/*
 * xfrm4_mode_beet.c - BEET mode encapsulation for IPv4.
 *
 * Copyright (c) 2006 Diego Beltrami <diego.beltrami@gmail.com>
 *                    Miika Komu     <miika@iki.fi>
 *                    Herbert Xu     <herbert@gondor.apana.org.au>
 *                    Abhinav Pathak <abhinav.pathak@hiit.fi>
 *                    Jeff Ahrenholz <ahrenholz@gmail.com>
 */

#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/ip.h>
#include <net/xfrm.h>

static void xfrm4_beet_make_header(struct sk_buff *skb)
{
	struct iphdr *iph = ip_hdr(skb);

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

	iph->protocol = XFRM_MODE_SKB_CB(skb)->protocol;
	iph->tos = XFRM_MODE_SKB_CB(skb)->tos;

	iph->id = XFRM_MODE_SKB_CB(skb)->id;
	iph->frag_off = XFRM_MODE_SKB_CB(skb)->frag_off;
	iph->ttl = XFRM_MODE_SKB_CB(skb)->ttl;
}

/* Add encapsulation header.
 *
 * The top IP header will be constructed per draft-nikander-esp-beet-mode-06.txt.
 */
static int xfrm4_beet_output(struct xfrm_state *x, struct sk_buff *skb)
{
	struct ip_beet_phdr *ph;
	struct iphdr *top_iph;
	int hdrlen, optlen;

	hdrlen = 0;
	optlen = XFRM_MODE_SKB_CB(skb)->optlen;
	if (unlikely(optlen))
		hdrlen += IPV4_BEET_PHMAXLEN - (optlen & 4);

	skb_set_network_header(skb, -x->props.header_len -
				    hdrlen + (XFRM_MODE_SKB_CB(skb)->ihl - sizeof(*top_iph)));
	if (x->sel.family != AF_INET6)
		skb->network_header += IPV4_BEET_PHMAXLEN;
	skb->mac_header = skb->network_header +
			  offsetof(struct iphdr, protocol);
	skb->transport_header = skb->network_header + sizeof(*top_iph);

	xfrm4_beet_make_header(skb);

	ph = (struct ip_beet_phdr *)
		__skb_pull(skb, XFRM_MODE_SKB_CB(skb)->ihl - hdrlen);

	top_iph = ip_hdr(skb);

	if (unlikely(optlen)) {
		BUG_ON(optlen < 0);

		ph->padlen = 4 - (optlen & 4);
		ph->hdrlen = optlen / 8;
		ph->nexthdr = top_iph->protocol;
		if (ph->padlen)
			memset(ph + 1, IPOPT_NOP, ph->padlen);

		top_iph->protocol = IPPROTO_BEETPH;
		top_iph->ihl = sizeof(struct iphdr) / 4;
	}

	top_iph->saddr = x->props.saddr.a4;
	top_iph->daddr = x->id.daddr.a4;

	return 0;
}

static int xfrm4_beet_input(struct xfrm_state *x, struct sk_buff *skb)
{
	struct iphdr *iph;
	int optlen = 0;
	int err = -EINVAL;

	if (unlikely(XFRM_MODE_SKB_CB(skb)->protocol == IPPROTO_BEETPH)) {
		struct ip_beet_phdr *ph;
		int phlen;

		if (!pskb_may_pull(skb, sizeof(*ph)))
			goto out;

		ph = (struct ip_beet_phdr *)skb->data;

		phlen = sizeof(*ph) + ph->padlen;
		optlen = ph->hdrlen * 8 + (IPV4_BEET_PHMAXLEN - phlen);
		if (optlen < 0 || optlen & 3 || optlen > 250)
			goto out;

		XFRM_MODE_SKB_CB(skb)->protocol = ph->nexthdr;

		if (!pskb_may_pull(skb, phlen))
			goto out;
		__skb_pull(skb, phlen);
	}

	skb_push(skb, sizeof(*iph));
	skb_reset_network_header(skb);
	skb_mac_header_rebuild(skb);

	xfrm4_beet_make_header(skb);

	iph = ip_hdr(skb);

	iph->ihl += optlen / 4;
	iph->tot_len = htons(skb->len);
	iph->daddr = x->sel.daddr.a4;
	iph->saddr = x->sel.saddr.a4;
	iph->check = 0;
	iph->check = ip_fast_csum(skb_network_header(skb), iph->ihl);
	err = 0;
out:
	return err;
}

static struct xfrm_mode xfrm4_beet_mode = {
	.input2 = xfrm4_beet_input,
	.input = xfrm_prepare_input,
	.output2 = xfrm4_beet_output,
	.output = xfrm4_prepare_output,
	.owner = THIS_MODULE,
	.encap = XFRM_MODE_BEET,
	.flags = XFRM_MODE_FLAG_TUNNEL,
};

static int __init xfrm4_beet_init(void)
{
	return xfrm_register_mode(&xfrm4_beet_mode, AF_INET);
}

static void __exit xfrm4_beet_exit(void)
{
	int err;

