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freebsd-nq/sys/netinet/tcp_ratelimit.c
Warner Losh 28540ab153 Fix copyright year and eliminate the obsolete all rights reserved line. 
Reviewed by: rrs@
2020-04-08 17:55:45 +00:00

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/*-
*
* SPDX-License-Identifier: BSD-3-Clause
*
* Copyright (c) 2018-2020
* Netflix Inc.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*
*/
/**
* Author: Randall Stewart <rrs@netflix.com>
*/
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
#include "opt_inet.h"
#include "opt_inet6.h"
#include "opt_ipsec.h"
#include "opt_tcpdebug.h"
#include "opt_ratelimit.h"
#include <sys/param.h>
#include <sys/kernel.h>
#include <sys/malloc.h>
#include <sys/mbuf.h>
#include <sys/socket.h>
#include <sys/socketvar.h>
#include <sys/sysctl.h>
#include <sys/eventhandler.h>
#include <sys/mutex.h>
#include <sys/ck.h>
#include <net/if.h>
#include <net/if_var.h>
#include <netinet/in.h>
#include <netinet/in_pcb.h>
#define TCPSTATES /* for logging */
#include <netinet/tcp_var.h>
#ifdef INET6
#include <netinet6/tcp6_var.h>
#endif
#include <netinet/tcp_ratelimit.h>
#ifndef USECS_IN_SECOND
#define USECS_IN_SECOND 1000000
#endif
/*
* For the purposes of each send, what is the size
* of an ethernet frame.
*/
MALLOC_DEFINE(M_TCPPACE, "tcp_hwpace", "TCP Hardware pacing memory");
#ifdef RATELIMIT
/*
* The following preferred table will seem weird to
* the casual viewer. Why do we not have any rates below
* 1Mbps? Why do we have a rate at 1.44Mbps called common?
* Why do the rates cluster in the 1-100Mbps range more
* than others? Why does the table jump around at the beginnign
* and then be more consistently raising?
*
* Let me try to answer those questions. A lot of
* this is dependant on the hardware. We have three basic
* supporters of rate limiting
*
* Chelsio - Supporting 16 configurable rates.
* Mlx - c4 supporting 13 fixed rates.
* Mlx - c5 & c6 supporting 127 configurable rates.
*
* The c4 is why we have a common rate that is available
* in all rate tables. This is a selected rate from the
* c4 table and we assure its available in all ratelimit
* tables. This way the tcp_ratelimit code has an assured
* rate it should always be able to get. This answers a
* couple of the questions above.
*
* So what about the rest, well the table is built to
* try to get the most out of a joint hardware/software
* pacing system. The software pacer will always pick
* a rate higher than the b/w that it is estimating
*
* on the path. This is done for two reasons.
* a) So we can discover more b/w
* and
* b) So we can send a block of MSS's down and then
* have the software timer go off after the previous
* send is completely out of the hardware.
*
* But when we do <b> we don't want to have the delay
* between the last packet sent by the hardware be
* excessively long (to reach our desired rate).
*
* So let me give an example for clarity.
*
* Lets assume that the tcp stack sees that 29,110,000 bps is
* what the bw of the path is. The stack would select the
* rate 31Mbps. 31Mbps means that each send that is done
* by the hardware will cause a 390 micro-second gap between
* the packets sent at that rate. For 29,110,000 bps we
* would need 416 micro-seconds gap between each send.
*
* Note that are calculating a complete time for pacing
* which includes the ethernet, IP and TCP overhead. So
* a full 1514 bytes is used for the above calculations.
* My testing has shown that both cards are also using this
* as their basis i.e. full payload size of the ethernet frame.
* The TCP stack caller needs to be aware of this and make the
* appropriate overhead calculations be included in its choices.
*
* Now, continuing our example, we pick a MSS size based on the
* delta between the two rates (416 - 390) divided into the rate
* we really wish to send at rounded up. That results in a MSS
* send of 17 mss's at once. The hardware then will
* run out of data in a single 17MSS send in 6,630 micro-seconds.
*
* On the other hand the software pacer will send more data
* in 7,072 micro-seconds. This means that we will refill
* the hardware 52 microseconds after it would have sent
* next if it had not ran out of data. This is a win since we are
* only sending every 7ms or so and yet all the packets are spaced on
* the wire with 94% of what they should be and only
* the last packet is delayed extra to make up for the
* difference.
*
* Note that the above formula has two important caveat.
* If we are above (b/w wise) over 100Mbps we double the result
* of the MSS calculation. The second caveat is if we are 500Mbps
* or more we just send the maximum MSS at once i.e. 45MSS. At
* the higher b/w's even the cards have limits to what times (timer granularity)
* they can insert between packets and start to send more than one
