Experimental support for DHCPv6 prefix-class option.

src/dhcp6-protocol.h

@@ -59,6 +59,11 @@
 #define OPTION6_SUBSCRIBER_ID   38
 #define OPTION6_FQDN            39
 
+/* replace this with the real number when allocated.
+   defining this also enables the relevant code. */ 
+/* #define OPTION6_PREFIX_CLASS    99 */
+
+
 #define DHCP6SUCCESS     0
 #define DHCP6UNSPEC      1
 #define DHCP6NOADDRS     2

src/dhcp6.c

@@ -266,7 +266,7 @@ struct dhcp_config *config_find_by_address6(struct dhcp_config *configs, struct
 }
 
 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 iaid, int serial, struct dhcp_netid *netids, int plain_range, struct in6_addr *ans)   
 {
   /* Find a free address: exclude anything in use and anything allocated to
      a particular hwaddr/clientid/hostname in our configuration.
@@ -286,7 +286,7 @@ struct dhcp_context *address6_allocate(struct dhcp_context *context,  unsigned c
   for (j = iaid, i = 0; i < clid_len; i++)
     j += clid[i] + (j << 6) + (j << 16) - j;
   
-  for (pass = 0; pass <= 1; pass++)
+  for (pass = 0; pass <= plain_range ? 1 : 0; pass++)
     for (c = context; c; c = c->current)
       if (c->flags & (CONTEXT_DEPRECATE | CONTEXT_STATIC | CONTEXT_RA_STATELESS | CONTEXT_USED))
 	continue;
@@ -296,7 +296,7 @@ struct dhcp_context *address6_allocate(struct dhcp_context *context,  unsigned c
 	{ 
 	  if (option_bool(OPT_CONSEC_ADDR))
 	    /* seed is largest extant lease addr in this context */
-	    start = lease_find_max_addr6(c);
+	    start = lease_find_max_addr6(c) + serial;
 	  else
 	    start = addr6part(&c->start6) + ((j + c->addr_epoch) % (1 + addr6part(&c->end6) - addr6part(&c->start6)));
 
@@ -332,7 +332,8 @@ struct dhcp_context *address6_allocate(struct dhcp_context *context,  unsigned c
 /* can dynamically allocate addr */
 struct dhcp_context *address6_available(struct dhcp_context *context, 
 					struct in6_addr *taddr,
-					struct dhcp_netid *netids)
+					struct dhcp_netid *netids,
+					int plain_range)
 {
   u64 start, end, addr = addr6part(taddr);
   struct dhcp_context *tmp;
@@ -347,7 +348,7 @@ struct dhcp_context *address6_available(struct dhcp_context *context,
 	  is_same_net6(&tmp->end6, taddr, tmp->prefix) &&
 	  addr >= start &&
           addr <= end &&
-          match_netid(tmp->filter, netids, 1))
+          match_netid(tmp->filter, netids, plain_range))
         return tmp;
     }
 
@@ -356,14 +357,15 @@ struct dhcp_context *address6_available(struct dhcp_context *context,
 
 /* address OK if configured */
 struct dhcp_context *address6_valid(struct dhcp_context *context, 
-					struct in6_addr *taddr,
-					struct dhcp_netid *netids)
+				    struct in6_addr *taddr,
+				    struct dhcp_netid *netids,
+				    int plain_range)
 {
   struct dhcp_context *tmp;
  
   for (tmp = context; tmp; tmp = tmp->current)
     if (is_same_net6(&tmp->start6, taddr, tmp->prefix) &&
-	match_netid(tmp->filter, netids, 1))
+	match_netid(tmp->filter, netids, plain_range))
       return tmp;
 
   return NULL;

src/dnsmasq.h

@@ -684,7 +684,7 @@ struct cond_domain {
 #ifdef OPTION6_PREFIX_CLASS 
 struct prefix_class {
   int class;
-  struct dhcp_netid netid;
+  struct dhcp_netid tag;
   struct prefix_class *next;
 };
 #endif
@@ -829,6 +829,9 @@ extern struct daemon {
   unsigned char *duid_config;
   char *dbus_name;
   unsigned long soa_sn, soa_refresh, soa_retry, soa_expiry;
+#ifdef OPTION6_PREFIX_CLASS 
+  struct prefix_class *prefix_classes;
+#endif
 
