tethering: Use fallback nameservers if dnsproxy is not in use

If user has disabled dnsproxy with -r option, then fallback to
user specified nameservers instead of using the Google one.

diff --git a/src/tethering.c b/src/tethering.c
index bd79804..7042040 100644 (file)
--- a/src/tethering.c
+++ b/src/tethering.c
@@ -49,12 +49,11 @@
 #endif
 
 #define BRIDGE_NAME "tether"
-#define BRIDGE_DNS "8.8.8.8"
 
 #define DEFAULT_MTU    1500
 
-#define PRIVATE_NETWORK_PRIMARY_DNS BRIDGE_DNS
-#define PRIVATE_NETWORK_SECONDARY_DNS "8.8.4.4"
+static char *private_network_primary_dns = NULL;
+static char *private_network_secondary_dns = NULL;
 
 static volatile int tethering_enabled;
 static GDHCPServer *tethering_dhcp_server = NULL;
@@ -73,8 +72,8 @@ struct connman_private_network {
        int index;
        guint iface_watch;
        struct connman_ippool *pool;
-       const char *primary_dns;
-       const char *secondary_dns;
+       char *primary_dns;
+       char *secondary_dns;
 };
 
 const char *__connman_tethering_get_bridge(void)
@@ -192,6 +191,7 @@ void __connman_tethering_set_enabled(void)
        const char *end_ip;
        const char *dns;
        unsigned char prefixlen;
+       char **ns;
 
        DBG("enabled %d", tethering_enabled + 1);
 
@@ -228,11 +228,28 @@ void __connman_tethering_set_enabled(void)
                return;
        }
 
+       ns = connman_setting_get_string_list("FallbackNameservers");
+       if (ns != NULL) {
+               if (ns[0] != NULL) {
+                       g_free(private_network_primary_dns);
+                       private_network_primary_dns = g_strdup(ns[0]);
+               }
+               if (ns[1] != NULL) {
+                       g_free(private_network_secondary_dns);
+                       private_network_secondary_dns = g_strdup(ns[1]);
+               }
+
+               DBG("Fallback ns primary %s secondary %s",
+                       private_network_primary_dns,
+                       private_network_secondary_dns);
+       }
+
        dns = gateway;
        if (__connman_dnsproxy_add_listener(index) < 0) {
                connman_error("Can't add listener %s to DNS proxy",
                                                                BRIDGE_NAME);
-               dns = BRIDGE_DNS;
+               dns = private_network_primary_dns;
+               DBG("Serving %s nameserver to clients", dns);
        }
 
        tethering_dhcp_server = dhcp_server_start(BRIDGE_NAME,
@@ -278,6 +295,11 @@ void __connman_tethering_set_disabled(void)
 
        __connman_bridge_remove(BRIDGE_NAME);
 
+       g_free(private_network_primary_dns);
+       private_network_primary_dns = NULL;
+       g_free(private_network_secondary_dns);
+       private_network_secondary_dns = NULL;
+
        DBG("tethering stopped");
 }
 
@@ -329,9 +351,12 @@ static void setup_tun_interface(unsigned int flags, unsigned change,
                                        DBUS_TYPE_STRING, &server_ip);
        connman_dbus_dict_append_basic(&dict, "PeerIPv4",
                                        DBUS_TYPE_STRING, &peer_ip);
-       connman_dbus_dict_append_basic(&dict, "PrimaryDNS",
+       if (pn->primary_dns != NULL)
+               connman_dbus_dict_append_basic(&dict, "PrimaryDNS",
                                        DBUS_TYPE_STRING, &pn->primary_dns);
-       connman_dbus_dict_append_basic(&dict, "SecondaryDNS",
+
+       if (pn->secondary_dns != NULL)
+               connman_dbus_dict_append_basic(&dict, "SecondaryDNS",
                                        DBUS_TYPE_STRING, &pn->secondary_dns);
 
        connman_dbus_dict_close(&array, &dict);
@@ -367,6 +392,8 @@ static void remove_private_network(gpointer user_data)
        g_free(pn->interface);
        g_free(pn->owner);
        g_free(pn->path);
+       g_free(pn->primary_dns);
+       g_free(pn->secondary_dns);
        g_free(pn);
 }
 
@@ -447,8 +474,8 @@ int __connman_private_network_request(DBusMessage *msg, const char *owner)
                goto error;
        }
 
-       pn->primary_dns = PRIVATE_NETWORK_PRIMARY_DNS;
-       pn->secondary_dns = PRIVATE_NETWORK_SECONDARY_DNS;
+       pn->primary_dns = g_strdup(private_network_primary_dns);
+       pn->secondary_dns = g_strdup(private_network_secondary_dns);
 
        pn->iface_watch = connman_rtnl_add_newlink_watch(index,
                                                setup_tun_interface, pn);