#!/usr/bin/env python

################################################################
# This is a command line interpreter used to edit
# cowrie file system pickle files.
#
# It is intended to mimic a basic bash shell and supports
# relative file references.
#
# Do not use to build a complete file system. Use:
# /opt/cowrie/bin/createfs
#
# Instead it should be used to edit existing file systems
# such as the default: /opt/cowrie/data/fs.pickle.
#
# Donovan Hubbard
# Douglas Hubbard
# March 2013
################################################################

import cmd
import copy
import os
import pickle
import sys
import time
from stat import *

A_NAME, A_TYPE, A_UID, A_GID, A_SIZE, A_MODE, A_CTIME, A_CONTENTS, A_TARGET, A_REALFILE = list(range(0, 10))
T_LINK, T_DIR, T_FILE, T_BLK, T_CHR, T_SOCK, T_FIFO = list(range(0, 7))


def getpath(fs, path):
    cwd = fs
    for part in path.split('/'):
        if not len(part):
            continue
        ok = False
        for c in cwd[A_CONTENTS]:
            if c[A_NAME] == part:
                cwd = c
                ok = True
                break
        if not ok:
            raise Exception('File not found')
    return cwd


def exists(fs, path):
    try:
        getpath(fs, path)
        return True
    except Exception as e:
        if str(e) == 'File not found':
            return False
        else:
            raise Exception(e)


def is_directory(fs, path):
    """
    Returns whether or not the file at 'path' is a directory

    :param fs:
    :param path:
    :return:
    """
    file = getpath(fs, path)
    if file[A_TYPE] == T_DIR:
        return True
    else:
        return False


def resolve_reference(pwd, relativeReference):
    """
    Used to resolve a current working directory and a relative reference into an absolute file reference.
    """

    tempPath = os.path.join(pwd, relativeReference)
    absoluteReference = os.path.normpath(tempPath)

    return absoluteReference


class fseditCmd(cmd.Cmd):

    def __init__(self, pickle_file_path):
        cmd.Cmd.__init__(self)

        if not os.path.isfile(pickle_file_path):
            print(("File %s does not exist." % pickle_file_path))
            sys.exit(1)

        try:
            pickle_file = open(pickle_file_path, 'rb')
        except IOError as e:
            print(("Unable to open file %s" % pickle_file_path))
            sys.exit(1)

        try:
            self.fs = pickle.load(pickle_file)
        except:
            print((("Unable to load file '%s'. " + \
                    "Are you sure it is a valid pickle file?") % \
                   (pickle_file_path,)))
            sys.exit(1)

        self.pickle_file_path = pickle_file_path

        # get the name of the file so we can display it as the prompt
        path_parts = pickle_file_path.split('/')
        self.fs_name = path_parts[-1]

        self.update_pwd("/")

        self.intro = "\nKippo/Cowrie file system interactive editor\n" + \
                     "Donovan Hubbard, Douglas Hubbard, March 2013\n" + \
                     "Type 'help' for help\n"

    def save_pickle(self):
        """
        saves the current file system to the pickle
        :return:
        """
        try:
            pickle.dump(self.fs, open(self.pickle_file_path, 'wb'))
        except Exception as e:
            print((("Unable to save pickle file '%s'. " + \
                    "Are you sure you have write access?") % \
                   (self.pickle_file_path,)))
            print(str(e))
            sys.exit(1)

    def do_exit(self, args):
        """
        Exits the file system editor
        """
        return True

    def do_EOF(self, args):
        """
        The escape character ctrl+d exits the session
        """
        # exiting from the do_EOF method does not create a newline automatically
        # so we add it manually
        print()
        return True

    def do_ls(self, args):
        """
        Prints the contents of a directory, use ls -l to list in long format
        Prints the current directory if no arguments are specified
        """

        longls = False

        if args.startswith('-l'):
            longls = True
            args = args[3:]

        if not len(args):
            path = self.pwd
        else:
            path = resolve_reference(self.pwd, args)

