projects / deliverable / linux.git / blame
| Commit | Line | Data |
|---|---|---|
| b59f45d0 HX |
1 | /* |
| 2 | * xfrm4_mode_transport.c - Transport mode encapsulation for IPv4. | |
| 3 | * | |
| 4 | * Copyright (c) 2004-2006 Herbert Xu <herbert@gondor.apana.org.au> | |
| 5 | */ | |
| 6 | ||
| 7 | #include <linux/init.h> | |
| 8 | #include <linux/kernel.h> | |
| 9 | #include <linux/module.h> | |
| 10 | #include <linux/skbuff.h> | |
| 11 | #include <linux/stringify.h> | |
| 12 | #include <net/dst.h> | |
| 13 | #include <net/ip.h> | |
| 14 | #include <net/xfrm.h> | |
| 15 | ||
| 16 | /* Add encapsulation header. | |
| 17 | * | |
| 18 | * The IP header will be moved forward to make space for the encapsulation | |
| 19 | * header. | |
| 20 | * | |
| 21 | * On exit, skb->h will be set to the start of the payload to be processed | |
| 22 | * by x->type->output and skb->nh will be set to the top IP header. | |
| 23 | */ | |
| eb878e84 | 24 | static int xfrm4_transport_output(struct xfrm_state *x, struct sk_buff *skb) |
| b59f45d0 | 25 | { |
| eddc9ec5 ACM |
26 | struct iphdr *iph = ip_hdr(skb); |
| 27 | int ihl = iph->ihl * 4; | |
| b59f45d0 | 28 | |
| b0e380b1 | 29 | skb->transport_header = skb->network_header + ihl; |
| 7b277b1a HX |
30 | skb_set_network_header(skb, -x->props.header_len); |
| 31 | __skb_pull(skb, ihl); | |
| d56f90a7 | 32 | memmove(skb_network_header(skb), iph, ihl); |
| b59f45d0 HX |
33 | return 0; |
| 34 | } | |
| 35 | ||
| 31a4ab93 HX |
36 | /* Remove encapsulation header. |
| 37 | * | |
| 38 | * The IP header will be moved over the top of the encapsulation header. | |
| 39 | * | |
| 40 | * On entry, skb->h shall point to where the IP header should be and skb->nh | |
| 41 | * shall be set to where the IP header currently is. skb->data shall point | |
| 42 | * to the start of the payload. | |
| 43 | */ | |
| b59f45d0 HX |
44 | static int xfrm4_transport_input(struct xfrm_state *x, struct sk_buff *skb) |
| 45 | { | |
| 9c70220b | 46 | int ihl = skb->data - skb_transport_header(skb); |
| 31a4ab93 | 47 | |
| b0e380b1 | 48 | if (skb->transport_header != skb->network_header) { |
| 9c70220b ACM |
49 | memmove(skb_transport_header(skb), |
| 50 | skb_network_header(skb), ihl); | |
| b0e380b1 | 51 | skb->network_header = skb->transport_header; |
| 7f5c0cb0 | 52 | } |
| eddc9ec5 | 53 | ip_hdr(skb)->tot_len = htons(skb->len + ihl); |
| badff6d0 | 54 | skb_reset_transport_header(skb); |
| b59f45d0 HX |
55 | return 0; |
| 56 | } | |
| 57 | ||
| 58 | static struct xfrm_mode xfrm4_transport_mode = { | |
| 59 | .input = xfrm4_transport_input, | |
| 60 | .output = xfrm4_transport_output, | |
| 61 | .owner = THIS_MODULE, | |
| 62 | .encap = XFRM_MODE_TRANSPORT, | |
| 63 | }; | |
| 64 | ||
| 65 | static int __init xfrm4_transport_init(void) | |
| 66 | { | |
| 67 | return xfrm_register_mode(&xfrm4_transport_mode, AF_INET); | |
| 68 | } | |
| 69 | ||
| 70 | static void __exit xfrm4_transport_exit(void) | |
| 71 | { | |
| 72 | int err; | |
| 73 | ||
| 74 | err = xfrm_unregister_mode(&xfrm4_transport_mode, AF_INET); | |
| 75 | BUG_ON(err); | |
| 76 | } | |
| 77 | ||
| 78 | module_init(xfrm4_transport_init); | |
| 79 | module_exit(xfrm4_transport_exit); | |
| 80 | MODULE_LICENSE("GPL"); | |
| 81 | MODULE_ALIAS_XFRM_MODE(AF_INET, XFRM_MODE_TRANSPORT); |