149 * compiler bug where in the compiler is convinced
1150 * that rs can never be NULL (which is not true). Because
1151 * of its conviction it nicely optimizes out the if ((rs == NULL
1152 * below which means if you get a NULL back you dereference it.
1153 */
1154 volatile struct tcp_rate_set *rs;
1155 struct epoch_tracker et;
1156 struct ifnet *oifp = ifp;
1157 int err;
1158
1159 NET_EPOCH_ENTER(et);
1160 use_real_interface:
1161 rs = find_rs_for_ifp(ifp);
1162 if ((rs == NULL) ||
1163 (rs->rs_flags & RS_INTF_NO_SUP) ||
1164 (rs->rs_flags & RS_IS_DEAD)) {
1165 /*
1166 * This means we got a packet *before*
1167 * the IF-UP was processed below, <or>
1168 * while or after we already received an interface
1169 * departed event. In either case we really don't
1170 * want to do anything with pacing, in
1171 * the departing case the packet is not
1172 * going to go very far. The new case
1173 * might be arguable, but its impossible
1174 * to tell from the departing case.
1175 */
1176 if (error)
1177 *error = ENODEV;
1178 NET_EPOCH_EXIT(et);
1179 return (NULL);
1180 }
1181
1182 if ((rs == NULL) || (rs->rs_disable != 0)) {
1183 if (error)
1184 *error = ENOSPC;
1185 NET_EPOCH_EXIT(et);
1186 return (NULL);
1187 }
1188 if (rs->rs_flags & RS_IS_DEFF) {
1189 /* We need to find the real interface */
1190 struct ifnet *tifp;
1191
1192 tifp = rt_find_real_interface(ifp, inp, error);
1193 if (tifp == NULL) {
1194 if (rs->rs_disable && error)
1195 *error = ENOTSUP;
1196 NET_EPOCH_EXIT(et);
1197 return (NULL);
1198 }
1199 KASSERT((tifp != ifp),
1200 ("Lookup failure ifp:%p inp:%p rt_find_real_interface() returns the same interface tifp:%p?\n",
1201 ifp, inp, tifp));
1202 ifp = tifp;
1203 goto use_real_interface;
1204 }
1205 if (rs->rs_flow_limit &&
1206 ((rs->rs_flows_using + 1) > rs->rs_flow_limit)) {
1207 if (error)
1208 *error = ENOSPC;
1209 NET_EPOCH_EXIT(et);
1210 return (NULL);
1211 }
1212 rte = tcp_find_suitable_rate(rs, bytes_per_sec, flags, lower_rate);
1213 if (rte) {
1214 err = in_pcbattach_txrtlmt(inp, oifp,
1215 inp->inp_flowtype,
1216 inp->inp_flowid,
1217 rte->rate,
1218 &inp->inp_snd_tag);
1219 if (err) {
1220 /* Failed to attach */
1221 if (error)
1222 *error = err;
1223 rte = NULL;
1224 } else {
1225 KASSERT((inp->inp_snd_tag != NULL) ,
1226 ("Setup rate has no snd_tag inp:%p rte:%p rate:%llu rs:%p",
1227 inp, rte, (unsigned long long)rte->rate, rs));
1228 #ifdef INET
1229 counter_u64_add(rate_limit_new, 1);
1230 #endif
1231 }
1232 }
1233 if (rte) {
1234 /*
1235 * We use an atomic here for accounting so we don't have to
1236 * use locks when freeing.
1237 */
1238 atomic_add_64(&rs->rs_flows_using, 1);
1239 }
1240 NET_EPOCH_EXIT(et);
1241 return (rte);
1242 }
1243
1244 static void
tcp_rl_ifnet_link(void * arg __unused,struct ifnet * ifp,int link_state)1245 tcp_rl_ifnet_link(void *arg __unused, struct ifnet *ifp, int link_state)
1246 {
1247 int error;
1248 struct tcp_rate_set *rs;
1249 struct epoch_tracker et;
1250
1251 if (((ifp->if_capenable & IFCAP_TXRTLMT) == 0) ||
1252 (link_state != LINK_STATE_UP)) {
1253 /*
1254 * We only care on an interface going up that is rate-limit
1255 * capable.
