05-Interfaces: Add module use sysfs for uppercase and statistics

05-Interfaces/sysfs/Makefile

@@ -0,0 +1,9 @@
+obj-m += sysfs_module_uppercase.o
+
+BUILD_KERNEL?=/lib/modules/$(shell uname -r)/build/
+
+all:
+	make -C ${BUILD_KERNEL} M=$(PWD) modules
+
+clean:
+	make -C ${BUILD_KERNEL} M=$(PWD) clean

05-Interfaces/sysfs/README.md

@@ -0,0 +1,7 @@
+# Homework:
+
+procfs and sysfs Kernel module interfaces:
+
+1. Create a simple string uppercase converter using procfs (write: input string, read: that string in uppercase).
+2. Create a simple string lowercase converter using sysfs (store: input string, show: that string in lowercase).
+3. Add read only attributes for both filesystems showing statistics (using cat): e.g. total calls, total characters processed, characters converted etc).

05-Interfaces/sysfs/sysfs_module_uppercase.c

@@ -0,0 +1,146 @@
+#include <linux/init.h>
+#include <linux/module.h>
+#include <linux/sysfs.h>
+#include <linux/device.h>
+#include <linux/err.h>
+
+
+
+static int amount_read_calls, amount_write_calls, amount_converted_chars,amount_chars_finished_converted;
+static ssize_t text_for_convert_size;
+static char text_for_convert[PAGE_SIZE];
+
+
+static void convert_to_upper_case(char *temp_buffer)
+{
+	int i = 0;
+	while(temp_buffer[i] != 0)
+	{
+		if(temp_buffer[i] >= 'a' && temp_buffer[i] <= 'z')
+		{
+			temp_buffer[i] = temp_buffer[i] - 'a' + 'A';
+			amount_chars_finished_converted++;
+		}
+		i++;
+		amount_converted_chars++;
+	}
+}
+
+static ssize_t option_store(struct class *class, struct class_attribute *attr, const char *buf, size_t count)
+{
+	pr_info("sysfs_module_uppercase: write data");
+
+	size_t template_count;
+	if (count <= PAGE_SIZE)
+		template_count = count;
+	else
+		template_count = PAGE_SIZE - 1;
+	int i;
+	for(i = 0; i < template_count; i++)
+		text_for_convert[i] = buf[i];
+	text_for_convert[template_count] = 0;
+
+
+	amount_write_calls++;
+	convert_to_upper_case(text_for_convert);
+	return count;
+}
+
+static ssize_t option_show(struct class *class, struct class_attribute *attr, char *buf)
+{
+	pr_info("sysfs_module_uppercase: read data");
+
+	strcpy(buf, text_for_convert);
+
+	amount_read_calls++;
+
+	return strlen(buf);
+}
+
+static ssize_t statistic_show(struct class *class, struct class_attribute *attr, char *buf)
+{
+	char buff[600] = "";
+	/*strcat(buff, "View statistic \n");
+	sprintf(buff, "amount write calls %d \n", amount_write_calls);
+	sprintf(buff, "amount calls %d \n", amount_read_calls);
+	sprintf(buff, "amount converted chars %d \n", amount_converted_chars);
+	sprintf(buff, "amount chars finished converted %d \n", amount_chars_finished_converted);*/
+
+	sprintf(buff, "View statistic \n"
+		"amount write calls %d \n"
+		"amount calls %d \n"
+		"amount converted chars %d \n"
+		"amount chars finished converted %d \n"
+	 , amount_write_calls,amount_read_calls,
+	  amount_converted_chars,amount_chars_finished_converted);
+	strcpy(buf, buff);
+	return strlen(buf);
+}
+
+struct class_attribute class_attr_statisitc = {
+	.attr = { .name = "statistic", .mode = 0444 },
+	.show	= statistic_show,
+
+};
+
+static struct class *attr_class = 0;
+
+struct class_attribute class_attr_option = {
+	.attr = { .name = "option", .mode = 0666 },
+	.show	= option_show,
+	.store	= option_store
+};
+
+static struct proc_dir_entry *entstat;
+
+//init moudle
+static int mymodule_init(void)
+{
+	static int amount_read_calls = 0;
+	static int amount_write_calls = 0;
+	static int amount_converted_chars = 0;
+	static int amount_chars_finished_converted = 0;
+
+	int ret;
+
+	attr_class = class_create(THIS_MODULE, "base_class");
+	if (attr_class == NULL) {
+		pr_err("procfs_module_uppercase: error creating sysfs entry\n");
+		return -ENOMEM;
+	}
+
+	ret = class_create_file(attr_class, &class_attr_option);
+	if (ret) {
+		pr_err("sysfs_module_uppercase: error creating sysfs class attribute\n");
+		class_destroy(attr_class);
+		return ret;
+	}
+
+	ret = class_create_file(attr_class, &class_attr_statisitc);
+	if (ret) {
+		pr_err("sysfs_module_uppercase: error creating sysfs class attribute\n");
+		class_remove_file(attr_class, &class_attr_option);
+		class_destroy(attr_class);
+		return ret;
+	}
+
+	pr_info("sysfs_module_uppercase: module loaded\n");
+	return 0;
+}
+
+//exit module
+static void mymodule_exit(void)
+{
+	class_remove_file(attr_class, &class_attr_statisitc);
+	class_remove_file(attr_class, &class_attr_option);
+	class_destroy(attr_class);
+	pr_info("procfs_module_uppercase: module exited\n");
+}
+
+module_init(mymodule_init);
+module_exit(mymodule_exit);
+
+MODULE_AUTHOR("Vladyslav");
+MODULE_DESCRIPTION(" Use procfs kernel module for uppercase.");
+MODULE_LICENSE("GPL");
+MODULE_VERSION("0.1");