Brian Warner d27a57cb49 Avoid Popen() of executables that don't exist ... The stdlib 'subprocess' module in python-2.7.4 through 2.7.7 suffers from http://bugs.python.org/issue18851 which causes unrelated file descriptors to be closed when `subprocess.call()` fails the `exec()`, such as when the executable being invoked does not actually exist. There appears to be some randomness involved. This was fixed in python-2.7.8. Tahoe's iputil.py uses subprocess.call on many different "ifconfig"-type executables, most of which don't exist on any given platform (added in git commit 8e31d66cd0). This results in a lot of file-descriptor closing, which (at least during unit tests) tends to clobber important things like Tub TCP sockets. This seems to be the root cause behind ticket:2121, in which normal code tries to close already-closed sockets, crashing the unit tests. Since different platforms have different ifconfigs, some platforms will experience more failed execs than others, so this bug could easily behave differently on linux vs freebsd, as well as working normally on python-2.7.8 or 2.7.4. This patch inserts a guard to make sure that os.path.isfile() is true before allowing Popen.call() to try executing the target. This ought to be enough to avoid the bug. It changes both iputil.py and allmydata.__init__ (which uses Popen for calling "lsb_release"), which are all the places where 'subprocess' is used outside of unit tests. Other potential fixes: use the 'subprocess32' module from PyPI (which is a bug-free backport of the Python3 stdlib subprocess module, but would introduce a new dependency), or require python >= 2.7.8 (but this would rule out development/deployment on the current OS-X 10.9 release, which ships with 2.7.5, as well as other distributions like Ubuntu 14.04 LTS). I believe this closes ticket:2121, and given the apparent relationship between 2121 and 2023, I think it also closes ticket:2023 (although since 2023 doesn't have copies of the failing log files, it's hard to tell). I'm hoping that this will tide us over until 1.11 is released, at which point we can execute on the plan to remove iputil.py entirely by changing the way that nodes learn their externally-facing IP address.		2014-09-12 13:01:56 -07:00
..
__init__.py
abbreviate.py	Make abbreviate_space able to output in exabytes. refs #1812	2012-12-27 20:08:27 +00:00
assertutil.py	Change relative imports to absolute	2010-02-26 01:14:33 -07:00
base32.py	Change relative imports to absolute	2010-02-26 01:14:33 -07:00
base62.py	remove interpreter shbang lines from non-executables	2011-10-14 10:23:01 -07:00
cachedir.py
consumer.py	setup: ignore _darcs in the "test-clean" test and make the "clean" step remove all .egg's in the root dir	2009-12-06 10:48:35 -08:00
deferredutil.py	util: deferredutil: undo my recent patch to use our own implementation of gatherResults	2009-01-07 11:00:05 -07:00
dictutil.py	dictutil.DictOfSets: remove .union() method, it was misleading	2012-05-16 16:55:09 -07:00
encodingutil.py	Only quote newline characters where necessary. fixes #1484	2013-03-07 16:22:47 +00:00
fake_inotify.py	Drop-upload frontend, rerecorded for 1.9 beta (and correcting a minor mistake). Includes some fixes for Windows but not the Windows inotify implementation. fixes #1429	2011-08-08 16:40:49 -07:00
fileutil.py	Revert [603f5eba32] which was applied unintentionally.	2014-05-05 22:09:33 +01:00
happinessutil.py	util/happinessutil.py: suppress a warning from check-miscaptures. (It is not a bug because the capturing function is only used by a 'map' in the same iteration.) refs #1556	2011-10-08 22:21:06 -07:00
hashutil.py	Use bigger random one-time keys in timing_safe_compare. fixes #2165	2014-02-24 20:43:23 +00:00
humanreadable.py	doc: licensing cleanups	2009-09-20 10:16:31 -07:00
idlib.py
iputil.py	Avoid Popen() of executables that don't exist	2014-09-12 13:01:56 -07:00
keyutil.py	'tahoe admin generate-keypair/derive-pubkey': add Ed25519 keypair commands	2012-03-13 18:24:32 -07:00
limiter.py	switch all foolscap imports to use foolscap.api or foolscap.logging	2009-05-21 17:38:23 -07:00
log.py	Change relative imports to absolute	2010-02-26 01:14:33 -07:00
mathutil.py	hush pyflakes-0.4.0 warnings: remove trivial unused variables. For #900.	2010-01-14 14:15:29 -08:00
netstring.py	directories: keep track of your position as you decode netstring after netstring from an input buffer instead of copying the trailing part	2009-07-04 19:51:09 -07:00
nummedobj.py	Change relative imports to absolute	2010-02-26 01:14:33 -07:00
observer.py	util/observer.py: add EventStreamObserver	2010-08-04 00:26:12 -07:00
pipeline.py	PipelineError: fix str() on python2.4 . Closes #842.	2009-11-24 13:25:12 -08:00
pkgresutil.py
pollmixin.py	tests: raise the timeout on pollmixin from 100s to 1000s -- it looks like it may have triggered too eagerly on Zandr's 266 MHz armel	2009-07-08 21:47:29 -07:00
repeatable_random.py	Change relative imports to absolute	2010-02-26 01:14:33 -07:00
rrefutil.py	Fix introweb display for mixed V1/V2 clients. Closes #1721.	2012-04-23 18:30:53 -04:00
sibpath.py
spans.py	util/spans.py: __nonzero__ cannot return a long either. for #1154	2010-08-05 11:55:07 -07:00
statistics.py	setup: fix error in licensing declaration from Shawn Willden, as noted by the FSF compliance division	2010-03-09 08:37:36 -08:00
time_format.py	trivial: remove obsolete comment text	2009-07-20 06:08:43 -07:00
verlib.py	setup.py: get version from git or darcs	2011-12-04 20:40:01 -08:00