sdb.c

bind-3.2.

/*
 * Copyright (C) 2000, 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 INTERNET SOFTWARE CONSORTIUM
 * DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL
 * INTERNET SOFTWARE CONSORTIUM 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: sdb.c,v 1.35.2.2 2003/10/09 07:32:38 marka Exp $ */

#include <config.h>

#include <string.h>

#include <isc/buffer.h>
#include <isc/lex.h>
#include <isc/log.h>
#include <isc/magic.h>
#include <isc/mem.h>
#include <isc/once.h>
#include <isc/print.h>
#include <isc/region.h>
#include <isc/util.h>

#include <dns/callbacks.h>
#include <dns/db.h>
#include <dns/dbiterator.h>
#include <dns/fixedname.h>
#include <dns/log.h>
#include <dns/rdata.h>
#include <dns/rdatalist.h>
#include <dns/rdataset.h>
#include <dns/rdatasetiter.h>
#include <dns/rdatatype.h>
#include <dns/result.h>
#include <dns/sdb.h>
#include <dns/types.h>

#include "rdatalist_p.h"

struct dns_sdbimplementation {
	const dns_sdbmethods_t		*methods;
	void				*driverdata;
	unsigned int			flags;
	isc_mem_t			*mctx;
	isc_mutex_t			driverlock;
	dns_dbimplementation_t		*dbimp;
};

struct dns_sdb {
	/* Unlocked */
	dns_db_t			common;
	char				*zone;
	dns_sdbimplementation_t		*implementation;
	void				*dbdata;
	isc_mutex_t			lock;
	/* Locked */
	unsigned int			references;
};

struct dns_sdblookup {
	/* Unlocked */
	unsigned int			magic;
	dns_sdb_t			*sdb;
	ISC_LIST(dns_rdatalist_t)	lists;
	ISC_LIST(isc_buffer_t)		buffers;
	dns_name_t			*name;
	ISC_LINK(dns_sdblookup_t)	link;
	isc_mutex_t			lock;
	dns_rdatacallbacks_t		callbacks;
	/* Locked */
	unsigned int			references;
};

typedef struct dns_sdblookup dns_sdbnode_t;

struct dns_sdballnodes {
	dns_dbiterator_t		common;
	ISC_LIST(dns_sdbnode_t)		nodelist;
	dns_sdbnode_t			*current;
	dns_sdbnode_t			*origin;
};

typedef dns_sdballnodes_t sdb_dbiterator_t;

typedef struct sdb_rdatasetiter {
	dns_rdatasetiter_t		common;
	dns_rdatalist_t			*current;
} sdb_rdatasetiter_t;

#define SDB_MAGIC		ISC_MAGIC('S', 'D', 'B', '-')

/*
 * Note that "impmagic" is not the first four bytes of the struct, so
 * ISC_MAGIC_VALID cannot be used.
 */
#define VALID_SDB(sdb)		((sdb) != NULL && \
				 (sdb)->common.impmagic == SDB_MAGIC)

#define SDBLOOKUP_MAGIC		ISC_MAGIC('S','D','B','L')
#define VALID_SDBLOOKUP(sdbl)	ISC_MAGIC_VALID(sdbl, SDBLOOKUP_MAGIC)
#define VALID_SDBNODE(sdbn)	VALID_SDBLOOKUP(sdbn)

/* These values are taken from RFC 1537 */
#define SDB_DEFAULT_REFRESH	(60 * 60 * 8)
#define SDB_DEFAULT_RETRY	(60 * 60 * 2)
#define SDB_DEFAULT_EXPIRE	(60 * 60 * 24 * 7)
#define SDB_DEFAULT_MINIMUM	(60 * 60 * 24)

/* This is a reasonable value */
#define SDB_DEFAULT_TTL		(60 * 60 * 24)

