mirror of https://gitee.com/openkylin/linux.git
131 lines
2.8 KiB
C
131 lines
2.8 KiB
C
/*
|
|
* IPV4 GSO/GRO offload support
|
|
* Linux INET implementation
|
|
*
|
|
* 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.
|
|
*
|
|
* GRE GSO support
|
|
*/
|
|
|
|
#include <linux/skbuff.h>
|
|
#include <net/protocol.h>
|
|
#include <net/gre.h>
|
|
|
|
static int gre_gso_send_check(struct sk_buff *skb)
|
|
{
|
|
if (!skb->encapsulation)
|
|
return -EINVAL;
|
|
return 0;
|
|
}
|
|
|
|
static struct sk_buff *gre_gso_segment(struct sk_buff *skb,
|
|
netdev_features_t features)
|
|
{
|
|
struct sk_buff *segs = ERR_PTR(-EINVAL);
|
|
netdev_features_t enc_features;
|
|
int ghl = GRE_HEADER_SECTION;
|
|
struct gre_base_hdr *greh;
|
|
int mac_len = skb->mac_len;
|
|
__be16 protocol = skb->protocol;
|
|
int tnl_hlen;
|
|
bool csum;
|
|
|
|
if (unlikely(skb_shinfo(skb)->gso_type &
|
|
~(SKB_GSO_TCPV4 |
|
|
SKB_GSO_TCPV6 |
|
|
SKB_GSO_UDP |
|
|
SKB_GSO_DODGY |
|
|
SKB_GSO_TCP_ECN |
|
|
SKB_GSO_GRE)))
|
|
goto out;
|
|
|
|
if (unlikely(!pskb_may_pull(skb, sizeof(*greh))))
|
|
goto out;
|
|
|
|
greh = (struct gre_base_hdr *)skb_transport_header(skb);
|
|
|
|
if (greh->flags & GRE_KEY)
|
|
ghl += GRE_HEADER_SECTION;
|
|
if (greh->flags & GRE_SEQ)
|
|
ghl += GRE_HEADER_SECTION;
|
|
if (greh->flags & GRE_CSUM) {
|
|
ghl += GRE_HEADER_SECTION;
|
|
csum = true;
|
|
} else
|
|
csum = false;
|
|
|
|
/* setup inner skb. */
|
|
skb->protocol = greh->protocol;
|
|
skb->encapsulation = 0;
|
|
|
|
if (unlikely(!pskb_may_pull(skb, ghl)))
|
|
goto out;
|
|
|
|
__skb_pull(skb, ghl);
|
|
skb_reset_mac_header(skb);
|
|
skb_set_network_header(skb, skb_inner_network_offset(skb));
|
|
skb->mac_len = skb_inner_network_offset(skb);
|
|
|
|
/* segment inner packet. */
|
|
enc_features = skb->dev->hw_enc_features & netif_skb_features(skb);
|
|
segs = skb_mac_gso_segment(skb, enc_features);
|
|
if (!segs || IS_ERR(segs))
|
|
goto out;
|
|
|
|
skb = segs;
|
|
tnl_hlen = skb_tnl_header_len(skb);
|
|
do {
|
|
__skb_push(skb, ghl);
|
|
if (csum) {
|
|
__be32 *pcsum;
|
|
|
|
if (skb_has_shared_frag(skb)) {
|
|
int err;
|
|
|
|
err = __skb_linearize(skb);
|
|
if (err) {
|
|
kfree_skb_list(segs);
|
|
segs = ERR_PTR(err);
|
|
goto out;
|
|
}
|
|
}
|
|
|
|
greh = (struct gre_base_hdr *)(skb->data);
|
|
pcsum = (__be32 *)(greh + 1);
|
|
*pcsum = 0;
|
|
*(__sum16 *)pcsum = csum_fold(skb_checksum(skb, 0, skb->len, 0));
|
|
}
|
|
__skb_push(skb, tnl_hlen - ghl);
|
|
|
|
skb_reset_inner_headers(skb);
|
|
skb->encapsulation = 1;
|
|
|
|
skb_reset_mac_header(skb);
|
|
skb_set_network_header(skb, mac_len);
|
|
skb->mac_len = mac_len;
|
|
skb->protocol = protocol;
|
|
} while ((skb = skb->next));
|
|
out:
|
|
return segs;
|
|
}
|
|
|
|
static const struct net_offload gre_offload = {
|
|
.callbacks = {
|
|
.gso_send_check = gre_gso_send_check,
|
|
.gso_segment = gre_gso_segment,
|
|
},
|
|
};
|
|
|
|
int __init gre_offload_init(void)
|
|
{
|
|
return inet_add_offload(&gre_offload, IPPROTO_GRE);
|
|
}
|
|
|
|
void __exit gre_offload_exit(void)
|
|
{
|
|
inet_del_offload(&gre_offload, IPPROTO_GRE);
|
|
}
|