The limitation to only 1500 byte mtu's limits the utility of the veth device for testing routing.
Signed-off-by: Eric Biederman <[email protected]> --- drivers/net/veth.c | 24 +++++++++++++++++++++++- 1 files changed, 23 insertions(+), 1 deletions(-) diff --git a/drivers/net/veth.c b/drivers/net/veth.c index 124fe75..88778bb 100644 --- a/drivers/net/veth.c +++ b/drivers/net/veth.c @@ -19,6 +19,10 @@ #define DRV_NAME "veth" #define DRV_VERSION "1.0" +#define MIN_MTU 68 /* Min L3 MTU */ +#define MAX_MTU 65535 /* Max L3 MTU (arbitrary) */ +#define MTU_PAD (ETH_HLEN + 4) /* Max difference between L2 and L3 size MTU */ + struct veth_net_stats { unsigned long rx_packets; unsigned long tx_packets; @@ -159,7 +163,7 @@ static int veth_xmit(struct sk_buff *skb, struct net_device *dev) cpu = smp_processor_id(); stats = per_cpu_ptr(priv->stats, cpu); - if (!(rcv->flags & IFF_UP)) + if (!(rcv->flags & IFF_UP) || (skb->len > (rcv->mtu + MTU_PAD))) goto outf; skb->pkt_type = PACKET_HOST; @@ -249,6 +253,19 @@ static int veth_close(struct net_device *dev) return 0; } +static int is_valid_veth_mtu(int new_mtu) +{ + return (new_mtu >= MIN_MTU && new_mtu <= MAX_MTU); +} + +static int veth_change_mtu(struct net_device *dev, int new_mtu) +{ + if (is_valid_veth_mtu(new_mtu)) + return -EINVAL; + dev->mtu = new_mtu; + return 0; +} + static int veth_dev_init(struct net_device *dev) { struct veth_net_stats *stats; @@ -277,6 +294,7 @@ static const struct net_device_ops veth_netdev_ops = { .ndo_open = veth_open, .ndo_stop = veth_close, .ndo_start_xmit = veth_xmit, + .ndo_change_mtu = veth_change_mtu, .ndo_get_stats = veth_get_stats, .ndo_set_mac_address = eth_mac_addr, }; @@ -303,6 +321,10 @@ static int veth_validate(struct nlattr *tb[], struct nlattr *data[]) if (!is_valid_ether_addr(nla_data(tb[IFLA_ADDRESS]))) return -EADDRNOTAVAIL; } + if (tb[IFLA_MTU]) { + if (is_valid_veth_mtu(nla_get_u32(tb[IFLA_MTU]))) + return -EINVAL; + } return 0; } -- 1.6.1.2.350.g88cc _______________________________________________ Containers mailing list [email protected] https://lists.linux-foundation.org/mailman/listinfo/containers _______________________________________________ Devel mailing list [email protected] https://openvz.org/mailman/listinfo/devel
