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- /* Copyright 2001,2002,2003 Roger Dingledine, Matej Pfajfar. */
- /* See LICENSE for licensing information */
- /* $Id$ */
- #include "or.h"
- extern or_options_t options; /* command-line and config-file options */
- static void circuit_free_cpath(crypt_path_t *cpath);
- static void circuit_free_cpath_node(crypt_path_t *victim);
- static aci_t get_unique_aci_by_addr_port(uint32_t addr, uint16_t port, int aci_type);
- unsigned long stats_n_relay_cells_relayed = 0;
- unsigned long stats_n_relay_cells_delivered = 0;
- /********* START VARIABLES **********/
- static circuit_t *global_circuitlist=NULL;
- char *circuit_state_to_string[] = {
- "receiving the onion", /* 0 */
- "waiting to process create", /* 1 */
- "connecting to firsthop", /* 2 */
- "open" /* 3 */
- };
- /********* END VARIABLES ************/
- void circuit_add(circuit_t *circ) {
- if(!global_circuitlist) { /* first one */
- global_circuitlist = circ;
- circ->next = NULL;
- } else {
- circ->next = global_circuitlist;
- global_circuitlist = circ;
- }
- }
- void circuit_remove(circuit_t *circ) {
- circuit_t *tmpcirc;
- assert(circ && global_circuitlist);
- if(global_circuitlist == circ) {
- global_circuitlist = global_circuitlist->next;
- return;
- }
- for(tmpcirc = global_circuitlist;tmpcirc->next;tmpcirc = tmpcirc->next) {
- if(tmpcirc->next == circ) {
- tmpcirc->next = circ->next;
- return;
- }
- }
- }
- circuit_t *circuit_new(aci_t p_aci, connection_t *p_conn) {
- circuit_t *circ;
- circ = (circuit_t *)tor_malloc(sizeof(circuit_t));
- memset(circ,0,sizeof(circuit_t)); /* zero it out */
- circ->timestamp_created = time(NULL);
- circ->p_aci = p_aci;
- circ->p_conn = p_conn;
- circ->state = CIRCUIT_STATE_ONIONSKIN_PENDING;
- /* ACIs */
- circ->p_aci = p_aci;
- /* circ->n_aci remains 0 because we haven't identified the next hop yet */
- circ->package_window = CIRCWINDOW_START;
- circ->deliver_window = CIRCWINDOW_START;
- circuit_add(circ);
- return circ;
- }
- void circuit_free(circuit_t *circ) {
- if (circ->n_crypto)
- crypto_free_cipher_env(circ->n_crypto);
- if (circ->p_crypto)
- crypto_free_cipher_env(circ->p_crypto);
- circuit_free_cpath(circ->cpath);
- free(circ);
- }
- static void circuit_free_cpath(crypt_path_t *cpath) {
- crypt_path_t *victim, *head=cpath;
- if(!cpath)
- return;
- /* it's a doubly linked list, so we have to notice when we've
- * gone through it once. */
- while(cpath->next && cpath->next != head) {
- victim = cpath;
- cpath = victim->next;
- circuit_free_cpath_node(victim);
- }
- circuit_free_cpath_node(cpath);
- }
- static void circuit_free_cpath_node(crypt_path_t *victim) {
- if(victim->f_crypto)
- crypto_free_cipher_env(victim->f_crypto);
- if(victim->b_crypto)
- crypto_free_cipher_env(victim->b_crypto);
- if(victim->handshake_state)
- crypto_dh_free(victim->handshake_state);
- free(victim);
- }
- /* return 0 if can't get a unique aci. */
- static aci_t get_unique_aci_by_addr_port(uint32_t addr, uint16_t port, int aci_type) {
- aci_t test_aci;
- connection_t *conn;
- uint16_t high_bit;
- high_bit = (aci_type == ACI_TYPE_HIGHER) ? 1<<15 : 0;
- conn = connection_exact_get_by_addr_port(addr,port);
- /* XXX race condition: if conn is marked_for_close it won't be noticed */
- if (!conn)
- return (1|high_bit); /* No connection exists; conflict is impossible. */
- do {
- /* Sequentially iterate over test_aci=1...1<<15-1 until we find an
- * aci such that (high_bit|test_aci) is not already used. */
- /* XXX Will loop forever if all aci's in our range are used.
