--- embedaddon/dnsmasq/src/network.c	2013/07/29 19:37:40	1.1.1.1
+++ embedaddon/dnsmasq/src/network.c	2023/09/27 11:02:07	1.1.1.5
@@ -1,4 +1,4 @@
-/* dnsmasq is Copyright (c) 2000-2013 Simon Kelley
+/* dnsmasq is Copyright (c) 2000-2022 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
@@ -29,9 +29,9 @@ int indextoname(int fd, int index, char *name)
   if (ioctl(fd, SIOCGIFNAME, &ifr) == -1)
     return 0;
 
-  strncpy(name, ifr.ifr_name, IF_NAMESIZE);
+  safe_strncpy(name, ifr.ifr_name, IF_NAMESIZE);
 
-  return 1;
+ return 1;
 }
 
 
@@ -82,12 +82,12 @@ int indextoname(int fd, int index, char *name)
   for (i = lifc.lifc_len / sizeof(struct lifreq); i; i--, lifrp++) 
     {
       struct lifreq lifr;
-      strncpy(lifr.lifr_name, lifrp->lifr_name, IF_NAMESIZE);
+      safe_strncpy(lifr.lifr_name, lifrp->lifr_name, IF_NAMESIZE);
       if (ioctl(fd, SIOCGLIFINDEX, &lifr) < 0) 
 	return 0;
       
       if (lifr.lifr_index == index) {
-	strncpy(name, lifr.lifr_name, IF_NAMESIZE);
+	safe_strncpy(name, lifr.lifr_name, IF_NAMESIZE);
 	return 1;
       }
     }
@@ -99,6 +99,8 @@ int indextoname(int fd, int index, char *name)
 
 int indextoname(int fd, int index, char *name)
 { 
+  (void)fd;
+
   if (index == 0 || !if_indextoname(index, name))
     return 0;
 
@@ -107,17 +109,14 @@ int indextoname(int fd, int index, char *name)
 
 #endif
 
-int iface_check(int family, struct all_addr *addr, char *name, int *auth)
+int iface_check(int family, union all_addr *addr, char *name, int *auth)
 {
   struct iname *tmp;
-  int ret = 1;
+  int ret = 1, match_addr = 0;
 
-  /* Note: have to check all and not bail out early, so that we set the
-     "used" flags. */
+  /* Note: have to check all and not bail out early, so that we set the "used" flags.
+     May be called with family == AF_LOCAL to check interface by name only. */
   
-  if (auth)
-    *auth = 0;
-  
   if (daemon->if_names || daemon->if_addrs)
     {
       ret = 0;
@@ -131,58 +130,60 @@ int iface_check(int family, struct all_addr *addr, cha
 	  if (tmp->addr.sa.sa_family == family)
 	    {
 	      if (family == AF_INET &&
-		  tmp->addr.in.sin_addr.s_addr == addr->addr.addr4.s_addr)
-		ret = tmp->used = 1;
-#ifdef HAVE_IPV6
+		  tmp->addr.in.sin_addr.s_addr == addr->addr4.s_addr)
+		ret = match_addr = tmp->used = 1;
 	      else if (family == AF_INET6 &&
 		       IN6_ARE_ADDR_EQUAL(&tmp->addr.in6.sin6_addr, 
-					  &addr->addr.addr6))
-		ret = tmp->used = 1;
-#endif
+					  &addr->addr6))
+		ret = match_addr = tmp->used = 1;
 	    }          
     }
   
-  for (tmp = daemon->if_except; tmp; tmp = tmp->next)
-    if (tmp->name && wildcard_match(tmp->name, name))
-      ret = 0;
+  if (!match_addr)
+    for (tmp = daemon->if_except; tmp; tmp = tmp->next)
+      if (tmp->name && wildcard_match(tmp->name, name))
+	ret = 0;
     
+  if (auth)
+    {
+      *auth = 0;
 
-  for (tmp = daemon->authinterface; tmp; tmp = tmp->next)
-    if (tmp->name)
-      {
-	if (strcmp(tmp->name, name) == 0)
+      for (tmp = daemon->authinterface; tmp; tmp = tmp->next)
+	if (tmp->name)
+	  {
+	    if (strcmp(tmp->name, name) == 0 &&
+		(tmp->addr.sa.sa_family == 0 || tmp->addr.sa.sa_family == family))
+	      break;
+	  }
+	else if (addr && tmp->addr.sa.sa_family == AF_INET && family == AF_INET &&
+		 tmp->addr.in.sin_addr.s_addr == addr->addr4.s_addr)
 	  break;
-      }
-    else if (addr && tmp->addr.sa.sa_family == AF_INET && family == AF_INET &&
-	     tmp->addr.in.sin_addr.s_addr == addr->addr.addr4.s_addr)
-      break;
-#ifdef HAVE_IPV6
-    else if (addr && tmp->addr.sa.sa_family == AF_INET6 && family == AF_INET6 &&
-	     IN6_ARE_ADDR_EQUAL(&tmp->addr.in6.sin6_addr, &addr->addr.addr6))
-      break;
-#endif      
-
-  if (tmp && auth) 
-    {
-      *auth = 1;
-      ret = 1;
+	else if (addr && tmp->addr.sa.sa_family == AF_INET6 && family == AF_INET6 &&
+		 IN6_ARE_ADDR_EQUAL(&tmp->addr.in6.sin6_addr, &addr->addr6))
+	  break;
+      
+      if (tmp) 
+	{
+	  *auth = 1;
+	  ret = 1;
+	}
     }
 
   return ret; 
 }
 
 
-/* Fix for problem that the kernel sometimes reports the loopback inerface as the
+/* Fix for problem that the kernel sometimes reports the loopback interface as the
    arrival interface when a packet originates locally, even when sent to address of 
    an interface other than the loopback. Accept packet if it arrived via a loopback 
    interface, even when we're not accepting packets that way, as long as the destination
    address is one we're believing. Interface list must be up-to-date before calling. */
-int loopback_exception(int fd, int family, struct all_addr *addr, char *name)    
+int loopback_exception(int fd, int family, union all_addr *addr, char *name)    
 {
   struct ifreq ifr;
   struct irec *iface;
 
-  strncpy(ifr.ifr_name, name, IF_NAMESIZE);
+  safe_strncpy(ifr.ifr_name, name, IF_NAMESIZE);
   if (ioctl(fd, SIOCGIFFLAGS, &ifr) != -1 &&
       ifr.ifr_flags & IFF_LOOPBACK)
     {
@@ -191,65 +192,311 @@ int loopback_exception(int fd, int family, struct all_
 	  {
 	    if (family == AF_INET)
 	      {
-		if (iface->addr.in.sin_addr.s_addr == addr->addr.addr4.s_addr)
+		if (iface->addr.in.sin_addr.s_addr == addr->addr4.s_addr)
 		  return 1;
 	      }
-#ifdef HAVE_IPV6
-	    else if (IN6_ARE_ADDR_EQUAL(&iface->addr.in6.sin6_addr, &addr->addr.addr6))
+	    else if (IN6_ARE_ADDR_EQUAL(&iface->addr.in6.sin6_addr, &addr->addr6))
 	      return 1;
-#endif
-	    
 	  }
     }
   return 0;
 }
 
-static int iface_allowed(struct irec **irecp, int if_index, 
-			 union mysockaddr *addr, struct in_addr netmask, int dad) 
+/* If we're configured with something like --interface=eth0:0 then we'll listen correctly
+   on the relevant address, but the name of the arrival interface, derived from the
+   index won't match the config. Check that we found an interface address for the arrival 
+   interface: daemon->interfaces must be up-to-date. */
+int label_exception(int index, int family, union all_addr *addr)
 {
   struct irec *iface;
-  int fd, mtu = 0, loopback;
+
+  /* labels only supported on IPv4 addresses. */
+  if (family != AF_INET)
+    return 0;
+
+  for (iface = daemon->interfaces; iface; iface = iface->next)
+    if (iface->index == index && iface->addr.sa.sa_family == AF_INET &&
+	iface->addr.in.sin_addr.s_addr == addr->addr4.s_addr)
+      return 1;
+
+  return 0;
+}
+
+struct iface_param {
+  struct addrlist *spare;
+  int fd;
+};
+
+static int iface_allowed(struct iface_param *param, int if_index, char *label,
+			 union mysockaddr *addr, struct in_addr netmask, int prefixlen, int iface_flags) 
+{
+  struct irec *iface;
+  struct cond_domain *cond;
+  int loopback;
   struct ifreq ifr;
   int tftp_ok = !!option_bool(OPT_TFTP);
   int dhcp_ok = 1;
   int auth_dns = 0;
-#ifdef HAVE_DHCP
+  int is_label = 0;
+#if defined(HAVE_DHCP) || defined(HAVE_TFTP)
   struct iname *tmp;
 #endif
 
