/*
   Unix SMB/CIFS implementation.
   Privileges handling functions
   Copyright (C) Jean François Micouleau	1998-2001
   Copyright (C) Simo Sorce			2002-2003
   Copyright (C) Gerald (Jerry) Carter          2005
   Copyright (C) Michael Adam			2007
   Copyright (C) Andrew Bartlett		2010

   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 3 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, see <http://www.gnu.org/licenses/>.
*/

/*
 * Basic privileges functions (mask-operations and conversion
 * functions between the different formats (se_priv, privset, luid)
 * moved here * from lib/privileges.c to minimize linker deps.
 *
 * generally SID- and LUID-related code is left in lib/privileges.c
 *
 * some extra functions to hide privs array from lib/privileges.c
 */

#include "includes.h"

const uint64_t se_priv_all         = SE_ALL_PRIVS;
static const uint64_t se_priv_end  = SE_END;

/* Define variables for all privileges so we can use the
   uint64_t* in the various se_priv_XXX() functions */

const uint64_t se_priv_none       = SE_NONE;
const uint64_t se_machine_account = SE_MACHINE_ACCOUNT;
const uint64_t se_print_operator  = SE_PRINT_OPERATOR;
const uint64_t se_add_users       = SE_ADD_USERS;
const uint64_t se_disk_operators  = SE_DISK_OPERATOR;
const uint64_t se_remote_shutdown = SE_REMOTE_SHUTDOWN;
const uint64_t se_restore         = SE_RESTORE;
const uint64_t se_take_ownership  = SE_TAKE_OWNERSHIP;

PRIVS privs[] = {
#if 0	/* usrmgr will display these twice if you include them.  We don't
	   use them but we'll keep the bitmasks reserved in privileges.h anyways */

	{SE_NETWORK_LOGON,	"SeNetworkLogonRight",		"Access this computer from network", 	   0x0},
	{SE_INTERACTIVE_LOGON,	"SeInteractiveLogonRight",	"Log on locally", 			   0x0},
	{SE_BATCH_LOGON,	"SeBatchLogonRight",		"Log on as a batch job",		   0x0},
	{SE_SERVICE_LOGON,	"SeServiceLogonRight",		"Log on as a service",			   0x0},
#endif
	{SE_MACHINE_ACCOUNT,	"SeMachineAccountPrivilege",	"Add machines to domain",		   SEC_PRIV_MACHINE_ACCOUNT},
	{SE_TAKE_OWNERSHIP,     "SeTakeOwnershipPrivilege",     "Take ownership of files or other objects",SEC_PRIV_TAKE_OWNERSHIP},
        {SE_BACKUP,             "SeBackupPrivilege",            "Back up files and directories",	   SEC_PRIV_BACKUP},
        {SE_RESTORE,            "SeRestorePrivilege",           "Restore files and directories",	   SEC_PRIV_RESTORE},
	{SE_REMOTE_SHUTDOWN,	"SeRemoteShutdownPrivilege",	"Force shutdown from a remote system",	   SEC_PRIV_REMOTE_SHUTDOWN},

	{SE_PRINT_OPERATOR,	"SePrintOperatorPrivilege",	"Manage printers",			   SEC_PRIV_PRINT_OPERATOR},
	{SE_ADD_USERS,		"SeAddUsersPrivilege",		"Add users and groups to the domain",	   SEC_PRIV_ADD_USERS},
	{SE_DISK_OPERATOR,	"SeDiskOperatorPrivilege",	"Manage disk shares",			   SEC_PRIV_DISK_OPERATOR},

	{SE_END, "", "", 0x0}
};

/***************************************************************************
 copy an uint64_t structure
****************************************************************************/

bool se_priv_copy( uint64_t *dst, const uint64_t *src )
{
	if ( !dst || !src )
		return false;

	memcpy( dst, src, sizeof(uint64_t) );

	return true;
}

/***************************************************************************
 put all privileges into a mask
****************************************************************************/

bool se_priv_put_all_privileges(uint64_t *privilege_mask)
{
	int i;
	uint32_t num_privs = count_all_privileges();

	if (!se_priv_copy(privilege_mask, &se_priv_none)) {
		return false;
	}
	for ( i=0; i<num_privs; i++ ) {
		se_priv_add(privilege_mask, &privs[i].privilege_mask);
	}
	return true;
}

