[PATCH] casperd should detach from controlling session

[Xin Li]

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Hi, Pawel,

I have noticed that casperd's child (zygote) would still use
controlling session from parent.  This can be observed by running ps
- -ax on systems running casperd, where the child have a spurious
console associated.

The attached patch would fix it.  May I commit it against -HEAD?

By the way, the zygote child also closes file descriptor 4 twice
(harmless; it's either sp[0] or the /dev/null which is closed before
starting zygote_main, or before returning from stdnull().  Based on
the construct of the code, I believe both close() can be omitted.  If
this makes sense I'll submit a new patch.

Cheers,
- -- 
Xin LI <delphij at delphij.net>    https://www.delphij.net/
FreeBSD - The Power to Serve!           Live free or die
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Index: sbin/casperd/zygote.c
===================================================================
--- sbin/casperd/zygote.c	(revision 263112)
+++ sbin/casperd/zygote.c	(working copy)
@@ -63,6 +63,9 @@ stdnull(void)
 	if (fd == -1)
 		errx(1, "Unable to open %s", _PATH_DEVNULL);
 
+	if (setsid() == -1)
+		errx(1, "Unable to detach from session");
+
 	if (dup2(fd, STDIN_FILENO) == -1)
 		errx(1, "Unable to cover stdin");
 	if (dup2(fd, STDOUT_FILENO) == -1)