* packet at a time on the wire.
*
*/
#define COMMON_RATE 180500
const uint64_t desired_rates[] = {
122500, /* 1Mbps - rate 1 */
180500, /* 1.44Mpbs - rate 2 common rate */
375000, /* 3Mbps - rate 3 */
625000, /* 5Mbps - rate 4 */
875000, /* 7Mbps - rate 5 */
1125000, /* 9Mbps - rate 6 */
1375000, /* 11Mbps - rate 7 */
1625000, /* 13Mbps - rate 8 */
2625000, /* 21Mbps - rate 9 */
3875000, /* 31Mbps - rate 10 */
5125000, /* 41Meg - rate 11 */
12500000, /* 100Mbps - rate 12 */
25000000, /* 200Mbps - rate 13 */
50000000, /* 400Mbps - rate 14 */
63750000, /* 51Mbps - rate 15 */
100000000, /* 800Mbps - rate 16 */
1875000, /* 15Mbps - rate 17 */
2125000, /* 17Mbps - rate 18 */
2375000, /* 19Mbps - rate 19 */
2875000, /* 23Mbps - rate 20 */
3125000, /* 25Mbps - rate 21 */
3375000, /* 27Mbps - rate 22 */
3625000, /* 29Mbps - rate 23 */
4125000, /* 33Mbps - rate 24 */
4375000, /* 35Mbps - rate 25 */
4625000, /* 37Mbps - rate 26 */
4875000, /* 39Mbps - rate 27 */
5375000, /* 43Mbps - rate 28 */
5625000, /* 45Mbps - rate 29 */
5875000, /* 47Mbps - rate 30 */
6125000, /* 49Mbps - rate 31 */
6625000, /* 53Mbps - rate 32 */
6875000, /* 55Mbps - rate 33 */
7125000, /* 57Mbps - rate 34 */
7375000, /* 59Mbps - rate 35 */
7625000, /* 61Mbps - rate 36 */
7875000, /* 63Mbps - rate 37 */
8125000, /* 65Mbps - rate 38 */
8375000, /* 67Mbps - rate 39 */
8625000, /* 69Mbps - rate 40 */
8875000, /* 71Mbps - rate 41 */
9125000, /* 73Mbps - rate 42 */
9375000, /* 75Mbps - rate 43 */
9625000, /* 77Mbps - rate 44 */
9875000, /* 79Mbps - rate 45 */
10125000, /* 81Mbps - rate 46 */
10375000, /* 83Mbps - rate 47 */
10625000, /* 85Mbps - rate 48 */
10875000, /* 87Mbps - rate 49 */
11125000, /* 89Mbps - rate 50 */
11375000, /* 91Mbps - rate 51 */
11625000, /* 93Mbps - rate 52 */
11875000, /* 95Mbps - rate 53 */
13125000, /* 105Mbps - rate 54 */
13750000, /* 110Mbps - rate 55 */
14375000, /* 115Mbps - rate 56 */
15000000, /* 120Mbps - rate 57 */
15625000, /* 125Mbps - rate 58 */
16250000, /* 130Mbps - rate 59 */
16875000, /* 135Mbps - rate 60 */
17500000, /* 140Mbps - rate 61 */
18125000, /* 145Mbps - rate 62 */
18750000, /* 150Mbps - rate 64 */
20000000, /* 160Mbps - rate 65 */
21250000, /* 170Mbps - rate 66 */
22500000, /* 180Mbps - rate 67 */
23750000, /* 190Mbps - rate 68 */
26250000, /* 210Mbps - rate 69 */
27500000, /* 220Mbps - rate 70 */
28750000, /* 230Mbps - rate 71 */
30000000, /* 240Mbps - rate 72 */
31250000, /* 250Mbps - rate 73 */
34375000, /* 275Mbps - rate 74 */
37500000, /* 300Mbps - rate 75 */
40625000, /* 325Mbps - rate 76 */
43750000, /* 350Mbps - rate 77 */
46875000, /* 375Mbps - rate 78 */
53125000, /* 425Mbps - rate 79 */
56250000, /* 450Mbps - rate 80 */
59375000, /* 475Mbps - rate 81 */
62500000, /* 500Mbps - rate 82 */
68750000, /* 550Mbps - rate 83 */
75000000, /* 600Mbps - rate 84 */
81250000, /* 650Mbps - rate 85 */
87500000, /* 700Mbps - rate 86 */
93750000, /* 750Mbps - rate 87 */
106250000, /* 850Mbps - rate 88 */
112500000, /* 900Mbps - rate 89 */
125000000, /* 1Gbps - rate 90 */
156250000, /* 1.25Gps - rate 91 */
187500000, /* 1.5Gps - rate 92 */
218750000, /* 1.75Gps - rate 93 */
250000000, /* 2Gbps - rate 94 */
281250000, /* 2.25Gps - rate 95 */
312500000, /* 2.5Gbps - rate 96 */
343750000, /* 2.75Gbps - rate 97 */
375000000, /* 3Gbps - rate 98 */
500000000, /* 4Gbps - rate 99 */
625000000, /* 5Gbps - rate 100 */
750000000, /* 6Gbps - rate 101 */
875000000, /* 7Gbps - rate 102 */
1000000000, /* 8Gbps - rate 103 */
1125000000, /* 9Gbps - rate 104 */
1250000000, /* 10Gbps - rate 105 */
1875000000, /* 15Gbps - rate 106 */
2500000000 /* 20Gbps - rate 107 */
};
#define MAX_HDWR_RATES (sizeof(desired_rates)/sizeof(uint64_t))
#define RS_ORDERED_COUNT 16 /*
* Number that are in order
* at the beginning of the table,
* over this a sort is required.
*/
#define RS_NEXT_ORDER_GROUP 16 /*
* The point in our table where
* we come fill in a second ordered
* group (index wise means -1).
*/
#define ALL_HARDWARE_RATES 1004 /*
* 1Meg - 1Gig in 1 Meg steps
* plus 100, 200k and 500k and
* 10Gig
*/
#define RS_ONE_MEGABIT_PERSEC 1000000
#define RS_ONE_GIGABIT_PERSEC 1000000000
#define RS_TEN_GIGABIT_PERSEC 10000000000
static struct head_tcp_rate_set int_rs;
static struct mtx rs_mtx;
uint32_t rs_number_alive;
uint32_t rs_number_dead;
SYSCTL_NODE(_net_inet_tcp, OID_AUTO, rl, CTLFLAG_RW | CTLFLAG_MPSAFE, 0,
"TCP Ratelimit stats");
SYSCTL_UINT(_net_inet_tcp_rl, OID_AUTO, alive, CTLFLAG_RW,
&rs_number_alive, 0,
"Number of interfaces initialized for ratelimiting");
SYSCTL_UINT(_net_inet_tcp_rl, OID_AUTO, dead, CTLFLAG_RW,
&rs_number_dead, 0,
"Number of interfaces departing from ratelimiting");
static void
rl_add_syctl_entries(struct sysctl_oid *rl_sysctl_root, struct tcp_rate_set *rs)
{
/*
* Add sysctl entries for thus interface.
