r10042: Add in external LGPL library for accessing the share mode db. Allow

others to examine & test. May not end up here eventually...
Jeremy.
(This used to be commit 7cc70ae63399eacd55bd0bf51ac2c7b004d761bf)

4 files changed, 627 insertions, 3 deletions

diff --git a/source3/Makefile.in b/source3/Makefile.in
index ff0d0ff61d..0c51b3b818 100644
--- a/source3/Makefile.in
+++ b/source3/Makefile.in
@@ -97,8 +97,12 @@ LIBSMBCLIENT=bin/libsmbclient.a @LIBSMBCLIENT_SHARED@
 LIBSMBCLIENT_MAJOR=0
 LIBSMBCLIENT_MINOR=1
 
+LIBSMBSHAREMODES=bin/libsmbsharemodes.a @LIBSMBSHAREMODES_SHARED@
+LIBSMBSHAREMODES_MAJOR=0
+LIBSMBSHAREMODES_MINOR=1
 
-FLAGS1 = $(CFLAGS) @FLAGS1@ -Iinclude -I$(srcdir)/include -I$(srcdir)/ubiqx @SMBWRAP_INC@ -I. $(CPPFLAGS) -I$(srcdir)
+
+FLAGS1 = $(CFLAGS) @FLAGS1@ -Iinclude -I$(srcdir)/include -I$(srcdir)/ubiqx @SMBWRAP_INC@ -I. $(CPPFLAGS) -I$(srcdir) -I$(srcdir)/tdb
 FLAGS2 = 
 FLAGS3 = 
 FLAGS4 = 
@@ -137,7 +141,7 @@ BIN_PROGS = $(BIN_PROGS1) $(BIN_PROGS2) $(BIN_PROGS3) @EXTRA_BIN_PROGS@
 EVERYTHING_PROGS = bin/debug2html@EXEEXT@ bin/smbfilter@EXEEXT@ bin/talloctort@EXEEXT@ \
 	bin/log2pcap@EXEEXT@
 
-SHLIBS = @SHLIB_PROGS@ @LIBSMBCLIENT@ 
+SHLIBS = @SHLIB_PROGS@ @LIBSMBCLIENT@ @LIBSMBSHAREMODES@
 
 SCRIPTS = $(srcdir)/script/smbtar $(builddir)/script/findsmb
 
@@ -513,6 +517,8 @@ LIBSMBCLIENT_OBJ = libsmb/libsmbclient.o libsmb/libsmb_compat.o \
 		   $(LIBMSRPC_OBJ) $(RPC_PARSE_OBJ) \
 		   $(SECRETS_OBJ) $(PASSDB_OBJ) $(SMBLDAP_OBJ) $(GROUPDB_OBJ)
 
+LIBSMBSHAREMODES_OBJ = libsmb/smb_share_modes.o tdb/tdb.o
+
 CAC_OBJ = $(LIBSMBCLIENT_OBJ) \
           libmsrpc/libmsrpc.o libmsrpc/libmsrpc_internal.o \
           libmsrpc/cac_lsarpc.o libmsrpc/cac_winreg.o libmsrpc/cac_samr.o \
@@ -641,6 +647,7 @@ WINBIND_WINS_NSS_PICOBJS = $(WINBIND_WINS_NSS_OBJ:.o=.@PICSUFFIX@)
 
 PICOBJS = $(SMBWRAPPER_OBJ:.o=.@PICSUFFIX@)
 LIBSMBCLIENT_PICOBJS = $(LIBSMBCLIENT_OBJ:.o=.@PICSUFFIX@)
+LIBSMBSHAREMODES_PICOBJS = $(LIBSMBSHAREMODES_OBJ:.o=.@PICSUFFIX@)
 
 CAC_PICOBJS = $(CAC_OBJ:.o=.@PICSUFFIX@)
 
@@ -1016,6 +1023,15 @@ bin/libsmbclient.a: $(LIBSMBCLIENT_PICOBJS)
 	@echo Linking libsmbclient non-shared library $@
 	@-$(AR) -rc $@ $(LIBSMBCLIENT_PICOBJS)
 
