interface-ip: Fix broadcast address when using /31 or /32 IPv4 addressing
[project/netifd.git] / interface-ip.c
index 2444cda..54f56d6 100644 (file)
 #include <string.h>
 #include <stdlib.h>
 #include <stdio.h>
-#include <unistd.h>
 
+#include <limits.h>
 #include <arpa/inet.h>
+#include <netinet/in.h>
 
 #include "netifd.h"
 #include "device.h"
@@ -36,6 +37,9 @@ enum {
        ROUTE_MTU,
        ROUTE_VALID,
        ROUTE_TABLE,
+       ROUTE_SOURCE,
+       ROUTE_ONLINK,
+       ROUTE_TYPE,
        __ROUTE_MAX
 };
 
@@ -48,9 +52,12 @@ static const struct blobmsg_policy route_attr[__ROUTE_MAX] = {
        [ROUTE_MTU] = { .name = "mtu", .type = BLOBMSG_TYPE_INT32 },
        [ROUTE_TABLE] = { .name = "table", .type = BLOBMSG_TYPE_STRING },
        [ROUTE_VALID] = { .name = "valid", .type = BLOBMSG_TYPE_INT32 },
+       [ROUTE_SOURCE] = { .name = "source", .type = BLOBMSG_TYPE_STRING },
+       [ROUTE_ONLINK] = { .name = "onlink", .type = BLOBMSG_TYPE_BOOL },
+       [ROUTE_TYPE] = { .name = "type", .type = BLOBMSG_TYPE_STRING }
 };
 
-const struct config_param_list route_attr_list = {
+const struct uci_blob_param_list route_attr_list = {
        .n_params = __ROUTE_MAX,
        .params = route_attr,
 };
@@ -68,8 +75,8 @@ clear_if_addr(union if_addr *a, int mask)
        uint8_t m_clear = (1 << (m_bytes * 8 - mask)) - 1;
        uint8_t *p = (uint8_t *) a;
 
-       if (m_bytes < sizeof(a))
-               memset(p + m_bytes, 0, sizeof(a) - m_bytes);
+       if (m_bytes < sizeof(*a))
+               memset(p + m_bytes, 0, sizeof(*a) - m_bytes);
 
        p[m_bytes - 1] &= ~m_clear;
 }
@@ -91,37 +98,35 @@ match_if_addr(union if_addr *a1, union if_addr *a2, int mask)
 }
 
 static int set_ip_source_policy(bool add, bool v6, unsigned int priority,
-               const union if_addr *addr, uint8_t mask, struct interface *iface)
+               const union if_addr *addr, uint8_t mask, unsigned int table,
+               struct interface *in_iface, const char *action)
 {
-
-
        struct iprule rule = {
-               .flags = IPRULE_SRC | IPRULE_LOOKUP | IPRULE_PRIORITY,
-               .priority = priority,
-               .lookup = (v6) ? iface->ip6table : iface->ip4table,
-               .src_addr = *addr,
-               .src_mask = mask,
+               .flags = IPRULE_PRIORITY,
+               .priority = priority
        };
 
-       if (!rule.lookup)
-               return 0;
-
-       rule.flags |= (v6) ? IPRULE_INET6 : IPRULE_INET4;
+       if (addr) {
+               rule.flags |= IPRULE_SRC;
+               rule.src_addr = *addr;
+               rule.src_mask = mask;
+       }
 
-       return (add) ? system_add_iprule(&rule) : system_del_iprule(&rule);
-}
+       if (table) {
+               rule.flags |= IPRULE_LOOKUP;
+               rule.lookup = table;
 
-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;
+       } else if (action) {
+               rule.flags |= IPRULE_ACTION;
+               system_resolve_iprule_action(action, &rule.action);
+       }
 
-       if (!rule.lookup)
-               return 0;
+       if (in_iface && in_iface->l3_dev.dev) {
+               rule.flags |= IPRULE_IN;
+               strcpy(rule.in_dev, in_iface->l3_dev.dev->ifname);
+       }
 
        rule.flags |= (v6) ? IPRULE_INET6 : IPRULE_INET4;
 