   /* globally used stuff for DNS */
   char *packet; /* packet buffer */
@@ -1171,14 +1174,16 @@ int get_incoming_mark(union mysockaddr *peer_addr, struct all_addr *local_addr,
 void dhcp6_init(void);
 void dhcp6_packet(time_t now);
 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 iaid, int serial, struct dhcp_netid *netids, int plain_range, 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,
-					struct dhcp_netid *netids);
+					struct dhcp_netid *netids,
+					int plain_range);
 struct dhcp_context *address6_valid(struct dhcp_context *context, 
 				    struct in6_addr *taddr,
-				    struct dhcp_netid *netids);
+				    struct dhcp_netid *netids,
+				    int plain_range);
 struct dhcp_config *find_config6(struct dhcp_config *configs,
 				 struct dhcp_context *context,
 				 unsigned char *duid, int duid_len,

src/option.c

@@ -128,6 +128,9 @@ struct myoption {
 #define LOPT_AUTHSFS   317
 #define LOPT_AUTHPEER  318
 #define LOPT_IPSET     319
+#ifdef OPTION6_PREFIX_CLASS 
+#define LOPT_PREF_CLSS 320
+#endif
 
 #ifdef HAVE_GETOPT_LONG
 static const struct option opts[] =  
@@ -261,6 +264,9 @@ static const struct myoption opts[] =
     { "auth-sec-servers", 1, 0, LOPT_AUTHSFS },
     { "auth-peer", 1, 0, LOPT_AUTHPEER }, 
     { "ipset", 1, 0, LOPT_IPSET },
+#ifdef OPTION6_PREFIX_CLASS 
+    { "dhcp-prefix-class", 1, 0, LOPT_PREF_CLSS },
+#endif
     { NULL, 0, 0, 0 }
   };
 
@@ -400,6 +406,9 @@ static struct {
   { LOPT_AUTHSFS, ARG_DUP, "<NS>[,<NS>...]", gettext_noop("Secondary authoritative nameservers for forward domains"), NULL },
   { LOPT_AUTHPEER, ARG_DUP, "<ipaddr>[,<ipaddr>...]", gettext_noop("Peers which are allowed to do zone transfer"), NULL },
   { LOPT_IPSET, ARG_DUP, "/<domain>/<ipset>[,<ipset>...]", gettext_noop("Specify ipsets to which matching domains should be added"), NULL },
+#ifdef OPTION6_PREFIX_CLASS 
+  { LOPT_PREF_CLSS, ARG_DUP, "set:tag,<class>", gettext_noop("Specify DHCPv6 prefix class"), NULL },
+#endif
   { 0, 0, NULL, NULL, NULL }
 }; 
 
@@ -2943,7 +2952,25 @@ static int one_opt(int option, char *arg, char *errstr, char *gen_err, int comma
 	  }
       }
       break;
-      
+
+#ifdef OPTION6_PREFIX_CLASS 
+    case LOPT_PREF_CLSS: /* --dhcp-prefix-class */
+      {
+	struct prefix_class *new = opt_malloc(sizeof(struct prefix_class));
+	
+	if (!(comma = split(arg)) ||
+	    !atoi_check16(comma, &new->class))
+	  ret_err(gen_err);
+	
+	new->tag.net = opt_string_alloc(set_prefix(arg));
+	new->next = daemon->prefix_classes;
+	daemon->prefix_classes = new;
+	
+	break;
+      }
+#endif
+			      
+
     case 'U':           /* --dhcp-vendorclass */
     case 'j':           /* --dhcp-userclass */
     case LOPT_CIRCUIT:  /* --dhcp-circuitid */

src/rfc3315.c

@@ -29,6 +29,9 @@ struct state {
   char *iface_name;
   void *packet_options, *end;
   struct dhcp_netid *tags, *context_tags;
+#ifdef OPTION6_PREFIX_CLASS
+  struct prefix_class *send_prefix_class;
+#endif
 };
 