-  /* check whether the interface IP has been added already 
-     we call this routine multiple times. */
-  for (iface = *irecp; iface; iface = iface->next) 
-    if (sockaddr_isequal(&iface->addr, addr))
-      {
-	iface->dad = dad;
-	return 1;
-      }
+  (void)prefixlen;
 
-  if ((fd = socket(PF_INET, SOCK_DGRAM, 0)) == -1 ||
-      !indextoname(fd, if_index, ifr.ifr_name) ||
-      ioctl(fd, SIOCGIFFLAGS, &ifr) == -1)
+  if (!indextoname(param->fd, if_index, ifr.ifr_name) ||
+      ioctl(param->fd, SIOCGIFFLAGS, &ifr) == -1)
+    return 0;
+   
+  loopback = ifr.ifr_flags & IFF_LOOPBACK;
+  
+  if (loopback)
+    dhcp_ok = 0;
+  
+  if (!label)
+    label = ifr.ifr_name;
+  else
+    is_label = strcmp(label, ifr.ifr_name);
+ 
+  /* maintain a list of all addresses on all interfaces for --local-service option */
+  if (option_bool(OPT_LOCAL_SERVICE))
     {
-      if (fd != -1)
+      struct addrlist *al;
+
+      if (param->spare)
 	{
-	  int errsave = errno;
-	  close(fd);
-	  errno = errsave;
+	  al = param->spare;
+	  param->spare = al->next;
 	}
-      return 0;
+      else
+	al = whine_malloc(sizeof(struct addrlist));
+      
+      if (al)
+	{
+	  al->next = daemon->interface_addrs;
+	  daemon->interface_addrs = al;
+	  al->prefixlen = prefixlen;
+	  
+	  if (addr->sa.sa_family == AF_INET)
+	    {
+	      al->addr.addr4 = addr->in.sin_addr;
+	      al->flags = 0;
+	    }
+	  else
+	    {
+	      al->addr.addr6 = addr->in6.sin6_addr;
+	      al->flags = ADDRLIST_IPV6;
+	    } 
+	}
     }
-   
-  loopback = ifr.ifr_flags & IFF_LOOPBACK;
   
-  if (loopback)
-     dhcp_ok = 0;
+  if (addr->sa.sa_family != AF_INET6 || !IN6_IS_ADDR_LINKLOCAL(&addr->in6.sin6_addr))
+    {
+      struct interface_name *int_name;
+      struct addrlist *al;
+#ifdef HAVE_AUTH
+      struct auth_zone *zone;
+      struct auth_name_list *name;
 
-  if (ioctl(fd, SIOCGIFMTU, &ifr) != -1)
-    mtu = ifr.ifr_mtu;
+      /* Find subnets in auth_zones */
+      for (zone = daemon->auth_zones; zone; zone = zone->next)
+	for (name = zone->interface_names; name; name = name->next)
+	  if (wildcard_match(name->name, label))
+	    {
+	      if (addr->sa.sa_family == AF_INET && (name->flags & AUTH4))
+		{
+		  if (param->spare)
+		    {
+		      al = param->spare;
+		      param->spare = al->next;
+		    }
+		  else
+		    al = whine_malloc(sizeof(struct addrlist));
+		  
+		  if (al)
+		    {
+		      al->next = zone->subnet;
+		      zone->subnet = al;
+		      al->prefixlen = prefixlen;
+		      al->addr.addr4 = addr->in.sin_addr;
+		      al->flags = 0;
+		    }
+		}
+	      
+	      if (addr->sa.sa_family == AF_INET6 && (name->flags & AUTH6))
+		{
+		  if (param->spare)
+		    {
+		      al = param->spare;
+		      param->spare = al->next;
+		    }
+		  else
+		    al = whine_malloc(sizeof(struct addrlist));
+		  
+		  if (al)
+		    {
+		      al->next = zone->subnet;
+		      zone->subnet = al;
+		      al->prefixlen = prefixlen;
+		      al->addr.addr6 = addr->in6.sin6_addr;
+		      al->flags = ADDRLIST_IPV6;
+		    }
+		} 
+	    }
+#endif
+       
+      /* Update addresses from interface_names. These are a set independent
+	 of the set we're listening on. */  
+      for (int_name = daemon->int_names; int_name; int_name = int_name->next)
+	if (strncmp(label, int_name->intr, IF_NAMESIZE) == 0)
+	  {
+	    struct addrlist *lp;
+
+	    al = NULL;
+	    
+	    if (addr->sa.sa_family == AF_INET && (int_name->flags & (IN4 | INP4)))
+	      {
+		struct in_addr newaddr = addr->in.sin_addr;
+		
+		if (int_name->flags & INP4)
+		  {
+		    if (netmask.s_addr == 0xffffffff)
+		      continue;
+
+		    newaddr.s_addr = (addr->in.sin_addr.s_addr & netmask.s_addr) |
+		      (int_name->proto4.s_addr & ~netmask.s_addr);
+		  }
+		
+		/* check for duplicates. */
+		for (lp = int_name->addr; lp; lp = lp->next)
+		  if (lp->flags == 0 && lp->addr.addr4.s_addr == newaddr.s_addr)
+		    break;
+		
+		if (!lp)
+		  {
+		    if (param->spare)
+		      {
+			al = param->spare;
+			param->spare = al->next;
+		      }
+		    else
+		      al = whine_malloc(sizeof(struct addrlist));
+
+		    if (al)
+		      {
+			al->flags = 0;
+			al->addr.addr4 = newaddr;
+		      }
+		  }
+	      }
+
+	    if (addr->sa.sa_family == AF_INET6 && (int_name->flags & (IN6 | INP6)))
+	      {
+		struct in6_addr newaddr = addr->in6.sin6_addr;
+		
+		if (int_name->flags & INP6)
+		  {
+		    int i;
+
+		    /* No sense in doing /128. */
+		    if (prefixlen == 128)
+		      continue;
+		    
+		    for (i = 0; i < 16; i++)
+		      {
+			int bits = ((i+1)*8) - prefixlen;
+		       
+			if (bits >= 8)
+			  newaddr.s6_addr[i] = int_name->proto6.s6_addr[i];
+			else if (bits >= 0)
+			  {
+			    unsigned char mask = 0xff << bits;
+			    newaddr.s6_addr[i] =
+			      (addr->in6.sin6_addr.s6_addr[i] & mask) |
+			      (int_name->proto6.s6_addr[i] & ~mask);
+			  }
+		      }
+		  }
+		
+		/* check for duplicates. */
+		for (lp = int_name->addr; lp; lp = lp->next)
+		  if ((lp->flags & ADDRLIST_IPV6) &&
+		      IN6_ARE_ADDR_EQUAL(&lp->addr.addr6, &newaddr))
+		    break;
+					
+		if (!lp)
+		  {
+		    if (param->spare)
+		      {
+			al = param->spare;
+			param->spare = al->next;
+		      }
+		    else
+		      al = whine_malloc(sizeof(struct addrlist));
+		    
+		    if (al)
+		      {
+			al->flags = ADDRLIST_IPV6;
+			al->addr.addr6 = newaddr;
+
+			/* Privacy addresses and addresses still undergoing DAD and deprecated addresses
+			   don't appear in forward queries, but will in reverse ones. */
+			if (!(iface_flags & IFACE_PERMANENT) || (iface_flags & (IFACE_DEPRECATED | IFACE_TENTATIVE)))
+			  al->flags |= ADDRLIST_REVONLY;
+		      }
+		  }
+	      }
+	    
+	    if (al)
+	      {
+		al->next = int_name->addr;
+		int_name->addr = al;
+	      }
+	  }
+    }
+
+  /* Update addresses for domain=<domain>,<interface> */
+  for (cond = daemon->cond_domain; cond; cond = cond->next)
+    if (cond->interface && strncmp(label, cond->interface, IF_NAMESIZE) == 0)
+      {
+	struct addrlist *al;
+
+	if (param->spare)
+	  {
+	    al = param->spare;
+	    param->spare = al->next;
+	  }
+	else
+	  al = whine_malloc(sizeof(struct addrlist));
+
+	if (addr->sa.sa_family == AF_INET)
+	  {
+	    al->addr.addr4 = addr->in.sin_addr;
+	    al->flags = 0;
+	  }
+	else
+	  {
+	    al->addr.addr6 =  addr->in6.sin6_addr;
+	    al->flags = ADDRLIST_IPV6;
+	  }
+
+	al->prefixlen = prefixlen;
+	al->next = cond->al;
+	cond->al = al;
+      }
   
