RDNSS and DNSSL data in router advertisements.

CHANGELOG

@@ -69,9 +69,12 @@ version 2.61
 
 	    Fix bug in address6_available() which caused DHCPv6 lease
 	    aquistion to fail of more than one dhcp-range in use.
+
+	    Provide RDNSS and DNSSL data in router advertisements,
+	    using the settings provided for DHCP options
+	    option6:domain-search and option6:dns-server.
 	    
 
- 
 version 2.60
             Fix compilation problem in Mac OS X Lion. Thanks to Olaf
             Flebbe for the patch.

man/dnsmasq.8

@@ -1343,6 +1343,10 @@ the machine running dnsmasq. By default, he "managed address" bits are set, and
 the "use SLAAC" bit is reset. This can be changed for individual
 subnets with the mode keywords described in
 .B --dhcp-range.
+RFC6106 DNS parameters are included in the advertisements. By default,
+the relevant link-local address of the machine running dnsmasq is sent
+as recursive DNS server. If provided, the DHCPv6 options dns-server and
+domain-search are used for RDNSS and DNSSL.
 .TP
 .B --enable-tftp[=<interface>]
 Enable the TFTP server function. This is deliberately limited to that

src/dhcp6-protocol.h

@@ -54,6 +54,7 @@
 #define OPTION6_RECONFIGURE_MSG 19
 #define OPTION6_RECONF_ACCEPT   20
 #define OPTION6_DNS_SERVER      23
+#define OPTION6_DOMAIN_SEARCH   24
 #define OPTION6_REMOTE_ID       37
 #define OPTION6_SUBSCRIBER_ID   38
 #define OPTION6_FQDN            39

src/option.c

@@ -1000,6 +1000,7 @@ static char *parse_dhcp_opt(char *arg, int flags)
 	      while (arg && *arg)
 		{
 		  u16 len = strlen(arg);
+		  unhide_metas(arg);
 		  PUTSHORT(len, p);
 		  memcpy(p, arg, len);
 		  p += len; 
@@ -1013,29 +1014,40 @@ static char *parse_dhcp_opt(char *arg, int flags)
 	    }
 	  else if (comma && (opt_len & OT_RFC1035_NAME))
 	    {
-	      int i, commas = 1;
-	      unsigned char *p, *newp;
-	      
-	      for (i = 0; comma[i]; i++)
-		if (comma[i] == ',')
-		  commas++;
-	      
-	      newp = opt_malloc(strlen(comma)+(2*commas));
-	      p = newp;
+	      unsigned char *p = NULL, *newp, *end;
+	      int len = 0;
 	      arg = comma;
 	      comma = split(arg);
 	      
 	      while (arg && *arg)
 		{
-		  p = do_rfc1035_name(p, arg);
-		  *p++ = 0;
+		  char *dom = canonicalise_opt(arg);
+		  if (!dom)
+		    {
+		      problem = _("bad domain in dhcp-option");
+		      break;
+		    }
+		  
+		  newp = opt_malloc(len + strlen(dom) + 2);
+		  
+		  if (p)
+		    {
+		      memcpy(newp, p, len);
+		      free(p);
+		    }
 		  
+		  p = newp;
+		  end = do_rfc1035_name(p + len, dom);
+		  *end++ = 0;
+		  len = end - p;
+		  free(dom);
+
 		  arg = comma;
 		  comma = split(arg);
 		}
 	      
-	      new->val = newp;
-	      new->len = p - newp;
+	      new->val = p;
+	      new->len = len;
 	    }
 #endif
 	  else

src/radv-protocol.h

@@ -43,6 +43,7 @@ struct prefix_opt {
 #define ICMP6_OPT_PREFIX       3
 #define ICMP6_OPT_MTU          5
 #define ICMP6_OPT_RDNSS       25
+#define ICMP6_OPT_DNSSL       31
 
 
 

src/radv.c

@@ -29,6 +29,7 @@
 struct ra_param {
   int ind, managed, other, found_context, first;
   char *if_name;
+  struct dhcp_netid *tags;
   struct in6_addr link_local;
 };
 
@@ -189,7 +190,10 @@ static void send_ra(int iface, char *iface_name, struct in6_addr *dest)
   struct ifreq ifr;
   struct sockaddr_in6 addr;
   struct dhcp_context *context;
-
+  struct dhcp_netid iface_id;
+  struct dhcp_opt *opt_cfg;
+  int done_dns = 0;
+ 
   save_counter(0);
   ra = expand(sizeof(struct ra_packet));
   
