[tor-talk] Tor client pushing large amounts of data?

[George Kadianakis]

tl;dr Did you by any chance compile tor with bufferevents enabled
(--enable-bufferevents)?

Let's see the path of the sent bytes string:

The heartbeat code (src/or/status.c) receives the bytes sent in
log_heartbeat() using 'uint64_t get_bytes_written(void)' and stores it
into a uint64_t.

Then it passes it to 'static char *bytes_to_usage(uint64_t bytes)'
which has an 'if' statement checking the number of bytes so that it
can return a meaningful string.

In this case we got into the 'else' part of the 'if' which is
activated iff '(bytes >= (1<<30))', which means more or equals to a
gigabyte.

Then 'bytes', a uint64_t, is casted into a double and printed into a
string.

The only problem I can see here is if 'bytes' is bigger than what the
"mantissa" part of double can represent, in which case we start losing
precision.
The "mantissa" part is usually™ 53-bits which can represent 9~
petabytes; so it's gonna take a while and is probably irrelevant with
this thread's problem.

I don't see an integer overflow or underflow happening anywhere
either.

>From what I can gather, 'bytes' got into bytes_to_usage() with a
value around 48.08*(2^30).

Did you by any chance compile tor with bufferevents enabled?