*/
if (rs->rs_flags & RS_INTF_NO_SUP) {
SYSCTL_ADD_S32(&rs->sysctl_ctx,
SYSCTL_CHILDREN(rl_sysctl_root),
OID_AUTO, "disable", CTLFLAG_RD,
&rs->rs_disable, 0,
"Disable this interface from new hdwr limiting?");
} else {
SYSCTL_ADD_S32(&rs->sysctl_ctx,
SYSCTL_CHILDREN(rl_sysctl_root),
OID_AUTO, "disable", CTLFLAG_RW,
&rs->rs_disable, 0,
"Disable this interface from new hdwr limiting?");
}
SYSCTL_ADD_S32(&rs->sysctl_ctx,
SYSCTL_CHILDREN(rl_sysctl_root),
OID_AUTO, "minseg", CTLFLAG_RW,
&rs->rs_min_seg, 0,
"What is the minimum we need to send on this interface?");
SYSCTL_ADD_U64(&rs->sysctl_ctx,
SYSCTL_CHILDREN(rl_sysctl_root),
OID_AUTO, "flow_limit", CTLFLAG_RW,
&rs->rs_flow_limit, 0,
"What is the limit for number of flows (0=unlimited)?");
SYSCTL_ADD_S32(&rs->sysctl_ctx,
SYSCTL_CHILDREN(rl_sysctl_root),
OID_AUTO, "highest", CTLFLAG_RD,
&rs->rs_highest_valid, 0,
"Highest valid rate");
SYSCTL_ADD_S32(&rs->sysctl_ctx,
SYSCTL_CHILDREN(rl_sysctl_root),
OID_AUTO, "lowest", CTLFLAG_RD,
&rs->rs_lowest_valid, 0,
"Lowest valid rate");
SYSCTL_ADD_S32(&rs->sysctl_ctx,
SYSCTL_CHILDREN(rl_sysctl_root),
OID_AUTO, "flags", CTLFLAG_RD,
&rs->rs_flags, 0,
"What lags are on the entry?");
SYSCTL_ADD_S32(&rs->sysctl_ctx,
SYSCTL_CHILDREN(rl_sysctl_root),
OID_AUTO, "numrates", CTLFLAG_RD,
&rs->rs_rate_cnt, 0,
"How many rates re there?");
SYSCTL_ADD_U64(&rs->sysctl_ctx,
SYSCTL_CHILDREN(rl_sysctl_root),
OID_AUTO, "flows_using", CTLFLAG_RD,
&rs->rs_flows_using, 0,
"How many flows are using this interface now?");
#ifdef DETAILED_RATELIMIT_SYSCTL
if (rs->rs_rlt && rs->rs_rate_cnt > 0) {
/* Lets display the rates */
int i;
struct sysctl_oid *rl_rates;
struct sysctl_oid *rl_rate_num;
char rate_num[16];
rl_rates = SYSCTL_ADD_NODE(&rs->sysctl_ctx,
SYSCTL_CHILDREN(rl_sysctl_root),
OID_AUTO,
"rate",
CTLFLAG_RW | CTLFLAG_MPSAFE, 0,
"Ratelist");
for( i = 0; i < rs->rs_rate_cnt; i++) {
sprintf(rate_num, "%d", i);
rl_rate_num = SYSCTL_ADD_NODE(&rs->sysctl_ctx,
SYSCTL_CHILDREN(rl_rates),
OID_AUTO,
rate_num,
CTLFLAG_RW | CTLFLAG_MPSAFE, 0,
"Individual Rate");
SYSCTL_ADD_U32(&rs->sysctl_ctx,
SYSCTL_CHILDREN(rl_rate_num),
OID_AUTO, "flags", CTLFLAG_RD,
&rs->rs_rlt[i].flags, 0,
"Flags on this rate");
SYSCTL_ADD_U32(&rs->sysctl_ctx,
SYSCTL_CHILDREN(rl_rate_num),
OID_AUTO, "pacetime", CTLFLAG_RD,
&rs->rs_rlt[i].time_between, 0,
"Time hardware inserts between 1500 byte sends");
SYSCTL_ADD_U64(&rs->sysctl_ctx,
SYSCTL_CHILDREN(rl_rate_num),
OID_AUTO, "rate", CTLFLAG_RD,
&rs->rs_rlt[i].rate, 0,
"Rate in bytes per second");
}
}
#endif
}
static void
rs_destroy(epoch_context_t ctx)
{
struct tcp_rate_set *rs;
bool do_free_rs;
rs = __containerof(ctx, struct tcp_rate_set, rs_epoch_ctx);
mtx_lock(&rs_mtx);
rs->rs_flags &= ~RS_FUNERAL_SCHD;
/*
* In theory its possible (but unlikely)
* that while the delete was occuring
* and we were applying the DEAD flag
* someone slipped in and found the
* interface in a lookup. While we
* decided rs_flows_using were 0 and
* scheduling the epoch_call, the other
* thread incremented rs_flow_using. This
* is because users have a pointer and
* we only use the rs_flows_using in an
* atomic fashion, i.e. the other entities
* are not protected. To assure this did
* not occur, we check rs_flows_using here
* before deleting.
*/
do_free_rs = (rs->rs_flows_using == 0);
rs_number_dead--;
mtx_unlock(&rs_mtx);
if (do_free_rs) {
sysctl_ctx_free(&rs->sysctl_ctx);
free(rs->rs_rlt, M_TCPPACE);
free(rs, M_TCPPACE);
}
}
static void
rs_defer_destroy(struct tcp_rate_set *rs)
{
mtx_assert(&rs_mtx, MA_OWNED);
/* Check if already pending. */
if (rs->rs_flags & RS_FUNERAL_SCHD)
return;
rs_number_dead++;
/* Set flag to only defer once. */
rs->rs_flags |= RS_FUNERAL_SCHD;
NET_EPOCH_CALL(rs_destroy, &rs->rs_epoch_ctx);
}
#ifdef INET
extern counter_u64_t rate_limit_set_ok;
extern counter_u64_t rate_limit_active;
extern counter_u64_t rate_limit_alloc_fail;
#endif
static int
rl_attach_txrtlmt(struct ifnet *ifp,
uint32_t flowtype,
int flowid,
uint64_t cfg_rate,
struct m_snd_tag **tag)
{
int error;
union if_snd_tag_alloc_params params = {
.rate_limit.hdr.type = IF_SND_TAG_TYPE_RATE_LIMIT,
.rate_limit.hdr.flowid = flowid,
.rate_limit.hdr.flowtype = flowtype,
.rate_limit.max_rate = cfg_rate,
.rate_limit.flags = M_NOWAIT,
};
if (ifp->if_snd_tag_alloc == NULL) {
error = EOPNOTSUPP;
} else {
error = ifp->if_snd_tag_alloc(ifp, &params, tag);
#ifdef INET
if (error == 0) {
if_ref((*tag)->ifp);
counter_u64_add(rate_limit_set_ok, 1);
counter_u64_add(rate_limit_active, 1);
} else
counter_u64_add(rate_limit_alloc_fail, 1);
#endif
}
return (error);
}
static void
populate_canned_table(struct tcp_rate_set *rs, const uint64_t *rate_table_act)
{
/*
* The internal table is "special", it
* is two seperate ordered tables that
* must be merged. We get here when the
* adapter specifies a number of rates that
* covers both ranges in the table in some
* form.
*/
int i, at_low, at_high;
uint8_t low_disabled = 0, high_disabled = 0;
for(i = 0, at_low = 0, at_high = RS_NEXT_ORDER_GROUP; i < rs->rs_rate_cnt; i++) {
rs->rs_rlt[i].flags = 0;
rs->rs_rlt[i].time_between = 0;
if ((low_disabled == 0) &&
(high_disabled ||
(rate_table_act[at_low] < rate_table_act[at_high]))) {
rs->rs_rlt[i].rate = rate_table_act[at_low];
at_low++;
if (at_low == RS_NEXT_ORDER_GROUP)
low_disabled = 1;
} else if (high_disabled == 0) {
rs->rs_rlt[i].rate = rate_table_act[at_high];
at_high++;
if (at_high == MAX_HDWR_RATES)
high_disabled = 1;
}
}
}
static struct tcp_rate_set *
rt_setup_new_rs(struct ifnet *ifp, int *error)
{
struct tcp_rate_set *rs;
const uint64_t *rate_table_act;
uint64_t lentim, res;
size_t sz;
uint32_t hash_type;
int i;
struct if_ratelimit_query_results rl;
struct sysctl_oid *rl_sysctl_root;
/*
* We expect to enter with the
* mutex locked.
*/
if (ifp->if_ratelimit_query == NULL) {
/*
* We can do nothing if we cannot
* get a query back from the driver.