@@ -305,7 +310,8 @@ interface_ip_add_route(struct interface *iface, struct blob_attr *attr, bool v6)
        if ((cur = tb[ROUTE_METRIC]) != NULL) {
                route->metric = blobmsg_get_u32(cur);
                route->flags |= DEVROUTE_METRIC;
-       }
+       } else
+               route->metric = iface->metric;
 
        if ((cur = tb[ROUTE_MTU]) != NULL) {
                route->mtu = blobmsg_get_u32(cur);
@@ -313,6 +319,24 @@ interface_ip_add_route(struct interface *iface, struct blob_attr *attr, bool v6)
        }
 
        // Use source-based routing
+       if ((cur = tb[ROUTE_SOURCE]) != NULL) {
+               char *saveptr, *source = alloca(blobmsg_data_len(cur));
+               memcpy(source, blobmsg_data(cur), blobmsg_data_len(cur));
+
+               const char *addr = strtok_r(source, "/", &saveptr);
+               const char *mask = strtok_r(NULL, "/", &saveptr);
+
+               if (!addr || inet_pton(af, addr, &route->source) < 1) {
+                       DPRINTF("Failed to parse route source: %s\n", addr);
+                       goto error;
+               }
+
+               route->sourcemask = (mask) ? atoi(mask) : ((af == AF_INET6) ? 128 : 32);
+       }
+
+       if ((cur = tb[ROUTE_ONLINK]) != NULL && blobmsg_get_bool(cur))
+               route->flags |= DEVROUTE_ONLINK;
+
        if (is_proto_route) {
                route->table = (v6) ? iface->ip6table : iface->ip4table;
                route->flags |= DEVROUTE_SRCTABLE;
@@ -324,12 +348,28 @@ interface_ip_add_route(struct interface *iface, struct blob_attr *attr, bool v6)
                        goto error;
                }
 
+               /* only set the table flag if not using the main (default) table */
+               if (system_is_default_rt_table(route->table))
+                       route->table = 0;
+
                if (route->table)
                        route->flags |= DEVROUTE_TABLE;
        }
 
-       if ((cur = tb[ROUTE_VALID]) != NULL)
-               route->valid_until = system_get_rtime() + blobmsg_get_u32(cur);
+       if ((cur = tb[ROUTE_VALID]) != NULL) {
+               int64_t valid = blobmsg_get_u32(cur);
+               int64_t valid_until = valid + (int64_t)system_get_rtime();
+               if (valid_until <= LONG_MAX && valid != 0xffffffffLL) // Catch overflow
+                       route->valid_until = valid_until;
+       }
+
+       if ((cur = tb[ROUTE_TYPE]) != NULL) {
+               if (!system_resolve_rt_type(blobmsg_data(cur), &route->type)) {
+                       DPRINTF("Failed to resolve routing type: %s\n", (char *) blobmsg_data(cur));
+                       goto error;
+               }
+               route->flags |= DEVROUTE_TYPE;
+       }
 
        vlist_add(&ip->route, &route->node, route);
        return;
@@ -359,13 +399,23 @@ route_cmp(const void *k1, const void *k2, void *ptr)
        if (r1->flags != r2->flags)
                return r2->flags - r1->flags;
 
+       if (r1->sourcemask != r2->sourcemask)
+               return r1->sourcemask - r2->sourcemask;
+
+       if (r1->table != r2->table)
+               return r1->table - r2->table;
+
+       int maskcmp = memcmp(&r1->source, &r2->source, sizeof(r1->source));
+       if (maskcmp)
+               return maskcmp;
+
        return memcmp(&r1->addr, &r2->addr, sizeof(r1->addr));
 }
 
 static int
 prefix_cmp(const void *k1, const void *k2, void *ptr)
 {
-       return memcmp(k1, k2, sizeof(struct device_prefix) -
+       return memcmp(k1, k2, offsetof(struct device_prefix, pclass) -
                        offsetof(struct device_prefix, addr));
 }
 
@@ -375,6 +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;
@@ -386,14 +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);
        }
 }
 
