dnsproxy: Add or remove ::1 to/from resolv.conf when necessary

We add IPv6 loopback address to resolv.conf if we have created
an IPv6 listening socket to port 53. Also remove ::1 from resolv.conf
when deleting the proxy.

diff --git a/src/dnsproxy.c b/src/dnsproxy.c
index 60b1512..f1f7e4c 100644 (file)
--- a/src/dnsproxy.c
+++ b/src/dnsproxy.c
@@ -2924,8 +2924,19 @@ static GIOChannel *get_listener(int family, int protocol, int index)
        return channel;
 }
 
+#define UDP_IPv4_FAILED 0x01
+#define TCP_IPv4_FAILED 0x02
+#define UDP_IPv6_FAILED 0x04
+#define TCP_IPv6_FAILED 0x08
+#define UDP_FAILED (UDP_IPv4_FAILED | UDP_IPv6_FAILED)
+#define TCP_FAILED (TCP_IPv4_FAILED | TCP_IPv6_FAILED)
+#define IPv6_FAILED (UDP_IPv6_FAILED | TCP_IPv6_FAILED)
+#define IPv4_FAILED (UDP_IPv4_FAILED | TCP_IPv4_FAILED)
+
 static int create_dns_listener(int protocol, struct listener_data *ifdata)
 {
+       int ret = 0;
+
        if (protocol == IPPROTO_TCP) {
                ifdata->tcp4_listener_channel = get_listener(AF_INET, protocol,
                                                        ifdata->index);
@@ -2934,6 +2945,8 @@ static int create_dns_listener(int protocol, struct listener_data *ifdata)
                                g_io_add_watch(ifdata->tcp4_listener_channel,
                                        G_IO_IN, tcp4_listener_event,
                                        (gpointer)ifdata);
+               else
+                       ret |= TCP_IPv4_FAILED;
 
                ifdata->tcp6_listener_channel = get_listener(AF_INET6, protocol,
                                                        ifdata->index);
@@ -2942,6 +2955,8 @@ static int create_dns_listener(int protocol, struct listener_data *ifdata)
                                g_io_add_watch(ifdata->tcp6_listener_channel,
                                        G_IO_IN, tcp6_listener_event,
                                        (gpointer)ifdata);
+               else
+                       ret |= TCP_IPv6_FAILED;
        } else {
                ifdata->udp4_listener_channel = get_listener(AF_INET, protocol,
                                                        ifdata->index);
@@ -2950,6 +2965,8 @@ static int create_dns_listener(int protocol, struct listener_data *ifdata)
                                g_io_add_watch(ifdata->udp4_listener_channel,
                                        G_IO_IN, udp4_listener_event,
                                        (gpointer)ifdata);
+               else
+                       ret |= UDP_IPv4_FAILED;
 
                ifdata->udp6_listener_channel = get_listener(AF_INET6, protocol,
                                                        ifdata->index);
@@ -2958,9 +2975,11 @@ static int create_dns_listener(int protocol, struct listener_data *ifdata)
                                g_io_add_watch(ifdata->udp6_listener_channel,
                                        G_IO_IN, udp6_listener_event,
                                        (gpointer)ifdata);
+               else
+                       ret |= UDP_IPv6_FAILED;
        }
 
-       return 0;
+       return ret;
 }
 
 static void destroy_udp_listener(struct listener_data *ifdata)
@@ -2995,18 +3014,23 @@ static int create_listener(struct listener_data *ifdata)
        int err, index;
 
        err = create_dns_listener(IPPROTO_UDP, ifdata);
-       if (err < 0)
-               return err;
+       if ((err & UDP_FAILED) == UDP_FAILED)
+               return -EIO;
 
-       err = create_dns_listener(IPPROTO_TCP, ifdata);
-       if (err < 0) {
+       err |= create_dns_listener(IPPROTO_TCP, ifdata);
+       if ((err & TCP_FAILED) == TCP_FAILED) {
                destroy_udp_listener(ifdata);
-               return err;
+               return -EIO;
        }
 
        index = connman_inet_ifindex("lo");
-       if (ifdata->index == index)
-               __connman_resolvfile_append(index, NULL, "127.0.0.1");
+       if (ifdata->index == index) {
+               if ((err & IPv6_FAILED) != IPv6_FAILED)
+                       __connman_resolvfile_append(index, NULL, "::1");
+
+               if ((err & IPv4_FAILED) != IPv4_FAILED)
+                       __connman_resolvfile_append(index, NULL, "127.0.0.1");
+       }
 
        return 0;
 }
@@ -3017,8 +3041,10 @@ static void destroy_listener(struct listener_data *ifdata)
        GSList *list;
 
        index = connman_inet_ifindex("lo");
-       if (ifdata->index == index)
+       if (ifdata->index == index) {
                __connman_resolvfile_remove(index, NULL, "127.0.0.1");
+               __connman_resolvfile_remove(index, NULL, "::1");
+       }
 
        for (list = request_list; list; list = list->next) {
                struct request_data *req = list->data;