Commit 16f7eb2b authored by Sabrina Dubroca's avatar Sabrina Dubroca Committed by David S. Miller

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: default avatarSabrina Dubroca <sd@queasysnail.net>
Reviewed-by: default avatarStefano Brivio <sbrivio@redhat.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 8840c3e2
...@@ -80,7 +80,7 @@ void iptunnel_xmit(struct sock *sk, struct rtable *rt, struct sk_buff *skb, ...@@ -80,7 +80,7 @@ void iptunnel_xmit(struct sock *sk, struct rtable *rt, struct sk_buff *skb,
iph->version = 4; iph->version = 4;
iph->ihl = sizeof(struct iphdr) >> 2; iph->ihl = sizeof(struct iphdr) >> 2;
iph->frag_off = df; iph->frag_off = ip_mtu_locked(&rt->dst) ? 0 : df;
iph->protocol = proto; iph->protocol = proto;
iph->tos = tos; iph->tos = tos;
iph->daddr = dst; iph->daddr = dst;
......
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