/***************************************************************************
 combine 2 uint64_t structures and store the resulting set in mew_mask
****************************************************************************/

void se_priv_add( uint64_t *privilege_mask, const uint64_t *addpriv )
{
	*privilege_mask |= *addpriv;
}

/***************************************************************************
 remove one uint64_t sytucture from another and store the resulting set
 in mew_mask
****************************************************************************/

void se_priv_remove( uint64_t *privilege_mask, const uint64_t *removepriv )
{
	*privilege_mask &= ~*removepriv;
}

/***************************************************************************
 invert a given uint64_t and store the set in new_mask
****************************************************************************/

static void se_priv_invert( uint64_t *new_mask, const uint64_t *privilege_mask )
{
	uint64_t allprivs;

	se_priv_copy( &allprivs, &se_priv_all );
	se_priv_remove( &allprivs, privilege_mask );
	se_priv_copy( new_mask, &allprivs );
}

/***************************************************************************
 check if 2 uint64_t structure are equal
****************************************************************************/

bool se_priv_equal( const uint64_t *privilege_mask1, const uint64_t *privilege_mask2 )
{
	return *privilege_mask1 == *privilege_mask2;
}

/***************************************************************************
 check if a uint64_t has any assigned privileges
****************************************************************************/

static bool se_priv_empty( const uint64_t *privilege_mask )
{
	uint64_t p1;

	se_priv_copy( &p1, privilege_mask );

	p1 &= se_priv_all;

	return se_priv_equal( &p1, &se_priv_none );
}

/*********************************************************************
 Lookup the uint64_t value for a privilege name
*********************************************************************/

bool se_priv_from_name( const char *name, uint64_t *privilege_mask )
{
	int i;

	for ( i=0; !se_priv_equal(&privs[i].privilege_mask, &se_priv_end); i++ ) {
		if ( strequal( privs[i].name, name ) ) {
			se_priv_copy( privilege_mask, &privs[i].privilege_mask );
			return true;
		}
	}

	return false;
}

/****************************************************************************
 check if the privilege is in the privilege list
****************************************************************************/

bool is_privilege_assigned(const uint64_t *privileges,
			   const uint64_t *check)
{
	uint64_t p1, p2;

	if ( !privileges || !check )
		return false;

	/* everyone has privileges if you aren't checking for any */

	if ( se_priv_empty( check ) ) {
		DEBUG(1,("is_privilege_assigned: no privileges in check_mask!\n"));
		return true;
	}

	se_priv_copy( &p1, check );

	/* invert the uint64_t we want to check for and remove that from the
	   original set.  If we are left with the uint64_t we are checking
	   for then return true */

	se_priv_invert( &p1, check );
	se_priv_copy( &p2, privileges );
	se_priv_remove( &p2, &p1 );

	return se_priv_equal( &p2, check );
}

/****************************************************************************
 check if the privilege is in the privilege list
****************************************************************************/

static bool is_any_privilege_assigned( uint64_t *privileges, const uint64_t *check )
{
	uint64_t p1, p2;

	if ( !privileges || !check )
		return false;

	/* everyone has privileges if you aren't checking for any */

	if ( se_priv_empty( check ) ) {
		DEBUG(1,("is_any_privilege_assigned: no privileges in check_mask!\n"));
		return true;
	}

	se_priv_copy( &p1, check );

	/* invert the uint64_t we want to check for and remove that from the
	   original set.  If we are left with the uint64_t we are checking
	   for then return true */

	se_priv_invert( &p1, check );
	se_priv_copy( &p2, privileges );
	se_priv_remove( &p2, &p1 );

	/* see if we have any bits left */

	return !se_priv_empty( &p2 );
}

/*********************************************************************
 Generate the struct lsa_LUIDAttribute structure based on a bitmask
*********************************************************************/

const char* get_privilege_dispname( const char *name )
{
	int i;

	if (!name) {
		return NULL;
	}

	for ( i=0; !se_priv_equal(&privs[i].privilege_mask, &se_priv_end); i++ ) {

		if ( strequal( privs[i].name, name ) ) {
			return privs[i].description;
		}
	}

	return NULL;
}

/****************************************************************************
 initialise a privilege list and set the talloc context
 ****************************************************************************/