        if exists(self.fs, path) == False:
            print(("ls: cannot access %s: No such file or directory" % (path,)))
            return

        if is_directory(self.fs, path) == False:
            print(("ls: %s is not a directory" % (path,)))
            return

        cwd = getpath(self.fs, path)
        files = cwd[A_CONTENTS];
        files.sort()

        largest = 0
        if len(files):
            largest = max([x[A_SIZE] for x in files])

        for file in files:
            if not longls:
                if file[A_TYPE] == T_DIR:
                    print((file[A_NAME] + '/'))
                else:
                    print((file[A_NAME]))
                continue

            perms = ['-'] * 10

            if file[A_MODE] & S_IRUSR: perms[1] = 'r'
            if file[A_MODE] & S_IWUSR: perms[2] = 'w'
            if file[A_MODE] & S_IXUSR: perms[3] = 'x'

            if file[A_MODE] & S_IRGRP: perms[4] = 'r'
            if file[A_MODE] & S_IWGRP: perms[5] = 'w'
            if file[A_MODE] & S_IXGRP: perms[6] = 'x'

            if file[A_MODE] & S_IROTH: perms[7] = 'r'
            if file[A_MODE] & S_IWOTH: perms[8] = 'w'
            if file[A_MODE] & S_IXOTH: perms[9] = 'x'

            linktarget = ''

            if file[A_TYPE] == T_DIR:
                perms[0] = 'd'
            elif file[A_TYPE] == T_LINK:
                perms[0] = 'l'
                linktarget = ' -> %s' % (file[A_TARGET],)

            perms = ''.join(perms)
            ctime = time.localtime(file[A_CTIME])
            uid = file[A_UID]
            gid = file[A_GID]

            if uid == 0:
                uid = 'root'
            else:
                uid = str(uid).rjust(4)

            if gid == 0:
                gid = 'root'
            else:
                gid = str(gid).rjust(4)

            print(('%s 1 %s %s %s %s %s%s' % \
                   (perms,
                    uid,
                    gid,
                    str(file[A_SIZE]).rjust(len(str(largest))),
                    time.strftime('%Y-%m-%d %H:%M', ctime),
                    file[A_NAME],
                    linktarget)))

    def update_pwd(self, directory):
        self.pwd = directory
        self.prompt = self.fs_name + ":" + self.pwd + "$ "

    def do_cd(self, args):
        """
        Changes the current directory.\nUsage: cd <target directory>
        """

        # count  the number of arguments
        # 1 or more arguments: changes the directory to the first arg
        #                      and ignores the rest
        # 0 arguments: changes to '/'
        arguments = args.split()

        if not len(arguments):
            self.update_pwd("/")
        else:
            relative_dir = arguments[0]
            target_dir = resolve_reference(self.pwd, relative_dir)

            if exists(self.fs, target_dir) == False:
                print(("cd: %s: No such file or directory" % target_dir))
            elif is_directory(self.fs, target_dir):
                self.update_pwd(target_dir)
            else:
                print(("cd: %s: Not a directory" % target_dir))

    def do_pwd(self, args):
        """
        Prints the current working directory

        :param args:
        :return:
        """
        print((self.pwd))

    def do_mkdir(self, args):
        """
        Add a new directory in the target directory.
        Handles relative or absolute file paths. \n
        Usage: mkdir <destination>...
        """

        arg_list = args.split()
        if len(arg_list) < 1:
            print("usage: mkdir <new directory> <new directory>...")
        else:
            for arg in arg_list:
                self.mkfile(arg.split(), T_DIR)

    def do_touch(self, args):
        """
        Add a new file in the target directory.
        Handles relative or absolute file paths. \n
        Usage: touch <destination> [<size in bytes>]
        """

        arg_list = args.split()

        if len(arg_list) < 1:
            print('Usage: touch <destination> (<size in bytes>)')
        else:
            self.mkfile(arg_list, T_FILE)

    def mkfile(self, args, file_type):
        """
        args must be a list of arguments
        """
        cwd = self.fs
        path = resolve_reference(self.pwd, args[0])
        pathList = path.split('/')
        parentdir = '/'.join(pathList[:-1])
        fileName = pathList[len(pathList) - 1]

        if not exists(self.fs, parentdir):
            print((('Parent directory %s doesn\'t exist!') % \
                   (parentdir,)))
            self.mkfile(parentdir.split(), T_DIR)

        if exists(self.fs, path):
            print(('Error: %s already exists!' % (path,)))
            return

        cwd = getpath(self.fs, parentdir)

