zone.c

bind 9.3结合mysql数据库

/*
 * Copyright (C) 2004  Internet Systems Consortium, Inc. ("ISC")
 * Copyright (C) 1999-2003  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: zone.c,v 1.333.2.23.2.50 2004/08/28 05:53:37 marka Exp $ */

#include <config.h>

#include <isc/file.h>
#include <isc/mutex.h>
#include <isc/print.h>
#include <isc/random.h>
#include <isc/ratelimiter.h>
#include <isc/refcount.h>
#include <isc/serial.h>
#include <isc/string.h>
#include <isc/taskpool.h>
#include <isc/timer.h>
#include <isc/util.h>

#include <dns/acl.h>
#include <dns/adb.h>
#include <dns/callbacks.h>
#include <dns/db.h>
#include <dns/events.h>
#include <dns/journal.h>
#include <dns/log.h>
#include <dns/master.h>
#include <dns/masterdump.h>
#include <dns/message.h>
#include <dns/name.h>
#include <dns/peer.h>
#include <dns/rcode.h>
#include <dns/rdataclass.h>
#include <dns/rdatalist.h>
#include <dns/rdataset.h>
#include <dns/rdatastruct.h>
#include <dns/rdatatype.h>
#include <dns/request.h>
#include <dns/resolver.h>
#include <dns/result.h>
#include <dns/stats.h>
#include <dns/ssu.h>
#include <dns/tsig.h>
#include <dns/xfrin.h>
#include <dns/zone.h>

#define ZONE_MAGIC			ISC_MAGIC('Z', 'O', 'N', 'E')
#define DNS_ZONE_VALID(zone)		ISC_MAGIC_VALID(zone, ZONE_MAGIC)

#define NOTIFY_MAGIC			ISC_MAGIC('N', 't', 'f', 'y')
#define DNS_NOTIFY_VALID(notify)	ISC_MAGIC_VALID(notify, NOTIFY_MAGIC)

#define STUB_MAGIC			ISC_MAGIC('S', 't', 'u', 'b')
#define DNS_STUB_VALID(stub)		ISC_MAGIC_VALID(stub, STUB_MAGIC)

#define ZONEMGR_MAGIC			ISC_MAGIC('Z', 'm', 'g', 'r')
#define DNS_ZONEMGR_VALID(stub)		ISC_MAGIC_VALID(stub, ZONEMGR_MAGIC)

#define LOAD_MAGIC			ISC_MAGIC('L', 'o', 'a', 'd')
#define DNS_LOAD_VALID(load)		ISC_MAGIC_VALID(load, LOAD_MAGIC)

#define FORWARD_MAGIC			ISC_MAGIC('F', 'o', 'r', 'w')
#define DNS_FORWARD_VALID(load)		ISC_MAGIC_VALID(load, FORWARD_MAGIC)

#define IO_MAGIC			ISC_MAGIC('Z', 'm', 'I', 'O')
#define DNS_IO_VALID(load)		ISC_MAGIC_VALID(load, IO_MAGIC)

/*
 * Ensure 'a' is at least 'min' but not more than 'max'.
 */
#define RANGE(a, min, max) \
		(((a) < (min)) ? (min) : ((a) < (max) ? (a) : (max)))

/*
 * Default values.
 */
#define DNS_DEFAULT_IDLEIN 3600		/* 1 hour */
#define DNS_DEFAULT_IDLEOUT 3600	/* 1 hour */
#define MAX_XFER_TIME (2*3600)		/* Documented default is 2 hours */

#ifndef DNS_MAX_EXPIRE
#define DNS_MAX_EXPIRE	14515200	/* 24 weeks */
#endif

#ifndef DNS_DUMP_DELAY
#define DNS_DUMP_DELAY 900		/* 15 minutes */
#endif

typedef struct dns_notify dns_notify_t;
typedef struct dns_stub dns_stub_t;
typedef struct dns_load dns_load_t;
typedef struct dns_forward dns_forward_t;
typedef struct dns_io dns_io_t;
typedef ISC_LIST(dns_io_t) dns_iolist_t;

