862b82c6f9
As part of the work on asynchrnous cryptographic operations, we need to be able to resume from the spot where they occur. As such, it helps if we isolate them to one spot. This patch moves most of the remaining family-specific processing into the common output code. Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au> Signed-off-by: David S. Miller <davem@davemloft.net>
91 lines
2.0 KiB
C
91 lines
2.0 KiB
C
/*
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* xfrm4_output.c - Common IPsec encapsulation code for IPv4.
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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/netfilter_ipv4.h>
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#include <net/dst.h>
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#include <net/ip.h>
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#include <net/xfrm.h>
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#include <net/icmp.h>
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static int xfrm4_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;
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if (IPCB(skb)->flags & IPSKB_XFRM_TUNNEL_SIZE)
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goto out;
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if (!(ip_hdr(skb)->frag_off & htons(IP_DF)) || skb->local_df)
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goto out;
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dst = skb->dst;
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mtu = dst_mtu(dst);
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if (skb->len > mtu) {
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icmp_send(skb, ICMP_DEST_UNREACH, ICMP_FRAG_NEEDED, htonl(mtu));
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ret = -EMSGSIZE;
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}
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out:
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return ret;
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}
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int xfrm4_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 = xfrm4_tunnel_check_size(skb);
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if (err)
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return err;
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return xfrm4_extract_header(skb);
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}
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int xfrm4_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(IPCB(skb), 0, sizeof(*IPCB(skb)));
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IPCB(skb)->flags |= IPSKB_XFRM_TUNNEL_SIZE | IPSKB_XFRM_TRANSFORMED;
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skb->protocol = htons(ETH_P_IP);
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return x->outer_mode->output2(x, skb);
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}
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EXPORT_SYMBOL(xfrm4_prepare_output);
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static int xfrm4_output_finish(struct sk_buff *skb)
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{
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#ifdef CONFIG_NETFILTER
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if (!skb->dst->xfrm) {
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IPCB(skb)->flags |= IPSKB_REROUTED;
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return dst_output(skb);
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}
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IPCB(skb)->flags |= IPSKB_XFRM_TRANSFORMED;
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#endif
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skb->protocol = htons(ETH_P_IP);
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return xfrm_output(skb);
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}
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int xfrm4_output(struct sk_buff *skb)
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{
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return NF_HOOK_COND(PF_INET, NF_IP_POST_ROUTING, skb, NULL, skb->dst->dev,
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xfrm4_output_finish,
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!(IPCB(skb)->flags & IPSKB_REROUTED));
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}
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