73 lines
1.5 KiB
C
73 lines
1.5 KiB
C
|
// SPDX-License-Identifier: GPL-2.0
|
||
|
|
/* Copyright (c) 2021 Facebook */
|
||
|
|
#include "bpf_iter.h"
|
||
|
|
#include "bpf_tracing_net.h"
|
||
|
|
#include <bpf/bpf_helpers.h>
|
||
|
|
#include <bpf/bpf_endian.h>
|
||
|
|
|
||
|
|
#define bpf_tcp_sk(skc) ({ \
|
||
|
|
struct sock_common *_skc = skc; \
|
||
|
|
sk = NULL; \
|
||
|
|
tp = NULL; \
|
||
|
|
if (_skc) { \
|
||
|
|
tp = bpf_skc_to_tcp_sock(_skc); \
|
||
|
|
sk = (struct sock *)tp; \
|
||
|
|
} \
|
||
|
|
tp; \
|
||
|
|
})
|
||
|
|
|
||
|
|
unsigned short reuse_listen_hport = 0;
|
||
|
|
unsigned short listen_hport = 0;
|
||
|
|
char cubic_cc[TCP_CA_NAME_MAX] = "bpf_cubic";
|
||
|
|
char dctcp_cc[TCP_CA_NAME_MAX] = "bpf_dctcp";
|
||
|
|
bool random_retry = false;
|
||
|
|
|
||
|
|
static bool tcp_cc_eq(const char *a, const char *b)
|
||
|
|
{
|
||
|
|
int i;
|
||
|
|
|
||
|
|
for (i = 0; i < TCP_CA_NAME_MAX; i++) {
|
||
|
|
if (a[i] != b[i])
|
||
|
|
return false;
|
||
|
|
if (!a[i])
|
||
|
|
break;
|
||
|
|
}
|
||
|
|
|
||
|
|
return true;
|
||
|
|
}
|
||
|
|
|
||
|
|
SEC("iter/tcp")
|
||
|
|
int change_tcp_cc(struct bpf_iter__tcp *ctx)
|
||
|
|
{
|
||
|
|
char cur_cc[TCP_CA_NAME_MAX];
|
||
|
|
struct tcp_sock *tp;
|
||
|
|
struct sock *sk;
|
||
|
|
int ret;
|
||
|
|
|
||
|
|
if (!bpf_tcp_sk(ctx->sk_common))
|
||
|
|
return 0;
|
||
|
|
|
||
|
|
if (sk->sk_family != AF_INET6 ||
|
||
|
|
(sk->sk_state != TCP_LISTEN &&
|
||
|
|
sk->sk_state != TCP_ESTABLISHED) ||
|
||
|
|
(sk->sk_num != reuse_listen_hport &&
|
||
|
|
sk->sk_num != listen_hport &&
|
||
|
|
bpf_ntohs(sk->sk_dport) != listen_hport))
|
||
|
|
return 0;
|
||
|
|
|
||
|
|
if (bpf_getsockopt(tp, SOL_TCP, TCP_CONGESTION,
|
||
|
|
cur_cc, sizeof(cur_cc)))
|
||
|
|
return 0;
|
||
|
|
|
||
|
|
if (!tcp_cc_eq(cur_cc, cubic_cc))
|
||
|
|
return 0;
|
||
|
|
|
||
|
|
if (random_retry && bpf_get_prandom_u32() % 4 == 1)
|
||
|
|
return 1;
|
||
|
|
|
||
|
|
bpf_setsockopt(tp, SOL_TCP, TCP_CONGESTION, dctcp_cc, sizeof(dctcp_cc));
|
||
|
|
return 0;
|
||
|
|
}
|
||
|
|
|
||
|
|
char _license[] SEC("license") = "GPL";
|