-  close(fd);
-  
-  /* If we are restricting the set of interfaces to use, make
+  /* check whether the interface IP has been added already 
+     we call this routine multiple times. */
+  for (iface = daemon->interfaces; iface; iface = iface->next) 
+    if (sockaddr_isequal(&iface->addr, addr) && iface->index == if_index)
+      {
+	iface->dad = !!(iface_flags & IFACE_TENTATIVE);
+	iface->found = 1; /* for garbage collection */
+	iface->netmask = netmask;
+	return 1;
+      }
+
+ /* If we are restricting the set of interfaces to use, make
      sure that loopback interfaces are in that set. */
   if (daemon->if_names && loopback)
     {
@@ -273,14 +520,12 @@ static int iface_allowed(struct irec **irecp, int if_i
     }
   
   if (addr->sa.sa_family == AF_INET &&
-      !iface_check(AF_INET, (struct all_addr *)&addr->in.sin_addr, ifr.ifr_name, &auth_dns))
+      !iface_check(AF_INET, (union all_addr *)&addr->in.sin_addr, label, &auth_dns))
     return 1;
 
-#ifdef HAVE_IPV6
   if (addr->sa.sa_family == AF_INET6 &&
-      !iface_check(AF_INET6, (struct all_addr *)&addr->in6.sin6_addr, ifr.ifr_name, &auth_dns))
+      !iface_check(AF_INET6, (union all_addr *)&addr->in6.sin6_addr, label, &auth_dns))
     return 1;
-#endif
     
 #ifdef HAVE_DHCP
   /* No DHCP where we're doing auth DNS. */
@@ -298,23 +543,42 @@ static int iface_allowed(struct irec **irecp, int if_i
 	}
 #endif
  
+  
+#ifdef HAVE_TFTP
+  if (daemon->tftp_interfaces)
+    {
+      /* dedicated tftp interface list */
+      tftp_ok = 0;
+      for (tmp = daemon->tftp_interfaces; tmp; tmp = tmp->next)
+	if (tmp->name && wildcard_match(tmp->name, ifr.ifr_name))
+	  tftp_ok = 1;
+    }
+#endif
+  
   /* add to list */
   if ((iface = whine_malloc(sizeof(struct irec))))
     {
+      int mtu = 0;
+
+      if (ioctl(param->fd, SIOCGIFMTU, &ifr) != -1)
+	mtu = ifr.ifr_mtu;
+
       iface->addr = *addr;
       iface->netmask = netmask;
       iface->tftp_ok = tftp_ok;
       iface->dhcp_ok = dhcp_ok;
       iface->dns_auth = auth_dns;
       iface->mtu = mtu;
-      iface->dad = dad;
-      iface->done = iface->multicast_done = 0;
+      iface->dad = !!(iface_flags & IFACE_TENTATIVE);
+      iface->found = 1;
+      iface->done = iface->multicast_done = iface->warned = 0;
       iface->index = if_index;
+      iface->label = is_label;
       if ((iface->name = whine_malloc(strlen(ifr.ifr_name)+1)))
 	{
 	  strcpy(iface->name, ifr.ifr_name);
-	  iface->next = *irecp;
-	  *irecp = iface;
+	  iface->next = daemon->interfaces;
+	  daemon->interfaces = iface;
 	  return 1;
 	}
       free(iface);
@@ -325,7 +589,6 @@ static int iface_allowed(struct irec **irecp, int if_i
   return 0;
 }
 
-#ifdef HAVE_IPV6
 static int iface_allowed_v6(struct in6_addr *local, int prefix, 
 			    int scope, int if_index, int flags, 
 			    int preferred, int valid, void *vparam)
@@ -334,7 +597,6 @@ static int iface_allowed_v6(struct in6_addr *local, in
   struct in_addr netmask; /* dummy */
   netmask.s_addr = 0;
 
-  (void)prefix; /* warning */
   (void)scope; /* warning */
   (void)preferred;
   (void)valid;
@@ -346,37 +608,271 @@ static int iface_allowed_v6(struct in6_addr *local, in
   addr.in6.sin6_family = AF_INET6;
   addr.in6.sin6_addr = *local;
   addr.in6.sin6_port = htons(daemon->port);
-  addr.in6.sin6_scope_id = if_index;
+  /* FreeBSD insists this is zero for non-linklocal addresses */
+  if (IN6_IS_ADDR_LINKLOCAL(local))
+    addr.in6.sin6_scope_id = if_index;
+  else
+    addr.in6.sin6_scope_id = 0;
   
-  return iface_allowed((struct irec **)vparam, if_index, &addr, netmask, !!(flags & IFACE_TENTATIVE));
+  return iface_allowed((struct iface_param *)vparam, if_index, NULL, &addr, netmask, prefix, flags);
 }
-#endif
 
-static int iface_allowed_v4(struct in_addr local, int if_index, 
+static int iface_allowed_v4(struct in_addr local, int if_index, char *label,
 			    struct in_addr netmask, struct in_addr broadcast, void *vparam)
 {
   union mysockaddr addr;
+  int prefix, bit;
+ 
+  (void)broadcast; /* warning */
 
   memset(&addr, 0, sizeof(addr));
 #ifdef HAVE_SOCKADDR_SA_LEN
   addr.in.sin_len = sizeof(addr.in);
 #endif
   addr.in.sin_family = AF_INET;
-  addr.in.sin_addr = broadcast; /* warning */
   addr.in.sin_addr = local;
   addr.in.sin_port = htons(daemon->port);
 
-  return iface_allowed((struct irec **)vparam, if_index, &addr, netmask, 0);
+  /* determine prefix length from netmask */
+  for (prefix = 32, bit = 1; (bit & ntohl(netmask.s_addr)) == 0 && prefix != 0; bit = bit << 1, prefix--);
+
+  return iface_allowed((struct iface_param *)vparam, if_index, label, &addr, netmask, prefix, 0);
 }
-   
-int enumerate_interfaces(void)
+
+/*
+ * Clean old interfaces no longer found.
+ */
+static void clean_interfaces()
 {
-#ifdef HAVE_IPV6
-  if (!iface_enumerate(AF_INET6, &daemon->interfaces, iface_allowed_v6))
-    return 0; 
+  struct irec *iface;
+  struct irec **up = &daemon->interfaces;
+
+  for (iface = *up; iface; iface = *up)
+  {
+    if (!iface->found && !iface->done)
+      {
+        *up = iface->next;
+        free(iface->name);
+        free(iface);
+      }
+    else
+      {
+        up = &iface->next;
+      }
+  }
+}
+
+/** Release listener if no other interface needs it.
+ *
+ * @return 1 if released, 0 if still required
+ */
+static int release_listener(struct listener *l)
+{
+  if (l->used > 1)
+    {
+      struct irec *iface;
+      for (iface = daemon->interfaces; iface; iface = iface->next)
+	if (iface->done && sockaddr_isequal(&l->addr, &iface->addr))
+	  {
+	    if (iface->found)
+	      {
+		/* update listener to point to active interface instead */
+		if (!l->iface->found)
+		  l->iface = iface;
+	      }
+	    else
+	      {
+		l->used--;
+		iface->done = 0;
+	      }
+	  }
+
+      /* Someone is still using this listener, skip its deletion */
+      if (l->used > 0)
+	return 0;
+    }
+
+  if (l->iface->done)
+    {
+      int port;
+
+      port = prettyprint_addr(&l->iface->addr, daemon->addrbuff);
+      my_syslog(LOG_DEBUG|MS_DEBUG, _("stopped listening on %s(#%d): %s port %d"),
+		l->iface->name, l->iface->index, daemon->addrbuff, port);
+      /* In case it ever returns */
+      l->iface->done = 0;
+    }
+
+  if (l->fd != -1)
+    close(l->fd);
+  if (l->tcpfd != -1)
+    close(l->tcpfd);
+  if (l->tftpfd != -1)
+    close(l->tftpfd);
+
+  free(l);
+  return 1;
+}
+
+int enumerate_interfaces(int reset)
+{
+  static struct addrlist *spare = NULL;
+  static int done = 0;
+  struct iface_param param;
+  int errsave, ret = 1;
+  struct addrlist *addr, *tmp;
+  struct interface_name *intname;
+  struct cond_domain *cond;
+  struct irec *iface;
+#ifdef HAVE_AUTH
+  struct auth_zone *zone;
 #endif
+  struct server *serv;
+  
+  /* Do this max once per select cycle  - also inhibits netlink socket use
+   in TCP child processes. */
 
