Merge CTDB-related fixes from samba-ctdb 3.0 branch (http://samba.org/~tridge/3_0-ctdb)

Signed-off-by: Alexander Bokovoy <ab@samba.org>(This used to be commit 0c8e23afbbb2d081fc23908bafcad04650bfacea)

9 files changed, 276 insertions, 85 deletions

diff --git a/source3/lib/conn_tdb.c b/source3/lib/conn_tdb.c
index dd0a354a85..22d85c873d 100644
--- a/source3/lib/conn_tdb.c
+++ b/source3/lib/conn_tdb.c
@@ -34,7 +34,7 @@ static struct db_context *connections_db_ctx(bool rw)
 	}
 	else {
 		db_ctx = db_open(NULL, lock_path("connections.tdb"), 0,
-				 TDB_DEFAULT, O_RDONLY, 0);
+				 TDB_CLEAR_IF_FIRST|TDB_DEFAULT, O_RDONLY, 0);
 	}
 
 	return db_ctx;
diff --git a/source3/lib/ctdbd_conn.c b/source3/lib/ctdbd_conn.c
index 899bbcfcce..18e9879601 100644
--- a/source3/lib/ctdbd_conn.c
+++ b/source3/lib/ctdbd_conn.c
@@ -1203,6 +1203,42 @@ NTSTATUS ctdbd_register_reconfigure(struct ctdbd_connection *conn)
 	return register_with_ctdbd(conn, CTDB_SRVID_RECONFIGURE);
 }
 
+/*
+  persstent store. Used when we update a record in a persistent database
+ */
+NTSTATUS ctdbd_persistent_store(struct ctdbd_connection *conn, uint32_t db_id, TDB_DATA key, TDB_DATA data)
+{
+       int cstatus=0;
+       struct ctdb_rec_data *rec;
+       TDB_DATA recdata;
+       size_t length;
+       NTSTATUS status;
+
+       length = offsetof(struct ctdb_rec_data, data) + key.dsize + data.dsize;
+
+       rec = (struct ctdb_rec_data *)talloc_size(conn, length);
+       NT_STATUS_HAVE_NO_MEMORY(rec);
+
+       rec->length = length;
+       rec->reqid  = db_id;
+       rec->keylen = key.dsize;
+       rec->datalen= data.dsize;
+       memcpy(&rec->data[0], key.dptr, key.dsize);
+       memcpy(&rec->data[key.dsize], data.dptr, data.dsize);
+
+       recdata.dptr  = (uint8_t *)rec;
+       recdata.dsize = length;
+
+       status = ctdbd_control(conn, CTDB_CURRENT_NODE, 
+                              CTDB_CONTROL_PERSISTENT_STORE, 
+                              0, recdata, NULL, NULL, &cstatus);
+       if (cstatus != 0) {
+               return NT_STATUS_INTERNAL_DB_CORRUPTION;
+       }
+       return status;
+}
+
+
 #else
 
 NTSTATUS ctdbd_init_connection(TALLOC_CTX *mem_ctx,
diff --git a/source3/lib/dbwrap.c b/source3/lib/dbwrap.c
index 4e16d18682..001424a6c0 100644
--- a/source3/lib/dbwrap.c
+++ b/source3/lib/dbwrap.c
@@ -20,7 +20,9 @@
 */
 
 #include "includes.h"
-
+#ifdef CLUSTER_SUPPORT
+#include "ctdb_private.h"
+#endif
 /*
  * Fall back using fetch_locked if no genuine fetch operation is provided
  */
@@ -46,10 +48,16 @@ struct db_context *db_open(TALLOC_CTX *mem_ctx,
 			   int open_flags, mode_t mode)
 {
 	struct db_context *result = NULL;
+#ifdef CLUSTER_SUPPORT
+	const char *sockname = lp_ctdbd_socket();
+#endif
 
 #ifdef CLUSTER_SUPPORT
+	if(!sockname || !*sockname) {
+		sockname = CTDB_PATH;
+	}
 
-	if (lp_clustering()) {
+	if (lp_clustering() && socket_exist(sockname)) {
 		const char *partname;
 		/* ctdb only wants the file part of the name */
 		partname = strrchr(name, '/');
diff --git a/source3/lib/dbwrap_ctdb.c b/source3/lib/dbwrap_ctdb.c
index 90d0b260c5..f497f871d2 100644
--- a/source3/lib/dbwrap_ctdb.c
+++ b/source3/lib/dbwrap_ctdb.c
@@ -18,16 +18,14 @@
 */
 
