tjh.dev
Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * MPLS GSO Support
4 *
5 * Authors: Simon Horman (horms@verge.net.au)
6 *
7 * Based on: GSO portions of net/ipv4/gre.c
8 */
9
10#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
11
12#include <linux/err.h>
13#include <linux/module.h>
14#include <linux/netdev_features.h>
15#include <linux/netdevice.h>
16#include <linux/skbuff.h>
17
18static struct sk_buff *mpls_gso_segment(struct sk_buff *skb,
19 netdev_features_t features)
20{
21 struct sk_buff *segs = ERR_PTR(-EINVAL);
22 u16 mac_offset = skb->mac_header;
23 netdev_features_t mpls_features;
24 u16 mac_len = skb->mac_len;
25 __be16 mpls_protocol;
26 unsigned int mpls_hlen;
27
28 skb_reset_network_header(skb);
29 mpls_hlen = skb_inner_network_header(skb) - skb_network_header(skb);
30 if (unlikely(!pskb_may_pull(skb, mpls_hlen)))
31 goto out;
32
33 /* Setup inner SKB. */
34 mpls_protocol = skb->protocol;
35 skb->protocol = skb->inner_protocol;
36
37 __skb_pull(skb, mpls_hlen);
38
39 skb->mac_len = 0;
40 skb_reset_mac_header(skb);
41
42 /* Segment inner packet. */
43 mpls_features = skb->dev->mpls_features & features;
44 segs = skb_mac_gso_segment(skb, mpls_features);
45 if (IS_ERR_OR_NULL(segs)) {
46 skb_gso_error_unwind(skb, mpls_protocol, mpls_hlen, mac_offset,
47 mac_len);
48 goto out;
49 }
50 skb = segs;
51
52 mpls_hlen += mac_len;
53 do {
54 skb->mac_len = mac_len;
55 skb->protocol = mpls_protocol;
56
57 skb_reset_inner_network_header(skb);
58
59 __skb_push(skb, mpls_hlen);
60
61 skb_reset_mac_header(skb);
62 skb_set_network_header(skb, mac_len);
63 } while ((skb = skb->next));
64
65out:
66 return segs;
67}
68
69static struct packet_offload mpls_mc_offload __read_mostly = {
70 .type = cpu_to_be16(ETH_P_MPLS_MC),
71 .priority = 15,
72 .callbacks = {
73 .gso_segment = mpls_gso_segment,
74 },
75};
76
77static struct packet_offload mpls_uc_offload __read_mostly = {
78 .type = cpu_to_be16(ETH_P_MPLS_UC),
79 .priority = 15,
80 .callbacks = {
81 .gso_segment = mpls_gso_segment,
82 },
83};
84
85static int __init mpls_gso_init(void)
86{
87 pr_info("MPLS GSO support\n");
88
89 dev_add_offload(&mpls_uc_offload);
90 dev_add_offload(&mpls_mc_offload);
91
92 return 0;
93}
94
95static void __exit mpls_gso_exit(void)
96{
97 dev_remove_offload(&mpls_uc_offload);
98 dev_remove_offload(&mpls_mc_offload);
99}
100
101module_init(mpls_gso_init);
102module_exit(mpls_gso_exit);
103
104MODULE_DESCRIPTION("MPLS GSO support");
105MODULE_AUTHOR("Simon Horman (horms@verge.net.au)");
106MODULE_LICENSE("GPL");