*/
printf("Warning:No query functions for %s:%d-- failed\n",
ifp->if_dname, ifp->if_dunit);
return (NULL);
}
rs = malloc(sizeof(struct tcp_rate_set), M_TCPPACE, M_NOWAIT | M_ZERO);
if (rs == NULL) {
if (error)
*error = ENOMEM;
printf("Warning:No memory for malloc of tcp_rate_set\n");
return (NULL);
}
memset(&rl, 0, sizeof(rl));
rl.flags = RT_NOSUPPORT;
ifp->if_ratelimit_query(ifp, &rl);
if (rl.flags & RT_IS_UNUSABLE) {
/*
* The interface does not really support
* the rate-limiting.
*/
memset(rs, 0, sizeof(struct tcp_rate_set));
rs->rs_ifp = ifp;
rs->rs_if_dunit = ifp->if_dunit;
rs->rs_flags = RS_INTF_NO_SUP;
rs->rs_disable = 1;
rs_number_alive++;
sysctl_ctx_init(&rs->sysctl_ctx);
rl_sysctl_root = SYSCTL_ADD_NODE(&rs->sysctl_ctx,
SYSCTL_STATIC_CHILDREN(_net_inet_tcp_rl),
OID_AUTO,
rs->rs_ifp->if_xname,
CTLFLAG_RW | CTLFLAG_MPSAFE, 0,
"");
rl_add_syctl_entries(rl_sysctl_root, rs);
mtx_lock(&rs_mtx);
CK_LIST_INSERT_HEAD(&int_rs, rs, next);
mtx_unlock(&rs_mtx);
return (rs);
} else if ((rl.flags & RT_IS_INDIRECT) == RT_IS_INDIRECT) {
memset(rs, 0, sizeof(struct tcp_rate_set));
rs->rs_ifp = ifp;
rs->rs_if_dunit = ifp->if_dunit;
rs->rs_flags = RS_IS_DEFF;
rs_number_alive++;
sysctl_ctx_init(&rs->sysctl_ctx);
rl_sysctl_root = SYSCTL_ADD_NODE(&rs->sysctl_ctx,
SYSCTL_STATIC_CHILDREN(_net_inet_tcp_rl),
OID_AUTO,
rs->rs_ifp->if_xname,
CTLFLAG_RW | CTLFLAG_MPSAFE, 0,
"");
rl_add_syctl_entries(rl_sysctl_root, rs);
mtx_lock(&rs_mtx);
CK_LIST_INSERT_HEAD(&int_rs, rs, next);
mtx_unlock(&rs_mtx);
return (rs);
} else if ((rl.flags & RT_IS_FIXED_TABLE) == RT_IS_FIXED_TABLE) {
/* Mellanox C4 likely */
rs->rs_ifp = ifp;
rs->rs_if_dunit = ifp->if_dunit;
rs->rs_rate_cnt = rl.number_of_rates;
rs->rs_min_seg = rl.min_segment_burst;
rs->rs_highest_valid = 0;
rs->rs_flow_limit = rl.max_flows;
rs->rs_flags = RS_IS_INTF | RS_NO_PRE;
rs->rs_disable = 0;
rate_table_act = rl.rate_table;
} else if ((rl.flags & RT_IS_SELECTABLE) == RT_IS_SELECTABLE) {
/* Chelsio, C5 and C6 of Mellanox? */
rs->rs_ifp = ifp;
rs->rs_if_dunit = ifp->if_dunit;
rs->rs_rate_cnt = rl.number_of_rates;
rs->rs_min_seg = rl.min_segment_burst;
rs->rs_disable = 0;
rs->rs_flow_limit = rl.max_flows;
rate_table_act = desired_rates;
if ((rs->rs_rate_cnt > MAX_HDWR_RATES) &&
(rs->rs_rate_cnt < ALL_HARDWARE_RATES)) {
/*
* Our desired table is not big
* enough, do what we can.
*/
rs->rs_rate_cnt = MAX_HDWR_RATES;
}
if (rs->rs_rate_cnt <= RS_ORDERED_COUNT)
rs->rs_flags = RS_IS_INTF;
else
rs->rs_flags = RS_IS_INTF | RS_INT_TBL;
if (rs->rs_rate_cnt >= ALL_HARDWARE_RATES)
rs->rs_rate_cnt = ALL_HARDWARE_RATES;
} else {
free(rs, M_TCPPACE);
return (NULL);
}
sz = sizeof(struct tcp_hwrate_limit_table) * rs->rs_rate_cnt;
rs->rs_rlt = malloc(sz, M_TCPPACE, M_NOWAIT);
if (rs->rs_rlt == NULL) {
if (error)
*error = ENOMEM;
bail:
free(rs, M_TCPPACE);
return (NULL);
}
if (rs->rs_rate_cnt >= ALL_HARDWARE_RATES) {
/*
* The interface supports all
* the rates we could possibly want.
*/
uint64_t rat;
rs->rs_rlt[0].rate = 12500; /* 100k */
rs->rs_rlt[1].rate = 25000; /* 200k */
rs->rs_rlt[2].rate = 62500; /* 500k */
/* Note 125000 == 1Megabit
* populate 1Meg - 1000meg.
*/
for(i = 3, rat = 125000; i< (ALL_HARDWARE_RATES-1); i++) {
rs->rs_rlt[i].rate = rat;
rat += 125000;
}
rs->rs_rlt[(ALL_HARDWARE_RATES-1)].rate = 1250000000;
} else if (rs->rs_flags & RS_INT_TBL) {
/* We populate this in a special way */
populate_canned_table(rs, rate_table_act);
} else {
/*
* Just copy in the rates from
* the table, it is in order.
*/
for (i=0; i<rs->rs_rate_cnt; i++) {
rs->rs_rlt[i].rate = rate_table_act[i];
rs->rs_rlt[i].time_between = 0;
rs->rs_rlt[i].flags = 0;
}
}
for (i = (rs->rs_rate_cnt - 1); i >= 0; i--) {
/*
* We go backwards through the list so that if we can't get
* a rate and fail to init one, we have at least a chance of
* getting the highest one.
*/
rs->rs_rlt[i].ptbl = rs;
rs->rs_rlt[i].tag = NULL;
/*
* Calculate the time between.