-  return iface_enumerate(AF_INET, &daemon->interfaces, iface_allowed_v4); 
+  if (reset)
+    {
+      done = 0;
+      return 1;
+    }
+
+  if (done)
+    return 1;
+
+  done = 1;
+
+  if ((param.fd = socket(PF_INET, SOCK_DGRAM, 0)) == -1)
+    return 0;
+
+  /* iface indexes can change when interfaces are created/destroyed. 
+     We use them in the main forwarding control path, when the path
+     to a server is specified by an interface, so cache them.
+     Update the cache here. */
+  for (serv = daemon->servers; serv; serv = serv->next)
+    if (serv->interface[0] != 0)
+      {
+#ifdef HAVE_LINUX_NETWORK
+	struct ifreq ifr;
+	
+	safe_strncpy(ifr.ifr_name, serv->interface, IF_NAMESIZE);
+	if (ioctl(param.fd, SIOCGIFINDEX, &ifr) != -1) 
+	  serv->ifindex = ifr.ifr_ifindex;
+#else
+	serv->ifindex = if_nametoindex(serv->interface);
+#endif
+      }
+    
+again:
+  /* Mark interfaces for garbage collection */
+  for (iface = daemon->interfaces; iface; iface = iface->next) 
+    iface->found = 0;
+
+  /* remove addresses stored against interface_names */
+  for (intname = daemon->int_names; intname; intname = intname->next)
+    {
+      for (addr = intname->addr; addr; addr = tmp)
+	{
+	  tmp = addr->next;
+	  addr->next = spare;
+	  spare = addr;
+	}
+      
+      intname->addr = NULL;
+    }
+
+  /* remove addresses stored against cond-domains. */
+  for (cond = daemon->cond_domain; cond; cond = cond->next)
+    {
+      for (addr = cond->al; addr; addr = tmp)
+	{
+	  tmp = addr->next;
+	  addr->next = spare;
+	  spare = addr;
+      }
+      
+      cond->al = NULL;
+    }
+  
+  /* Remove list of addresses of local interfaces */
+  for (addr = daemon->interface_addrs; addr; addr = tmp)
+    {
+      tmp = addr->next;
+      addr->next = spare;
+      spare = addr;
+    }
+  daemon->interface_addrs = NULL;
+  
+#ifdef HAVE_AUTH
+  /* remove addresses stored against auth_zone subnets, but not 
+   ones configured as address literals */
+  for (zone = daemon->auth_zones; zone; zone = zone->next)
+    if (zone->interface_names)
+      {
+	struct addrlist **up;
+	for (up = &zone->subnet, addr = zone->subnet; addr; addr = tmp)
+	  {
+	    tmp = addr->next;
+	    if (addr->flags & ADDRLIST_LITERAL)
+	      up = &addr->next;
+	    else
+	      {
+		*up = addr->next;
+		addr->next = spare;
+		spare = addr;
+	      }
+	  }
+      }
+#endif
+
+  param.spare = spare;
+  
+  ret = iface_enumerate(AF_INET6, &param, iface_allowed_v6);
+  if (ret < 0)
+    goto again;
+  else if (ret)
+    {
+      ret = iface_enumerate(AF_INET, &param, iface_allowed_v4);
+      if (ret < 0)
+	goto again;
+    }
+ 
+  errsave = errno;
+  close(param.fd);
+  
+  if (option_bool(OPT_CLEVERBIND))
+    { 
+      /* Garbage-collect listeners listening on addresses that no longer exist.
+	 Does nothing when not binding interfaces or for listeners on localhost, 
+	 since the ->iface field is NULL. Note that this needs the protections
+	 against reentrancy, hence it's here.  It also means there's a possibility,
+	 in OPT_CLEVERBIND mode, that at listener will just disappear after
+	 a call to enumerate_interfaces, this is checked OK on all calls. */
+      struct listener *l, *tmp, **up;
+      int freed = 0;
+      
+      for (up = &daemon->listeners, l = daemon->listeners; l; l = tmp)
+	{
+	  tmp = l->next;
+	  
+	  if (!l->iface || l->iface->found)
+	    up = &l->next;
+	  else if (release_listener(l))
+	    {
+	      *up = tmp;
+	      freed = 1;
+	    }
+	}
+
+      if (freed)
+	clean_interfaces();
+    }
+
+  errno = errsave;
+  spare = param.spare;
+  
+  return ret;
 }
 
 /* set NONBLOCK bit on fd: See Stevens 16.6 */
@@ -398,7 +894,7 @@ static int make_sock(union mysockaddr *addr, int type,
   
   if ((fd = socket(family, type, 0)) == -1)
     {
-      int port;
+      int port, errsave;
       char *s;
 
       /* No error if the kernel just doesn't support this IP flavour */
@@ -408,6 +904,7 @@ static int make_sock(union mysockaddr *addr, int type,
 	return -1;
       
     err:
+      errsave = errno;
       port = prettyprint_addr(addr, daemon->addrbuff);
       if (!option_bool(OPT_NOWILD) && !option_bool(OPT_CLEVERBIND))
 	sprintf(daemon->addrbuff, "port %d", port);
@@ -415,7 +912,9 @@ static int make_sock(union mysockaddr *addr, int type,
       
       if (fd != -1)
 	close (fd);
-      
+	
+      errno = errsave;
+
       if (dienow)
 	{
 	  /* failure to bind addresses given by --listen-address at this point
@@ -432,22 +931,25 @@ static int make_sock(union mysockaddr *addr, int type,
   if (setsockopt(fd, SOL_SOCKET, SO_REUSEADDR, &opt, sizeof(opt)) == -1 || !fix_fd(fd))
     goto err;
   
-#ifdef HAVE_IPV6
   if (family == AF_INET6 && setsockopt(fd, IPPROTO_IPV6, IPV6_V6ONLY, &opt, sizeof(opt)) == -1)
     goto err;
-#endif
   
   if ((rc = bind(fd, (struct sockaddr *)addr, sa_len(addr))) == -1)
     goto err;
   
   if (type == SOCK_STREAM)
     {
-      if (listen(fd, 5) == -1)
+#ifdef TCP_FASTOPEN
+      int qlen = 5;                           
+      setsockopt(fd, IPPROTO_TCP, TCP_FASTOPEN, &qlen, sizeof(qlen));
+#endif
+      
+      if (listen(fd, TCP_BACKLOG) == -1)
 	goto err;
     }
-  else if (!option_bool(OPT_NOWILD))
+  else if (family == AF_INET)
     {
-      if (family == AF_INET)
+      if (!option_bool(OPT_NOWILD))
 	{
 #if defined(HAVE_LINUX_NETWORK) 
 	  if (setsockopt(fd, IPPROTO_IP, IP_PKTINFO, &opt, sizeof(opt)) == -1)
@@ -458,16 +960,13 @@ static int make_sock(union mysockaddr *addr, int type,
 	    goto err;
 #endif
 	}
-#ifdef HAVE_IPV6
-      else if (!set_ipv6pktinfo(fd))
-	goto err;
-#endif
     }
+  else if (!set_ipv6pktinfo(fd))
+    goto err;
   
   return fd;
 }
 
-#ifdef HAVE_IPV6  
 int set_ipv6pktinfo(int fd)
 {
   int opt = 1;
@@ -494,43 +993,47 @@ int set_ipv6pktinfo(int fd)
 
   return 0;
 }
-#endif
 
 
 /* Find the interface on which a TCP connection arrived, if possible, or zero otherwise. */
 int tcp_interface(int fd, int af)
 { 
+  (void)fd; /* suppress potential unused warning */
+  (void)af; /* suppress potential unused warning */
   int if_index = 0;
 
 #ifdef HAVE_LINUX_NETWORK
   int opt = 1;
   struct cmsghdr *cmptr;
   struct msghdr msg;
+  socklen_t len;
   
-  /* use mshdr do that the CMSDG_* macros are available */
+  /* use mshdr so that the CMSDG_* macros are available */
   msg.msg_control = daemon->packet;
-  msg.msg_controllen = daemon->packet_buff_sz;
-  
+  msg.msg_controllen = len = daemon->packet_buff_sz;
+
   /* we overwrote the buffer... */
-  daemon->srv_save = NULL;
-  
+  daemon->srv_save = NULL; 
+
   if (af == AF_INET)
     {
       if (setsockopt(fd, IPPROTO_IP, IP_PKTINFO, &opt, sizeof(opt)) != -1 &&
-	  getsockopt(fd, IPPROTO_IP, IP_PKTOPTIONS, msg.msg_control, (socklen_t *)&msg.msg_controllen) != -1)
-	for (cmptr = CMSG_FIRSTHDR(&msg); cmptr; cmptr = CMSG_NXTHDR(&msg, cmptr))
-	  if (cmptr->cmsg_level == IPPROTO_IP && cmptr->cmsg_type == IP_PKTINFO)
-            {
-              union {
-                unsigned char *c;
-                struct in_pktinfo *p;
-              } p;
-	      
-	      p.c = CMSG_DATA(cmptr);
-	      if_index = p.p->ipi_ifindex;
-	    }
+	  getsockopt(fd, IPPROTO_IP, IP_PKTOPTIONS, msg.msg_control, &len) != -1)
+	{
+	  msg.msg_controllen = len;
+	  for (cmptr = CMSG_FIRSTHDR(&msg); cmptr; cmptr = CMSG_NXTHDR(&msg, cmptr))
+	    if (cmptr->cmsg_level == IPPROTO_IP && cmptr->cmsg_type == IP_PKTINFO)
+	      {
+		union {
+		  unsigned char *c;
+		  struct in_pktinfo *p;
+		} p;
+		
+		p.c = CMSG_DATA(cmptr);
+		if_index = p.p->ipi_ifindex;
+	      }
+	}
     }
-#ifdef HAVE_IPV6
   else
     {
       /* Only the RFC-2292 API has the ability to find the interface for TCP connections,
@@ -546,9 +1049,10 @@ int tcp_interface(int fd, int af)
 #endif
 