@@ -406,6 +456,7 @@ interface_update_proto_addr(struct vlist_tree *tree,
        struct interface *iface;
        struct device *dev;
        struct device_addr *a_new = NULL, *a_old = NULL;
+       bool replace = false;
        bool keep = false;
        bool v6 = false;
 
@@ -413,17 +464,26 @@ interface_update_proto_addr(struct vlist_tree *tree,
        iface = ip->iface;
        dev = iface->l3_dev.dev;
 
+       if (!node_new || !node_old)
+               iface->updated |= IUF_ADDRESS;
+
        if (node_new) {
                a_new = container_of(node_new, struct device_addr, node);
 
                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);
+                       }
                }
        }
 
@@ -433,52 +493,73 @@ interface_update_proto_addr(struct vlist_tree *tree,
        if (a_new && a_old) {
                keep = true;
 
-               if (a_old->flags != a_new->flags ||
-                               a_old->valid_until != a_new->valid_until ||
-                               a_old->preferred_until != a_new->preferred_until)
+               if (a_old->flags != a_new->flags || a_old->failed)
                        keep = false;
 
+               if (a_old->valid_until != a_new->valid_until ||
+                               a_old->preferred_until != a_new->preferred_until)
+                       replace = true;
+
                if ((a_new->flags & DEVADDR_FAMILY) == DEVADDR_INET4 &&
                    a_new->broadcast != a_old->broadcast)
                        keep = false;
        }
 
        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;
 
+                       unsigned int table = (v6) ? iface->ip6table : iface->ip4table;
+
                        //This is needed for source routing to work correctly. If a device
                        //has two connections to a network using the same subnet, adding
                        //only the network-rule will cause packets to be routed through the
                        //first matching network (source IP matches both masks).
-                       set_ip_source_policy(false, v6, IPRULE_PRIORITY_ADDR, &a_old->addr,
-                               (v6) ? 128 : 32, iface);
-                       set_ip_source_policy(false, v6, IPRULE_PRIORITY_NW, &a_old->addr,
-                               a_old->mask, iface);
+                       if (table) {
+                               set_ip_source_policy(false, v6, IPRULE_PRIORITY_ADDR, &a_old->addr,
+                                               (v6) ? 128 : 32, table, NULL, NULL);
 
-                       system_del_address(dev, a_old);
+                               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);
+                       }
+
+                       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);
        }
 
        if (node_new) {
                a_new->enabled = true;
-               if (!(a_new->flags & DEVADDR_EXTERNAL) && !keep) {
-                       system_add_address(dev, a_new);
+               if (!keep || replace) {
+                       if (!(a_new->flags & DEVADDR_EXTERNAL)) {
+                               if (system_add_address(dev, a_new))
+                                       a_new->failed = true;
 
-                       if ((a_new->flags & DEVADDR_FAMILY) == DEVADDR_INET6)
-                               v6 = true;
+                               if (iface->metric)
+                                       interface_handle_subnet_route(iface, a_new, true);
+                       }
+
+                       if (!keep) {
+                               if ((a_new->flags & DEVADDR_FAMILY) == DEVADDR_INET6)
+                                       v6 = true;
 
-                       set_ip_source_policy(true, v6, IPRULE_PRIORITY_ADDR, &a_new->addr,
-                               (v6) ? 128 : 32, iface);
-                       set_ip_source_policy(true, v6, IPRULE_PRIORITY_NW, &a_new->addr,
-                               a_new->mask, iface);
+                               unsigned int table = (v6) ? iface->ip6table : iface->ip4table;
 
-                       if ((a_new->flags & DEVADDR_OFFLINK) || iface->metric)
-                               interface_handle_subnet_route(iface, a_new, true);
+                               if (table) {
+                                       set_ip_source_policy(true, v6, IPRULE_PRIORITY_ADDR, &a_new->addr,
+                                                       (v6) ? 128 : 32, 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);
+                               }
+                       }
                }
        }
 }
@@ -507,26 +588,30 @@ interface_update_proto_route(struct vlist_tree *tree,
        iface = ip->iface;
        dev = iface->l3_dev.dev;
 
