/* Copyright 2001,2002,2003 Roger Dingledine, Matej Pfajfar. */ /* See LICENSE for licensing information */ /* $Id$ */ #include "or.h" #include "tree.h" extern or_options_t options; /* command-line and config-file options */ extern char *conn_state_to_string[][_CONN_TYPE_MAX+1]; static int connection_ap_handshake_process_socks(connection_t *conn); static int connection_ap_handshake_attach_circuit(connection_t *conn); static int connection_ap_handshake_attach_circuit_helper(connection_t *conn); static void connection_ap_handshake_send_begin(connection_t *ap_conn, circuit_t *circ); static void connection_ap_handshake_socks_reply(connection_t *conn, char *reply, int replylen, char success); static int connection_exit_begin_conn(cell_t *cell, circuit_t *circ); static void connection_edge_consider_sending_sendme(connection_t *conn); static uint32_t client_dns_lookup_entry(const char *address); static void client_dns_set_entry(const char *address, uint32_t val); void relay_header_pack(char *dest, const relay_header_t *src) { *(uint8_t*)(dest) = src->command; *(uint16_t*)(dest+1) = htons(src->recognized); *(uint16_t*)(dest+3) = htons(src->stream_id); memcpy(dest+5, src->integrity, 4); *(uint16_t*)(dest+9) = htons(src->length); } void relay_header_unpack(relay_header_t *dest, const char *src) { dest->command = *(uint8_t*)(src); dest->recognized = ntohs(*(uint16_t*)(src+1)); dest->stream_id = ntohs(*(uint16_t*)(src+3)); memcpy(dest->integrity, src+5, 4); dest->length = ntohs(*(uint16_t*)(src+9)); } int connection_edge_process_inbuf(connection_t *conn) { assert(conn); assert(conn->type == CONN_TYPE_AP || conn->type == CONN_TYPE_EXIT); if(conn->inbuf_reached_eof) { #ifdef HALF_OPEN /* eof reached; we're done reading, but we might want to write more. */ conn->done_receiving = 1; shutdown(conn->s, 0); /* XXX check return, refactor NM */ if (conn->done_sending) { connection_mark_for_close(conn, END_STREAM_REASON_DONE); } else { connection_edge_send_command(conn, circuit_get_by_conn(conn), RELAY_COMMAND_END, NULL, 0, conn->cpath_layer); } return 0; #else /* eof reached, kill it. */ log_fn(LOG_INFO,"conn (fd %d) reached eof. Closing.", conn->s); connection_mark_for_close(conn, END_STREAM_REASON_DONE); conn->hold_open_until_flushed = 1; /* just because we shouldn't read doesn't mean we shouldn't write */ return 0; #endif } switch(conn->state) { case AP_CONN_STATE_SOCKS_WAIT: if(connection_ap_handshake_process_socks(conn) < 0) { connection_mark_for_close(conn, END_STREAM_REASON_MISC); conn->hold_open_until_flushed = 1; return -1; } return 0; case AP_CONN_STATE_OPEN: case EXIT_CONN_STATE_OPEN: if(conn->package_window <= 0) { log_fn(LOG_WARN,"called with package_window %d. Tell Roger.", conn->package_window); return 0; } if(connection_edge_package_raw_inbuf(conn) < 0) { connection_mark_for_close(conn, END_STREAM_REASON_MISC); return -1; } return 0; case EXIT_CONN_STATE_CONNECTING: log_fn(LOG_INFO,"text from server while in 'connecting' state at exit. Leaving it on buffer."); return 0; } log_fn(LOG_WARN,"Got unexpected state %d. Closing.",conn->state); return -1; } int connection_edge_destroy(uint16_t circ_id, connection_t *conn) { assert(conn->type == CONN_TYPE_AP || conn->type == CONN_TYPE_EXIT); if(conn->marked_for_close) return 0; /* already marked; probably got an 'end' */ log_fn(LOG_INFO,"CircID %d: At an edge. Marking connection for close.", circ_id); conn->has_sent_end = 1; /* we're closing the circuit, nothing to send to */ connection_mark_for_close(conn, END_STREAM_REASON_DESTROY); conn->hold_open_until_flushed = 1; return 0; } static char *connection_edge_end_reason(char *payload, uint16_t length) { if(length < 1) { log_fn(LOG_WARN,"End cell arrived with length 0. Should be at least 1."); return "MALFORMED"; } if(*payload < _MIN_END_STREAM_REASON || *payload > _MAX_END_STREAM_REASON) { log_fn(LOG_WARN,"Reason for ending (%d) not recognized.",*payload); return "MALFORMED"; } switch(*payload) { case END_STREAM_REASON_MISC: return "misc error"; case END_STREAM_REASON_RESOLVEFAILED: return "resolve failed"; case END_STREAM_REASON_CONNECTFAILED: return "connect failed"; case END_STREAM_REASON_EXITPOLICY: return "exit policy failed"; case