sdlz.c

非常好的dns解析软件

	NULL,
	NULL,
	NULL
};

static void
list_tordataset(dns_rdatalist_t *rdatalist,
		dns_db_t *db, dns_dbnode_t *node,
		dns_rdataset_t *rdataset)
{
	/*
	 * The sdlz rdataset is an rdatalist with some additions.
	 *	- private1 & private2 are used by the rdatalist.
	 *	- private3 & private 4 are unused.
	 *	- private5 is the node.
	 */

	/* This should never fail. */
	RUNTIME_CHECK(dns_rdatalist_tordataset(rdatalist, rdataset) ==
		      ISC_R_SUCCESS);

	rdataset->methods = &rdataset_methods;
	dns_db_attachnode(db, node, &rdataset->private5);
}

/*
 * SDLZ core methods. This is the core of the new DLZ functionality.
 */

/*%
 * Build a 'bind' database driver structure to be returned by
 * either the find zone or the allow zone transfer method.
 * This method is only available in this source file, it is
 * not made available anywhere else.
 */

static isc_result_t
dns_sdlzcreateDBP(isc_mem_t *mctx, void *driverarg, void *dbdata,
		  dns_name_t *name, dns_rdataclass_t rdclass, dns_db_t **dbp)
{
	isc_result_t result;
	dns_sdlz_db_t *sdlzdb;
	dns_sdlzimplementation_t *imp;

	/* check that things are as we expect */
	REQUIRE(dbp != NULL && *dbp == NULL);
	REQUIRE(name != NULL);

	imp = (dns_sdlzimplementation_t *) driverarg;

	/* allocate and zero memory for driver structure */
	sdlzdb = isc_mem_get(mctx, sizeof(dns_sdlz_db_t));
	if (sdlzdb == NULL)
		return (ISC_R_NOMEMORY);
	memset(sdlzdb, 0, sizeof(dns_sdlz_db_t));

	/* initialize and set origin */
	dns_name_init(&sdlzdb->common.origin, NULL);
	result = dns_name_dupwithoffsets(name, mctx, &sdlzdb->common.origin);
	if (result != ISC_R_SUCCESS)
		goto mem_cleanup;

	/* initialize the reference count mutex */
	result = isc_mutex_init(&sdlzdb->refcnt_lock);
	if (result != ISC_R_SUCCESS)
		goto name_cleanup;

	/* set the rest of the database structure attributes */
	sdlzdb->dlzimp = imp;
	sdlzdb->common.methods = &sdlzdb_methods;
	sdlzdb->common.attributes = 0;
	sdlzdb->common.rdclass = rdclass;
	sdlzdb->common.mctx = NULL;
	sdlzdb->dbdata = dbdata;
	sdlzdb->references = 1;

	/* attach to the memory context */
	isc_mem_attach(mctx, &sdlzdb->common.mctx);

	/* mark structure as valid */
	sdlzdb->common.magic = DNS_DB_MAGIC;
	sdlzdb->common.impmagic = SDLZDB_MAGIC;
	*dbp = (dns_db_t *) sdlzdb;

	return (result);

	/*
	 * reference count mutex could not be initialized, clean up
	 * name memory
	 */
 name_cleanup:
	dns_name_free(&sdlzdb->common.origin, mctx);
 mem_cleanup:
	isc_mem_put(mctx, sdlzdb, sizeof(dns_sdlz_db_t));
	return (result);
}

static isc_result_t
dns_sdlzallowzonexfr(void *driverarg, void *dbdata, isc_mem_t *mctx,
		     dns_rdataclass_t rdclass, dns_name_t *name,
		     isc_sockaddr_t *clientaddr, dns_db_t **dbp)
{
	isc_buffer_t b;
	isc_buffer_t b2;
	char namestr[DNS_NAME_MAXTEXT + 1];
	char clientstr[(sizeof "xxxx:xxxx:xxxx:xxxx:xxxx:xxxx:255.255.255.255")
		       + 1];
	isc_netaddr_t netaddr;
	isc_result_t result;
	dns_sdlzimplementation_t *imp;

	/*
	 * Perform checks to make sure data is as we expect it to be.
	 */
	REQUIRE(driverarg != NULL);
	REQUIRE(name != NULL);
	REQUIRE(clientaddr != NULL);
	REQUIRE(dbp != NULL && *dbp == NULL);

	imp = (dns_sdlzimplementation_t *) driverarg;