- * This matters because it's an external DoS vulnerability. */
- test_aci = conn->next_aci++;
- if (test_aci == 0 || test_aci >= 1<<15) {
- test_aci = 1;
- conn->next_aci = 2;
- }
- test_aci |= high_bit;
- } while(circuit_get_by_aci_conn(test_aci, conn));
- return test_aci;
- }
- circuit_t *circuit_enumerate_by_naddr_nport(circuit_t *circ, uint32_t naddr, uint16_t nport) {
- if(!circ) /* use circ if it's defined, else start from the beginning */
- circ = global_circuitlist;
- else
- circ = circ->next;
- for( ; circ; circ = circ->next) {
- if(circ->n_addr == naddr && circ->n_port == nport)
- return circ;
- }
- return NULL;
- }
- circuit_t *circuit_get_by_aci_conn(aci_t aci, connection_t *conn) {
- circuit_t *circ;
- connection_t *tmpconn;
- for(circ=global_circuitlist;circ;circ = circ->next) {
- if(circ->p_aci == aci) {
- if(circ->p_conn == conn)
- return circ;
- for(tmpconn = circ->p_streams; tmpconn; tmpconn = tmpconn->next_stream) {
- if(tmpconn == conn)
- return circ;
- }
- }
- if(circ->n_aci == aci) {
- if(circ->n_conn == conn)
- return circ;
- for(tmpconn = circ->n_streams; tmpconn; tmpconn = tmpconn->next_stream) {
- if(tmpconn == conn)
- return circ;
- }
- }
- }
- return NULL;
- }
- circuit_t *circuit_get_by_conn(connection_t *conn) {
- circuit_t *circ;
- connection_t *tmpconn;
- for(circ=global_circuitlist;circ;circ = circ->next) {
- if(circ->p_conn == conn)
- return circ;
- if(circ->n_conn == conn)
- return circ;
- for(tmpconn = circ->p_streams; tmpconn; tmpconn=tmpconn->next_stream)
- if(tmpconn == conn)
- return circ;
- for(tmpconn = circ->n_streams; tmpconn; tmpconn=tmpconn->next_stream)
- if(tmpconn == conn)
- return circ;
- }
- return NULL;
- }
- circuit_t *circuit_get_newest_open(void) {
- circuit_t *circ, *bestcirc=NULL;
- for(circ=global_circuitlist;circ;circ = circ->next) {
- if(circ->cpath && circ->state == CIRCUIT_STATE_OPEN && circ->n_conn && (!bestcirc ||
- bestcirc->timestamp_created < circ->timestamp_created)) {
- log_fn(LOG_DEBUG,"Choosing circuit %s:%d:%d.", circ->n_conn->address, circ->n_port, circ->n_aci);
- assert(circ->n_aci);
- bestcirc = circ;
- }
- }
- return bestcirc;
- }
- int circuit_deliver_relay_cell(cell_t *cell, circuit_t *circ,
- int cell_direction, crypt_path_t *layer_hint) {
- connection_t *conn=NULL;
- char recognized=0;
- char buf[256];
- assert(cell && circ);
- assert(cell_direction == CELL_DIRECTION_OUT || cell_direction == CELL_DIRECTION_IN);
- buf[0] = cell->length;
- memcpy(buf+1, cell->payload, CELL_PAYLOAD_SIZE);
- log_fn(LOG_DEBUG,"direction %d, streamid %d before crypt.", cell_direction, *(int*)(cell->payload+1));
- if(relay_crypt(circ, buf, 1+CELL_PAYLOAD_SIZE, cell_direction, &layer_hint, &recognized, &conn) < 0) {
- log_fn(LOG_WARN,"relay crypt failed. Dropping connection.");
- return -1;
- }
- cell->length = buf[0];
- memcpy(cell->payload, buf+1, CELL_PAYLOAD_SIZE);
- if(recognized) {
- if(cell_direction == CELL_DIRECTION_OUT) {
- ++stats_n_relay_cells_delivered;
- log_fn(LOG_DEBUG,"Sending to exit.");
- return connection_edge_process_relay_cell(cell, circ, conn, EDGE_EXIT, NULL);
- }
- if(cell_direction == CELL_DIRECTION_IN) {
- ++stats_n_relay_cells_delivered;
- log_fn(LOG_DEBUG,"Sending to AP.");
- return connection_edge_process_relay_cell(cell, circ, conn, EDGE_AP, layer_hint);
- }
- }
- ++stats_n_relay_cells_relayed;
- /* not recognized. pass it on. */
- if(cell_direction == CELL_DIRECTION_OUT)
- conn = circ->n_conn;
- else
- conn = circ->p_conn;
- if(!conn) { //|| !connection_speaks_cells(conn)) {
- log_fn(LOG_INFO,"Didn't recognize cell (%d), but circ stops here! Dropping.", *(int *)(cell->payload+1));
- return 0;
- }
- log_fn(LOG_DEBUG,"Passing on unrecognized cell.");
- connection_or_write_cell_to_buf(cell, conn);
- return 0;
- }
- int relay_crypt(circuit_t *circ, char *in, int inlen, char cell_direction,
