diff --git a/src/dhcp6.c b/src/dhcp6.c
index 76aaf87..832c3a6 100644
--- a/src/dhcp6.c
+++ b/src/dhcp6.c
@@ -265,8 +265,8 @@ struct dhcp_config *config_find_by_address6(struct dhcp_config *configs, struct
   return NULL;
 }
 
-int address6_allocate(struct dhcp_context *context,  unsigned char *clid, int clid_len, 
-		      int serial, struct dhcp_netid *netids, struct in6_addr *ans)   
+struct dhcp_context *address6_allocate(struct dhcp_context *context,  unsigned char *clid, int clid_len, 
+				       int iaid, struct dhcp_netid *netids, struct in6_addr *ans)   
 {
   /* Find a free address: exclude anything in use and anything allocated to
      a particular hwaddr/clientid/hostname in our configuration.
@@ -283,12 +283,12 @@ int address6_allocate(struct dhcp_context *context,  unsigned char *clid, int cl
 
   /* hash hwaddr: use the SDBM hashing algorithm.  This works
      for MAC addresses, let's see how it manages with client-ids! */
-  for (j = 0, i = 0; i < clid_len; i++)
+  for (j = iaid, i = 0; i < clid_len; i++)
     j += clid[i] + (j << 6) + (j << 16) - j;
   
   for (pass = 0; pass <= 1; pass++)
     for (c = context; c; c = c->current)
-      if (c->flags & (CONTEXT_DEPRECATE | CONTEXT_STATIC | CONTEXT_RA_STATELESS))
+      if (c->flags & (CONTEXT_DEPRECATE | CONTEXT_STATIC | CONTEXT_RA_STATELESS | CONTEXT_USED))
 	continue;
       else if (!match_netid(c->filter, netids, pass))
 	continue;
@@ -296,9 +296,9 @@ int address6_allocate(struct dhcp_context *context,  unsigned char *clid, int cl
 	{ 
 	  if (option_bool(OPT_CONSEC_ADDR))
 	    /* seed is largest extant lease addr in this context */
-	    start = lease_find_max_addr6(c) + serial;
+	    start = lease_find_max_addr6(c);
 	  else
-	    start = addr6part(&c->start6) + ((j + c->addr_epoch + serial) % (1 + addr6part(&c->end6) - addr6part(&c->start6)));
+	    start = addr6part(&c->start6) + ((j + c->addr_epoch) % (1 + addr6part(&c->end6) - addr6part(&c->start6)));
 
 	  /* iterate until we find a free address. */
 	  addr = start;
@@ -315,7 +315,7 @@ int address6_allocate(struct dhcp_context *context,  unsigned char *clid, int cl
 	      {
 		*ans = c->start6;
 		setaddr6part (ans, addr);
-		return 1;
+		return c;
 	      }
 	
 	    addr++;
@@ -325,7 +325,7 @@ int address6_allocate(struct dhcp_context *context,  unsigned char *clid, int cl
 	    
 	  } while (addr != start);
 	}
-  
+	   
   return 0;
 }
 
@@ -369,34 +369,6 @@ struct dhcp_context *address6_valid(struct dhcp_context *context,
   return NULL;
 }
 
-struct dhcp_context *narrow_context6(struct dhcp_context *context, 
-				     struct in6_addr *taddr,
-				     struct dhcp_netid *netids)
-{
-  /* We start of with a set of possible contexts, all on the current physical interface.
-     These are chained on ->current.
-     Here we have an address, and return the actual context correponding to that
-     address. Note that none may fit, if the address came a dhcp-host and is outside
-     any dhcp-range. In that case we return a static range if possible, or failing that,
-     any context on the correct subnet. (If there's more than one, this is a dodgy 
-     configuration: maybe there should be a warning.) */
-  
-  struct dhcp_context *tmp;
-
-  if (!(tmp = address6_available(context, taddr, netids)) &&
-      !(tmp = address6_valid(context, taddr, netids)))
-    for (tmp = context; tmp; tmp = tmp->current)
-      if (match_netid(tmp->filter, netids, 1) &&
-	  is_same_net6(taddr, &tmp->start6, tmp->prefix))
-	break;
-  
-  /* Only one context allowed now */
-  if (tmp)
-    tmp->current = NULL;
-  
-  return tmp;
-}
-
 static int is_config_in_context6(struct dhcp_context *context, struct dhcp_config *config)
 {
   /* expand wildcard on contructed contexts */
diff --git a/src/dnsmasq.h b/src/dnsmasq.h
index a24cf41..3a872c4 100644
--- a/src/dnsmasq.h
+++ b/src/dnsmasq.h
@@ -681,6 +681,14 @@ struct cond_domain {
   struct cond_domain *next;
 }; 
 
+#ifdef OPTION6_PREFIX_CLASS 
+struct prefix_class {
+  int class;
+  struct dhcp_netid netid;
+  struct prefix_class *next;
+};
+#endif
+
 struct dhcp_context {
   unsigned int lease_time, addr_epoch;
   struct in_addr netmask, broadcast;
@@ -714,6 +722,7 @@ struct dhcp_context {
 #define CONTEXT_GC          4096
 #define CONTEXT_RA          8192
 #define CONTEXT_WILDCARD   16384
+#define CONTEXT_USED       32768
 
 struct ping_result {
   struct in_addr addr;
@@ -1055,7 +1064,8 @@ struct dhcp_lease *lease4_allocate(struct in_addr addr);
 struct dhcp_lease *lease6_allocate(struct in6_addr *addrp, int lease_type);
 struct dhcp_lease *lease6_find(unsigned char *clid, int clid_len, 
 			       int lease_type, int iaid, struct in6_addr *addr);
-void lease6_filter(int lease_type, int iaid, struct dhcp_context *context);
+void lease6_reset(void);
+struct dhcp_lease *lease6_find_by_client(struct dhcp_lease *first, int lease_type, unsigned char *clid, int clid_len, int iaid);
 struct dhcp_lease *lease6_find_by_addr(struct in6_addr *net, int prefix, u64 addr);
 u64 lease_find_max_addr6(struct dhcp_context *context);
 void lease_ping_reply(struct in6_addr *sender, unsigned char *packet, char *interface);
@@ -1160,8 +1170,8 @@ int get_incoming_mark(union mysockaddr *peer_addr, struct all_addr *local_addr,
 #ifdef HAVE_DHCP6
 void dhcp6_init(void);
 void dhcp6_packet(time_t now);
-int address6_allocate(struct dhcp_context *context,  unsigned char *clid, int clid_len, 
-		      int serial, struct dhcp_netid *netids, struct in6_addr *ans);
+struct dhcp_context *address6_allocate(struct dhcp_context *context,  unsigned char *clid, int clid_len, 
+				       int iaid, struct dhcp_netid *netids, struct in6_addr *ans);
 int is_addr_in_context6(struct dhcp_context *context, struct in6_addr *addr);
 struct dhcp_context *address6_available(struct dhcp_context *context, 
 					struct in6_addr *taddr,
@@ -1169,9 +1179,6 @@ struct dhcp_context *address6_available(struct dhcp_context *context,
 struct dhcp_context *address6_valid(struct dhcp_context *context, 
 				    struct in6_addr *taddr,
 				    struct dhcp_netid *netids);
-struct dhcp_context *narrow_context6(struct dhcp_context *context, 
-				     struct in6_addr *taddr,
-				     struct dhcp_netid *netids);
 struct dhcp_config *find_config6(struct dhcp_config *configs,
 				 struct dhcp_context *context,
 				 unsigned char *duid, int duid_len,
diff --git a/src/lease.c b/src/lease.c
index 889d6f3..a29cd9e 100644
--- a/src/lease.c
+++ b/src/lease.c
@@ -555,8 +555,7 @@ struct dhcp_lease *lease_find_by_addr(struct in_addr addr)
 }
 
 #ifdef HAVE_DHCP6
-/* addr or clid may be NULL for "don't care, both NULL resets "USED" flags both
-   set activates USED check */
+/* find address for {CLID, IAID, address} */
 struct dhcp_lease *lease6_find(unsigned char *clid, int clid_len, 
 			       int lease_type, int iaid, struct in6_addr *addr)
 {
@@ -567,40 +566,52 @@ struct dhcp_lease *lease6_find(unsigned char *clid, int clid_len,
       if (!(lease->flags & lease_type) || lease->hwaddr_type != iaid)
 	continue;
 
-      if (clid && addr && (lease->flags & LEASE_USED))
+      if (memcmp(lease->hwaddr, addr, IN6ADDRSZ) != 0)
 	continue;
       
-      if (addr && memcmp(lease->hwaddr, addr, IN6ADDRSZ) != 0)
-	continue;
-      
-      if (clid &&
-	  (clid_len != lease->clid_len ||
+      if ((clid_len != lease->clid_len ||
 	   memcmp(clid, lease->clid, clid_len) != 0))
 	continue;
       
-      lease->flags |= LEASE_USED;
       return lease;
     }
   
   return NULL;
 }
 
-void lease6_filter(int lease_type, int iaid, struct dhcp_context *context)
+/* reset "USED flags */
+void lease6_reset(void)
 {
   struct dhcp_lease *lease;
   
   for (lease = leases; lease; lease = lease->next)
+    lease->flags &= ~LEASE_USED;
+}
+
+/* enumerate all leases belonging to {CLID, IAID} */
+struct dhcp_lease *lease6_find_by_client(struct dhcp_lease *first, int lease_type, unsigned char *clid, int clid_len, int iaid)
+{
+  struct dhcp_lease *lease;
+
+  if (!first)
+    first = leases;
+
+  for (lease = first; lease; lease = lease->next)
     {
-      /* reset "USED flag */
-      lease->flags &= ~LEASE_USED;
-      
+      if (lease->flags & LEASE_USED)
+	continue;
+
       if (!(lease->flags & lease_type) || lease->hwaddr_type != iaid)
 	continue;
-      
-      /* leases on the wrong interface get filtered out here */
-      if (!is_addr_in_context6(context, (struct in6_addr *)&lease->hwaddr))
-	lease->flags |= LEASE_USED;
+ 
+      if ((clid_len != lease->clid_len ||
+	   memcmp(clid, lease->clid, clid_len) != 0))
+	continue;
+
+      return lease;
     }
+  
+  return NULL;
 }
 
 struct dhcp_lease *lease6_find_by_addr(struct in6_addr *net, int prefix, u64 addr)
diff --git a/src/rfc3315.c b/src/rfc3315.c
index 785a426..bf3d2a6 100644
--- a/src/rfc3315.c
+++ b/src/rfc3315.c
@@ -19,16 +19,37 @@
 
