dhcpv6-ia: make free_dhcpv6_assignment static
[project/odhcpd.git] / src / dhcpv6-ia.c
index 0bcb453..35c6ae3 100644 (file)
@@ -1,5 +1,6 @@
 /**
  * Copyright (C) 2013 Steven Barth <steven@midlink.org>
+ * Copyright (C) 2016 Hans Dedecker <dedeckeh@gmail.com>
  *
  * This program is free software; you can redistribute it and/or modify
  * it under the terms of the GNU General Public License v2 as published by
 #include <arpa/inet.h>
 #include <sys/timerfd.h>
 
-
-static void update(struct interface *iface);
+static void free_dhcpv6_assignment(struct dhcpv6_assignment *c);
 static void reconf_timer(struct uloop_timeout *event);
 static struct uloop_timeout reconf_event = {.cb = reconf_timer};
 static uint32_t serial = 0;
 static uint8_t statemd5[16];
 
-
 int dhcpv6_ia_init(void)
 {
        uloop_timeout_set(&reconf_event, 2000);
        return 0;
 }
 
-
-void free_dhcpv6_assignment(struct dhcpv6_assignment *c)
-{
-       if (c->managed_sock.fd.registered) {
-               ustream_free(&c->managed_sock.stream);
-               close(c->managed_sock.fd.fd);
-       }
-
-       if (c->head.next)
-               list_del(&c->head);
-
-       free(c->managed);
-       free(c->hostname);
-       free(c);
-}
-
-
 int setup_dhcpv6_ia_interface(struct interface *iface, bool enable)
 {
        if (!enable && iface->ia_assignments.next) {
@@ -84,25 +66,27 @@ int setup_dhcpv6_ia_interface(struct interface *iface, bool enable)
                                syslog(LOG_ERR, "Calloc failed for border on interface %s", iface->ifname);
                                return -1;
                        }
-                       
+
                        border->length = 64;
                        list_add(&border->head, &iface->ia_assignments);
                }
 
-               update(iface);
-
                // Parse static entries
                struct lease *lease;
                list_for_each_entry(lease, &leases, head) {
                        // Construct entry
-                       struct dhcpv6_assignment *a = calloc(1, sizeof(*a) + lease->duid_len);
+                       size_t duid_len = lease->duid_len ? lease->duid_len : 14;
+                       struct dhcpv6_assignment *a = calloc(1, sizeof(*a) + duid_len);
                        if (!a) {
                                syslog(LOG_ERR, "Calloc failed for static lease assignment on interface %s",
                                        iface->ifname);
                                return -1;
                        }
 
-                       a->clid_len = lease->duid_len;
+                       if (lease->dhcpv4_leasetime > 0)
+                               a->leasetime = lease->dhcpv4_leasetime;
+
+                       a->clid_len = duid_len;
                        a->length = 128;
                        if (lease->hostid) {
                                a->assigned = lease->hostid;
@@ -111,8 +95,12 @@ int setup_dhcpv6_ia_interface(struct interface *iface, bool enable)
                                a->assigned = ((i4a / 100) << 8) | (((i4a % 100) / 10) << 4) | (i4a % 10);
                        }
                        odhcpd_urandom(a->key, sizeof(a->key));
-                       memcpy(a->clid_data, lease->duid, a->clid_len);
+                       memcpy(a->clid_data, lease->duid, lease->duid_len);
                        memcpy(a->mac, lease->mac.ether_addr_octet, sizeof(a->mac));
+                       /* Static assignment */
+                       a->flags |= OAF_STATIC;
+                       /* Infinite valid */
+                       a->valid_until = 0;
 
                        // Assign to all interfaces
                        struct dhcpv6_assignment *c;
@@ -140,6 +128,20 @@ int setup_dhcpv6_ia_interface(struct interface *iface, bool enable)
        return 0;
 }
 
+static void free_dhcpv6_assignment(struct dhcpv6_assignment *c)
+{
+       if (c->managed_sock.fd.registered) {
+               ustream_free(&c->managed_sock.stream);
+               close(c->managed_sock.fd.fd);
+       }
+
+       if (c->head.next)
+               list_del(&c->head);
+
+       free(c->managed);
+       free(c->hostname);
+       free(c);
+}
 
 static int send_reconf(struct interface *iface, struct dhcpv6_assignment *assign)
 {
@@ -204,7 +206,6 @@ static int send_reconf(struct interface *iface, struct dhcpv6_assignment *assign
        return odhcpd_send(iface->dhcpv6_event.uloop.fd, &assign->peer, &iov, 1, iface);
 }
 