#define MAYBE_LOCK(sdb)							\
	do {								\
		unsigned int flags = sdb->implementation->flags;	\
		if ((flags & DNS_SDBFLAG_THREADSAFE) == 0)		\
			LOCK(&sdb->implementation->driverlock);		\
	} while (0)

#define MAYBE_UNLOCK(sdb)						\
	do {								\
		unsigned int flags = sdb->implementation->flags;	\
		if ((flags & DNS_SDBFLAG_THREADSAFE) == 0)		\
			UNLOCK(&sdb->implementation->driverlock);	\
	} while (0)

static int dummy;

static isc_result_t dns_sdb_create(isc_mem_t *mctx, dns_name_t *origin,
				   dns_dbtype_t type, dns_rdataclass_t rdclass,
				   unsigned int argc, char *argv[],
				   void *driverarg, dns_db_t **dbp);

static isc_result_t findrdataset(dns_db_t *db, dns_dbnode_t *node,
				 dns_dbversion_t *version,
				 dns_rdatatype_t type, dns_rdatatype_t covers,
				 isc_stdtime_t now, dns_rdataset_t *rdataset,
				 dns_rdataset_t *sigrdataset);

static isc_result_t createnode(dns_sdb_t *sdb, dns_sdbnode_t **nodep);

static void destroynode(dns_sdbnode_t *node);

static void detachnode(dns_db_t *db, dns_dbnode_t **targetp);


static void list_tordataset(dns_rdatalist_t *rdatalist,
			    dns_db_t *db, dns_dbnode_t *node,
			    dns_rdataset_t *rdataset);

static void		dbiterator_destroy(dns_dbiterator_t **iteratorp);
static isc_result_t	dbiterator_first(dns_dbiterator_t *iterator);
static isc_result_t	dbiterator_last(dns_dbiterator_t *iterator);
static isc_result_t	dbiterator_seek(dns_dbiterator_t *iterator,
					dns_name_t *name);
static isc_result_t	dbiterator_prev(dns_dbiterator_t *iterator);
static isc_result_t	dbiterator_next(dns_dbiterator_t *iterator);
static isc_result_t	dbiterator_current(dns_dbiterator_t *iterator,
					   dns_dbnode_t **nodep,
					   dns_name_t *name);
static isc_result_t	dbiterator_pause(dns_dbiterator_t *iterator);
static isc_result_t	dbiterator_origin(dns_dbiterator_t *iterator,
					  dns_name_t *name);

static dns_dbiteratormethods_t dbiterator_methods = {
	dbiterator_destroy,
	dbiterator_first,
	dbiterator_last,
	dbiterator_seek,
	dbiterator_prev,
	dbiterator_next,
	dbiterator_current,
	dbiterator_pause,
	dbiterator_origin
};

static void		rdatasetiter_destroy(dns_rdatasetiter_t **iteratorp);
static isc_result_t	rdatasetiter_first(dns_rdatasetiter_t *iterator);
static isc_result_t	rdatasetiter_next(dns_rdatasetiter_t *iterator);
static void		rdatasetiter_current(dns_rdatasetiter_t *iterator,
					     dns_rdataset_t *rdataset);

static dns_rdatasetitermethods_t rdatasetiter_methods = {
	rdatasetiter_destroy,
	rdatasetiter_first,
	rdatasetiter_next,
	rdatasetiter_current
};

/*
 * Functions used by implementors of simple databases
 */
isc_result_t
dns_sdb_register(const char *drivername, const dns_sdbmethods_t *methods,
		 void *driverdata, unsigned int flags, isc_mem_t *mctx,
		 dns_sdbimplementation_t **sdbimp)
{
	dns_sdbimplementation_t *imp;
	isc_result_t result;

