projects / deliverable / linux.git / blame
| Commit | Line | Data |
|---|---|---|
| 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> | |
| 16 | ||
| 17 | /* Add encapsulation header. | |
| 18 | * | |
| 19 | * The IP header and mutable extension headers will be moved forward to make | |
| 20 | * space for the encapsulation header. | |
| 21 | * | |
| 22 | * On exit, skb->h will be set to the start of the encapsulation header to be | |
| 23 | * filled in by x->type->output and skb->nh will be set to the nextheader field | |
| 24 | * of the extension header directly preceding the encapsulation header, or in | |
| 25 | * its absence, that of the top IP header. The value of skb->data will always | |
| 26 | * point to the top IP header. | |
| 27 | */ | |
| 28 | static int xfrm6_transport_output(struct sk_buff *skb) | |
| 29 | { | |
| 30 | struct xfrm_state *x = skb->dst->xfrm; | |
| 31 | struct ipv6hdr *iph; | |
| 32 | u8 *prevhdr; | |
| 33 | int hdr_len; | |
| 34 | ||
| 35 | skb_push(skb, x->props.header_len); | |
| 36 | iph = skb->nh.ipv6h; | |
| 37 | ||
| 38 | hdr_len = ip6_find_1stfragopt(skb, &prevhdr); | |
| 39 | skb->nh.raw = prevhdr - x->props.header_len; | |
| 40 | skb->h.raw = skb->data + hdr_len; | |
| 41 | memmove(skb->data, iph, hdr_len); | |
| 42 | return 0; | |
| 43 | } | |
| 44 | ||
| 31a4ab93 HX |
45 | /* Remove encapsulation header. |
| 46 | * | |
| 47 | * The IP header will be moved over the top of the encapsulation header. | |
| 48 | * | |
| 49 | * On entry, skb->h shall point to where the IP header should be and skb->nh | |
| 50 | * shall be set to where the IP header currently is. skb->data shall point | |
| 51 | * to the start of the payload. | |
| 52 | */ | |
| b59f45d0 HX |
53 | static int xfrm6_transport_input(struct xfrm_state *x, struct sk_buff *skb) |
| 54 | { | |
| 31a4ab93 HX |
55 | int ihl = skb->data - skb->h.raw; |
| 56 | ||
| 57 | if (skb->h.raw != skb->nh.raw) | |
| 58 | skb->nh.raw = memmove(skb->h.raw, skb->nh.raw, ihl); | |
| 59 | skb->nh.ipv6h->payload_len = htons(skb->len + ihl - | |
| 60 | sizeof(struct ipv6hdr)); | |
| 61 | skb->h.raw = skb->data; | |
| b59f45d0 HX |
62 | return 0; |
| 63 | } | |
| 64 | ||
| 65 | static struct xfrm_mode xfrm6_transport_mode = { | |
| 66 | .input = xfrm6_transport_input, | |
| 67 | .output = xfrm6_transport_output, | |
| 68 | .owner = THIS_MODULE, | |
| 69 | .encap = XFRM_MODE_TRANSPORT, | |
| 70 | }; | |
| 71 | ||
| 72 | static int __init xfrm6_transport_init(void) | |
| 73 | { | |
| 74 | return xfrm_register_mode(&xfrm6_transport_mode, AF_INET6); | |
| 75 | } | |
| 76 | ||
| 77 | static void __exit xfrm6_transport_exit(void) | |
| 78 | { | |
| 79 | int err; | |
| 80 | ||
| 81 | err = xfrm_unregister_mode(&xfrm6_transport_mode, AF_INET6); | |
| 82 | BUG_ON(err); | |
| 83 | } | |
| 84 | ||
| 85 | module_init(xfrm6_transport_init); | |
| 86 | module_exit(xfrm6_transport_exit); | |
| 87 | MODULE_LICENSE("GPL"); | |
| 88 | MODULE_ALIAS_XFRM_MODE(AF_INET6, XFRM_MODE_TRANSPORT); |