"""
virtual ethernet classes that implement the interfaces available under Linux.
"""
import logging
import math
from pathlib import Path
from typing import TYPE_CHECKING, Callable, Optional
import netaddr
from core import utils
from core.emulator.data import InterfaceData, LinkOptions
from core.emulator.enumerations import TransportType
from core.errors import CoreCommandError, CoreError
from core.executables import TC
from core.nodes.netclient import LinuxNetClient, get_net_client
logger = logging.getLogger(__name__)
if TYPE_CHECKING:
from core.emulator.session import Session
from core.emulator.distributed import DistributedServer
from core.nodes.base import CoreNetworkBase, CoreNode, NodeBase
DEFAULT_MTU: int = 1500
IFACE_NAME_LENGTH: int = 15
def tc_clear_cmd(name: str) -> str:
"""
Create tc command to clear device configuration.
:param name: name of device to clear
:return: tc command
"""
return f"{TC} qdisc delete dev {name} root handle 10:"
def tc_cmd(name: str, options: LinkOptions, mtu: int) -> str:
"""
Create tc command to configure a device with given name and options.
:param name: name of device to configure
:param options: options to configure with
:param mtu: mtu for configuration
:return: tc command
"""
netem = ""
if options.bandwidth is not None:
limit = 1000
bw = options.bandwidth / 1000
if options.buffer is not None and options.buffer > 0:
limit = options.buffer
elif options.delay and options.bandwidth:
delay = options.delay / 1000
limit = max(2, math.ceil((2 * bw * delay) / (8 * mtu)))
netem += f" rate {bw}kbit"
netem += f" limit {limit}"
if options.delay is not None:
netem += f" delay {options.delay}us"
if options.jitter is not None:
if options.delay is None:
netem += f" delay 0us {options.jitter}us 25%"
else:
netem += f" {options.jitter}us 25%"
if options.loss is not None and options.loss > 0:
netem += f" loss {min(options.loss, 100)}%"
if options.dup is not None and options.dup > 0:
netem += f" duplicate {min(options.dup, 100)}%"
return f"{TC} qdisc replace dev {name} root handle 10: netem {netem}"
class CoreInterface:
"""
Base class for network interfaces.
"""
def __init__(
self,
_id: int,
name: str,
localname: str,
use_ovs: bool,
mtu: int = DEFAULT_MTU,
node: "NodeBase" = None,
server: "DistributedServer" = None,
) -> None:
"""
Creates a CoreInterface instance.
:param _id: interface id for associated node
:param name: interface name
:param localname: interface local name
:param use_ovs: True to use ovs, False otherwise
:param mtu: mtu value
:param node: node associated with this interface
:param server: remote server node will run on, default is None for localhost
"""
if len(name) >= IFACE_NAME_LENGTH:
raise CoreError(
f"interface name ({name}) too long, max {IFACE_NAME_LENGTH}"
)
if len(localname) >= IFACE_NAME_LENGTH:
raise CoreError(
f"interface local name ({localname}) too long, max {IFACE_NAME_LENGTH}"
)
self.id: int = _id
self.node: Optional["NodeBase"] = node
# id of interface for network, used by wlan/emane
self.net_id: Optional[int] = None
self.name: str = name
self.localname: str = localname
self.up: bool = False
self.mtu: int = mtu
self.net: Optional[CoreNetworkBase] = None
self.ip4s: list[netaddr.IPNetwork] = []
self.ip6s: list[netaddr.IPNetwork] = []
self.mac: Optional[netaddr.EUI] = None
# placeholder position hook
self.poshook: Callable[[CoreInterface], None] = lambda x: None
# used with EMANE
self.transport_type: TransportType = TransportType.VIRTUAL
# id used to find flow data
self.flow_id: Optional[int] = None
self.server: Optional["DistributedServer"] = server
self.net_client: LinuxNetClient = get_net_client(use_ovs, self.host_cmd)
self.control: bool = False
# configuration data
self.has_netem: bool = False
self.options: LinkOptions = LinkOptions()
def host_cmd(
self,
args: str,
env: dict[str, str] = None,
cwd: Path = None,
wait: bool = True,
shell: bool = False,
) -> str:
"""
Runs a command on the host system or distributed server.
:param args: command to run
:param env: environment to run command with
:param cwd: directory to run command in
:param wait: True to wait for status, False otherwise
:param shell: True to use shell, False otherwise
:return: combined stdout and stderr
:raises CoreCommandError: when a non-zero exit status occurs
"""
if self.server is None:
return utils.cmd(args, env, cwd, wait, shell)
else:
return self.server.remote_cmd(args, env, cwd, wait)
def startup(self) -> None:
"""
Startup method for the interface.
:return: nothing
"""
self.net_client.create_veth(self.localname, self.name)
if self.mtu > 0:
self.net_client.set_mtu(self.name, self.mtu)
self.net_client.set_mtu(self.localname, self.mtu)
self.net_client.device_up(self.name)
self.net_client.device_up(self.localname)
self.up = True
def shutdown(self) -> None:
"""
Shutdown method for the interface.
:return: nothing
"""
if not self.up:
return
if self.localname:
try:
self.net_client.delete_device(self.localname)
except CoreCommandError:
pass
self.up = False
def add_ip(self, ip: str) -> None:
"""
Add ip address in the format "10.0.0.1/24".
:param ip: ip address to add
:return: nothing
:raises CoreError: when ip address provided is invalid
"""
try:
ip = netaddr.IPNetwork(ip)
address = str(ip.ip)
if netaddr.valid_ipv4(address):
self.ip4s.append(ip)
else:
self.ip6s.append(ip)
except netaddr.AddrFormatError as e:
raise CoreError(f"adding invalid address {ip}: {e}")
def remove_ip(self, ip: str) -> None:
"""
Remove ip address in the format "10.0.0.1/24".
