This is ticket 2479. Roger's original explanation was:
We have a series of bugs where relays publish a descriptor within
12 hours of their last descriptor, but the authorities drop it
because it's not different "enough" from the last one and it's
too close to the last one.
The original goal of this idea was to a) reduce the number of new
descriptors authorities accept (and thus have to store) and b)
reduce the total number of descriptors that clients and mirrors
fetch. It's a defense against bugs where relays publish a new
descriptor every minute.
Now that we're putting out one consensus per hour, we're doing
better at the total damage that can be caused by 'b'.
There are broader-scale design changes that would help here, and
we've had a trac entry open for years about how relays should
recognize that they're not in the consensus, or recognize when
their publish failed, and republish sooner.
In the mean time, I think we should change some of the parameters
to make the problem less painful.
When we started RefuseUnknownExits back in 0.2.2.11-alpha, we
started making exits act like they cache directory info (since they
need an up-to-date idea of who is really a router). But this
included fetching needless (unrecognized) authorities' certs, which
doesn't make any sense for them.
This is related to, but not necessarily the same as, the issue that
Ian reported for bug #2297.
(This patch is based on a patch from a user who I believe has asked
not to be named. If I'm wrong about that, please add the
appropriate name onto the changelog.)
==
Nick here. I tweaked this patch a little to make it apply cleanly to
master, to extract some common code into a function, and to replace
snprintf with tor_snprintf.
-- nickm
Specifically, it was a fix on 33e2053ebc, where we introduced the
WRA_* and ROUTER_* codes for dirserv_add_descriptor. Previously, we
had checked for a _negative_ return from dirserv_add_descriptor, which
meant "rejected". An insufficiently new descriptor would give a
0-valued return. But when we switched from numbers to enums, we got
this check wrong and had init_keys() give an error whenever the
descriptor wasn't accepted.
This mitigates an attack proposed by wanoskarnet, in which all of a
client's bridges collude to restrict the exit nodes that the client
knows about. Fixes bug 5343.
Since 0.2.3.1-alpha, we've supported the Linux extensions to socket(),
open(), socketpair(), and accept() that enable us to create an fd and
make it close-on-exec with a single syscall. This not only saves us a
syscall (big deal), but makes us less vulnerable to race conditions
where we open a socket and then exec before we can make it
close-on-exec.
But these extensions are not supported on all Linuxes: They were added
between 2.6.23 or so and 2.6.28 or so. If you were to build your Tor
against a recent Linux's kernel headers, and then run it with a older
kernel, you would find yourselve unable to open sockets. Ouch!
The solution here is that, when one of these syscalls fails with
EINVAL, we should try again in the portable way. This adds an extra
syscall in the case where we built with new headers and are running
with old ones, but it will at least allow Tor to work.
Fixes bug 5112; bugfix on 0.2.3.1-alpha.
The big change here is a patch (first added to Libevent by Ed Day)
to make sure that the CreateProcess forked-test trick works even
when the main test program is invoked without its .exe suffix.
Previously we'd been using "we have clock_gettime()" as a proxy for
"we need -lrt to link a static libevent". But that's not really
accurate: we should only add -lrt if searching for clock_gettime
function adds -lrt to our libraries.
in Makefile.am, we used it without quoting it, causing build failure if
your openssl/sed/sha1sum happened to live in a directory with a space in
it (very common on windows)
This reverts commit 55e8cae815.
The conversation from irc:
> weasel: i had intended to leave torrc.sample.in alone in maint-0.2.2,
since i don't want to make all your stable users have to deal with
a torrc change. but nickm changed it. is it in fact the case that a
change in that file means a change in the deb?
<weasel> it means you'll prompt every single user who ever touched
their torrc
<weasel> and they will be asked if they like your new version better
than what they have right now
<weasel> so it's not great
Instead I changed the website to redirect requests for the tor-manual
URL listed in maint-0.2.2's torrc.sample.in so the link will still work.
If we don't do this, [::] can be interpreted to mean all v4 and all
v6 addresses. Found by dcf. Fixes bug 4760. See RFC 3493 section
5.3 for more info.
There was one MS_WINDOWS that remained because it wasn't on a macro
line; a few remaining uses (and the definition!) in configure.in;
and a now-nonsensical stanza of eventdns_tor.h that previously
defined 'WIN32' if it didn't exist.
