From f6d5dc486776019e0799f95f8d1982be8fba4da5 Mon Sep 17 00:00:00 2001
From: Joshua Harlow <jxharlow@godaddy.com>
Date: Thu, 15 Sep 2016 14:46:14 -0700
Subject: Replace usage of sys_netdev_info with read_sys_net
I've seen cases of unable to read from files as
well as the existing os errors so catch io error
and skip by using the smarter read_sys_net instead.
LP: #1625766
---
cloudinit/net/__init__.py | 166 +++++++++++++++++++++++-----------------------
cloudinit/net/cmdline.py | 9 ++-
2 files changed, 90 insertions(+), 85 deletions(-)
mode change 100644 => 100755 cloudinit/net/__init__.py
mode change 100644 => 100755 cloudinit/net/cmdline.py
(limited to 'cloudinit/net')
diff --git a/cloudinit/net/__init__.py b/cloudinit/net/__init__.py
old mode 100644
new mode 100755
index 7e58bfea..465c2a01
--- a/cloudinit/net/__init__.py
+++ b/cloudinit/net/__init__.py
@@ -32,25 +32,53 @@ def sys_dev_path(devname, path=""):
return SYS_CLASS_NET + devname + "/" + path
-def read_sys_net(devname, path, translate=None, enoent=None, keyerror=None):
+def read_sys_net(devname, path, translate=None,
+ on_enoent=None, on_keyerror=None,
+ on_einval=None):
+ dev_path = sys_dev_path(devname, path)
try:
- contents = util.load_file(sys_dev_path(devname, path))
+ contents = util.load_file(dev_path)
except (OSError, IOError) as e:
- if getattr(e, 'errno', None) in (errno.ENOENT, errno.ENOTDIR):
- if enoent is not None:
- return enoent
+ e_errno = getattr(e, 'errno', None)
+ if e_errno in (errno.ENOENT, errno.ENOTDIR):
+ if on_enoent is not None:
+ return on_enoent(e)
+ if e_errno in (errno.EINVAL,):
+ if on_einval is not None:
+ return on_einval(e)
raise
contents = contents.strip()
if translate is None:
return contents
try:
- return translate.get(contents)
- except KeyError:
- LOG.debug("found unexpected value '%s' in '%s/%s'", contents,
- devname, path)
- if keyerror is not None:
- return keyerror
- raise
+ return translate[contents]
+ except KeyError as e:
+ if on_keyerror is not None:
+ return on_keyerror(e)
+ else:
+ LOG.debug("Found unexpected (not translatable) value"
+ " '%s' in '%s", contents, dev_path)
+ raise
+
+
+def read_sys_net_safe(iface, field, translate=None):
+ def on_excp_false(e):
+ return False
+ return read_sys_net(iface, field,
+ on_keyerror=on_excp_false,
+ on_enoent=on_excp_false,
+ on_einval=on_excp_false,
+ translate=translate)
+
+
+def read_sys_net_int(iface, field):
+ val = read_sys_net_safe(iface, field)
+ if val is False:
+ return None
+ try:
+ return int(val)
+ except TypeError:
+ return None
def is_up(devname):
@@ -58,8 +86,7 @@ def is_up(devname):
# operstate as up for the purposes of network configuration. See
# Documentation/networking/operstates.txt in the kernel source.
translate = {'up': True, 'unknown': True, 'down': False}
- return read_sys_net(devname, "operstate", enoent=False, keyerror=False,
- translate=translate)
+ return read_sys_net_safe(devname, "operstate", translate=translate)
def is_wireless(devname):
@@ -70,21 +97,14 @@ def is_connected(devname):
