Re: SO_BINDTODEVICE mismatch with man page & comments.

[David Miller <davem@davemloft.net>]

From: Ben Greear <greearb@candelatech.com>
Date: Fri, 14 Sep 2007 15:11:39 -0700

>  From user-space, does this imply that the 'empty string' we use to
> unbind must be at least 4 bytes long, but with the first byte /0?
>
> If so, I think it might be confusing for the comments to say use ""
> to unbind, since that would not be a long enough chunk of memory.
> 
> Maybe something like "Use a character array of at least 4 bytes in
> length with the first byte set to '/0'."

I realize this, I'll try to come up with some clean way to
deal with this.

I don't want to touch that "if (optlen < sizeof(int))" test
at all because it makes all of the logic incredibly complicated
because you then have to forcefully initialize the 'val' and
'valbool' if you bypass reading the int.

> This brings up another issue as well:  What if the device name is "tr1",
> to bind to it we'd have to pass in "tr1/0" and optlen of 4.  Not that this
> is difficult to do, but it does seem like a weird thing to have to do.

You always to account for the NULL termination, thus you always have
to pass in "strlen(X) + 1" as optlen.

But I see your point, and my answer is the same as the first one.

Instead of nit-picking, can you instead try the patch and let me
know if it makes things work for you?

Thanks.