1256 */
1257 return;
1258 }
1259 NET_EPOCH_ENTER(et);
1260 mtx_lock(&rs_mtx);
1261 rs = find_rs_for_ifp(ifp);
1262 if (rs) {
1263 /* We already have initialized this guy */
1264 mtx_unlock(&rs_mtx);
1265 NET_EPOCH_EXIT(et);
1266 return;
1267 }
1268 mtx_unlock(&rs_mtx);
1269 NET_EPOCH_EXIT(et);
1270 rt_setup_new_rs(ifp, &error);
1271 }
1272
1273 static void
tcp_rl_ifnet_departure(void * arg __unused,struct ifnet * ifp)1274 tcp_rl_ifnet_departure(void *arg __unused, struct ifnet *ifp)
1275 {
1276 struct tcp_rate_set *rs;
1277 struct epoch_tracker et;
1278 int i;
1279
1280 NET_EPOCH_ENTER(et);
1281 mtx_lock(&rs_mtx);
1282 rs = find_rs_for_ifp(ifp);
1283 if (rs) {
1284 CK_LIST_REMOVE(rs, next);
1285 rs_number_alive--;
1286 rs->rs_flags |= RS_IS_DEAD;
1287 for (i = 0; i < rs->rs_rate_cnt; i++) {
1288 if (rs->rs_rlt[i].flags & HDWRPACE_TAGPRESENT) {
1289 in_pcbdetach_tag(rs->rs_rlt[i].tag);
1290 rs->rs_rlt[i].tag = NULL;
1291 }
1292 rs->rs_rlt[i].flags = HDWRPACE_IFPDEPARTED;
1293 }
1294 if (rs->rs_flows_using == 0)
1295 rs_defer_destroy(rs);
1296 }
1297 mtx_unlock(&rs_mtx);
1298 NET_EPOCH_EXIT(et);
1299 }
1300
1301 void
tcp_rl_release_ifnet(struct ifnet * ifp)1302 tcp_rl_release_ifnet(struct ifnet *ifp)
1303 {
1304 tcp_rl_ifnet_departure(NULL, ifp);
1305 }
1306
1307 static void
tcp_rl_shutdown(void * arg __unused,int howto __unused)1308 tcp_rl_shutdown(void *arg __unused, int howto __unused)
1309 {
1310 struct tcp_rate_set *rs, *nrs;
1311 struct epoch_tracker et;
1312 int i;
1313
1314 NET_EPOCH_ENTER(et);
1315 mtx_lock(&rs_mtx);
1316 CK_LIST_FOREACH_SAFE(rs, &int_rs, next, nrs) {
1317 CK_LIST_REMOVE(rs, next);
1318 rs_number_alive--;
1319 rs->rs_flags |= RS_IS_DEAD;
1320 for (i = 0; i < rs->rs_rate_cnt; i++) {
1321 if (rs->rs_rlt[i].flags & HDWRPACE_TAGPRESENT) {
1322 in_pcbdetach_tag(rs->rs_rlt[i].tag);
1323 rs->rs_rlt[i].tag = NULL;
1324 }
1325 rs->rs_rlt[i].flags = HDWRPACE_IFPDEPARTED;
1326 }
1327 if (rs->rs_flows_using == 0)
1328 rs_defer_destroy(rs);
1329 }
1330 mtx_unlock(&rs_mtx);
1331 NET_EPOCH_EXIT(et);
1332 }
1333
1334 const struct tcp_hwrate_limit_table *
tcp_set_pacing_rate(struct tcpcb * tp,struct ifnet * ifp,uint64_t bytes_per_sec,int flags,int * error,uint64_t * lower_rate)1335 tcp_set_pacing_rate(struct tcpcb *tp, struct ifnet *ifp,
1336 uint64_t bytes_per_sec, int flags, int *error, uint64_t *lower_rate)
1337 {
1338 struct inpcb *inp = tptoinpcb(tp);
1339 const struct tcp_hwrate_limit_table *rte;
1340 #ifdef KERN_TLS
1341 struct ktls_session *tls;
1342 #endif
1343
1344 INP_WLOCK_ASSERT(inp);
1345
1346 if (inp->inp_snd_tag == NULL) {
1347 /*
1348 * We are setting up a rate for the first time.
