Commit Graph

334 Commits

Author SHA1 Message Date
Roger Dingledine
6190593256 use channel_is_client for create cell counts
When a relay is collecting internal statistics about how many
create cell requests it has seen of each type, accurately count the
requests from relays that temporarily fall out of the consensus.

(To be extra conservative, we were already ignoring requests from clients
in our counts, and we continue ignoring them here.)

Fixes bug 24910; bugfix on 0.2.4.17-rc.
2018-04-02 01:00:31 -04:00
Roger Dingledine
a7440d9c9d more fixes for typos, grammar, whitespace, etc
some of these ought to have been noticed by the "misspell" tool,
so if anybody is debugging it, here are some bug reports :)
2018-02-07 12:22:29 -05:00
David Goulet
cd81403cc0 Merge branch 'ticket24902_029_05' into ticket24902_033_02 2018-01-30 09:33:12 -05:00
David Goulet
1bfc91a029 dos: Apply defense for circuit creation DoS
If the client address was detected as malicious, apply a defense which is at
this commit to return a DESTROY cell.

Signed-off-by: David Goulet <dgoulet@torproject.org>
2018-01-30 09:18:15 -05:00
David Goulet
97abb3543b dos: Detect circuit creation denial of service
Add a function that notifies the DoS subsystem that a new CREATE cell has
arrived. The statistics are updated accordingly and the IP address can also be
marked as malicious if it is above threshold.

At this commit, no defense is applied, just detection with a circuit creation
token bucket system.

Signed-off-by: David Goulet <dgoulet@torproject.org>
2018-01-30 09:18:15 -05:00
Nick Mathewson
4e653ac2ca Merge branch 'maint-0.3.1' into maint-0.3.2 2018-01-17 11:12:15 -05:00
Roger Dingledine
af8cadf3a9 Remove false positives from channel_is_client()
Fix a set of false positives where relays would consider connections
to other relays as being client-only connections (and thus e.g.
deserving different link padding schemes) if those relays fell out
of the consensus briefly.

Now we look only at the initial handshake and whether the connection
authenticated as a relay.

Fixes bug 24898; bugfix on 0.3.1.1-alpha.
2018-01-15 22:33:40 -05:00
Nick Mathewson
91467e04b1 Merge branch 'bug22805_v2_squashed' 2017-09-22 08:58:17 -04:00
Nick Mathewson
95a7e7e925 Stop using CREATE_FAST as a signifier of clienthood.
Relays send it, and we may as well let them.  Part of our fix for
22805.
2017-09-22 08:57:45 -04:00
Nick Mathewson
d1e0e486e9 Stop clearing the is_client flag on channel directly 2017-09-22 08:55:53 -04:00
Nick Mathewson
c1deabd3b0 Run our #else/#endif annotator on our source code. 2017-09-15 16:24:44 -04:00
George Kadianakis
c4d17faf81 Explicit length checks in circuit_init_cpath_crypto(). 2017-07-07 11:12:27 -04:00
Nick Mathewson
4d30dde156 Merge branch 'netflow_padding-v6-rebased2-squashed' 2017-05-08 13:54:59 -04:00
Mike Perry
02a5835c27 Fix issues from dgoulet's code review.
https://gitlab.com/dgoulet/tor/merge_requests/24
2017-05-08 13:49:23 -04:00
Mike Perry
b0e92634d8 Netflow record collapsing defense.
This defense will cause Cisco, Juniper, Fortinet, and other routers operating
in the default configuration to collapse netflow records that would normally
be split due to the 15 second flow idle timeout.

Collapsing these records should greatly reduce the utility of default netflow
data for correlation attacks, since all client-side records should become 30
minute chunks of total bytes sent/received, rather than creating multiple
separate records for every webpage load/ssh command interaction/XMPP chat/whatever
else happens to be inactive for more than 15 seconds.

The defense adds consensus parameters to govern the range of timeout values
for sending padding packets, as well as for keeping connections open.

The defense only sends padding when connections are otherwise inactive, and it
does not pad connections used solely for directory traffic at all. By default
it also doesn't pad inter-relay connections.

Statistics on the total padding in the last 24 hours are exported to the
extra-info descriptors.
2017-05-08 13:49:21 -04:00
Nick Mathewson
7bc9f93abb Merge branch 'teor_connection-with-client-v2_squashed' 2017-05-02 19:18:04 -04:00
teor
f9af7e8bd0 Accurately identify client connections by their lack of peer authentication
This means that we bail out earlier if asked to extend to a client.

