dhcp: detect NMIP4Config 'metered' flag based on ANDROID_METERED DHCP option

Some versions of Android's DHCP server send option 43 (Vendor specific
information) with value "ANDROID_METERED" in Wi-Fi hotspot mode.

Mark the NMIP4Config as metered when such option is received.

(cherry picked from commit 1e39b2320dfe42ca33dfbf12746d63935818ac5a)

3 files changed, 35 insertions, 0 deletions

diff --git a/src/dhcp-manager/nm-dhcp-systemd.c b/src/dhcp-manager/nm-dhcp-systemd.c
index 12dc03cc84..2bd0d72ffc 100644
--- a/src/dhcp-manager/nm-dhcp-systemd.c
+++ b/src/dhcp-manager/nm-dhcp-systemd.c
@@ -224,6 +224,8 @@ lease_to_ip4_config (sd_dhcp_lease *lease,
 	guint16 mtu;
 	int r, num;
 	guint64 end_time;
+	uint8_t *data;
+	gboolean metered = FALSE;
 
 	g_return_val_if_fail (lease != NULL, NULL);
 
@@ -355,6 +357,11 @@ lease_to_ip4_config (sd_dhcp_lease *lease,
 		g_string_free (l, TRUE);
 	}
 
+	num = sd_dhcp_lease_get_vendor_specific (lease, &data);
+	if (num > 0)
+		metered = !!memmem (data, num, "ANDROID_METERED", STRLEN ("ANDROID_METERED"));
+	nm_ip4_config_set_metered (ip4_config, metered);
+
 	return ip4_config;
 }
 
diff --git a/src/dhcp-manager/nm-dhcp-utils.c b/src/dhcp-manager/nm-dhcp-utils.c
index 8cd4359abb..ab7f26d5fa 100644
--- a/src/dhcp-manager/nm-dhcp-utils.c
+++ b/src/dhcp-manager/nm-dhcp-utils.c
@@ -575,6 +575,9 @@ nm_dhcp_utils_ip4_config_from_options (const char *iface,
 		g_strfreev (nis);
 	}
 
+	str = g_hash_table_lookup (options, "vendor_encapsulated_options");
+	nm_ip4_config_set_metered (ip4_config, str && strstr (str, "ANDROID_METERED"));
+
 	return ip4_config;
 
 error:
diff --git a/src/dhcp-manager/tests/test-dhcp-utils.c b/src/dhcp-manager/tests/test-dhcp-utils.c
index 53688a5b1b..e022a1ae74 100644
--- a/src/dhcp-manager/tests/test-dhcp-utils.c
+++ b/src/dhcp-manager/tests/test-dhcp-utils.c
@@ -176,6 +176,30 @@ test_wins_options (void)
 }
 
 static void
+test_vendor_option_metered (void)
+{
+	GHashTable *options;
+	NMIP4Config *ip4_config;
+	static const Option data[] = {
+		{ "vendor_encapsulated_options", "ANDROID_METERED" },
+		{ NULL, NULL }
+	};
+
+	options = fill_table (generic_options, NULL);
+	ip4_config = nm_dhcp_utils_ip4_config_from_options ("eth0", options, 0);
+	g_assert (ip4_config);
+	g_assert (nm_ip4_config_get_metered (ip4_config) == FALSE);
+	g_hash_table_destroy (options);
+
+	options = fill_table (generic_options, NULL);
+	options = fill_table (data, options);
+	ip4_config = nm_dhcp_utils_ip4_config_from_options ("eth0", options, 0);
+	g_assert (ip4_config);
+	g_assert (nm_ip4_config_get_metered (ip4_config) == TRUE);
+	g_hash_table_destroy (options);
+}
+
+static void
 ip4_test_route (NMIP4Config *ip4_config,
                 guint route_num,
                 const char *expected_dest,
@@ -716,6 +740,7 @@ int main (int argc, char **argv)
 	g_test_add_func ("/dhcp/ip4-missing-prefix-8", test_ip4_missing_prefix_8);
 	g_test_add_func ("/dhcp/ip4-prefix-classless", test_ip4_prefix_classless);
 	g_test_add_func ("/dhcp/client-id-from-string", test_client_id_from_string);
+	g_test_add_func ("/dhcp/vendor-option-metered", test_vendor_option_metered);
 
 	return g_test_run ();
 }