Did you mean D28559?

I figured out that if a loop is detected, this netgraph message moves the host from one link to another.

But, you are adding a public API/ABI that is visible from user space. This way people can use it to add a host to the specific link:

ngctl msg bridge: movehost <MAC> <hook>

Here, I think, it is better to use generally accepted conventions.

"Move" is like:

# mv <src> <dst>

or

memmove (void * dst, const void * src, size_t len);

The proposed message has add/put semantics.

P/S. If you don't want to add a public API, you may use the ng_send_fn () function, which also forces write semantics for the node.

In D28516#644387, @afedorov wrote:

Did you mean D28559?

Yes.

I figured out that if a loop is detected, this netgraph message moves the host from one link to another.

Yes, that's part of the "move". This kind of loop detection is taken as given.

But, you are adding a public API/ABI that is visible from user space. This way people can use it to add a host to the specific link:

ngctl msg bridge: movehost <MAC> <hook>

Nope. Usually the command is using a struct:

ngctl msg bridge: movehost { addr = 00:00:00:01:02:03 , hook = "link17" }

Even if you assume a "direction" in the order of arguments you usually say "move the address to the hook".

The proposed message has add/put semantics.

Only for the first part.

P/S. If you don't want to add a public API, you may use the ng_send_fn () function, which also forces write semantics for the node.

I considered this option of private messaging, but I found some situations, that an external injection is helpful of practical operations.

Example: If you have to destroy and rebuild a netgraph network running in production, you can backup the gettable output and reinject this after recreating the node/network. I do have this situation.

I'm not an English expert, so you may be right.
Technically, I have no questions, I think this patch can be committed.