diff options
| -rw-r--r-- | include/linux/netdevice.h | 4 | ||||
| -rw-r--r-- | net/core/dev.c | 13 |
2 files changed, 15 insertions, 2 deletions
diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h index 780e717..2082b7d 100644 --- a/include/linux/netdevice.h +++ b/include/linux/netdevice.h @@ -1507,6 +1507,8 @@ enum netdev_priv_flags { * @if_port: Selectable AUI, TP, ... * @dma: DMA channel * @mtu: Interface MTU value + * @min_mtu: Interface Minimum MTU value + * @max_mtu: Interface Maximum MTU value * @type: Interface hardware type * @hard_header_len: Maximum hardware header length. * @min_header_len: Minimum hardware header length @@ -1728,6 +1730,8 @@ struct net_device { unsigned char dma; unsigned int mtu; + unsigned int min_mtu; + unsigned int max_mtu; unsigned short type; unsigned short hard_header_len; unsigned short min_header_len; diff --git a/net/core/dev.c b/net/core/dev.c index 2e04fd1..c7ec56e 100644 --- a/net/core/dev.c +++ b/net/core/dev.c @@ -6524,9 +6524,18 @@ int dev_set_mtu(struct net_device *dev, int new_mtu) if (new_mtu == dev->mtu) return 0; - /* MTU must be positive. */ - if (new_mtu < 0) + /* MTU must be positive, and in range */ + if (new_mtu < 0 || new_mtu < dev->min_mtu) { + net_err_ratelimited("%s: Invalid MTU %d requested, hw min %d\n", + dev->name, new_mtu, dev->min_mtu); return -EINVAL; + } + + if (dev->max_mtu > 0 && new_mtu > dev->max_mtu) { + net_err_ratelimited("%s: Invalid MTU %d requested, hw max %d\n", + dev->name, new_mtu, dev->min_mtu); + return -EINVAL; + } if (!netif_device_present(dev)) return -ENODEV; |