+bin/libsmbsharemodes.@SHLIBEXT@: $(LIBSMBSHAREMODES_PICOBS)
+	@echo Linking libsmbsharemodes shared library $@
+	@$(SHLD) $(LDSHFLAGS) -o $@ $(LIBSMBSHAREMODES_PICOBS) $(LDFLAGS) $(LIBS) \
+		$(KRB5LIBS) $(LDAP_LIBS) \
+		@SONAMEFLAG@`basename $@`.$(LIBSMBSHAREMODES_MAJOR)
+
+bin/libsmbsharemodes.a: $(LIBSMBSHAREMODES_PICOBJS)
+	@echo Linking libsmbsharemodes non-shared library $@
+	@-$(AR) -rc $@ $(LIBSMBSHAREMODES_PICOBJS)
 
 bin/libmsrpc.@SHLIBEXT@: $(CAC_PICOBJS)
 	@echo Linking libmsrpc shared library $@
@@ -1041,6 +1057,7 @@ bin/libbigballofmud.@SHLIBEXT@: $(LIBBIGBALLOFMUD_PICOBJS)
 # library.
 
 libsmbclient: $(LIBSMBCLIENT)
+libsmbsharemodes: $(LIBSMBSHAREMODES)
 
 bin/librpc_lsarpc.@SHLIBEXT@: $(RPC_LSA_OBJ)
 	@echo "Linking $@"
@@ -1461,7 +1478,7 @@ TOPFILES=dynconfig.o dynconfig.@PICSUFFIX@
 clean: delheaders python_clean
 	-rm -f core */*~ *~ */*.o */*.@PICSUFFIX@ */*.@SHLIBEXT@ \
 		$(TOPFILES) $(BIN_PROGS) $(SBIN_PROGS) $(MODULES) $(TORTURE_PROGS) \
-		$(LIBSMBCLIENT) $(EVERYTHING_PROGS) .headers.stamp 
+		$(LIBSMBCLIENT) $(LIBSMBSHAREMODES) $(EVERYTHING_PROGS) .headers.stamp 
 	-rm -rf t_dir
 
 # Making this target will just make sure that the prototype files
diff --git a/source3/configure.in b/source3/configure.in
index 95df1ba476..3a77584aec 100644
--- a/source3/configure.in
+++ b/source3/configure.in
@@ -219,6 +219,8 @@ AC_SUBST(INSTALLCLIENTCMD_SH)
 AC_SUBST(INSTALLCLIENTCMD_A)
 AC_SUBST(LIBSMBCLIENT_SHARED)
 AC_SUBST(LIBSMBCLIENT)
+AC_SUBST(LIBSMBSHAREMODES_SHARED)
+AC_SUBST(LIBSMBSHAREMODES)
 AC_SUBST(PRINT_LIBS)
 AC_SUBST(AUTH_LIBS)
 AC_SUBST(ACL_LIBS)
@@ -3872,6 +3874,56 @@ AC_ARG_WITH(libsmbclient,
 )
 
