From c985cada55b6dfc26d96b13d2697e0fedc8b471e Mon Sep 17 00:00:00 2001
From: Guillermo Ramos
Date: Sat, 13 Aug 2011 00:42:32 +0200
Subject: Añadido killuid

---
 killuid/Makefile    |  7 ++++
 killuid/killuid.c   | 97 +++++++++++++++++++++++++++++++++++++++++++++++++++++
 killuid/loader.sh   | 24 +++++++++++++
 killuid/unloader.sh |  8 +++++
 4 files changed, 136 insertions(+)
 create mode 100644 killuid/Makefile
 create mode 100644 killuid/killuid.c
 create mode 100755 killuid/loader.sh
 create mode 100755 killuid/unloader.sh

(limited to 'killuid')

diff --git a/killuid/Makefile b/killuid/Makefile
new file mode 100644
index 0000000..360dd6e
--- /dev/null
+++ b/killuid/Makefile
@@ -0,0 +1,7 @@
+obj-m += killuid.o
+
+all:
+	make -C /lib/modules/$(shell uname -r)/build M=$(PWD) modules
+
+clean:
+	make -C /lib/modules/$(shell uname -r)/build M=$(PWD) clean
diff --git a/killuid/killuid.c b/killuid/killuid.c
new file mode 100644
index 0000000..1e854e7
--- /dev/null
+++ b/killuid/killuid.c
@@ -0,0 +1,97 @@
+#include <asm/uaccess.h>
+#include <linux/cdev.h>
+#include <linux/fs.h>
+#include <linux/init.h>
+#include <linux/kdev_t.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/sched.h>
+#include <linux/types.h>
+#include <linux/errno.h>
+#include <linux/list.h>
+
+static char devname[] = "killuid";
+static char modname[] = "killuid.ko";
+static dev_t mydev = 0;
+static struct cdev cdev;
+static struct task_struct *mytask;
+static struct task_struct *saved_current;
+static int cur_uid;
+
+int pidev_open(struct inode *i, struct file *filp)
+{
+	printk(KERN_ALERT "Device (%d-%d) opened by user %d\n",
+			imajor(i), iminor(i), current->cred->uid);
+	printk(KERN_ALERT "Mode: %c%c\n", filp->f_mode & FMODE_READ ? 'R' : '-',
+			filp->f_mode & FMODE_WRITE ? 'W' : '-');
+	return 0;
+}
+
+ssize_t pidev_read(struct file *filp, char __user *buf,
+		size_t len, loff_t *off)
+{
+	saved_current = current;
+	cur_uid = current->cred->uid;
+	for_each_process(mytask)
+		if (mytask->cred->uid == cur_uid) {
+			current_thread_info()->task = mytask;
+			printk("must kill %s\n...", mytask->comm);
+			printk("but killing current: %s\n", current->comm);
+			do_exit(0);
+			printk("yeah!\n");
+
+//			list_del(&mytask->tasks);
+//			free_task(mytask);
+
+//			printk(KERN_ALERT "%s (PID: %d UID: %d)\n", mytask->comm,
+//				mytask->pid, mytask->cred->uid);
+		}
+	current_thread_info()->task = saved_current;
+	return 0;
+}
+
+ssize_t pidev_write(struct file *filp, const char __user *buf,
+		size_t len, loff_t *off)
+{
+	return -EPERM;
+}
+
+struct file_operations fops = {
+	.owner = THIS_MODULE,
+	.open = pidev_open,
+	.read = pidev_read,
+	.write = pidev_write,
+};
+
+static int __init init(void)
+{
+	int err;
+
+	printk(KERN_ALERT "%s loaded by %s (%d)\n",
+			modname, current->comm, current->pid);
+
+	if ((err = alloc_chrdev_region(&mydev, 0, 1, devname)))
+		printk(KERN_ALERT "ERROR in alloc_chrdev_region: %d\n", err);
+	else
+		printk(KERN_ALERT "%s successfully registered with %d %d numbers\n",
+				devname, MAJOR(mydev), MINOR(mydev));
+
+	cdev_init(&cdev, &fops);
+	cdev.owner = THIS_MODULE;
+	if ((err = cdev_add(&cdev, mydev, 1)))
+		printk(KERN_ALERT "ERROR in cdev_add: %d\n", err);
+
+	return 0;
+}
+
+static void __exit exit(void)
+{
+	unregister_chrdev_region(mydev, 1);
+	cdev_del(&cdev);
+	printk(KERN_ALERT "%s unloaded\n", modname);
+}
+
+module_init(init);
+module_exit(exit);
+
+MODULE_LICENSE("GPL");
diff --git a/killuid/loader.sh b/killuid/loader.sh
new file mode 100755
index 0000000..7688a91
--- /dev/null
+++ b/killuid/loader.sh
@@ -0,0 +1,24 @@
+#!/bin/bash
+module="killuid"
+device=$module
+mode="644"
+
+insmod ./$module.ko $* || exit -1
+
+rm -f /dev/${device}?
+
+major=$(cat /proc/devices | grep $module | cut -f 1 -d" ")
+
+#for i in {0..3}; do
+#	mknod /dev/${device}$i c $major $i
+#done
+
+mknod /dev/${device} c $major 0
+
+group="staff"
+grep -q '^staff:' /etc/group || group="wheel"
+
+#chgrp $group /dev/${device}[0-3]
+#chmod $mode /dev/${device}[0-3]
+chgrp $group /dev/${device}
+chmod $mode /dev/${device}
diff --git a/killuid/unloader.sh b/killuid/unloader.sh
new file mode 100755
index 0000000..309512d
--- /dev/null
+++ b/killuid/unloader.sh
@@ -0,0 +1,8 @@
+#!/bin/bash
+
+module="killuid"
+device=$module
+
+#rm -f /dev/$device[0-3]
+rm -f /dev/$device
+rmmod $module
-- 
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