+       if (!node_new || !node_old)
+               iface->updated |= IUF_ROUTE;
+
        route_old = container_of(node_old, struct device_route, node);
        route_new = container_of(node_new, struct device_route, node);
 
        if (node_old && node_new)
-               keep = !memcmp(&route_old->nexthop, &route_new->nexthop, sizeof(route_old->nexthop));
+               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->failed;
 
        if (node_old) {
                if (!(route_old->flags & DEVADDR_EXTERNAL) && route_old->enabled && !keep)
                        system_del_route(dev, route_old);
+
                free(route_old);
        }
 
        if (node_new) {
                bool _enabled = enable_route(ip, route_new);
 
-               if (!(route_new->flags & DEVROUTE_METRIC))
-                       route_new->metric = iface->metric;
-
                if (!(route_new->flags & DEVADDR_EXTERNAL) && !keep && _enabled)
-                       system_add_route(dev, route_new);
+                       if (system_add_route(dev, route_new))
+                               route_new->failed = true;
 
                route_new->iface = iface;
                route_new->enabled = _enabled;
@@ -553,45 +638,62 @@ interface_update_host_route(struct vlist_tree *tree,
                free(route_old);
        }
 
-       if (node_new)
-               system_add_route(dev, route_new);
+       if (node_new) {
+               if (system_add_route(dev, route_new))
+                       route_new->failed = true;
+       }
 }
 
-
 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)
+random_ifaceid(struct in6_addr *addr)
 {
-       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;
-                       }
-               }
-
+       static bool initialized = false;
+       struct timeval t;
+
+       if (!initialized) {
+               long int seed = 0;
+               gettimeofday(&t, NULL);
+               seed = t.tv_sec ^ t.tv_usec ^ getpid();
+               srand48(seed);
+               initialized = true;
        }
+       addr->s6_addr32[2] = (uint32_t)mrand48();
+       addr->s6_addr32[3] = (uint32_t)mrand48();
+}
 
-       // 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
+eui64_ifaceid(struct interface *iface, struct in6_addr *addr)
+{
+       /* get mac address */
+       uint8_t *macaddr = iface->l3_dev.dev->settings.macaddr;
+       uint8_t *ifaceid = addr->s6_addr + 8;
+       memcpy(ifaceid,macaddr,3);
+       memcpy(ifaceid + 5,macaddr + 3, 3);
+       ifaceid[3] = 0xff;
+       ifaceid[4] = 0xfe;
+       ifaceid[0] ^= 0x02;
 }
 
+static void
+generate_ifaceid(struct interface *iface, struct in6_addr *addr)
+{
+       /* generate new iface id */
+       switch (iface->assignment_iface_id_selection) {
+       case IFID_FIXED:
+               /* fixed */
+               /* copy host part from assignment_fixed_iface_id */
+               memcpy(addr->s6_addr + 8, iface->assignment_fixed_iface_id.s6_addr + 8, 8);
+               break;
+       case IFID_RANDOM:
+               /* randomize last 64 bits */
+               random_ifaceid(addr);
+               break;
+       case IFID_EUI64:
+               /* eui64 */
+               eui64_ifaceid(iface, addr);
+               break;
+       }
+}
 
 static void
 interface_set_prefix_address(struct device_prefix_assignment *assignment,
@@ -604,35 +706,72 @@ 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));
-       addr.addr.in6 = prefix->addr;
-       addr.addr.in6.s6_addr32[1] |= htonl(assignment->assigned);
-       addr.addr.in6.s6_addr[15] += 1;
+       memset(&route, 0, sizeof(route));
+
+       if (IN6_IS_ADDR_UNSPECIFIED(&assignment->addr)) {
+               addr.addr.in6 = prefix->addr;
+               addr.addr.in6.s6_addr32[1] |= htonl(assignment->assigned);
+               generate_ifaceid(iface, &addr.addr.in6);
+               assignment->addr = addr.addr.in6;
+       }
+       else
+               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;
 