/****************************************************************************
 Does the user have the specified privilege ?  We only deal with one privilege
 at a time here.
*****************************************************************************/

bool user_has_privileges(const struct security_token *token, const uint64_t *privilege_bit)
{
	if ( !token )
		return false;

	return is_privilege_assigned( &token->privilege_mask, privilege_bit );
}

/****************************************************************************
 Does the user have any of the specified privileges ?  We only deal with one privilege
 at a time here.
*****************************************************************************/

bool user_has_any_privilege(struct security_token *token, const uint64_t *privilege_mask)
{
	if ( !token )
		return false;

	return is_any_privilege_assigned( &token->privilege_mask, privilege_mask );
}

/*******************************************************************
 return the number of elements in the privlege array
*******************************************************************/

int count_all_privileges( void )
{
	/*
	 * The -1 is due to the weird SE_END record...
	 */
	return (sizeof(privs) / sizeof(privs[0])) - 1;
}


/*********************************************************************
 Generate the struct lsa_LUIDAttribute structure based on a bitmask
 The assumption here is that the privilege has already been validated
 so we are guaranteed to find it in the list.
*********************************************************************/

struct lsa_LUIDAttribute get_privilege_luid( uint64_t *privilege_mask )
{
	struct lsa_LUIDAttribute priv_luid;
	int i;

	ZERO_STRUCT( priv_luid );

	for ( i=0; !se_priv_equal(&privs[i].privilege_mask, &se_priv_end); i++ ) {

		if ( se_priv_equal( &privs[i].privilege_mask, privilege_mask ) ) {
			priv_luid.luid.low = privs[i].luid;
			priv_luid.luid.high = 0;
			break;
		}
	}

	return priv_luid;
}

/****************************************************************************
 Convert a LUID to a named string
****************************************************************************/

const char *luid_to_privilege_name(const struct lsa_LUID *set)
{
	int i;

	if (set->high != 0)
		return NULL;

	for ( i=0; !se_priv_equal(&privs[i].privilege_mask, &se_priv_end); i++ ) {
		if ( set->low == privs[i].luid ) {
			return privs[i].name;
		}
	}

	return NULL;
}


/****************************************************************************
 add a privilege to a privilege array
 ****************************************************************************/

static bool privilege_set_add(PRIVILEGE_SET *priv_set, struct lsa_LUIDAttribute set)
{
	struct lsa_LUIDAttribute *new_set;

	/* we can allocate memory to add the new privilege */

	new_set = talloc_realloc(priv_set->mem_ctx, priv_set->set, struct lsa_LUIDAttribute, priv_set->count + 1);
	if ( !new_set ) {
		DEBUG(0,("privilege_set_add: failed to allocate memory!\n"));
		return false;
	}

	new_set[priv_set->count].luid.high = set.luid.high;
	new_set[priv_set->count].luid.low = set.luid.low;
	new_set[priv_set->count].attribute = set.attribute;

	priv_set->count++;
	priv_set->set = new_set;

	return true;
}

/*******************************************************************
*******************************************************************/

bool se_priv_to_privilege_set( PRIVILEGE_SET *set, uint64_t *privilege_mask )
{
	int i;
	uint32_t num_privs = count_all_privileges();
	struct lsa_LUIDAttribute luid;

	luid.attribute = 0;
	luid.luid.high = 0;

	for ( i=0; i<num_privs; i++ ) {
		if ( !is_privilege_assigned(privilege_mask, &privs[i].privilege_mask) )
			continue;

		luid.luid.high = 0;
		luid.luid.low = privs[i].luid;

		if ( !privilege_set_add( set, luid ) )
			return false;
	}

	return true;
}

/*******************************************************************
*******************************************************************/

static bool luid_to_se_priv( struct lsa_LUID *luid, uint64_t *privilege_mask )
{
	int i;
	uint32_t num_privs = count_all_privileges();

	for ( i=0; i<num_privs; i++ ) {
		if ( luid->low == privs[i].luid ) {
			se_priv_copy( privilege_mask, &privs[i].privilege_mask );
			return true;
		}
	}

	return false;
}

/*******************************************************************
*******************************************************************/

bool privilege_set_to_se_priv( uint64_t *privilege_mask, struct lsa_PrivilegeSet *privset )
{
	int i;

	ZERO_STRUCTP( privilege_mask );

	for ( i=0; i<privset->count; i++ ) {
		uint64_t r;

		/* sanity check for invalid privilege.  we really
		   only care about the low 32 bits */

		if ( privset->set[i].luid.high != 0 )
			return false;

		if ( luid_to_se_priv( &privset->set[i].luid, &r ) )
			se_priv_add( privilege_mask, &r );
	}

	return true;
}