 
+INSTALLCLIENTCMD_SH=:
+INSTALLCLIENTCMD_A=:
+INSTALLCLIENT=
+LIBSMBCLIENT_SHARED=
+LIBSMBCLIENT=
+AC_MSG_CHECKING(whether to build the libsmbsharemodes shared library)
+AC_ARG_WITH(libsmbsharemodes,
+[  --with-libsmbsharemodes     Build the libsmbsharemodes shared library (default=yes if shared libs supported)],
+[ case "$withval" in
+  no) 
+     AC_MSG_RESULT(no)
+     ;;
+  *)
+     if test $BLDSHARED = true; then
+        INSTALLCLIENTCMD_SH="\$(INSTALLCMD)"
+	## build the static version of libsmbsharemodes as well
+	INSTALLCLIENTCMD_A="\$(INSTALLCMD)"
+        LIBSMBSHAREMODES_SHARED=bin/libsmbsharemodes.$SHLIBEXT
+        LIBSMBSHAREMODES=libsmbclient
+        AC_MSG_RESULT(yes)
+     else
+	enable_static=yes
+        AC_MSG_RESULT(no shared library support -- will supply static library)
+     fi
+     if test $enable_static = yes; then
+        INSTALLCLIENTCMD_A="\$(INSTALLCMD)"
+        LIBSMBCLIENT=libsmbsharemodes
+     fi
+     INSTALLCLIENT=installclientlib
+     ;;
+  esac ],
+[
+# if unspecified, default is to built it iff possible.
+  if test $BLDSHARED = true; then
+     INSTALLCLIENTCMD_SH="\$(INSTALLCMD)"
+     LIBSMBSHAREMODES_SHARED=bin/libsmbsharemodes.$SHLIBEXT
+     LIBSMBSHAREMODES=libsmbsharemodes
+     AC_MSG_RESULT(yes)
+   else
+     enable_static=yes
+     AC_MSG_RESULT(no shared library support -- will supply static library)
+   fi
+   if test $enable_static = yes; then
+     INSTALLCLIENTCMD_A="\$(INSTALLCMD)"
+     LIBSMBCLIENT=libsmbsharemodes
+  fi]
+  INSTALLCLIENT=installclientlib
+)
+
+
 #################################################
 # these tests are taken from the GNU fileutils package
 AC_CHECKING(how to get filesystem space usage)
diff --git a/source3/include/smb_share_modes.h b/source3/include/smb_share_modes.h
new file mode 100644
index 0000000000..5a79e171d5
--- /dev/null
+++ b/source3/include/smb_share_modes.h
@@ -0,0 +1,103 @@
+/*
+   Samba share mode database library.
+
+   Copyright (C) Jeremy Allison 2005.
+
+   This library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2 of the License, or (at your option) any later version.
+
+   This library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with this library; if not, write to the Free Software
+   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+*/
+
+#ifndef _SMB_SHARE_MODES_H_
+#define _SMB_STATE_MODES_H_
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+#include <stdint.h>
+#include "tdb.h"
+
+/* Database context handle. */
+struct smbdb_ctx {
+	TDB_CONTEXT *smb_tdb;
+};
+
+/* Share mode entry. */
+/*
+ We use 64 bit types for device and inode as
+ we don't know what size mode Samba has been
+ compiled in - dev/ino may be 32, may be 64
+ bits. This interface copes with either.
+*/
+  
+struct smb_share_mode_entry {
+	uint64_t dev;
+	uint64_t ino;
+	uint32_t share_access;
+	uint32_t access_mask;
+	struct timeval open_time;
+	uint32_t file_id;
+	pid_t pid;
+};
+
+/*
+ * open/close sharemode database.
+ */
+
+struct smbdb_ctx *smb_share_mode_db_open(const char *db_path);
+int smb_share_mode_db_close(struct smbdb_ctx *db_ctx);
+
+/*
+ * lock/unlock entry in sharemode database.
+ */
+
+int smb_lock_share_mode_entry(struct smbdb_ctx *db_ctx,
+				uint64_t dev,
+				uint64_t ino);
+
+int smb_unlock_share_mode_entry(struct smbdb_ctx *db_ctx,
+				uint64_t dev,
+				uint64_t ino);
+
+/*
+ * Share mode database accessor functions.
+ */
+
+int smb_get_share_mode_entries(struct smbdb_ctx *db_ctx,
+				uint64_t dev,
+				uint64_t ino,
+				struct smb_share_mode_entry **pp_list,