       if (set_ipv6pktinfo(fd) &&
-	  getsockopt(fd, IPPROTO_IPV6, PKTOPTIONS, msg.msg_control, (socklen_t *)&msg.msg_controllen) != -1)
+	  getsockopt(fd, IPPROTO_IPV6, PKTOPTIONS, msg.msg_control, &len) != -1)
 	{
-          for (cmptr = CMSG_FIRSTHDR(&msg); cmptr; cmptr = CMSG_NXTHDR(&msg, cmptr))
+          msg.msg_controllen = len;
+	  for (cmptr = CMSG_FIRSTHDR(&msg); cmptr; cmptr = CMSG_NXTHDR(&msg, cmptr))
             if (cmptr->cmsg_level == IPPROTO_IPV6 && cmptr->cmsg_type == daemon->v6pktinfo)
               {
                 union {
@@ -561,7 +1065,6 @@ int tcp_interface(int fd, int af)
               }
 	}
     }
-#endif /* IPV6 */
 #endif /* Linux */
  
   return if_index;
@@ -572,6 +1075,8 @@ static struct listener *create_listeners(union mysocka
   struct listener *l = NULL;
   int fd = -1, tcpfd = -1, tftpfd = -1;
 
+  (void)do_tftp;
+
   if (daemon->port != 0)
     {
       fd = make_sock(addr, SOCK_DGRAM, dienow);
@@ -589,7 +1094,6 @@ static struct listener *create_listeners(union mysocka
 	  tftpfd = make_sock(addr, SOCK_DGRAM, dienow);
 	  addr->in.sin_port = save;
 	}
-#  ifdef HAVE_IPV6
       else
 	{
 	  short save = addr->in6.sin6_port;
@@ -597,7 +1101,6 @@ static struct listener *create_listeners(union mysocka
 	  tftpfd = make_sock(addr, SOCK_DGRAM, dienow);
 	  addr->in6.sin6_port = save;
 	}  
-#  endif
     }
 #endif
 
@@ -605,10 +1108,12 @@ static struct listener *create_listeners(union mysocka
     {
       l = safe_malloc(sizeof(struct listener));
       l->next = NULL;
-      l->family = addr->sa.sa_family;
       l->fd = fd;
       l->tcpfd = tcpfd;
       l->tftpfd = tftpfd;
+      l->addr = *addr;
+      l->used = 1;
+      l->iface = NULL;
     }
 
   return l;
@@ -629,11 +1134,10 @@ void create_wildcard_listeners(void)
 
   l = create_listeners(&addr, !!option_bool(OPT_TFTP), 1);
 
-#ifdef HAVE_IPV6
   memset(&addr, 0, sizeof(addr));
-#  ifdef HAVE_SOCKADDR_SA_LEN
+#ifdef HAVE_SOCKADDR_SA_LEN
   addr.in6.sin6_len = sizeof(addr.in6);
-#  endif
+#endif
   addr.in6.sin6_family = AF_INET6;
   addr.in6.sin6_addr = in6addr_any;
   addr.in6.sin6_port = htons(daemon->port);
@@ -643,25 +1147,52 @@ void create_wildcard_listeners(void)
     l->next = l6;
   else 
     l = l6;
-#endif
 
   daemon->listeners = l;
 }
 
+static struct listener *find_listener(union mysockaddr *addr)
+{
+  struct listener *l;
+  for (l = daemon->listeners; l; l = l->next)
+    if (sockaddr_isequal(&l->addr, addr))
+      return l;
+  return NULL;
+}
+
 void create_bound_listeners(int dienow)
 {
   struct listener *new;
   struct irec *iface;
   struct iname *if_tmp;
+  struct listener *existing;
 
   for (iface = daemon->interfaces; iface; iface = iface->next)
-    if (!iface->done && !iface->dad && 
-	(new = create_listeners(&iface->addr, iface->tftp_ok, dienow)))
+    if (!iface->done && !iface->dad && iface->found)
       {
-	new->iface = iface;
-	new->next = daemon->listeners;
-	daemon->listeners = new;
-	iface->done = 1;
+	existing = find_listener(&iface->addr);
+	if (existing)
+	  {
+	    iface->done = 1;
+	    existing->used++; /* increase usage counter */
+	  }
+	else if ((new = create_listeners(&iface->addr, iface->tftp_ok, dienow)))
+	  {
+	    new->iface = iface;
+	    new->next = daemon->listeners;
+	    daemon->listeners = new;
+	    iface->done = 1;
+
+	    /* Don't log the initial set of listen addresses created
+               at startup, since this is happening before the logging
+               system is initialised and the sign-on printed. */
+            if (!dienow)
+              {
+		int port = prettyprint_addr(&iface->addr, daemon->addrbuff);
+		my_syslog(LOG_DEBUG|MS_DEBUG, _("listening on %s(#%d): %s port %d"),
+			  iface->name, iface->index, daemon->addrbuff, port);
+	      }
+	  }
       }
 
   /* Check for --listen-address options that haven't been used because there's
@@ -679,12 +1210,73 @@ void create_bound_listeners(int dienow)
     if (!if_tmp->used && 
 	(new = create_listeners(&if_tmp->addr, !!option_bool(OPT_TFTP), dienow)))
       {
-	new->iface = NULL;
 	new->next = daemon->listeners;
 	daemon->listeners = new;
+
+	if (!dienow)
+	  {
+	    int port = prettyprint_addr(&if_tmp->addr, daemon->addrbuff);
+	    my_syslog(LOG_DEBUG|MS_DEBUG, _("listening on %s port %d"), daemon->addrbuff, port);
+	  }
       }
 }
 
+/* In --bind-interfaces, the only access control is the addresses we're listening on. 
+   There's nothing to avoid a query to the address of an internal interface arriving via
+   an external interface where we don't want to accept queries, except that in the usual 
+   case the addresses of internal interfaces are RFC1918. When bind-interfaces in use, 
+   and we listen on an address that looks like it's probably globally routeable, shout.
+
+   The fix is to use --bind-dynamic, which actually checks the arrival interface too.
+   Tough if your platform doesn't support this.
+
+   Note that checking the arrival interface is supported in the standard IPv6 API and
+   always done, so we don't warn about any IPv6 addresses here.
+*/
+
+void warn_bound_listeners(void)
+{
+  struct irec *iface; 	
+  int advice = 0;
+
+  for (iface = daemon->interfaces; iface; iface = iface->next)
+    if (!iface->dns_auth)
+      {
+	if (iface->addr.sa.sa_family == AF_INET)
+	  {
+	    if (!private_net(iface->addr.in.sin_addr, 1))
+	      {
+		inet_ntop(AF_INET, &iface->addr.in.sin_addr, daemon->addrbuff, ADDRSTRLEN);
+		iface->warned = advice = 1;
+		my_syslog(LOG_WARNING, 
+			  _("LOUD WARNING: listening on %s may accept requests via interfaces other than %s"),
+			  daemon->addrbuff, iface->name);
+	      }
+	  }
+      }
+  
+  if (advice)
+    my_syslog(LOG_WARNING, _("LOUD WARNING: use --bind-dynamic rather than --bind-interfaces to avoid DNS amplification attacks via these interface(s)")); 
+}
+
+void warn_wild_labels(void)
+{
+  struct irec *iface;
+
+  for (iface = daemon->interfaces; iface; iface = iface->next)
+    if (iface->found && iface->name && iface->label)
+      my_syslog(LOG_WARNING, _("warning: using interface %s instead"), iface->name);
+}
+
+void warn_int_names(void)
+{
+  struct interface_name *intname;
+ 
+  for (intname = daemon->int_names; intname; intname = intname->next)
+    if (!intname->addr)
+      my_syslog(LOG_WARNING, _("warning: no addresses found for interface %s"), intname->intr);
+}
+ 
 int is_dad_listeners(void)
 {
   struct irec *iface;
@@ -722,25 +1314,32 @@ void join_multicast(int dienow)      
 	    
 	    inet_pton(AF_INET6, ALL_RELAY_AGENTS_AND_SERVERS, &mreq.ipv6mr_multiaddr);
 	    
