From: Mira Ressel <ara...@aixah.de> Date: Wed, 26 Aug 2020 16:29:01 +0000
> On Wed, Aug 26, 2020 at 08:28:57AM -0700, David Miller wrote: >> From: Mira Ressel <ara...@aixah.de> >> Date: Wed, 26 Aug 2020 15:20:00 +0000 >> >> > I'm setting the peer->perm_addr, which would otherwise be zero, to its >> > dev_addr, which has been either generated randomly by the kernel or >> > provided by userland in a netlink attribute. >> >> Which by definition makes it not necessarily a "permanent address" and >> therefore is subject to being different across boots, which is exactly >> what you don't want to happen for automatic address generation. > > That's true, but since veth devices aren't backed by any hardware, I > unfortunately don't have a good source for a permanent address. The only > inherently permanent thing about them is their name. > > People who use the default eui64-based address generation don't get > persistent link-local addresses for their veth devices out of the box > either -- the EUI64 is derived from the device's dev_addr, which is > randomized by default. > > If that presents a problem for anyone, they can configure their userland > to set the dev_addr to a static value, which handily fixes this problem > for both address generation algorithms. > > I'm admittedly glancing over one problem here -- I'm only setting the > perm_addr during device creation, whereas userland can change the > dev_addr at any time. I'm not sure if it'd make sense here to update the > perm_addr if the dev_addr is changed later on? We are talking about which parent device address to inherit from, you have choosen to use dev_addr and I am saying you should use perm_addr. Can you explain why this isn't clear?
