| Message ID | 1380808166-13280-1-git-send-email-ou.ghorbel@gmail.com |
|---|---|
| State | Accepted, archived |
| Delegated to: | David Miller |
| Headers | show |
On Thu, Oct 03, 2013 at 02:49:26PM +0100, Oussama Ghorbel wrote: > The (inner) MTU of a ipip6 (IPv4-in-IPv6) tunnel cannot be set below 1280, which is the minimum MTU in IPv6. > However, there should be no IPv6 on the tunnel interface at all, so the IPv6 rules should not apply. > More info at https://bugzilla.kernel.org/show_bug.cgi?id=15530 > > This patch allows to check the minimum MTU for ipv6 tunnel according to these rules: > -In case the tunnel is configured with ipip6 mode the minimum MTU is 68. > -In case the tunnel is configured with ip6ip6 or any mode the minimum MTU is 1280. > > Signed-off-by: Oussama Ghorbel <ou.ghorbel@gmail.com> > --- > net/ipv6/ip6_tunnel.c | 12 ++++++++++-- > 1 file changed, 10 insertions(+), 2 deletions(-) > > diff --git a/net/ipv6/ip6_tunnel.c b/net/ipv6/ip6_tunnel.c > index 46ba243..4b51b03 100644 > --- a/net/ipv6/ip6_tunnel.c > +++ b/net/ipv6/ip6_tunnel.c > @@ -1429,9 +1429,17 @@ ip6_tnl_ioctl(struct net_device *dev, struct ifreq *ifr, int cmd) > static int > ip6_tnl_change_mtu(struct net_device *dev, int new_mtu) > { > - if (new_mtu < IPV6_MIN_MTU) { > - return -EINVAL; > + struct ip6_tnl *tnl = netdev_priv(dev); > + > + if (tnl->parms.proto == IPPROTO_IPIP) { > + if (new_mtu < 68) > + return -EINVAL; > + } else { > + if (new_mtu < IPV6_MIN_MTU) > + return -EINVAL; > } > + if (new_mtu > 0xFFF8 - dev->hard_header_len) > + return -EINVAL; > dev->mtu = new_mtu; > return 0; > } Acked-by: Hannes Frederic Sowa <hannes@stressinduktion.org> Anytime soon we should replace all the FFF8 with a symbolic constant. Thanks, Hannes -- To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
From: Hannes Frederic Sowa <hannes@stressinduktion.org> Date: Fri, 4 Oct 2013 15:32:23 +0200 > On Thu, Oct 03, 2013 at 02:49:26PM +0100, Oussama Ghorbel wrote: >> The (inner) MTU of a ipip6 (IPv4-in-IPv6) tunnel cannot be set below 1280, which is the minimum MTU in IPv6. >> However, there should be no IPv6 on the tunnel interface at all, so the IPv6 rules should not apply. >> More info at https://bugzilla.kernel.org/show_bug.cgi?id=15530 >> >> This patch allows to check the minimum MTU for ipv6 tunnel according to these rules: >> -In case the tunnel is configured with ipip6 mode the minimum MTU is 68. >> -In case the tunnel is configured with ip6ip6 or any mode the minimum MTU is 1280. >> >> Signed-off-by: Oussama Ghorbel <ou.ghorbel@gmail.com> ... > Acked-by: Hannes Frederic Sowa <hannes@stressinduktion.org> Applied, but please do not capitalize "IPv6" when using it as a subsystem prefix in Subject lines. Thanks. -- To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/net/ipv6/ip6_tunnel.c b/net/ipv6/ip6_tunnel.c index 46ba243..4b51b03 100644 --- a/net/ipv6/ip6_tunnel.c +++ b/net/ipv6/ip6_tunnel.c @@ -1429,9 +1429,17 @@ ip6_tnl_ioctl(struct net_device *dev, struct ifreq *ifr, int cmd) static int ip6_tnl_change_mtu(struct net_device *dev, int new_mtu) { - if (new_mtu < IPV6_MIN_MTU) { - return -EINVAL; + struct ip6_tnl *tnl = netdev_priv(dev); + + if (tnl->parms.proto == IPPROTO_IPIP) { + if (new_mtu < 68) + return -EINVAL; + } else { + if (new_mtu < IPV6_MIN_MTU) + return -EINVAL; } + if (new_mtu > 0xFFF8 - dev->hard_header_len) + return -EINVAL; dev->mtu = new_mtu; return 0; }
The (inner) MTU of a ipip6 (IPv4-in-IPv6) tunnel cannot be set below 1280, which is the minimum MTU in IPv6. However, there should be no IPv6 on the tunnel interface at all, so the IPv6 rules should not apply. More info at https://bugzilla.kernel.org/show_bug.cgi?id=15530 This patch allows to check the minimum MTU for ipv6 tunnel according to these rules: -In case the tunnel is configured with ipip6 mode the minimum MTU is 68. -In case the tunnel is configured with ip6ip6 or any mode the minimum MTU is 1280. Signed-off-by: Oussama Ghorbel <ou.ghorbel@gmail.com> --- net/ipv6/ip6_tunnel.c | 12 ++++++++++-- 1 file changed, 10 insertions(+), 2 deletions(-)