*/
lentim = ETHERNET_SEGMENT_SIZE * USECS_IN_SECOND;
res = lentim / rs->rs_rlt[i].rate;
if (res > 0)
rs->rs_rlt[i].time_between = res;
else
rs->rs_rlt[i].time_between = 1;
if (rs->rs_flags & RS_NO_PRE) {
rs->rs_rlt[i].flags = HDWRPACE_INITED;
rs->rs_lowest_valid = i;
} else {
int err;
if ((rl.flags & RT_IS_SETUP_REQ) &&
(ifp->if_ratelimit_query)) {
err = ifp->if_ratelimit_setup(ifp,
rs->rs_rlt[i].rate, i);
if (err)
goto handle_err;
}
#ifdef RSS
hash_type = M_HASHTYPE_RSS_TCP_IPV4;
#else
hash_type = M_HASHTYPE_OPAQUE_HASH;
#endif
err = rl_attach_txrtlmt(ifp,
hash_type,
(i + 1),
rs->rs_rlt[i].rate,
&rs->rs_rlt[i].tag);
if (err) {
handle_err:
if (i == (rs->rs_rate_cnt - 1)) {
/*
* Huh - first rate and we can't get
* it?
*/
free(rs->rs_rlt, M_TCPPACE);
if (error)
*error = err;
goto bail;
} else {
if (error)
*error = err;
}
break;
} else {
rs->rs_rlt[i].flags = HDWRPACE_INITED | HDWRPACE_TAGPRESENT;
rs->rs_lowest_valid = i;
}
}
}
/* Did we get at least 1 rate? */
if (rs->rs_rlt[(rs->rs_rate_cnt - 1)].flags & HDWRPACE_INITED)
rs->rs_highest_valid = rs->rs_rate_cnt - 1;
else {
free(rs->rs_rlt, M_TCPPACE);
goto bail;
}
rs_number_alive++;
sysctl_ctx_init(&rs->sysctl_ctx);
rl_sysctl_root = SYSCTL_ADD_NODE(&rs->sysctl_ctx,
SYSCTL_STATIC_CHILDREN(_net_inet_tcp_rl),
OID_AUTO,
rs->rs_ifp->if_xname,
CTLFLAG_RW | CTLFLAG_MPSAFE, 0,
"");
rl_add_syctl_entries(rl_sysctl_root, rs);
mtx_lock(&rs_mtx);
CK_LIST_INSERT_HEAD(&int_rs, rs, next);
mtx_unlock(&rs_mtx);
return (rs);
}
static const struct tcp_hwrate_limit_table *
tcp_int_find_suitable_rate(const struct tcp_rate_set *rs,
uint64_t bytes_per_sec, uint32_t flags)
{
struct tcp_hwrate_limit_table *arte = NULL, *rte = NULL;
uint64_t mbits_per_sec, ind_calc;
int i;
mbits_per_sec = (bytes_per_sec * 8);
if (flags & RS_PACING_LT) {
if ((mbits_per_sec < RS_ONE_MEGABIT_PERSEC) &&
(rs->rs_lowest_valid <= 2)){
/*
* Smaller than 1Meg, only
* 3 entries can match it.
*/
for(i = rs->rs_lowest_valid; i < 3; i++) {
if (bytes_per_sec <= rs->rs_rlt[i].rate) {
rte = &rs->rs_rlt[i];
break;
} else if (rs->rs_rlt[i].flags & HDWRPACE_INITED) {
arte = &rs->rs_rlt[i];
}
}
goto done;
} else if ((mbits_per_sec > RS_ONE_GIGABIT_PERSEC) &&
(rs->rs_rlt[(ALL_HARDWARE_RATES-1)].flags & HDWRPACE_INITED)){
/*
* Larger than 1G (the majority of
* our table.
*/
if (mbits_per_sec < RS_TEN_GIGABIT_PERSEC)
rte = &rs->rs_rlt[(ALL_HARDWARE_RATES-1)];
else
arte = &rs->rs_rlt[(ALL_HARDWARE_RATES-1)];
goto done;
}
/*
* If we reach here its in our table (between 1Meg - 1000Meg),
* just take the rounded down mbits per second, and add
* 1Megabit to it, from this we can calculate
* the index in the table.
*/
ind_calc = mbits_per_sec/RS_ONE_MEGABIT_PERSEC;
if ((ind_calc * RS_ONE_MEGABIT_PERSEC) != mbits_per_sec)
ind_calc++;
/* our table is offset by 3, we add 2 */
ind_calc += 2;
if (ind_calc > (ALL_HARDWARE_RATES-1)) {
/* This should not happen */
ind_calc = ALL_HARDWARE_RATES-1;
}
if ((ind_calc >= rs->rs_lowest_valid) &&
(ind_calc <= rs->rs_highest_valid))
rte = &rs->rs_rlt[ind_calc];
} else if (flags & RS_PACING_EXACT_MATCH) {
if ((mbits_per_sec < RS_ONE_MEGABIT_PERSEC) &&
(rs->rs_lowest_valid <= 2)){
for(i = rs->rs_lowest_valid; i < 3; i++) {
if (bytes_per_sec == rs->rs_rlt[i].rate) {
rte = &rs->rs_rlt[i];
break;
}
}
} else if ((mbits_per_sec > RS_ONE_GIGABIT_PERSEC) &&
(rs->rs_rlt[(ALL_HARDWARE_RATES-1)].flags & HDWRPACE_INITED)) {
/* > 1Gbps only one rate */
if (bytes_per_sec == rs->rs_rlt[(ALL_HARDWARE_RATES-1)].rate) {
/* Its 10G wow */
rte = &rs->rs_rlt[(ALL_HARDWARE_RATES-1)];
}
} else {
/* Ok it must be a exact meg (its between 1G and 1Meg) */
ind_calc = mbits_per_sec/RS_ONE_MEGABIT_PERSEC;
if ((ind_calc * RS_ONE_MEGABIT_PERSEC) == mbits_per_sec) {
/* its an exact Mbps */
ind_calc += 2;
if (ind_calc > (ALL_HARDWARE_RATES-1)) {
/* This should not happen */
ind_calc = ALL_HARDWARE_RATES-1;
}
if (rs->rs_rlt[ind_calc].flags & HDWRPACE_INITED)
rte = &rs->rs_rlt[ind_calc];
}
}
} else {
/* we want greater than the requested rate */
if ((mbits_per_sec < RS_ONE_MEGABIT_PERSEC) &&
(rs->rs_lowest_valid <= 2)){
arte = &rs->rs_rlt[3]; /* set alternate to 1Meg */
for (i=2; i>=rs->rs_lowest_valid; i--) {
if (bytes_per_sec < rs->rs_rlt[i].rate) {
rte = &rs->rs_rlt[i];
break;
} else if ((flags & RS_PACING_GEQ) &&
(bytes_per_sec == rs->rs_rlt[i].rate)) {
rte = &rs->rs_rlt[i];
break;
} else {
arte = &rs->rs_rlt[i]; /* new alternate */
}
}
} else if (mbits_per_sec > RS_ONE_GIGABIT_PERSEC) {
if ((bytes_per_sec < rs->rs_rlt[(ALL_HARDWARE_RATES-1)].rate) &&
(rs->rs_rlt[(ALL_HARDWARE_RATES-1)].flags & HDWRPACE_INITED)){
/* Our top rate is larger than the request */
rte = &rs->rs_rlt[(ALL_HARDWARE_RATES-1)];
} else if ((flags & RS_PACING_GEQ) &&
(bytes_per_sec == rs->rs_rlt[(ALL_HARDWARE_RATES-1)].rate) &&
