mpls_gso.c
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/*
* MPLS GSO Support
*
* Authors: Simon Horman (horms@verge.net.au)
*
* 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.
*
* Based on: GSO portions of net/ipv4/gre.c
*/
#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
#include <linux/err.h>
#include <linux/module.h>
#include <linux/netdev_features.h>
#include <linux/netdevice.h>
#include <linux/skbuff.h>
static struct sk_buff *mpls_gso_segment(struct sk_buff *skb,
netdev_features_t features)
{
struct sk_buff *segs = ERR_PTR(-EINVAL);
netdev_features_t mpls_features;
__be16 mpls_protocol;
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 |
SKB_GSO_IPIP |
SKB_GSO_MPLS)))
goto out;
/* Setup inner SKB. */
mpls_protocol = skb->protocol;
skb->protocol = skb->inner_protocol;
/* Push back the mac header that skb_mac_gso_segment() has pulled.
* It will be re-pulled by the call to skb_mac_gso_segment() below
*/
__skb_push(skb, skb->mac_len);
/* Segment inner packet. */
mpls_features = skb->dev->mpls_features & netif_skb_features(skb);
segs = skb_mac_gso_segment(skb, mpls_features);
/* Restore outer protocol. */
skb->protocol = mpls_protocol;
/* Re-pull the mac header that the call to skb_mac_gso_segment()
* above pulled. It will be re-pushed after returning
* skb_mac_gso_segment(), an indirect caller of this function.
*/
__skb_push(skb, skb->data - skb_mac_header(skb));
out:
return segs;
}
static int mpls_gso_send_check(struct sk_buff *skb)
{
return 0;
}
static struct packet_offload mpls_mc_offload = {
.type = cpu_to_be16(ETH_P_MPLS_MC),
.callbacks = {
.gso_send_check = mpls_gso_send_check,
.gso_segment = mpls_gso_segment,
},
};
static struct packet_offload mpls_uc_offload = {
.type = cpu_to_be16(ETH_P_MPLS_UC),
.callbacks = {
.gso_send_check = mpls_gso_send_check,
.gso_segment = mpls_gso_segment,
},
};
static int __init mpls_gso_init(void)
{
pr_info("MPLS GSO support\n");
dev_add_offload(&mpls_uc_offload);
dev_add_offload(&mpls_mc_offload);
return 0;
}
static void __exit mpls_gso_exit(void)
{
dev_remove_offload(&mpls_uc_offload);
dev_remove_offload(&mpls_mc_offload);
}
module_init(mpls_gso_init);
module_exit(mpls_gso_exit);
MODULE_DESCRIPTION("MPLS GSO support");
MODULE_AUTHOR("Simon Horman (horms@verge.net.au)");
MODULE_LICENSE("GPL");