Follow-up to 21407.
Fixes bug 21406; bugfix on 0.2.4.23.
2017-05-02 19:17:56 -04:00
Nick Mathewson
7505f452c8 Run the copyright update script. 2017-03-15 16:13:17 -04:00
Nick Mathewson
aae034d13e Write a bunch of module documentation.
This commit adds or improves the module-level documenation for:

  buffers.c circuitstats.c command.c connection_edge.c control.c
  cpuworker.c crypto_curve25519.c crypto_curve25519.h
  crypto_ed25519.c crypto_format.c dircollate.c dirserv.c dns.c
  dns_structs.h fp_pair.c geoip.c hibernate.c keypin.c ntmain.c
  onion.c onion_fast.c onion_ntor.c onion_tap.c periodic.c
  protover.c protover.h reasons.c rephist.c replaycache.c
  routerlist.c routerparse.c routerset.c statefile.c status.c
  tor_main.c workqueue.c

In particular, I've tried to explain (for each documented module)
what each module does, what's in it, what the big idea is, why it
belongs in Tor, and who calls it.  In a few cases, I've added TODO
notes about refactoring opportunities.

I've also renamed an argument, and fixed a few DOCDOC comments.
2016-10-17 10:16:59 -04:00
Nick Mathewson
57699de005 Update the copyright year. 2016-02-27 18:48:19 +01:00
Isis Lovecruft
2e0a50abf4 Remove redundant tor_free() in command_process_create_cell().
* FIXES #16823: https://bugs.torproject.org/16823
   If an OP were to send a CREATE_FAST cell to an OR, and that
   CREATE_FAST cell had unparseable key material, then tor_free() would
   be called on the create cell twice.  This fix removes the second
   (conditional on the key material being bad) call to tor_free(), so
   that now the create cell is always freed once, regardless of the status of
   the key material.

   (This isn't actually a double-free bug, since tor_free() sets its
   input to NULL, and has no effect when called with input NULL.)
2015-08-17 09:26:07 -04:00
Nick Mathewson
d03e1da232 Merge remote-tracking branch 'public/bug9635_warnings_025'
Conflicts:
	src/test/test.c
2015-02-02 16:31:32 -05:00
Nick Mathewson
1e896214e7 Refactor cpuworker to use workqueue/threadpool code. 2015-01-14 11:23:34 -05:00
Nick Mathewson
f54e54b0b4 Bump copyright dates to 2015, in case someday this matters. 2015-01-02 14:27:39 -05:00
George Kadianakis
14e83e626b Add two hidden-service related statistics.
The two statistics are:
 1. number of RELAY cells observed on successfully established
    rendezvous circuits; and
 2. number of .onion addresses observed as hidden-service
    directory.

Both statistics are accumulated over 24 hours, obfuscated by rounding
up to the next multiple of a given number and adding random noise,
and written to local file stats/hidserv-stats.

Notably, no statistics will be gathered on clients or services, but
only on relays.
2014-12-19 10:35:25 -05:00
Nick Mathewson
fcdcb377a4 Add another year to our copyright dates.
Because in 95 years, we or our successors will surely care about
enforcing the BSD license terms on this code.  Right?
2014-10-28 15:30:16 -04:00
Nick Mathewson
fb91d647ac Downgrade 'invalid result from curve25519 handshake: 4' warning
Also, refactor the way we handle failed handshakes so that this
warning doesn't propagate itself to "onion_skin_client_handshake
failed" and "circuit_finish_handshake failed" and
"connection_edge_process_relay_cell (at origin) failed."

Resolves warning from 9635.
2014-10-16 13:26:42 -04:00
Roger Dingledine
29a82b5a8b Merge branch 'maint-0.2.4' into maint-0.2.5 2014-07-28 02:47:15 -04:00
Roger Dingledine
68a2e4ca4b Warn and drop the circuit if we receive an inbound 'relay early' cell
Those used to be normal to receive on hidden service circuits due to bug
1038, but the buggy Tor versions are long gone from the network so we
can afford to resume watching for them. Resolves the rest of bug 1038;
bugfix on 0.2.1.19.
2014-07-28 02:44:05 -04:00
Nick Mathewson
d5558f0072 circuit_build_failed: distinguish "first hop chan failed", "CREATE failed"
Roger spotted this on tor-dev in his comments on proposal 221.

(Actually, detect DESTROY vs everything else, since arma likes
network timeout indicating failure but not overload indicating failure.)
2014-07-25 11:59:00 -04:00
Nick Mathewson
f9f450d688 Also raise the check for 0 circuit ID in created cell.
And add a comment about why conditions that would cause us to drop a
cell should get checked before actions that would cause us to send a
destroy cell.

Spotted by 'cypherpunks'.

