This commit was generated by cvs2svn to compensate for changes in r53910,

which included commits to RCS files with non-trunk default branches.

1 files changed, 861 insertions, 0 deletions

diff --git a/contrib/bind/bin/named/db_ixfr.c b/contrib/bind/bin/named/db_ixfr.c
new file mode 100644
index 0000000..a009f4d
--- /dev/null
+++ b/contrib/bind/bin/named/db_ixfr.c
@@ -0,0 +1,861 @@
+#if !defined(lint) && !defined(SABER)
+static char     rcsid[] = "$Id: db_ixfr.c,v 8.18 1999/10/15 19:48:57 vixie Exp $";
+#endif                /* not lint */
+
+/*
+ * Portions Copyright (c) 1999 by Check Point Software Technologies, Inc.
+ * 
+ * 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, and that
+ * the name of Check Point Software Technologies Incorporated not be used 
+ * in advertising or publicity pertaining to distribution of the document 
+ * or software without specific, written prior permission.
+ * 
+ * THE SOFTWARE IS PROVIDED "AS IS" AND CHECK POINT SOFTWARE TECHNOLOGIES 
+ * INCORPORATED DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS SOFTWARE, 
+ * INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS.   
+ * IN NO EVENT SHALL CHECK POINT SOFTWARE TECHNOLOGIES INCORPRATED
+ * 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.
+ */
+
+/*
+ * Manage ixfr transaction log
+ */
+
+#include "port_before.h"
+
+#include <sys/types.h>
+#include <sys/param.h>
+#include <sys/stat.h>
+#include <sys/socket.h>
+
+#include <netinet/in.h>
+#include <arpa/nameser.h>
+#include <arpa/inet.h>
+
+#include <ctype.h>
+#include <errno.h>
+#include <netdb.h>
+#include <resolv.h>
+#include <res_update.h>
+#include <errno.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <syslog.h>
+#include <time.h>
+
+#include <isc/eventlib.h>
+#include <isc/logging.h>
+
+#include "port_after.h"
+
+#include "named.h"
+
+#define DBIXFR_ERROR            -1
+#define DBIXFR_FOUND_RR         2
+#define DBIXFR_END              3
+
+static int ixfr_getrr(struct zoneinfo *, FILE *, const char *, char *,
+		      ns_updrec **, u_int32_t *, u_int32_t *);
+
+ns_updrec *
+ixfr_get_change_list(struct zoneinfo *zp,
+		     u_int32_t from_serial, u_int32_t to_serial)
+{
+	FILE *		fp;
+	u_int32_t	old_serial, new_serial;
+	char		origin[MAXDNAME];
+	struct namebuf *np, *listnp, *finlistnp;
+	LIST(ns_updrec)	listuprec;
+	int		ret, mode;
+	ns_updrec	*uprec;
+
+	if (SEQ_GT(from_serial, to_serial))
+		return (NULL);
+	listnp = finlistnp = NULL;
+	INIT_LIST(listuprec);
+	if ((fp = fopen(zp->z_ixfr_base, "r")) == NULL) {
+		ns_warning(ns_log_db, "%s: %s",
+			   zp->z_ixfr_base, strerror(errno));
+		return (NULL);
+	}
+	strcpy(origin, zp->z_origin);
+	lineno = 1;
+	np = NULL;
+	mode = 0;
+	old_serial = new_serial = 0;
+	for (;;) {
+		ret = ixfr_getrr(zp, fp, zp->z_ixfr_base, origin, &uprec,
+				 &old_serial, &new_serial);
+		switch (ret) {
+		case DBIXFR_ERROR:
+			(void) my_fclose(fp);
+			ns_warning(ns_log_db, "Logical error in %s line %d", 
+				   zp->z_ixfr_base, lineno);
+			return (NULL);
+		case DBIXFR_FOUND_RR:
+			if (EMPTY(listuprec)) {
+				/* skip updates prior to the one we want */
+				if (uprec->r_zone != from_serial) {
+					while (uprec != NULL) {
+						ns_updrec *prev;
+
+						if (uprec->r_dp != NULL)
+						      db_freedata(uprec->r_dp);
+						uprec->r_dp = NULL;
+						prev = PREV(uprec, r_link);
+						res_freeupdrec(uprec);
+						uprec = prev;
+					}
+					break;
+				}
+			}
+			APPEND(listuprec, uprec, r_link);
+			/* continue; */
+			break;
+		case DBIXFR_END:
+			(void) my_fclose(fp);
+			return (HEAD(listuprec));
+		default:
+			(void) my_fclose(fp);
+			return (NULL);
+		}
+	}
+}
+
+/*
+ * int ixfr_have_log(struct zoneinfo *zp,u_int32_t from_serial,
+ *                   u_int32_t to_serial)
+ * 
+ * verify that ixfr transaction log contains changes  
+ * from from_serial to to_serial
+ * 
+ * returns: 
+ *         0 = serial number is up to date
+ *         1 = transision is possible 
+ *        -1 = error while opening the ixfr transaction log
+ *        -2 = error in parameters
+ *        -3 = logical error in the history file 
+ */
+int
+ixfr_have_log(struct zoneinfo *zp, u_int32_t from_serial, u_int32_t to_serial)
+{
+	FILE           *fp;
+	u_int32_t       old_serial = 0, new_serial = 0;
+	char            buf[BUFSIZ];
+	char           *cp;
+	struct stat     st;
+	int             nonempty_lineno = -1, prev_pktdone = 0, cont = 0,
+			inside_next = 0;
+	int             err;
+	int             id, rcode = NOERROR;
+
+	if (SEQ_GT(from_serial, to_serial))
+		return (-2);
+	if (from_serial == to_serial)
+		return (0);
+	/* If there is no log file, just return. */
+	if (zp->z_ixfr_base == NULL || zp->z_updatelog == NULL)
+		return (-1);
+	if (stat(zp->z_ixfr_base, &st) < 0) {
+		if (errno != ENOENT)
+			ns_error(ns_log_db,
+				 "unexpected stat(%s) failure: %s",
+				 zp->z_ixfr_base, strerror(errno));
+		return (-1);
+	}
+	if ((fp = fopen(zp->z_ixfr_base, "r")) == NULL) {
+		ns_warning(ns_log_db, "%s: %s",
+			   zp->z_ixfr_base, strerror(errno));
+		return (-1);
+	}
+	if (fgets(buf, sizeof(buf), fp) == NULL) {
+		ns_error(ns_log_update, "fgets() from %s failed: %s",
+			 zp->z_updatelog, strerror(errno));
+		fclose(fp);
+		return (-1);
+	}
+	if (strcmp(buf, LogSignature) != 0) {
+		ns_error(ns_log_update, "invalid log file %s",
+			 zp->z_updatelog);
+		fclose(fp);
+		return (-3);
+	}
+	lineno = 1;
+	for (;;) {
+		if (getword(buf, sizeof buf, fp, 0)) {
+			nonempty_lineno = lineno;
+		} else {
+			if (lineno == (nonempty_lineno + 1))
+				continue;
+			inside_next = 0;
+			prev_pktdone = 1;
+			cont = 1;
+		}
+		if (!strcasecmp(buf, "[DYNAMIC_UPDATE]") ||
+		    !strcasecmp(buf, "[IXFR_UPDATE]")) {
+			err = 0;
+			rcode = NOERROR;
+			cp = fgets(buf, sizeof buf, fp);
+			if (cp != NULL)
+				lineno++;
+			if (cp == NULL || !sscanf((char *) cp, "id %d", &id))
+				id = -1;
+			inside_next = 1;
+			prev_pktdone = 1;
+			cont = 1;
+		} else if (!strcasecmp(buf, "serial")) {
+			cp = fgets(buf, sizeof buf, fp);
+			if (cp != NULL)
+				lineno++;
+			if (sscanf((char *) cp, "%u", &old_serial)) {