(rs->rs_rlt[(ALL_HARDWARE_RATES-1)].flags & HDWRPACE_INITED)) {
/* It matches our top rate */
rte = &rs->rs_rlt[(ALL_HARDWARE_RATES-1)];
} else if (rs->rs_rlt[(ALL_HARDWARE_RATES-1)].flags & HDWRPACE_INITED) {
/* The top rate is an alternative */
arte = &rs->rs_rlt[(ALL_HARDWARE_RATES-1)];
}
} else {
/* Its in our range 1Meg - 1Gig */
if (flags & RS_PACING_GEQ) {
ind_calc = mbits_per_sec/RS_ONE_MEGABIT_PERSEC;
if ((ind_calc * RS_ONE_MEGABIT_PERSEC) == mbits_per_sec) {
if (ind_calc > (ALL_HARDWARE_RATES-1)) {
/* This should not happen */
ind_calc = (ALL_HARDWARE_RATES-1);
}
rte = &rs->rs_rlt[ind_calc];
}
goto done;
}
ind_calc = (mbits_per_sec + (RS_ONE_MEGABIT_PERSEC-1))/RS_ONE_MEGABIT_PERSEC;
ind_calc += 2;
if (ind_calc > (ALL_HARDWARE_RATES-1)) {
/* This should not happen */
ind_calc = ALL_HARDWARE_RATES-1;
}
if (rs->rs_rlt[ind_calc].flags & HDWRPACE_INITED)
rte = &rs->rs_rlt[ind_calc];
}
}
done:
if ((rte == NULL) &&
(arte != NULL) &&
(flags & RS_PACING_SUB_OK)) {
/* We can use the substitute */
rte = arte;
}
return (rte);
}
static const struct tcp_hwrate_limit_table *
tcp_find_suitable_rate(const struct tcp_rate_set *rs, uint64_t bytes_per_sec, uint32_t flags)
{
/**
* Hunt the rate table with the restrictions in flags and find a
* suitable rate if possible.
* RS_PACING_EXACT_MATCH - look for an exact match to rate.
* RS_PACING_GT - must be greater than.
* RS_PACING_GEQ - must be greater than or equal.
* RS_PACING_LT - must be less than.
* RS_PACING_SUB_OK - If we don't meet criteria a
* substitute is ok.
*/
int i, matched;
struct tcp_hwrate_limit_table *rte = NULL;
if ((rs->rs_flags & RS_INT_TBL) &&
(rs->rs_rate_cnt >= ALL_HARDWARE_RATES)) {
/*
* Here we don't want to paw thru
* a big table, we have everything
* from 1Meg - 1000Meg in 1Meg increments.
* Use an alternate method to "lookup".
*/
return (tcp_int_find_suitable_rate(rs, bytes_per_sec, flags));
}
if ((flags & RS_PACING_LT) ||
(flags & RS_PACING_EXACT_MATCH)) {
/*
* For exact and less than we go forward through the table.
* This way when we find one larger we stop (exact was a
* toss up).
*/
for (i = rs->rs_lowest_valid, matched = 0; i <= rs->rs_highest_valid; i++) {
if ((flags & RS_PACING_EXACT_MATCH) &&
(bytes_per_sec == rs->rs_rlt[i].rate)) {
rte = &rs->rs_rlt[i];
matched = 1;
break;
} else if ((flags & RS_PACING_LT) &&
(bytes_per_sec <= rs->rs_rlt[i].rate)) {
rte = &rs->rs_rlt[i];
matched = 1;
break;
}
if (bytes_per_sec > rs->rs_rlt[i].rate)
break;
}
if ((matched == 0) &&
(flags & RS_PACING_LT) &&
(flags & RS_PACING_SUB_OK)) {
/* Kick in a substitute (the lowest) */
rte = &rs->rs_rlt[rs->rs_lowest_valid];
}
} else {
/*
* Here we go backward through the table so that we can find
* the one greater in theory faster (but its probably a
* wash).
*/
for (i = rs->rs_highest_valid, matched = 0; i >= rs->rs_lowest_valid; i--) {
if (rs->rs_rlt[i].rate > bytes_per_sec) {
/* A possible candidate */
rte = &rs->rs_rlt[i];
}
if ((flags & RS_PACING_GEQ) &&
(bytes_per_sec == rs->rs_rlt[i].rate)) {
/* An exact match and we want equal */
matched = 1;
rte = &rs->rs_rlt[i];
break;
} else if (rte) {
/*
* Found one that is larger than but don't
* stop, there may be a more closer match.
*/
matched = 1;
}
if (rs->rs_rlt[i].rate < bytes_per_sec) {
/*
* We found a table entry that is smaller,
* stop there will be none greater or equal.
*/
break;
}
}
if ((matched == 0) &&
(flags & RS_PACING_SUB_OK)) {
/* Kick in a substitute (the highest) */
rte = &rs->rs_rlt[rs->rs_highest_valid];
}
}
return (rte);
}
static struct ifnet *
rt_find_real_interface(struct ifnet *ifp, struct inpcb *inp, int *error)
{
struct ifnet *tifp;
struct m_snd_tag *tag;
union if_snd_tag_alloc_params params = {
.rate_limit.hdr.type = IF_SND_TAG_TYPE_RATE_LIMIT,
.rate_limit.hdr.flowid = 1,
.rate_limit.hdr.numa_domain = inp->inp_numa_domain,
.rate_limit.max_rate = COMMON_RATE,
.rate_limit.flags = M_NOWAIT,
};
int err;
#ifdef RSS
params.rate_limit.hdr.flowtype = ((inp->inp_vflag & INP_IPV6) ?
M_HASHTYPE_RSS_TCP_IPV6 : M_HASHTYPE_RSS_TCP_IPV4);
#else
params.rate_limit.hdr.flowtype = M_HASHTYPE_OPAQUE_HASH;
#endif
tag = NULL;
if (ifp->if_snd_tag_alloc) {
if (error)
*error = ENODEV;
return (NULL);
}
err = ifp->if_snd_tag_alloc(ifp, &params, &tag);
if (err) {
/* Failed to setup a tag? */
if (error)
*error = err;
return (NULL);
}
tifp = tag->ifp;
tifp->if_snd_tag_free(tag);
return (tifp);
}
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)
{
/* First lets find the interface if it exists */
const struct tcp_hwrate_limit_table *rte;
struct tcp_rate_set *rs;
struct epoch_tracker et;
int err;
NET_EPOCH_ENTER(et);
use_real_interface:
CK_LIST_FOREACH(rs, &int_rs, next) {
/*
* Note we don't look with the lock since we either see a
* new entry or will get one when we try to add it.