#define DNS_ZONE_CHECKLOCK
#ifdef DNS_ZONE_CHECKLOCK
#define LOCK_ZONE(z) \
	 do { LOCK(&(z)->lock); \
	      INSIST((z)->locked == ISC_FALSE); \
	     (z)->locked = ISC_TRUE; \
		} while (0)
#define UNLOCK_ZONE(z) \
	do { (z)->locked = ISC_FALSE; UNLOCK(&(z)->lock); } while (0)
#define LOCKED_ZONE(z) ((z)->locked)
#else
#define LOCK_ZONE(z) LOCK(&(z)->lock)
#define UNLOCK_ZONE(z) UNLOCK(&(z)->lock)
#define LOCKED_ZONE(z) ISC_TRUE
#endif

struct dns_zone {
	/* Unlocked */
	unsigned int		magic;
	isc_mutex_t		lock;
#ifdef DNS_ZONE_CHECKLOCK
	isc_boolean_t		locked;
#endif
	isc_mem_t		*mctx;
	isc_refcount_t		erefs;

	/* Locked */
	dns_db_t		*db;
	dns_zonemgr_t		*zmgr;
	ISC_LINK(dns_zone_t)	link;		/* Used by zmgr. */
	isc_timer_t		*timer;
	unsigned int		irefs;
	dns_name_t		origin;
	char			*masterfile;
	char			*journal;
	isc_int32_t		journalsize;
	dns_rdataclass_t	rdclass;
	dns_zonetype_t		type;
	unsigned int		flags;
	unsigned int		options;
	unsigned int		db_argc;
	char			**db_argv;
	isc_time_t		expiretime;
	isc_time_t		refreshtime;
	isc_time_t		dumptime;
	isc_time_t		loadtime;
	isc_uint32_t		serial;
	isc_uint32_t		refresh;
	isc_uint32_t		retry;
	isc_uint32_t		expire;
	isc_uint32_t		minimum;
	char			*keydirectory;

	isc_uint32_t		maxrefresh;
	isc_uint32_t		minrefresh;
	isc_uint32_t		maxretry;
	isc_uint32_t		minretry;

	isc_sockaddr_t		*masters;
	dns_name_t		**masterkeynames;
	unsigned int		masterscnt;
	unsigned int		curmaster;
	isc_sockaddr_t		masteraddr;
	dns_notifytype_t	notifytype;
	isc_sockaddr_t		*notify;
	unsigned int		notifycnt;
	isc_sockaddr_t		notifyfrom;
	isc_task_t		*task;
	isc_sockaddr_t	 	notifysrc4;
	isc_sockaddr_t	 	notifysrc6;
	isc_sockaddr_t	 	xfrsource4;
	isc_sockaddr_t	 	xfrsource6;
	isc_sockaddr_t	 	altxfrsource4;
	isc_sockaddr_t	 	altxfrsource6;
	isc_sockaddr_t	 	sourceaddr;
	dns_xfrin_ctx_t		*xfr;		/* task locked */
	dns_tsigkey_t		*tsigkey;	/* key used for xfr */
	/* Access Control Lists */
	dns_acl_t		*update_acl;
	dns_acl_t		*forward_acl;
	dns_acl_t		*notify_acl;
	dns_acl_t		*query_acl;
	dns_acl_t		*xfr_acl;
	isc_boolean_t		update_disabled;
	dns_severity_t		check_names;
	ISC_LIST(dns_notify_t)	notifies;
	dns_request_t		*request;
	dns_loadctx_t		*lctx;
	dns_io_t		*readio;
	dns_dumpctx_t		*dctx;
	dns_io_t		*writeio;
	isc_uint32_t		maxxfrin;
	isc_uint32_t		maxxfrout;
	isc_uint32_t		idlein;
	isc_uint32_t		idleout;
	isc_event_t		ctlevent;
	dns_ssutable_t		*ssutable;
	isc_uint32_t		sigvalidityinterval;
	dns_view_t		*view;
	/*
	 * Zones in certain states such as "waiting for zone transfer"
	 * or "zone transfer in progress" are kept on per-state linked lists
	 * in the zone manager using the 'statelink' field.  The 'statelist'
	 * field points at the list the zone is currently on.  It the zone
	 * is not on any such list, statelist is NULL.
	 */
	ISC_LINK(dns_zone_t)	statelink;
	dns_zonelist_t		*statelist;
	/*
	 * Optional per-zone statistics counters (NULL if not present).
	 */
	isc_uint64_t	    *counters;
};