-
 void dhcpv6_write_statefile(void)
 {
        md5_ctx_t md5;
@@ -233,7 +234,7 @@ void dhcpv6_write_statefile(void)
                        if (iface->dhcpv6 == RELAYD_SERVER && iface->ia_assignments.next) {
                                struct dhcpv6_assignment *c;
                                list_for_each_entry(c, &iface->ia_assignments, head) {
-                                       if (c->clid_len == 0 || c->managed_size < 0)
+                                       if (!(c->flags & OAF_BOUND) || c->managed_size < 0)
                                                continue;
 
                                        char ipbuf[INET6_ADDRSTRLEN];
@@ -242,11 +243,12 @@ void dhcpv6_write_statefile(void)
                                        odhcpd_hexlify(duidbuf, c->clid_data, c->clid_len);
 
                                        // iface DUID iaid hostname lifetime assigned length [addrs...]
-                                       int l = snprintf(leasebuf, sizeof(leasebuf), "# %s %s %x %s %u %x %u ",
+                                       int l = snprintf(leasebuf, sizeof(leasebuf), "# %s %s %x %s %ld %x %u ",
                                                        iface->ifname, duidbuf, ntohl(c->iaid),
                                                        (c->hostname ? c->hostname : "-"),
-                                                       (unsigned)(c->valid_until > now ?
-                                                                       (c->valid_until - now + wall_time) : 0),
+                                                       (c->valid_until > now ?
+                                                               (c->valid_until - now + wall_time) :
+                                                               (INFINITE_VALID(c->valid_until) ? -1 : 0)),
                                                        c->assigned, (unsigned)c->length);
 
                                        struct in6_addr addr;
@@ -261,7 +263,7 @@ void dhcpv6_write_statefile(void)
                                                        m = i;
 
                                        for (size_t i = 0; i < addrlen; ++i) {
-                                               if (addrs[i].prefix > 96 || c->valid_until <= now ||
+                                               if (addrs[i].prefix > 96 || (!INFINITE_VALID(c->valid_until) && c->valid_until <= now) ||
                                                                (iface->managed < RELAYD_MANAGED_NO_AFLAG && i != m &&
                                                                                addrs[i].prefix == 64))
                                                        continue;
@@ -278,9 +280,9 @@ void dhcpv6_write_statefile(void)
                                                        fputs(ipbuf, fp);
 
                                                        char b[256];
-                                                       if (dn_expand(iface->search, iface->search + iface->search_len,
-                                                                       iface->search, b, sizeof(b)) > 0)
-                                                               fprintf(fp, "\t%s.%s", c->hostname, b);
+                                                       if (dn_expand(iface->search, iface->search + iface->search_len,
+                                                                       iface->search, b, sizeof(b)) > 0)
+                                                               fprintf(fp, "\t%s.%s", c->hostname, b);
 
                                                        fprintf(fp, "\t%s\n", c->hostname);
                                                        md5_hash(ipbuf, strlen(ipbuf), &md5);
@@ -298,29 +300,33 @@ void dhcpv6_write_statefile(void)
                        if (iface->dhcpv4 == RELAYD_SERVER && iface->dhcpv4_assignments.next) {
                                struct dhcpv4_assignment *c;
                                list_for_each_entry(c, &iface->dhcpv4_assignments, head) {
+                                       if (!(c->flags & OAF_BOUND))
+                                               continue;
+
                                        char ipbuf[INET6_ADDRSTRLEN];
                                        char leasebuf[512];
                                        char duidbuf[16];
                                        odhcpd_hexlify(duidbuf, c->hwaddr, sizeof(c->hwaddr));
 
                                        // iface DUID iaid hostname lifetime assigned length [addrs...]
-                                       int l = snprintf(leasebuf, sizeof(leasebuf), "# %s %s ipv4 %s %u %x 32 ",
+                                       int l = snprintf(leasebuf, sizeof(leasebuf), "# %s %s ipv4 %s %ld %x 32 ",
                                                        iface->ifname, duidbuf,
                                                        (c->hostname ? c->hostname : "-"),
-                                                       (unsigned)(c->valid_until > now ?
-                                                                       (c->valid_until - now + wall_time) : 0),
+                                                       (c->valid_until > now ?
+                                                               (c->valid_until - now + wall_time) :
+                                                               (INFINITE_VALID(c->valid_until) ? -1 : 0)),
                                                        c->addr);
 
