diff --git a/Module/tempMonitor.c b/Module/tempMonitor.c index 72600b3..3410c9d 100644 --- a/Module/tempMonitor.c +++ b/Module/tempMonitor.c @@ -1,120 +1,144 @@ -#include -#include -#include -#include -#include -#include +/************************************************************** + * Class:: CSC-415-01 Fall 2024 + * Name:: Uzair Hamed Mohammed + * Student ID:: 920142896 + * GitHub-Name:: gamersekofy + * Project:: Assignment 6 - Device Driver + * + * File:: tempMonitor.c + * + * Description:: This is a complex kernel module that retrieves CPU temperature + *data from /sys/class/thermal/thermal_zone*\/temp + * + **************************************************************/ + #include +#include +#include +#include +#include +#include +#include +#include #include #include -#include -#include -#include +#include #define DEVICE_NAME "temp_monitor" #define IOCTL_GET_TEMP _IOR('t', 1, int) + +// The CPU temperature will be accessed from thermal_zone0/temp #define TEMP_SENSOR_PATH "/sys/class/thermal/thermal_zone0/temp" #define BUF_LEN 100 static int major_number; -static struct class* temp_monitor_class = NULL; -static struct device* temp_monitor_device = NULL; +static struct class *temp_monitor_class = NULL; +static struct device *temp_monitor_device = NULL; static char temp_unit[BUF_LEN] = "C"; // Default unit is Celsius + +/* A similar flag exists in the test/user application. If it's detected that + * the user is in a virtual machine, a smulated temperature is returned */ static bool simulate_temp = false; -static int device_open(struct inode *inode, struct file *file) { - return 0; +static int device_open(struct inode *inode, struct file *file) { return 0; } + +static int device_release(struct inode *inode, struct file *file) { return 0; } + +static ssize_t device_read(struct file *file, char __user *buffer, size_t len, + loff_t *offset) { + int temp = 0; + char temp_str[BUF_LEN]; + struct file *f; + char *buf; + loff_t pos = 0; + bool is_simulated = false; + + // Check if the temperature file exists. If it doesn't, simulate the + // temperature. + f = filp_open(TEMP_SENSOR_PATH, O_RDONLY, 0); + if (IS_ERR(f)) { + printk(KERN_INFO "temp_monitor: Temperature file not found\n"); + is_simulated = true; + get_random_bytes(&temp, sizeof(temp)); + // Simulate a temperature between 10 and 50 degrees + temp = (temp % 40) + 10; + } else { + buf = kmalloc(16, GFP_KERNEL); + if (!buf) { + filp_close(f, NULL); + return -ENOMEM; + } + + // Read the temperature + kernel_read(f, buf, 16, &pos); + sscanf(buf, "%d", &temp); + // Convert to degrees Celsius + temp /= 1000; + filp_close(f, NULL); + kfree(buf); + } + + // Convert to desired unit + if (strcmp(temp_unit, "F") == 0) { + temp = temp * 9 / 5 + 32; + // Convert to Fahrenheit + } else if (strcmp(temp_unit, "K") == 0) { + temp += 273; + // Convert to Kelvin + } + + snprintf(temp_str, BUF_LEN, "%d %s%s\n", temp, temp_unit, + is_simulated ? " (simulated temperature)" : ""); + + // Copy the result to user-space + if (copy_to_user(buffer, temp_str, strlen(temp_str) + 1)) { + return -EFAULT; + } + + return strlen(temp_str) + 1; } -static int device_release(struct inode *inode, struct file *file) { - return 0; +static ssize_t device_write(struct file *file, const char __user *buffer, + size_t len, loff_t *offset) { + char msg[BUF_LEN]; + + // Check if input too long + if (len > BUF_LEN - 1) { + return -EINVAL; + } + + if (copy_from_user(msg, buffer, len)) { + return -EFAULT; + } + msg[len] = '\0'; + + if (strcmp(msg, "simulate") == 0) { + simulate_temp = true; + } else { + simulate_temp = false; + strncpy(temp_unit, msg, BUF_LEN - 1); + } + + printk(KERN_INFO "temp_monitor: Write operation: %s\n", msg); + + return len; } -static ssize_t device_read(struct file *file, char __user *buffer, size_t len, loff_t *offset) { +static long device_ioctl(struct file *file, unsigned int cmd, + unsigned long arg) { + switch (cmd) { + case IOCTL_GET_TEMP: { int temp = 0; - char temp_str[BUF_LEN]; - struct file *f; - char *buf; - loff_t pos = 0; - bool is_simulated = false; - - // Check if the temperature file exists - f = filp_open(TEMP_SENSOR_PATH, O_RDONLY, 0); - if (IS_ERR(f)) { - printk(KERN_INFO "temp_monitor: Temperature file not found\n"); - is_simulated = true; - get_random_bytes(&temp, sizeof(temp)); - temp = (temp % 40) + 10; // Simulate a temperature between 10 and 50 degrees - } else { - buf = kmalloc(16, GFP_KERNEL); - if (!buf) { - filp_close(f, NULL); - return -ENOMEM; - } - - // Read the temperature - kernel_read(f, buf, 16, &pos); - sscanf(buf, "%d", &temp); - temp /= 1000; // Convert to degrees Celsius - filp_close(f, NULL); - kfree(buf); + // Retrieve the temperature data + if (copy_to_user((int *)arg, &temp, sizeof(temp))) { + return -EACCES; } - - // Convert to desired unit - if (strcmp(temp_unit, "F") == 0) { - temp = temp * 9 / 5 + 32; // Convert to Fahrenheit - } else if (strcmp(temp_unit, "K") == 0) { - temp += 273; // Convert to Kelvin - } - - snprintf(temp_str, BUF_LEN, "%d %s%s\n", temp, temp_unit, is_simulated ? " (simulated temperature)" : ""); - - // Copy the result to user-space - if (copy_to_user(buffer, temp_str, strlen(temp_str) + 1)) { - return -EFAULT; - } - - return strlen(temp_str) + 1; -} - -static ssize_t device_write(struct file *file, const char __user *buffer, size_t len, loff_t *offset) { - char msg[BUF_LEN]; - - if (len > BUF_LEN - 1) { - return -EINVAL; // Input too long - } - - if (copy_from_user(msg, buffer, len)) { - return -EFAULT; - } - msg[len] = '\0'; // Null-terminate the string - - if (strcmp(msg, "simulate") == 0) { - simulate_temp = true; - } else { - simulate_temp = false; - strncpy(temp_unit, msg, BUF_LEN - 1); - } - - printk(KERN_INFO "temp_monitor: Write operation: %s\n", msg); - - return len; -} - -static long device_ioctl(struct file *file, unsigned int cmd, unsigned long arg) { - switch (cmd) { - case IOCTL_GET_TEMP: { - int temp = 0; - // Retrieve the temperature data here - if (copy_to_user((int *)arg, &temp, sizeof(temp))) { - return -EACCES; - } - break; - } - default: - return -EINVAL; - } - return 0; + break; + } + default: + return -EINVAL; + } + return 0; } static struct file_operations fops = { @@ -126,39 +150,41 @@ static struct file_operations fops = { }; static int __init temp_monitor_init(void) { - major_number = register_chrdev(0, DEVICE_NAME, &fops); - if (major_number < 0) { - printk(KERN_ALERT "temp_monitor: Failed to register a major number\n"); - return major_number; - } - temp_monitor_class = class_create(THIS_MODULE->name); // Updated this line - if (IS_ERR(temp_monitor_class)) { - unregister_chrdev(major_number, DEVICE_NAME); - printk(KERN_ALERT "temp_monitor: Failed to register device class\n"); - return PTR_ERR(temp_monitor_class); - } - temp_monitor_device = device_create(temp_monitor_class, NULL, MKDEV(major_number, 0), NULL, DEVICE_NAME); - if (IS_ERR(temp_monitor_device)) { - class_destroy(temp_monitor_class); - unregister_chrdev(major_number, DEVICE_NAME); - printk(KERN_ALERT "temp_monitor: Failed to create the device\n"); - return PTR_ERR(temp_monitor_device); - } - printk(KERN_INFO "temp_monitor: Device initialized with major number %d\n", major_number); - return 0; + major_number = register_chrdev(0, DEVICE_NAME, &fops); + if (major_number < 0) { + printk(KERN_ALERT "temp_monitor: Failed to register a major number\n"); + return major_number; + } + temp_monitor_class = class_create(THIS_MODULE->name); // Updated this line + if (IS_ERR(temp_monitor_class)) { + unregister_chrdev(major_number, DEVICE_NAME); + printk(KERN_ALERT "temp_monitor: Failed to register device class\n"); + return PTR_ERR(temp_monitor_class); + } + temp_monitor_device = device_create( + temp_monitor_class, NULL, MKDEV(major_number, 0), NULL, DEVICE_NAME); + if (IS_ERR(temp_monitor_device)) { + class_destroy(temp_monitor_class); + unregister_chrdev(major_number, DEVICE_NAME); + printk(KERN_ALERT "temp_monitor: Failed to create the device\n"); + return PTR_ERR(temp_monitor_device); + } + printk(KERN_INFO "temp_monitor: Device initialized with major number %d\n", + major_number); + return 0; } static void __exit temp_monitor_exit(void) { - device_destroy(temp_monitor_class, MKDEV(major_number, 0)); - class_unregister(temp_monitor_class); - class_destroy(temp_monitor_class); - unregister_chrdev(major_number, DEVICE_NAME); - printk(KERN_INFO "temp_monitor: Device removed\n"); + device_destroy(temp_monitor_class, MKDEV(major_number, 0)); + class_unregister(temp_monitor_class); + class_destroy(temp_monitor_class); + unregister_chrdev(major_number, DEVICE_NAME); + printk(KERN_INFO "temp_monitor: Device removed\n"); } module_init(temp_monitor_init); module_exit(temp_monitor_exit); -MODULE_LICENSE("GPL"); -MODULE_AUTHOR("Your Name"); -MODULE_DESCRIPTION("A CPU Temperature Monitoring Kernel Module"); +MODULE_AUTHOR("Uzair Hamed Mohammed"); +MODULE_DESCRIPTION( + "An Awesome and Super Complex CPU Temperature Monitoring Kernel Module"); diff --git a/Test/Mohammed_UzairHamed_HW6_main.c b/Test/Mohammed_UzairHamed_HW6_main.c index bc40b09..2a76702 100644 --- a/Test/Mohammed_UzairHamed_HW6_main.c +++ b/Test/Mohammed_UzairHamed_HW6_main.c @@ -1,8 +1,23 @@ -#include +/************************************************************** + * Class:: CSC-415-01 Fall 2024 + * Name:: Uzair Hamed Mohammed + * Student ID:: 920142896 + * GitHub-Name:: gamersekofy + * Project:: Assignment 6 - Device Driver + + * + * File:: Mohammed_UzairHamed_HW6_main.c + * + * Description:: This file contains a very easy to use and application that + reads and writes data + * to the tempMonitor kernel module. + **************************************************************/ + #include -#include -#include +#include #include +#include +#include #define IOCTL_GET_TEMP _IOR('t', 1, int) @@ -10,62 +25,67 @@ #define RESET "\033[0m" void read_temp(int fd, const char *unit) { - char buffer[128]; - ssize_t bytes_read; - int is_simulated = 0; + char buffer[128]; + ssize_t bytes_read; - // Writing the desired unit or "simulate" command to the device - ssize_t bytes_written = write(fd, unit, strlen(unit)); - if (bytes_written < 0) { - return; // Exit the function if writing fails + /* Declare this variable because /sys/class/thermal/thermal_zonex/ isn't + available on virtual machines. In case of a virtual machine, set this flag + that will make the kernel module return a simulated temperature. */ + int is_simulated = 0; + + // Writing the desired unit or "simulate" command to the device + ssize_t bytes_written = write(fd, unit, strlen(unit)); + if (bytes_written < 0) { + return; + } + + // Reading the temperature + bytes_read = read(fd, buffer, sizeof(buffer)); + if (bytes_read < 0) { + return; + } else { + buffer[bytes_read] = '\0'; + + // Check if the temperature is simulated. If it is, set flag here. + if (strstr(buffer, "(simulated temperature)") != NULL) { + is_simulated = 1; } - // Reading the temperature - bytes_read = read(fd, buffer, sizeof(buffer)); - if (bytes_read < 0) { - return; // Exit the function if reading fails + if (is_simulated) { + printf(GREEN "CPU Temperature\n--- -----------\n" RESET "%s\n", buffer); } else { - buffer[bytes_read] = '\0'; // Null-terminate the string - - // Check if the temperature is simulated - if (strstr(buffer, "(simulated temperature)") != NULL) { - is_simulated = 1; - } - - if (is_simulated) { - printf(GREEN "CPU Temperature\n--- -----------\n" RESET "%s\n", buffer); - } else { - printf(GREEN "CPU Temperature\n--- -----------\n" RESET "%s\n", buffer); - } + printf(GREEN "CPU Temperature\n--- -----------\n" RESET "%s\n", buffer); } + } } int main() { - int fd; - char choice; + int fd; + char choice; - fd = open("/dev/temp_monitor", O_RDWR); - if (fd < 0) { - perror("Failed to open the device"); - return -1; - } + // Access kernel module here + fd = open("/dev/temp_monitor", O_RDWR); + if (fd < 0) { + perror("Failed to open the device"); + return -1; + } - // Ask the user for the preferred temperature unit - printf("Choose temperature unit (C/F): "); - scanf(" %c", &choice); - - if (choice == 'C' || choice == 'c') { - // Requesting the temperature in Celsius - read_temp(fd, "C"); - } else if (choice == 'F' || choice == 'f') { - // Requesting the temperature in Fahrenheit - read_temp(fd, "F"); - } else { - printf("Invalid choice. Please choose 'C' or 'F'.\n"); - close(fd); - return -1; - } + // Ask the user for the preferred temperature unit + printf("Choose temperature unit (C/F): "); + scanf(" %c", &choice); + if (choice == 'C' || choice == 'c') { + // Request the kernel module provide temperature in Celsius + read_temp(fd, "C"); + } else if (choice == 'F' || choice == 'f') { + // Request the kernel module provide the temperature in Fahrenheit + read_temp(fd, "F"); + } else { + printf("Invalid choice. Please choose 'C' or 'F'.\n"); close(fd); - return 0; + return -1; + } + + close(fd); + return 0; }