From 881980d3999c698e52cbe1299ca2e63dd3838170 Mon Sep 17 00:00:00 2001
From: Guillaume Valadon <guillaume.valadon@ssi.gouv.fr>
Date: Tue, 27 Jun 2017 13:08:54 +0200
Subject: [PATCH] Catch OSError exceptions from subprocess.Popen()
---
scapy/packet.py | 9 ++++--
scapy/plist.py | 6 ++--
scapy/utils.py | 76 +++++++++++++++++++++++++++++++++----------------
3 files changed, 62 insertions(+), 29 deletions(-)
diff --git a/scapy/packet.py b/scapy/packet.py
index 77f75c76..ac8dd4dd 100644
--- a/scapy/packet.py
+++ b/scapy/packet.py
@@ -19,7 +19,8 @@ from scapy.fields import StrField, ConditionalField, Emph, PacketListField, BitF
from scapy.config import conf
from scapy.base_classes import BasePacket, Gen, SetGen, Packet_metaclass
from scapy.volatile import VolatileValue
-from scapy.utils import import_hexcap,tex_escape,colgen,get_temp_file
+from scapy.utils import import_hexcap,tex_escape,colgen,get_temp_file, \
+ ContextManagerSubprocess
from scapy.error import Scapy_Exception, log_runtime
from scapy.consts import PYX
import scapy.modules.six as six
@@ -472,7 +473,8 @@ class Packet(six.with_metaclass(Packet_metaclass, BasePacket)):
if filename is None:
fname = get_temp_file(autoext=".eps")
canvas.writeEPSfile(fname)
- subprocess.Popen([conf.prog.psreader, fname+".eps"])
+ with ContextManagerSubprocess("psdump()"):
+ subprocess.Popen([conf.prog.psreader, fname+".eps"])
else:
canvas.writeEPSfile(filename)
@@ -489,7 +491,8 @@ class Packet(six.with_metaclass(Packet_metaclass, BasePacket)):
if filename is None:
fname = get_temp_file(autoext=".pdf")
canvas.writePDFfile(fname)
- subprocess.Popen([conf.prog.pdfreader, fname+".pdf"])
+ with ContextManagerSubprocess("pdfdump()"):
+ subprocess.Popen([conf.prog.pdfreader, fname+".pdf"])
else:
canvas.writePDFfile(filename)
diff --git a/scapy/plist.py b/scapy/plist.py
index e476756d..a066f490 100644
--- a/scapy/plist.py
+++ b/scapy/plist.py
@@ -432,7 +432,8 @@ lfilter: truth function to apply to each packet to decide whether it will be dis
if filename is None:
filename = get_temp_file(autoext=".ps")
d.writePSfile(filename)
- subprocess.Popen([conf.prog.psreader, filename+".ps"])
+ with ContextManagerSubprocess("psdump()"):
+ subprocess.Popen([conf.prog.psreader, filename+".ps"])
else:
d.writePSfile(filename)
print()
@@ -445,7 +446,8 @@ lfilter: truth function to apply to each packet to decide whether it will be dis
if filename is None:
filename = get_temp_file(autoext=".pdf")
d.writePDFfile(filename)
- subprocess.Popen([conf.prog.pdfreader, filename+".pdf"])
+ with ContextManagerSubprocess("psdump()"):
+ subprocess.Popen([conf.prog.pdfreader, filename+".pdf"])
else:
d.writePDFfile(filename)
print()
diff --git a/scapy/utils.py b/scapy/utils.py
index 6def3584..efa3698b 100644
--- a/scapy/utils.py
+++ b/scapy/utils.py
@@ -407,6 +407,27 @@ def ltoa(x):
def itom(x):
return (0xffffffff00000000>>x)&0xffffffff
+class ContextManagerSubprocess(object):
+ """
+ Context manager that eases checking for unknown command.
