| lists.openwall.net | lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC | |
|
Open Source and information security mailing list archives
| ||
|
Message-ID: <20130125063713.GA1659@minipsycho.orion>
Date: Fri, 25 Jan 2013 07:37:13 +0100
From: Jiri Pirko <jiri@...nulli.us>
To: Jay Vosburgh <fubar@...ibm.com>
Cc: netdev@...r.kernel.org, davem@...emloft.net, andy@...yhouse.net,
stephen@...workplumber.org, psimerda@...hat.com, dcbw@...hat.com
Subject: Re: [patch net-next V2] bond: have random dev address by default
instead of zeroes
Fri, Jan 25, 2013 at 02:35:01AM CET, fubar@...ibm.com wrote:
>Jiri Pirko <jiri@...nulli.us> wrote:
>
>>Makes more sense to have randomly generated address by default than to
>>have all zeroes. It also allows user to for example put the bond into
>>bridge without need to have any slaves in it.
>>
>>Also note that this changes only behaviour of bonds with no slaves. Once
>>the first slave device is enslaved, its address will be used (no change
>>here).
>>
>>Also, fix dev_assign_type values on the way.
>>
>>Reported-by: Pavel Šimerda <psimerda@...hat.com>
>>Signed-off-by: Jiri Pirko <jiri@...nulli.us>
>
> Maybe I don't see it, but this feels like a bit of a hack just
>to get a bond with no slaves into a bridge. Am I missing something
>here? I just have this feeling that down the road I'm going to get
>questions as to why the bond gets a MAC, and then, poof, it vanishes
>when a slave is added. What's the point of the MAC address if it's only
>used to fool the bridge code?
I think that generally, the device should have valid mac address in
every point of its lifetime. I believe that bond is the only device who
behaves differently (bridge also uses random mac when no ports are
there)
>
> Also, when the bond's MAC changes from the random MAC to the
>first slave's MAC, does a notifier call need to happen? There isn't one
>now from the all zeroes to the first slave's, but that's from an invalid
>MAC to a valid one. There is already a notifier when the bond goes back
>to all zeroes, though.
You are right, all_netdevice_notifiers(NETDEV_CHANGEADDR, bond->dev);
should be called from bond_enslave() after calling bond_set_dev_addr()
>
> -J
>
>---
> -Jay Vosburgh, IBM Linux Technology Center, fubar@...ibm.com
>
>>
>>v1->v2:
>>- fixed assign value of bond_dev->addr_assign_type in bond_set_dev_addr()
>>- added note to patch description
>>
>> drivers/net/bonding/bond_main.c | 28 ++++++++++++++++------------
>> 1 file changed, 16 insertions(+), 12 deletions(-)
>>
>>diff --git a/drivers/net/bonding/bond_main.c b/drivers/net/bonding/bond_main.c
>>index 564cf42..1d56ac9 100644
>>--- a/drivers/net/bonding/bond_main.c
>>+++ b/drivers/net/bonding/bond_main.c
>>@@ -1320,14 +1320,14 @@ static void bond_netpoll_cleanup(struct net_device *bond_dev)
>>
>> /*---------------------------------- IOCTL ----------------------------------*/
>>
>>-static int bond_sethwaddr(struct net_device *bond_dev,
>>- struct net_device *slave_dev)
>>+static void bond_set_dev_addr(struct net_device *bond_dev,
>>+ struct net_device *slave_dev)
>> {
>> pr_debug("bond_dev=%p\n", bond_dev);
>> pr_debug("slave_dev=%p\n", slave_dev);
>> pr_debug("slave_dev->addr_len=%d\n", slave_dev->addr_len);
>> memcpy(bond_dev->dev_addr, slave_dev->dev_addr, slave_dev->addr_len);
>>- return 0;
>>+ bond_dev->addr_assign_type = NET_ADDR_SET;
>> }
>>
>> static netdev_features_t bond_fix_features(struct net_device *dev,
>>@@ -1628,10 +1628,8 @@ int bond_enslave(struct net_device *bond_dev, struct net_device *slave_dev)
>>
>> /* If this is the first slave, then we need to set the master's hardware
>> * address to be the same as the slave's. */
>>- if (is_zero_ether_addr(bond->dev->dev_addr))
>>- memcpy(bond->dev->dev_addr, slave_dev->dev_addr,
>>- slave_dev->addr_len);
>>-
>>+ if (bond->dev->addr_assign_type != NET_ADDR_SET)
>>+ bond_set_dev_addr(bond->dev, slave_dev);
>>
>> new_slave = kzalloc(sizeof(struct slave), GFP_KERNEL);
>> if (!new_slave) {
>>@@ -2049,11 +2047,11 @@ int bond_release(struct net_device *bond_dev, struct net_device *slave_dev)
>> if (bond->slave_cnt == 0) {
>> bond_set_carrier(bond);
>>
>>- /* if the last slave was removed, zero the mac address
>>- * of the master so it will be set by the application
>>- * to the mac address of the first slave
>>+ /* If the last slave was removed, set random mac address
>>+ * of the master so it will be set by bond_enslave()
>>+ * to the mac address of the first slave.
>> */
>>- memset(bond_dev->dev_addr, 0, bond_dev->addr_len);
>>+ eth_hw_addr_random(bond_dev);
>>
>> if (bond_vlan_used(bond)) {
>> pr_warning("%s: Warning: clearing HW address of %s while it still has VLANs.\n",
>>@@ -3708,7 +3706,8 @@ static int bond_do_ioctl(struct net_device *bond_dev, struct ifreq *ifr, int cmd
>> break;
>> case BOND_SETHWADDR_OLD:
>> case SIOCBONDSETHWADDR:
>>- res = bond_sethwaddr(bond_dev, slave_dev);
>>+ bond_set_dev_addr(bond_dev, slave_dev);
>>+ res = 0;
>> break;
>> case BOND_CHANGE_ACTIVE_OLD:
>> case SIOCBONDCHANGEACTIVE:
>>@@ -4858,6 +4857,11 @@ static int bond_init(struct net_device *bond_dev)
>>
>> bond_debug_register(bond);
>>
>>+ /* Ensure valid dev_addr */
>>+ if (is_zero_ether_addr(bond_dev->dev_addr) &&
>>+ bond_dev->addr_assign_type == NET_ADDR_PERM)
>>+ eth_hw_addr_random(bond_dev);
>>+
>> __hw_addr_init(&bond->mc_list);
>> return 0;
>> }
>>--
>>1.8.1
>>
>
--
To unsubscribe from this list: send the line "unsubscribe netdev" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Powered by blists - more mailing lists