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authorPeter Wu <peter@lekensteyn.nl>2016-10-16 17:05:46 +0200
committerPeter Wu <peter@lekensteyn.nl>2016-10-16 22:45:09 +0000
commit763a059fe967b5be4db4ca7b07279ae990a07c7d (patch)
treeb91117338de8ff4cdc6be841b83d4bc52c404779 /doc/extcap_example.py
parent2176423b4ab5ddb5b23d9bfd1417c7280b3f5129 (diff)
extcap_example.py: fix hang on exit
I guess that when SIGINT is intercepted, then the writes are restarted and the doExit condition is never checked. Remove this racy check in favor of catching the KeyboardInterrupt exception. Test: tshark -i example1; kill tshark; check process list for python. Bug: 11657 Change-Id: Ia8b1ee560b9dcd31dd91df27fbfb8e91237581c9 Reviewed-on: https://code.wireshark.org/review/18218 Petri-Dish: Peter Wu <peter@lekensteyn.nl> Reviewed-by: Stig Bjørlykke <stig@bjorlykke.org> Tested-by: Petri Dish Buildbot <buildbot-no-reply@wireshark.org> Reviewed-by: Peter Wu <peter@lekensteyn.nl>
Diffstat (limited to 'doc/extcap_example.py')
-rwxr-xr-xdoc/extcap_example.py61
1 files changed, 20 insertions, 41 deletions
diff --git a/doc/extcap_example.py b/doc/extcap_example.py
index de28da01af..0847cb5648 100755
--- a/doc/extcap_example.py
+++ b/doc/extcap_example.py
@@ -57,7 +57,6 @@ ERROR_INTERFACE = 2
ERROR_FIFO = 3
ERROR_DELAY = 4
-doExit = False
globalinterface = 0
"""
@@ -87,10 +86,6 @@ class ArgumentParser(argparse.ArgumentParser):
raise exc
super(ArgumentParser, self).error(message)
-def signalHandler(signal, frame):
- global doExit
- doExit = True
-
#### EXTCAP FUNCTIONALITY
"""@brief Extcap configuration
@@ -212,47 +207,28 @@ def pcap_fake_package ( message, fake_ip ):
return pcap
def extcap_capture(interface, fifo, delay, verify, message, remote, fake_ip):
- global doExit
-
- signal.signal(signal.SIGINT, signalHandler)
- signal.signal(signal.SIGTERM , signalHandler)
-
tdelay = delay if delay != 0 else 5
- try:
- os.stat(fifo)
- except OSError:
- doExit = True
- print ( "Fifo does not exist, exiting!" )
+ if not os.path.exists(fifo):
+ print ( "Fifo does not exist, exiting!", file=sys.stderr )
+ sys.exit(1)
- fh = open(fifo, 'w+b', 0 )
- fh.write (pcap_fake_header())
+ with open(fifo, 'wb', 0 ) as fh:
+ fh.write (pcap_fake_header())
- while doExit == False:
- out = ("%s|%04X%s|%s" % ( remote.strip(), len(message), message, verify )).encode("utf8")
- try:
+ while True:
+ out = ("%s|%04X%s|%s" % ( remote.strip(), len(message), message, verify )).encode("utf8")
fh.write (pcap_fake_package(out, fake_ip))
time.sleep(tdelay)
- except IOError:
- doExit = True
-
- fh.close()
-def extcap_close_fifo(interface, fifo):
- global doExit
+def extcap_close_fifo(fifo):
+ if not os.path.exists(fifo):
+ print ( "Fifo does not exist!", file=sys.stderr )
+ return
- signal.signal(signal.SIGINT, signalHandler)
- signal.signal(signal.SIGTERM , signalHandler)
-
- tdelay = delay if delay != 0 else 5
-
- try:
- os.stat(fifo)
- except OSError:
- doExit = True
- print ( "Fifo does not exist!" )
-
- fh = open(fifo, 'w+b', 0 )
+ # This is apparently needed to workaround an issue on Windows/macOS
+ # where the message cannot be read. (really?)
+ fh = open(fifo, 'wb', 0 )
fh.close()
####
@@ -301,7 +277,7 @@ if __name__ == '__main__':
elif ( fifo_found == 1 ):
fifo = arg
break
- extcap_close_fifo("", fifo)
+ extcap_close_fifo(fifo)
sys.exit(ERROR_ARG)
if ( len(sys.argv) <= 1 ):
@@ -340,10 +316,13 @@ if __name__ == '__main__':
# The following code demonstrates error management with extcap
if args.delay > 5:
print("Value for delay [%d] too high" % args.delay, file=sys.stderr)
- extcap_close_fifo(interface, args.fifo)
+ extcap_close_fifo(args.fifo)
sys.exit(ERROR_DELAY)
- extcap_capture(interface, args.fifo, args.delay, args.verify, message, args.remote, fake_ip)
+ try:
+ extcap_capture(interface, args.fifo, args.delay, args.verify, message, args.remote, fake_ip)
+ except KeyboardInterrupt:
+ pass
else:
usage()
sys.exit(ERROR_USAGE)