-	    if (daemon->doing_dhcp6 &&
+	    if ((daemon->doing_dhcp6 || daemon->relay6) &&
 		setsockopt(daemon->dhcp6fd, IPPROTO_IPV6, IPV6_JOIN_GROUP, &mreq, sizeof(mreq)) == -1)
-	      err = 1;
+	      err = errno;
 	    
 	    inet_pton(AF_INET6, ALL_SERVERS, &mreq.ipv6mr_multiaddr);
 	    
 	    if (daemon->doing_dhcp6 && 
 		setsockopt(daemon->dhcp6fd, IPPROTO_IPV6, IPV6_JOIN_GROUP, &mreq, sizeof(mreq)) == -1)
-	      err = 1;
+	      err = errno;
 	    
 	    inet_pton(AF_INET6, ALL_ROUTERS, &mreq.ipv6mr_multiaddr);
 	    
 	    if (daemon->doing_ra &&
 		setsockopt(daemon->icmp6fd, IPPROTO_IPV6, IPV6_JOIN_GROUP, &mreq, sizeof(mreq)) == -1)
-	      err = 1;
+	      err = errno;
 	    
 	    if (err)
 	      {
 		char *s = _("interface %s failed to join DHCPv6 multicast group: %s");
+		errno = err;
+
+#ifdef HAVE_LINUX_NETWORK
+		if (errno == ENOMEM)
+		  my_syslog(LOG_ERR, _("try increasing /proc/sys/net/core/optmem_max"));
+#endif
+
 		if (dienow)
 		  die(s, iface->name, EC_BADNET);
 		else
@@ -751,82 +1350,87 @@ void join_multicast(int dienow)      
 }
 #endif
 
-/* return a UDP socket bound to a random port, have to cope with straying into
-   occupied port nos and reserved ones. */
-int random_sock(int family)
+int local_bind(int fd, union mysockaddr *addr, char *intname, unsigned int ifindex, int is_tcp)
 {
-  int fd;
+  union mysockaddr addr_copy = *addr;
+  unsigned short port;
+  int tries = 1;
+  unsigned short ports_avail = 1;
 
-  if ((fd = socket(family, SOCK_DGRAM, 0)) != -1)
-    {
-      union mysockaddr addr;
-      unsigned int ports_avail = 65536u - (unsigned short)daemon->min_port;
-      int tries = ports_avail < 30 ? 3 * ports_avail : 100;
+  if (addr_copy.sa.sa_family == AF_INET)
+    port = addr_copy.in.sin_port;
+  else
+    port = addr_copy.in6.sin6_port;
 
-      memset(&addr, 0, sizeof(addr));
-      addr.sa.sa_family = family;
-
-      /* don't loop forever if all ports in use. */
-
-      if (fix_fd(fd))
-	while(tries--)
-	  {
-	    unsigned short port = rand16();
-	    
-	    if (daemon->min_port != 0)
-	      port = htons(daemon->min_port + (port % ((unsigned short)ports_avail)));
-	    
-	    if (family == AF_INET) 
-	      {
-		addr.in.sin_addr.s_addr = INADDR_ANY;
-		addr.in.sin_port = port;
-#ifdef HAVE_SOCKADDR_SA_LEN
-		addr.in.sin_len = sizeof(struct sockaddr_in);
-#endif
-	      }
-#ifdef HAVE_IPV6
-	    else
-	      {
-		addr.in6.sin6_addr = in6addr_any; 
-		addr.in6.sin6_port = port;
-#ifdef HAVE_SOCKADDR_SA_LEN
-		addr.in6.sin6_len = sizeof(struct sockaddr_in6);
-#endif
-	      }
-#endif
-	    
-	    if (bind(fd, (struct sockaddr *)&addr, sa_len(&addr)) == 0)
-	      return fd;
-	    
-	    if (errno != EADDRINUSE && errno != EACCES)
-	      break;
-	  }
-
-      close(fd);
+  /* cannot set source _port_ for TCP connections. */
+  if (is_tcp)
+    port = 0;
+  else if (port == 0 && daemon->max_port != 0)
+    {
+      /* Bind a random port within the range given by min-port and max-port if either
+	 or both are set. Otherwise use the OS's random ephemeral port allocation by
+	 leaving port == 0 and tries == 1 */
+      ports_avail = daemon->max_port - daemon->min_port + 1;
+      tries =  (ports_avail < SMALL_PORT_RANGE) ? ports_avail : 100;
+      port = htons(daemon->min_port + (rand16() % ports_avail));
     }
-
-  return -1; 
-}
   
+  while (1)
+    {
+      /* elide bind() call if it's to port 0, address 0 */
+      if (addr_copy.sa.sa_family == AF_INET)
+	{
+	  if (port == 0 && addr_copy.in.sin_addr.s_addr == 0)
+	    break;
+	  addr_copy.in.sin_port = port;
+	}
+      else
+	{
+	  if (port == 0 && IN6_IS_ADDR_UNSPECIFIED(&addr_copy.in6.sin6_addr))
+	    break;
+	  addr_copy.in6.sin6_port = port;
+	}
+      
+      if (bind(fd, (struct sockaddr *)&addr_copy, sa_len(&addr_copy)) != -1)
+	break;
+      
+       if (errno != EADDRINUSE && errno != EACCES) 
+	 return 0;
 
-int local_bind(int fd, union mysockaddr *addr, char *intname, int is_tcp)
-{
-  union mysockaddr addr_copy = *addr;
+      if (--tries == 0)
+	return 0;
 
-  /* cannot set source _port_ for TCP connections. */
-  if (is_tcp)
+      /* For small ranges, do a systematic search, not a random one. */
+      if (ports_avail < SMALL_PORT_RANGE)
+	{
+	  unsigned short hport = ntohs(port);
+	  if (hport++ == daemon->max_port)
+	    hport = daemon->min_port;
+	  port = htons(hport);
+	}
+      else
+	port = htons(daemon->min_port + (rand16() % ports_avail));
+    }
+
+  if (!is_tcp && ifindex > 0)
     {
+#if defined(IP_UNICAST_IF)
       if (addr_copy.sa.sa_family == AF_INET)
-	addr_copy.in.sin_port = 0;
-#ifdef HAVE_IPV6
-      else
-	addr_copy.in6.sin6_port = 0;
+        {
+          uint32_t ifindex_opt = htonl(ifindex);
+          return setsockopt(fd, IPPROTO_IP, IP_UNICAST_IF, &ifindex_opt, sizeof(ifindex_opt)) == 0;
+        }
 #endif
+#if defined (IPV6_UNICAST_IF)
+      if (addr_copy.sa.sa_family == AF_INET6)
+        {
+          uint32_t ifindex_opt = htonl(ifindex);
+          return setsockopt(fd, IPPROTO_IPV6, IPV6_UNICAST_IF, &ifindex_opt, sizeof(ifindex_opt)) == 0;
+        }
+#endif
     }
-  
-  if (bind(fd, (struct sockaddr *)&addr_copy, sa_len(&addr_copy)) == -1)
-    return 0;
-    
+
+  (void)intname; /* suppress potential unused warning */
 #if defined(SO_BINDTODEVICE)
   if (intname[0] != 0 &&
       setsockopt(fd, SOL_SOCKET, SO_BINDTODEVICE, intname, IF_NAMESIZE) == -1)
@@ -836,33 +1440,32 @@ int local_bind(int fd, union mysockaddr *addr, char *i
   return 1;
 }
 
-static struct serverfd *allocate_sfd(union mysockaddr *addr, char *intname)
+static struct serverfd *allocate_sfd(union mysockaddr *addr, char *intname, unsigned int ifindex)
 {
   struct serverfd *sfd;
   int errsave;
-
+  int opt = 1;
+  
   /* when using random ports, servers which would otherwise use
-     the INADDR_ANY/port0 socket have sfd set to NULL */
-  if (!daemon->osport && intname[0] == 0)
+     the INADDR_ANY/port0 socket have sfd set to NULL, this is 
+     anything without an explictly set source port. */
+  if (!daemon->osport)
     {
       errno = 0;
       
       if (addr->sa.sa_family == AF_INET &&
-	  addr->in.sin_addr.s_addr == INADDR_ANY &&
 	  addr->in.sin_port == htons(0)) 
 	return NULL;
 
-#ifdef HAVE_IPV6
       if (addr->sa.sa_family == AF_INET6 &&
-	  memcmp(&addr->in6.sin6_addr, &in6addr_any, sizeof(in6addr_any)) == 0 &&
 	  addr->in6.sin6_port == htons(0)) 
 	return NULL;
-#endif
     }
-      
+
   /* may have a suitable one already */
   for (sfd = daemon->sfds; sfd; sfd = sfd->next )
-    if (sockaddr_isequal(&sfd->source_addr, addr) &&
+    if (ifindex == sfd->ifindex &&
+	sockaddr_isequal(&sfd->source_addr, addr) &&
 	strcmp(intname, sfd->interface) == 0)
       return sfd;
   
