Rewrite IPv6 prefix assignment

diff --git a/config.c b/config.c
index 556daf8f0efa91f3406175ee47ff5ca82554af2e..3b44bcee9eeddd980810f231dbca88ed81407abc 100644 (file)
--- a/config.c
+++ b/config.c
@@ -474,5 +474,6 @@ config_init_all(void)
        device_init_pending();
        vlist_flush(&interfaces);
        device_free_unused(NULL);
+       interface_refresh_assignments(false);
        interface_start_pending();
 }

diff --git a/interface-ip.c b/interface-ip.c
index 21c603dfbbdf66b429fb1c87cb0fc481e2d5939d..ed95b2ee264f3360692ae8f408c7fef40aad07c6 100644 (file)
--- a/interface-ip.c
+++ b/interface-ip.c
@@ -449,10 +449,10 @@ interface_update_host_route(struct vlist_tree *tree,
 
 
 static void
-interface_set_prefix_address(struct interface *iface, bool add,
-               struct device_prefix_assignment *assignment)
+interface_set_prefix_address(struct device_prefix_assignment *assignment,
+               const struct device_prefix *prefix, struct interface *iface, bool add)
 {
-       struct interface *uplink = assignment->prefix->iface;
+       const struct interface *uplink = prefix->iface;
        if (!iface->l3_dev.dev)
                return;
 
@@ -460,113 +460,146 @@ interface_set_prefix_address(struct interface *iface, bool add,
 
        struct device_addr addr;
        memset(&addr, 0, sizeof(addr));
-       addr.addr.in6 = assignment->addr;
+       addr.addr.in6 = prefix->addr;
+       addr.addr.in6.s6_addr32[1] |= htonl(assignment->assigned);
+       addr.addr.in6.s6_addr[15] += 1;
        addr.mask = assignment->length;
        addr.flags = DEVADDR_INET6;
-       addr.preferred_until = assignment->prefix->preferred_until;
-       addr.valid_until = assignment->prefix->valid_until;
-
-       if (!add) {
-               if (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_add_address(l3_downlink, &addr);
-               }
-       } else {
+       addr.preferred_until = prefix->preferred_until;
+       addr.valid_until = prefix->valid_until;
+
+       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_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);
-
                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;
+       }
+}
+
+static bool interface_prefix_assign(struct list_head *list,
+               struct device_prefix_assignment *assign)
+{
+       int32_t current = 0, asize = (1 << (64 - assign->length)) - 1;
+       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) {
+                               list_add_tail(&assign->head, &c->head);
+                               return true;
+                       }
+               } else if (assign->assigned == -1) {
+                       current = (current + asize) & (~asize);
+                       if (current + asize < c->assigned) {
+                               assign->assigned = current;
+                               list_add_tail(&assign->head, &c->head);
+                               return true;
+                       }
+               }
+               current = (c->assigned + (1 << (64 - c->length)));
        }
-       assignment->enabled = add;
+       return false;
 }
 
-
-static void
-interface_update_prefix_assignments(struct vlist_tree *tree,
-                            struct vlist_node *node_new,
-                            struct vlist_node *node_old)
+static void interface_update_prefix_assignments(struct device_prefix *prefix, bool setup)
 {
-       struct device_prefix_assignment *old, *new;
-       old = container_of(node_old, struct device_prefix_assignment, node);
-       new = container_of(node_new, struct device_prefix_assignment, node);
-
-       // Assignments persist across interface reloads etc.
-       // so use indirection to avoid dangling pointers
-       struct interface *iface = vlist_find(&interfaces,
-                       (node_new) ? new->name : old->name, iface, node);
-
-       if (node_old && node_new) {
-               new->addr = old->addr;
-               new->length = old->length;
-       } else if (node_old) {
-               if (iface)
-                       interface_set_prefix_address(iface, false, old);
-               free(old);
-       } else if (node_new) {
-               struct device_prefix *prefix = new->prefix;
-               uint64_t want = 1ULL << (64 - new->length);
-               prefix->avail &= ~(want - 1);
-               prefix->avail -= want;
-
-               // Invert assignment
-               uint64_t assigned = ~prefix->avail;
-               assigned &= (1ULL << (64 - prefix->length)) - 1;
-               assigned &= ~(want - 1);
+       struct device_prefix_assignment *c;
+       struct interface *iface;
 
