If we failed to connect at the TCP level to a relay, note it down and refuse
to connect again for another 60 seconds.
Fixes#24767
Signed-off-by: David Goulet <dgoulet@torproject.org>
Remove a series of connection counters that were only used when dumping the
rephist statistics with SIGUSR1 signal.
This reduces the or_history_t structure size.
Closes#25163
Signed-off-by: David Goulet <dgoulet@torproject.org>
Stop adding unneeded channel padding right after we finish flushing
to a connection that has been trying to flush for many seconds.
Instead, treat all partial or complete flushes as activity on the
channel, which will defer the time until we need to add padding.
This fix should resolve confusing and scary log messages like
"Channel padding timeout scheduled 221453ms in the past."
Fixes bug 22212; bugfix on 0.3.1.1-alpha.
I think technically we could resolve bug 22212 by adding a call to
channel_timestamp_active() only in the finished_flushing case. But I added
a call in the flushed_some case too since that seems to more accurately
reflect the notion of "active".
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.
The channel subsystem was doing a whole lot to track and try to predict the
channel queue size but they are gone due to previous commit.
Signed-off-by: David Goulet <dgoulet@torproject.org>
Change the contract of control_event_bootstrap_problem() to be more
general and to take a connection_t. New function
control_event_bootstrap_prob_or() has the specific or_connection_t
funcionality previously used.
Before, this function meant "can we connect to this node and
authenticate it using its ed25519 key?" Now it can additionally
mean, "when somebody else connects to this node, do we expect that
they can authenticate using the node's ed25519 key"?
This change lets us future-proof our link authentication a bit.
Closes ticket 20895. No backport needed, since ed25519 link
authentication support has not been in any LTS release yet, and
existing releases with it should be obsolete before any releases
without support for linkauth=3 are released.
Our convention is that functions which manipulate a type T should be
named T_foo. But the buffer functions were super old, and followed
all kinds of conventions. Now they're uniform.
Here's the perl I used to do this:
\#!/usr/bin/perl -w -i -p
s/read_to_buf\(/buf_read_from_socket\(/;
s/flush_buf\(/buf_flush_to_socket\(/;
s/read_to_buf_tls\(/buf_read_from_tls\(/;
s/flush_buf_tls\(/buf_flush_to_tls\(/;
s/write_to_buf\(/buf_add\(/;
s/write_to_buf_compress\(/buf_add_compress\(/;
s/move_buf_to_buf\(/buf_move_to_buf\(/;
s/peek_from_buf\(/buf_peek\(/;
s/fetch_from_buf\(/buf_get_bytes\(/;
s/fetch_from_buf_line\(/buf_get_line\(/;
s/fetch_from_buf_line\(/buf_get_line\(/;
s/buf_remove_from_front\(/buf_drain\(/;
s/peek_buf_startswith\(/buf_peek_startswith\(/;
s/assert_buf_ok\(/buf_assert_ok\(/;
These statistics were largely ununsed, and kept track of statistical information
on things like how many time we had done TLS or how many signatures we had
verified. This information is largely not useful, and would only be logged
after receiving a SIGUSR1 signal (but only if the logging severity level was
less than LOG_INFO).
* FIXES#19871.
* REMOVES note_crypto_pk_op(), dump_pk_op(), and pk_op_counts from
src/or/rephist.c.
* REMOVES every external call to these functions.
This mistake causes two possible bugs. I believe they are both
harmless IRL.
BUG 1: memory stomping
When we call the memset, we are overwriting two 0 bytes past the end
of packed_cell_t.body. But I think that's harmless in practice,
because the definition of packed_cell_t is:
// ...
typedef struct packed_cell_t {
TOR_SIMPLEQ_ENTRY(packed_cell_t) next;
char body[CELL_MAX_NETWORK_SIZE];
uint32_t inserted_time;
} packed_cell_t;
So we will overwrite either two bytes of inserted_time, or two bytes
of padding, depending on how the platform handles alignment.
If we're overwriting padding, that's safe.
If we are overwriting the inserted_time field, that's also safe: In
every case where we call cell_pack() from connection_or.c, we ignore
the inserted_time field. When we call cell_pack() from relay.c, we
don't set or use inserted_time until right after we have called
cell_pack(). SO I believe we're safe in that case too.
BUG 2: memory exposure
The original reason for this memset was to avoid the possibility of
accidentally leaking uninitialized ram to the network. Now
remember, if wide_circ_ids is false on a connection, we shouldn't
actually be sending more than 512 bytes of packed_cell_t.body, so
these two bytes can only leak to the network if there is another bug
somewhere else in the code that sends more data than is correct.
Fortunately, in relay.c, where we allocate packed_cell_t in
packed_cell_new() , we allocate it with tor_malloc_zero(), which
clears the RAM, right before we call cell_pack. So those
packed_cell_t.body bytes can't leak any information.
That leaves the two calls to cell_pack() in connection_or.c, which
use stack-alocated packed_cell_t instances.
In or_handshake_state_record_cell(), we pass the cell's contents to
crypto_digest_add_bytes(). When we do so, we get the number of
bytes to pass using the same setting of wide_circ_ids as we passed
to cell_pack(). So I believe that's safe.
In connection_or_write_cell_to_buf(), we also use the same setting
of wide_circ_ids in both calls. So I believe that's safe too.
I introduced this bug with 1c0e87f6d8
back in 0.2.4.11-alpha; it is bug 22737 and CID 1401591
It's okay to call add_ed25519_cert with a NULL argument: so,
document that. Also, add a tor_assert_nonfatal() to catch any case
where we have failed to set own_link_cert when conn_in_server_mode.
Whenever we rotate our TLS context, we change our Ed25519
Signing->Link certificate. But if we've already started a TLS
connection, then we've already sent the old X509 link certificate,
so the new Ed25519 Signing->Link certificate won't match it.
To fix this, we now store a copy of the Signing->Link certificate
when we initialize the handshake state, and send that certificate
as part of our CERTS cell.
Fixes one case of bug22460; bugfix on 0.3.0.1-alpha.
Accomplished via the following:
1. Use NETINFO cells to determine if both peers will agree on canonical
status. Prefer connections where they agree to those where they do not.
2. Alter channel_is_better() to prefer older orconns in the case of multiple
canonical connections, and use the orconn with more circuits on it in case
of age ties.
Also perform some hourly accounting on how many of these types of connections
there are and log it at info or notice level.
This unifies CircuitIdleTimeout and PredictedCircsRelevanceTime into a single
option, and randomizes it.
It also gives us control over the default value as well as relay-to-relay
connection lifespan through the consensus.
Conflicts:
src/or/circuituse.c
src/or/config.c
src/or/main.c
src/test/testing_common.c
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.
