Handle --dhcp-option DNS6 on Windows using netsh

index 9e828d8..97be7fa 100644
@@ -6407,14 +6407,20 @@ add_option (struct options *options,
 	{
 	  dhcp_option_address_parse ("DNS", p[2], o->dns, &o->dns_len, msglevel);
 	}
-      else if (streq (p[1], "DNS6") && p[2])
-	{
-	  /* this is somewhat of a placeholder - we understand the option,
-	   * but cannot act upon it - so we'll just accept it and put it
-	   * into the environment, as we would do on all non-win32 platforms
-	   */
-	  foreign_option (options, p, 3, es);
-	}
+      else if (streq (p[1], "DNS6") && p[2] && ipv6_addr_safe(p[2]))
+        {
+          struct in6_addr addr;
+          foreign_option (options, p, 3, es);
+          if (o->dns6_len >= N_DHCP_ADDR)
+            {
+              msg (msglevel, "--dhcp-option DNS6: maximum of %d dns servers can be specified",
+	           N_DHCP_ADDR);
+            }
+          else if (get_ipv6_addr (p[2], &addr, NULL, msglevel))
+            {
+              o->dns6[o->dns6_len++] = addr;
+            }
+        }
       else if (streq (p[1], "WINS") && p[2])
 	{
 	  dhcp_option_address_parse ("WINS", p[2], o->wins, &o->wins_len, msglevel);

index 77ae72f..5950906 100644
@@ -68,6 +68,9 @@ static void netsh_ifconfig (const struct tuntap_options *to,
 			    const in_addr_t ip,
 			    const in_addr_t netmask,
 			    const unsigned int flags);
+static void netsh_dns6_servers (const struct in6_addr *addr_list,
+                                const int addr_len,
+                                const char *flex_name);
 static void netsh_command (const struct argv *a, int n, int msglevel);
 
 static const char *netsh_get_id (const char *dev_node, struct gc_arena *gc);

@@ -1375,6 +1378,7 @@ do_ifconfig (struct tuntap *tt,
 	if (tt->options.msg_channel)
 	  {
 	    do_address_service (true, AF_INET6, tt);
+            /* TODO: do_dns6_service() */
 	  }
 	else
 	  {

@@ -1388,6 +1392,8 @@ do_ifconfig (struct tuntap *tt,
 			 iface,
 			 ifconfig_ipv6_local );
 	    netsh_command (&argv, 4, M_FATAL);
+            /* set ipv6 dns servers if any are specified */
+	    netsh_dns6_servers(tt->options.dns6, tt->options.dns6_len, actual);
 	  }
 
 	/* explicit route needed */

@@ -4618,6 +4624,30 @@ ip_addr_member_of (const in_addr_t addr, const IP_ADDR_STRING *ias)
 }
 
 static void
+netsh_dns6_servers (const struct in6_addr *addr_list,
+                    const int addr_len,
+                    const char *flex_name)
+{
+    struct gc_arena gc = gc_new ();
+    struct argv argv = argv_new ();
+
+    for (int i = 0; i < addr_len; ++i)
+    {
+        const char *fmt = (i == 0) ?
+            "%s%sc interface ipv6 set dnsservers %s static %s validate=no"
+	    : "%s%sc interface ipv6 add dnsservers %s %s validate=no";
+        argv_printf (&argv, fmt, get_win_sys_path(),
+                     NETSH_PATH_SUFFIX, flex_name,
+                     print_in6_addr (addr_list[i], 0, &gc));
+        /* Treat errors while adding as non-fatal as we do not check for duplicates */
+        netsh_command (&argv, 2, (i==0)? M_FATAL : M_NONFATAL);
+    }
+
+    argv_reset (&argv);
+    gc_free (&gc);
+}
+
+static void
 netsh_ifconfig_options (const char *type,
 			const in_addr_t *addr_list,
 			const int addr_len,

index dedd915..9b5a1b7 100644
@@ -107,6 +107,9 @@ struct tuntap_options {
   bool dhcp_release;
 
   bool register_dns;
+
+  struct in6_addr dns6[N_DHCP_ADDR];
+  int dns6_len;
 };
 
 #elif TARGET_LINUX

index f30e62d..9ee6f27 100644
@@ -6407,14 +6407,20 @@ add_option (struct options *options,
 	{
 	  dhcp_option_address_parse ("DNS", p[2], o->dns, &o->dns_len, msglevel);
 	}
-      else if (streq (p[1], "DNS6") && p[2])
-	{
-	  /* this is somewhat of a placeholder - we understand the option,
-	   * but cannot act upon it - so we'll just accept it and put it
-	   * into the environment, as we would do on all non-win32 platforms
-	   */
-	  foreign_option (options, p, 3, es);
-	}
+      else if (streq (p[1], "DNS6") && p[2] && ipv6_addr_safe(p[2]))
+        {
+          struct in6_addr addr;
+          foreign_option (options, p, 3, es);
+          if (o->dns6_len >= N_DHCP_ADDR)
+            {
+              msg (msglevel, "--dhcp-option DNS6: maximum of %d dns servers can be specified",
+	           N_DHCP_ADDR);
+            }
+          else if (get_ipv6_addr (p[2], &addr, NULL, msglevel))
+            {
+              o->dns6[o->dns6_len++] = addr;
+            }
+        }
       else if (streq (p[1], "WINS") && p[2])
 	{
 	  dhcp_option_address_parse ("WINS", p[2], o->wins, &o->wins_len, msglevel);

82 lines not on this page · raw message

index dedd915..9b5a1b7 100644
@@ -107,6 +107,9 @@ struct tuntap_options {
   bool dhcp_release;
 
   bool register_dns;
+
+  struct in6_addr dns6[N_DHCP_ADDR];
+  int dns6_len;
 };
 
 #elif TARGET_LINUX