From dd767856a36e00b631d65ebc4bb81b19915532d6 Mon Sep 17 00:00:00 2001 From: Steffen Klassert Date: Tue, 11 Oct 2011 01:44:30 +0000 Subject: [PATCH] xfrm6: Don't call icmpv6_send on local error 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 Signed-off-by: David S. Miller --- net/ipv6/xfrm6_output.c | 56 +++++++++++++++++++++++++++++++++++++++-- 1 file changed, 54 insertions(+), 2 deletions(-) diff --git a/net/ipv6/xfrm6_output.c b/net/ipv6/xfrm6_output.c index 49a91c5f5623..faae41737fca 100644 --- a/net/ipv6/xfrm6_output.c +++ b/net/ipv6/xfrm6_output.c @@ -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); }