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>
194 lines
4.2 KiB
C
194 lines
4.2 KiB
C
// SPDX-License-Identifier: GPL-2.0-or-later
|
|
/*
|
|
* xfrm6_output.c - Common IPsec encapsulation code for IPv6.
|
|
* Copyright (C) 2002 USAGI/WIDE Project
|
|
* Copyright (c) 2004 Herbert Xu <herbert@gondor.apana.org.au>
|
|
*/
|
|
|
|
#include <linux/if_ether.h>
|
|
#include <linux/kernel.h>
|
|
#include <linux/module.h>
|
|
#include <linux/skbuff.h>
|
|
#include <linux/icmpv6.h>
|
|
#include <linux/netfilter_ipv6.h>
|
|
#include <net/dst.h>
|
|
#include <net/ipv6.h>
|
|
#include <net/ip6_route.h>
|
|
#include <net/xfrm.h>
|
|
|
|
int xfrm6_find_1stfragopt(struct xfrm_state *x, struct sk_buff *skb,
|
|
u8 **prevhdr)
|
|
{
|
|
return ip6_find_1stfragopt(skb, prevhdr);
|
|
}
|
|
EXPORT_SYMBOL(xfrm6_find_1stfragopt);
|
|
|
|
static int xfrm6_local_dontfrag(struct sk_buff *skb)
|
|
{
|
|
int proto;
|
|
struct sock *sk = skb->sk;
|
|
|
|
if (sk) {
|
|
if (sk->sk_family != AF_INET6)
|
|
return 0;
|
|
|
|
proto = sk->sk_protocol;
|
|
if (proto == IPPROTO_UDP || proto == IPPROTO_RAW)
|
|
return inet6_sk(sk)->dontfrag;
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
static void xfrm6_local_rxpmtu(struct sk_buff *skb, u32 mtu)
|
|
{
|
|
struct flowi6 fl6;
|
|
struct sock *sk = skb->sk;
|
|
|
|
fl6.flowi6_oif = sk->sk_bound_dev_if;
|
|
fl6.daddr = ipv6_hdr(skb)->daddr;
|
|
|
|
ipv6_local_rxpmtu(sk, &fl6, mtu);
|
|
}
|
|
|
|
void xfrm6_local_error(struct sk_buff *skb, u32 mtu)
|
|
{
|
|
struct flowi6 fl6;
|
|
const struct ipv6hdr *hdr;
|
|
struct sock *sk = skb->sk;
|
|
|
|
hdr = skb->encapsulation ? inner_ipv6_hdr(skb) : ipv6_hdr(skb);
|
|
fl6.fl6_dport = inet_sk(sk)->inet_dport;
|
|
fl6.daddr = hdr->daddr;
|
|
|
|
ipv6_local_error(sk, EMSGSIZE, &fl6, mtu);
|
|
}
|
|
|
|
static int xfrm6_tunnel_check_size(struct sk_buff *skb)
|
|
{
|
|
int mtu, ret = 0;
|
|
struct dst_entry *dst = skb_dst(skb);
|
|
|
|
if (skb->ignore_df)
|
|
goto out;
|
|
|
|
mtu = dst_mtu(dst);
|
|
if (mtu < IPV6_MIN_MTU)
|
|
mtu = IPV6_MIN_MTU;
|
|
|
|
if ((!skb_is_gso(skb) && skb->len > mtu) ||
|
|
(skb_is_gso(skb) &&
|
|
!skb_gso_validate_network_len(skb, ip6_skb_dst_mtu(skb)))) {
|
|
skb->dev = dst->dev;
|
|
skb->protocol = htons(ETH_P_IPV6);
|
|
|
|
if (xfrm6_local_dontfrag(skb))
|
|
xfrm6_local_rxpmtu(skb, mtu);
|
|
else if (skb->sk)
|
|
xfrm_local_error(skb, mtu);
|
|
else
|
|
icmpv6_send(skb, ICMPV6_PKT_TOOBIG, 0, mtu);
|
|
ret = -EMSGSIZE;
|
|
}
|
|
out:
|
|
return ret;
