diff options
Diffstat (limited to 'src/or/circuit.c')
| -rw-r--r-- | src/or/circuit.c | 1736 |
1 files changed, 0 insertions, 1736 deletions
diff --git a/src/or/circuit.c b/src/or/circuit.c deleted file mode 100644 index 26c0501c15..0000000000 --- a/src/or/circuit.c +++ /dev/null @@ -1,1736 +0,0 @@ -/* Copyright 2001 Matej Pfajfar, 2001-2004 Roger Dingledine. */ -/* See LICENSE for licensing information */ -/* $Id$ */ - -/** - * \file circuit.c - * \brief Manage circuits and the global circuit list. - **/ - -#include "or.h" - -extern or_options_t options; /* command-line and config-file options */ - -static int circuit_resume_edge_reading_helper(connection_t *conn, - circuit_t *circ, - crypt_path_t *layer_hint); -static void circuit_free_cpath_node(crypt_path_t *victim); -static uint16_t get_unique_circ_id_by_conn(connection_t *conn, int circ_id_type); -static void circuit_rep_hist_note_result(circuit_t *circ); - -void circuit_expire_old_circuits(void); -static void circuit_is_open(circuit_t *circ); -static void circuit_build_failed(circuit_t *circ); -static circuit_t *circuit_establish_circuit(uint8_t purpose, const char *exit_nickname); -static void circuit_free(circuit_t *circ); -static void circuit_free_cpath(crypt_path_t *cpath); - -/********* START VARIABLES **********/ - -/** A global (within this file) list of all circuits at this hop. */ -static circuit_t *global_circuitlist=NULL; -/** How many entries are in global_circuitlist? */ -static int circuitlist_len=0; -/** Array of strings to make circ-\>state human-readable */ -char *circuit_state_to_string[] = { - "doing handshakes", /* 0 */ - "processing the onion", /* 1 */ - "connecting to firsthop", /* 2 */ - "open" /* 3 */ -}; - -/********* END VARIABLES ************/ - -/** Add <b>circ</b> to the global list of circuits. This is called only from - * within circuit_new. - */ -static 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; - } - ++circuitlist_len; -} - -/** Detach from the global circuit list, and deallocate, all - * circuits that have been marked for close. - */ -void circuit_close_all_marked() -{ - circuit_t *tmp,*m; - - while (global_circuitlist && global_circuitlist->marked_for_close) { - tmp = global_circuitlist->next; - circuit_free(global_circuitlist); - global_circuitlist = tmp; - } - - tmp = global_circuitlist; - while (tmp && tmp->next) { - if (tmp->next->marked_for_close) { - m = tmp->next->next; - circuit_free(tmp->next); - tmp->next = m; - /* Need to check new tmp->next; don't advance tmp. */ - } else { - /* Advance tmp. */ - tmp = tmp->next; - } - } -} - -/** Allocate space for a new circuit, initializing with <b>p_circ_id</b> - * and <b>p_conn</b>. Add it to the global circuit list. - */ -circuit_t *circuit_new(uint16_t p_circ_id, connection_t *p_conn) { - circuit_t *circ; - - circ = tor_malloc_zero(sizeof(circuit_t)); - circ->magic = CIRCUIT_MAGIC; - - circ->timestamp_created = time(NULL); - - circ->p_circ_id = p_circ_id; - circ->p_conn = p_conn; - - circ->state = CIRCUIT_STATE_ONIONSKIN_PENDING; - - /* CircIDs */ - circ->p_circ_id = p_circ_id; - /* circ->n_circ_id remains 0 because we haven't identified the next hop yet */ - - circ->package_window = CIRCWINDOW_START; - circ->deliver_window = CIRCWINDOW_START; - - circ->next_stream_id = crypto_pseudo_rand_int(1<<16); - - circuit_add(circ); - - return circ; -} - -/** Deallocate space associated with circ. - */ -static void circuit_free(circuit_t *circ) { - tor_assert(circ); - tor_assert(circ->magic == CIRCUIT_MAGIC); - if (circ->n_crypto) - crypto_free_cipher_env(circ->n_crypto); - if (circ->p_crypto) - crypto_free_cipher_env(circ->p_crypto); - if (circ->n_digest) - crypto_free_digest_env(circ->n_digest); - if (circ->p_digest) - crypto_free_digest_env(circ->p_digest); - if(circ->build_state) { - tor_free(circ->build_state->chosen_exit); - if (circ->build_state->pending_final_cpath) - circuit_free_cpath_node(circ->build_state->pending_final_cpath); - } - tor_free(circ->build_state); - circuit_free_cpath(circ->cpath); - if (circ->rend_splice) { - circ->rend_splice->rend_splice = NULL; - } - - memset(circ, 0xAA, sizeof(circuit_t)); /* poison memory */ - free(circ); -} - -/** Deallocate space associated with the linked list <b>cpath</b>. */ -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); -} - -/** Deallocate space associated with the cpath node <b>victim</b>. */ -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->f_digest) - crypto_free_digest_env(victim->f_digest); - if(victim->b_digest) - crypto_free_digest_env(victim->b_digest); - if(victim->handshake_state) - crypto_dh_free(victim->handshake_state); - free(victim); -} - -/** Iterate over values of circ_id, starting from conn-\>next_circ_id, - * and with the high bit specified by circ_id_type (see - * decide_circ_id_type()), until we get a circ_id that is not in use - * by any other circuit on that conn. - * - * Return it, or 0 if can't get a unique circ_id. - */ -static uint16_t get_unique_circ_id_by_conn(connection_t *conn, int circ_id_type) { - uint16_t test_circ_id; - int attempts=0; - uint16_t high_bit; - - tor_assert(conn && conn->type == CONN_TYPE_OR); - high_bit = (circ_id_type == CIRC_ID_TYPE_HIGHER) ? 1<<15 : 0; - do { - /* Sequentially iterate over test_circ_id=1...1<<15-1 until we find a - * circID such that (high_bit|test_circ_id) is not already used. */ - test_circ_id = conn->next_circ_id++; - if (test_circ_id == 0 || test_circ_id >= 1<<15) { - test_circ_id = 1; - conn->next_circ_id = 2; - } - if(++attempts > 1<<15) { - /* Make sure we don't loop forever if all circ_id's are used. This - * matters because it's an external DoS vulnerability. - */ - log_fn(LOG_WARN,"No unused circ IDs. Failing."); - return 0; - } - test_circ_id |= high_bit; - } while(circuit_get_by_circ_id_conn(test_circ_id, conn)); - return test_circ_id; -} - -/** Return a circ such that: - * - circ-\>n_circ_id or circ-\>p_circ_id is equal to <b>circ_id</b>, and - * - circ is attached to <b>conn</b>, either as p_conn, n-conn, or - * in p_streams or n_streams. - * Return NULL if no such circuit exists. - */ -circuit_t *circuit_get_by_circ_id_conn(uint16_t circ_id, connection_t *conn) { - circuit_t *circ; - connection_t *tmpconn; - - for(circ=global_circuitlist;circ;circ = circ->next) { - if (circ->marked_for_close) - continue; - - if(circ->p_circ_id == circ_id) { - 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_circ_id == circ_id) { - if(circ->n_conn == conn) - return circ; - for(tmpconn = circ->n_streams; tmpconn; tmpconn = tmpconn->next_stream) { - if(tmpconn == conn) - return circ; - } - for(tmpconn = circ->resolving_streams; tmpconn; tmpconn = tmpconn->next_stream) { - if(tmpconn == conn) - return circ; - } - } - } - return NULL; -} - -/** Return a circ such that circ is attached to <b>conn</b>, either as - * p_conn, n-conn, or in p_streams or n_streams. - * - * Return NULL if no such circuit exists. - */ -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->marked_for_close) - continue; - - 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; - for(tmpconn = circ->resolving_streams; tmpconn; tmpconn=tmpconn->next_stream) - if(tmpconn == conn) - return circ; - } - return NULL; -} - -/* Return 1 if <b>circ</b> could be returned by circuit_get_best(). - * Else return 0. - */ -static int circuit_is_acceptable(circuit_t *circ, - connection_t *conn, - int must_be_open, - uint8_t purpose, - time_t now) -{ - routerinfo_t *exitrouter; - - if (!CIRCUIT_IS_ORIGIN(circ)) - return 0; /* this circ doesn't start at us */ - if (must_be_open && (circ->state != CIRCUIT_STATE_OPEN || !circ->n_conn)) - return 0; /* ignore non-open circs */ - if (circ->marked_for_close) - return 0; - - /* if this circ isn't our purpose, skip. */ - if(purpose == CIRCUIT_PURPOSE_C_REND_JOINED && !must_be_open) { - if(circ->purpose != CIRCUIT_PURPOSE_C_ESTABLISH_REND && - circ->purpose != CIRCUIT_PURPOSE_C_REND_READY && - circ->purpose != CIRCUIT_PURPOSE_C_REND_READY_INTRO_ACKED && - circ->purpose != CIRCUIT_PURPOSE_C_REND_JOINED) - return 0; - } else if (purpose == CIRCUIT_PURPOSE_C_INTRODUCE_ACK_WAIT && !must_be_open) { - if (circ->purpose != CIRCUIT_PURPOSE_C_INTRODUCING && - circ->purpose != CIRCUIT_PURPOSE_C_INTRODUCE_ACK_WAIT) - return 0; - } else { - if(purpose != circ->purpose) - return 0; - } - - if(purpose == CIRCUIT_PURPOSE_C_GENERAL) - if(circ->timestamp_dirty && - circ->timestamp_dirty+options.NewCircuitPeriod < now) - return 0; - - if(conn) { - /* decide if this circ is suitable for this conn */ - - /* for rend circs, circ->cpath->prev is not the last router in the - * circuit, it's the magical extra bob hop. so just check the nickname - * of the one we meant to finish at. - */ - exitrouter = router_get_by_nickname(circ->build_state->chosen_exit); - - if(!exitrouter) { - log_fn(LOG_INFO,"Skipping broken circ (exit router vanished)"); - return 0; /* this circuit is screwed and doesn't know it yet */ - } - - if(purpose == CIRCUIT_PURPOSE_C_GENERAL) { - if(connection_ap_can_use_exit(conn, exitrouter) == ADDR_POLICY_REJECTED) { - /* can't exit from this router */ - return 0; - } - } else { /* not general */ - if(rend_cmp_service_ids(conn->rend_query, circ->rend_query) && - (circ->rend_query[0] || purpose != CIRCUIT_PURPOSE_C_REND_JOINED)) { - /* this circ is not for this conn, and it's not suitable - * for cannibalizing either */ - return 0; - } - } - } - return 1; -} - -/* Return 1 if circuit <b>a</b> is better than circuit <b>b</b> for - * <b>purpose</b>, and return 0 otherwise. Used by circuit_get_best. - */ -static int circuit_is_better(circuit_t *a, circuit_t *b, uint8_t purpose) -{ - switch(purpose) { - case CIRCUIT_PURPOSE_C_GENERAL: - /* if it's used but less dirty it's best; - * else if it's more recently created it's best - */ - if(b->timestamp_dirty) { - if(a->timestamp_dirty && - a->timestamp_dirty > b->timestamp_dirty) - return 1; - } else { - if(a->timestamp_dirty || - a->timestamp_created > b->timestamp_created) - return 1; - } - break; - case CIRCUIT_PURPOSE_C_INTRODUCE_ACK_WAIT: - /* the closer it is to ack_wait the better it is */ - if(a->purpose > b->purpose) - return 1; - break; - case CIRCUIT_PURPOSE_C_REND_JOINED: - /* the closer it is to rend_joined the better it is */ - if(a->purpose > b->purpose) - return 1; - break; - } - return 0; -} - -/** Find the best circ that conn can use, preferably one which is - * dirty. Circ must not be too old. - * - * Conn must be defined. - * - * If must_be_open, ignore circs not in CIRCUIT_STATE_OPEN. - * - * circ_purpose specifies what sort of circuit we must have. - * It can be C_GENERAL, C_INTRODUCE_ACK_WAIT, or C_REND_JOINED. - * - * If it's REND_JOINED and must_be_open==0, then return the closest - * rendezvous-purposed circuit that you can find. - * - * If it's INTRODUCE_ACK_WAIT and must_be_open==0, then return the - * closest introduce-purposed circuit that you can find. - */ -circuit_t *circuit_get_best(connection_t *conn, - int must_be_open, uint8_t purpose) { - circuit_t *circ, *best=NULL; - time_t now = time(NULL); - - tor_assert(conn); - - tor_assert(purpose == CIRCUIT_PURPOSE_C_GENERAL || - purpose == CIRCUIT_PURPOSE_C_INTRODUCE_ACK_WAIT || - purpose == CIRCUIT_PURPOSE_C_REND_JOINED); - - for (circ=global_circuitlist;circ;circ = circ->next) { - if (!circuit_is_acceptable(circ,conn,must_be_open,purpose,now)) - continue; - - /* now this is an acceptable circ to hand back. but that doesn't - * mean it's the *best* circ to hand back. try to decide. - */ - if(!best || circuit_is_better(circ,best,purpose)) - best = circ; - } - - return best; -} - -/** Return a circ such that: - * - circ-\>rend_query is equal to <b>rend_query</b>, and - * - circ-\>purpose is equal to <b>purpose</b>. - * - * Return NULL if no such circuit exists. - */ -circuit_t *circuit_get_by_rend_query_and_purpose(const char *rend_query, uint8_t purpose) { - circuit_t *circ; - - for (circ = global_circuitlist; circ; circ = circ->next) { - if (!circ->marked_for_close && - circ->purpose == purpose && - !rend_cmp_service_ids(rend_query, circ->rend_query)) - return circ; - } - return NULL; -} - -/** Return the first circuit in global_circuitlist after <b>start</b> whose - * rend_pk_digest field is <b>digest</b> and whose purpose is <b>purpose</b>. Returns - * NULL if no circuit is found. If <b>start</b> is NULL, begin at the start of - * the list. - */ -circuit_t *circuit_get_next_by_pk_and_purpose(circuit_t *start, - const char *digest, uint8_t purpose) -{ - circuit_t *circ; - if (start == NULL) - circ = global_circuitlist; - else - circ = start->next; - - for( ; circ; circ = circ->next) { - if (circ->marked_for_close) - continue; - if (circ->purpose != purpose) - continue; - if (!memcmp(circ->rend_pk_digest, digest, DIGEST_LEN)) - return circ; - } - return NULL; -} - -/** Return the circuit waiting for a rendezvous with the provided cookie. - * Return NULL if no such circuit is found. - */ -circuit_t *circuit_get_rendezvous(const char *cookie) -{ - circuit_t *circ; - for (circ = global_circuitlist; circ; circ = circ->next) { - if (! circ->marked_for_close && - circ->purpose == CIRCUIT_PURPOSE_REND_POINT_WAITING && - ! memcmp(circ->rend_cookie, cookie, REND_COOKIE_LEN) ) - return circ; - } - return NULL; -} - -/** Circuits that were born at the end of their second might be expired - * after 30.1 seconds; circuits born at the beginning might be expired - * after closer to 31 seconds. - */ -#define MIN_SECONDS_BEFORE_EXPIRING_CIRC 30 - -/** Close all circuits that start at us, aren't open, and were born - * at least MIN_SECONDS_BEFORE_EXPIRING_CIRC seconds ago. - */ -void circuit_expire_building(time_t now) { - circuit_t *victim, *circ = global_circuitlist; - - while(circ) { - victim = circ; - circ = circ->next; - if(!CIRCUIT_IS_ORIGIN(victim)) - continue; /* didn't originate here */ - if(victim->marked_for_close) - continue; /* don't mess with marked circs */ - if(victim->timestamp_created + MIN_SECONDS_BEFORE_EXPIRING_CIRC > now) - continue; /* it's young still, don't mess with it */ - - /* some debug logs, to help track bugs */ - if(victim->purpose >= CIRCUIT_PURPOSE_C_INTRODUCING && - victim->purpose <= CIRCUIT_PURPOSE_C_REND_READY_INTRO_ACKED) { - if(!victim->timestamp_dirty) - log_fn(LOG_DEBUG,"Considering %sopen purp %d to %s (circid %d). (clean).", - victim->state == CIRCUIT_STATE_OPEN ? "" : "non", - victim->purpose, victim->build_state->chosen_exit, - victim->n_circ_id); - else - log_fn(LOG_DEBUG,"Considering %sopen purp %d to %s (circid %d). %d secs since dirty.", - victim->state == CIRCUIT_STATE_OPEN ? "" : "non", - victim->purpose, victim->build_state->chosen_exit, - victim->n_circ_id, - (int)(now - victim->timestamp_dirty)); - } - - /* if circ is !open, or if it's open but purpose is a non-finished - * intro or rend, then mark it for close */ - if(victim->state != CIRCUIT_STATE_OPEN || - victim->purpose == CIRCUIT_PURPOSE_C_ESTABLISH_REND || - victim->purpose == CIRCUIT_PURPOSE_C_INTRODUCING || - victim->purpose == CIRCUIT_PURPOSE_S_ESTABLISH_INTRO || - - /* it's a rend_ready circ, but it's already picked a query */ - (victim->purpose == CIRCUIT_PURPOSE_C_REND_READY && - victim->rend_query[0]) || - - /* c_rend_ready circs measure age since timestamp_dirty, - * because that's set when they switch purposes - */ - /* rend and intro circs become dirty each time they - * make an introduction attempt. so timestamp_dirty - * will reflect the time since the last attempt. - */ - ((victim->purpose == CIRCUIT_PURPOSE_C_REND_READY || - victim->purpose == CIRCUIT_PURPOSE_C_REND_READY_INTRO_ACKED || - victim->purpose == CIRCUIT_PURPOSE_C_INTRODUCE_ACK_WAIT) && - victim->timestamp_dirty + MIN_SECONDS_BEFORE_EXPIRING_CIRC > now)) { - if(victim->n_conn) - log_fn(LOG_INFO,"Abandoning circ %s:%d:%d (state %d:%s, purpose %d)", - victim->n_conn->address, victim->n_port, victim->n_circ_id, - victim->state, circuit_state_to_string[victim->state], victim->purpose); - else - log_fn(LOG_INFO,"Abandoning circ %d (state %d:%s, purpose %d)", victim->n_circ_id, - victim->state, circuit_state_to_string[victim->state], victim->purpose); - circuit_log_path(LOG_INFO,victim); - circuit_mark_for_close(victim); - } - } -} - -/** Count the number of circs originating here that aren't open, and - * that have the specified <b>purpose</b>. */ -int circuit_count_building(uint8_t purpose) { - circuit_t *circ; - int num=0; - - for(circ=global_circuitlist;circ;circ = circ->next) { - if(CIRCUIT_IS_ORIGIN(circ) && - circ->state != CIRCUIT_STATE_OPEN && - circ->purpose == purpose && - !circ->marked_for_close) - num++; - } - return num; -} - -/** How many circuits do we want simultaneously in-progress to handle - * a given stream? - */ -#define MIN_CIRCUITS_HANDLING_STREAM 2 - -/** Return 1 if at least MIN_CIRCUITS_HANDLING_STREAM non-open - * general-purpose circuits will have an acceptable exit node for - * conn. Else return 0. - */ -int circuit_stream_is_being_handled(connection_t *conn) { - circuit_t *circ; - routerinfo_t *exitrouter; - int num=0; - time_t now = time(NULL); - - for(circ=global_circuitlist;circ;circ = circ->next) { - if(CIRCUIT_IS_ORIGIN(circ) && circ->state != CIRCUIT_STATE_OPEN && - !circ->marked_for_close && circ->purpose == CIRCUIT_PURPOSE_C_GENERAL && - (!circ->timestamp_dirty || - circ->timestamp_dirty + options.NewCircuitPeriod < now)) { - exitrouter = router_get_by_nickname(circ->build_state->chosen_exit); - if(exitrouter && connection_ap_can_use_exit(conn, exitrouter) != ADDR_POLICY_REJECTED) - if(++num >= MIN_CIRCUITS_HANDLING_STREAM) - return 1; - } - } - return 0; -} - -/** Return the circuit that is open, has specified <b>purpose</b>, - * has a timestamp_dirty value of 0, and was created most recently, - * or NULL if no circuit fits this description. - */ -static circuit_t * -circuit_get_youngest_clean_open(uint8_t purpose) { - circuit_t *circ; - circuit_t *youngest=NULL; - - for(circ=global_circuitlist;circ;circ = circ->next) { - if(CIRCUIT_IS_ORIGIN(circ) && circ->state == CIRCUIT_STATE_OPEN && - !circ->marked_for_close && circ->purpose == purpose && - !circ->timestamp_dirty && - (!youngest || youngest->timestamp_created < circ->timestamp_created)) - youngest = circ; - } - return youngest; -} - -/** Build a new test circuit every 5 minutes */ -#define TESTING_CIRCUIT_INTERVAL 300 - -/** This function is called once a second. Its job is to make sure - * all services we offer have enough circuits available. Some - * services just want enough circuits for current tasks, whereas - * others want a minimum set of idle circuits hanging around. - */ -void circuit_build_needed_circs(time_t now) { - static long time_to_new_circuit = 0; - circuit_t *circ; - - /* launch a new circ for any pending streams that need one */ - connection_ap_attach_pending(); - - /* make sure any hidden services have enough intro points */ - rend_services_introduce(); - - circ = circuit_get_youngest_clean_open(CIRCUIT_PURPOSE_C_GENERAL); - - if(time_to_new_circuit < now) { - circuit_reset_failure_count(); - time_to_new_circuit = now + options.NewCircuitPeriod; - if(options.SocksPort) - client_dns_clean(); - circuit_expire_old_circuits(); - - if(options.RunTesting && circ && - circ->timestamp_created + TESTING_CIRCUIT_INTERVAL < now) { - log_fn(LOG_INFO,"Creating a new testing circuit."); - circuit_launch_new(CIRCUIT_PURPOSE_C_GENERAL, NULL); - } - } - -/** How many simultaneous in-progress general-purpose circuits do we - * want to be building at once, if there are no open general-purpose - * circuits? - */ -#define CIRCUIT_MIN_BUILDING_GENERAL 3 - /* if there's no open circ, and less than 3 are on the way, - * go ahead and try another. */ - if(!circ && circuit_count_building(CIRCUIT_PURPOSE_C_GENERAL) - < CIRCUIT_MIN_BUILDING_GENERAL) { - circuit_launch_new(CIRCUIT_PURPOSE_C_GENERAL, NULL); - } - - /* XXX count idle rendezvous circs and build more */ -} - -/** The circuit <b>circ</b> has received a circuit-level sendme - * (on hop <b>layer_hint</b>, if we're the OP). Go through all the - * attached streams and let them resume reading and packaging, if - * their stream windows allow it. - */ -void circuit_resume_edge_reading(circuit_t *circ, crypt_path_t *layer_hint) { - - log_fn(LOG_DEBUG,"resuming"); - - /* have to check both n_streams and p_streams, to handle rendezvous */ - if(circuit_resume_edge_reading_helper(circ->n_streams, circ, layer_hint) >= 0) - circuit_resume_edge_reading_helper(circ->p_streams, circ, layer_hint); -} - -/** A helper function for circuit_resume_edge_reading() above. - * The arguments are the same, except that <b>conn</b> is the head - * of a linked list of edge streams that should each be considered. - */ -static int -circuit_resume_edge_reading_helper(connection_t *conn, - circuit_t *circ, - crypt_path_t *layer_hint) { - - for( ; conn; conn=conn->next_stream) { - if((!layer_hint && conn->package_window > 0) || - (layer_hint && conn->package_window > 0 && conn->cpath_layer == layer_hint)) { - connection_start_reading(conn); - /* handle whatever might still be on the inbuf */ - connection_edge_package_raw_inbuf(conn); - - /* 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, layer_hint)) - return -1; - } - } - return 0; -} - -/** Check if the package window for <b>circ</b> is empty (at - * hop <b>layer_hint</b> if it's defined). - * - * If yes, tell edge streams to stop reading and return -1. - * Else return 0. - */ -int circuit_consider_stop_edge_reading(circuit_t *circ, crypt_path_t *layer_hint) { - connection_t *conn = NULL; - - log_fn(LOG_DEBUG,"considering"); - if(!layer_hint && circ->package_window <= 0) { - log_fn(LOG_DEBUG,"yes, not-at-origin. stopped."); - for(conn = circ->n_streams; conn; conn=conn->next_stream) - connection_stop_reading(conn); - return -1; - } else if(layer_hint && layer_hint->package_window <= 0) { - log_fn(LOG_DEBUG,"yes, at-origin. stopped."); - for(conn = circ->n_streams; conn; conn=conn->next_stream) - if(conn->cpath_layer == layer_hint) - connection_stop_reading(conn); - for(conn = circ->p_streams; conn; conn=conn->next_stream) - if(conn->cpath_layer == layer_hint) - connection_stop_reading(conn); - return -1; - } - return 0; -} - -/** Check if the deliver_window for circuit <b>circ</b> (at hop - * <b>layer_hint</b> if it's defined) is low enough that we should - * send a circuit-level sendme back down the circuit. If so, send - * enough sendmes that the window would be overfull if we sent any - * more. - */ -void circuit_consider_sending_sendme(circuit_t *circ, crypt_path_t *layer_hint) { -// log_fn(LOG_INFO,"Considering: layer_hint is %s", -// layer_hint ? "defined" : "null"); - while((layer_hint ? layer_hint->deliver_window : circ->deliver_window) < - CIRCWINDOW_START - CIRCWINDOW_INCREMENT) { - log_fn(LOG_DEBUG,"Queueing circuit sendme."); - if(layer_hint) - layer_hint->deliver_window += CIRCWINDOW_INCREMENT; - else - circ->deliver_window += CIRCWINDOW_INCREMENT; - if(connection_edge_send_command(NULL, circ, RELAY_COMMAND_SENDME, - NULL, 0, layer_hint) < 0) { - log_fn(LOG_WARN,"connection_edge_send_command failed. Circuit's closed."); - return; /* the circuit's closed, don't continue */ - } - } -} - -/** Mark <b>circ</b> to be closed next time we call - * circuit_close_all_marked(). Do any cleanup needed: - * - If state is onionskin_pending, remove circ from the onion_pending - * list. - * - If circ isn't open yet, call circuit_build_failed() if we're - * the origin, and in case call circuit_rep_hist_note_result() - * to note stats. - * - If purpose is C_INTRODUCE_ACK_WAIT, remove the intro point we - * just tried from our list of intro points for that service - * descriptor. - * - Send appropriate destroys and edge_destroys for conns and - * streams attached to circ. - * - If circ->rend_splice is set (we are the midpoint of a joined - * rendezvous stream), then mark the other circuit to close as well. - */ -int _circuit_mark_for_close(circuit_t *circ) { - connection_t *conn; - - assert_circuit_ok(circ); - if (circ->marked_for_close) - return -1; - - if(circ->state == CIRCUIT_STATE_ONIONSKIN_PENDING) { - onion_pending_remove(circ); - } - /* If the circuit ever became OPEN, we sent it to the reputation history - * module then. If it isn't OPEN, we send it there now to remember which - * links worked and which didn't. - */ - if (circ->state != CIRCUIT_STATE_OPEN) { - if(CIRCUIT_IS_ORIGIN(circ)) - circuit_build_failed(circ); /* take actions if necessary */ - circuit_rep_hist_note_result(circ); - } - if (circ->purpose == CIRCUIT_PURPOSE_C_INTRODUCE_ACK_WAIT) { - tor_assert(circ->state == CIRCUIT_STATE_OPEN); - /* treat this like getting a nack from it */ - log_fn(LOG_INFO,"Failed intro circ %s to %s (awaiting ack). Removing from descriptor.", - circ->rend_query, circ->build_state->chosen_exit); - rend_client_remove_intro_point(circ->build_state->chosen_exit, circ->rend_query); - } - - if(circ->n_conn) - connection_send_destroy(circ->n_circ_id, circ->n_conn); - for(conn=circ->n_streams; conn; conn=conn->next_stream) - connection_edge_destroy(circ->n_circ_id, conn); - while(circ->resolving_streams) { - conn = circ->resolving_streams; - circ->resolving_streams = conn->next_stream; - log_fn(LOG_INFO,"Freeing resolving-conn."); - connection_free(conn); - } - if(circ->p_conn) - connection_send_destroy(circ->p_circ_id, circ->p_conn); - for(conn=circ->p_streams; conn; conn=conn->next_stream) - connection_edge_destroy(circ->p_circ_id, conn); - - circ->marked_for_close = 1; - - if (circ->rend_splice && !circ->rend_splice->marked_for_close) { - /* do this after marking this circuit, to avoid infinite recursion. */ - circuit_mark_for_close(circ->rend_splice); - circ->rend_splice = NULL; - } - return 0; -} - -/** If the stream <b>conn</b> is a member of any of the linked - * lists of <b>circ</b>, then remove it from the list. - */ -void circuit_detach_stream(circuit_t *circ, connection_t *conn) { - connection_t *prevconn; - - tor_assert(circ && conn); - - if(conn == circ->p_streams) { - circ->p_streams = conn->next_stream; - return; - } - if(conn == circ->n_streams) { - circ->n_streams = conn->next_stream; - return; - } - if(conn == circ->resolving_streams) { - circ->resolving_streams = conn->next_stream; - return; - } - - 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; - return; - } - - 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; - return; - } - - for(prevconn = circ->resolving_streams; - prevconn && prevconn->next_stream && prevconn->next_stream != conn; - prevconn = prevconn->next_stream) - ; - if(prevconn && prevconn->next_stream) { - prevconn->next_stream = conn->next_stream; - return; - } - - log_fn(LOG_ERR,"edge conn not in circuit's list?"); - tor_assert(0); /* should never get here */ -} - -/** Notify the global circuit list that <b>conn</b> is about to be - * removed and then freed. - * - * If it's an OR conn, then mark-for-close all the circuits that use - * that conn. - * - * If it's an edge conn, then detach it from its circ, so we don't - * try to reference it later. - */ -void circuit_about_to_close_connection(connection_t *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; - - switch(conn->type) { - case CONN_TYPE_OR: - /* 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_mark_for_close(circ); - } - return; - case CONN_TYPE_AP: - case CONN_TYPE_EXIT: - - /* It's an edge conn. Need to remove it from the linked list of - * conn's for this circuit. Confirm that 'end' relay command has - * been sent. But don't kill the circuit. - */ - - circ = circuit_get_by_conn(conn); - if(!circ) - return; - - circuit_detach_stream(circ, conn); - - } /* end switch */ -} - -/** Log, at severity <b>severity</b>, the nicknames of each router in - * circ's cpath. Also log the length of the cpath, and the intended - * exit point. - */ -void circuit_log_path(int severity, circuit_t *circ) { - char buf[1024]; - char *s = buf; - struct crypt_path_t *hop; - char *states[] = {"closed", "waiting for keys", "open"}; - routerinfo_t *router; - tor_assert(CIRCUIT_IS_ORIGIN(circ) && circ->cpath); - - snprintf(s, sizeof(buf)-1, "circ (length %d, exit %s): ", - circ->build_state->desired_path_len, circ->build_state->chosen_exit); - hop=circ->cpath; - do { - s = buf + strlen(buf); - router = router_get_by_addr_port(hop->addr,hop->port); - if(router) { - snprintf(s, sizeof(buf) - (s - buf), "%s(%s) ", - router->nickname, states[hop->state]); - } else { - if(circ->purpose == CIRCUIT_PURPOSE_C_REND_JOINED) { - snprintf(s, sizeof(buf) - (s - buf), "(rendjoin hop)"); - } else { - snprintf(s, sizeof(buf) - (s - buf), "UNKNOWN "); - } - } - hop=hop->next; - } while(hop!=circ->cpath); - log_fn(severity,"%s",buf); -} - -/** Tell the rep(utation)hist(ory) module about the status of the links - * in circ. Hops that have become OPEN are marked as successfully - * extended; the _first_ hop that isn't open (if any) is marked as - * unable to extend. - */ -static void -circuit_rep_hist_note_result(circuit_t *circ) -{ - struct crypt_path_t *hop; - char *prev_nickname = NULL; - routerinfo_t *router; - hop = circ->cpath; - if(!hop) { - /* XXX - * if !hop, then we're not the beginning of this circuit. - * for now, just forget about it. later, we should remember when - * extends-through-us failed, too. - */ - return; - } - if (options.ORPort) { - prev_nickname = options.Nickname; - } - do { - router = router_get_by_addr_port(hop->addr,hop->port); - if (router) { - if (prev_nickname) { - if (hop->state == CPATH_STATE_OPEN) - rep_hist_note_extend_succeeded(prev_nickname, router->nickname); - else { - rep_hist_note_extend_failed(prev_nickname, router->nickname); - break; - } - } - prev_nickname = router->nickname; - } else { - prev_nickname = NULL; - } - hop=hop->next; - } while (hop!=circ->cpath); -} - -/** A helper function for circuit_dump_by_conn() below. Log a bunch - * of information about circuit <b>circ</b>. - */ -static void -circuit_dump_details(int severity, circuit_t *circ, int poll_index, - char *type, int this_circid, int other_circid) { - struct crypt_path_t *hop; - log(severity,"Conn %d has %s circuit: circID %d (other side %d), state %d (%s), born %d", - poll_index, type, this_circid, other_circid, circ->state, - circuit_state_to_string[circ->state], (int)circ->timestamp_created); - if(CIRCUIT_IS_ORIGIN(circ)) { /* circ starts at this node */ - if(circ->state == CIRCUIT_STATE_BUILDING) - log(severity,"Building: desired len %d, planned exit node %s.", - circ->build_state->desired_path_len, circ->build_state->chosen_exit); - for(hop=circ->cpath;hop->next != circ->cpath; hop=hop->next) - log(severity,"hop: state %d, addr 0x%.8x, port %d", hop->state, - (unsigned int)hop->addr, - (int)hop->port); - } -} - -/** Log, at severity <b>severity</b>, information about each circuit - * that is connected to <b>conn</b>. - */ -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) - circuit_dump_details(severity, circ, conn->poll_index, "App-ward", - circ->p_circ_id, circ->n_circ_id); - for(tmpconn=circ->p_streams; tmpconn; tmpconn=tmpconn->next_stream) { - if(tmpconn == conn) { - circuit_dump_details(severity, circ, conn->poll_index, "App-ward", - circ->p_circ_id, circ->n_circ_id); - } - } - if(circ->n_conn == conn) - circuit_dump_details(severity, circ, conn->poll_index, "Exit-ward", - circ->n_circ_id, circ->p_circ_id); - for(tmpconn=circ->n_streams; tmpconn; tmpconn=tmpconn->next_stream) { - if(tmpconn == conn) { - circuit_dump_details(severity, circ, conn->poll_index, "Exit-ward", - circ->n_circ_id, circ->p_circ_id); - } - } - } -} - -/** Don't keep more than 10 unused open circuits around. */ -#define MAX_UNUSED_OPEN_CIRCUITS 10 - -/** Find each circuit that has been dirty for