And note that these issues have been present since 0.0.8pre1 (commit
0da256ef), where we added a "shutting down" state, and started
responding to all create cells with DESTROY when shutting down.
2014-06-13 08:39:39 -04:00
Nick Mathewson
af53e4bd1c Move circuit-id-in-use check for CREATE cells to before all other checks
This means that we never send a DESTROY cell in response to an attempt
to CREATE an existing circuit.  Fixes bug 12191.
2014-06-10 22:41:13 -04:00
Nick Mathewson
e74c360156 Merge remote-tracking branch 'public/bug12195' 2014-06-04 12:16:03 -04:00
Nick Mathewson
84ed086d48 Fix ancient code that only checked circ_id, not circ_id and chan
This code mis-handled the case where a circuit got the same circuit
ID in both directions.  I found three instances of it in the
codebase, by grepping for [pn]_circ_id.

Because of the issue in command_process_relay_cell(), this would
have made roughly one circuit in a million completely nonfunctional.

Fixes bug 12195.
2014-06-03 18:19:08 -04:00
Nick Mathewson
12dc55f487 Merge branch 'prop221_squashed_024'
Conflicts:
	src/or/or.h
2013-11-01 10:28:01 -04:00
Nick Mathewson
5de88dda0a circuit_build_failed: distinguish "got DESTROY" case
Roger spotted this on tor-dev in his comments on proposal 221.

We etect DESTROY vs everything else, since arma likes network
timeout indicating failure but not overload indicating failure.
2013-11-01 10:04:48 -04:00
Karsten Loesing
2e0fad542c Merge branch 'morestats4' into morestats5
Conflicts:
	doc/tor.1.txt
	src/or/config.c
	src/or/connection.h
	src/or/control.c
	src/or/control.h
	src/or/or.h
	src/or/relay.c
	src/or/relay.h
	src/test/test.c
2013-10-28 12:09:42 +01:00
Roger Dingledine
2c877d2da4 collect and log statistics about onionskins received/processed
we skip onionskins that came from non-relays, so we're less likely to
run into privacy troubles.

starts to implement ticket 9658.
2013-09-05 01:44:52 -04:00
Karsten Loesing
26b49f525d Tweak CELL_STATS event based on comments by nickm.
- Move cell_command_to_string from control.c to command.c.
- Use accessor for global_circuitlist instead of extern.
- Add a struct for cell statistics by command instead of six arrays.
- Split up control_event_circuit_cell_stats by using two helper functions.
- Add TestingEnableCellStatsEvent option.
- Prepare functions for testing.
- Rename a few variables and document a few things better.
2013-05-25 19:51:38 +02:00
Nick Mathewson
339df5df08 Fix 8447: use %u to format circid_t.
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.
2013-03-10 19:52:06 -04:00
Nick Mathewson
d6634001c9 Merge remote-tracking branch 'public/wide_circ_ids'
Conflicts:
	src/or/channel.h
	src/or/connection_or.c
	src/or/cpuworker.c
2013-02-15 16:23:43 -05:00
Nick Mathewson
4da083db3b Update the copyright date to 201. 2013-01-16 01:54:56 -05:00
Nick Mathewson
b5ce4f94c3 Forward-port fix for 7889 2013-01-15 16:33:53 -05:00
Nick Mathewson
938cb6a55e Merge remote-tracking branch 'origin/maint-0.2.3' 2013-01-15 16:30:26 -05:00
Nick Mathewson
4ccf09b1c2 Reject create/begin/etc cells with {circ,stream}ID 0.
Otherwise, it's possible to create streams or circuits with these
bogus IDs, leading to orphaned circuits or streams, or to ones that
can cause bandwidth DOS problems.

Fixes bug 7889; bugfix on all released Tors.
2013-01-14 14:02:13 -05:00
Nick Mathewson
ecf88b16b8 Enable handling of create2/extend2/created2/extended2 2013-01-03 11:29:47 -05:00
Nick Mathewson
115e8fe9a5 Use created_cell_format where appropriate 2013-01-03 11:29:47 -05:00
Nick Mathewson
2802ccaeb6 Teach cpuworker and others about create_cell_t and friends
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
2013-01-03 11:29:46 -05:00
Nick Mathewson
f58d4dfcd6 Massive refactoring of the various handshake types
The three handshake types are now accessed from a unified interface;
their state is abstracted from the rest of the cpath state, and so on.
2013-01-03 11:29:46 -05:00
Nick Mathewson
f7e590df05 Split onion.[ch] into onion{,_fast,_tap}.[ch]
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.
2013-01-02 14:11:14 -05:00