Router Advertisement

Makefile

@@ -47,9 +47,11 @@ VERSION=    -DVERSION='\"`../bld/get-version`\"'
 
 OBJS = cache.o rfc1035.o util.o option.o forward.o network.o \
        dnsmasq.o dhcp.o lease.o rfc2131.o netlink.o dbus.o bpf.o \
-       helper.o tftp.o log.o conntrack.o dhcp6.o rfc3315.o dhcp-common.o 
+       helper.o tftp.o log.o conntrack.o dhcp6.o rfc3315.o \
+       dhcp-common.o outpacket.o radv.o
 
-HDRS = dnsmasq.h config.h dhcp_protocol.h dhcp6_protocol.h dns_protocol.h
+HDRS = dnsmasq.h config.h dhcp_protocol.h dhcp6_protocol.h \
+       dns_protocol.h radv_protocol.h
 
 
 all : $(BUILDDIR)

bld/Android.mk

@@ -7,7 +7,8 @@ LOCAL_SRC_FILES :=  bpf.c cache.c dbus.c dhcp.c dnsmasq.c \
                     forward.c helper.c lease.c log.c \
                     netlink.c network.c option.c rfc1035.c \
 		    rfc2131.c tftp.c util.c conntrack.c \
-		    dhcp6.c rfc3315.c dhcp-common.c 
+		    dhcp6.c rfc3315.c dhcp-common.c outpacket.c \
+		    radv.c
 
 LOCAL_MODULE := dnsmasq
 

man/dnsmasq.8

@@ -529,14 +529,18 @@ The optional
 sets an alphanumeric label which marks this network so that
 dhcp options may be specified on a per-network basis. 
 When it is prefixed with 'tag:' instead, then its meaning changes from setting
-a tag to matching it. Only one tag may be set, but more than one tag may be matched.
+a tag to matching it. Only one tag may be set, but more than one tag
+may be matched.
+
 The end address may be replaced by the keyword 
 .B static
 which tells dnsmasq to enable DHCP for the network specified, but not
 to dynamically allocate IP addresses: only hosts which have static
 addresses given via 
 .B dhcp-host
-or from /etc/ethers will be served. The end address may be replaced by
+or from /etc/ethers will be served. 
+
+The end address may be replaced by
 the keyword
 .B proxy
 in which case dnsmasq will provide proxy-DHCP on the specified
@@ -546,6 +550,14 @@ and
 .B pxe-service
 for details, applies to IPv4 only.)
 
+The end address may be replaced by
+the keyword
+.B ra-only
+which tells dnsmasq to offer Router Advertisement only on this subnet,
+and not DHCP. This applies to IPv6 only, see
+.B enable-ra
+for details.
+
 The interface:<interface name> section is not normally used. See the
 NOTES section for details of this.
 .TP
@@ -1234,6 +1246,20 @@ added into dnsmasq's DNS view. This flag suppresses that behaviour,
 this is useful, for instance, to allow Windows clients to update
 Active Directory servers. See RFC 4702 for details. 
 .TP
+.B --enable-ra
+Enable dnsmasq's IPv6 Router Advertisement feature. DHCPv6 doesn't
+handle complete network configuration in the same way as DHCPv4. Router
+discovery and (possibly) prefix discovery for autonomous address
+creation are handled by a different protocol. When DHCP is in use,
+only a subset of this is needed, and dnsmasq can handle it, using
+existing DHCP configuration to provide most data. When RA is enabled,
+dnsmasq will advertise a prefix for each dhcp-range, with default
+router and recursive DNS server as the relevant link-local address on 
+the machine running dnsmasq. The "managed address" bits are set,
+except for a dhcp-range which is marked as "ra-only". In which case RA
+is provided by no DHCPv6 service and the managed address bits are
+cleared.
+.TP
 .B --enable-tftp[=<interface>]
 Enable the TFTP server function. This is deliberately limited to that
 needed to net-boot a client. Only reading is allowed; the tsize and

