Nick Mathewson [Tue, 26 Jun 2012 14:55:23 +0000 (10:55 -0400)]
Fix a warning when using glibc's strcspn with clang.
With glibc 2.15 and clang 3.0, I get warnings from where we use the
strcpsn implementation in the header as strcspn(string, "="). This
is apparently because clang sees that part of the strcspn macro
expands to "="[2], and doesn't realize that that part of the macro
is only evaluated when "="[1] != 0.
Don't do DNS lookups when parsing corrupted managed proxy messages.
The functions parse_{s,c}method_line() were using
tor_addr_port_lookup() which is capable of doing DNS lookups. DNS
lookups should not be necessary when parsing {C,S}METHOD lines.
Nick Mathewson [Sat, 23 Jun 2012 19:51:48 +0000 (15:51 -0400)]
Catch a few more K&R violations with make check-spaces
We now catch bare {s that should be on the previous line with a do,
while, if, or for, and elses that should share a line with their
preceding }.
That is,
if (foo)
{
and
if (foo) {
...
}
else
are now detected.
We should think about maybe making Tor uncrustify-clean some day,
but configuring uncrustify is an exercise in bizarreness, and
reformatting huge gobs of Tor is always painful.
Nick Mathewson [Sat, 23 Jun 2012 19:30:01 +0000 (15:30 -0400)]
Resolve crash caused by format_helper_exit_status changes in #5557
Because the string output was no longer equal in length to
HEX_ERRNO_SIZE, the write() call would add some extra spaces and
maybe a NUL, and the NUL would trigger an assert in
get_string_from_pipe.
Fixes bug 6225; bug not in any released version of Tor.
Nick Mathewson [Tue, 19 Jun 2012 23:45:28 +0000 (19:45 -0400)]
Fix a regression bug in AllowDotExit
The code that detected the source of a remapped address checked that
an address mapping's source was a given rewrite rule if addr_orig had
no .exit, and addr did have a .exit after processing that rule. But
addr_orig was formatted for logging: it was not the original address
at all, but rather was the address escaped for logging and possibly
replaced with "[scrubbed]".
This new logic will correctly set ADDRMAPSRC_NONE in the case when the
address starts life as a .exit address, so that AllowDotExit can work
again.
Nick Mathewson [Tue, 19 Jun 2012 15:48:03 +0000 (11:48 -0400)]
Disable warning for marked-but-reading in main.c
It turns out this can happen. Even though there is no reason for
connections to be marked but reading, we leave them reading anyway,
so warning here is unwarranted. Let's turn that back on once we do
something sensible and disable reading when we mark. Bugfix for
6203 on Tor 0.2.3.17-beta.
Thanks to cypherpunks for pointing out the general stupidity of the
original code here.
Nick Mathewson [Sat, 16 Jun 2012 01:04:07 +0000 (21:04 -0400)]
More sophisticated attempt at detecting working linker options
On some platforms, the linker is perfectly happy to produce binaries
that won't run if you give it the wrong set of flags. So when not
cross-compiling, try to link-and-run a little test program, rather
than just linking it.
Nick Mathewson [Fri, 15 Jun 2012 14:50:41 +0000 (10:50 -0400)]
Check the correct consensus before giving it to the client
Previously, a directory would check the latest NS consensus for
having the signatures the client wanted, and use that consensus's
valid_until time to set the HTTP lifetime. With this patch, the
directory looks at NS consensus or the microdesc consensus,
depending on what the client asked for.
Mike Perry [Fri, 15 Jun 2012 04:15:08 +0000 (21:15 -0700)]
Lower the default path bias notice rate to 40%.
I saw 72% on a test run with 26 circuits. 70% might be a little close to the
line. That, or min_circs is too low and we need to be more patient. We still
need to test/simulate more.
Mike Perry [Fri, 4 May 2012 03:15:34 +0000 (20:15 -0700)]
Defend against entry node path bias attacks
The defense counts the circuit failure rate for each guard for the past N
circuits. Failure is defined as the ability to complete a first hop, but not
finish completing the circuit all the way to the exit.
If the failure rate exceeds a certain amount, a notice is emitted.
If it exceeds a greater amount, a warn is emitted and the guard is disabled.
These values are governed by consensus parameters which we intend to tune as
we perform experiments and statistical simulations.
Remove validate_pluggable_transports_config(): redundant since 9d9b5ed0.
The warning message of validate_pluggable_transports_config() is
superseded by the changes in the warning message of
connection_or_connect() when the proxy credentials can't be found.
Rob G. Jansen [Tue, 28 Feb 2012 23:19:49 +0000 (18:19 -0500)]
Fix busy Libevent loops (infinite loops in Shadow)
There is a bug causing busy loops in Libevent and infinite loops in
the Shadow simulator. A connection that is marked for close, wants
to flush, is held open to flush, but is rate limited (the token
bucket is empty) triggers the bug.
This commit fixes the bug. Details are below.
This currently happens on read and write callbacks when the active
socket is marked for close. In this case, Tor doesn't actually try
to complete the read or write (it returns from those methods when
marked), but instead tries to clear the connection with
conn_close_if_marked(). Tor will not close a marked connection that
contains data: it must be flushed first. The bug occurs when this
flush operation on the marked connection can not occur because the
connection is rate-limited (its write token bucket is empty).
The fix is to detect when rate limiting is preventing a marked
connection from properly flushing. In this case, it should be
flagged as read/write_blocked_on_bandwidth and the read/write events
de-registered from Libevent. When the token bucket gets refilled, it
will check the associated read/write_blocked_on_bandwidth flag, and
add the read/write event back to Libevent, which will cause it to
fire. This time, it will be properly flushed and closed.
The reason that both read and write events are both de-registered
when the marked connection can not flush is because both result in
the same behavior. Both read/write events on marked connections will
never again do any actual reads/writes, and are only useful to
trigger the flush and close the connection. By setting the
associated read/write_blocked_on_bandwidth flag, we ensure that the
event will get added back to Libevent, properly flushed, and closed.
Why is this important? Every Shadow event occurs at a discrete time
instant. If Tor does not properly deregister Libevent events that
fire but result in Tor essentially doing nothing, Libevent will
repeatedly fire the event. In Shadow this means infinite loop,
outside of Shadow this means wasted CPU cycles.
Nick Mathewson [Tue, 15 May 2012 19:32:18 +0000 (15:32 -0400)]
Implement the client side of proposal 198
This is a feature removal: we no longer fake any ciphersuite other
than the not-really-standard SSL_RSA_FIPS_WITH_3DES_EDE_CBC_SHA
(0xfeff). This change will let servers rely on our actually
supporting what we claim to support, and thereby let Tor migrate to
better TLS ciphersuites.
As a drawback, Tor instances that use old openssl versions and
openssl builds with ciphers disabled will no longer give the
"firefox" cipher list.
projects / thirdparty / tor.git / log