 #ifdef HAVE_DHCP6
 
+struct state {
+  unsigned char *clid;
+  int clid_len, iaid, ia_type, interface, hostname_auth;
+  char *client_hostname, *hostname, *domain, *send_domain;
+  struct dhcp_context *context;
+  struct in6_addr *link_address;
+  unsigned int xid, fqdn_flags;
+  char *iface_name;
+  void *packet_options, *end;
+  struct dhcp_netid *tags, *context_tags;
+};
+
 static int dhcp6_maybe_relay(struct in6_addr *link_address, struct dhcp_netid **relay_tagsp, struct dhcp_context *context, 
 			     int interface, char *iface_name, struct in6_addr *fallback, void *inbuff, size_t sz, int is_unicast, time_t now);
 static int dhcp6_no_relay(int msg_type,  struct in6_addr *link_address, struct dhcp_netid *tags, struct dhcp_context *context, 
 			  int interface, char *iface_name, struct in6_addr *fallback, void *inbuff, size_t sz, int is_unicast, time_t now);
 static void log6_opts(int nest, unsigned int xid, void *start_opts, void *end_opts);
-static void log6_packet(char *type, unsigned char *clid, int clid_len, struct in6_addr *addr, int xid, char *iface, char *string);
+static void log6_packet(struct state *state, char *type, struct in6_addr *addr, char *string);
 
 static void *opt6_find (void *opts, void *end, unsigned int search, unsigned int minsize);
 static void *opt6_next(void *opts, void *end);
 static unsigned int opt6_uint(unsigned char *opt, int offset, int size);
+static void get_context_tag(struct state *state, struct dhcp_context *context);
+static void *check_ia(struct state *state, void *opt, void **endp);
+static int build_ia(struct state *state, int *t1cntr);
+static void end_ia(int t1cntr, unsigned int min_time, int do_fuzz);
+static void add_address(struct state *state, struct dhcp_context *context, unsigned int lease_time, unsigned int requested_time, 
+			unsigned int *min_time, struct in6_addr *addr, int update_lease, time_t now);
+static void update_leases(struct state *state, struct dhcp_context *context, struct in6_addr *addr, unsigned int lease_time, time_t now);
+static int add_local_addrs(struct dhcp_context *context);
+struct dhcp_netid *add_options(struct state *state, struct in6_addr *fallback, struct dhcp_context *context);
 
 #define opt6_len(opt) ((int)(opt6_uint(opt, -2, 2)))
 #define opt6_type(opt) (opt6_uint(opt, -4, 2))
@@ -172,39 +193,49 @@ static int dhcp6_maybe_relay(struct in6_addr *link_address, struct dhcp_netid **
 static int dhcp6_no_relay(int msg_type, struct in6_addr *link_address, struct dhcp_netid *tags, struct dhcp_context *context, 
 			  int interface, char *iface_name, struct in6_addr *fallback, void *inbuff, size_t sz, int is_unicast, time_t now)
 {
-  void *packet_options = inbuff + 4;
-  void *end = inbuff + sz;
-  void *opt, *oro;
-  int i, o, o1;
-  unsigned char *clid = NULL;
-  int clid_len = 0, start_opts;
-  struct dhcp_netid *tagif, *context_tags = NULL;
-  char *client_hostname= NULL, *hostname = NULL;
-  char *domain = NULL, *send_domain = NULL;
+  void *opt;
+  int i, o, o1, start_opts;
+  struct dhcp_opt *opt_cfg;
+  struct dhcp_netid *tagif;
   struct dhcp_config *config = NULL;
   struct dhcp_netid known_id, iface_id, v6_id;
-  int done_dns = 0, hostname_auth = 0, do_encap = 0;
   unsigned char *outmsgtypep;
-  struct dhcp_opt *opt_cfg;
   struct dhcp_vendor *vendor;
   struct dhcp_context *context_tmp;
-  unsigned int xid, ignore = 0;
-  unsigned int fqdn_flags = 0x01; /* default to send if we recieve no FQDN option */
+  unsigned int ignore = 0;
+  struct state state;
+
+  state.packet_options = inbuff + 4;
+  state.end = inbuff + sz;
+  state.clid = NULL;
+  state.clid_len = 0;
+  state.context_tags = NULL;
+  state.tags = tags;
+  state.link_address = link_address;
+  state.interface = interface;
+  state.domain = NULL;
+  state.send_domain = NULL;
+  state.context = context;
+  state.hostname_auth = 0;
+  state.hostname = NULL;
+  state.client_hostname = NULL;
+  state.iface_name = iface_name;
+  state.fqdn_flags = 0x01; /* default to send if we recieve no FQDN option */
 
   /* set tag with name == interface */
   iface_id.net = iface_name;
-  iface_id.next = tags;
-  tags = &iface_id; 
+  iface_id.next = state.tags;
+  state.tags = &iface_id; 
 
   /* set tag "dhcpv6" */
   v6_id.net = "dhcpv6";
-  v6_id.next = tags;
-  tags = &v6_id;
+  v6_id.next = state.tags;
+  state.tags = &v6_id;
 
   /* copy over transaction-id, and save pointer to message type */
   outmsgtypep = put_opt6(inbuff, 4);
   start_opts = save_counter(-1);
-  xid = outmsgtypep[3] | outmsgtypep[2] << 8 | outmsgtypep[1] << 16;
+  state.xid = outmsgtypep[3] | outmsgtypep[2] << 8 | outmsgtypep[1] << 16;
    
   /* We're going to be linking tags from all context we use. 
      mark them as unused so we don't link one twice and break the list */
@@ -218,19 +249,19 @@ static int dhcp6_no_relay(int msg_type, struct in6_addr *link_address, struct dh
 	   inet_ntop(AF_INET6, &context_tmp->end6, daemon->dhcp_buff2, ADDRSTRLEN); 
 	   if (context_tmp->flags & (CONTEXT_STATIC))
 	     my_syslog(MS_DHCP | LOG_INFO, _("%u available DHCPv6 subnet: %s/%d"),
-		       xid, daemon->dhcp_buff, context_tmp->prefix);
+		       state.xid, daemon->dhcp_buff, context_tmp->prefix);
 	   else
 	     my_syslog(MS_DHCP | LOG_INFO, _("%u available DHCP range: %s -- %s"), 
-		       xid, daemon->dhcp_buff, daemon->dhcp_buff2);
+		       state.xid, daemon->dhcp_buff, daemon->dhcp_buff2);
 	}
     }
 
-  if ((opt = opt6_find(packet_options, end, OPTION6_CLIENT_ID, 1)))
+  if ((opt = opt6_find(state.packet_options, state.end, OPTION6_CLIENT_ID, 1)))
     {
-      clid = opt6_ptr(opt, 0);
-      clid_len = opt6_len(opt);
+      state.clid = opt6_ptr(opt, 0);
+      state.clid_len = opt6_len(opt);
       o = new_opt6(OPTION6_CLIENT_ID);
-      put_opt6(clid, clid_len);
+      put_opt6(state.clid, state.clid_len);
       end_opt6(o);
     }
   else if (msg_type != DHCP6IREQ)
@@ -238,7 +269,7 @@ static int dhcp6_no_relay(int msg_type, struct in6_addr *link_address, struct dh
 
   /* server-id must match except for SOLICIT and CONFIRM messages */
   if (msg_type != DHCP6SOLICIT && msg_type != DHCP6CONFIRM && msg_type != DHCP6IREQ &&
-      (!(opt = opt6_find(packet_options, end, OPTION6_SERVER_ID, 1)) ||
+      (!(opt = opt6_find(state.packet_options, state.end, OPTION6_SERVER_ID, 1)) ||
        opt6_len(opt) != daemon->duid_len ||
        memcmp(opt6_ptr(opt, 0), daemon->duid, daemon->duid_len) != 0))
     return 0;
@@ -270,7 +301,7 @@ static int dhcp6_no_relay(int msg_type, struct in6_addr *link_address, struct dh
       else
 	continue;
 
-      if ((opt = opt6_find(packet_options, end, mopt, 2)))
+      if ((opt = opt6_find(state.packet_options, state.end, mopt, 2)))
 	{
 	  void *enc_opt, *enc_end = opt6_ptr(opt, opt6_len(opt));
 	  int offset = 0;
@@ -290,15 +321,15 @@ static int dhcp6_no_relay(int msg_type, struct in6_addr *link_address, struct dh
 	    for (i = 0; i <= (opt6_len(enc_opt) - vendor->len); i++)
 	      if (memcmp(vendor->data, opt6_ptr(enc_opt, i), vendor->len) == 0)
 		{
-		  vendor->netid.next = tags;
-		  tags = &vendor->netid;
+		  vendor->netid.next = state.tags;
+		  state.tags = &vendor->netid;
 		  break;
 		}
 	}
     }
 
-  if (option_bool(OPT_LOG_OPTS) && (opt = opt6_find(packet_options, end, OPTION6_VENDOR_CLASS, 4)))
-    my_syslog(MS_DHCP | LOG_INFO, _("%u vendor class: %u"), xid, opt6_uint(opt, 0, 4));
+  if (option_bool(OPT_LOG_OPTS) && (opt = opt6_find(state.packet_options, state.end, OPTION6_VENDOR_CLASS, 4)))
+    my_syslog(MS_DHCP | LOG_INFO, _("%u vendor class: %u"), state.xid, opt6_uint(opt, 0, 4));
   
   /* dhcp-match. If we have hex-and-wildcards, look for a left-anchored match.
      Otherwise assume the option is an array, and look for a matching element. 
@@ -310,9 +341,9 @@ static int dhcp6_no_relay(int msg_type, struct in6_addr *link_address, struct dh
       
       if (opt_cfg->flags & DHOPT_RFC3925)
 	{
-	  for (opt = opt6_find(packet_options, end, OPTION6_VENDOR_OPTS, 4);
+	  for (opt = opt6_find(state.packet_options, state.end, OPTION6_VENDOR_OPTS, 4);
 	       opt;
-	       opt = opt6_find(opt6_next(opt, end), end, OPTION6_VENDOR_OPTS, 4))
+	       opt = opt6_find(opt6_next(opt, state.end), state.end, OPTION6_VENDOR_OPTS, 4))
 	    {
 	      void *vopt;
 	      void *vend = opt6_ptr(opt, opt6_len(opt));
@@ -328,7 +359,7 @@ static int dhcp6_no_relay(int msg_type, struct in6_addr *link_address, struct dh
 	}
       else
 	{
-	  if (!(opt = opt6_find(packet_options, end, opt_cfg->opt, 1)))
+	  if (!(opt = opt6_find(state.packet_options, state.end, opt_cfg->opt, 1)))
 	    continue;
 	  
 	  match = match_bytes(opt_cfg, opt6_ptr(opt, 0), opt6_len(opt));
@@ -336,23 +367,23 @@ static int dhcp6_no_relay(int msg_type, struct in6_addr *link_address, struct dh
   
       if (match)
 	{
-	  opt_cfg->netid->next = tags;
-	  tags = opt_cfg->netid;
+	  opt_cfg->netid->next = state.tags;
+	  state.tags = opt_cfg->netid;
 	}
     }
   
