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Diffstat (limited to 'cloudinit/net/cmdline.py')
| -rw-r--r-- | cloudinit/net/cmdline.py | 200 |
1 files changed, 200 insertions, 0 deletions
diff --git a/cloudinit/net/cmdline.py b/cloudinit/net/cmdline.py new file mode 100644 index 00000000..39523be2 --- /dev/null +++ b/cloudinit/net/cmdline.py @@ -0,0 +1,200 @@ +# Copyright (C) 2013-2014 Canonical Ltd. +# +# Author: Scott Moser <scott.moser@canonical.com> +# Author: Blake Rouse <blake.rouse@canonical.com> +# +# Curtin is free software: you can redistribute it and/or modify it under +# the terms of the GNU Affero General Public License as published by the +# Free Software Foundation, either version 3 of the License, or (at your +# option) any later version. +# +# Curtin 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 Affero General Public License for +# more details. +# +# You should have received a copy of the GNU Affero General Public License +# along with Curtin. If not, see <http://www.gnu.org/licenses/>. + +import base64 +import glob +import gzip +import io +import shlex + +from . import compat +from . import get_devicelist +from . import read_file +from . import sys_netdev_info + +from cloudinit import util + + +def _shlex_split(blob): + if compat.PY26 and isinstance(blob, compat.text_type): + # Older versions don't support unicode input + blob = blob.encode("utf8") + return shlex.split(blob) + + +def _load_shell_content(content, add_empty=False, empty_val=None): + """Given shell like syntax (key=value\nkey2=value2\n) in content + return the data in dictionary form. If 'add_empty' is True + then add entries in to the returned dictionary for 'VAR=' + variables. Set their value to empty_val.""" + data = {} + for line in shlex.split(content): + key, value = line.split("=", 1) + if not value: + value = empty_val + if add_empty or value: + data[key] = value + + return data + + +def _klibc_to_config_entry(content, mac_addrs=None): + """Convert a klibc writtent shell content file to a 'config' entry + When ip= is seen on the kernel command line in debian initramfs + and networking is brought up, ipconfig will populate + /run/net-<name>.cfg. + + The files are shell style syntax, and examples are in the tests + provided here. There is no good documentation on this unfortunately. + + DEVICE=<name> is expected/required and PROTO should indicate if + this is 'static' or 'dhcp'. + """ + + if mac_addrs is None: + mac_addrs = {} + + data = _load_shell_content(content) + try: + name = data['DEVICE'] + except KeyError: + raise ValueError("no 'DEVICE' entry in data") + + # ipconfig on precise does not write PROTO + proto = data.get('PROTO') + if not proto: + if data.get('filename'): + proto = 'dhcp' + else: + proto = 'static' + + if proto not in ('static', 'dhcp'): + raise ValueError("Unexpected value for PROTO: %s" % proto) + + iface = { + 'type': 'physical', + 'name': name, + 'subnets': [], + } + + if name in mac_addrs: + iface['mac_address'] = mac_addrs[name] + + # originally believed there might be IPV6* values + for v, pre in (('ipv4', 'IPV4'),): + # if no IPV4ADDR or IPV6ADDR, then go on. + if pre + "ADDR" not in data: + continue + subnet = {'type': proto, 'control': 'manual'} + + # these fields go right on the subnet + for key in ('NETMASK', 'BROADCAST', 'GATEWAY'): + if pre + key in data: + subnet[key.lower()] = data[pre + key] + + dns = [] + # handle IPV4DNS0 or IPV6DNS0 + for nskey in ('DNS0', 'DNS1'): + ns = data.get(pre + nskey) + # verify it has something other than 0.0.0.0 (or ipv6) + if ns and len(ns.strip(":.0")): + dns.append(data[pre + nskey]) + if dns: + subnet['dns_nameservers'] = dns + # add search to both ipv4 and ipv6, as it has no namespace + search = data.get('DOMAINSEARCH') + if search: + if ',' in search: + subnet['dns_search'] = search.split(",") + else: + subnet['dns_search'] = search.split() + + iface['subnets'].append(subnet) + + return name, iface + + +def config_from_klibc_net_cfg(files=None, mac_addrs=None): + if files is None: + files = glob.glob('/run/net*.conf') + + entries = [] + names = {} + for cfg_file in files: + name, entry = _klibc_to_config_entry(read_file(cfg_file), + mac_addrs=mac_addrs) + if name in names: + raise ValueError( + "device '%s' defined multiple times: %s and %s" % ( + name, names[name], cfg_file)) + + names[name] = cfg_file + entries.append(entry) + return {'config': entries, 'version': 1} + + +def _decomp_gzip(blob, strict=True): + # decompress blob. raise exception if not compressed unless strict=False. + with io.BytesIO(blob) as iobuf: + gzfp = None + try: + gzfp = gzip.GzipFile(mode="rb", fileobj=iobuf) + return gzfp.read() + except IOError: + if strict: + raise + return blob + finally: + if gzfp: + gzfp.close() + + +def _b64dgz(b64str, gzipped="try"): + # decode a base64 string. If gzipped is true, transparently uncompresss + # if gzipped is 'try', then try gunzip, returning the original on fail. + try: + blob = base64.b64decode(b64str) + except TypeError: + raise ValueError("Invalid base64 text: %s" % b64str) + + if not gzipped: + return blob + + return _decomp_gzip(blob, strict=gzipped != "try") + + +def read_kernel_cmdline_config(files=None, mac_addrs=None, cmdline=None): + if cmdline is None: + cmdline = util.get_cmdline() + + if 'network-config=' in cmdline: + data64 = None + for tok in cmdline.split(): + if tok.startswith("network-config="): + data64 = tok.split("=", 1)[1] + if data64: + return util.load_yaml(_b64dgz(data64)) + + if 'ip=' not in cmdline: + return None + + if mac_addrs is None: + mac_addrs = dict((k, sys_netdev_info(k, 'address')) + for k in get_devicelist()) + + return config_from_klibc_net_cfg(files=files, mac_addrs=mac_addrs) |