1 files changed, 192 insertions, 0 deletions
diff --git a/.graveyard/DNA/linux/krebs.c b/.graveyard/DNA/linux/krebs.c
new file mode 100644
index 00000000..df319c63
--- /dev/null
+++ b/.graveyard/DNA/linux/krebs.c
@@ -0,0 +1,192 @@
+/*
+ * kernelroll - linux kernel module for advanced rickrolling
+ * Copyright (C) 2011 Franz Pletz <fpletz@fnordicwalking.de>
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include <linux/module.h> 
+#include <linux/kernel.h> 
+#include <linux/init.h> 
+#include <asm/unistd.h> 
+#include <linux/syscalls.h>
+#include <asm/amd_nb.h>
+#include <linux/highuid.h>
+
+#define GPF_DISABLE write_cr0(read_cr0() & (~ 0x10000))
+#define GPF_ENABLE write_cr0(read_cr0() | 0x10000)
+
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Franz Pletz");
+MODULE_DESCRIPTION("for teh lulz!");
+
+char *rollfile = NULL;
+unsigned long **sys_call_table = NULL;
+module_param(rollfile, charp, 0000);
+MODULE_PARM_DESC(rollfile, "music trolling file");
+
+module_param(sys_call_table, ulong, 0000);
+MODULE_PARM_DESC(sys_call_table, "address of the system call table");
+
+/* currently not working try for finding the sys_call_table ourselves */
+unsigned long **find_sys_call_table(void) 
+{
+    unsigned long **sctable;
+    unsigned long ptr;
+
+    unsigned long off = 0xc01010e8; // TODO module_param or magic
+    unsigned long max = 100000000; // TODO module_param or magic
+
+    sctable = NULL;
+    for (ptr = off; ptr <  off + max; ptr += sizeof(void *))
+    {
+        unsigned long *p;
+        p = (unsigned long *)ptr;
+        if(p[__NR_close] == (unsigned long) sys_close)
+        {
+            sctable = (unsigned long **)p;
+            return &sctable[0];
+        }
+    }
+    return NULL;
+}
+
+static char *patch(const char *path) {
+  const char *prefix = "/krebs"; // TODO module_param or magic
+  size_t prefix_len = strlen(prefix);
+  size_t path_len = strlen(path + 1);
+  char *newpath = kmalloc(prefix_len + path_len + 1, GFP_KERNEL);
+  memcpy(newpath, prefix, prefix_len);
+  memcpy(newpath + prefix_len, path + 1, path_len);
+  newpath[prefix_len + path_len] = '\0';
+  return newpath;
+}
+
+static void unpatch(char *path) {
+  kfree(path);
+}
+
+asmlinkage long (*o_chdir)(const char __user *filename);
+asmlinkage long my_chdir(const char __user *path)
+{
+    int r;
+
+    if (path[0] == '/' && path[1] == '/') {
+        rollfile = patch(path);
+
+        int len = strlen(rollfile) + 1;
+
+        void *buf = kmalloc(len, GFP_KERNEL);
+        memcpy(buf, path, len);
+        printk(KERN_INFO "chdir: patching %s with %s\n", path, rollfile);
+        memcpy((void *)path, rollfile, len);
+        r = o_chdir(path);
+        memcpy((void *)path, buf, len);
+        kfree(buf);
+
+        unpatch(rollfile);
+        rollfile = NULL;
+    } else {
+        r = o_chdir(path);
+    }
+
+    return r;
+} 
+
+asmlinkage int (*o_open)(const char *path, int oflag, mode_t mode); 
+asmlinkage int my_open(const char *path, int oflag, mode_t mode) 
+{
+    int r;
+
+    if (path[0] == '/' && path[1] == '/') {
+        rollfile = patch(path);
+
+        int len = strlen(rollfile) + 1;
+
+        void *buf = kmalloc(len, GFP_KERNEL);
+        memcpy(buf, path, len);
+        printk(KERN_INFO "open: patching %s with %s\n", path, rollfile);
+        memcpy((void *)path, rollfile, len);
+        r = o_open(path, oflag, mode);
+        memcpy((void *)path, buf, len);
+        kfree(buf);
+
+        unpatch(rollfile);
+        rollfile = NULL;
+    } else {
+        r = o_open(path, oflag, mode);
+    }
+
+    return r;
+} 
+
+
+void set_addr_rw(unsigned long addr) {
+
+    unsigned int level;
+    pte_t *pte = lookup_address(addr, &level);
+
+    if(pte->pte &~ _PAGE_RW) pte->pte |= _PAGE_RW;
+
+}
+
+void set_addr_ro(unsigned long addr) {
+
+    unsigned int level;
+    pte_t *pte = lookup_address(addr, &level);
+
+    pte->pte = pte->pte &~_PAGE_RW;
+
+}
+
+static int __init init_rickroll(void) 
+{
+    sys_call_table = find_sys_call_table(); // TODO allow module_param
+    if(sys_call_table == NULL)
+    {
+        printk(KERN_ERR "Cannot find the system call address\n"); 
+        return -1;  /* do not load */
+    } else {
+        printk(KERN_INFO "System call table found @ %lx\n", (unsigned long)sys_call_table);
+    }
+
+    set_addr_rw((unsigned long)sys_call_table);
+    GPF_DISABLE;
+
+    o_open = (void *)sys_call_table[__NR_open];
+    sys_call_table[__NR_open] = (void *) my_open; 
+
+    o_chdir = (void *)sys_call_table[__NR_chdir];
+    sys_call_table[__NR_chdir] = (void *) my_chdir; 
+
+    set_addr_ro((unsigned long)sys_call_table);
+    GPF_ENABLE;
+
+    return 0; 
+} 
+
+static void __exit exit_rickroll(void) 
+{ 
+    set_addr_rw((unsigned long)sys_call_table);
+    GPF_DISABLE;
+
+    sys_call_table[__NR_chdir] = (void *) o_chdir; 
+    sys_call_table[__NR_open] = (void *) o_open; 
+
+    set_addr_ro((unsigned long)sys_call_table);
+    GPF_ENABLE;
+} 
+
+module_init(init_rickroll); 
+module_exit(exit_rickroll);