Commit | Line | Data |
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b59f45d0 HX |
1 | /* |
2 | * xfrm6_mode_transport.c - Transport mode encapsulation for IPv6. | |
3 | * | |
4 | * Copyright (C) 2002 USAGI/WIDE Project | |
5 | * Copyright (c) 2004-2006 Herbert Xu <herbert@gondor.apana.org.au> | |
6 | */ | |
7 | ||
8 | #include <linux/init.h> | |
9 | #include <linux/kernel.h> | |
10 | #include <linux/module.h> | |
11 | #include <linux/skbuff.h> | |
12 | #include <linux/stringify.h> | |
13 | #include <net/dst.h> | |
14 | #include <net/ipv6.h> | |
15 | #include <net/xfrm.h> | |
c35fe410 | 16 | #include <net/protocol.h> |
b59f45d0 HX |
17 | |
18 | /* Add encapsulation header. | |
19 | * | |
20 | * The IP header and mutable extension headers will be moved forward to make | |
21 | * space for the encapsulation header. | |
b59f45d0 | 22 | */ |
eb878e84 | 23 | static int xfrm6_transport_output(struct xfrm_state *x, struct sk_buff *skb) |
b59f45d0 | 24 | { |
b59f45d0 HX |
25 | struct ipv6hdr *iph; |
26 | u8 *prevhdr; | |
27 | int hdr_len; | |
28 | ||
0660e03f | 29 | iph = ipv6_hdr(skb); |
f1bd7d65 | 30 | skb_set_inner_transport_header(skb, skb_transport_offset(skb)); |
b59f45d0 | 31 | |
aee5adb4 | 32 | hdr_len = x->type->hdr_offset(x, skb, &prevhdr); |
6e80ac5c BH |
33 | if (hdr_len < 0) |
34 | return hdr_len; | |
007f0211 | 35 | skb_set_mac_header(skb, (prevhdr - x->props.header_len) - skb->data); |
7b277b1a | 36 | skb_set_network_header(skb, -x->props.header_len); |
37fedd3a | 37 | skb->transport_header = skb->network_header + hdr_len; |
7b277b1a HX |
38 | __skb_pull(skb, hdr_len); |
39 | memmove(ipv6_hdr(skb), iph, hdr_len); | |
b59f45d0 HX |
40 | return 0; |
41 | } | |
42 | ||
31a4ab93 HX |
43 | /* Remove encapsulation header. |
44 | * | |
45 | * The IP header will be moved over the top of the encapsulation header. | |
46 | * | |
47 | * On entry, skb->h shall point to where the IP header should be and skb->nh | |
48 | * shall be set to where the IP header currently is. skb->data shall point | |
49 | * to the start of the payload. | |
50 | */ | |
b59f45d0 HX |
51 | static int xfrm6_transport_input(struct xfrm_state *x, struct sk_buff *skb) |
52 | { | |
9c70220b | 53 | int ihl = skb->data - skb_transport_header(skb); |
31a4ab93 | 54 | |
b0e380b1 | 55 | if (skb->transport_header != skb->network_header) { |
9c70220b ACM |
56 | memmove(skb_transport_header(skb), |
57 | skb_network_header(skb), ihl); | |
b0e380b1 | 58 | skb->network_header = skb->transport_header; |
d56f90a7 | 59 | } |
0660e03f | 60 | ipv6_hdr(skb)->payload_len = htons(skb->len + ihl - |
31a4ab93 | 61 | sizeof(struct ipv6hdr)); |
bfc0698b | 62 | skb_reset_transport_header(skb); |
b59f45d0 HX |
63 | return 0; |
64 | } | |
65 | ||
c35fe410 SK |
66 | static struct sk_buff *xfrm4_transport_gso_segment(struct xfrm_state *x, |
67 | struct sk_buff *skb, | |
68 | netdev_features_t features) | |
69 | { | |
70 | const struct net_offload *ops; | |
71 | struct sk_buff *segs = ERR_PTR(-EINVAL); | |
72 | struct xfrm_offload *xo = xfrm_offload(skb); | |
73 | ||
74 | skb->transport_header += x->props.header_len; | |
75 | ops = rcu_dereference(inet6_offloads[xo->proto]); | |
76 | if (likely(ops && ops->callbacks.gso_segment)) | |
77 | segs = ops->callbacks.gso_segment(skb, features); | |
78 | ||
79 | return segs; | |
80 | } | |
81 | ||
82 | static void xfrm6_transport_xmit(struct xfrm_state *x, struct sk_buff *skb) | |
83 | { | |
84 | struct xfrm_offload *xo = xfrm_offload(skb); | |
85 | ||
86 | skb_reset_mac_len(skb); | |
87 | pskb_pull(skb, skb->mac_len + sizeof(struct ipv6hdr) + x->props.header_len); | |
88 | ||
89 | if (xo->flags & XFRM_GSO_SEGMENT) { | |
90 | skb_reset_transport_header(skb); | |
91 | skb->transport_header -= x->props.header_len; | |
92 | } | |
93 | } | |
94 | ||
95 | ||
b59f45d0 HX |
96 | static struct xfrm_mode xfrm6_transport_mode = { |
97 | .input = xfrm6_transport_input, | |
98 | .output = xfrm6_transport_output, | |
c35fe410 SK |
99 | .gso_segment = xfrm4_transport_gso_segment, |
100 | .xmit = xfrm6_transport_xmit, | |
b59f45d0 HX |
101 | .owner = THIS_MODULE, |
102 | .encap = XFRM_MODE_TRANSPORT, | |
103 | }; | |
104 | ||
105 | static int __init xfrm6_transport_init(void) | |
106 | { | |
107 | return xfrm_register_mode(&xfrm6_transport_mode, AF_INET6); | |
108 | } | |
109 | ||
110 | static void __exit xfrm6_transport_exit(void) | |
111 | { | |
112 | int err; | |
113 | ||
114 | err = xfrm_unregister_mode(&xfrm6_transport_mode, AF_INET6); | |
115 | BUG_ON(err); | |
116 | } | |
117 | ||
118 | module_init(xfrm6_transport_init); | |
119 | module_exit(xfrm6_transport_exit); | |
120 | MODULE_LICENSE("GPL"); | |
121 | MODULE_ALIAS_XFRM_MODE(AF_INET6, XFRM_MODE_TRANSPORT); |