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 } 138