YueGuobin b17d021bf6
fix: derive per-node IOL app id so linked routers get distinct MACs
IOL derives interface MACs from its application ID. With a constant
local-app every node shared the same MACs, and linked routers dropped
each other's frames as MAC loops — ARP never resolved and pings were
100% lost even though the whole uBridge datapath was forwarding.

Derive local-app from the node UUID (stable across restarts, kept in
1..1022) and align remote-app with the netiomux convention CML uses
(1023). Verified end to end: two iol-xe nodes, Ethernet0/0 link,
ARP resolves both ways, ping 4/5 (first loss = ARP), graceful
stop/start keeps the NVRAM config.
2026-09-05 21:54:51 +08:00

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#
# Copyright (C) 2025 GNS3 Technologies Inc.
#
# This program is free software: you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation, either version 3 of the License, or
# (at your option) any later version.
#
# This program 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 General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program. If not, see <http://www.gnu.org/licenses/>.
"""
IOL (IOS on Linux) Docker container subclass.
Supports IOL images packaged with Cisco CML's container runner
(``iol-runner``, ``virl.lab/cmd/iol-runner``), e.g. ``iol-xe/iol-xe:17-18-02``:
a scratch image whose ENTRYPOINT is ``iol-runner -config /config/iol-config.json
-stdio``. The runner generates the license, writes the NETMAP, manages NVRAM
and muxes the IOS console onto PID 1 stdio (works with the plain ``telnet``
console type; requires a TTY, which GNS3 always allocates).
Networking does not use the container's network namespace at all: the runner's
netiomux exposes per-interface AF_UNIX datagram sockets in the container's
``/tmp`` (``s%02d.sock`` receive, ``c%02d.sock`` send — raw Ethernet frames),
wired by the generic ``GNS3_UNIX_SOCKET_NIO`` capability of VendorDockerVM
(uBridge reaches them through a per-node runtime directory bound at /tmp —
see ``VendorDockerVM._unix_socket_host_dir``). The local application ID is
derived from the node ID so that linked nodes get distinct MACs.
This class is selected by the ``GNS3_IOL_RUNNER=1`` environment marker.
"""
import contextlib
import glob
import json
import logging
import os
import shutil
from gns3server.compute.adapters.ethernet_adapter import EthernetAdapter
from gns3server.compute.docker.docker_error import DockerHttp404Error
from gns3server.compute.docker.docker_vm import DockerVM
from gns3server.compute.docker.vendor_docker_vm import VendorDockerVM
log = logging.getLogger(__name__)
class IOLDockerVM(VendorDockerVM):
"""
VendorDockerVM subclass for iol-runner images.
Extra opt-in knob (beyond the inherited vendor ones):
* ``GNS3_IOL_MEMORY=<MB>`` — IOL router memory passed via the generated
config (default 2048). The template ``memory`` field caps the whole
container: keep it at IOL memory + ~512 MB headroom or the kernel
OOM-killer will fire.
The marker itself forces ``GNS3_SKIP_INIT`` and the unix-socket NIO wiring,
and auto-adds the ``/config`` and ``/tmp/run`` persistent volumes, so a
template containing only ``GNS3_IOL_RUNNER=1`` is fully configured.
"""
_IOL_CONFIG_DIR = "/config"
_IOL_RUN_DIR = "/tmp/run"
def _parse_vendor_environment(self):
super()._parse_vendor_environment()
# The image has no shell (scratch): init.sh could neither run (its
# #!/bin/sh shebang doesn't exist) nor wait for eth interfaces that
# are never created. The console is IOS itself on PID 1 stdio.
self._gns3_init = False
self._unix_socket_nio = True
self._unix_socket_dir = "/tmp"
self._iol_memory = 2048
if self._environment:
for _line in self._environment.splitlines():
_line = _line.strip().rstrip(",")
if _line.startswith("GNS3_IOL_MEMORY="):
try:
memory = int(_line.split("=", 1)[1].strip())
if memory > 0:
self._iol_memory = memory
except ValueError:
pass
@DockerVM.adapters.setter
def adapters(self, adapters):
"""
Override: one IOL adapter is a 4-port unit — the IOU model. The
template's adapter count is the number of units (2 adapters =
Ethernet0/0-3 + Ethernet1/0-3); the generated config asks the runner
for adapters × 4 interfaces and links address ports as
(adapter_number, port_number 0-3).
