> On 4/9/19 12:48 PM, Rodney W. Grimes wrote: > >> On 4/9/19 9:59 AM, Ian Lepore wrote: > >>> On Tue, 2019-04-09 at 09:33 -0700, John Baldwin wrote: > >>>> On 4/9/19 9:17 AM, Ian Lepore wrote: > >>>>> On Tue, 2019-04-09 at 09:11 -0700, John Baldwin wrote: > >>>>>> On 4/9/19 6:54 AM, Ganbold Tsagaankhuu wrote: > >>>>>>> Author: ganbold > >>>>>>> Date: Tue Apr 9 13:54:08 2019 > >>>>>>> New Revision: 346052 > >>>>>>> URL: https://svnweb.freebsd.org/changeset/base/346052 > >>>>>>> > >>>>>>> Log: > >>>>>>> In some cases like NanoPI R1, its second USB ethernet > >>>>>>> RTL8152 (chip version URE_CHIP_VER_4C10) doesn't > >>>>>>> have hardwired MAC address, in other words, it is all zeros. > >>>>>>> This commit fixes it by setting random MAC address > >>>>>>> when MAC address is all zeros. > >>>>>>> > >>>>>>> Reviewed by: kevlo > >>>>>>> Differential Revision: > >>>>>>> https://reviews.freebsd.org/D19856 > >>>>>> > >>>>>> It would be best to not use a purely random mac address and to > >>>>>> use > >>>>>> the > >>>>>> function kevans@ added recently. That function generates a MAC > >>>>>> address > >>>>>> from the FreeBSD OUI using a cryptographic hash so you get a > >>>>>> stable address across boots on a given host. > >>>>>> > >>>>> > >>>>> How could that possibly work? If it's not random, you can't have > >>>>> two > >>>>> such devices on the same network. If it is random, it's not stable > >>>>> from one boot to the next. > >>>> > >>>> It uses the UUID and interface name as input into the hash. > >>> > >>>> The UUID is per-host. > >>> > >>> Oh, so it only works on x86 (or I guess any system that has something > >>> like a bios that can provide you with a uuid that doesn't change from > >>> one boot to the next). > >> > >> The function is in one centralized place where you are free to add other > >> data as input into the hash. We do always generate a uuid that we save > >> on boot if we aren't seeded with one by firmware, though that is probably > >> too late for this driver (so +1 may in fact be a better route). It should > >> be fine for psuedo interfaces created post-boot though even on non-x86 due > >> to /etc/rc.d/hostid. Pure random MAC's are not really great either. > > > > Cant the loader load /etc/rc.d/hostid and put it in something that > > the kernel could get at, or a module written that handles this? > > It's a different file, and yes in theory the loader could look at the file > and set UUID and hostid env vars. However, that's a no-op for most use > cases. If other platforms have some kind of firmware-provided thing that > isn't a UUID, it would be good to teach the centralized function about > those as an input to the hash, but at least that can be done in place > rather than having open-coded MAC generators in various drivers.
Simple enough, can one not just store /etc/rc.d/hostid into a env variable in /boot/loader.conf too on those platforms that do not have a uuid mechanism? -- Rod Grimes rgri...@freebsd.org _______________________________________________ svn-src-head@freebsd.org mailing list https://lists.freebsd.org/mailman/listinfo/svn-src-head To unsubscribe, send any mail to "svn-src-head-unsubscr...@freebsd.org"
