[mirror_ubuntu-bionic-kernel.git] / net / ipv6 / xfrm6_mode_transport.c

/*
 * xfrm6_mode_transport.c - Transport mode encapsulation for IPv6.
 *
 * Copyright (C) 2002 USAGI/WIDE Project
 * Copyright (c) 2004-2006 Herbert Xu <herbert@gondor.apana.org.au>
 */

#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/ipv6.h>
#include <net/xfrm.h>
#include <net/protocol.h>

/* Add encapsulation header.
 *
 * The IP header and mutable extension headers will be moved forward to make
 * space for the encapsulation header.
 */
static int xfrm6_transport_output(struct xfrm_state *x, struct sk_buff *skb)
{
	struct ipv6hdr *iph;
	u8 *prevhdr;
	int hdr_len;

	iph = ipv6_hdr(skb);
	skb_set_inner_transport_header(skb, skb_transport_offset(skb));

	hdr_len = x->type->hdr_offset(x, skb, &prevhdr);
	if (hdr_len < 0)
		return hdr_len;
	skb_set_mac_header(skb, (prevhdr - x->props.header_len) - skb->data);
	skb_set_network_header(skb, -x->props.header_len);
	skb->transport_header = skb->network_header + hdr_len;
	__skb_pull(skb, hdr_len);
	memmove(ipv6_hdr(skb), iph, hdr_len);
	return 0;
}

/* Remove encapsulation header.
 *
 * The IP header will be moved over the top of the encapsulation header.
 *
 * On entry, skb->h shall point to where the IP header should be and skb->nh
 * shall be set to where the IP header currently is.  skb->data shall point
 * to the start of the payload.
 */
static int xfrm6_transport_input(struct xfrm_state *x, struct sk_buff *skb)
{
	int ihl = skb->data - skb_transport_header(skb);

	if (skb->transport_header != skb->network_header) {
		memmove(skb_transport_header(skb),
			skb_network_header(skb), ihl);
		skb->network_header = skb->transport_header;
	}
	ipv6_hdr(skb)->payload_len = htons(skb->len + ihl -
					   sizeof(struct ipv6hdr));
	skb_reset_transport_header(skb);
	return 0;
}

static struct sk_buff *xfrm4_transport_gso_segment(struct xfrm_state *x,
						   struct sk_buff *skb,
						   netdev_features_t features)
{
	const struct net_offload *ops;
	struct sk_buff *segs = ERR_PTR(-EINVAL);
	struct xfrm_offload *xo = xfrm_offload(skb);

	skb->transport_header += x->props.header_len;
	ops = rcu_dereference(inet6_offloads[xo->proto]);
	if (likely(ops && ops->callbacks.gso_segment))
		segs = ops->callbacks.gso_segment(skb, features);

	return segs;
}

static void xfrm6_transport_xmit(struct xfrm_state *x, struct sk_buff *skb)
{
	struct xfrm_offload *xo = xfrm_offload(skb);

	skb_reset_mac_len(skb);
	pskb_pull(skb, skb->mac_len + sizeof(struct ipv6hdr) + x->props.header_len);

	if (xo->flags & XFRM_GSO_SEGMENT) {
		 skb_reset_transport_header(skb);
		 skb->transport_header -= x->props.header_len;
	}
}


static struct xfrm_mode xfrm6_transport_mode = {
	.input = xfrm6_transport_input,
	.output = xfrm6_transport_output,
	.gso_segment = xfrm4_transport_gso_segment,
	.xmit = xfrm6_transport_xmit,
	.owner = THIS_MODULE,
	.encap = XFRM_MODE_TRANSPORT,
};

static int __init xfrm6_transport_init(void)
{
	return xfrm_register_mode(&xfrm6_transport_mode, AF_INET6);
}

static void __exit xfrm6_transport_exit(void)
{
	int err;