+				if (from_serial >= old_serial) {
+					fclose(fp);
+					return (1);
+				} else {
+					fclose(fp);
+					return (-1);
+				}
+			}
+			prev_pktdone = 1;
+			cont = 1;
+		} else if (!strcasecmp(buf, "[INCR_SERIAL]")) {
+			/* XXXRTH not enough error checking here */
+			cp = fgets(buf, sizeof buf, fp);
+			if (cp != NULL)
+				lineno++;
+			if (cp == NULL ||
+			    sscanf((char *) cp, "from %u to %u",
+				    &old_serial, &new_serial) != 2) {
+				fclose(fp);
+				return (-3);
+			} else if (from_serial >= old_serial) {
+				fclose(fp);
+				return (1);
+			}
+			fclose(fp);
+			return (-1);
+		}
+		if (prev_pktdone) {
+			prev_pktdone = 0;
+			if (feof(fp))
+				break;
+		}
+	}
+	fclose(fp);
+	return (0);
+}
+
+/* from db_load.c */
+
+static struct map m_section[] = {
+	{"zone", S_ZONE},
+	{"prereq", S_PREREQ},
+	{"update", S_UPDATE},
+	{"reserved", S_ADDT},
+};
+#define M_SECTION_CNT (sizeof(m_section) / sizeof(struct map))
+
+/* from ns_req.c */
+
+static struct map m_opcode[] = {
+	{"nxdomain", NXDOMAIN},
+	{"yxdomain", YXDOMAIN},
+	{"nxrrset", NXRRSET},
+	{"yxrrset", YXRRSET},
+	{"delete", DELETE},
+	{"add", ADD},
+};
+#define M_OPCODE_CNT (sizeof(m_opcode) / sizeof(struct map))
+
+/* XXXRTH workaround map difficulties */
+#define M_CLASS_CNT m_class_cnt
+#define M_TYPE_CNT m_type_cnt
+
+/*
+ * int
+ * ixfr_getrr(struct zoneinfo *zp, FILE *fp,
+ *            const char *filename, char *origin, struct namebuf **np,
+ *            u_int32_t *old_serial, u_int32_t *new_serial)
+ * 
+ * read a line from the historic of a zone.
+ * 
+ * returns:
+ * 
+ *         DBIXFR_ERROR = an error occured 
+ *         DBIXFR_FOUND_RR = a rr encountered 
+ *         DBIXFR_END = end of file
+ */
+static int
+ixfr_getrr(struct zoneinfo *zp, FILE *fp, const char *filename, char *origin,
+	   ns_updrec **uprec, u_int32_t *old_serial,
+	   u_int32_t *new_serial)
+{
+	static int      read_soa, read_ns, rrcount;
+
+	char            data[MAXDATA], dnbuf[MAXDNAME], sclass[3];
+	const char     *errtype = "Database";
+	char           *dname, *cp, *cp1;
+	char            buf[MAXDATA];
+	u_int32_t       serial, ttl;
+	int             nonempty_lineno = -1, prev_pktdone = 0, cont = 0,
+			inside_next = 0;
+	int             id, rcode = NOERROR;
+	int             i, c, section, opcode, matches, zonenum, err, multiline;
+	int             type, class;
+	u_int32_t       n;
+	enum transport  transport;
+	struct map     *mp;
+	int             zonelist[MAXDNAME];
+	struct databuf *dp;
+	struct in_addr  ina;
+	struct sockaddr_in empty_from;
+	int             datasize;
+	ns_updque	listuprec;
+	ns_updrec *	rrecp;
+	u_long		l;
+
+#define    ERRTO(msg)  if (1) { errtype = msg; goto err; } else (void)NULL
+
+	err = 0;
+	transport = primary_trans;
+	lineno = 1;
+	INIT_LIST(listuprec);
+	for (;;) {
+		if (!getword(buf, sizeof buf, fp, 0)) {
+			if (lineno == (nonempty_lineno + 1) && !(feof(fp))) {
+				/*
+				 * End of a nonempty line inside an update
+				 * packet or not inside an update packet.
