1 files changed, 125 insertions, 0 deletions
diff --git a/samples/bpf/xdp2_kern.c b/samples/bpf/xdp2_kern.c
new file mode 100644
index 000000000..8bca67445
--- /dev/null
+++ b/samples/bpf/xdp2_kern.c
@@ -0,0 +1,125 @@
+/* Copyright (c) 2016 PLUMgrid
+ *
+ * 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.
+ */
+#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/bpf_helpers.h>
+
+struct {
+	__uint(type, BPF_MAP_TYPE_PERCPU_ARRAY);
+	__type(key, u32);
+	__type(value, long);
+	__uint(max_entries, 256);
+} 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];
+}
+
+static int parse_ipv4(void *data, u64 nh_off, void *data_end)
+{
+	struct iphdr *iph = data + nh_off;
+
+	if (iph + 1 > data_end)
+		return 0;
+	return iph->protocol;
+}
+
+static int parse_ipv6(void *data, u64 nh_off, void *data_end)
+{
+	struct ipv6hdr *ip6h = data + nh_off;
+
+	if (ip6h + 1 > data_end)
+		return 0;
+	return ip6h->nexthdr;
+}
+
+#define XDPBUFSIZE	60
+SEC("xdp.frags")
+int xdp_prog1(struct xdp_md *ctx)
+{
+	__u8 pkt[XDPBUFSIZE] = {};
+	void *data_end = &pkt[XDPBUFSIZE-1];
+	void *data = pkt;
+	struct ethhdr *eth = data;
+	int rc = XDP_DROP;
+	long *value;
+	u16 h_proto;
+	u64 nh_off;
+	u32 ipproto;
+
+	if (bpf_xdp_load_bytes(ctx, 0, pkt, sizeof(pkt)))
+		return rc;
+
+	nh_off = sizeof(*eth);
+	if (data + nh_off > data_end)
+		return rc;
+
+	h_proto = eth->h_proto;
+
+	/* Handle VLAN tagged packet */
+	if (h_proto == htons(ETH_P_8021Q) || h_proto == htons(ETH_P_8021AD)) {
+		struct vlan_hdr *vhdr;
+
+		vhdr = data + nh_off;
+		nh_off += sizeof(struct vlan_hdr);
+		if (data + nh_off > data_end)
+			return rc;
+		h_proto = vhdr->h_vlan_encapsulated_proto;
+	}
+	/* Handle double VLAN tagged packet */
+	if (h_proto == htons(ETH_P_8021Q) || h_proto == htons(ETH_P_8021AD)) {
+		struct vlan_hdr *vhdr;
+
+		vhdr = data + nh_off;
+		nh_off += sizeof(struct vlan_hdr);
+		if (data + nh_off > data_end)
+			return rc;
+		h_proto = vhdr->h_vlan_encapsulated_proto;
+	}
+
+	if (h_proto == htons(ETH_P_IP))
+		ipproto = parse_ipv4(data, nh_off, data_end);
+	else if (h_proto == htons(ETH_P_IPV6))
+		ipproto = parse_ipv6(data, nh_off, data_end);
+	else
+		ipproto = 0;
+
+	value = bpf_map_lookup_elem(&rxcnt, &ipproto);
+	if (value)
+		*value += 1;
+
+	if (ipproto == IPPROTO_UDP) {
+		swap_src_dst_mac(data);
+
+		if (bpf_xdp_store_bytes(ctx, 0, pkt, sizeof(pkt)))
+			return rc;
+
+		rc = XDP_TX;
+	}
+
+	return rc;
+}
+
+char _license[] SEC("license") = "GPL";