interface-ip: Fix broadcast address when using /31 or /32 IPv4 addressing
[project/netifd.git] / interface-ip.c
index 1a22ce6..54f56d6 100644 (file)
@@ -133,23 +133,6 @@ static int set_ip_source_policy(bool add, bool v6, unsigned int priority,
        return (add) ? system_add_iprule(&rule) : system_del_iprule(&rule);
 }
 
-static int set_ip_lo_policy(bool add, bool v6, struct interface *iface)
-{
-       struct iprule rule = {
-               .flags = IPRULE_IN | IPRULE_LOOKUP | IPRULE_PRIORITY,
-               .priority = IPRULE_PRIORITY_NW + iface->l3_dev.dev->ifindex,
-               .lookup = (v6) ? iface->ip6table : iface->ip4table,
-               .in_dev = "lo"
-       };
-
-       if (!rule.lookup)
-               return 0;
-
-       rule.flags |= (v6) ? IPRULE_INET6 : IPRULE_INET4;
-
-       return (add) ? system_add_iprule(&rule) : system_del_iprule(&rule);
-}
-
 static bool
 __find_ip_addr_target(struct interface_ip_settings *ip, union if_addr *a, bool v6)
 {
@@ -442,6 +425,9 @@ interface_handle_subnet_route(struct interface *iface, struct device_addr *addr,
        struct device *dev = iface->l3_dev.dev;
        struct device_route route;
 
+       if (addr->flags & DEVADDR_OFFLINK)
+               return;
+
        memset(&route, 0, sizeof(route));
        route.iface = iface;
        route.flags = addr->flags;
@@ -453,14 +439,11 @@ interface_handle_subnet_route(struct interface *iface, struct device_addr *addr,
                route.flags |= DEVADDR_KERNEL;
                system_del_route(dev, &route);
 
-               if (!(addr->flags & DEVADDR_OFFLINK)) {
-                       route.flags &= ~DEVADDR_KERNEL;
-                       route.metric = iface->metric;
-                       system_add_route(dev, &route);
-               }
+               route.flags &= ~DEVADDR_KERNEL;
+               route.metric = iface->metric;
+               system_add_route(dev, &route);
        } else {
-               if (!(addr->flags & DEVADDR_OFFLINK))
-                       system_del_route(dev, &route);
+               system_del_route(dev, &route);
        }
 }
 
@@ -490,11 +473,17 @@ interface_update_proto_addr(struct vlist_tree *tree,
                if ((a_new->flags & DEVADDR_FAMILY) == DEVADDR_INET4 &&
                    !a_new->broadcast) {
 
-                       uint32_t mask = ~0;
-                       uint32_t *a = (uint32_t *) &a_new->addr;
+                       /* /31 and /32 addressing need 255.255.255.255
+                        * as broadcast address. */
+                       if (a_new->mask >= 31) {
+                               a_new->broadcast = (uint32_t) ~0;
+                       } else {
+                               uint32_t mask = ~0;
+                               uint32_t *a = (uint32_t *) &a_new->addr;
 
-                       mask >>= a_new->mask;
-                       a_new->broadcast = *a | htonl(mask);
+                               mask >>= a_new->mask;
+                               a_new->broadcast = *a | htonl(mask);
+                       }
                }
        }
 
@@ -517,9 +506,7 @@ interface_update_proto_addr(struct vlist_tree *tree,
        }
 
        if (node_old) {
-               if (!(a_old->flags & DEVADDR_EXTERNAL) && a_old->enabled && !keep) {
-                       interface_handle_subnet_route(iface, a_old, false);
-
+               if (a_old->enabled && !keep) {
                        if ((a_old->flags & DEVADDR_FAMILY) == DEVADDR_INET6)
                                v6 = true;
 
@@ -532,11 +519,16 @@ interface_update_proto_addr(struct vlist_tree *tree,
                        if (table) {
                                set_ip_source_policy(false, v6, IPRULE_PRIORITY_ADDR, &a_old->addr,
                                                (v6) ? 128 : 32, table, NULL, NULL);
-                               set_ip_source_policy(false, v6, IPRULE_PRIORITY_NW, &a_old->addr,
-                                               a_old->mask, table, NULL, NULL);
+
+                               if (a_old->mask != ((v6) ? 128 : 32))
+                                       set_ip_source_policy(false, v6, IPRULE_PRIORITY_NW, &a_old->addr,
+                                                       a_old->mask, table, NULL, NULL);
                        }
 
-                       system_del_address(dev, a_old);
+                       if (!(a_old->flags & DEVADDR_EXTERNAL)) {
+                               interface_handle_subnet_route(iface, a_old, false);
+                               system_del_address(dev, a_old);
+                       }
                }
                free(a_old->pclass);
                free(a_old);
@@ -544,9 +536,14 @@ interface_update_proto_addr(struct vlist_tree *tree,
 
        if (node_new) {
                a_new->enabled = true;
-               if (!(a_new->flags & DEVADDR_EXTERNAL) && (!keep || replace)) {
-                       if (system_add_address(dev, a_new))
-                               a_new->failed = true;
+               if (!keep || replace) {
+                       if (!(a_new->flags & DEVADDR_EXTERNAL)) {
+                               if (system_add_address(dev, a_new))
+                                       a_new->failed = true;
+
+                               if (iface->metric)
+                                       interface_handle_subnet_route(iface, a_new, true);
+                       }
 
