diff mbox series

[ipsec,v2] xfrm: interface: fix ipv4 pmtu check to honor ip header df

Message ID 20210220130115.2914135-1-eyal.birger@gmail.com (mailing list archive)
State Awaiting Upstream
Delegated to: Netdev Maintainers
Headers show
Series [ipsec,v2] xfrm: interface: fix ipv4 pmtu check to honor ip header df | expand

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netdev/cc_maintainers fail 3 blamed authors not CCed: lorenzo@google.com shannon.nelson@oracle.com benedictwong@google.com; 3 maintainers not CCed: lorenzo@google.com shannon.nelson@oracle.com benedictwong@google.com
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netdev/module_param success Was 0 now: 0
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netdev/build_allmodconfig_warn success Errors and warnings before: 0 this patch: 0
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netdev/stable success Stable not CCed

Commit Message

Eyal Birger Feb. 20, 2021, 1:01 p.m. UTC
Frag needed should only be sent if the header enables DF.

This fix allows packets larger than MTU to pass the xfrm interface
and be fragmented after encapsulation, aligning behavior with
non-interface xfrm.

Fixes: f203b76d7809 ("xfrm: Add virtual xfrm interfaces")
Signed-off-by: Eyal Birger <eyal.birger@gmail.com>

-----

v2: better align coding with ip_vti
---
 net/xfrm/xfrm_interface.c | 3 +++
 1 file changed, 3 insertions(+)

Comments

Sabrina Dubroca Feb. 23, 2021, 3:12 p.m. UTC | #1
2021-02-20, 15:01:15 +0200, Eyal Birger wrote:
> Frag needed should only be sent if the header enables DF.
> 
> This fix allows packets larger than MTU to pass the xfrm interface
> and be fragmented after encapsulation, aligning behavior with
> non-interface xfrm.
> 
> Fixes: f203b76d7809 ("xfrm: Add virtual xfrm interfaces")
> Signed-off-by: Eyal Birger <eyal.birger@gmail.com>
> 
> -----
> 
> v2: better align coding with ip_vti

LGTM. We also need to do the same thing in ip_vti and ip6_vti. Do you
want to take care of it, or should I?

Either way, for this patch:
Reviewed-by: Sabrina Dubroca <sd@queasysnail.net>
Bram Yvahk Feb. 23, 2021, 3:24 p.m. UTC | #2
On 23/02/2021 16:12, Sabrina Dubroca wrote:
> LGTM. We also need to do the same thing in ip_vti and ip6_vti. Do you
> want to take care of it, or should I?
>   
See the thread
https://lore.kernel.org/netdev/1552865877-13401-1-git-send-email-bram-yvahk@mail.wizbit.be/
(I'm assuming the patches no longer applies cleanly but given that I was
ignored last time I will not be resubmitting them.)

--
Bram
Eyal Birger Feb. 23, 2021, 3:37 p.m. UTC | #3
Hi,

On Tue, Feb 23, 2021 at 5:18 PM Sabrina Dubroca <sd@queasysnail.net> wrote:
>
> 2021-02-20, 15:01:15 +0200, Eyal Birger wrote:
> > Frag needed should only be sent if the header enables DF.
> >
> > This fix allows packets larger than MTU to pass the xfrm interface
> > and be fragmented after encapsulation, aligning behavior with
> > non-interface xfrm.
> >
> > Fixes: f203b76d7809 ("xfrm: Add virtual xfrm interfaces")
> > Signed-off-by: Eyal Birger <eyal.birger@gmail.com>
> >
> > -----
> >
> > v2: better align coding with ip_vti
>
> LGTM. We also need to do the same thing in ip_vti and ip6_vti. Do you
> want to take care of it, or should I?

I can submit the same fix for vti{,6}.

>
> Either way, for this patch:
> Reviewed-by: Sabrina Dubroca <sd@queasysnail.net>

Thanks!
Eyal.
Steffen Klassert Feb. 23, 2021, 5:26 p.m. UTC | #4
On Tue, Feb 23, 2021 at 04:12:34PM +0100, Sabrina Dubroca wrote:
> 2021-02-20, 15:01:15 +0200, Eyal Birger wrote:
> > Frag needed should only be sent if the header enables DF.
> > 
> > This fix allows packets larger than MTU to pass the xfrm interface
> > and be fragmented after encapsulation, aligning behavior with
> > non-interface xfrm.
> > 
> > Fixes: f203b76d7809 ("xfrm: Add virtual xfrm interfaces")
> > Signed-off-by: Eyal Birger <eyal.birger@gmail.com>
> > 
> > -----
> > 
> > v2: better align coding with ip_vti
> 
> LGTM. We also need to do the same thing in ip_vti and ip6_vti. Do you
> want to take care of it, or should I?
> 
> Either way, for this patch:
> Reviewed-by: Sabrina Dubroca <sd@queasysnail.net>

Applied, thanks everyone!
diff mbox series

Patch

diff --git a/net/xfrm/xfrm_interface.c b/net/xfrm/xfrm_interface.c
index 697cdcfbb5e1..3f42c2f15ba4 100644
--- a/net/xfrm/xfrm_interface.c
+++ b/net/xfrm/xfrm_interface.c
@@ -305,6 +305,8 @@  xfrmi_xmit2(struct sk_buff *skb, struct net_device *dev, struct flowi *fl)
 
 			icmpv6_ndo_send(skb, ICMPV6_PKT_TOOBIG, 0, mtu);
 		} else {
+			if (!(ip_hdr(skb)->frag_off & htons(IP_DF)))
+				goto xmit;
 			icmp_ndo_send(skb, ICMP_DEST_UNREACH, ICMP_FRAG_NEEDED,
 				      htonl(mtu));
 		}
@@ -313,6 +315,7 @@  xfrmi_xmit2(struct sk_buff *skb, struct net_device *dev, struct flowi *fl)
 		return -EMSGSIZE;
 	}
 
+xmit:
 	xfrmi_scrub_packet(skb, !net_eq(xi->net, dev_net(dev)));
 	skb_dst_set(skb, dst);
 	skb->dev = tdev;