Previously the client would ask the bridge for microdescriptors, which are
only supported in 0.2.3.x and later, and then fail to bootstrap when it
didn't get the answers it wanted. Fixes bug 4013; bugfix on 0.2.3.2-alpha.
The fix here is to revert to using normal descriptors if any of our
bridges are known to not support microdescs. This is not ideal, a) because
we'll start downloading a microdesc consensus as soon as we get a bridge
descriptor, and that will waste time if we later get a bridge descriptor
that tells us we don't like microdescriptors; and b) by changing our mind
we're leaking to our other bridges that we have an old-version bridge.
The alternate fix would have been to change
we_use_microdescriptors_for_circuits() to ask if *any* of our bridges
can support microdescriptors, and then change the directory logic that
picks a bridge to only select from those that do. For people living in
the future, where 0.2.2.x is obsolete, there won't be a difference.
Note that in either of these potential fixes, we have risk of oscillation
if our one funny-looking bridges goes away / comes back.
This option seems to be supported all the way back to at least 10.4, so
enabling it for OS X in general should be fine. If not, someone will
yell.
With no libs statically linked, that's a 3% win in binary size, with
just libevent linked statically, this gives us an advantage of 5% in
terms of binary size, and with libevent and openssl statically linked,
we gain over 18% or over 500KB.
Implements ticket 2915.
These were found by looking for tor_snprintf() instances that were
followed closely by tor_strdup(), though I probably converted some
other snprintfs as well.
(To ensure correctness, in every case, make sure that the temporary
variable is deleted, renamed, or lowered in scope, so we can't have
any bugs related to accidentally relying on the no-longer-filled
variable.)
To solve bug 4779, we want to avoid OpenSSL 1.0.0's counter mode.
But Fedora (and maybe others) lie about the actual OpenSSL version,
so we can't trust the header to tell us if it's safe.
Instead, let's do a run-time test to see whether it's safe, and if
not, use our built-in version.
fermenthor contributed a pretty essential fixup to this patch. Thanks!
When we have an effective bandwidthrate configured so that we cannot
exceed our bandwidth limit in one accounting interval, don't disable
advertising the dirport. Implements ticket 2434.
Fixes bug 4413; bugfix on xxxx.
Hostname components cannot be larger than 63 characters.
This simple check makes certain randlen cannot overflow rand_bytes_len.
We used to do this as a workaround for older Tors, but now it's never
the correct thing to do (especially since anything that didn't
understand RELAY_EARLY is now deprecated hard).
This patch should make us reject every Tor that was vulnerable to
CVE-2011-0427. Additionally, it makes us reject every Tor that couldn't
handle RELAY_EARLY cells, which helps with proposal 110 (#4339).
Previously we required 1.0.0, but there was a bug in the 1.0.0 counter
mode. Found by Pascal. Fixes bug 4779.
A more elegant solution would be good here if somebody has time to code
one.
Back in #1240, r1eo linked to information about how this could happen
with older Linux kernels in response to nmap. Bugs #4545 and #4547
are about how our approach to trying to deal with this condition was
broken and stupid. Thanks to wanoskarnet for reminding us about #1240.
This is a fix for the abovementioned bugs, and is a bugfix on
0.1.0.3-rc.
Preprocessor directives should not be put inside the arguments
of a macro. This is not supported on older GCC releases (< 3.3)
thus broke compilation on Haiku (running gcc2).
--enable-gcc-warnings enables two warnings that clang doesn't support,
so the build fails. We had hoped clang 3.0 would add those, but it
didn't, so let's just always disable those warnings when building with
clang. We can still fix it later once they add support
If a relay is dormant at startup, it will call init_keys before
crypto_set_tls_dh_prime. This is bad. Let's make it not so bad, because
someday it *will* happen again.
Conflicts:
src/or/connection_or.c
The conflict in src/or/connection_or.c is resolved by taking the
version in master, since e27a26d5 already fixed bug 4531 on master.
This merge just adds the changes file from 0.2.2.
Some controllers want this so they can mess with Tor's configuration
for a while via the control port before actually letting Tor out of
the house.