	/* Convert DNS name to ascii text */
	isc_buffer_init(&b, namestr, sizeof(namestr));
	result = dns_name_totext(name, ISC_TRUE, &b);
	if (result != ISC_R_SUCCESS)
		return (result);
	isc_buffer_putuint8(&b, 0);

	/* convert client address to ascii text */
	isc_buffer_init(&b2, clientstr, sizeof(clientstr));
	isc_netaddr_fromsockaddr(&netaddr, clientaddr);
	result = isc_netaddr_totext(&netaddr, &b2);
	if (result != ISC_R_SUCCESS)
		return (result);
	isc_buffer_putuint8(&b2, 0);

        /* make sure strings are always lowercase */
	dns_sdlz_tolower(namestr);
	dns_sdlz_tolower(clientstr);

	/* Call SDLZ driver's find zone method */
	if (imp->methods->allowzonexfr != NULL) {
		MAYBE_LOCK(imp);
		result = imp->methods->allowzonexfr(imp->driverarg, dbdata,
						    namestr, clientstr);
		MAYBE_UNLOCK(imp);
		/*
		 * if zone is supported and transfers allowed build a 'bind'
		 * database driver
		 */
		if (result == ISC_R_SUCCESS)
			result = dns_sdlzcreateDBP(mctx, driverarg, dbdata,
						   name, rdclass, dbp);
		return (result);
	}

	return (ISC_R_NOTIMPLEMENTED);
}

static isc_result_t
dns_sdlzcreate(isc_mem_t *mctx, const char *dlzname, unsigned int argc,
	       char *argv[], void *driverarg, void **dbdata)
{
	dns_sdlzimplementation_t *imp;
	isc_result_t result = ISC_R_NOTFOUND;

	/* Write debugging message to log */
	isc_log_write(dns_lctx, DNS_LOGCATEGORY_DATABASE,
		      DNS_LOGMODULE_DLZ, ISC_LOG_DEBUG(2),
		      "Loading SDLZ driver.");

	/*
	 * Performs checks to make sure data is as we expect it to be.
	 */
	REQUIRE(driverarg != NULL);
	REQUIRE(dlzname != NULL);
	REQUIRE(dbdata != NULL);
	UNUSED(mctx);

	imp = driverarg;

	/* If the create method exists, call it. */
	if (imp->methods->create != NULL) {
		MAYBE_LOCK(imp);
		result = imp->methods->create(dlzname, argc, argv,
					      imp->driverarg, dbdata);
		MAYBE_UNLOCK(imp);
	}

	/* Write debugging message to log */
	if (result == ISC_R_SUCCESS) {
		isc_log_write(dns_lctx, DNS_LOGCATEGORY_DATABASE,
			      DNS_LOGMODULE_DLZ, ISC_LOG_DEBUG(2),
			      "SDLZ driver loaded successfully.");
	} else {
		isc_log_write(dns_lctx, DNS_LOGCATEGORY_DATABASE,
			      DNS_LOGMODULE_DLZ, ISC_LOG_ERROR,
			      "SDLZ driver failed to load.");
	}

	return (result);
}

static void
dns_sdlzdestroy(void *driverdata, void **dbdata)
{

	dns_sdlzimplementation_t *imp;

	/* Write debugging message to log */
	isc_log_write(dns_lctx, DNS_LOGCATEGORY_DATABASE,
		      DNS_LOGMODULE_DLZ, ISC_LOG_DEBUG(2),
		      "Unloading SDLZ driver.");

	imp = driverdata;

	/* If the destroy method exists, call it. */
	if (imp->methods->destroy != NULL) {
		MAYBE_LOCK(imp);
		imp->methods->destroy(imp->driverarg, dbdata);
		MAYBE_UNLOCK(imp);
	}
}

static isc_result_t
dns_sdlzfindzone(void *driverarg, void *dbdata, isc_mem_t *mctx,
		 dns_rdataclass_t rdclass, dns_name_t *name, dns_db_t **dbp)
{
	isc_buffer_t b;
	char namestr[DNS_NAME_MAXTEXT + 1];
	isc_result_t result;
	dns_sdlzimplementation_t *imp;

