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Simon Horman0d89d202013-05-23 21:02:52 +00001/*
2 * MPLS GSO Support
3 *
4 * Authors: Simon Horman (horms@verge.net.au)
5 *
6 * This program is free software; you can redistribute it and/or
7 * modify it under the terms of the GNU General Public License
8 * as published by the Free Software Foundation; either version
9 * 2 of the License, or (at your option) any later version.
10 *
11 * Based on: GSO portions of net/ipv4/gre.c
12 */
13
14#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
15
16#include <linux/err.h>
17#include <linux/module.h>
18#include <linux/netdev_features.h>
19#include <linux/netdevice.h>
20#include <linux/skbuff.h>
21
22static struct sk_buff *mpls_gso_segment(struct sk_buff *skb,
23 netdev_features_t features)
24{
25 struct sk_buff *segs = ERR_PTR(-EINVAL);
26 netdev_features_t mpls_features;
27 __be16 mpls_protocol;
28
29 if (unlikely(skb_shinfo(skb)->gso_type &
30 ~(SKB_GSO_TCPV4 |
31 SKB_GSO_TCPV6 |
32 SKB_GSO_UDP |
33 SKB_GSO_DODGY |
34 SKB_GSO_TCP_ECN |
35 SKB_GSO_GRE |
Tom Herbert4749c092014-06-04 17:20:23 -070036 SKB_GSO_GRE_CSUM |
Eric Dumazetcb32f512013-10-19 11:42:57 -070037 SKB_GSO_IPIP |
Simon Horman0d89d202013-05-23 21:02:52 +000038 SKB_GSO_MPLS)))
39 goto out;
40
41 /* Setup inner SKB. */
42 mpls_protocol = skb->protocol;
43 skb->protocol = skb->inner_protocol;
44
45 /* Push back the mac header that skb_mac_gso_segment() has pulled.
46 * It will be re-pulled by the call to skb_mac_gso_segment() below
47 */
48 __skb_push(skb, skb->mac_len);
49
50 /* Segment inner packet. */
51 mpls_features = skb->dev->mpls_features & netif_skb_features(skb);
52 segs = skb_mac_gso_segment(skb, mpls_features);
53
54
55 /* Restore outer protocol. */
56 skb->protocol = mpls_protocol;
57
58 /* Re-pull the mac header that the call to skb_mac_gso_segment()
59 * above pulled. It will be re-pushed after returning
60 * skb_mac_gso_segment(), an indirect caller of this function.
61 */
62 __skb_push(skb, skb->data - skb_mac_header(skb));
63
64out:
65 return segs;
66}
67
Simon Horman0d89d202013-05-23 21:02:52 +000068static struct packet_offload mpls_mc_offload = {
69 .type = cpu_to_be16(ETH_P_MPLS_MC),
70 .callbacks = {
Simon Horman0d89d202013-05-23 21:02:52 +000071 .gso_segment = mpls_gso_segment,
72 },
73};
74
75static struct packet_offload mpls_uc_offload = {
76 .type = cpu_to_be16(ETH_P_MPLS_UC),
77 .callbacks = {
Simon Horman0d89d202013-05-23 21:02:52 +000078 .gso_segment = mpls_gso_segment,
79 },
80};
81
82static int __init mpls_gso_init(void)
83{
84 pr_info("MPLS GSO support\n");
85
86 dev_add_offload(&mpls_uc_offload);
87 dev_add_offload(&mpls_mc_offload);
88
89 return 0;
90}
91
92static void __exit mpls_gso_exit(void)
93{
94 dev_remove_offload(&mpls_uc_offload);
95 dev_remove_offload(&mpls_mc_offload);
96}
97
98module_init(mpls_gso_init);
99module_exit(mpls_gso_exit);
100
101MODULE_DESCRIPTION("MPLS GSO support");
102MODULE_AUTHOR("Simon Horman (horms@verge.net.au)");
103MODULE_LICENSE("GPL");