diff options
Diffstat (limited to 'src/net/netdev_settings.c')
| -rw-r--r-- | src/net/netdev_settings.c | 22 |
1 files changed, 15 insertions, 7 deletions
diff --git a/src/net/netdev_settings.c b/src/net/netdev_settings.c index 67a45bede..c54288d4f 100644 --- a/src/net/netdev_settings.c +++ b/src/net/netdev_settings.c @@ -393,7 +393,8 @@ static int apply_netdev_settings ( void ) { struct net_device *netdev; struct settings *settings; struct ll_protocol *ll_protocol; - size_t old_max_pkt_len; + size_t max_mtu; + size_t old_mtu; size_t mtu; int rc; @@ -410,18 +411,25 @@ static int apply_netdev_settings ( void ) { if ( ! mtu ) continue; - /* Update maximum packet length */ + /* Limit MTU to maximum supported by hardware */ ll_protocol = netdev->ll_protocol; - old_max_pkt_len = netdev->max_pkt_len; - netdev->max_pkt_len = ( mtu + ll_protocol->ll_header_len ); - if ( netdev->max_pkt_len != old_max_pkt_len ) { + max_mtu = ( netdev->max_pkt_len - ll_protocol->ll_header_len ); + if ( mtu > max_mtu ) { + DBGC ( netdev, "NETDEV %s cannot support MTU %zd (max " + "%zd)\n", netdev->name, mtu, max_mtu ); + mtu = max_mtu; + } + + /* Update maximum packet length */ + old_mtu = netdev->mtu; + netdev->mtu = mtu; + if ( mtu != old_mtu ) { DBGC ( netdev, "NETDEV %s MTU is %zd\n", netdev->name, mtu ); } /* Close and reopen network device if MTU has increased */ - if ( netdev_is_open ( netdev ) && - ( netdev->max_pkt_len > old_max_pkt_len ) ) { + if ( netdev_is_open ( netdev ) && ( mtu > old_mtu ) ) { netdev_close ( netdev ); if ( ( rc = netdev_open ( netdev ) ) != 0 ) { DBGC ( netdev, "NETDEV %s could not reopen: " |