linux/net/ipv6/xfrm6_output.c
Vadim Fedorenko 40fc3054b4 net: ipv6: fix return value of ip6_skb_dst_mtu
Commit 628a5c5618 ("[INET]: Add IP(V6)_PMTUDISC_RPOBE") introduced
ip6_skb_dst_mtu with return value of signed int which is inconsistent
with actually returned values. Also 2 users of this function actually
assign its value to unsigned int variable and only __xfrm6_output
assigns result of this function to signed variable but actually uses
as unsigned in further comparisons and calls. Change this function
to return unsigned int value.

Fixes: 628a5c5618 ("[INET]: Add IP(V6)_PMTUDISC_RPOBE")
Reviewed-by: David Ahern <dsahern@kernel.org>
Signed-off-by: Vadim Fedorenko <vfedorenko@novek.ru>
Signed-off-by: David S. Miller <davem@davemloft.net>
2021-07-02 11:57:01 -07:00

97 lines
2.3 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>
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_output_finish(struct net *net, struct sock *sk, struct sk_buff *skb)
{
return xfrm_output(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;
unsigned 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->sk)) {
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 xfrm_output(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));
}