 static int dhcp6_maybe_relay(struct in6_addr *link_address, struct dhcp_netid **relay_tagsp, struct dhcp_context *context, 
@@ -42,9 +45,13 @@ static void *opt6_find (void *opts, void *end, unsigned int search, unsigned int
 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 check_ia(struct state *state, void *opt, void **endp, void **ia_option);
 static int build_ia(struct state *state, int *t1cntr);
 static void end_ia(int t1cntr, unsigned int min_time, int do_fuzz);
+#ifdef OPTION6_PREFIX_CLASS
+static struct prefix_class *prefix_class_from_context(struct dhcp_context *context);
+#endif
+static void mark_context_used(struct state *state, struct dhcp_context *context, struct in6_addr *addr);
 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);
@@ -204,6 +211,9 @@ static int dhcp6_no_relay(int msg_type, struct in6_addr *link_address, struct dh
   struct dhcp_context *context_tmp;
   unsigned int ignore = 0;
   struct state state;
+#ifdef OPTION6_PREFIX_CLASS
+ struct prefix_class *p;
+#endif
 
   state.packet_options = inbuff + 4;
   state.end = inbuff + sz;
@@ -221,6 +231,9 @@ static int dhcp6_no_relay(int msg_type, struct in6_addr *link_address, struct dh
   state.client_hostname = NULL;
   state.iface_name = iface_name;
   state.fqdn_flags = 0x01; /* default to send if we recieve no FQDN option */
+#ifdef OPTION6_PREFIX_CLASS
+  state.send_prefix_class = NULL;
+#endif
 
   /* set tag with name == interface */
   iface_id.net = iface_name;
@@ -460,8 +473,22 @@ static int dhcp6_no_relay(int msg_type, struct in6_addr *link_address, struct dh
       if (have_config(config, CONFIG_DISABLE))
 	ignore = 1;
     }
-   
-  tagif = run_tag_if(state.tags);
+
+  tagif = state.tags;
+
+#ifdef OPTION6_PREFIX_CLASS
+  /* Add the tags associated with prefix classes so we can use the DHCP ranges.
+     These are removed and added back one-at-time for SOLICITs
+     Neccessary to allow REQUEST or RENEW of addresses ADVERTISED under
+     specific classes. */
+  for (p = daemon->prefix_classes; p ; p = p->next)
+    {
+      p->tag.next = tagif;
+      tagif = &p->tag;
+    }	
+#endif
+
+  tagif = run_tag_if(tagif);
   
   /* if all the netids in the ignore list are present, ignore this client */
   if (daemon->dhcp_ignore)
@@ -496,7 +523,9 @@ static int dhcp6_no_relay(int msg_type, struct in6_addr *link_address, struct dh
       {
 	void *rapid_commit = opt6_find(state.packet_options, state.end, OPTION6_RAPID_COMMIT, 0);
       	int used_config = 0, address_assigned = 0;
-	
+	/* tags without all prefix-class tags */
+	struct dhcp_netid *solicit_tags = run_tag_if(state.tags);
+
 	if (rapid_commit)
 	  {
 	    o = new_opt6(OPTION6_RAPID_COMMIT);
@@ -511,19 +540,29 @@ static int dhcp6_no_relay(int msg_type, struct in6_addr *link_address, struct dh
 	if (ignore)
 	  return 0;
 	
+	/* reset USED bits in leases */
+	lease6_reset();
+	
 	for (opt = state.packet_options; opt; opt = opt6_next(opt, state.end))
 	  {   
 	    void *ia_option, *ia_end;
 	    unsigned int min_time = 0xffffffff;
 	    int t1cntr;
 	    int config_ok = 0;
+	    int ia_counter;
+	    /* set unless we're sending a particular prefix-class, when we
+	       want only dhcp-ranges with the correct tags set and not those without any tags. */
+	    int plain_range = 1;
 	    struct dhcp_context *c;
 	    u32 lease_time, requested_time;
 	    struct dhcp_lease *ltmp;
 	    struct in6_addr *req_addr;
 	    struct in6_addr addr;
-	    
-	    if (!(ia_option = check_ia(&state, opt, &ia_end)))
+#ifdef OPTION6_PREFIX_CLASS
+	    int dump_all_prefix_classes = 0;
+#endif
+
+	    if (!check_ia(&state, opt, &ia_end, &ia_option))
 	      continue;
 	    