too long, and has - * no streams on it: mark it for close. - * - * Also, if there are more than MAX_UNUSED_OPEN_CIRCUITS open and - * unused circuits, then mark the excess circs for close. - */ -void circuit_expire_old_circuits(void) { - circuit_t *circ; - time_t now = time(NULL); - smartlist_t *unused_open_circs; - int i; - - unused_open_circs = smartlist_create(); - - for (circ = global_circuitlist; circ; circ = circ->next) { - if (circ->marked_for_close) - continue; - /* If the circuit has been dirty for too long, and there are no streams - * on it, mark it for close. - */ - if (circ->timestamp_dirty && - circ->timestamp_dirty + options.NewCircuitPeriod < now && - !circ->p_conn && /* we're the origin */ - !circ->p_streams /* nothing attached */ ) { - log_fn(LOG_DEBUG,"Closing n_circ_id %d (dirty %d secs ago, purp %d)",circ->n_circ_id, - (int)(now - circ->timestamp_dirty), circ->purpose); - /* (only general and purpose_c circs can get dirty) */ - tor_assert(!circ->n_streams); - tor_assert(circ->purpose <= CIRCUIT_PURPOSE_C_REND_JOINED); - circuit_mark_for_close(circ); - } else if (!circ->timestamp_dirty && CIRCUIT_IS_ORIGIN(circ) && - circ->state == CIRCUIT_STATE_OPEN && - circ->purpose == CIRCUIT_PURPOSE_C_GENERAL) { - /* Also, gather a list of open unused general circuits that we created. - * Because we add elements to the front of global_circuitlist, - * the last elements of unused_open_circs will be the oldest - * ones. - */ - smartlist_add(unused_open_circs, circ); - } - } - for (i = MAX_UNUSED_OPEN_CIRCUITS; i < smartlist_len(unused_open_circs); ++i) { - circuit_t *circ = smartlist_get(unused_open_circs, i); - log_fn(LOG_DEBUG,"Expiring excess clean circ (n_circ_id %d, purp %d)", - circ->n_circ_id, circ->purpose); - circuit_mark_for_close(circ); - } - smartlist_free(unused_open_circs); -} - -/** The circuit <b>circ</b> has just become open. Take the next - * step: for rendezvous circuits, we pass circ to the appropriate - * function in rendclient or rendservice. For general circuits, we - * call connection_ap_attach_pending, which looks for pending streams - * that could use circ. - */ -static void circuit_is_open(circuit_t *circ) { - - switch(circ->purpose) { - case CIRCUIT_PURPOSE_C_ESTABLISH_REND: - rend_client_rendcirc_is_open(circ); - break; - case CIRCUIT_PURPOSE_C_INTRODUCING: - rend_client_introcirc_is_open(circ); - break; - case CIRCUIT_PURPOSE_C_GENERAL: - /* Tell any AP connections that have been waiting for a new - * circuit that one is ready. */ - connection_ap_attach_pending(); - break; - case CIRCUIT_PURPOSE_S_ESTABLISH_INTRO: - /* at Bob, waiting for introductions */ - rend_service_intro_is_ready(circ); - break; - case CIRCUIT_PURPOSE_S_CONNECT_REND: - /* at Bob, connecting to rend point */ - rend_service_rendezvous_is_ready(circ); - break; - default: - log_fn(LOG_ERR,"unhandled purpose %d",circ->purpose); - tor_assert(0); - } -} - -/*~ Called whenever a circuit could not be successfully built. - */ -static void circuit_build_failed(circuit_t *circ) { - - /* we should examine circ and see if it failed because of - * the last hop or an earlier hop. then use this info below. - */ - int failed_at_last_hop = 0; - /* If the last hop isn't open, and the second-to-last is, we failed - * at the last hop. */ - if (circ->cpath && - circ->cpath->prev->state != CPATH_STATE_OPEN && - circ->cpath->prev->prev->state == CPATH_STATE_OPEN) { - failed_at_last_hop = 1; - } - - switch(circ->purpose) { - case CIRCUIT_PURPOSE_C_GENERAL: - if (circ->state != CIRCUIT_STATE_OPEN) { - /* If we never built the circuit, note it as a failure. */ - /* Note that we can't just check circ->cpath here, because if - * circuit-building failed immediately, it won't be set yet. */ - circuit_increment_failure_count(); - } - break; - case CIRCUIT_PURPOSE_S_ESTABLISH_INTRO: - /* at Bob, waiting for introductions */ - if (circ->state != CIRCUIT_STATE_OPEN) { - circuit_increment_failure_count(); - } - /* no need to care here, because bob will rebuild intro - * points periodically. */ - break; - case CIRCUIT_PURPOSE_C_INTRODUCING: - /* at Alice, connecting to intro point */ - /* Don't increment failure count, since Bob may have picked - * the introduction point maliciously */ - /* Alice will pick a new intro point when this one dies, if - * the stream in question still cares. No need to act here. */ - break; - case CIRCUIT_PURPOSE_C_ESTABLISH_REND: - /* at Alice, waiting for Bob */ - if (circ->state != CIRCUIT_STATE_OPEN) { - circuit_increment_failure_count(); - } - /* Alice will pick a new rend point when this one dies, if - * the stream in question still cares. No need to act here. */ - break; - case CIRCUIT_PURPOSE_S_CONNECT_REND: - /* at Bob, connecting to rend point */ - /* Don't increment failure count, since Alice may have picked - * the rendezvous point maliciously */ - if (failed_at_last_hop) { - log_fn(LOG_INFO,"Couldn't connect to Alice's chosen rend point %s. Sucks to be Alice.", circ->build_state->chosen_exit); - } else { - log_fn(LOG_INFO,"Couldn't connect to Alice's chosen rend point %s, because an earlier node failed.", - circ->build_state->chosen_exit); - rend_service_relaunch_rendezvous(circ); - } - break; - default: - /* Other cases are impossible, since this function is only called with - * unbuilt circuits. */ - tor_assert(0); - } -} - -/** Number of consecutive failures so far; should only be touched by - * circuit_launch_new and circuit_*_failure_count. - */ -static int n_circuit_failures = 0; - -/** Don't retry launching a new circuit if we try this many times with no - * success. */ -#define MAX_CIRCUIT_FAILURES 5 - -/** Launch a new circuit and return a pointer to it. Return NULL if you failed. */ -circuit_t *circuit_launch_new(uint8_t purpose, const char *exit_nickname) { - - if (n_circuit_failures > MAX_CIRCUIT_FAILURES) { - /* too many failed circs in a row. don't try. */ -// log_fn(LOG_INFO,"%d failures so far, not trying.",n_circuit_failures); - return NULL; - } - - /* try a circ. if it fails, circuit_mark_for_close will increment n_circuit_failures */ - return circuit_establish_circuit(purpose, exit_nickname); -} - -/** Record another failure at opening a general circuit. When we have - * too many, we'll stop trying for the remainder of this minute. - */ -void