IPv6: Try harder to assign prefix parts

[project/netifd.git] / interface-ip.c

diff --git a/interface-ip.c b/interface-ip.c
index bf7cf40..afdf67b 100644 (file)
--- a/interface-ip.c
+++ b/interface-ip.c
@@ -476,6 +476,41 @@ interface_update_host_route(struct vlist_tree *tree,
 
 static void
 interface_set_prefix_address(struct device_prefix_assignment *assignment,
+               const struct device_prefix *prefix, struct interface *iface, bool add);
+
+static void interface_trigger_ula_prefix(struct interface *iface,
+               const struct device_prefix *prefix, bool enable)
+{
+       if (prefix == ula_prefix || (prefix->addr.s6_addr[0] & 0xfe) != 0xfc)
+               return;
+
+       bool external_ula = false;
+       struct device_prefix_assignment *ula_assign = NULL;
+       struct device_prefix *c;
+       list_for_each_entry(c, &prefixes, head) {
+               if (c != ula_prefix && (c->addr.s6_addr[0] & 0xfe) != 0xfc)
+                       continue;
+
+               struct device_prefix_assignment *a;
+               list_for_each_entry(a, &c->assignments, head) {
+                       if (!strcmp(a->name, iface->name)) {
+                               if (c == ula_prefix)
+                                       ula_assign = a;
+                               else if (a->enabled)
+                                       external_ula = true;
+                       }
+               }
+
+       }
+
+       // Remove ULA assignment if there is an externally managed ULA and vice versa
+       if (ula_assign && ((enable && !external_ula) || (!enable && external_ula)))
+               interface_set_prefix_address(ula_assign, ula_prefix, iface, enable);
+}
+
+
+static void
+interface_set_prefix_address(struct device_prefix_assignment *assignment,
                const struct device_prefix *prefix, struct interface *iface, bool add)
 {
        const struct interface *uplink = prefix->iface;
@@ -501,6 +536,8 @@ interface_set_prefix_address(struct device_prefix_assignment *assignment,
                        addr.valid_until = now + 7200;
                system_add_address(l3_downlink, &addr);
                assignment->enabled = false;
+
+               interface_trigger_ula_prefix(iface, prefix, true);
        } else if (add && (iface->state == IFS_UP || iface->state == IFS_SETUP)) {
                system_add_address(l3_downlink, &addr);
                if (uplink && uplink->l3_dev.dev) {
@@ -510,6 +547,8 @@ interface_set_prefix_address(struct device_prefix_assignment *assignment,
                                system_update_ipv6_mtu(l3_downlink, mtu);
                }
                assignment->enabled = true;
+
+               interface_trigger_ula_prefix(iface, prefix, false);
        }
 }
 
@@ -601,7 +640,13 @@ static void interface_update_prefix_assignments(struct device_prefix *prefix, bo
        while (!list_empty(&assign_later)) {
                c = list_first_entry(&assign_later, struct device_prefix_assignment, head);
                list_del(&c->head);
-               if (!interface_prefix_assign(&prefix->assignments, c)) {
+
+               bool assigned = false;
+               do {
+                       assigned = interface_prefix_assign(&prefix->assignments, c);
+               } while (!assigned && ++c->length <= 64);
+
+               if (!assigned) {
                        netifd_log_message(L_WARNING, "Failed to assign subprefix "
                                        "of size %hhu for %s\n", c->length, c->name);
                        free(c);