 	    if (have_config(config, CONFIG_ADDR6))
@@ -539,22 +578,81 @@ static int dhcp6_no_relay(int msg_type, struct in6_addr *link_address, struct dh
 		  config_ok = 0; /* configured address leased elsewhere */
 	      }
 	      
-	    /* reset USED bits in leases */
-	    lease6_reset();
-	    
+	    /* reset USED bits in contexts - one address per prefix per IAID */
+	    for (c = context; c; c = c->current)
+	      c->flags &= ~CONTEXT_USED;
+
+#ifdef OPTION6_PREFIX_CLASS
+	    if (daemon->prefix_classes && state.ia_type == OPTION6_IA_NA)
+	      {
+		void *prefix_opt, *oro;
+		int prefix_class;
+		
+		if ((oro = opt6_find(state.packet_options, state.end, OPTION6_ORO, 0)))
+		  for (i = 0; i <  opt6_len(oro) - 1; i += 2)
+		    if (opt6_uint(oro, i, 2) == OPTION6_PREFIX_CLASS)
+		      break;
+		
+		if (oro && (i < opt6_len(oro) - 1))
+		  {
+		    /* OPTION_PREFIX_CLASS in ORO, send addresses in all prefix classes */
+		    plain_range = 0;
+		    dump_all_prefix_classes = 1;
+		  }
+		else 
+		  { 
+		    if ((prefix_opt = opt6_find(opt6_ptr(opt, 12), ia_end, OPTION6_PREFIX_CLASS, 2)))
+		      {
+			
+			prefix_class = opt6_uint(prefix_opt, 0, 2);
+			
+			for (p = daemon->prefix_classes; p ; p = p->next)
+			  if (p->class == prefix_class)
+			    break;
+			
+			if (!p)
+			  my_syslog(MS_DHCP | LOG_WARNING, _("unknown prefix-class %d"), prefix_class);
+			else
+			  {
+			    /* add tag to list, and exclude undecorated dhcp-ranges */
+			    p->tag.next = state.tags;
+			    solicit_tags = run_tag_if(&p->tag);
+			    plain_range = 0;
+			    state.send_prefix_class = p;
+			  }
+		      }
+		    else
+		      {
+			/* client didn't ask for a prefix class, lets see if we can find one. */
+			for (p = daemon->prefix_classes; p ; p = p->next)
+			  {
+			    p->tag.next = NULL;
+			    if (match_netid(&p->tag, solicit_tags, 1))
+			      break;
+			  }
+			
+			if (p)
+			  {
+			    plain_range = 0;
+			    state.send_prefix_class = p;
+			  }
+		      }
+
+		    if (p && option_bool(OPT_LOG_OPTS))
+		      my_syslog(MS_DHCP | LOG_INFO, "%u prefix class %d tag:%s", state.xid, p->class, p->tag.net); 
+		  }
+	      }
+#endif
+
 	    o = build_ia(&state, &t1cntr);
 
-	    for (; ia_option; ia_option = opt6_find(opt6_next(ia_option, ia_end), ia_end, OPTION6_IAADDR, 24))
+	    for (ia_counter = 0; ia_option; ia_counter++, 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)))
+		if ((c = address6_valid(context, req_addr, solicit_tags, plain_range)))
 		  {
 		    lease_time = c->lease_time;
 		    /* If the client asks for an address on the same network as a configured address, 
@@ -567,7 +665,7 @@ static int dhcp6_no_relay(int msg_type, struct in6_addr *link_address, struct dh
 			if (have_config(config, CONFIG_TIME))
 			  lease_time = config->lease_time;
 		      }
-		    else if (!(c = address6_available(context, req_addr, tagif)))
+		    else if (!(c = address6_available(context, req_addr, solicit_tags, plain_range)))
 		      continue; /* not an address we're allowed */
 		    else if (ltmp && 
 			     (ltmp->clid_len != state.clid_len || 
@@ -576,20 +674,30 @@ static int dhcp6_no_relay(int msg_type, struct in6_addr *link_address, struct dh
 		      continue; /* address leased elsewhere */
 		    
