*: convert `struct interface->connected` to DLIST

Replace `struct list *` with `DLIST(if_connected, ...)`.

NB: while converting this, I found multiple places using connected
prefixes assuming they were IPv4 without checking:

- vrrpd/vrrp.c: vrrp_socket()
- zebra/irdp_interface.c: irdp_get_prefix(), irdp_if_start(),
  irdp_advert_off()

(these fixes are really hard to split off into separate commits as that
would require going back and reapplying the change but with the old list
handling)

Signed-off-by: David Lamparter <equinox@opensourcerouting.org>

3 files changed, 26 insertions, 40 deletions

diff --git a/lib/bfd.c b/lib/bfd.c
index 8c3246ff9..2222bb954 100644
--- a/lib/bfd.c
+++ b/lib/bfd.c
@@ -1282,7 +1282,6 @@ static bool bfd_source_cache_update(struct bfd_source_cache *source,
 		const struct zapi_nexthop *nh = &route->nexthops[nh_index];
 		const struct interface *interface;
 		const struct connected *connected;
-		const struct listnode *node;
 
 		interface = if_lookup_by_index(nh->ifindex, nh->vrf_id);
 		if (interface == NULL) {
@@ -1291,8 +1290,7 @@ static bool bfd_source_cache_update(struct bfd_source_cache *source,
 			continue;
 		}
 
-		for (ALL_LIST_ELEMENTS_RO(interface->connected, node,
-					  connected)) {
+		frr_each (if_connected_const, interface->connected, connected) {
 			if (source->address.family !=
 			    connected->address->family)
 				continue;
diff --git a/lib/if.c b/lib/if.c
index f583638d7..a42064005 100644
--- a/lib/if.c
+++ b/lib/if.c
@@ -164,8 +164,7 @@ static struct interface *if_new(struct vrf *vrf)
 
 	ifp->vrf = vrf;
 
-	ifp->connected = list_new();
-	ifp->connected->del = ifp_connected_free;
+	if_connected_init(ifp->connected);
 
 	ifp->nbr_connected = list_new();
 	ifp->nbr_connected->del = (void (*)(void *))nbr_connected_free;
@@ -243,11 +242,14 @@ void if_update_to_new_vrf(struct interface *ifp, vrf_id_t vrf_id)
 /* Delete interface structure. */
 void if_delete_retain(struct interface *ifp)
 {
+	struct connected *ifc;
+
 	hook_call(if_del, ifp);
 	QOBJ_UNREG(ifp);
 
 	/* Free connected address list */
-	list_delete_all_node(ifp->connected);
+	while ((ifc = if_connected_pop(ifp->connected)))
+		ifp_connected_free(ifc);
 
 	/* Free connected nbr address list */
 	list_delete_all_node(ifp->nbr_connected);
@@ -265,7 +267,7 @@ void if_delete(struct interface **ifp)
 
 	if_delete_retain(ptr);
 
-	list_delete(&ptr->connected);
+	if_connected_fini(ptr->connected);
 	list_delete(&ptr->nbr_connected);
 
 	if_link_params_free(ptr);
@@ -427,7 +429,6 @@ struct interface *if_lookup_address_local(const void *src, int family,
 					  vrf_id_t vrf_id)
 {
 	struct vrf *vrf = vrf_lookup_by_id(vrf_id);
-	struct listnode *cnode;
 	struct interface *ifp, *best_down = NULL;
 	struct prefix *p;
 	struct connected *c;
@@ -436,7 +437,7 @@ struct interface *if_lookup_address_local(const void *src, int family,
 		return NULL;
 
 	FOR_ALL_INTERFACES (vrf, ifp) {
-		for (ALL_LIST_ELEMENTS_RO(ifp->connected, cnode, c)) {
+		frr_each (if_connected, ifp->connected, c) {
 			p = c->address;
 
 			if (!p || p->family != family)
@@ -468,7 +469,6 @@ struct connected *if_lookup_address(const void *matchaddr, int family,
 	struct vrf *vrf = vrf_lookup_by_id(vrf_id);
 	struct prefix addr;
 	int bestlen = 0;
-	struct listnode *cnode;
 	struct interface *ifp;
 	struct connected *c;
 	struct connected *match;
@@ -487,7 +487,7 @@ struct connected *if_lookup_address(const void *matchaddr, int family,
 	match = NULL;
 
 	FOR_ALL_INTERFACES (vrf, ifp) {
-		for (ALL_LIST_ELEMENTS_RO(ifp->connected, cnode, c)) {
+		frr_each (if_connected, ifp->connected, c) {
 			if (c->address && (c->address->family == AF_INET)
 			    && prefix_match(CONNECTED_PREFIX(c), &addr)
 			    && (c->address->prefixlen > bestlen)) {
@@ -503,12 +503,11 @@ struct connected *if_lookup_address(const void *matchaddr, int family,
 struct interface *if_lookup_prefix(const struct prefix *prefix, vrf_id_t vrf_id)
 {
 	struct vrf *vrf = vrf_lookup_by_id(vrf_id);
-	struct listnode *cnode;
 	struct interface *ifp;
 	struct connected *c;
 
 	FOR_ALL_INTERFACES (vrf, ifp) {
-		for (ALL_LIST_ELEMENTS_RO(ifp->connected, cnode, c)) {
+		frr_each (if_connected, ifp->connected, c) {
 			if (prefix_cmp(c->address, prefix) == 0) {
 				return ifp;
 			}
@@ -775,10 +774,9 @@ const char *if_flag_dump(unsigned long flag)
 /* For debugging */
 static void if_dump(const struct interface *ifp)
 {
-	struct listnode *node;
-	struct connected *c __attribute__((unused));
+	const struct connected *c;
 
