mirror of
https://mirrors.bfsu.edu.cn/git/linux.git
synced 2024-11-13 14:24:11 +08:00
f4dea9689c
Using sizeof(nv) or strlen(nv)+1 is correct.
Fixes: c890063e44 ("bpf: sample BPF_SOCKET_OPS_BASE_RTT program")
Signed-off-by: Pengcheng Yang <yangpc@wangsu.com>
Link: https://lore.kernel.org/r/1683276658-2860-1-git-send-email-yangpc@wangsu.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
72 lines
1.7 KiB
C
72 lines
1.7 KiB
C
/* Copyright (c) 2017 Facebook
|
|
*
|
|
* This program is free software; you can redistribute it and/or
|
|
* modify it under the terms of version 2 of the GNU General Public
|
|
* License as published by the Free Software Foundation.
|
|
*
|
|
* BPF program to set base_rtt to 80us when host is running TCP-NV and
|
|
* both hosts are in the same datacenter (as determined by IPv6 prefix).
|
|
*
|
|
* Use "bpftool cgroup attach $cg sock_ops $prog" to load this BPF program.
|
|
*/
|
|
|
|
#include <uapi/linux/bpf.h>
|
|
#include <uapi/linux/tcp.h>
|
|
#include <uapi/linux/if_ether.h>
|
|
#include <uapi/linux/if_packet.h>
|
|
#include <uapi/linux/ip.h>
|
|
#include <linux/socket.h>
|
|
#include <bpf/bpf_helpers.h>
|
|
#include <bpf/bpf_endian.h>
|
|
|
|
#define DEBUG 1
|
|
|
|
SEC("sockops")
|
|
int bpf_basertt(struct bpf_sock_ops *skops)
|
|
{
|
|
char cong[20];
|
|
char nv[] = "nv";
|
|
int rv = 0, n;
|
|
int op;
|
|
|
|
op = (int) skops->op;
|
|
|
|
#ifdef DEBUG
|
|
bpf_printk("BPF command: %d\n", op);
|
|
#endif
|
|
|
|
/* Check if both hosts are in the same datacenter. For this
|
|
* example they are if the 1st 5.5 bytes in the IPv6 address
|
|
* are the same.
|
|
*/
|
|
if (skops->family == AF_INET6 &&
|
|
skops->local_ip6[0] == skops->remote_ip6[0] &&
|
|
(bpf_ntohl(skops->local_ip6[1]) & 0xfff00000) ==
|
|
(bpf_ntohl(skops->remote_ip6[1]) & 0xfff00000)) {
|
|
switch (op) {
|
|
case BPF_SOCK_OPS_BASE_RTT:
|
|
n = bpf_getsockopt(skops, SOL_TCP, TCP_CONGESTION,
|
|
cong, sizeof(cong));
|
|
if (!n && !__builtin_memcmp(cong, nv, sizeof(nv))) {
|
|
/* Set base_rtt to 80us */
|
|
rv = 80;
|
|
} else if (n) {
|
|
rv = n;
|
|
} else {
|
|
rv = -1;
|
|
}
|
|
break;
|
|
default:
|
|
rv = -1;
|
|
}
|
|
} else {
|
|
rv = -1;
|
|
}
|
|
#ifdef DEBUG
|
|
bpf_printk("Returning %d\n", rv);
|
|
#endif
|
|
skops->reply = rv;
|
|
return 1;
|
|
}
|
|
char _license[] SEC("license") = "GPL";
|