treewide: init assignment lists head

When allocating an assignment in alloc_assignment; init the circular head
and lease_list circular lists. Avoids checking NULL pointer when freeing
the assignment in free_assignment.

Signed-off-by: Hans Dedecker <dedeckeh@gmail.com>

3 files changed, 22 insertions, 12 deletions

diff --git a/src/dhcpv4.c b/src/dhcpv4.c
index 9d21423..2634f65 100644
--- a/src/dhcpv4.c
+++ b/src/dhcpv4.c
@@ -1024,9 +1024,9 @@ dhcpv4_lease(struct interface *iface, enum dhcpv4_msg msg, const uint8_t *mac,
 		if (!a) {
 			if (!iface->no_dynamic_dhcp || l) {
 				/* Create new binding */
-				a = calloc(1, sizeof(*a));
+				a = alloc_assignment(0);
 				if (!a) {
-					syslog(LOG_ERR, "Failed to calloc binding on interface %s",
+					syslog(LOG_ERR, "Failed to alloc assignment on interface %s",
 							iface->ifname);
 					return NULL;
 				}
@@ -1057,7 +1057,7 @@ dhcpv4_lease(struct interface *iface, enum dhcpv4_msg msg, const uint8_t *mac,
 		} else if (((a->addr & iface->dhcpv4_mask.s_addr) !=
 			    (iface->dhcpv4_start_ip.s_addr & iface->dhcpv4_mask.s_addr)) &&
 			    !(a->flags & OAF_STATIC)) {
-			list_del(&a->head);
+			list_del_init(&a->head);
 			a->addr = INADDR_ANY;
 
 			assigned = dhcpv4_assign(iface, a, reqaddr);
diff --git a/src/dhcpv6-ia.c b/src/dhcpv6-ia.c
index 81c2481..9559b96 100644
--- a/src/dhcpv6-ia.c
+++ b/src/dhcpv6-ia.c
@@ -75,10 +75,10 @@ int dhcpv6_ia_setup_interface(struct interface *iface, bool enable)
 		struct dhcp_assignment *border;
 
 		if (list_empty(&iface->ia_assignments)) {
-			border = calloc(1, sizeof(*border));
+			border = alloc_assignment(0);
 
 			if (!border) {
-				syslog(LOG_ERR, "Calloc failed for border on %s", iface->name);
+				syslog(LOG_ERR, "Failed to alloc border on %s", iface->name);
 				return -1;
 			}
 
@@ -719,7 +719,7 @@ static void handle_addrlist_change(struct netevent_handler_info *info)
 
 	while (!list_empty(&reassign)) {
 		c = list_first_entry(&reassign, struct dhcp_assignment, head);
-		list_del(&c->head);
+		list_del_init(&c->head);
 		if (!assign_pd(iface, c)) {
 			c->assigned = 0;
 			list_add(&c->head, &iface->ia_assignments);
@@ -1237,7 +1237,7 @@ ssize_t dhcpv6_ia_handle_IAs(uint8_t *buf, size_t buflen, struct interface *ifac
 				if ((!iface->no_dynamic_dhcp || (l && is_na)) &&
 				    (iface->dhcpv6_pd || iface->dhcpv6_na)) {
 					/* Create new binding */
-					a = calloc(1, sizeof(*a) + clid_len);
+					a = alloc_assignment(clid_len);
 
 					if (a) {
 						a->clid_len = clid_len;
diff --git a/src/odhcpd.h b/src/odhcpd.h
index 9535e75..37a5a4a 100644
--- a/src/odhcpd.h
+++ b/src/odhcpd.h
@@ -309,11 +309,8 @@ extern struct avl_tree interfaces;
 
 inline static void free_assignment(struct dhcp_assignment *a)
 {
-	if (a->head.next)
-		list_del(&a->head);
-
-	if (a->lease_list.next)
-		list_del(&a->lease_list);
+	list_del(&a->head);
+	list_del(&a->lease_list);
 
 	if (a->dhcp_free_cb)
 		a->dhcp_free_cb(a);
@@ -323,6 +320,19 @@ inline static void free_assignment(struct dhcp_assignment *a)
 	free(a);
 }
 
+inline static struct dhcp_assignment *alloc_assignment(size_t extra_len)
+{
+	struct dhcp_assignment *a = calloc(1, sizeof(*a) + extra_len);
+
+	if (!a)
+		return NULL;
+
+	INIT_LIST_HEAD(&a->head);
+	INIT_LIST_HEAD(&a->lease_list);
+
+	return a;
+}
+
 // Exported main functions
 int odhcpd_register(struct odhcpd_event *event);
 int odhcpd_deregister(struct odhcpd_event *event);