xfrm6_mode_ro.c revision a2deb6d26f16ed7bf787dbd6a58c5d7be47d8db3
1/* 2 * xfrm6_mode_ro.c - Route optimization mode for IPv6. 3 * 4 * Copyright (C)2003-2006 Helsinki University of Technology 5 * Copyright (C)2003-2006 USAGI/WIDE Project 6 * 7 * This program is free software; you can redistribute it and/or modify 8 * it under the terms of the GNU General Public License as published by 9 * the Free Software Foundation; either version 2 of the License, or 10 * (at your option) any later version. 11 * 12 * This program is distributed in the hope that it will be useful, 13 * but WITHOUT ANY WARRANTY; without even the implied warranty of 14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 15 * GNU General Public License for more details. 16 * 17 * You should have received a copy of the GNU General Public License 18 * along with this program; if not, write to the Free Software 19 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA 20 */ 21/* 22 * Authors: 23 * Noriaki TAKAMIYA @USAGI 24 * Masahide NAKAMURA @USAGI 25 */ 26 27#include <linux/init.h> 28#include <linux/kernel.h> 29#include <linux/module.h> 30#include <linux/skbuff.h> 31#include <linux/spinlock.h> 32#include <linux/stringify.h> 33#include <linux/time.h> 34#include <net/ipv6.h> 35#include <net/xfrm.h> 36 37/* Add route optimization header space. 38 * 39 * The IP header and mutable extension headers will be moved forward to make 40 * space for the route optimization header. 41 */ 42static int xfrm6_ro_output(struct xfrm_state *x, struct sk_buff *skb) 43{ 44 struct ipv6hdr *iph; 45 u8 *prevhdr; 46 int hdr_len; 47 48 iph = ipv6_hdr(skb); 49 50 hdr_len = x->type->hdr_offset(x, skb, &prevhdr); 51 skb_set_mac_header(skb, (prevhdr - x->props.header_len) - skb->data); 52 skb_set_network_header(skb, -x->props.header_len); 53 skb->transport_header = skb->network_header + hdr_len; 54 __skb_pull(skb, hdr_len); 55 memmove(ipv6_hdr(skb), iph, hdr_len); 56 57 spin_lock_bh(&x->lock); 58 x->lastused = get_seconds(); 59 spin_unlock_bh(&x->lock); 60 61 return 0; 62} 63 64static struct xfrm_mode xfrm6_ro_mode = { 65 .output = xfrm6_ro_output, 66 .owner = THIS_MODULE, 67 .encap = XFRM_MODE_ROUTEOPTIMIZATION, 68}; 69 70static int __init xfrm6_ro_init(void) 71{ 72 return xfrm_register_mode(&xfrm6_ro_mode, AF_INET6); 73} 74 75static void __exit xfrm6_ro_exit(void) 76{ 77 int err; 78 79 err = xfrm_unregister_mode(&xfrm6_ro_mode, AF_INET6); 80 BUG_ON(err); 81} 82 83module_init(xfrm6_ro_init); 84module_exit(xfrm6_ro_exit); 85MODULE_LICENSE("GPL"); 86MODULE_ALIAS_XFRM_MODE(AF_INET6, XFRM_MODE_ROUTEOPTIMIZATION); 87