blob: 1bec1219ab815ff37c3970a4e2473e0a4bb62809 [file] [log] [blame]
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 |
36 SKB_GSO_MPLS)))
37 goto out;
38
39 /* Setup inner SKB. */
40 mpls_protocol = skb->protocol;
41 skb->protocol = skb->inner_protocol;
42
43 /* Push back the mac header that skb_mac_gso_segment() has pulled.
44 * It will be re-pulled by the call to skb_mac_gso_segment() below
45 */
46 __skb_push(skb, skb->mac_len);
47
48 /* Segment inner packet. */
49 mpls_features = skb->dev->mpls_features & netif_skb_features(skb);
50 segs = skb_mac_gso_segment(skb, mpls_features);
51
52
53 /* Restore outer protocol. */
54 skb->protocol = mpls_protocol;
55
56 /* Re-pull the mac header that the call to skb_mac_gso_segment()
57 * above pulled. It will be re-pushed after returning
58 * skb_mac_gso_segment(), an indirect caller of this function.
59 */
60 __skb_push(skb, skb->data - skb_mac_header(skb));
61
62out:
63 return segs;
64}
65
66static int mpls_gso_send_check(struct sk_buff *skb)
67{
68 return 0;
69}
70
71static struct packet_offload mpls_mc_offload = {
72 .type = cpu_to_be16(ETH_P_MPLS_MC),
73 .callbacks = {
74 .gso_send_check = mpls_gso_send_check,
75 .gso_segment = mpls_gso_segment,
76 },
77};
78
79static struct packet_offload mpls_uc_offload = {
80 .type = cpu_to_be16(ETH_P_MPLS_UC),
81 .callbacks = {
82 .gso_send_check = mpls_gso_send_check,
83 .gso_segment = mpls_gso_segment,
84 },
85};
86
87static int __init mpls_gso_init(void)
88{
89 pr_info("MPLS GSO support\n");
90
91 dev_add_offload(&mpls_uc_offload);
92 dev_add_offload(&mpls_mc_offload);
93
94 return 0;
95}
96
97static void __exit mpls_gso_exit(void)
98{
99 dev_remove_offload(&mpls_uc_offload);
100 dev_remove_offload(&mpls_mc_offload);
101}
102
103module_init(mpls_gso_init);
104module_exit(mpls_gso_exit);
105
106MODULE_DESCRIPTION("MPLS GSO support");
107MODULE_AUTHOR("Simon Horman (horms@verge.net.au)");
108MODULE_LICENSE("GPL");