check.c

非常好的dns解析软件

/*
 * Copyright (C) 2004-2006  Internet Systems Consortium, Inc. ("ISC")
 * Copyright (C) 2001-2003  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.
 */

/* $Id: check.c,v 1.44.18.31 2006/08/21 00:09:52 marka Exp $ */

/*! \file */

#include <config.h>

#include <stdlib.h>
#include <string.h>

#include <isc/buffer.h>
#include <isc/log.h>
#include <isc/mem.h>
#include <isc/netaddr.h>
#include <isc/parseint.h>
#include <isc/region.h>
#include <isc/result.h>
#include <isc/sockaddr.h>
#include <isc/symtab.h>
#include <isc/util.h>

#include <dns/acl.h>
#include <dns/fixedname.h>
#include <dns/rdataclass.h>
#include <dns/rdatatype.h>
#include <dns/secalg.h>

#include <isccfg/aclconf.h>
#include <isccfg/cfg.h>

#include <bind9/check.h>

static void
freekey(char *key, unsigned int type, isc_symvalue_t value, void *userarg) {
	UNUSED(type);
	UNUSED(value);
	isc_mem_free(userarg, key);
}

static isc_result_t
check_orderent(const cfg_obj_t *ent, isc_log_t *logctx) {
	isc_result_t result = ISC_R_SUCCESS;
	isc_result_t tresult;
	isc_textregion_t r;
	dns_fixedname_t fixed;
	const cfg_obj_t *obj;
	dns_rdataclass_t rdclass;
	dns_rdatatype_t rdtype;
	isc_buffer_t b;
	const char *str;

	dns_fixedname_init(&fixed);
	obj = cfg_tuple_get(ent, "class");
	if (cfg_obj_isstring(obj)) {

		DE_CONST(cfg_obj_asstring(obj), r.base);
		r.length = strlen(r.base);
		tresult = dns_rdataclass_fromtext(&rdclass, &r);
		if (tresult != ISC_R_SUCCESS) {
			cfg_obj_log(obj, logctx, ISC_LOG_ERROR,
				    "rrset-order: invalid class '%s'",
				    r.base);
			result = ISC_R_FAILURE;
		}
	}

	obj = cfg_tuple_get(ent, "type");
	if (cfg_obj_isstring(obj)) {

		DE_CONST(cfg_obj_asstring(obj), r.base);
		r.length = strlen(r.base);
		tresult = dns_rdatatype_fromtext(&rdtype, &r);
		if (tresult != ISC_R_SUCCESS) {
			cfg_obj_log(obj, logctx, ISC_LOG_ERROR,
				    "rrset-order: invalid type '%s'",
				    r.base);
			result = ISC_R_FAILURE;
		}
	}

	obj = cfg_tuple_get(ent, "name");
	if (cfg_obj_isstring(obj)) {
		str = cfg_obj_asstring(obj);
		isc_buffer_init(&b, str, strlen(str));
		isc_buffer_add(&b, strlen(str));
		tresult = dns_name_fromtext(dns_fixedname_name(&fixed), &b,
					    dns_rootname, ISC_FALSE, NULL);
		if (tresult != ISC_R_SUCCESS) {
			cfg_obj_log(obj, logctx, ISC_LOG_ERROR,
				    "rrset-order: invalid name '%s'", str);
			result = ISC_R_FAILURE;
		}
	}

	obj = cfg_tuple_get(ent, "order");
	if (!cfg_obj_isstring(obj) ||
	    strcasecmp("order", cfg_obj_asstring(obj)) != 0) {
		cfg_obj_log(ent, logctx, ISC_LOG_ERROR,
			    "rrset-order: keyword 'order' missing");
		result = ISC_R_FAILURE;
	}

	obj = cfg_tuple_get(ent, "ordering");
	if (!cfg_obj_isstring(obj)) {
	    cfg_obj_log(ent, logctx, ISC_LOG_ERROR,
			"rrset-order: missing ordering");
		result = ISC_R_FAILURE;
	} else if (strcasecmp(cfg_obj_asstring(obj), "fixed") != 0 &&
		   strcasecmp(cfg_obj_asstring(obj), "random") != 0 &&
		   strcasecmp(cfg_obj_asstring(obj), "cyclic") != 0) {
		cfg_obj_log(obj, logctx, ISC_LOG_ERROR,
			    "rrset-order: invalid order '%s'",
			    cfg_obj_asstring(obj));
		result = ISC_R_FAILURE;
	}
	return (result);
}

static isc_result_t
check_order(const cfg_obj_t *options, isc_log_t *logctx) {
	isc_result_t result = ISC_R_SUCCESS;
	isc_result_t tresult;
	const cfg_listelt_t *element;
	const cfg_obj_t *obj = NULL;

