From mboxrd@z Thu Jan  1 00:00:00 1970
From: Mitchell Blank Jr <mitch@sfgoth.com>
Subject: Re: [PATCH] Added support for dropping privileges to git-daemon.
Date: Sat, 19 Aug 2006 10:25:33 -0700
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To: Tilman Sauerbeck <tilman@code-monkey.de>
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Tilman Sauerbeck wrote:
> +	if (user && group)
> +		drop_privileges();

It seems "if (user)" would be sufficient here.

> +	if (!user ^ !group)
> +		die("either set both user and group or none of them");

For simplicities sake I'd actually suggest allowing group==NULL.  So
change this test to be

	if (group && !user)
		die("--group supplied without --user");

Then in drop_privileges() do something like:

	struct passwd *p;
	gid_t gid;

	p = getpwnam(user);
	if (!p)
		die("user not found - %s", user);
	if (group == NULL)
		gid = p->pw_gid;
	else {
		struct group *g = getgrnam(group);
		if (!g)
			die("group not found - %s", group);
		gid = g->gr_gid;
	}

Since usually you want to use the same gid that is normally associated
with that pid, this just makes things a little easier on the user

-Mitch