samples/bpf/hbm_kern.h

   1 /* SPDX-License-Identifier: GPL-2.0
   2  *
   3  * Copyright (c) 2019 Facebook
   4  *
   5  * This program is free software; you can redistribute it and/or
   6  * modify it under the terms of version 2 of the GNU General Public
   7  * License as published by the Free Software Foundation.
   8  *
   9  * Include file for sample Host Bandwidth Manager (HBM) BPF programs
  10  */
  11 #define KBUILD_MODNAME "foo"
  12 #include <stddef.h>
  13 #include <stdbool.h>
  14 #include <uapi/linux/bpf.h>
  15 #include <uapi/linux/if_ether.h>
  16 #include <uapi/linux/if_packet.h>
  17 #include <uapi/linux/ip.h>
  18 #include <uapi/linux/ipv6.h>
  19 #include <uapi/linux/in.h>
  20 #include <uapi/linux/tcp.h>
  21 #include <uapi/linux/filter.h>
  22 #include <uapi/linux/pkt_cls.h>
  23 #include <net/ipv6.h>
  24 #include <net/inet_ecn.h>
  25 #include <bpf/bpf_endian.h>
  26 #include <bpf/bpf_helpers.h>
  27 #include "hbm.h"
  28
  29 #define DROP_PKT        0
  30 #define ALLOW_PKT       1
  31 #define TCP_ECN_OK      1
  32 #define CWR             2
  33
  34 #ifndef HBM_DEBUG  // Define HBM_DEBUG to enable debugging
  35 #undef bpf_printk
  36 #define bpf_printk(fmt, ...)
  37 #endif
  38
  39 #define INITIAL_CREDIT_PACKETS  100
  40 #define MAX_BYTES_PER_PACKET    1500
  41 #define MARK_THRESH             (40 * MAX_BYTES_PER_PACKET)
  42 #define DROP_THRESH             (80 * 5 * MAX_BYTES_PER_PACKET)
  43 #define LARGE_PKT_DROP_THRESH   (DROP_THRESH - (15 * MAX_BYTES_PER_PACKET))
  44 #define MARK_REGION_SIZE        (LARGE_PKT_DROP_THRESH - MARK_THRESH)
  45 #define LARGE_PKT_THRESH        120
  46 #define MAX_CREDIT              (100 * MAX_BYTES_PER_PACKET)
  47 #define INIT_CREDIT             (INITIAL_CREDIT_PACKETS * MAX_BYTES_PER_PACKET)
  48
  49 // Time base accounting for fq's EDT
  50 #define BURST_SIZE_NS           100000 // 100us
  51 #define MARK_THRESH_NS          50000 // 50us
  52 #define DROP_THRESH_NS          500000 // 500us
  53 // Reserve 20us of queuing for small packets (less than 120 bytes)
  54 #define LARGE_PKT_DROP_THRESH_NS (DROP_THRESH_NS - 20000)
  55 #define MARK_REGION_SIZE_NS     (LARGE_PKT_DROP_THRESH_NS - MARK_THRESH_NS)
  56
  57 // rate in bytes per ns << 20
  58 #define CREDIT_PER_NS(delta, rate) ((((u64)(delta)) * (rate)) >> 20)
  59 #define BYTES_PER_NS(delta, rate) ((((u64)(delta)) * (rate)) >> 20)
  60 #define BYTES_TO_NS(bytes, rate) div64_u64(((u64)(bytes)) << 20, (u64)(rate))
  61
  62 struct {
  63         __uint(type, BPF_MAP_TYPE_CGROUP_STORAGE);
  64         __type(key, struct bpf_cgroup_storage_key);
  65         __type(value, struct hbm_vqueue);
  66 } queue_state SEC(".maps");
  67
  68 struct {
  69         __uint(type, BPF_MAP_TYPE_ARRAY);
  70         __uint(max_entries, 1);
  71         __type(key, u32);
  72         __type(value, struct hvm_queue_stats);
  73 } queue_stats SEC(".maps");
  74
  75 struct hbm_pkt_info {
  76         int     cwnd;
  77         int     rtt;
  78         int     packets_out;
  79         bool    is_ip;
  80         bool    is_tcp;
  81         short   ecn;
  82 };
  83
  84 static int get_tcp_info(struct __sk_buff *skb, struct hbm_pkt_info *pkti)
  85 {
  86         struct bpf_sock *sk;
  87         struct bpf_tcp_sock *tp;
  88
  89         sk = skb->sk;
  90         if (sk) {
  91                 sk = bpf_sk_fullsock(sk);
  92                 if (sk) {
  93                         if (sk->protocol == IPPROTO_TCP) {
  94                                 tp = bpf_tcp_sock(sk);
  95                                 if (tp) {
  96                                         pkti->cwnd = tp->snd_cwnd;
  97                                         pkti->rtt = tp->srtt_us >> 3;
  98                                         pkti->packets_out = tp->packets_out;
  99                                         return 0;
 100                                 }
 101                         }
 102                 }
 103         }
 104         pkti->cwnd = 0;
 105         pkti->rtt = 0;
 106         pkti->packets_out = 0;
 107         return 1;
 108 }
 109
 110 static void hbm_get_pkt_info(struct __sk_buff *skb,
 111                              struct hbm_pkt_info *pkti)
 112 {
 113         struct iphdr iph;
 114         struct ipv6hdr *ip6h;
 115
 116         pkti->cwnd = 0;
 117         pkti->rtt = 0;
 118         bpf_skb_load_bytes(skb, 0, &iph, 12);
 119         if (iph.version == 6) {
 120                 ip6h = (struct ipv6hdr *)&iph;
 121                 pkti->is_ip = true;
 122                 pkti->is_tcp = (ip6h->nexthdr == 6);
 123                 pkti->ecn = (ip6h->flow_lbl[0] >> 4) & INET_ECN_MASK;
 124         } else if (iph.version == 4) {
