/** Process a 'create' <b>cell</b> that just arrived from <b>conn</b>. Make a * new circuit with the p_circ_id specified in cell. Put the circuit in state * onionskin_pending, and pass the onionskin to the cpuworker. Circ will get * picked up again when the cpuworker finishes decrypting it. */ static void command_process_create_cell(cell_t *cell, or_connection_t *conn) { or_circuit_t *circ; const or_options_t *options = get_options(); int id_is_high; if (we_are_hibernating()) { log_info(LD_OR, "Received create cell but we're shutting down. Sending back " "destroy."); connection_or_send_destroy(cell->circ_id, conn, END_CIRC_REASON_HIBERNATING); return; } if (!server_mode(options) || (!public_server_mode(options) && conn->is_outgoing)) { log_fn(LOG_PROTOCOL_WARN, LD_PROTOCOL, "Received create cell (type %d) from %s:%d, but we're connected " "to it as a client. " "Sending back a destroy.", (int)cell->command, conn->_base.address, conn->_base.port); connection_or_send_destroy(cell->circ_id, conn, END_CIRC_REASON_TORPROTOCOL); return; } /* If the high bit of the circuit ID is not as expected, close the * circ. */ id_is_high = cell->circ_id & (1<<15); if ((id_is_high && conn->circ_id_type == CIRC_ID_TYPE_HIGHER) || (!id_is_high && conn->circ_id_type == CIRC_ID_TYPE_LOWER)) { log_fn(LOG_PROTOCOL_WARN, LD_PROTOCOL, "Received create cell with unexpected circ_id %d. Closing.", cell->circ_id); connection_or_send_destroy(cell->circ_id, conn, END_CIRC_REASON_TORPROTOCOL); return; } if (circuit_id_in_use_on_orconn(cell->circ_id, conn)) { const node_t *node = node_get_by_id(conn->identity_digest); log_fn(LOG_PROTOCOL_WARN, LD_PROTOCOL, "Received CREATE cell (circID %d) for known circ. " "Dropping (age %d).", cell->circ_id, (int)(time(NULL) - conn->_base.timestamp_created)); 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, conn); circ->_base.purpose = CIRCUIT_PURPOSE_OR; circuit_set_state(TO_CIRCUIT(circ), CIRCUIT_STATE_ONIONSKIN_PENDING); if (cell->command == CELL_CREATE) { char *onionskin = tor_malloc(ONIONSKIN_CHALLENGE_LEN); memcpy(onionskin, cell->payload, ONIONSKIN_CHALLENGE_LEN); /* hand it off to the cpuworkers, and then return. */ if (assign_onionskin_to_cpuworker(NULL, circ, onionskin) < 0) { #define WARN_HANDOFF_FAILURE_INTERVAL (6*60*60) static ratelim_t handoff_warning = RATELIM_INIT(WARN_HANDOFF_FAILURE_INTERVAL); char *m; if ((m = rate_limit_log(&handoff_warning, approx_time()))) { log_warn(LD_GENERAL,"Failed to hand off onionskin. Closing.%s",m); tor_free(m); } circuit_mark_for_close(TO_CIRCUIT(circ), END_CIRC_REASON_INTERNAL); return; } log_debug(LD_OR,"success: handed off onionskin."); } else { /* This is a CREATE_FAST cell; we can handle it immediately without using * a CPU worker. */ char keys[CPATH_KEY_MATERIAL_LEN]; char reply[DIGEST_LEN*2]; tor_assert(cell->command == CELL_CREATE_FAST); /* Make sure we never try to use the OR connection on which we * received this cell to satisfy an EXTEND request, */ conn->is_connection_with_client = 1; if (fast_server_handshake(cell->payload, (uint8_t*)reply, (uint8_t*)keys, sizeof(keys))<0) { log_warn(LD_OR,"Failed to generate key material. Closing."); circuit_mark_for_close(TO_CIRCUIT(circ), END_CIRC_REASON_INTERNAL); return; } if (onionskin_answer(circ, CELL_CREATED_FAST, reply, keys)<0) { log_warn(LD_OR,"Failed to reply to CREATE_FAST cell. Closing."); circuit_mark_for_close(TO_CIRCUIT(circ), END_CIRC_REASON_INTERNAL); return; } } }