src/bpf.c

@@ -199,7 +199,8 @@ int iface_enumerate(int family, void *parm, int (*callback)())
 	    { 
 	      /* Assume ethernet again here */
 	      struct sockaddr_dl *sdl = (struct sockaddr_dl *)&ifr->ifr_addr;
-	      if (sdl->sdl_alen != 0 && !((*callback)(ARPHRD_ETHER, LLADDR(sdl), sdl->sdl_alen, parm)))
+	      if (sdl->sdl_alen != 0 && !((*callback)((int)if_nametoindex(ifr->ifr_name),
+						      ARPHRD_ETHER, LLADDR(sdl), sdl->sdl_alen, parm)))
 		goto err;
 	    }
 #endif 

src/dhcp-common.c

@@ -53,14 +53,14 @@ ssize_t recv_dhcp_packet(int fd, struct msghdr *msg)
 
       /* Very new Linux kernels return the actual size needed, 
 	 older ones always return truncated size */
-      if ((size_t)sz == daemon->dhcp_packet.iov_len)
+      if ((size_t)sz == msg->msg_iov->iov_len)
 	{
-	  if (!expand_buf(&daemon->dhcp_packet, sz + 100))
+	  if (!expand_buf(msg->msg_iov, sz + 100))
 	    return -1;
 	}
       else
 	{
-	  expand_buf(&daemon->dhcp_packet, sz);
+	  expand_buf(msg->msg_iov, sz);
 	  break;
 	}
     }

src/dhcp6.c

@@ -35,7 +35,7 @@ static int join_multicast(struct in6_addr *local, int prefix,
 static int complete_context6(struct in6_addr *local,  int prefix,
 			     int scope, int if_index, int dad, void *vparam);
 
-static int make_duid1(unsigned int type, char *mac, size_t maclen, void *parm); 
+static int make_duid1(int index, unsigned int type, char *mac, size_t maclen, void *parm); 
 
 void dhcp6_init(void)
 {
@@ -101,6 +101,13 @@ static int join_multicast(struct in6_addr *local, int prefix,
     if (if_index == listenp->fd_or_iface)
       return 1;
   
+  mreq.ipv6mr_interface = if_index;
+  inet_pton(AF_INET6, ALL_ROUTERS, &mreq.ipv6mr_multiaddr);
+  
+  if (daemon->icmp6fd != -1 &&
+      setsockopt(daemon->icmp6fd, IPPROTO_IPV6, IPV6_JOIN_GROUP, &mreq, sizeof(mreq)) == -1)
+    return 0;
+
   if (!indextoname(fd, if_index, ifrn_name))
     return 0;
 
@@ -120,7 +127,6 @@ static int join_multicast(struct in6_addr *local, int prefix,
   if (!context)
     return 1;
 
-  mreq.ipv6mr_interface = if_index;
   inet_pton(AF_INET6, ALL_RELAY_AGENTS_AND_SERVERS, &mreq.ipv6mr_multiaddr);
   
   if (setsockopt(fd, IPPROTO_IPV6, IPV6_JOIN_GROUP, &mreq, sizeof(mreq)) == -1)
@@ -151,7 +157,7 @@ void dhcp6_packet(time_t now)
     struct cmsghdr align; /* this ensures alignment */
     char control6[CMSG_SPACE(sizeof(struct in6_pktinfo))];
   } control_u;
-  union mysockaddr from;
+  struct sockaddr_in6 from;
   struct all_addr dest;
   ssize_t sz; 
   struct ifreq ifr;
@@ -215,8 +221,8 @@ void dhcp6_packet(time_t now)
   
   lease_prune(NULL, now); /* lose any expired leases */
 
-  msg.msg_iov =  &daemon->dhcp_packet;
-  sz = dhcp6_reply(parm.current, if_index, ifr.ifr_name, &parm.fallback, sz, IN6_IS_ADDR_MULTICAST(&from.in6.sin6_addr), now);
+  sz = dhcp6_reply(parm.current, if_index, ifr.ifr_name, &parm.fallback, 
+		   sz, IN6_IS_ADDR_MULTICAST(&from.sin6_addr), now);
   
   lease_update_file(now);
   lease_update_dns();
@@ -455,13 +461,15 @@ void make_duid(time_t now)
     die("Cannot create DHCPv6 server DUID: %s", NULL, EC_MISC);
 }
 