        # get uid, gid, mode from parent
        uid = cwd[A_UID]
        gid = cwd[A_GID]
        mode = cwd[A_MODE]

        # create default file/directory size if none is specified
        if len(args) == 1:
            size = 4096
        else:
            size = args[1]

        # set the last update time stamp to now
        ctime = time.time()

        cwd[A_CONTENTS].append(
            [fileName, file_type, uid, gid, size, mode, ctime, [], None, None])

        self.save_pickle()

        print(("Added '%s'" % path))

    def do_rm(self, arguments):
        """
        Remove an object from the file system.
        Will not remove a directory unless the -r switch is invoked.\n
        Usage: rm [-r] <target>
        """

        args = arguments.split()

        if len(args) < 1 or len(args) > 2:
            print('Usage: rm [-r] <target>')
            return

        if len(args) == 2 and args[0] != "-r":
            print('Usage: rm [-r] <target>')
            return

        if len(args) == 1:
            target_path = resolve_reference(self.pwd, args[0])
        else:
            target_path = resolve_reference(self.pwd, args[1])

        if exists(self.fs, target_path) == False:
            print(("File \'%s\' doesn\'t exist" % (target_path,)))
            return

        if target_path == "/":
            print("rm: cannot delete root directory '/'")
            return

        target_object = getpath(self.fs, target_path)

        if target_object[A_TYPE] == T_DIR and args[0] != "-r":
            print(("rm: cannot remove '%s': Is a directory" % (target_path,)))
            return

        parent_path = '/'.join(target_path.split('/')[:-1])
        parent_object = getpath(self.fs, parent_path)

        parent_object[A_CONTENTS].remove(target_object)

        self.save_pickle()

        print(("Deleted %s" % target_path))

    def do_rmdir(self, arguments):
        """
        Remove a file object. Like the unix command,
        this can only delete empty directories.
        Use rm -r to recursively delete full directories.\n
        Usage: rmdir <target directory>
        """
        args = arguments.split()

        if len(args) != 1:
            print('Usage: rmdir <target>')
            return

        target_path = resolve_reference(self.pwd, args[0])

        if exists(self.fs, target_path) == False:
            print(("File \'%s\' doesn\'t exist" % (target_path,)))
            return

        target_object = getpath(self.fs, target_path)

        if target_object[A_TYPE] != T_DIR:
            print(("rmdir: failed to remove '%s': Not a directory" % \
                   (target_path,)))
            return

        # The unix rmdir command does not delete directories if they are not
        # empty
        if len(target_object[A_CONTENTS]) != 0:
            print(("rmdir: failed to remove '%s': Directory not empty" % \
                   (target_path,)))
            return

        parent_path = '/'.join(target_path.split('/')[:-1])
        parent_object = getpath(self.fs, parent_path)

        parent_object[A_CONTENTS].remove(target_object)

        self.save_pickle()

        if self.pwd == target_path:
            self.do_cd("..")

        print(("Deleted %s" % target_path))

    def do_mv(self, arguments):
        """
        Moves a file/directory from one directory to another.\n
        Usage: mv <source file> <destination file>
        """
        args = arguments.split()
        if len(args) != 2:
            print('Usage: mv <source> <destination>')
            return
        src = resolve_reference(self.pwd, args[0])
        dst = resolve_reference(self.pwd, args[1])

        if src == "/":
            print("mv: cannot move the root directory '/'")
            return

        src = src.strip('/')
        dst = dst.strip('/')

        if not exists(self.fs, src):
            print(("Source file \'%s\' does not exist!" % src))
            return