- crypt_path_t **layer_hint, char *recognized, connection_t **conn) {
- crypt_path_t *thishop;
- char out[256];
- assert(circ && in && recognized && conn);
- assert(inlen < 256);
- if(cell_direction == CELL_DIRECTION_IN) {
- if(circ->cpath) { /* we're at the beginning of the circuit. We'll want to do layered crypts. */
- thishop = circ->cpath;
- if(thishop->state != CPATH_STATE_OPEN) {
- log_fn(LOG_WARN,"Relay cell before first created cell?");
- return -1;
- }
- do { /* Remember: cpath is in forward order, that is, first hop first. */
- assert(thishop);
- log_fn(LOG_DEBUG,"before decrypt: %d",*(int*)(in+2));
- /* decrypt */
- if(crypto_cipher_decrypt(thishop->b_crypto, in, inlen, out)) {
- log_fn(LOG_WARN,"Error performing onion decryption: %s", crypto_perror());
- return -1;
- }
- memcpy(in,out,inlen);
- log_fn(LOG_DEBUG,"after decrypt: %d",*(int*)(in+2));
- if( (*recognized = relay_check_recognized(circ, cell_direction, in+2, conn))) {
- *layer_hint = thishop;
- return 0;
- }
- thishop = thishop->next;
- } while(thishop != circ->cpath && thishop->state == CPATH_STATE_OPEN);
- log_fn(LOG_INFO,"in-cell at OP not recognized. Dropping.");
- return 0;
- } else { /* we're in the middle. Just one crypt. */
- log_fn(LOG_DEBUG,"before encrypt: %d",*(int*)(in+2));
- if(crypto_cipher_encrypt(circ->p_crypto, in, inlen, out)) {
- log_fn(LOG_WARN,"Onion encryption failed for ACI %u: %s",
- circ->p_aci, crypto_perror());
- return -1;
- }
- memcpy(in,out,inlen);
- log_fn(LOG_DEBUG,"after encrypt: %d",*(int*)(in+2));
- log_fn(LOG_DEBUG,"Skipping recognized check, because we're not the OP.");
- /* don't check for recognized. only the OP can recognize a stream on the way back. */
- }
- } else if(cell_direction == CELL_DIRECTION_OUT) {
- if(circ->cpath) { /* we're at the beginning of the circuit. We'll want to do layered crypts. */
- thishop = *layer_hint; /* we already know which layer, from when we package_raw_inbuf'ed */
- /* moving from last to first hop */
- do {
- assert(thishop);
- log_fn(LOG_DEBUG,"before encrypt: %d",*(int*)(in+2));
- if(crypto_cipher_encrypt(thishop->f_crypto, in, inlen, out)) {
- log_fn(LOG_WARN,"Error performing encryption: %s", crypto_perror());
- return -1;
- }
- memcpy(in,out,inlen);
- log_fn(LOG_DEBUG,"after encrypt: %d",*(int*)(in+2));
- thishop = thishop->prev;
- } while(thishop != circ->cpath->prev);
- } else { /* we're in the middle. Just one crypt. */
- if(crypto_cipher_decrypt(circ->n_crypto,in, inlen, out)) {
- log_fn(LOG_WARN,"Decryption failed for ACI %u: %s",
- circ->n_aci, crypto_perror());
- return -1;
- }
- memcpy(in,out,inlen);
- if( (*recognized = relay_check_recognized(circ, cell_direction, in+2, conn)))
- return 0;
- }
- } else {
- log_fn(LOG_ERR,"unknown cell direction %d.", cell_direction);
- assert(0);
- }
- return 0;
- }
- int relay_check_recognized(circuit_t *circ, int cell_direction, char *stream, connection_t **conn) {
- /* FIXME can optimize by passing thishop in */
- connection_t *tmpconn;
- if(!memcmp(stream,ZERO_STREAM,STREAM_ID_SIZE)) {
- log_fn(LOG_DEBUG,"It's the zero stream. Recognized.");
- return 1; /* the zero stream is always recognized */
- }
- log_fn(LOG_DEBUG,"not the zero stream.");
- if(cell_direction == CELL_DIRECTION_OUT)
- tmpconn = circ->n_streams;
- else
- tmpconn = circ->p_streams;
- if(!tmpconn) {
- log_fn(LOG_DEBUG,"No conns. Not recognized.");
- return 0;
- }
- for( ; tmpconn; tmpconn=tmpconn->next_stream) {
- if(!memcmp(stream,tmpconn->stream_id, STREAM_ID_SIZE)) {
- log_fn(LOG_DEBUG,"recognized stream %d.", *(int*)stream);
- *conn = tmpconn;
- return 1;
- }
- log_fn(LOG_DEBUG,"considered stream %d, not it.",*(int*)tmpconn->stream_id);
- }
- log_fn(LOG_DEBUG,"Didn't recognize on this iteration of decryption.");
- return 0;
- }
- void circuit_resume_edge_reading(circuit_t *circ, int edge_type, crypt_path_t *layer_hint) {