-static int make_duid1(unsigned int type, char *mac, size_t maclen, void *parm)
+static int make_duid1(int index, unsigned int type, char *mac, size_t maclen, void *parm)
 {
   /* create DUID as specified in RFC3315. We use the MAC of the
      first interface we find that isn't loopback or P-to-P */
   
   unsigned char *p;
 
+  (void)index;
+
   daemon->duid = p = safe_malloc(maclen + 8);
   daemon->duid_len = maclen + 8;
   

src/dnsmasq.c

@@ -157,8 +157,14 @@ int main (int argc, char **argv)
       if (daemon->dhcp)
 	dhcp_init();
 #ifdef HAVE_DHCP6
+      daemon->icmp6fd = -1;
       if (daemon->dhcp6)
+	{
+	  /* ra_init before dhcp6_init, so dhcp6_init can setup multicast listening */
+	  if (option_bool(OPT_RA))
+	    ra_init(now); 
 	  dhcp6_init();
+	}
 #endif
     }
 #endif
@@ -496,6 +502,9 @@ int main (int argc, char **argv)
   if (daemon->max_logs != 0)
     my_syslog(LOG_INFO, _("asynchronous logging enabled, queue limit is %d messages"), daemon->max_logs);
  
+  if (option_bool(OPT_RA))
+    my_syslog(MS_DHCP | LOG_INFO, _("IPv6 router advertisement enabled"));
+
 #ifdef HAVE_DHCP
   if (daemon->dhcp || daemon->dhcp6)
     {
@@ -525,6 +534,8 @@ int main (int argc, char **argv)
 	  my_syslog(MS_DHCP | LOG_INFO, 
 		    (dhcp_tmp->flags & CONTEXT_STATIC) ? 
 		    _("DHCP, static leases only on %.0s%s, lease time %s") :
+		    (dhcp_tmp->flags & CONTEXT_RA_ONLY) ? 
+		    _("router advertisement only on %.0s%s, lifetime %s") :
 		    (dhcp_tmp->flags & CONTEXT_PROXY) ?
 		    _("DHCP, proxy on subnet %.0s%s%.0s") :
 		    _("DHCP, IP range %s -- %s, lease time %s"),
@@ -535,6 +546,9 @@ int main (int argc, char **argv)
       if (family == AF_INET)
 	{
 	  family = AF_INET6;
+	  if (daemon->ra_contexts)
+	    dhcp_tmp = daemon->ra_contexts;
+	  else
 	    dhcp_tmp = daemon->dhcp6;
 	  goto again;
 	}
@@ -653,6 +667,12 @@ int main (int argc, char **argv)
 	{
 	  FD_SET(daemon->dhcp6fd, &rset);
 	  bump_maxfd(daemon->dhcp6fd, &maxfd);
+	  
+	  if (daemon->icmp6fd != -1)
+	    {
+	      FD_SET(daemon->icmp6fd, &rset);
+	      bump_maxfd(daemon->icmp6fd, &maxfd); 
+	    }
 	}
 #endif
 
@@ -756,6 +776,9 @@ int main (int argc, char **argv)
 	{
 	  if (FD_ISSET(daemon->dhcp6fd, &rset))
 	    dhcp6_packet(now);
+
+	  if (daemon->icmp6fd != -1 && FD_ISSET(daemon->icmp6fd, &rset))
+	    icmp6_packet();
 	}
 #endif
 
@@ -1373,6 +1396,14 @@ int icmp_ping(struct in_addr addr)
       set_dns_listeners(now, &rset, &maxfd);
       set_log_writer(&wset, &maxfd);
       