:param ip: ip address to delete
:return: nothing
:raises CoreError: when ip address provided is invalid
"""
try:
ip = netaddr.IPNetwork(ip)
address = str(ip.ip)
if netaddr.valid_ipv4(address):
self.ip4s.remove(ip)
else:
self.ip6s.remove(ip)
except (netaddr.AddrFormatError, ValueError) as e:
raise CoreError(f"deleting invalid address {ip}: {e}")
def get_ip4(self) -> Optional[netaddr.IPNetwork]:
"""
Looks for the first ip4 address.
:return: ip4 address, None otherwise
"""
return next(iter(self.ip4s), None)
def get_ip6(self) -> Optional[netaddr.IPNetwork]:
"""
Looks for the first ip6 address.
:return: ip6 address, None otherwise
"""
return next(iter(self.ip6s), None)
def ips(self) -> list[netaddr.IPNetwork]:
"""
Retrieve a list of all ip4 and ip6 addresses combined.
:return: ip4 and ip6 addresses
"""
return self.ip4s + self.ip6s
def set_mac(self, mac: Optional[str]) -> None:
"""
Set mac address.
:param mac: mac address to set, None for random mac
:return: nothing
:raises CoreError: when there is an invalid mac address
"""
if mac is None:
self.mac = mac
else:
try:
self.mac = netaddr.EUI(mac, dialect=netaddr.mac_unix_expanded)
except netaddr.AddrFormatError as e:
raise CoreError(f"invalid mac address({mac}): {e}")
def setposition(self) -> None:
"""
Dispatch position hook handler when possible.
:return: nothing
"""
if self.poshook and self.node:
self.poshook(self)
def __lt__(self, other: "CoreInterface") -> bool:
"""
Used for comparisons of this object.
:param other: other interface
:return: true if less than, false otherwise
"""
return id(self) < id(other)
def is_raw(self) -> bool:
"""
Used to determine if this interface is considered a raw interface.
:return: True if raw interface, False otherwise
"""
return self.transport_type == TransportType.RAW
def is_virtual(self) -> bool:
"""
Used to determine if this interface is considered a virtual interface.
:return: True if virtual interface, False otherwise
"""
return self.transport_type == TransportType.VIRTUAL
def set_config(self) -> None:
# clear current settings
if self.options.is_clear():
if self.has_netem:
cmd = tc_clear_cmd(self.name)
if self.node:
self.node.cmd(cmd)
else:
self.host_cmd(cmd)
self.has_netem = False
# set updated settings
else:
cmd = tc_cmd(self.name, self.options, self.mtu)
if self.node:
self.node.cmd(cmd)
else:
self.host_cmd(cmd)
self.has_netem = True
def get_data(self) -> InterfaceData:
"""
Retrieve the data representation of this interface.
:return: interface data
"""
ip4 = self.get_ip4()
ip4_addr = str(ip4.ip) if ip4 else None
ip4_mask = ip4.prefixlen if ip4 else None
ip6 = self.get_ip6()
ip6_addr = str(ip6.ip) if ip6 else None
ip6_mask = ip6.prefixlen if ip6 else None
mac = str(self.mac) if self.mac else None
return InterfaceData(
id=self.id,
name=self.name,
mac=mac,
ip4=ip4_addr,
ip4_mask=ip4_mask,
ip6=ip6_addr,
ip6_mask=ip6_mask,
)
class GreTap(CoreInterface):
"""
GRE TAP device for tunneling between emulation servers.
Uses the "gretap" tunnel device type from Linux which is a GRE device
having a MAC address. The MAC address is required for bridging.
"""
def __init__(
self,
session: "Session",
remoteip: str,
key: int = None,
node: "CoreNode" = None,
mtu: int = DEFAULT_MTU,
_id: int = None,
localip: str = None,
ttl: int = 255,
server: "DistributedServer" = None,
) -> None:
"""
Creates a GreTap instance.
:param session: session for this gre tap
:param remoteip: remote address
:param key: gre tap key
:param node: related core node
:param mtu: interface mtu
:param _id: object id
:param localip: local address
:param ttl: ttl value
:param server: remote server node
will run on, default is None for localhost
:raises CoreCommandError: when there is a command exception
"""
if _id is None:
_id = ((id(self) >> 16) ^ (id(self) & 0xFFFF)) & 0xFFFF
self.id: int = _id
sessionid = session.short_session_id()
localname = f"gt.{self.id}.{sessionid}"
name = f"{localname}p"
super().__init__(0, name, localname, session.use_ovs(), mtu, node, server)
self.transport_type: TransportType = TransportType.RAW
self.remote_ip: str = remoteip
self.ttl: int = ttl
self.key: Optional[int] = key
self.local_ip: Optional[str] = localip
def startup(self) -> None:
"""
Startup logic for a GreTap.
:return: nothing
"""
self.net_client.create_gretap(
self.localname, self.remote_ip, self.local_ip, self.ttl, self.key
)
if self.mtu > 0:
self.net_client.set_mtu(self.localname, self.mtu)
self.net_client.device_up(self.localname)
self.up = True
def shutdown(self) -> None:
"""
Shutdown logic for a GreTap.
:return: nothing
"""
if self.localname:
try:
self.net_client.device_down(self.localname)
self.net_client.delete_device(self.localname)
except CoreCommandError:
logger.exception("error during shutdown")
self.localname = None