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Diffstat (limited to 'doc/TODO')
| -rw-r--r-- | doc/TODO | 37 |
1 files changed, 37 insertions, 0 deletions
@@ -68,6 +68,43 @@ R - actually cause the directory.c functions to know about or_port and use it when we're supposed to. N - for tunneled edge conns, stop reading to the bridge connection when the or_conn we're writing to has a full outbuf. + - This is iffy. Really, it would've been better to stop writing + on the dir conn when the edge conn's inbuf is getting full. + But the issue there is that we package from edge + connections aggressively until we hit their package windows or the + circuit package windows, even if the buffer on the corresponding OR + connection is pretty damn big. This sucks from a RAM usage POV. + Now, we could try to stop reading on the edges (or just the edges + connected to a local bridge) when an or_conn's outbuf is full. But + if we're a server, and we stop reading on some exit conns when OR + conns are full, soon OR conns will contain only traffic from other OR + conns, and the exit data in question will never get written. + + - The right solution in the long run (0.2.0) is probably as follows: + - Remove socketpair-based bridges: use shared (or connected) buffers + for communication, rather than sockets. + - When relaying cells from an OR conn to an OR conn, have them wait + in a queue on the or_circuit_t object; don't move them onto the + target conn until there is space in the target conn's outbuf. + Also, only package data from exitconns when there is space in the + target conn's outbuf. + - As an added advantage, this would let us kill stalled _circuits_ + when their buffers get too full, rather than killing entire OR + conns. But we must think about anonymity implications of that. + - We'll probably want to do some kind of big refactoring of our + dataflow when we do these changes; stuff is hairy enough already, + and it will only get harrier with this stuff. + + - For the short run, our options seem to be: + - Disable BEGIN_DIR support at the server-side unless it's + explicitly turned on. + - Go ahead and make directory bridge data not get produced when the + corresponding or_conn is full, and accept the sometimes directory + data will just never get written. + - Rate-limit directory bridge data somehow when the corresponding + or_conn is full. Possibly based on the flush rate of the or_conn? + - Reject BEGIN_DIR requests that we think will be insanely big. + N - DNS improvements . Asynchronous DNS |