	err = xfrm_unregister_mode(&xfrm6_transport_mode, AF_INET6);
	BUG_ON(err);
}

module_init(xfrm6_transport_init);
module_exit(xfrm6_transport_exit);
MODULE_LICENSE("GPL");
MODULE_ALIAS_XFRM_MODE(AF_INET6, XFRM_MODE_TRANSPORT);
Commit	Line	Data
b59f45d0 HX	1	/*
	2	* xfrm6_mode_transport.c - Transport mode encapsulation for IPv6.
	3	*
	4	* Copyright (C) 2002 USAGI/WIDE Project
	5	* Copyright (c) 2004-2006 Herbert Xu <herbert@gondor.apana.org.au>
	6	*/
	7
	8	#include <linux/init.h>
	9	#include <linux/kernel.h>
	10	#include <linux/module.h>
	11	#include <linux/skbuff.h>
	12	#include <linux/stringify.h>
	13	#include <net/dst.h>
	14	#include <net/ipv6.h>
	15	#include <net/xfrm.h>
c35fe410	16	#include <net/protocol.h>
b59f45d0 HX	17
	18	/* Add encapsulation header.
	19	*
	20	* The IP header and mutable extension headers will be moved forward to make
	21	* space for the encapsulation header.
b59f45d0	22	*/
eb878e84	23	static int xfrm6_transport_output(struct xfrm_state x, struct sk_buff skb)
b59f45d0	24	{
b59f45d0 HX	25	struct ipv6hdr *iph;
	26	u8 *prevhdr;
	27	int hdr_len;
	28
0660e03f	29	iph = ipv6_hdr(skb);
f1bd7d65	30	skb_set_inner_transport_header(skb, skb_transport_offset(skb));
b59f45d0	31
aee5adb4	32	hdr_len = x->type->hdr_offset(x, skb, &prevhdr);
6e80ac5c BH	33	if (hdr_len < 0)
6e80ac5c BH	34	return hdr_len;
007f0211	35	skb_set_mac_header(skb, (prevhdr - x->props.header_len) - skb->data);
7b277b1a	36	skb_set_network_header(skb, -x->props.header_len);
37fedd3a	37	skb->transport_header = skb->network_header + hdr_len;
7b277b1a HX	38	__skb_pull(skb, hdr_len);
7b277b1a HX	39	memmove(ipv6_hdr(skb), iph, hdr_len);
b59f45d0 HX	40	return 0;
	41	}
	42
31a4ab93 HX	43	/* Remove encapsulation header.
	44	*
	45	* The IP header will be moved over the top of the encapsulation header.
	46	*
	47	* On entry, skb->h shall point to where the IP header should be and skb->nh
	48	* shall be set to where the IP header currently is. skb->data shall point
	49	* to the start of the payload.
	50	*/
b59f45d0 HX	51	static int xfrm6_transport_input(struct xfrm_state x, struct sk_buff skb)
b59f45d0 HX	52	{
9c70220b	53	int ihl = skb->data - skb_transport_header(skb);
31a4ab93	54
b0e380b1	55	if (skb->transport_header != skb->network_header) {
9c70220b ACM	56	memmove(skb_transport_header(skb),
9c70220b ACM	57	skb_network_header(skb), ihl);
b0e380b1	58	skb->network_header = skb->transport_header;
d56f90a7	59	}
0660e03f	60	ipv6_hdr(skb)->payload_len = htons(skb->len + ihl -
31a4ab93	61	sizeof(struct ipv6hdr));
3b1bf943	62	skb_reset_transport_header(skb);
b59f45d0 HX	63	return 0;
	64	}
	65
c35fe410 SK	66	static struct sk_buff xfrm4_transport_gso_segment(struct xfrm_state x,
	67	struct sk_buff *skb,
	68	netdev_features_t features)
	69	{
	70	const struct net_offload *ops;
	71	struct sk_buff *segs = ERR_PTR(-EINVAL);
	72	struct xfrm_offload *xo = xfrm_offload(skb);
	73
	74	skb->transport_header += x->props.header_len;
	75	ops = rcu_dereference(inet6_offloads[xo->proto]);
	76	if (likely(ops && ops->callbacks.gso_segment))
	77	segs = ops->callbacks.gso_segment(skb, features);
	78
	79	return segs;
	80	}
	81
	82	static void xfrm6_transport_xmit(struct xfrm_state x, struct sk_buff skb)
	83	{
	84	struct xfrm_offload *xo = xfrm_offload(skb);
	85
	86	skb_reset_mac_len(skb);
	87	pskb_pull(skb, skb->mac_len + sizeof(struct ipv6hdr) + x->props.header_len);
	88
	89	if (xo->flags & XFRM_GSO_SEGMENT) {
	90	skb_reset_transport_header(skb);
	91	skb->transport_header -= x->props.header_len;
	92	}
	93	}
	94
	95
b59f45d0 HX	96	static struct xfrm_mode xfrm6_transport_mode = {
	97	.input = xfrm6_transport_input,
	98	.output = xfrm6_transport_output,
c35fe410 SK	99	.gso_segment = xfrm4_transport_gso_segment,
c35fe410 SK	100	.xmit = xfrm6_transport_xmit,
b59f45d0 HX	101	.owner = THIS_MODULE,
	102	.encap = XFRM_MODE_TRANSPORT,
	103	};
	104
	105	static int __init xfrm6_transport_init(void)
	106	{
	107	return xfrm_register_mode(&xfrm6_transport_mode, AF_INET6);
	108	}
	109
	110	static void __exit xfrm6_transport_exit(void)
	111	{
	112	int err;
	113
	114	err = xfrm_unregister_mode(&xfrm6_transport_mode, AF_INET6);
	115	BUG_ON(err);
	116	}
	117
	118	module_init(xfrm6_transport_init);
	119	module_exit(xfrm6_transport_exit);
	120	MODULE_LICENSE("GPL");
	121	MODULE_ALIAS_XFRM_MODE(AF_INET6, XFRM_MODE_TRANSPORT);