circuit_increment_failure_count(void) { - ++n_circuit_failures; - log_fn(LOG_DEBUG,"n_circuit_failures now %d.",n_circuit_failures); -} - -/** Reset the failure count for opening general circuits. This means - * we will try MAX_CIRCUIT_FAILURES times more (if necessary) before - * stopping again. - */ -void circuit_reset_failure_count(void) { - n_circuit_failures = 0; -} - -/** Build a new circuit for <b>purpose</b>. If <b>exit_nickname</b> - * is defined, then use that as your exit router, else choose a suitable - * exit node. - * - * Also launch a connection to the first OR in the chosen path, if - * it's not open already. - */ -static circuit_t *circuit_establish_circuit(uint8_t purpose, - const char *exit_nickname) { - routerinfo_t *firsthop; - connection_t *n_conn; - circuit_t *circ; - - circ = circuit_new(0, NULL); /* sets circ->p_circ_id and circ->p_conn */ - circ->state = CIRCUIT_STATE_OR_WAIT; - circ->build_state = onion_new_cpath_build_state(purpose, exit_nickname); - circ->purpose = purpose; - - if (! circ->build_state) { - log_fn(LOG_INFO,"Generating cpath failed."); - circuit_mark_for_close(circ); - return NULL; - } - - onion_extend_cpath(&circ->cpath, circ->build_state, &firsthop); - if(!CIRCUIT_IS_ORIGIN(circ)) { - log_fn(LOG_INFO,"Generating first cpath hop failed."); - circuit_mark_for_close(circ); - return NULL; - } - - /* 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(!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_mark_for_close(circ); - return NULL; - } - } - - log_fn(LOG_DEBUG,"connecting in progress (or finished). Good."); - /* return success. The onion/circuit/etc will be taken care of automatically - * (may already have been) whenever n_conn reaches OR_CONN_STATE_OPEN. - */ - return circ; - } 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_mark_for_close(circ); - return NULL; - } - } - return circ; -} - -/** Find circuits that are waiting on <b>or_conn</b> to become open, - * if any, and get them to send their create cells forward. - */ -void circuit_n_conn_open(connection_t *or_conn) { - circuit_t *circ; - - for(circ=global_circuitlist;circ;circ = circ->next) { - if (circ->marked_for_close) - continue; - if(CIRCUIT_IS_ORIGIN(circ) && circ->n_addr == or_conn->addr && circ->n_port == or_conn->port) { - tor_assert(circ->state == CIRCUIT_STATE_OR_WAIT); - log_fn(LOG_DEBUG,"Found circ %d, sending onion skin.", circ->n_circ_id); - 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_mark_for_close(circ); - continue; - /* XXX could this be bad, eg if next_onion_skin failed because conn died? */ - } - } - } -} - -extern int has_completed_circuit; - -/** This is the backbone function for building circuits. - * - * If circ's first hop is closed, then we need to build a create - * cell and send it forward. - * - * Otherwise, we need to build a relay extend cell and send it - * forward. - * - * Return -1 if we want to tear down circ, else return 0. - */ -int circuit_send_next_onion_skin(circuit_t *circ) { - cell_t cell; - crypt_path_t *hop; - routerinfo_t *router; - int r; - int circ_id_type; - char payload[2+4+ONIONSKIN_CHALLENGE_LEN]; - - tor_assert(circ && CIRCUIT_IS_ORIGIN(circ)); - - if(circ->cpath->state == CPATH_STATE_CLOSED) { - tor_assert(circ->n_conn && circ->n_conn->type == CONN_TYPE_OR); - - log_fn(LOG_DEBUG,"First skin; sending create cell."); - circ_id_type = decide_circ_id_type(options.Nickname, - circ->n_conn->nickname); - circ->n_circ_id = get_unique_circ_id_by_conn(circ->n_conn, circ_id_type); - - memset(&cell, 0, sizeof(cell_t)); - cell.command = CELL_CREATE; - cell.circ_id = circ->n_circ_id; - - router = router_get_by_nickname(circ->n_conn->nickname); - if (!router) { - log_fn(LOG_WARN,"Couldn't find routerinfo for %s", - circ->n_conn->nickname); - return -1; - } - - if(onion_skin_create(router->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 { - tor_assert(circ->cpath->state == CPATH_STATE_OPEN); - tor_assert(circ->state == CIRCUIT_STATE_BUILDING); - log_fn(LOG_DEBUG,"starting to send subsequent skin."); - r = onion_extend_cpath(&circ->cpath, circ->build_state, &router); - if (r==1) { - /* done building the circuit. whew. */ - circ->state = CIRCUIT_STATE_OPEN; - log_fn(LOG_INFO,"circuit built!"); - circuit_reset_failure_count(); - if(!has_completed_circuit) { - has_completed_circuit=1; - log_fn(LOG_NOTICE,"Tor has successfully opened a circuit. Looks like it's working."); - } - circuit_rep_hist_note_result(circ); - circuit_is_open(circ); /* do other actions as necessary */ - return 0; - } else if (r<0) { - log_fn(LOG_INFO,"Unable to extend circuit path."); - return -1; - } - hop = circ->cpath->prev; - - *(uint32_t*)payload = htonl(hop->addr); - *(uint16_t*)(payload+4) = htons(hop->port); - if(onion_skin_create(router->onion_pkey, &(hop->handshake_state), payload+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(connection_edge_send_command(NULL, circ, RELAY_COMMAND_EXTEND, - payload, sizeof(payload), hop->prev) < 0) - return 0; /* circuit is closed */ - - 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; - int circ_id_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(get_uint32(cell->payload+RELAY_HEADER_SIZE)); - circ->n_port = ntohs(get_uint16(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. - * - * 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. - */ - struct in_addr in; - in.s_addr = htonl(circ->n_addr); - log_fn(LOG_INFO,"Next router (%s:%d) not connected. Closing.", inet_ntoa(in), circ->n_port); -#if 0 /* if we do truncateds, no need to kill circ */ - connection_edge_send_command(NULL, circ, RELAY_COMMAND_TRUNCATED, - NULL, 0, NULL); - return 0; -#endif - circuit_mark_for_close(circ); - return 0; - } - - 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); - - circ_id_type = decide_circ_id_type(options.Nickname, n_conn->nickname); - -// log_fn(LOG_DEBUG,"circ_id_type = %u.",circ_id_type); - circ->n_circ_id = get_unique_circ_id_by_conn(circ->n_conn, circ_id_type); - if(!circ->n_circ_id) { - log_fn(LOG_WARN,"failed to get unique circID."); - return -1; - } - log_fn(LOG_DEBUG,"Chosen circID %u.",circ->n_circ_id); - - memset(&newcell, 0, sizeof(cell_t)); - newcell.command = CELL_CREATE; - newcell.circ_id = circ->n_circ_id; - - memcpy(newcell.payload, cell->payload+RELAY_HEADER_SIZE+2+4, - ONIONSKIN_CHALLENGE_LEN); - - connection_or_write_cell_to_buf(&newcell, circ->n_conn); - return 0; -} - -/** Initialize cpath-\>{f|b}_{crypto|digest} from the key material in - * key_data. key_data must contain CPATH_KEY_MATERIAL bytes, which are - * used as follows: - * - 20 to initialize f_digest - * - 20 to initialize b_digest - * - 16 to key f_crypto - * - 16 to key b_crypto - * - * (If 'reverse' is true, then f_XX and b_XX are swapped.) - */ -int circuit_init_cpath_crypto(crypt_path_t *cpath, char *key_data, int reverse) -{ - crypto_digest_env_t *tmp_digest; - crypto_cipher_env_t *tmp_crypto; - - tor_assert(cpath && key_data); - tor_assert(!