-               // Assignment
-               new->addr = prefix->addr;
-               new->addr.s6_addr32[0] |=
-                               htonl(assigned >> 32);
-               new->addr.s6_addr32[1] |=
-                               htonl(assigned & 0xffffffffU);
-               new->addr.s6_addr[15] += 1;
+       // Delete all assignments
+       while (!list_empty(&prefix->assignments)) {
+               c = list_first_entry(&prefix->assignments,
+                               struct device_prefix_assignment, head);
+               if ((iface = vlist_find(&interfaces, c->name, iface, node)))
+                       interface_set_prefix_address(c, prefix, iface, false);
+               list_del(&c->head);
+               free(c);
        }
 
-       if (node_new && (iface->state == IFS_UP || iface->state == IFS_SETUP))
-               interface_set_prefix_address(iface, true, new);
-}
-
+       if (!setup)
+               return;
 
-void
-interface_ip_set_prefix_assignment(struct device_prefix *prefix,
-               struct interface *iface, uint8_t length)
-{
-       struct device_prefix_assignment *assignment;
+       // End-of-assignment sentinel
+       c = malloc(sizeof(*c) + 1);
+       c->assigned = 1 << (64 - prefix->length);
+       c->length = 64;
+       c->name[0] = 0;
+       list_add(&c->head, &prefix->assignments);
+
+       // Excluded prefix
+       if (prefix->excl_length > 0) {
+               const char name[] = "!excluded";
+               c = malloc(sizeof(*c) + sizeof(name));
+               c->assigned = ntohl(prefix->excl_addr.s6_addr32[1]) &
+                               ((1 << (64 - prefix->length)) - 1);
+               c->length = prefix->excl_length;
+               memcpy(c->name, name, sizeof(name));
+               list_add(&c->head, &prefix->assignments);
+       }
+
+       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)
+                       continue;
 
-       if (!length || length > 64) {
-               assignment = vlist_find(prefix->assignments, iface->name, assignment, node);
-               if (assignment)
-                       interface_set_prefix_address(iface, false, assignment);
-       } else {
-               uint64_t want = 1ULL << (64 - length);
-               char *name;
+               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->enabled = false;
+               memcpy(c->name, iface->name, namelen);
+
+               // First process all custom assignments, put all others in later-list
+               if (c->assigned == -1 || !interface_prefix_assign(&prefix->assignments, c)) {
+                       if (c->assigned != -1) {
+                               c->assigned = -1;
+                               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);
+               }
+       }
 
-               if (prefix->avail < want && prefix->avail > 0) {
-                       do {
-                               want = 1ULL << (64 - ++length);
-                       } while (want > prefix->avail);
+       // Then try to assign all other + failed custom assignments
+       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)) {
+                       netifd_log_message(L_WARNING, "Failed to assign subprefix "
+                                       "of size %hhu for %s\n", c->length, c->name);
+                       free(c);
                }
+       }
 
-               if (prefix->avail < want)
-                       return;
+       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);
+}
 
-               assignment = calloc_a(sizeof(*assignment),
-                       &name, strlen(iface->name) + 1);
-               assignment->prefix = prefix;
-               assignment->length = length;
-               assignment->name = strcpy(name, iface->name);
 
-               vlist_add(prefix->assignments, &assignment->node, assignment->name);
+void interface_refresh_assignments(bool hint)
+{
+       static bool refresh = false;
+       if (!hint && refresh) {
+               struct device_prefix *p;
+               list_for_each_entry(p, &prefixes, head)
+                       interface_update_prefix_assignments(p, true);
        }
+       refresh = hint;
 }
 
+
 static void
 interface_update_prefix(struct vlist_tree *tree,
                             struct vlist_node *node_new,
@@ -583,55 +616,43 @@ interface_update_prefix(struct vlist_tree *tree,
        route.mask = (node_new) ? prefix_new->length : prefix_old->length;
        route.addr.in6 = (node_new) ? prefix_new->addr : prefix_old->addr;
 
