/*
 * xfrm4_output.c - Common IPsec encapsulation code for IPv4.
 * Copyright (c) 2004 Herbert Xu <herbert@gondor.apana.org.au>
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * as published by the Free Software Foundation; either version
 * 2 of the License, or (at your option) any later version.
 */

#include <linux/if_ether.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/skbuff.h>
#include <linux/netfilter_ipv4.h>
#include <net/dst.h>
#include <net/ip.h>
#include <net/xfrm.h>
#include <net/icmp.h>

static int xfrm4_tunnel_check_size(struct sk_buff *skb)
{
	int mtu, ret = 0;

	if (IPCB(skb)->flags & IPSKB_XFRM_TUNNEL_SIZE)
		goto out;

	if (!(ip_hdr(skb)->frag_off & htons(IP_DF)) || skb->ignore_df)
		goto out;

	mtu = dst_mtu(skb_dst(skb));
	if (skb->len > mtu) {
		skb->protocol = htons(ETH_P_IP);

		if (skb->sk)
			xfrm_local_error(skb, mtu);
		else
			icmp_send(skb, ICMP_DEST_UNREACH,
				  ICMP_FRAG_NEEDED, htonl(mtu));
		ret = -EMSGSIZE;
	}
out:
	return ret;
}

int xfrm4_extract_output(struct xfrm_state *x, struct sk_buff *skb)
{
	int err;

	err = xfrm4_tunnel_check_size(skb);
	if (err)
		return err;

	XFRM_MODE_SKB_CB(skb)->protocol = ip_hdr(skb)->protocol;

	return xfrm4_extract_header(skb);
}

int xfrm4_prepare_output(struct xfrm_state *x, struct sk_buff *skb)
{
	int err;

	err = xfrm_inner_extract_output(x, skb);
	if (err)
		return err;

	IPCB(skb)->flags |= IPSKB_XFRM_TUNNEL_SIZE;
	skb->protocol = htons(ETH_P_IP);

	return x->outer_mode->output2(x, skb);
}
EXPORT_SYMBOL(xfrm4_prepare_output);

int xfrm4_output_finish(struct sock *sk, struct sk_buff *skb)
{
	memset(IPCB(skb), 0, sizeof(*IPCB(skb)));

#ifdef CONFIG_NETFILTER
	IPCB(skb)->flags |= IPSKB_XFRM_TRANSFORMED;
#endif

	return xfrm_output(sk, skb);
}

static int __xfrm4_output(struct net *net, struct sock *sk, struct sk_buff *skb)
{
	struct xfrm_state *x = skb_dst(skb)->xfrm;

#ifdef CONFIG_NETFILTER
	if (!x) {
		IPCB(skb)->flags |= IPSKB_REROUTED;
		return dst_output(net, sk, skb);
	}
#endif

	return x->outer_mode->afinfo->output_finish(sk, skb);
}

int xfrm4_output(struct net *net, struct sock *sk, struct sk_buff *skb)
{
	return NF_HOOK_COND(NFPROTO_IPV4, NF_INET_POST_ROUTING,
			    net, sk, skb, NULL, skb_dst(skb)->dev,
			    __xfrm4_output,
			    !(IPCB(skb)->flags & IPSKB_REROUTED));
}

void xfrm4_local_error(struct sk_buff *skb, u32 mtu)
{
	struct iphdr *hdr;

	hdr = skb->encapsulation ? inner_ip_hdr(skb) : ip_hdr(skb);
	ip_local_error(skb->sk, EMSGSIZE, hdr->daddr,
		       inet_sk(skb->sk)->inet_dport, mtu);
}
'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>Jan Kara &lt;jack@suse.cz&gt;</td><td class='right'>2016-12-14 15:07:45 -0800</td></tr>
<tr><th>committer</th><td>Linus Torvalds &lt;torvalds@linux-foundation.org&gt;</td><td class='right'>2016-12-14 16:04:09 -0800</td></tr>
<tr><th>commit</th><td colspan='2' class='oid'><a href='/cgit.cgi/linux/net-next.git/commit/?id=cae1240257d9ba4b40eb240124c530de8ee349bc'>cae1240257d9ba4b40eb240124c530de8ee349bc</a> (<a href='/cgit.cgi/linux/net-next.git/patch/?id=cae1240257d9ba4b40eb240124c530de8ee349bc'>patch</a>)</td></tr>
<tr><th>tree</th><td colspan='2' class='oid'><a href='/cgit.cgi/linux/net-next.git/tree/?id=cae1240257d9ba4b40eb240124c530de8ee349bc'>8655c822aa48bb1dd03eb229c9e3010a7218006c</a></td></tr>
<tr><th>parent</th><td colspan='2' class='oid'><a href='/cgit.cgi/linux/net-next.git/commit/?id=a19e25536ed3a20845f642ce531e10c27fb2add5'>a19e25536ed3a20845f642ce531e10c27fb2add5</a> (<a href='/cgit.cgi/linux/net-next.git/diff/?id=cae1240257d9ba4b40eb240124c530de8ee349bc&amp;id2=a19e25536ed3a20845f642ce531e10c27fb2add5'>diff</a>)</td></tr></table>
<div class='commit-subject'>mm: export follow_pte()</div><div class='commit-msg'>DAX will need to implement its own version of page_check_address().  To
avoid duplicating page table walking code, export follow_pte() which
does what we need.

Link: http://lkml.kernel.org/r/1479460644-25076-18-git-send-email-jack@suse.cz
Signed-off-by: Jan Kara &lt;jack@suse.cz&gt;
Reviewed-by: Ross Zwisler &lt;ross.zwisler@linux.intel.com&gt;
Cc: Kirill A. Shutemov &lt;kirill.shutemov@linux.intel.com&gt;
Cc: Dan Williams &lt;dan.j.williams@intel.com&gt;
Signed-off-by: Andrew Morton &lt;akpm@linux-foundation.org&gt;
Signed-off-by: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
</div><div class='diffstat-header'><a href='/cgit.cgi/linux/net-next.git/diff/?id=cae1240257d9ba4b40eb240124c530de8ee349bc'>Diffstat</a></div><table summary='diffstat' class='diffstat'><tr><td class='mode'>-rw-r--r--</td><td class='upd'><a href='/cgit.cgi/linux/net-next.git/diff/include/linux/mm.h?id=cae1240257d9ba4b40eb240124c530de8ee349bc'>include/linux/mm.h</a></td><td class='right'>2</td><td class='graph'><table summary='file diffstat' width='4%'><tr><td class='add' style='width: 50.0%;'/><td class='rem' style='width: 0.0%;'/><td class='none' style='width: 50.0%;'/></tr></table></td></tr>
<tr><td class='mode'>-rw-r--r--</td><td class='upd'><a href='/cgit.cgi/linux/net-next.git/diff/mm/memory.c?id=cae1240257d9ba4b40eb240124c530de8ee349bc'>mm/memory.c</a></td><td class='right'>4</td><td class='graph'><table summary='file diffstat' width='4%'><tr><td class='add' style='width: 50.0%;'/><td class='rem' style='width: 50.0%;'/><td class='none' style='width: 0.0%;'/></tr></table></td></tr>
</table><div class='diffstat-summary'>2 files changed, 4 insertions, 2 deletions</div><table summary='diff' class='diff'><tr><td><div class='head'>diff --git a/include/linux/mm.h b/include/linux/mm.h