+				 */
+				continue;
+			}
+			/*
+			 * Empty line or EOF.
+			 * 
+			 * Marks completion of current update packet.
+			 */
+			inside_next = 0;
+			prev_pktdone = 1;
+			cont = 1;
+		} else {
+			nonempty_lineno = lineno;
+		}
+
+		if (!strcasecmp(buf, "[DYNAMIC_UPDATE]") ||
+		    !strcasecmp(buf, "[IXFR_UPDATE]")) {
+			err = 0;
+			rcode = NOERROR;
+			cp = fgets(buf, sizeof buf, fp);
+			if (cp != NULL)
+				lineno++;
+			if (cp == NULL || !sscanf((char *) cp, "id %d", &id))
+				id = -1;
+			inside_next = 1;
+			prev_pktdone = 1;
+			cont = 1;
+		} else if (!strcasecmp(buf, "[INCR_SERIAL]")) {
+			/* XXXRTH not enough error checking here */
+			cp = fgets(buf, sizeof buf, fp);
+			if (cp != NULL)
+				lineno++;
+			if (cp == NULL ||
+			    sscanf((char *) cp, "from %u to %u",
+				    old_serial, new_serial) != 2) {
+				ns_error(ns_log_update,
+					 "incr_serial problem with %s",
+					 zp->z_updatelog);
+			} else {
+				serial = get_serial(zp);
+			}
+			cont = 1;
+		} else if (!strcasecmp(buf, "[END_DELTA]")) {
+			prev_pktdone = 1;
+			cont = 1;
+			lineno++;
+		}
+		if (prev_pktdone) {
+			if (!EMPTY(listuprec)) {
+				n++;
+				*uprec = TAIL(listuprec);
+				return (DBIXFR_FOUND_RR);
+			}
+			prev_pktdone = 0;
+			if (feof(fp))
+				break;
+		}
+		if (cont) {
+			cont = 0;
+			continue;
+		}
+		if (!inside_next)
+			continue;
+		/*
+		 * inside the same update packet, continue accumulating
+		 * records.
+		 */
+		section = -1;
+		n = strlen(buf);
+		if (buf[n - 1] == ':')
+			buf[--n] = '\0';
+		for (mp = m_section; mp < m_section + M_SECTION_CNT; mp++)
+			if (!strcasecmp(buf, mp->token)) {
+				section = mp->val;
+				break;
+			}
+		ttl = 0;
+		type = -1;
+		class = zp->z_class;
+		n = 0;
+		data[0] = '\0';
+		switch (section) {
+		case S_ZONE:
+			cp = fgets(buf, sizeof buf, fp);
+			if (!cp)
+				*buf = '\0';
+			n = sscanf(cp, "origin %s class %s serial %ul",
+				   origin, sclass, &serial);
+			if (n != 3 || ns_samename(origin, zp->z_origin) != 1)
+				err++;
+			if (cp)
+				lineno++;
+			if (!err && inside_next) {
+				int             success;
+
+				dname = origin;
+				type = T_SOA;
+				class = sym_ston(__p_class_syms, sclass,
+						 &success);
+				if (!success) {
+					err++;
+					break;
+				}
+				matches = findzone(dname, class, 0,
+						   zonelist, MAXDNAME);
+				if (matches)
+					zonenum = zonelist[0];
+				else
+					err++;
+			}
+			break;
+		case S_PREREQ:
+		case S_UPDATE:
+			/* Operation code. */
+			if (!getword(buf, sizeof buf, fp, 0)) {
+				err++;
+				break;
+			}
+			opcode = -1;
+			if (buf[0] == '{') {
+				n = strlen(buf);
+				for (i = 0; (u_int32_t) i < n; i++)
+					buf[i] = buf[i + 1];
+				if (buf[n - 2] == '}')
+					buf[n - 2] = '\0';
+			}
+			for (mp = m_opcode; mp < m_opcode + M_OPCODE_CNT; mp++)
+				if (!strcasecmp(buf, mp->token)) {
+					opcode = mp->val;
+					break;
+				}
+			if (opcode == -1) {
+				err++;
+				break;
+			}
+			/* Owner's domain name. */
+			if (!getword((char *) dnbuf, sizeof dnbuf, fp, 0)) {
+				err++;
+				break;
+			}
+			n = strlen((char *) dnbuf) - 1;
+			if (dnbuf[n] == '.')
