remarkable-linux/net/ipv6/xfrm6_mode_transport.c
Ilan Tayari f1bd7d659e xfrm: Add encapsulation header offsets while SKB is not encrypted
Both esp4 and esp6 used to assume that the SKB payload is encrypted
and therefore the inner_network and inner_transport offsets are
not relevant.
When doing crypto offload in the NIC, this is no longer the case
and the NIC driver needs these offsets so it can do TX TCP checksum
offloading.
This patch sets the inner_network and inner_transport members of
the SKB, as well as encapsulation, to reflect the actual positions
of these headers, and removes them only once encryption is done
on the payload.

Signed-off-by: Ilan Tayari <ilant@mellanox.com>
Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>
2017-04-14 10:07:39 +02:00

122 lines
3.3 KiB
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);
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);
struct xfrm_offload *xo = xfrm_offload(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));
if (!xo || !(xo->flags & XFRM_GRO))
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);