"""
Detect physical devices that can be used by chutes.
This module detects physical devices (for now just network interfaces) that can
be used by chutes. This includes WAN interfaces for Internet connectivity and
WiFi interfaces which can host APs.
It also makes sure certain entries exist in the system UCI files for these
devices, for example "wifi-device" sections. These are shared between chutes,
so they only need to be added when missing.
"""
import itertools
import os
import re
from paradrop.lib.utils import uci
from pdtools.lib.output import out
from paradrop.lib import settings
SYS_DIR = "/sys/class/net"
EXCLUDE_IFACES = set(["lo"])
CHANNELS = [1, 6, 11]
# Strings that identify a virtual interface.
VIF_MARKERS = [".", "veth"]
[docs]def isVirtual(ifname):
"""
Test if an interface is a virtual one.
FIXME: This just tests for the presence of certain strings in the interface
name, so it is not very robust.
"""
for marker in VIF_MARKERS:
if marker in ifname:
return True
return False
[docs]def isWAN(ifname):
"""
Test if an interface is a WAN interface.
"""
pattern = re.compile(r"(\w+)\s+(\w+)*")
with open("/proc/net/route", "r") as routeList:
for line in routeList:
match = pattern.match(line)
if match is not None and \
match.group(1) == ifname and \
match.group(2) == "00000000":
return True
return False
[docs]def isWireless(ifname):
"""
Test if an interface is a wireless device.
"""
check_path = "{}/{}/wireless".format(SYS_DIR, ifname)
return os.path.exists(check_path)
[docs]def setConfig(chuteName, sections, filepath):
cfgFile = uci.UCIConfig(filepath)
# Set the name in the comment field.
for config, options in sections:
config['comment'] = chuteName
oldSections = cfgFile.getChuteConfigs(chuteName)
if not uci.chuteConfigsMatch(oldSections, sections):
cfgFile.delConfigs(oldSections)
cfgFile.addConfigs(sections)
cfgFile.save(internalid=chuteName)
#
# Chute update functions
#
[docs]def getSystemDevices(update):
"""
Detect devices on the system.
Store device information in cache key "networkDevices".
"""
devices = dict()
devices['wan'] = list()
devices['wifi'] = list()
devices['lan'] = list()
for ifname in os.listdir(SYS_DIR):
if ifname in EXCLUDE_IFACES:
continue
# Only want to detect physical interfaces.
if isVirtual(ifname):
continue
dev = {"name": ifname}
if isWAN(ifname):
devices['wan'].append(dev)
elif isWireless(ifname):
devices['wifi'].append(dev)
else:
devices['lan'].append(dev)
update.new.setCache('networkDevices', devices)
[docs]def setSystemDevices(update):
"""
Initialize system configuration files.
Creates basic sections that all chutes require such as the "wan" interface.
"""
devices = update.new.getCache('networkDevices')
if devices is None:
return
if len(devices['wan']) == 0:
out.warn("No WAN interface found; "
"chute may not have Internet connectivity.")
if len(devices['wifi']) == 0:
out.warn("No available wireless interfaces found.")
networkSections = list()
firewallSections = list()
wirelessSections = list()
if len(devices['wan']) >= 1:
# Only use one WAN device for now.
wanDev = devices['wan'][0]
config = {"type": "interface", "name": "wan"}
options = {"ifname": wanDev['name'], "proto": "dhcp"}
networkSections.append((config, options))
config = {"type": "zone"}
options = {
"name": "wan",
"masq": "1",
"input": "ACCEPT",
"forward": "REJECT",
"output": "ACCEPT",
"network": "wan"
}
firewallSections.append((config, options))
# Cycle through the channel list to assign different channels to
# WiFi interfaces.
channels = itertools.cycle(CHANNELS)
for dev in devices['wifi']:
config = {"type": "wifi-device", "name": dev['name']}
options = {"type": "auto", "channel": channels.next()}
wirelessSections.append((config, options))
setConfig(settings.RESERVED_CHUTE, networkSections,
uci.getSystemPath("network"))
setConfig(settings.RESERVED_CHUTE, firewallSections,
uci.getSystemPath("firewall"))
setConfig(settings.RESERVED_CHUTE, wirelessSections,
uci.getSystemPath("wireless"))