sys/netinet/tcp_ratelimit.h

   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 #ifndef __tcp_ratelimit_h__
  34 #define __tcp_ratelimit_h__
  35
  36 struct m_snd_tag;
  37
  38 #define RL_MIN_DIVISOR 50
  39 #define RL_DEFAULT_DIVISOR 1000
  40
  41 /* Flags on an individual rate */
  42 #define HDWRPACE_INITED         0x0001
  43 #define HDWRPACE_TAGPRESENT     0x0002
  44 #define HDWRPACE_IFPDEPARTED    0x0004
  45 struct tcp_hwrate_limit_table {
  46         const struct tcp_rate_set *ptbl;        /* Pointer to parent table */
  47         struct m_snd_tag *tag;  /* Send tag if needed (chelsio) */
  48         long     rate;          /* Rate we get in Bytes per second (Bps) */
  49         long     using;         /* How many flows are using this hdwr rate. */
  50         long     rs_num_enobufs;
  51         uint32_t time_between;  /* Time-Gap between packets at this rate */
  52         uint32_t flags;
  53 };
  54
  55 /* Rateset flags */
  56 #define RS_IS_DEFF      0x0001  /* Its a lagg, do a double lookup */
  57 #define RS_IS_INTF      0x0002  /* Its a plain interface */
  58 #define RS_NO_PRE       0x0004  /* The interfacd has set rates */
  59 #define RS_INT_TBL      0x0010  /*
  60                                  * The table is the internal version
  61                                  * which has special setup requirements.
  62                                  */
  63 #define RS_IS_DEAD      0x0020  /* The RS is dead list */
  64 #define RS_FUNERAL_SCHD 0x0040  /* Is a epoch call scheduled to bury this guy?*/
  65 #define RS_INTF_NO_SUP  0x0100  /* The interface does not support the ratelimiting */
  66
  67 struct tcp_rate_set {
  68         struct sysctl_ctx_list sysctl_ctx;
  69         CK_LIST_ENTRY(tcp_rate_set) next;
  70         struct ifnet *rs_ifp;
  71         struct tcp_hwrate_limit_table *rs_rlt;
  72         uint64_t rs_flows_using;
  73         uint64_t rs_flow_limit;
  74         uint32_t rs_if_dunit;
  75         int rs_rate_cnt;
  76         int rs_min_seg;
  77         int rs_highest_valid;
  78         int rs_lowest_valid;
  79         int rs_disable;
  80         int rs_flags;
  81         struct epoch_context rs_epoch_ctx;
  82 };
  83
  84 CK_LIST_HEAD(head_tcp_rate_set, tcp_rate_set);
  85
  86 /* Request flags */
  87 #define RS_PACING_EXACT_MATCH   0x0001  /* Need an exact match for rate */
  88 #define RS_PACING_GT            0x0002  /* Greater than requested */
  89 #define RS_PACING_GEQ           0x0004  /* Greater than or equal too */
  90 #define RS_PACING_LT            0x0008  /* Less than requested rate */
  91 #define RS_PACING_SUB_OK        0x0010  /* If a rate can't be found get the
  92                                          * next best rate (highest or lowest). */
  93 #ifdef _KERNEL
  94 #ifndef ETHERNET_SEGMENT_SIZE
  95 #define ETHERNET_SEGMENT_SIZE 1514
  96 #endif
  97 struct tcpcb;
  98
  99 #ifdef RATELIMIT
 100 #define DETAILED_RATELIMIT_SYSCTL 1     /*
 101                                          * Undefine this if you don't want
 102                                          * detailed rates to appear in
 103                                          * net.inet.tcp.rl.
 104                                          * With the defintion each rate
 105                                          * shows up in your sysctl tree
 106                                          * this can be big.
