diff options
Diffstat (limited to 'src/or/command.c')
| -rw-r--r-- | src/or/command.c | 119 |
1 files changed, 89 insertions, 30 deletions
diff --git a/src/or/command.c b/src/or/command.c index 78fd4fad33..5866c386e4 100644 --- a/src/or/command.c +++ b/src/or/command.c @@ -1,12 +1,32 @@ /* Copyright (c) 2001 Matej Pfajfar. * Copyright (c) 2001-2004, Roger Dingledine. * Copyright (c) 2004-2006, Roger Dingledine, Nick Mathewson. - * Copyright (c) 2007-2013, The Tor Project, Inc. */ + * Copyright (c) 2007-2016, The Tor Project, Inc. */ /* See LICENSE for licensing information */ /** * \file command.c * \brief Functions for processing incoming cells. + * + * When we receive a cell from a client or a relay, it arrives on some + * channel, and tells us what to do with it. In this module, we dispatch based + * on the cell type using the functions command_process_cell() and + * command_process_var_cell(), and deal with the cell accordingly. (These + * handlers are installed on a channel with the command_setup_channel() + * function.) + * + * Channels have a chance to handle some cell types on their own before they + * are ever passed here --- typically, they do this for cells that are + * specific to a given channel type. For example, in channeltls.c, the cells + * for the initial connection handshake are handled before we get here. (Of + * course, the fact that there _is_ only one channel type for now means that + * we may have gotten the factoring wrong here.) + * + * Handling other cell types is mainly farmed off to other modules, after + * initial sanity-checking. CREATE* cells are handled ultimately in onion.c, + * CREATED* cells trigger circuit creation in circuitbuild.c, DESTROY cells + * are handled here (since they're simple), and RELAY cells, in all their + * complexity, are passed off to relay.c. **/ /* In-points to command.c: @@ -53,6 +73,33 @@ static void command_process_created_cell(cell_t *cell, channel_t *chan); static void command_process_relay_cell(cell_t *cell, channel_t *chan); static void command_process_destroy_cell(cell_t *cell, channel_t *chan); +/** Convert the cell <b>command</b> into a lower-case, human-readable + * string. */ +const char * +cell_command_to_string(uint8_t command) +{ + switch (command) { + case CELL_PADDING: return "padding"; + case CELL_CREATE: return "create"; + case CELL_CREATED: return "created"; + case CELL_RELAY: return "relay"; + case CELL_DESTROY: return "destroy"; + case CELL_CREATE_FAST: return "create_fast"; + case CELL_CREATED_FAST: return "created_fast"; + case CELL_VERSIONS: return "versions"; + case CELL_NETINFO: return "netinfo"; + case CELL_RELAY_EARLY: return "relay_early"; + case CELL_CREATE2: return "create2"; + case CELL_CREATED2: return "created2"; + case CELL_VPADDING: return "vpadding"; + case CELL_CERTS: return "certs"; + case CELL_AUTH_CHALLENGE: return "auth_challenge"; + case CELL_AUTHENTICATE: return "authenticate"; + case CELL_AUTHORIZE: return "authorize"; + default: return "unrecognized"; + } +} + #ifdef KEEP_TIMING_STATS /** This is a wrapper function around the actual function that processes the * <b>cell</b> that just arrived on <b>conn</b>. Increment <b>*time</b> @@ -200,6 +247,34 @@ command_process_create_cell(cell_t *cell, channel_t *chan) (unsigned)cell->circ_id, U64_PRINTF_ARG(chan->global_identifier), chan); + /* We check for the conditions that would make us drop the cell before + * we check for the conditions that would make us send a DESTROY back, + * since those conditions would make a DESTROY nonsensical. */ + if (cell->circ_id == 0) { + log_fn(LOG_PROTOCOL_WARN, LD_PROTOCOL, + "Received a create cell (type %d) from %s with zero circID; " + " ignoring.", (int)cell->command, + channel_get_actual_remote_descr(chan)); + return; + } + + if (circuit_id_in_use_on_channel(cell->circ_id, chan)) { + const node_t *node = node_get_by_id(chan->identity_digest); + log_fn(LOG_PROTOCOL_WARN, LD_PROTOCOL, + "Received CREATE cell (circID %u) for known circ. " + "Dropping (age %d).", + (unsigned)cell->circ_id, + (int)(time(NULL) - channel_when_created(chan))); + if (node) { + char *p = esc_for_log(node_get_platform(node)); + log_fn(LOG_PROTOCOL_WARN, LD_PROTOCOL, + "Details: