/*
 * xfrm4_mode_tunnel.c - Tunnel mode encapsulation for IPv4.
 *
 * Copyright (c) 2004-2006 Herbert Xu <herbert@gondor.apana.org.au>
 */

#include <linux/gfp.h>
#include <linux/init.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/skbuff.h>
#include <linux/stringify.h>
#include <net/dst.h>
#include <net/inet_ecn.h>
#include <net/ip.h>
#include <net/xfrm.h>

static inline void ipip_ecn_decapsulate(struct sk_buff *skb)
{
	struct iphdr *inner_iph = ipip_hdr(skb);

	if (INET_ECN_is_ce(XFRM_MODE_SKB_CB(skb)->tos))
		IP_ECN_set_ce(inner_iph);
}

/* Add encapsulation header.
 *
 * The top IP header will be constructed per RFC 2401.
 */
static int xfrm4_mode_tunnel_output(struct xfrm_state *x, struct sk_buff *skb)
{
	struct dst_entry *dst = skb_dst(skb);
	struct iphdr *top_iph;
	int flags;

	skb_set_network_header(skb, -x->props.header_len);
	skb->mac_header = skb->network_header +
			  offsetof(struct iphdr, protocol);
	skb->transport_header = skb->network_header + sizeof(*top_iph);
	top_iph = ip_hdr(skb);

	top_iph->ihl = 5;
	top_iph->version = 4;

	top_iph->protocol = xfrm_af2proto(skb_dst(skb)->ops->family);

	/* DS disclosing depends on XFRM_SA_XFLAG_DONT_ENCAP_DSCP */
	if (x->props.extra_flags & XFRM_SA_XFLAG_DONT_ENCAP_DSCP)
		top_iph->tos = 0;
	else
		top_iph->tos = XFRM_MODE_SKB_CB(skb)->tos;
	top_iph->tos = INET_ECN_encapsulate(top_iph->tos,
					    XFRM_MODE_SKB_CB(skb)->tos);

	flags = x->props.flags;
	if (flags & XFRM_STATE_NOECN)
		IP_ECN_clear(top_iph);

	top_iph->frag_off = (flags & XFRM_STATE_NOPMTUDISC) ?
		0 : (XFRM_MODE_SKB_CB(skb)->frag_off & htons(IP_DF));

	top_iph->ttl = ip4_dst_hoplimit(dst->child);

	top_iph->saddr = x->props.saddr.a4;
	top_iph->daddr = x->id.daddr.a4;
	ip_select_ident(dev_net(dst->dev), skb, NULL);

	return 0;
}

static int xfrm4_mode_tunnel_input(struct xfrm_state *x, struct sk_buff *skb)
{
	int err = -EINVAL;

	if (XFRM_MODE_SKB_CB(skb)->protocol != IPPROTO_IPIP)
		goto out;

	if (!pskb_may_pull(skb, sizeof(struct iphdr)))
		goto out;

	err = skb_unclone(skb, GFP_ATOMIC);
	if (err)
		goto out;

	if (x->props.flags & XFRM_STATE_DECAP_DSCP)
		ipv4_copy_dscp(XFRM_MODE_SKB_CB(skb)->tos, ipip_hdr(skb));
	if (!(x->props.flags & XFRM_STATE_NOECN))
		ipip_ecn_decapsulate(skb);

	skb_reset_network_header(skb);
	skb_mac_header_rebuild(skb);

	err = 0;

out:
	return err;
}

static struct xfrm_mode xfrm4_tunnel_mode = {
	.input2 = xfrm4_mode_tunnel_input,
	.input = xfrm_prepare_input,
	.output2 = xfrm4_mode_tunnel_output,
	.output = xfrm4_prepare_output,
	.owner = THIS_MODULE,
	.encap = XFRM_MODE_TUNNEL,
	.flags = XFRM_MODE_FLAG_TUNNEL,
};

static int __init xfrm4_mode_tunnel_init(void)
{
	return xfrm_register_mode(&xfrm4_tunnel_mode, AF_INET);
}