+				unsigned char *p_delete_on_close);
+
+int smb_create_share_mode_entry(struct smbdb_ctx *db_ctx,
+				uint64_t dev,
+				uint64_t ino,
+				const struct smb_share_mode_entry *set_entry,
+				const char *path);
+
+int smb_delete_share_mode_entry(struct smbdb_ctx *db_ctx,
+				uint64_t dev,
+				uint64_t ino,
+				const struct smb_share_mode_entry *set_entry);
+
+int smb_change_share_mode_entry(struct smbdb_ctx *db_ctx,
+				uint64_t dev,
+				uint64_t ino,
+				const struct smb_share_mode_entry *set_entry,
+				const struct smb_share_mode_entry *new_entry);
+
+#ifdef __cplusplus
+}
+#endif
+#endif
diff --git a/source3/libsmb/smb_share_modes.c b/source3/libsmb/smb_share_modes.c
new file mode 100644
index 0000000000..0ba68aed06
--- /dev/null
+++ b/source3/libsmb/smb_share_modes.c
@@ -0,0 +1,452 @@
+/*
+   Samba share mode database library external interface library.
+   Used by non-Samba products needing access to the Samba share mode db.
+                                                                                                                                  
+   Copyright (C) Jeremy Allison 2005.
+                                                                                                                                  
+   This library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2 of the License, or (at your option) any later version.
+                                                                                                                                  
+   This library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Lesser General Public License for more details.
+                                                                                                                                  
+   You should have received a copy of the GNU Lesser General Public
+   License along with this library; if not, write to the Free Software
+   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+*/
+
+#include "includes.h"
+#include "smb_share_modes.h"
+
+/*
+ * open/close sharemode database.
+ */
+
+struct smbdb_ctx *smb_share_mode_db_open(const char *db_path)
+{
+	struct smbdb_ctx *smb_db = SMB_MALLOC_P(struct smbdb_ctx);
+
+	if (!smb_db) {
+		return NULL;
+	}
+
+	memset(smb_db, '\0', sizeof(struct smbdb_ctx));
+
+	smb_db->smb_tdb = tdb_open_log(lock_path("locking.tdb"),
+				0, TDB_DEFAULT|TDB_CLEAR_IF_FIRST,
+				O_RDWR|O_CREAT,
+				0644);
+
+	if (!smb_db->smb_tdb) {
+		free(smb_db);
+		return NULL;
+	}
+
+	/* Should check that this is the correct version.... */
+	return smb_db;
+}
+
+int smb_share_mode_db_close(struct smbdb_ctx *db_ctx)
+{
+	int ret = tdb_close(db_ctx->smb_tdb);
+	free(db_ctx);
+	return ret;
+}
+
+/* Create locking key. */
+
+struct samba_locking_key {
+	SMB_DEV_T dev;
+	SMB_INO_T ino;
+};
+
+static TDB_DATA get_locking_key(uint64_t dev, uint64_t ino)
+{
+	static struct samba_locking_key lk;
+	TDB_DATA ld;
+
+	memset(&lk, '\0', sizeof(struct samba_locking_key));
+	lk.dev = (SMB_DEV_T)dev;
+	lk.ino = (SMB_INO_T)ino;
+	ld.dptr = (char *)&lk;
+	ld.dsize = sizeof(lk);
+	return ld;
+}
+
+/*
+ * lock/unlock entry in sharemode database.
+ */
+
+int smb_lock_share_mode_entry(struct smbdb_ctx *db_ctx,
+				uint64_t dev,
+				uint64_t ino)
+{
+	return tdb_chainlock(db_ctx->smb_tdb, get_locking_key(dev, ino));
+}
+                                                                                                                                  
+int smb_unlock_share_mode_entry(struct smbdb_ctx *db_ctx,
+                                dev_t dev,
