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_endian.h"
  26 #include "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
  33 #define HBM_DEBUG 0  // Set to 1 to enable debugging
  34 #if HBM_DEBUG
  35 #define bpf_printk(fmt, ...)                                    \
  36 ({                                                              \
  37         char ____fmt[] = fmt;                                   \
  38         bpf_trace_printk(____fmt, sizeof(____fmt),              \
  39                          ##__VA_ARGS__);                        \
  40 })
  41 #else
  42 #define bpf_printk(fmt, ...)
  43 #endif
  44
  45 #define INITIAL_CREDIT_PACKETS  100
  46 #define MAX_BYTES_PER_PACKET    1500
  47 #define MARK_THRESH             (40 * MAX_BYTES_PER_PACKET)
  48 #define DROP_THRESH             (80 * 5 * MAX_BYTES_PER_PACKET)
  49 #define LARGE_PKT_DROP_THRESH   (DROP_THRESH - (15 * MAX_BYTES_PER_PACKET))
  50 #define MARK_REGION_SIZE        (LARGE_PKT_DROP_THRESH - MARK_THRESH)
  51 #define LARGE_PKT_THRESH        120
  52 #define MAX_CREDIT              (100 * MAX_BYTES_PER_PACKET)
  53 #define INIT_CREDIT             (INITIAL_CREDIT_PACKETS * MAX_BYTES_PER_PACKET)
  54
  55 // rate in bytes per ns << 20
  56 #define CREDIT_PER_NS(delta, rate) ((((u64)(delta)) * (rate)) >> 20)
  57
  58 struct bpf_map_def SEC("maps") queue_state = {
  59         .type = BPF_MAP_TYPE_CGROUP_STORAGE,
  60         .key_size = sizeof(struct bpf_cgroup_storage_key),
  61         .value_size = sizeof(struct hbm_vqueue),
  62 };
  63 BPF_ANNOTATE_KV_PAIR(queue_state, struct bpf_cgroup_storage_key,
  64                      struct hbm_vqueue);
  65
  66 struct bpf_map_def SEC("maps") queue_stats = {
  67         .type = BPF_MAP_TYPE_ARRAY,
  68         .key_size = sizeof(u32),
  69         .value_size = sizeof(struct hbm_queue_stats),
  70         .max_entries = 1,
  71 };
  72 BPF_ANNOTATE_KV_PAIR(queue_stats, int, struct hbm_queue_stats);
  73
  74 struct hbm_pkt_info {
  75         bool    is_ip;
  76         bool    is_tcp;
  77         short   ecn;
  78 };
  79
  80 static __always_inline void hbm_get_pkt_info(struct __sk_buff *skb,
  81                                              struct hbm_pkt_info *pkti)
  82 {
  83         struct iphdr iph;
  84         struct ipv6hdr *ip6h;
  85
  86         bpf_skb_load_bytes(skb, 0, &iph, 12);
  87         if (iph.version == 6) {
  88                 ip6h = (struct ipv6hdr *)&iph;
  89                 pkti->is_ip = true;
  90                 pkti->is_tcp = (ip6h->nexthdr == 6);
  91                 pkti->ecn = (ip6h->flow_lbl[0] >> 4) & INET_ECN_MASK;
  92         } else if (iph.version == 4) {
  93                 pkti->is_ip = true;
  94                 pkti->is_tcp = (iph.protocol == 6);
  95                 pkti->ecn = iph.tos & INET_ECN_MASK;
  96         } else {
  97                 pkti->is_ip = false;
  98                 pkti->is_tcp = false;
  99                 pkti->ecn = 0;
 100         }
 101 }
 102
 103 static __always_inline void hbm_init_vqueue(struct hbm_vqueue *qdp, int rate)
 104 {
 105                 bpf_printk("Initializing queue_state, rate:%d\n", rate * 128);
 106                 qdp->lasttime = bpf_ktime_get_ns();
 107                 qdp->credit = INIT_CREDIT;
 108                 qdp->rate = rate * 128;
 109 }
 110
 111 static __always_inline void hbm_update_stats(struct hbm_queue_stats *qsp,
 112                                              int len,
 113                                              unsigned long long curtime,
 114                                              bool congestion_flag,
 115                                              bool drop_flag)
 116 {
 117         if (qsp != NULL) {
 118                 // Following is needed for work conserving
 119                 __sync_add_and_fetch(&(qsp->bytes_total), len);
 120                 if (qsp->stats) {
 121                         // Optionally update statistics
 122                         if (qsp->firstPacketTime == 0)
 123                                 qsp->firstPacketTime = curtime;
 124                         qsp->lastPacketTime = curtime;
 125                         __sync_add_and_fetch(&(qsp->pkts_total), 1);
 126                         if (congestion_flag || drop_flag) {
 127                                 __sync_add_and_fetch(&(qsp->pkts_marked), 1);
 128                                 __sync_add_and_fetch(&(qsp->bytes_marked), len);
 129                         }
 130                         if (drop_flag) {
 131                                 __sync_add_and_fetch(&(qsp->pkts_dropped), 1);
 132                                 __sync_add_and_fetch(&(qsp->bytes_dropped),
 133                                                      len);
 134                         }
 135                 }
 136         }
 137 }