This project introduces the prob_distr.c subsystem which implements all the
probability distributions that WTF-PAD needs. It also adds unittests for all of
them.
Code and tests courtesy of Riastradh.
Co-authored-by: Taylor R Campbell <campbell+tor@mumble.net>
Co-authored-by: Mike Perry <mikeperry-git@torproject.org>
Hope is this will make it easier to test on the live tor network.
Does not need to be merged if we don't want to, but will come in handy
for researchers.
Co-authored-by: George Kadianakis <desnacked@riseup.net>
This implements all of the event handling, state machines, and padding
decisions for circuit padding.
I recommend reviewing this after you look at the call-in points into it from
the rest of Tor.
Co-authored-by: George Kadianakis <desnacked@riseup.net>
These callbacks allow the padding state machines to react to various types of
sent and received relay cells.
Co-authored-by: George Kadianakis <desnacked@riseup.net>
These event callbacks allow circuit padding to decide when to attempt to
launch and negotiate new padding machines, and when to tear old ones down.
Co-authored-by: George Kadianakis <desnacked@riseup.net>
This is a good code review start point, to get an overview of the interfaces
and types used in circuit padding.
Co-authored-by: George Kadianakis <desnacked@riseup.net>
We need this for padding negotiation so that we can have later machine
revisions supercede earlier ones.
Co-authored-by: George Kadianakis <desnacked@riseup.net>
signed_descriptor_digest has a length of DIGEST_LEN but the memset
used to fill it used DIGEST256_LEN.
Signed-off-by: Kris Katterjohn <katterjohn@gmail.com>
Redefine the set of bootstrap phases to allow display of finer-grained
progress in the early connection stages of connecting to a relay.
This includes adding intermediate phases for proxy and PT connections.
Also add a separate new phase to indicate obtaining enough directory
info to build circuits so we can report that independently of actually
initiating an ORCONN to build the first application circuit.
Previously, we would claim to be connecting to a relay when we had
merely finished obtaining directory info.
Part of ticket 27167.
Replace a few invocations of control_event_bootstrap() with calls from
the bootstrap tracker subsystem. This mostly leaves behavior
unchanged. The actual behavior changes come in the next commit.
Part of ticket 27167.
Linked connections aren't woken up by libevent due to I/O but rather
artificially so we can, by chunks, empty the spooled object(s).
Commit 5719dfb48f (in 0.3.4.1-alpha) made it
that the schedule_active_linked_connections_event would be only called once at
startup but this is wrong because then we would never go through again the
active linked connections.
Fortunately, everytime a new linked connection is created, the event is
activated and thus we would go through the active list again. On a busy relay,
this issue is mitigated by that but on a slower relays or bridge, a connection
could get stuck for a while until a new directory information request would
show up.
Fixes#28717, #28912
Add a tracker for bootstrap progress, tracking events related to
origin circuit and ORCONN states. This uses the ocirc_event and
orconn_event publish-subscribe subsystems.
Part of ticket 27167.
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.
Add a publish-subscribe subsystem to publish messages about changes to
OR connections.
connection_or_change_state() in connection_or.c and
control_event_or_conn_event() in control.c publish messages to this
subsystem via helper functions.
Move state constants from connection_or.h to orconn_state.h so that
subscribers don't have to include all of connection_or.h to take
actions based on changes in OR connection state. Move event constants
from control.h for similar reasons.
Part of ticket 27167.
connection_or_change_state() saved an old_state to pass to
channel_tls_handle_state_change_on_orconn(), which promptly cast it to
void. Remove this unused variable and parameter.
This patch changes the CancelIoEx() example code to use CancelIo(),
which is available for older versions of Windows too. I still think the
kernel handles this nicely by sending broken pipes if either side
closes the pipe while I/O operations are pending.
See: https://bugs.torproject.org/28179
Handle `ERROR_BROKEN_PIPE` from ReadFileEx() and WriteFileEx() in
process_win32_stdin_write_done() and
process_win32_handle_read_completion() instead of in the early handler.
This most importantmly makes sure that `reached_eof` is set to true when
these errors appears.
See: https://bugs.torproject.org/28179
This patch adds some missing calls to set `reached_eof` of our handles
when various error conditions happens or when we close our handle (which
happens at `process_terminate()`.
See: https://bugs.torproject.org/28179
This patch adds some additional error checking after calls to
ReadFileEx() and WriteFileEx(). I have not managed to get this code to
reach the branch where `error_code` is NOT `ERROR_SUCCESS`, but MSDN
says one should check for this condition so we do so just to be safe.
See: https://bugs.torproject.org/28179
This patch makes us delay checking for whether we have an exit code
value (via GetExitCodeProcess()) until both stdout and stderr have been
closed by the operating system either by the process itself or by
process cleanup after termination.
See: https://bugs.torproject.org/28179
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
Previously we had decoded the asn.1 to get a public key, and then
discarded the asn.1 so that we had to re-encode the key to store it
in the onion_pkey field of a microdesc_t or routerinfo_t.
Now we can just do a tor_memdup() instead, which should be loads
faster.