 125                 pkti->is_ip = true;
 126                 pkti->is_tcp = (iph.protocol == 6);
 127                 pkti->ecn = iph.tos & INET_ECN_MASK;
 128         } else {
 129                 pkti->is_ip = false;
 130                 pkti->is_tcp = false;
 131                 pkti->ecn = 0;
 132         }
 133         if (pkti->is_tcp)
 134                 get_tcp_info(skb, pkti);
 135 }
 136
 137 static __always_inline void hbm_init_vqueue(struct hbm_vqueue *qdp, int rate)
 138 {
 139         bpf_printk("Initializing queue_state, rate:%d\n", rate * 128);
 140         qdp->lasttime = bpf_ktime_get_ns();
 141         qdp->credit = INIT_CREDIT;
 142         qdp->rate = rate * 128;
 143 }
 144
 145 static __always_inline void hbm_init_edt_vqueue(struct hbm_vqueue *qdp,
 146                                                 int rate)
 147 {
 148         unsigned long long curtime;
 149
 150         curtime = bpf_ktime_get_ns();
 151         bpf_printk("Initializing queue_state, rate:%d\n", rate * 128);
 152         qdp->lasttime = curtime - BURST_SIZE_NS;        // support initial burst
 153         qdp->credit = 0;                                // not used
 154         qdp->rate = rate * 128;
 155 }
 156
 157 static __always_inline void hbm_update_stats(struct hbm_queue_stats *qsp,
 158                                              int len,
 159                                              unsigned long long curtime,
 160                                              bool congestion_flag,
 161                                              bool drop_flag,
 162                                              bool cwr_flag,
 163                                              bool ecn_ce_flag,
 164                                              struct hbm_pkt_info *pkti,
 165                                              int credit)
 166 {
 167         int rv = ALLOW_PKT;
 168
 169         if (qsp != NULL) {
 170                 // Following is needed for work conserving
 171                 __sync_add_and_fetch(&(qsp->bytes_total), len);
 172                 if (qsp->stats) {
 173                         // Optionally update statistics
 174                         if (qsp->firstPacketTime == 0)
 175                                 qsp->firstPacketTime = curtime;
 176                         qsp->lastPacketTime = curtime;
 177                         __sync_add_and_fetch(&(qsp->pkts_total), 1);
 178                         if (congestion_flag) {
 179                                 __sync_add_and_fetch(&(qsp->pkts_marked), 1);
 180                                 __sync_add_and_fetch(&(qsp->bytes_marked), len);
 181                         }
 182                         if (drop_flag) {
 183                                 __sync_add_and_fetch(&(qsp->pkts_dropped), 1);
 184                                 __sync_add_and_fetch(&(qsp->bytes_dropped),
 185                                                      len);
 186                         }
 187                         if (ecn_ce_flag)
 188                                 __sync_add_and_fetch(&(qsp->pkts_ecn_ce), 1);
 189                         if (pkti->cwnd) {
 190                                 __sync_add_and_fetch(&(qsp->sum_cwnd),
 191                                                      pkti->cwnd);
 192                                 __sync_add_and_fetch(&(qsp->sum_cwnd_cnt), 1);
 193                         }
 194                         if (pkti->rtt)
 195                                 __sync_add_and_fetch(&(qsp->sum_rtt),
 196                                                      pkti->rtt);
 197                         __sync_add_and_fetch(&(qsp->sum_credit), credit);
 198
 199                         if (drop_flag)
 200                                 rv = DROP_PKT;
 201                         if (cwr_flag)
 202                                 rv |= 2;
 203                         if (rv == DROP_PKT)
 204                                 __sync_add_and_fetch(&(qsp->returnValCount[0]),
 205                                                      1);
 206                         else if (rv == ALLOW_PKT)
 207                                 __sync_add_and_fetch(&(qsp->returnValCount[1]),
 208                                                      1);
 209                         else if (rv == 2)
 210                                 __sync_add_and_fetch(&(qsp->returnValCount[2]),
 211                                                      1);
 212                         else if (rv == 3)
 213                                 __sync_add_and_fetch(&(qsp->returnValCount[3]),
 214                                                      1);
 215                 }
 216         }
 217 }