diff options
| -rw-r--r-- | net/bridge/br.c | 2 | ||||
| -rw-r--r-- | net/bridge/br_device.c | 5 | ||||
| -rw-r--r-- | net/bridge/br_if.c | 36 | ||||
| -rw-r--r-- | net/bridge/br_private.h | 3 |
4 files changed, 26 insertions, 20 deletions
diff --git a/net/bridge/br.c b/net/bridge/br.c index 565ff055813b..671d13c10f6f 100644 --- a/net/bridge/br.c +++ b/net/bridge/br.c @@ -52,7 +52,7 @@ static int br_device_event(struct notifier_block *unused, unsigned long event, v switch (event) { case NETDEV_CHANGEMTU: - dev_set_mtu(br->dev, br_mtu(br, false)); + br_mtu_auto_adjust(br); break; case NETDEV_CHANGEADDR: diff --git a/net/bridge/br_device.c b/net/bridge/br_device.c index edb9967eb165..e682a668ce57 100644 --- a/net/bridge/br_device.c +++ b/net/bridge/br_device.c @@ -225,11 +225,10 @@ static int br_change_mtu(struct net_device *dev, int new_mtu) { struct net_bridge *br = netdev_priv(dev); - if (new_mtu > br_mtu(br, br_vlan_enabled(dev))) - return -EINVAL; - dev->mtu = new_mtu; + /* this flag will be cleared if the MTU was automatically adjusted */ + br->mtu_set_by_user = true; #if IS_ENABLED(CONFIG_BRIDGE_NETFILTER) /* remember the MTU in the rtable for PMTU */ dst_metric_set(&br->fake_rtable.dst, RTAX_MTU, new_mtu); diff --git a/net/bridge/br_if.c b/net/bridge/br_if.c index 7d5dc5a91084..82c1a6f430b3 100644 --- a/net/bridge/br_if.c +++ b/net/bridge/br_if.c @@ -424,28 +424,34 @@ int br_del_bridge(struct net *net, const char *name) return ret; } -/* MTU of the bridge pseudo-device: ETH_DATA_LEN if there are no ports, the - * minimum of the ports if @max is false or the maximum if it's true - */ -int br_mtu(const struct net_bridge *br, bool max) +/* MTU of the bridge pseudo-device: ETH_DATA_LEN or the minimum of the ports */ +static int br_mtu_min(const struct net_bridge *br) { const struct net_bridge_port *p; int ret_mtu = 0; - ASSERT_RTNL(); - - list_for_each_entry(p, &br->port_list, list) { - if (!max) { - if (!ret_mtu || ret_mtu > p->dev->mtu) - ret_mtu = p->dev->mtu; - } else if (p->dev->mtu > ret_mtu) { + list_for_each_entry(p, &br->port_list, list) + if (!ret_mtu || ret_mtu > p->dev->mtu) ret_mtu = p->dev->mtu; - } - } return ret_mtu ? ret_mtu : ETH_DATA_LEN; } +void br_mtu_auto_adjust(struct net_bridge *br) +{ + ASSERT_RTNL(); + + /* if the bridge MTU was manually configured don't mess with it */ + if (br->mtu_set_by_user) + return; + + /* change to the minimum MTU and clear the flag which was set by + * the bridge ndo_change_mtu callback + */ + dev_set_mtu(br->dev, br_mtu_min(br)); + br->mtu_set_by_user = false; +} + static void br_set_gso_limits(struct net_bridge *br) { unsigned int gso_max_size = GSO_MAX_SIZE; @@ -597,7 +603,7 @@ int br_add_if(struct net_bridge *br, struct net_device *dev, if (changed_addr) call_netdevice_notifiers(NETDEV_CHANGEADDR, br->dev); - dev_set_mtu(br->dev, br_mtu(br, false)); + br_mtu_auto_adjust(br); br_set_gso_limits(br); kobject_uevent(&p->kobj, KOBJ_ADD); @@ -644,7 +650,7 @@ int br_del_if(struct net_bridge *br, struct net_device *dev) */ del_nbp(p); - dev_set_mtu(br->dev, br_mtu(br, false)); + br_mtu_auto_adjust(br); br_set_gso_limits(br); spin_lock_bh(&br->lock); diff --git a/net/bridge/br_private.h b/net/bridge/br_private.h index 586f84b9670d..a7cb3ece5031 100644 --- a/net/bridge/br_private.h +++ b/net/bridge/br_private.h @@ -410,6 +410,7 @@ struct net_bridge { int offload_fwd_mark; #endif bool neigh_suppress_enabled; + bool mtu_set_by_user; struct hlist_head fdb_list; }; @@ -578,7 +579,7 @@ int br_del_bridge(struct net *net, const char *name); int br_add_if(struct net_bridge *br, struct net_device *dev, struct netlink_ext_ack *extack); int br_del_if(struct net_bridge *br, struct net_device *dev); -int br_mtu(const struct net_bridge *br, bool max); +void br_mtu_auto_adjust(struct net_bridge *br); netdev_features_t br_features_recompute(struct net_bridge *br, netdev_features_t features); void br_port_flags_change(struct net_bridge_port *port, unsigned long mask); |