1
2#define KBUILD_MODNAME "foo"
3#include <string.h>
4#include <linux/in.h>
5#include <linux/if_ether.h>
6#include <linux/if_packet.h>
7#include <linux/ip.h>
8#include <linux/ipv6.h>
9
10#include <linux/bpf.h>
11#include <bpf/bpf_helpers.h>
12#include <bpf/bpf_endian.h>
13
14
15struct {
16 __uint(type, BPF_MAP_TYPE_DEVMAP);
17 __uint(key_size, sizeof(int));
18 __uint(value_size, sizeof(int));
19 __uint(max_entries, 1024);
20} map_all SEC(".maps");
21
22struct {
23 __uint(type, BPF_MAP_TYPE_DEVMAP_HASH);
24 __uint(key_size, sizeof(int));
25 __uint(value_size, sizeof(struct bpf_devmap_val));
26 __uint(max_entries, 128);
27} map_egress SEC(".maps");
28
29
30struct {
31 __uint(type, BPF_MAP_TYPE_HASH);
32 __type(key, __u32);
33 __type(value, __be64);
34 __uint(max_entries, 128);
35} mac_map SEC(".maps");
36
37SEC("xdp_redirect_map_multi")
38int xdp_redirect_map_multi_prog(struct xdp_md *ctx)
39{
40 void *data_end = (void *)(long)ctx->data_end;
41 void *data = (void *)(long)ctx->data;
42 int if_index = ctx->ingress_ifindex;
43 struct ethhdr *eth = data;
44 __u16 h_proto;
45 __u64 nh_off;
46
47 nh_off = sizeof(*eth);
48 if (data + nh_off > data_end)
49 return XDP_DROP;
50
51 h_proto = eth->h_proto;
52
53
54 if (h_proto == bpf_htons(ETH_P_IP))
55 return bpf_redirect_map(&map_all, 0,
56 BPF_F_BROADCAST | BPF_F_EXCLUDE_INGRESS);
57
58 else if (h_proto == bpf_htons(ETH_P_IPV6))
59 return bpf_redirect_map(&map_all, if_index, 0);
60
61 else
62 return bpf_redirect_map(&map_all, 0, BPF_F_BROADCAST);
63}
64
65
66SEC("xdp_redirect_map_ingress")
67int xdp_redirect_map_all_prog(struct xdp_md *ctx)
68{
69 return bpf_redirect_map(&map_egress, 0,
70 BPF_F_BROADCAST | BPF_F_EXCLUDE_INGRESS);
71}
72
73SEC("xdp_devmap/map_prog")
74int xdp_devmap_prog(struct xdp_md *ctx)
75{
76 void *data_end = (void *)(long)ctx->data_end;
77 void *data = (void *)(long)ctx->data;
78 __u32 key = ctx->egress_ifindex;
79 struct ethhdr *eth = data;
80 __u64 nh_off;
81 __be64 *mac;
82
83 nh_off = sizeof(*eth);
84 if (data + nh_off > data_end)
85 return XDP_DROP;
86
87 mac = bpf_map_lookup_elem(&mac_map, &key);
88 if (mac)
89 __builtin_memcpy(eth->h_source, mac, ETH_ALEN);
90
91 return XDP_PASS;
92}
93
94char _license[] SEC("license") = "GPL";
95