class.c

DHCP服务器源码

/* class.c

   Handling for client classes. */

/*
 * Copyright (c) 2004 by Internet Systems Consortium, Inc. ("ISC")
 * Copyright (c) 1998-2003 by Internet Software Consortium
 *
 * Permission to use, copy, modify, and distribute this software for any
 * purpose with or without fee is hereby granted, provided that the above
 * copyright notice and this permission notice appear in all copies.
 *
 * THE SOFTWARE IS PROVIDED "AS IS" AND ISC DISCLAIMS ALL WARRANTIES
 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
 * MERCHANTABILITY AND FITNESS.  IN NO EVENT SHALL ISC BE LIABLE FOR
 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT
 * OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 *
 *   Internet Systems Consortium, Inc.
 *   950 Charter Street
 *   Redwood City, CA 94063
 *   <[e-mail]>
 *   http://www.isc.org/
 *
 * This software has been written for Internet Systems Consortium
 * by Ted Lemon in cooperation with Vixie Enterprises and Nominum, Inc.
 * To learn more about Internet Systems Consortium, see
 * ``http://www.isc.org/''.  To learn more about Vixie Enterprises,
 * see ``http://www.vix.com''.   To learn more about Nominum, Inc., see
 * ``http://www.nominum.com''.
 */

#ifndef lint
static char copyright[] =
"$Id: class.c,v 1.29.2.4 2004/06/10 17:59:51 dhankins Exp $ Copyright (c) 2004 Internet Systems Consortium.  All rights reserved.\n";

#endif /* not lint */

#include "dhcpd.h"

struct collection default_collection = {
	(struct collection *)0,
	"default",
	(struct class *)0,
};

struct collection *collections = &default_collection;
struct executable_statement *default_classification_rules;

int have_billing_classes;

/* Build the default classification rule tree. */

void classification_setup ()
{
	/* eval ... */
	default_classification_rules = (struct executable_statement *)0;
	if (!executable_statement_allocate (&default_classification_rules,
					    MDL))
		log_fatal ("Can't allocate check of default collection");
	default_classification_rules -> op = eval_statement;

	/* check-collection "default" */
	if (!expression_allocate (&default_classification_rules -> data.eval,
				  MDL))
		log_fatal ("Can't allocate default check expression");
	default_classification_rules -> data.eval -> op = expr_check;
	default_classification_rules -> data.eval -> data.check =
		&default_collection;
}

void classify_client (packet)
	struct packet *packet;
{
	execute_statements ((struct binding_value **)0, packet,
			    (struct lease *)0, (struct client_state *)0,
			    packet -> options, (struct option_state *)0,
			    &global_scope, default_classification_rules);
}

int check_collection (packet, lease, collection)
	struct packet *packet;
	struct lease *lease;
	struct collection *collection;
{
	struct class *class, *nc;
	struct data_string data;
	int matched = 0;
	int status;
	int ignorep;

	for (class = collection -> classes; class; class = class -> nic) {
#if defined (DEBUG_CLASS_MATCHING)
		log_info ("checking against class %s...", class -> name);
#endif
		memset (&data, 0, sizeof data);

		/* If there is a "match if" expression, check it.   If
		   we get a match, and there's no subclass expression,
		   it's a match.   If we get a match and there is a subclass
		   expression, then we check the submatch.   If it's not a
		   match, that's final - we don't check the submatch. */

		if (class -> expr) {
			status = (evaluate_boolean_expression_result
				  (&ignorep, packet, lease,
				   (struct client_state *)0,
				   packet -> options, (struct option_state *)0,
				   lease ? &lease -> scope : &global_scope,
				   class -> expr));
			if (status) {
				if (!class -> submatch) {
					matched = 1;
#if defined (DEBUG_CLASS_MATCHING)
					log_info ("matches class.");
#endif
					classify (packet, class);
					continue;
				}
			} else
				continue;
		}