 #include "includes.h"
-
 #ifdef CLUSTER_SUPPORT
-
 #include "ctdb.h"
 #include "ctdb_private.h"
+#include "ctdbd_conn.h"
 
 struct db_ctdb_ctx {
 	struct tdb_wrap *wtdb;
 	uint32 db_id;
-	struct ctdbd_connection *conn;
 };
 
 struct db_ctdb_rec {
@@ -35,8 +33,6 @@ struct db_ctdb_rec {
 	struct ctdb_ltdb_header header;
 };
 
-static struct ctdbd_connection *db_ctdbd_conn(struct db_ctdb_ctx *ctx);
-
 static NTSTATUS db_ctdb_store(struct db_record *rec, TDB_DATA data, int flag)
 {
 	struct db_ctdb_rec *crec = talloc_get_type_abort(
@@ -60,6 +56,42 @@ static NTSTATUS db_ctdb_store(struct db_record *rec, TDB_DATA data, int flag)
 	return (ret == 0) ? NT_STATUS_OK : NT_STATUS_INTERNAL_DB_CORRUPTION;
 }
 
+
+/* for persistent databases the store is a bit different. We have to
+   ask the ctdb daemon to push the record to all nodes after the
+   store */
+static NTSTATUS db_ctdb_store_persistent(struct db_record *rec, TDB_DATA data, int flag)
+{
+	struct db_ctdb_rec *crec = talloc_get_type_abort(
+		rec->private_data, struct db_ctdb_rec);
+	TDB_DATA cdata;
+	int ret;
+	NTSTATUS status;
+
+	cdata.dsize = sizeof(crec->header) + data.dsize;
+
+	if (!(cdata.dptr = SMB_MALLOC_ARRAY(uint8, cdata.dsize))) {
+		return NT_STATUS_NO_MEMORY;
+	}
+
+	crec->header.rsn++;
+
+	memcpy(cdata.dptr, &crec->header, sizeof(crec->header));
+	memcpy(cdata.dptr + sizeof(crec->header), data.dptr, data.dsize);
+
+	ret = tdb_store(crec->ctdb_ctx->wtdb->tdb, rec->key, cdata, TDB_REPLACE);
+	status = (ret == 0) ? NT_STATUS_OK : NT_STATUS_INTERNAL_DB_CORRUPTION;
+	
+	/* now tell ctdbd to update this record on all other nodes */
+	if (NT_STATUS_IS_OK(status)) {
+		status = ctdbd_persistent_store(messaging_ctdbd_connection(), crec->ctdb_ctx->db_id, rec->key, cdata);
+	}
+
+	SAFE_FREE(cdata.dptr);
+
+	return status;
+}
+
 static NTSTATUS db_ctdb_delete(struct db_record *rec)
 {
 	struct db_ctdb_rec *crec = talloc_get_type_abort(
@@ -110,6 +142,7 @@ static struct db_record *db_ctdb_fetch_locked(struct db_context *db,
 	struct db_ctdb_rec *crec;
 	NTSTATUS status;
 	TDB_DATA ctdb_data;
+	int migrate_attempts = 0;
 
 	if (!(result = talloc(mem_ctx, struct db_record))) {
 		DEBUG(0, ("talloc failed\n"));
@@ -153,7 +186,11 @@ again:
 		return NULL;
 	}
 
-	result->store = db_ctdb_store;
+	if (db->persistent) {
+		result->store = db_ctdb_store_persistent;
+	} else {
+		result->store = db_ctdb_store;
+	}
 	result->delete_rec = db_ctdb_delete;
 	talloc_set_destructor(result, db_ctdb_record_destr);
 
@@ -175,12 +212,14 @@ again:
 		tdb_chainunlock(ctx->wtdb->tdb, key);
 		talloc_set_destructor(result, NULL);
 
+		migrate_attempts += 1;
+
 		DEBUG(10, ("ctdb_data.dptr = %p, dmaster = %u (%u)\n",
 			   ctdb_data.dptr, ctdb_data.dptr ?
 			   ((struct ctdb_ltdb_header *)ctdb_data.dptr)->dmaster : -1,
 			   get_my_vnn()));
 