                        if (!keep) {
                                if ((a_new->flags & DEVADDR_FAMILY) == DEVADDR_INET6)
@@ -557,13 +554,12 @@ interface_update_proto_addr(struct vlist_tree *tree,
                                if (table) {
                                        set_ip_source_policy(true, v6, IPRULE_PRIORITY_ADDR, &a_new->addr,
                                                        (v6) ? 128 : 32, table, NULL, NULL);
-                                       set_ip_source_policy(true, v6, IPRULE_PRIORITY_NW, &a_new->addr,
-                                                       a_new->mask, table, NULL, NULL);
+
+                                       if (a_new->mask != ((v6) ? 128 : 32))
+                                               set_ip_source_policy(true, v6, IPRULE_PRIORITY_NW, &a_new->addr,
+                                                               a_new->mask, table, NULL, NULL);
                                }
                        }
-
-                       if ((a_new->flags & DEVADDR_OFFLINK) || iface->metric)
-                               interface_handle_subnet_route(iface, a_new, true);
                }
        }
 }
@@ -601,7 +597,7 @@ interface_update_proto_route(struct vlist_tree *tree,
        if (node_old && node_new)
                keep = !memcmp(&route_old->nexthop, &route_new->nexthop, sizeof(route_old->nexthop)) &&
                        (route_old->mtu == route_new->mtu) && (route_old->type == route_new->type) &&
-                       (route_old->valid_until == route_new->valid_until) && !route_old->failed;
+                       !route_old->failed;
 
        if (node_old) {
                if (!(route_old->flags & DEVADDR_EXTERNAL) && route_old->enabled && !keep)
@@ -710,7 +706,9 @@ interface_set_prefix_address(struct device_prefix_assignment *assignment,
        struct device *l3_downlink = iface->l3_dev.dev;
 
        struct device_addr addr;
+       struct device_route route;
        memset(&addr, 0, sizeof(addr));
+       memset(&route, 0, sizeof(route));
 
        if (IN6_IS_ADDR_UNSPECIFIED(&assignment->addr)) {
                addr.addr.in6 = prefix->addr;
@@ -722,15 +720,14 @@ interface_set_prefix_address(struct device_prefix_assignment *assignment,
                addr.addr.in6 = assignment->addr;
 
        addr.mask = assignment->length;
-       addr.flags = DEVADDR_INET6;
+       addr.flags = DEVADDR_INET6 | DEVADDR_OFFLINK;
        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;
-       }
+       route.flags = DEVADDR_INET6;
+       route.mask = addr.mask < 64 ? 64 : addr.mask;
+       route.addr = addr.addr;
+       clear_if_addr(&route.addr, route.mask);
 
        if (!add && assignment->enabled) {
                time_t now = system_get_rtime();
@@ -738,8 +735,6 @@ interface_set_prefix_address(struct device_prefix_assignment *assignment,
                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
-
                if (prefix->iface) {
                        if (prefix->iface->ip6table)
                                set_ip_source_policy(false, true, IPRULE_PRIORITY_NW, &addr.addr,
@@ -749,16 +744,12 @@ 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_del_route(l3_downlink, &route);
                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,
@@ -769,15 +760,14 @@ interface_set_prefix_address(struct device_prefix_assignment *assignment,
                                                addr.mask, prefix->iface->ip6table, iface, NULL);
                }
 
-               if (addr.mask < 64)
-                       addr.mask = 64;
+               route.metric = iface->metric;
+               system_add_route(l3_downlink, &route);
 
-               interface_handle_subnet_route(iface, &addr, true);
+               if (uplink && uplink->l3_dev.dev && !(l3_downlink->settings.flags & DEV_OPT_MTU6)) {
+                       int mtu = system_update_ipv6_mtu(uplink->l3_dev.dev, 0);
+                       int mtu_old = system_update_ipv6_mtu(l3_downlink, 0);
 
-               if (uplink && uplink->l3_dev.dev) {
-                       int mtu = system_update_ipv6_mtu(
-                                       uplink->l3_dev.dev, 0);
-                       if (mtu > 0)
+                       if (mtu > 0 && mtu_old > mtu)
                                system_update_ipv6_mtu(l3_downlink, mtu);
                }
 
@@ -1228,7 +1218,7 @@ void interface_ip_set_enabled(struct interface_ip_settings *ip, bool enabled)
 
                if (enabled) {
                        system_add_address(dev, addr);
-                       if ((addr->flags & DEVADDR_OFFLINK) || iface->metric)
+                       if (iface->metric)
                                interface_handle_subnet_route(iface, addr, true);
                } else {
                        interface_handle_subnet_route(iface, addr, false);
@@ -1250,6 +1240,15 @@ void interface_ip_set_enabled(struct interface_ip_settings *ip, bool enabled)
                        if (!(route->flags & DEVROUTE_METRIC))
                                route->metric = ip->iface->metric;
 
+                       if (!(route->flags & DEVROUTE_TABLE)) {
+                               route->flags &= ~DEVROUTE_SRCTABLE;
+                               route->table = ((route->flags & DEVADDR_FAMILY) == DEVADDR_INET6) ?
+                                                       iface->ip6table : iface->ip4table;
+
+                               if (route->table)
+                                       route->flags |= DEVROUTE_SRCTABLE;
+                       }
+
                        if (system_add_route(dev, route))
                                route->failed = true;
                } else
@@ -1264,13 +1263,9 @@ void interface_ip_set_enabled(struct interface_ip_settings *ip, bool enabled)
                        if (!strcmp(a->name, ip->iface->name))
                                interface_set_prefix_address(a, c, ip->iface, enabled);
 
-       if (ip->iface && ip->iface->l3_dev.dev) {
-               set_ip_lo_policy(enabled, true, ip->iface);
-               set_ip_lo_policy(enabled, false, ip->iface);
-
+       if (ip->iface && ip->iface->l3_dev.dev)
                set_ip_source_policy(enabled, true, IPRULE_PRIORITY_REJECT + ip->iface->l3_dev.dev->ifindex,
                        NULL, 0, 0, ip->iface, "failed_policy");
-       }
 }
 
 void