linux-stable/samples/bpf/xdp_redirect_map_kern.c
Daniel T. Lee 451d1dc886 samples: bpf: update map definition to new syntax BTF-defined map
Since, the new syntax of BTF-defined map has been introduced,
the syntax for using maps under samples directory are mixed up.
For example, some are already using the new syntax, and some are using
existing syntax by calling them as 'legacy'.

As stated at commit abd29c9314 ("libbpf: allow specifying map
definitions using BTF"), the BTF-defined map has more compatablility
with extending supported map definition features.

The commit doesn't replace all of the map to new BTF-defined map,
because some of the samples still use bpf_load instead of libbpf, which
can't properly create BTF-defined map.

This will only updates the samples which uses libbpf API for loading bpf
program. (ex. bpf_prog_load_xattr)

Signed-off-by: Daniel T. Lee <danieltimlee@gmail.com>
Acked-by: Andrii Nakryiko <andriin@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2019-11-08 19:21:52 -08:00

92 lines
2.2 KiB
C

/* Copyright (c) 2017 Covalent IO, Inc. http://covalent.io
*
* 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.
*
* This program is distributed in the hope that it will be useful, but
* WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* General Public License for more details.
*/
#define KBUILD_MODNAME "foo"
#include <uapi/linux/bpf.h>
#include <linux/in.h>
#include <linux/if_ether.h>
#include <linux/if_packet.h>
#include <linux/if_vlan.h>
#include <linux/ip.h>
#include <linux/ipv6.h>
#include "bpf_helpers.h"
struct {
__uint(type, BPF_MAP_TYPE_DEVMAP);
__uint(key_size, sizeof(int));
__uint(value_size, sizeof(int));
__uint(max_entries, 100);
} tx_port SEC(".maps");
/* Count RX packets, as XDP bpf_prog doesn't get direct TX-success
* feedback. Redirect TX errors can be caught via a tracepoint.
*/
struct {
__uint(type, BPF_MAP_TYPE_PERCPU_ARRAY);
__type(key, u32);
__type(value, long);
__uint(max_entries, 1);
} rxcnt SEC(".maps");
static void swap_src_dst_mac(void *data)
{
unsigned short *p = data;
unsigned short dst[3];
dst[0] = p[0];
dst[1] = p[1];
dst[2] = p[2];
p[0] = p[3];
p[1] = p[4];
p[2] = p[5];
p[3] = dst[0];
p[4] = dst[1];
p[5] = dst[2];
}
SEC("xdp_redirect_map")
int xdp_redirect_map_prog(struct xdp_md *ctx)
{
void *data_end = (void *)(long)ctx->data_end;
void *data = (void *)(long)ctx->data;
struct ethhdr *eth = data;
int rc = XDP_DROP;
int vport, port = 0, m = 0;
long *value;
u32 key = 0;
u64 nh_off;
nh_off = sizeof(*eth);
if (data + nh_off > data_end)
return rc;
/* constant virtual port */
vport = 0;
/* count packet in global counter */
value = bpf_map_lookup_elem(&rxcnt, &key);
if (value)
*value += 1;
swap_src_dst_mac(data);
/* send packet out physical port */
return bpf_redirect_map(&tx_port, vport, 0);
}
/* Redirect require an XDP bpf_prog loaded on the TX device */
SEC("xdp_redirect_dummy")
int xdp_redirect_dummy_prog(struct xdp_md *ctx)
{
return XDP_PASS;
}
char _license[] SEC("license") = "GPL";