 		    /* add address to output packet */
+#ifdef OPTION6_PREFIX_CLASS
+		    if (dump_all_prefix_classes)
+		      state.send_prefix_class = prefix_class_from_context(c);
+#endif		    
 		    add_address(&state, c, lease_time, requested_time, &min_time, req_addr, rapid_commit != NULL, now);
+		    mark_context_used(&state, context, req_addr);
 		    get_context_tag(&state, c);
 		    address_assigned = 1;
 		  }
 	      }
 	    
 	    /* Suggest configured address */
-	    if (!used_config && config_ok && (c = address6_valid(context, &config->addr6, tagif)))
+	    if (!used_config && config_ok && (c = address6_valid(context, &config->addr6, solicit_tags, plain_range)))
 	      {
 		used_config = 1;
 		if (have_config(config, CONFIG_TIME))
 		  lease_time = config->lease_time;
 		/* add address to output packet */
+#ifdef OPTION6_PREFIX_CLASS
+		if (dump_all_prefix_classes)
+		  state.send_prefix_class = prefix_class_from_context(c);
+#endif
 		add_address(&state, c, lease_time, requested_time, &min_time, &config->addr6, rapid_commit != NULL, now);
+		mark_context_used(&state, context, &config->addr6);
 		get_context_tag(&state, c);
 		address_assigned = 1;
 	      }
@@ -599,18 +707,28 @@ static int dhcp6_no_relay(int msg_type, struct in6_addr *link_address, struct dh
 	    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)))
+		if ((c = address6_available(context, req_addr, solicit_tags, plain_range)))
 		  {
+#ifdef OPTION6_PREFIX_CLASS
+		    if (dump_all_prefix_classes)
+		      state.send_prefix_class = prefix_class_from_context(c);
+#endif
 		    add_address(&state, c, c->lease_time, c->lease_time, &min_time, req_addr, rapid_commit != NULL, now);
+		    mark_context_used(&state, context, req_addr);
 		    get_context_tag(&state, c);
 		    address_assigned = 1;
 		  }
 	      }
 		 	   
 	    /* 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)))
+	    while ((c = address6_allocate(context, state.clid, state.clid_len, state.iaid, ia_counter, solicit_tags, plain_range, &addr)))
 	      {
+#ifdef OPTION6_PREFIX_CLASS
+		if (dump_all_prefix_classes)
+		  state.send_prefix_class = prefix_class_from_context(c);
+#endif
 		add_address(&state, c, c->lease_time, c->lease_time, &min_time, &addr, rapid_commit != NULL, now);
+		mark_context_used(&state, context, &addr);
 		get_context_tag(&state, c);
 		address_assigned = 1;
 	      }
@@ -631,6 +749,7 @@ static int dhcp6_no_relay(int msg_type, struct in6_addr *link_address, struct dh
 	    o = new_opt6(OPTION6_PREFERENCE);
 	    put_opt6_char(option_bool(OPT_AUTHORITATIVE) ? 255 : 0);
 	    end_opt6(o);
+	    tagif = add_options(&state, fallback, context);
 	  }
 	else
 	  { 
@@ -639,9 +758,9 @@ static int dhcp6_no_relay(int msg_type, struct in6_addr *link_address, struct dh
 	    put_opt6_short(DHCP6NOADDRS);
 	    put_opt6_string("No addresses available");
 	    end_opt6(o1);
+	    log6_packet(&state, "DHCPADVERTISE", NULL, _("No addresses available"));
 	  }
 
-	tagif = add_options(&state, fallback, context);
 	break;
       }
       
@@ -663,8 +782,8 @@ static int dhcp6_no_relay(int msg_type, struct in6_addr *link_address, struct dh
 	    unsigned int min_time = 0xffffffff;
 	    int t1cntr;
 	    
