commit 7163ce7f62d6c487193fe43828420ba4fe721b9f Author: David Goulet dgoulet@torproject.org Date: Wed May 10 13:43:37 2017 -0400
hs: Refactor the service exit connection code
This commit simply moves the code from the if condition of a rendezvous circuit to a function to handle such a connection. No code was modified _except_ the use or rh.stream_id changed to n_stream->stream_id so we don't have to pass the cell header to the function.
This is groundwork for prop224 support which will break down the handle_hs_exit_conn() depending on the version of hidden service the circuit and edge connection is for.
Signed-off-by: David Goulet dgoulet@torproject.org --- src/or/connection_edge.c | 112 ++++++++++++++++++++++++++--------------------- 1 file changed, 61 insertions(+), 51 deletions(-)
diff --git a/src/or/connection_edge.c b/src/or/connection_edge.c index ddcff6aa9..8e447131f 100644 --- a/src/or/connection_edge.c +++ b/src/or/connection_edge.c @@ -3066,6 +3066,64 @@ begin_cell_parse(const cell_t *cell, begin_cell_t *bcell, return 0; }
+/** For the given <b>circ</b> and the edge connection <b>n_stream</b>, setup + * the the connection, attach it to the circ and connect it. Return 0 on + * success or END_CIRC_AT_ORIGIN if we can't find the requested hidden + * service port where the caller should close the circuit. */ +static int +handle_hs_exit_conn(circuit_t *circ, edge_connection_t *n_stream) +{ + origin_circuit_t *origin_circ = TO_ORIGIN_CIRCUIT(circ); + log_info(LD_REND,"begin is for rendezvous. configuring stream."); + n_stream->base_.address = tor_strdup("(rendezvous)"); + n_stream->base_.state = EXIT_CONN_STATE_CONNECTING; + n_stream->rend_data = rend_data_dup(origin_circ->rend_data); + tor_assert(connection_edge_is_rendezvous_stream(n_stream)); + assert_circuit_ok(circ); + + const int r = rend_service_set_connection_addr_port(n_stream, origin_circ); + if (r < 0) { + log_info(LD_REND,"Didn't find rendezvous service (port %d)", + n_stream->base_.port); + /* Send back reason DONE because we want to make hidden service port + * scanning harder thus instead of returning that the exit policy + * didn't match, which makes it obvious that the port is closed, + * return DONE and kill the circuit. That way, a user (malicious or + * not) needs one circuit per bad port unless it matches the policy of + * the hidden service. */ + relay_send_end_cell_from_edge(n_stream->stream_id, circ, + END_STREAM_REASON_DONE, + origin_circ->cpath->prev); + connection_free(TO_CONN(n_stream)); + + /* Drop the circuit here since it might be someone deliberately + * scanning the hidden service ports. Note that this mitigates port + * scanning by adding more work on the attacker side to successfully + * scan but does not fully solve it. */ + if (r < -1) + return END_CIRC_AT_ORIGIN; + else + return 0; + } + assert_circuit_ok(circ); + log_debug(LD_REND,"Finished assigning addr/port"); + n_stream->cpath_layer = origin_circ->cpath->prev; /* link it */ + + /* add it into the linked list of p_streams on this circuit */ + n_stream->next_stream = origin_circ->p_streams; + n_stream->on_circuit = circ; + origin_circ->p_streams = n_stream; + assert_circuit_ok(circ); + + origin_circ->rend_data->nr_streams++; + + connection_exit_connect(n_stream); + + /* For path bias: This circuit was used successfully */ + pathbias_mark_use_success(origin_circ); + return 0; +} + /** A relay 'begin' or 'begin_dir' cell has arrived, and either we are * an exit hop for the circuit, or we are the origin and it is a * rendezvous begin. @@ -3217,58 +3275,10 @@ connection_exit_begin_conn(cell_t *cell, circuit_t *circ) n_stream->deliver_window = STREAMWINDOW_START;
if (circ->purpose == CIRCUIT_PURPOSE_S_REND_JOINED) { - tor_assert(origin_circ); - log_info(LD_REND,"begin is for rendezvous. configuring stream."); - n_stream->base_.address = tor_strdup("(rendezvous)"); - n_stream->base_.state = EXIT_CONN_STATE_CONNECTING; - n_stream->rend_data = rend_data_dup(origin_circ->rend_data); - tor_assert(connection_edge_is_rendezvous_stream(n_stream)); - assert_circuit_ok(circ); - - const int r = rend_service_set_connection_addr_port(n_stream, origin_circ); - if (r < 0) { - log_info(LD_REND,"Didn't find rendezvous service (port %d)", - n_stream->base_.port); - /* Send back reason DONE because we want to make hidden service port - * scanning harder thus instead of returning that the exit policy - * didn't match, which makes it obvious that the port is closed, - * return DONE and kill the circuit. That way, a user (malicious or - * not) needs one circuit per bad port unless it matches the policy of - * the hidden service. */ - relay_send_end_cell_from_edge(rh.stream_id, circ, - END_STREAM_REASON_DONE, - layer_hint); - connection_free(TO_CONN(n_stream)); - tor_free(address); - - /* Drop the circuit here since it might be someone deliberately - * scanning the hidden service ports. Note that this mitigates port - * scanning by adding more work on the attacker side to successfully - * scan but does not fully solve it. */ - if (r < -1) - return END_CIRC_AT_ORIGIN; - else - return 0; - } - assert_circuit_ok(circ); - log_debug(LD_REND,"Finished assigning addr/port"); - n_stream->cpath_layer = origin_circ->cpath->prev; /* link it */ - - /* add it into the linked list of p_streams on this circuit */ - n_stream->next_stream = origin_circ->p_streams; - n_stream->on_circuit = circ; - origin_circ->p_streams = n_stream; - assert_circuit_ok(circ); - - origin_circ->rend_data->nr_streams++; - - connection_exit_connect(n_stream); - - /* For path bias: This circuit was used successfully */ - pathbias_mark_use_success(origin_circ); - tor_free(address); - return 0; + /* We handle this circuit and stream in this function for all supported + * hidden service version. */ + return handle_hs_exit_conn(circ, n_stream); } tor_strlower(address); n_stream->base_.address = address;