blob: 851cd880b0c048c4dcd45e1b6652888338490cf9 [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 |
Eric Dumazetcb32f512013-10-19 11:42:57 -070036 SKB_GSO_IPIP |
Simon Horman0d89d202013-05-23 21:02:52 +000037 SKB_GSO_MPLS)))
38 goto out;
39
40 /* Setup inner SKB. */
41 mpls_protocol = skb->protocol;
42 skb->protocol = skb->inner_protocol;
43
44 /* Push back the mac header that skb_mac_gso_segment() has pulled.
45 * It will be re-pulled by the call to skb_mac_gso_segment() below
46 */
47 __skb_push(skb, skb->mac_len);
48
49 /* Segment inner packet. */
50 mpls_features = skb->dev->mpls_features & netif_skb_features(skb);
51 segs = skb_mac_gso_segment(skb, mpls_features);
52
53
54 /* Restore outer protocol. */
55 skb->protocol = mpls_protocol;
56
57 /* Re-pull the mac header that the call to skb_mac_gso_segment()
58 * above pulled. It will be re-pushed after returning
59 * skb_mac_gso_segment(), an indirect caller of this function.
60 */
61 __skb_push(skb, skb->data - skb_mac_header(skb));
62
63out:
64 return segs;
65}
66
67static int mpls_gso_send_check(struct sk_buff *skb)
68{
69 return 0;
70}
71
72static struct packet_offload mpls_mc_offload = {
73 .type = cpu_to_be16(ETH_P_MPLS_MC),
74 .callbacks = {
75 .gso_send_check = mpls_gso_send_check,
76 .gso_segment = mpls_gso_segment,
77 },
78};
79
80static struct packet_offload mpls_uc_offload = {
81 .type = cpu_to_be16(ETH_P_MPLS_UC),
82 .callbacks = {
83 .gso_send_check = mpls_gso_send_check,
84 .gso_segment = mpls_gso_segment,
85 },
86};
87
88static int __init mpls_gso_init(void)
89{
90 pr_info("MPLS GSO support\n");
91
92 dev_add_offload(&mpls_uc_offload);
93 dev_add_offload(&mpls_mc_offload);
94
95 return 0;
96}
97
98static void __exit mpls_gso_exit(void)
99{
100 dev_remove_offload(&mpls_uc_offload);
101 dev_remove_offload(&mpls_mc_offload);
102}
103
104module_init(mpls_gso_init);
105module_exit(mpls_gso_exit);
106
107MODULE_DESCRIPTION("MPLS GSO support");
108MODULE_AUTHOR("Simon Horman (horms@verge.net.au)");
109MODULE_LICENSE("GPL");