Messages in this thread | | | Date | Fri, 03 Aug 2007 18:04:11 +0200 | From | Carl-Daniel Hailfinger <> | Subject | Re: forcedeth ? |
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On 02.08.2007 13:33, Kay Sievers wrote: > On 7/31/07, Kay Sievers <kay.sievers@vrfy.org> wrote: >> On 7/31/07, Carl-Daniel Hailfinger <c-d.hailfinger.devel.2006@gmx.net> wrote: >>> On 31.07.2007 00:17, Gabriel C wrote: >>>> Sasa Ostrouska wrote: >>>> >>>>> Gabriel, hmm, shouldnt udev be able to autoconfigure that ? But I need >>>>> to check that, thx for the tip. >>>> Yes udev does this based on the MAC address but AFAIK forcedeth is 'special' for some reason >>>> ( which I can really remember now and gets on each boot a new MAC address or alike ) >>> Ah yes, that's a workaround for certain buggy boards to make sure you're >>> not left without networking even if the MAC address stored on the board >>> is bogus. >>> >>> Basically, forcedeth checks if the MAC address supplied by your >>> mainboard is bogus and autogenerates a random MAC address from a private >>> range (prefix 00:00:6c) as workaround. However, it will complain loudly >>> if it has to do that. >>> >>> Quoting from forcedeth.c: >>>> if (!is_valid_ether_addr(dev->perm_addr)) { >>>> /* >>>> * Bad mac address. At least one bios sets the mac address >>>> * to 01:23:45:67:89:ab >>>> */ >>>> printk(KERN_ERR "%s: Invalid Mac address detected: %02x:%02x:%02x:%02x:%02x:%02x\n", >>>> pci_name(pci_dev), >>>> dev->dev_addr[0], dev->dev_addr[1], dev->dev_addr[2], >>>> dev->dev_addr[3], dev->dev_addr[4], dev->dev_addr[5]); >>>> printk(KERN_ERR "Please complain to your hardware vendor. Switching to a random MAC.\n"); >>>> dev->dev_addr[0] = 0x00; >>>> dev->dev_addr[1] = 0x00; >>>> dev->dev_addr[2] = 0x6c; >>>> get_random_bytes(&dev->dev_addr[3], 3); >>>> } >>> Sometimes it helps to update the BIOS and/or set the MAC address which >>> is printed on the board as MAC address in the BIOS. >> In any case, it would be nice if the network core could add something like: >> MAC_ORIGIN=device >> MAC_ORIGIN=user >> MAC_ORIGIN=random >> or whatever makes sense here, to the uevent environment. So userspace >> can handle according to that, like falling back using the >> bus-slot-number to lookup the persistent name, or whatever is >> appropriate. > > Can't we use the "locally administered" bit in the MAC address? By > checking for ENV{address}=="?[2367abef]:*", we would skip the > persistent rule generation based on the MAC address?
Yes and no. Theoretically, that would work. However, there are two problems with your rule specification: - ENV{address}=="?[13579bdf]:*" are multicast addresses, so you wouldn't want them tobe part of a network card MAC address at all. - http://standards.ieee.org/regauth/oui/oui.txt tells us that the following OIDs would be excluded by your rule: 02-07-01 (hex) RACAL-DATACOM 02-1C-7C (hex) PERQ SYSTEMS CORPORATION 02-60-86 (hex) LOGIC REPLACEMENT TECH. LTD. 02-60-8C (hex) 3COM CORPORATION 02-70-01 (hex) RACAL-DATACOM 02-70-B0 (hex) M/A-COM INC. COMPANIES 02-70-B3 (hex) DATA RECALL LTD 02-9D-8E (hex) CARDIAC RECORDERS INC. 02-AA-3C (hex) OLIVETTI TELECOMM SPA (OLTECO) 02-BB-01 (hex) OCTOTHORPE CORP. 02-C0-8C (hex) 3COM CORPORATION 02-CF-1C (hex) COMMUNICATION MACHINERY CORP. 02-E6-D3 (hex) NIXDORF COMPUTER CORPORATION AA-00-00 (hex) DIGITAL EQUIPMENT CORPORATION AA-00-01 (hex) DIGITAL EQUIPMENT CORPORATION AA-00-02 (hex) DIGITAL EQUIPMENT CORPORATION AA-00-03 (hex) DIGITAL EQUIPMENT CORPORATION AA-00-04 (hex) DIGITAL EQUIPMENT CORPORATION
Since it seems that real OIDs conflict with the "locally adminstered" bit of the MAC address, I don't see a way to use the MAC address as indicator for persistent rule eligibility.
Regards, Carl-Daniel - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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