        # Get the parent directory of the source file
        # srcparent = '/'.join(src.split('/')[:-1])
        srcparent = "/".join(src.split('/')[:-1])

        # Get the object for source
        srcl = getpath(self.fs, src)

        # Get the object for the source's parent
        srcparentl = getpath(self.fs, srcparent)

        # if the specified filepath is a directory, maintain the current name
        if exists(self.fs, dst) and is_directory(self.fs, dst):
            dstparent = dst
            dstname = srcl[A_NAME]
        else:
            dstparent = '/'.join(dst.split('/')[:-1])
            dstname = dst.split('/')[-1]

        if exists(self.fs, dstparent + '/' + dstname):
            print(("A file already exists at " + dst + "!"))
            return

        if not exists(self.fs, dstparent):
            print(('Destination directory \'%s\' doesn\'t exist!' % dst))
            return

        if src == self.pwd:
            self.do_cd("..")

        dstparentl = getpath(self.fs, dstparent)
        copy = srcl[:]
        copy[A_NAME] = dstname
        dstparentl[A_CONTENTS].append(copy)
        srcparentl[A_CONTENTS].remove(srcl)

        self.save_pickle()

        print(('File moved from /%s to /%s' % (src, dst)))

    def do_cp(self, arguments):
        """
        Copies a file/directory from one directory to another.\n
        Usage: cp <source file> <destination file>
        """
        args = arguments.split()
        if len(args) != 2:
            print('Usage: cp <source> <destination>')
            return

        # src, dst = args[0], args[1]

        src = resolve_reference(self.pwd, args[0])
        dst = resolve_reference(self.pwd, args[1])

        src = src.strip('/')
        dst = dst.strip('/')

        if not exists(self.fs, src):
            print(("Source file '%s' does not exist!" % (src,)))
            return

        # Get the parent directory of the source file
        srcparent = '/'.join(src.split('/')[:-1])

        # Get the object for source
        srcl = getpath(self.fs, src)

        # Get the object for the source's parent
        srcparentl = getpath(self.fs, srcparent)

        # if the specified filepath is a directory, maintain the current name
        if exists(self.fs, dst) and is_directory(self.fs, dst):
            dstparent = dst
            dstname = srcl[A_NAME]
        else:
            dstparent = '/'.join(dst.split('/')[:-1])
            dstname = dst.split('/')[-1]

        if exists(self.fs, dstparent + '/' + dstname):
            print(('A file already exists at %s/%s!' % (dstparent, dstname)))
            return

        if not exists(self.fs, dstparent):
            print(('Destination directory %s doesn\'t exist!' % (dstparent,)))
            return

        dstparentl = getpath(self.fs, dstparent)
        coppy = copy.deepcopy(srcl)
        coppy[A_NAME] = dstname
        dstparentl[A_CONTENTS].append(coppy)

        self.save_pickle()

        print(('File copied from /%s to /%s/%s' % (src, dstparent, dstname)))

    def do_chown(self, args):
        """
        Change file ownership
        """
        arg_list = args.split()

        if len(arg_list) != 2:
            print("Incorrect number of arguments.\nUsage: chown <uid> <file>")
            return

        uid = arg_list[0]
        target_path = resolve_reference(self.pwd, arg_list[1])

        if not exists(self.fs, target_path):
            print(("File '%s' doesn't exist." % target_path))
            return

        target_object = getpath(self.fs, target_path)
        olduid = target_object[A_UID]
        target_object[A_UID] = int(uid)
        print(("former UID: " + str(olduid) + ". New UID: " + str(uid)))
        self.save_pickle()

    def do_chgrp(self, args):
        """
        Change file ownership
        """
        arg_list = args.split()

        if len(arg_list) != 2:
            print("Incorrect number of arguments.\nUsage: chgrp <gid> <file>")
            return

        gid = arg_list[0]
        target_path = resolve_reference(self.pwd, arg_list[1])