END_STREAM_REASON_DESTROY: return "destroyed"; case END_STREAM_REASON_DONE: return "closed normally"; case END_STREAM_REASON_TIMEOUT: return "gave up (timeout)"; } assert(0); return ""; } int connection_edge_end(connection_t *conn, char reason, crypt_path_t *cpath_layer) { char payload[5]; int payload_len=1; circuit_t *circ; if(conn->has_sent_end) { log_fn(LOG_WARN,"It appears I've already sent the end. Are you calling me twice?"); return -1; } payload[0] = reason; if(reason == END_STREAM_REASON_EXITPOLICY) { *(uint32_t *)(payload+1) = htonl(conn->addr); payload_len += 4; } circ = circuit_get_by_conn(conn); if(circ && !circ->marked_for_close) { log_fn(LOG_DEBUG,"Marking conn (fd %d) and sending end.",conn->s); connection_edge_send_command(conn, circ, RELAY_COMMAND_END, payload, payload_len, cpath_layer); } else { log_fn(LOG_DEBUG,"Marking conn (fd %d); no circ to send end.",conn->s); } conn->has_sent_end = 1; return 0; } int connection_edge_send_command(connection_t *fromconn, circuit_t *circ, int relay_command, void *payload, int payload_len, crypt_path_t *cpath_layer) { cell_t cell; relay_header_t rh; int cell_direction; if(!circ) { log_fn(LOG_WARN,"no circ. Closing conn."); assert(fromconn); connection_mark_for_close(fromconn, 0); return -1; } memset(&cell, 0, sizeof(cell_t)); cell.command = CELL_RELAY; // if(fromconn && fromconn->type == CONN_TYPE_AP) { if(cpath_layer) { cell.circ_id = circ->n_circ_id; cell_direction = CELL_DIRECTION_OUT; } else { cell.circ_id = circ->p_circ_id; cell_direction = CELL_DIRECTION_IN; } memset(&rh, 0, sizeof(rh)); rh.command = relay_command; if(fromconn) rh.stream_id = fromconn->stream_id; /* else it's 0 */ rh.length = payload_len; relay_header_pack(cell.payload, &rh); if(payload_len) memcpy(cell.payload+RELAY_HEADER_SIZE, payload, payload_len); log_fn(LOG_DEBUG,"delivering %d cell %s.", relay_command, cell_direction == CELL_DIRECTION_OUT ? "forward" : "backward"); if(circuit_package_relay_cell(&cell, circ, cell_direction, cpath_layer) < 0) { log_fn(LOG_WARN,"circuit_package_relay_cell failed. Closing."); circuit_mark_for_close(circ); return -1; } return 0; } /* an incoming relay cell has arrived. return -1 if you want to tear down the * circuit, else 0. */ int connection_edge_process_relay_cell(cell_t *cell, circuit_t *circ, connection_t *conn, int edge_type, crypt_path_t *layer_hint) { static int num_seen=0; uint32_t addr; relay_header_t rh; assert(cell && circ); relay_header_unpack(&rh, cell->payload); // log_fn(LOG_DEBUG,"command %d stream %d", rh.command, rh.stream_id); num_seen++; log_fn(LOG_DEBUG,"Now seen %d relay cells here.", num_seen); /* either conn is NULL, in which case we've got a control cell, or else * conn points to the recognized stream. */ if(conn && conn->state != AP_CONN_STATE_OPEN && conn->state != EXIT_CONN_STATE_OPEN) { if(rh.command == RELAY_COMMAND_END) { log_fn(LOG_INFO,"Edge got end (%s) before we're connected. Marking for close.", connection_edge_end_reason(cell->payload+RELAY_HEADER_SIZE, rh.length)); conn->has_sent_end = 1; /* we just got an 'end', don't need to send one */ connection_mark_for_close(conn, 0); /* XXX This is where we should check if reason is EXITPOLICY, and reattach */ /* XXX here we should send a socks reject back if necessary, and hold * open til flushed */ return 0; } if(conn->type == CONN_TYPE_AP && rh.command == RELAY_COMMAND_CONNECTED) { if(conn->state != AP_CONN_STATE_CONNECT_WAIT) { log_fn(LOG_WARN,"Got 'connected' while not in state connect_wait. Dropping."); return 0; } // log_fn(LOG_INFO,"Connected! Notifying application."); conn->state = AP_CONN_STATE_OPEN; if (rh.length >= 4) { addr = ntohl(*(uint32_t*)(cell->payload + RELAY_HEADER_SIZE)); client_dns_set_entry(conn->socks_request->address, addr); } log_fn(LOG_INFO,"'connected' received after %d seconds.", (int)(time(NULL) - conn->timestamp_lastread)); circuit_log_path(LOG_INFO,circ); connection_ap_handshake_socks_reply(conn, NULL, 0, 1); return 0; } else { log_fn(LOG_WARN,"Got an unexpected relay command %d, in state %d (%s). Closing.", rh.command, conn->state, conn_state_to_string[conn->type][conn->state]); connection_mark_for_close(conn, END_STREAM_REASON_MISC); return -1; } } switch(rh.command) { case RELAY_COMMAND_DROP: log_fn(LOG_INFO,"Got a relay-level padding cell. Dropping."); return 0; case RELAY_COMMAND_BEGIN: if(edge_type == EDGE_AP) { log_fn(LOG_WARN,"relay begin request unsupported at AP. Dropping."); return 0; } if(conn) { log_fn(LOG_WARN,"begin cell for known stream. Dropping."); return 0; } connection_exit_begin_conn(cell, circ); return 0; case RELAY_COMMAND_DATA: ++stats_n_data_cells_received; if((edge_type == EDGE_AP && --layer_hint->deliver_window < 0) || (edge_type == EDGE_EXIT && --circ->deliver_window < 0)) { log_fn(LOG_WARN,"(relay data) circ deliver_window below 0. Killing."); connection_mark_for_close(conn, END_STREAM_REASON_MISC); return -1; } log_fn(LOG_DEBUG,"circ deliver_window now %d.", edge_type == EDGE_AP ? layer_hint->deliver_window : circ->deliver_window); circuit_consider_sending_sendme(circ, edge_type, layer_hint); if(!conn) { log_fn(LOG_INFO,"data cell dropped, unknown stream."); return 0; } if(--conn->deliver_window < 0) { /* is it below 0 after decrement? */ log_fn(LOG_WARN,"(relay data) conn deliver_window below 0. Killing."); return -1; /* somebody's breaking protocol. kill the whole circuit. */ } stats_n_data_bytes_received += rh.length; connection_write_to_buf(cell->payload + RELAY_HEADER_SIZE, rh.length, conn); connection_edge_consider_sending_sendme(conn); return 0; case RELAY_COMMAND_END: if(!conn) { log_fn(LOG_INFO,"end cell (%s) dropped, unknown stream.", connection_edge_end_reason(cell->payload+RELAY_HEADER_SIZE, rh.length)); return 0; } if(rh.length >= 5 && *(cell->payload+RELAY_HEADER_SIZE) == END_STREAM_REASON_EXITPOLICY) { /* XXX this will never be reached, since we're in 'connect_wait' state * but this is only reached when we're in 'open' state. Put it higher. */ /* No need to close the connection. We'll hold it open while * we try a new exit node. * cell->payload+RELAY_HEADER_SIZE+1 holds the destination addr. */ addr = ntohl(*(uint32_t*)(cell->payload+RELAY_HEADER_SIZE+1)); client_dns_set_entry(conn->socks_request->address, addr); conn->state = AP_CONN_STATE_CIRCUIT_WAIT; if(connection_ap_handshake_attach_circuit(conn) >= 0) return 0; /* else, conn will get closed below */ } /* XXX add to this log_fn the exit node's nickname? */ log_fn(LOG_INFO,"end cell (%s) for stream %d. Removing stream.", connection_edge_end_reason(cell->payload+RELAY_HEADER_SIZE, rh.length), conn->stream_id); #ifdef HALF_OPEN conn->done_sending = 1; shutdown(conn->s, 1); /* XXX check return; refactor NM */ if (conn->done_receiving) { /* We just *got* an end; no reason to send one. */ conn->has_sent_end = 1; connection_mark_for_close(conn, 0); conn->hold_open_until_flushed = 1; } #else /* We just *got* an end; no reason to send one. */ conn->has_sent_end = 1; connection_mark_for_close(conn, 0); conn->hold_open_until_flushed = 1; #endif return 0; case RELAY_COMMAND_EXTEND: if(conn) { log_fn(LOG_WARN,"'extend' for non-zero stream. Dropping."); return 0; } return circuit_extend(cell, circ); case RELAY_COMMAND_EXTENDED: if(edge_type == EDGE_EXIT) { log_fn(LOG_WARN,"'extended' unsupported at exit. Dropping."); return 0; } log_fn(LOG_DEBUG,"Got an extended cell! Yay."); if(circuit_finish_handshake(circ, cell->payload+RELAY_HEADER_SIZE) < 0) { log_fn(LOG_WARN,"circuit_finish_handshake failed."); return -1; } if (circuit_send_next_onion_skin(circ)<0) { log_fn(LOG_INFO,"circuit_send_next_onion_skin() failed."); return -1; } return 0; case RELAY_COMMAND_TRUNCATE: if(edge_type == EDGE_AP) { log_fn(LOG_WARN,"'truncate' unsupported at AP. Dropping."); return 0; } if(circ->n_conn) { connection_send_destroy(circ->n_circ_id, circ->n_conn); circ->n_conn = NULL; } log_fn(LOG_DEBUG, "Processed 'truncate', replying."); connection_edge_send_command(NULL, circ, RELAY_COMMAND_TRUNCATED, NULL, 0, NULL); return 0; case RELAY_COMMAND_TRUNCATED: if(edge_type == EDGE_EXIT) { log_fn(LOG_WARN,"'truncated' unsupported at exit. Dropping."); return 0; } circuit_truncated(circ, layer_hint); return 0; case RELAY_COMMAND_CONNECTED: if(conn) { log_fn(LOG_WARN,"'connected' unsupported while open. Closing conn."); return -1; } log_fn(LOG_INFO,"'connected' received, no conn attached anymore. Ignoring."); return 