+                                ino_t ino)
+{
+	return tdb_chainunlock(db_ctx->smb_tdb, get_locking_key(dev, ino));
+}
+
+/* Internal structure of Samba share mode db. */
+/* FIXME ! This should be moved into a Samba include file. */
+
+struct locking_data {
+	union {
+		struct {
+			int num_share_mode_entries;
+			BOOL delete_on_close;
+		} s;
+		share_mode_entry dummy; /* Needed for alignment. */
+	} u;
+	/* the following two entries are implicit
+	   share_mode_entry modes[num_share_mode_entries];
+	   char file_name[];
+	*/
+};
+
+/*
+ * Check if an external smb_share_mode_entry and an internal share_mode entry match.
+ */
+
+static int share_mode_entry_equal(const struct smb_share_mode_entry *e_entry, const share_mode_entry *entry)
+{
+	return (e_entry->pid == entry->pid &&
+		e_entry->file_id == (uint32_t)entry->share_file_id &&
+		e_entry->open_time.tv_sec == entry->time.tv_sec &&
+		e_entry->open_time.tv_usec == entry->time.tv_usec &&
+		e_entry->share_access == (uint32_t)entry->share_access &&
+		e_entry->access_mask == (uint32_t)entry->access_mask &&
+		e_entry->dev == (uint64_t)entry->dev && 
+		e_entry->ino == (uint64_t)entry->inode);
+}
+
+/*
+ * Create an internal Samba share_mode entry from an external smb_share_mode_entry.
+ */
+
+static void create_share_mode_entry(share_mode_entry *out, const struct smb_share_mode_entry *in)
+{
+	memset(out, '\0', sizeof(share_mode_entry));
+
+	out->pid = in->pid;
+	out->share_file_id = (unsigned long)in->file_id;
+	out->time.tv_sec = in->open_time.tv_sec;
+	out->time.tv_usec = in->open_time.tv_usec;
+	out->share_access = in->share_access;
+	out->access_mask = in->access_mask;
+	out->dev = (SMB_DEV_T)in->dev;
+	out->inode = (SMB_INO_T)in->ino;
+}
+
+/*
+ * Return the current share mode list for an open file.
+ * This uses similar (but simplified) logic to locking/locking.c
+ */
+
+int smb_get_share_mode_entries(struct smbdb_ctx *db_ctx,
+				uint64_t dev,
+				uint64_t ino,
+				struct smb_share_mode_entry **pp_list,
+				unsigned char *p_delete_on_close)
+{
+	TDB_DATA db_data;
+	struct smb_share_mode_entry *list = NULL;
+	int num_share_modes = 0;
+	struct locking_data *ld = NULL; /* internal samba db state. */
+	share_mode_entry *shares = NULL;
+	size_t i;
+
+	*pp_list = NULL;
+	*p_delete_on_close = 0;
+
+	db_data = tdb_fetch(db_ctx->smb_tdb, get_locking_key(dev, ino));
+	if (!db_data.dptr) {
+		return 0;
+	}
+
+	ld = (struct locking_data *)db_data.dptr;
+	num_share_modes = ld->u.s.num_share_mode_entries;
+
+	if (!num_share_modes) {
+		free(db_data.dptr);
+		return 0;
+	}
+
+	list = SMB_MALLOC_ARRAY(struct smb_share_mode_entry, num_share_modes);
+	if (!list) {
+		free(db_data.dptr);
+		return -1;
+	}
+
+	memset(list, '\0', num_share_modes * sizeof(struct smb_share_mode_entry));
+
+	shares = (share_mode_entry *)(db_data.dptr + sizeof(struct locking_data));
+
+	for (i = 0; i < num_share_modes; i++) {
+		share_mode_entry *share = &shares[i];
+		struct smb_share_mode_entry *sme = &list[i];
+		pid_t pid = share->pid;
+
+		/* Check this process really exists. */
+		if (kill(pid, 0) == -1 && (errno == ESRCH)) {
+			continue; /* No longer exists. */
+		}
+
+		/* Copy into the external list. */
+		sme->dev = (uint64_t)share->dev;
+		sme->ino = (uint64_t)share->inode;
+		sme->share_access = (uint32_t)share->share_access;
+		sme->access_mask = (uint32_t)share->access_mask;
+		sme->open_time.tv_sec = share->time.tv_sec;
+		sme->open_time.tv_usec = share->time.tv_usec;
+        	sme->file_id = (uint32_t)share->share_file_id;
+		sme->pid = share->pid;
+	}
+
+	if (i == 0) {
