Fixes a possible root cause of 11553 by only making 64 attempts at
most to pick a circuitID. Previously, we would test every possible
circuit ID until we found one or ran out.
This algorithm succeeds probabilistically. As the comment says:
This potentially causes us to give up early if our circuit ID
space is nearly full. If we have N circuit IDs in use, then we
will reject a new circuit with probability (N / max_range) ^
MAX_CIRCID_ATTEMPTS. This means that in practice, a few percent
of our circuit ID capacity will go unused.
The alternative here, though, is to do a linear search over the
whole circuit ID space every time we extend a circuit, which is
not so great either.
This makes new vs old clients distinguishable, so we should try to
batch it with other patches that do that, like 11438.
Right now this accounts for about 1% of circuits over all, but if you
pick a guard that's running 0.2.3, it will be about 6% of the circuits
running through that guard.
Making sure that every circuit has at least one ntor link means that
we're getting plausibly good forward secrecy on every circuit.
This implements ticket 9777,
The old code had logic to use a shorter path length if we didn't
have enough nodes. But we don't support 2-node networks anwyay.
Fix for #9926. I'm not calling this a bugfix on any particular
version, since a 2-node network would fail to work for you for a lot
of other reasons too, and it's not clear to me when that began, or if
2-node networks would ever have worked.
We need to subtract both the current built circuits *and* the attempted
circuits from the attempt count during scaling, since *both* have already been
counted there.
It seems that some versions of clang that would prefer the
-Wswitch-enum compiler flag to warn about switch statements with
missing enum values, even if those switch statements have a
default.
Fixes bug 8598; bugfix on 0.2.4.10-alpha.
Now that circid_t is 4 bytes long, the default integer promotions will
leave it alone when sizeof(int) == 4, which will leave us formatting an
unsigned as an int. That's technically undefined behavior.
Fixes bug 8447 on bfffc1f0fc. Bug not
in any released Tor.
These seem to have gotten conflicted out of existence while mike was
working on path bias stuff.
Thanks to sysrqb for collecting these in a handy patch.
Now we can specify to skip bridges that wouldn't be able to answer the
type of dir fetch we're launching.
It's still the responsibility of the rest of the code to prevent us from
launching a given dir fetch if we have no bridges that could handle it.
Now as we move into a future where most bridges can handle microdescs
we will generally find ourselves using them, rather than holding back
just because one of our bridges doesn't use them.
Also, deprecate the torrc options for the scaling values. It's unlikely anyone
but developers will ever tweak them, even if we provided a single ratio value.
If any circuits were opened during a scaling event, we were scaling attempts
and successes by different amounts. This leads to rounding error.
The fix is to record how many circuits are in a state that hasn't been fully
counted yet, and subtract that before scaling, and add it back afterwords.
Since they use RELAY_EARLY (which can be seen by all hops on the path),
it's not safe to say they actually count as a successful use.
There are also problems with trying to allow them to finish extending due to
the circuit purpose state machine logic. It is way less complicated (and
possibly more semantically coherent) to simply wait until we actually try to
do something with them before claiming we 'used' them.
Also, we shouldn't call timed out circuits 'used' either, for semantic
consistency.
Path use bias measures how often we can actually succeed using the circuits we
actually try to use. It is a subset of path bias accounting, but it is
computed as a separate statistic because the rate of client circuit use may
vary depending on use case.
This is an automatically generated commit, from the following perl script,
run with the options "-w -i -p".
s/smartlist_string_num_isin/smartlist_contains_int_as_string/g;
s/smartlist_string_isin((?:_case)?)/smartlist_contains_string$1/g;
s/smartlist_digest_isin/smartlist_contains_digest/g;
s/smartlist_isin/smartlist_contains/g;
s/digestset_isin/digestset_contains/g;
In general, if we tried to use a circ for a stream, but then decided to place
that stream on a different circuit, we need to probe the original circuit
before deciding it was a "success".
We also need to do the same for cannibalized circuits that go unused.
The unit of work sent to a cpuworker is now a create_cell_t; its
response is now a created_cell_t. Several of the things that call or
get called by this chain of logic now take create_cell_t or
created_cell_t too.
Since all cpuworkers are forked or spawned by Tor, they don't need a
stable wire protocol, so we can just send structs. This saves us some
insanity, and helps p
The handshake_digest field was never meaningfully a digest *of* the
handshake, but rather is a digest *from* the handshake that we exapted
to prevent replays of ESTABLISH_INTRO cells. The ntor handshake will
generate it as more key material rather than taking it from any part
of the circuit handshake reply..
I'm going to want a generic "onionskin" type and set of wrappers, and
for that, it will be helpful to isolate the different circuit creation
handshakes. Now the original handshake is in onion_tap.[ch], the
CREATE_FAST handshake is in onion_fast.[ch], and onion.[ch] now
handles the onion queue.
This commit does nothing but move code and adjust header files.
This has several advantages, including more resilience to ambient failure.
I still need to rename all the first_hop vars tho.. Saving that for a separate
commit.
Turns out there's more than one way to block a tagged circuit.