(cpath->f_crypto || cpath->b_crypto || - cpath->f_digest || cpath->b_digest)); - - log_fn(LOG_DEBUG,"hop init digest forward 0x%.8x, backward 0x%.8x.", - (unsigned int)*(uint32_t*)key_data, (unsigned int)*(uint32_t*)(key_data+20)); - cpath->f_digest = crypto_new_digest_env(); - crypto_digest_add_bytes(cpath->f_digest, key_data, DIGEST_LEN); - cpath->b_digest = crypto_new_digest_env(); - crypto_digest_add_bytes(cpath->b_digest, key_data+DIGEST_LEN, DIGEST_LEN); - - log_fn(LOG_DEBUG,"hop init cipher forward 0x%.8x, backward 0x%.8x.", - (unsigned int)*(uint32_t*)(key_data+40), (unsigned int)*(uint32_t*)(key_data+40+16)); - if (!(cpath->f_crypto = - crypto_create_init_cipher(key_data+(2*DIGEST_LEN),1))) { - log(LOG_WARN,"forward cipher initialization failed."); - return -1; - } - if (!(cpath->b_crypto = - crypto_create_init_cipher(key_data+(2*DIGEST_LEN)+CIPHER_KEY_LEN,0))) { - log(LOG_WARN,"backward cipher initialization failed."); - return -1; - } - - if (reverse) { - tmp_digest = cpath->f_digest; - cpath->f_digest = cpath->b_digest; - cpath->b_digest = tmp_digest; - tmp_crypto = cpath->f_crypto; - cpath->f_crypto = cpath->b_crypto; - cpath->b_crypto = tmp_crypto; - } - - return 0; -} - -/** A created or extended cell came back to us on the circuit, - * and it included <b>reply</b> (the second DH key, plus KH). - * - * Calculate the appropriate keys and digests, make sure KH is - * correct, and initialize this hop of the cpath. - * - * Return -1 if we want to mark circ for close, else return 0. - */ -int circuit_finish_handshake(circuit_t *circ, char *reply) { - unsigned char keys[CPATH_KEY_MATERIAL_LEN]; - crypt_path_t *hop; - - tor_assert(CIRCUIT_IS_ORIGIN(circ)); - 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; - } - } - tor_assert(hop->state == CPATH_STATE_AWAITING_KEYS); - - if(onion_skin_client_handshake(hop->handshake_state, reply, keys, - DIGEST_LEN*2+CIPHER_KEY_LEN*2) < 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; - /* Remember hash of g^xy */ - memcpy(hop->handshake_digest, reply+DH_KEY_LEN, DIGEST_LEN); - - if (circuit_init_cpath_crypto(hop, keys, 0)<0) { - return -1; - } - - hop->state = CPATH_STATE_OPEN; - log_fn(LOG_INFO,"finished"); - circuit_log_path(LOG_INFO,circ); - return 0; -} - -/** We received a relay truncated cell on circ. - * - * Since we don't ask for truncates currently, getting a truncated - * means that a connection broke or an extend failed. For now, - * just give up: for circ to close, and return 0. - */ -int circuit_truncated(circuit_t *circ, crypt_path_t *layer) { - crypt_path_t *victim; - connection_t *stream; - - tor_assert(circ && CIRCUIT_IS_ORIGIN(circ)); - tor_assert(layer); - - /* XXX Since we don't ask for truncates currently, getting a truncated - * means that a connection broke or an extend failed. For now, - * just give up. - */ - circuit_mark_for_close(circ); - return 0; - - 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.", stream->stream_id); - /* no need to send 'end' relay cells, - * because the other side's already dead - */ - stream->has_sent_end = 1; - connection_mark_for_close(stream); - } - } - - layer->next = victim->next; - circuit_free_cpath_node(victim); - } - - log_fn(LOG_INFO, "finished"); - return 0; -} - -/** Verify that cpath layer <b>cp</b> has all of its invariants - * correct. Trigger an assert if anything is invalid. - */ -void assert_cpath_layer_ok(const crypt_path_t *cp) -{ - tor_assert(cp->f_crypto); - tor_assert(cp->b_crypto); -// tor_assert(cp->addr); /* these are zero for rendezvous extra-hops */ -// tor_assert(cp->port); - switch(cp->state) - { - case CPATH_STATE_CLOSED: - case CPATH_STATE_OPEN: - tor_assert(!cp->handshake_state); - break; - case CPATH_STATE_AWAITING_KEYS: - tor_assert(cp->handshake_state); - break; - default: - tor_assert(0); - } - tor_assert(cp->package_window >= 0); - tor_assert(cp->deliver_window >= 0); -} - -/** Verify that cpath <b>cp</b> has all of its invariants - * correct. Trigger an assert if anything is invalid. - */ -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) { - tor_assert(cp->state == CPATH_STATE_CLOSED || - cp->state == CPATH_STATE_AWAITING_KEYS); - } else { - tor_assert(cp->state == CPATH_STATE_CLOSED); - } - } - cp = cp->next; - } -} - -/** Verify that circuit <b>c</b> has all of its invariants - * correct. Trigger an assert if anything is invalid. - */ -void assert_circuit_ok(const circuit_t *c) -{ - connection_t *conn; - - tor_assert(c); - tor_assert(c->magic == CIRCUIT_MAGIC); - tor_assert(c->purpose >= _CIRCUIT_PURPOSE_MIN && - c->purpose <= _CIRCUIT_PURPOSE_MAX); - - if (c->n_conn) - tor_assert(c->n_conn->type == CONN_TYPE_OR); - if (c->p_conn) - tor_assert(c->p_conn->type == CONN_TYPE_OR); - for (conn = c->p_streams; conn; conn = conn->next_stream) - tor_assert(conn->type == CONN_TYPE_AP); - for (conn = c->n_streams; conn; conn = conn->next_stream) - tor_assert(conn->type == CONN_TYPE_EXIT); - - tor_assert(c->deliver_window >= 0); - tor_assert(c->package_window >= 0); - if (c->state == CIRCUIT_STATE_OPEN) { - if (c->cpath) { - tor_assert(CIRCUIT_IS_ORIGIN(c)); - tor_assert(!c->n_crypto); - tor_assert(!c->p_crypto); - tor_assert(!c->n_digest); - tor_assert(!c->p_digest); - } else { - tor_assert(!CIRCUIT_IS_ORIGIN(c)); - tor_assert(c->n_crypto); - tor_assert(c->p_crypto); - tor_assert(c->n_digest); - tor_assert(c->p_digest); - } - } - if (c->cpath) { -//XXX assert_cpath_ok(c->cpath); - } - if (c->purpose == CIRCUIT_PURPOSE_REND_ESTABLISHED) { - if (!c->marked_for_close) { - tor_assert(c->rend_splice); - tor_assert(c->rend_splice->rend_splice == c); - } - tor_assert(c->rend_splice != c); - } else { - tor_assert(!c->rend_splice); - } -} - -/* - Local Variables: - mode:c - indent-tabs-mode:nil - c-basic-offset:2 - End: -*/ |