-	    if (!(ia_option = check_ia(&state, opt, &ia_end)))
-	      continue;
+	     if (!check_ia(&state, opt, &ia_end, &ia_option))
+	       continue;
 	    
 	    o = build_ia(&state, &t1cntr);
 	      
@@ -675,7 +794,7 @@ static int dhcp6_no_relay(int msg_type, struct in6_addr *link_address, struct dh
 		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 = address6_available(context, req_addr, tagif, 1)) || (c = address6_valid(context, req_addr, tagif, 1)))
 		  {
 		    if (!dynamic && !(have_config(config, CONFIG_ADDR6) || !IN6_ARE_ADDR_EQUAL(&config->addr6, req_addr)))
 		      {
@@ -739,6 +858,7 @@ static int dhcp6_no_relay(int msg_type, struct in6_addr *link_address, struct dh
 	    put_opt6_short(DHCP6NOADDRS);
 	    put_opt6_string("No addresses available");
 	    end_opt6(o1);
+	    log6_packet(&state, "DHCPREPLY", NULL, _("No addresses available"));
 	  }
 
 	tagif = add_options(&state, fallback, context);
@@ -759,7 +879,7 @@ static int dhcp6_no_relay(int msg_type, struct in6_addr *link_address, struct dh
 	    unsigned int min_time = 0xffffffff;
 	    int t1cntr, iacntr;
 	    
-	    if (!(ia_option = check_ia(&state, opt, &ia_end)))
+	    if (!check_ia(&state, opt, &ia_end, &ia_option))
 	      continue;
 	    
 	    o = build_ia(&state, &t1cntr);
@@ -798,8 +918,8 @@ static int dhcp6_no_relay(int msg_type, struct in6_addr *link_address, struct dh
 		  }
 		
 		
-		if ((this_context = address6_available(context, req_addr, tagif)) ||
-		    (this_context = address6_valid(context, req_addr, tagif)))
+		if ((this_context = address6_available(context, req_addr, tagif, 1)) ||
+		    (this_context = address6_valid(context, req_addr, tagif, 1)))
 		  {
 		    get_context_tag(&state, this_context);
 		    
@@ -853,13 +973,13 @@ static int dhcp6_no_relay(int msg_type, struct in6_addr *link_address, struct dh
 	  {
 	    void *ia_option, *ia_end;
 	    
-	    for (ia_option = check_ia(&state, opt, &ia_end);
+	    for (check_ia(&state, opt, &ia_end, &ia_option);
 		 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, tagif))
+		if (!address6_available(context, req_addr, tagif, 1))
 		  {
 		    o1 = new_opt6(OPTION6_STATUS_CODE);
 		    put_opt6_short(DHCP6NOTONLINK);
@@ -909,7 +1029,7 @@ static int dhcp6_no_relay(int msg_type, struct in6_addr *link_address, struct dh
 	    void *ia_option, *ia_end;
 	    int made_ia = 0;
 	    	    
-	    for (ia_option = check_ia(&state, opt, &ia_end);
+	    for (check_ia(&state, opt, &ia_end, &ia_option);
 		 ia_option;
 		 ia_option = opt6_find(opt6_next(ia_option, ia_end), ia_end, OPTION6_IAADDR, 24)) 
 	      {
@@ -971,7 +1091,7 @@ static int dhcp6_no_relay(int msg_type, struct in6_addr *link_address, struct dh
 	    void *ia_option, *ia_end;
 	    int made_ia = 0;
 	    	    