+       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();
                addr.preferred_until = now;
                if (!addr.valid_until || addr.valid_until - now > 7200)
                        addr.valid_until = now + 7200;
+
+               if (prefix->iface) {
+                       if (prefix->iface->ip6table)
+                               set_ip_source_policy(false, true, IPRULE_PRIORITY_NW, &addr.addr,
+                                               addr.mask, prefix->iface->ip6table, iface, NULL);
+
+                       set_ip_source_policy(false, true, IPRULE_PRIORITY_REJECT, &addr.addr,
+                                                       addr.mask, 0, iface, "unreachable");
+               }
+
+               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_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) {
-                       int mtu = system_update_ipv6_mtu(
-                                       uplink->l3_dev.dev, 0);
-                       if (mtu > 0)
+               if (prefix->iface && !assignment->enabled) {
+                       set_ip_source_policy(true, true, IPRULE_PRIORITY_REJECT, &addr.addr,
+                                       addr.mask, 0, iface, "unreachable");
+
+                       if (prefix->iface->ip6table)
+                               set_ip_source_policy(true, true, IPRULE_PRIORITY_NW, &addr.addr,
+                                               addr.mask, prefix->iface->ip6table, iface, NULL);
+               }
+
+               route.metric = iface->metric;
+               system_add_route(l3_downlink, &route);
+
+               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 (mtu > 0 && mtu_old > mtu)
                                system_update_ipv6_mtu(l3_downlink, mtu);
                }
-               assignment->enabled = true;
 
-               interface_trigger_ula_prefix(iface, prefix, false);
+               assignment->enabled = true;
        }
 }
 
@@ -643,7 +782,7 @@ static bool interface_prefix_assign(struct list_head *list,
        struct device_prefix_assignment *c;
        list_for_each_entry(c, list, head) {
                if (assign->assigned != -1) {
-                       if (assign->assigned > current && assign->assigned + asize < c->assigned) {
+                       if (assign->assigned >= current && assign->assigned + asize < c->assigned) {
                                list_add_tail(&assign->head, &c->head);
                                return true;
                        }
@@ -683,6 +822,7 @@ static void interface_update_prefix_assignments(struct device_prefix *prefix, bo
        c->assigned = 1 << (64 - prefix->length);
        c->length = 64;
        c->name[0] = 0;
+       c->addr = in6addr_any;
        list_add(&c->head, &prefix->assignments);
 
        // Excluded prefix
@@ -692,20 +832,39 @@ static void interface_update_prefix_assignments(struct device_prefix *prefix, bo
                c->assigned = ntohl(prefix->excl_addr.s6_addr32[1]) &
                                ((1 << (64 - prefix->length)) - 1);
                c->length = prefix->excl_length;
+               c->addr = in6addr_any;
                memcpy(c->name, name, sizeof(name));
                list_add(&c->head, &prefix->assignments);
        }
 
+       bool assigned_any = false;
        struct list_head assign_later = LIST_HEAD_INIT(assign_later);
        vlist_for_each_element(&interfaces, iface, node) {
-               if (iface->config_ip.assignment_length < 48 ||
-                               iface->config_ip.assignment_length > 64)
+               if (iface->assignment_length < 48 ||
+                               iface->assignment_length > 64)
                        continue;
 
+               // Test whether there is a matching class
+               if (!list_empty(&iface->assignment_classes)) {
+                       bool found = false;
+
+                       struct interface_assignment_class *c;
+                       list_for_each_entry(c, &iface->assignment_classes, head) {
+                               if (!strcmp(c->name, prefix->pclass)) {
+                                       found = true;
+                                       break;
+                               }
+                       }
+
+                       if (!found)
+                               continue;
+               }
+
                size_t namelen = strlen(iface->name) + 1;
                c = malloc(sizeof(*c) + namelen);
-               c->length = iface->config_ip.assignment_length;
-               c->assigned = iface->config_ip.assignment_hint;
+               c->length = iface->assignment_length;
+               c->assigned = iface->assignment_hint;
+               c->addr = in6addr_any;
                c->enabled = false;
                memcpy(c->name, iface->name, namelen);
 