-		status = ctdbd_migrate(db_ctdbd_conn(ctx), ctx->db_id, key);
+		status = ctdbd_migrate(messaging_ctdbd_connection(),ctx->db_id, key);
 		if (!NT_STATUS_IS_OK(status)) {
 			DEBUG(5, ("ctdb_migrate failed: %s\n",
 				  nt_errstr(status)));
@@ -191,6 +230,11 @@ again:
 		goto again;
 	}
 
+	if (migrate_attempts > 10) {
+		DEBUG(0, ("db_ctdb_fetch_locked needed %d attempts\n",
+			  migrate_attempts));
+	}
+
 	memcpy(&crec->header, ctdb_data.dptr, sizeof(crec->header));
 
 	result->value.dsize = ctdb_data.dsize - sizeof(crec->header);
@@ -226,10 +270,12 @@ static int db_ctdb_fetch(struct db_context *db, TALLOC_CTX *mem_ctx,
 	/*
 	 * See if we have a valid record and we are the dmaster. If so, we can
 	 * take the shortcut and just return it.
+	 * we bypass the dmaster check for persistent databases
 	 */
 	if ((ctdb_data.dptr != NULL) &&
 	    (ctdb_data.dsize >= sizeof(struct ctdb_ltdb_header)) &&
-	    ((struct ctdb_ltdb_header *)ctdb_data.dptr)->dmaster == get_my_vnn()) {
+	    (db->persistent ||
+	     ((struct ctdb_ltdb_header *)ctdb_data.dptr)->dmaster == get_my_vnn())) {
 		/* we are the dmaster - avoid the ctdb protocol op */
 
 		data->dsize = ctdb_data.dsize - sizeof(struct ctdb_ltdb_header);
@@ -254,8 +300,7 @@ static int db_ctdb_fetch(struct db_context *db, TALLOC_CTX *mem_ctx,
 	SAFE_FREE(ctdb_data.dptr);
 
 	/* we weren't able to get it locally - ask ctdb to fetch it for us */
-	status = ctdbd_fetch(db_ctdbd_conn(ctx), ctx->db_id, key, mem_ctx,
-			     data);
+	status = ctdbd_fetch(messaging_ctdbd_connection(),ctx->db_id, key, mem_ctx, data);
 	if (!NT_STATUS_IS_OK(status)) {
 		DEBUG(5, ("ctdbd_fetch failed: %s\n", nt_errstr(status)));
 		return -1;
@@ -283,6 +328,22 @@ static void traverse_callback(TDB_DATA key, TDB_DATA data, void *private_data)
 	talloc_free(tmp_ctx);
 }
 
+static int traverse_persistent_callback(TDB_CONTEXT *tdb, TDB_DATA kbuf, TDB_DATA dbuf,
+					void *private_data)
+{
+	struct traverse_state *state = (struct traverse_state *)private_data;
+	struct db_record *rec;
+	TALLOC_CTX *tmp_ctx = talloc_new(state->db);
+	int ret = 0;
+	/* we have to give them a locked record to prevent races */
+	rec = db_ctdb_fetch_locked(state->db, tmp_ctx, kbuf);
+	if (rec && rec->value.dsize > 0) {
+		ret = state->fn(rec, state->private_data);
+	}
+	talloc_free(tmp_ctx);
+	return ret;
+}
+
 static int db_ctdb_traverse(struct db_context *db,
 			    int (*fn)(struct db_record *rec,
 				      void *private_data),
@@ -296,6 +357,13 @@ static int db_ctdb_traverse(struct db_context *db,
 	state.fn = fn;
 	state.private_data = private_data;
 
+	if (db->persistent) {
+		/* for persistent databases we don't need to do a ctdb traverse,
+		   we can do a faster local traverse */
+		return tdb_traverse(ctx->wtdb->tdb, traverse_persistent_callback, &state);
+	}
+
+
 	ctdbd_traverse(ctx->db_id, traverse_callback, &state);
 	return 0;
 }
@@ -322,6 +390,27 @@ static void traverse_read_callback(TDB_DATA key, TDB_DATA data, void *private_da
 	state->fn(&rec, state->private_data);
 }
 