1349 */
1350 if ((ifp->if_capenable & IFCAP_TXRTLMT) == 0) {
1351 /* Not supported by the egress */
1352 if (error)
1353 *error = ENODEV;
1354 return (NULL);
1355 }
1356 #ifdef KERN_TLS
1357 tls = NULL;
1358 if (tp->t_nic_ktls_xmit != 0) {
1359 tls = tptosocket(tp)->so_snd.sb_tls_info;
1360
1361 if ((ifp->if_capenable & IFCAP_TXTLS_RTLMT) == 0 ||
1362 tls->mode != TCP_TLS_MODE_IFNET) {
1363 if (error)
1364 *error = ENODEV;
1365 return (NULL);
1366 }
1367 }
1368 #endif
1369 rte = rt_setup_rate(inp, ifp, bytes_per_sec, flags, error, lower_rate);
1370 if (rte)
1371 rl_increment_using(rte);
1372 #ifdef KERN_TLS
1373 if (rte != NULL && tls != NULL && tls->snd_tag != NULL) {
1374 /*
1375 * Fake a route change error to reset the TLS
1376 * send tag. This will convert the existing
1377 * tag to a TLS ratelimit tag.
1378 */
1379 MPASS(tls->snd_tag->sw->type == IF_SND_TAG_TYPE_TLS);
1380 ktls_output_eagain(inp, tls);
1381 }
1382 #endif
1383 } else {
1384 /*
1385 * We are modifying a rate, wrong interface?
1386 */
1387 if (error)
1388 *error = EINVAL;
1389 rte = NULL;
1390 }
1391 if (rte != NULL) {
1392 tp->t_pacing_rate = rte->rate;
1393 *error = 0;
1394 }
1395 return (rte);
1396 }
1397
1398 const struct tcp_hwrate_limit_table *
tcp_chg_pacing_rate(const struct tcp_hwrate_limit_table * crte,struct tcpcb * tp,struct ifnet * ifp,uint64_t bytes_per_sec,int flags,int * error,uint64_t * lower_rate)1399 tcp_chg_pacing_rate(const struct tcp_hwrate_limit_table *crte,
1400 struct tcpcb *tp, struct ifnet *ifp,
1401 uint64_t bytes_per_sec, int flags, int *error, uint64_t *lower_rate)
1402 {
1403 struct inpcb *inp = tptoinpcb(tp);
1404 const struct tcp_hwrate_limit_table *nrte;
1405 const struct tcp_rate_set *rs;
1406 #ifdef KERN_TLS
1407 struct ktls_session *tls = NULL;
1408 #endif
1409 int err;
1410
1411 INP_WLOCK_ASSERT(inp);
1412
1413 if (crte == NULL) {
1414 /* Wrong interface */
1415 if (error)
1416 *error = EINVAL;
1417 return (NULL);
1418 }
1419
1420 #ifdef KERN_TLS
1421 if (tp->t_nic_ktls_xmit) {
1422 tls = tptosocket(tp)->so_snd.sb_tls_info;
1423 if (tls->mode != TCP_TLS_MODE_IFNET)
1424 tls = NULL;
1425 else if (tls->snd_tag != NULL &&
1426 tls->snd_tag->sw->type != IF_SND_TAG_TYPE_TLS_RATE_LIMIT) {
1427 if (!tls->reset_pending) {
1428 /*
1429 * NIC probably doesn't support
1430 * ratelimit TLS tags if it didn't
1431 * allocate one when an existing rate
1432 * was present, so ignore.