*/
if (rs->rs_flags & RS_IS_DEAD) {
/* The dead are not looked at */
continue;
}
if ((rs->rs_ifp == ifp) &&
(rs->rs_if_dunit == ifp->if_dunit)) {
/* Ok we found it */
break;
}
}
if ((rs == NULL) ||
(rs->rs_flags & RS_INTF_NO_SUP) ||
(rs->rs_flags & RS_IS_DEAD)) {
/*
* This means we got a packet *before*
* the IF-UP was processed below, <or>
* while or after we already received an interface
* departed event. In either case we really don't
* want to do anything with pacing, in
* the departing case the packet is not
* going to go very far. The new case
* might be arguable, but its impossible
* to tell from the departing case.
*/
if (rs->rs_disable && error)
*error = ENODEV;
NET_EPOCH_EXIT(et);
return (NULL);
}
if ((rs == NULL) || (rs->rs_disable != 0)) {
if (rs->rs_disable && error)
*error = ENOSPC;
NET_EPOCH_EXIT(et);
return (NULL);
}
if (rs->rs_flags & RS_IS_DEFF) {
/* We need to find the real interface */
struct ifnet *tifp;
tifp = rt_find_real_interface(ifp, inp, error);
if (tifp == NULL) {
if (rs->rs_disable && error)
*error = ENOTSUP;
NET_EPOCH_EXIT(et);
return (NULL);
}
goto use_real_interface;
}
if (rs->rs_flow_limit &&
((rs->rs_flows_using + 1) > rs->rs_flow_limit)) {
if (error)
*error = ENOSPC;
NET_EPOCH_EXIT(et);
return (NULL);
}
rte = tcp_find_suitable_rate(rs, bytes_per_sec, flags);
if (rte) {
err = in_pcbattach_txrtlmt(inp, rs->rs_ifp,
inp->inp_flowtype,
inp->inp_flowid,
rte->rate,
&inp->inp_snd_tag);
if (err) {
/* Failed to attach */
if (error)
*error = err;
rte = NULL;
}
}
if (rte) {
/*
* We use an atomic here for accounting so we don't have to
* use locks when freeing.
*/
atomic_add_64(&rs->rs_flows_using, 1);
}
NET_EPOCH_EXIT(et);
return (rte);
}
static void
tcp_rl_ifnet_link(void *arg __unused, struct ifnet *ifp, int link_state)
{
int error;
struct tcp_rate_set *rs;
if (((ifp->if_capabilities & IFCAP_TXRTLMT) == 0) ||
(link_state != LINK_STATE_UP)) {
/*
* We only care on an interface going up that is rate-limit
* capable.
*/
return;
}
mtx_lock(&rs_mtx);
CK_LIST_FOREACH(rs, &int_rs, next) {
if ((rs->rs_ifp == ifp) &&
(rs->rs_if_dunit == ifp->if_dunit)) {
/* We already have initialized this guy */
mtx_unlock(&rs_mtx);
return;
}
}
mtx_unlock(&rs_mtx);
rt_setup_new_rs(ifp, &error);
}
static void
tcp_rl_ifnet_departure(void *arg __unused, struct ifnet *ifp)
{
struct tcp_rate_set *rs, *nrs;
struct ifnet *tifp;
int i;
mtx_lock(&rs_mtx);
CK_LIST_FOREACH_SAFE(rs, &int_rs, next, nrs) {
if ((rs->rs_ifp == ifp) &&
(rs->rs_if_dunit == ifp->if_dunit)) {
CK_LIST_REMOVE(rs, next);
rs_number_alive--;
rs->rs_flags |= RS_IS_DEAD;
for (i = 0; i < rs->rs_rate_cnt; i++) {
if (rs->rs_rlt[i].flags & HDWRPACE_TAGPRESENT) {
tifp = rs->rs_rlt[i].tag->ifp;
in_pcbdetach_tag(tifp, rs->rs_rlt[i].tag);
rs->rs_rlt[i].tag = NULL;
}
rs->rs_rlt[i].flags = HDWRPACE_IFPDEPARTED;
}
if (rs->rs_flows_using == 0)
rs_defer_destroy(rs);
break;
}
}
mtx_unlock(&rs_mtx);
}
static void
tcp_rl_shutdown(void *arg __unused, int howto __unused)
{
struct tcp_rate_set *rs, *nrs;
struct ifnet *tifp;
int i;
mtx_lock(&rs_mtx);
CK_LIST_FOREACH_SAFE(rs, &int_rs, next, nrs) {
CK_LIST_REMOVE(rs, next);
rs_number_alive--;
rs->rs_flags |= RS_IS_DEAD;
for (i = 0; i < rs->rs_rate_cnt; i++) {
if (rs->rs_rlt[i].flags & HDWRPACE_TAGPRESENT) {
tifp = rs->rs_rlt[i].tag->ifp;
in_pcbdetach_tag(tifp, rs->rs_rlt[i].tag);
rs->rs_rlt[i].tag = NULL;
}
rs->rs_rlt[i].flags = HDWRPACE_IFPDEPARTED;
}
if (rs->rs_flows_using == 0)
rs_defer_destroy(rs);
}
mtx_unlock(&rs_mtx);
}
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)
{
const struct tcp_hwrate_limit_table *rte;
if (tp->t_inpcb->inp_snd_tag == NULL) {
/*
* We are setting up a rate for the first time.
*/
if ((ifp->if_capabilities & IFCAP_TXRTLMT) == 0) {
/* Not supported by the egress */
if (error)
*error = ENODEV;
return (NULL);
}
#ifdef KERN_TLS
if (tp->t_inpcb->inp_socket->so_snd.sb_flags & SB_TLS_IFNET) {
/*
* We currently can't do both TLS and hardware
* pacing
*/
if (error)
*error = EINVAL;
return (NULL);
}
#endif
rte = rt_setup_rate(tp->t_inpcb, ifp, bytes_per_sec, flags, error);
} else {
/*
* We are modifying a rate, wrong interface?
*/
if (error)
*error = EINVAL;
rte = NULL;
}
*error = 0;
return (rte);
}
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)
{
const struct tcp_hwrate_limit_table *nrte;
const struct tcp_rate_set *rs;
int is_indirect = 0;
int err;
if ((tp->t_inpcb->inp_snd_tag == NULL) ||
(crte == NULL)) {
/* Wrong interface */
if (error)
*error = EINVAL;
return (NULL);
}
rs = crte->ptbl;
if ((rs->rs_flags & RS_IS_DEAD) ||
(crte->flags & HDWRPACE_IFPDEPARTED)) {
/* Release the rate, and try anew */
re_rate:
tcp_rel_pacing_rate(crte, tp);
nrte = tcp_set_pacing_rate(tp, ifp,
bytes_per_sec, flags, error);
return (nrte);
}
if ((rs->rs_flags & RT_IS_INDIRECT ) == RT_IS_INDIRECT)
is_indirect = 1;
else
is_indirect = 0;
if ((is_indirect == 0) &&
((ifp != rs->rs_ifp) ||
(ifp->if_dunit != rs->rs_if_dunit))) {
/*
* Something changed, the user is not pointing to the same
* ifp? Maybe a route updated on this guy?
