[SOLVED] How to create VLAN interface(in linux kernel)?

poplinux · 07-13-2014, 11:49 PM

Dear Sir.

My old linux kernel(Ver 2.6.21.7) are create VLAN intface using register_vlan_device() API.

Code:

struct net_device *trunk = NULL;
struct net_device *vlan  = NULL;

trunk = dev_get_by_name(&init_net, "eth0");
vlan  = register_vlan_device(trunk, 10);

But my new linux kernel(Ver 2.6.32.27) are not support this way, and change another way. I guess.

Please show to me or advise to me. "How to create vlan in linux kernel"

Thank you.

GaWdLy · 07-15-2014, 01:02 AM

These instructions should work for 2.6.32-x kernels.

http://www.reddit.com/r/linuxadmin/c..._tagging_need/

poplinux · 07-15-2014, 07:40 PM

Dear GaWdLy.

Thank's your reply.

But, your reply is not helply to me.

I'm already know "how to create vlan interface on user space". see below.

Code:

sudo ip link add link eth0 name eth0.5 type vlan id 5

But, My question is "How to create vlan interface in KERNEL SPACE, using kernel api".

However, Thank's your advisce.

Thank you.

GaWdLy · 07-15-2014, 08:50 PM

I see a reference that implies that the kernel API for vlans might have been removed?

http://lists.shmoo.com/pipermail/hos...ly/026292.html

So I guess there's a possibility that you need to use netlink, as opposed to the "old" kernel API...

poplinux · 07-16-2014, 03:24 AM

Dear GaWdLy.

Thank's your reply.

But It is user space too.

I'm found some way from Documentation/generic_netlink.txt.

This document say to me that see http://www.linuxfoundation.org/colla..._netlink_howto

And I'm found very useful document on this site.

Thank you.

nini09 · 07-16-2014, 02:49 PM

You can try to call 'vlan_ioctl_set' to create VLAN.

poplinux · 07-16-2014, 07:53 PM

Dear nini09.

Thank's your advise.

I'm searching "vlan_ioctl_set()" from linux kernel tree(2.6.32). And found this API in "net/socket.c".

This api purpose are register "ioctl" api to subsystem, I guess.

"net/8021q/vlan.c::vlan_proto_init()" is registed vlan_ioctl_handler() api to subsystem using "vlan_ioctl_set" api.

Can you show to me pseudocode? - "How to create vlan interface using vlan_ioctl_set()" -

Thank you.

nini09 · 07-17-2014, 02:44 PM

I checked code again. The ioctl has to be called from user space only.
Why do you need to create a VLAN in kernel space?

poplinux · 07-17-2014, 07:44 PM

Dear nini09.

Thank's your reply.

Because my customer required "Must create in kernel space".

Older kernel is possible without error(2.6.21). But kernel version (2.6.32.27) not support this way.

I guess, 2.6.32.27 are support another way. ex) direct call some API or Using netlink API.

But I'm can't found some example code, using netlink api.

Thank you.

nini09 · 07-22-2014, 03:19 PM

Following link might help a little but not complete. Just netlink example code in kernel, not relative to create VLAN.
http://stackoverflow.com/questions/1...x-linux-kernel

hmatrix · 11-15-2021, 11:19 AM

I know we are 2021 and the initial question was asked in 2014.
May I suggest an alternate solution which involves using the usermode-helper API, this basically allows kernel code to invoke user space programs/tool, thus from kernel one can run "ip ..." to create such vlan interface.
I know it is a little bit of a hack, but this is how some drivers used this API to upload firmware file that exist in user space file system into the chip (example wifi).

Personally I had used this feature as doing it in the kernel is too much complicated.

But hey, it is your system you do what ever needed.

Take care.

Hmatrix

computersavvy · 11-17-2021, 03:36 PM

The 'ip' command is now the mostly used tool to do what we previously did with ifconfig and the like. You are correct in suggesting that.