router %s, platform %s.", + node_describe(node), p); + tor_free(p); + } + return; + } + if (we_are_hibernating()) { log_info(LD_OR, "Received create cell but we're shutting down. Sending back " @@ -221,14 +296,6 @@ command_process_create_cell(cell_t *cell, channel_t *chan) return; } - if (cell->circ_id == 0) { - log_fn(LOG_PROTOCOL_WARN, LD_PROTOCOL, - "Received a create cell (type %d) from %s with zero circID; " - " ignoring.", (int)cell->command, - channel_get_actual_remote_descr(chan)); - return; - } - /* If the high bit of the circuit ID is not as expected, close the * circ. */ if (chan->wide_circ_ids) @@ -247,23 +314,6 @@ command_process_create_cell(cell_t *cell, channel_t *chan) return; } - if (circuit_id_in_use_on_channel(cell->circ_id, chan)) { - const node_t *node = node_get_by_id(chan->identity_digest); - log_fn(LOG_PROTOCOL_WARN, LD_PROTOCOL, - "Received CREATE cell (circID %u) for known circ. " - "Dropping (age %d).", - (unsigned)cell->circ_id, - (int)(time(NULL) - channel_when_created(chan))); - if (node) { - char *p = esc_for_log(node_get_platform(node)); - log_fn(LOG_PROTOCOL_WARN, LD_PROTOCOL, - "Details: router %s, platform %s.", - node_describe(node), p); - tor_free(p); - } - return; - } - circ = or_circuit_new(cell->circ_id, chan); circ->base_.purpose = CIRCUIT_PURPOSE_OR; circuit_set_state(TO_CIRCUIT(circ), CIRCUIT_STATE_ONIONSKIN_PENDING); @@ -280,7 +330,7 @@ command_process_create_cell(cell_t *cell, channel_t *chan) /* hand it off to the cpuworkers, and then return. */ if (connection_or_digest_is_known_relay(chan->identity_digest)) rep_hist_note_circuit_handshake_requested(create_cell->handshake_type); - if (assign_onionskin_to_cpuworker(NULL, circ, create_cell) < 0) { + if (assign_onionskin_to_cpuworker(circ, create_cell) < 0) { log_debug(LD_GENERAL,"Failed to hand off onionskin. Closing."); circuit_mark_for_close(TO_CIRCUIT(circ), END_CIRC_REASON_RESOURCELIMIT); return; @@ -310,7 +360,6 @@ command_process_create_cell(cell_t *cell, channel_t *chan) if (len < 0) { log_warn(LD_OR,"Failed to generate key material. Closing."); circuit_mark_for_close(TO_CIRCUIT(circ), END_CIRC_REASON_INTERNAL); - tor_free(create_cell); return; } created_cell.cell_type = CELL_CREATED_FAST; @@ -349,7 +398,7 @@ command_process_created_cell(cell_t *cell, channel_t *chan) return; } - if (circ->n_circ_id != cell->circ_id) { + if (circ->n_circ_id != cell->circ_id || circ->n_chan != chan) { log_fn(LOG_PROTOCOL_WARN,LD_PROTOCOL, "got created cell from Tor client? Closing."); circuit_mark_for_close(circ, END_CIRC_REASON_TORPROTOCOL); @@ -368,7 +417,6 @@ command_process_created_cell(cell_t *cell, channel_t *chan) log_debug(LD_OR,"at OP. Finishing handshake."); if ((err_reason = circuit_finish_handshake(origin_circ, &extended_cell.created_cell)) < 0) { - log_warn(LD_OR,"circuit_finish_handshake failed."); circuit_mark_for_close(circ, -err_reason); return; } @@ -408,6 +456,7 @@ command_process_created_cell(cell_t *cell, channel_t *chan) static void command_process_relay_cell(cell_t *cell, channel_t *chan) { + const or_options_t *options = get_options(); circuit_t *circ; int reason, direction; @@ -434,6 +483,7 @@ command_process_relay_cell(cell_t *cell, channel_t *chan) } if (!CIRCUIT_IS_ORIGIN(circ) && + chan == TO_OR_CIRCUIT(circ)->p_chan && cell->circ_id == TO_OR_CIRCUIT(circ)->p_circ_id) direction = CELL_DIRECTION_OUT; else @@ -480,6 +530,14 @@ command_process_relay_cell(cell_t *cell, channel_t *chan) direction==CELL_DIRECTION_OUT?"forward":"backward"); circuit_mark_for_close(circ, -reason); } + + /* If this is a cell in an RP circuit, count it as part of the + hidden service stats */ + if (options->HiddenServiceStatistics && + !CIRCUIT_IS_ORIGIN(circ) && + TO_OR_CIRCUIT(circ)->circuit_carries_hs_traffic_stats) { + rep_hist_seen_new_rp_cell(); + } } /** Process a 'destroy' <b>cell</b> that just arrived from @@ -514,6 +572,7 @@ command_process_destroy_cell(cell_t *cell, channel_t *chan) circ->received_destroy = 1; if (!CIRCUIT_IS_ORIGIN(circ) && + chan == TO_OR_CIRCUIT(circ)->p_chan && cell->circ_id == TO_OR_CIRCUIT(circ)->p_circ_id) { /* the destroy came from behind */ circuit_set_p_circid_chan(TO_OR_CIRCUIT(circ), 0, NULL); |