1 /* Copyright (c) 2016 PLUMgrid
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 #define KBUILD_MODNAME "foo"
8 #include <uapi/linux/bpf.h>
10 #include <linux/if_ether.h>
11 #include <linux/if_packet.h>
12 #include <linux/if_vlan.h>
14 #include <linux/ipv6.h>
15 #include <bpf/bpf_helpers.h>
18 __uint(type, BPF_MAP_TYPE_PERCPU_ARRAY);
21 __uint(max_entries, 256);
24 static void swap_src_dst_mac(void *data)
26 unsigned short *p = data;
27 unsigned short dst[3];
40 static int parse_ipv4(void *data, u64 nh_off, void *data_end)
42 struct iphdr *iph = data + nh_off;
44 if (iph + 1 > data_end)
49 static int parse_ipv6(void *data, u64 nh_off, void *data_end)
51 struct ipv6hdr *ip6h = data + nh_off;
53 if (ip6h + 1 > data_end)
60 int xdp_prog1(struct xdp_md *ctx)
62 __u8 pkt[XDPBUFSIZE] = {};
63 void *data_end = &pkt[XDPBUFSIZE-1];
65 struct ethhdr *eth = data;
72 if (bpf_xdp_load_bytes(ctx, 0, pkt, sizeof(pkt)))
75 nh_off = sizeof(*eth);
76 if (data + nh_off > data_end)
79 h_proto = eth->h_proto;
81 /* Handle VLAN tagged packet */
82 if (h_proto == htons(ETH_P_8021Q) || h_proto == htons(ETH_P_8021AD)) {
83 struct vlan_hdr *vhdr;
86 nh_off += sizeof(struct vlan_hdr);
87 if (data + nh_off > data_end)
89 h_proto = vhdr->h_vlan_encapsulated_proto;
91 /* Handle double VLAN tagged packet */
92 if (h_proto == htons(ETH_P_8021Q) || h_proto == htons(ETH_P_8021AD)) {
93 struct vlan_hdr *vhdr;
96 nh_off += sizeof(struct vlan_hdr);
97 if (data + nh_off > data_end)
99 h_proto = vhdr->h_vlan_encapsulated_proto;
102 if (h_proto == htons(ETH_P_IP))
103 ipproto = parse_ipv4(data, nh_off, data_end);
104 else if (h_proto == htons(ETH_P_IPV6))
105 ipproto = parse_ipv6(data, nh_off, data_end);
109 value = bpf_map_lookup_elem(&rxcnt, &ipproto);
113 if (ipproto == IPPROTO_UDP) {
114 swap_src_dst_mac(data);
116 if (bpf_xdp_store_bytes(ctx, 0, pkt, sizeof(pkt)))
125 char _license[] SEC("license") = "GPL";