Jiri Pirko a écrit : > [PATCH net-next] bonding: allow bond in mode balance-alb to work properly in bridge -try4.2 > > (updated) > changes v4.1 -> v4.2 > - use skb->pkt_type == PACKET_HOST compare rather then comparing skb dest addr > against skb->dev->dev_addr > > Hi all. > > 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 fail_over_mac). Only balance-alb > will simultaneously use multiple MAC addresses across different slaves. 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. > > *** > When the multiple addresses for bridge port approach failed to solve this issue > due to STP I started to think other way to solve this. I returned to previous > solution but tweaked one. > > This patch solves the situation in the bonding without touching bridge code. > For every incoming frame to bonding the destination address is compared to > current address of the slave device from which tha packet came. If these two > match destination address is replaced by mac address of the master. This address > is known by bridge so it is delivered properly. Note that the comparsion is not > made directly, it's used skb->pkt_type == PACKET_HOST instead. This is "set" > previously in eth_type_trans(). > > I experimentally tried that this works as good as searching through the slave > list (v4 of this patch). > > I was forced to create a new header because I need to use > compare_ether_addr_64bits() (defined in linux/etherdevice.h) in > linux/netdevice.h. I've hit some cross include issues. I think that it's good > to have skb_bond_should_drop() in a separate file anyway. > > Jirka > > > Signed-off-by: Jiri Pirko <jpirko@xxxxxxxxxx> > > diff --git a/include/linux/bonding.h b/include/linux/bonding.h > new file mode 100644 > index 0000000..e50939d > --- /dev/null > +++ b/include/linux/bonding.h > @@ -0,0 +1,78 @@ > +/* > + * include/linux/bonding.h > + * > + * Copyright (C) 2009 Jiri Pirko <jpirko@xxxxxxxxxx> > + * > + * This program is free software; you can redistribute it and/or modify > + * it under the terms of the GNU General Public License version 2 > + * as published by the Free Software Foundation. > + * > + * Bonding device helpers. > + */ > + > +#ifndef _LINUX_BONDING_H > +#define _LINUX_BONDING_H > + > +#ifdef __KERNEL__ > + > +#include <linux/skbuff.h> > +#include <linux/netdevice.h> > +#include <linux/if.h> > +#include <linux/etherdevice.h> > +#include <linux/if_ether.h> > +#include <linux/if_packet.h> > + > +static inline void skb_bond_set_mac_by_master(struct sk_buff *skb, > + struct net_device *master) > +{ > + unsigned char *dest = eth_hdr(skb)->h_dest; > + > + if (compare_ether_addr_64bits(dest, master->dev_addr) && > + (skb->pkt_type == PACKET_HOST)) > + memcpy(dest, master->dev_addr, ETH_ALEN); Just overwriting the dest would be faster, and avoids to include <linux/etherdevice.h>, maybe a new include file could be avoided ? If it is already the master->dev_addr, then memcpy() is a no-op If it wasnt the master->dev_addr, then memcpy() does what you wanted. You can also give a hint to gcc as h_dest is guaranteed to be 16 bit aligned static inline void skb_bond_set_mac_by_master(struct sk_buff *skb, struct net_device *master) { if (skb->pkt_type == PACKET_HOST) { u16 *dest = (u16 *)eth_hdr(skb)->h_dest; memcpy(dest, master->dev_addr, ETH_ALEN); } } Compiler will emit better code for memcpy() on some arches. (not on x86, as it already does one 32bit and one 16bit move) _______________________________________________ Bridge mailing list Bridge@xxxxxxxxxxxxxxxxxxxxxxxxxx https://lists.linux-foundation.org/mailman/listinfo/bridge
