path: root/net/ipv4/ip_tunnel_core.c
diff options
authorSabrina Dubroca <sd@queasysnail.net>2018-11-16 16:58:19 +0100
committerDavid S. Miller <davem@davemloft.net>2018-11-17 21:50:55 -0800
commit16f7eb2b77b55da816c4e207f3f9440a8cafc00a (patch)
tree36d7653261e4dda4b1766c21f44fc3f5550775a3 /net/ipv4/ip_tunnel_core.c
parentMAINTAINERS: Add entry for CAKE qdisc (diff)
ip_tunnel: don't force DF when MTU is locked
The various types of tunnels running over IPv4 can ask to set the DF bit to do PMTU discovery. However, PMTU discovery is subject to the threshold set by the net.ipv4.route.min_pmtu sysctl, and is also disabled on routes with "mtu lock". In those cases, we shouldn't set the DF bit. This patch makes setting the DF bit conditional on the route's MTU locking state. This issue seems to be older than git history. Signed-off-by: Sabrina Dubroca <sd@queasysnail.net> Reviewed-by: Stefano Brivio <sbrivio@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/ipv4/ip_tunnel_core.c')
1 files changed, 1 insertions, 1 deletions
diff --git a/net/ipv4/ip_tunnel_core.c b/net/ipv4/ip_tunnel_core.c
index dde671e97829..c248e0dccbe1 100644
--- a/net/ipv4/ip_tunnel_core.c
+++ b/net/ipv4/ip_tunnel_core.c
@@ -80,7 +80,7 @@ void iptunnel_xmit(struct sock *sk, struct rtable *rt, struct sk_buff *skb,
iph->version = 4;
iph->ihl = sizeof(struct iphdr) >> 2;
- iph->frag_off = df;
+ iph->frag_off = ip_mtu_locked(&rt->dst) ? 0 : df;
iph->protocol = proto;
iph->tos = tos;
iph->daddr = dst;