0; case RELAY_COMMAND_SENDME: if(!conn) { if(edge_type == EDGE_AP) { assert(layer_hint); layer_hint->package_window += CIRCWINDOW_INCREMENT; log_fn(LOG_DEBUG,"circ-level sendme at AP, packagewindow %d.", layer_hint->package_window); circuit_resume_edge_reading(circ, EDGE_AP, layer_hint); } else { assert(!layer_hint); circ->package_window += CIRCWINDOW_INCREMENT; log_fn(LOG_DEBUG,"circ-level sendme at exit, packagewindow %d.", circ->package_window); circuit_resume_edge_reading(circ, EDGE_EXIT, layer_hint); } return 0; } conn->package_window += STREAMWINDOW_INCREMENT; log_fn(LOG_DEBUG,"stream-level sendme, packagewindow now %d.", conn->package_window); connection_start_reading(conn); connection_edge_package_raw_inbuf(conn); /* handle whatever might still be on the inbuf */ return 0; } log_fn(LOG_WARN,"unknown relay command %d.",rh.command); return -1; } int connection_edge_finished_flushing(connection_t *conn) { unsigned char connected_payload[4]; int e, len=sizeof(e); assert(conn); assert(conn->type == CONN_TYPE_AP || conn->type == CONN_TYPE_EXIT); switch(conn->state) { case EXIT_CONN_STATE_CONNECTING: if (getsockopt(conn->s, SOL_SOCKET, SO_ERROR, (void*)&e, &len) < 0) { /* not yet */ if(!ERRNO_CONN_EINPROGRESS(errno)) { /* yuck. kill it. */ log_fn(LOG_DEBUG,"in-progress exit connect failed. Removing."); connection_mark_for_close(conn, END_STREAM_REASON_CONNECTFAILED); return -1; } else { log_fn(LOG_DEBUG,"in-progress exit connect still waiting."); return 0; /* no change, see if next time is better */ } } /* the connect has finished. */ log_fn(LOG_INFO,"Exit connection to %s:%u established.", conn->address,conn->port); conn->state = EXIT_CONN_STATE_OPEN; connection_watch_events(conn, POLLIN); /* stop writing, continue reading */ if(connection_wants_to_flush(conn)) /* in case there are any queued relay cells */ connection_start_writing(conn); /* deliver a 'connected' relay cell back through the circuit. */ *(uint32_t*)connected_payload = htonl(conn->addr); if(connection_edge_send_command(conn, circuit_get_by_conn(conn), RELAY_COMMAND_CONNECTED, connected_payload, 4, NULL) < 0) return 0; /* circuit is closed, don't continue */ assert(conn->package_window > 0); return connection_edge_process_inbuf(conn); /* in case the server has written anything */ case AP_CONN_STATE_OPEN: case EXIT_CONN_STATE_OPEN: connection_stop_writing(conn); connection_edge_consider_sending_sendme(conn); return 0; case AP_CONN_STATE_SOCKS_WAIT: case AP_CONN_STATE_CIRCUIT_WAIT: case AP_CONN_STATE_CONNECT_WAIT: connection_stop_writing(conn); return 0; default: log_fn(LOG_WARN,"BUG: called in unexpected state: %d", conn->state); return -1; } return 0; } uint64_t stats_n_data_cells_packaged = 0; uint64_t stats_n_data_bytes_packaged = 0; uint64_t stats_n_data_cells_received = 0; uint64_t stats_n_data_bytes_received = 0; int connection_edge_package_raw_inbuf(connection_t *conn) { int amount_to_process, length; char payload[CELL_PAYLOAD_SIZE]; circuit_t *circ; assert(conn); assert(!connection_speaks_cells(conn)); repeat_connection_edge_package_raw_inbuf: circ = circuit_get_by_conn(conn); if(!circ) { log_fn(LOG_INFO,"conn has no circuits! Closing."); return -1; } if(circuit_consider_stop_edge_reading(circ, conn->type, conn->cpath_layer)) return 0; if(conn->package_window <= 0) { log_fn(LOG_WARN,"called with package_window %d. Tell Roger.", conn->package_window); connection_stop_reading(conn); return 0; } amount_to_process = buf_datalen(conn->inbuf); if(!amount_to_process) return 0; if(amount_to_process > RELAY_PAYLOAD_SIZE) { length = RELAY_PAYLOAD_SIZE; } else { length = amount_to_process; } stats_n_data_bytes_packaged += length; stats_n_data_cells_packaged += 1; connection_fetch_from_buf(payload, length, conn); log_fn(LOG_DEBUG,"(%d) Packaging %d bytes (%d waiting).", conn->s, length, (int)buf_datalen(conn->inbuf)); if(connection_edge_send_command(conn, circ, RELAY_COMMAND_DATA, payload, length, conn->cpath_layer) < 0) return 0; /* circuit is closed, don't continue */ if(conn->type == CONN_TYPE_EXIT) { assert(circ->package_window > 0); circ->package_window--; } else { /* we're an AP */ assert(conn->type == CONN_TYPE_AP); assert(conn->cpath_layer->package_window > 