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https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
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28f8bfd1ac
Instead of generally passing NULL to NF_HOOK_COND() for input device, pass skb->dev which contains input device for routed skbs. Note that iptables (both legacy and nft) reject rules with input interface match from being added to POSTROUTING chains, but nftables allows this. Cc: Eric Garver <eric@garver.life> Signed-off-by: Phil Sutter <phil@nwl.cc> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
107 lines
2.4 KiB
C
107 lines
2.4 KiB
C
// SPDX-License-Identifier: GPL-2.0-or-later
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/*
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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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#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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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->ignore_df)
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goto out;
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mtu = dst_mtu(skb_dst(skb));
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if ((!skb_is_gso(skb) && skb->len > mtu) ||
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(skb_is_gso(skb) &&
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!skb_gso_validate_network_len(skb, ip_skb_dst_mtu(skb->sk, skb)))) {
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skb->protocol = htons(ETH_P_IP);
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if (skb->sk)
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xfrm_local_error(skb, mtu);
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else
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icmp_send(skb, ICMP_DEST_UNREACH,
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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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XFRM_MODE_SKB_CB(skb)->protocol = ip_hdr(skb)->protocol;
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return xfrm4_extract_header(skb);
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}
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int xfrm4_output_finish(struct sock *sk, struct sk_buff *skb)
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{
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memset(IPCB(skb), 0, sizeof(*IPCB(skb)));
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#ifdef CONFIG_NETFILTER
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IPCB(skb)->flags |= IPSKB_XFRM_TRANSFORMED;
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#endif
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return xfrm_output(sk, skb);
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}
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static int __xfrm4_output(struct net *net, struct sock *sk, struct sk_buff *skb)
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{
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struct xfrm_state *x = skb_dst(skb)->xfrm;
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const struct xfrm_state_afinfo *afinfo;
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int ret = -EAFNOSUPPORT;
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#ifdef CONFIG_NETFILTER
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if (!x) {
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IPCB(skb)->flags |= IPSKB_REROUTED;
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return dst_output(net, sk, skb);
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}
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#endif
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rcu_read_lock();
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afinfo = xfrm_state_afinfo_get_rcu(x->outer_mode.family);
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if (likely(afinfo))
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ret = afinfo->output_finish(sk, skb);
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else
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kfree_skb(skb);
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rcu_read_unlock();
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return ret;
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}
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int xfrm4_output(struct net *net, struct sock *sk, struct sk_buff *skb)
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{
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return NF_HOOK_COND(NFPROTO_IPV4, NF_INET_POST_ROUTING,
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net, sk, skb, skb->dev, skb_dst(skb)->dev,
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__xfrm4_output,
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!(IPCB(skb)->flags & IPSKB_REROUTED));
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}
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void xfrm4_local_error(struct sk_buff *skb, u32 mtu)
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{
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struct iphdr *hdr;
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hdr = skb->encapsulation ? inner_ip_hdr(skb) : ip_hdr(skb);
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ip_local_error(skb->sk, EMSGSIZE, hdr->daddr,
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inet_sk(skb->sk)->inet_dport, mtu);
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}
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