From 2a443c48bde3ad11c17e31cbf66aff9e04acc7f2 Mon Sep 17 00:00:00 2001
From: fdai7354 <alan.muhemad@informatik.hs-fulda.de>
Date: Wed, 12 Feb 2025 11:30:31 +0100
Subject: [PATCH] CRC32 added
---
Kernel/kernel_M.c | 17 +++++++++++++++++
1 file changed, 17 insertions(+)
diff --git a/Kernel/kernel_M.c b/Kernel/kernel_M.c
index fcd60ec..67a1fa5 100644
--- a/Kernel/kernel_M.c
+++ b/Kernel/kernel_M.c
@@ -6,6 +6,7 @@
#include <linux/cdev.h> // For cdev
#include <linux/device.h> // For device_create, class_create
#include <linux/slab.h> // For kmalloc, kfree
+#include <linux/crc32.h> // Include CRC32
#define DEVICE_NAME "packet_receiver"
#define CLASS_NAME "packet_class"
@@ -51,6 +52,11 @@ static struct file_operations fops = {
.release = packet_release, //not used
};
+// CRC32 Calculation Function
+static u32 calculate_crc32(const char *data, size_t len) {
+ return crc32(0, data, len);
+}
+
// ====================== Device Open ======================
static int packet_open(struct inode *inode, struct file *file) {
printk(KERN_INFO "packet_receiver: Device opened.\n");
@@ -124,6 +130,17 @@ static ssize_t packet_write(struct file *filp, const char __user *buf, size_t le
printk(KERN_INFO " value_id_1=%d value_1=\"%s\"\n", value_id_1, value_str_1);
printk(KERN_INFO " crc=0x%lX\n", crc_val);
+ // Calculate CRC32 for the received data excluding the CRC field
+ size_t crc_len = strrchr(recv_buffer, 'C') - recv_buffer;
+ u32 calculated_crc = calculate_crc32(recv_buffer, crc_len);
+
+ if (calculated_crc == received_crc) {
+ printk(KERN_INFO "packet_receiver: CRC check passed!\n");
+ } else {
+ printk(KERN_ERR "packet_receiver: CRC mismatch! Expected: 0x%08X, Received: 0x%08lX\n",
+ calculated_crc, received_crc);
+ }
+
// Return the number of bytes written
return len;
}
--
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