diff mbox series

[ipsec,1/2] vti: fix ipv4 pmtu check to honor ip header df

Message ID 20210226213506.506799-2-eyal.birger@gmail.com (mailing list archive)
State Awaiting Upstream
Delegated to: Netdev Maintainers
Headers show
Series vti(6): fix ipv4 pmtu check to honor ip header df | expand

Checks

Context Check Description
netdev/cover_letter success Link
netdev/fixes_present success Link
netdev/patch_count success Link
netdev/tree_selection success Guessed tree name to be net-next
netdev/subject_prefix warning Target tree name not specified in the subject
netdev/cc_maintainers warning 2 maintainers not CCed: dsahern@kernel.org yoshfuji@linux-ipv6.org
netdev/source_inline success Was 0 now: 0
netdev/verify_signedoff success Link
netdev/module_param success Was 0 now: 0
netdev/build_32bit success Errors and warnings before: 0 this patch: 0
netdev/kdoc success Errors and warnings before: 0 this patch: 0
netdev/verify_fixes success Link
netdev/checkpatch success total: 0 errors, 0 warnings, 0 checks, 24 lines checked
netdev/build_allmodconfig_warn success Errors and warnings before: 0 this patch: 0
netdev/header_inline success Link
netdev/stable success Stable not CCed

Commit Message

Eyal Birger Feb. 26, 2021, 9:35 p.m. UTC
Frag needed should only be sent if the header enables DF.

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

Fixes: d6af1a31cc72 ("vti: Add pmtu handling to vti_xmit.")
Signed-off-by: Eyal Birger <eyal.birger@gmail.com>
---
 net/ipv4/ip_vti.c | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)
diff mbox series

Patch

diff --git a/net/ipv4/ip_vti.c b/net/ipv4/ip_vti.c
index abc171e79d3e..613741384490 100644
--- a/net/ipv4/ip_vti.c
+++ b/net/ipv4/ip_vti.c
@@ -218,7 +218,7 @@  static netdev_tx_t vti_xmit(struct sk_buff *skb, struct net_device *dev,
 	}
 
 	if (dst->flags & DST_XFRM_QUEUE)
-		goto queued;
+		goto xmit;
 
 	if (!vti_state_check(dst->xfrm, parms->iph.daddr, parms->iph.saddr)) {
 		dev->stats.tx_carrier_errors++;
@@ -238,6 +238,8 @@  static netdev_tx_t vti_xmit(struct sk_buff *skb, struct net_device *dev,
 	if (skb->len > mtu) {
 		skb_dst_update_pmtu_no_confirm(skb, mtu);
 		if (skb->protocol == htons(ETH_P_IP)) {
+			if (!(ip_hdr(skb)->frag_off & htons(IP_DF)))
+				goto xmit;
 			icmp_send(skb, ICMP_DEST_UNREACH, ICMP_FRAG_NEEDED,
 				  htonl(mtu));
 		} else {
@@ -251,7 +253,7 @@  static netdev_tx_t vti_xmit(struct sk_buff *skb, struct net_device *dev,
 		goto tx_error;
 	}
 
-queued:
+xmit:
 	skb_scrub_packet(skb, !net_eq(tunnel->net, dev_net(dev)));
 	skb_dst_set(skb, dst);
 	skb->dev = skb_dst(skb)->dev;