-  if ((opt = opt6_find(packet_options, end, OPTION6_FQDN, 1)))
+  if ((opt = opt6_find(state.packet_options, state.end, OPTION6_FQDN, 1)))
     {
       /* RFC4704 refers */
        int len = opt6_len(opt) - 1;
        
-       fqdn_flags = opt6_uint(opt, 0, 1);
+       state.fqdn_flags = opt6_uint(opt, 0, 1);
        
        /* Always force update, since the client has no way to do it itself. */
-       if (!option_bool(OPT_FQDN_UPDATE) && !(fqdn_flags & 0x01))
-	 fqdn_flags |= 0x03;
+       if (!option_bool(OPT_FQDN_UPDATE) && !(state.fqdn_flags & 0x01))
+	 state.fqdn_flags |= 0x03;
  
-       fqdn_flags &= ~0x04;
+       state.fqdn_flags &= ~0x04;
 
        if (len != 0 && len < 255)
 	 {
@@ -374,36 +405,36 @@ static int dhcp6_no_relay(int msg_type, struct in6_addr *link_address, struct dh
 	   
 	   if (legal_hostname(daemon->dhcp_buff))
 	     {
-	       client_hostname = daemon->dhcp_buff;
+	       state.client_hostname = daemon->dhcp_buff;
 	       if (option_bool(OPT_LOG_OPTS))
-		 my_syslog(MS_DHCP | LOG_INFO, _("%u client provides name: %s"), xid, client_hostname); 
+		 my_syslog(MS_DHCP | LOG_INFO, _("%u client provides name: %s"), state.xid, state.client_hostname); 
 	     }
 	 }
     }	 
   
-  if (clid)
+  if (state.clid)
     {
-      config = find_config6(daemon->dhcp_conf, context, clid, clid_len, NULL);
+      config = find_config6(daemon->dhcp_conf, context, state.clid, state.clid_len, NULL);
       
       if (have_config(config, CONFIG_NAME))
 	{
-	  hostname = config->hostname;
-	  domain = config->domain;
-	  hostname_auth = 1;
+	  state.hostname = config->hostname;
+	  state.domain = config->domain;
+	  state.hostname_auth = 1;
 	}
-      else if (client_hostname)
+      else if (state.client_hostname)
 	{
-	  domain = strip_hostname(client_hostname);
+	  state.domain = strip_hostname(state.client_hostname);
 	  
-	  if (strlen(client_hostname) != 0)
+	  if (strlen(state.client_hostname) != 0)
 	    {
-	      hostname = client_hostname;
+	      state.hostname = state.client_hostname;
 	      if (!config)
 		{
 		  /* Search again now we have a hostname. 
 		     Only accept configs without CLID here, (it won't match)
 		     to avoid impersonation by name. */
-		  struct dhcp_config *new = find_config6(daemon->dhcp_conf, context, NULL, 0, hostname);
+		  struct dhcp_config *new = find_config6(daemon->dhcp_conf, context, NULL, 0, state.hostname);
 		  if (new && !have_config(new, CONFIG_CLID) && !new->hwaddr)
 		    config = new;
 		}
@@ -417,20 +448,20 @@ static int dhcp6_no_relay(int msg_type, struct in6_addr *link_address, struct dh
       
       for (list = config->netid; list; list = list->next)
         {
-          list->list->next = tags;
-          tags = list->list;
+          list->list->next = state.tags;
+          state.tags = list->list;
         }
 
       /* set "known" tag for known hosts */
       known_id.net = "known";
-      known_id.next = tags;
-      tags = &known_id;
+      known_id.next = state.tags;
+      state.tags = &known_id;
 
       if (have_config(config, CONFIG_DISABLE))
 	ignore = 1;
     }
    
-  tagif = run_tag_if(tags);
+  tagif = run_tag_if(state.tags);
   
   /* if all the netids in the ignore list are present, ignore this client */
   if (daemon->dhcp_ignore)
@@ -443,7 +474,7 @@ static int dhcp6_no_relay(int msg_type, struct in6_addr *link_address, struct dh
     }
   
   /* if all the netids in the ignore_name list are present, ignore client-supplied name */
-  if (!hostname_auth)
+  if (!state.hostname_auth)
     {
        struct dhcp_netid_list *id_list;
        
@@ -451,7 +482,7 @@ static int dhcp6_no_relay(int msg_type, struct in6_addr *link_address, struct dh
 	 if ((!id_list->list) || match_netid(id_list->list, tagif, 0))
 	   break;
        if (id_list)
-	 hostname = NULL;
+	 state.hostname = NULL;
     }
   
 
@@ -460,13 +491,12 @@ static int dhcp6_no_relay(int msg_type, struct in6_addr *link_address, struct dh
     default:
       return 0;
 
-    case DHCP6SOLICIT:
-    case DHCP6REQUEST:
-      {
-	void *rapid_commit = opt6_find(packet_options, end, OPTION6_RAPID_COMMIT, 0);
-	int make_lease = (msg_type == DHCP6REQUEST || rapid_commit); 
-	int serial = 0, used_config = 0;
 
+    case DHCP6SOLICIT:
+      {
+	void *rapid_commit = opt6_find(state.packet_options, state.end, OPTION6_RAPID_COMMIT, 0);
+      	int used_config = 0, address_assigned = 0;
+	
 	if (rapid_commit)
 	  {
 	    o = new_opt6(OPTION6_RAPID_COMMIT);
@@ -474,396 +504,268 @@ static int dhcp6_no_relay(int msg_type, struct in6_addr *link_address, struct dh
 	  }
 
 	/* set reply message type */
-	*outmsgtypep = make_lease ? DHCP6REPLY : DHCP6ADVERTISE;
-	
-	log6_packet(msg_type == DHCP6SOLICIT ? "DHCPSOLICIT" : "DHCPREQUEST",
-		    clid, clid_len, NULL, xid, iface_name, ignore ? "ignored" : NULL);
+	*outmsgtypep = rapid_commit ? DHCP6REPLY : DHCP6ADVERTISE;
+
+	log6_packet(&state, "DHCPSOLICIT", NULL, ignore ? "ignored" : NULL);
 	
 	if (ignore)
 	  return 0;
 	
-	for (opt = packet_options; opt; opt = opt6_next(opt, end))
+	for (opt = state.packet_options; opt; opt = opt6_next(opt, state.end))
 	  {   
-	    int iaid, ia_type = opt6_type(opt);
 	    void *ia_option, *ia_end;
 	    unsigned int min_time = 0xffffffff;
-	    int t1cntr = 0;
-	    int address_assigned = 0;
+	    int t1cntr;
+	    int config_ok = 0;
+	    struct dhcp_context *c;
+	    u32 lease_time, requested_time;
+	    struct dhcp_lease *ltmp;
+	    struct in6_addr *req_addr;
+	    struct in6_addr addr;
 	    
-	    if (ia_type != OPTION6_IA_NA && ia_type != OPTION6_IA_TA)
+	    if (!(ia_option = check_ia(&state, opt, &ia_end)))
 	      continue;
 	    
-	    if (ia_type == OPTION6_IA_NA && opt6_len(opt) < 12)
-	      continue;
-	    
-	    if (ia_type == OPTION6_IA_TA && opt6_len(opt) < 4)
-	      continue;
-	    
-	    iaid = opt6_uint(opt, 0, 4);
-	    ia_end = opt6_ptr(opt, opt6_len(opt));
-	    ia_option =  opt6_find(opt6_ptr(opt, ia_type == OPTION6_IA_NA ? 12 : 4), ia_end, OPTION6_IAADDR, 24);
-	    
-	    /* reset "USED" flags on leases */
-	    lease6_filter(ia_type == OPTION6_IA_NA ? LEASE_NA : LEASE_TA, iaid, context);
-	    
-	    o = new_opt6(ia_type);
-	    put_opt6_long(iaid);
-	    if (ia_type == OPTION6_IA_NA)
+	    if (have_config(config, CONFIG_ADDR6))
 	      {
-		/* save pointer */
-		t1cntr = save_counter(-1);
-		/* so we can fill these in later */
-		put_opt6_long(0);
-		put_opt6_long(0); 
+		struct dhcp_lease *config_lease = lease6_find_by_addr(&config->addr6, 128, 0);
+		
+		config_ok = 1;
+		
+		if (config_lease && 
+		    (config_lease->clid_len != state.clid_len || 
+		     memcmp(config_lease->clid, state.clid, state.clid_len) != 0 ||
+		     config_lease->hwaddr_type != state.iaid))
+		  config_ok = 0; /* configured address leased elsewhere */
+	      }
+	      
+	    /* reset USED bits in leases */
+	    lease6_reset();
+	    
+	    o = build_ia(&state, &t1cntr);
+
+	    for (; ia_option; ia_option = opt6_find(opt6_next(ia_option, ia_end), ia_end, OPTION6_IAADDR, 24))
+	      {
+		req_addr = opt6_ptr(ia_option, 0);
+		ltmp = lease6_find_by_addr(req_addr, 128, 0);
+		requested_time = opt6_uint(ia_option, 16, 4);
+
+		/* reset USED bits in contexts - one address per prefix per IAID */
+		for (c = context; c; c = c->current)
+		  c->flags &= ~CONTEXT_USED;
+		
+		if ((c = address6_valid(context, req_addr, tagif)))
+		  {
+		    lease_time = c->lease_time;
+		    /* If the client asks for an address on the same network as a configured address, 
+		       offer the configured address instead, to make moving to newly-configured
+		       addresses automatic. */
+		    if (!used_config && config_ok && is_same_net6(req_addr, &config->addr6, c->prefix))
+		      {
+			req_addr = &config->addr6;
+			used_config = 1;
+			if (have_config(config, CONFIG_TIME))
+			  lease_time = config->lease_time;
+		      }
+		    else if (!(c = address6_available(context, req_addr, tagif)))
+		      continue; /* not an address we're allowed */
+		    else if (ltmp && 
+			     (ltmp->clid_len != state.clid_len || 
+			      memcmp(ltmp->clid, state.clid, state.clid_len) != 0 ||
+			      ltmp->hwaddr_type != state.iaid))
+		      continue; /* address leased elsewhere */
+		    
+		    /* add address to output packet */
+		    add_address(&state, c, lease_time, requested_time, &min_time, req_addr, rapid_commit != NULL, now);
+		    get_context_tag(&state, c);
+		    address_assigned = 1;
+		  }
 	      }
 	    