	if (cfg_map_get(options, "rrset-order", &obj) != ISC_R_SUCCESS)
		return (result);

	for (element = cfg_list_first(obj);
	     element != NULL;
	     element = cfg_list_next(element))
	{
		tresult = check_orderent(cfg_listelt_value(element), logctx);
		if (tresult != ISC_R_SUCCESS)
			result = tresult;
	}
	return (result);
}

static isc_result_t
check_dual_stack(const cfg_obj_t *options, isc_log_t *logctx) {
	const cfg_listelt_t *element;
	const cfg_obj_t *alternates = NULL;
	const cfg_obj_t *value;
	const cfg_obj_t *obj;
	const char *str;
	dns_fixedname_t fixed;
	dns_name_t *name;
	isc_buffer_t buffer;
	isc_result_t result = ISC_R_SUCCESS;
	isc_result_t tresult;

	(void)cfg_map_get(options, "dual-stack-servers", &alternates);

	if (alternates == NULL)
		return (ISC_R_SUCCESS);

	obj = cfg_tuple_get(alternates, "port");
	if (cfg_obj_isuint32(obj)) {
		isc_uint32_t val = cfg_obj_asuint32(obj);
		if (val > ISC_UINT16_MAX) {
			cfg_obj_log(obj, logctx, ISC_LOG_ERROR,
				    "port '%u' out of range", val);
			result = ISC_R_FAILURE;
		}
	}
	obj = cfg_tuple_get(alternates, "addresses");
	for (element = cfg_list_first(obj);
	     element != NULL;
	     element = cfg_list_next(element)) {
		value = cfg_listelt_value(element);
		if (cfg_obj_issockaddr(value))
			continue;
		obj = cfg_tuple_get(value, "name");
		str = cfg_obj_asstring(obj);
		isc_buffer_init(&buffer, str, strlen(str));
		isc_buffer_add(&buffer, strlen(str));
		dns_fixedname_init(&fixed);
		name = dns_fixedname_name(&fixed);
		tresult = dns_name_fromtext(name, &buffer, dns_rootname,
					   ISC_FALSE, NULL);
		if (tresult != ISC_R_SUCCESS) {
			cfg_obj_log(obj, logctx, ISC_LOG_ERROR,
				    "bad name '%s'", str);
			result = ISC_R_FAILURE;
		}
		obj = cfg_tuple_get(value, "port");
		if (cfg_obj_isuint32(obj)) {
			isc_uint32_t val = cfg_obj_asuint32(obj);
			if (val > ISC_UINT16_MAX) {
				cfg_obj_log(obj, logctx, ISC_LOG_ERROR,
					    "port '%u' out of range", val);
				result = ISC_R_FAILURE;
			}
		}
	}
	return (result);
}

static isc_result_t
check_forward(const cfg_obj_t *options, isc_log_t *logctx) {
	const cfg_obj_t *forward = NULL;
	const cfg_obj_t *forwarders = NULL;

	(void)cfg_map_get(options, "forward", &forward);
	(void)cfg_map_get(options, "forwarders", &forwarders);

	if (forward != NULL && forwarders == NULL) {
		cfg_obj_log(forward, logctx, ISC_LOG_ERROR,
			    "no matching 'forwarders' statement");
		return (ISC_R_FAILURE);
	}
	return (ISC_R_SUCCESS);
}

static isc_result_t
disabled_algorithms(const cfg_obj_t *disabled, isc_log_t *logctx) {
	isc_result_t result = ISC_R_SUCCESS;
	isc_result_t tresult;
	const cfg_listelt_t *element;
	const char *str;
	isc_buffer_t b;
	dns_fixedname_t fixed;
	dns_name_t *name;
	const cfg_obj_t *obj;

	dns_fixedname_init(&fixed);
	name = dns_fixedname_name(&fixed);
	obj = cfg_tuple_get(disabled, "name");
	str = cfg_obj_asstring(obj);
	isc_buffer_init(&b, str, strlen(str));
	isc_buffer_add(&b, strlen(str));
	tresult = dns_name_fromtext(name, &b, dns_rootname, ISC_FALSE, NULL);
	if (tresult != ISC_R_SUCCESS) {
		cfg_obj_log(obj, logctx, ISC_LOG_ERROR,
			    "bad domain name '%s'", str);
		result = tresult;
	}

	obj = cfg_tuple_get(disabled, "algorithms");

	for (element = cfg_list_first(obj);
	     element != NULL;
	     element = cfg_list_next(element))
	{
		isc_textregion_t r;
		dns_secalg_t alg;
		isc_result_t tresult;

