Real memeory leak(buildup) issue in loadparm.

BUG: https://bugzilla.samba.org/show_bug.cgi?id=11740

As part of reload services, unused service ptr structures are getting
unloaded without actually freeingup the memory associated to them.

Made changes to freeup those allocations on unload. On reload, reuse the
slots in ServicePtr global array instead of extending the array with
holes.

Also we should mark shares like IPC$ as auto loaded as they never be
exposed to users.

Signed-off-by: Hemanth Thummala <hemanth.thummala@nutanix.com>
Reviewed-by: Volker Lendecke <Volker.Lendecke@SerNet.DE>
Reviewed-by: Jeremy Allison <jra@samba.org>

Autobuild-User(master): Jeremy Allison <jra@samba.org>
Autobuild-Date(master): Wed Feb 17 22:30:25 CET 2016 on sn-devel-144

(cherry picked from commit 03081c2c1484504bdcc0e111b2df95e073c1c166)

Autobuild-User(v4-4-test): Karolin Seeger <kseeger@samba.org>
Autobuild-Date(v4-4-test): Mon Feb 22 19:33:58 CET 2016 on sn-devel-144

1 files changed, 27 insertions, 13 deletions

diff --git a/source3/param/loadparm.c b/source3/param/loadparm.c
index fb92230ffba..605555e4c87 100644
--- a/source3/param/loadparm.c
+++ b/source3/param/loadparm.c
@@ -93,8 +93,11 @@ static struct smbconf_csn conf_last_csn;
 static int config_backend = CONFIG_BACKEND_FILE;
 
 /* some helpful bits */
-#define LP_SNUM_OK(i) (((i) >= 0) && ((i) < iNumServices) && (ServicePtrs != NULL) && ServicePtrs[(i)]->valid)
-#define VALID(i) (ServicePtrs != NULL && ServicePtrs[i]->valid)
+#define LP_SNUM_OK(i) (((i) >= 0) && ((i) < iNumServices) && \
+                       (ServicePtrs != NULL) && \
+		       (ServicePtrs[(i)] != NULL) && ServicePtrs[(i)]->valid)
+#define VALID(i) ((ServicePtrs != NULL) && (ServicePtrs[i]!= NULL) && \
+                  ServicePtrs[i]->valid)
 
 #define USERSHARE_VALID 1
 #define USERSHARE_PENDING_DELETE 2
@@ -1358,7 +1361,7 @@ static void free_service_byindex(int idx)
 	}
 
 	free_service(ServicePtrs[idx]);
-	talloc_free_children(ServicePtrs[idx]);
+	TALLOC_FREE(ServicePtrs[idx]);
 }
 
 /***************************************************************************
@@ -1380,20 +1383,30 @@ static int add_a_service(const struct loadparm_service *pservice, const char *na
 		}
 	}
 
-	/* if not, then create one */
-	i = iNumServices;
-	tsp = talloc_realloc(NULL, ServicePtrs, struct loadparm_service *, num_to_alloc);
-	if (tsp == NULL) {
-		DEBUG(0,("add_a_service: failed to enlarge ServicePtrs!\n"));
-		return (-1);
+	/* Re use empty slots if any before allocating new one.*/
+	for (i=0; i < iNumServices; i++) {
+		if (ServicePtrs[i] == NULL) {
+			break;
+		}
 	}
-	ServicePtrs = tsp;
-	ServicePtrs[iNumServices] = talloc_zero(ServicePtrs, struct loadparm_service);
-	if (!ServicePtrs[iNumServices]) {
+	if (i == iNumServices) {
+		/* if not, then create one */
+		tsp = talloc_realloc(NULL, ServicePtrs,
+				     struct loadparm_service *,
+				     num_to_alloc);
+		if (tsp == NULL) {
+			DEBUG(0, ("add_a_service: failed to enlarge "
+				  "ServicePtrs!\n"));
+			return (-1);
+		}
+		ServicePtrs = tsp;
+		iNumServices++;
+	}
+	ServicePtrs[i] = talloc_zero(ServicePtrs, struct loadparm_service);
+	if (!ServicePtrs[i]) {
 		DEBUG(0,("add_a_service: out of memory!\n"));
 		return (-1);
 	}
-	iNumServices++;
 
 	ServicePtrs[i]->valid = true;
 
@@ -1559,6 +1572,7 @@ static bool lp_add_ipc(const char *ipc_name, bool guest_ok)
 	ServicePtrs[i]->guest_ok = guest_ok;
 	ServicePtrs[i]->printable = false;
 	ServicePtrs[i]->browseable = sDefault.browseable;
+	ServicePtrs[i]->autoloaded = true;
 
 	DEBUG(3, ("adding IPC service\n"));