+		free(db_data.dptr);
+		free(list);
+		return 0;
+	}
+
+	*p_delete_on_close = ld->u.s.delete_on_close;
+	*pp_list = list;
+	return i;
+}
+
+/* 
+ * Create an entry in the Samba share mode db.
+ */
+
+int smb_create_share_mode_entry(struct smbdb_ctx *db_ctx,
+				uint64_t dev,
+				uint64_t ino,
+				const struct smb_share_mode_entry *new_entry,
+				const char *filename) /* Must be abolute utf8 path. */
+{
+	TDB_DATA db_data;
+	TDB_DATA locking_key =  get_locking_key(dev, ino);
+	int orig_num_share_modes = 0;
+	struct locking_data *ld = NULL; /* internal samba db state. */
+	share_mode_entry *shares = NULL;
+	char *new_data_p = NULL;
+	size_t new_data_size = 0;
+
+	db_data = tdb_fetch(db_ctx->smb_tdb, locking_key);
+	if (!db_data.dptr) {
+		/* We must create the entry. */
+		db_data.dptr = SMB_MALLOC(sizeof(struct locking_data) + sizeof(share_mode_entry) + strlen(filename) + 1);
+		if (!db_data.dptr) {
+			return -1;
+		}
+		ld = (struct locking_data *)db_data.dptr;
+		ld->u.s.num_share_mode_entries = 1;
+		ld->u.s.delete_on_close = 0;
+		shares = (share_mode_entry *)db_data.dptr + sizeof(struct locking_data);
+		create_share_mode_entry(shares, new_entry);
+		memcpy(db_data.dptr + sizeof(struct locking_data) + sizeof(share_mode_entry),
+			filename,
+			strlen(filename) + 1);
+
+		db_data.dsize = sizeof(struct locking_data) + sizeof(share_mode_entry) + strlen(filename) + 1;
+		if (tdb_store(db_ctx->smb_tdb, locking_key, db_data, TDB_INSERT) == -1) {
+			free(db_data.dptr);
+			return -1;
+		}
+		free(db_data.dptr);
+		return 0;
+	}
+
+	/* Entry exists, we must add a new entry. */
+	new_data_p = SMB_MALLOC(db_data.dsize + sizeof(share_mode_entry));
+	if (!new_data_p) {
+		free(db_data.dptr);
+		return -1;
+	}
+
+	ld = (struct locking_data *)db_data.dptr;
+	orig_num_share_modes = ld->u.s.num_share_mode_entries;
+
+	/* Copy the original data. */
+	memcpy(new_data_p, db_data.dptr, sizeof(struct locking_data) + (orig_num_share_modes*sizeof(share_mode_entry)));
+
+	/* Add in the new share mode */
+	shares = (share_mode_entry *)(db_data.dptr + sizeof(struct locking_data) + (orig_num_share_modes*sizeof(share_mode_entry)));
+	create_share_mode_entry(shares, new_entry);
+
+	ld = (struct locking_data *)new_data_p;
+	ld->u.s.num_share_mode_entries++;
+
+	/* Append the original filename */
+	memcpy(new_data_p + sizeof(struct locking_data) + (ld->u.s.num_share_mode_entries * sizeof(share_mode_entry)),
+		db_data.dptr + sizeof(struct locking_data) + (orig_num_share_modes * sizeof(share_mode_entry)),
+		db_data.dsize - (sizeof(struct locking_data) + (orig_num_share_modes * sizeof(share_mode_entry))));
+
+	new_data_size = db_data.dsize + sizeof(share_mode_entry);
+
+	free(db_data.dptr);
+
+	db_data.dptr = new_data_p;
+	db_data.dsize = new_data_size;
+
+	if (tdb_store(db_ctx->smb_tdb, locking_key, db_data, TDB_REPLACE) == -1) {
+		free(db_data.dptr);
+		return -1;
+	}
+	free(db_data.dptr);
+	return 0;
+}
+
+int smb_delete_share_mode_entry(struct smbdb_ctx *db_ctx,
+				uint64_t dev,
+				uint64_t ino,
+				const struct smb_share_mode_entry *del_entry)
+{
+	TDB_DATA db_data;
+	TDB_DATA locking_key =  get_locking_key(dev, ino);
+	int orig_num_share_modes = 0;
+	struct locking_data *ld = NULL; /* internal samba db state. */
+	share_mode_entry *shares = NULL;
+	char *new_data_p = NULL;
+	size_t filename_size = 0;
+	size_t i;
+
+	db_data = tdb_fetch(db_ctx->smb_tdb, locking_key);
+	if (!db_data.dptr) {
+		return -1; /* Error - missing entry ! */
+	}
+
+	ld = (struct locking_data *)db_data.dptr;
+	orig_num_share_modes = ld->u.s.num_share_mode_entries;