0); conn->cpath_layer->package_window--; } if(--conn->package_window <= 0) { /* is it 0 after decrement? */ connection_stop_reading(conn); log_fn(LOG_DEBUG,"conn->package_window reached 0."); circuit_consider_stop_edge_reading(circ, conn->type, conn->cpath_layer); return 0; /* don't process the inbuf any more */ } log_fn(LOG_DEBUG,"conn->package_window is now %d",conn->package_window); /* handle more if there's more, or return 0 if there isn't */ goto repeat_connection_edge_package_raw_inbuf; } void connection_ap_expire_beginning(void) { connection_t **carray; connection_t *conn; circuit_t *circ; int n, i; time_t now = time(NULL); get_connection_array(&carray, &n); for (i = 0; i < n; ++i) { conn = carray[i]; if (conn->type != CONN_TYPE_AP || conn->state != AP_CONN_STATE_CONNECT_WAIT) continue; if (now - conn->timestamp_lastread >= 15) { log_fn(LOG_WARN,"Stream is %d seconds late. Retrying.", (int)(now - conn->timestamp_lastread)); circ = circuit_get_by_conn(conn); circuit_log_path(LOG_WARN, circ); /* send an end down the circuit */ connection_edge_end(conn, END_STREAM_REASON_TIMEOUT, conn->cpath_layer); /* un-mark it as ending, since we're going to reuse it */ conn->has_sent_end = 0; /* move it back into 'pending' state. It's possible it will * reattach to this same circuit, but that's good enough for now. */ conn->state = AP_CONN_STATE_CIRCUIT_WAIT; circuit_detach_stream(circ, conn); /* kludge to make us not try this circuit again, yet to allow * current streams on it to survive if they can: make it * unattractive to use for new streams */ assert(circ->timestamp_dirty); circ->timestamp_dirty -= options.NewCircuitPeriod; /* give our stream another 15 seconds to try */ conn->timestamp_lastread += 15; if(connection_ap_handshake_attach_circuit(conn)<0) { /* it will never work */ /* Don't need to send end -- we're not connected */ connection_mark_for_close(conn, 0); } } } } /* Tell any APs that are waiting for a new circuit that one is available */ void connection_ap_attach_pending(void) { connection_t **carray; connection_t *conn; int n, i; get_connection_array(&carray, &n); for (i = 0; i < n; ++i) { conn = carray[i]; if (conn->type != CONN_TYPE_AP || conn->state != AP_CONN_STATE_CIRCUIT_WAIT) continue; if(connection_ap_handshake_attach_circuit(conn) < 0) { /* -1 means it will never work */ /* Don't send end; there is no 'other side' yet */ connection_mark_for_close(conn,0); } } } static void connection_edge_consider_sending_sendme(connection_t *conn) { circuit_t *circ; if(connection_outbuf_too_full(conn)) return; circ = circuit_get_by_conn(conn); if(!circ) { /* this can legitimately happen if the destroy has already * arrived and torn down the circuit */ log_fn(LOG_INFO,"No circuit associated with conn. Skipping."); return; } while(conn->deliver_window < STREAMWINDOW_START - STREAMWINDOW_INCREMENT) { log_fn(LOG_DEBUG,"Outbuf %d, Queueing stream sendme.", conn->outbuf_flushlen); conn->deliver_window += STREAMWINDOW_INCREMENT; if(connection_edge_send_command(conn, circ, RELAY_COMMAND_SENDME, NULL, 0, conn->cpath_layer) < 0) { log_fn(LOG_WARN,"connection_edge_send_command failed. Returning."); return; /* the circuit's closed, don't continue */ } } } static int connection_ap_handshake_process_socks(connection_t *conn) { socks_request_t *socks; int sockshere; assert(conn); assert(conn->type == CONN_TYPE_AP); assert(conn->state == AP_CONN_STATE_SOCKS_WAIT); assert(conn->socks_request); socks = conn->socks_request; log_fn(LOG_DEBUG,"entered."); sockshere = fetch_from_buf_socks(conn->inbuf, socks); if(sockshere == -1 || sockshere == 0) { if(socks->replylen) { /* we should send reply back */ log_fn(LOG_DEBUG,"reply is already set for us. Using it."); connection_ap_handshake_socks_reply(conn, socks->reply, socks->replylen, 0); } else if(sockshere == -1) { /* send normal reject */ log_fn(LOG_WARN,"Fetching socks handshake failed. Closing."); connection_ap_handshake_socks_reply(conn, NULL, 0, 0); } else { log_fn(LOG_DEBUG,"socks handshake not all here yet."); } return sockshere; } /* else socks handshake is done, continue processing */ conn->state = AP_CONN_STATE_CIRCUIT_WAIT; return connection_ap_handshake_attach_circuit(conn); } static