#!/usr/bin/env python

###############################################################
# This program creates a cowrie file system pickle file.
#
# This is meant to build a brand new filesystem.
# To edit the file structure, please use 'bin/fsctl'
#
##############################################################

import fnmatch
import getopt
import os
import pickle
import sys
from stat import *

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

blacklist_files = [
    '/root/fs.pickle',
    '/root/createfs',
    '*cowrie*',
    '*kippo*',
]


def logit(ftxt):
    if VERBOSE:
        sys.stderr.write(ftxt)


def checkblacklist(ftxt):
    for value in blacklist_files:
        if fnmatch.fnmatch(ftxt, value):
            return True
    return False


def recurse(localroot, root, tree, maxdepth=100):
    if maxdepth == 0: return

    localpath = os.path.join(localroot, root[1:])

    logit(' %s\n' % (localpath))

    if not os.access(localpath, os.R_OK):
        logit(' Cannot access %s\n' % localpath)
        return

    for name in os.listdir(localpath):
        fspath = os.path.join(root, name)
        if checkblacklist(fspath):
            continue

        path = os.path.join(localpath, name)

        try:
            if os.path.islink(path):
                s = os.lstat(path)
            else:
                s = os.stat(path)
        except OSError:
            continue

        entry = [name, T_FILE, s.st_uid, s.st_gid, s.st_size, s.st_mode, \
                 int(s.st_mtime), [], None, None]

        if S_ISLNK(s[ST_MODE]):
            if not os.access(path, os.R_OK):
                logit(' Cannot access link: %s\n' % path)
                continue
            realpath = os.path.realpath(path)
            if not realpath.startswith(localroot):
                logit(' Link "%s" has real path "%s" outside local root "%s"\n' \
                      % (path, realpath, localroot))
                continue
            else:
                entry[A_TYPE] = T_LINK
                entry[A_TARGET] = realpath[len(localroot):]
        elif S_ISDIR(s[ST_MODE]):
            entry[A_TYPE] = T_DIR
            if (PROC or not localpath.startswith('/proc/')) and maxdepth > 0:
                recurse(localroot, fspath, entry[A_CONTENTS], maxdepth - 1)
        elif S_ISREG(s[ST_MODE]):
            entry[A_TYPE] = T_FILE
        elif S_ISBLK(s[ST_MODE]):
            entry[A_TYPE] = T_BLK
        elif S_ISCHR(s[ST_MODE]):
            entry[A_TYPE] = T_CHR
        elif S_ISSOCK(s[ST_MODE]):
            entry[A_TYPE] = T_SOCK
        elif S_ISFIFO(s[ST_MODE]):
            entry[A_TYPE] = T_FIFO
        else:
            sys.stderr.write('We should handle %s' % path)
            sys.exit(1)

        tree.append(entry)


def help(brief=False):
    print('Usage: %s [-h] [-v] [-p] [-l dir] [-d maxdepth] [-o file]\n' % \
          os.path.basename(sys.argv[0]))

    if not brief:
        print('  -v             verbose')
        print('  -p             include /proc')
        print('  -l <dir>       local root directory (default is current working directory)')
        print('  -d <depth>     maximum depth (default is full depth)')
        print('  -o <file>      write output to file instead of stdout')
        print('  -h             display this help\n')

    sys.exit(1)


if __name__ == '__main__':
    maxdepth = 100
    localroot = os.getcwd()
    output = ''

    try:
        optlist, args = getopt.getopt(sys.argv[1:], 'hvpl:d:o:', ['help'])
    except getopt.GetoptError as error:
        sys.stderr.write('Error: %s\n' % error)
        help()

    for o, a in optlist:
        if o == '-v':
            VERBOSE = True
        elif o == '-p':
            PROC = True
        elif o == '-l':
            localroot = a
        elif o == '-d':
            maxdepth = int(a)
        elif o == '-o':
            output = a
        elif o in ['-h', '--help']:
            help()

    if output and os.path.isfile(output):
        sys.stderr.write('File: %s exists!\n' % output)
        sys.exit(1)

    logit('Processing:\n')

    tree = ['/', T_DIR, 0, 0, 0, 0, 0, [], '']
    recurse(localroot, '/', tree[A_CONTENTS], maxdepth)

    if output:
        pickle.dump(tree, open(output, 'wb'))
    else:
        print(pickle.dumps(tree))