- connection_t *conn;
- assert(edge_type == EDGE_EXIT || edge_type == EDGE_AP);
- log_fn(LOG_DEBUG,"resuming");
- if(edge_type == EDGE_EXIT)
- conn = circ->n_streams;
- else
- conn = circ->p_streams;
- for( ; conn; conn=conn->next_stream) {
- if((edge_type == EDGE_EXIT && conn->package_window > 0) ||
- (edge_type == EDGE_AP && conn->package_window > 0 && conn->cpath_layer == layer_hint)) {
- connection_start_reading(conn);
- connection_edge_package_raw_inbuf(conn); /* handle whatever might still be on the inbuf */
- /* If the circuit won't accept any more data, return without looking
- * at any more of the streams. Any connections that should be stopped
- * have already been stopped by connection_edge_package_raw_inbuf. */
- if(circuit_consider_stop_edge_reading(circ, edge_type, layer_hint))
- return;
- }
- }
- }
- /* returns 1 if the window is empty, else 0. If it's empty, tell edge conns to stop reading. */
- int circuit_consider_stop_edge_reading(circuit_t *circ, int edge_type, crypt_path_t *layer_hint) {
- connection_t *conn = NULL;
- assert(edge_type == EDGE_EXIT || edge_type == EDGE_AP);
- assert(edge_type == EDGE_EXIT || layer_hint);
- log_fn(LOG_DEBUG,"considering");
- if(edge_type == EDGE_EXIT && circ->package_window <= 0)
- conn = circ->n_streams;
- else if(edge_type == EDGE_AP && layer_hint->package_window <= 0)
- conn = circ->p_streams;
- else
- return 0;
- for( ; conn; conn=conn->next_stream)
- if(!layer_hint || conn->cpath_layer == layer_hint)
- connection_stop_reading(conn);
- log_fn(LOG_DEBUG,"yes. stopped.");
- return 1;
- }
- int circuit_consider_sending_sendme(circuit_t *circ, int edge_type, crypt_path_t *layer_hint) {
- cell_t cell;
- assert(circ);
- memset(&cell, 0, sizeof(cell_t));
- cell.command = CELL_RELAY;
- SET_CELL_RELAY_COMMAND(cell, RELAY_COMMAND_SENDME);
- SET_CELL_STREAM_ID(cell, ZERO_STREAM);
- cell.length = RELAY_HEADER_SIZE;
- if(edge_type == EDGE_AP) { /* i'm the AP */
- cell.aci = circ->n_aci;
- while(layer_hint->deliver_window < CIRCWINDOW_START-CIRCWINDOW_INCREMENT) {
- log_fn(LOG_DEBUG,"deliver_window %d, Queueing sendme forward.", layer_hint->deliver_window);
- layer_hint->deliver_window += CIRCWINDOW_INCREMENT;
- if(circuit_deliver_relay_cell(&cell, circ, CELL_DIRECTION_OUT, layer_hint) < 0) {
- return -1;
- }
- }
- } else if(edge_type == EDGE_EXIT) { /* i'm the exit */
- cell.aci = circ->p_aci;
- while(circ->deliver_window < CIRCWINDOW_START-CIRCWINDOW_INCREMENT) {
- log_fn(LOG_DEBUG,"deliver_window %d, Queueing sendme back.", circ->deliver_window);
- circ->deliver_window += CIRCWINDOW_INCREMENT;
- if(circuit_deliver_relay_cell(&cell, circ, CELL_DIRECTION_IN, layer_hint) < 0) {
- return -1;
- }
- }
- }
- return 0;
- }
- void circuit_close(circuit_t *circ) {
- connection_t *conn;
- circuit_t *youngest=NULL;
- assert(circ);
- if(options.APPort) {
- youngest = circuit_get_newest_open();
- log_fn(LOG_DEBUG,"youngest %d, circ %d.",(int)youngest, (int)circ);
- }
- circuit_remove(circ);
- if(circ->n_conn)
- connection_send_destroy(circ->n_aci, circ->n_conn);
- for(conn=circ->n_streams; conn; conn=conn->next_stream) {
- connection_send_destroy(circ->n_aci, conn);
- }
- if(circ->p_conn)
- connection_send_destroy(circ->n_aci, circ->p_conn);
- for(conn=circ->p_streams; conn; conn=conn->next_stream) {
- connection_send_destroy(circ->p_aci, conn);
- }
- if(options.APPort && youngest == circ) { /* check this after we've sent the destroys, to reduce races */
- /* our current circuit just died. Launch another one pronto. */
- log_fn(LOG_INFO,"Youngest circuit dying. Launching a replacement.");
- circuit_launch_new(1);
- }
- circuit_free(circ);
- }
- void circuit_about_to_close_connection(connection_t *conn) {
- /* send destroys for all circuits using conn */
- /* currently, we assume it's too late to flush conn's buf here.
