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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
parent8840c3e2344a456267d7989b97d097e798b28b0b (diff)
downloadlinux-fsi-16f7eb2b77b55da816c4e207f3f9440a8cafc00a.tar.gz
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>
-rw-r--r--net/ipv4/ip_tunnel_core.c2
1 files changed, 1 insertions, 1 deletions
diff --git a/net/ipv4/ip_tunnel_core.c b/net/ipv4/ip_tunnel_core.c
index dde671e978298..c248e0dccbe17 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;