/** Process a 'create' <b>cell</b> that just arrived from <b>conn</b>. Make a * new circuit with the p_circ_id specified in cell. Put the circuit in state * onionskin_pending, and pass the onionskin to the cpuworker. Circ will get * picked up again when the cpuworker finishes decrypting it. */ static void command_process_create_cell(cell_t *cell, or_connection_t *conn) { or_circuit_t *circ; int id_is_high; if (we_are_hibernating()) { log_info(LD_OR, "Received create cell but we're shutting down. Sending back " "destroy."); connection_or_send_destroy(cell->circ_id, conn, END_CIRC_REASON_HIBERNATING); return; } if (!server_mode(get_options())) { log_fn(LOG_PROTOCOL_WARN, LD_PROTOCOL, "Received create cell (type %d) from %s:%d, but we're a client. " "Sending back a destroy.", (int)cell->command, conn->_base.address, conn->_base.port); connection_or_send_destroy(cell->circ_id, conn, END_CIRC_REASON_TORPROTOCOL); return; } /* If the high bit of the circuit ID is not as expected, close the * circ. */ id_is_high = cell->circ_id & (1<<15); if ((id_is_high && conn->circ_id_type == CIRC_ID_TYPE_HIGHER) || (!id_is_high && conn->circ_id_type == CIRC_ID_TYPE_LOWER)) { log_fn(LOG_PROTOCOL_WARN, LD_PROTOCOL, "Received create cell with unexpected circ_id %d. Closing.", cell->circ_id); connection_or_send_destroy(cell->circ_id, conn, END_CIRC_REASON_TORPROTOCOL); return; } if (circuit_id_in_use_on_orconn(cell->circ_id, conn)) { routerinfo_t *router = router_get_by_digest(conn->identity_digest); log_fn(LOG_PROTOCOL_WARN, LD_PROTOCOL, "Received CREATE cell (circID %d) for known circ. " "Dropping (age %d).", cell->circ_id, (int)(time(NULL) - conn->_base.timestamp_created)); if (router) log_fn(LOG_PROTOCOL_WARN, LD_PROTOCOL, "Details: nickname \"%s\", platform %s.", router->nickname, escaped(router->platform)); return; } circ = or_circuit_new(cell->circ_id, conn); circ->_base.purpose = CIRCUIT_PURPOSE_OR; circuit_set_state(TO_CIRCUIT(circ), CIRCUIT_STATE_ONIONSKIN_PENDING); if (cell->command == CELL_CREATE) { char *onionskin = tor_malloc(ONIONSKIN_CHALLENGE_LEN); memcpy(onionskin, cell->payload, ONIONSKIN_CHALLENGE_LEN); /* hand it off to the cpuworkers, and then return. */ if (assign_onionskin_to_cpuworker(NULL, circ, onionskin) < 0) { log_warn(LD_GENERAL,"Failed to hand off onionskin. Closing."); circuit_mark_for_close(TO_CIRCUIT(circ), END_CIRC_REASON_INTERNAL); return; } log_debug(LD_OR,"success: handed off onionskin."); } else { /* This is a CREATE_FAST cell; we can handle it immediately without using * a CPU worker. */ char keys[CPATH_KEY_MATERIAL_LEN]; char reply[DIGEST_LEN*2]; tor_assert(cell->command == CELL_CREATE_FAST); if (fast_server_handshake(cell->payload, reply, keys, sizeof(keys))<0) { log_warn(LD_OR,"Failed to generate key material. Closing."); circuit_mark_for_close(TO_CIRCUIT(circ), END_CIRC_REASON_INTERNAL); return; } if (onionskin_answer(circ, CELL_CREATED_FAST, reply, keys)<0) { log_warn(LD_OR,"Failed to reply to CREATE_FAST cell. Closing."); circuit_mark_for_close(TO_CIRCUIT(circ), END_CIRC_REASON_INTERNAL); return; } } }