1 files changed, 144 insertions, 0 deletions
diff --git a/mod/src/cyber_file.c b/mod/src/cyber_file.c
new file mode 100644
index 0000000..4ff5581
--- /dev/null
+++ b/mod/src/cyber_file.c
@@ -0,0 +1,144 @@
+/*
+ * cyber - Add CYBER to your system
+ * Copyright (C) 2017 Felix Morgner
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms and conditions of the GNU General Public License,
+ * version 2, as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope 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
+ * this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include "cyber.h"
+#include "cyber_file.h"
+
+#include <asm/uaccess.h>
+#include <linux/module.h>
+#include <linux/fs.h>
+#include <linux/mm.h>
+#include <linux/moduleparam.h>
+
+static unsigned char separator = ' ';
+module_param(separator, byte, S_IRUGO);
+MODULE_PARM_DESC(separator, "The string to separate the CYBER by");
+
+
+static char cyberPattern[] = {'!', 'C', 'Y', 'B', 'E', 'R', '!', ' '};
+static char * cyberSpace;
+
+/**
+ * Handler for CYBER device open events
+ *
+ * @param inode The kernel inode associated with the CYBER device
+ * @param file The kernel file associated with the CYBER device
+ * @return zero on success, non-zero otherwise
+ */
+static int cyber_file_open(struct inode * inode, struct file * file)
+{
+	return 0;
+}
+
+/**
+ * Handler for CYBER device read events
+ *
+ * @param file The kernel file associated with the CYBER device
+ * @param buffer The user-space target buffer for all the CYBER
+ * @param size The size of the user-space buffer
+ * @param offset The offset into the CYBER
+ * @return The number of bytes that were read, negative on error
+ */
+static ssize_t cyber_file_read(struct file * file, char __user * buffer, size_t size, loff_t * offset)
+{
+	int const cyberChunks = (size + PAGE_SIZE - 1) / PAGE_SIZE;
+	int const cybersPerChunk = (size > PAGE_SIZE ? PAGE_SIZE : size) / 8;
+	int copiedCybers = 0;
+
+	for(; copiedCybers < cyberChunks; ++copiedCybers)
+	{
+		if(raw_copy_to_user(buffer + copiedCybers * PAGE_SIZE, cyberSpace, cybersPerChunk * 8))
+		{
+			return -EFAULT;
+		}
+	}
+
+	return cyberChunks * cybersPerChunk * 8;
+}
+
+static int cyber_file_mmap(struct file * file, struct vm_area_struct * vma)
+{
+	ssize_t vmaSize = vma->vm_end - vma->vm_start;
+	ssize_t offset = 0;
+	for(; vmaSize; vmaSize -= PAGE_SIZE, ++offset)
+	{
+		vm_insert_page(vma, vma->vm_start + offset * PAGE_SIZE, virt_to_page(cyberSpace));
+	}
+	return 0;
+}
+
+/**
+ * Handler for CYBER device write events
+ *
+ * @param file The kernel file associated with the CYBER device
+ * @param buffer The user-space source buffer for all the CYBER
+ * @param size The size of the user-space buffer
+ * @param offset The offset into the CYBER
+ * @param The number of bytes that were written, negative on error
+ */
+static ssize_t cyber_file_write(struct file * file, char __user const * buffer, size_t size, loff_t * offset)
+{
+	return size;
+}
+
+/**
+ * Handler for CYBER device close events
+ *
+ * @param inode The kernel inode associated with the CYBER device
+ * @param file The kernel file associated with the CYBER device
+ * @param zero on success, non-zero otherwise
+ */
+static int cyber_file_close(struct inode * inode, struct file * file)
+{
+	return 0;
+}
+
+struct file_operations const cyber_operations = {
+	.owner = THIS_MODULE,
+	.open = cyber_file_open,
+	.read = cyber_file_read,
+	.write = cyber_file_write,
+	.release = cyber_file_close,
+	.mmap = cyber_file_mmap,
+};
+
+int cyber_file_init(void)
+{
+	int i;
+
+	printk(KERN_INFO DEV_NAME ": Initializing CYBER space\n");
+	cyberSpace = (char *)__get_free_page(GFP_KERNEL);
+	if(!cyberSpace)
+	{
+		printk(KERN_ALERT DEV_NAME ": Out of CYBER space!\n");
+		return ENOMEM;
+	}
+
+	cyberPattern[7] = separator;
+	for(i = 0; i < PAGE_SIZE; ++i)
+	{
+		cyberSpace[i] = cyberPattern[i % 8];
+	}
+
+	return 0;
+}
+
+void cyber_file_shutdown(void)
+{
+	printk(KERN_INFO DEV_NAME ": Releasing CYBER space\n");
+	free_page((unsigned long)cyberSpace);
+}