	/*
	 * Perform checks to make sure data is as we expect it to be.
	 */
	REQUIRE(driverarg != NULL);
	REQUIRE(name != NULL);
	REQUIRE(dbp != NULL && *dbp == NULL);

	imp = (dns_sdlzimplementation_t *) driverarg;

	/* Convert DNS name to ascii text */
	isc_buffer_init(&b, namestr, sizeof(namestr));
	result = dns_name_totext(name, ISC_TRUE, &b);
	if (result != ISC_R_SUCCESS)
		return (result);
	isc_buffer_putuint8(&b, 0);

        /* make sure strings are always lowercase */
	dns_sdlz_tolower(namestr);

	/* Call SDLZ driver's find zone method */
	MAYBE_LOCK(imp);
	result = imp->methods->findzone(imp->driverarg, dbdata, namestr);
	MAYBE_UNLOCK(imp);

	/*
	 * if zone is supported build a 'bind' database driver
	 * structure to return
	 */
	if (result == ISC_R_SUCCESS)
		result = dns_sdlzcreateDBP(mctx, driverarg, dbdata, name,
					   rdclass, dbp);

	return (result);
}

static dns_dlzmethods_t sdlzmethods = {
	dns_sdlzcreate,
	dns_sdlzdestroy,
	dns_sdlzfindzone,
	dns_sdlzallowzonexfr
};

/*
 * Public functions.
 */

isc_result_t
dns_sdlz_putrr(dns_sdlzlookup_t *lookup, const char *type, dns_ttl_t ttl,
	       const char *data)
{
	dns_rdatalist_t *rdatalist;
	dns_rdata_t *rdata;
	dns_rdatatype_t typeval;
	isc_consttextregion_t r;
	isc_buffer_t b;
	isc_buffer_t *rdatabuf = NULL;
	isc_lex_t *lex;
	isc_result_t result;
	unsigned int size;
	isc_mem_t *mctx;
	dns_name_t *origin;

	REQUIRE(VALID_SDLZLOOKUP(lookup));
	REQUIRE(type != NULL);
	REQUIRE(data != NULL);

	mctx = lookup->sdlz->common.mctx;

	r.base = type;
	r.length = strlen(type);
	result = dns_rdatatype_fromtext(&typeval, (void *) &r);
	if (result != ISC_R_SUCCESS)
		return (result);

	rdatalist = ISC_LIST_HEAD(lookup->lists);
	while (rdatalist != NULL) {
		if (rdatalist->type == typeval)
			break;
		rdatalist = ISC_LIST_NEXT(rdatalist, link);
	}

	if (rdatalist == NULL) {
		rdatalist = isc_mem_get(mctx, sizeof(dns_rdatalist_t));
		if (rdatalist == NULL)
			return (ISC_R_NOMEMORY);
		rdatalist->rdclass = lookup->sdlz->common.rdclass;
		rdatalist->type = typeval;
		rdatalist->covers = 0;
		rdatalist->ttl = ttl;
		ISC_LIST_INIT(rdatalist->rdata);
		ISC_LINK_INIT(rdatalist, link);
		ISC_LIST_APPEND(lookup->lists, rdatalist, link);
	} else
		if (rdatalist->ttl != ttl)
			return (DNS_R_BADTTL);

	rdata = isc_mem_get(mctx, sizeof(dns_rdata_t));
	if (rdata == NULL)
		return (ISC_R_NOMEMORY);
	dns_rdata_init(rdata);

	if ((lookup->sdlz->dlzimp->flags & DNS_SDLZFLAG_RELATIVERDATA) != 0)
		origin = &lookup->sdlz->common.origin;
	else
		origin = dns_rootname;

	lex = NULL;
	result = isc_lex_create(mctx, 64, &lex);
	if (result != ISC_R_SUCCESS)
		goto failure;

	size = initial_size(data);
	do {
		isc_buffer_init(&b, data, strlen(data));
		isc_buffer_add(&b, strlen(data));

		result = isc_lex_openbuffer(lex, &b);
		if (result != ISC_R_SUCCESS)
			goto failure;

		rdatabuf = NULL;
		result = isc_buffer_allocate(mctx, &rdatabuf, size);
		if (result != ISC_R_SUCCESS)
			goto failure;

		result = dns_rdata_fromtext(rdata, rdatalist->rdclass,
					    rdatalist->type, lex,
					    origin, ISC_FALSE,
					    mctx, rdatabuf,
					    &lookup->callbacks);
		if (result != ISC_R_SUCCESS)
			isc_buffer_free(&rdatabuf);
		size *= 2;
	} while (result == ISC_R_NOSPACE);

	if (result != ISC_R_SUCCESS)
		goto failure;

