linux/samples/bpf/tcp_tos_reflect_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

81 lines
1.8 KiB
C

// SPDX-License-Identifier: GPL-2.0
/*
* Copyright (c) 2018 Facebook
*
* BPF program to automatically reflect TOS option from received syn packet
*
* 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 <uapi/linux/ipv6.h>
#include <uapi/linux/in.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 header[sizeof(struct ipv6hdr)];
struct ipv6hdr *hdr6;
struct iphdr *hdr;
int hdr_size = 0;
int save_syn = 1;
int tos = 0;
int rv = 0;
int op;
op = (int) skops->op;
#ifdef DEBUG
bpf_printk("BPF command: %d\n", op);
#endif
switch (op) {
case BPF_SOCK_OPS_TCP_LISTEN_CB:
rv = bpf_setsockopt(skops, SOL_TCP, TCP_SAVE_SYN,
&save_syn, sizeof(save_syn));
break;
case BPF_SOCK_OPS_PASSIVE_ESTABLISHED_CB:
if (skops->family == AF_INET)
hdr_size = sizeof(struct iphdr);
else
hdr_size = sizeof(struct ipv6hdr);
rv = bpf_getsockopt(skops, SOL_TCP, TCP_SAVED_SYN,
header, hdr_size);
if (!rv) {
if (skops->family == AF_INET) {
hdr = (struct iphdr *) header;
tos = hdr->tos;
if (tos != 0)
bpf_setsockopt(skops, SOL_IP, IP_TOS,
&tos, sizeof(tos));
} else {
hdr6 = (struct ipv6hdr *) header;
tos = ((hdr6->priority) << 4 |
(hdr6->flow_lbl[0]) >> 4);
if (tos)
bpf_setsockopt(skops, SOL_IPV6,
IPV6_TCLASS,
&tos, sizeof(tos));
}
rv = 0;
}
break;
default:
rv = -1;
}
#ifdef DEBUG
bpf_printk("Returning %d\n", rv);
#endif
skops->reply = rv;
return 1;
}
char _license[] SEC("license") = "GPL";