ipv6: assign prefixes with length <64 with /64 on-link routes

on-link routes for prefixes bigger than /64 make no sense and
might confuse some users

Signed-off-by: Steven Barth <steven@midlink.org>

diff --git a/interface-ip.c b/interface-ip.c
index 8d4434b42cea3d28f3cccde5ceba273004cd5369..8d1265882f6e16e88d496328679d2d5eac59d4f0 100644 (file)
--- a/interface-ip.c
+++ b/interface-ip.c
@@ -669,13 +669,20 @@ interface_set_prefix_address(struct device_prefix_assignment *assignment,
        addr.preferred_until = prefix->preferred_until;
        addr.valid_until = prefix->valid_until;
 
+       if (addr.mask < 64) {
+               addr.mask = 64;
+               system_del_address(l3_downlink, &addr);
+               addr.mask = assignment->length;
+       }
+
        if (!add && assignment->enabled) {
                time_t now = system_get_rtime();
                addr.preferred_until = now;
                if (!addr.valid_until || addr.valid_until - now > 7200)
                        addr.valid_until = now + 7200;
+
                system_del_address(l3_downlink, &addr); // Work around dangling prefix routes
-               system_add_address(l3_downlink, &addr);
+
                if (prefix->iface) {
                        if (prefix->iface->ip6table)
                                set_ip_source_policy(false, true, IPRULE_PRIORITY_NW, &addr.addr,
@@ -685,9 +692,17 @@ interface_set_prefix_address(struct device_prefix_assignment *assignment,
                                                        addr.mask, 0, iface, "unreachable");
                }
 
+               if (addr.mask < 64)
+                       addr.mask = 64;
+
+               interface_handle_subnet_route(iface, &addr, false);
+               system_add_address(l3_downlink, &addr);
+
                assignment->enabled = false;
        } else if (add && (iface->state == IFS_UP || iface->state == IFS_SETUP) &&
                        !system_add_address(l3_downlink, &addr)) {
+               interface_handle_subnet_route(iface, &addr, false);
+
                if (prefix->iface && !assignment->enabled) {
                        set_ip_source_policy(true, true, IPRULE_PRIORITY_REJECT, &addr.addr,
                                        addr.mask, 0, iface, "unreachable");
@@ -696,12 +711,19 @@ interface_set_prefix_address(struct device_prefix_assignment *assignment,
                                set_ip_source_policy(true, true, IPRULE_PRIORITY_NW, &addr.addr,
                                                addr.mask, prefix->iface->ip6table, iface, NULL);
                }
+
+               if (addr.mask < 64)
+                       addr.mask = 64;
+
+               interface_handle_subnet_route(iface, &addr, true);
+
                if (uplink && uplink->l3_dev.dev) {
                        int mtu = system_update_ipv6_mtu(
                                        uplink->l3_dev.dev, 0);
                        if (mtu > 0)
                                system_update_ipv6_mtu(l3_downlink, mtu);
                }
+
                assignment->enabled = true;
        }
 }