+				dnbuf[n] = '\0';
+			dname = dnbuf;
+			ttl = 0;
+			type = -1;
+			class = zp->z_class;
+			n = 0;
+			data[0] = '\0';
+			(void) getword(buf, sizeof buf, fp, 1);
+			if (isdigit(buf[0])) {    /* ttl */
+				if (ns_parse_ttl(buf, &l) < 0) {
+					err++;
+					break;
+				}
+				ttl = l;
+				(void) getword(buf, sizeof buf, fp, 1);
+			}
+			/* possibly class */
+			if (buf[0] != '\0') {
+				int             success;
+				int             maybe_class;
+
+				maybe_class = sym_ston(__p_class_syms,
+						       buf, &success);
+				if (success) {
+					class = maybe_class;
+					(void) getword(buf, sizeof buf, fp, 1);
+				}
+			}
+			/* possibly type */
+			if (buf[0] != '\0') {
+				int             success;
+				int             maybe_type;
+
+				maybe_type = sym_ston(__p_type_syms,
+						      buf, &success);
+
+				if (success) {
+					type = maybe_type;
+					(void) getword(buf, sizeof buf, fp, 1);
+				}
+			}
+			if (buf[0] != '\0')    /* possibly rdata */
+			/*
+			 * Convert the ascii data 'buf' to the proper
+			 * format based on the type and pack into
+			 * 'data'.
+			 * 
+			 * XXX - same as in db_load(), consolidation
+			 * needed
+			 */
+			switch (type) {
+			case T_A:
+				if (!inet_aton(buf, &ina)) {
+					err++;
+					break;
+				}
+				n = ntohl(ina.s_addr);
+				cp = data;
+				PUTLONG(n, cp);
+				n = INT32SZ;
+				break;
+			case T_HINFO:
+			case T_ISDN:
+				n = strlen(buf);
+				data[0] = n;
+				memcpy(data + 1, buf, n);
+				n++;
+				if (!getword(buf, sizeof buf, fp, 0)) {
+					i = 0;
+				} else {
+					endline(fp);
+					i = strlen(buf);
+				}
+				data[n] = i;
+				n++;
+				memcpy(data + n + 1, buf, i);
+				n += i;
+				break;
+			case T_SOA:
+			case T_MINFO:
+			case T_RP:
+				(void) strcpy(data, buf);
+				cp = data + strlen(data) + 1;
+				if (!getword((char *) cp,
+					     sizeof data - (cp - data),
+					     fp, 1)) {
+					err++;
+					break;
+				}
+				cp += strlen((char *) cp) + 1;
+				if (type != T_SOA) {
+					n = cp - data;
+					break;
+				}
+				if (class != zp->z_class ||
+				    ns_samename(dname, zp->z_origin) != 1) {
+					err++;
+					break;
+				}
+				c = getnonblank(fp, zp->z_updatelog);
+				if (c == '(') {
+					multiline = 1;
+				} else {
+					multiline = 0;
+					ungetc(c, fp);
+				}
+				n = getnum(fp, zp->z_updatelog, GETNUM_SERIAL);
+				if (getnum_error) {
+					err++;
+					break;
+				}
+				if (opcode == ADD && i == 0)
+					*new_serial = n;
+				PUTLONG(n, cp);
+				for (i = 0; i < 4; i++) {
+					if (!getword(buf, sizeof buf, fp, 1)) {
+						err++;
+						break;
+					}
+					if (ns_parse_ttl(buf, &l) < 0) {
+						err++;
+						break;
+					}
+					n = l;
+					PUTLONG(n, cp);
+				}
+				if (multiline &&
+				    getnonblank(fp, zp->z_updatelog) != ')')
+				{
+					err++;
+					break;
+				}
