Add a publish-subscribe subsystem to publish messages about changes to
origin circuits.

Functions in circuitbuild.c and circuitlist.c publish messages to this
subsystem.

Move circuit event constants out of control.h so that subscribers
don't have to include all of control.h to take actions based on
messages they receive.

Part of ticket 27167.

When storing a descriptor in the client cache, if we are about to replace an
existing descriptor, make sure to close every introduction circuits of the old
descriptor so we don't have leftovers lying around.

Ticket 27471 describes a situation where tor is sending an INTRODUCE1 cell on
an introduction circuit for which it doesn't have a matching intro point
object (taken from the descriptor).

The main theory is that, after a new descriptor showed up, the introduction
points changed which led to selecting an introduction circuit not used by the
service anymore thus for which we are unable to find the corresponding
introduction point within the descriptor we just fetched.

Closes #27471.

Signed-off-by: David Goulet <dgoulet@torproject.org>

It differs from the rest of the rephist code in that it's actually
necessary for Tor to operate, so it should probably go somewhere
else.  I'm not sure where yet, so I'll leave it in the same
directory, but give it its own file.

Parts of this C file naturally belong in dircache, dirclient, and
dircommon: so, move them there.

The main.c code is responsible for initialization and shutdown;
the mainloop.c code is responsible for running the main loop of Tor.

Splitting the "generic event loop" part of mainloop.c from the
event-loop-specific part is not done as part of this patch.

The parts for handling cell formats should be in src/core/or.

The parts for handling onionskin queues should be in src/core/or.

Only the crypto wrapper belongs in src/core/crypto.

I am very glad to have written this script.

This commit won't build yet -- it just puts everything in a slightly
more logical place.

The reasoning here is that "src/core" will hold the stuff that every (or
nearly every) tor instance will need in order to do onion routing.
Other features (including some necessary ones) will live in
"src/feature".  The "src/app" directory will hold the stuff needed
to have Tor be an application you can actually run.

This commit DOES NOT refactor the former contents of src/or into a
logical set of acyclic libraries, or change any code at all.  That
will have to come in the future.

We will continue to move things around and split them in the future,
but I hope this lays a reasonable groundwork for doing so.

These were mostly cases where our previous macros had been casting,
and the values that we were trying to printf were not in fact
uint64_t.

The standard is printf("%"PRIu64, x);

or.h should really include only the minimum of stuff from or/*,
common/*, and lib/*.

More modules use this than I had expected!

Implements ticket 25932.

 * ADD new /src/common/crypto_rand.[ch] module.
 * ADD new /src/common/crypto_util.[ch] module (contains the memwipe()
   function, since all crypto_* modules need this).
 * FIXES part of #24658: https://bugs.torproject.org/24658

Alexander Færøy authored Feb 27, 2018 and Nick Mathewson committed Mar 20, 2018

This patch adds some additional logging to circuits_handle_oom() to give
us more information about which specific compression backend that is
using a certain amount of memory.

See: https://bugs.torproject.org/25372

Additionally, this change extracts the functions that created and
freed these elements.

These structures had common "forward&reverse stream&digest"
elements, but they were initialized and freed through cpath objects,
and different parts of the code depended on them.  Now all that code
is extacted, and kept in relay_crypto.c

Since 0.2.4, tor uses EWMA circuit policy to prioritize. The previous
algorithm, round-robin, hasn't been used since then but was still used as a
fallback.

Now that EWMA is mandatory, remove that code entirely and enforce a cmux
policy to be set.

This is part of a circuitmux cleanup to improve performance and reduce
complexity in the code. We'll be able to address future optimization with this
work.

Closes #25268

Signed-off-by: David Goulet <dgoulet@torproject.org>

This removes the code that tracks the extend attemps a client makes. We don't
use it and it was only used to provide statistics on a SIGUSR1 from the
rephist dump stats function.

Part of #25163

Signed-off-by: David Goulet <dgoulet@torproject.org>

Tor preemptiely builds circuits and they can be cannibalized later in their
lifetime. A Guard node can become unusable (from our guard state) but we can
still have circuits using that node opened. It is important to not pick those
circuits for any usage through the cannibalization process.

Fixes #24469

Signed-off-by: David Goulet <dgoulet@torproject.org>

This is only half of the changes needed. We should also parameterize the
number of concurrent cbt learning circuits in needs_circuits_for_build().

Prebuilt circs are 4 hops, since only server side HSDIR and intro circs
are 3 hops, and it is OK if those sometimes take longer to build.

This lets us control their path len and usage.

Define TOR_PRIuSZ as minGW compiler doesn't support zu format specifier for
size_t type.

Fixes #24861 on ac9eebd6

.

Signed-off-by: Fernando Fernandez Mancera <ffernandezmancera@gmail.com>

Exposing cell_queues_get_total_allocation(), buf_get_total_allocation(),
tor_compress_get_total_allocation(), tor_compress_get_total_allocation() when
hit MaxMemInQueues threshold.

Fixes #24501

Signed-off-by: Fernando Fernandez Mancera <ffernandezmancera@gmail.com>

This covers addressmap.h (no change needed) through confparse.h