                                        struct in_addr addr = {htonl(c->addr)};
                                        inet_ntop(AF_INET, &addr, ipbuf, sizeof(ipbuf) - 1);
 
-                                       if (c->hostname[0]) {
+                                       if (c->hostname) {
                                                fputs(ipbuf, fp);
 
                                                char b[256];
-                                               if (dn_expand(iface->search, iface->search + iface->search_len,
-                                                               iface->search, b, sizeof(b)) > 0)
-                                                       fprintf(fp, "\t%s.%s", c->hostname, b);
+                                               if (dn_expand(iface->search, iface->search + iface->search_len,
+                                                               iface->search, b, sizeof(b)) > 0)
+                                                       fprintf(fp, "\t%s.%s", c->hostname, b);
 
                                                fprintf(fp, "\t%s\n", c->hostname);
                                                md5_hash(ipbuf, strlen(ipbuf), &md5);
@@ -363,11 +369,10 @@ static void apply_lease(struct interface *iface, struct dhcpv6_assignment *a, bo
                struct in6_addr prefix = addrs[i].addr;
                prefix.s6_addr32[1] |= htonl(a->assigned);
                odhcpd_setup_route(&prefix, (a->managed_size) ? addrs[i].prefix : a->length,
-                               iface, &a->peer.sin6_addr, add);
+                               iface, &a->peer.sin6_addr, 1024, add);
        }
 }
 
-
 // More data was received from TCP connection
 static void managed_handle_pd_data(struct ustream *s, _unused int bytes_new)
 {
@@ -449,8 +454,6 @@ static void managed_handle_pd_done(struct ustream *s)
                c->reconf_cnt = 1;
 }
 
-
-
 static bool assign_pd(struct interface *iface, struct dhcpv6_assignment *assign)
 {
        struct dhcpv6_assignment *c;
@@ -524,7 +527,6 @@ static bool assign_pd(struct interface *iface, struct dhcpv6_assignment *assign)
        return false;
 }
 
-
 static bool assign_na(struct interface *iface, struct dhcpv6_assignment *assign)
 {
        // Seed RNG with checksum of DUID
@@ -556,108 +558,75 @@ static bool assign_na(struct interface *iface, struct dhcpv6_assignment *assign)
        return false;
 }
 
-
-static int prefixcmp(const void *va, const void *vb)
+void dhcpv6_ia_preupdate(struct interface *iface)
 {
-       const struct odhcpd_ipaddr *a = va, *b = vb;
-       uint32_t a_pref = ((a->addr.s6_addr[0] & 0xfe) != 0xfc) ? a->preferred : 1;
-       uint32_t b_pref = ((b->addr.s6_addr[0] & 0xfe) != 0xfc) ? b->preferred : 1;
-       return (a_pref < b_pref) ? 1 : (a_pref > b_pref) ? -1 : 0;
-}
+       if (iface->dhcpv6 != RELAYD_SERVER)
+               return;
 
+       struct dhcpv6_assignment *c, *border = list_last_entry(
+                       &iface->ia_assignments, struct dhcpv6_assignment, head);
+       list_for_each_entry(c, &iface->ia_assignments, head)
+               if (c != border && !iface->managed)
+                       apply_lease(iface, c, false);
+}
 
-static void update(struct interface *iface)
+void dhcpv6_ia_postupdate(struct interface *iface, time_t now)
 {
-       struct odhcpd_ipaddr addr[8];
-       memset(addr, 0, sizeof(addr));
-       int len = odhcpd_get_interface_addresses(iface->ifindex, addr, 8);
-
-       if (len < 0)
+       if (iface->dhcpv6 != RELAYD_SERVER)
                return;
 