1433 */
1434 tcp_rel_pacing_rate(crte, tp);
1435 if (error)
1436 *error = EOPNOTSUPP;
1437 return (NULL);
1438 }
1439
1440 /*
1441 * The send tag is being converted, so set the
1442 * rate limit on the inpcb tag. There is a
1443 * race that the new NIC send tag might use
1444 * the current rate instead of this one.
1445 */
1446 tls = NULL;
1447 }
1448 }
1449 #endif
1450 if (inp->inp_snd_tag == NULL) {
1451 /* Wrong interface */
1452 tcp_rel_pacing_rate(crte, tp);
1453 if (error)
1454 *error = EINVAL;
1455 return (NULL);
1456 }
1457 rs = crte->ptbl;
1458 if ((rs->rs_flags & RS_IS_DEAD) ||
1459 (crte->flags & HDWRPACE_IFPDEPARTED)) {
1460 /* Release the rate, and try anew */
1461
1462 tcp_rel_pacing_rate(crte, tp);
1463 nrte = tcp_set_pacing_rate(tp, ifp,
1464 bytes_per_sec, flags, error, lower_rate);
1465 return (nrte);
1466 }
1467 nrte = tcp_find_suitable_rate(rs, bytes_per_sec, flags, lower_rate);
1468 if (nrte == crte) {
1469 /* No change */
1470 if (error)
1471 *error = 0;
1472 return (crte);
1473 }
1474 if (nrte == NULL) {
1475 /* Release the old rate */
1476 if (error)
1477 *error = ENOENT;
1478 tcp_rel_pacing_rate(crte, tp);
1479 return (NULL);
1480 }
1481 rl_decrement_using(crte);
1482 rl_increment_using(nrte);
1483 /* Change rates to our new entry */
1484 #ifdef KERN_TLS
1485 if (tls != NULL)
1486 err = ktls_modify_txrtlmt(tls, nrte->rate);
1487 else
1488 #endif
1489 err = in_pcbmodify_txrtlmt(inp, nrte->rate);
1490 if (err) {
1491 struct tcp_rate_set *lrs;
1492 uint64_t pre;
1493
1494 rl_decrement_using(nrte);
1495 lrs = __DECONST(struct tcp_rate_set *, rs);
1496 pre = atomic_fetchadd_64(&lrs->rs_flows_using, -1);
1497 /* Do we still have a snd-tag attached? */
1498 if (inp->inp_snd_tag)
1499 in_pcbdetach_txrtlmt(inp);
1500
1501 if (pre == 1) {
1502 struct epoch_tracker et;
1503
1504 NET_EPOCH_ENTER(et);
1505 mtx_lock(&rs_mtx);
1506 /*
1507 * Is it dead?
1508 */
1509 if (lrs->rs_flags & RS_IS_DEAD)
1510 rs_defer_destroy(lrs);
1511 mtx_unlock(&rs_mtx);
1512 NET_EPOCH_EXIT(et);
1513 }
1514 if (error)
1515 *error = err;
1516 return (NULL);
1517 } else {
1518 #ifdef INET
1519 counter_u64_add(rate_limit_chg, 1);
1520 #endif
1521 }
1522 if (error)
1523 *error = 0;
1524 tp->t_pacing_rate = nrte->rate;
1525 return (nrte);
1526 }
1527
1528 void
tcp_rel_pacing_rate(const struct tcp_hwrate_limit_table * crte,struct tcpcb * tp)1529 tcp_rel_pacing_rate(const struct tcp_hwrate_limit_table *crte, struct tcpcb *tp)
1530 {
1531 struct inpcb *inp = tptoinpcb(tp);
1532 const struct tcp_rate_set *crs;
1533 struct tcp_rate_set *rs;
1534 uint64_t pre;
1535
1536 INP_WLOCK_ASSERT(inp);
1537
1538 tp->t_pacing_rate = -1;
1539 crs = crte->ptbl;
1540 /*
1541 * Now we must break the const
1542 * in order to release our refcount.