+#ifdef HAVE_DHCP6
+      if (daemon->icmp6fd != -1)
+	{
+	  FD_SET(daemon->icmp6fd, &rset);
+	  bump_maxfd(daemon->icmp6fd, &maxfd); 
+	}
+#endif
+      
       if (select(maxfd+1, &rset, &wset, NULL, &tv) < 0)
 	{
 	  FD_ZERO(&rset);
@@ -1384,6 +1415,11 @@ int icmp_ping(struct in_addr addr)
       check_log_writer(&wset);
       check_dns_listeners(&rset, now);
 
+#ifdef HAVE_DHCP6
+      if (daemon->icmp6fd != -1 && FD_ISSET(daemon->icmp6fd, &rset))
+	icmp6_packet();
+#endif
+      
 #ifdef HAVE_TFTP
       check_tftp_listeners(&rset, now);
 #endif

src/dnsmasq.h

@@ -60,6 +60,7 @@ typedef unsigned long long u64;
 #include "dhcp_protocol.h"
 #ifdef HAVE_DHCP6
 #include "dhcp6_protocol.h"
+#include "radv_protocol.h"
 #endif
 
 #define gettext_noop(S) (S)
@@ -215,7 +216,8 @@ struct event_desc {
 #define OPT_CONSEC_ADDR    34
 #define OPT_CONNTRACK      35
 #define OPT_FQDN_UPDATE    36
-#define OPT_LAST           37
+#define OPT_RA             37
+#define OPT_LAST           38
 
 /* extra flags for my_syslog, we use a couple of facilities since they are known 
    not to occupy the same bits as priorities, no matter how syslog.h is set up. */
@@ -605,6 +607,7 @@ struct dhcp_context {
   struct in6_addr start6, end6; /* range of available addresses */
   struct in6_addr local6;
   int prefix;
+  time_t ra_time;
 #endif
   int flags;
   char *interface;
@@ -616,6 +619,8 @@ struct dhcp_context {
 #define CONTEXT_NETMASK   2
 #define CONTEXT_BRDCAST   4
 #define CONTEXT_PROXY     8
+#define CONTEXT_RA_ONLY  16
+#define CONTEXT_RA_DONE  32
 
 struct ping_result {
   struct in_addr addr;
@@ -694,7 +699,7 @@ extern struct daemon {
   int port, query_port, min_port;
   unsigned long local_ttl, neg_ttl, max_ttl;
   struct hostsfile *addn_hosts;
-  struct dhcp_context *dhcp, *dhcp6;
+  struct dhcp_context *dhcp, *dhcp6, *ra_contexts;
   struct dhcp_config *dhcp_conf;
   struct dhcp_opt *dhcp_opts, *dhcp_match, *dhcp_opts6, *dhcp_match6;
   struct dhcp_vendor *dhcp_vendors;
@@ -754,7 +759,7 @@ extern struct daemon {
   int duid_len;
   unsigned char *duid;
   struct iovec outpacket;
-  int dhcp6fd;
+  int dhcp6fd, icmp6fd;
 #endif
   /* DBus stuff */
   /* void * here to avoid depending on dbus headers outside dbus.c */
@@ -1054,3 +1059,24 @@ int match_bytes(struct dhcp_opt *o, unsigned char *p, int len);
 void dhcp_update_configs(struct dhcp_config *configs);
 void check_dhcp_hosts(int fatal);
 #endif
+
+/* outpacket.c */
+#ifdef HAVE_DHCP6
+void end_opt6(int container);
+int save_counter(int newval);
+void *expand(size_t headroom);
+int new_opt6(int opt);
+void *put_opt6(void *data, size_t len);
+void put_opt6_long(unsigned int val);
+void put_opt6_short(unsigned int val);
+void put_opt6_char(unsigned int val);
+void put_opt6_string(char *s);
+#endif
+
+/* radv.c */
+#ifdef HAVE_DHCP6
+void ra_init(time_t now);
+void icmp6_packet(void);
+time_t periodic_ra(time_t now);
+void ra_start_unsolicted(time_t now);
+#endif