-       if (node_old && node_new) {
-               prefix_new->avail = prefix_old->avail;
-               prefix_new->assignments = prefix_old->assignments;
-               prefix_old->assignments = NULL;
-
-               // Update all assignments
-               struct device_prefix_assignment *assignment;
-               struct vlist_tree *assignments = prefix_new->assignments;
-               vlist_for_each_element(assignments, assignment, node) {
-                       assignment->prefix = prefix_new;
-                       assignments->update(assignments,
-                                       &assignment->node, &assignment->node);
-               }
-       } else if (node_new) {
-               prefix_new->avail = 1ULL << (64 - prefix_new->length);
-               prefix_new->assignments = calloc(1, sizeof(*prefix_new->assignments));
-               vlist_init(prefix_new->assignments, avl_strcmp,
-                               interface_update_prefix_assignments);
+       struct device_prefix_assignment *c;
+       struct interface *iface;
 
-               // Create initial assignments for interfaces
-               struct interface *iface;
-               vlist_for_each_element(&interfaces, iface, node)
-                       interface_ip_set_prefix_assignment(prefix_new, iface,
-                                       iface->proto_ip.assignment_length);
+       if (node_old && node_new) {
+               // Move assignments and refresh addresses to update valid times
+               list_splice_init(&prefix_old->assignments, &prefix_new->assignments);
 
+               list_for_each_entry(c, &prefix_new->assignments, head)
+                       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
                system_add_route(NULL, &route);
-       }
 
-       if (node_old) {
+               INIT_LIST_HEAD(&prefix_new->assignments);
+               interface_update_prefix_assignments(prefix_new, true);
+       } else if (node_old) {
+               interface_update_prefix_assignments(prefix_old, false);
+
                // Remove null-route
                system_del_route(NULL, &route);
+       }
 
+       if (node_old) {
                list_del(&prefix_old->head);
-
-               if (prefix_old->assignments) {
-                       vlist_flush_all(prefix_old->assignments);
-                       free(prefix_old->assignments);
-               }
                free(prefix_old);
        }
 
        if (node_new)
                list_add(&prefix_new->head, &prefixes);
+
 }
 
 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)
+               uint8_t length, time_t valid_until, time_t preferred_until,
+               struct in6_addr *excl_addr, uint8_t excl_length)
 {
        struct device_prefix *prefix = calloc(1, sizeof(*prefix));
        prefix->length = length;
@@ -640,6 +661,11 @@ interface_ip_add_device_prefix(struct interface *iface, struct in6_addr *addr,
        prefix->valid_until = valid_until;
        prefix->iface = iface;
 
+       if (excl_addr) {
+               prefix->excl_addr = *excl_addr;
+               prefix->excl_length = excl_length;
+       }
+
        if (iface)
                vlist_add(&iface->proto_ip.prefix, &prefix->node, &prefix->addr);
        else
@@ -675,7 +701,8 @@ interface_ip_set_ula_prefix(const char *prefix)
                if (ula_prefix)
                        interface_update_prefix(NULL, NULL, &ula_prefix->node);
 
-               ula_prefix = interface_ip_add_device_prefix(NULL, &addr, length, 0, 0);
+               ula_prefix = interface_ip_add_device_prefix(NULL, &addr, length,
+                               0, 0, NULL, 0);
        }
 }
 
@@ -866,6 +893,13 @@ void interface_ip_set_enabled(struct interface_ip_settings *ip, bool enabled)
                        system_del_route(dev, route);
                route->enabled = _enabled;
        }
+
+       struct device_prefix *c;
+       struct device_prefix_assignment *a;
+       list_for_each_entry(c, &prefixes, head)
+               list_for_each_entry(a, &c->assignments, head)
+                       if (!strcmp(a->name, ip->iface->name))
+                               interface_set_prefix_address(a, c, ip->iface, enabled);
 }
 
 void

diff --git a/interface-ip.h b/interface-ip.h
index 9b4f0a1d54e009038f2b6e0ef0f31f1c3c875f64..91358b84944bb1311cd06a9d15893e1717316711 100644 (file)
--- a/interface-ip.h
+++ b/interface-ip.h
@@ -43,26 +43,27 @@ union if_addr {
        struct in6_addr in6;
 };
 
