/** Process an ESTABLISH_RENDEZVOUS cell by setting the circuit's purpose and
* rendezvous cookie.
*/
int
rend_mid_establish_rendezvous(or_circuit_t *circ, const uint8_t *request,
size_t request_len)
{
char hexid[9];
int reason = END_CIRC_REASON_TORPROTOCOL;
log_info(LD_REND, "Received an ESTABLISH_RENDEZVOUS request on circuit %u",
(unsigned)circ->p_circ_id);
if (circ->base_.purpose != CIRCUIT_PURPOSE_OR) {
log_warn(LD_PROTOCOL,
"Tried to establish rendezvous on non-OR circuit with purpose %s",
circuit_purpose_to_string(circ->base_.purpose));
goto err;
}
if (circ->base_.n_chan) {
log_warn(LD_PROTOCOL,
"Tried to establish rendezvous on non-edge circuit");
goto err;
}
if (request_len != REND_COOKIE_LEN) {
log_fn(LOG_PROTOCOL_WARN,
LD_PROTOCOL, "Invalid length on ESTABLISH_RENDEZVOUS.");
goto err;
}
if (circuit_get_rendezvous(request)) {
log_warn(LD_PROTOCOL,
"Duplicate rendezvous cookie in ESTABLISH_RENDEZVOUS.");
goto err;
}
/* Acknowledge the request. */
if (relay_send_command_from_edge(0,TO_CIRCUIT(circ),
RELAY_COMMAND_RENDEZVOUS_ESTABLISHED,
"", 0, NULL)<0) {
log_warn(LD_PROTOCOL, "Couldn't send RENDEZVOUS_ESTABLISHED cell.");
reason = END_CIRC_REASON_INTERNAL;
goto err;
}
circuit_change_purpose(TO_CIRCUIT(circ), CIRCUIT_PURPOSE_REND_POINT_WAITING);
circuit_set_rendezvous_cookie(circ, request);
base16_encode(hexid,9,(char*)request,4);
log_info(LD_REND,
"Established rendezvous point on circuit %u for cookie %s",
(unsigned)circ->p_circ_id, hexid);
return 0;
err:
circuit_mark_for_close(TO_CIRCUIT(circ), reason);
return -1;
}
static void
test_rend_token_maps(void *arg)
{
or_circuit_t *c1, *c2, *c3, *c4;
const uint8_t tok1[REND_TOKEN_LEN] = "The cat can't tell y";
const uint8_t tok2[REND_TOKEN_LEN] = "ou its name, and it ";
const uint8_t tok3[REND_TOKEN_LEN] = "doesn't really care.";
/* -- Adapted from a quote by Fredrik Lundh. */
(void)arg;
(void)tok1; //xxxx
c1 = or_circuit_new(0, NULL);
c2 = or_circuit_new(0, NULL);
c3 = or_circuit_new(0, NULL);
c4 = or_circuit_new(0, NULL);
/* Make sure we really filled up the tok* variables */
tt_int_op(tok1[REND_TOKEN_LEN-1], OP_EQ, 'y');
tt_int_op(tok2[REND_TOKEN_LEN-1], OP_EQ, ' ');
tt_int_op(tok3[REND_TOKEN_LEN-1], OP_EQ, '.');
/* No maps; nothing there. */
tt_ptr_op(NULL, OP_EQ, circuit_get_rendezvous(tok1));
tt_ptr_op(NULL, OP_EQ, circuit_get_intro_point(tok1));
circuit_set_rendezvous_cookie(c1, tok1);
circuit_set_intro_point_digest(c2, tok2);
tt_ptr_op(NULL, OP_EQ, circuit_get_rendezvous(tok3));
tt_ptr_op(NULL, OP_EQ, circuit_get_intro_point(tok3));
tt_ptr_op(NULL, OP_EQ, circuit_get_rendezvous(tok2));
tt_ptr_op(NULL, OP_EQ, circuit_get_intro_point(tok1));
/* Without purpose set, we don't get the circuits */
tt_ptr_op(NULL, OP_EQ, circuit_get_rendezvous(tok1));
tt_ptr_op(NULL, OP_EQ, circuit_get_intro_point(tok2));
c1->base_.purpose = CIRCUIT_PURPOSE_REND_POINT_WAITING;
c2->base_.purpose = CIRCUIT_PURPOSE_INTRO_POINT;
/* Okay, make sure they show up now. */
tt_ptr_op(c1, OP_EQ, circuit_get_rendezvous(tok1));
tt_ptr_op(c2, OP_EQ, circuit_get_intro_point(tok2));
/* Two items at the same place with the same token. */
c3->base_.purpose = CIRCUIT_PURPOSE_REND_POINT_WAITING;
circuit_set_rendezvous_cookie(c3, tok2);
tt_ptr_op(c2, OP_EQ, circuit_get_intro_point(tok2));
tt_ptr_op(c3, OP_EQ, circuit_get_rendezvous(tok2));
/* Marking a circuit makes it not get returned any more */
