/* Copyright 2001 Matej Pfajfar. * Copyright (c) 2001-2004, Roger Dingledine. * Copyright (c) 2004-2007, 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" #include "../common/ht.h" /********* START VARIABLES **********/ /** A global list of all circuits at this hop. */ circuit_t *global_circuitlist=NULL; /** A list of all the circuits in CIRCUIT_STATE_OR_WAIT. */ static smartlist_t *circuits_pending_or_conns=NULL; 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); /********* END VARIABLES ************/ /** A map from OR connection and circuit ID to circuit. (Lookup performance is * very important here, since we need to do it every time a cell arrives.) */ typedef struct orconn_circid_circuit_map_t { HT_ENTRY(orconn_circid_circuit_map_t) node; or_connection_t *or_conn; uint16_t circ_id; circuit_t *circuit; } orconn_circid_circuit_map_t; /** Helper for hash tables: compare the OR connection and circuit ID for a and * b, and return less than, equal to, or greater than zero appropriately. */ static INLINE int _orconn_circid_entries_eq(orconn_circid_circuit_map_t *a, orconn_circid_circuit_map_t *b) { return a->or_conn == b->or_conn && a->circ_id == b->circ_id; } /** Helper: return a hash based on circuit ID and the pointer value of * or_conn in a. */ static INLINE unsigned int _orconn_circid_entry_hash(orconn_circid_circuit_map_t *a) { return (((unsigned)a->circ_id)<<16) ^ (unsigned)(uintptr_t)(a->or_conn); } /** Map from [orconn,circid] to circuit. */ static HT_HEAD(orconn_circid_map, orconn_circid_circuit_map_t) orconn_circid_circuit_map = HT_INITIALIZER(); HT_PROTOTYPE(orconn_circid_map, orconn_circid_circuit_map_t, node, _orconn_circid_entry_hash, _orconn_circid_entries_eq) HT_GENERATE(orconn_circid_map, orconn_circid_circuit_map_t, node, _orconn_circid_entry_hash, _orconn_circid_entries_eq, 0.6, malloc, realloc, free) /** The most recently returned entry from circuit_get_by_circid_orconn; * used to improve performance when many cells arrive in a row from the * same circuit. */ orconn_circid_circuit_map_t *_last_circid_orconn_ent = NULL; /** Implementation helper for circuit_set_{p,n}_circid_orconn: A circuit ID * and/or or_connection for circ has just changed from old_conn, old_id * to conn, id. Adjust the conn,circid map as appropriate, removing * the old entry (if any) and adding a new one. If active is true, * remove the circuit from the list of active circuits on old_conn and add it * to the list of active circuits on conn. * XXX "active" isn't an arg anymore */ static void circuit_set_circid_orconn_helper(circuit_t *circ, int direction, uint16_t id, or_connection_t *conn) { orconn_circid_circuit_map_t search; orconn_circid_circuit_map_t *found; or_connection_t *old_conn, **conn_ptr; uint16_t old_id, *circid_ptr; int was_active, make_active; if (direction == CELL_DIRECTION_OUT) { conn_ptr = &circ->n_conn; circid_ptr = &circ->n_circ_id; was_active = circ->next_active_on_n_conn != NULL; make_active = circ->n_conn_cells.n > 0; } else { or_circuit_t *c = TO_OR_CIRCUIT(circ); conn_ptr = &c->p_conn; circid_ptr = &c->p_circ_id; was_active = c->next_active_on_p_conn != NULL; make_active = c->p_conn_cells.n > 0; } old_conn = *conn_ptr; old_id = *circid_ptr; if (id == old_id && conn == old_conn) return; if (_last_circid_orconn_ent && ((old_id == _last_circid_orconn_ent->circ_id && old_conn == _last_circid_orconn_ent->or_conn) || (id == _last_circid_orconn_ent->circ_id && conn == _last_circid_orconn_ent->or_conn))) { _last_circid_orconn_ent = NULL; } if (old_conn) { /* we may need to remove it from the conn-circid map */ tor_assert(old_conn->_base.magic == OR_CONNECTION_MAGIC); search.circ_id = old_id; search.or_conn = old_conn; found = HT_REMOVE(orconn_circid_map, &orconn_circid_circuit_map, &search); if (found) { tor_free(found); --old_conn->n_circuits; } if (was_active && old_conn != conn) make_circuit_inactive_on_conn(circ,old_conn); } /* Change the values only after we have possibly made the circuit inactive * on the previous conn. */ *conn_ptr = conn; *circid_ptr = id; if (conn == NULL) return; /* now add the new one to the conn-circid map */ search.circ_id = id; search.or_conn = conn; found = HT_FIND(orconn_circid_map, &orconn_circid_circuit_map, &search); if (found) { found->circuit = circ; } else { found = tor_malloc_zero(sizeof(orconn_circid_circuit_map_t)); found->circ_id = id; found->or_conn = conn; found->circuit = circ; HT_INSERT(orconn_circid_map, &orconn_circid_circuit_map, found); } if (make_active && old_conn != conn) make_circuit_active_on_conn(circ,conn); ++conn->n_circuits; } /** Set the p_conn field of a circuit circ, along * with the corresponding circuit ID, and add the circuit as appropriate * to the (orconn,id)-\>circuit map. */ void circuit_set_p_circid_orconn(or_circuit_t *circ, uint16_t id, or_connection_t *conn) { circuit_set_circid_orconn_helper(TO_CIRCUIT(circ), CELL_DIRECTION_IN, id, conn); if (conn) tor_assert(bool_eq(circ->p_conn_cells.n, circ->next_active_on_p_conn)); } /** Set the n_conn field of a circuit circ, along * with the corresponding circuit ID, and add the circuit as appropriate * to the (orconn,id)-\>circuit map. */ void circuit_set_n_circid_orconn(circuit_t *circ, uint16_t id, or_connection_t *conn) { circuit_set_circid_orconn_helper(circ, CELL_DIRECTION_OUT, id, conn); if (conn) tor_assert(bool_eq(circ->n_conn_cells.n, circ->next_active_on_n_conn)); } /** Change the state of circ to state, adding it to or removing * it from lists as appropriate. */ void circuit_set_state(circuit_t *circ, int state) { tor_assert(circ); if (state == circ->state) return; if (!circuits_pending_or_conns) circuits_pending_or_conns = smartlist_create(); if (circ->state == CIRCUIT_STATE_OR_WAIT) { /* remove from waiting-circuit list. */ smartlist_remove(circuits_pending_or_conns, circ); } if (state == CIRCUIT_STATE_OR_WAIT) { /* add to waiting-circuit list. */ smartlist_add(circuits_pending_or_conns, circ); } circ->state = state; } /** Add circ 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; } } /** Append to out all circuits in state OR_WAIT waiting for * the given connection. */ void circuit_get_all_pending_on_or_conn(smartlist_t *out, or_connection_t *or_conn) { tor_assert(out); tor_assert(or_conn); if (!circuits_pending_or_conns) return; SMARTLIST_FOREACH(circuits_pending_or_conns, circuit_t *, circ, { if (circ->marked_for_close) continue; tor_assert(circ->state == CIRCUIT_STATE_OR_WAIT); if (tor_digest_is_zero(circ->n_conn_id_digest)) { /* Look at addr/port. This is an unkeyed connection. */ if (circ->n_addr != or_conn->_base.addr || circ->n_port != or_conn->_base.port) continue; } else { /* We expected a key. See if it's the right one. */ if (memcmp(or_conn->identity_digest, circ->n_conn_id_digest, DIGEST_LEN)) continue; } smartlist_add(out, circ); }); } /** Return the number of circuits in state OR_WAIT, waiting for the given * connection. */ int circuit_count_pending_on_or_conn(or_connection_t *or_conn) { int cnt; smartlist_t *sl = smartlist_create(); circuit_get_all_pending_on_or_conn(sl, or_conn); cnt = smartlist_len(sl); smartlist_free(sl); log_debug(LD_CIRC,"or_conn to %s, %d pending circs", or_conn->nickname ? or_conn->nickname : "NULL", cnt); return cnt; } /** 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; } } } /** Return the head of the global linked list of circuits. */ circuit_t * _circuit_get_global_list(void) { return global_circuitlist; } /** Function to make circ-\>state human-readable */ const char * circuit_state_to_string(int state) { static char buf[64]; switch (state) { case CIRCUIT_STATE_BUILDING: return "doing handshakes"; case CIRCUIT_STATE_ONIONSKIN_PENDING: return "processing the onion"; case CIRCUIT_STATE_OR_WAIT: return "connecting to