diff options
Diffstat (limited to 'cloudinit/net')
| -rw-r--r-- | cloudinit/net/dhcp.py | 43 | ||||
| -rw-r--r-- | cloudinit/net/network_state.py | 12 |
2 files changed, 54 insertions, 1 deletions
diff --git a/cloudinit/net/dhcp.py b/cloudinit/net/dhcp.py index 875a4609..087c0c03 100644 --- a/cloudinit/net/dhcp.py +++ b/cloudinit/net/dhcp.py @@ -10,7 +10,9 @@ import os import re import signal -from cloudinit.net import find_fallback_nic, get_devicelist +from cloudinit.net import ( + EphemeralIPv4Network, find_fallback_nic, get_devicelist) +from cloudinit.net.network_state import mask_and_ipv4_to_bcast_addr as bcip from cloudinit import temp_utils from cloudinit import util from six import StringIO @@ -29,6 +31,45 @@ class InvalidDHCPLeaseFileError(Exception): pass +class NoDHCPLeaseError(Exception): + """Raised when unable to get a DHCP lease.""" + pass + + +class EphemeralDHCPv4(object): + def __init__(self, iface=None): + self.iface = iface + self._ephipv4 = None + + def __enter__(self): + try: + leases = maybe_perform_dhcp_discovery(self.iface) + except InvalidDHCPLeaseFileError: + raise NoDHCPLeaseError() + if not leases: + raise NoDHCPLeaseError() + lease = leases[-1] + LOG.debug("Received dhcp lease on %s for %s/%s", + lease['interface'], lease['fixed-address'], + lease['subnet-mask']) + nmap = {'interface': 'interface', 'ip': 'fixed-address', + 'prefix_or_mask': 'subnet-mask', + 'broadcast': 'broadcast-address', + 'router': 'routers'} + kwargs = dict([(k, lease.get(v)) for k, v in nmap.items()]) + if not kwargs['broadcast']: + kwargs['broadcast'] = bcip(kwargs['prefix_or_mask'], kwargs['ip']) + ephipv4 = EphemeralIPv4Network(**kwargs) + ephipv4.__enter__() + self._ephipv4 = ephipv4 + return lease + + def __exit__(self, excp_type, excp_value, excp_traceback): + if not self._ephipv4: + return + self._ephipv4.__exit__(excp_type, excp_value, excp_traceback) + + def maybe_perform_dhcp_discovery(nic=None): """Perform dhcp discovery if nic valid and dhclient command exists. diff --git a/cloudinit/net/network_state.py b/cloudinit/net/network_state.py index 31738c73..fe667d88 100644 --- a/cloudinit/net/network_state.py +++ b/cloudinit/net/network_state.py @@ -961,4 +961,16 @@ def mask_to_net_prefix(mask): return ipv4_mask_to_net_prefix(mask) +def mask_and_ipv4_to_bcast_addr(mask, ip): + """Calculate the broadcast address from the subnet mask and ip addr. + + Supports ipv4 only.""" + ip_bin = int(''.join([bin(int(x) + 256)[3:] for x in ip.split('.')]), 2) + mask_dec = ipv4_mask_to_net_prefix(mask) + bcast_bin = ip_bin | (2**(32 - mask_dec) - 1) + bcast_str = '.'.join([str(bcast_bin >> (i << 3) & 0xFF) + for i in range(4)[::-1]]) + return bcast_str + + # vi: ts=4 expandtab |