-	    while (1)
+	    /* Suggest configured address */
+	    if (!used_config && config_ok && (c = address6_valid(context, &config->addr6, tagif)))
 	      {
-		struct in6_addr alloced_addr, *addrp = NULL;
-		u32 requested_time = 0;
-		struct dhcp_lease *lease = NULL;
-		
-		if (ia_option)
-		  {
-		    struct in6_addr *req_addr = opt6_ptr(ia_option, 0);
-		    requested_time = opt6_uint(ia_option, 16, 4);
-		    struct dhcp_context *dynamic;
+		used_config = 1;
+		if (have_config(config, CONFIG_TIME))
+		  lease_time = config->lease_time;
+		/* add address to output packet */
+		add_address(&state, c, lease_time, requested_time, &min_time, &config->addr6, rapid_commit != NULL, now);
+		get_context_tag(&state, c);
+		address_assigned = 1;
+	      }
 
-		    if ((dynamic = address6_available(context, req_addr, tags)) || address6_valid(context, req_addr, tags))
-		      {
-			if (!dynamic && !(have_config(config, CONFIG_ADDR6) && memcmp(&config->addr6, req_addr, IN6ADDRSZ) == 0))
-			  {
-			    /* Static range, not configured. */
-			    o1 = new_opt6(OPTION6_STATUS_CODE);
-			    put_opt6_short(DHCP6UNSPEC);
-			    put_opt6_string("Address unavailable");
-			    end_opt6(o1);
-			  }
-			else if (lease6_find_by_addr(req_addr, 128, 0) &&
-				 !(lease = lease6_find(clid, clid_len, ia_type == OPTION6_IA_NA ? LEASE_NA : LEASE_TA, iaid, req_addr)))
-			  {
-			    /* Address leased to another DUID/IAID */
-			    o1 = new_opt6(OPTION6_STATUS_CODE);
-			    put_opt6_short(DHCP6UNSPEC);
-			    put_opt6_string("Address in use");
-			    end_opt6(o1);
-			  } 
-			else 
-			  addrp = req_addr;
-		      }
-		    else if (msg_type == DHCP6REQUEST)
-		      {
-			/* requested address not on the correct link */
-			o1 = new_opt6(OPTION6_STATUS_CODE);
-			put_opt6_short(DHCP6NOTONLINK);
-			put_opt6_string("Not on link");
-			end_opt6(o1);
-		      }
-		  }
-		else
+	    /* return addresses for existing leases */
+	    ltmp = NULL;
+	    while ((ltmp = lease6_find_by_client(ltmp, state.ia_type == OPTION6_IA_NA ? LEASE_NA : LEASE_TA, state.clid, state.clid_len, state.iaid)))
+	      {
+		req_addr = (struct in6_addr *)ltmp->hwaddr;
+		if ((c = address6_available(context, req_addr, tagif)))
 		  {
-		    /* must have an address to CONFIRM */
-		    if (msg_type == DHCP6REQUEST && ia_type == OPTION6_IA_NA)
-		      return 0;
-		    
-		    /* Don't used configured addresses for temporary leases. */
-		    if (have_config(config, CONFIG_ADDR6) && !used_config && ia_type == OPTION6_IA_NA)
-		      {
-			struct dhcp_lease *ltmp = lease6_find_by_addr(&config->addr6, 128, 0);
-			 
-			used_config = 1;
-			inet_ntop(AF_INET6, &config->addr6, daemon->addrbuff, ADDRSTRLEN);
-			
-			if (ltmp && ltmp->clid && 
-			    (ltmp->clid_len != clid_len || memcmp(ltmp->clid, clid, clid_len) != 0 || ltmp->hwaddr_type != iaid))
-			  my_syslog(MS_DHCP | LOG_WARNING, _("not using configured address %s because it is leased to %s#%d"),
-				    daemon->addrbuff, print_mac(daemon->namebuff, ltmp->clid, ltmp->clid_len), ltmp->hwaddr_type);
-			else if (have_config(config, CONFIG_DECLINED) &&
-				 difftime(now, config->decline_time) < (float)DECLINE_BACKOFF)
-			  my_syslog(MS_DHCP | LOG_WARNING, _("not using configured address %s because it was previously declined"), 
-				    daemon->addrbuff);
-			else
-			  {
-			    addrp = &config->addr6;
-			    /* may have existing lease for this address */
-			    lease = lease6_find(clid, clid_len, 
-						ia_type == OPTION6_IA_NA ? LEASE_NA : LEASE_TA, iaid, addrp); 
-			  }
-		      }
-		    
-		    /* existing lease */
-		    if (!addrp &&
-			(lease = lease6_find(clid, clid_len, 
-					     ia_type == OPTION6_IA_NA ? LEASE_NA : LEASE_TA, iaid, NULL)) &&
-			!config_find_by_address6(daemon->dhcp_conf, (struct in6_addr *)&lease->hwaddr, 128, 0))
-		      addrp = (struct in6_addr *)&lease->hwaddr;
-		    
-		    if (!addrp && address6_allocate(context, clid, clid_len, serial++, tags, &alloced_addr))
-		      addrp = &alloced_addr;		    
-		  }
-		
-		if (addrp)
-		  {
-		    unsigned int lease_time;
-		    struct dhcp_context *this_context;
-		    struct dhcp_config *valid_config = config;
-
-		    /* don't use a config to set lease time if it specifies an address which isn't this. */
-		    if (have_config(config, CONFIG_ADDR6) && memcmp(&config->addr6, addrp, IN6ADDRSZ) != 0)
-		      valid_config = NULL;
-
+		    add_address(&state, c, c->lease_time, c->lease_time, &min_time, req_addr, rapid_commit != NULL, now);
+		    get_context_tag(&state, c);
 		    address_assigned = 1;
-		    
-		    /* shouldn't ever fail */
-		    if ((this_context = narrow_context6(context, addrp, tagif)))
-		      {
-			/* get tags from context if we've not used it before */
-			if (this_context->netid.next == &this_context->netid && this_context->netid.net)
-			  {
-			    this_context->netid.next = context_tags;
-			    context_tags = &this_context->netid;
-			    if (!hostname_auth)
-			      {
-				struct dhcp_netid_list *id_list;
-				
-				for (id_list = daemon->dhcp_ignore_names; id_list; id_list = id_list->next)
-				  if ((!id_list->list) || match_netid(id_list->list, &this_context->netid, 0))
-				    break;
-				if (id_list)
-				  hostname = NULL;
-			      }
-			  }
-		       	
-			if (have_config(valid_config, CONFIG_TIME))
-			  lease_time = valid_config->lease_time;
-			else
-			  lease_time = this_context->lease_time;
-			
-			 if (this_context->valid < lease_time)
-			   lease_time = this_context->valid;
-			
-			 if (ia_option)
-			  {
-			    if (requested_time < 120u )
-			      requested_time = 120u; /* sanity */
-			    if (lease_time == 0xffffffff || (requested_time != 0xffffffff && requested_time < lease_time))
-			      lease_time = requested_time;
-			  }
-			  
-			if (lease_time < min_time)
-			  min_time = lease_time;
-			
-			/* May fail to create lease */
-			if (!lease && make_lease)
-			  lease = lease6_allocate(addrp, ia_type == OPTION6_IA_NA ? LEASE_NA : LEASE_TA);
-			
-			if (lease)
-			  {
-			    lease_set_expires(lease, lease_time, now);
-			    lease_set_hwaddr(lease, NULL, clid, 0, iaid, clid_len, now, 0);
-			    lease_set_interface(lease, interface, now);
-			    if (hostname && ia_type == OPTION6_IA_NA)
-			      {
-				char *addr_domain = get_domain6(addrp);
-				if (!send_domain)
-				  send_domain = addr_domain;
-				lease_set_hostname(lease, hostname, hostname_auth, addr_domain, domain);
-			      }
-
-#ifdef HAVE_SCRIPT
-			    if (daemon->lease_change_command)
-			      {
-				void *class_opt;
-				lease->flags |= LEASE_CHANGED;
-				free(lease->extradata);
-				lease->extradata = NULL;
-				lease->extradata_size = lease->extradata_len = 0;
-				lease->hwaddr_len = 0; /* surrogate for no of vendor classes */
-
-				if ((class_opt = opt6_find(packet_options, end, OPTION6_VENDOR_CLASS, 4)))
-				  {
-				    void *enc_opt, *enc_end = opt6_ptr(class_opt, opt6_len(class_opt));
-				    lease->hwaddr_len++;
-				    /* send enterprise number first  */
-				    sprintf(daemon->dhcp_buff2, "%u", opt6_uint(class_opt, 0, 4));
-				    lease_add_extradata(lease, (unsigned char *)daemon->dhcp_buff2, strlen(daemon->dhcp_buff2), 0);
-				    
-				    if (opt6_len(class_opt) >= 6) 
-				      for (enc_opt = opt6_ptr(class_opt, 4); enc_opt; enc_opt = opt6_next(enc_opt, enc_end))
-					{
-					  lease->hwaddr_len++;
-					  lease_add_extradata(lease, opt6_ptr(enc_opt, 0), opt6_len(enc_opt), 0);
-					}
-				  }
-				
-				lease_add_extradata(lease, (unsigned char *)client_hostname, 
-						    client_hostname ? strlen(client_hostname) : 0, 0);				
-				
-				/* space-concat tag set */
-				if (!tagif && !context_tags)
-				  lease_add_extradata(lease, NULL, 0, 0);
-				else
-				  {
-				    struct dhcp_netid *n, *l, *tmp = tags;
-				    
-				    /* link temporarily */
-				    for (n = context_tags; n && n->next; n = n->next);
-				    if ((l = n))
-				      {
-					l->next = tags;
-					tmp = context_tags;
-				      }
-				    
-				    for (n = run_tag_if(tmp); n; n = n->next)
-				      {
-					struct dhcp_netid *n1;
-					/* kill dupes */
-					for (n1 = n->next; n1; n1 = n1->next)
-					  if (strcmp(n->net, n1->net) == 0)
-					    break;
-					if (!n1)
-					  lease_add_extradata(lease, (unsigned char *)n->net, strlen(n->net), n->next ? ' ' : 0); 
-				      }
-
-				    /* unlink again */
-				    if (l)
-				      l->next = NULL;
-				  }
-
-				if (link_address)
-				  inet_ntop(AF_INET6, link_address, daemon->addrbuff, ADDRSTRLEN);
-				
-				lease_add_extradata(lease, (unsigned char *)daemon->addrbuff, link_address ? strlen(daemon->addrbuff) : 0, 0);
-				  
-				if ((class_opt = opt6_find(packet_options, end, OPTION6_USER_CLASS, 2)))
-				  {
-				    void *enc_opt, *enc_end = opt6_ptr(class_opt, opt6_len(class_opt));
-				    for (enc_opt = opt6_ptr(class_opt, 0); enc_opt; enc_opt = opt6_next(enc_opt, enc_end))
-				      lease_add_extradata(lease, opt6_ptr(enc_opt, 0), opt6_len(enc_opt), 0);
-				  }
-			      }
-#endif	
-			    
-			  }
-			else if (!send_domain)
-			  send_domain = get_domain6(addrp);
-			  
-			
-			if (lease || !make_lease)
-			  {
-			    o1 =  new_opt6(OPTION6_IAADDR);
-			    put_opt6(addrp, sizeof(*addrp));
-			    /* preferred lifetime */
-			    put_opt6_long(this_context && (this_context->preferred < lease_time) ? 
-					  this_context->preferred : lease_time);
-			    put_opt6_long(lease_time); /* valid lifetime */
-			    end_opt6(o1);
-
-			    log6_packet( make_lease ? "DHCPREPLY" : "DHCPADVERTISE", 
-					 clid, clid_len, addrp, xid, iface_name, hostname);
-			  }
-			
-		      }
 		  }
-		
-		
-		if (!ia_option || 
-		    !(ia_option = opt6_find(opt6_next(ia_option, ia_end), ia_end, OPTION6_IAADDR, 24)))
-		  {
-		    if (address_assigned) 
-		      {
-			o1 = new_opt6(OPTION6_STATUS_CODE);
-			put_opt6_short(DHCP6SUCCESS);
-			put_opt6_string("Oh hai from dnsmasq");
-			end_opt6(o1);
-			
-			if (ia_type == OPTION6_IA_NA)
-			  {
-			    /* go back an fill in fields in IA_NA option */
-			    unsigned int t1 = min_time == 0xffffffff ? 0xffffffff : min_time/2;
-			    unsigned int t2 = min_time == 0xffffffff ? 0xffffffff : (min_time/8) * 7;
-			    int sav = save_counter(t1cntr);
-			    put_opt6_long(t1);
-			    put_opt6_long(t2);
-			    save_counter(sav);
-			  }
-		      }
-		    else
-		      { 
-			/* no address, return error */
-			o1 = new_opt6(OPTION6_STATUS_CODE);
-			put_opt6_short(DHCP6NOADDRS);
-			put_opt6_string("No addresses available");
-			end_opt6(o1);
-		      }
-		    
-		    end_opt6(o);
-		    	
-		    if (address_assigned) 
-		      {
-			/* If --dhcp-authoritative is set, we can tell client not to wait for
-			   other possible servers */
-			o = new_opt6(OPTION6_PREFERENCE);
-			put_opt6_char(option_bool(OPT_AUTHORITATIVE) ? 255 : 0);
-			end_opt6(o);
-		      }
-		    
-		    break;
-		  }
-	      } 
+	      }
+		 	   
+	    /* Return addresses for all valid contexts which don't yet have one */
+	    while ((c = address6_allocate(c, state.clid, state.clid_len, state.iaid, tagif, &addr)))
+	      {
+		add_address(&state, c, c->lease_time, c->lease_time, &min_time, &addr, rapid_commit != NULL, now);
+		get_context_tag(&state, c);
+		address_assigned = 1;
+	      }
+	    
+	    end_ia(t1cntr, min_time, 0);
+	    end_opt6(o);	
 	  }
-  
+
+	if (address_assigned) 
+	  {
+	    o1 = new_opt6(OPTION6_STATUS_CODE);
+	    put_opt6_short(DHCP6SUCCESS);
+	    put_opt6_string("Oh hai from dnsmasq");
+	    end_opt6(o1);
+	    
+	    /* If --dhcp-authoritative is set, we can tell client not to wait for
+	       other possible servers */
+	    o = new_opt6(OPTION6_PREFERENCE);
+	    put_opt6_char(option_bool(OPT_AUTHORITATIVE) ? 255 : 0);
+	    end_opt6(o);
+	  }
+	else
+	  { 
+	    /* no address, return error */
+	    o1 = new_opt6(OPTION6_STATUS_CODE);
+	    put_opt6_short(DHCP6NOADDRS);
+	    put_opt6_string("No addresses available");
+	    end_opt6(o1);
+	  }
+
+	tagif = add_options(&state, fallback, context);
 	break;
-      }   
-   
+      }
+      
+    case DHCP6REQUEST:
+      {
+	int address_assigned = 0;
+	
+	/* set reply message type */
+	*outmsgtypep = DHCP6REPLY;
+
+	log6_packet(&state, "DHCPREQUEST", NULL, ignore ? "ignored" : NULL);
+	
+	if (ignore)
+	  return 0;
+	
+	for (opt = state.packet_options; opt; opt = opt6_next(opt, state.end))
+	  {   
+	    void *ia_option, *ia_end;
+	    unsigned int min_time = 0xffffffff;
+	    int t1cntr;
+	    
+	    if (!(ia_option = check_ia(&state, opt, &ia_end)))
+	      continue;
+	    
+	    o = build_ia(&state, &t1cntr);
+	      
+	    for (; ia_option; ia_option = opt6_find(opt6_next(ia_option, ia_end), ia_end, OPTION6_IAADDR, 24))
+	      {
+		struct in6_addr *req_addr = opt6_ptr(ia_option, 0);
+		u32 requested_time = opt6_uint(ia_option, 16, 4);
+		struct dhcp_context *dynamic, *c;
+		unsigned int lease_time;
+	
+		if ((dynamic = address6_available(context, req_addr, tagif)) || (c = address6_valid(context, req_addr, tagif)))
+		  {
+		    if (!dynamic && !(have_config(config, CONFIG_ADDR6) || !IN6_ARE_ADDR_EQUAL(&config->addr6, req_addr)))
+		      {
+			/* Static range, not configured. */
+			o1 = new_opt6(OPTION6_STATUS_CODE);
+			put_opt6_short(DHCP6UNSPEC);
+			put_opt6_string("Address unavailable");
+			end_opt6(o1);
+		      }
+		    else if (lease6_find_by_addr(req_addr, 128, 0) &&
+			     !lease6_find(state.clid, state.clid_len, state.ia_type == OPTION6_IA_NA ? LEASE_NA : LEASE_TA, state.iaid, req_addr))
+		      {
+			/* Address leased to another DUID/IAID */
+			o1 = new_opt6(OPTION6_STATUS_CODE);
+			put_opt6_short(DHCP6UNSPEC);
+			put_opt6_string("Address in use");
+			end_opt6(o1);
+		      } 
+		    else 
+		      {
+			if (!dynamic)
+			  dynamic = c;
+
+			lease_time = dynamic->lease_time;
+			
+			if (have_config(config, CONFIG_ADDR6) && 
+			    IN6_ARE_ADDR_EQUAL(&config->addr6, req_addr) &&
+			    have_config(config, CONFIG_TIME))
+			  lease_time = config->lease_time;
+
+			add_address(&state, dynamic, lease_time, requested_time, &min_time, req_addr, 1, now);
+			get_context_tag(&state, dynamic);
+			address_assigned = 1;
+		      }
+		  }
+		else if (msg_type == DHCP6REQUEST)
+		  {
+		    /* requested address not on the correct link */
+		    o1 = new_opt6(OPTION6_STATUS_CODE);
+		    put_opt6_short(DHCP6NOTONLINK);
+		    put_opt6_string("Not on link");
+		    end_opt6(o1);
+		  }
+	      }
+	 
+	    end_ia(t1cntr, min_time, 0);
+	    end_opt6(o);	
+	  }
+
+	if (address_assigned) 
+	  {
+	    o1 = new_opt6(OPTION6_STATUS_CODE);
+	    put_opt6_short(DHCP6SUCCESS);
+	    put_opt6_string("Oh hai from dnsmasq");
+	    end_opt6(o1);
+	  }
+	else
+	  { 
+	    /* no address, return error */
+	    o1 = new_opt6(OPTION6_STATUS_CODE);
+	    put_opt6_short(DHCP6NOADDRS);
+	    put_opt6_string("No addresses available");
+	    end_opt6(o1);
+	  }
+
+	tagif = add_options(&state, fallback, context);
+	break;
+      }
+      
+  
     case DHCP6RENEW:
       {
 	/* set reply message type */
 	*outmsgtypep = DHCP6REPLY;
 	