		/* Check to see if the client matches an existing subclass.
		   If it doesn't, and this is a spawning class, spawn a new
		   subclass and put the client in it. */
		if (class -> submatch) {
			status = (evaluate_data_expression
				  (&data, packet, lease,
				   (struct client_state *)0,
				   packet -> options, (struct option_state *)0,
				   lease ? &lease -> scope : &global_scope,
				   class -> submatch, MDL));
			if (status && data.len) {
				nc = (struct class *)0;
				if (class_hash_lookup (&nc, class -> hash,
						       (const char *)data.data,
						       data.len, MDL)) {
#if defined (DEBUG_CLASS_MATCHING)
					log_info ("matches subclass %s.",
					      print_hex_1 (data.len,
							   data.data, 60));
#endif
					data_string_forget (&data, MDL);
					classify (packet, nc);
					matched = 1;
					class_dereference (&nc, MDL);
					continue;
				}
				if (!class -> spawning) {
					data_string_forget (&data, MDL);
					continue;
				}
				/* XXX Write out the spawned class? */
#if defined (DEBUG_CLASS_MATCHING)
				log_info ("spawning subclass %s.",
				      print_hex_1 (data.len, data.data, 60));
#endif
				status = class_allocate (&nc, MDL);
				group_reference (&nc -> group,
						 class -> group, MDL);
				class_reference (&nc -> superclass,
						 class, MDL);
				nc -> lease_limit = class -> lease_limit;
				nc -> dirty = 1;
				if (nc -> lease_limit) {
					nc -> billed_leases =
						(dmalloc
						 (nc -> lease_limit *
						  sizeof (struct lease *),
						  MDL));
					if (!nc -> billed_leases) {
						log_error ("no memory for%s",
							   " billing");
						data_string_forget
							(&nc -> hash_string,
							 MDL);
						class_dereference (&nc, MDL);
						data_string_forget (&data,
								    MDL);
						continue;
					}
					memset (nc -> billed_leases, 0,
						(nc -> lease_limit *
						 sizeof nc -> billed_leases));
				}
				data_string_copy (&nc -> hash_string, &data,
						  MDL);
				data_string_forget (&data, MDL);
				if (!class -> hash)
				    class_new_hash (&class -> hash, 0, MDL);
				class_hash_add (class -> hash,
						(const char *)
						nc -> hash_string.data,
						nc -> hash_string.len,
						nc, MDL);
				classify (packet, nc);
				class_dereference (&nc, MDL);
			}
		}
	}
	return matched;
}

void classify (packet, class)
	struct packet *packet;
	struct class *class;
{
	if (packet -> class_count < PACKET_MAX_CLASSES)
		class_reference (&packet -> classes [packet -> class_count++],
				 class, MDL);
	else
		log_error ("too many classes match %s",
		      print_hw_addr (packet -> raw -> htype,
				     packet -> raw -> hlen,
				     packet -> raw -> chaddr));
}

isc_result_t find_class (struct class **class, const char *name,
			 const char *file, int line)
{
	struct collection *lp;
	struct class *cp;

	for (lp = collections; lp; lp = lp -> next) {
		for (cp = lp -> classes; cp; cp = cp -> nic)
			if (cp -> name && !strcmp (name, cp -> name)) {
				return class_reference (class, cp, file, line);
			}
	}
	return ISC_R_NOTFOUND;
}

int unbill_class (lease, class)
	struct lease *lease;
	struct class *class;
{
	int i;

	for (i = 0; i < class -> lease_limit; i++)
		if (class -> billed_leases [i] == lease)
			break;
	if (i == class -> lease_limit) {
		log_error ("lease %s unbilled with no billing arrangement.",
		      piaddr (lease -> ip_addr));
		return 0;
	}
	class_dereference (&lease -> billing_class, MDL);
	lease_dereference (&class -> billed_leases [i], MDL);
	class -> leases_consumed--;
	return 1;
}

int bill_class (lease, class)
	struct lease *lease;
	struct class *class;
{
	int i;

	if (lease -> billing_class) {
		log_error ("lease billed with existing billing arrangement.");
		unbill_class (lease, lease -> billing_class);
	}

	if (class -> leases_consumed == class -> lease_limit)
		return 0;

	for (i = 0; i < class -> lease_limit; i++)
		if (!class -> billed_leases [i])
			break;

	if (i == class -> lease_limit) {
		log_error ("class billing consumption disagrees with leases.");
		return 0;
	}

	lease_reference (&class -> billed_leases [i], lease, MDL);
	class_reference (&lease -> billing_class, class, MDL);
	class -> leases_consumed++;
	return 1;
}