On Sat, 14 Mar 2009 10:49:11 +0100 Jiri Pirko <[email protected]> wrote:
> Sat, Mar 14, 2009 at 06:39:32AM CET, [email protected] wrote: > >On Fri, 13 Mar 2009 19:33:04 +0100 > >Jiri Pirko <[email protected]> wrote: > > > >> Hi all. > >> > >> This is only a draft of patch to consult. I'm aware that it should be > >> divided > >> into multiple patches. I want to know opinion from you folks. > >> > >> The problem is described in following bugzilla: > >> https://bugzilla.redhat.com/show_bug.cgi?id=487763 > >> > >> Basically here's what's going on. In every mode, bonding interface uses > >> the same > >> mac address for all enslaved devices. Except for mode balance-alb. When > >> you put > >> this kind of bond device into a bridge it will only add one of mac > >> adresses into > >> a hash list of mac addresses, say X. This mac address is marked as local. > >> But > >> this bonding interface also has mac address Y. Now then packet arrives with > >> destination address Y, this address is not marked as local and the packed > >> looks > >> like it needs to be forwarded. This packet is then lost which is wrong. > >> > >> Notice that interfaces can be added and removed from bond while it is in > >> bridge. > >> Therefore I introduce another function pointer in struct net_device_ops - > >> ndo_check_mac_address. This function when it's implemented should check > >> passed > >> mac address against the one set in device. I'm using this in bonding > >> driver when > >> the bond is in mode balance-alb to walk thru all slaves and checking if > >> any of > >> them equals passed address. > >> > >> Then in bridge function br_handle_frame_finish() I'm using > >> ndo_check_mac_address > >> to recognize the destination mac address as local. > >> > >> Please look at this and tell me what you think about it. > >> > >> Thanks > >> > >> Jirka > >> > > > >A better and more general way to do this have the dev_set_mac_address > >function check the return of the notifier and unwind. Then any protocol > >can easily prevent address from changing. > > Can you please describe this thougth a bit more? I can't understand it now... > > Thanks > > Jirka Something like this: --- a/net/core/dev.c 2009-03-15 15:55:02.098126056 -0700 +++ b/net/core/dev.c 2009-03-15 16:02:43.999251305 -0700 @@ -3830,6 +3830,7 @@ int dev_set_mac_address(struct net_devic { const struct net_device_ops *ops = dev->netdev_ops; int err; + char save_addr[MAX_ADDR_LEN]; if (!ops->ndo_set_mac_address) return -EOPNOTSUPP; @@ -3837,9 +3838,17 @@ int dev_set_mac_address(struct net_devic return -EINVAL; if (!netif_device_present(dev)) return -ENODEV; + + memcpy(save_addr, dev->dev_addr, dev->addr_len); err = ops->ndo_set_mac_address(dev, sa); - if (!err) - call_netdevice_notifiers(NETDEV_CHANGEADDR, dev); + if (err) + return err; + + err = call_netdevice_notifiers(NETDEV_CHANGEADDR, dev); + if (err) { + memcpy(sa->sa_data, save_addr, dev->addr_len); + ops->ndo_set_mac_address(dev, sa); + } return err; } And something like this: --- a/drivers/net/bonding/bond_main.c 2009-03-15 16:03:53.909000973 -0700 +++ b/drivers/net/bonding/bond_main.c 2009-03-15 16:11:43.227127031 -0700 @@ -3534,6 +3534,7 @@ static int bond_slave_netdev_event(unsig { struct net_device *bond_dev = slave_dev->master; struct bonding *bond = netdev_priv(bond_dev); + int err; switch (event) { case NETDEV_UNREGISTER: @@ -3570,6 +3571,15 @@ static int bond_slave_netdev_event(unsig * servitude. */ break; + case NETDEV_CHANGEADDR: + if (bond->params.mode == BOND_MODE_ALB) + err = bond_alb_check_mac_address(bond); + else if (compare_ether_addr(bond_dev->dev_addr, addr) != 0) + err = -EINVAL; + + if (err) + return notifier_from_errno(err); + break; case NETDEV_CHANGENAME: /* * TODO: handle changing the primary's name _______________________________________________ Bridge mailing list [email protected] https://lists.linux-foundation.org/mailman/listinfo/bridge