-	for (ALL_LIST_ELEMENTS_RO(ifp->connected, node, c))
+	frr_each (if_connected_const, ifp->connected, c)
 		zlog_info(
 			"Interface %s vrf %s(%u) index %d metric %d mtu %d mtu6 %d %s",
 			ifp->name, ifp->vrf->name, ifp->vrf->vrf_id,
@@ -905,11 +903,10 @@ static int connected_same_prefix(const struct prefix *p1,
 /* count the number of connected addresses that are in the given family */
 unsigned int connected_count_by_family(struct interface *ifp, int family)
 {
-	struct listnode *cnode;
 	struct connected *connected;
 	unsigned int cnt = 0;
 
-	for (ALL_LIST_ELEMENTS_RO(ifp->connected, cnode, connected))
+	frr_each (if_connected, ifp->connected, connected)
 		if (connected->address->family == family)
 			cnt++;
 
@@ -919,14 +916,9 @@ unsigned int connected_count_by_family(struct interface *ifp, int family)
 struct connected *connected_lookup_prefix_exact(struct interface *ifp,
 						const struct prefix *p)
 {
-	struct listnode *node;
-	struct listnode *next;
 	struct connected *ifc;
 
-	for (node = listhead(ifp->connected); node; node = next) {
-		ifc = listgetdata(node);
-		next = node->next;
-
+	frr_each (if_connected, ifp->connected, ifc) {
 		if (connected_same_prefix(ifc->address, p))
 			return ifc;
 	}
@@ -936,17 +928,12 @@ struct connected *connected_lookup_prefix_exact(struct interface *ifp,
 struct connected *connected_delete_by_prefix(struct interface *ifp,
 					     struct prefix *p)
 {
-	struct listnode *node;
-	struct listnode *next;
 	struct connected *ifc;
 
 	/* In case of same prefix come, replace it with new one. */
-	for (node = listhead(ifp->connected); node; node = next) {
-		ifc = listgetdata(node);
-		next = node->next;
-
+	frr_each_safe (if_connected, ifp->connected, ifc) {
 		if (connected_same_prefix(ifc->address, p)) {
-			listnode_delete(ifp->connected, ifc);
+			if_connected_del(ifp->connected, ifc);
 			return ifc;
 		}
 	}
@@ -958,13 +945,12 @@ struct connected *connected_delete_by_prefix(struct interface *ifp,
 struct connected *connected_lookup_prefix(struct interface *ifp,
 					  const struct prefix *addr)
 {
-	struct listnode *cnode;
 	struct connected *c;
 	struct connected *match;
 
 	match = NULL;
 
-	for (ALL_LIST_ELEMENTS_RO(ifp->connected, cnode, c)) {
+	frr_each (if_connected, ifp->connected, c) {
 		if (c->address && (c->address->family == addr->family)
 		    && prefix_match(CONNECTED_PREFIX(c), addr)
 		    && (!match
@@ -995,16 +981,15 @@ struct connected *connected_add_by_prefix(struct interface *ifp,
 	}
 
 	/* Add connected address to the interface. */
-	listnode_add(ifp->connected, ifc);
+	if_connected_add_tail(ifp->connected, ifc);
 	return ifc;
 }
 
 struct connected *connected_get_linklocal(struct interface *ifp)
 {
-	struct listnode *n;
 	struct connected *c = NULL;
 
-	for (ALL_LIST_ELEMENTS_RO(ifp->connected, n, c)) {
+	frr_each (if_connected, ifp->connected, c) {
 		if (c->address->family == AF_INET6
 		    && IN6_IS_ADDR_LINKLOCAL(&c->address->u.prefix6))
 			break;
diff --git a/lib/if.h b/lib/if.h
index e93205758..dd67c32a6 100644
--- a/lib/if.h
+++ b/lib/if.h
@@ -204,6 +204,8 @@ struct if_link_params {
 #define INTERFACE_LINK_PARAMS_SIZE   sizeof(struct if_link_params)
 #define HAS_LINK_PARAMS(ifp)  ((ifp)->link_params != NULL)
 
+PREDECL_DLIST(if_connected);
+
 /* Interface structure */
 struct interface {
 	RB_ENTRY(interface) name_entry, index_entry;
@@ -278,7 +280,7 @@ struct interface {
 	void *distribute_out;
 
 	/* Connected address list. */
-	struct list *connected;
+	struct if_connected_head connected[1];
 
 	/* Neighbor connected address list. */
 	struct list *nbr_connected;
@@ -373,9 +375,6 @@ DECLARE_QOBJ_TYPE(interface);
 	if (vrf)                                                               \
 		RB_FOREACH (ifp, if_name_head, &vrf->ifaces_by_name)
 
-#define FOR_ALL_INTERFACES_ADDRESSES(ifp, connected, node)                     \
-	for (ALL_LIST_ELEMENTS_RO(ifp->connected, node, connected))
-
 /* called from the library code whenever interfaces are created/deleted
  * note: interfaces may not be fully realized at that point; also they
  * may not exist in the system (ifindex = IFINDEX_INTERNAL)
@@ -410,6 +409,8 @@ DECLARE_KOOH(if_down, (struct interface *ifp), (ifp));
 
 /* Connected address structure. */
 struct connected {
+	struct if_connected_item item;
+
 	/* Attached interface. */
 	struct interface *ifp;
 
@@ -459,6 +460,8 @@ struct connected {
 	uint32_t metric;
 };
 
+DECLARE_DLIST(if_connected, struct connected, item);
+
 /* Nbr Connected address structure. */
 struct nbr_connected {
 	/* Attached interface. */