 107                                          */
 108 uint64_t inline
 109 tcp_hw_highest_rate(const struct tcp_hwrate_limit_table *rle)
 110 {
 111         return (rle->ptbl->rs_rlt[rle->ptbl->rs_highest_valid].rate);
 112 }
 113
 114 uint64_t
 115 tcp_hw_highest_rate_ifp(struct ifnet *ifp, struct inpcb *inp);
 116
 117 const struct tcp_hwrate_limit_table *
 118 tcp_set_pacing_rate(struct tcpcb *tp, struct ifnet *ifp,
 119     uint64_t bytes_per_sec, int flags, int *error, uint64_t *lower_rate);
 120
 121 const struct tcp_hwrate_limit_table *
 122 tcp_chg_pacing_rate(const struct tcp_hwrate_limit_table *crte,
 123     struct tcpcb *tp, struct ifnet *ifp,
 124     uint64_t bytes_per_sec, int flags, int *error, uint64_t *lower_rate);
 125 void
 126 tcp_rel_pacing_rate(const struct tcp_hwrate_limit_table *crte,
 127     struct tcpcb *tp);
 128
 129 uint32_t
 130 tcp_get_pacing_burst_size_w_divisor(struct tcpcb *tp, uint64_t bw, uint32_t segsiz, int can_use_1mss,
 131     const struct tcp_hwrate_limit_table *te, int *err, int divisor);
 132
 133 void
 134 tcp_rl_log_enobuf(const struct tcp_hwrate_limit_table *rte);
 135
 136 void
 137 tcp_rl_release_ifnet(struct ifnet *ifp);
 138
 139 #else
 140 static inline const struct tcp_hwrate_limit_table *
 141 tcp_set_pacing_rate(struct tcpcb *tp, struct ifnet *ifp,
 142     uint64_t bytes_per_sec, int flags, int *error, uint64_t *lower_rate)
 143 {
 144         if (error)
 145                 *error = EOPNOTSUPP;
 146         return (NULL);
 147 }
 148
 149 static inline const struct tcp_hwrate_limit_table *
 150 tcp_chg_pacing_rate(const struct tcp_hwrate_limit_table *crte,
 151     struct tcpcb *tp, struct ifnet *ifp,
 152     uint64_t bytes_per_sec, int flags, int *error, uint64_t *lower_rate)
 153 {
 154         if (error)
 155                 *error = EOPNOTSUPP;
 156         return (NULL);
 157 }
 158
 159 static inline void
 160 tcp_rel_pacing_rate(const struct tcp_hwrate_limit_table *crte,
 161     struct tcpcb *tp)
 162 {
 163         return;
 164 }
 165
 166 static uint64_t inline
 167 tcp_hw_highest_rate(const struct tcp_hwrate_limit_table *rle)
 168 {
 169         return (0);
 170 }
 171
 172 static uint64_t inline
 173 tcp_hw_highest_rate_ifp(struct ifnet *ifp, struct inpcb *inp)
 174 {
 175         return (0);
 176 }
 177
 178 static inline uint32_t
 179 tcp_get_pacing_burst_size_w_divisor(struct tcpcb *tp, uint64_t bw, uint32_t segsiz, int can_use_1mss,
 180    const struct tcp_hwrate_limit_table *te, int *err, int divisor)
 181 {
 182         /*
 183          * We use the google formula to calculate the
 184          * TSO size. I.E.
 185          * bw < 24Meg
 186          *   tso = 2mss
 187          * else
 188          *   tso = min(bw/(div=1000), 64k)
 189          *
 190          * Note for these calculations we ignore the
 191          * packet overhead (enet hdr, ip hdr and tcp hdr).
 192          * We only get the google formula when we have
 193          * divisor = 1000, which is the default for now.
 194          */
 195         uint64_t bytes;
 196         uint32_t new_tso, min_tso_segs;
 197
 198         /* It can't be zero */
 199         if ((divisor == 0) ||
 200             (divisor < RL_MIN_DIVISOR)) {
 201                 bytes = bw / RL_DEFAULT_DIVISOR;
 202         } else
 203                 bytes = bw / divisor;
 204         /* We can't ever send more than 65k in a TSO */
 205         if (bytes > 0xffff) {
 206                 bytes = 0xffff;
 207         }
 208         /* Round up */
 209         new_tso = (bytes + segsiz - 1) / segsiz;
 210         if (can_use_1mss)
 211                 min_tso_segs = 1;
 212         else
 213                 min_tso_segs = 2;
 214         if (new_tso < min_tso_segs)
 215                 new_tso = min_tso_segs;
 216         new_tso *= segsiz;
 217         return (new_tso);
 218 }
 219
 220 /* Do nothing if RATELIMIT is not defined */
 221 static inline void
 222 tcp_rl_log_enobuf(const struct tcp_hwrate_limit_table *rte)
 223 {
 224 }
 225
 226 static inline void
 227 tcp_rl_release_ifnet(struct ifnet *ifp)
 228 {
 229 }
 230 #endif
 231
 232 /*
 233  * Given a b/w and a segsiz, and optional hardware
 234  * rate limit, return the ideal size to burst
 235  * out at once. Note the parameter can_use_1mss
 236  * dictates if the transport will tolerate a 1mss
 237  * limit, if not it will bottom out at 2mss (think
 238  * delayed ack).
 239  */
 240 static inline uint32_t
 241 tcp_get_pacing_burst_size(struct tcpcb *tp, uint64_t bw, uint32_t segsiz, int can_use_1mss,
 242                           const struct tcp_hwrate_limit_table *te, int *err)
 243 {
 244
 245         return (tcp_get_pacing_burst_size_w_divisor(tp, bw, segsiz,
 246                                                     can_use_1mss,
 247                                                     te, err, 0));
 248 }
 249
 250 #endif
 251 #endif