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28a89453b1
This is a long-standing bug in the IPsec IPv6 code that breaks when we emit a IPsec tunnel-mode datagram packet. The problem is that the code the emits the packet assumes the IPv6 stack will fragment it later, but the IPv6 stack assumes that whoever is emitting the packet is going to pre-fragment the packet. In the long term we need to fix both sides, e.g., to get the datagram code to pre-fragment as well as to get the IPv6 stack to fragment locally generated tunnel-mode packet. For now this patch does the second part which should make it work for the IPsec host case. Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au> Signed-off-by: David S. Miller <davem@davemloft.net>
94 lines
2.1 KiB
C
94 lines
2.1 KiB
C
/*
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* xfrm6_output.c - Common IPsec encapsulation code for IPv6.
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* Copyright (C) 2002 USAGI/WIDE Project
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* Copyright (c) 2004 Herbert Xu <herbert@gondor.apana.org.au>
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*
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* This program is free software; you can redistribute it and/or
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* modify it under the terms of the GNU General Public License
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* as published by the Free Software Foundation; either version
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* 2 of the License, or (at your option) any later version.
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*/
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#include <linux/if_ether.h>
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#include <linux/kernel.h>
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#include <linux/module.h>
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#include <linux/skbuff.h>
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#include <linux/icmpv6.h>
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#include <linux/netfilter_ipv6.h>
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#include <net/dst.h>
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#include <net/ipv6.h>
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#include <net/xfrm.h>
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int xfrm6_find_1stfragopt(struct xfrm_state *x, struct sk_buff *skb,
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u8 **prevhdr)
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{
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return ip6_find_1stfragopt(skb, prevhdr);
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}
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EXPORT_SYMBOL(xfrm6_find_1stfragopt);
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static int xfrm6_tunnel_check_size(struct sk_buff *skb)
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{
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int mtu, ret = 0;
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struct dst_entry *dst = skb->dst;
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mtu = dst_mtu(dst);
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if (mtu < IPV6_MIN_MTU)
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mtu = IPV6_MIN_MTU;
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if (!skb->local_df && skb->len > mtu) {
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skb->dev = dst->dev;
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icmpv6_send(skb, ICMPV6_PKT_TOOBIG, 0, mtu, skb->dev);
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ret = -EMSGSIZE;
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}
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return ret;
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}
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int xfrm6_extract_output(struct xfrm_state *x, struct sk_buff *skb)
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{
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int err;
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err = xfrm6_tunnel_check_size(skb);
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if (err)
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return err;
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XFRM_MODE_SKB_CB(skb)->protocol = ipv6_hdr(skb)->nexthdr;
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return xfrm6_extract_header(skb);
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}
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int xfrm6_prepare_output(struct xfrm_state *x, struct sk_buff *skb)
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{
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int err;
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err = x->inner_mode->afinfo->extract_output(x, skb);
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if (err)
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return err;
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memset(IP6CB(skb), 0, sizeof(*IP6CB(skb)));
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#ifdef CONFIG_NETFILTER
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IP6CB(skb)->flags |= IP6SKB_XFRM_TRANSFORMED;
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#endif
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skb->protocol = htons(ETH_P_IPV6);
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return x->outer_mode->output2(x, skb);
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}
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EXPORT_SYMBOL(xfrm6_prepare_output);
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static int xfrm6_output_finish(struct sk_buff *skb)
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{
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#ifdef CONFIG_NETFILTER
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IP6CB(skb)->flags |= IP6SKB_XFRM_TRANSFORMED;
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#endif
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skb->protocol = htons(ETH_P_IPV6);
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return xfrm_output(skb);
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}
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int xfrm6_output(struct sk_buff *skb)
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{
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return NF_HOOK(PF_INET6, NF_INET_POST_ROUTING, skb, NULL, skb->dst->dev,
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xfrm6_output_finish);
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}
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