-       qsort(addr, len, sizeof(*addr), prefixcmp);
-
-       time_t now = odhcpd_time();
        int minprefix = -1;
-
-       for (int i = 0; i < len; ++i) {
-               if (addr[i].preferred > 0 && addr[i].prefix < 64 &&
-                               addr[i].prefix > minprefix)
-                       minprefix = addr[i].prefix;
-
-               addr[i].addr.s6_addr32[3] = 0;
-
-               if (addr[i].preferred < UINT32_MAX - now)
-                       addr[i].preferred += now;
-
-               if (addr[i].valid < UINT32_MAX - now)
-                       addr[i].valid += now;
+       for (size_t i = 0; i < iface->ia_addr_len; ++i) {
+               if (iface->ia_addr[i].preferred > (uint32_t)now &&
+                               iface->ia_addr[i].prefix < 64 &&
+                               iface->ia_addr[i].prefix > minprefix)
+                       minprefix = iface->ia_addr[i].prefix;
        }
 
-       struct dhcpv6_assignment *border = list_last_entry(&iface->ia_assignments, struct dhcpv6_assignment, head);
+       struct dhcpv6_assignment *border = list_last_entry(
+                       &iface->ia_assignments, struct dhcpv6_assignment, head);
        if (minprefix > 32 && minprefix <= 64)
                border->assigned = 1U << (64 - minprefix);
        else
                border->assigned = 0;
 
-       bool change = len != (int)iface->ia_addr_len;
-       for (int i = 0; !change && i < len; ++i)
-               if (addr[i].addr.s6_addr32[0] != iface->ia_addr[i].addr.s6_addr32[0] ||
-                               addr[i].addr.s6_addr32[1] != iface->ia_addr[i].addr.s6_addr32[1] ||
-                               (addr[i].preferred > 0) != (iface->ia_addr[i].preferred > 0) ||
-                               (addr[i].valid > (uint32_t)now + 7200) !=
-                                               (iface->ia_addr[i].valid > (uint32_t)now + 7200))
-                       change = true;
-
-       if (change) {
-               struct dhcpv6_assignment *c;
-               list_for_each_entry(c, &iface->ia_assignments, head)
-                       if (c != border && !iface->managed)
-                               apply_lease(iface, c, false);
-       }
-
-       memcpy(iface->ia_addr, addr, len * sizeof(*addr));
-       iface->ia_addr_len = len;
+       struct list_head reassign = LIST_HEAD_INIT(reassign);
+       struct dhcpv6_assignment *c, *d;
+       list_for_each_entry_safe(c, d, &iface->ia_assignments, head) {
+               if (c->clid_len == 0 || (!INFINITE_VALID(c->valid_until) && c->valid_until < now) ||
+                               c->managed_size)
+                       continue;
 
-       if (change) { // Addresses / prefixes have changed
-               struct list_head reassign = LIST_HEAD_INIT(reassign);
-               struct dhcpv6_assignment *c, *d;
-               list_for_each_entry_safe(c, d, &iface->ia_assignments, head) {
-                       if (c->clid_len == 0 || c->valid_until < now || c->managed_size)
-                               continue;
+               if (c->length < 128 && c->assigned >= border->assigned && c != border)
+                       list_move(&c->head, &reassign);
+               else if (c != border)
+                       apply_lease(iface, c, true);
 
-                       if (c->length < 128 && c->assigned >= border->assigned && c != border)
-                               list_move(&c->head, &reassign);
-                       else if (c != border)
-                               apply_lease(iface, c, true);
-
-                       if (c->accept_reconf && c->reconf_cnt == 0) {
-                               c->reconf_cnt = 1;
-                               c->reconf_sent = now;
-                               send_reconf(iface, c);
-
-                               // Leave all other assignments of that client alone
-                               struct dhcpv6_assignment *a;
-                               list_for_each_entry(a, &iface->ia_assignments, head)
-                                       if (a != c && a->clid_len == c->clid_len &&
-                                                       !memcmp(a->clid_data, c->clid_data, a->clid_len))
-                                               c->reconf_cnt = INT_MAX;
-                       }
+               if (c->accept_reconf && c->reconf_cnt == 0) {
+                       c->reconf_cnt = 1;
+                       c->reconf_sent = now;
+                       send_reconf(iface, c);
+
+                       // Leave all other assignments of that client alone
+                       struct dhcpv6_assignment *a;
+                       list_for_each_entry(a, &iface->ia_assignments, head)
+                               if (a != c && a->clid_len == c->clid_len &&
+                                               !memcmp(a->clid_data, c->clid_data, a->clid_len))
+                                       c->reconf_cnt = INT_MAX;
                }
+       }
 