	err = xfrm_unregister_mode(&xfrm4_beet_mode, AF_INET);
	BUG_ON(err);
}

module_init(xfrm4_beet_init);
module_exit(xfrm4_beet_exit);
MODULE_LICENSE("GPL");
MODULE_ALIAS_XFRM_MODE(AF_INET, XFRM_MODE_BEET);
tion><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>Jiri Kosina &lt;jkosina@suse.cz&gt;</td><td class='right'>2017-01-27 22:25:52 +0000</td></tr>
<tr><th>committer</th><td>Ingo Molnar &lt;mingo@kernel.org&gt;</td><td class='right'>2017-01-28 09:18:56 +0100</td></tr>
<tr><th>commit</th><td colspan='2' class='oid'><a href='/cgit.cgi/linux/net-next.git/commit/net/mac80211/rate.h?id=bf29bddf0417a4783da3b24e8c9e017ac649326f'>bf29bddf0417a4783da3b24e8c9e017ac649326f</a> (<a href='/cgit.cgi/linux/net-next.git/patch/net/mac80211/rate.h?id=bf29bddf0417a4783da3b24e8c9e017ac649326f'>patch</a>)</td></tr>
<tr><th>tree</th><td colspan='2' class='oid'><a href='/cgit.cgi/linux/net-next.git/tree/?id=bf29bddf0417a4783da3b24e8c9e017ac649326f'>54a05a4883b73f80e4e1d8c4b15750aa01c39932</a> /<a href='/cgit.cgi/linux/net-next.git/tree/net/mac80211/rate.h?id=bf29bddf0417a4783da3b24e8c9e017ac649326f'>net/mac80211/rate.h</a></td></tr>
<tr><th>parent</th><td colspan='2' class='oid'><a href='/cgit.cgi/linux/net-next.git/commit/net/mac80211/rate.h?id=883af14e67e8b8702b5560aa64c888c0cd0bd66c'>883af14e67e8b8702b5560aa64c888c0cd0bd66c</a> (<a href='/cgit.cgi/linux/net-next.git/diff/net/mac80211/rate.h?id=bf29bddf0417a4783da3b24e8c9e017ac649326f&amp;id2=883af14e67e8b8702b5560aa64c888c0cd0bd66c'>diff</a>)</td></tr></table>
<div class='commit-subject'>x86/efi: Always map the first physical page into the EFI pagetables</div><div class='commit-msg'>Commit:

  129766708 ("x86/efi: Only map RAM into EFI page tables if in mixed-mode")

stopped creating 1:1 mappings for all RAM, when running in native 64-bit mode.

It turns out though that there are 64-bit EFI implementations in the wild
(this particular problem has been reported on a Lenovo Yoga 710-11IKB),
which still make use of the first physical page for their own private use,
even though they explicitly mark it EFI_CONVENTIONAL_MEMORY in the memory
map.

In case there is no mapping for this particular frame in the EFI pagetables,
as soon as firmware tries to make use of it, a triple fault occurs and the
system reboots (in case of the Yoga 710-11IKB this is very early during bootup).

Fix that by always mapping the first page of physical memory into the EFI
pagetables. We're free to hand this page to the BIOS, as trim_bios_range()
will reserve the first page and isolate it away from memory allocators anyway.

Note that just reverting 129766708 alone is not enough on v4.9-rc1+ to fix the
regression on affected hardware, as this commit:

   ab72a27da ("x86/efi: Consolidate region mapping logic")

later made the first physical frame not to be mapped anyway.

Reported-by: Hanka Pavlikova &lt;hanka@ucw.cz&gt;
Signed-off-by: Jiri Kosina &lt;jkosina@suse.cz&gt;
Signed-off-by: Matt Fleming &lt;matt@codeblueprint.co.uk&gt;
Cc: Ard Biesheuvel &lt;ard.biesheuvel@linaro.org&gt;
Cc: Borislav Petkov &lt;bp@alien8.de&gt;
Cc: Borislav Petkov &lt;bp@suse.de&gt;
Cc: Laura Abbott &lt;labbott@redhat.com&gt;
Cc: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
Cc: Peter Zijlstra &lt;peterz@infradead.org&gt;
Cc: Thomas Gleixner &lt;tglx@linutronix.de&gt;
Cc: Vojtech Pavlik &lt;vojtech@ucw.cz&gt;
Cc: Waiman Long &lt;waiman.long@hpe.com&gt;
Cc: linux-efi@vger.kernel.org
Cc: stable@kernel.org # v4.8+
Fixes: 129766708 ("x86/efi: Only map RAM into EFI page tables if in mixed-mode")
Link: http://lkml.kernel.org/r/20170127222552.22336-1-matt@codeblueprint.co.uk
[ Tidied up the changelog and the comment. ]
Signed-off-by: Ingo Molnar &lt;mingo@kernel.org&gt;
</div><div class='diffstat-header'><a href='/cgit.cgi/linux/net-next.git/diff/?id=bf29bddf0417a4783da3b24e8c9e017ac649326f'>Diffstat</a> (limited to 'net/mac80211/rate.h')</div><table summary='diffstat' class='diffstat'>