[mirror_ubuntu-bionic-kernel.git] / net / ipv4 / xfrm4_mode_transport.c

/*
 * xfrm4_mode_transport.c - Transport mode encapsulation for IPv4.
 *
 * 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/ip.h>
#include <net/xfrm.h>
#include <net/protocol.h>

/* Add encapsulation header.
 *
 * The IP header will be moved forward to make space for the encapsulation
 * header.
 */
static int xfrm4_transport_output(struct xfrm_state *x, struct sk_buff *skb)
{
	struct iphdr *iph = ip_hdr(skb);
	int ihl = iph->ihl * 4;

	skb_set_inner_transport_header(skb, skb_transport_offset(skb));

	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 + ihl;
	__skb_pull(skb, ihl);
	memmove(skb_network_header(skb), iph, ihl);
	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 xfrm4_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;
	}
	ip_hdr(skb)->tot_len = htons(skb->len + ihl);
	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(inet_offloads[xo->proto]);
	if (likely(ops && ops->callbacks.gso_segment))
		segs = ops->callbacks.gso_segment(skb, features);

	return segs;
}

static void xfrm4_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 iphdr) + 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 xfrm4_transport_mode = {
	.input = xfrm4_transport_input,
	.output = xfrm4_transport_output,
	.gso_segment = xfrm4_transport_gso_segment,
	.xmit = xfrm4_transport_xmit,
	.owner = THIS_MODULE,
	.encap = XFRM_MODE_TRANSPORT,
};

static int __init xfrm4_transport_init(void)
{
	return xfrm_register_mode(&xfrm4_transport_mode, AF_INET);
}

static void __exit xfrm4_transport_exit(void)
{
	int err;

	err = xfrm_unregister_mode(&xfrm4_transport_mode, AF_INET);
	BUG_ON(err);
}

module_init(xfrm4_transport_init);
module_exit(xfrm4_transport_exit);
MODULE_LICENSE("GPL");
MODULE_ALIAS_XFRM_MODE(AF_INET, XFRM_MODE_TRANSPORT);
Commit	Line	Data
b59f45d0 HX	1	/*
	2	* xfrm4_mode_transport.c - Transport mode encapsulation for IPv4.
	3	*
	4	* Copyright (c) 2004-2006 Herbert Xu <herbert@gondor.apana.org.au>
	5	*/
	6
	7	#include <linux/init.h>
	8	#include <linux/kernel.h>
	9	#include <linux/module.h>
	10	#include <linux/skbuff.h>
	11	#include <linux/stringify.h>
	12	#include <net/dst.h>
	13	#include <net/ip.h>
	14	#include <net/xfrm.h>
c35fe410	15	#include <net/protocol.h>
b59f45d0 HX	16
	17	/* Add encapsulation header.
	18	*
	19	* The IP header will be moved forward to make space for the encapsulation
	20	* header.
b59f45d0	21	*/
eb878e84	22	static int xfrm4_transport_output(struct xfrm_state x, struct sk_buff skb)
b59f45d0	23	{
eddc9ec5 ACM	24	struct iphdr *iph = ip_hdr(skb);
eddc9ec5 ACM	25	int ihl = iph->ihl * 4;
b59f45d0	26
f1bd7d65 IT	27	skb_set_inner_transport_header(skb, skb_transport_offset(skb));
f1bd7d65 IT	28
7b277b1a	29	skb_set_network_header(skb, -x->props.header_len);
37fedd3a HX	30	skb->mac_header = skb->network_header +
	31	offsetof(struct iphdr, protocol);
	32	skb->transport_header = skb->network_header + ihl;
7b277b1a	33	__skb_pull(skb, ihl);
d56f90a7	34	memmove(skb_network_header(skb), iph, ihl);
b59f45d0 HX	35	return 0;
	36	}
	37
31a4ab93 HX	38	/* Remove encapsulation header.
	39	*
	40	* The IP header will be moved over the top of the encapsulation header.
	41	*
	42	* On entry, skb->h shall point to where the IP header should be and skb->nh
	43	* shall be set to where the IP header currently is. skb->data shall point
	44	* to the start of the payload.
	45	*/
b59f45d0 HX	46	static int xfrm4_transport_input(struct xfrm_state x, struct sk_buff skb)
b59f45d0 HX	47	{
9c70220b	48	int ihl = skb->data - skb_transport_header(skb);
31a4ab93	49
b0e380b1	50	if (skb->transport_header != skb->network_header) {
9c70220b ACM	51	memmove(skb_transport_header(skb),
9c70220b ACM	52	skb_network_header(skb), ihl);
b0e380b1	53	skb->network_header = skb->transport_header;
7f5c0cb0	54	}
eddc9ec5	55	ip_hdr(skb)->tot_len = htons(skb->len + ihl);
3b1bf943	56	skb_reset_transport_header(skb);
b59f45d0 HX	57	return 0;
	58	}
	59
c35fe410 SK	60	static struct sk_buff xfrm4_transport_gso_segment(struct xfrm_state x,
	61	struct sk_buff *skb,
	62	netdev_features_t features)
	63	{
	64	const struct net_offload *ops;
	65	struct sk_buff *segs = ERR_PTR(-EINVAL);
	66	struct xfrm_offload *xo = xfrm_offload(skb);
	67
	68	skb->transport_header += x->props.header_len;
	69	ops = rcu_dereference(inet_offloads[xo->proto]);
	70	if (likely(ops && ops->callbacks.gso_segment))
	71	segs = ops->callbacks.gso_segment(skb, features);
	72
	73	return segs;
	74	}
	75
	76	static void xfrm4_transport_xmit(struct xfrm_state x, struct sk_buff skb)
	77	{
	78	struct xfrm_offload *xo = xfrm_offload(skb);
	79
	80	skb_reset_mac_len(skb);
	81	pskb_pull(skb, skb->mac_len + sizeof(struct iphdr) + x->props.header_len);
	82
	83	if (xo->flags & XFRM_GSO_SEGMENT) {
	84	skb_reset_transport_header(skb);
	85	skb->transport_header -= x->props.header_len;
	86	}
	87	}
	88
b59f45d0 HX	89	static struct xfrm_mode xfrm4_transport_mode = {
	90	.input = xfrm4_transport_input,
	91	.output = xfrm4_transport_output,
c35fe410 SK	92	.gso_segment = xfrm4_transport_gso_segment,
c35fe410 SK	93	.xmit = xfrm4_transport_xmit,
b59f45d0 HX	94	.owner = THIS_MODULE,
	95	.encap = XFRM_MODE_TRANSPORT,
	96	};
	97
	98	static int __init xfrm4_transport_init(void)
	99	{
	100	return xfrm_register_mode(&xfrm4_transport_mode, AF_INET);
	101	}
	102
	103	static void __exit xfrm4_transport_exit(void)
	104	{
	105	int err;
	106
	107	err = xfrm_unregister_mode(&xfrm4_transport_mode, AF_INET);
	108	BUG_ON(err);
	109	}
	110
	111	module_init(xfrm4_transport_init);
	112	module_exit(xfrm4_transport_exit);
	113	MODULE_LICENSE("GPL");
	114	MODULE_ALIAS_XFRM_MODE(AF_INET, XFRM_MODE_TRANSPORT);