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/*
Unix SMB/Netbios implementation.
Version 2.0
Copyright (C) Jeremy Allison 1998.
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.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software
Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
*/
#include "includes.h"
/****************************************************************************
Gain root privilege before doing something.
****************************************************************************/
void gain_root_privilege(void)
{
#if defined(HAVE_SETRESUID)
/*
* Ensure all our uids are set to root.
* Easy method - just use setresuid().
*/
setresuid(0,0,0);
#else /* !HAVE_SETRESUID */
/*
* Ensure all our uids are set to root.
* Older method - first use setuid.
*/
setuid(0);
#if defined(HAVE_SETREUID)
setreuid(0,0);
#else
seteuid(0);
#endif
#endif /* HAVE_SETRESUID */
}
/****************************************************************************
Ensure our real and effective groups are zero.
****************************************************************************/
void gain_root_group_privilege(void)
{
#ifdef HAVE_SETRESGID
setresgid(0,0,0);
#elif defined(HAVE_SETREGID)
setregid(0,0);
#elif defined(HAVE_SETEGID)
setegid(0);
#endif
setgid(0);
}
/****************************************************************************
Set *only* the effective uid.
****************************************************************************/
int set_effective_uid(uid_t uid)
{
#if defined(HAVE_TRAPDOOR_UID)
#if defined(HAVE_SETUIDX)
/* AIX3 has setuidx which is NOT a trapoor function (tridge) */
if (setuidx(ID_EFFECTIVE, uid) != 0) {
if (seteuid(uid) != 0) {
return -1;
}
}
return 0;
#endif
#endif
#if defined(HAVE_SETRESUID)
return setresuid(-1,uid,-1);
#elif defined(HAVE_SETREUID)
return setreuid(-1,uid);
#else
if ((seteuid(uid) != 0) && (setuid(uid) != 0))
return -1;
return 0;
#endif
}
/****************************************************************************
Set *only* the effective gid.
****************************************************************************/
int set_effective_gid(gid_t gid)
{
#if defined(HAVE_SETRESGID)
return setresgid(-1,gid,-1);
#elif defined(HAVE_SETREGID)
return setregid(-1,gid);
#else
if ((setegid(gid) != 0) && (setgid(gid) != 0))
return -1;
return 0;
#endif
}
/****************************************************************************
Set *only* the real uid.
****************************************************************************/
int set_real_uid(uid_t uid)
{
#if defined(HAVE_TRAPDOOR_UID)
#if defined(HAVE_SETUIDX)
/* AIX3 has setuidx which is NOT a trapoor function (tridge) */
return setuidx(ID_REAL,uid);
#endif
#endif
#if defined(HAVE_SETRESUID)
return setresuid(uid,-1,-1);
#elif defined(HAVE_SETREUID)
return setreuid(uid,-1);
#else
/*
* Without either setresuid or setreuid we cannot
* independently set the real uid.
*/
return -1;
#endif
}
/****************************************************************************
Become the specified uid - permanently !
****************************************************************************/
BOOL become_user_permanently(uid_t uid, gid_t gid)
{
/*
* Now completely lose our privileges. This is a fairly paranoid
* way of doing it, but it does work on all systems that I know of.
*/
/*
* First - gain root privilege. We do this to ensure
* we can lose it again.
*/
gain_root_privilege();
gain_root_group_privilege();
#if defined(HAVE_SETRESUID) && defined(HAVE_SETRESGID)
/*
* Ensure we change all our gids.
*/
setresgid(gid,gid,gid);
/*
* Ensure all the uids are the user.
*/
setresuid(uid,uid,uid);
#else /* !( defined(HAVE_SETRESUID) && defined(HAVE_SETRESGID) ) */
/*
* Ensure we change all our gids.
*/
setgid(gid);
#if defined(HAVE_SETREGID)
setregid(gid,gid);
#else
setegid(gid);
#endif
/*
* Ensure all the uids are the user.
*/
setuid(uid);
#if defined(HAVE_SETREUID)
setreuid(uid,uid);
#else
seteuid(uid);
#endif
#endif /* !( defined(HAVE_SETRESUID) && defined(HAVE_SETRESGID) ) */
if (getuid() != uid || geteuid() != uid ||
getgid() != gid || getegid() != gid) {
/* We failed to lose our privileges. */
return False;
}
return(True);
}
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