How Debian managed the systemd transition [LWN.net]

How Debian managed the systemd transition

Posted Sep 19, 2015 20:40 UTC (Sat) by Cyberax (✭ supporter ✭, #52523)
In reply to: How Debian managed the systemd transition by cortana
Parent article: How Debian managed the systemd transition

> I wonder why no one has ever looked into increasing the maximum network interface name length, and adding a new kind of 'n' device node that network interfaces can use, so that they can show up in /dev just like other devices.
As usual - legacy. The interface name is limited by IFNAMSIZ value which is used in multiple contexts, so you can not use long strings like '/dev/ethN' for interface names. And also there are no provisions for multiple interface names in getifaddrs() calls or similar functions.

Adding new functions that work with regular device nodes is certainly possible, but probably nobody cares too much about it.

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How Debian managed the systemd transition

Posted Sep 20, 2015 0:02 UTC (Sun) by dlang (guest, #313) [Link] (1 responses)

if they can do eth<mac> then /dev/ethN isn't unreasonably long

How Debian managed the systemd transition

Posted Sep 20, 2015 7:37 UTC (Sun) by Cyberax (✭ supporter ✭, #52523) [Link]

IFNAMSIZ is equal to 16, so you only have 15 letters for the full path.

And the second problem is that you don't actually _need_ your devices to be mounted at '/dev'. A device node can be anywhere on the system.

It doesn't even require anything exotic - a host might simply with to get info about a TAP/TUN device in a container.

The correct way to fix it would be by creating a new API that uses file descriptors instead of interface names.