mpls: Fix config check for mpls.
[cascardo/linux.git] / net / mpls / mpls_gso.c
1 /*
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
22 static 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_GRE_CSUM |
37                                   SKB_GSO_IPIP)))
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 & features;
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_pull(skb, skb->data - skb_mac_header(skb));
62 out:
63         return segs;
64 }
65
66 static struct packet_offload mpls_mc_offload = {
67         .type = cpu_to_be16(ETH_P_MPLS_MC),
68         .callbacks = {
69                 .gso_segment    =       mpls_gso_segment,
70         },
71 };
72
73 static struct packet_offload mpls_uc_offload = {
74         .type = cpu_to_be16(ETH_P_MPLS_UC),
75         .callbacks = {
76                 .gso_segment    =       mpls_gso_segment,
77         },
78 };
79
80 static int __init mpls_gso_init(void)
81 {
82         pr_info("MPLS GSO support\n");
83
84         dev_add_offload(&mpls_uc_offload);
85         dev_add_offload(&mpls_mc_offload);
86
87         return 0;
88 }
89
90 static void __exit mpls_gso_exit(void)
91 {
92         dev_remove_offload(&mpls_uc_offload);
93         dev_remove_offload(&mpls_mc_offload);
94 }
95
96 module_init(mpls_gso_init);
97 module_exit(mpls_gso_exit);
98
99 MODULE_DESCRIPTION("MPLS GSO support");
100 MODULE_AUTHOR("Simon Horman (horms@verge.net.au)");
101 MODULE_LICENSE("GPL");