	ISC_LIST_APPEND(rdatalist->rdata, rdata, link);
	ISC_LIST_APPEND(lookup->buffers, rdatabuf, link);

	if (lex != NULL)
		isc_lex_destroy(&lex);

	return (ISC_R_SUCCESS);

 failure:
 	if (rdatabuf != NULL)
		isc_buffer_free(&rdatabuf);
	if (lex != NULL)
		isc_lex_destroy(&lex);
	isc_mem_put(mctx, rdata, sizeof(dns_rdata_t));

	return (result);
}

isc_result_t
dns_sdlz_putnamedrr(dns_sdlzallnodes_t *allnodes, const char *name,
		    const char *type, dns_ttl_t ttl, const char *data)
{
	dns_name_t *newname, *origin;
	dns_fixedname_t fnewname;
	dns_sdlz_db_t *sdlz = (dns_sdlz_db_t *)allnodes->common.db;
	dns_sdlznode_t *sdlznode;
	isc_mem_t *mctx = sdlz->common.mctx;
	isc_buffer_t b;
	isc_result_t result;

	dns_fixedname_init(&fnewname);
	newname = dns_fixedname_name(&fnewname);

	if ((sdlz->dlzimp->flags & DNS_SDLZFLAG_RELATIVERDATA) != 0)
		origin = &sdlz->common.origin;
	else
		origin = dns_rootname;
	isc_buffer_init(&b, name, strlen(name));
	isc_buffer_add(&b, strlen(name));

	result = dns_name_fromtext(newname, &b, origin, ISC_FALSE, NULL);
	if (result != ISC_R_SUCCESS)
		return (result);

	if (allnodes->common.relative_names) {
		/* All names are relative to the root */
		unsigned int nlabels = dns_name_countlabels(newname);
		dns_name_getlabelsequence(newname, 0, nlabels - 1, newname);
	}

	sdlznode = ISC_LIST_HEAD(allnodes->nodelist);
	if (sdlznode == NULL || !dns_name_equal(sdlznode->name, newname)) {
		sdlznode = NULL;
		result = createnode(sdlz, &sdlznode);
		if (result != ISC_R_SUCCESS)
			return (result);
		sdlznode->name = isc_mem_get(mctx, sizeof(dns_name_t));
		if (sdlznode->name == NULL) {
			destroynode(sdlznode);
			return (ISC_R_NOMEMORY);
		}
		dns_name_init(sdlznode->name, NULL);
		result = dns_name_dup(newname, mctx, sdlznode->name);
		if (result != ISC_R_SUCCESS) {
			isc_mem_put(mctx, sdlznode->name, sizeof(dns_name_t));
			destroynode(sdlznode);
			return (result);
		}
		ISC_LIST_PREPEND(allnodes->nodelist, sdlznode, link);
		if (allnodes->origin == NULL &&
		    dns_name_equal(newname, &sdlz->common.origin))
			allnodes->origin = sdlznode;
	}
	return (dns_sdlz_putrr(sdlznode, type, ttl, data));

}

isc_result_t
dns_sdlz_putsoa(dns_sdlzlookup_t *lookup, const char *mname, const char *rname,
		isc_uint32_t serial)
{
	char str[2 * DNS_NAME_MAXTEXT + 5 * (sizeof("2147483647")) + 7];
	int n;

	REQUIRE(mname != NULL);
	REQUIRE(rname != NULL);

	n = snprintf(str, sizeof str, "%s %s %u %u %u %u %u",
		     mname, rname, serial,
		     SDLZ_DEFAULT_REFRESH, SDLZ_DEFAULT_RETRY,
		     SDLZ_DEFAULT_EXPIRE, SDLZ_DEFAULT_MINIMUM);
	if (n >= (int)sizeof(str) || n < 0)
		return (ISC_R_NOSPACE);
	return (dns_sdlz_putrr(lookup, "SOA", SDLZ_DEFAULT_TTL, str));
}

isc_result_t
dns_sdlzregister(const char *drivername, const dns_sdlzmethods_t *methods,
		 void *driverarg, unsigned int flags, isc_mem_t *mctx,
		 dns_sdlzimplementation_t **sdlzimp)
{

	dns_sdlzimplementation_t *imp;
	isc_result_t result;