circuit_mark_for_close(TO_CIRCUIT(c1), END_CIRC_REASON_FINISHED);
tt_ptr_op(NULL, OP_EQ, circuit_get_rendezvous(tok1));
circuit_free(TO_CIRCUIT(c1));
c1 = NULL;
/* Freeing a circuit makes it not get returned any more. */
circuit_free(TO_CIRCUIT(c2));
c2 = NULL;
tt_ptr_op(NULL, OP_EQ, circuit_get_intro_point(tok2));
/* c3 -- are you still there? */
tt_ptr_op(c3, OP_EQ, circuit_get_rendezvous(tok2));
/* Change its cookie. This never happens in Tor per se, but hey. */
c3->base_.purpose = CIRCUIT_PURPOSE_INTRO_POINT;
circuit_set_intro_point_digest(c3, tok3);
tt_ptr_op(NULL, OP_EQ, circuit_get_rendezvous(tok2));
tt_ptr_op(c3, OP_EQ, circuit_get_intro_point(tok3));
/* Now replace c3 with c4. */
c4->base_.purpose = CIRCUIT_PURPOSE_INTRO_POINT;
circuit_set_intro_point_digest(c4, tok3);
tt_ptr_op(c4, OP_EQ, circuit_get_intro_point(tok3));
tt_ptr_op(c3->rendinfo, OP_EQ, NULL);
tt_ptr_op(c4->rendinfo, OP_NE, NULL);
tt_mem_op(c4->rendinfo, OP_EQ, tok3, REND_TOKEN_LEN);
/* Now clear c4's cookie. */
circuit_set_intro_point_digest(c4, NULL);
tt_ptr_op(c4->rendinfo, OP_EQ, NULL);
tt_ptr_op(NULL, OP_EQ, circuit_get_intro_point(tok3));
done:
if (c1)
circuit_free(TO_CIRCUIT(c1));
if (c2)
circuit_free(TO_CIRCUIT(c2));
if (c3)
circuit_free(TO_CIRCUIT(c3));
if (c4)
circuit_free(TO_CIRCUIT(c4));
}
/** Process a RENDEZVOUS1 cell by looking up the correct rendezvous
* circuit by its relaying the cell's body in a RENDEZVOUS2 cell, and
* connecting the two circuits.
*/
int
rend_mid_rendezvous(or_circuit_t *circ, const uint8_t *request,
size_t request_len)
{
or_circuit_t *rend_circ;
char hexid[9];
int reason = END_CIRC_REASON_INTERNAL;
if (circ->base_.purpose != CIRCUIT_PURPOSE_OR || circ->base_.n_chan) {
log_info(LD_REND,
"Tried to complete rendezvous on non-OR or non-edge circuit %u.",
(unsigned)circ->p_circ_id);
reason = END_CIRC_REASON_TORPROTOCOL;
goto err;
}
if (request_len != REND_COOKIE_LEN+DH_KEY_LEN+DIGEST_LEN) {
log_fn(LOG_PROTOCOL_WARN, LD_PROTOCOL,
"Rejecting RENDEZVOUS1 cell with bad length (%d) on circuit %u.",
(int)request_len, (unsigned)circ->p_circ_id);
reason = END_CIRC_REASON_TORPROTOCOL;
goto err;
}
base16_encode(hexid, sizeof(hexid), (const char*)request, 4);
log_info(LD_REND,
"Got request for rendezvous from circuit %u to cookie %s.",
(unsigned)circ->p_circ_id, hexid);
rend_circ = circuit_get_rendezvous(request);
if (!rend_circ) {
log_fn(LOG_PROTOCOL_WARN, LD_PROTOCOL,
"Rejecting RENDEZVOUS1 cell with unrecognized rendezvous cookie %s.",
hexid);
reason = END_CIRC_REASON_TORPROTOCOL;
goto err;
}
/* Send the RENDEZVOUS2 cell to Alice. */
if (relay_send_command_from_edge(0, TO_CIRCUIT(rend_circ),
RELAY_COMMAND_RENDEZVOUS2,
(char*)(request+REND_COOKIE_LEN),
request_len-REND_COOKIE_LEN, NULL)) {
log_warn(LD_GENERAL,
"Unable to send RENDEZVOUS2 cell to client on circuit %u.",
(unsigned)rend_circ->p_circ_id);
goto err;
}
/* Join the circuits. */
log_info(LD_REND,
"Completing rendezvous: circuit %u joins circuit %u (cookie %s)",
(unsigned)circ->p_circ_id, (unsigned)rend_circ->p_circ_id, hexid);
circuit_change_purpose(TO_CIRCUIT(circ), CIRCUIT_PURPOSE_REND_ESTABLISHED);
circuit_change_purpose(TO_CIRCUIT(rend_circ),
CIRCUIT_PURPOSE_REND_ESTABLISHED);
circuit_set_rendezvous_cookie(circ, NULL);
rend_circ->rend_splice = circ;
circ->rend_splice = rend_circ;
return 0;
err:
circuit_mark_for_close(TO_CIRCUIT(circ), reason);
return -1;
}