+static int traverse_persistent_callback_read(TDB_CONTEXT *tdb, TDB_DATA kbuf, TDB_DATA dbuf,
+					void *private_data)
+{
+	struct traverse_state *state = (struct traverse_state *)private_data;
+	struct db_record rec;
+	rec.key = kbuf;
+	rec.value = dbuf;
+	rec.store = db_ctdb_store_deny;
+	rec.delete_rec = db_ctdb_delete_deny;
+	rec.private_data = state->db;
+
+	if (rec.value.dsize <= sizeof(struct ctdb_ltdb_header)) {
+		/* a deleted record */
+		return 0;
+	}
+	rec.value.dsize -= sizeof(struct ctdb_ltdb_header);
+	rec.value.dptr += sizeof(struct ctdb_ltdb_header);
+
+	return state->fn(&rec, state->private_data);
+}
+
 static int db_ctdb_traverse_read(struct db_context *db,
 				 int (*fn)(struct db_record *rec,
 					   void *private_data),
@@ -335,6 +424,12 @@ static int db_ctdb_traverse_read(struct db_context *db,
 	state.fn = fn;
 	state.private_data = private_data;
 
+	if (db->persistent) {
+		/* for persistent databases we don't need to do a ctdb traverse,
+		   we can do a faster local traverse */
+		return tdb_traverse_read(ctx->wtdb->tdb, traverse_persistent_callback_read, &state);
+	}
+
 	ctdbd_traverse(ctx->db_id, traverse_read_callback, &state);
 	return 0;
 }
@@ -346,41 +441,6 @@ static int db_ctdb_get_seqnum(struct db_context *db)
 	return tdb_get_seqnum(ctx->wtdb->tdb);
 }
 
-/*
- * Get the ctdbd connection for a database. If possible, re-use the messaging
- * ctdbd connection
- */
-static struct ctdbd_connection *db_ctdbd_conn(struct db_ctdb_ctx *ctx)
-{
-	struct ctdbd_connection *result;
-
-	result = messaging_ctdbd_connection();
-
-	if (result != NULL) {
-
-		if (ctx->conn == NULL) {
-			/*
-			 * Someone has initialized messaging since we
-			 * initialized our own connection, we don't need it
-			 * anymore.
-			 */
-			TALLOC_FREE(ctx->conn);
-		}
-
-		return result;
-	}
-
-	if (ctx->conn == NULL) {
-		NTSTATUS status;
-		status = ctdbd_init_connection(ctx, &ctx->conn);
-		if (!NT_STATUS_IS_OK(status)) {
-			return NULL;
-		}
-		set_my_vnn(ctdbd_vnn(ctx->conn));
-	}
-
-	return ctx->conn;
-}
 
 struct db_context *db_open_ctdb(TALLOC_CTX *mem_ctx,
 				const char *name,
@@ -390,7 +450,6 @@ struct db_context *db_open_ctdb(TALLOC_CTX *mem_ctx,
 	struct db_context *result;
 	struct db_ctdb_ctx *db_ctdb;
 	char *db_path;
-	NTSTATUS status;
 
 	if (!lp_clustering()) {
 		DEBUG(10, ("Clustering disabled -- no ctdb\n"));
@@ -409,20 +468,15 @@ struct db_context *db_open_ctdb(TALLOC_CTX *mem_ctx,
 		return NULL;
 	}
 
-	db_ctdb->conn = NULL;
-
-	status = ctdbd_db_attach(db_ctdbd_conn(db_ctdb), name,
-				 &db_ctdb->db_id, tdb_flags);
-
-	if (!NT_STATUS_IS_OK(status)) {
-		DEBUG(0, ("ctdbd_db_attach failed for %s: %s\n", name,
-			  nt_errstr(status)));
+	if (!NT_STATUS_IS_OK(ctdbd_db_attach(messaging_ctdbd_connection(),name, &db_ctdb->db_id, tdb_flags))) {
+		DEBUG(0, ("ctdbd_db_attach failed for %s\n", name));
 		TALLOC_FREE(result);
 		return NULL;
 	}
 
-	db_path = ctdbd_dbpath(db_ctdbd_conn(db_ctdb), db_ctdb,
-			       db_ctdb->db_id);
+	db_path = ctdbd_dbpath(messaging_ctdbd_connection(), db_ctdb, db_ctdb->db_id);
+
+	result->persistent = ((tdb_flags & TDB_CLEAR_IF_FIRST) == 0);
 