static void __exit xfrm4_mode_tunnel_exit(void)
{
	int err;

	err = xfrm_unregister_mode(&xfrm4_tunnel_mode, AF_INET);
	BUG_ON(err);
}

module_init(xfrm4_mode_tunnel_init);
module_exit(xfrm4_mode_tunnel_exit);
MODULE_LICENSE("GPL");
MODULE_ALIAS_XFRM_MODE(AF_INET, XFRM_MODE_TUNNEL);
mit/net?h=nds-private-remove&amp;id=53a20465e6b674eb6ce594b0e9e8940495e95f33'>net</a>/<a href='/cgit.cgi/linux/net-next.git/commit/net/dccp?h=nds-private-remove&amp;id=53a20465e6b674eb6ce594b0e9e8940495e95f33'>dccp</a>/<a href='/cgit.cgi/linux/net-next.git/commit/net/dccp/Makefile?h=nds-private-remove&amp;id=53a20465e6b674eb6ce594b0e9e8940495e95f33'>Makefile</a></div><div class='content'><div class='cgit-panel'><b>diff options</b><form method='get'><input type='hidden' name='h' value='nds-private-remove'/><input type='hidden' name='id' value='53a20465e6b674eb6ce594b0e9e8940495e95f33'/><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><table summary='commit info' class='commit-info'>
<tr><th>author</th><td>Mark Brown &lt;broonie@kernel.org&gt;</td><td class='right'>2016-11-15 15:01:09 +0000</td></tr>
<tr><th>committer</th><td>Mark Brown &lt;broonie@kernel.org&gt;</td><td class='right'>2016-11-15 15:22:10 +0000</td></tr>
<tr><th>commit</th><td colspan='2' class='oid'><a href='/cgit.cgi/linux/net-next.git/commit/net/dccp/Makefile?h=nds-private-remove&amp;id=53a20465e6b674eb6ce594b0e9e8940495e95f33'>53a20465e6b674eb6ce594b0e9e8940495e95f33</a> (<a href='/cgit.cgi/linux/net-next.git/patch/net/dccp/Makefile?id=53a20465e6b674eb6ce594b0e9e8940495e95f33'>patch</a>)</td></tr>
<tr><th>tree</th><td colspan='2' class='oid'><a href='/cgit.cgi/linux/net-next.git/tree/?h=nds-private-remove&amp;id=53a20465e6b674eb6ce594b0e9e8940495e95f33'>4d4c29c7c68ab2a1b69e4bd3903949356d2467e8</a> /<a href='/cgit.cgi/linux/net-next.git/tree/net/dccp/Makefile?h=nds-private-remove&amp;id=53a20465e6b674eb6ce594b0e9e8940495e95f33'>net/dccp/Makefile</a></td></tr>
<tr><th>parent</th><td colspan='2' class='oid'><a href='/cgit.cgi/linux/net-next.git/commit/net/dccp/Makefile?h=nds-private-remove&amp;id=1001354ca34179f3db924eb66672442a173147dc'>1001354ca34179f3db924eb66672442a173147dc</a> (<a href='/cgit.cgi/linux/net-next.git/diff/net/dccp/Makefile?h=nds-private-remove&amp;id=53a20465e6b674eb6ce594b0e9e8940495e95f33&amp;id2=1001354ca34179f3db924eb66672442a173147dc'>diff</a>)</td></tr></table>
<div class='commit-subject'>regulator: pwm: Add missing quotes to DT example</div><div class='commit-msg'>Reported-by: Peter Rosin &lt;peda@axentia.se&gt;
Signed-off-by: Mark Brown &lt;broonie@kernel.org&gt;
Acked-by: Rob Herring &lt;robh@kernel.org&gt;
</div><div class='diffstat-header'><a href='/cgit.cgi/linux/net-next.git/diff/?h=nds-private-remove&amp;id=53a20465e6b674eb6ce594b0e9e8940495e95f33'>Diffstat</a> (limited to 'net/dccp/Makefile')</div><table summary='diffstat' class='diffstat'>