From cfe55847a066960b05c73e27436500c58f9efbcb Mon Sep 17 00:00:00 2001
From: Samuel Ortiz <sameo@linux.intel.com>
Date: Thu, 10 Feb 2011 17:13:46 +0100
Subject: [PATCH] tethering: Check for kernel bridge support

---
 src/technology.c |  2 ++
 src/tethering.c  | 11 +++++++++++
 2 files changed, 13 insertions(+)

diff --git a/src/technology.c b/src/technology.c
index a5366dc..2a48698 100644
--- a/src/technology.c
+++ b/src/technology.c
@@ -388,6 +388,8 @@ static DBusMessage *set_property(DBusConnection *conn,
 			return __connman_error_in_progress(msg);
 
 		bridge = __connman_tethering_get_bridge();
+		if (bridge == NULL)
+			return __connman_error_not_supported(msg);
 
 		err = set_tethering(technology, bridge, tethering);
 		if (err < 0)
diff --git a/src/tethering.c b/src/tethering.c
index 2609ab0..705f5ee 100644
--- a/src/tethering.c
+++ b/src/tethering.c
@@ -23,6 +23,8 @@
 #include <config.h>
 #endif
 
+#include <sys/types.h>
+#include <sys/stat.h>
 #include <unistd.h>
 #include <stdio.h>
 #include <sys/ioctl.h>
@@ -33,6 +35,8 @@
 
 #include <gdhcp/gdhcp.h>
 
+#define BRIDGE_SYSFS_DIR "/sys/module/bridge"
+
 #define BRIDGE_NAME "tether"
 #define BRIDGE_IP "192.168.218.1"
 #define BRIDGE_BCAST "192.168.218.255"
@@ -47,6 +51,13 @@ static GDHCPServer *tethering_dhcp_server = NULL;
 
 const char *__connman_tethering_get_bridge(void)
 {
+	struct stat st;
+
+	if (stat(BRIDGE_SYSFS_DIR, &st) < 0) {
+		connman_error("Missing support for 802.1d ethernet bridging");
+		return NULL;
+	}
+
 	return BRIDGE_NAME;
 }
 
-- 
2.7.4