src/lease.c

@@ -313,7 +313,15 @@ void lease_update_file(time_t now)
     }
   
   /* Set alarm for when the first lease expires + slop. */
-  for (next_event = 0, lease = leases; lease; lease = lease->next)
+  next_event = 0;
+
+#ifdef HAVE_DHCP6
+  /* do timed RAs and determine when the next is */
+  if (option_bool(OPT_RA))
+    next_event = periodic_ra(now);
+#endif
+
+  for (lease = leases; lease; lease = lease->next)
     if (lease->expires != 0 &&
 	(next_event == 0 || difftime(next_event, lease->expires + 10) > 0.0))
       next_event = lease->expires + 10;

src/netlink.c

@@ -284,7 +284,7 @@ int iface_enumerate(int family, void *parm, int (*callback)())
 	      }
 
 	    if (mac && callback_ok && !((link->ifi_flags & (IFF_LOOPBACK | IFF_POINTOPOINT))) && 
-		!((*callback)((unsigned int)link->ifi_type, mac, maclen, parm)))
+		!((*callback)((int)link->ifi_index, (unsigned int)link->ifi_type, mac, maclen, parm)))
 	      callback_ok = 0;
 	  }
 #endif
@@ -341,6 +341,17 @@ static void nl_routechange(struct nlmsghdr *h)
       /* Force re-reading resolv file right now, for luck. */
       daemon->last_resolv = 0;
       
+#ifdef HAVE_DHCP6
+      /* force RAs to sync new network and pick up new interfaces.  */
+      if (option_bool(OPT_RA))
+	{
+	  ra_start_unsolicted(dnsmasq_time());
+	  /* cause lease_update_file to run after we return, in case we were called from
+	     iface_enumerate and can't re-enter it now */
+	  alarm(1);
+	}
+#endif
+
       if (daemon->srv_save)
 	{
 	  if (daemon->srv_save->sfd)

src/option.c

@@ -114,6 +114,7 @@ struct myoption {
 #define LOPT_CONNTRACK 303
 #define LOPT_FQDN      304
 #define LOPT_LUASCRIPT 305
+#define LOPT_RA        306
 
 #ifdef HAVE_GETOPT_LONG
 static const struct option opts[] =  
@@ -233,6 +234,7 @@ static const struct myoption opts[] =
     { "conntrack", 0, 0, LOPT_CONNTRACK },
     { "dhcp-client-update", 0, 0, LOPT_FQDN },
     { "dhcp-luascript", 1, 0, LOPT_LUASCRIPT },
+    { "enable-ra", 0, 0, LOPT_RA },
     { NULL, 0, 0, 0 }
   };
 
@@ -359,6 +361,7 @@ static struct {
   { LOPT_INCR_ADDR, OPT_CONSEC_ADDR, NULL, gettext_noop("Attempt to allocate sequential IP addresses to DHCP clients."), NULL },
   { LOPT_CONNTRACK, OPT_CONNTRACK, NULL, gettext_noop("Copy connection-track mark from queries to upstream connections."), NULL },
   { LOPT_FQDN, OPT_FQDN_UPDATE, NULL, gettext_noop("Allow DHCP clients to do their own DDNS updates."), NULL },
+  { LOPT_RA, OPT_RA, NULL, gettext_noop("Send router-advertisements for interfaces doing DHCPv6"), NULL },
   { 0, 0, NULL, NULL, NULL }
 }; 
 
