linux_dsm_epyc7002/net/ipv6/xfrm6_output.c
Steffen Klassert 044a832a77 xfrm: Fix local error reporting crash with interfamily tunnels
We set the outer mode protocol too early. As a result, the
local error handler might dispatch to the wrong address family
and report the error to a wrong socket type. We fix this by
setting the outer protocol to the skb after we accessed the
inner mode for the last time, right before we do the atcual
encapsulation where we switch finally to the outer mode.

Reported-by: Chris Ruehl <chris.ruehl@gtsys.com.hk>
Tested-by: Chris Ruehl <chris.ruehl@gtsys.com.hk>
Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>
2015-02-09 11:14:17 +01:00

174 lines
3.8 KiB
C

/*
* 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>
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation; either version
* 2 of the License, or (at your option) any later version.
*/
#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);
mtu = dst_mtu(dst);
if (mtu < IPV6_MIN_MTU)
mtu = IPV6_MIN_MTU;
if (!skb->ignore_df && skb->len > mtu) {
skb->dev = dst->dev;
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;
}
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_prepare_output(struct xfrm_state *x, struct sk_buff *skb)
{
int err;
err = xfrm_inner_extract_output(x, skb);
if (err)
return err;
skb->ignore_df = 1;
skb->protocol = htons(ETH_P_IPV6);
return x->outer_mode->output2(x, skb);
}
EXPORT_SYMBOL(xfrm6_prepare_output);
int xfrm6_output_finish(struct sk_buff *skb)
{
memset(IP6CB(skb), 0, sizeof(*IP6CB(skb)));
#ifdef CONFIG_NETFILTER
IP6CB(skb)->flags |= IP6SKB_XFRM_TRANSFORMED;
#endif
return xfrm_output(skb);
}
static int __xfrm6_output(struct sk_buff *skb)
{
struct dst_entry *dst = skb_dst(skb);
struct xfrm_state *x = dst->xfrm;
int mtu;
#ifdef CONFIG_NETFILTER
if (!x) {
IP6CB(skb)->flags |= IP6SKB_REROUTED;
return dst_output(skb);
}
#endif
if (skb->protocol == htons(ETH_P_IPV6))
mtu = ip6_skb_dst_mtu(skb);
else
mtu = dst_mtu(skb_dst(skb));
if (skb->len > mtu && xfrm6_local_dontfrag(skb)) {
xfrm6_local_rxpmtu(skb, mtu);
return -EMSGSIZE;
} else if (!skb->ignore_df && skb->len > mtu && skb->sk) {
xfrm_local_error(skb, mtu);
return -EMSGSIZE;
}
if (x->props.mode == XFRM_MODE_TUNNEL &&
((skb->len > mtu && !skb_is_gso(skb)) ||
dst_allfrag(skb_dst(skb)))) {
return ip6_fragment(skb, x->outer_mode->afinfo->output_finish);
}
return x->outer_mode->afinfo->output_finish(skb);
}
int xfrm6_output(struct sock *sk, struct sk_buff *skb)
{
return NF_HOOK_COND(NFPROTO_IPV6, NF_INET_POST_ROUTING, skb,
NULL, skb_dst(skb)->dev, __xfrm6_output,
!(IP6CB(skb)->flags & IP6SKB_REROUTED));
}