@@ -876,20 +1479,24 @@ static struct serverfd *allocate_sfd(union mysockaddr 
       free(sfd);
       return NULL;
     }
-  
-  if (!local_bind(sfd->fd, addr, intname, 0) || !fix_fd(sfd->fd))
+
+  if ((addr->sa.sa_family == AF_INET6 && setsockopt(sfd->fd, IPPROTO_IPV6, IPV6_V6ONLY, &opt, sizeof(opt)) == -1) ||
+      !local_bind(sfd->fd, addr, intname, ifindex, 0) || !fix_fd(sfd->fd))
     { 
-      errsave = errno; /* save error from bind. */
+      errsave = errno; /* save error from bind/setsockopt. */
       close(sfd->fd);
       free(sfd);
       errno = errsave;
       return NULL;
     }
-    
-  strcpy(sfd->interface, intname); 
+
+  safe_strncpy(sfd->interface, intname, sizeof(sfd->interface)); 
   sfd->source_addr = *addr;
   sfd->next = daemon->sfds;
+  sfd->ifindex = ifindex;
+  sfd->preallocated = 0;
   daemon->sfds = sfd;
+
   return sfd; 
 }
 
@@ -898,6 +1505,7 @@ static struct serverfd *allocate_sfd(union mysockaddr 
 void pre_allocate_sfds(void)
 {
   struct server *srv;
+  struct serverfd *sfd;
   
   if (daemon->query_port != 0)
     {
@@ -909,8 +1517,9 @@ void pre_allocate_sfds(void)
 #ifdef HAVE_SOCKADDR_SA_LEN
       addr.in.sin_len = sizeof(struct sockaddr_in);
 #endif
-      allocate_sfd(&addr, "");
-#ifdef HAVE_IPV6
+      if ((sfd = allocate_sfd(&addr, "", 0)))
+	sfd->preallocated = 1;
+
       memset(&addr, 0, sizeof(addr));
       addr.in6.sin6_family = AF_INET6;
       addr.in6.sin6_addr = in6addr_any;
@@ -918,17 +1527,16 @@ void pre_allocate_sfds(void)
 #ifdef HAVE_SOCKADDR_SA_LEN
       addr.in6.sin6_len = sizeof(struct sockaddr_in6);
 #endif
-      allocate_sfd(&addr, "");
-#endif
+      if ((sfd = allocate_sfd(&addr, "", 0)))
+	sfd->preallocated = 1;
     }
   
   for (srv = daemon->servers; srv; srv = srv->next)
-    if (!(srv->flags & (SERV_LITERAL_ADDRESS | SERV_NO_ADDR | SERV_USE_RESOLV | SERV_NO_REBIND)) &&
-	!allocate_sfd(&srv->source_addr, srv->interface) &&
+    if (!allocate_sfd(&srv->source_addr, srv->interface, srv->ifindex) &&
 	errno != 0 &&
 	option_bool(OPT_NOWILD))
       {
-	prettyprint_addr(&srv->source_addr, daemon->namebuff);
+	(void)prettyprint_addr(&srv->source_addr, daemon->namebuff);
 	if (srv->interface[0] != 0)
 	  {
 	    strcat(daemon->namebuff, " ");
@@ -939,87 +1547,170 @@ void pre_allocate_sfds(void)
       }  
 }
 
-
-void check_servers(void)
+void check_servers(int no_loop_check)
 {
   struct irec *iface;
-  struct server *new, *tmp, *ret = NULL;
-  int port = 0;
+  struct server *serv;
+  struct serverfd *sfd, *tmp, **up;
+  int port = 0, count;
+  int locals = 0;
+  
+#ifdef HAVE_LOOP
+  if (!no_loop_check)
+    loop_send_probes();
+#endif
 
-  /* interface may be new since startup */
-  if (!option_bool(OPT_NOWILD))
-    enumerate_interfaces();
+  /* clear all marks. */
+  mark_servers(0);
   
-  for (new = daemon->servers; new; new = tmp)
-    {
-      tmp = new->next;
-      
-      if (!(new->flags & (SERV_LITERAL_ADDRESS | SERV_NO_ADDR | SERV_USE_RESOLV | SERV_NO_REBIND)))
-	{
-	  port = prettyprint_addr(&new->addr, daemon->namebuff);
+ /* interface may be new since startup */
+  if (!option_bool(OPT_NOWILD))
+    enumerate_interfaces(0);
 
-	  /* 0.0.0.0 is nothing, the stack treats it like 127.0.0.1 */
-	  if (new->addr.sa.sa_family == AF_INET &&
-	      new->addr.in.sin_addr.s_addr == 0)
-	    {
-	      free(new);
-	      continue;
-	    }
+  /* don't garbage collect pre-allocated sfds. */
+  for (sfd = daemon->sfds; sfd; sfd = sfd->next)
+    sfd->used = sfd->preallocated;
 
-	  for (iface = daemon->interfaces; iface; iface = iface->next)
-	    if (sockaddr_isequal(&new->addr, &iface->addr))
-	      break;
-	  if (iface)
-	    {
-	      my_syslog(LOG_WARNING, _("ignoring nameserver %s - local interface"), daemon->namebuff);
-	      free(new);
-	      continue;
-	    }
+  for (count = 0, serv = daemon->servers; serv; serv = serv->next)
+    {
+      /* Init edns_pktsz for newly created server records. */
+      if (serv->edns_pktsz == 0)
+	serv->edns_pktsz = daemon->edns_pktsz;
+      
+#ifdef HAVE_DNSSEC
+      if (option_bool(OPT_DNSSEC_VALID))
+	{ 
+	  if (!(serv->flags & SERV_FOR_NODOTS))
+	    serv->flags |= SERV_DO_DNSSEC;
 	  
-	  /* Do we need a socket set? */
-	  if (!new->sfd && 
-	      !(new->sfd = allocate_sfd(&new->source_addr, new->interface)) &&
-	      errno != 0)
+	  /* Disable DNSSEC validation when using server=/domain/.... servers
+	     unless there's a configured trust anchor. */
+	  if (strlen(serv->domain) != 0)
 	    {
-	      my_syslog(LOG_WARNING, 
-			_("ignoring nameserver %s - cannot make/bind socket: %s"),
-			daemon->namebuff, strerror(errno));
-	      free(new);
-	      continue;
+	      struct ds_config *ds;
+	      char *domain = serv->domain;
+	      
+	      /* .example.com is valid */
+	      while (*domain == '.')
+		domain++;
+	      
+	      for (ds = daemon->ds; ds; ds = ds->next)
+		if (ds->name[0] != 0 && hostname_isequal(domain, ds->name))
+		  break;
+	      
+	      if (!ds)
+		serv->flags &= ~SERV_DO_DNSSEC;
 	    }
 	}
+#endif
       
-      /* reverse order - gets it right. */
-      new->next = ret;
-      ret = new;
+      port = prettyprint_addr(&serv->addr, daemon->namebuff);
       
-      if (!(new->flags & SERV_NO_REBIND))
+      /* 0.0.0.0 is nothing, the stack treats it like 127.0.0.1 */
+      if (serv->addr.sa.sa_family == AF_INET &&
+	  serv->addr.in.sin_addr.s_addr == 0)
 	{
-	  if (new->flags & (SERV_HAS_DOMAIN | SERV_FOR_NODOTS | SERV_USE_RESOLV))
-	    {
-	      char *s1, *s2;
-	      if (!(new->flags & SERV_HAS_DOMAIN))
-		s1 = _("unqualified"), s2 = _("names");
-	      else if (strlen(new->domain) == 0)
-		s1 = _("default"), s2 = "";
-	      else
-		s1 = _("domain"), s2 = new->domain;
-	      
-	      if (new->flags & SERV_NO_ADDR)
-		my_syslog(LOG_INFO, _("using local addresses only for %s %s"), s1, s2);
-	      else if (new->flags & SERV_USE_RESOLV)
-		my_syslog(LOG_INFO, _("using standard nameservers for %s %s"), s1, s2);
-	      else if (!(new->flags & SERV_LITERAL_ADDRESS))
-		my_syslog(LOG_INFO, _("using nameserver %s#%d for %s %s"), daemon->namebuff, port, s1, s2);
-	    }
-	  else if (new->interface[0] != 0)
-	    my_syslog(LOG_INFO, _("using nameserver %s#%d(via %s)"), daemon->namebuff, port, new->interface); 
+	  serv->flags |= SERV_MARK;
+	  continue;
+	}
+      
+      for (iface = daemon->interfaces; iface; iface = iface->next)
+	if (sockaddr_isequal(&serv->addr, &iface->addr))
+	  break;
+      if (iface)
+	{
+	  my_syslog(LOG_WARNING, _("ignoring nameserver %s - local interface"), daemon->namebuff);
+	  serv->flags |= SERV_MARK;
+	  continue;
+	}
+      
+      /* Do we need a socket set? */
+      if (!serv->sfd && 
+	  !(serv->sfd = allocate_sfd(&serv->source_addr, serv->interface, serv->ifindex)) &&
+	  errno != 0)
+	{
+	  my_syslog(LOG_WARNING, 
+		    _("ignoring nameserver %s - cannot make/bind socket: %s"),
+		    daemon->namebuff, strerror(errno));
+	  serv->flags |= SERV_MARK;
+	  continue;
+	}
+      
+      if (serv->sfd)
+	serv->sfd->used = 1;
+      
+      if (count == SERVERS_LOGGED)
+	my_syslog(LOG_INFO, _("more servers are defined but not logged"));
+      
+      if (++count > SERVERS_LOGGED)
+	continue;
+      
+      if (strlen(serv->domain) != 0 || (serv->flags & SERV_FOR_NODOTS))
+	{
+	  char *s1, *s2, *s3 = "", *s4 = "";
+
+#ifdef HAVE_DNSSEC
+	  if (option_bool(OPT_DNSSEC_VALID) && !(serv->flags & SERV_DO_DNSSEC))
+	    s3 = _("(no DNSSEC)");
+#endif
+	  if (serv->flags & SERV_FOR_NODOTS)
+	    s1 = _("unqualified"), s2 = _("names");
+	  else if (strlen(serv->domain) == 0)
+	    s1 = _("default"), s2 = "";
 	  else
-	    my_syslog(LOG_INFO, _("using nameserver %s#%d"), daemon->namebuff, port); 
+	    s1 = _("domain"), s2 = serv->domain, s4 = (serv->flags & SERV_WILDCARD) ? "*" : "";
+	  
+	  my_syslog(LOG_INFO, _("using nameserver %s#%d for %s %s%s %s"), daemon->namebuff, port, s1, s4, s2, s3);
 	}
+#ifdef HAVE_LOOP
+      else if (serv->flags & SERV_LOOP)
+	my_syslog(LOG_INFO, _("NOT using nameserver %s#%d - query loop detected"), daemon->namebuff, port); 
+#endif
+      else if (serv->interface[0] != 0)
+	my_syslog(LOG_INFO, _("using nameserver %s#%d(via %s)"), daemon->namebuff, port, serv->interface); 
+      else
+	my_syslog(LOG_INFO, _("using nameserver %s#%d"), daemon->namebuff, port); 
+
     }
   