        if not exists(self.fs, target_path):
            print(("File '%s' doesn't exist." % target_path))
            return

        target_object = getpath(self.fs, target_path)
        oldgid = target_object[A_GID]
        target_object[A_GID] = int(gid)
        print(("former GID: " + str(oldgid) + ". New GID: " + str(gid)))
        self.save_pickle()

    def do_chmod(self, args):
        """
        Change file permissions
        only modes between 000 and 777 are implemented
        """

        arg_list = args.split()

        if len(arg_list) != 2:
            print("Incorrect number of arguments.\nUsage: chmod <mode> <file>")
            return

        mode = arg_list[0]
        target_path = resolve_reference(self.pwd, arg_list[1])

        if not exists(self.fs, target_path):
            print("File '%s' doesn't exist." % target_path)
            return

        target_object = getpath(self.fs, target_path)
        oldmode = target_object[A_MODE]

        if target_object[A_TYPE] == T_LINK:
            print(target_path + " is a link, nothing changed.")
            return

        try:
            num = int(mode, 8)
        except:
            print("Incorrect mode: " + mode)
            return

        if num < 0 or num > 511:
            print("Incorrect mode: " + mode)
            return

        target_object[A_MODE] = (oldmode & 0o7777000) | (num & 0o777)
        self.save_pickle()

    def do_file(self, args):
        """
        Identifies file types.\nUsage: file <file name>
        """
        arg_list = args.split()

        if len(arg_list) != 1:
            print("Incorrect number of arguments.\nUsage: file <file>")
            return

        target_path = resolve_reference(self.pwd, arg_list[0])

        if not exists(self.fs, target_path):
            print("File '%s' doesn't exist." % target_path)
            return

        target_object = getpath(self.fs, target_path)

        file_type = target_object[A_TYPE]

        if file_type == T_FILE:
            msg = "normal file object"
        elif file_type == T_DIR:
            msg = "directory"
        elif file_type == T_LINK:
            msg = "link"
        elif file_type == T_BLK:
            msg = "block file"
        elif file_type == T_CHR:
            msg = "character special"
        elif file_type == T_SOCK:
            msg = "socket"
        elif file_type == T_FIFO:
            msg = "named pipe"
        else:
            msg = "unrecognized file"

        print(target_path + " is a " + msg)

    def do_clear(self, args):
        """
        Clears the screen
        """
        os.system('clear')

    def emptyline(self):
        """
        By default the cmd object will repeat the last command
        if a blank line is entered. Since this is different than
        bash behavior, overriding this method will stop it.
        """
        pass

    def help_help(self):
        print("Type help <topic> to get more information.")

    def help_about(self):
        print("Kippo/Cowrie stores information about its file systems in a " + \
              "series of nested lists. Once the lists are made, they are " + \
              "stored in a pickle file on the hard drive. Every time cowrie " + \
              "gets a new client, it reads from the pickle file and loads " + \
              "the fake file system into memory. By default this file " + \
              "is /opt/cowrie/data/fs.pickle. Originally the script " + \
              "/opt/cowrie/bin/createfs was used to copy the file system " + \
              "of the existing computer. However, it quite difficult to " + \
              "edit the pickle file by hand.\n\nThis script strives to be " + \
              "a bash-like interface that allows users to modify " + \
              "existing fs pickle files. It supports many of the " + \
              "common bash commands and even handles relative file " + \
              "paths. Keep in mind that you need to restart the " + \
              "cowrie process in order for the new file system to be " + \
              "reloaded into memory.\n\nDonovan Hubbard, Douglas Hubbard, " + \
              "March 2013\nVersion 1.0")


if __name__ == '__main__':
    if len(sys.argv) != 2:
        print("Usage: %s <fs.pickle>" % os.path.basename(sys.argv[0], ))
        sys.exit(1)

    pickle_file_name = sys.argv[1].strip()
    print(pickle_file_name)

    fseditCmd(pickle_file_name).cmdloop()