FreeBSD/Linux Kernel Cross Reference
sys/netinet/tcp_ratelimit.h

     /*-
      *
      * 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.
     * __FBSDID("$FreeBSD$");
     *
     */
    /**
     * Author: Randall Stewart <rrs@netflix.com>
     */
    #ifndef __tcp_ratelimit_h__
    #define __tcp_ratelimit_h__
    
    struct m_snd_tag;
    
    #define RL_MIN_DIVISOR 50
    #define RL_DEFAULT_DIVISOR 1000
    
    /* Flags on an individual rate */
    #define HDWRPACE_INITED         0x0001
    #define HDWRPACE_TAGPRESENT     0x0002
    #define HDWRPACE_IFPDEPARTED    0x0004
    struct tcp_hwrate_limit_table {
            const struct tcp_rate_set *ptbl;        /* Pointer to parent table */
            struct m_snd_tag *tag;  /* Send tag if needed (chelsio) */
            long     rate;          /* Rate we get in Bytes per second (Bps) */
            long     using;         /* How many flows are using this hdwr rate. */
            long     rs_num_enobufs;
            uint32_t time_between;  /* Time-Gap between packets at this rate */
            uint32_t flags;
    };
    
    /* Rateset flags */
    #define RS_IS_DEFF      0x0001  /* Its a lagg, do a double lookup */
    #define RS_IS_INTF      0x0002  /* Its a plain interface */
    #define RS_NO_PRE       0x0004  /* The interfacd has set rates */
    #define RS_INT_TBL      0x0010  /*
                                     * The table is the internal version
                                     * which has special setup requirements.
                                     */
    #define RS_IS_DEAD      0x0020  /* The RS is dead list */
    #define RS_FUNERAL_SCHD 0x0040  /* Is a epoch call scheduled to bury this guy?*/
    #define RS_INTF_NO_SUP  0x0100  /* The interface does not support the ratelimiting */
    
    struct tcp_rate_set {
            struct sysctl_ctx_list sysctl_ctx;
            CK_LIST_ENTRY(tcp_rate_set) next;
            struct ifnet *rs_ifp;
            struct tcp_hwrate_limit_table *rs_rlt;
            uint64_t rs_flows_using;
            uint64_t rs_flow_limit;
            uint32_t rs_if_dunit;
            int rs_rate_cnt;
            int rs_min_seg;
            int rs_highest_valid;
            int rs_lowest_valid;
            int rs_disable;
            int rs_flags;
            struct epoch_context rs_epoch_ctx;
    };
    
    CK_LIST_HEAD(head_tcp_rate_set, tcp_rate_set);
    
    /* Request flags */
    #define RS_PACING_EXACT_MATCH   0x0001  /* Need an exact match for rate */
    #define RS_PACING_GT            0x0002  /* Greater than requested */
    #define RS_PACING_GEQ           0x0004  /* Greater than or equal too */
    #define RS_PACING_LT            0x0008  /* Less than requested rate */
    #define RS_PACING_SUB_OK        0x0010  /* If a rate can't be found get the
                                             * next best rate (highest or lowest). */
    #ifdef _KERNEL
    #ifndef ETHERNET_SEGMENT_SIZE
    #define ETHERNET_SEGMENT_SIZE 1514
    #endif
    #ifdef RATELIMIT
    #define DETAILED_RATELIMIT_SYSCTL 1     /*
                                            * Undefine this if you don't want
                                            * detailed rates to appear in
                                            * net.inet.tcp.rl.
                                            * With the defintion each rate
                                            * shows up in your sysctl tree
                                            * this can be big.
                                            */
   uint64_t inline
   tcp_hw_highest_rate(const struct tcp_hwrate_limit_table *rle)
   {
           return (rle->ptbl->rs_rlt[rle->ptbl->rs_highest_valid].rate);
   }
   
   uint64_t
   tcp_hw_highest_rate_ifp(struct ifnet *ifp, struct inpcb *inp);
   
   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);
   
   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);
   void
   tcp_rel_pacing_rate(const struct tcp_hwrate_limit_table *crte,
       struct tcpcb *tp);
   
   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);
   
   void
   tcp_rl_log_enobuf(const struct tcp_hwrate_limit_table *rte);
   
   #else
   static inline 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)
   {
           if (error)
                   *error = EOPNOTSUPP;
           return (NULL);
   }
   
   static inline 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)
   {
           if (error)
                   *error = EOPNOTSUPP;
           return (NULL);
   }
   
   static inline void
   tcp_rel_pacing_rate(const struct tcp_hwrate_limit_table *crte,
       struct tcpcb *tp)
   {
           return;
   }
   
   static uint64_t inline
   tcp_hw_highest_rate(const struct tcp_hwrate_limit_table *rle)
   {
           return (0);
   }
   
   static uint64_t inline
   tcp_hw_highest_rate_ifp(struct ifnet *ifp, struct inpcb *inp)
   {
           return (0);
   }
   
   static inline 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)
   {
           /*
            * We use the google formula to calculate the
            * TSO size. I.E.
            * bw < 24Meg
            *   tso = 2mss
            * else
            *   tso = min(bw/(div=1000), 64k)
            *
            * Note for these calculations we ignore the
            * packet overhead (enet hdr, ip hdr and tcp hdr).
            * We only get the google formula when we have
            * divisor = 1000, which is the default for now.
            */
           uint64_t bytes;
           uint32_t new_tso, min_tso_segs;
   
           /* It can't be zero */
           if ((divisor == 0) ||
               (divisor < RL_MIN_DIVISOR)) {
                   bytes = bw / RL_DEFAULT_DIVISOR;
           } else
                   bytes = bw / divisor;
           /* We can't ever send more than 65k in a TSO */
           if (bytes > 0xffff) {
                   bytes = 0xffff;
           }
           /* Round up */
           new_tso = (bytes + segsiz - 1) / segsiz;
           if (can_use_1mss)
                   min_tso_segs = 1;
           else
                   min_tso_segs = 2;
           if (new_tso < min_tso_segs)
                   new_tso = min_tso_segs;
           new_tso *= segsiz;
           return (new_tso);
   }
   
   /* Do nothing if RATELIMIT is not defined */
   static void
   tcp_rl_log_enobuf(const struct tcp_hwrate_limit_table *rte)
   {
   }
   
   #endif
   
   /*
    * Given a b/w and a segsiz, and optional hardware
    * rate limit, return the ideal size to burst
    * out at once. Note the parameter can_use_1mss
    * dictates if the transport will tolerate a 1mss
    * limit, if not it will bottom out at 2mss (think
    * delayed ack).
    */
   static inline uint32_t
   tcp_get_pacing_burst_size(struct tcpcb *tp, uint64_t bw, uint32_t segsiz, int can_use_1mss,
                             const struct tcp_hwrate_limit_table *te, int *err)
   {
   
           return (tcp_get_pacing_burst_size_w_divisor(tp, bw, segsiz,
                                                       can_use_1mss,
                                                       te, err, 0));
   }
   
   #endif
   #endif

Cache object: b7fea1bb9bc54ff28a8ac91bc3138942