1543 */
1544 rs = __DECONST(struct tcp_rate_set *, crs);
1545 rl_decrement_using(crte);
1546 pre = atomic_fetchadd_64(&rs->rs_flows_using, -1);
1547 if (pre == 1) {
1548 struct epoch_tracker et;
1549
1550 NET_EPOCH_ENTER(et);
1551 mtx_lock(&rs_mtx);
1552 /*
1553 * Is it dead?
1554 */
1555 if (rs->rs_flags & RS_IS_DEAD)
1556 rs_defer_destroy(rs);
1557 mtx_unlock(&rs_mtx);
1558 NET_EPOCH_EXIT(et);
1559 }
1560
1561 /*
1562 * XXX: If this connection is using ifnet TLS, should we
1563 * switch it to using an unlimited rate, or perhaps use
1564 * ktls_output_eagain() to reset the send tag to a plain
1565 * TLS tag?
1566 */
1567 in_pcbdetach_txrtlmt(inp);
1568 }
1569
1570 #define ONE_POINT_TWO_MEG 150000 /* 1.2 megabits in bytes */
1571 #define ONE_HUNDRED_MBPS 12500000 /* 100Mbps in bytes per second */
1572 #define FIVE_HUNDRED_MBPS 62500000 /* 500Mbps in bytes per second */
1573 #define MAX_MSS_SENT 43 /* 43 mss = 43 x 1500 = 64,500 bytes */
1574
1575 static void
tcp_log_pacing_size(struct tcpcb * tp,uint64_t bw,uint32_t segsiz,uint32_t new_tso,uint64_t hw_rate,uint32_t time_between,uint32_t calc_time_between,uint32_t segs,uint32_t res_div,uint16_t mult,uint8_t mod)1576 tcp_log_pacing_size(struct tcpcb *tp, uint64_t bw, uint32_t segsiz, uint32_t new_tso,
1577 uint64_t hw_rate, uint32_t time_between, uint32_t calc_time_between,
1578 uint32_t segs, uint32_t res_div, uint16_t mult, uint8_t mod)
1579 {
1580 if (tcp_bblogging_on(tp)) {
1581 union tcp_log_stackspecific log;
1582 struct timeval tv;
1583
1584 memset(&log, 0, sizeof(log));
1585 log.u_bbr.flex1 = segsiz;
1586 log.u_bbr.flex2 = new_tso;
1587 log.u_bbr.flex3 = time_between;
1588 log.u_bbr.flex4 = calc_time_between;
1589 log.u_bbr.flex5 = segs;
1590 log.u_bbr.flex6 = res_div;
1591 log.u_bbr.flex7 = mult;
1592 log.u_bbr.flex8 = mod;
1593 log.u_bbr.timeStamp = tcp_get_usecs(&tv);
1594 log.u_bbr.cur_del_rate = bw;
1595 log.u_bbr.delRate = hw_rate;
1596 TCP_LOG_EVENTP(tp, NULL,
1597 &tptosocket(tp)->so_rcv,
1598 &tptosocket(tp)->so_snd,
1599 TCP_HDWR_PACE_SIZE, 0,
1600 0, &log, false, &tv);
1601 }
1602 }
1603
1604 uint32_t
tcp_get_pacing_burst_size_w_divisor(struct tcpcb * tp,uint64_t bw,uint32_t segsiz,int can_use_1mss,const struct tcp_hwrate_limit_table * te,int * err,int divisor)1605 tcp_get_pacing_burst_size_w_divisor(struct tcpcb *tp, uint64_t bw, uint32_t segsiz, int can_use_1mss,
1606 const struct tcp_hwrate_limit_table *te, int *err, int divisor)
1607 {
1608 /*
1609 * We use the google formula to calculate the
1610 * TSO size. I.E.
