[SLOF] [PATCH] slof/fs/accept: Allow Unix LF line endings, too

[Segher Boessenkool]

On Mon, Aug 30, 2021 at 12:53:08PM +0200, Thomas Huth wrote:
> Currently SLOF only accepts CR (0x0d) line endings at the command prompt,
> since this is the default line ending used on serial consoles.

> However,
> sometimes people try to connect to SLOF directly in a way that uses the
> typical Unix LF line endings (0x0a) which are then completely ignored,
> for example running QEMU like this:
> 
>  qemu-system-ppc64 -nodefaults \
>     -chardev socket,path=/tmp/mysocket,wait=off,id=cs0,server=on \
>     -device spapr-vty,id=serial0,reg=0x30000000,chardev=cs0
> 
> and then connect to that Unix socket via "nc -U /tmp/mysocket".
> 
> For such use cases, allow the 0x0a line ending in SLOF, too.

How does that work if you feed text with CRLF combos?  If it does accept
a new line at both CR and LF, that is problematic (it violates both the
OF and ANS specifications of ACCEPT).

A "real" terminal sends CR only, by default, and can be switched to
send CRLF instead (by CSI 20h; switch back with CSI 20l).  You cannot do
only LF on a standard terminal.

Can't you just use  nc -C  or similar?


Segher