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0d89d203 SH |
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_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 | ||
62 | out: | |
63 | return segs; | |
64 | } | |
65 | ||
66 | static int mpls_gso_send_check(struct sk_buff *skb) | |
67 | { | |
68 | return 0; | |
69 | } | |
70 | ||
71 | static 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 | ||
79 | static 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 | ||
87 | static 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 | ||
97 | static void __exit mpls_gso_exit(void) | |
98 | { | |
99 | dev_remove_offload(&mpls_uc_offload); | |
100 | dev_remove_offload(&mpls_mc_offload); | |
101 | } | |
102 | ||
103 | module_init(mpls_gso_init); | |
104 | module_exit(mpls_gso_exit); | |
105 | ||
106 | MODULE_DESCRIPTION("MPLS GSO support"); | |
107 | MODULE_AUTHOR("Simon Horman (horms@verge.net.au)"); | |
108 | MODULE_LICENSE("GPL"); |