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- /* Copyright 2001 Matej Pfajfar.
- * Copyright 2001-2004 Roger Dingledine.
- * Copyright 2004 Roger Dingledine, Nick Mathewson. */
- /* See LICENSE for licensing information */
- /* $Id$ */
- const char circuitlist_c_id[] = "$Id$";
- /**
- * \file circuitlist.c
- * \brief Manage the global circuit list.
- **/
- #include "or.h"
- /********* START VARIABLES **********/
- /** A global list of all circuits at this hop. */
- circuit_t *global_circuitlist=NULL;
- /** Array of strings to make circ-\>state human-readable */
- const char *circuit_state_to_string[] = {
- "doing handshakes", /* 0 */
- "processing the onion", /* 1 */
- "connecting to firsthop", /* 2 */
- "open" /* 3 */
- };
- /********* END VARIABLES ************/
- static void circuit_free(circuit_t *circ);
- static void circuit_free_cpath(crypt_path_t *cpath);
- static void circuit_free_cpath_node(crypt_path_t *victim);
- /** 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;
- }
- }
- /** Detach from the global circuit list, and deallocate, all
- * circuits that have been marked for close.
- */
- void circuit_close_all_marked(void)
- {
- 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;
- static uint32_t n_circuits_allocated = 0;
- 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);
- circ->global_identifier = n_circuits_allocated++;
- 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_name);
- 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 */
- tor_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);
- tor_free(victim);
- }
- /** 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 or resolving_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 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;
- }
- /** 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;
- }
- /** 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.
- */
- 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;
- }
- /** 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 either 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 (CIRCUIT_IS_ORIGIN(circ)) {
- control_event_circuit_status(circ,
- (circ->state == CIRCUIT_STATE_OPEN)?CIRC_EVENT_CLOSED:CIRC_EVENT_FAILED);
- }
- 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_name);
- rend_client_remove_intro_point(circ->build_state->chosen_exit_name, 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;
- connection_dns_remove(conn); /* remove it from resolve lists */
- 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;
- }
- /** 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->addr); /* these are zero for rendezvous extra-hops */
- // tor_assert(cp->port);
- switch (cp->state)
- {
- case CPATH_STATE_OPEN:
- tor_assert(cp->f_crypto);
- tor_assert(cp->b_crypto);
- /* fall through */
- case CPATH_STATE_CLOSED:
- tor_assert(!cp->handshake_state);
- break;
- case CPATH_STATE_AWAITING_KEYS:
- tor_assert(cp->handshake_state);
- break;
- default:
- log_fn(LOG_ERR,"Unexpected state %d",cp->state);
- 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.
- */
- static void
- assert_cpath_ok(const crypt_path_t *cp)
- {
- const crypt_path_t *start = cp;
- do {
- assert_cpath_layer_ok(cp);
- /* layers must be in sequence of: "open* awaiting? closed*" */
- if (cp != start) {
- if (cp->state == CPATH_STATE_AWAITING_KEYS) {
- tor_assert(cp->prev->state == CPATH_STATE_OPEN);
- } else if (cp->state == CPATH_STATE_OPEN) {
- tor_assert(cp->prev->state == CPATH_STATE_OPEN);
- }
- }
- cp = cp->next;
- tor_assert(cp);
- } while (cp != start);
- }
- /** 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);
- tor_assert(!memcmp(c->n_conn->identity_digest, c->n_conn_id_digest, DIGEST_LEN));
- }
- 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) {
- 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);
- }
- }
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