	REQUIRE(drivername != NULL);
	REQUIRE(methods != NULL);
	REQUIRE(methods->lookup != NULL);
	REQUIRE(mctx != NULL);
	REQUIRE(sdbimp != NULL && *sdbimp == NULL);
	REQUIRE((flags & ~(DNS_SDBFLAG_RELATIVEOWNER |
			   DNS_SDBFLAG_RELATIVERDATA |
			   DNS_SDBFLAG_THREADSAFE)) == 0);

	imp = isc_mem_get(mctx, sizeof(dns_sdbimplementation_t));
	if (imp == NULL)
		return (ISC_R_NOMEMORY);
	imp->methods = methods;
	imp->driverdata = driverdata;
	imp->flags = flags;
	imp->mctx = NULL;
	isc_mem_attach(mctx, &imp->mctx);
	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->dbimp = NULL;
	result = dns_db_register(drivername, dns_sdb_create, imp, mctx,
				 &imp->dbimp);
	if (result != ISC_R_SUCCESS)
		goto cleanup_mutex;
	*sdbimp = imp;

	return (ISC_R_SUCCESS);

 cleanup_mutex:
	DESTROYLOCK(&imp->driverlock);
 cleanup_mctx:
	isc_mem_put(mctx, imp, sizeof(dns_sdbimplementation_t));
	return (result);
}

void
dns_sdb_unregister(dns_sdbimplementation_t **sdbimp) {
	dns_sdbimplementation_t *imp;
	isc_mem_t *mctx;

	REQUIRE(sdbimp != NULL && *sdbimp != NULL);

	imp = *sdbimp;
	dns_db_unregister(&imp->dbimp);
	DESTROYLOCK(&imp->driverlock);

	mctx = imp->mctx;
	isc_mem_put(mctx, imp, sizeof(dns_sdbimplementation_t));
	isc_mem_detach(&mctx);

	*sdbimp = NULL;
}

static inline unsigned int
initial_size(const char *data) {
	unsigned int len = strlen(data);
	unsigned int size;
	for (size = 64; size < (64 * 1024); size *= 2)
		if (len < size)
			return (size);
	return (64 * 1024);
}

isc_result_t
dns_sdb_putrr(dns_sdblookup_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;
	isc_lex_t *lex;
	isc_result_t result;
	unsigned int size;
	isc_mem_t *mctx;
	dns_sdbimplementation_t *imp;
	dns_name_t *origin;

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

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

	r.base = type;
	r.length = strlen(type);
	result = dns_rdatatype_fromtext(&typeval, (isc_textregion_t *)&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->sdb->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);

	imp = lookup->sdb->implementation;
	if ((imp->flags & DNS_SDBFLAG_RELATIVERDATA) != 0)
		origin = &lookup->sdb->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_sdb_putnamedrr(dns_sdballnodes_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_sdb_t *sdb = (dns_sdb_t *)allnodes->common.db;
	dns_sdbimplementation_t *imp = sdb->implementation;
	dns_sdbnode_t *sdbnode;
	isc_mem_t *mctx = sdb->common.mctx;
	isc_buffer_t b;
	isc_result_t result;

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

	if ((imp->flags & DNS_SDBFLAG_RELATIVERDATA) != 0)
		origin = &sdb->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);
	}

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

}

isc_result_t
dns_sdb_putsoa(dns_sdblookup_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,
		     SDB_DEFAULT_REFRESH, SDB_DEFAULT_RETRY,
		     SDB_DEFAULT_EXPIRE, SDB_DEFAULT_MINIMUM);
	if (n >= (int)sizeof(str) || n < 0)
		return (ISC_R_NOSPACE);
	return (dns_sdb_putrr(lookup, "SOA", SDB_DEFAULT_TTL, str));
}

/*
 * DB routines
 */

static void
attach(dns_db_t *source, dns_db_t **targetp) {
	dns_sdb_t *sdb = (dns_sdb_t *) source;

	REQUIRE(VALID_SDB(sdb));

	LOCK(&sdb->lock);
	REQUIRE(sdb->references > 0);
	sdb->references++;
	UNLOCK(&sdb->lock);

	*targetp = source;
}

static void