|
|
}
|
|
|
|
int xfrm6_extract_output(struct xfrm_state *x, struct sk_buff *skb)
|
|
{
|
|
int err;
|
|
|
|
err = xfrm6_tunnel_check_size(skb);
|
|
if (err)
|
|
return err;
|
|
|
|
XFRM_MODE_SKB_CB(skb)->protocol = ipv6_hdr(skb)->nexthdr;
|
|
|
|
return xfrm6_extract_header(skb);
|
|
}
|
|
|
|
int xfrm6_output_finish(struct sock *sk, struct sk_buff *skb)
|
|
{
|
|
memset(IP6CB(skb), 0, sizeof(*IP6CB(skb)));
|
|
|
|
#ifdef CONFIG_NETFILTER
|
|
IP6CB(skb)->flags |= IP6SKB_XFRM_TRANSFORMED;
|
|
#endif
|
|
|
|
return xfrm_output(sk, skb);
|
|
}
|
|
|
|
static int __xfrm6_output_state_finish(struct xfrm_state *x, struct sock *sk,
|
|
struct sk_buff *skb)
|
|
{
|
|
const struct xfrm_state_afinfo *afinfo;
|
|
int ret = -EAFNOSUPPORT;
|
|
|
|
rcu_read_lock();
|
|
afinfo = xfrm_state_afinfo_get_rcu(x->outer_mode.family);
|
|
if (likely(afinfo))
|
|
ret = afinfo->output_finish(sk, skb);
|
|
else
|
|
kfree_skb(skb);
|
|
rcu_read_unlock();
|
|
|
|
return ret;
|
|
}
|
|
|
|
static int __xfrm6_output_finish(struct net *net, struct sock *sk, struct sk_buff *skb)
|
|
{
|
|
struct xfrm_state *x = skb_dst(skb)->xfrm;
|
|
|
|
return __xfrm6_output_state_finish(x, sk, skb);
|
|
}
|
|
|
|
static int __xfrm6_output(struct net *net, struct sock *sk, struct sk_buff *skb)
|
|
{
|
|
struct dst_entry *dst = skb_dst(skb);
|
|
struct xfrm_state *x = dst->xfrm;
|
|
int mtu;
|
|
bool toobig;
|
|
|
|
#ifdef CONFIG_NETFILTER
|
|
if (!x) {
|
|
IP6CB(skb)->flags |= IP6SKB_REROUTED;
|
|
return dst_output(net, sk, skb);
|
|
}
|
|
#endif
|
|
|
|
if (x->props.mode != XFRM_MODE_TUNNEL)
|
|
goto skip_frag;
|
|
|
|
if (skb->protocol == htons(ETH_P_IPV6))
|
|
mtu = ip6_skb_dst_mtu(skb);
|
|
else
|
|
mtu = dst_mtu(skb_dst(skb));
|
|
|
|
toobig = skb->len > mtu && !skb_is_gso(skb);
|
|
|
|
if (toobig && xfrm6_local_dontfrag(skb)) {
|
|
xfrm6_local_rxpmtu(skb, mtu);
|
|
kfree_skb(skb);
|
|
return -EMSGSIZE;
|
|
} else if (!skb->ignore_df && toobig && skb->sk) {
|
|
xfrm_local_error(skb, mtu);
|
|
kfree_skb(skb);
|
|
return -EMSGSIZE;
|
|
}
|
|
|
|
if (toobig || dst_allfrag(skb_dst(skb)))
|
|
return ip6_fragment(net, sk, skb,
|
|
__xfrm6_output_finish);
|
|
|
|
skip_frag:
|
|
return __xfrm6_output_state_finish(x, sk, skb);
|
|
}
|
|
|
|
int xfrm6_output(struct net *net, struct sock *sk, struct sk_buff *skb)
|
|
{
|
|
return NF_HOOK_COND(NFPROTO_IPV6, NF_INET_POST_ROUTING,
|
|
net, sk, skb, skb->dev, skb_dst(skb)->dev,
|
|
__xfrm6_output,
|
|
!(IP6CB(skb)->flags & IP6SKB_REROUTED));
|
|
}
|