Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit b4331a68 authored by Stefano Brivio's avatar Stefano Brivio Committed by Steffen Klassert
Browse files

vti6: Change minimum MTU to IPV4_MIN_MTU, vti6 can carry IPv4 too 



A vti6 interface can carry IPv4 as well, so it makes no sense to
enforce a minimum MTU of IPV6_MIN_MTU.

If the user sets an MTU below IPV6_MIN_MTU, IPv6 will be
disabled on the interface, courtesy of addrconf_notify().

Reported-by: default avatarXin Long <lucien.xin@gmail.com>
Fixes: b96f9afe ("ipv4/6: use core net MTU range checking")
Fixes: c6741fbe ("vti6: Properly adjust vti6 MTU from MTU of lower device")
Fixes: 53c81e95 ("ip6_vti: adjust vti mtu according to mtu of lower device")
Signed-off-by: default avatarStefano Brivio <sbrivio@redhat.com>
Signed-off-by: default avatarSteffen Klassert <steffen.klassert@secunet.com>
parent b48c05ab

net/ipv6/ip6_vti.c

+2 −2
Original line number Diff line number Diff line
@@ -669,7 +669,7 @@ static void vti6_link_config(struct ip6_tnl *t, bool keep_mtu) 
	else

		mtu = ETH_DATA_LEN - LL_MAX_HEADER - sizeof(struct ipv6hdr);



	dev->mtu = max_t(int, mtu, IPV6_MIN_MTU);

	dev->mtu = max_t(int, mtu, IPV4_MIN_MTU);

}



/**
@@ -881,7 +881,7 @@ static void vti6_dev_setup(struct net_device *dev) 
	dev->priv_destructor = vti6_dev_free;



	dev->type = ARPHRD_TUNNEL6;

	dev->min_mtu = IPV6_MIN_MTU;

	dev->min_mtu = IPV4_MIN_MTU;

	dev->max_mtu = IP_MAX_MTU - sizeof(struct ipv6hdr);

	dev->flags |= IFF_NOARP;

	dev->addr_len = sizeof(struct in6_addr);