-	log6_packet("DHCPRENEW", clid, clid_len, NULL, xid, iface_name, NULL);
+	log6_packet(&state, "DHCPRENEW", NULL, NULL);
 
-	for (opt = packet_options; opt; opt = opt6_next(opt, end))
+	for (opt = state.packet_options; opt; opt = opt6_next(opt, state.end))
 	  {
-	    int ia_type = opt6_type(opt);
 	    void *ia_option, *ia_end;
 	    unsigned int min_time = 0xffffffff;
-	    int t1cntr = 0, iacntr;
-	    unsigned int iaid;
+	    int t1cntr, iacntr;
 	    
-	    if (ia_type != OPTION6_IA_NA && ia_type != OPTION6_IA_TA)
+	    if (!(ia_option = check_ia(&state, opt, &ia_end)))
 	      continue;
 	    
-	    if (ia_type == OPTION6_IA_NA && opt6_len(opt) < 12)
-	      continue;
-   
-	    if (ia_type == OPTION6_IA_TA && opt6_len(opt) < 4)
-	      continue;
-	    
-	    iaid = opt6_uint(opt, 0, 4);
-	    	      	      
-	    o = new_opt6(ia_type);
-	    put_opt6_long(iaid);
-	    if (ia_type == OPTION6_IA_NA)
-	      {
-		/* save pointer */
-		t1cntr = save_counter(-1);
-		/* so we can fill these in later */
-		put_opt6_long(0);
-		put_opt6_long(0); 
-	      }
-	    
+	    o = build_ia(&state, &t1cntr);
 	    iacntr = save_counter(-1); 
 	    
-	    /* reset "USED" flags on leases */
-	    lease6_filter(ia_type == OPTION6_IA_NA ? LEASE_NA : LEASE_TA, iaid, context);
-	    
-	    ia_option = opt6_ptr(opt, ia_type == OPTION6_IA_NA ? 12 : 4);
-	    ia_end = opt6_ptr(opt, opt6_len(opt));
-
-	    for (ia_option = opt6_find(ia_option, ia_end, OPTION6_IAADDR, 24);
-		 ia_option;
-		 ia_option = opt6_find(opt6_next(ia_option, ia_end), ia_end, OPTION6_IAADDR, 24))
+	    for (; ia_option; ia_option = opt6_find(opt6_next(ia_option, ia_end), ia_end, OPTION6_IAADDR, 24))
 	      {
 		struct dhcp_lease *lease = NULL;
 		struct in6_addr *req_addr = opt6_ptr(ia_option, 0);
@@ -873,12 +775,12 @@ static int dhcp6_no_relay(int msg_type, struct in6_addr *link_address, struct dh
 		struct dhcp_config *valid_config = config;
 		
