66 lines · c
1// SPDX-License-Identifier: GPL-2.02 3#include "bpf_tracing_net.h"4#include <bpf/bpf_helpers.h>5#include <bpf/bpf_tracing.h>6 7char _license[] SEC("license") = "GPL";8 9#define USEC_PER_SEC 1000000UL10 11#define min(a, b) ((a) < (b) ? (a) : (b))12 13static unsigned int tcp_left_out(const struct tcp_sock *tp)14{15 return tp->sacked_out + tp->lost_out;16}17 18static unsigned int tcp_packets_in_flight(const struct tcp_sock *tp)19{20 return tp->packets_out - tcp_left_out(tp) + tp->retrans_out;21}22 23SEC("struct_ops")24void BPF_PROG(write_sk_pacing_init, struct sock *sk)25{26#ifdef ENABLE_ATOMICS_TESTS27 __sync_bool_compare_and_swap(&sk->sk_pacing_status, SK_PACING_NONE,28 SK_PACING_NEEDED);29#else30 sk->sk_pacing_status = SK_PACING_NEEDED;31#endif32}33 34SEC("struct_ops")35void BPF_PROG(write_sk_pacing_cong_control, struct sock *sk,36 const struct rate_sample *rs)37{38 struct tcp_sock *tp = tcp_sk(sk);39 unsigned long rate =40 ((tp->snd_cwnd * tp->mss_cache * USEC_PER_SEC) << 3) /41 (tp->srtt_us ?: 1U << 3);42 sk->sk_pacing_rate = min(rate, sk->sk_max_pacing_rate);43 tp->app_limited = (tp->delivered + tcp_packets_in_flight(tp)) ?: 1;44}45 46SEC("struct_ops")47__u32 BPF_PROG(write_sk_pacing_ssthresh, struct sock *sk)48{49 return tcp_sk(sk)->snd_ssthresh;50}51 52SEC("struct_ops")53__u32 BPF_PROG(write_sk_pacing_undo_cwnd, struct sock *sk)54{55 return tcp_sk(sk)->snd_cwnd;56}57 58SEC(".struct_ops")59struct tcp_congestion_ops write_sk_pacing = {60 .init = (void *)write_sk_pacing_init,61 .cong_control = (void *)write_sk_pacing_cong_control,62 .ssthresh = (void *)write_sk_pacing_ssthresh,63 .undo_cwnd = (void *)write_sk_pacing_undo_cwnd,64 .name = "bpf_w_sk_pacing",65};66