+struct device_prefix_assignment {
+       struct list_head head;
+       int32_t assigned;
+       uint8_t length;
+       bool enabled;
+       char name[];
+};
+
 struct device_prefix {
        struct vlist_node node;
        struct list_head head;
-       struct vlist_tree *assignments;
+       struct list_head assignments;
        struct interface *iface;
-       uint64_t avail;
        time_t valid_until;
        time_t preferred_until;
 
        struct in6_addr addr;
-       uint8_t length;
-};
+       struct in6_addr excl_addr;
 
-struct device_prefix_assignment {
-       struct vlist_node node;
-       struct device_prefix *prefix;
-       struct in6_addr addr;
-       bool enabled;
        uint8_t length;
-       char *name;
+       uint8_t excl_length;
 };
 
 struct device_addr {
@@ -131,10 +132,10 @@ void interface_ip_update_metric(struct interface_ip_settings *ip, int metric);
 
 struct interface *interface_ip_add_target_route(union if_addr *addr, bool v6);
 
-void interface_ip_set_prefix_assignment(struct device_prefix *prefix,
-               struct interface *iface, uint8_t length);
 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 *addr, uint8_t length, time_t valid_until, time_t preferred_until,
+               struct in6_addr *excl_addr, uint8_t excl_length);
 void interface_ip_set_ula_prefix(const char *prefix);
+void interface_refresh_assignments(bool hint);
 
 #endif

diff --git a/interface.c b/interface.c
index b304e00e6a407b251132840e6d664aa6833e6de9..335e0be3fd841803c7cfce86a3110d1fd3d68989 100644 (file)
--- a/interface.c
+++ b/interface.c
@@ -37,6 +37,8 @@ enum {
        IFACE_ATTR_DNS_SEARCH,
        IFACE_ATTR_METRIC,
        IFACE_ATTR_INTERFACE,
+       IFACE_ATTR_IP6ASSIGN,
+       IFACE_ATTR_IP6HINT,
        IFACE_ATTR_MAX
 };
 
@@ -50,6 +52,8 @@ static const struct blobmsg_policy iface_attrs[IFACE_ATTR_MAX] = {
        [IFACE_ATTR_DNS] = { .name = "dns", .type = BLOBMSG_TYPE_ARRAY },
        [IFACE_ATTR_DNS_SEARCH] = { .name = "dns_search", .type = BLOBMSG_TYPE_ARRAY },
        [IFACE_ATTR_INTERFACE] = { .name = "interface", .type = BLOBMSG_TYPE_STRING },
+       [IFACE_ATTR_IP6ASSIGN] = { .name = "ip6assign", .type = BLOBMSG_TYPE_INT32 },
+       [IFACE_ATTR_IP6HINT] = { .name = "ip6hint", .type = BLOBMSG_TYPE_STRING },
 };
 
 static const union config_param_info iface_attr_info[IFACE_ATTR_MAX] = {
@@ -483,6 +487,14 @@ interface_init(struct interface *iface, const char *name,
        if ((cur = tb[IFACE_ATTR_METRIC]))
                iface->metric = blobmsg_get_u32(cur);
 
+       if ((cur = tb[IFACE_ATTR_IP6ASSIGN]))
+               iface->config_ip.assignment_length = blobmsg_get_u32(cur);
+
+       iface->config_ip.assignment_hint = -1;
+       if ((cur = tb[IFACE_ATTR_IP6HINT]))
+               iface->config_ip.assignment_hint = strtol(blobmsg_get_string(cur), NULL, 16) &
+                               ~((1 << (64 - iface->config_ip.assignment_length)) - 1);
+
        iface->config_autostart = iface->autostart;
 }
 
