Re: [PATCH] Applying inappropriate ioctl operation on socket should return ENOTTY

[Eric Dumazet <eric.dumazet@gmail.com>]

Le mercredi 27 avril 2011 à 14:37 +0800, Lifeng Sun a écrit :
> On 07:58 Wed 04/27/11 Apr, Eric Dumazet wrote:
> > Really ?
> > 
> > EINVAL is ok too : Request or argp is not valid.
> 
> I'm afraid not. SUSv4 specifies, say,
> 
>   int tcsetattr(int fildes, int optional_actions,
>          const struct termios *termios_p);
> 
>  ERROR:
>   [EINVAL]
>       The optional_actions argument is not a supported value, or an
>       attempt was made to change an attribute represented in the
>       termios structure to an unsupported value.
> 
>   [ENOTTY]
>       The file associated with fildes is not a terminal.
> 
> which means when we apply tcsetattr (implemented by ioctl) to _any_
> non-terminal file descriptor, it should set errno to ENOTTY rather
> than EINVAL.
> 

You quote manpage for a library call, not a system call.

If you feel your glibc doesnt implement well this, please complain to
glibc maintainer.