+
+ Example:
+ >>> with ContextManagerSubprocess("my custom message"):
+ >>> subprocess.Popen(["unknown_command"])
+
+ """
+ def __init__(self, name):
+ self.name = name
+
+ def __enter__(self):
+ pass
+
+ def __exit__(self, exc_type, exc_value, traceback):
+ if exc_type == OSError:
+ msg = "%s: executing %r failed"
+ log_scapy.error(msg, self.name, conf.prog.wireshark, exc_info=1)
+ return True # Suppress the exception
+
def do_graph(graph,prog=None,format=None,target=None,type=None,string=None,options=None):
"""do_graph(graph, prog=conf.prog.dot, format="svg",
target="| conf.prog.display", options=None, [string=1]):
@@ -456,7 +477,8 @@ def do_graph(graph,prog=None,format=None,target=None,type=None,string=None,optio
if conf.prog.display == conf.prog._default:
os.startfile(tempfile)
else:
- subprocess.Popen([conf.prog.display, tempfile])
+ with ContextManagerSubprocess("do_graph()"):
+ subprocess.Popen([conf.prog.display, tempfile])
_TEX_TR = {
"{":"{\\tt\\char123}",
@@ -1127,7 +1149,8 @@ def wireshark(pktlist):
"""Run wireshark on a list of packets"""
f = get_temp_file()
wrpcap(f, pktlist)
- subprocess.Popen([conf.prog.wireshark, "-r", f])
+ with ContextManagerSubprocess("wireshark()"):
+ subprocess.Popen([conf.prog.wireshark, "-r", f])
@conf.commands.register
def tcpdump(pktlist, dump=False, getfd=False, args=None,
@@ -1185,17 +1208,19 @@ u'64'
elif isinstance(prog, six.string_types):
prog = [prog]
if pktlist is None:
- proc = subprocess.Popen(
- prog + (args if args is not None else []),
- stdout=subprocess.PIPE if dump or getfd else None,
- stderr=open(os.devnull),
- )
+ with ContextManagerSubprocess("tcpdump()"):
+ proc = subprocess.Popen(
+ prog + (args if args is not None else []),
+ stdout=subprocess.PIPE if dump or getfd else None,
+ stderr=open(os.devnull),
+ )
elif isinstance(pktlist, six.string_types):
- proc = subprocess.Popen(
- prog + ["-r", pktlist] + (args if args is not None else []),
- stdout=subprocess.PIPE if dump or getfd else None,
- stderr=open(os.devnull),
- )
+ with ContextManagerSubprocess("tcpdump()"):
+ proc = subprocess.Popen(
+ prog + ["-r", pktlist] + (args if args is not None else []),
+ stdout=subprocess.PIPE if dump or getfd else None,
+ stderr=open(os.devnull),
+ )
elif DARWIN:
# Tcpdump cannot read from stdin, see
# <http://apple.stackexchange.com/questions/152682/>
@@ -1206,19 +1231,21 @@ u'64'
wrpcap(tmpfile, pktlist)
else:
tmpfile.close()
- proc = subprocess.Popen(
- prog + ["-r", tmpfile.name] + (args if args is not None else []),
- stdout=subprocess.PIPE if dump or getfd else None,
- stderr=open(os.devnull),
- )
+ with ContextManagerSubprocess("tcpdump()"):
+ proc = subprocess.Popen(
+ prog + ["-r", tmpfile.name] + (args if args is not None else []),
+ stdout=subprocess.PIPE if dump or getfd else None,
+ stderr=open(os.devnull),
+ )
conf.temp_files.append(tmpfile.name)
else:
- proc = subprocess.Popen(
- prog + ["-r", "-"] + (args if args is not None else []),
- stdin=subprocess.PIPE,
- stdout=subprocess.PIPE if dump or getfd else None,
- stderr=open(os.devnull),
- )
+ with ContextManagerSubprocess("tcpdump()"):
+ proc = subprocess.Popen(
+ prog + ["-r", "-"] + (args if args is not None else []),
+ stdin=subprocess.PIPE,
+ stdout=subprocess.PIPE if dump or getfd else None,
+ stderr=open(os.devnull),
+ )
try:
proc.stdin.writelines(iter(lambda: pktlist.read(1048576), ""))
except AttributeError:
@@ -1236,7 +1263,8 @@ def hexedit(x):
x = str(x)
f = get_temp_file()
open(f,"w").write(x)
- subprocess.call([conf.prog.hexedit, f])
+ with ContextManagerSubprocess("hexedit()"):
+ subprocess.call([conf.prog.hexedit, f])
x = open(f).read()
os.unlink(f)
return x
--
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