vdi-cloud/tools/usb-device-qmp.py

178 lines
6.7 KiB
Python

#!/usr/bin/env python3
"""Run on the PVE node as an administrator; the terminal never calls PVE APIs.
Runtime-only USB redirection, carried over a separately authenticated SSH tunnel.
No VM config writes, drivers, controller replacement or VM restarts.
"""
import argparse
import json
import re
import socket
import time
class Qmp:
def __init__(self, vm):
self.sock = socket.socket(socket.AF_UNIX, socket.SOCK_STREAM)
self.sock.settimeout(10)
self.sock.connect(f"/var/run/qemu-server/{vm}.qmp")
self.stream = self.sock.makefile("rwb", buffering=0)
greeting = json.loads(self.stream.readline())
if "QMP" not in greeting:
raise RuntimeError("Not a QMP socket")
self.sequence = 0
self.call("qmp_capabilities")
def call(self, command, arguments=None):
self.sequence += 1
ident = self.sequence
message = {"execute": command, "id": ident}
if arguments is not None:
message["arguments"] = arguments
self.stream.write(json.dumps(message).encode() + b"\n")
while True:
raw = self.stream.readline()
if not raw:
raise RuntimeError("QMP disconnected")
reply = json.loads(raw)
if reply.get("id") != ident:
continue
if "error" in reply:
raise RuntimeError(f"{command}: {reply['error']}")
return reply["return"]
def close(self):
self.stream.close()
self.sock.close()
def ids(vm):
return f"vdi_usb_box_{vm}", f"vdi_usb_redir_{vm}"
def peripherals(qmp):
return {x["name"] for x in qmp.call("qom-list", {"path": "/machine/peripheral"})}
def storage_filter(vendor=None, product=None):
"""Allow only USB Mass Storage, optionally narrowed to one VID/PID."""
if vendor is None or product is None:
return "0x08:-1:-1:-1:1|-1:-1:-1:-1:0"
return f"0x08:0x{vendor}:0x{product}:-1:1|-1:-1:-1:-1:0"
def attach(qmp, vm, port, bus, vendor=None, product=None):
channel, device = ids(vm)
channels = {x["label"]: x for x in qmp.call("query-chardev")}
if channel in channels or device in peripherals(qmp):
raise RuntimeError("POC endpoint already exists; inspect status before changing it")
qmp.call("chardev-add", {
"id": channel,
"backend": {"type": "socket", "data": {
"addr": {"type": "inet", "data": {"host": "127.0.0.1", "port": str(port)}},
"server": False, "reconnect-ms": 1000,
}},
})
try:
qmp.call("device_add", {
"driver": "usb-redir", "id": device, "chardev": channel, "bus": bus,
# QEMU uses ':' within rules; spice-client uses ',' instead.
"filter": storage_filter(vendor, product),
})
except Exception:
# Roll back only the channel created by this invocation.
qmp.call("chardev-remove", {"id": channel})
raise
def detach(qmp, vm):
channel, device = ids(vm)
if device in peripherals(qmp):
qmp.call("device_del", {"id": device})
deadline = time.monotonic() + 8
while device in peripherals(qmp):
if time.monotonic() >= deadline:
raise RuntimeError("USB removal pending; leave its channel intact and inspect guest")
time.sleep(0.2)
if any(x["label"] == channel for x in qmp.call("query-chardev")):
qmp.call("chardev-remove", {"id": channel})
def status(qmp, vm):
channel, device = ids(vm)
return {
"vm": vm,
"device_present": device in peripherals(qmp),
"channels": [x for x in qmp.call("query-chardev") if x["label"] == channel],
"usb": qmp.call("human-monitor-command", {"command-line": "info usb"}),
"vm_status": qmp.call("query-status"),
}
def ensure(qmp, vm, port, bus, vendor=None, product=None):
"""Attach the runtime endpoint if the VM is running and it is absent."""
channel, device = ids(vm)
if device not in peripherals(qmp):
attach(qmp, vm, port, bus, vendor, product)
def watch(vm, port, bus, vendor=None, product=None, interval=3):
"""Keep the runtime endpoint attached across VM restarts."""
while True:
try:
qmp = Qmp(vm)
try:
ensure(qmp, vm, port, bus, vendor, product)
finally:
qmp.close()
except (OSError, RuntimeError) as exc:
print(f"waiting for VM/QMP: {exc}", flush=True)
time.sleep(interval)
def main():
parser = argparse.ArgumentParser(description=__doc__)
parser.add_argument("action", choices=["status", "attach", "detach", "watch"])
parser.add_argument("--vm", type=int, required=True)
parser.add_argument("--port", type=int, default=40001)
parser.add_argument("--bus", default="ehci-2.0")
parser.add_argument("--vendor")
parser.add_argument("--product")
parser.add_argument("--any-storage", action="store_true",
help="Allow any pure USB Mass Storage device")
parser.add_argument("--guest-ejected", action="store_true",
help="Confirm the guest has safely ejected the USB device before detach")
args = parser.parse_args()
if args.vm < 100 or not 1 <= args.port <= 65535:
parser.error("invalid VM ID or local tunnel port")
if args.action in ("attach", "watch"):
exact = all(re.fullmatch(r"[0-9a-fA-F]{4}", x or "") for x in [args.vendor, args.product])
if args.any_storage and (args.vendor or args.product):
parser.error("--any-storage cannot be combined with --vendor/--product")
if not args.any_storage and not exact:
parser.error("attach/watch requires --any-storage or exact --vendor and --product")
elif args.any_storage or args.vendor or args.product:
parser.error("--vendor/--product/--any-storage are only valid for attach/watch")
if args.action == "watch":
watch(args.vm, args.port, args.bus,
None if args.any_storage else args.vendor.lower(),
None if args.any_storage else args.product.lower())
return
if args.action == "detach" and not args.guest_ejected:
parser.error("safely eject in the guest first, then pass --guest-ejected")
qmp = Qmp(args.vm)
try:
if args.action == "attach":
attach(qmp, args.vm, args.port, args.bus,
None if args.any_storage else args.vendor.lower(),
None if args.any_storage else args.product.lower())
elif args.action == "detach":
detach(qmp, args.vm)
print(json.dumps(status(qmp, args.vm), ensure_ascii=False, indent=2))
finally:
qmp.close()
if __name__ == "__main__":
main()