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#include <linux/init.h>
#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/file.h>
#include <linux/fs.h>
#include <linux/sched.h>
#include <linux/syscalls.h>
#include <linux/time.h>
#include <asm/unistd.h>
#include <asm/current.h>
#include <linux/debugfs.h>
#include <linux/seq_file.h>
MODULE_LICENSE("GPL");
MODULE_AUTHOR("Olivier Blin <blino@mandriva.com>");
struct opened_file {
struct list_head s_list;
char *name;
};
unsigned long **sys_call_table;
static struct dentry *dbg_dir;
static struct dentry *dbg_file;
struct opened_file bp;
DECLARE_MUTEX(files_mutex);
ssize_t (*read)(int f, const void *buf, size_t n);
long (*open)(const char __user *filename, int flags, int mode);
static void *profile_seq_start(struct seq_file *file, loff_t *pos)
{
struct list_head *p;
loff_t l = *pos;
down(&files_mutex);
list_for_each(p, &bp.s_list)
if (!l--)
return list_entry(p, struct opened_file, s_list);
return NULL;
}
static void *profile_seq_next(struct seq_file *file, void *v, loff_t *pos)
{
struct list_head *p = ((struct opened_file *)v)->s_list.next;
(*pos)++;
return p == &bp.s_list ? NULL : list_entry(p, struct opened_file, s_list);
}
static void profile_seq_stop(struct seq_file *file, void *v)
{
up(&files_mutex);
}
static int profile_seq_show(struct seq_file *file, void *v)
{
seq_printf(file, ((struct opened_file *)v)->name);
seq_putc(file, '\n');
return 0;
}
static struct seq_operations profile_seq_ops = {
.start = profile_seq_start,
.next = profile_seq_next,
.stop = profile_seq_stop,
.show = profile_seq_show,
};
static int profile_open(struct inode *inode, struct file *file)
{
return seq_open(file, &profile_seq_ops);
}
static struct file_operations profile_fops = {
.owner = THIS_MODULE,
.open = profile_open,
.read = seq_read,
.llseek = seq_lseek,
.release = seq_release
};
/* Borrowed from
* http://downloads.securityfocus.com/downloads/scprint.tar.gz
* http://www.gnome.org/~lcolitti/gnome-startup/linux-iolog/readlog.c
* http://kerneltrap.org/node/5793
*/
unsigned long **find_sys_call_table(void) {
unsigned long *p;
for (p = (unsigned long *)((init_mm.end_code + 4) & 0xfffffffc);
p < (unsigned long *)init_mm.end_data; p++) {
if (p[__NR_close] == (unsigned long) sys_close){
return (unsigned long **) p;
}
}
return NULL;
}
void addfilename(const char *filename) {
struct opened_file *f;
f = kmalloc(sizeof(struct opened_file), GFP_KERNEL);
if (f == NULL)
return;
f->name = kmalloc(strlen(filename) + 1, GFP_KERNEL);
if (f->name == NULL)
return;
strcpy(f->name, filename);
INIT_LIST_HEAD(&f->s_list);
printk(KERN_INFO "locking while adding: %s\n", filename);
down(&files_mutex);
list_add_tail(&f->s_list, &bp.s_list);
up(&files_mutex);
printk(KERN_INFO "unlocking after adding: %s\n", filename);
}
long loggingopen(const char __user *filename, int flags, int mode) {
struct file *f = NULL;
long fd;
fd = open(filename, flags, mode);
printk(KERN_INFO "opening fd %ld for %s\n", fd, filename);
if(fd > 0 && current) {
f = current->files->fd_array[fd];
if(f && f->f_dentry && f->f_vfsmnt) {
char tmpname[PATH_MAX];
char *name = d_path(f->f_dentry, f->f_vfsmnt, tmpname, sizeof(tmpname) - 1);
if (name)
addfilename(name);
}
}
return fd;
}
ssize_t loggingread(int fd, const void *buf, size_t n) {
struct file *f = NULL;
char *name = NULL;
loff_t offset = 0;
struct timeval tv;
char tmpname[256];
do_gettimeofday(&tv);
if(current)
f = current->files->fd_array[fd];
printk(KERN_DEBUG "READ: f: %p\n", f);
if(f)
offset = f->f_pos;
if (f)
printk(KERN_DEBUG "READ: d_entry: %p, vfsmnt: %p\n", f->f_dentry, f->f_vfsmnt);
if(f && f->f_dentry && f->f_vfsmnt) {
printk(KERN_DEBUG "READ: d_path\n");
name = d_path(f->f_dentry, f->f_vfsmnt, tmpname, sizeof(tmpname) - 1);
if (name)
addfilename(name);
}
printk(KERN_DEBUG "READ: %lu.%lu (%s/%d) %Lu %s\n",
tv.tv_sec, tv.tv_usec,
current ? current->comm : "?",
current ? current->pid : 0,
offset,
name ? name : "<no dentry>"
);
return read(fd, buf, n);
}
static int __init readlog_init(void) {
sys_call_table = find_sys_call_table();
/* compare with grep sys_call_table /boot/System.map */
printk(KERN_INFO "Found sys_call_table at %p\n", sys_call_table);
open = (void *) (sys_call_table[__NR_open]);
sys_call_table[__NR_open] = (void *) loggingopen;
read = (void *) (sys_call_table[__NR_read]);
/* sys_call_table[__NR_read] = (void *) loggingread; */
dbg_dir = debugfs_create_dir("dmc", NULL);
if (IS_ERR(dbg_dir)) {
printk(KERN_NOTICE ": debugfs is not available\n");
return -ENODEV;
}
if (dbg_dir == NULL) {
printk(KERN_NOTICE ": unable to create usbmon directory\n");
return -ENODEV;
}
dbg_file = debugfs_create_file("bp", 0600, dbg_dir, NULL, &profile_fops);
if (dbg_file == NULL) {
debugfs_remove(dbg_dir);
return -ENODEV;
}
INIT_LIST_HEAD(&bp.s_list);
return 0;
}
static void __exit readlog_exit(void) {
debugfs_remove(dbg_file);
debugfs_remove(dbg_dir);
sys_call_table[__NR_open] = (void *) open;
sys_call_table[__NR_read] = (void *) read;
printk(KERN_INFO "sys_call_table restored\n");
}
module_init(readlog_init);
module_exit(readlog_exit);
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