# is_connected isn't really as simple as that. 2 is
# 'physically connected'. 3 is 'not connected'. but a wlan interface will
# always show 3.
- try:
- iflink = read_sys_net(devname, "iflink", enoent=False)
- if iflink == "2":
- return True
- if not is_wireless(devname):
- return False
- LOG.debug("'%s' is wireless, basing 'connected' on carrier", devname)
-
- return read_sys_net(devname, "carrier", enoent=False, keyerror=False,
- translate={'0': False, '1': True})
-
- except IOError as e:
- if e.errno == errno.EINVAL:
- return False
- raise
+ iflink = read_sys_net_safe(devname, "iflink")
+ if iflink == "2":
+ return True
+ if not is_wireless(devname):
+ return False
+ LOG.debug("'%s' is wireless, basing 'connected' on carrier", devname)
+ return read_sys_net_safe(devname, "carrier",
+ translate={'0': False, '1': True})
def is_physical(devname):
@@ -109,25 +129,9 @@ def is_disabled_cfg(cfg):
return cfg.get('config') == "disabled"
-def sys_netdev_info(name, field):
- if not os.path.exists(os.path.join(SYS_CLASS_NET, name)):
- raise OSError("%s: interface does not exist in %s" %
- (name, SYS_CLASS_NET))
- fname = os.path.join(SYS_CLASS_NET, name, field)
- if not os.path.exists(fname):
- raise OSError("%s: could not find sysfs entry: %s" % (name, fname))
- data = util.load_file(fname)
- if data[-1] == '\n':
- data = data[:-1]
- return data
-
-
def generate_fallback_config():
"""Determine which attached net dev is most likely to have a connection and
generate network state to run dhcp on that interface"""
- # by default use eth0 as primary interface
- nconf = {'config': [], 'version': 1}
-
# get list of interfaces that could have connections
invalid_interfaces = set(['lo'])
potential_interfaces = set(get_devicelist())
@@ -142,30 +146,21 @@ def generate_fallback_config():
if os.path.exists(sys_dev_path(interface, "bridge")):
# skip any bridges
continue
- try:
- carrier = int(sys_netdev_info(interface, 'carrier'))
- if carrier:
- connected.append(interface)
- continue
- except OSError:
- pass
+ carrier = read_sys_net_int(interface, 'carrier')
+ if carrier:
+ connected.append(interface)
+ continue
# check if nic is dormant or down, as this may make a nick appear to
# not have a carrier even though it could acquire one when brought
# online by dhclient
- try:
- dormant = int(sys_netdev_info(interface, 'dormant'))
- if dormant:
- possibly_connected.append(interface)
- continue
- except OSError:
- pass
- try:
- operstate = sys_netdev_info(interface, 'operstate')
- if operstate in ['dormant', 'down', 'lowerlayerdown', 'unknown']:
- possibly_connected.append(interface)
- continue
- except OSError:
- pass
+ dormant = read_sys_net_int(interface, 'dormant')
+ if dormant:
+ possibly_connected.append(interface)
+ continue
+ operstate = read_sys_net_safe(interface, 'operstate')
+ if operstate in ['dormant', 'down', 'lowerlayerdown', 'unknown']:
+ possibly_connected.append(interface)
+ continue
# don't bother with interfaces that might not be connected if there are
# some that definitely are
@@ -173,23 +168,30 @@ def generate_fallback_config():
potential_interfaces = connected
else:
potential_interfaces = possibly_connected
- # if there are no interfaces, give up
- if not potential_interfaces:
- return
+
# if eth0 exists use it above anything else, otherwise get the interface
- # that looks 'first'
- if DEFAULT_PRIMARY_INTERFACE in potential_interfaces:
- name = DEFAULT_PRIMARY_INTERFACE
+ # that we can read 'first' (using the sorted defintion of first).
+ names = list(sorted(potential_interfaces))
+ if DEFAULT_PRIMARY_INTERFACE in names:
+ names.remove(DEFAULT_PRIMARY_INTERFACE)
+ names.insert(0, DEFAULT_PRIMARY_INTERFACE)
+ target_name = None
+ target_mac = None
+ for name in names:
+ mac = read_sys_net_safe(name, 'address')
+ if mac:
+ target_name = name
+ target_mac = mac
+ break
+ if target_mac and target_name:
+ nconf = {'config': [], 'version': 1}
+ nconf['config'].append(
+ {'type': 'physical', 'name': target_name,
+ 'mac_address': target_mac, 'subnets': [{'type': 'dhcp'}]})
+ return nconf
else:
- name = sorted(potential_interfaces)[0]
-
- mac = sys_netdev_info(name, 'address')
- target_name = name
-
- nconf['config'].append(
- {'type': 'physical', 'name': target_name,
- 'mac_address': mac, 'subnets': [{'type': 'dhcp'}]})
- return nconf
+ # can't read any interfaces addresses (or there are none); give up
+ return None
def apply_network_config_names(netcfg, strict_present=True, strict_busy=True):
@@ -352,7 +354,7 @@ def get_interface_mac(ifname):
# for a bond slave, get the nic's hwaddress, not the address it
# is using because its part of a bond.
path = "bonding_slave/perm_hwaddr"
- return read_sys_net(ifname, path, enoent=False)
+ return read_sys_net_safe(ifname, path)
def get_interfaces_by_mac(devs=None):
diff --git a/cloudinit/net/cmdline.py b/cloudinit/net/cmdline.py
old mode 100644
new mode 100755
index cbed908d..a8bf73fb
--- a/cloudinit/net/cmdline.py
+++ b/cloudinit/net/cmdline.py
@@ -26,7 +26,7 @@ import sys
import six
from . import get_devicelist
-from . import sys_netdev_info
+from . import read_sys_net_safe
from cloudinit import util
@@ -210,7 +210,10 @@ def read_kernel_cmdline_config(files=None, mac_addrs=None, cmdline=None):
return None
if mac_addrs is None:
- mac_addrs = dict((k, sys_netdev_info(k, 'address'))
- for k in get_devicelist())
+ mac_addrs = {}
+ for k in get_devicelist():
+ mac_addr = read_sys_net_safe(k, 'address')
+ if mac_addr:
+ mac_addrs[k] = mac_addr
return config_from_klibc_net_cfg(files=files, mac_addrs=mac_addrs)
--
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