/* 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_helpers.h"

struct bpf_map_def SEC("maps") rxcnt = {
	.type = BPF_MAP_TYPE_PERCPU_ARRAY,
	.key_size = sizeof(u32),
	.value_size = sizeof(long),
	.max_entries = 256,
};

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;
}

SEC("xdp1")
int xdp_prog1(struct xdp_md *ctx)
{
	void *data_end = (void *)(long)ctx->data_end;
	void *data = (void *)(long)ctx->data;
	struct ethhdr *eth = data;
	int rc = XDP_DROP;
	long *value;
	u16 h_proto;
	u64 nh_off;
	u32 ipproto;

	nh_off = sizeof(*eth);
	if (data + nh_off > data_end)
		return rc;

	h_proto = eth->h_proto;

	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_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);
		rc = XDP_TX;
	}

	return rc;
}

char _license[] SEC("license") = "GPL";
'id2' value='90f92c631b210c1e97080b53a9d863783281a932'/><select name='qt'>
<option value='grep'>log msg</option>
<option value='author'>author</option>
<option value='committer'>committer</option>
<option value='range'>range</option>
</select>
<input class='txt' type='search' size='10' name='q' value=''/>
<input type='submit' value='search'/>
</form>
</td></tr></table>
<div class='path'>path: <a href='/cgit.cgi/linux/net-next.git/diff/?id=fa19a769f82fb9a5ca000b83cacd13fcaeda51ac&amp;id2=90f92c631b210c1e97080b53a9d863783281a932'>root</a>/<a href='/cgit.cgi/linux/net-next.git/diff/include?id=fa19a769f82fb9a5ca000b83cacd13fcaeda51ac&amp;id2=90f92c631b210c1e97080b53a9d863783281a932'>include</a>/<a href='/cgit.cgi/linux/net-next.git/diff/include/net?id=fa19a769f82fb9a5ca000b83cacd13fcaeda51ac&amp;id2=90f92c631b210c1e97080b53a9d863783281a932'>net</a>/<a href='/cgit.cgi/linux/net-next.git/diff/include/net/sctp?id=fa19a769f82fb9a5ca000b83cacd13fcaeda51ac&amp;id2=90f92c631b210c1e97080b53a9d863783281a932'>sctp</a></div><div class='content'><div class='cgit-panel'><b>diff options</b><form method='get'><input type='hidden' name='id' value='fa19a769f82fb9a5ca000b83cacd13fcaeda51ac'/><input type='hidden' name='id2' value='90f92c631b210c1e97080b53a9d863783281a932'/><table><tr><td colspan='2'/></tr><tr><td class='label'>context:</td><td class='ctrl'><select name='context' onchange='this.form.submit();'><option value='1'>1</option><option value='2'>2</option><option value='3' selected='selected'>3</option><option value='4'>4</option><option value='5'>5</option><option value='6'>6</option><option value='7'>7</option><option value='8'>8</option><option value='9'>9</option><option value='10'>10</option><option value='15'>15</option><option value='20'>20</option><option value='25'>25</option><option value='30'>30</option><option value='35'>35</option><option value='40'>40</option></select></td></tr><tr><td class='label'>space:</td><td class='ctrl'><select name='ignorews' onchange='this.form.submit();'><option value='0' selected='selected'>include</option><option value='1'>ignore</option></select></td></tr><tr><td class='label'>mode:</td><td class='ctrl'><select name='dt' onchange='this.form.submit();'><option value='0' selected='selected'>unified</option><option value='1'>ssdiff</option><option value='2'>stat only</option></select></td></tr><tr><td/><td class='ctrl'><noscript><input type='submit' value='reload'/></noscript></td></tr></table></form></div><div class='diffstat-header'><a href='/cgit.cgi/linux/net-next.git/diff/?id=fa19a769f82fb9a5ca000b83cacd13fcaeda51ac&amp;id2=90f92c631b210c1e97080b53a9d863783281a932'>Diffstat</a> (limited to 'include/net/sctp')</div><table summary='diffstat' class='diffstat'>