/* * xfrm6_mode_ro.c - Route optimization mode for IPv6. * * Copyright (C)2003-2006 Helsinki University of Technology * Copyright (C)2003-2006 USAGI/WIDE Project * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License as published by * the Free Software Foundation; either version 2 of the License, or * (at your option) any later version. * * This program is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU General Public License for more details. * * You should have received a copy of the GNU General Public License * along with this program; if not, write to the Free Software * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA */ /* * Authors: * Noriaki TAKAMIYA @USAGI * Masahide NAKAMURA @USAGI */ #include <linux/init.h> #include <linux/kernel.h> #include <linux/module.h> #include <linux/skbuff.h> #include <linux/stringify.h> #include <net/ipv6.h> #include <net/xfrm.h> /* Add route optimization header space. * * The IP header and mutable extension headers will be moved forward to make * space for the route optimization header. * * On exit, skb->h will be set to the start of the encapsulation header to be * filled in by x->type->output and skb->nh will be set to the nextheader field * of the extension header directly preceding the encapsulation header, or in * its absence, that of the top IP header. The value of skb->data will always * point to the top IP header. */ static int xfrm6_ro_output(struct xfrm_state *x, struct sk_buff *skb) { struct ipv6hdr *iph; u8 *prevhdr; int hdr_len; skb_push(skb, x->props.header_len); iph = ipv6_hdr(skb); hdr_len = x->type->hdr_offset(x, skb, &prevhdr); skb_set_network_header(skb, (prevhdr - x->props.header_len) - skb->data); skb_set_transport_header(skb, hdr_len); memmove(skb->data, iph, hdr_len); return 0; } /* * Do nothing about routing optimization header unlike IPsec. */ static int xfrm6_ro_input(struct xfrm_state *x, struct sk_buff *skb) { return 0; } static struct xfrm_mode xfrm6_ro_mode = { .input = xfrm6_ro_input, .output = xfrm6_ro_output, .owner = THIS_MODULE, .encap = XFRM_MODE_ROUTEOPTIMIZATION, }; static int __init xfrm6_ro_init(void) { return xfrm_register_mode(&xfrm6_ro_mode, AF_INET6); } static void __exit xfrm6_ro_exit(void) { int err; err = xfrm_unregister_mode(&xfrm6_ro_mode, AF_INET6); BUG_ON(err); } module_init(xfrm6_ro_init); module_exit(xfrm6_ro_exit); MODULE_LICENSE("GPL"); MODULE_ALIAS_XFRM_MODE(AF_INET6, XFRM_MODE_ROUTEOPTIMIZATION);