linux-kernel - Re: [PATCH net-next] sysfs: add attribute to indicate hw address assignment type

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

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Date:	Thu, 22 Jul 2010 16:47:40 +0200
From:	Stefan Assmann <sassmann@...hat.com>
To:	Ben Hutchings <bhutchings@...arflare.com>
CC:	David Miller <davem@...emloft.net>, abadea@...acom.com,
	netdev@...r.kernel.org, linux-kernel@...r.kernel.org,
	gospo@...hat.com, gregory.v.rose@...el.com,
	alexander.h.duyck@...el.com, leedom@...lsio.com, harald@...hat.com
Subject: Re: [PATCH net-next] sysfs: add attribute to indicate hw address
 assignment type

On 22.07.2010 16:07, Ben Hutchings wrote:
> On Thu, 2010-07-22 at 14:50 +0200, Stefan Assmann wrote:
>> On 21.07.2010 15:54, Ben Hutchings wrote:
>>> On Wed, 2010-07-21 at 10:10 +0200, Stefan Assmann wrote:
>>>> I put Alex' idea into code for further discussion, keeping the names
>>>> mentioned here until we agree on the scope of this attribute. When we
>>>> have settled I'll post a patch with proper patch description.
>>> [...]
>>>
>>> Just a little nitpick: I think it would be clearer to use a more
>>> specific term like 'address source' or 'address assignment type' rather
>>> than 'address type'.
>>
>> Here's a proposal for the final patch.
> 
> Looks good, but...
> 
> [...]
>>  /**
>> + * dev_hw_addr_random - Create random MAC and set device flag
>> + * @dev: pointer to net_device structure
>> + * @addr: Pointer to a six-byte array containing the Ethernet address
>> + *
>> + * Generate random MAC to be used by a device and set addr_assign_type
>> + * so the state can be read by sysfs and be used by udev.
>> + */
>> +static inline void dev_hw_addr_random(struct net_device *dev, u8 *hwaddr)
>> +{
>> +	dev->addr_assign_type |= NET_ADDR_RANDOM;
>> +	random_ether_addr(hwaddr);
>> +}
> [...]
> 
> ...why '|=' and not '='?

The intention is to use addr_assign_type as a bit field.

Okay it it might not make too much sense to 'steal' a random MAC
address but in case we add more types later it might get useful.

  Stefan
--
Stefan Assmann         | Red Hat GmbH
Software Engineer      | Otto-Hahn-Strasse 20, 85609 Dornach
                       | HR: Amtsgericht Muenchen HRB 153243
                       | GF: Brendan Lane, Charlie Peters,
sassmann at redhat.com |     Michael Cunningham, Charles Cachera
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/