68 lines
1.9 KiB
Python
68 lines
1.9 KiB
Python
# Copyright (C) 2012-2017 Nominum, Inc.
|
|
#
|
|
# Permission to use, copy, modify, and distribute this software and its
|
|
# documentation for any purpose with or without fee is hereby granted,
|
|
# provided that the above copyright notice and this permission notice
|
|
# appear in all copies.
|
|
#
|
|
# THE SOFTWARE IS PROVIDED "AS IS" AND NOMINUM DISCLAIMS ALL WARRANTIES
|
|
# WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
|
|
# MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL NOMINUM BE LIABLE FOR
|
|
# ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
|
|
# WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
|
|
# ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT
|
|
# OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
|
|
|
|
"""DNS GENERATE range conversion."""
|
|
|
|
import dns
|
|
|
|
def from_text(text):
|
|
"""Convert the text form of a range in a ``$GENERATE`` statement to an
|
|
integer.
|
|
|
|
*text*, a ``str``, the textual range in ``$GENERATE`` form.
|
|
|
|
Returns a tuple of three ``int`` values ``(start, stop, step)``.
|
|
"""
|
|
|
|
# TODO, figure out the bounds on start, stop and step.
|
|
step = 1
|
|
cur = ''
|
|
state = 0
|
|
# state 0 1 2 3 4
|
|
# x - y / z
|
|
|
|
if text and text[0] == '-':
|
|
raise dns.exception.SyntaxError("Start cannot be a negative number")
|
|
|
|
for c in text:
|
|
if c == '-' and state == 0:
|
|
start = int(cur)
|
|
cur = ''
|
|
state = 2
|
|
elif c == '/':
|
|
stop = int(cur)
|
|
cur = ''
|
|
state = 4
|
|
elif c.isdigit():
|
|
cur += c
|
|
else:
|
|
raise dns.exception.SyntaxError("Could not parse %s" % (c))
|
|
|
|
if state in (1, 3):
|
|
raise dns.exception.SyntaxError()
|
|
|
|
if state == 2:
|
|
stop = int(cur)
|
|
|
|
if state == 4:
|
|
step = int(cur)
|
|
|
|
assert step >= 1
|
|
assert start >= 0
|
|
assert start <= stop
|
|
# TODO, can start == stop?
|
|
|
|
return (start, stop, step)
|