linux/net/mpls/mpls_gso.c
Tom Herbert 5c7cdf339a gso: Remove arbitrary checks for unsupported GSO
In several gso_segment functions there are checks of gso_type against
a seemingly arbitrary list of SKB_GSO_* flags. This seems like an
attempt to identify unsupported GSO types, but since the stack is
the one that set these GSO types in the first place this seems
unnecessary to do. If a combination isn't valid in the first
place that stack should not allow setting it.

This is a code simplication especially for add new GSO types.

Signed-off-by: Tom Herbert <tom@herbertland.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-05-20 18:03:15 -04:00

93 lines
2.3 KiB
C

/*
* 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;
/* 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 & features;
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_pull(skb, skb->data - skb_mac_header(skb));
return segs;
}
static struct packet_offload mpls_mc_offload __read_mostly = {
.type = cpu_to_be16(ETH_P_MPLS_MC),
.priority = 15,
.callbacks = {
.gso_segment = mpls_gso_segment,
},
};
static struct packet_offload mpls_uc_offload __read_mostly = {
.type = cpu_to_be16(ETH_P_MPLS_UC),
.priority = 15,
.callbacks = {
.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");