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173 lines
3.8 KiB
173 lines
3.8 KiB
/* |
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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/ip6_route.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_local_dontfrag(struct sk_buff *skb) |
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{ |
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int proto; |
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struct sock *sk = skb->sk; |
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if (sk) { |
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if (sk->sk_family != AF_INET6) |
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return 0; |
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proto = sk->sk_protocol; |
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if (proto == IPPROTO_UDP || proto == IPPROTO_RAW) |
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return inet6_sk(sk)->dontfrag; |
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} |
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return 0; |
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} |
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static void xfrm6_local_rxpmtu(struct sk_buff *skb, u32 mtu) |
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{ |
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struct flowi6 fl6; |
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struct sock *sk = skb->sk; |
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fl6.flowi6_oif = sk->sk_bound_dev_if; |
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fl6.daddr = ipv6_hdr(skb)->daddr; |
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ipv6_local_rxpmtu(sk, &fl6, mtu); |
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} |
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void xfrm6_local_error(struct sk_buff *skb, u32 mtu) |
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{ |
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struct flowi6 fl6; |
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const struct ipv6hdr *hdr; |
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struct sock *sk = skb->sk; |
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hdr = skb->encapsulation ? inner_ipv6_hdr(skb) : ipv6_hdr(skb); |
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fl6.fl6_dport = inet_sk(sk)->inet_dport; |
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fl6.daddr = hdr->daddr; |
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ipv6_local_error(sk, EMSGSIZE, &fl6, mtu); |
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} |
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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(skb); |
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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->ignore_df && skb->len > mtu) { |
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skb->dev = dst->dev; |
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if (xfrm6_local_dontfrag(skb)) |
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xfrm6_local_rxpmtu(skb, mtu); |
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else if (skb->sk) |
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xfrm_local_error(skb, mtu); |
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else |
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icmpv6_send(skb, ICMPV6_PKT_TOOBIG, 0, mtu); |
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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 = xfrm_inner_extract_output(x, skb); |
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if (err) |
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return err; |
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skb->ignore_df = 1; |
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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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int xfrm6_output_finish(struct sk_buff *skb) |
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{ |
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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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#ifdef CONFIG_NETFILTER |
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IP6CB(skb)->flags |= IP6SKB_XFRM_TRANSFORMED; |
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#endif |
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return xfrm_output(skb); |
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} |
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static int __xfrm6_output(struct sk_buff *skb) |
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{ |
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struct dst_entry *dst = skb_dst(skb); |
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struct xfrm_state *x = dst->xfrm; |
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int mtu; |
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#ifdef CONFIG_NETFILTER |
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if (!x) { |
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IP6CB(skb)->flags |= IP6SKB_REROUTED; |
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return dst_output(skb); |
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} |
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#endif |
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if (skb->protocol == htons(ETH_P_IPV6)) |
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mtu = ip6_skb_dst_mtu(skb); |
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else |
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mtu = dst_mtu(skb_dst(skb)); |
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if (skb->len > mtu && xfrm6_local_dontfrag(skb)) { |
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xfrm6_local_rxpmtu(skb, mtu); |
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return -EMSGSIZE; |
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} else if (!skb->ignore_df && skb->len > mtu && skb->sk) { |
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xfrm_local_error(skb, mtu); |
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return -EMSGSIZE; |
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} |
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if (x->props.mode == XFRM_MODE_TUNNEL && |
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((skb->len > mtu && !skb_is_gso(skb)) || |
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dst_allfrag(skb_dst(skb)))) { |
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return ip6_fragment(skb, x->outer_mode->afinfo->output_finish); |
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} |
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return x->outer_mode->afinfo->output_finish(skb); |
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} |
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int xfrm6_output(struct sock *sk, struct sk_buff *skb) |
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{ |
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return NF_HOOK_COND(NFPROTO_IPV6, NF_INET_POST_ROUTING, skb, |
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NULL, skb_dst(skb)->dev, __xfrm6_output, |
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!(IP6CB(skb)->flags & IP6SKB_REROUTED)); |
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}
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