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1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * Network Service Header
4 *
5 * Copyright (c) 2017 Red Hat, Inc. -- Jiri Benc <jbenc@redhat.com>
6 */
7
8#include <linux/module.h>
9#include <linux/netdevice.h>
10#include <linux/skbuff.h>
11#include <net/nsh.h>
12#include <net/tun_proto.h>
13
14int nsh_push(struct sk_buff *skb, const struct nshhdr *pushed_nh)
15{
16 struct nshhdr *nh;
17 size_t length = nsh_hdr_len(pushed_nh);
18 u8 next_proto;
19
20 if (skb->mac_len) {
21 next_proto = TUN_P_ETHERNET;
22 } else {
23 next_proto = tun_p_from_eth_p(skb->protocol);
24 if (!next_proto)
25 return -EAFNOSUPPORT;
26 }
27
28 /* Add the NSH header */
29 if (skb_cow_head(skb, length) < 0)
30 return -ENOMEM;
31
32 skb_push(skb, length);
33 nh = (struct nshhdr *)(skb->data);
34 memcpy(nh, pushed_nh, length);
35 nh->np = next_proto;
36 skb_postpush_rcsum(skb, nh, length);
37
38 skb->protocol = htons(ETH_P_NSH);
39 skb_reset_mac_header(skb);
40 skb_reset_network_header(skb);
41 skb_reset_mac_len(skb);
42
43 return 0;
44}
45EXPORT_SYMBOL_GPL(nsh_push);
46
47int nsh_pop(struct sk_buff *skb)
48{
49 struct nshhdr *nh;
50 size_t length;
51 __be16 inner_proto;
52
53 if (!pskb_may_pull(skb, NSH_BASE_HDR_LEN))
54 return -ENOMEM;
55 nh = (struct nshhdr *)(skb->data);
56 length = nsh_hdr_len(nh);
57 if (length < NSH_BASE_HDR_LEN)
58 return -EINVAL;
59 inner_proto = tun_p_to_eth_p(nh->np);
60 if (!pskb_may_pull(skb, length))
61 return -ENOMEM;
62
63 if (!inner_proto)
64 return -EAFNOSUPPORT;
65
66 skb_pull_rcsum(skb, length);
67 skb_reset_mac_header(skb);
68 skb_reset_network_header(skb);
69 skb_reset_mac_len(skb);
70 skb->protocol = inner_proto;
71
72 return 0;
73}
74EXPORT_SYMBOL_GPL(nsh_pop);
75
76static struct sk_buff *nsh_gso_segment(struct sk_buff *skb,
77 netdev_features_t features)
78{
79 struct sk_buff *segs = ERR_PTR(-EINVAL);
80 unsigned int nsh_len, mac_len;
81 __be16 proto;
82 int nhoff;
83
84 skb_reset_network_header(skb);
85
86 nhoff = skb->network_header - skb->mac_header;
87 mac_len = skb->mac_len;
88
89 if (unlikely(!pskb_may_pull(skb, NSH_BASE_HDR_LEN)))
90 goto out;
91 nsh_len = nsh_hdr_len(nsh_hdr(skb));
92 if (nsh_len < NSH_BASE_HDR_LEN)
93 goto out;
94 if (unlikely(!pskb_may_pull(skb, nsh_len)))
95 goto out;
96
97 proto = tun_p_to_eth_p(nsh_hdr(skb)->np);
98 if (!proto)
99 goto out;
100
101 __skb_pull(skb, nsh_len);
102
103 skb_reset_mac_header(skb);
104 skb->mac_len = proto == htons(ETH_P_TEB) ? ETH_HLEN : 0;
105 skb->protocol = proto;
106
107 features &= NETIF_F_SG;
108 segs = skb_mac_gso_segment(skb, features);
109 if (IS_ERR_OR_NULL(segs)) {
110 skb_gso_error_unwind(skb, htons(ETH_P_NSH), nsh_len,
111 skb->network_header - nhoff,
112 mac_len);
113 goto out;
114 }
115
116 for (skb = segs; skb; skb = skb->next) {
117 skb->protocol = htons(ETH_P_NSH);
118 __skb_push(skb, nsh_len);
119 skb_set_mac_header(skb, -nhoff);
120 skb->network_header = skb->mac_header + mac_len;
121 skb->mac_len = mac_len;
122 }
123
124out:
125 return segs;
126}
127
128static struct packet_offload nsh_packet_offload __read_mostly = {
129 .type = htons(ETH_P_NSH),
130 .priority = 15,
131 .callbacks = {
132 .gso_segment = nsh_gso_segment,
133 },
134};
135
136static int __init nsh_init_module(void)
137{
138 dev_add_offload(&nsh_packet_offload);
139 return 0;
140}
141
142static void __exit nsh_cleanup_module(void)
143{
144 dev_remove_offload(&nsh_packet_offload);
145}
146
147module_init(nsh_init_module);
