Re: [Qemu-devel] PATCH: Put Psuedo-TTY in rawmode for char devices

[Aurelien Jarno <aurelien@aurel32.net>]

On Thu, May 01, 2008 at 06:14:24PM +0100, Daniel P. Berrange wrote:
> Re-posting patch for review/inclusion...
> 
> On Tue, Apr 22, 2008 at 01:50:57AM +0100, Daniel P. Berrange wrote:
> > If running a QEMU instance with a serial/parallel device connected to a
> > Psuedo-TTY, eg  '-serial pty',  every \r\n sequence output by the guest
> > is getting translated into a \n\n sequence by the TTY layer. So clients
> > interacting with the serial port via a TTY done get the correct \r\n
> > sequence and text marches to the right and wraps. This is because the 
> > TTY is not put into rawmode when QEMU sets it up. 
> > 
> > The following patch is a re-diff of a patch applied to Xen's QEMU code.
> > It uses cfmakeraw() to ensure the TTY is put into rawmode, thus avoiding
> > the incorrect \r\n translations. It also switches to tcsetattr() on the
> > slave_fd instead of master_fd - although this is effectively the same on
> > Linux, only slave_fd works on Solaris. Finally it stops using the 'name'
> > arg to openpty() which is a security risk because its buffer size is
> > undefined. Instead it makes use of the ptsname() function.
> 

cfmakeraw() is Linux specific, though also available on most BSD
systems. It is unavailable on Solaris, and probably the same on WIN32.

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