int connection_ap_handshake_attach_circuit(connection_t *conn) { /* try attaching. launch new circuit if needed. * return -1 if conn needs to die, else 0. */ switch(connection_ap_handshake_attach_circuit_helper(conn)) { case -1: /* it will never work */ return -1; case 0: /* no useful circuits available */ if(!circuit_get_newest(conn, 0)) /* is one already on the way? */ circuit_launch_new(); return 0; default: /* case 1, it succeeded, great */ return 0; } } /* Try to find a safe live circuit for CONN_TYPE_AP connection conn. If * we don't find one: if conn cannot be handled by any known nodes, * warn and return -1; else tell conn to stop reading and return 0. * Otherwise, associate conn with a safe live circuit, start * sending a BEGIN cell down the circuit, and return 1. */ static int connection_ap_handshake_attach_circuit_helper(connection_t *conn) { circuit_t *circ; uint32_t addr; assert(conn); assert(conn->type == CONN_TYPE_AP); assert(conn->state == AP_CONN_STATE_CIRCUIT_WAIT); assert(conn->socks_request); /* find the circuit that we should use, if there is one. */ circ = circuit_get_newest(conn, 1); if(!circ) { log_fn(LOG_INFO,"No safe circuit ready for edge connection; delaying."); addr = client_dns_lookup_entry(conn->socks_request->address); if(router_exit_policy_all_routers_reject(addr, conn->socks_request->port)) { log_fn(LOG_WARN,"No Tor server exists that allows exit to %s:%d. Rejecting.", conn->socks_request->address, conn->socks_request->port); return -1; } connection_stop_reading(conn); /* don't read until the connected cell arrives */ return 0; } connection_start_reading(conn); /* here, print the circ's path. so people can figure out which circs are sucking. */ circuit_log_path(LOG_INFO,circ); if(!circ->timestamp_dirty) circ->timestamp_dirty = time(NULL); /* add it into the linked list of streams on this circuit */ log_fn(LOG_DEBUG,"attaching new conn to circ. n_circ_id %d.", circ->n_circ_id); conn->next_stream = circ->p_streams; /* assert_connection_ok(conn, time(NULL)); */ circ->p_streams = conn; assert(circ->cpath && circ->cpath->prev); assert(circ->cpath->prev->state == CPATH_STATE_OPEN); conn->cpath_layer = circ->cpath->prev; connection_ap_handshake_send_begin(conn, circ); return 1; } /* Iterate over the two bytes of stream_id until we get one that is not * already in use. Return 0 if can't get a unique stream_id. */ static uint16_t get_unique_stream_id_by_circ(circuit_t *circ) { connection_t *tmpconn; uint16_t test_stream_id; uint32_t attempts=0; again: test_stream_id = circ->next_stream_id++; if(++attempts > 1<<16) { /* Make sure we don't loop forever if all stream_id's are used. */ log_fn(LOG_WARN,"No unused stream IDs. Failing."); return 0; } if (test_stream_id == 0) goto again; for(tmpconn = circ->p_streams; tmpconn; tmpconn=tmpconn->next_stream) if(tmpconn->stream_id == test_stream_id) goto again; return test_stream_id; } /* deliver the destaddr:destport in a relay cell */ static void connection_ap_handshake_send_begin(connection_t *ap_conn, circuit_t *circ) { char payload[CELL_PAYLOAD_SIZE]; int payload_len; struct in_addr in; const char *string_addr; assert(ap_conn->type == CONN_TYPE_AP); assert(ap_conn->state == AP_CONN_STATE_CIRCUIT_WAIT); assert(ap_conn->socks_request); ap_conn->stream_id = get_unique_stream_id_by_circ(circ); if (ap_conn->stream_id==0) { /* Don't send end: there is no 'other side' yet */ connection_mark_for_close(ap_conn, 0); return; } in.s_addr = htonl(client_dns_lookup_entry(ap_conn->socks_request->address)); string_addr = in.s_addr ? inet_ntoa(in) : NULL; snprintf(payload,RELAY_PAYLOAD_SIZE, "%s:%d", string_addr ? string_addr : ap_conn->socks_request->address, ap_conn->socks_request->port); payload_len = strlen(payload)+1; log_fn(LOG_DEBUG,"Sending relay cell to begin stream %d.",ap_conn->stream_id); if(connection_edge_send_command(ap_conn, circ, RELAY_COMMAND_BEGIN, payload, payload_len, ap_conn->cpath_layer) < 0) return; /* circuit is closed, don't continue */ ap_conn->package_window = STREAMWINDOW_START; ap_conn->deliver_window = STREAMWINDOW_START; ap_conn->state = AP_CONN_STATE_CONNECT_WAIT; /* XXX Right now, we rely on the socks client not to send us any data * XXX