forked from Minki/linux
ea9b636201
bpftool can do all the things load_sock_ops used to do, and more. Point users to bpftool instead of maintaining this sample utility. Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com> Reviewed-by: Quentin Monnet <quentin.monnet@netronome.com> Acked-by: Andrii Nakryiko <andriin@fb.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
105 lines
2.8 KiB
C
105 lines
2.8 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.
|
|
*
|
|
* Sample BPF program to set send and receive buffers to 150KB, sndcwnd clamp
|
|
* to 100 packets and SYN and SYN_ACK RTOs to 10ms when both hosts are within
|
|
* the same datacenter. For his example, we assume they are within the same
|
|
* datacenter when the first 5.5 bytes of their IPv6 addresses are the same.
|
|
*
|
|
* Use "bpftool cgroup attach $cg sock_ops $prog" to load this BPF program.
|
|
*/
|
|
|
|
#include <uapi/linux/bpf.h>
|
|
#include <uapi/linux/if_ether.h>
|
|
#include <uapi/linux/if_packet.h>
|
|
#include <uapi/linux/ip.h>
|
|
#include <linux/socket.h>
|
|
#include "bpf_helpers.h"
|
|
#include "bpf_endian.h"
|
|
|
|
#define DEBUG 1
|
|
|
|
#define bpf_printk(fmt, ...) \
|
|
({ \
|
|
char ____fmt[] = fmt; \
|
|
bpf_trace_printk(____fmt, sizeof(____fmt), \
|
|
##__VA_ARGS__); \
|
|
})
|
|
|
|
SEC("sockops")
|
|
int bpf_clamp(struct bpf_sock_ops *skops)
|
|
{
|
|
int bufsize = 150000;
|
|
int to_init = 10;
|
|
int clamp = 100;
|
|
int rv = 0;
|
|
int op;
|
|
|
|
/* For testing purposes, only execute rest of BPF program
|
|
* if neither port numberis 55601
|
|
*/
|
|
if (bpf_ntohl(skops->remote_port) != 55601 && skops->local_port != 55601) {
|
|
skops->reply = -1;
|
|
return 0;
|
|
}
|
|
|
|
op = (int) skops->op;
|
|
|
|
#ifdef DEBUG
|
|
bpf_printk("BPF command: %d\n", op);
|
|
#endif
|
|
|
|
/* Check that both hosts are within same datacenter. For this example
|
|
* it is the case when the first 5.5 bytes of their IPv6 addresses 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_TIMEOUT_INIT:
|
|
rv = to_init;
|
|
break;
|
|
case BPF_SOCK_OPS_TCP_CONNECT_CB:
|
|
/* Set sndbuf and rcvbuf of active connections */
|
|
rv = bpf_setsockopt(skops, SOL_SOCKET, SO_SNDBUF,
|
|
&bufsize, sizeof(bufsize));
|
|
rv += bpf_setsockopt(skops, SOL_SOCKET,
|
|
SO_RCVBUF, &bufsize,
|
|
sizeof(bufsize));
|
|
break;
|
|
case BPF_SOCK_OPS_ACTIVE_ESTABLISHED_CB:
|
|
rv = bpf_setsockopt(skops, SOL_TCP,
|
|
TCP_BPF_SNDCWND_CLAMP,
|
|
&clamp, sizeof(clamp));
|
|
break;
|
|
case BPF_SOCK_OPS_PASSIVE_ESTABLISHED_CB:
|
|
/* Set sndbuf and rcvbuf of passive connections */
|
|
rv = bpf_setsockopt(skops, SOL_TCP,
|
|
TCP_BPF_SNDCWND_CLAMP,
|
|
&clamp, sizeof(clamp));
|
|
rv += bpf_setsockopt(skops, SOL_SOCKET,
|
|
SO_SNDBUF, &bufsize,
|
|
sizeof(bufsize));
|
|
rv += bpf_setsockopt(skops, SOL_SOCKET,
|
|
SO_RCVBUF, &bufsize,
|
|
sizeof(bufsize));
|
|
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";
|