@@ -755,6 +767,9 @@ interface_change_config(struct interface *if_old, struct interface *if_new)
                interface_ip_set_enabled(&if_old->proto_ip, if_new->proto_ip.enabled);
        }
 
+       if (UPDATE(config_ip.assignment_length) || UPDATE(config_ip.assignment_hint))
+               interface_refresh_assignments(true);
+
        interface_write_resolv_conf();
 
 #undef UPDATE

diff --git a/interface.h b/interface.h
index b8c9cad21d764ec1315f5b8c0ac303502641ea7a..0c56b3640c30376857173d1fede1785316d2375c 100644 (file)
--- a/interface.h
+++ b/interface.h
@@ -59,7 +59,9 @@ struct interface_ip_settings {
        bool enabled;
        bool no_defaultroute;
        bool no_dns;
+
        uint8_t assignment_length;
+       int32_t assignment_hint;
 
        struct vlist_tree addr;
        struct vlist_tree route;

diff --git a/proto-static.c b/proto-static.c
index 833b6b844199c4d89bb64e3212a6d2a5da16833a..77a536a0cdce2375d8a08e8a4675bb44e0122481 100644 (file)
--- a/proto-static.c
+++ b/proto-static.c
@@ -54,6 +54,7 @@ static_handler(struct interface_proto_state *proto,
        case PROTO_CMD_TEARDOWN:
                break;
        }
+
        return ret;
 }
 

diff --git a/proto.c b/proto.c
index 3d611a274f5ef067bc2511e77d93db3a2ac01e3b..31b36488b33d501c7d06ee683257ce2724808337 100644 (file)
--- a/proto.c
+++ b/proto.c
@@ -34,7 +34,6 @@ enum {
        OPT_GATEWAY,
        OPT_IP6GW,
        OPT_IP6PREFIX,
-       OPT_IP6ASSIGN,
        __OPT_MAX,
 };
 
@@ -46,7 +45,6 @@ static const struct blobmsg_policy proto_ip_attributes[__OPT_MAX] = {
        [OPT_GATEWAY] = { .name = "gateway", .type = BLOBMSG_TYPE_STRING },
        [OPT_IP6GW] = { .name = "ip6gw", .type = BLOBMSG_TYPE_STRING },
        [OPT_IP6PREFIX] = { .name = "ip6prefix", .type = BLOBMSG_TYPE_ARRAY },
-       [OPT_IP6ASSIGN] = { .name = "ip6assign", .type = BLOBMSG_TYPE_INT32 },
 };
 
 static const union config_param_info proto_ip_attr_info[__OPT_MAX] = {
@@ -257,25 +255,6 @@ parse_gateway_option(struct interface *iface, struct blob_attr *attr, bool v6)
        return true;
 }
 
-static bool
-parse_ip6assign_option(struct interface *iface, struct blob_attr *attr)
-{
-       uint8_t oldval = iface->proto_ip.assignment_length;
-       uint8_t newval = blobmsg_get_u32(attr);
-
-       struct device_prefix *prefix;
-       list_for_each_entry(prefix, &prefixes, head) {
-               if (oldval && oldval != newval)
-                       interface_ip_set_prefix_assignment(prefix, iface, 0);
-
-               if (newval && newval <= 64)
-                       interface_ip_set_prefix_assignment(prefix, iface, newval);
-       }
-
-       iface->proto_ip.assignment_length = newval;
-       return true;
-}
-
 static bool
 parse_prefix_option(struct interface *iface, const char *str, size_t len)
 {
@@ -294,18 +273,33 @@ parse_prefix_option(struct interface *iface, const char *str, size_t len)
 
        char *prefstr = strtok_r(NULL, ",", &saveptr);
        char *validstr = (!prefstr) ? NULL : strtok_r(NULL, ",", &saveptr);
+       char *excludestr = (!validstr) ? NULL : strtok_r(NULL, ",", &saveptr);
 
        uint32_t pref = (!prefstr) ? 0 : strtoul(prefstr, NULL, 10);
        uint32_t valid = (!validstr) ? 0 : strtoul(validstr, NULL, 10);
 