until we've sent back a socks reply. (If it does, we could wind * XXX up packaging that data and sending it to the exit, then later having * XXX the exit refuse us.) */ log_fn(LOG_INFO,"Address/port sent, ap socket %d, n_circ_id %d",ap_conn->s,circ->n_circ_id); return; } static void connection_ap_handshake_socks_reply(connection_t *conn, char *reply, int replylen, char success) { char buf[256]; if(replylen) { /* we already have a reply in mind */ connection_write_to_buf(reply, replylen, conn); return; } assert(conn->socks_request); if(conn->socks_request->socks_version == 4) { memset(buf,0,SOCKS4_NETWORK_LEN); #define SOCKS4_GRANTED 90 #define SOCKS4_REJECT 91 buf[1] = (success ? SOCKS4_GRANTED : SOCKS4_REJECT); /* leave version, destport, destip zero */ connection_write_to_buf(buf, SOCKS4_NETWORK_LEN, conn); } if(conn->socks_request->socks_version == 5) { buf[0] = 5; /* version 5 */ #define SOCKS5_SUCCESS 0 #define SOCKS5_GENERIC_ERROR 1 buf[1] = success ? SOCKS5_SUCCESS : SOCKS5_GENERIC_ERROR; buf[2] = 0; buf[3] = 1; /* ipv4 addr */ memset(buf+4,0,6); /* Set external addr/port to 0. The spec doesn't seem to say what to do here. -RD */ connection_write_to_buf(buf,10,conn); } /* if socks_version isn't 4 or 5, don't send anything */ return; } static int connection_exit_begin_conn(cell_t *cell, circuit_t *circ) { connection_t *n_stream; relay_header_t rh; char *colon; relay_header_unpack(&rh, cell->payload); /* XXX currently we don't send an end cell back if we drop the * begin because it's malformed. */ if(!memchr(cell->payload+RELAY_HEADER_SIZE, 0, rh.length)) { log_fn(LOG_WARN,"relay begin cell has no \\0. Dropping."); return 0; } colon = strchr(cell->payload+RELAY_HEADER_SIZE, ':'); if(!colon) { log_fn(LOG_WARN,"relay begin cell has no colon. Dropping."); return 0; } *colon = 0; if(!atoi(colon+1)) { /* bad port */ log_fn(LOG_WARN,"relay begin cell has invalid port. Dropping."); return 0; } log_fn(LOG_DEBUG,"Creating new exit connection."); n_stream = connection_new(CONN_TYPE_EXIT); n_stream->stream_id = rh.stream_id; n_stream->address = tor_strdup(cell->payload + RELAY_HEADER_SIZE); n_stream->port = atoi(colon+1); n_stream->state = EXIT_CONN_STATE_RESOLVING; /* leave n_stream->s at -1, because it's not yet valid */ n_stream->package_window = STREAMWINDOW_START; n_stream->deliver_window = STREAMWINDOW_START; if(connection_add(n_stream) < 0) { /* no space, forget it */ log_fn(LOG_WARN,"connection_add failed. Dropping."); connection_free(n_stream); return 0; } /* add it into the linked list of streams on this circuit */ n_stream->next_stream = circ->n_streams; circ->n_streams = n_stream; /* send it off to the gethostbyname farm */ switch(dns_resolve(n_stream)) { case 1: /* resolve worked */ connection_exit_connect(n_stream); return 0; case -1: /* resolve failed */ log_fn(LOG_INFO,"Resolve failed (%s).", n_stream->address); /* Set the state so that we don't try to remove n_stream from a DNS * pending list. */ n_stream->state = EXIT_CONN_STATE_RESOLVEFAILED; connection_mark_for_close(n_stream, END_STREAM_REASON_RESOLVEFAILED); break; case 0: /* resolve added to pending list */ ; } return 0; } void connection_exit_connect(connection_t *conn) { unsigned char connected_payload[4]; if(router_compare_to_my_exit_policy(conn) == ADDR_POLICY_REJECTED) { log_fn(LOG_INFO,"%s:%d failed exit policy. Closing.", conn->address, conn->port); connection_mark_for_close(conn, END_STREAM_REASON_EXITPOLICY); return; } switch(connection_connect(conn, conn->address, conn->addr, conn->port)) { case -1: connection_mark_for_close(conn, END_STREAM_REASON_CONNECTFAILED); return; case 0: connection_set_poll_socket(conn); conn->state = EXIT_CONN_STATE_CONNECTING; connection_watch_events(conn, POLLOUT | POLLIN | POLLERR); /* writable indicates finish, readable indicates broken link, error indicates broken link in windowsland. */ return; /* case 1: fall through */ } connection_set_poll_socket(conn); conn->state = EXIT_CONN_STATE_OPEN; if(connection_wants_to_flush(conn)) { /* in case there are any queued data cells */ log_fn(LOG_WARN,"tell roger: newly connected conn had data waiting!"); // connection_start_writing(conn); } // connection_process_inbuf(conn); connection_watch_events(conn, POLLIN); /* also, deliver