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? -- Regards, Mira