#define DNS_ZONE_FLAG(z,f) (ISC_TF(((z)->flags & (f)) != 0))
#define DNS_ZONE_SETFLAG(z,f) do { \
		INSIST(LOCKED_ZONE(z)); \
		(z)->flags |= (f); \
		} while (0)
#define DNS_ZONE_CLRFLAG(z,f) do { \
		INSIST(LOCKED_ZONE(z)); \
		(z)->flags &= ~(f); \
		} while (0)
	/* XXX MPA these may need to go back into zone.h */
#define DNS_ZONEFLG_REFRESH	0x00000001U	/* refresh check in progress */
#define DNS_ZONEFLG_NEEDDUMP	0x00000002U	/* zone need consolidation */
#define DNS_ZONEFLG_USEVC	0x00000004U	/* use tcp for refresh query */
#define DNS_ZONEFLG_DUMPING	0x00000008U	/* a dump is in progress */
#define DNS_ZONEFLG_HASINCLUDE	0x00000010U	/* $INCLUDE in zone file */
#define DNS_ZONEFLG_LOADED	0x00000020U	/* database has loaded */
#define DNS_ZONEFLG_EXITING	0x00000040U	/* zone is being destroyed */
#define DNS_ZONEFLG_EXPIRED	0x00000080U	/* zone has expired */
#define DNS_ZONEFLG_NEEDREFRESH	0x00000100U	/* refresh check needed */
#define DNS_ZONEFLG_UPTODATE	0x00000200U	/* zone contents are
						 * uptodate */
#define DNS_ZONEFLG_NEEDNOTIFY	0x00000400U	/* need to send out notify
						 * messages */
#define DNS_ZONEFLG_DIFFONRELOAD 0x00000800U	/* generate a journal diff on
						 * reload */
#define DNS_ZONEFLG_NOMASTERS	0x00001000U	/* an attempt to refresh a
						 * zone with no masters
						 * occured */
#define DNS_ZONEFLG_LOADING	0x00002000U	/* load from disk in progress*/
#define DNS_ZONEFLG_HAVETIMERS	0x00004000U	/* timer values have been set
						 * from SOA (if not set, we
						 * are still using
						 * default timer values) */
#define DNS_ZONEFLG_FORCEXFER   0x00008000U     /* Force a zone xfer */
#define DNS_ZONEFLG_NOREFRESH	0x00010000U
#define DNS_ZONEFLG_DIALNOTIFY	0x00020000U
#define DNS_ZONEFLG_DIALREFRESH	0x00040000U
#define DNS_ZONEFLG_SHUTDOWN	0x00080000U
#define DNS_ZONEFLAG_NOIXFR	0x00100000U	/* IXFR failed, force AXFR */
#define DNS_ZONEFLG_FLUSH	0x00200000U
#define DNS_ZONEFLG_NOEDNS	0x00400000U
#define DNS_ZONEFLG_USEALTXFRSRC 0x00800000U

#define DNS_ZONE_OPTION(z,o) (((z)->options & (o)) != 0)

/* Flags for zone_load() */
#define DNS_ZONELOADFLAG_NOSTAT	0x00000001U	/* Do not stat() master files */

struct dns_zonemgr {
	unsigned int		magic;
	isc_mem_t *		mctx;
	int			refs;		/* Locked by rwlock */
	isc_taskmgr_t *		taskmgr;
	isc_timermgr_t *	timermgr;
	isc_socketmgr_t *	socketmgr;
	isc_taskpool_t *	zonetasks;
	isc_task_t *		task;
	isc_ratelimiter_t *	rl;
	isc_rwlock_t		rwlock;
	isc_mutex_t		iolock;

	/* Locked by rwlock. */
	dns_zonelist_t		zones;
	dns_zonelist_t		waiting_for_xfrin;
	dns_zonelist_t		xfrin_in_progress;

	/* Configuration data. */
	isc_uint32_t		transfersin;
	isc_uint32_t		transfersperns;
	unsigned int		serialqueryrate;

	/* Locked by iolock */
	isc_uint32_t		iolimit;
	isc_uint32_t		ioactive;
	dns_iolist_t		high;
	dns_iolist_t		low;
};

