Commit 2b63fa40 authored by Roger Dingledine's avatar Roger Dingledine
Browse files

three hacks to workaround bug 1038

The problem is that clients and hidden services are receiving
relay_early cells, and they tear down the circuit.

Hack #1 is for rendezvous points to rewrite relay_early cells to
relay cells. That way there are never any incoming relay_early cells.

Hack #2 is for clients and hidden services to never send a relay_early
cell on an established rendezvous circuit. That works around rendezvous
points that haven't upgraded yet.

Hack #3 is for clients and hidden services to not tear down the circuit
when they receive an inbound relay_early cell. We already refuse extend
cells at clients.
parent f39cee37
Changes in version 0.2.1.19 - 2009-07-??
o Major bugfixes:
- Make accessing hidden services on 0.2.1.x work right
again. Bugfix on 0.2.1.3-alpha; workaround for bug 1038.
Changes in version 0.2.1.18 - 2009-07-24
o Build fixes:
- Add LIBS=-lrt to Makefile.am so the Tor RPMs use a static libevent.
......
......@@ -395,12 +395,8 @@ command_process_relay_cell(cell_t *cell, or_connection_t *conn)
* gotten no more than MAX_RELAY_EARLY_CELLS_PER_CIRCUIT of them. */
if (cell->command == CELL_RELAY_EARLY) {
if (direction == CELL_DIRECTION_IN) {
log_fn(LOG_PROTOCOL_WARN, LD_OR,
"Received an inbound RELAY_EARLY cell on circuit %d from %s:%d."
" Closing circuit.",
cell->circ_id, conn->_base.address, conn->_base.port);
circuit_mark_for_close(circ, END_CIRC_REASON_TORPROTOCOL);
return;
/* XXX Allow an unlimited number of inbound relay_early cells for
* now, for hidden service compatibility. See bug 1038. -RD */
} else {
or_circuit_t *or_circ = TO_OR_CIRCUIT(circ);
if (or_circ->remaining_relay_early_cells == 0) {
......
......@@ -488,6 +488,11 @@ typedef enum {
(p)<=_CIRCUIT_PURPOSE_C_MAX)
/** True iff the circuit_t <b>c</b> is actually an origin_circuit_t. */
#define CIRCUIT_IS_ORIGIN(c) (CIRCUIT_PURPOSE_IS_ORIGIN((c)->purpose))
/** True iff the circuit purpose <b>p</b> is for an established rendezvous
* circuit. */
#define CIRCUIT_PURPOSE_IS_ESTABLISHED_REND(p) \
((p) == CIRCUIT_PURPOSE_C_REND_JOINED || \
(p) == CIRCUIT_PURPOSE_S_REND_JOINED)
/** How many circuits do we want simultaneously in-progress to handle
* a given stream? */
......
......@@ -208,6 +208,7 @@ circuit_receive_relay_cell(cell_t *cell, circuit_t *circ,
tor_assert(circ->purpose == CIRCUIT_PURPOSE_REND_ESTABLISHED);
tor_assert(splice->_base.purpose == CIRCUIT_PURPOSE_REND_ESTABLISHED);
cell->circ_id = splice->p_circ_id;
cell->command = CELL_RELAY; /* can't be relay_early anyway */
if ((reason = circuit_receive_relay_cell(cell, TO_CIRCUIT(splice),
CELL_DIRECTION_IN)) < 0) {
log_warn(LD_REND, "Error relaying cell across rendezvous; closing "
......@@ -541,11 +542,17 @@ relay_send_command_from_edge(uint16_t stream_id, circuit_t *circ,
origin_circuit_t *origin_circ = TO_ORIGIN_CIRCUIT(circ);
if (origin_circ->remaining_relay_early_cells > 0 &&
(relay_command == RELAY_COMMAND_EXTEND ||
cpath_layer != origin_circ->cpath)) {
/* If we've got any relay_early cells left, and we're sending a relay
* cell or we're not talking to the first hop, use one of them. Don't
* worry about the conn protocol version: append_cell_to_circuit_queue
* will fix it up. */
(cpath_layer != origin_circ->cpath &&
!CIRCUIT_PURPOSE_IS_ESTABLISHED_REND(circ->purpose)))) {
/* If we've got any relay_early cells left, and we're sending
* an extend cell or (we're not talking to the first hop and we're
* not talking to a rendezvous circuit), use one of them.
* Don't worry about the conn protocol version:
* append_cell_to_circuit_queue will fix it up. */
/* XXX For now, clients don't use RELAY_EARLY cells when sending
* relay cells on rendezvous circuits. See bug 1038. Eventually,
* we can take this behavior away in favor of having clients avoid
* rendezvous points running 0.2.1.3-alpha through 0.2.1.18. -RD */
cell.command = CELL_RELAY_EARLY;
--origin_circ->remaining_relay_early_cells;
log_debug(LD_OR, "Sending a RELAY_EARLY cell; %d remaining.",
......
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