 	/* only pass through specific flags */
 	tdb_flags &= TDB_SEQNUM;
@@ -447,16 +501,4 @@ struct db_context *db_open_ctdb(TALLOC_CTX *mem_ctx,
 
 	return result;
 }
-
-#else
-
-struct db_context *db_open_ctdb(TALLOC_CTX *mem_ctx,
-				const char *name,
-				int hash_size, int tdb_flags,
-				int open_flags, mode_t mode)
-{
-	DEBUG(0, ("no clustering compiled in\n"));
-	return NULL;
-}
-
 #endif
diff --git a/source3/lib/dbwrap_file.c b/source3/lib/dbwrap_file.c
index 5b41f5941b..e3779de1e4 100644
--- a/source3/lib/dbwrap_file.c
+++ b/source3/lib/dbwrap_file.c
@@ -17,10 +17,6 @@
    along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */
 
-/*
- * Be aware that this is just sample code that has not seen too much testing
- */
-
 #include "includes.h"
 
 struct db_file_ctx {
@@ -367,6 +363,7 @@ struct db_context *db_open_file(TALLOC_CTX *mem_ctx,
 	result->fetch_locked = db_file_fetch_locked;
 	result->traverse = db_file_traverse;
 	result->traverse_read = db_file_traverse;
+	result->persistent = ((tdb_flags & TDB_CLEAR_IF_FIRST) == 0);
 
 	ctx->locked_record = NULL;
 	if (!(ctx->dirname = talloc_strdup(ctx, name))) {
diff --git a/source3/lib/dbwrap_tdb.c b/source3/lib/dbwrap_tdb.c
index 710e45de6b..e87ceb428f 100644
--- a/source3/lib/dbwrap_tdb.c
+++ b/source3/lib/dbwrap_tdb.c
@@ -31,6 +31,11 @@ static int db_tdb_record_destr(struct db_record* data)
 	struct db_tdb_ctx *ctx =
 		talloc_get_type_abort(data->private_data, struct db_tdb_ctx);
 
+	/* This hex_encode() call allocates memory on data context. By way how current 
+	   __talloc_free() code works, it is OK to allocate in the destructor as 
+	   the children of data will be freed after call to the destructor and this 
+	   new 'child' will be caught and freed correctly.
+	 */
 	DEBUG(10, (DEBUGLEVEL > 10
 		   ? "Unlocking key %s\n" : "Unlocking key %.20s\n",
 		   hex_encode(data, (unsigned char *)data->key.dptr,
@@ -88,8 +93,9 @@ static struct db_record *db_tdb_fetch_locked(struct db_context *db,
 	struct tdb_fetch_locked_state state;
 	int res;
 
-	if (DEBUGLEVEL >= 10) {
-		char *keystr = hex_encode(NULL, key.dptr, key.dsize);
+	/* Do not accidently allocate/deallocate w/o need when debug level is lower than needed */
+	if(DEBUGLEVEL >= 10) {
+		char *keystr = hex_encode(NULL, (unsigned char*)key.dptr, key.dsize);
 		DEBUG(10, (DEBUGLEVEL > 10
 			   ? "Locking key %s\n" : "Locking key %.20s\n",
 			   keystr));
@@ -191,15 +197,9 @@ static NTSTATUS db_tdb_delete(struct db_record *rec)
 {
 	struct db_tdb_ctx *ctx = talloc_get_type_abort(rec->private_data,
 						       struct db_tdb_ctx);
-	int res;
-	
-	res = tdb_delete(ctx->wtdb->tdb, rec->key);
 
-	if (res == 0) {
-		return NT_STATUS_OK;
-	}
-
-	return map_nt_error_from_tdb(tdb_error(ctx->wtdb->tdb));
+	return (tdb_delete(ctx->wtdb->tdb, rec->key) == 0) ?
+		NT_STATUS_OK : NT_STATUS_UNSUCCESSFUL;
 }
 
 struct db_tdb_traverse_ctx {
@@ -318,6 +318,7 @@ struct db_context *db_open_tdb(TALLOC_CTX *mem_ctx,
 	result->traverse = db_tdb_traverse;
 	result->traverse_read = db_tdb_traverse_read;
 	result->get_seqnum = db_tdb_get_seqnum;
+	result->persistent = ((tdb_flags & TDB_CLEAR_IF_FIRST) == 0);
 	return result;
 
