75 lines
1.4 KiB
C
75 lines
1.4 KiB
C
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#include <linux/miscdevice.h>
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#include <linux/fs.h>
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#include <linux/kernel.h>
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#include <linux/module.h>
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#include <linux/init.h>
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#define STUDENT_LOGIN "cchauvet"
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MODULE_LICENSE("GPL");
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static ssize_t misc_write(struct file *file, const char __user *buf,
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size_t len, loff_t *ppos)
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{
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char data[10];
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size_t len_red = 10 > len ? len : 10;
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if (copy_from_user(data, buf, len_red))
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return -EFAULT;
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if (strcmp(data, STUDENT_LOGIN))
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return -EINVAL;
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return len_red;
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}
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static ssize_t misc_read(struct file *file, char __user *buf,
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size_t count, loff_t *f_pos)
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{
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char data[] = STUDENT_LOGIN;
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size_t len = strlen(data);
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if(*f_pos > 0)
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return 0;
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if (copy_to_user(buf, data, len))
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return -EFAULT;
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*f_pos += len;
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return len;
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}
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const struct file_operations fops = {
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.write = misc_write,
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.read = misc_read,
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};
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static struct miscdevice misc_device = {
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.name = "fortytwo",
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.minor = MISC_DYNAMIC_MINOR,
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.fops = &fops,
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};
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static int __init module_start(void)
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{
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int error = misc_register(&misc_device);
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if (error) {
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pr_err("misc_register failed!!!\n");
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return error;
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}
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pr_info("misc_register init done!!!\n");
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return 0;
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}
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static void __exit module_end(void)
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{
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misc_deregister(&misc_device);
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pr_info("misc_register exit done!!!\n");
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}
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module_init(module_start)
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module_exit(module_end)
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