- * down the road, maybe we'll consider that eof doesn't mean can't-write
- */
- circuit_t *circ;
- connection_t *prevconn;
- if(!connection_speaks_cells(conn)) {
- /* it's an edge conn. need to remove it from the linked list of
- * conn's for this circuit. Send an 'end' relay command.
- * But don't kill the circuit.
- */
- circ = circuit_get_by_conn(conn);
- if(!circ)
- return;
- if(conn == circ->p_streams) {
- circ->p_streams = conn->next_stream;
- goto send_end;
- }
- if(conn == circ->n_streams) {
- circ->n_streams = conn->next_stream;
- goto send_end;
- }
- for(prevconn = circ->p_streams; prevconn && prevconn->next_stream && prevconn->next_stream != conn; prevconn = prevconn->next_stream) ;
- if(prevconn && prevconn->next_stream) {
- prevconn->next_stream = conn->next_stream;
- goto send_end;
- }
- for(prevconn = circ->n_streams; prevconn && prevconn->next_stream && prevconn->next_stream != conn; prevconn = prevconn->next_stream) ;
- if(prevconn && prevconn->next_stream) {
- prevconn->next_stream = conn->next_stream;
- goto send_end;
- }
- log_fn(LOG_ERR,"edge conn not in circuit's list?");
- assert(0); /* should never get here */
- send_end:
- connection_edge_send_command(conn, circ, RELAY_COMMAND_END,
- NULL, 0, conn->cpath_layer);
- return;
- }
- /* this connection speaks cells. We must close all the circuits on it. */
- while((circ = circuit_get_by_conn(conn))) {
- if(circ->n_conn == conn) /* it's closing in front of us */
- circ->n_conn = NULL;
- if(circ->p_conn == conn) /* it's closing behind us */
- circ->p_conn = NULL;
- circuit_close(circ);
- }
- }
- /* FIXME this now leaves some out */
- void circuit_dump_by_conn(connection_t *conn, int severity) {
- circuit_t *circ;
- connection_t *tmpconn;
- for(circ=global_circuitlist;circ;circ = circ->next) {
- if(circ->p_conn == conn)
- log(severity, "Conn %d has App-ward circuit: aci %d (other side %d), state %d (%s)",
- conn->poll_index, circ->p_aci, circ->n_aci, circ->state, circuit_state_to_string[circ->state]);
- for(tmpconn=circ->p_streams; tmpconn; tmpconn=tmpconn->next_stream) {
- if(tmpconn == conn) {
- log(severity,"Conn %d has App-ward circuit: aci %d (other side %d), state %d (%s)",
- conn->poll_index, circ->p_aci, circ->n_aci, circ->state, circuit_state_to_string[circ->state]);
- }
- }
- if(circ->n_conn == conn)
- log(severity,"Conn %d has Exit-ward circuit: aci %d (other side %d), state %d (%s)",
- conn->poll_index, circ->n_aci, circ->p_aci, circ->state, circuit_state_to_string[circ->state]);
- for(tmpconn=circ->n_streams; tmpconn; tmpconn=tmpconn->next_stream) {
- if(tmpconn == conn) {
- log(severity,"Conn %d has Exit-ward circuit: aci %d (other side %d), state %d (%s)",
- conn->poll_index, circ->n_aci, circ->p_aci, circ->state, circuit_state_to_string[circ->state]);
- }
- }
- }
- }
- void circuit_expire_unused_circuits(void) {
- circuit_t *circ, *tmpcirc;
- circuit_t *youngest;
- youngest = circuit_get_newest_open();
- circ = global_circuitlist;
- while(circ) {
- tmpcirc = circ;
- circ = circ->next;
- if(tmpcirc != youngest && !tmpcirc->p_conn && !tmpcirc->p_streams) {
- log_fn(LOG_DEBUG,"Closing n_aci %d",tmpcirc->n_aci);
- circuit_close(tmpcirc);
- }
- }
- }
- /* failure_status code: negative means reset failures to 0. Other values mean
- * add that value to the current number of failures, then if we don't have too
- * many failures on record, try to make a new circuit.