  fail:
diff --git a/source3/lib/dbwrap_util.c b/source3/lib/dbwrap_util.c
new file mode 100644
index 0000000000..002d572019
--- /dev/null
+++ b/source3/lib/dbwrap_util.c
@@ -0,0 +1,90 @@
+/* 
+   Unix SMB/CIFS implementation.
+   Utility functions for the dbwrap API
+   Copyright (C) Volker Lendecke 2007
+   
+   This program is free software; you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation; either version 2 of the License, or
+   (at your option) any later version.
+   
+   This program 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 General Public License for more details.
+   
+   You should have received a copy of the GNU General Public License
+   along with this program; if not, write to the Free Software
+   Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+*/
+
+#include "includes.h"
+
+int32_t dbwrap_fetch_int32(struct db_context *db, const char *keystr)
+{
+	TDB_DATA dbuf;
+	int32 ret;
+
+	if (db->fetch(db, NULL, string_term_tdb_data(keystr), &dbuf) != 0) {
+		return -1;
+	}
+
+	if ((dbuf.dptr == NULL) || (dbuf.dsize != sizeof(int32_t))) {
+		TALLOC_FREE(dbuf.dptr);
+		return -1;
+	}
+
+	ret = IVAL(dbuf.dptr, 0);
+	TALLOC_FREE(dbuf.dptr);
+	return ret;
+}
+
+int dbwrap_store_int32(struct db_context *db, const char *keystr, int32_t v)
+{
+	struct db_record *rec;
+	int32 v_store;
+	NTSTATUS status;
+
+	rec = db->fetch_locked(db, NULL, string_term_tdb_data(keystr));
+	if (rec == NULL) {
+		return -1;
+	}
+
+	SIVAL(&v_store, 0, v);
+
+	status = rec->store(rec, make_tdb_data((const uint8 *)&v_store,
+					       sizeof(v_store)),
+			    TDB_REPLACE);
+	TALLOC_FREE(rec);
+	return NT_STATUS_IS_OK(status) ? 0 : -1;
+}
+
+uint32_t dbwrap_change_uint32_atomic(struct db_context *db, const char *keystr,
+				     uint32_t *oldval, uint32_t change_val)
+{
+	struct db_record *rec;
+	uint32 val = -1;
+	TDB_DATA data;
+
+	if (!(rec = db->fetch_locked(db, NULL,
+				     string_term_tdb_data(keystr)))) {
+		return -1;
+	}
+
+	if ((rec->value.dptr != NULL)
+	    && (rec->value.dsize == sizeof(val))) {
+		val = IVAL(rec->value.dptr, 0);
+	}
+
+	val += change_val;
+
+	data.dsize = sizeof(val);
+	data.dptr = (uint8 *)&val;
+
+	rec->store(rec, data, TDB_REPLACE);
+
+	TALLOC_FREE(rec);
+
+	return 0;
+}
+
diff --git a/source3/lib/messages_ctdbd.c b/source3/lib/messages_ctdbd.c
index 6e9b934a75..f1a02e6af9 100644
--- a/source3/lib/messages_ctdbd.c
+++ b/source3/lib/messages_ctdbd.c
@@ -22,6 +22,10 @@
 #ifdef CLUSTER_SUPPORT
 
 #include "librpc/gen_ndr/messaging.h"
+#include "ctdb.h"
+#include "ctdb_private.h"
+#include "ctdbd_conn.h"
+
 
 struct messaging_ctdbd_context {
 	struct ctdbd_connection *conn;
diff --git a/source3/lib/util.c b/source3/lib/util.c
index 0653fc9d3f..bc3eaa8d5e 100644
--- a/source3/lib/util.c
+++ b/source3/lib/util.c
@@ -506,6 +506,19 @@ bool file_exist(const char *fname,SMB_STRUCT_STAT *sbuf)
 }
 
 /*******************************************************************
+ Check if a unix domain socket exists - call vfs_file_exist for samba files.
+********************************************************************/
+
+bool socket_exist(const char *fname)
+{
+	SMB_STRUCT_STAT st;
+	if (sys_stat(fname,&st) != 0) 
+		return(False);
+
+	return S_ISSOCK(st.st_mode);
+}
+
+/*******************************************************************
  Check a files mod time.
 ********************************************************************/