+				endline(fp);
+				n = cp - data;
+				break;
+			case T_WKS:
+				if (!inet_aton(buf, &ina)) {
+					err++;
+					break;
+				}
+				n = ntohl(ina.s_addr);
+				cp = data;
+				PUTLONG(n, cp);
+				*cp = (char) getprotocol(fp, zp->z_updatelog);
+				n = INT32SZ + sizeof(char);
+				n = getservices((int) n, data,
+						fp, zp->z_updatelog);
+				break;
+			case T_NS:
+			case T_CNAME:
+			case T_MB:
+			case T_MG:
+			case T_MR:
+			case T_PTR:
+				(void) strcpy(data, buf);
+				if (makename(data, origin,
+					     sizeof(data)) == -1) {
+					err++;
+					break;
+				}
+				n = strlen(data) + 1;
+				break;
+			case T_MX:
+			case T_AFSDB:
+			case T_RT:
+				n = 0;
+				cp = buf;
+				while (isdigit(*cp))
+					n = n * 10 + (*cp++ - '0');
+				/* catch bad values */
+				cp = data;
+				PUTSHORT((u_int16_t) n, cp);
+				if (!getword(buf, sizeof(buf), fp, 1)) {
+					err++;
+					break;
+				}
+				(void) strcpy((char *) cp, buf);
+				if (makename((char *) cp, origin,
+					     sizeof(data) - (cp - data)) == -1)
+				{
+					err++;
+					break;
+				}
+				/* advance pointer to end of data */
+				cp += strlen((char *) cp) + 1;
+				/* now save length */
+				n = (cp - data);
+				break;
+			case T_PX:
+				n = 0;
+				data[0] = '\0';
+				cp = buf;
+				while (isdigit(*cp))
+					n = n * 10 + (*cp++ - '0');
+				cp = data;
+				PUTSHORT((u_int16_t) n, cp);
+				for (i = 0; i < 2; i++) {
+					if (!getword(buf, sizeof(buf), fp, 0))
+					{
+						err++;
+						break;
+					}
+					(void) strcpy((char *) cp, buf);
+					cp += strlen((char *) cp) + 1;
+				}
+				n = cp - data;
+				break;
+			case T_TXT:
+			case T_X25:
+				i = strlen(buf);
+				cp = data;
+				datasize = sizeof data;
+				cp1 = buf;
+				while (i > MAXCHARSTRING) {
+					if (datasize <= MAXCHARSTRING) {
+						ns_error(ns_log_update,
+							 "record too big");
+						return (-1);
+					}
+					datasize -= MAXCHARSTRING;
+					*cp++ = (char)MAXCHARSTRING;
+					memcpy(cp, cp1, MAXCHARSTRING);
+					cp += MAXCHARSTRING;
+					cp1 += MAXCHARSTRING;
+					i -= MAXCHARSTRING;
+				}
+				if (datasize < i + 1) {
+					ns_error(ns_log_update,
+						 "record too big");
+					return (-1);
+				}
+				*cp++ = i;
+				memcpy(cp, cp1, i);
+				cp += i;
+				n = cp - data;
+				endline(fp);
+				/* XXXVIX: segmented texts 4.9.5 */
+				break;
+			case T_NSAP:
+				n = inet_nsap_addr(buf, (u_char *) data,
+						   sizeof data);
+				endline(fp);
+				break;
+			case T_LOC:
+				cp = buf + (n = strlen(buf));
+				*cp = ' ';
+				cp++;
+				while ((i = getc(fp), *cp = i, i != EOF)
+				       && *cp != '\n' && (n < MAXDATA))
+				{
+					cp++;
+					n++;
+				}
+				if (*cp == '\n')
+					ungetc(*cp, fp);
+				*cp = '\0';
+				n = loc_aton(buf, (u_char *) data);
+				if (n == 0) {
+					err++;
+					break;
+				}
+				endline(fp);
