LXR linux/samples/bpf/xdp

   1// SPDX-License-Identifier: GPL-2.0
   2/* Copyright (c) 2016 John Fastabend <john.r.fastabend@intel.com>
   3 *
   4 * This program is free software; you can redistribute it and/or
   5 * modify it under the terms of version 2 of the GNU General Public
   6 * License as published by the Free Software Foundation.
   7 *
   8 * This program is distributed in the hope that it will be useful, but
   9 * WITHOUT ANY WARRANTY; without even the implied warranty of
  10 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
  11 * General Public License for more details.
  12 */
  13#include "vmlinux.h"
  14#include "xdp_sample.bpf.h"
  15#include "xdp_sample_shared.h"
  16
  17const volatile int ifindex_out;
  18
  19SEC("xdp")
  20int xdp_redirect_prog(struct xdp_md *ctx)
  21{
  22        void *data_end = (void *)(long)ctx->data_end;
  23        void *data = (void *)(long)ctx->data;
  24        u32 key = bpf_get_smp_processor_id();
  25        struct ethhdr *eth = data;
  26        struct datarec *rec;
  27        u64 nh_off;
  28
  29        nh_off = sizeof(*eth);
  30        if (data + nh_off > data_end)
  31                return XDP_DROP;
  32
  33        rec = bpf_map_lookup_elem(&rx_cnt, &key);
  34        if (!rec)
  35                return XDP_PASS;
  36        NO_TEAR_INC(rec->processed);
  37
  38        swap_src_dst_mac(data);
  39        return bpf_redirect(ifindex_out, 0);
  40}
  41
  42/* Redirect require an XDP bpf_prog loaded on the TX device */
  43SEC("xdp")
  44int xdp_redirect_dummy_prog(struct xdp_md *ctx)
  45{
  46        return XDP_PASS;
  47}
  48
  49char _license[] SEC("license") = "GPL";
  50