From owner-svn-src-head@freebsd.org Tue Apr 9 20:19:27 2019 Return-Path: Delivered-To: svn-src-head@mailman.ysv.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2610:1c1:1:606c::19:1]) by mailman.ysv.freebsd.org (Postfix) with ESMTP id 06936156C577; Tue, 9 Apr 2019 20:19:27 +0000 (UTC) (envelope-from jhb@FreeBSD.org) Received: from smtp.freebsd.org (smtp.freebsd.org [IPv6:2610:1c1:1:606c::24b:4]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) server-signature RSA-PSS (4096 bits) client-signature RSA-PSS (4096 bits) client-digest SHA256) (Client CN "smtp.freebsd.org", Issuer "Let's Encrypt Authority X3" (verified OK)) by mx1.freebsd.org (Postfix) with ESMTPS id 8AE9E8025D; Tue, 9 Apr 2019 20:19:26 +0000 (UTC) (envelope-from jhb@FreeBSD.org) Received: from John-Baldwins-MacBook-Pro-3.local (ralph.baldwin.cx [66.234.199.215]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (Client did not present a certificate) (Authenticated sender: jhb) by smtp.freebsd.org (Postfix) with ESMTPSA id B9CE4FFF1; Tue, 9 Apr 2019 20:19:25 +0000 (UTC) (envelope-from jhb@FreeBSD.org) Subject: Re: svn commit: r346052 - head/sys/dev/usb/net To: rgrimes@freebsd.org Cc: Ian Lepore , Ganbold Tsagaankhuu , src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-head@freebsd.org References: <201904091948.x39JmBZk061857@gndrsh.dnsmgr.net> From: John Baldwin Openpgp: preference=signencrypt Autocrypt: addr=jhb@FreeBSD.org; keydata= mQGiBETQ+XcRBADMFybiq69u+fJRy/0wzqTNS8jFfWaBTs5/OfcV7wWezVmf9sgwn8TW0Dk0 c9MBl0pz+H01dA2ZSGZ5fXlmFIsee1WEzqeJzpiwd/pejPgSzXB9ijbLHZ2/E0jhGBcVy5Yo /Tw5+U/+laeYKu2xb0XPvM0zMNls1ah5OnP9a6Ql6wCgupaoMySb7DXm2LHD1Z9jTsHcAQMD /1jzh2BoHriy/Q2s4KzzjVp/mQO5DSm2z14BvbQRcXU48oAosHA1u3Wrov6LfPY+0U1tG47X 1BGfnQH+rNAaH0livoSBQ0IPI/8WfIW7ub4qV6HYwWKVqkDkqwcpmGNDbz3gfaDht6nsie5Z pcuCcul4M9CW7Md6zzyvktjnbz61BADGDCopfZC4of0Z3Ka0u8Wik6UJOuqShBt1WcFS8ya1 oB4rc4tXfSHyMF63aPUBMxHR5DXeH+EO2edoSwViDMqWk1jTnYza51rbGY+pebLQOVOxAY7k do5Ordl3wklBPMVEPWoZ61SdbcjhHVwaC5zfiskcxj5wwXd2E9qYlBqRg7QeSm9obiBCYWxk d2luIDxqaGJARnJlZUJTRC5vcmc+iGAEExECACAFAkTQ+awCGwMGCwkIBwMCBBUCCAMEFgID AQIeAQIXgAAKCRBy3lIGd+N/BI6RAJ9S97fvbME+3hxzE3JUyUZ6vTewDACdE1stFuSfqMvM jomvZdYxIYyTUpC5Ag0ERND5ghAIAPwsO0B7BL+bz8sLlLoQktGxXwXQfS5cInvL17Dsgnr3 1AKa94j9EnXQyPEj7u0d+LmEe6CGEGDh1OcGFTMVrof2ZzkSy4+FkZwMKJpTiqeaShMh+Goj XlwIMDxyADYvBIg3eN5YdFKaPQpfgSqhT+7El7w+wSZZD8pPQuLAnie5iz9C8iKy4/cMSOrH YUK/tO+Nhw8Jjlw94Ik0T80iEhI2t+XBVjwdfjbq3HrJ0ehqdBwukyeJRYKmbn298KOFQVHO EVbHA4rF/37jzaMadK43FgJ0SAhPPF5l4l89z5oPu0b/+5e2inA3b8J3iGZxywjM+Csq1tqz hltEc7Q+E08AAwUIAL+15XH8bPbjNJdVyg2CMl10JNW2wWg2Q6qdljeaRqeR6zFus7EZTwtX sNzs5bP8y51PSUDJbeiy2RNCNKWFMndM22TZnk3GNG45nQd4OwYK0RZVrikalmJY5Q6m7Z16 4yrZgIXFdKj2t8F+x613/SJW1lIr9/bDp4U9tw0V1g3l2dFtD3p3ZrQ3hpoDtoK70ioIAjjH aIXIAcm3FGZFXy503DOA0KaTWwvOVdYCFLm3zWuSOmrX/GsEc7ovasOWwjPn878qVjbUKWwx Q4QkF4OhUV9zPtf9tDSAZ3x7QSwoKbCoRCZ/xbyTUPyQ1VvNy/mYrBcYlzHodsaqUDjHuW+I SQQYEQIACQUCRND5ggIbDAAKCRBy3lIGd+N/BCO8AJ9j1dWVQWxw/YdTbEyrRKOY8YZNwwCf afMAg8QvmOWnHx3wl8WslCaXaE8= Message-ID: <8c5292c0-5464-8995-4518-181886201692@FreeBSD.org> Date: Tue, 9 Apr 2019 13:19:24 -0700 User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.12; rv:60.0) Gecko/20100101 Thunderbird/60.6.1 MIME-Version: 1.0 In-Reply-To: <201904091948.x39JmBZk061857@gndrsh.dnsmgr.net> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit X-Rspamd-Queue-Id: 8AE9E8025D X-Spamd-Bar: ------ Authentication-Results: mx1.freebsd.org X-Spamd-Result: default: False [-6.93 / 15.00]; NEURAL_HAM_MEDIUM(-1.00)[-0.996,0]; NEURAL_HAM_SHORT(-0.93)[-0.934,0]; REPLY(-4.00)[]; NEURAL_HAM_LONG(-1.00)[-1.000,0] X-BeenThere: svn-src-head@freebsd.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: SVN commit messages for the src tree for head/-current List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Tue, 09 Apr 2019 20:19:27 -0000 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. -- John Baldwin