- */
- void circuit_launch_new(int failure_status) {
- static int failures=0;
- if(!options.APPort) /* we're not an application proxy. no need for circuits. */
- return;
- if(failure_status == -1) { /* I was called because a circuit succeeded */
- failures = 0;
- return;
- }
- failures += failure_status;
- retry_circuit:
- if(failures > 5) {
- log_fn(LOG_INFO,"Giving up for now, %d failures.", failures);
- return;
- }
- if(circuit_establish_circuit() < 0) {
- failures++;
- goto retry_circuit;
- }
- failures = 0;
- return;
- }
- int circuit_establish_circuit(void) {
- routerinfo_t *firsthop;
- connection_t *n_conn;
- circuit_t *circ;
- circ = circuit_new(0, NULL); /* sets circ->p_aci and circ->p_conn */
- circ->state = CIRCUIT_STATE_OR_WAIT;
- circ->cpath = onion_generate_cpath(&firsthop);
- if(!circ->cpath) {
- log_fn(LOG_INFO,"Generating cpath failed.");
- circuit_close(circ);
- return -1;
- }
- /* now see if we're already connected to the first OR in 'route' */
- log_fn(LOG_DEBUG,"Looking for firsthop '%s:%u'",
- firsthop->address,firsthop->or_port);
- n_conn = connection_twin_get_by_addr_port(firsthop->addr,firsthop->or_port);
- if(!n_conn || n_conn->state != OR_CONN_STATE_OPEN) { /* not currently connected */
- circ->n_addr = firsthop->addr;
- circ->n_port = firsthop->or_port;
- if(options.OnionRouter) { /* we would be connected if he were up. but he's not. */
- log_fn(LOG_INFO,"Route's firsthop isn't connected.");
- circuit_close(circ);
- return -1;
- }
- if(!n_conn) { /* launch the connection */
- n_conn = connection_or_connect(firsthop);
- if(!n_conn) { /* connect failed, forget the whole thing */
- log_fn(LOG_INFO,"connect to firsthop failed. Closing.");
- circuit_close(circ);
- return -1;
- }
- }
- log_fn(LOG_DEBUG,"connecting in progress (or finished). Good.");
- return 0; /* return success. The onion/circuit/etc will be taken care of automatically
- * (may already have been) whenever n_conn reaches OR_CONN_STATE_OPEN.
- */
- } else { /* it (or a twin) is already open. use it. */
- circ->n_addr = n_conn->addr;
- circ->n_port = n_conn->port;
- circ->n_conn = n_conn;
- log_fn(LOG_DEBUG,"Conn open. Delivering first onion skin.");
- if(circuit_send_next_onion_skin(circ) < 0) {
- log_fn(LOG_INFO,"circuit_send_next_onion_skin failed.");
- circuit_close(circ);
- return -1;
- }
- }
- return 0;
- }
- /* find circuits that are waiting on me, if any, and get them to send the onion */
- void circuit_n_conn_open(connection_t *or_conn) {
- circuit_t *circ;
- log_fn(LOG_DEBUG,"Starting.");
- circ = circuit_enumerate_by_naddr_nport(NULL, or_conn->addr, or_conn->port);
- for(;;) {
- if(!circ)
- return;
- log_fn(LOG_DEBUG,"Found circ, sending onion skin.");
- circ->n_conn = or_conn;
- if(circuit_send_next_onion_skin(circ) < 0) {
- log_fn(LOG_INFO,"send_next_onion_skin failed; circuit marked for closing.");
- circuit_close(circ);
- return; /* FIXME will want to try the other circuits too? */
- }
- circ = circuit_enumerate_by_naddr_nport(circ, or_conn->addr, or_conn->port);
- }
- }
- int circuit_send_next_onion_skin(circuit_t *circ) {
- cell_t cell;
- crypt_path_t *hop;
- routerinfo_t *router;
- assert(circ && circ->cpath);
- if(circ->cpath->state == CPATH_STATE_CLOSED) {
- log_fn(LOG_DEBUG,"First skin; sending create cell.");
- circ->n_aci = get_unique_aci_by_addr_port(circ->n_addr, circ->n_port, ACI_TYPE_BOTH);
- memset(&cell, 0, sizeof(cell_t));
- cell.command = CELL_CREATE;
- cell.aci = circ->n_aci;
- cell.length = DH_ONIONSKIN_LEN;
- if(onion_skin_create(circ->n_conn->onion_pkey, &(circ->cpath->handshake_state), cell.payload) < 0) {
- log_fn(LOG_WARN,"onion_skin_create (first hop) failed.");
- return -1;
- }
- connection_or_write_cell_to_buf(&cell, circ->n_conn);