-  daemon->servers = ret;
+  for (count = 0, serv = daemon->local_domains; serv; serv = serv->next)
+    {
+       if (++count > SERVERS_LOGGED)
+	 continue;
+       
+       if ((serv->flags & SERV_LITERAL_ADDRESS) &&
+	   !(serv->flags & (SERV_6ADDR | SERV_4ADDR | SERV_ALL_ZEROS)) &&
+	   strlen(serv->domain))
+	 {
+	   count--;
+	   if (++locals <= LOCALS_LOGGED)
+	     my_syslog(LOG_INFO, _("using only locally-known addresses for %s"), serv->domain);
+	 }
+       else if (serv->flags & SERV_USE_RESOLV)
+	 my_syslog(LOG_INFO, _("using standard nameservers for %s"), serv->domain);
+    }
+  
+  if (locals > LOCALS_LOGGED)
+    my_syslog(LOG_INFO, _("using %d more local addresses"), locals - LOCALS_LOGGED);
+  if (count - 1 > SERVERS_LOGGED)
+    my_syslog(LOG_INFO, _("using %d more nameservers"), count - SERVERS_LOGGED - 1);
+
+  /* Remove unused sfds */
+  for (sfd = daemon->sfds, up = &daemon->sfds; sfd; sfd = tmp)
+    {
+       tmp = sfd->next;
+       if (!sfd->used) 
+	{
+	  *up = sfd->next;
+	  close(sfd->fd);
+	  free(sfd);
+	} 
+      else
+	up = &sfd->next;
+    }
+  
+  cleanup_servers(); /* remove servers we just deleted. */
+  build_server_array(); 
 }
 
 /* Return zero if no servers found, in that case we keep polling.
@@ -1028,9 +1719,6 @@ int reload_servers(char *fname)
 {
   FILE *f;
   char *line;
-  struct server *old_servers = NULL;
-  struct server *new_servers = NULL;
-  struct server *serv;
   int gotone = 0;
 
   /* buff happens to be MAXDNAME long... */
@@ -1039,28 +1727,9 @@ int reload_servers(char *fname)
       my_syslog(LOG_ERR, _("failed to read %s: %s"), fname, strerror(errno));
       return 0;
     }
-  
-  /* move old servers to free list - we can reuse the memory 
-     and not risk malloc if there are the same or fewer new servers. 
-     Servers which were specced on the command line go to the new list. */
-  for (serv = daemon->servers; serv;)
-    {
-      struct server *tmp = serv->next;
-      if (serv->flags & SERV_FROM_RESOLV)
-	{
-	  serv->next = old_servers;
-	  old_servers = serv; 
-	  /* forward table rules reference servers, so have to blow them away */
-	  server_gone(serv);
-	}
-      else
-	{
-	  serv->next = new_servers;
-	  new_servers = serv;
-	}
-      serv = tmp;
-    }
-  
+   
+  mark_servers(SERV_FROM_RESOLV);
+    
   while ((line = fgets(daemon->namebuff, MAXDNAME, f)))
     {
       union mysockaddr addr, source_addr;
@@ -1076,7 +1745,7 @@ int reload_servers(char *fname)
       memset(&addr, 0, sizeof(addr));
       memset(&source_addr, 0, sizeof(source_addr));
       
-      if ((addr.in.sin_addr.s_addr = inet_addr(token)) != (in_addr_t) -1)
+      if (inet_pton(AF_INET, token, &addr.in.sin_addr) > 0)
 	{
 #ifdef HAVE_SOCKADDR_SA_LEN
 	  source_addr.in.sin_len = addr.in.sin_len = sizeof(source_addr.in);
@@ -1086,7 +1755,6 @@ int reload_servers(char *fname)
 	  source_addr.in.sin_addr.s_addr = INADDR_ANY;
 	  source_addr.in.sin_port = htons(daemon->query_port);
 	}
-#ifdef HAVE_IPV6
       else 
 	{	
 	  int scope_index = 0;
@@ -1114,69 +1782,48 @@ int reload_servers(char *fname)
 	  else
 	    continue;
 	}
-#else /* IPV6 */
-      else
-	continue;
-#endif 
 
-      if (old_servers)
-	{
-	  serv = old_servers;
-	  old_servers = old_servers->next;
-	}
-      else if (!(serv = whine_malloc(sizeof (struct server))))
-	continue;
-      
-      /* this list is reverse ordered: 
-	 it gets reversed again in check_servers */
-      serv->next = new_servers;
-      new_servers = serv;
-      serv->addr = addr;
-      serv->source_addr = source_addr;
-      serv->domain = NULL;
-      serv->interface[0] = 0;
-      serv->sfd = NULL;
-      serv->flags = SERV_FROM_RESOLV;
-      serv->queries = serv->failed_queries = 0;
+      add_update_server(SERV_FROM_RESOLV, &addr, &source_addr, NULL, NULL, NULL);
       gotone = 1;
     }
   
-  /* Free any memory not used. */
-  while (old_servers)
-    {
-      struct server *tmp = old_servers->next;
-      free(old_servers);
-      old_servers = tmp;
-    }
-
-  daemon->servers = new_servers;
   fclose(f);
+  cleanup_servers();
 
   return gotone;
 }
 
-
-/* Use an IPv4 listener socket for ioctling */
-struct in_addr get_ifaddr(char *intr)
+/* Called when addresses are added or deleted from an interface */
+void newaddress(time_t now)
 {
-  struct listener *l;
-  struct ifreq ifr;
-  struct sockaddr_in ret;
+  struct dhcp_relay *relay;
+
+  (void)now;
   
-  ret.sin_addr.s_addr = -1;
+  if (option_bool(OPT_CLEVERBIND) || option_bool(OPT_LOCAL_SERVICE) ||
+      daemon->doing_dhcp6 || daemon->relay6 || daemon->doing_ra)
+    enumerate_interfaces(0);
+  
+  if (option_bool(OPT_CLEVERBIND))
+    create_bound_listeners(0);
 
-  for (l = daemon->listeners; 
-       l && (l->family != AF_INET || l->fd == -1);
-       l = l->next);
+#ifdef HAVE_DHCP
+  /* clear cache of subnet->relay index */
+  for (relay = daemon->relay4; relay; relay = relay->next)
+    relay->iface_index = 0;
+#endif
   
-  strncpy(ifr.ifr_name, intr, IF_NAMESIZE);
-  ifr.ifr_addr.sa_family = AF_INET;
+#ifdef HAVE_DHCP6
+  if (daemon->doing_dhcp6 || daemon->relay6 || daemon->doing_ra)
+    join_multicast(0);
   
-  if (l &&  ioctl(l->fd, SIOCGIFADDR, &ifr) != -1)
-    memcpy(&ret, &ifr.ifr_addr, sizeof(ret)); 
+  if (daemon->doing_dhcp6 || daemon->doing_ra)
+    dhcp_construct_contexts(now);
   
-  return ret.sin_addr;
-}
+  if (daemon->doing_dhcp6)
+    lease_find_interfaces(now);
 
-
-
+  for (relay = daemon->relay6; relay; relay = relay->next)
+    relay->iface_index = 0;
+#endif
+}