@@ -2330,17 +2333,32 @@ static char *one_opt(int option, char *arg, char *gen_prob, int command_line)
 #ifdef HAVE_DHCP6
 	else if (inet_pton(AF_INET6, a[0], &new->start6))
 	  {
-	    new->next = daemon->dhcp6;
 	    new->prefix = 64; /* default */
-	    daemon->dhcp6 = new;
+	    
 	    if (strcmp(a[1], "static") == 0)
 	      {
 		memcpy(&new->end6, &new->start6, IN6ADDRSZ);
 		new->flags |= CONTEXT_STATIC;
 	      }
+	    else if (strcmp(a[1], "ra-only") == 0)
+	      {
+		memcpy(&new->end6, &new->start6, IN6ADDRSZ);
+		new->flags |= CONTEXT_RA_ONLY;
+	      }
 	    else if (!inet_pton(AF_INET6, a[1], &new->end6))
 	      option = '?';
 	    
+	    if (new->flags & CONTEXT_RA_ONLY)
+	      {
+		new->next = daemon->ra_contexts;
+		daemon->ra_contexts = new;
+	      }
+	    else
+	      {
+		new->next = daemon->dhcp6;
+		daemon->dhcp6 = new;
+	      }
+
 	    /* bare integer < 128 is prefix value */
 	    if (option != '?' && k >= 3)
 	      {

src/outpacket.c

+/* dnsmasq is Copyright (c) 2000-2012 Simon Kelley
+
+   This program is free software; you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation; version 2 dated June, 1991, or
+   (at your option) version 3 dated 29 June, 2007.
+ 
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+     
+   You should have received a copy of the GNU General Public License
+   along with this program.  If not, see <http://www.gnu.org/licenses/>.
+*/
+
+
+#include "dnsmasq.h"
+ 
+#ifdef HAVE_DHCP6
+
+static size_t outpacket_counter;
+
+void end_opt6(int container)
+{
+   void *p = daemon->outpacket.iov_base + container + 2;
+   u16 len = outpacket_counter - container - 4 ;
+   
+   PUTSHORT(len, p);
+}
+
+int save_counter(int newval)
+{
+  int ret = outpacket_counter;
+  if (newval != -1)
+    outpacket_counter = newval;
+
+  return ret;
+}
+
+void *expand(size_t headroom)
+{
+  void *ret;
+
+  if (expand_buf(&daemon->outpacket, outpacket_counter + headroom))
+    {
+      ret = daemon->outpacket.iov_base + outpacket_counter;
+      outpacket_counter += headroom;
+      return ret;
+    }
+  
+  return NULL;
+}
+    
+int new_opt6(int opt)
+{
+  int ret = outpacket_counter;
+  void *p;
+
+  if ((p = expand(4)))
+    {
+      PUTSHORT(opt, p);
+      PUTSHORT(0, p);
+    }
+
+  return ret;
+}
+
+void *put_opt6(void *data, size_t len)
+{
+  void *p;
+
+  if ((p = expand(len)))
+    memcpy(p, data, len);   
+
+  return p;
+}
+  
+void put_opt6_long(unsigned int val)
+{
+  void *p;
+  
+  if ((p = expand(4)))  
+    PUTLONG(val, p);
+}
+
+void put_opt6_short(unsigned int val)
+{
+  void *p;
+
+  if ((p = expand(2)))
+    PUTSHORT(val, p);   
+}
+
+void put_opt6_char(unsigned int val)
+{
+  unsigned char *p;
+
+  if ((p = expand(1)))
+    *p = val;   
+}
+
+void put_opt6_string(char *s)
+{
+  put_opt6(s, strlen(s));
+}
+
+#endif

