treewide: always init interface list heads during initialization

When allocating interface, init dhcpv4_assignments, dhcpv4_fr_ips
and ia_assignments circular list heads to point to self. Avoids
checking whether next pointer is not null all over the place.

Signed-off-by: Dainis Jonitis <dainis.jonitis@ubnt.com>

4 files changed, 15 insertions, 20 deletions

diff --git a/src/config.c b/src/config.c
index 399922b..dfeadac 100644
--- a/src/config.c
+++ b/src/config.c
@@ -440,6 +440,10 @@ int config_parse_interface(void *data, size_t len, const char *name, bool overwr
 		iface->ndp_event.uloop.fd = -1;
 		iface->ndp_ping_fd = -1;
 		iface->dhcpv4_event.uloop.fd = -1;
+		INIT_LIST_HEAD(&iface->ia_assignments);
+		INIT_LIST_HEAD(&iface->dhcpv4_assignments);
+		INIT_LIST_HEAD(&iface->dhcpv4_fr_ips);
+
 		set_interface_defaults(iface);
 
 		avl_insert(&interfaces, &iface->avl);
diff --git a/src/dhcpv4.c b/src/dhcpv4.c
index b25046d..905f66f 100644
--- a/src/dhcpv4.c
+++ b/src/dhcpv4.c
@@ -88,12 +88,6 @@ int dhcpv4_setup_interface(struct interface *iface, bool enable)
 					{INADDR_ANY}, {0}};
 		int val = 1;
 
-		if (!iface->dhcpv4_assignments.next)
-			INIT_LIST_HEAD(&iface->dhcpv4_assignments);
-
-		if (!iface->dhcpv4_fr_ips.next)
-			INIT_LIST_HEAD(&iface->dhcpv4_fr_ips);
-
 		iface->dhcpv4_event.uloop.fd = socket(AF_INET, SOCK_DGRAM | SOCK_CLOEXEC, IPPROTO_UDP);
 		if (iface->dhcpv4_event.uloop.fd < 0) {
 			syslog(LOG_ERR, "socket(AF_INET): %m");
@@ -160,7 +154,7 @@ int dhcpv4_setup_interface(struct interface *iface, bool enable)
 
 		iface->dhcpv4_event.handle_dgram = handle_dhcpv4;
 		odhcpd_register(&iface->dhcpv4_event);
-	} else if (iface->dhcpv4_assignments.next) {
+	} else {
 		while (!list_empty(&iface->dhcpv4_assignments))
 			free_assignment(list_first_entry(&iface->dhcpv4_assignments,
 							struct dhcp_assignment, head));
@@ -347,10 +341,11 @@ static void valid_until_cb(struct uloop_timeout *event)
 	time_t now = odhcpd_time();
 
 	avl_for_each_element(&interfaces, iface, avl) {
-		if (iface->dhcpv4 != MODE_SERVER || iface->dhcpv4_assignments.next == NULL)
+		struct dhcp_assignment *a, *n;
+
+		if (iface->dhcpv4 != MODE_SERVER)
 			continue;
 
-		struct dhcp_assignment *a, *n;
 		list_for_each_entry_safe(a, n, &iface->dhcpv4_assignments, head) {
 			if (!INFINITE_VALID(a->valid_until) && a->valid_until < now)
 				free_assignment(a);
diff --git a/src/dhcpv6-ia.c b/src/dhcpv6-ia.c
index 6426a74..81c2481 100644
--- a/src/dhcpv6-ia.c
+++ b/src/dhcpv6-ia.c
@@ -62,7 +62,7 @@ int dhcpv6_ia_init(void)
 
 int dhcpv6_ia_setup_interface(struct interface *iface, bool enable)
 {
-	if (!enable && iface->ia_assignments.next) {
+	if (!enable) {
 		struct dhcp_assignment *c;
 
 		while (!list_empty(&iface->ia_assignments)) {
@@ -74,9 +74,6 @@ int dhcpv6_ia_setup_interface(struct interface *iface, bool enable)
 	if (enable && iface->dhcpv6 == MODE_SERVER) {
 		struct dhcp_assignment *border;
 
-		if (!iface->ia_assignments.next)
-			INIT_LIST_HEAD(&iface->ia_assignments);
-
 		if (list_empty(&iface->ia_assignments)) {
 			border = calloc(1, sizeof(*border));
 
@@ -326,8 +323,7 @@ void dhcpv6_ia_write_statefile(void)
 					ctxt.iface->dhcpv4 != MODE_SERVER)
 				continue;
 
-			if (ctxt.iface->dhcpv6 == MODE_SERVER &&
-					ctxt.iface->ia_assignments.next) {
+			if (ctxt.iface->dhcpv6 == MODE_SERVER) {
 				list_for_each_entry(ctxt.c, &ctxt.iface->ia_assignments, head) {
 					if (!(ctxt.c->flags & OAF_BOUND) || ctxt.c->managed_size < 0)
 						continue;
@@ -355,9 +351,9 @@ void dhcpv6_ia_write_statefile(void)
 				}
 			}
 
-			if (ctxt.iface->dhcpv4 == MODE_SERVER &&
-					ctxt.iface->dhcpv4_assignments.next) {
+			if (ctxt.iface->dhcpv4 == MODE_SERVER) {
 				struct dhcp_assignment *c;
+
 				list_for_each_entry(c, &ctxt.iface->dhcpv4_assignments, head) {
 					if (!(c->flags & OAF_BOUND))
 						continue;
@@ -771,7 +767,7 @@ static void valid_until_cb(struct uloop_timeout *event)
 	avl_for_each_element(&interfaces, iface, avl) {
 		struct dhcp_assignment *a, *n;
 
-		if (iface->dhcpv6 != MODE_SERVER || iface->ia_assignments.next == NULL)
+		if (iface->dhcpv6 != MODE_SERVER)
 			continue;
 
 		list_for_each_entry_safe(a, n, &iface->ia_assignments, head) {
diff --git a/src/ubus.c b/src/ubus.c
index 1bb8237..e9c5b6f 100644
--- a/src/ubus.c
+++ b/src/ubus.c
@@ -29,7 +29,7 @@ static int handle_dhcpv4_leases(struct ubus_context *ctx, _unused struct ubus_ob
 	a = blobmsg_open_table(&b, "device");
 
 	avl_for_each_element(&interfaces, iface, avl) {
-		if (iface->dhcpv4 != MODE_SERVER || iface->dhcpv4_assignments.next == NULL)
+		if (iface->dhcpv4 != MODE_SERVER)
 			continue;
 
 		void *i = blobmsg_open_table(&b, iface->ifname);
@@ -122,7 +122,7 @@ static int handle_dhcpv6_leases(_unused struct ubus_context *ctx, _unused struct
 	a = blobmsg_open_table(&b, "device");
 
 	avl_for_each_element(&interfaces, iface, avl) {
-		if (iface->dhcpv6 != MODE_SERVER || iface->ia_assignments.next == NULL)
+		if (iface->dhcpv6 != MODE_SERVER)
 			continue;
 
 		void *i = blobmsg_open_table(&b, iface->ifname);