#
# regexes.py: anaconda regular expressions
#
# Copyright (C) 2013  Red Hat, Inc.  All rights reserved.
#
# 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 2 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/>.
#
# Author(s): David Shea <dshea@redhat.com>
#

import re

# Validation expressions

# The full name field can contain anything except a colon.
# The empty string allowed.
GECOS_VALID = re.compile(r'^[^:]*$')

# Everyone has different ideas for what can go in a username. Here's ours:
# POSIX recommends that user and group names use only the characters within
# the portable filesystem character set (ASCII alnum plus dot, underscore,
# and hyphen), with the additional restriction that names not start with a
# hyphen. The Red Hat modification to shadow-utils starts with these rules
# and additionally allows a final $, because Samba.
#
# shadow-utils also defines length limits for names: 32 for group names,
# and UT_NAMESIZE for user names (which is defined as 32 bits/utmp.h). This
# expression captures all of that: the initial character, followed by either
# up to 30 portable characters and a dollar sign or up to 31 portable characters,
# both for a maximum total of 32. The empty string is not allowed. "root" is not
# allowed.

# a base expression without anchors, helpful for building other expressions
# If the string is the right length to match "root", use a lookback expression
# to make sure it isn't.
_USERNAME_BASE = r'[a-zA-Z0-9._](([a-zA-Z0-9._-]{0,2})|([a-zA-Z0-9._-]{3}(?<!root))|([a-zA-Z0-9._-]{4,31})|([a-zA-Z0-9._-]{,30}\$))'

USERNAME_VALID = re.compile(r'^' + _USERNAME_BASE + '$')
GROUPNAME_VALID = USERNAME_VALID

# A comma-separated list of groups, validated as in GROUPNAME_VALID
# Any number of spaces are allowed at the start and end of the list and
# before and after the commas. The empty string is allowed.
GROUPLIST_SIMPLE_VALID = re.compile(r'^\s*(' + _USERNAME_BASE + r'(\s*,\s*' + _USERNAME_BASE + r')*)?\s*$')

# Parse the <gr-name> (<gid>) strings in the group list.
#
# The name match is non-greedy so that it doesn't match the whitespace betweeen
# the name and ID.
#
# There's some non-capturing groups ("clusters" in the perlre parlance) thrown
# in there, and, haha, wow, that's confusing to look at. There are two groups
# that actually end up in the match object, and they're named to try to make
# it a little easier: the first is "name", and the second is "gid".
#
# EVERY STRING IS MATCHED. This expression cannot be used for validation.
# If there is no GID, or the GID contains non-digits, everything except
# leading or trailing whitespace ends up in the name group. The result needs to
# be validated with GROUPNAME_VALID.
GROUPLIST_FANCY_PARSE = re.compile(r'^(?:\s*)(?P<name>.*?)\s*(?:\((?P<gid>\d+)\))?(?:\s*)$')

# Proxy parsing
PROXY_URL_PARSE = re.compile("([A-Za-z]+://)?(([A-Za-z0-9]+)(:[^:@]+)?@)?([^:/]+)(:[0-9]+)?(/.*)?")

# IPv4 address without anchors
IPV4_PATTERN_WITHOUT_ANCHORS = r'(?:(?:25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?)\.){3}(?:25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?)'