-               while (!list_empty(&reassign)) {
-                       c = list_first_entry(&reassign, struct dhcpv6_assignment, head);
-                       list_del(&c->head);
-                       if (!assign_pd(iface, c)) {
-                               c->assigned = 0;
-                               list_add(&c->head, &iface->ia_assignments);
-                       }
+       while (!list_empty(&reassign)) {
+               c = list_first_entry(&reassign, struct dhcpv6_assignment, head);
+               list_del(&c->head);
+               if (!assign_pd(iface, c)) {
+                       c->assigned = 0;
+                       list_add(&c->head, &iface->ia_assignments);
                }
-
-               dhcpv6_write_statefile();
        }
-}
 
+       dhcpv6_write_statefile();
+}
 
 static void reconf_timer(struct uloop_timeout *event)
 {
@@ -669,7 +638,7 @@ static void reconf_timer(struct uloop_timeout *event)
 
                struct dhcpv6_assignment *a, *n;
                list_for_each_entry_safe(a, n, &iface->ia_assignments, head) {
-                       if (a->valid_until < now) {
+                       if (!INFINITE_VALID(a->valid_until) && a->valid_until < now) {
                                if ((a->length < 128 && a->clid_len > 0) ||
                                                (a->length == 128 && a->clid_len == 0)) {
                                        list_del(&a->head);
@@ -686,7 +655,6 @@ static void reconf_timer(struct uloop_timeout *event)
        uloop_timeout_set(event, 2000);
 }
 
-
 static size_t append_reply(uint8_t *buf, size_t buflen, uint16_t status,
                const struct dhcpv6_ia_hdr *ia, struct dhcpv6_assignment *a,
                struct interface *iface, bool request)
@@ -710,7 +678,12 @@ static size_t append_reply(uint8_t *buf, size_t buflen, uint16_t status,
                datalen += sizeof(stat);
        } else {
                if (a) {
-                       uint32_t leasetime = iface->dhcpv4_leasetime;
+                       uint32_t leasetime;
+                       if (a->leasetime > 0) {
+                               leasetime = a->leasetime;
+                       } else {
+                               leasetime = iface->dhcpv4_leasetime;
+                       }
                        if (leasetime == 0)
                                leasetime = 3600;
                        else if (leasetime < 60)
@@ -775,7 +748,7 @@ static size_t append_reply(uint8_t *buf, size_t buflen, uint16_t status,
                                        size_t entrlen = sizeof(n) - 4;
 
                                        if (iface->managed < RELAYD_MANAGED_NO_AFLAG && i != m &&
-                                                       addrs[i].prefix == 64)
+                                                       addrs[i].prefix <= 64)
                                                continue;
 
                                        if (datalen + entrlen + 4 > buflen || a->assigned == 0)
@@ -795,9 +768,12 @@ static size_t append_reply(uint8_t *buf, size_t buflen, uint16_t status,
                                }
                        }
 
-                       a->valid_until = valid + now;
-                       out.t1 = htonl(pref * 5 / 10);
-                       out.t2 = htonl(pref * 8 / 10);
+                       if (!INFINITE_VALID(a->valid_until))
+                               /* UINT32_MAX is considered as infinite leasetime */
+                               a->valid_until = (valid == UINT32_MAX) ? 0 : valid + now;
+
+                       out.t1 = htonl((pref == UINT32_MAX) ? pref : pref * 5 / 10);
+                       out.t2 = htonl((pref == UINT32_MAX) ? pref : pref * 8 / 10);
 
                        if (!out.t1)
                                out.t1 = htonl(1);
@@ -883,7 +859,6 @@ static size_t append_reply(uint8_t *buf, size_t buflen, uint16_t status,
        return datalen;
 }
 
-
 static void dhcpv6_log(uint8_t msgtype, struct interface *iface, time_t now,
                const char *duidbuf, bool is_pd, struct dhcpv6_assignment *a, int code)
 {
@@ -963,8 +938,6 @@ static void dhcpv6_log(uint8_t msgtype, struct interface *iface, time_t now,
                        duidbuf, iface->ifname, status, leasebuf);
 }
 