We do this with a new DisableNetwork option, that prevents Tor from
making any outbound connections or binding any non-control
listeners. Additionally, it shuts down the same functionality as
shuts down when we are hibernating, plus the code that launches
directory downloads.
To make sure I didn't miss anything, I added a clause straight to
connection_connect, so that we won't even try to open an outbound
socket when the network is disabled. In my testing, I made this an
assert, but since I probably missed something, I've turned it into a
BUG warning for testing.
This will mainly help distributors by giving a way to set system or package
defaults that a user can override, and that a later package can replace.
No promises about the particular future location or semantics for this:
we will probably want to tweak it some before 0.2.3.x-rc
The file is searched for in CONFDIR/torrc-defaults , which can be
overridden with the "--defaults-torrc" option on the command line.
This starts an effort to refactor torrc handling code to make it easier
to live with. It makes it possible to override exit policies from the
command line, and possible to override (rather than append to) socksport
lists from the command line.
It'll be necessary to make a "base" torrc implementation work at all.
This shaves about 7% off our per-cell AES crypto time for me; the
effect for accelerated AES crypto should be even more, since the AES
calculation itself will make an even smaller portion of the
counter-mode performance.
(We don't want to do this for pre-1.0.0 OpenSSL, since our AES_CTR
implementation was actually faster than OpenSSL's there, by about
10%.)
Fixes issue #4526.
The timercmp macro uses triggers a "space between function name and
opening parentheses" warning for the check spaces script. Work around
this by simply disabling the check for all "functions" named 'op()'.
The function is over 10 or 20% on some of Moritz's profiles, depending
on how you could.
Since it's checking for a multi-hour timeout, this is safe to do.
Fixes bug 4518.
Completely disable stats if we aren't running as a relay. We won't
collect any anyway, so setting up the infrastructure for them and
logging about them is wrong. This also removes a confusing log
message that clients without a geoip db would have seen.
Fixes bug 4353.
When running with IOCP, we are in theory able to use userspace-
allocated buffers to avoid filling up the stingy amount of kernel
space allocated for sockets buffers.
The bufferevent_async implementation in Libevent provides this
ability, in theory. (There are likely to be remaining bugs). This
patch adds a new option that, when using IOCP bufferevents, sets
each socket's send and receive buffers to 0, so that we should use
this ability.
When all the bugs are worked out here, if we are right about bug 98,
this might solve or mitigate bug 98.
This option is experimental and will likely require lots of testing
and debugging.
This is a fancier bug4457 workaround for 0.2.3. In 0.2.2, we could
just tell Libevent "Don't enable locking!" so it wouldn't try to make
the event_base notifiable. But for IOCP, we need a notifiable base.
(Eventually, we'll want a notifiable base for other stuff, like
multithreaded crypto.) So the solution is to try a full-featured
initialization, and then retry with all the options turned off if that
fails.
Conflicts:
src/common/compat_libevent.c
Resolving conflict by not taking 7363eae13c ("Use the
EVENT_BASE_FLAG_NOLOCK flag to prevent socketpair() invocation"): in
Tor 0.2.3.x, we _do_ sometimes use notifiable event bases.
In Tor 0.2.2, we never need the event base to be notifiable, since we
don't call it from other threads. This is a workaround for bug 4457,
which is not actually a Tor bug IMO.
This thing was pretty pointless on versions of OpenSSL 0.9.8 and later,
and almost totally pointless on OpenSSL 1.0.0.
Also, favor EVP by default, since it lets us get hardware acceleration
where present. (See issue 4442)
The old behavior was susceptible to the compiler optimizing out our
assertion check, *and* could still overflow size_t on 32-bit systems
even when it did work.
- Rename tor_tls_got_server_hello() to tor_tls_got_client_hello().
- Replaced some aggressive asserts with LD_BUG logging.
They were the innocent "I believe I understand how these callbacks
work, and this assert proves it" type of callbacks, and not the "If
this statement is not true, computer is exploding." type of
callbacks.
- Added a changes file.
We would stash the certs in the handshake state before checking them
for validity... and then if they turned out to be invalid, we'd give
an error and free them. Then, later, we'd free them again when we
tore down the connection.
Fixes bug 4343; fix on 0.2.3.6-alpha.
