1 /* Copyright (c) 2017 Covalent IO, Inc. http://covalent.io
3 * This program is free software; you can redistribute it and/or
4 * modify it under the terms of version 2 of the GNU General Public
5 * License as published by the Free Software Foundation.
7 * This program is distributed in the hope that it will be useful, but
8 * WITHOUT ANY WARRANTY; without even the implied warranty of
9 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
10 * General Public License for more details.
12 #define KBUILD_MODNAME "foo"
13 #include <uapi/linux/bpf.h>
15 #include <linux/if_ether.h>
16 #include <linux/if_packet.h>
17 #include <linux/if_vlan.h>
19 #include <linux/ipv6.h>
20 #include <bpf/bpf_helpers.h>
23 __uint(type, BPF_MAP_TYPE_DEVMAP);
24 __uint(key_size, sizeof(int));
25 __uint(value_size, sizeof(int));
26 __uint(max_entries, 100);
27 } tx_port SEC(".maps");
29 /* Count RX packets, as XDP bpf_prog doesn't get direct TX-success
30 * feedback. Redirect TX errors can be caught via a tracepoint.
33 __uint(type, BPF_MAP_TYPE_PERCPU_ARRAY);
36 __uint(max_entries, 1);
39 static void swap_src_dst_mac(void *data)
41 unsigned short *p = data;
42 unsigned short dst[3];
55 SEC("xdp_redirect_map")
56 int xdp_redirect_map_prog(struct xdp_md *ctx)
58 void *data_end = (void *)(long)ctx->data_end;
59 void *data = (void *)(long)ctx->data;
60 struct ethhdr *eth = data;
62 int vport, port = 0, m = 0;
67 nh_off = sizeof(*eth);
68 if (data + nh_off > data_end)
71 /* constant virtual port */
74 /* count packet in global counter */
75 value = bpf_map_lookup_elem(&rxcnt, &key);
79 swap_src_dst_mac(data);
81 /* send packet out physical port */
82 return bpf_redirect_map(&tx_port, vport, 0);
85 /* Redirect require an XDP bpf_prog loaded on the TX device */
86 SEC("xdp_redirect_dummy")
87 int xdp_redirect_dummy_prog(struct xdp_md *ctx)
92 char _license[] SEC("license") = "GPL";