 		/* don't use a config to set lease time if it specifies an address which isn't this. */
-		if (have_config(config, CONFIG_ADDR6) && memcmp(&config->addr6, req_addr, IN6ADDRSZ) != 0)
+		if (have_config(config, CONFIG_ADDR6) && !IN6_ARE_ADDR_EQUAL(&config->addr6, req_addr))
 		  valid_config = NULL;
 
-		if (!(lease = lease6_find(clid, clid_len,
-					  ia_type == OPTION6_IA_NA ? LEASE_NA : LEASE_TA, 
-					  iaid, req_addr)))
+		if (!(lease = lease6_find(state.clid, state.clid_len,
+					  state.ia_type == OPTION6_IA_NA ? LEASE_NA : LEASE_TA, 
+					  state.iaid, req_addr)))
 		  {
 		    /* If the server cannot find a client entry for the IA the server
 		       returns the IA containing no addresses with a Status Code option set
@@ -886,7 +788,7 @@ static int dhcp6_no_relay(int msg_type, struct in6_addr *link_address, struct dh
 		    save_counter(iacntr);
 		    t1cntr = 0;
 		    
-		    log6_packet("DHCPREPLY", clid, clid_len, req_addr, xid, iface_name, "lease not found");
+		    log6_packet(&state, "DHCPREPLY", req_addr, "lease not found");
 		    
 		    o1 = new_opt6(OPTION6_STATUS_CODE);
 		    put_opt6_short(DHCP6NOBINDING);
@@ -896,30 +798,10 @@ static int dhcp6_no_relay(int msg_type, struct in6_addr *link_address, struct dh
 		  }
 		
 		
-		if (!address6_available(context, req_addr, tagif) || 
-		    !(this_context = narrow_context6(context, req_addr, tagif)))
+		if ((this_context != address6_available(context, req_addr, tagif)) ||
+		    (this_context != address6_valid(context, req_addr, tagif)))
 		  {
-		    lease_time = 0;
-		    this_context = NULL;
-		  }
-		else
-		  {
-		    /* get tags from context if we've not used it before */
-		    if (this_context->netid.next == &this_context->netid && this_context->netid.net)
-		      {
-			this_context->netid.next = context_tags;
-			context_tags = &this_context->netid;
-			if (!hostname_auth)
-			  {
-			    struct dhcp_netid_list *id_list;
-			    
-			    for (id_list = daemon->dhcp_ignore_names; id_list; id_list = id_list->next)
-			      if ((!id_list->list) || match_netid(id_list->list, &this_context->netid, 0))
-				break;
-			    if (id_list)
-			      hostname = NULL;
-			  }
-		      }
+		    get_context_tag(&state, this_context);
 		    
 		    lease_time = have_config(valid_config, CONFIG_TIME) ? valid_config->lease_time : this_context->lease_time;
 		    
@@ -929,46 +811,33 @@ static int dhcp6_no_relay(int msg_type, struct in6_addr *link_address, struct dh
 		      lease_time = requested_time;
 		    
 		    lease_set_expires(lease, lease_time, now);
-		    if (ia_type == OPTION6_IA_NA && hostname)
+		    if (state.ia_type == OPTION6_IA_NA && state.hostname)
 		      {
 			char *addr_domain = get_domain6(req_addr);
-			if (!send_domain)
-			  send_domain = addr_domain;
-			lease_set_hostname(lease, hostname, hostname_auth, addr_domain, domain);
+			if (!state.send_domain)
+			  state.send_domain = addr_domain;
+			lease_set_hostname(lease, state.hostname, state.hostname_auth, addr_domain, state.domain);
 		      }
 		    
 		    if (lease_time < min_time)
 		      min_time = lease_time;
 		  }
 		
-		log6_packet("DHCPREPLY", clid, clid_len, req_addr, xid, iface_name, hostname);	
+		log6_packet(&state, "DHCPREPLY", req_addr, state.hostname);	
 		
 		o1 =  new_opt6(OPTION6_IAADDR);
 		put_opt6(req_addr, sizeof(*req_addr));
 		/* preferred lifetime */
-		put_opt6_long(this_context && (this_context->flags & CONTEXT_DEPRECATE) ? 0 : lease_time);
-		put_opt6_long(lease_time); /* valid lifetime */
+		put_opt6_long(!this_context || (this_context->flags & CONTEXT_DEPRECATE) ? 0 : lease_time);
+		put_opt6_long(!this_context ?  0 : lease_time); /* valid lifetime */
 		end_opt6(o1);
 	      }
 	    
-	    if (t1cntr != 0)
-	      {
-		/* go back an fill in fields in IA_NA option */
-		int sav = save_counter(t1cntr);
-		unsigned int t1, t2, fuzz = rand16();
-		
-		while (fuzz > (min_time/16))
-		  fuzz = fuzz/2; 
-		t1 = min_time == 0xffffffff ? 0xffffffff : min_time/2 - fuzz;
-		t2 = min_time == 0xffffffff ? 0xffffffff : ((min_time/8)*7) - fuzz;
-		
-		put_opt6_long(t1);
-		put_opt6_long(t2);
-		save_counter(sav);
-	      }
-	    
+	    end_ia(t1cntr, min_time, 1);
 	    end_opt6(o);
 	  }
+	
+	tagif = add_options(&state, fallback, context);
 	break;
 	
       }
@@ -978,32 +847,19 @@ static int dhcp6_no_relay(int msg_type, struct in6_addr *link_address, struct dh
 	/* set reply message type */
 	*outmsgtypep = DHCP6REPLY;
 	
-	log6_packet("DHCPCONFIRM", clid, clid_len, NULL, xid, iface_name, NULL);
+	log6_packet(&state, "DHCPCONFIRM", NULL, NULL);
 	
-	for (opt = packet_options; opt; opt = opt6_next(opt, end))
+	for (opt = state.packet_options; opt; opt = opt6_next(opt, state.end))
 	  {
-	    int ia_type = opt6_type(opt);
 	    void *ia_option, *ia_end;
 	    
-	    if (ia_type != OPTION6_IA_NA && ia_type != OPTION6_IA_TA)
-	      continue;
-	    
-	    if (ia_type == OPTION6_IA_NA && opt6_len(opt) < 12)
-	      continue;
-	     
-	    if (ia_type == OPTION6_IA_TA && opt6_len(opt) < 4)
-	      continue;
-	    
-	    ia_option = opt6_ptr(opt, ia_type == OPTION6_IA_NA ? 12 : 4);
-	    ia_end = opt6_ptr(opt, opt6_len(opt));
-	    
-	    for (ia_option = opt6_find(ia_option, ia_end, OPTION6_IAADDR, 24);
+	    for (ia_option = check_ia(&state, opt, &ia_end);
 		 ia_option;
 		 ia_option = opt6_find(opt6_next(ia_option, ia_end), ia_end, OPTION6_IAADDR, 24))
 	      {
 		struct in6_addr *req_addr = opt6_ptr(ia_option, 0);
 		
-		if (!address6_available(context, req_addr, run_tag_if(tags)))
+		if (!address6_available(context, req_addr, tagif))
 		  {
 		    o1 = new_opt6(OPTION6_STATUS_CODE);
 		    put_opt6_short(DHCP6NOTONLINK);
@@ -1012,7 +868,7 @@ static int dhcp6_no_relay(int msg_type, struct in6_addr *link_address, struct dh
 		    return 1;
 		  }
 
-		log6_packet("DHCPREPLY", clid, clid_len, req_addr, xid, iface_name, hostname);
+		log6_packet(&state, "DHCPREPLY", req_addr, state.hostname);
 	      }
 	  }	 
 
@@ -1020,7 +876,7 @@ static int dhcp6_no_relay(int msg_type, struct in6_addr *link_address, struct dh
 	put_opt6_short(DHCP6SUCCESS );
 	put_opt6_string("All addresses still on link");
 	end_opt6(o1);
-	return 1;
+	break;
     }
       
     case DHCP6IREQ:
@@ -1030,12 +886,13 @@ static int dhcp6_no_relay(int msg_type, struct in6_addr *link_address, struct dh
 	if (context && context->netid.net && !context->current)
 	  {
 	    context->netid.next = NULL;
-	    context_tags =  &context->netid;
+	    state.context_tags =  &context->netid;
 	  }
-	log6_packet("DHCPINFORMATION-REQUEST", clid, clid_len, NULL, xid, iface_name, ignore ? "ignored" : hostname);
+	log6_packet(&state, "DHCPINFORMATION-REQUEST", NULL, ignore ? "ignored" : state.hostname);
 	if (ignore)
 	  return 0;
 	*outmsgtypep = DHCP6REPLY;
+	tagif = add_options(&state, fallback, context);
 	break;
       }
       
@@ -1045,46 +902,29 @@ static int dhcp6_no_relay(int msg_type, struct in6_addr *link_address, struct dh
 	/* set reply message type */
 	*outmsgtypep = DHCP6REPLY;
 
-	log6_packet("DHCPRELEASE", clid, clid_len, NULL, xid, iface_name, NULL);
+	log6_packet(&state, "DHCPRELEASE", NULL, NULL);
 
-	for (opt = packet_options; opt; opt = opt6_next(opt, end))
+	for (opt = state.packet_options; opt; opt = opt6_next(opt, state.end))
 	  {
-	    int iaid, ia_type = opt6_type(opt);
 	    void *ia_option, *ia_end;
 	    int made_ia = 0;
 	    	    
-	    if (ia_type != OPTION6_IA_NA && ia_type != OPTION6_IA_TA)
-	      continue;
-
-	    if (ia_type == OPTION6_IA_NA && opt6_len(opt) < 12)
-	      continue;
-	    
-	    if (ia_type == OPTION6_IA_TA && opt6_len(opt) < 4)
-	      continue;
-	    
-	    iaid = opt6_uint(opt, 0, 4);
-	    ia_end = opt6_ptr(opt, opt6_len(opt));
-	    ia_option = opt6_ptr(opt, ia_type == OPTION6_IA_NA ? 12 : 4);
-	    
-	    /* reset "USED" flags on leases */
-	    lease6_filter(ia_type == OPTION6_IA_NA ? LEASE_NA : LEASE_TA, iaid, context);
-		
-	    for (ia_option = opt6_find(ia_option, ia_end, OPTION6_IAADDR, 24);
+	    for (ia_option = check_ia(&state, opt, &ia_end);
 		 ia_option;
-		 ia_option = opt6_find(opt6_next(ia_option, ia_end), ia_end, OPTION6_IAADDR, 24))
+		 ia_option = opt6_find(opt6_next(ia_option, ia_end), ia_end, OPTION6_IAADDR, 24)) 
 	      {
 		struct dhcp_lease *lease;
 		