a 'connected' cell back through the circuit. */ *((uint32_t*) connected_payload) = htonl(conn->addr); connection_edge_send_command(conn, circuit_get_by_conn(conn), RELAY_COMMAND_CONNECTED, connected_payload, 4, NULL); } int connection_ap_can_use_exit(connection_t *conn, routerinfo_t *exit) { uint32_t addr; assert(conn); assert(conn->type == CONN_TYPE_AP); assert(conn->socks_request); log_fn(LOG_DEBUG,"considering nickname %s, for address %s / port %d:", exit->nickname, conn->socks_request->address, conn->socks_request->port); addr = client_dns_lookup_entry(conn->socks_request->address); return router_compare_addr_to_exit_policy(addr, conn->socks_request->port, exit->exit_policy); } /* ***** Client DNS code ***** */ /* XXX Perhaps this should get merged with the dns.c code somehow. */ /* XXX But we can't just merge them, because then nodes that act as * both OR and OP could be attacked: people could rig the dns cache * by answering funny things to stream begin requests, and later * other clients would reuse those funny addr's. Hm. */ struct client_dns_entry { SPLAY_ENTRY(client_dns_entry) node; char *address; uint32_t addr; time_t expires; }; static int client_dns_size = 0; static SPLAY_HEAD(client_dns_tree, client_dns_entry) client_dns_root; static int compare_client_dns_entries(struct client_dns_entry *a, struct client_dns_entry *b) { return strcasecmp(a->address, b->address); } static void client_dns_entry_free(struct client_dns_entry *ent) { tor_free(ent->address); tor_free(ent); } SPLAY_PROTOTYPE(client_dns_tree, client_dns_entry, node, compare_client_dns_entries); SPLAY_GENERATE(client_dns_tree, client_dns_entry, node, compare_client_dns_entries); void client_dns_init(void) { SPLAY_INIT(&client_dns_root); client_dns_size = 0; } static uint32_t client_dns_lookup_entry(const char *address) { struct client_dns_entry *ent; struct client_dns_entry search; struct in_addr in; time_t now; assert(address); if (inet_aton(address, &in)) { log_fn(LOG_DEBUG, "Using static address %s (%08lX)", address, (unsigned long)ntohl(in.s_addr)); return ntohl(in.s_addr); } search.address = (char*)address; ent = SPLAY_FIND(client_dns_tree, &client_dns_root, &search); if (!ent) { log_fn(LOG_DEBUG, "No entry found for address %s", address); return 0; } else { now = time(NULL); if (ent->expires < now) { log_fn(LOG_DEBUG, "Expired entry found for address %s", address); SPLAY_REMOVE(client_dns_tree, &client_dns_root, ent); client_dns_entry_free(ent); --client_dns_size; return 0; } in.s_addr = htonl(ent->addr); log_fn(LOG_DEBUG, "Found cached entry for address %s: %s", address, inet_ntoa(in)); return ent->addr; } } static void client_dns_set_entry(const char *address, uint32_t val) { struct client_dns_entry *ent; struct client_dns_entry search; struct in_addr in; time_t now; assert(address); assert(val); if (inet_aton(address, &in)) return; search.address = (char*) address; now = time(NULL); ent = SPLAY_FIND(client_dns_tree, &client_dns_root, &search); if (ent) { in.s_addr = htonl(val); log_fn(LOG_DEBUG, "Updating entry for address %s: %s", address, inet_ntoa(in)); ent->addr = val; ent->expires = now+MAX_DNS_ENTRY_AGE; } else { in.s_addr = htonl(val); log_fn(LOG_DEBUG, "Caching result for address %s: %s", address, inet_ntoa(in)); ent = tor_malloc(sizeof(struct client_dns_entry)); ent->address = tor_strdup(address); ent->addr = val; ent->expires = now+MAX_DNS_ENTRY_AGE; SPLAY_INSERT(client_dns_tree, &client_dns_root, ent); ++client_dns_size; } } void client_dns_clean(void) { struct client_dns_entry **expired_entries; int n_expired_entries = 0; struct client_dns_entry *ent; time_t now; int i; if(!client_dns_size) return; expired_entries = tor_malloc(client_dns_size * sizeof(struct client_dns_entry *)); now = time(NULL); SPLAY_FOREACH(ent, client_dns_tree, &client_dns_root) { if (ent->expires < now) { expired_entries[n_expired_entries++] = ent; } } for (i = 0; i < n_expired_entries; ++i) { SPLAY_REMOVE(client_dns_tree, &client_dns_root, expired_entries[i]); client_dns_entry_free(expired_entries[i]); } tor_free(expired_entries); } /* Local Variables: mode:c indent-tabs-mode:nil c-basic-offset:2 End: */