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#!/usr/bin/env python
# -*- coding: utf-8 -*-
""" Verify a v2 format migration stream """
from __future__ import print_function
import sys
import struct
import os, os.path
import syslog
import traceback
from xen.util import open_file_or_fd as open_file_or_fd
from xen.migration.verify import StreamError, RecordError
from xen.migration.libxc import VerifyLibxc
from xen.migration.libxl import VerifyLibxl
fin = None # Input file/fd
log_to_syslog = False # Boolean - Log to syslog instead of stdout/err?
verbose = False # Boolean - Summarise stream contents
quiet = False # Boolean - Suppress error printing
def info(msg):
"""Info message, routed to appropriate destination"""
if not quiet and verbose:
if log_to_syslog:
for line in msg.split("\n"):
syslog.syslog(syslog.LOG_INFO, line)
else:
print(msg)
def err(msg):
"""Error message, routed to appropriate destination"""
if not quiet:
if log_to_syslog:
for line in msg.split("\n"):
syslog.syslog(syslog.LOG_ERR, line)
print(msg, file = sys.stderr)
def stream_read(_ = None):
"""Read from input"""
return fin.read(_)
def rdexact(nr_bytes):
"""Read exactly nr_bytes from fin"""
_ = stream_read(nr_bytes)
if len(_) != nr_bytes:
raise IOError("Stream truncated")
return _
def unpack_exact(fmt):
"""Unpack a format from fin"""
sz = struct.calcsize(fmt)
return struct.unpack(fmt, rdexact(sz))
def skip_xl_header():
"""Skip over an xl header in the stream"""
hdr = rdexact(32)
if hdr != b"Xen saved domain, xl format\n \0 \r":
raise StreamError("No xl header")
_, mflags, _, optlen = unpack_exact("=IIII")
_ = rdexact(optlen)
info("Processed xl header")
if mflags & 2: # XL_MANDATORY_FLAG_STREAMv2
return "libxl"
else:
return "libxc"
def read_stream(fmt):
""" Read an entire stream """
try:
if fmt == "xl":
fmt = skip_xl_header()
if fmt == "libxc":
VerifyLibxc(info, stream_read).verify()
else:
VerifyLibxl(info, stream_read).verify()
except (IOError, StreamError, RecordError):
err("Stream Error:")
err(traceback.format_exc())
return 1
except Exception:
err("Script Error:")
err(traceback.format_exc())
err("Please fix me")
return 2
return 0
def main():
""" main """
from optparse import OptionParser
global fin, quiet, verbose
# Change stdout to be line-buffered.
sys.stdout = os.fdopen(sys.stdout.fileno(), 'w', 1)
parser = OptionParser(usage = "%prog [options]",
description =
"Verify a stream according to the v2 (or later) spec")
# Optional options
parser.add_option("-i", "--in", dest = "fin", metavar = "<FD or FILE>",
default = "0",
help = "Stream to verify (defaults to stdin)")
parser.add_option("-v", "--verbose", action = "store_true", default = False,
help = "Summarise stream contents")
parser.add_option("-q", "--quiet", action = "store_true", default = False,
help = "Suppress all logging/errors")
parser.add_option("-f", "--format", dest = "format",
metavar = "<libxc|libxl|xl>", default = "libxc",
choices = ["libxc", "libxl", "xl"],
help = "Format of the incoming stream (defaults to libxc)")
parser.add_option("--syslog", action = "store_true", default = False,
help = "Log to syslog instead of stdout")
opts, _ = parser.parse_args()
if opts.syslog:
global log_to_syslog
syslog.openlog("verify-stream-v2", syslog.LOG_PID)
log_to_syslog = True
verbose = opts.verbose
quiet = opts.quiet
fin = open_file_or_fd(opts.fin, "rb", 0)
return read_stream(opts.format)
if __name__ == "__main__":
try:
sys.exit(main())
except SystemExit as e:
sys.exit(e.code)
except KeyboardInterrupt:
sys.exit(2)
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