-	    for (ia_option = check_ia(&state, opt, &ia_end);
+	    for (check_ia(&state, opt, &ia_end, &ia_option);
 		 ia_option;
 		 ia_option = opt6_find(opt6_next(ia_option, ia_end), ia_end, OPTION6_IAADDR, 24)) 
 	      {
@@ -1044,7 +1164,7 @@ static int dhcp6_no_relay(int msg_type, struct in6_addr *link_address, struct dh
 
 struct dhcp_netid *add_options(struct state *state, struct in6_addr *fallback, struct dhcp_context *context)  
 {
-  void *opt, *oro;
+  void *oro;
   /* filter options based on tags, those we want get DHOPT_TAGOK bit set */
   struct dhcp_netid *tagif = option_filter(state->tags, state->context_tags, daemon->dhcp_opts6);
   struct dhcp_opt *opt_cfg;
@@ -1255,23 +1375,41 @@ static void get_context_tag(struct state *state, struct dhcp_context *context)
 	}
     }
 } 
-static void *check_ia(struct state *state, void *opt, void **endp)
+
+#ifdef OPTION6_PREFIX_CLASS
+static struct prefix_class *prefix_class_from_context(struct dhcp_context *context)
+{
+  struct prefix_class *p;
+  struct dhcp_netid *t;
+  
+  for (p = daemon->prefix_classes; p ; p = p->next)
+    for (t = context->filter; t; t = t->next)
+      if (strcmp(p->tag.net, t->net) == 0)
+	return p;
+  
+ return NULL;
+}
+#endif
+
+static int check_ia(struct state *state, void *opt, void **endp, void **ia_option)
 {
   state->ia_type = opt6_type(opt);
+  *ia_option = NULL;
 
   if (state->ia_type != OPTION6_IA_NA && state->ia_type != OPTION6_IA_TA)
-    return NULL;
+    return 0;
   
   if (state->ia_type == OPTION6_IA_NA && opt6_len(opt) < 12)
-    return NULL;
+    return 0;
 	    
   if (state->ia_type == OPTION6_IA_TA && opt6_len(opt) < 4)
-    return NULL;
+    return 0;
   
   *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);
+  *ia_option = opt6_find(opt6_ptr(opt, state->ia_type == OPTION6_IA_NA ? 12 : 4), *endp, OPTION6_IAADDR, 24);
+
+  return 1;
 }
 
 
@@ -1339,6 +1477,15 @@ static void add_address(struct state *state, struct dhcp_context *context, unsig
   put_opt6_long((context->preferred < lease_time) ? context->preferred : lease_time);
   put_opt6_long(valid_time); /* valid lifetime */		    
  
+#ifdef OPTION6_PREFIX_CLASS
+  if (state->send_prefix_class)
+    {
+      int o1 = new_opt6(OPTION6_PREFIX_CLASS);
+      put_opt6_short(state->send_prefix_class->class);
+      end_opt6(o1);
+    }
+#endif
+
   end_opt6(o);
   
   if (do_update)
@@ -1365,15 +1512,26 @@ static void add_address(struct state *state, struct dhcp_context *context, unsig
 	}
     }
 
-  /* 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 mark_context_used(struct state *state, struct dhcp_context *context, struct in6_addr *addr)
+{
+  /* Mark that we have an address for this prefix. */
+#ifdef OPTION6_PREFIX_CLASS
+  for (; context; context = context->current)
+    if (is_same_net6(addr, &context->start6, context->prefix) &&
+	(!state->send_prefix_class || state->send_prefix_class == prefix_class_from_context(context)))
+      context->flags |= CONTEXT_USED;
+#else
+  (void)state; /* warning */
+  for (; context; context = context->current)
+    if (is_same_net6(addr, &context->start6, context->prefix))
+      context->flags |= CONTEXT_USED;
+#endif
+}
+
 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);
@@ -1502,6 +1660,13 @@ static void log6_opts(int nest, unsigned int xid, void *start_opts, void *end_op
 	  optname = "iaaddr";
 	  ia_options = opt6_ptr(opt, 24);
 	}
+#ifdef OPTION6_PREFIX_CLASS
+      else if (type == OPTION6_PREFIX_CLASS)
+	{
+	  optname = "prefix-class";
+	  sprintf(daemon->namebuff, "class=%u", opt6_uint(opt, 0, 2));
+	}
+#endif
       else if (type == OPTION6_STATUS_CODE)
 	{
 	  int len = sprintf(daemon->namebuff, "%u ", opt6_uint(opt, 0, 2));