| Message ID | 20180109064837.12916-1-liuqifa@huawei.com |
|---|---|
| State | Changes Requested, archived |
| Delegated to: | David Miller |
| Headers | show |
| Series | ipvlan: fix ipvlan MTU limits | expand |
On Mon, Jan 8, 2018 at 10:48 PM, <liuqifa@huawei.com> wrote: > From: Keefe Liu <liuqifa@huawei.com> > > The MTU of ipvlan interface should not bigger than the phy device, When we > run following scripts, we will find there are some problems. > Step1: > ip link add link eth0 name ipv1 type ipvlan mode l2 > ip netns add net1 > ip link set dev ipv1 netns net1 > Step2: > ip netns exec net1 ip link set dev ipv1 mtu 1501 > RTNETLINK answers: Invalid argument > dmesg info: "ipv1: Invalid MTU 1501 requested, hw max 1500" > Step3: > ip link set dev eth0 mtu 1600 > ip netns exec net1 ip link set dev ipv1 mtu 1501 > RTNETLINK answers: Invalid argument > dmesg info: "ipv1: Invalid MTU 1501 requested, hw max 1500" > Step4: > ip link set dev eth0 mtu 1400 > ip netns exec net1 ip link set dev ipv1 mtu 1500 > The result of Step2 is we expected, but the result of Step3 and Step4 > are not. > > This patch set ipvlan's maximum MTU to ETH_MAX_MTU, and when we change > the ipvlan device's MTU, ipvlan_change_mtu() will make sure the new MTU > no larger than the phy device's MTU. > > Signed-off-by: Keefe Liu <liuqifa@huawei.com> > --- > drivers/net/ipvlan/ipvlan_main.c | 14 ++++++++++++++ > 1 file changed, 14 insertions(+) > > diff --git a/drivers/net/ipvlan/ipvlan_main.c b/drivers/net/ipvlan/ipvlan_main.c > index 30cb803..84c007d 100644 > --- a/drivers/net/ipvlan/ipvlan_main.c > +++ b/drivers/net/ipvlan/ipvlan_main.c > @@ -380,12 +380,24 @@ static int ipvlan_get_iflink(const struct net_device *dev) > return ipvlan->phy_dev->ifindex; > } > > +static int ipvlan_change_mtu(struct net_device *dev, int new_mtu) > +{ > + struct ipvl_dev *ipvlan = netdev_priv(dev); > + > + if (ipvlan->phy_dev->mtu < new_mtu) > + return -EINVAL; > + > + dev->mtu = new_mtu; > + return 0; > +} > + > static const struct net_device_ops ipvlan_netdev_ops = { > .ndo_init = ipvlan_init, > .ndo_uninit = ipvlan_uninit, > .ndo_open = ipvlan_open, > .ndo_stop = ipvlan_stop, > .ndo_start_xmit = ipvlan_start_xmit, > + .ndo_change_mtu = ipvlan_change_mtu, > .ndo_fix_features = ipvlan_fix_features, > .ndo_change_rx_flags = ipvlan_change_rx_flags, > .ndo_set_rx_mode = ipvlan_set_multicast_mac_filter, > @@ -680,6 +692,8 @@ void ipvlan_link_setup(struct net_device *dev) > { > ether_setup(dev); > > + dev->min_mtu = 0; should be ETH_MIN_MTU since we expect the underlying device to be ETH_ARPHDR and IPvlan deals with IPv4/IPv6. > + dev->max_mtu = ETH_MAX_MTU; > dev->priv_flags &= ~(IFF_XMIT_DST_RELEASE | IFF_TX_SKB_SHARING); > dev->priv_flags |= IFF_UNICAST_FLT | IFF_NO_QUEUE; > dev->netdev_ops = &ipvlan_netdev_ops; > -- > 1.8.3.1 > > These changes are not sufficient if you want to have different per-slave mtu settings. One can always change the MTU of the master device and all per-slave settings will get wiped. I don't think that's a desired outcome.
diff --git a/drivers/net/ipvlan/ipvlan_main.c b/drivers/net/ipvlan/ipvlan_main.c index 30cb803..84c007d 100644 --- a/drivers/net/ipvlan/ipvlan_main.c +++ b/drivers/net/ipvlan/ipvlan_main.c @@ -380,12 +380,24 @@ static int ipvlan_get_iflink(const struct net_device *dev) return ipvlan->phy_dev->ifindex; } +static int ipvlan_change_mtu(struct net_device *dev, int new_mtu) +{ + struct ipvl_dev *ipvlan = netdev_priv(dev); + + if (ipvlan->phy_dev->mtu < new_mtu) + return -EINVAL; + + dev->mtu = new_mtu; + return 0; +} + static const struct net_device_ops ipvlan_netdev_ops = { .ndo_init = ipvlan_init, .ndo_uninit = ipvlan_uninit, .ndo_open = ipvlan_open, .ndo_stop = ipvlan_stop, .ndo_start_xmit = ipvlan_start_xmit, + .ndo_change_mtu = ipvlan_change_mtu, .ndo_fix_features = ipvlan_fix_features, .ndo_change_rx_flags = ipvlan_change_rx_flags, .ndo_set_rx_mode = ipvlan_set_multicast_mac_filter, @@ -680,6 +692,8 @@ void ipvlan_link_setup(struct net_device *dev) { ether_setup(dev); + dev->min_mtu = 0; + dev->max_mtu = ETH_MAX_MTU; dev->priv_flags &= ~(IFF_XMIT_DST_RELEASE | IFF_TX_SKB_SHARING); dev->priv_flags |= IFF_UNICAST_FLT | IFF_NO_QUEUE; dev->netdev_ops = &ipvlan_netdev_ops;