1611 * bw < 24Meg
1612 * tso = 2mss
1613 * else
1614 * tso = min(bw/(div=1000), 64k)
1615 *
1616 * Note for these calculations we ignore the
1617 * packet overhead (enet hdr, ip hdr and tcp hdr).
1618 * We only get the google formula when we have
1619 * divisor = 1000, which is the default for now.
1620 */
1621 uint64_t lentim, res, bytes;
1622 uint32_t new_tso, min_tso_segs;
1623
1624 /* It can't be zero */
1625 if ((divisor == 0) ||
1626 (divisor < RL_MIN_DIVISOR)) {
1627 if (mss_divisor)
1628 bytes = bw / mss_divisor;
1629 else
1630 bytes = bw / 1000;
1631 } else
1632 bytes = bw / divisor;
1633 /* We can't ever send more than 65k in a TSO */
1634 if (bytes > 0xffff) {
1635 bytes = 0xffff;
1636 }
1637 /* Round up */
1638 new_tso = (bytes + segsiz - 1) / segsiz;
1639 /* Are we enforcing even boundaries? */
1640 if (even_num_segs && (new_tso & 1) && (new_tso > even_threshold))
1641 new_tso++;
1642 if (can_use_1mss)
1643 min_tso_segs = 1;
1644 else
1645 min_tso_segs = 2;
1646 if (rs_floor_mss && (new_tso < rs_floor_mss))
1647 new_tso = rs_floor_mss;
1648 else if (new_tso < min_tso_segs)
1649 new_tso = min_tso_segs;
1650 if (new_tso > MAX_MSS_SENT)
1651 new_tso = MAX_MSS_SENT;
1652 new_tso *= segsiz;
1653 tcp_log_pacing_size(tp, bw, segsiz, new_tso,
1654 0, 0, 0, 0, 0, 0, 1);
1655 /*
1656 * If we are not doing hardware pacing
1657 * then we are done.
1658 */
1659 if (te == NULL) {
1660 if (err)
1661 *err = 0;
1662 return(new_tso);
1663 }
1664 /*
1665 * For hardware pacing we look at the
1666 * rate you are sending at and compare
1667 * that to the rate you have in hardware.
1668 *
1669 * If the hardware rate is slower than your
1670 * software rate then you are in error and
1671 * we will build a queue in our hardware whic
1672 * is probably not desired, in such a case
1673 * just return the non-hardware TSO size.
1674 *
1675 * If the rate in hardware is faster (which
1676 * it should be) then look at how long it
1677 * takes to send one ethernet segment size at
1678 * your b/w and compare that to the time it
1679 * takes to send at the rate you had selected.
1680 *
1681 * If your time is greater (which we hope it is)
1682 * we get the delta between the two, and then
1683 * divide that into your pacing time. This tells
1684 * us how many MSS you can send down at once (rounded up).
1685 *
1686 * Note we also double this value if the b/w is over
1687 * 100Mbps. If its over 500meg we just set you to the
1688 * max (43 segments).
