Add autoconf test for CAN.

Signed-off-by: Zeng Linggang <zenglg.jy@cn.fujitsu.com>
diff --git a/configure.ac b/configure.ac
index 0e1c3b8..8f03af1 100644
--- a/configure.ac
+++ b/configure.ac
@@ -187,5 +187,6 @@
 LTP_CHECK_TEE
 LTP_CHECK_SPLICE
 LTP_CHECK_VMSPLICE
+LTP_CHECK_CAN_SUPPORT
 
 AC_OUTPUT
diff --git a/m4/ltp-can.m4 b/m4/ltp-can.m4
new file mode 100644
index 0000000..af437ef
--- /dev/null
+++ b/m4/ltp-can.m4
@@ -0,0 +1,25 @@
+dnl
+dnl Copyright (c) Linux Test Project, 2014
+dnl
+dnl This program is free software;  you can redistribute it and/or modify
+dnl it under the terms of the GNU General Public License as published by
+dnl the Free Software Foundation; either version 2 of the License, or
+dnl (at your option) any later version.
+dnl
+dnl This program is distributed in the hope that it will be useful,
+dnl but WITHOUT ANY WARRANTY;  without even the implied warranty of
+dnl MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See
+dnl the GNU General Public License for more details.
+dnl
+dnl You should have received a copy of the GNU General Public License
+dnl along with this program;  if not, write to the Free Software
+dnl Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
+dnl
+
+dnl
+dnl LTP_CHECK_CAN_SUPPORT
+dnl ----------------------------
+dnl
+AC_DEFUN([LTP_CHECK_CAN_SUPPORT],[
+AC_CHECK_HEADERS([linux/can.h])
+])
diff --git a/testcases/network/can/filter-tests/tst-filter.c b/testcases/network/can/filter-tests/tst-filter.c
index 1ffc893..e5fddc7 100644
--- a/testcases/network/can/filter-tests/tst-filter.c
+++ b/testcases/network/can/filter-tests/tst-filter.c
@@ -55,6 +55,9 @@
 #include <sys/ioctl.h>
 #include <sys/time.h>
 #include <net/if.h>
+#include "config.h"
+
+#ifdef HAVE_LINUX_CAN_H
 
 #include <linux/can.h>
 #include <linux/can/raw.h>
@@ -256,3 +259,13 @@
 
 	return 0;
 }
+
+#else
+
+int main(void)
+{
+	printf("The linux/can.h was missing upon compilation.\n");
+	return 32;
+}
+
+#endif /* HAVE_LINUX_CAN_H */
diff --git a/testcases/network/can/filter-tests/tst-rcv-own-msgs.c b/testcases/network/can/filter-tests/tst-rcv-own-msgs.c
index 808b11e..5730fd3 100644
--- a/testcases/network/can/filter-tests/tst-rcv-own-msgs.c
+++ b/testcases/network/can/filter-tests/tst-rcv-own-msgs.c
@@ -55,6 +55,9 @@
 #include <sys/ioctl.h>
 #include <sys/time.h>
 #include <net/if.h>
+#include "config.h"
+
+#ifdef HAVE_LINUX_CAN_H
 
 #include <linux/can.h>
 #include <linux/can/raw.h>
@@ -243,3 +246,13 @@
 
 	return 0;
 }
+
+#else
+
+int main(void)
+{
+	printf("The linux/can.h was missing upon compilation.\n");
+	return 32;
+}
+
+#endif /* HAVE_LINUX_CAN_H */