server"; case CIRCUIT_STATE_OPEN: return "open"; default: log_warn(LD_BUG, "Unknown circuit state %d", state); tor_snprintf(buf, sizeof(buf), "unknown state [%d]", state); return buf; } } /** Initialize the common elements in a circuit_t, and add it to the global * list. */ static void init_circuit_base(circuit_t *circ) { circ->timestamp_created = time(NULL); circ->package_window = CIRCWINDOW_START; circ->deliver_window = CIRCWINDOW_START; circuit_add(circ); } /** Allocate space for a new circuit, initializing with p_circ_id * and p_conn. Add it to the global circuit list. */ origin_circuit_t * origin_circuit_new(void) { origin_circuit_t *circ; /* never zero, since a global ID of 0 is treated specially by the * controller */ static uint32_t n_circuits_allocated = 1; circ = tor_malloc_zero(sizeof(origin_circuit_t)); circ->_base.magic = ORIGIN_CIRCUIT_MAGIC; circ->next_stream_id = crypto_rand_int(1<<16); circ->global_identifier = n_circuits_allocated++; init_circuit_base(TO_CIRCUIT(circ)); return circ; } /** Allocate a new or_circuit_t, connected to p_conn as * p_circ_id. If p_conn is NULL, the circuit is unattached. */ or_circuit_t * or_circuit_new(uint16_t p_circ_id, or_connection_t *p_conn) { /* CircIDs */ or_circuit_t *circ; circ = tor_malloc_zero(sizeof(or_circuit_t)); circ->_base.magic = OR_CIRCUIT_MAGIC; if (p_conn) circuit_set_p_circid_orconn(circ, p_circ_id, p_conn); init_circuit_base(TO_CIRCUIT(circ)); return circ; } /** Deallocate space associated with circ. */ static void circuit_free(circuit_t *circ) { void *mem; tor_assert(circ); if (CIRCUIT_IS_ORIGIN(circ)) { origin_circuit_t *ocirc = TO_ORIGIN_CIRCUIT(circ); mem = ocirc; tor_assert(circ->magic == ORIGIN_CIRCUIT_MAGIC); if (ocirc->build_state) { if (ocirc->build_state->chosen_exit) extend_info_free(ocirc->build_state->chosen_exit); if (ocirc->build_state->pending_final_cpath) circuit_free_cpath_node(ocirc->build_state->pending_final_cpath); } tor_free(ocirc->build_state); circuit_free_cpath(ocirc->cpath); } else { or_circuit_t *ocirc = TO_OR_CIRCUIT(circ); mem = ocirc; tor_assert(circ->magic == OR_CIRCUIT_MAGIC); if (ocirc->p_crypto) crypto_free_cipher_env(ocirc->p_crypto); if (ocirc->p_digest) crypto_free_digest_env(ocirc->p_digest); if (ocirc->n_crypto) crypto_free_cipher_env(ocirc->n_crypto); if (ocirc->n_digest) crypto_free_digest_env(ocirc->n_digest); if (ocirc->rend_splice) { or_circuit_t *other = ocirc->rend_splice; tor_assert(other->_base.magic == OR_CIRCUIT_MAGIC); other->rend_splice = NULL; } tor_free(circ->onionskin); /* remove from map. */ circuit_set_p_circid_orconn(ocirc, 0, NULL); /* Clear cell queue _after_ removing it from the map. Otherwise our * "active" checks will be violated. */ cell_queue_clear(ô->p_conn_cells); } /* Remove from map. */ circuit_set_n_circid_orconn(circ, 0, NULL); /* Clear cell queue _after_ removing it from the map. Otherwise our * "active" checks will be violated. */ cell_queue_clear(&circ->n_conn_cells); memset(circ, 0xAA, sizeof(circuit_t)); /* poison memory */ tor_free(mem); } /** Deallocate space associated with the linked list cpath. */ 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); } /** Release all storage held by circuits. */ void circuit_free_all(void) { circuit_t *next; while (global_circuitlist) { next = global_circuitlist->next; if (! CIRCUIT_IS_ORIGIN(global_circuitlist)) { or_circuit_t *or_circ = TO_OR_CIRCUIT(global_circuitlist); while (or_circ->resolving_streams) { edge_connection_t *next_conn; next_conn = or_circ->resolving_streams->next_stream; connection_free(TO_CONN(or_circ->resolving_streams)); or_circ->resolving_streams = next_conn; } } circuit_free(global_circuitlist); global_circuitlist = next; } if (circuits_pending_or_conns) { smartlist_free(circuits_pending_or_conns); circuits_pending_or_conns = NULL; } HT_CLEAR(orconn_circid_map, &orconn_circid_circuit_map); } /** Deallocate