-       uint8_t length = strtoul(lengthstr, NULL, 10);
+       uint8_t length = strtoul(lengthstr, NULL, 10), excl_length = 0;
        if (length < 1 || length > 64)
                return false;
 
-       struct in6_addr addr;
+       struct in6_addr addr, excluded, *excludedp = NULL;
        if (inet_pton(AF_INET6, addrstr, &addr) < 1)
                return false;
 
+       if (excludestr) {
+               char *sep = strchr(excludestr, '/');
+               if (!sep)
+                       return false;
+
+               *sep = 0;
+               excl_length = atoi(sep + 1);
+
+               if (inet_pton(AF_INET6, excludestr, &excluded) < 1)
+                       return false;
+
+               excludedp = &excluded;
+       }
+
        time_t now = system_get_rtime();
        time_t preferred_until = 0;
        if (prefstr && pref != 0xffffffffU)
@@ -316,7 +310,8 @@ parse_prefix_option(struct interface *iface, const char *str, size_t len)
                valid_until = valid + now;
 
        interface_ip_add_device_prefix(iface, &addr, length,
-                       valid_until, preferred_until);
+                       valid_until, preferred_until,
+                       excludedp, excl_length);
        return true;
 }
 
@@ -392,10 +387,6 @@ proto_apply_static_ip_settings(struct interface *iface, struct blob_attr *attr)
                        goto out;
        }
 
-       if ((cur = tb[OPT_IP6ASSIGN]))
-               if (!parse_ip6assign_option(iface, cur))
-                       goto out;
-
        return 0;
 
 error:
@@ -436,10 +427,6 @@ proto_apply_ip_settings(struct interface *iface, struct blob_attr *attr, bool ex
                        goto out;
        }
 
-       if ((cur = tb[OPT_IP6ASSIGN]))
-               if (!parse_ip6assign_option(iface, cur))
-                       goto out;
-
        return 0;
 
 out:

diff --git a/ubus.c b/ubus.c
index f2421cc3f66b23afa892ea1fca7ba79e093ea692..10368998c32b57db83387d5ec43de4833316536f 100644 (file)
--- a/ubus.c
+++ b/ubus.c
@@ -457,11 +457,17 @@ interface_ip_dump_prefix_list(struct interface_ip_settings *ip)
 
                c = blobmsg_open_table(&b, "assigned");
                struct device_prefix_assignment *assign;
-               vlist_for_each_element(prefix->assignments, assign, node) {
+               list_for_each_entry(assign, &prefix->assignments, head) {
+                       if (!assign->name[0])
+                               continue;
+
+                       struct in6_addr addr = prefix->addr;
+                       addr.s6_addr32[1] |= htonl(assign->assigned);
+
                        void *d = blobmsg_open_table(&b, assign->name);
 
                        buf = blobmsg_alloc_string_buffer(&b, "address", buflen);
-                       inet_ntop(AF_INET6, &assign->addr, buf, buflen);
+                       inet_ntop(AF_INET6, &addr, buf, buflen);
                        blobmsg_add_string_buffer(&b);
 
                        blobmsg_add_u32(&b, "mask", assign->length);
@@ -486,14 +492,17 @@ interface_ip_dump_prefix_assignment_list(struct interface *iface)
        struct device_prefix *prefix;
        list_for_each_entry(prefix, &prefixes, head) {
                struct device_prefix_assignment *assign;
-               vlist_for_each_element(prefix->assignments, assign, node) {
+               list_for_each_entry(assign, &prefix->assignments, head) {
                        if (strcmp(assign->name, iface->name))
                                continue;
 
+                       struct in6_addr addr = prefix->addr;
+                       addr.s6_addr32[1] |= htonl(assign->assigned);
+
                        a = blobmsg_open_table(&b, NULL);
 
                        buf = blobmsg_alloc_string_buffer(&b, "address", buflen);
-                       inet_ntop(AF_INET6, &assign->addr, buf, buflen);
+                       inet_ntop(AF_INET6, &addr, buf, buflen);
                        blobmsg_add_string_buffer(&b);
 
                        blobmsg_add_u32(&b, "mask", assign->length);