isc-dhcp/common/execute.c

/* execute.c

   Support for executable statements. */

/*
 * Copyright (c) 1998 The Internet Software Consortium.
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. Neither the name of The Internet Software Consortium nor the names
 *    of its contributors may be used to endorse or promote products derived
 *    from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE INTERNET SOFTWARE CONSORTIUM AND
 * CONTRIBUTORS ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES,
 * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
 * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
 * DISCLAIMED.  IN NO EVENT SHALL THE INTERNET SOFTWARE CONSORTIUM OR
 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
 * USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
 * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
 * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 *
 * This software has been written for the Internet Software Consortium
 * by Ted Lemon <mellon@fugue.com> in cooperation with Vixie
 * Enterprises.  To learn more about the Internet Software Consortium,
 * see ``http://www.vix.com/isc''.  To learn more about Vixie
 * Enterprises, see ``http://www.vix.com''.
 */

#ifndef lint
static char copyright[] =
"$Id: execute.c,v 1.2 1998/11/05 18:40:40 mellon Exp $ Copyright (c) 1998 The Internet Software Consortium.  All rights reserved.\n";
#endif /* not lint */

#include "dhcpd.h"

int execute_statements (packet, in_options, out_options, statements)
	struct packet *packet;
	struct option_state *in_options;
	struct option_state *out_options;
	struct executable_statement *statements;
{
	struct executable_statement *r;
	int result;
	int status;

	if (!statements)
		return 1;

	for (r = statements; r; r = r -> next) {
		switch (r -> op) {
		      case if_statement:
			status = evaluate_boolean_expression
				(&result, packet,
				 in_options, r -> data.ie.expr);
			
#if defined (DEBUG_EXPRESSIONS)
			note ("exec: if %s", (status
					      ? (result ? "true" : "false")
					      : "NULL"));
#endif
			/* XXX Treat NULL as false */
			if (!status)
				result = 0;
			if (!execute_statements
			    (packet, in_options, out_options,
			     result ? r -> data.ie.true : r -> data.ie.false))
				return 0;
			break;

		      case eval_statement:
			status = evaluate_boolean_expression
				(&result,
				 packet, in_options, r -> data.eval);
#if defined (DEBUG_EXPRESSIONS)
			note ("exec: evaluate: %s",
			      (status
			       ? (result ? "true" : "false") : "NULL"));
#endif
			break;

		      case add_statement:
#if defined (DEBUG_EXPRESSIONS)
			note ("exec: add %s", (r -> data.add -> name
					       ? r -> data.add -> name
					       : "<unnamed class>"));
#endif
			classify (packet, r -> data.add);
			break;

		      case break_statement:
#if defined (DEBUG_EXPRESSIONS)
			note ("exec: break");
#endif
			return 0;

		      case supersede_option_statement:
#if defined (DEBUG_EXPRESSIONS)
			note ("exec: supersede option %s.%s",
			      r -> data.option -> option -> universe -> name,
			      r -> data.option -> option -> name);
			goto option_statement;
#endif
		      case default_option_statement:
#if defined (DEBUG_EXPRESSIONS)
			note ("exec: default option %s.%s",
			      r -> data.option -> option -> universe -> name,
			      r -> data.option -> option -> name);
			goto option_statement;
#endif
		      case append_option_statement:
#if defined (DEBUG_EXPRESSIONS)
			note ("exec: append option %s.%s",
			      r -> data.option -> option -> universe -> name,
			      r -> data.option -> option -> name);
			goto option_statement;
#endif
		      case prepend_option_statement:
#if defined (DEBUG_EXPRESSIONS)
			note ("exec: prepend option %s.%s",
			      r -> data.option -> option -> universe -> name,
			      r -> data.option -> option -> name);
		      option_statement:
#endif
			if (r -> data.option -> option -> universe -> set_func)
				(r -> data.option -> option ->
				 universe -> set_func) (out_options,
							r -> data.option,
							r -> op);
			break;

		      default:
			error ("bogus classification rule type %d\n", r -> op);
		}
	}

	return 1;
}

/* Execute all the statements in a particular scope, and all statements in
   scopes outer from that scope, but if a particular limiting scope is
   reached, do not execute statements in that scope or in scopes outer
   from it. */

void execute_statements_in_scope (packet, options, group, limiting_group)
	struct packet *packet;
	struct option_state *options;
	struct group *group;
	struct group *limiting_group;
{
	struct group *scope;

	for (scope = group;
	     scope && scope != limiting_group; scope = scope -> next) {
		execute_statements (packet, options, options,
				    scope -> statements);
	}
}