- circ->cpath->state = CPATH_STATE_AWAITING_KEYS;
- circ->state = CIRCUIT_STATE_BUILDING;
- log_fn(LOG_DEBUG,"first skin; finished sending create cell.");
- } else {
- assert(circ->cpath->state == CPATH_STATE_OPEN);
- assert(circ->state == CIRCUIT_STATE_BUILDING);
- log_fn(LOG_DEBUG,"starting to send subsequent skin.");
- for(hop=circ->cpath->next;
- hop != circ->cpath && hop->state == CPATH_STATE_OPEN;
- hop=hop->next) ;
- if(hop == circ->cpath) { /* done building the circuit. whew. */
- circ->state = CIRCUIT_STATE_OPEN;
- log_fn(LOG_INFO,"circuit built!");
- return 0;
- }
- router = router_get_by_addr_port(hop->addr,hop->port);
- if(!router) {
- log_fn(LOG_WARN,"couldn't lookup router %d:%d",hop->addr,hop->port);
- return -1;
- }
- memset(&cell, 0, sizeof(cell_t));
- cell.command = CELL_RELAY;
- cell.aci = circ->n_aci;
- SET_CELL_RELAY_COMMAND(cell, RELAY_COMMAND_EXTEND);
- SET_CELL_STREAM_ID(cell, ZERO_STREAM);
- cell.length = RELAY_HEADER_SIZE + 6 + DH_ONIONSKIN_LEN;
- *(uint32_t*)(cell.payload+RELAY_HEADER_SIZE) = htonl(hop->addr);
- *(uint16_t*)(cell.payload+RELAY_HEADER_SIZE+4) = htons(hop->port);
- if(onion_skin_create(router->onion_pkey, &(hop->handshake_state), cell.payload+RELAY_HEADER_SIZE+6) < 0) {
- log_fn(LOG_WARN,"onion_skin_create failed.");
- return -1;
- }
- log_fn(LOG_DEBUG,"Sending extend relay cell.");
- /* send it to hop->prev, because it will transfer it to a create cell and then send to hop */
- if(circuit_deliver_relay_cell(&cell, circ, CELL_DIRECTION_OUT, hop->prev) < 0) {
- log_fn(LOG_WARN,"failed to deliver extend cell. Closing.");
- return -1;
- }
- hop->state = CPATH_STATE_AWAITING_KEYS;
- }
- return 0;
- }
- /* take the 'extend' cell, pull out addr/port plus the onion skin. Make
- * sure we're connected to the next hop, and pass it the onion skin in
- * a create cell.
- */
- int circuit_extend(cell_t *cell, circuit_t *circ) {
- connection_t *n_conn;
- aci_t aci_type;
- cell_t newcell;
- if(circ->n_conn) {
- log_fn(LOG_WARN,"n_conn already set. Bug/attack. Closing.");
- return -1;
- }
- circ->n_addr = ntohl(*(uint32_t*)(cell->payload+RELAY_HEADER_SIZE));
- circ->n_port = ntohs(*(uint16_t*)(cell->payload+RELAY_HEADER_SIZE+4));
- n_conn = connection_twin_get_by_addr_port(circ->n_addr,circ->n_port);
- if(!n_conn || n_conn->type != CONN_TYPE_OR) {
- /* i've disabled making connections through OPs, but it's definitely
- * possible here. I'm not sure if it would be a bug or a feature. -RD
- */
- /* note also that this will close circuits where the onion has the same
- * router twice in a row in the path. i think that's ok. -RD
- */
- struct in_addr in;
- in.s_addr = htonl(circ->n_addr);
- log_fn(LOG_DEBUG,"Next router (%s:%d) not connected. Closing.", inet_ntoa(in), circ->n_port);
- /* XXX later we should fail more gracefully here, like with a 'truncated' */
- return -1;
- }
- circ->n_addr = n_conn->addr; /* these are different if we found a twin instead */
- circ->n_port = n_conn->port;
- circ->n_conn = n_conn;
- log_fn(LOG_DEBUG,"n_conn is %s:%u",n_conn->address,n_conn->port);
- aci_type = decide_aci_type(options.Nickname, n_conn->nickname);
- log_fn(LOG_DEBUG,"aci_type = %u.",aci_type);
- circ->n_aci = get_unique_aci_by_addr_port(circ->n_addr, circ->n_port, aci_type);
- if(!circ->n_aci) {
- log_fn(LOG_WARN,"failed to get unique aci.");
- return -1;
- }
- log_fn(LOG_DEBUG,"Chosen ACI %u.",circ->n_aci);
- memset(&newcell, 0, sizeof(cell_t));
- newcell.command = CELL_CREATE;
- newcell.aci = circ->n_aci;
- newcell.length = DH_ONIONSKIN_LEN;
- memcpy(newcell.payload, cell->payload+RELAY_HEADER_SIZE+6, DH_ONIONSKIN_LEN);
- connection_or_write_cell_to_buf(&newcell, circ->n_conn);
- return 0;
- }
- int circuit_finish_handshake(circuit_t *circ, char *reply) {