-		if ((lease = lease6_find(clid, clid_len, ia_type == OPTION6_IA_NA ? LEASE_NA : LEASE_TA,
-					 iaid, opt6_ptr(ia_option, 0))))
+		if ((lease = lease6_find(state.clid, state.clid_len, state.ia_type == OPTION6_IA_NA ? LEASE_NA : LEASE_TA,
+					 state.iaid, opt6_ptr(ia_option, 0))))
 		  lease_prune(lease, now);
 		else
 		  {
 		    if (!made_ia)
 		      {
-			o = new_opt6(ia_type);
-			put_opt6_long(iaid);
-			if (ia_type == OPTION6_IA_NA)
+			o = new_opt6(state.ia_type);
+			put_opt6_long(state.iaid);
+			if (state.ia_type == OPTION6_IA_NA)
 			  {
 			    put_opt6_long(0);
 			    put_opt6_long(0); 
@@ -1116,7 +956,7 @@ static int dhcp6_no_relay(int msg_type, struct in6_addr *link_address, struct dh
 	put_opt6_string("Release received");
 	end_opt6(o1);
 	
-	return 1;
+	break;
       }
 
     case DHCP6DECLINE:
@@ -1124,39 +964,21 @@ static int dhcp6_no_relay(int msg_type, struct in6_addr *link_address, struct dh
 	/* set reply message type */
 	*outmsgtypep = DHCP6REPLY;
 	
-	log6_packet("DHCPDECLINE", clid, clid_len, NULL, xid, iface_name, NULL);
+	log6_packet(&state, "DHCPDECLINE", NULL, NULL);
 
-	for (opt = packet_options; opt; opt = opt6_next(opt, end))
+	for (opt = state.packet_options; opt; opt = opt6_next(opt, state.end))
 	  {
-	    int iaid, ia_type = opt6_type(opt);
 	    void *ia_option, *ia_end;
 	    int made_ia = 0;
 	    	    
-	    if (ia_type != OPTION6_IA_NA && ia_type != OPTION6_IA_TA)
-	      continue;
-
-	    if (ia_type == OPTION6_IA_NA && opt6_len(opt) < 12)
-	      continue;
-	    
-	    if (ia_type == OPTION6_IA_TA && opt6_len(opt) < 4)
-	      continue;
-	    
-	    iaid = opt6_uint(opt, 0, 4);
-	    ia_end = opt6_ptr(opt, opt6_len(opt));
-	    ia_option = opt6_ptr(opt, ia_type == OPTION6_IA_NA ? 12 : 4);
-	    
-	    /* reset "USED" flags on leases */
-	    lease6_filter(ia_type == OPTION6_IA_NA ? LEASE_NA : LEASE_TA, iaid, context);
-		
-	    for (ia_option = opt6_find(ia_option, ia_end, OPTION6_IAADDR, 24);
+	    for (ia_option = check_ia(&state, opt, &ia_end);
 		 ia_option;
-		 ia_option = opt6_find(opt6_next(ia_option, ia_end), ia_end, OPTION6_IAADDR, 24))
+		 ia_option = opt6_find(opt6_next(ia_option, ia_end), ia_end, OPTION6_IAADDR, 24)) 
 	      {
 		struct dhcp_lease *lease;
 		struct in6_addr *addrp = opt6_ptr(ia_option, 0);
 
-		if (have_config(config, CONFIG_ADDR6) && 
-		    memcmp(&config->addr6, addrp, IN6ADDRSZ) == 0)
+		if (have_config(config, CONFIG_ADDR6) && IN6_ARE_ADDR_EQUAL(&config->addr6, addrp))
 		  {
 		    prettyprint_time(daemon->dhcp_buff3, DECLINE_BACKOFF);
 		    inet_ntop(AF_INET6, addrp, daemon->addrbuff, ADDRSTRLEN);
@@ -1170,16 +992,16 @@ static int dhcp6_no_relay(int msg_type, struct in6_addr *link_address, struct dh
 		  for (; context; context = context->current)
 		    context->addr_epoch++;
 		
-		if ((lease = lease6_find(clid, clid_len, ia_type == OPTION6_IA_NA ? LEASE_NA : LEASE_TA,
-					 iaid, opt6_ptr(ia_option, 0))))
+		if ((lease = lease6_find(state.clid, state.clid_len, state.ia_type == OPTION6_IA_NA ? LEASE_NA : LEASE_TA,
+					 state.iaid, opt6_ptr(ia_option, 0))))
 		  lease_prune(lease, now);
 		else
 		  {
 		    if (!made_ia)
 		      {
-			o = new_opt6(ia_type);
-			put_opt6_long(iaid);
-			if (ia_type == OPTION6_IA_NA)
+			o = new_opt6(state.ia_type);
+			put_opt6_long(state.iaid);
+			if (state.ia_type == OPTION6_IA_NA)
 			  {
 			    put_opt6_long(0);
 			    put_opt6_long(0); 
@@ -1206,16 +1028,30 @@ static int dhcp6_no_relay(int msg_type, struct in6_addr *link_address, struct dh
 	      }
 	    
 	  }
-	return 1;
+	break;
       }
 
     }
   
+  log_tags(tagif, state.xid);
   
+  if (option_bool(OPT_LOG_OPTS))
+    log6_opts(0, state.xid, daemon->outpacket.iov_base + start_opts, daemon->outpacket.iov_base + save_counter(-1));
+  
+  return 1;
+
+}
+
+struct dhcp_netid *add_options(struct state *state, struct in6_addr *fallback, struct dhcp_context *context)  
+{
+  void *opt, *oro;
   /* filter options based on tags, those we want get DHOPT_TAGOK bit set */
-  tagif = option_filter(tags, context_tags, daemon->dhcp_opts6);
-  
-  oro = opt6_find(packet_options, end, OPTION6_ORO, 0);
+  struct dhcp_netid *tagif = option_filter(state->tags, state->context_tags, daemon->dhcp_opts6);
+  struct dhcp_opt *opt_cfg;
+  int done_dns = 0, do_encap = 0;
+  int i, o, o1;
+
+  oro = opt6_find(state->packet_options, state->end, OPTION6_ORO, 0);
   
   for (opt_cfg = daemon->dhcp_opts6; opt_cfg; opt_cfg = opt_cfg->next)
     {
@@ -1251,10 +1087,8 @@ static int dhcp6_no_relay(int msg_type, struct in6_addr *link_address, struct dh
               /* zero means "self" (but not in vendorclass options.) */
               if (IN6_IS_ADDR_UNSPECIFIED(a))
                 {
-		  if (IN6_IS_ADDR_UNSPECIFIED(&context->local6))
+		  if (!add_local_addrs(context))
 		    put_opt6(fallback, IN6ADDRSZ);
-		  else
-		    put_opt6(&context->local6, IN6ADDRSZ);
 		}
               else
                 put_opt6(a, IN6ADDRSZ);
@@ -1270,10 +1104,8 @@ static int dhcp6_no_relay(int msg_type, struct in6_addr *link_address, struct dh
        !IN6_IS_ADDR_UNSPECIFIED(fallback)))
     {
       o = new_opt6(OPTION6_DNS_SERVER);
-      if (IN6_IS_ADDR_UNSPECIFIED(&context->local6))
+      if (!add_local_addrs(context))
 	put_opt6(fallback, IN6ADDRSZ);
-      else
-	put_opt6(&context->local6, IN6ADDRSZ);
       end_opt6(o); 
     }
    
@@ -1334,21 +1166,21 @@ static int dhcp6_no_relay(int msg_type, struct in6_addr *link_address, struct dh
     }      
 
 
-  if (hostname)
+  if (state->hostname)
     {
       unsigned char *p;
-      size_t len = strlen(hostname);
+      size_t len = strlen(state->hostname);
       
-      if (send_domain)
-	len += strlen(send_domain) + 1;
+      if (state->send_domain)
+	len += strlen(state->send_domain) + 1;
 
       o = new_opt6(OPTION6_FQDN);
       if ((p = expand(len + 3)))
 	{
-	  *(p++) = fqdn_flags;
-	  p = do_rfc1035_name(p, hostname);
-	  if (send_domain)
-	    p = do_rfc1035_name(p, send_domain);
+	  *(p++) = state->fqdn_flags;
+	  p = do_rfc1035_name(p, state->hostname);
+	  if (state->send_domain)
+	    p = do_rfc1035_name(p, state->send_domain);
 	  *p = 0;
 	}
       end_opt6(o);
@@ -1371,19 +1203,270 @@ static int dhcp6_no_relay(int msg_type, struct in6_addr *link_address, struct dh
 	  if ( i >  opt6_len(oro) - 3 || (q - daemon->namebuff) > 40)
 	    {
 	      q = daemon->namebuff;
-	      my_syslog(MS_DHCP | LOG_INFO, _("%u requested options: %s"), xid, daemon->namebuff);
+	      my_syslog(MS_DHCP | LOG_INFO, _("%u requested options: %s"), state->xid, daemon->namebuff);
 	    }
 	}
-    }
- 
-  log_tags(tagif, xid);
+    } 
 
-  if (option_bool(OPT_LOG_OPTS))
-    log6_opts(0, xid, daemon->outpacket.iov_base + start_opts, daemon->outpacket.iov_base + save_counter(-1));
+  return tagif;
+}
+ 
+static int add_local_addrs(struct dhcp_context *context)
+{
+  int done = 0;
   
-  return 1;
+  for (; context; context = context->current)
+    if ((context->flags & CONTEXT_USED) && !IN6_IS_ADDR_UNSPECIFIED(&context->local6))
+      {
+	/* squash duplicates */
+	struct dhcp_context *c;
+	for (c = context->current; c; c = c->current)
+	  if ((c->flags & CONTEXT_USED) &&
+	      IN6_ARE_ADDR_EQUAL(&context->local6, &c->local6))
+	    break;
+	
+	if (!c)
+	  { 
+	    done = 1;
+	    put_opt6(&context->local6, IN6ADDRSZ);
+	  }
+      }
+
+  return done;
 }
 
