[PATCH 0/1] openpty: use TIOCGPTPEER to open slave side fd

[Christian Brauner <christian.brauner@ubuntu.com>]

Hi,

Newer kernels expose the ioctl TIOCGPTPEER [1] call to userspace which allows to
safely allocate a file descriptor for a pty slave based solely on the master
file descriptor. This allows us to avoid path-based operations and makes this
function a lot safer in the face of devpts mounts in different mount namespaces.

[1]: https://patchwork.kernel.org/patch/9760743/

The way I wrote this patch it doesn't use the snprintf() and open() routine as a
fallback in case the ioctl() call fails. If this is a compatibility issue for
non-Linux systems I can rewrite. But the musl documentation gave me the
impression that this is not really a concern.

If possible, please Cc me on this since I'm not subscribed to the mailing list
(yet).

Thanks!
Christian

Christian Brauner (1):
  openpty: use TIOCGPTPEER to open slave side fd

 src/misc/openpty.c | 34 +++++++++++++++++++++++++++++++---
 1 file changed, 31 insertions(+), 3 deletions(-)

-- 
2.14.1