/*
 * Hold notify state.
 */
struct dns_notify {
	unsigned int		magic;
	unsigned int		flags;
	isc_mem_t		*mctx;
	dns_zone_t		*zone;
	dns_adbfind_t		*find;
	dns_request_t		*request;
	dns_name_t		ns;
	isc_sockaddr_t		dst;
	ISC_LINK(dns_notify_t)	link;
};

#define DNS_NOTIFY_NOSOA	0x0001U

/*
 *	dns_stub holds state while performing a 'stub' transfer.
 *	'db' is the zone's 'db' or a new one if this is the initial
 *	transfer.
 */

struct dns_stub {
	unsigned int		magic;
	isc_mem_t		*mctx;
	dns_zone_t		*zone;
	dns_db_t		*db;
	dns_dbversion_t		*version;
};

/*
 *	Hold load state.
 */
struct dns_load {
	unsigned int		magic;
	isc_mem_t		*mctx;
	dns_zone_t		*zone;
	dns_db_t		*db;
	isc_time_t		loadtime;
	dns_rdatacallbacks_t	callbacks;
};

/*
 *	Hold forward state.
 */
struct dns_forward {
	unsigned int		magic;
	isc_mem_t		*mctx;
	dns_zone_t		*zone;
	isc_buffer_t		*msgbuf;
	dns_request_t		*request;
	isc_uint32_t		which;
	isc_sockaddr_t		addr;
	dns_updatecallback_t	callback;
	void			*callback_arg;
};

/*
 *	Hold IO request state.
 */
struct dns_io {
	unsigned int	magic;
	dns_zonemgr_t	*zmgr;
	isc_boolean_t	high;
	isc_task_t	*task;
	ISC_LINK(dns_io_t) link;
	isc_event_t	*event;
};

#define SEND_BUFFER_SIZE 2048

static void zone_settimer(dns_zone_t *, isc_time_t *);
static void cancel_refresh(dns_zone_t *);
static void zone_debuglog(dns_zone_t *zone, const char *, int debuglevel,
			  const char *msg, ...) ISC_FORMAT_PRINTF(4, 5);
static void notify_log(dns_zone_t *zone, int level, const char *fmt, ...)
     ISC_FORMAT_PRINTF(3, 4);
static void queue_xfrin(dns_zone_t *zone);
static void zone_unload(dns_zone_t *zone);
static void zone_expire(dns_zone_t *zone);
static void zone_iattach(dns_zone_t *source, dns_zone_t **target);
static void zone_idetach(dns_zone_t **zonep);
static isc_result_t zone_replacedb(dns_zone_t *zone, dns_db_t *db,
				   isc_boolean_t dump);
static isc_result_t default_journal(dns_zone_t *zone);
static void zone_xfrdone(dns_zone_t *zone, isc_result_t result);
static isc_result_t zone_postload(dns_zone_t *zone, dns_db_t *db,
				  isc_time_t loadtime, isc_result_t result);
static void zone_needdump(dns_zone_t *zone, unsigned int delay);
static void zone_shutdown(isc_task_t *, isc_event_t *);
static void zone_loaddone(void *arg, isc_result_t result);
static isc_result_t zone_startload(dns_db_t *db, dns_zone_t *zone,
				   isc_time_t loadtime);

#if 0
/* ondestroy example */
static void dns_zonemgr_dbdestroyed(isc_task_t *task, isc_event_t *event);
#endif

static void refresh_callback(isc_task_t *, isc_event_t *);
static void stub_callback(isc_task_t *, isc_event_t *);
static void queue_soa_query(dns_zone_t *zone);
static void soa_query(isc_task_t *, isc_event_t *);
static void ns_query(dns_zone_t *zone, dns_rdataset_t *soardataset,
		     dns_stub_t *stub);
static int message_count(dns_message_t *msg, dns_section_t section,
			 dns_rdatatype_t type);
static void notify_cancel(dns_zone_t *zone);
static void notify_find_address(dns_notify_t *notify);
static void notify_send(dns_notify_t *notify);
static isc_result_t notify_createmessage(dns_zone_t *zone,
					 unsigned int flags,
					 dns_message_t **messagep);
static void notify_done(isc_task_t *task, isc_event_t *event);
static void notify_send_toaddr(isc_task_t *task, isc_event_t *event);
static isc_result_t zone_dump(dns_zone_t *, isc_boolean_t);
static void got_transfer_quota(isc_task_t *task, isc_event_t *event);
static isc_result_t zmgr_start_xfrin_ifquota(dns_zonemgr_t *zmgr,
					     dns_zone_t *zone);
static void zmgr_resume_xfrs(dns_zonemgr_t *zmgr, isc_boolean_t multi);
static void zonemgr_free(dns_zonemgr_t *zmgr);
static isc_result_t zonemgr_getio(dns_zonemgr_t *zmgr, isc_boolean_t high,
				  isc_task_t *task, isc_taskaction_t action,
				  void *arg, dns_io_t **iop);
static void zonemgr_putio(dns_io_t **iop);
static void zonemgr_cancelio(dns_io_t *io);