@@ -716,8 +875,20 @@ static void interface_update_prefix_assignments(struct device_prefix *prefix, bo
                                netifd_log_message(L_WARNING, "Failed to assign requested subprefix "
                                                "of size %hhu for %s, trying other\n", c->length, c->name);
                        }
-                       list_add_tail(&c->head, &assign_later);
+
+                       struct list_head *next = &assign_later;
+                       struct device_prefix_assignment *n;
+                       list_for_each_entry(n, &assign_later, head) {
+                               if (n->length < c->length) {
+                                       next = &n->head;
+                                       break;
+                               }
+                       }
+                       list_add_tail(&c->head, next);
                }
+
+               if (c->assigned != -1)
+                       assigned_any = true;
        }
 
        // Then try to assign all other + failed custom assignments
@@ -734,12 +905,18 @@ static void interface_update_prefix_assignments(struct device_prefix *prefix, bo
                        netifd_log_message(L_WARNING, "Failed to assign subprefix "
                                        "of size %hhu for %s\n", c->length, c->name);
                        free(c);
+               } else {
+                       assigned_any = true;
                }
        }
 
        list_for_each_entry(c, &prefix->assignments, head)
                if ((iface = vlist_find(&interfaces, c->name, iface, node)))
                        interface_set_prefix_address(c, prefix, iface, true);
+
+       if (!assigned_any)
+               netifd_log_message(L_WARNING, "You have delegated IPv6-prefixes but haven't assigned them "
+                               "to any interface. Did you forget to set option ip6assign on your lan-interfaces?");
 }
 
 
@@ -764,6 +941,10 @@ interface_update_prefix(struct vlist_tree *tree,
        prefix_old = container_of(node_old, struct device_prefix, node);
        prefix_new = container_of(node_new, struct device_prefix, node);
 
+       struct interface_ip_settings *ip = container_of(tree, struct interface_ip_settings, prefix);
+       if (tree && (!node_new || !node_old))
+               ip->iface->updated |= IUF_PREFIX;
+
        struct device_route route;
        memset(&route, 0, sizeof(route));
        route.flags = DEVADDR_INET6;
@@ -783,30 +964,24 @@ interface_update_prefix(struct vlist_tree *tree,
                        if ((iface = vlist_find(&interfaces, c->name, iface, node)))
                                interface_set_prefix_address(c, prefix_new, iface, true);
        } else if (node_new) {
-               // Set null-route to avoid routing loops and set routing policy
+               // Set null-route to avoid routing loops
                system_add_route(NULL, &route);
-               if (prefix_new->iface)
-                       set_ip_source_policy(true, true, IPRULE_PRIORITY_NW, &route.addr,
-                                       route.mask, prefix_new->iface);
-
 
-               interface_update_prefix_assignments(prefix_new, true);
+               if (!prefix_new->iface || !prefix_new->iface->proto_ip.no_delegation)
+                       interface_update_prefix_assignments(prefix_new, true);
        } else if (node_old) {
-               interface_update_prefix_assignments(prefix_old, false);
-
                // Remove null-route
-               if (prefix_old->iface)
-                       set_ip_source_policy(false, true, IPRULE_PRIORITY_NW, &route.addr,
-                                       route.mask, prefix_old->iface);
+               interface_update_prefix_assignments(prefix_old, false);
                system_del_route(NULL, &route);
        }
 
        if (node_old) {
-               list_del(&prefix_old->head);
+               if (prefix_old->head.next)
+                       list_del(&prefix_old->head);
                free(prefix_old);
        }
 
-       if (node_new)
+       if (node_new && (!prefix_new->iface || !prefix_new->iface->proto_ip.no_delegation))
                list_add(&prefix_new->head, &prefixes);
 
 }
@@ -814,9 +989,12 @@ interface_update_prefix(struct vlist_tree *tree,
 struct device_prefix*
 interface_ip_add_device_prefix(struct interface *iface, struct in6_addr *addr,
                uint8_t length, time_t valid_until, time_t preferred_until,
-               struct in6_addr *excl_addr, uint8_t excl_length)
+               struct in6_addr *excl_addr, uint8_t excl_length, const char *pclass)
 {
-       struct device_prefix *prefix = calloc(1, sizeof(*prefix));
+       if (!pclass)
+               pclass = (iface) ? iface->name : "local";
+
+       struct device_prefix *prefix = calloc(1, sizeof(*prefix) + strlen(pclass) + 1);
        prefix->length = length;
        prefix->addr = *addr;
        prefix->preferred_until = preferred_until;
@@ -829,6 +1007,8 @@ interface_ip_add_device_prefix(struct interface *iface, struct in6_addr *addr,
                prefix->excl_length = excl_length;
        }
 
