switchuser.cpp

/*
 * SLiM - Simple Login Manager
 * Copyright (C) 1997, 1998 Per Liden
 * Copyright (C) 2004-06 Simone Rota <sip@varlock.com>
 * Copyright (C) 2004-06 Johannes Winkelmann <jw@tks6.net>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 */

#include "switchuser.h"
#include "util.h"
#include <cstdio>

using namespace std;

SwitchUser::SwitchUser(
	struct passwd * pw, Cfg & c, const string & display, char ** _env)
	: cfg(c), Pw(pw), displayName(display), env(_env)
{
}

SwitchUser::~SwitchUser()
{ /* Never called */
}

void SwitchUser::Login(const char * cmd, const char * mcookie)
{
	SetUserId();
	SetClientAuth(mcookie);
	Execute(cmd);
}

void SwitchUser::SetUserId()
{
	if ((Pw == 0) || (initgroups(Pw->pw_name, Pw->pw_gid) != 0) ||
		(setgid(Pw->pw_gid) != 0) || (setuid(Pw->pw_uid) != 0)) {
		logStream << APPNAME << ": could not switch user id" << endl;
		exit(ERR_EXIT);
	}
}

void SwitchUser::Execute(const char * cmd)
{
	chdir(Pw->pw_dir);
	execle(Pw->pw_shell, Pw->pw_shell, "-c", cmd, NULL, env);
	logStream << APPNAME << ": could not execute login command" << endl;
}

void SwitchUser::SetClientAuth(const char * mcookie)
{
	string home = string(Pw->pw_dir);
	string authfile = home + "/.Xauthority";
	remove(authfile.c_str());
	Util::add_mcookie(mcookie, ":0", cfg.getOption("xauth_path"), authfile);
}