		DE_CONST(cfg_obj_asstring(cfg_listelt_value(element)), r.base);
		r.length = strlen(r.base);

		tresult = dns_secalg_fromtext(&alg, &r);
		if (tresult != ISC_R_SUCCESS) {
			isc_uint8_t ui;
			result = isc_parse_uint8(&ui, r.base, 10);
		}
		if (tresult != ISC_R_SUCCESS) {
			cfg_obj_log(cfg_listelt_value(element), logctx,
				    ISC_LOG_ERROR, "invalid algorithm '%s'",
				    r.base);
			result = tresult;
		}
	}
	return (result);
}

static isc_result_t
nameexist(const cfg_obj_t *obj, const char *name, int value,
	  isc_symtab_t *symtab, const char *fmt, isc_log_t *logctx,
	  isc_mem_t *mctx)
{
	char *key;
	const char *file;
	unsigned int line;
	isc_result_t result;
	isc_symvalue_t symvalue;

	key = isc_mem_strdup(mctx, name);
	if (key == NULL)
		return (ISC_R_NOMEMORY);
	symvalue.as_cpointer = obj;
	result = isc_symtab_define(symtab, key, value, symvalue,
				   isc_symexists_reject);
	if (result == ISC_R_EXISTS) {
		RUNTIME_CHECK(isc_symtab_lookup(symtab, key, value,
						&symvalue) == ISC_R_SUCCESS);
		file = cfg_obj_file(symvalue.as_cpointer);
		line = cfg_obj_line(symvalue.as_cpointer);

		if (file == NULL)
			file = "<unknown file>";
		cfg_obj_log(obj, logctx, ISC_LOG_ERROR, fmt, key, file, line);
		isc_mem_free(mctx, key);
		result = ISC_R_EXISTS;
	} else if (result != ISC_R_SUCCESS) {
		isc_mem_free(mctx, key);
	}
	return (result);
}

static isc_result_t
mustbesecure(const cfg_obj_t *secure, isc_symtab_t *symtab, isc_log_t *logctx,
	     isc_mem_t *mctx)
{
	const cfg_obj_t *obj;
	char namebuf[DNS_NAME_FORMATSIZE];
	const char *str;
	dns_fixedname_t fixed;
	dns_name_t *name;
	isc_buffer_t b;
	isc_result_t result = ISC_R_SUCCESS;

	dns_fixedname_init(&fixed);
	name = dns_fixedname_name(&fixed);
	obj = cfg_tuple_get(secure, "name");
	str = cfg_obj_asstring(obj);
	isc_buffer_init(&b, str, strlen(str));
	isc_buffer_add(&b, strlen(str));
	result = dns_name_fromtext(name, &b, dns_rootname, ISC_FALSE, NULL);
	if (result != ISC_R_SUCCESS) {
		cfg_obj_log(obj, logctx, ISC_LOG_ERROR,
			    "bad domain name '%s'", str);
	} else {
		dns_name_format(name, namebuf, sizeof(namebuf));
		result = nameexist(secure, namebuf, 1, symtab,
				   "dnssec-must-be-secure '%s': already "
				   "exists previous definition: %s:%u",
				   logctx, mctx);
	}
	return (result);
}

static isc_result_t
checkacl(const char *aclname, cfg_aclconfctx_t *actx, const cfg_obj_t *zconfig,
	 const cfg_obj_t *voptions, const cfg_obj_t *config,
	 isc_log_t *logctx, isc_mem_t *mctx)
{
	isc_result_t result;
	const cfg_obj_t *aclobj = NULL;
	const cfg_obj_t *options;
	dns_acl_t *acl = NULL;

	if (zconfig != NULL) {
		options = cfg_tuple_get(zconfig, "options");
		cfg_map_get(options, aclname, &aclobj);
	}
	if (voptions != NULL && aclobj == NULL)
		cfg_map_get(voptions, aclname, &aclobj);
	if (config != NULL && aclobj == NULL) {
		options = NULL;
		cfg_map_get(config, "options", &options);
		if (options != NULL)
			cfg_map_get(options, aclname, &aclobj);
	}
	if (aclobj == NULL)
		return (ISC_R_SUCCESS);
	result = cfg_acl_fromconfig(aclobj, config, logctx, actx, mctx, &acl);
	if (acl != NULL)
		dns_acl_detach(&acl);
	return (result);
}

static isc_result_t
check_viewacls(cfg_aclconfctx_t *actx, const cfg_obj_t *voptions,
	       const cfg_obj_t *config, isc_log_t *logctx, isc_mem_t *mctx)
{
	isc_result_t result = ISC_R_SUCCESS, tresult;
	int i = 0;
	