This seems to successfully handle all of the normal exit circuits. Hidden
services need additional tweaks, still.
Conflicts:
src/or/circuitbuild.c
There was a huge-looking conflict in circuitbuild.c, but the only
change that had been made to circuitbuild.c since I forked off the
split_circuitbuild branch was 17442560c4. So I took the
split_circuitbuild version of the conflicting part, and manually
re-applied the change from 17442560c44e8093f9a..
Conflicts:
src/or/circuitbuild.c
The conflict was trivial, since no line of code actually changed in
both branches: There was a fmt_addr() that turned into fmt_addrport()
in bug7011, and a "if (!n_conn)" that turned into "if (!n_chan)" in
master.
This is mostly a conversion from this pattern:
log("... %s:%d ...", fmt_and_decorate_addr(&addr), port);
to this:
log("... %s ...", fmt_addrport(&addr, port));
The output is the same in all cases.
Look at the address family of the preferred OR port rather than the
node.ipv6_preferred flag since the logic has changed with new
ClientUseIPv6 config option.
Fixes ticket 6884.
When I removed version_supports_begindir, I accidentally removed the
mechanism we had been using to make a directory cache self-test its
directory port. This caused bug 6815, which caused 6814 (both in
0.2.4.2-alpha).
To fix this bug, I'm replacing the "anonymized_connection" argument to
directory_initiate_command_* with an enumeration to say how indirectly
to connect to a directory server. (I don't want to reinstate the
"version_supports_begindir" argument as "begindir_ok" or anything --
these functions already take too many arguments.)
For safety, I made sure that passing 0 and 1 for 'indirection' gives
the same result as you would have gotten before -- just in case I
missed any 0s or 1s.
extend_info_from_node() used to use the primary OR port (i.e. IPv4)
unless the node had routerinfo. Now that we have IPv6 addresses in
microdescs we may want to use them.
Note that this patch changes using r->cache_info.identity_digest into
using node->identity. I count on these being well synchronised, or
things would break in other ways. Right?
Add ClientUseIPv6 and ClientPreferIPv6ORPort configuration options.
Use "preferred OR port" for all entry nodes, not only for bridges.
Mark bridges with "prefer IPv6 OR port" if an IPv6 address is
configured in Bridge line and ClientPreferIPv6ORPort is set.
Mark relays with "prefer IPv6 OR port" if an IPv6 address is found in
descriptor and ClientPreferIPv6ORPort is set.
Filter "preferred OR port" through the ClientUseIPv6 config option. We
might want to move this test to where actual connection is being set
up once we have a fall back mechanism in place.
Have only non-servers pick an IPv6 address for the first hop: We
don't want relays to connect over IPv6 yet. (IPv6 has never been used
for second or third hops.)
Implements ticket 5535.
We've had over two months to fix them, and didn't. Now we need
0.2.3.x stable. Yes, it would be cool to get this working in
0.2.3.x, but not at the expense of delaying every other feature that
_does_ work in 0.2.3.x. We can do a real fix in 0.2.4.
This is important, since otherwise an attacker can use timing info
to probe the internal network.
Also, add an option (ExtendAllowPrivateAddresses) so that
TestingTorNetwork won't break.
Fix for bug 6710; bugfix on all released versions of Tor.
Move extend_info_from_router() from circuitbuild.c to router.c and
make it static.
Add get_configured_bridge_by_orports_digest() and have
get_configured_bridge_by_routerinfo() and
node_is_a_configured_bridge() use it. We now consider all OR ports of
a bridge when looking for it.
Move node_get_*_orport to nodelist.c.
Fix a cut'n'paste error in header of nodelist.h.
Add node_assert_ok().
Add router_get_all_orports(). It's duplicating code from
node_get_all_orports(). Worth fixing at the cost of complicating the
API slightly?
This is done to avoid spurious warns. Additional log lines are also
added to try to track down the codepaths where we are somehow overcounting
success counts.
The SMARTLIST_FOREACH macro is more convenient than BEGIN/END when
you have a nice short loop body, but using it for long bodies makes
your preprocessor tell the compiler that all the code is on the same
line. That causes grief, since compiler warnings and debugger lines
will all refer to that one line.
So, here's a new style rule: SMARTLIST_FOREACH blocks need to be
short.
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.
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.
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.
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.
Also, try to resolve some doxygen issues. First, define a magic
"This is doxygen!" macro so that we take the correct branch in
various #if/#else/#endifs in order to get the right documentation.
Second, add in a few grouping @{ and @} entries in order to get some
variables and fields to get grouped together.
Previously, we only did this check at startup, which could lead to
us holding a guard indefinitely, and give weird results. Fixes bug
5380; bugfix on 0.2.1.14-rc.
(Patch by Roger; changes file and commit message by Nick)
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.
These were found by looking for tor_snprintf() instances that were
preceeded closely by tor_malloc(), though I probably converted some
more snprintfs as well.
(In every case, make sure that the length variable (if any) is
removed, renamed, or lowered, so that anything else that might have
assumed a longer buffer doesn't exist.)
