ipv4: ipv4_default_advmss() should use route mtu

ipv4_default_advmss() incorrectly uses the device MTU instead
of the route provided one. IPv6 has the proper behavior,
lets harmonize the two protocols.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Eric Dumazet 2017-10-18 17:02:03 -07:00 committed by David S. Miller
parent 520d0d75dd
commit 164a5e7ad5

View File

@ -1250,7 +1250,7 @@ static void set_class_tag(struct rtable *rt, u32 tag)
static unsigned int ipv4_default_advmss(const struct dst_entry *dst)
{
unsigned int header_size = sizeof(struct tcphdr) + sizeof(struct iphdr);
unsigned int advmss = max_t(unsigned int, dst->dev->mtu - header_size,
unsigned int advmss = max_t(unsigned int, ipv4_mtu(dst) - header_size,
ip_rt_min_advmss);
return min(advmss, IPV4_MAX_PMTU - header_size);