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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);
David Ahern48d2ab62016-08-24 20:10:44 -070026 u16 mac_offset = skb->mac_header;
Simon Horman0d89d202013-05-23 21:02:52 +000027 netdev_features_t mpls_features;
David Ahern48d2ab62016-08-24 20:10:44 -070028 u16 mac_len = skb->mac_len;
Simon Horman0d89d202013-05-23 21:02:52 +000029 __be16 mpls_protocol;
David Ahern48d2ab62016-08-24 20:10:44 -070030 unsigned int mpls_hlen;
31
32 skb_reset_network_header(skb);
33 mpls_hlen = skb_inner_network_header(skb) - skb_network_header(skb);
34 if (unlikely(!pskb_may_pull(skb, mpls_hlen)))
35 goto out;
Simon Horman0d89d202013-05-23 21:02:52 +000036
Simon Horman0d89d202013-05-23 21:02:52 +000037 /* Setup inner SKB. */
38 mpls_protocol = skb->protocol;
39 skb->protocol = skb->inner_protocol;
40
David Ahern48d2ab62016-08-24 20:10:44 -070041 __skb_pull(skb, mpls_hlen);
42
43 skb->mac_len = 0;
44 skb_reset_mac_header(skb);
Simon Horman0d89d202013-05-23 21:02:52 +000045
46 /* Segment inner packet. */
Florian Westphal1e16aa32014-10-20 13:49:16 +020047 mpls_features = skb->dev->mpls_features & features;
Simon Horman0d89d202013-05-23 21:02:52 +000048 segs = skb_mac_gso_segment(skb, mpls_features);
David Ahern48d2ab62016-08-24 20:10:44 -070049 if (IS_ERR_OR_NULL(segs)) {
50 skb_gso_error_unwind(skb, mpls_protocol, mpls_hlen, mac_offset,
51 mac_len);
52 goto out;
53 }
54 skb = segs;
Simon Horman0d89d202013-05-23 21:02:52 +000055
David Ahern48d2ab62016-08-24 20:10:44 -070056 mpls_hlen += mac_len;
57 do {
58 skb->mac_len = mac_len;
59 skb->protocol = mpls_protocol;
Simon Horman0d89d202013-05-23 21:02:52 +000060
David Ahern48d2ab62016-08-24 20:10:44 -070061 skb_reset_inner_network_header(skb);
Simon Horman0d89d202013-05-23 21:02:52 +000062
David Ahern48d2ab62016-08-24 20:10:44 -070063 __skb_push(skb, mpls_hlen);
Tom Herbert5c7cdf332016-05-18 09:06:09 -070064
David Ahern48d2ab62016-08-24 20:10:44 -070065 skb_reset_mac_header(skb);
66 skb_set_network_header(skb, mac_len);
67 } while ((skb = skb->next));
68
69out:
Simon Horman0d89d202013-05-23 21:02:52 +000070 return segs;
71}
72
Daniel Borkmann207895fd32015-01-29 12:15:03 +010073static struct packet_offload mpls_mc_offload __read_mostly = {
Simon Horman0d89d202013-05-23 21:02:52 +000074 .type = cpu_to_be16(ETH_P_MPLS_MC),
David S. Millerbdef7de2015-06-01 14:56:09 -070075 .priority = 15,
Simon Horman0d89d202013-05-23 21:02:52 +000076 .callbacks = {
Simon Horman0d89d202013-05-23 21:02:52 +000077 .gso_segment = mpls_gso_segment,
78 },
79};
80
Daniel Borkmann207895fd32015-01-29 12:15:03 +010081static struct packet_offload mpls_uc_offload __read_mostly = {
Simon Horman0d89d202013-05-23 21:02:52 +000082 .type = cpu_to_be16(ETH_P_MPLS_UC),
David S. Millerbdef7de2015-06-01 14:56:09 -070083 .priority = 15,
Simon Horman0d89d202013-05-23 21:02:52 +000084 .callbacks = {
Simon Horman0d89d202013-05-23 21:02:52 +000085 .gso_segment = mpls_gso_segment,
86 },
87};
88
89static int __init mpls_gso_init(void)
90{
91 pr_info("MPLS GSO support\n");
92
93 dev_add_offload(&mpls_uc_offload);
94 dev_add_offload(&mpls_mc_offload);
95
96 return 0;
97}
98
99static void __exit mpls_gso_exit(void)
100{
101 dev_remove_offload(&mpls_uc_offload);
102 dev_remove_offload(&mpls_mc_offload);
103}
104
105module_init(mpls_gso_init);
106module_exit(mpls_gso_exit);
107
108MODULE_DESCRIPTION("MPLS GSO support");
109MODULE_AUTHOR("Simon Horman (horms@verge.net.au)");
110MODULE_LICENSE("GPL");