src/radv_protocol.h

+/* dnsmasq is Copyright (c) 2000-2012 Simon Kelley
+
+   This program is free software; you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation; version 2 dated June, 1991, or
+   (at your option) version 3 dated 29 June, 2007.
+ 
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+     
+   You should have received a copy of the GNU General Public License
+   along with this program.  If not, see <http://www.gnu.org/licenses/>.
+*/
+
+#define ALL_HOSTS                 "FF02::1"
+#define ALL_ROUTERS               "FF02::2"
+
+struct ra_packet {
+  u8 type, code;
+  u16 checksum;
+  u8 hop_limit, flags;
+  u16 lifetime;
+  u32 reachable_time;
+  u32 retrans_time;
+};
+
+struct prefix_opt {
+  u8 type, len, prefix_len, flags;
+  u32 valid_lifetime, preferred_lifetime, reserved;
+  struct in6_addr prefix;
+};
+
+#define ICMP6_ROUTER_SOLICIT 133
+#define ICMP6_ROUTER_ADVERT  134
+
+#define ICMP6_OPT_SOURCE_MAC   1
+#define ICMP6_OPT_PREFIX       3
+#define ICMP6_OPT_MTU          5
+#define ICMP6_OPT_RDNSS       25
+
+
+

src/rfc3315.c

@@ -19,17 +19,6 @@
 
 #ifdef HAVE_DHCP6
 
-static size_t outpacket_counter;
-
-static void end_opt6(int container);
-static int save_counter(int newval);
-static void *expand(size_t headroom);
-static int new_opt6(int opt);
-static void *put_opt6(void *data, size_t len);
-static void put_opt6_short(unsigned int val);
-static void put_opt6_long(unsigned int val);
-static void put_opt6_string(char *s);
-
 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, 
@@ -55,10 +44,10 @@ size_t dhcp6_reply(struct dhcp_context *context, int interface, char *iface_name
   for (vendor = daemon->dhcp_vendors; vendor; vendor = vendor->next)
     vendor->netid.next = &vendor->netid;
   
-  outpacket_counter = 0;
+  save_counter(0);
   
   if (dhcp6_maybe_relay(NULL, &relay_tags, context, interface, iface_name, fallback, daemon->dhcp_packet.iov_base, sz, is_unicast, now))
-    return outpacket_counter;
+    return save_counter(0);
 
   return 0;
 }
@@ -1274,12 +1263,14 @@ static int dhcp6_no_relay(int msg_type, struct in6_addr *link_address, struct dh
 	len += strlen(send_domain) + 1;
 
       o = new_opt6(OPTION6_FQDN);
-      p = expand(len + 3);
+      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 = 0;
+	}
       end_opt6(o);
     }
 
@@ -1422,80 +1413,4 @@ static unsigned int opt6_uint(unsigned char *opt, int offset, int size)
   return ret;
 } 
 
-static void end_opt6(int container)
-{
-   void *p = daemon->outpacket.iov_base + container + 2;
-   u16 len = outpacket_counter - container - 4 ;
-   
-   PUTSHORT(len, p);
-}
-
-static int save_counter(int newval)
-{
-  int ret = outpacket_counter;
-  if (newval != -1)
-    outpacket_counter = newval;
-
-  return ret;
-}
-
-static void *expand(size_t headroom)
-{
-  void *ret;
-
-  if (expand_buf(&daemon->outpacket, outpacket_counter + headroom))
-    {
-      ret = daemon->outpacket.iov_base + outpacket_counter;
-      outpacket_counter += headroom;
-      return ret;
-    }
-  
-  return NULL;
-}
-    
-static int new_opt6(int opt)
-{
-  int ret = outpacket_counter;
-  void *p;
-
-  if ((p = expand(4)))
-    {
-      PUTSHORT(opt, p);
-      PUTSHORT(0, p);
-    }
-
-  return ret;
-}
-
-static void *put_opt6(void *data, size_t len)
-{
-  void *p;
-
-  if ((p = expand(len)))
-    memcpy(p, data, len);   
-
-  return p;
-}
-  
-static void put_opt6_long(unsigned int val)
-{
-  void *p;
-  
-  if ((p = expand(4)))  
-    PUTLONG(val, p);
-}
-
-static void put_opt6_short(unsigned int val)
-{
-  void *p;
-
-  if ((p = expand(2)))
-    PUTSHORT(val, p);   
-}
-
-static void put_opt6_string(char *s)
-{
-  put_opt6(s, strlen(s));
-}
-
 #endif