alistair23-linux/samples/bpf/tcp_basertt_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

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)+1)) {
/* 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";