ceb1eec829
This patch moves the setting of the IP length and checksum fields out of the transforms and into the xfrmX_output functions. This would help future efforts in merging the transforms themselves. It also adds an optimisation to ipcomp due to the fact that the transport offset is guaranteed to be zero. Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au> Signed-off-by: David S. Miller <davem@davemloft.net>
145 lines
2.9 KiB
C
145 lines
2.9 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/compiler.h>
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#include <linux/if_ether.h>
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#include <linux/kernel.h>
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#include <linux/skbuff.h>
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#include <linux/netfilter_ipv4.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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IPCB(skb)->flags |= IPSKB_XFRM_TUNNEL_SIZE;
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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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static inline int xfrm4_output_one(struct sk_buff *skb)
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{
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struct dst_entry *dst = skb->dst;
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struct xfrm_state *x = dst->xfrm;
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struct iphdr *iph;
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int err;
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if (x->props.mode == XFRM_MODE_TUNNEL) {
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err = xfrm4_tunnel_check_size(skb);
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if (err)
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goto error_nolock;
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}
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err = xfrm_output(skb);
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if (err)
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goto error_nolock;
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iph = ip_hdr(skb);
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iph->tot_len = htons(skb->len);
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ip_send_check(iph);
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IPCB(skb)->flags |= IPSKB_XFRM_TRANSFORMED;
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err = 0;
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out_exit:
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return err;
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error_nolock:
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kfree_skb(skb);
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goto out_exit;
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}
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static int xfrm4_output_finish2(struct sk_buff *skb)
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{
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int err;
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while (likely((err = xfrm4_output_one(skb)) == 0)) {
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nf_reset(skb);
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err = nf_hook(PF_INET, NF_IP_LOCAL_OUT, &skb, NULL,
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skb->dst->dev, dst_output);
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if (unlikely(err != 1))
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break;
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if (!skb->dst->xfrm)
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return dst_output(skb);
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err = nf_hook(PF_INET, NF_IP_POST_ROUTING, &skb, NULL,
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skb->dst->dev, xfrm4_output_finish2);
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if (unlikely(err != 1))
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break;
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}
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return err;
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}
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static int xfrm4_output_finish(struct sk_buff *skb)
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{
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struct sk_buff *segs;
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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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#endif
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if (!skb_is_gso(skb))
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return xfrm4_output_finish2(skb);
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skb->protocol = htons(ETH_P_IP);
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segs = skb_gso_segment(skb, 0);
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kfree_skb(skb);
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if (unlikely(IS_ERR(segs)))
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return PTR_ERR(segs);
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do {
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struct sk_buff *nskb = segs->next;
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int err;
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segs->next = NULL;
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err = xfrm4_output_finish2(segs);
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if (unlikely(err)) {
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while ((segs = nskb)) {
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nskb = segs->next;
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segs->next = NULL;
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kfree_skb(segs);
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}
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return err;
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}
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segs = nskb;
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} while (segs);
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return 0;
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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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