1/* 2 * xfrm6_output.c - Common IPsec encapsulation code for IPv6. 3 * Copyright (C) 2002 USAGI/WIDE Project 4 * Copyright (c) 2004 Herbert Xu <herbert@gondor.apana.org.au> 5 * 6 * This program is free software; you can redistribute it and/or 7 * modify it under the terms of the GNU General Public License 8 * as published by the Free Software Foundation; either version 9 * 2 of the License, or (at your option) any later version. 10 */ 11 12#include <linux/if_ether.h> 13#include <linux/kernel.h> 14#include <linux/module.h> 15#include <linux/skbuff.h> 16#include <linux/icmpv6.h> 17#include <linux/netfilter_ipv6.h> 18#include <net/dst.h> 19#include <net/ipv6.h> 20#include <net/xfrm.h> 21 22int xfrm6_find_1stfragopt(struct xfrm_state *x, struct sk_buff *skb, 23 u8 **prevhdr) 24{ 25 return ip6_find_1stfragopt(skb, prevhdr); 26} 27 28EXPORT_SYMBOL(xfrm6_find_1stfragopt); 29 30static int xfrm6_tunnel_check_size(struct sk_buff *skb) 31{ 32 int mtu, ret = 0; 33 struct dst_entry *dst = skb_dst(skb); 34 35 mtu = dst_mtu(dst); 36 if (mtu < IPV6_MIN_MTU) 37 mtu = IPV6_MIN_MTU; 38 39 if (!skb->local_df && skb->len > mtu) { 40 skb->dev = dst->dev; 41 icmpv6_send(skb, ICMPV6_PKT_TOOBIG, 0, mtu); 42 ret = -EMSGSIZE; 43 } 44 45 return ret; 46} 47 48int xfrm6_extract_output(struct xfrm_state *x, struct sk_buff *skb) 49{ 50 int err; 51 52 err = xfrm6_tunnel_check_size(skb); 53 if (err) 54 return err; 55 56 XFRM_MODE_SKB_CB(skb)->protocol = ipv6_hdr(skb)->nexthdr; 57 58 return xfrm6_extract_header(skb); 59} 60 61int xfrm6_prepare_output(struct xfrm_state *x, struct sk_buff *skb) 62{ 63 int err; 64 65 err = xfrm_inner_extract_output(x, skb); 66 if (err) 67 return err; 68 69 memset(IP6CB(skb), 0, sizeof(*IP6CB(skb))); 70#ifdef CONFIG_NETFILTER 71 IP6CB(skb)->flags |= IP6SKB_XFRM_TRANSFORMED; 72#endif 73 74 skb->protocol = htons(ETH_P_IPV6); 75 skb->local_df = 1; 76 77 return x->outer_mode->output2(x, skb); 78} 79EXPORT_SYMBOL(xfrm6_prepare_output); 80 81static int xfrm6_output_finish(struct sk_buff *skb) 82{ 83#ifdef CONFIG_NETFILTER 84 IP6CB(skb)->flags |= IP6SKB_XFRM_TRANSFORMED; 85#endif 86 87 skb->protocol = htons(ETH_P_IPV6); 88 return xfrm_output(skb); 89} 90 91int xfrm6_output(struct sk_buff *skb) 92{ 93 return NF_HOOK(NFPROTO_IPV6, NF_INET_POST_ROUTING, skb, NULL, 94 skb_dst(skb)->dev, xfrm6_output_finish); 95} 96