Previously, we would decode the PEM wrapper for keys twice: once in
get_next_token, and once later in PEM decode. Now we just do all of
the wrapper and base64 stuff in get_next_token, and store the
base64-decoded part in the token object for keys and non-keys alike.
This change should speed up parsing slightly by letting us skip a
bunch of stuff in crypto_pk_read_*from_string(), including the tag
detection parts of pem_decode(), and an extra key allocation and
deallocation pair.
Retaining the base64-decoded part in the token object will allow us
to speed up our microdesc parsing, since it is the asn1 portion that
we actually want to retain.
This patch makes sure that we terminate the event loop from the event
loop timer instead of directly in the process' exit handler. This allows
us to run the event loop an additional time to ensure that the SleepEx()
call on Windows is called and the data from stdout/stderr is delivered
to us.
Additionally we ensure that we don't try to read or write data from a
Unix process that have been terminated in the main loop, since its file
descriptors are closed at that time.
See: https://bugs.torproject.org/28179
This patch changes the API of the Windows backend of the Process
subsystem to allow the dormant interface to disable the Process event
timer.
See: https://bugs.torproject.org/28179
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
This patch changes our process_t's exit_callback to return a boolean
value. If the returned value is true, the process subsystem will call
process_free() on the given process_t.
See: https://bugs.torproject.org/28179
This patch changes the slow process_t tests to use
run_main_loop_until_done() instead of do_main_loop() since
do_main_loop() initializes a lot of subsystem callbacks that we don't
need to run in our tests.
See: https://bugs.torproject.org/28179
This patch disables fork()'ing of the slow process tests. This fixes the
tests on the MacOS and other kqueue() based platforms.
Without this patch the main loop exits eearly with EBADF as error.
See: https://bugs.torproject.org/28179
This patch moves the remaining code from subprocess.{h,c} to more
appropriate places in the process.c and process_win32.c module.
We also delete the now empty subprocess module files.
See: https://bugs.torproject.org/28179
This patch adds test cases for process_t which uses Tor's main loop.
This allows us to test that the callbacks are actually invoked by the
main loop when we expect them.
See: https://bugs.torproject.org/28179
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
This patch makes the managed proxy subsystem use the process_t data
structure such that we can get events from the PT process while Tor is
running and not just when the PT process is being configured.
See: https://bugs.torproject.org/28179
This patch adds a new function that allows us to reset the environment
of a given process_t with a list of key/value pairs.
See: https://bugs.torproject.org/28179
This patch makes sure that we call process_notify_event_exit() after we
have done any modifications we need to do to the state of a process_t.
This allows application developers to call process_free() in the
exit_callback of the process.
See: https://bugs.torproject.org/28179
This patch adds support for getting the unique process identifier from a
given process_t. This patch implements both support for both the Unix
and Microsoft Windows backend.
See: https://bugs.torproject.org/28179
This patch adds support for Microsoft Windows in the Process subsystem.
Libevent does not support mixing different types of handles (sockets,
named pipes, etc.) on Windows in its core event loop code. This have
historically meant that Tor have avoided attaching any non-networking
handles to the event loop. This patch uses a slightly different approach
to roughly support the same features for the Process subsystem as we do
with the Unix backend.
In this patch we use Windows Extended I/O functions (ReadFileEx() and
WriteFileEx()) which executes asynchronously in the background and
executes a completion routine when the scheduled read or write operation
have completed. This is much different from the Unix backend where the
operating system signals to us whenever a file descriptor is "ready" to
either being read from or written to.
To make the Windows operating system execute the completion routines of
ReadFileEx() and WriteFileEx() we must get the Tor process into what
Microsoft calls an "alertable" state. To do this we execute SleepEx()
with a zero millisecond sleep time from a main loop timer that ticks
once a second. This moves the process into the "alertable" state and
when we return from the zero millisecond timeout all the outstanding I/O
completion routines will be called and we can schedule the next reads
and writes.
The timer loop is also responsible for detecting whether our child
processes have terminated since the last timer tick.
See: https://bugs.torproject.org/28179
This patch adds the Unix backend for the Process subsystem. The Unix
backend attaches file descriptors from the child process's standard in,
out and error to Tor's libevent based main loop using traditional Unix
pipes. We use the already available `waitpid` module to get events
whenever the child process terminates.
See: https://bugs.torproject.org/28179
This patch adds a new Process subsystem for running external programs in
the background of Tor. The design is focused around a new type named
`process_t` which have an API that allows the developer to easily write
code that interacts with the given child process. These interactions
includes:
- Easy API for writing output to the child process's standard input
handle.
- Receive callbacks whenever the child has output on either its standard
output or standard error handles.
- Receive callback when the child process terminates.
We also support two different "protocols" for handling output from the
child process. The default protocol is the "line" protocol where the
process output callbacks will be invoked only when there is complete
lines (either "\r\n" or "\n" terminated). We also support the "raw"
protocol where the read callbacks will get whatever the operating system
delivered to us in a single read operation.
This patch does not include any operating system backends, but the Unix
and Windows backends will be included in separate commits.