1689 */
1690 if (te->rate > FIVE_HUNDRED_MBPS)
1691 goto max;
1692 if (te->rate == bw) {
1693 /* We are pacing at exactly the hdwr rate */
1694 max:
1695 tcp_log_pacing_size(tp, bw, segsiz, new_tso,
1696 te->rate, te->time_between, (uint32_t)0,
1697 (segsiz * MAX_MSS_SENT), 0, 0, 3);
1698 return (segsiz * MAX_MSS_SENT);
1699 }
1700 lentim = ETHERNET_SEGMENT_SIZE * USECS_IN_SECOND;
1701 res = lentim / bw;
1702 if (res > te->time_between) {
1703 uint32_t delta, segs, res_div;
1704
1705 res_div = ((res * num_of_waits_allowed) + wait_time_floor);
1706 delta = res - te->time_between;
1707 segs = (res_div + delta - 1)/delta;
1708 if (segs < min_tso_segs)
1709 segs = min_tso_segs;
1710 if (segs < rs_hw_floor_mss)
1711 segs = rs_hw_floor_mss;
1712 if (segs > MAX_MSS_SENT)
1713 segs = MAX_MSS_SENT;
1714 segs *= segsiz;
1715 tcp_log_pacing_size(tp, bw, segsiz, new_tso,
1716 te->rate, te->time_between, (uint32_t)res,
1717 segs, res_div, 1, 3);
1718 if (err)
1719 *err = 0;
1720 if (segs < new_tso) {
1721 /* unexpected ? */
1722 return(new_tso);
1723 } else {
1724 return (segs);
1725 }
1726 } else {
1727 /*
1728 * Your time is smaller which means
1729 * we will grow a queue on our
1730 * hardware. Send back the non-hardware
1731 * rate.
1732 */
1733 tcp_log_pacing_size(tp, bw, segsiz, new_tso,
1734 te->rate, te->time_between, (uint32_t)res,
1735 0, 0, 0, 4);
1736 if (err)
1737 *err = -1;
1738 return (new_tso);
1739 }
1740 }
1741
1742 uint64_t
tcp_hw_highest_rate_ifp(struct ifnet * ifp,struct inpcb * inp)1743 tcp_hw_highest_rate_ifp(struct ifnet *ifp, struct inpcb *inp)
1744 {
1745 struct epoch_tracker et;
1746 struct tcp_rate_set *rs;
1747 uint64_t rate_ret;
1748
1749 NET_EPOCH_ENTER(et);
1750 use_next_interface:
1751 rs = find_rs_for_ifp(ifp);
1752 if (rs == NULL) {
1753 /* This interface does not do ratelimiting */
1754 rate_ret = 0;
1755 } else if (rs->rs_flags & RS_IS_DEFF) {
1756 /* We need to find the real interface */
1757 struct ifnet *tifp;
1758
1759 tifp = rt_find_real_interface(ifp, inp, NULL);
1760 if (tifp == NULL) {
1761 NET_EPOCH_EXIT(et);
1762 return (0);
1763 }
1764 ifp = tifp;
1765 goto use_next_interface;
1766 } else {
1767 /* Lets return the highest rate this guy has */
1768 rate_ret = rs->rs_rlt[rs->rs_highest_valid].rate;
1769 }
1770 NET_EPOCH_EXIT(et);
1771 return(rate_ret);
1772 }
1773
1774 static eventhandler_tag rl_ifnet_departs;
1775 static eventhandler_tag rl_ifnet_arrives;
1776 static eventhandler_tag rl_shutdown_start;
1777
1778 static void
tcp_rs_init(void * st __unused)1779 tcp_rs_init(void *st __unused)
1780 {
1781 CK_LIST_INIT(&int_rs);
1782 rs_number_alive = 0;
1783 rs_number_dead = 0;
1784 mtx_init(&rs_mtx, "tcp_rs_mtx", "rsmtx", MTX_DEF);
1785 rl_ifnet_departs = EVENTHANDLER_REGISTER(ifnet_departure_event,
1786 tcp_rl_ifnet_departure,
1787 NULL, EVENTHANDLER_PRI_ANY);
1788 rl_ifnet_arrives = EVENTHANDLER_REGISTER(ifnet_link_event,
1789 tcp_rl_ifnet_link,
1790 NULL, EVENTHANDLER_PRI_ANY);
1791 rl_shutdown_start = EVENTHANDLER_REGISTER(shutdown_pre_sync,
1792 tcp_rl_shutdown, NULL,
1793 SHUTDOWN_PRI_FIRST);
1794 printf("TCP_ratelimit: Is now initialized\n");
1795 }
1796
1797 SYSINIT(tcp_rl_init, SI_SUB_SMP + 1, SI_ORDER_ANY, tcp_rs_init, NULL);
1798 #endif
1799