+	shares = (share_mode_entry *)(db_data.dptr + sizeof(struct locking_data));
+
+	if (orig_num_share_modes == 1) {
+		/* Only one entry - better be ours... */
+		if (!share_mode_entry_equal(del_entry, shares)) {
+			/* Error ! We can't delete someone else's entry ! */
+			free(db_data.dptr);
+			return -1;
+		}
+		/* It's ours - just remove the entire record. */
+		free(db_data.dptr);
+		return tdb_delete(db_ctx->smb_tdb, locking_key);
+	}
+
+	/* More than one - allocate a new record minus the one we'll delete. */
+	new_data_p = SMB_MALLOC(db_data.dsize - sizeof(share_mode_entry));
+	if (!new_data_p) {
+		free(db_data.dptr);
+		return -1;
+	}
+
+	/* Copy the header. */
+	memcpy(new_data_p, db_data.dptr, sizeof(struct locking_data));
+
+	for (i = 0; i < orig_num_share_modes; i++) {
+		share_mode_entry *share = &shares[i];
+		pid_t pid = share->pid;
+
+		/* Check this process really exists. */
+		if (kill(pid, 0) == -1 && (errno == ESRCH)) {
+			continue; /* No longer exists. */
+		}
+
+		if (share_mode_entry_equal(del_entry, share)) {
+			continue; /* This is our delete taget. */
+		}
+
+		memcpy(new_data_p + sizeof(struct locking_data) + (i*sizeof(share_mode_entry)),
+			share, sizeof(share_mode_entry) );
+	}
+
+	if (i == 0) {
+		/* None left after pruning. Delete record. */
+		free(db_data.dptr);
+		free(new_data_p);
+		return tdb_delete(db_ctx->smb_tdb, locking_key);
+	}
+
+	/* Copy the terminating filename. */
+	filename_size = db_data.dsize - ( sizeof(struct locking_data) + (orig_num_share_modes * sizeof(share_mode_entry)));
+
+	memcpy(new_data_p + sizeof(struct locking_data) + (i*sizeof(share_mode_entry)),
+		db_data.dptr + sizeof(struct locking_data) + (orig_num_share_modes * sizeof(share_mode_entry)),
+		filename_size);
+
+	free(db_data.dptr);
+
+	db_data.dptr = new_data_p;
+
+	/* Re-save smaller record. */
+	ld = (struct locking_data *)db_data.dptr;
+	ld->u.s.num_share_mode_entries = i;
+
+	db_data.dsize = sizeof(struct locking_data) + (i*sizeof(share_mode_entry)) + filename_size;
+
+	if (tdb_store(db_ctx->smb_tdb, locking_key, db_data, TDB_REPLACE) == -1) {
+		free(db_data.dptr);
+		return -1;
+	}
+	free(db_data.dptr);
+	return 0;
+}
+
+int smb_change_share_mode_entry(struct smbdb_ctx *db_ctx,
+				uint64_t dev,
+				uint64_t ino,
+				const struct smb_share_mode_entry *set_entry,
+				const struct smb_share_mode_entry *new_entry)
+{
+	TDB_DATA db_data;
+	TDB_DATA locking_key =  get_locking_key(dev, ino);
+	int num_share_modes = 0;
+	struct locking_data *ld = NULL; /* internal samba db state. */
+	share_mode_entry *shares = NULL;
+	size_t i;
+	int found_entry = 0;
+
+	db_data = tdb_fetch(db_ctx->smb_tdb, locking_key);
+	if (!db_data.dptr) {
+		return -1; /* Error - missing entry ! */
+	}
+
+	ld = (struct locking_data *)db_data.dptr;
+	num_share_modes = ld->u.s.num_share_mode_entries;
+	shares = (share_mode_entry *)(db_data.dptr + sizeof(struct locking_data));
+
+	for (i = 0; i < num_share_modes; i++) {
+		share_mode_entry *share = &shares[i];
+		pid_t pid = share->pid;
+
+		/* Check this process really exists. */
+		if (kill(pid, 0) == -1 && (errno == ESRCH)) {
+			continue; /* No longer exists. */
+		}
+
+		if (share_mode_entry_equal(set_entry, share)) {
+			create_share_mode_entry(share, new_entry);
+			break;
+		}
+	}
+
+	if (!found_entry) {
+		free(db_data.dptr);
+		return -1;
+	}
+
+	/* Save modified data. */
+	if (tdb_store(db_ctx->smb_tdb, locking_key, db_data, TDB_REPLACE) == -1) {
+		free(db_data.dptr);
+		return -1;
+	}
+	free(db_data.dptr);
+	return 0;
+}