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# This file is part of Checkbox.
#
# Copyright 2015 Canonical Ltd.
#
# Checkbox is free software: you can redistribute it and/or modify
# it under the terms of the GNU General Public License version 3,
# as published by the Free Software Foundation.
#
# Checkbox 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 Checkbox. If not, see <http://www.gnu.org/licenses/>.
from __future__ import absolute_import
from __future__ import division
from __future__ import print_function
from __future__ import unicode_literals
import io
import re
class PciSubsystemIdResult():
"""Simple class to hold PCI Subsystem ID parsing results."""
def __init__(self):
self.pci_subsystem_id = None
def setPciSubsystemId(self, pci_subsys_id):
self.pci_subsystem_id = pci_subsys_id
class PciSubsystemIdParser():
"""
Parser for lspci subsystem ID for devices.
This takes the output from lspci -x (which shows the standard part of
configuration space) and parses only the subsystem ID (4 hex digits)
for the first device.
"""
bdf_re = re.compile(r'[0-9a-fA-F]{2}:[0-9a-fA-F]{2}.[0-0a-fA-F] .*$')
config_re = re.compile(r'([0-9a-fA-F]{2}): (([0-9a-fA-F]{2} ).+)$')
def __init__(self, stream):
self.stream = stream
def run(self, result):
"""
Parse the initialized lspci output.
Returns nothing, but will call the result object's
setPciSubsystemId method once with the susbystem ID for the
first device found.
"""
for line_no, line in enumerate(self.stream):
if not line:
return None
line = line.strip()
if line_no == 0:
# This should be the BDF and device type and name
if not re.match(self.bdf_re, line):
return None
if line_no == 3:
# The fourth line should contain the value we want
matches = re.match(self.config_re, line)
if matches:
# The first group marks the offset which we expect
# to be 20 for the fourth line (first line is the
# BDF, second and third lines are offsets 00 and 10
# respectively but we don't care about them).
if matches.group(1) != "20":
return None
octets = matches.group(2).split(" ")
# After the offset marker, we expect exactly 16
# hex octets of data.
if not len(octets) == 16:
return None
# The ID we want consists of the last and next-to-last
# octets (in that order, hence the index reversal).
result.setPciSubsystemId(octets[-1] + octets[-2])
break
else:
return None
def parse_pci_subsys_id(output):
"""
Parse output of `lspci -x`.
:returns: an instance of PciSubsystemIdResult which will
have a pci_subsystem_id attribute. This can either contain the
actual subsystem ID, or None, if no valid subsystem ID could
be extracted.
"""
parser = PciSubsystemIdParser(io.StringIO(output))
result = PciSubsystemIdResult()
parser.run(result)
return result
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