linux/samples/bpf/tcp_cong_kern.c
Toke Høiland-Jørgensen 7cf245a37e samples/bpf: Use consistent include paths for libbpf
Fix all files in samples/bpf to include libbpf header files with the bpf/
prefix, to be consistent with external users of the library. Also ensure
that all includes of exported libbpf header files (those that are exported
on 'make install' of the library) use bracketed includes instead of quoted.

To make sure no new files are introduced that doesn't include the bpf/
prefix in its include, remove tools/lib/bpf from the include path entirely,
and use tools/lib instead.

Fixes: 6910d7d386 ("selftests/bpf: Ensure bpf_helper_defs.h are taken from selftests dir")
Signed-off-by: Toke Høiland-Jørgensen <toke@redhat.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Jesper Dangaard Brouer <brouer@redhat.com>
Acked-by: Andrii Nakryiko <andriin@fb.com>
Link: https://lore.kernel.org/bpf/157952560911.1683545.8795966751309534150.stgit@toke.dk
2020-01-20 16:37:45 -08:00

79 lines
1.9 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 congestion control to dctcp when both hosts are
* in the same datacenter (as deteremined 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_cong(struct bpf_sock_ops *skops)
{
char cong[] = "dctcp";
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 1;
}
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_NEEDS_ECN:
rv = 1;
break;
case BPF_SOCK_OPS_ACTIVE_ESTABLISHED_CB:
rv = bpf_setsockopt(skops, SOL_TCP, TCP_CONGESTION,
cong, sizeof(cong));
break;
case BPF_SOCK_OPS_PASSIVE_ESTABLISHED_CB:
rv = bpf_setsockopt(skops, SOL_TCP, TCP_CONGESTION,
cong, sizeof(cong));
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";