diff options
| -rw-r--r-- | drivers/net/tun.c | 14 |
1 files changed, 14 insertions, 0 deletions
diff --git a/drivers/net/tun.c b/drivers/net/tun.c index d279151f065..d8b8e68ef70 100644 --- a/drivers/net/tun.c +++ b/drivers/net/tun.c @@ -172,6 +172,18 @@ tun_net_mclist(struct net_device *dev) } } +#define MIN_MTU 68 +#define MAX_MTU 65535 + +static int +tun_net_change_mtu(struct net_device *dev, int new_mtu) +{ + if (new_mtu < MIN_MTU || new_mtu + dev->hard_header_len > MAX_MTU) + return -EINVAL; + dev->mtu = new_mtu; + return 0; +} + /* Initialize net device. */ static void tun_net_init(struct net_device *dev) { @@ -183,6 +195,7 @@ static void tun_net_init(struct net_device *dev) dev->hard_header_len = 0; dev->addr_len = 0; dev->mtu = 1500; + dev->change_mtu = tun_net_change_mtu; /* Zero header length */ dev->type = ARPHRD_NONE; @@ -195,6 +208,7 @@ static void tun_net_init(struct net_device *dev) dev->set_multicast_list = tun_net_mclist; ether_setup(dev); + dev->change_mtu = tun_net_change_mtu; /* random address already created for us by tun_set_iff, use it */ memcpy(dev->dev_addr, tun->dev_addr, min(sizeof(tun->dev_addr), sizeof(dev->dev_addr)) ); |