36cf9acf93
With inter-family transforms the inner mode differs from the outer mode. Attempting to handle both sides from the same function means that it needs to handle both IPv4 and IPv6 which creates duplication and confusion. This patch separates the two parts on the output path so that each function deals with one family only. In particular, the functions xfrm4_extract_output/xfrm6_extract_output moves the pertinent fields from the IPv4/IPv6 IP headers into a neutral format stored in skb->cb. This is then used by the outer mode output functions to write the outer IP header. In this way the output function no longer has to know about the inner address family. Since the extract functions are only called by tunnel modes (the only modes that can support inter-family transforms), I've also moved the xfrm*_tunnel_check_size calls into them. This allows the correct ICMP message to be sent as opposed to now where you might call icmp_send with an IPv6 packet and vice versa. Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au> Signed-off-by: David S. Miller <davem@davemloft.net>
161 lines
3.1 KiB
C
161 lines
3.1 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->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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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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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 inline int xfrm6_output_one(struct sk_buff *skb)
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{
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struct ipv6hdr *iph;
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int err;
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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 = ipv6_hdr(skb);
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iph->payload_len = htons(skb->len - sizeof(*iph));
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IP6CB(skb)->flags |= IP6SKB_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 xfrm6_output_finish2(struct sk_buff *skb)
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{
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int err;
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while (likely((err = xfrm6_output_one(skb)) == 0)) {
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nf_reset(skb);
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err = nf_hook(PF_INET6, NF_IP6_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_INET6, NF_IP6_POST_ROUTING, skb, NULL,
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skb->dst->dev, xfrm6_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 xfrm6_output_finish(struct sk_buff *skb)
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{
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struct sk_buff *segs;
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if (!skb_is_gso(skb))
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return xfrm6_output_finish2(skb);
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skb->protocol = htons(ETH_P_IPV6);
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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 = xfrm6_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 xfrm6_output(struct sk_buff *skb)
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{
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return NF_HOOK(PF_INET6, NF_IP6_POST_ROUTING, skb, NULL, skb->dst->dev,
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xfrm6_output_finish);
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}
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