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xfrm6: Don't call icmpv6_send on local error

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Calling icmpv6_send() on a local message size error leads to
an incorrect update of the path mtu. So use xfrm6_local_rxpmtu()
to notify about the pmtu if the IPV6_DONTFRAG socket option is
set on an udp or raw socket, according RFC 3542 and use
ipv6_local_error() otherwise.

Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Steffen Klassert 2011-10-11 01:44:30 +00:00 committed by David S. Miller
parent 299b076764
commit dd767856a3
1 changed files with 54 additions and 2 deletions
repo.diff.show_diff_stats Download patch file Download diff file Expand all files Collapse all files

56
net/ipv6/xfrm6_output.c
View file

@ -28,6 +28,43 @@ int xfrm6_find_1stfragopt(struct xfrm_state *x, struct sk_buff *skb,
EXPORT_SYMBOL(xfrm6_find_1stfragopt);
static int xfrm6_local_dontfrag(struct sk_buff *skb)
{
int proto;
struct sock *sk = skb->sk;
if (sk) {
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;
ipv6_addr_copy(&fl6.daddr, &ipv6_hdr(skb)->daddr);
ipv6_local_rxpmtu(sk, &fl6, mtu);
}
static void xfrm6_local_error(struct sk_buff *skb, u32 mtu)
{
struct flowi6 fl6;
struct sock *sk = skb->sk;
fl6.fl6_dport = inet_sk(sk)->inet_dport;
ipv6_addr_copy(&fl6.daddr, &ipv6_hdr(skb)->daddr);
ipv6_local_error(sk, EMSGSIZE, &fl6, mtu);
}
static int xfrm6_tunnel_check_size(struct sk_buff *skb)
{
int mtu, ret = 0;
@ -39,7 +76,13 @@ static int xfrm6_tunnel_check_size(struct sk_buff *skb)
if (!skb->local_df && skb->len > mtu) {
skb->dev = dst->dev;
icmpv6_send(skb, ICMPV6_PKT_TOOBIG, 0, mtu);
if (xfrm6_local_dontfrag(skb))
xfrm6_local_rxpmtu(skb, mtu);
else if (skb->sk)
xfrm6_local_error(skb, mtu);
else
icmpv6_send(skb, ICMPV6_PKT_TOOBIG, 0, mtu);
ret = -EMSGSIZE;
}
@ -93,9 +136,18 @@ static int __xfrm6_output(struct sk_buff *skb)
{
struct dst_entry *dst = skb_dst(skb);
struct xfrm_state *x = dst->xfrm;
int mtu = ip6_skb_dst_mtu(skb);
if (skb->len > mtu && xfrm6_local_dontfrag(skb)) {
xfrm6_local_rxpmtu(skb, mtu);
return -EMSGSIZE;
} else if (!skb->local_df && skb->len > mtu && skb->sk) {
xfrm6_local_error(skb, mtu);
return -EMSGSIZE;
}
if ((x && x->props.mode == XFRM_MODE_TUNNEL) &&
((skb->len > ip6_skb_dst_mtu(skb) && !skb_is_gso(skb)) ||
((skb->len > mtu && !skb_is_gso(skb)) ||
dst_allfrag(skb_dst(skb)))) {
return ip6_fragment(skb, x->outer_mode->afinfo->output_finish);
}