"""
if len(self._ethernet_adapters) == adapters:
return
self._ethernet_adapters.clear()
for _ in range(0, adapters):
self._ethernet_adapters.append(EthernetAdapter(interfaces=4))
log.debug(
"IOL container '%s': number of 4-port Ethernet adapters set to %d",
self._name, adapters,
)
def _persistent_volume_list(self, image_info, include_network_config=True):
"""
Override: the runner requires ``/config`` (its config file, generated
below) and ``/tmp/run`` (its working directory: startup-config and
NVRAM live there — NETMAP and the netiomux sockets are ephemeral and
stay in the container's own /tmp). Auto-add both so a minimal
template cannot be misconfigured.
"""
volumes = super()._persistent_volume_list(image_info, include_network_config)
for needed in (self._IOL_CONFIG_DIR, self._IOL_RUN_DIR):
if not any(needed == v or needed.startswith(v.rstrip("/") + "/") for v in volumes):
volumes.append(needed)
return volumes
async def start(self):
await self._prepare_iol_runtime()
await super().start()
async def restart(self):
"""
Override: the base restart is a bare ``docker restart`` — the runner
would read a stale config (no adapter-count/memory refresh) and
uBridge would keep wiring to the previous run's sockets. Stop
gracefully (SIGTERM lets the runner flush NVRAM) and start again.
"""
await self.stop(graceful=True)
await self.start()
async def _prepare_iol_runtime(self):
"""
Regenerate the node's runtime files before the container starts:
* ``<working_dir>/tmp/run/`` must exist or the IOL process dies at
boot (the runner writes NETMAP there but does not create it).
* ``<working_dir>/config/iol-config.json`` is rewritten on every
start so adapter-count and memory changes take effect.
* Sockets and netio bus directories left in the wiring directory by a
previous (possibly SIGKILLed) run are removed — the runner rebinds
them on boot and would fail on a stale file.
``tmp/run`` (startup-config, NVRAM) is never touched. Neither is
anything while the container is already running (idempotent start of
a live node: the sockets belong to the running runner).
"""
try:
state = await self._get_container_state()
except DockerHttp404Error:
state = "stopped"
os.makedirs(os.path.join(self.working_dir, "tmp", "run"), exist_ok=True)
self._write_iol_config()
if state == "running":
return
wiring_dir = self._unix_socket_wiring_dir()
for pattern in ("s??.sock", "c??.sock"):
for stale in glob.glob(os.path.join(wiring_dir, pattern)):
with contextlib.suppress(OSError):
os.unlink(stale)
for netio_dir in glob.glob(os.path.join(wiring_dir, "netio*")):
shutil.rmtree(netio_dir, ignore_errors=True)
def _write_iol_config(self):
"""
Write the runner's config file on the host side of the /config volume.
The runner drops to user-id/group-id after its setup, so everything it
creates is owned by the server user — which is also what lets the
(unprivileged) uBridge write into the node's socket directory.
"""
config = {
"binary": "/binary.iol",
"memory": self._iol_memory,
"num-eth": self.adapters * 4, # every adapter is a 4-port unit
"num-serial": 0, # GNS3 docker adapters are ethernet-only
# IOL derives interface MACs from the local application ID
# (aabb.cc00.0<app><iface>0); every node needs a distinct one or
# linked routers share MACs and drop each other's frames as loops.
# Derived from the node ID: stable across restarts, unique enough
# (CML allocates per-lab sequential IDs for the same reason).
"local-app": int(self.id.replace("-", ""), 16) % 1022 + 1,
"remote-app": 1023, # netiomux's fake peer application ID
"user-id": os.getuid(),
"group-id": os.getgid(),
}
config_file = os.path.join(self.working_dir, "config", "iol-config.json")
os.makedirs(os.path.dirname(config_file), exist_ok=True)
with open(config_file, "w", encoding="utf-8") as f:
json.dump(config, f, indent=2)
f.write("\n")
log.debug("Wrote iol-runner config for '%s': %s", self._name, config)
async def _fix_permissions(self):
"""
Override: no-op. The generated config maps the runner to the server's
uid/gid, so no root-owned files ever appear in the volumes, and this
image has no shell for the container-side busybox pass anyway.
"""
self._permissions_fixed = True