*/
goto re_rate;
} else if (is_indirect) {
/*
* For indirect we have to dig in and find the real interface.
*/
struct ifnet *rifp;
rifp = rt_find_real_interface(ifp, tp->t_inpcb, error);
if (rifp == NULL) {
/* Can't find it? */
goto re_rate;
}
if ((rifp != rs->rs_ifp) ||
(ifp->if_dunit != rs->rs_if_dunit)) {
goto re_rate;
}
}
nrte = tcp_find_suitable_rate(rs, bytes_per_sec, flags);
if (nrte == crte) {
/* No change */
if (error)
*error = 0;
return (crte);
}
if (nrte == NULL) {
/* Release the old rate */
tcp_rel_pacing_rate(crte, tp);
return (NULL);
}
/* Change rates to our new entry */
err = in_pcbmodify_txrtlmt(tp->t_inpcb, nrte->rate);
if (err) {
if (error)
*error = err;
return (NULL);
}
if (error)
*error = 0;
return (nrte);
}
void
tcp_rel_pacing_rate(const struct tcp_hwrate_limit_table *crte, struct tcpcb *tp)
{
const struct tcp_rate_set *crs;
struct tcp_rate_set *rs;
uint64_t pre;
crs = crte->ptbl;
/*
* Now we must break the const
* in order to release our refcount.
*/
rs = __DECONST(struct tcp_rate_set *, crs);
pre = atomic_fetchadd_64(&rs->rs_flows_using, -1);
if (pre == 1) {
mtx_lock(&rs_mtx);
/*
* Is it dead?
*/
if (rs->rs_flags & RS_IS_DEAD)
rs_defer_destroy(rs);
mtx_unlock(&rs_mtx);
}
in_pcbdetach_txrtlmt(tp->t_inpcb);
}
#define ONE_POINT_TWO_MEG 150000 /* 1.2 megabits in bytes */
#define ONE_HUNDRED_MBPS 12500000 /* 100Mbps in bytes per second */
#define FIVE_HUNDRED_MBPS 62500000 /* 500Mbps in bytes per second */
#define MAX_MSS_SENT 43 /* 43 mss = 43 x 1500 = 64,500 bytes */
uint32_t
tcp_get_pacing_burst_size (uint64_t bw, uint32_t segsiz, int can_use_1mss,
const struct tcp_hwrate_limit_table *te, int *err)
{
/*
* We use the google formula to calculate the
* TSO size. I.E.
* bw < 24Meg
* tso = 2mss
* else
* tso = min(bw/1000, 64k)
*
* Note for these calculations we ignore the
* packet overhead (enet hdr, ip hdr and tcp hdr).
*/
uint64_t lentim, res, bytes;
uint32_t new_tso, min_tso_segs;
bytes = bw / 1000;
if (bytes > (64 * 1000))
bytes = 64 * 1000;
/* Round up */
new_tso = (bytes + segsiz - 1) / segsiz;
if (can_use_1mss && (bw < ONE_POINT_TWO_MEG))
min_tso_segs = 1;
else
min_tso_segs = 2;
if (new_tso < min_tso_segs)
new_tso = min_tso_segs;
if (new_tso > MAX_MSS_SENT)
new_tso = MAX_MSS_SENT;
new_tso *= segsiz;
/*
* If we are not doing hardware pacing
* then we are done.
*/
if (te == NULL) {
if (err)
*err = 0;
return(new_tso);
}
/*
* For hardware pacing we look at the
* rate you are sending at and compare
* that to the rate you have in hardware.
*
* If the hardware rate is slower than your
* software rate then you are in error and
* we will build a queue in our hardware whic
* is probably not desired, in such a case
* just return the non-hardware TSO size.
*
* If the rate in hardware is faster (which
* it should be) then look at how long it
* takes to send one ethernet segment size at
* your b/w and compare that to the time it
* takes to send at the rate you had selected.
*
* If your time is greater (which we hope it is)
* we get the delta between the two, and then
* divide that into your pacing time. This tells
* us how many MSS you can send down at once (rounded up).
*
* Note we also double this value if the b/w is over
* 100Mbps. If its over 500meg we just set you to the
* max (43 segments).
*/
if (te->rate > FIVE_HUNDRED_MBPS)
return (segsiz * MAX_MSS_SENT);
if (te->rate == bw) {
/* We are pacing at exactly the hdwr rate */
return (segsiz * MAX_MSS_SENT);
}
lentim = ETHERNET_SEGMENT_SIZE * USECS_IN_SECOND;
res = lentim / bw;
if (res > te->time_between) {
uint32_t delta, segs;
delta = res - te->time_between;
segs = (res + delta - 1)/delta;
if (te->rate > ONE_HUNDRED_MBPS)
segs *= 2;
if (segs < min_tso_segs)
segs = min_tso_segs;
if (segs > MAX_MSS_SENT)
segs = MAX_MSS_SENT;
segs *= segsiz;
if (err)
*err = 0;
if (segs < new_tso) {
/* unexpected ? */
return(new_tso);
} else {
return (segs);
}
} else {
/*
* Your time is smaller which means
* we will grow a queue on our
* hardware. Send back the non-hardware
* rate.
*/
if (err)
*err = -1;
return (new_tso);
}
}
static eventhandler_tag rl_ifnet_departs;
static eventhandler_tag rl_ifnet_arrives;
static eventhandler_tag rl_shutdown_start;
static void
tcp_rs_init(void *st __unused)
{
CK_LIST_INIT(&int_rs);
rs_number_alive = 0;
rs_number_dead = 0;
mtx_init(&rs_mtx, "tcp_rs_mtx", "rsmtx", MTX_DEF);
rl_ifnet_departs = EVENTHANDLER_REGISTER(ifnet_departure_event,
tcp_rl_ifnet_departure,
NULL, EVENTHANDLER_PRI_ANY);
rl_ifnet_arrives = EVENTHANDLER_REGISTER(ifnet_link_event,
tcp_rl_ifnet_link,
NULL, EVENTHANDLER_PRI_ANY);
rl_shutdown_start = EVENTHANDLER_REGISTER(shutdown_pre_sync,
tcp_rl_shutdown, NULL,
SHUTDOWN_PRI_FIRST);
printf("TCP_ratelimit: Is now initialized\n");
}
SYSINIT(tcp_rl_init, SI_SUB_SMP + 1, SI_ORDER_ANY, tcp_rs_init, NULL);
#endif
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