Split the core reply formatting code out of control_fmt.c into
control_proto.c.  The remaining code in control_format.c deals with
specific subsystems and will eventually move to join those subsystems.

This makes it match control-spec.txt.

Now that the legacy handlers are gone, we can simplify the
structures and macros here.

These two presented their own challenge, because of their use of
QString, and their distinguished handling of quoted versus
non-quoted values.

This command does not fit perfectly with the others, since its
second argument is optional and may contain equal signs.  Still,
it's probably better to squeeze it into the new metaformat, since
doing so allows us to remove several pieces of the old
command-parsing machinery.

Here we get to throw away a LOT of unused code, since most of the
old parsing was redundant with kvline.

This should let us handle all (or nearly all) of the remaining
commands.

(This should be all of the command that work nicely with positional
arguments only.)

Some of these commands should probably treat extra arguments as
incorrect, but for now I'm trying to be careful not to break
any existing users.

The first line break in particular was mishandled: it was discarded
if no arguments came before it, which made it impossible to
distinguish arguments from the first line of the body.

To solve this, we need to allocate a copy of the command rather than
using NUL to separate it, since we might have "COMMAND\n" as our input.

Fixes ticket 29984.

There _is_ an underlying logic to these commands, but it isn't
wholly uniform, given years of tweaks and changes.  Fortunately I
think there is a superset that will work.

This commit adds a parser for some of the most basic cases -- the
ones currently handled by getargs_helper() and some of the
object-taking ones.  Soon will come initial tests; then I'll start using
the parser.

After that, I'll expand the parser to handle the other cases that come
up in the controller protocol.

Use a table-based lookup to find the right command handler.  This
will serve as the basement for several future improvements, as we
improve the API for parsing commands.

Also, split the formatting code shared by control.c and
control_events.c into controller_fmt.c.

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.

This makes it consistent with base64_decode().

Closes ticket 28913.

This patch adds support for the new STATUS message that PT's can emit
from their standard out. The STATUS message uses the `config_line_t` K/V
format that was recently added in Tor.

See: https://bugs.torproject.org/28846

This patch changes the LOG pluggable transport message to use the recent
K/V parser that landed in Tor. This allows PT's to specify the log
severity level as well as the message. A mapping between the PT log
severity levels and Tor's log serverity level is provided.

See: https://bugs.torproject.org/28846

This reverts commit 1b855af5.

Alexander Færøy authored Nov 29, 2018 and Nick Mathewson committed Dec 17, 2018

This patch changes our EVENT_TRANSPORT_LOG event to be EVENT_PT_LOG. The
new message includes the path to the PT executable instead of the
transport name, since one PT binary can include multiple transport they
sometimes might need to log messages that are not specific to a given
transport.

See: https://bugs.torproject.org/28179

Alexander Færøy authored Nov 23, 2018 and Nick Mathewson committed Dec 17, 2018

This patch adds support for the "LOG" protocol message from a pluggable
transport. This allows pluggable transport developers to relay log
messages from their binary to Tor, which will both emit them as log
messages from the Tor process itself, but also pass them on via the
control port.

See: https://bugs.torproject.org/28180
See: https://bugs.torproject.org/28181
See: https://bugs.torproject.org/28182

Closes ticket 28843.

Add the bootstrap tag name to the log messages, so people
troubleshooting connection problems can look up a symbol instead of a
number.  Closes ticket 28731.

Part of ticket 27402.

Reset the added bootstrap tracking state introduced by ticket 27169.
Fixes bug 28524; bugfix on 0.3.5.1-alpha.

This patch implements all of 28337, except for the part where we
turn off the role if we've been idle for a long time.

Part of making extra-dormant mode work; closes ticket 28421.