+
+static void get_context_tag(struct state *state, struct dhcp_context *context)
+{
+  /* get tags from context if we've not used it before */
+  if (context->netid.next == &context->netid && context->netid.net)
+    {
+      context->netid.next = state->context_tags;
+      state->context_tags = &context->netid;
+      if (!state->hostname_auth)
+	{
+	  struct dhcp_netid_list *id_list;
+	  
+	  for (id_list = daemon->dhcp_ignore_names; id_list; id_list = id_list->next)
+	    if ((!id_list->list) || match_netid(id_list->list, &context->netid, 0))
+	      break;
+	  if (id_list)
+	    state->hostname = NULL;
+	}
+    }
+} 
+static void *check_ia(struct state *state, void *opt, void **endp)
+{
+  state->ia_type = opt6_type(opt);
+
+  if (state->ia_type != OPTION6_IA_NA && state->ia_type != OPTION6_IA_TA)
+    return NULL;
+  
+  if (state->ia_type == OPTION6_IA_NA && opt6_len(opt) < 12)
+    return NULL;
+	    
+  if (state->ia_type == OPTION6_IA_TA && opt6_len(opt) < 4)
+    return NULL;
+  
+  *endp = opt6_ptr(opt, opt6_len(opt));
+  state->iaid = opt6_uint(opt, 0, 4);
+  
+  return opt6_find(opt6_ptr(opt, state->ia_type == OPTION6_IA_NA ? 12 : 4), *endp, OPTION6_IAADDR, 24);
+}
+
+
+static int build_ia(struct state *state, int *t1cntr)
+{
+  int  o = new_opt6(state->ia_type);
+ 
+  put_opt6_long(state->iaid);
+  *t1cntr = 0;
+	    
+  if (state->ia_type == OPTION6_IA_NA)
+    {
+      /* save pointer */
+      *t1cntr = save_counter(-1);
+      /* so we can fill these in later */
+      put_opt6_long(0);
+      put_opt6_long(0); 
+    }
+
+  return o;
+}
+
+static void end_ia(int t1cntr, unsigned int min_time, int do_fuzz)
+{
+  if (t1cntr != 0)
+    {
+      /* go back an fill in fields in IA_NA option */
+      int sav = save_counter(t1cntr);
+      unsigned int t1, t2, fuzz = 0;
+
+      if (do_fuzz)
+	{
+	  fuzz = rand16();
+      
+	  while (fuzz > (min_time/16))
+	    fuzz = fuzz/2;
+	}
+      
+      t1 = (min_time == 0xffffffff) ? 0xffffffff : min_time/2 - fuzz;
+      t2 = (min_time == 0xffffffff) ? 0xffffffff : ((min_time/8)*7) - fuzz;
+      put_opt6_long(t1);
+      put_opt6_long(t2);
+      save_counter(sav);
+    }	
+}
+
+static void add_address(struct state *state, struct dhcp_context *context, unsigned int lease_time, unsigned int requested_time, 
+			unsigned int *min_time, struct in6_addr *addr, int do_update, time_t now)
+{
+  unsigned int valid_time = (context->valid < lease_time) ? context->valid : lease_time;
+  int o = new_opt6(OPTION6_IAADDR);
+  struct dhcp_lease *lease;
+
+  put_opt6(addr, sizeof(*addr));
+  
+  /* preferred lifetime */
+  if (requested_time < 120u )
+    requested_time = 120u; /* sanity */
+  if (lease_time == 0xffffffff || (requested_time != 0xffffffff && requested_time < lease_time))
+    lease_time = requested_time;
+ 	
+  if (lease_time < *min_time)
+    *min_time = lease_time;
+
+  put_opt6_long((context->preferred < lease_time) ? context->preferred : lease_time);
+  put_opt6_long(valid_time); /* valid lifetime */		    
+ 
+  end_opt6(o);
+  
+  if (do_update)
+    update_leases(state, context, addr, valid_time, now);
+
+  if ((lease = lease6_find_by_addr(addr, 128, 0)))
+    lease->flags |= LEASE_USED;
+
+  /* get tags from context if we've not used it before */
+  if (context->netid.next == &context->netid && context->netid.net)
+    {
+      context->netid.next = state->context_tags;
+      state->context_tags = &context->netid;
+      
+      if (!state->hostname_auth)
+	{
+	  struct dhcp_netid_list *id_list;
+	  
+	  for (id_list = daemon->dhcp_ignore_names; id_list; id_list = id_list->next)
+	    if ((!id_list->list) || match_netid(id_list->list, &context->netid, 0))
+	      break;
+	  if (id_list)
+	    state->hostname = NULL;
+	}
+    }
+
+  /* Mark that we have an address for this prefix. */
+  for (context = state->context; context; context = context->current)
+    if (is_same_net6(addr, &context->start6, context->prefix))
+      context->flags |= CONTEXT_USED;
+
+  log6_packet(state, do_update ? "DHCPREPLY" : "DHCPADVERTISE", addr, state->hostname);
+
+}
+ 
+static void update_leases(struct state *state, struct dhcp_context *context, struct in6_addr *addr, unsigned int lease_time, time_t now)
+{
+  struct dhcp_lease *lease = lease6_find_by_addr(addr, 128, 0);
+  struct dhcp_netid *tagif = run_tag_if(state->tags);
+
+  if (!lease)
+    lease = lease6_allocate(addr, state->ia_type == OPTION6_IA_NA ? LEASE_NA : LEASE_TA);
+  
+  if (lease)
+    {
+      lease_set_expires(lease, lease_time, now);
+      lease_set_hwaddr(lease, NULL, state->clid, 0, state->iaid, state->clid_len, now, 0);
+      lease_set_interface(lease, state->interface, now);
+      if (state->hostname && state->ia_type == OPTION6_IA_NA)
+	{
+	  char *addr_domain = get_domain6(addr);
+	  if (!state->send_domain)
+	    state->send_domain = addr_domain;
+	  lease_set_hostname(lease, state->hostname, state->hostname_auth, addr_domain, state->domain);
+	}
+      
+#ifdef HAVE_SCRIPT
+      if (daemon->lease_change_command)
+	{
+	  void *class_opt;
+	  lease->flags |= LEASE_CHANGED;
+	  free(lease->extradata);
+	  lease->extradata = NULL;
+	  lease->extradata_size = lease->extradata_len = 0;
+	  lease->hwaddr_len = 0; /* surrogate for no of vendor classes */
+	  
+	  if ((class_opt = opt6_find(state->packet_options, state->end, OPTION6_VENDOR_CLASS, 4)))
+	    {
+	      void *enc_opt, *enc_end = opt6_ptr(class_opt, opt6_len(class_opt));
+	      lease->hwaddr_len++;
+	      /* send enterprise number first  */
+	      sprintf(daemon->dhcp_buff2, "%u", opt6_uint(class_opt, 0, 4));
+	      lease_add_extradata(lease, (unsigned char *)daemon->dhcp_buff2, strlen(daemon->dhcp_buff2), 0);
+	      
+	      if (opt6_len(class_opt) >= 6) 
+		for (enc_opt = opt6_ptr(class_opt, 4); enc_opt; enc_opt = opt6_next(enc_opt, enc_end))
+		  {
+		    lease->hwaddr_len++;
+		    lease_add_extradata(lease, opt6_ptr(enc_opt, 0), opt6_len(enc_opt), 0);
+		  }
+	    }
+	  
+	  lease_add_extradata(lease, (unsigned char *)state->client_hostname, 
+			      state->client_hostname ? strlen(state->client_hostname) : 0, 0);				
+	  
+	  /* space-concat tag set */
+	  if (!tagif && !context->netid.net)
+	    lease_add_extradata(lease, NULL, 0, 0);
+	  else
+	    {
+	      if (context->netid.net)
+		lease_add_extradata(lease, (unsigned char *)context->netid.net, strlen(context->netid.net), tagif ? ' ' : 0);
+	      
+	      if (tagif)
+		{
+		  struct dhcp_netid *n;
+		  for (n = tagif; n; n = n->next)
+		    {
+		      struct dhcp_netid *n1;
+		      /* kill dupes */
+		      for (n1 = n->next; n1; n1 = n1->next)
+			if (strcmp(n->net, n1->net) == 0)
+			  break;
+		      if (!n1)
+			lease_add_extradata(lease, (unsigned char *)n->net, strlen(n->net), n->next ? ' ' : 0); 
+		    }
+		}
+	    }
+	  
+	  if (state->link_address)
+	    inet_ntop(AF_INET6, state->link_address, daemon->addrbuff, ADDRSTRLEN);
+	  
+	  lease_add_extradata(lease, (unsigned char *)daemon->addrbuff, state->link_address ? strlen(daemon->addrbuff) : 0, 0);
+	  
+	  if ((class_opt = opt6_find(state->packet_options, state->end, OPTION6_USER_CLASS, 2)))
+	    {
+	      void *enc_opt, *enc_end = opt6_ptr(class_opt, opt6_len(class_opt));
+	      for (enc_opt = opt6_ptr(class_opt, 0); enc_opt; enc_opt = opt6_next(enc_opt, enc_end))
+		lease_add_extradata(lease, opt6_ptr(enc_opt, 0), opt6_len(enc_opt), 0);
+	    }
+	}
+#endif	
+      
+    }
+}
+			  
+			
+	
 static void log6_opts(int nest, unsigned int xid, void *start_opts, void *end_opts)
 {
   void *opt;
@@ -1441,13 +1524,15 @@ static void log6_opts(int nest, unsigned int xid, void *start_opts, void *end_op
     }
 }		 
  
-static void log6_packet(char *type, unsigned char *clid, int clid_len, struct in6_addr *addr, int xid, char *iface, char *string)
+static void log6_packet(struct state *state, char *type, struct in6_addr *addr, char *string)
 {
+  int clid_len = state->clid_len;
+
   /* avoid buffer overflow */
   if (clid_len > 100)
     clid_len = 100;
   
-  print_mac(daemon->namebuff, clid, clid_len);
+  print_mac(daemon->namebuff, state->clid, clid_len);
 
   if (addr)
     {
@@ -1459,16 +1544,16 @@ static void log6_packet(char *type, unsigned char *clid, int clid_len, struct in
 
   if(option_bool(OPT_LOG_OPTS))
     my_syslog(MS_DHCP | LOG_INFO, "%u %s(%s) %s%s %s",
-	      xid, 
+	      state->xid, 
 	      type,
-	      iface, 
+	      state->iface_name, 
 	      daemon->dhcp_buff2,
 	      daemon->namebuff,
 	      string ? string : "");
   else
     my_syslog(MS_DHCP | LOG_INFO, "%s(%s) %s%s %s",
 	      type,
-	      iface, 
+	      state->iface_name, 
 	      daemon->dhcp_buff2,
 	      daemon->namebuff,
 	      string ? string : "");