Add safeguard against kernel with network drivers

If the kernel has a network device, execute devnode instead, to make pfinet
use the kernel driver.

* check_kernel.c: New file.
* check_kernel.h: New file.
* Makefile (SRC_C): Add check_kernel.c
* main.c: Include "check_kernel.h"
(main): Call check_kernel.

4 files changed, 55 insertions, 1 deletions

diff --git a/Makefile b/Makefile
index 8a83573a7..38d463dcf 100644
--- a/Makefile
+++ b/Makefile
@@ -5,7 +5,7 @@ include Makeconf.local
 
 TARGET         = netdde
 
-SRC_C          = main.c
+SRC_C          = main.c check_kernel.c
 
 LIBS          += $(libmachdev_path) -ldde_linux26.o -ldde_linux26_net $(libddekit_path) -lfshelp -ltrivfs -lpciaccess -lz -lthreads -lshouldbeinlibc -lports $(libslab_path) $(libbpf_path)
 CFLAGS        += -g -I$(PKGDIR)/include -I$(BUILDDIR)/include
diff --git a/check_kernel.c b/check_kernel.c
new file mode 100644
index 000000000..717895c81
--- /dev/null
+++ b/check_kernel.c
@@ -0,0 +1,50 @@
+/*!
+   Copyright (C) 2012 Free Software Foundation, Inc.
+   Written by Samuel Thibault.
+
+   This file is part of the GNU Hurd.
+
+   The GNU Hurd is free software; you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation; either version 2, or (at your option)
+   any later version.
+
+   The GNU Hurd is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with the GNU Hurd; see the file COPYING.  If not, write to
+   the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA.  */
+
+#define _GNU_SOURCE
+#include <stdio.h>
+#include <stdlib.h>
+#include <unistd.h>
+
+#include <hurd.h>
+#include <mach.h>
+#include <device/device.h>
+
+#include "check_kernel.h"
+
+void check_kernel(void) {
+	mach_port_t device_master;
+
+	if (! get_privileged_ports (0, &device_master))
+	    {
+		device_t device;
+
+		if (! device_open (device_master, D_READ, "eth0", &device))
+		    {
+			error_t err;
+
+			fprintf (stderr, "Kernel is already driving a network device, starting devnode instead of netdde\n");
+			err = execl ("/hurd/devnode", "devnode", "eth0", NULL);
+			error (1, err, "Invocation of devnode failed");
+		    }
+	    }
+
+	mach_port_deallocate (mach_task_self (), device_master);
+}
diff --git a/check_kernel.h b/check_kernel.h
new file mode 100644
index 000000000..d74150489
--- /dev/null
+++ b/check_kernel.h
@@ -0,0 +1 @@
+void check_kernel(void);
diff --git a/main.c b/main.c
index 98f4452ab..d9eacaf85 100644
--- a/main.c
+++ b/main.c
@@ -7,11 +7,14 @@
 #include <linux/delay.h> // msleep()
 
 #include <hurd/machdev.h>
+#include "check_kernel.h"
 
 int using_std = 1;
 
 int main(int argc, char **argv)
 {
+	check_kernel();
+
 	l4dde26_init();
 	l4dde26_process_init();
 	l4dde26_softirq_init();