	/*
	 * Performs checks to make sure data is as we expect it to be.
	 */
	REQUIRE(drivername != NULL);
	REQUIRE(methods != NULL);
	REQUIRE(methods->findzone != NULL);
	REQUIRE(methods->lookup != NULL);
	REQUIRE(mctx != NULL);
	REQUIRE(sdlzimp != NULL && *sdlzimp == NULL);
	REQUIRE((flags & ~(DNS_SDLZFLAG_RELATIVEOWNER |
			   DNS_SDLZFLAG_RELATIVERDATA |
			   DNS_SDLZFLAG_THREADSAFE)) == 0);

	/* Write debugging message to log */
	isc_log_write(dns_lctx, DNS_LOGCATEGORY_DATABASE,
		      DNS_LOGMODULE_DLZ, ISC_LOG_DEBUG(2),
		      "Registering SDLZ driver '%s'", drivername);

	/*
	 * Allocate memory for a sdlz_implementation object.  Error if
	 * we cannot.
	 */
	imp = isc_mem_get(mctx, sizeof(dns_sdlzimplementation_t));
	if (imp == NULL)
		return (ISC_R_NOMEMORY);

	/* Make sure memory region is set to all 0's */
	memset(imp, 0, sizeof(dns_sdlzimplementation_t));

	/* Store the data passed into this method */
	imp->methods = methods;
	imp->driverarg = driverarg;
	imp->flags = flags;
	imp->mctx = NULL;

	/* attach the new sdlz_implementation object to a memory context */
	isc_mem_attach(mctx, &imp->mctx);

	/*
	 * initialize the driver lock, error if we cannot
	 * (used if a driver does not support multiple threads)
	 */
	result = isc_mutex_init(&imp->driverlock);
	if (result != ISC_R_SUCCESS) {
		UNEXPECTED_ERROR(__FILE__, __LINE__,
				 "isc_mutex_init() failed: %s",
				 isc_result_totext(result));
		goto cleanup_mctx;
	}

	imp->dlz_imp = NULL;

	/*
	 * register the DLZ driver.  Pass in our "extra" sdlz information as
	 * a driverarg.  (that's why we stored the passed in driver arg in our
	 * sdlz_implementation structure)  Also, store the dlz_implementation
	 * structure in our sdlz_implementation.
	 */
	result = dns_dlzregister(drivername, &sdlzmethods, imp, mctx,
				 &imp->dlz_imp);

	/* if registration fails, cleanup and get outta here. */
	if (result != ISC_R_SUCCESS)
		goto cleanup_mutex;

	*sdlzimp = imp;

	return (ISC_R_SUCCESS);

 cleanup_mutex:
	/* destroy the driver lock, we don't need it anymore */
	DESTROYLOCK(&imp->driverlock);

 cleanup_mctx:
	/*
	 * return the memory back to the available memory pool and
	 * remove it from the memory context.
	 */
	isc_mem_put(mctx, imp, sizeof(dns_sdlzimplementation_t));
	isc_mem_detach(&mctx);
	return (result);
}

void
dns_sdlzunregister(dns_sdlzimplementation_t **sdlzimp) {
	dns_sdlzimplementation_t *imp;
	isc_mem_t *mctx;

	/* Write debugging message to log */
	isc_log_write(dns_lctx, DNS_LOGCATEGORY_DATABASE,
		      DNS_LOGMODULE_DLZ, ISC_LOG_DEBUG(2),
		      "Unregistering SDLZ driver.");

	/*
	 * Performs checks to make sure data is as we expect it to be.
	 */
	REQUIRE(sdlzimp != NULL && *sdlzimp != NULL);

	imp = *sdlzimp;

	/* Unregister the DLZ driver implementation */
	dns_dlzunregister(&imp->dlz_imp);

	/* destroy the driver lock, we don't need it anymore */
	DESTROYLOCK(&imp->driverlock);

	mctx = imp->mctx;

	/*
	 * return the memory back to the available memory pool and
	 * remove it from the memory context.
	 */
	isc_mem_put(mctx, imp, sizeof(dns_sdlzimplementation_t));
	isc_mem_detach(&mctx);

	*sdlzimp = NULL;
}