Couple things happen in this commit. First, we do not re-queue a cell back in
the circuit queue if the write packed cell failed. Currently, it is close to
impossible to have it failed but just in case, the channel is mark as closed
and we move on.
The second thing is that the channel_write_packed_cell() always took ownership
of the cell whatever the outcome. This means, on success or failure, it needs
to free it.
It turns out that that we were using the wrong free function in one case and
not freeing it in an other possible code path. So, this commit makes sure we
only free it in one place that is at the very end of
channel_write_packed_cell() which is the top layer of the channel abstraction.
This makes also channel_tls_write_packed_cell_method() return a negative value
on error.
Two unit tests had to be fixed (quite trivial) due to a double free of the
packed cell in the test since now we do free it in all cases correctly.
Part of #23709
Signed-off-by: David Goulet <dgoulet@torproject.org>
For the rationale, see ticket #23709.
This is a pretty massive commit. Those queues were everywhere in channel.c and
it turns out that it was used by lots of dead code.
The channel subsystem *never* handles variable size cell (var_cell_t) or
unpacked cells (cell_t). The variable ones are only handled in channeltls and
outbound cells are always packed from the circuit queue so this commit removes
code related to variable and unpacked cells.
However, inbound cells are unpacked (cell_t), that is untouched and is handled
via channel_process_cell() function.
In order to make the commit compile, test have been modified but not passing
at this commit. Also, many tests have been removed but better improved ones
get added in future commits.
This commit also adds a XXX: which indicates that the handling process of
outbound cells isn't fully working. This as well is fixed in a future commit.
Finally, at this commit, more dead code remains, it will be cleanup in future
commits.
Fixes#23709
Signed-off-by: David Goulet <dgoulet@torproject.org>
is_canonical doesn't mean "am I connected to the one true address of
this relay"; it means "does this relay tell me that the address I'm
connected to belong to it." The point is to prevent TCP-based MITM,
not to prevent the relay from multi-homing.
Related to 22890.
An unnecessary routerlist check in the NETINFO clock skew detection in
channel_tls_process_netinfo_cell() was preventing clients from
reporting NETINFO clock skew to controllers.
This patch replaces a few calls to router_get_by_id_digest ("do we
have a routerinfo?") with connection_or_digest_is_known_relay ("do
we know this relay to be in the consensus, or have been there some
time recently?").
Found while doing the 21585 audit; fixes bug 23533. Bugfix on
0.3.0.1-alpha.
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\(/;
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 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.
Right now, there's only a mechanism to look for a channel where the
RSA ID matches *and* the ED ID matches. We can add a separate map
later if we want.
This function is allowed to return NULL if the certified key isn't
RSA. But in a couple of places we were treating this as a bug or
internal error, and in one other place we weren't checking for it at
all!
Caught by Isis during code review for #15055. The serious bug was
only on the 15055 branch, thank goodness.
This code stores the ed certs as appropriate, and tries to check
them. The Ed25519 result is not yet used, and (because of its
behavior) this will break RSA authenticate cells. That will get
fixed as we go, however.
This should implement 19157, but it needs tests, and it needs
to get wired in.
In particular, these functions are the ones that set the identity of
a given connection or channel, and/or confirm that we have learned
said IDs.
There's a lot of stub code here: we don't actually need to use the
new keys till we start looking up connections/channels by Ed25519
IDs. Still, we want to start passing the Ed25519 IDs in now, so it
makes sense to add these stubs as part of 15055.
The functions it warns about are:
assert, memcmp, strcat, strcpy, sprintf, malloc, free, realloc,
strdup, strndup, calloc.
Also, fix a few lingering instances of these in the code. Use other
conventions to indicate _intended_ use of assert and
malloc/realloc/etc.
This is a big-ish patch, but it's very straightforward. Under this
clang warning, we're not actually allowed to have a global variable
without a previous extern declaration for it. The cases where we
violated this rule fall into three roughly equal groups:
* Stuff that should have been static.
* Stuff that was global but where the extern was local to some
other C file.
* Stuff that was only global when built for the unit tests, that
needed a conditional extern in the headers.
The first two were IMO genuine problems; the last is a wart of how
we build tests.
This warning triggers on silently promoting a float to a double. In
our code, it's just a sign that somebody used a float by mistake,
since we always prefer double.
This warning, IIUC, means that the compiler doesn't like it when it
sees a NULL check _after_ we've already dereferenced the
variable. In such cases, it considers itself free to eliminate the
NULL check.
There are a couple of tricky cases:
One was the case related to the fact that tor_addr_to_in6() can
return NULL if it gets a non-AF_INET6 address. The fix was to
create a variant which asserts on the address type, and never
returns NULL.