It used to mean "Force": it would tell tor-resolve to ask tor to
resolve an address even if it ended with .onion. But when
AutomapHostsOnResolve was added, automatically refusing to resolve
.onion hosts stopped making sense. So in 0.2.1.16-rc (commit
298dc95dfd), we made tor-resolve happy to resolve anything.
The -F option stayed in, though, even though it didn't do anything.
Oddly, it never got documented.
Found while fixing GCC 4.6 "set, unused variable" warnings.
Previously we did this nearer to the end (in the old_options &&
transition_affects_workers() block). But other stuff cares about
keys being consistent with options... particularly anything which
tries to access a key, which can die in assert_identity_keys_ok().
Fixes bug 3228; bugfix on 0.2.2.18-alpha.
Conflicts:
src/or/config.c
When we added support for separate client tls certs on bridges in
a2bb0bfdd5 we forgot to correctly initialize this when changing
from relay to bridge or vice versa while Tor is running. Fix that
by always initializing keys when the state changes.
Fixes bug 2433.
Conflicts:
src/or/config.c
We use a hash of the identity key to seed a prng to tell when an
accounting period should end. But thanks to the bug998 changes,
clients no longer have server-identity keys to use as a long-term seed
in accounting calculations. In any case, their identity keys (as used
in TLS) were never never fixed. So we can just set the wakeup time
from a random seed instead there. Still open is whether everybody
should be random.
This patch fixes bug 2235, which was introduced in 0.2.2.18-alpha.
Diagnosed with help from boboper on irc.
From the code:
zlib 1.2.4 and 1.2.5 do some "clever" things with macros. Instead of
saying "(defined(FOO) ? FOO : 0)" they like to say "FOO-0", on the theory
that nobody will care if the compile outputs a no-such-identifier warning.
Sorry, but we like -Werror over here, so I guess we need to define these.
I hope that zlib 1.2.6 doesn't break these too.
Possible fix for bug 1526.
To get a better idea what's going on on Tonga, add some code to report
how often the most and least frequently fetched descriptor was fetched,
as well as 25, 50, 75 percentile.
Also ensure we only count bridge descriptors here.
This is used for the bridge authority currently, to get a better
intuition on how many descriptors are actually fetched from it and how
many fetches happen in total.
Implements ticket 4200.
Fixes bug 4259, bugfix on 0.2.2.25-alpha. Bugfix by "Tey'".
Original message by submitter:
Changing nodes restrictions using a controller while Tor is doing
DNS resolution could makes Tor crashes (on WinXP at least). The
problem can be repeated by trying to reach a non-existent domain
using Tor:
curl --socks4a 127.0.0.1:9050 inexistantdomain.ext
.. and changing the ExitNodes parameter through the control port
before Tor returns a DNS resolution error (of course, the following
command won't work directly if the control port is password
protected):
echo SETCONF ExitNodes=TinyTurtle | nc -v 127.0.0.1 9051
Using a non-existent domain is needed to repeat the issue so that
Tor takes a few seconds for resolving the domain (which allows us to
change the configuration). Tor will crash while processing the
configuration change.
The bug is located in the addressmap_clear_excluded_trackexithosts
method which iterates over the entries of the addresses map in order
to check whether the changes made to the configuration will impact
those entries. When a DNS resolving is in progress, the new_adress
field of the associated entry will be set to NULL. The method
doesn't expect this field to be NULL, hence the crash.
Now let's have "lookup" indicate that there can be a hostname
resolution, and "parse" indicate that there wasn't. Previously, we
had one "lookup" function that did resolution; four "parse" functions,
half of which did resolution; and a "from_str()" function that didn't
do resolution. That's confusing and error-prone!
The code changes in this commit are exactly the result of this perl
script, run under "perl -p -i.bak" :
s/tor_addr_port_parse/tor_addr_port_lookup/g;
s/parse_addr_port(?=[^_])/addr_port_lookup/g;
s/tor_addr_from_str/tor_addr_parse/g;
This patch leaves aton and pton alone: their naming convention and
behavior is is determined by the sockets API.
More renaming may be needed.
Change the default values for collecting directory request statistics and
inlcuding them in extra-info descriptors to 1.
Don't break if we are configured to collect directory request or entry
statistics and don't have a GeoIP database. Instead, print out a notice
and skip initializing the affected statistics code.
This is the cherry-picked 499661524b.
