Gitiles
Code Review Sign In
gerrit-public.fairphone.software / kernel / msm-4.19 / bb8822cbbc5334dc89b7415dbdc6d51421e74773 / . / net / nsh / nsh.c
blob: d7da99a0b0b852d7459eed9ac6d3cdf3d49a1a1c [file] [log] [blame]
Jiri Bencc411ed82017-08-28 21:43:24 +0200[diff] [blame]1/*
2 * Network Service Header
3 *
4 * Copyright (c) 2017 Red Hat, Inc. -- Jiri Benc <jbenc@redhat.com>
5 *
6 * This program is free software; you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License version 2 as
8 * published by the Free Software Foundation.
9 */
10
11#include <linux/module.h>
12#include <linux/netdevice.h>
13#include <linux/skbuff.h>
14#include <net/nsh.h>
15#include <net/tun_proto.h>
16
Yi Yangb2d0f5d2017-11-07 21:07:02 +0800[diff] [blame]17int nsh_push(struct sk_buff *skb, const struct nshhdr *pushed_nh)
18{
19 struct nshhdr *nh;
20 size_t length = nsh_hdr_len(pushed_nh);
21 u8 next_proto;
22
23 if (skb->mac_len) {
24 next_proto = TUN_P_ETHERNET;
25 } else {
26 next_proto = tun_p_from_eth_p(skb->protocol);
27 if (!next_proto)
28 return -EAFNOSUPPORT;
29 }
30
31 /* Add the NSH header */
32 if (skb_cow_head(skb, length) < 0)
33 return -ENOMEM;
34
35 skb_push(skb, length);
36 nh = (struct nshhdr *)(skb->data);
37 memcpy(nh, pushed_nh, length);
38 nh->np = next_proto;
39 skb_postpush_rcsum(skb, nh, length);
40
41 skb->protocol = htons(ETH_P_NSH);
42 skb_reset_mac_header(skb);
43 skb_reset_network_header(skb);
44 skb_reset_mac_len(skb);
45
46 return 0;
47}
48EXPORT_SYMBOL_GPL(nsh_push);
49
50int nsh_pop(struct sk_buff *skb)
51{
52 struct nshhdr *nh;
53 size_t length;
54 __be16 inner_proto;
55
56 if (!pskb_may_pull(skb, NSH_BASE_HDR_LEN))
57 return -ENOMEM;
58 nh = (struct nshhdr *)(skb->data);
59 length = nsh_hdr_len(nh);
60 inner_proto = tun_p_to_eth_p(nh->np);
61 if (!pskb_may_pull(skb, length))
62 return -ENOMEM;
63
64 if (!inner_proto)
65 return -EAFNOSUPPORT;
66
67 skb_pull_rcsum(skb, length);
68 skb_reset_mac_header(skb);
69 skb_reset_network_header(skb);
70 skb_reset_mac_len(skb);
71 skb->protocol = inner_proto;
72
73 return 0;
74}
75EXPORT_SYMBOL_GPL(nsh_pop);
76
Jiri Bencc411ed82017-08-28 21:43:24 +0200[diff] [blame]77static struct sk_buff *nsh_gso_segment(struct sk_buff *skb,
78 netdev_features_t features)
79{
80 struct sk_buff *segs = ERR_PTR(-EINVAL);
81 unsigned int nsh_len, mac_len;
82 __be16 proto;
83 int nhoff;
84
85 skb_reset_network_header(skb);
86
87 nhoff = skb->network_header - skb->mac_header;
88 mac_len = skb->mac_len;
89
90 if (unlikely(!pskb_may_pull(skb, NSH_BASE_HDR_LEN)))
91 goto out;
92 nsh_len = nsh_hdr_len(nsh_hdr(skb));
93 if (unlikely(!pskb_may_pull(skb, nsh_len)))
94 goto out;
95
96 proto = tun_p_to_eth_p(nsh_hdr(skb)->np);
97 if (!proto)
98 goto out;
99
100 __skb_pull(skb, nsh_len);
101
102 skb_reset_mac_header(skb);
103 skb_reset_mac_len(skb);
104 skb->protocol = proto;
105
106 features &= NETIF_F_SG;
107 segs = skb_mac_gso_segment(skb, features);
108 if (IS_ERR_OR_NULL(segs)) {
109 skb_gso_error_unwind(skb, htons(ETH_P_NSH), nsh_len,
110 skb->network_header - nhoff,
111 mac_len);
112 goto out;
113 }
114
115 for (skb = segs; skb; skb = skb->next) {
116 skb->protocol = htons(ETH_P_NSH);
117 __skb_push(skb, nsh_len);
118 skb_set_mac_header(skb, -nhoff);
119 skb->network_header = skb->mac_header + mac_len;
120 skb->mac_len = mac_len;
121 }
122
123out:
124 return segs;
125}
126
127static struct packet_offload nsh_packet_offload __read_mostly = {
128 .type = htons(ETH_P_NSH),
129 .priority = 15,
130 .callbacks = {
131 .gso_segment = nsh_gso_segment,
132 },
133};
134
135static int __init nsh_init_module(void)
136{
137 dev_add_offload(&nsh_packet_offload);
138 return 0;
139}
140
141static void __exit nsh_cleanup_module(void)
142{
143 dev_remove_offload(&nsh_packet_offload);
144}
145
146module_init(nsh_init_module);
147module_exit(nsh_cleanup_module);
148
149MODULE_AUTHOR("Jiri Benc <jbenc@redhat.com>");
150MODULE_DESCRIPTION("NSH protocol");
151MODULE_LICENSE("GPL v2");