See: https://bugs.torproject.org/28179
The strcmp_len() function was somewhat misconceived, since we're
only using it to test whether a length+extent string is equal to a
NUL-terminated string or not. By simplifying it and making it
inlined, we should be able to make it a little faster.
(It *does* show up in profiles.)
Closes ticket 28856.
The old implementation did some funky out-of-order lexing, and
tended to parse every port twice if the %d-%d pattern didn't match.
Closes ticket 28853.
I believe we originally added this for "just in case" safety, but it
isn't actually needed -- we never copy uninitialized stack here.
What's more, this one memset is showing up on our startup profiles,
so we ought to remove it.
Closes ticket 28852.
The point of this function is to make sure that the ed25519-based
implementation of curve25519_basepoint() actually works when we
start tor, and use the regular fallback implementation if it
doesn't. But it accounts for 9% of our startup time in the case
when we have directory information, and I think it's safe to make
the test shorter. After all, it has yet to find any actual bugs in
curved25519_scalarmult_basepoint_donna() on any platforms.
Closes ticket 28838.
When the clock jumps, and we have a record of last user activity,
adjust that record. This way if I'm inactive for 10 minutes and
then the laptop is sleeping for an hour, I'll still count as having
been inactive for 10 minutes.
Previously, we treat every jump as if it were activity, which is
ridiculous, and would prevent a Tor instance with a jumpy clock from
ever going dormant.
encoding and decoding.
There are bunches of places where we don't want to invest in a full
fuzzer, but we would like to make sure that some string operation
can handle all its possible inputs. This fuzzer uses the first byte
of its input to decide what to do with the rest of the input. Right
now, all the possibilities are decoding a string, and seeing whether
it is decodeable. If it is, we try to re-encode it and do the whole
thing again, to make sure we get the same result.
This turned up a lot of bugs in the key-value parser, and I think it
will help in other cases too.
Closes ticket 28808.
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.
Merge Phoul's two lists into teor's list.
Replace the 150 fallbacks originally introduced in Tor 0.3.3.1-alpha in
January 2018 (of which ~115 were still functional), with a list of
157 fallbacks (92 new, 65 existing, 85 removed) generated in
December 2018.
Closes ticket 24803.
Replace the 150 fallbacks originally introduced in Tor 0.3.3.1-alpha in
January 2018 (of which ~115 were still functional), with a list of
148 fallbacks (89 new, 59 existing, 91 removed) generated in
December 2018.
Closes ticket 24803.
When retrying all SOCKS connection because new directory information just
arrived, do not BUG() if a connection in state AP_CONN_STATE_RENDDESC_WAIT is
found to have a usable descriptor.
There is a rare case when this can happen as detailed in #28669 so the right
thing to do is put that connection back in circuit wait state so the
descriptor can be retried.
Fixes#28669
Signed-off-by: David Goulet <dgoulet@torproject.org>
This helper function marks an entry connection as pending for a circuit and
changes its state to AP_CONN_STATE_CIRCUIT_WAIT. The timestamps are set to
now() so it can be considered as new.
No behaviour change, this helper function will be used in next commit.
Part of #28669
Signed-off-by: David Goulet <dgoulet@torproject.org>
Use the helper function connection_ap_mark_as_waiting_for_renddesc()
introduced in previous commit everywhere in the code where an AP connection
state is transitionned to AP_CONN_STATE_RENDDESC_WAIT.
Part of #28669
Signed-off-by: David Goulet <dgoulet@torproject.org>
The transition for a connection to either become or go back in
AP_CONN_STATE_RENDDESC_WAIT state must make sure that the entry connection is
_not_ in the waiting for circuit list.
This commit implements the helper function
connection_ap_mark_as_waiting_for_renddesc() that removes the entry connection
from the pending list and then change its state. This code pattern is used in
many places in the code where next commit will remove this code duplication to
use this new helper function.
Part of #28669
Signed-off-by: David Goulet <dgoulet@torproject.org>
Rather than initializing the "Dormant" status to "off" and the "last
activity" count to "now", initialize them based on our state file:
stay dormant if we were dormant, or remember the amount of time
we've spent inactive.
Additionally, use it to test that is_staledesc is set correctly.
Eventually we'll want to test all the other flags, but I'm aiming
for only adding coverage on the changed code here.
Because the test is adding entries to the "rend_cache" directly, the
rend_cache_increment_allocation() was never called which made the
rend_cache_clean() call trigger that underflow warning:
rend_cache/clean: [forking] Nov 29 09:55:04.024 [warn] rend_cache_decrement_allocation(): Bug: Underflow in rend_cache_decrement_allocation (on Tor 0.4.0.0-alpha-dev 2240fe63feb9a8cf)
The test is still good and valid.
Fixes#28660
Signed-off-by: David Goulet <dgoulet@torproject.org>
This patch adds two new functions: buf_flush_to_pipe() and
buf_read_from_pipe(), which makes use of our new buf_flush_to_fd() and
buf_read_from_fd() functions.
See: https://bugs.torproject.org/28179