@@ -208,9 +212,17 @@ static void send_ra(int iface, char *iface_name, struct in6_addr *dest)
   parm.if_name = iface_name;
   parm.first = 1;
 
-  for (context = daemon->ra_contexts; context; context = context->next)
-    context->flags &= ~CONTEXT_RA_DONE;
+  /* set tag with name == interface */
+  iface_id.net = iface_name;
+  iface_id.next = NULL;
+  parm.tags = &iface_id; 
   
+  for (context = daemon->ra_contexts; context; context = context->next)
+    {
+      context->flags &= ~CONTEXT_RA_DONE;
+      context->netid.next = &context->netid;
+    }
+
   if (!iface_enumerate(AF_INET6, &parm, add_prefixes) ||
       !parm.found_context)
     return;
@@ -226,14 +238,63 @@ static void send_ra(int iface, char *iface_name, struct in6_addr *dest)
     }
      
   iface_enumerate(AF_LOCAL, &iface, add_lla);
+ 
+  /* RDNSS, RFC 6106, use relevant DHCP6 options */
+  (void)option_filter(parm.tags, NULL, daemon->dhcp_opts6);
   
-  /* RDNSS, RFC 6106 */
-  put_opt6_char(ICMP6_OPT_RDNSS);
-  put_opt6_char(3);
-  put_opt6_short(0);
-  put_opt6_long(1800); /* lifetime - twice RA retransmit */
-  put_opt6(&parm.link_local, IN6ADDRSZ);
+  for (opt_cfg = daemon->dhcp_opts6; opt_cfg; opt_cfg = opt_cfg->next)
+    {
+      int i;
+      
+      /* netids match and not encapsulated? */
+      if (!(opt_cfg->flags & DHOPT_TAGOK))
+        continue;
+      
+      if (opt_cfg->opt == OPTION6_DNS_SERVER)
+        {
+	  struct in6_addr *a = (struct in6_addr *)opt_cfg->val;
 
+	  done_dns = 1;
+          if (opt_cfg->len == 0)
+            continue;
+	  
+	  put_opt6_char(ICMP6_OPT_RDNSS);
+	  put_opt6_char((opt_cfg->len/8) + 1);
+	  put_opt6_short(0);
+	  put_opt6_long(1800); /* lifetime - twice RA retransmit */
+	  /* zero means "self" */
+	  for (i = 0; i < opt_cfg->len; i += IN6ADDRSZ, a++)
+	    if (IN6_IS_ADDR_UNSPECIFIED(a))
+	      put_opt6(&parm.link_local, IN6ADDRSZ);
+	    else
+	      put_opt6(a, IN6ADDRSZ);
+	}
+      
+      if (opt_cfg->opt == OPTION6_DOMAIN_SEARCH && opt_cfg->len != 0)
+	{
+	  int len = ((opt_cfg->len+7)/8);
+	  
+	  put_opt6_char(ICMP6_OPT_DNSSL);
+	  put_opt6_char(len + 1);
+	  put_opt6_short(0);
+	  put_opt6_long(1800); /* lifetime - twice RA retransmit */
+	  put_opt6(opt_cfg->val, opt_cfg->len);
+	  
+	  /* pad */
+	  for (i = opt_cfg->len; i < len * 8; i++)
+	    put_opt6_char(0);
+	}
+    }
+	
+  if (!done_dns)
+    {
+      /* default == us. */
+      put_opt6_char(ICMP6_OPT_RDNSS);
+      put_opt6_char(3);
+      put_opt6_short(0);
+      put_opt6_long(1800); /* lifetime - twice RA retransmit */
+      put_opt6(&parm.link_local, IN6ADDRSZ);
+    }
 
   /* set managed bits unless we're providing only RA on this link */
   if (parm.managed)
@@ -323,7 +384,14 @@ static int add_prefixes(struct in6_addr *local,  int prefix,
 		  context->ra_time = 0;
 		param->first = 0;
 		param->found_context = 1;
-		
+
+		/* collect dhcp-range tags */
+		if (context->netid.next == &context->netid && context->netid.net)
+		  {
+		    context->netid.next = param->tags;
+		    param->tags = &context->netid;
+		  }
+		  
 		if (!(context->flags & CONTEXT_RA_DONE))
 		  {
 		    context->flags |= CONTEXT_RA_DONE;