- unsigned char iv[16];
- unsigned char keys[32];
- crypt_path_t *hop;
- memset(iv, 0, 16);
- assert(circ->cpath);
- if(circ->cpath->state == CPATH_STATE_AWAITING_KEYS)
- hop = circ->cpath;
- else {
- for(hop=circ->cpath->next;
- hop != circ->cpath && hop->state == CPATH_STATE_OPEN;
- hop=hop->next) ;
- if(hop == circ->cpath) { /* got an extended when we're all done? */
- log_fn(LOG_WARN,"got extended when circ already built? Closing.");
- return -1;
- }
- }
- assert(hop->state == CPATH_STATE_AWAITING_KEYS);
- if(onion_skin_client_handshake(hop->handshake_state, reply, keys, 32) < 0) {
- log_fn(LOG_WARN,"onion_skin_client_handshake failed.");
- return -1;
- }
- crypto_dh_free(hop->handshake_state); /* don't need it anymore */
- hop->handshake_state = NULL;
- log_fn(LOG_DEBUG,"hop %d init cipher forward %d, backward %d.", (uint32_t)hop, *(uint32_t*)keys, *(uint32_t*)(keys+16));
- if (!(hop->f_crypto =
- crypto_create_init_cipher(CIRCUIT_CIPHER,keys,iv,1))) {
- log(LOG_WARN,"forward cipher initialization failed.");
- return -1;
- }
- if (!(hop->b_crypto =
- crypto_create_init_cipher(CIRCUIT_CIPHER,keys+16,iv,0))) {
- log(LOG_WARN,"backward cipher initialization failed.");
- return -1;
- }
- hop->state = CPATH_STATE_OPEN;
- log_fn(LOG_INFO,"finished");
- return 0;
- }
- int circuit_truncated(circuit_t *circ, crypt_path_t *layer) {
- crypt_path_t *victim;
- connection_t *stream;
- assert(circ);
- assert(layer);
- while(layer->next != circ->cpath) {
- /* we need to clear out layer->next */
- victim = layer->next;
- log_fn(LOG_DEBUG, "Killing a layer of the cpath.");
- for(stream = circ->p_streams; stream; stream=stream->next_stream) {
- if(stream->cpath_layer == victim) {
- log_fn(LOG_INFO, "Marking stream %d for close.", *(int*)stream->stream_id);
- /*ENDCLOSE*/ stream->marked_for_close = 1;
- }
- }
- layer->next = victim->next;
- circuit_free_cpath_node(victim);
- }
- log_fn(LOG_INFO, "finished");
- return 0;
- }
- void assert_cpath_layer_ok(const crypt_path_t *cp)
- {
- assert(cp->f_crypto);
- assert(cp->b_crypto);
- assert(cp->addr);
- assert(cp->port);
- switch(cp->state)
- {
- case CPATH_STATE_CLOSED:
- case CPATH_STATE_OPEN:
- assert(!cp->handshake_state);
- break;
- case CPATH_STATE_AWAITING_KEYS:
- assert(cp->handshake_state);
- break;
- default:
- assert(0);
- }
- assert(cp->package_window >= 0);
- assert(cp->deliver_window >= 0);
- }
- void assert_cpath_ok(const crypt_path_t *cp)
- {
- while(cp->prev)
- cp = cp->prev;
- while(cp->next) {
- assert_cpath_layer_ok(cp);
- /* layers must be in sequence of: "open* awaiting? closed*" */
- if (cp->prev) {
- if (cp->prev->state == CPATH_STATE_OPEN) {
- assert(cp->state == CPATH_STATE_CLOSED ||
- cp->state == CPATH_STATE_AWAITING_KEYS);
- } else {
- assert(cp->state == CPATH_STATE_CLOSED);
- }
- }
- cp = cp->next;
- }
- }
- void assert_circuit_ok(const circuit_t *c)
- {
- connection_t *conn;
- assert(c->n_addr);
- assert(c->n_port);
- assert(c->n_conn);
- assert(c->n_conn->type == CONN_TYPE_OR);
- if (c->p_conn)
- assert(c->p_conn->type == CONN_TYPE_OR);
- for (conn = c->p_streams; conn; conn = conn->next_stream)
- assert(c->p_conn->type == CONN_TYPE_EXIT);
- for (conn = c->n_streams; conn; conn = conn->next_stream)
- assert(conn->type == CONN_TYPE_EXIT);
- assert(c->deliver_window >= 0);
- assert(c->package_window >= 0);
- if (c->state == CIRCUIT_STATE_OPEN) {
- if (c->cpath) {
- assert(!c->n_crypto);
- assert(!c->p_crypto);
- } else {
- assert(c->n_crypto);
- assert(c->p_crypto);
- }
- }
- if (c->cpath) {
- assert_cpath_ok(c->cpath);
- }
- }
- /*
- Local Variables:
- mode:c
- indent-tabs-mode:nil
- c-basic-offset:2
- End:
- */
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