+       strcpy(prefix->pclass, pclass);
+
        if (iface)
                vlist_add(&iface->proto_ip.prefix, &prefix->node, &prefix->addr);
        else
@@ -865,7 +1045,7 @@ interface_ip_set_ula_prefix(const char *prefix)
                        interface_update_prefix(NULL, NULL, &ula_prefix->node);
 
                ula_prefix = interface_ip_add_device_prefix(NULL, &addr, length,
-                               0, 0, NULL, 0);
+                               0, 0, NULL, 0, NULL);
        }
 }
 
@@ -945,7 +1125,7 @@ interface_add_dns_search_list(struct interface_ip_settings *ip, struct blob_attr
 }
 
 static void
-write_resolv_conf_entries(FILE *f, struct interface_ip_settings *ip)
+write_resolv_conf_entries(FILE *f, struct interface_ip_settings *ip, const char *dev)
 {
        struct dns_server *s;
        struct dns_search_domain *d;
@@ -957,7 +1137,10 @@ write_resolv_conf_entries(FILE *f, struct interface_ip_settings *ip)
                if (!str)
                        continue;
 
-               fprintf(f, "nameserver %s\n", str);
+               if (s->af == AF_INET6 && IN6_IS_ADDR_LINKLOCAL(&s->addr.in6))
+                       fprintf(f, "nameserver %s%%%s\n", str, dev);
+               else
+                       fprintf(f, "nameserver %s\n", str);
        }
 
        vlist_simple_for_each_element(&ip->dns_search, d, node) {
@@ -992,9 +1175,9 @@ interface_write_resolv_conf(void)
                        continue;
 
                fprintf(f, "# Interface %s\n", iface->name);
-               write_resolv_conf_entries(f, &iface->config_ip);
+               write_resolv_conf_entries(f, &iface->config_ip, iface->ifname);
                if (!iface->proto_ip.no_dns)
-                       write_resolv_conf_entries(f, &iface->proto_ip);
+                       write_resolv_conf_entries(f, &iface->proto_ip, iface->ifname);
        }
        fflush(f);
        rewind(f);
@@ -1021,9 +1204,11 @@ void interface_ip_set_enabled(struct interface_ip_settings *ip, bool enabled)
        struct device_addr *addr;
        struct device_route *route;
        struct device *dev;
+       struct interface *iface;
 
        ip->enabled = enabled;
-       dev = ip->iface->l3_dev.dev;
+       iface = ip->iface;
+       dev = iface->l3_dev.dev;
        if (!dev)
                return;
 
@@ -1031,10 +1216,14 @@ void interface_ip_set_enabled(struct interface_ip_settings *ip, bool enabled)
                if (addr->enabled == enabled)
                        continue;
 
-               if (enabled)
+               if (enabled) {
                        system_add_address(dev, addr);
-               else
+                       if (iface->metric)
+                               interface_handle_subnet_route(iface, addr, true);
+               } else {
+                       interface_handle_subnet_route(iface, addr, false);
                        system_del_address(dev, addr);
+               }
                addr->enabled = enabled;
        }
 
@@ -1051,7 +1240,17 @@ void interface_ip_set_enabled(struct interface_ip_settings *ip, bool enabled)
                        if (!(route->flags & DEVROUTE_METRIC))
                                route->metric = ip->iface->metric;
 
-                       system_add_route(dev, route);
+                       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
                        system_del_route(dev, route);
                route->enabled = _enabled;
@@ -1064,8 +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);
 
-       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
@@ -1121,7 +1321,6 @@ interface_ip_init(struct interface *iface)
        __interface_ip_init(&iface->proto_ip, iface);
        __interface_ip_init(&iface->config_ip, iface);
        vlist_init(&iface->host_routes, route_cmp, interface_update_host_route);
-
 }
 
 static void