-
-
 ssize_t dhcpv6_handle_ia(uint8_t *buf, size_t buflen, struct interface *iface,
                const struct sockaddr_in6 *addr, const void *data, const uint8_t *end)
 {
@@ -1009,8 +982,6 @@ ssize_t dhcpv6_handle_ia(uint8_t *buf, size_t buflen, struct interface *iface,
        if (!clid_data || !clid_len || clid_len > 130)
                goto out;
 
-       update(iface);
-
        struct dhcpv6_assignment *first = NULL;
        dhcpv6_for_each_option(start, end, otype, olen, odata) {
                bool is_pd = (otype == DHCPV6_OPT_IA_PD);
@@ -1060,7 +1031,7 @@ ssize_t dhcpv6_handle_ia(uint8_t *buf, size_t buflen, struct interface *iface,
                        if (((c->clid_len == clid_len && !memcmp(c->clid_data, clid_data, clid_len)) ||
                                        (c->clid_len >= clid_len && !c->clid_data[0] && !c->clid_data[1]
                                                && !memcmp(c->mac, mac, sizeof(mac)))) &&
-                                       (c->iaid == ia->iaid || c->valid_until < now) &&
+                                       (c->iaid == ia->iaid || INFINITE_VALID(c->valid_until) || now < c->valid_until) &&
                                        ((is_pd && c->length <= 64) || (is_na && c->length == 128))) {
                                a = c;
 
@@ -1091,6 +1062,9 @@ ssize_t dhcpv6_handle_ia(uint8_t *buf, size_t buflen, struct interface *iface,
                                        a->length = reqlen;
                                        a->peer = *addr;
                                        a->assigned = reqhint;
+                                       // Set valid time to current time indicating
+                                       // assignment is not having infinite lifetime
+                                       a->valid_until = now;
 
                                        if (first)
                                                memcpy(a->key, first->key, sizeof(a->key));
@@ -1143,7 +1117,10 @@ ssize_t dhcpv6_handle_ia(uint8_t *buf, size_t buflen, struct interface *iface,
 
                        // Was only a solicitation: mark binding for removal
                        if (assigned && hdr->msg_type == DHCPV6_MSG_SOLICIT) {
-                               a->valid_until = 0;
+                               a->flags &= ~OAF_BOUND;
+
+                               if (!(a->flags & OAF_STATIC))
+                                       a->valid_until = now;
                        } else if (assigned && hdr->msg_type == DHCPV6_MSG_REQUEST) {
                                if (hostname_len > 0) {
                                        a->hostname = realloc(a->hostname, hostname_len + 1);
@@ -1153,6 +1130,7 @@ ssize_t dhcpv6_handle_ia(uint8_t *buf, size_t buflen, struct interface *iface,
                                        }
                                }
                                a->accept_reconf = accept_reconf;
+                               a->flags |= OAF_BOUND;
                                apply_lease(iface, a, true);
                        } else if (!assigned && a && a->managed_size == 0) { // Cleanup failed assignment
                                free_dhcpv6_assignment(a);
@@ -1167,14 +1145,23 @@ ssize_t dhcpv6_handle_ia(uint8_t *buf, size_t buflen, struct interface *iface,
                        } else if (hdr->msg_type == DHCPV6_MSG_RENEW ||
                                        hdr->msg_type == DHCPV6_MSG_REBIND) {
                                ia_response_len = append_reply(buf, buflen, status, ia, a, iface, false);
-                               if (a)
+                               if (a) {
+                                       a->flags |= OAF_BOUND;
                                        apply_lease(iface, a, true);
+                               }
                        } else if (hdr->msg_type == DHCPV6_MSG_RELEASE) {
-                               a->valid_until = 0;
+                               if (!(a->flags & OAF_STATIC))
+                                       a->valid_until = now - 1;
+
+                               a->flags &= ~OAF_BOUND;
                                apply_lease(iface, a, false);
                        } else if (hdr->msg_type == DHCPV6_MSG_DECLINE && a->length == 128) {
-                               a->clid_len = 0;
-                               a->valid_until = now + 3600; // Block address for 1h
+                               a->flags &= ~OAF_BOUND;
+
+                               if (!(a->flags & OAF_STATIC)) {
+                                       a->clid_len = 0;
+                                       a->valid_until = now + 3600; // Block address for 1h
+                               }
                        }
                } else if (hdr->msg_type == DHCPV6_MSG_CONFIRM && ia_addr_present) {
                        // Send NOTONLINK for CONFIRM with addr present so that clients restart connection