	static const char *acls[] = { "allow-query", "allow-query-cache",
		"allow-recursion", "blackhole", "match-clients",
		"match-destinations", "sortlist", NULL };

	while (acls[i] != NULL) {
		tresult = checkacl(acls[i++], actx, NULL, voptions, config,
				   logctx, mctx);
		if (tresult != ISC_R_SUCCESS)
			result = tresult;  
	}
	return (result);
}

typedef struct {
	const char *name;
	unsigned int scale;
	unsigned int max;
} intervaltable;

static isc_result_t
check_options(const cfg_obj_t *options, isc_log_t *logctx, isc_mem_t *mctx) {
	isc_result_t result = ISC_R_SUCCESS;
	isc_result_t tresult;
	unsigned int i;
	const cfg_obj_t *obj = NULL;
	const cfg_listelt_t *element;
	isc_symtab_t *symtab = NULL;
	dns_fixedname_t fixed;
	const char *str;
	dns_name_t *name;
	isc_buffer_t b;

	static intervaltable intervals[] = {
	{ "cleaning-interval", 60, 28 * 24 * 60 },	/* 28 days */
	{ "heartbeat-interval", 60, 28 * 24 * 60 },	/* 28 days */
	{ "interface-interval", 60, 28 * 24 * 60 },	/* 28 days */
	{ "max-transfer-idle-in", 60, 28 * 24 * 60 },	/* 28 days */
	{ "max-transfer-idle-out", 60, 28 * 24 * 60 },	/* 28 days */
	{ "max-transfer-time-in", 60, 28 * 24 * 60 },	/* 28 days */
	{ "max-transfer-time-out", 60, 28 * 24 * 60 },	/* 28 days */
	{ "sig-validity-interval", 86400, 10 * 366 },	/* 10 years */
	{ "statistics-interval", 60, 28 * 24 * 60 },	/* 28 days */
	};

	/*
	 * Check that fields specified in units of time other than seconds
	 * have reasonable values.
	 */
	for (i = 0; i < sizeof(intervals) / sizeof(intervals[0]); i++) {
		isc_uint32_t val;
		obj = NULL;
		(void)cfg_map_get(options, intervals[i].name, &obj);
		if (obj == NULL)
			continue;
		val = cfg_obj_asuint32(obj);
		if (val > intervals[i].max) {
			cfg_obj_log(obj, logctx, ISC_LOG_ERROR,
				    "%s '%u' is out of range (0..%u)",
				    intervals[i].name, val,
				    intervals[i].max);
			result = ISC_R_RANGE;
		} else if (val > (ISC_UINT32_MAX / intervals[i].scale)) {
			cfg_obj_log(obj, logctx, ISC_LOG_ERROR,
				    "%s '%d' is out of range",
				    intervals[i].name, val);
			result = ISC_R_RANGE;
		}
	}
	obj = NULL;
	(void)cfg_map_get(options, "preferred-glue", &obj);
	if (obj != NULL) {
		const char *str;
                str = cfg_obj_asstring(obj);
                if (strcasecmp(str, "a") != 0 &&
		    strcasecmp(str, "aaaa") != 0 &&
		    strcasecmp(str, "none") != 0)
			cfg_obj_log(obj, logctx, ISC_LOG_ERROR,
				    "preferred-glue unexpected value '%s'",
				    str);
	}
	obj = NULL;
	(void)cfg_map_get(options, "root-delegation-only", &obj);
	if (obj != NULL) {
		if (!cfg_obj_isvoid(obj)) {
			const cfg_listelt_t *element;
			const cfg_obj_t *exclude;
			const char *str;
			dns_fixedname_t fixed;
			dns_name_t *name;
			isc_buffer_t b;

			dns_fixedname_init(&fixed);
			name = dns_fixedname_name(&fixed);
			for (element = cfg_list_first(obj);
			     element != NULL;
			     element = cfg_list_next(element)) {
				exclude = cfg_listelt_value(element);
				str = cfg_obj_asstring(exclude);
				isc_buffer_init(&b, str, strlen(str));
				isc_buffer_add(&b, strlen(str));
				tresult = dns_name_fromtext(name, &b,
							   dns_rootname,
                                                           ISC_FALSE, NULL);
				if (tresult != ISC_R_SUCCESS) {
					cfg_obj_log(obj, logctx, ISC_LOG_ERROR,
						    "bad domain name '%s'",
						    str);
					result = tresult;
				}
			}
		}
	}
       
	/*
	 * Set supported DNSSEC algorithms.
	 */
	obj = NULL;
	(void)cfg_map_get(options, "disable-algorithms", &obj);
	if (obj != NULL) {
		for (element = cfg_list_first(obj);
		     element != NULL;
		     element = cfg_list_next(element))
		{