148module_exit(nsh_cleanup_module);
149
150MODULE_AUTHOR("Jiri Benc <jbenc@redhat.com>");
151MODULE_DESCRIPTION("NSH protocol");
152MODULE_LICENSE("GPL v2");
1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * Network Service Header
4 *
5 * Copyright (c) 2017 Red Hat, Inc. -- Jiri Benc <jbenc@redhat.com>
6 */
7
8#include <linux/module.h>
9#include <linux/netdevice.h>
10#include <linux/skbuff.h>
11#include <net/gso.h>
12#include <net/nsh.h>
13#include <net/tun_proto.h>
14
15int nsh_push(struct sk_buff *skb, const struct nshhdr *pushed_nh)
16{
17 struct nshhdr *nh;
18 size_t length = nsh_hdr_len(pushed_nh);
19 u8 next_proto;
20
21 if (skb->mac_len) {
22 next_proto = TUN_P_ETHERNET;
23 } else {
24 next_proto = tun_p_from_eth_p(skb->protocol);
25 if (!next_proto)
26 return -EAFNOSUPPORT;
27 }
28
29 /* Add the NSH header */
30 if (skb_cow_head(skb, length) < 0)
31 return -ENOMEM;
32
33 skb_push(skb, length);
34 nh = (struct nshhdr *)(skb->data);
35 memcpy(nh, pushed_nh, length);
36 nh->np = next_proto;
37 skb_postpush_rcsum(skb, nh, length);
38
39 skb->protocol = htons(ETH_P_NSH);
40 skb_reset_mac_header(skb);
41 skb_reset_network_header(skb);
42 skb_reset_mac_len(skb);
43
44 return 0;
45}
46EXPORT_SYMBOL_GPL(nsh_push);
47
48int nsh_pop(struct sk_buff *skb)
49{
50 struct nshhdr *nh;
51 size_t length;
52 __be16 inner_proto;
53
54 if (!pskb_may_pull(skb, NSH_BASE_HDR_LEN))
55 return -ENOMEM;
56 nh = (struct nshhdr *)(skb->data);
57 length = nsh_hdr_len(nh);
58 if (length < NSH_BASE_HDR_LEN)
59 return -EINVAL;
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
77static struct sk_buff *nsh_gso_segment(struct sk_buff *skb,
78 netdev_features_t features)
79{
80 unsigned int outer_hlen, mac_len, nsh_len;
81 struct sk_buff *segs = ERR_PTR(-EINVAL);
82 u16 mac_offset = skb->mac_header;
83 __be16 outer_proto, proto;
84
85 skb_reset_network_header(skb);
86
87 outer_proto = skb->protocol;
88 outer_hlen = skb_mac_header_len(skb);
89 mac_len = skb->mac_len;
90
91 if (unlikely(!pskb_may_pull(skb, NSH_BASE_HDR_LEN)))
92 goto out;
93 nsh_len = nsh_hdr_len(nsh_hdr(skb));
94 if (nsh_len < NSH_BASE_HDR_LEN)
95 goto out;
96 if (unlikely(!pskb_may_pull(skb, nsh_len)))
97 goto out;
98
99 proto = tun_p_to_eth_p(nsh_hdr(skb)->np);
100 if (!proto)
101 goto out;
102
103 __skb_pull(skb, nsh_len);
104
105 skb_reset_mac_header(skb);
106 skb->mac_len = proto == htons(ETH_P_TEB) ? ETH_HLEN : 0;
107 skb->protocol = proto;
108
109 features &= NETIF_F_SG;
110 segs = skb_mac_gso_segment(skb, features);
111 if (IS_ERR_OR_NULL(segs)) {
112 skb_gso_error_unwind(skb, htons(ETH_P_NSH), nsh_len,
113 mac_offset, mac_len);
114 goto out;
115 }
116
117 for (skb = segs; skb; skb = skb->next) {
118 skb->protocol = outer_proto;
119 __skb_push(skb, nsh_len + outer_hlen);
120 skb_reset_mac_header(skb);
121 skb_set_network_header(skb, outer_hlen);
122 skb->mac_len = mac_len;
123 }
124
125out:
126 return segs;
127}
128
129static struct packet_offload nsh_packet_offload __read_mostly = {
130 .type = htons(ETH_P_NSH),
131 .priority = 15,
132 .callbacks = {
133 .gso_segment = nsh_gso_segment,
134 },
135};
136
137static int __init nsh_init_module(void)
138{
139 dev_add_offload(&nsh_packet_offload);
140 return 0;
141}
142
143static void __exit nsh_cleanup_module(void)
144{
145 dev_remove_offload(&nsh_packet_offload);
146}
147
148module_init(nsh_init_module);
149module_exit(nsh_cleanup_module);
150
151MODULE_AUTHOR("Jiri Benc <jbenc@redhat.com>");
152MODULE_DESCRIPTION("NSH protocol");
153MODULE_LICENSE("GPL v2");