static isc_result_t
zone_get_from_db(dns_db_t *db, dns_name_t *origin, unsigned int *nscount,
		 unsigned int *soacount, isc_uint32_t *serial,
		 isc_uint32_t *refresh, isc_uint32_t *retry,
		 isc_uint32_t *expire, isc_uint32_t *minimum);

static void zone_freedbargs(dns_zone_t *zone);
static void forward_callback(isc_task_t *task, isc_event_t *event);
static void zone_saveunique(dns_zone_t *zone, const char *path,
			    const char *templat);
static void zone_maintenance(dns_zone_t *zone);
static void zone_notify(dns_zone_t *zone);
static void dump_done(void *arg, isc_result_t result);

#define ENTER zone_debuglog(zone, me, 1, "enter")

static const unsigned int dbargc_default = 1;
static const char *dbargv_default[] = { "rbt" };

#define DNS_ZONE_JITTER_ADD(a, b, c) \
	do { \
		isc_interval_t _i; \
		isc_uint32_t _j; \
		_j = isc_random_jitter((b), (b)/4); \
		isc_interval_set(&_i, _j, 0); \
		if (isc_time_add((a), &_i, (c)) != ISC_R_SUCCESS) { \
			dns_zone_log(zone, ISC_LOG_WARNING, \
				     "epoch approaching: upgrade required: " \
				     "now + %s failed", #b); \
			isc_interval_set(&_i, _j/2, 0); \
			(void)isc_time_add((a), &_i, (c)); \
		} \
	} while (0)

#define DNS_ZONE_TIME_ADD(a, b, c) \
	do { \
		isc_interval_t _i; \
		isc_interval_set(&_i, (b), 0); \
		if (isc_time_add((a), &_i, (c)) != ISC_R_SUCCESS) { \
			dns_zone_log(zone, ISC_LOG_WARNING, \
				     "epoch approaching: upgrade required: " \
				     "now + %s failed", #b); \
			isc_interval_set(&_i, (b)/2, 0); \
			(void)isc_time_add((a), &_i, (c)); \
		} \
	} while (0)

/***
 ***	Public functions.
 ***/

isc_result_t
dns_zone_create(dns_zone_t **zonep, isc_mem_t *mctx) {
	isc_result_t result;
	dns_zone_t *zone;

	REQUIRE(zonep != NULL && *zonep == NULL);
	REQUIRE(mctx != NULL);

	zone = isc_mem_get(mctx, sizeof(*zone));
	if (zone == NULL)
		return (ISC_R_NOMEMORY);

	result = isc_mutex_init(&zone->lock);
	if (result != ISC_R_SUCCESS) {
		isc_mem_put(mctx, zone, sizeof(*zone));
		UNEXPECTED_ERROR(__FILE__, __LINE__,
				 "isc_mutex_init() failed: %s",
				 isc_result_totext(result));
		return (ISC_R_UNEXPECTED);
	}

	/* XXX MPA check that all elements are initialised */
	zone->mctx = NULL;
#ifdef DNS_ZONE_CHECKLOCK
	zone->locked = ISC_FALSE;
#endif
	isc_mem_attach(mctx, &zone->mctx);
	zone->db = NULL;
	zone->zmgr = NULL;
	ISC_LINK_INIT(zone, link);
	isc_refcount_init(&zone->erefs, 1);	/* Implicit attach. */
	zone->irefs = 0;
	dns_name_init(&zone->origin, NULL);
	zone->masterfile = NULL;
	zone->keydirectory = NULL;
	zone->journalsize = -1;
	zone->journal = NULL;
	zone->rdclass = dns_rdataclass_none;
	zone->type = dns_zone_none;
	zone->flags = 0;