+				break;
+			case ns_t_sig: 
+			case ns_t_nxt:
+			case ns_t_key:
+			case ns_t_cert:{
+				char *errmsg = NULL;
+
+				n  = parse_sec_rdata(buf, sizeof(buf), 1,
+						     (u_char *) data,
+						     sizeof(data),
+						     fp, zp, dname, ttl,
+						     type, domain_ctx,
+						     transport, &errmsg);
+				if (errmsg) {
+					err++;
+					endline(fp);
+					n = 0;
+				}
+				break;
+			}
+			default:
+				err++;
+			}
+			if (section == S_PREREQ) {
+				ttl = 0;
+				if (opcode == NXDOMAIN) {
+					class = C_NONE;
+					type = T_ANY;
+					n = 0;
+				} else if (opcode == YXDOMAIN) {
+					class = C_ANY;
+					type = T_ANY;
+					n = 0;
+				} else if (opcode == NXRRSET) {
+					class = C_NONE;
+					n = 0;
+				} else if (opcode == YXRRSET) {
+					if (n == 0)
+					class = C_ANY;
+				}
+			} else {/* section == S_UPDATE */
+				if (opcode == DELETE) {
+					if (n == 0) {
+						class = C_ANY;
+						if (type == -1)
+						type = T_ANY;
+					} else {
+						class = zp->z_class;
+					}
+				}
+			}
+			break;
+		case S_ADDT:
+		default:
+			ns_debug(ns_log_update, 1,
+				 "cannot interpret section: %d", section);
+			inside_next = 0;
+			err++;
+		}
+		if (err) {
+			inside_next = 0;
+			ns_debug(ns_log_update, 1,
+			"merge of update id %d failed due to error at line %d",
+				 id, lineno);
+			memset(&empty_from, 0, sizeof empty_from);
+			free_rrecp(&listuprec, rcode, empty_from);
+			continue;
+		}
+		rrecp = res_mkupdrec(section, dname, class, type, ttl);
+		if (section != S_ZONE) {
+			dp = savedata(class, type, ttl, (u_char *) data, n);
+			dp->d_zone = zonenum;
+			dp->d_cred = DB_C_ZONE;
+			dp->d_clev = nlabels(zp->z_origin);
+			rrecp->r_dp = dp;
+			rrecp->r_opcode = opcode;
+		} else {
+			rrecp->r_zone = zonenum;
+			rrecp->r_opcode = opcode;
+		}
+
+		/* remove add/delete pairs */
+		if (section == S_UPDATE) {
+			ns_updrec *arp;
+			int foundmatch;
+
+			arp = TAIL(listuprec);
+			foundmatch = 0;
+			while (arp) {
+				if (arp->r_section == S_UPDATE &&
+				    ((arp->r_opcode == DELETE &&
+				      opcode == ADD) ||
+				     (opcode == DELETE &&
+				      arp->r_opcode == ADD)) &&
+				     arp->r_dp->d_type == dp->d_type &&
+				     arp->r_dp->d_class == dp->d_class &&
+				     arp->r_dp->d_ttl == dp->d_ttl &&
+				     ns_samename(arp->r_dname, dname) == 1 &&
+				     db_cmp(arp->r_dp, dp) == 0) {
+					db_freedata(dp);
+					db_freedata(arp->r_dp);
+					UNLINK(listuprec, arp, r_link);
+					res_freeupdrec(arp);
+					res_freeupdrec(rrecp);
+					foundmatch = 1;
+					break;
+				}
+				arp = PREV(arp, r_link);
+			}
+			if (foundmatch)
+				continue;
+		}
+
+		APPEND(listuprec, rrecp, r_link);
+		/* Override zone number with current zone serial number */
+		rrecp->r_zone = serial;
+	}   
+
+	if (err)
+		return (DBIXFR_ERROR);
+
+	return (DBIXFR_END);
+}