*: Convert list_delete(struct list *) to ** to allow nulling

Convert the list_delete(struct list *) function to use
struct list **.  This is to allow the list pointer to be nulled.

I keep running into uses of this list_delete function where we
forget to set the returned pointer to NULL and attempt to use
it and then experience a crash, usually after the developer
has long since left the building.

Let's make the api explicit in it setting the list pointer
to null.

Cynical Prediction:  This code will expose a attempt
to use the NULL'ed list pointer in some obscure bit
of code.

Signed-off-by: Donald Sharp <sharpd@cumulusnetworks.com>

7 files changed, 9 insertions, 10 deletions

diff --git a/zebra/interface.c b/zebra/interface.c
index 664e493d8..9a9f76eab 100644
--- a/zebra/interface.c
+++ b/zebra/interface.c
@@ -64,7 +64,7 @@ static void zebra_if_node_destroy(route_table_delegate_t *delegate,
 				  struct route_node *node)
 {
 	if (node->info)
-		list_delete(node->info);
+		list_delete_and_null((struct list **)&node->info);
 	route_node_destroy(delegate, table, node);
 }
 
@@ -627,7 +627,7 @@ static void if_delete_connected(struct interface *ifp)
 				}
 
 				/* Free chain list and respective route node. */
-				list_delete(addr_list);
+				list_delete_and_null(&addr_list);
 				rn->info = NULL;
 				route_unlock_node(rn);
 			} else if (cp.family == AF_INET6) {
diff --git a/zebra/irdp_interface.c b/zebra/irdp_interface.c
index 0df03860d..8234ed6bd 100644
--- a/zebra/irdp_interface.c
+++ b/zebra/irdp_interface.c
@@ -311,8 +311,7 @@ static void irdp_if_stop(struct interface *ifp)
 
 	irdp_advert_off(ifp);
 
-	list_delete(irdp->AdvPrefList);
-	irdp->AdvPrefList = NULL;
+	list_delete_and_null(&irdp->AdvPrefList);
 
 	irdp->flags = 0;
 }
diff --git a/zebra/label_manager.c b/zebra/label_manager.c
index 1ed5eacd8..6fbb75178 100644
--- a/zebra/label_manager.c
+++ b/zebra/label_manager.c
@@ -375,5 +375,5 @@ int release_daemon_chunks(u_char proto, u_short instance)
 
 void label_manager_close()
 {
-	list_delete(lbl_mgr.lc_list);
+	list_delete_and_null(&lbl_mgr.lc_list);
 }
diff --git a/zebra/main.c b/zebra/main.c
index bf1971c47..5a2979c86 100644
--- a/zebra/main.c
+++ b/zebra/main.c
@@ -145,7 +145,7 @@ static void sigint(void)
 	prefix_list_reset();
 	route_map_finish();
 
-	list_delete(zebrad.client_list);
+	list_delete_and_null(&zebrad.client_list);
 	work_queue_free(zebrad.ribq);
 	if (zebrad.lsp_process_q)
 		work_queue_free(zebrad.lsp_process_q);
diff --git a/zebra/zebra_mpls.c b/zebra/zebra_mpls.c
index 3c7319f35..9fd07d22d 100644
--- a/zebra/zebra_mpls.c
+++ b/zebra/zebra_mpls.c
@@ -2701,7 +2701,7 @@ void zebra_mpls_print_lsp_table(struct vty *vty, struct zebra_vrf *zvrf,
 		vty_out(vty, "\n");
 	}
 
-	list_delete(lsp_list);
+	list_delete_and_null(&lsp_list);
 }
 
 /*
@@ -2740,7 +2740,7 @@ int zebra_mpls_write_lsp_config(struct vty *vty, struct zebra_vrf *zvrf)
 		}
 	}
 
-	list_delete(slsp_list);
+	list_delete_and_null(&slsp_list);
 	return (zvrf->slsp_table->count ? 1 : 0);
 }
 
diff --git a/zebra/zebra_rib.c b/zebra/zebra_rib.c
index fab8c3c93..5c3ec10a7 100644
--- a/zebra/zebra_rib.c
+++ b/zebra/zebra_rib.c
@@ -1875,7 +1875,7 @@ void meta_queue_free(struct meta_queue *mq)
 	unsigned i;
 
 	for (i = 0; i < MQ_SIZE; i++)
-		list_delete(mq->subq[i]);
+		list_delete_and_null(&mq->subq[i]);
 
 	XFREE(MTYPE_WORK_QUEUE, mq);
 }
diff --git a/zebra/zebra_vxlan.c b/zebra/zebra_vxlan.c
index a3f43f947..b704b97c5 100644
--- a/zebra/zebra_vxlan.c
+++ b/zebra/zebra_vxlan.c
@@ -1587,7 +1587,7 @@ static int zvni_mac_del(zebra_vni_t *zvni, zebra_mac_t *mac)
 {
 	zebra_mac_t *tmp_mac;
 
-	list_delete(mac->neigh_list);
+	list_delete_and_null(&mac->neigh_list);
 
 	/* Free the VNI hash entry and allocated memory. */
 	tmp_mac = hash_release(zvni->mac_table, mac);