space associated with the cpath node victim. */ 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->dh_handshake_state) crypto_dh_free(victim->dh_handshake_state); if (victim->extend_info) extend_info_free(victim->extend_info); victim->magic = 0xDEADBEEFu; tor_free(victim); } /** A helper function for circuit_dump_by_conn() below. Log a bunch * of information about circuit circ. */ static void circuit_dump_details(int severity, circuit_t *circ, int conn_array_index, const char *type, int this_circid, int other_circid) { log(severity, LD_CIRC, "Conn %d has %s circuit: circID %d (other side %d), " "state %d (%s), born %d:", conn_array_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 */ circuit_log_path(severity, LD_CIRC, TO_ORIGIN_CIRCUIT(circ)); } } /** Log, at severity severity, information about each circuit * that is connected to conn. */ void circuit_dump_by_conn(connection_t *conn, int severity) { circuit_t *circ; edge_connection_t *tmpconn; for (circ=global_circuitlist;circ;circ = circ->next) { circid_t n_circ_id = circ->n_circ_id, p_circ_id = 0; if (circ->marked_for_close) continue; if (! CIRCUIT_IS_ORIGIN(circ)) p_circ_id = TO_OR_CIRCUIT(circ)->p_circ_id; if (! CIRCUIT_IS_ORIGIN(circ) && TO_OR_CIRCUIT(circ)->p_conn && TO_CONN(TO_OR_CIRCUIT(circ)->p_conn) == conn) circuit_dump_details(severity, circ, conn->conn_array_index, "App-ward", p_circ_id, n_circ_id); if (CIRCUIT_IS_ORIGIN(circ)) { for (tmpconn=TO_ORIGIN_CIRCUIT(circ)->p_streams; tmpconn; tmpconn=tmpconn->next_stream) { if (TO_CONN(tmpconn) == conn) { circuit_dump_details(severity, circ, conn->conn_array_index, "App-ward", p_circ_id, n_circ_id); } } } if (circ->n_conn && TO_CONN(circ->n_conn) == conn) circuit_dump_details(severity, circ, conn->conn_array_index, "Exit-ward", n_circ_id, p_circ_id); if (! CIRCUIT_IS_ORIGIN(circ)) { for (tmpconn=TO_OR_CIRCUIT(circ)->n_streams; tmpconn; tmpconn=tmpconn->next_stream) { if (TO_CONN(tmpconn) == conn) { circuit_dump_details(severity, circ, conn->conn_array_index, "Exit-ward", n_circ_id, p_circ_id); } } } if (!circ->n_conn && circ->n_addr && circ->n_port && circ->n_addr == conn->addr && circ->n_port == conn->port && conn->type == CONN_TYPE_OR && !memcmp(TO_OR_CONN(conn)->identity_digest, circ->n_conn_id_digest, DIGEST_LEN)) { circuit_dump_details(severity, circ, conn->conn_array_index, (circ->state == CIRCUIT_STATE_OPEN && !CIRCUIT_IS_ORIGIN(circ)) ? "Endpoint" : "Pending", n_circ_id, p_circ_id); } } } /** Return the circuit whose global ID is id, or NULL if no * such circuit exists. */ origin_circuit_t * circuit_get_by_global_id(uint32_t id) { circuit_t *circ; for (circ=global_circuitlist;circ;circ = circ->next) { if (CIRCUIT_IS_ORIGIN(circ) && TO_ORIGIN_CIRCUIT(circ)->global_identifier == id) { if (circ->marked_for_close) return NULL; else return TO_ORIGIN_CIRCUIT(circ); } } return NULL; } /** Return a circ such that: * - circ-\>n_circ_id or circ-\>p_circ_id is equal to circ_id, and * - circ is attached to conn, either as p_conn or n_conn. * Return NULL if no such circuit exists. */ static INLINE circuit_t * circuit_get_by_circid_orconn_impl(uint16_t circ_id, or_connection_t *conn) { orconn_circid_circuit_map_t search; orconn_circid_circuit_map_t *found; if (_last_circid_orconn_ent && circ_id == _last_circid_orconn_ent->circ_id && conn == _last_circid_orconn_ent->or_conn) { found = _last_circid_orconn_ent; } else { search.circ_id = circ_id; search.or_conn = conn; found = HT_FIND(orconn_circid_map, &orconn_circid_circuit_map, &search); _last_circid_orconn_ent = found; } if (found && found->circuit) return found->circuit; return NULL; /* The rest of this checks for bugs. Disabled by default. */ { circuit_t *circ; for (circ=global_circuitlist;circ;circ = circ->next) { if (! CIRCUIT_IS_ORIGIN(circ)) { or_circuit_t *or_circ = TO_OR_CIRCUIT(circ); if (or_circ->p_conn == conn && or_circ->p_circ_id == circ_id) { log_warn(LD_BUG, "circuit matches p_conn, but not in hash table (Bug!)"); return circ; } } if (circ->n_conn == conn && circ->n_circ_id == circ_id) { log_warn(LD_BUG, "circuit matches n_conn, but not in hash table (Bug!)"); return circ; } } return NULL; } } /** Return a circ such that: * - circ-\>n_circ_id or circ-\>p_circ_id is equal to circ_id, and * - circ is attached to conn, either as p_conn or n_conn. * - circ is not marked for close. * Return NULL if no such circuit exists. */ circuit_t * circuit_get_by_circid_orconn(uint16_t circ_id, or_connection_t *conn) { circuit_t *circ = circuit_get_by_circid_orconn_impl(circ_id, conn); if (!circ || circ->marked_for_close) return NULL; else return circ; } /** Return the circuit that a given edge connection is using. */ circuit_t * circuit_get_by_edge_conn(edge_connection_t *conn) { circuit_t *circ; circ = conn->on_circuit; tor_assert(!circ || (CIRCUIT_IS_ORIGIN(circ) ? circ->magic == ORIGIN_CIRCUIT_MAGIC : circ->magic == OR_CIRCUIT_MAGIC)); return circ; } /** For each circuit that has conn as n_conn or p_conn, unlink the * circuit from the orconn,circid map, and mark it for close if it hasn't * been marked already. */ void circuit_unlink_all_from_or_conn(or_connection_t *conn, int reason) { circuit_t *circ; connection_or_unlink_all_active_circs(conn); for (circ = global_circuitlist; circ; circ = circ->next) { int mark = 0; if (circ->n_conn == conn) { circuit_set_n_circid_orconn(circ, 0, NULL); mark = 1; } if (! CIRCUIT_IS_ORIGIN(circ)) { or_circuit_t *or_circ = TO_OR_CIRCUIT(circ); if (or_circ->p_conn == conn) { circuit_set_p_circid_orconn(or_circ, 0, NULL); mark = 1; } } if (mark && !circ->marked_for_close) circuit_mark_for_close(circ, reason); } } /** Return a circ such that: * - circ-\>rend_query is equal to rend_query, and * - circ-\>purpose is equal to purpose. * * Return NULL if no such circuit exists. */ origin_circuit_t * circuit_get_by_rend_query_and_purpose(const char *rend_query, uint8_t purpose) { circuit_t *circ; tor_assert(CIRCUIT_PURPOSE_IS_ORIGIN(purpose)); for (circ = global_circuitlist; circ; circ = circ->next) { if (!circ->marked_for_close && circ->purpose == purpose && !rend_cmp_service_ids(rend_query, TO_ORIGIN_CIRCUIT(circ)->rend_query)) return TO_ORIGIN_CIRCUIT(circ); } return NULL; } /** Return the first circuit originating here in global_circuitlist after * start whose purpose is purpose, and where * digest (if set) matches the rend_pk_digest field. Return NULL if no * circuit is found. If start is NULL, begin at the start of the list. */ origin_circuit_t * circuit_get_next_by_pk_and_purpose(origin_circuit_t *start, const char *digest, uint8_t purpose) { circuit_t *circ; tor_assert(CIRCUIT_PURPOSE_IS_ORIGIN(purpose)); if (start == NULL) circ = global_circuitlist; else circ = TO_CIRCUIT(start)->next; for ( ; circ; circ = circ->next) { if (circ->marked_for_close) continue; if (circ->purpose != purpose) continue; if (!digest) return TO_ORIGIN_CIRCUIT(circ); else if (!memcmp(TO_ORIGIN_CIRCUIT(circ)->rend_pk_digest, digest, DIGEST_LEN)) return TO_ORIGIN_CIRCUIT(circ); } return NULL; } /** Return the first OR circuit in the global list whose purpose is * purpose, and whose rend_token is the len-byte * token. */ static or_circuit_t * circuit_get_by_rend_token_and_purpose(uint8_t purpose, const char *token, size_t len) { circuit_t *circ; for (circ = global_circuitlist; circ; circ = circ->next) { if (! circ->marked_for_close && circ->purpose == purpose && ! memcmp(TO_OR_CIRCUIT(circ)->rend_token, token, len)) return TO_OR_CIRCUIT(circ); } return NULL; } /** Return the circuit waiting for a rendezvous with the provided cookie. * Return NULL if no such circuit is found. */ or_circuit_t * circuit_get_rendezvous(const char *cookie) { return circuit_get_by_rend_token_and_purpose( CIRCUIT_PURPOSE_REND_POINT_WAITING, cookie, REND_COOKIE_LEN); } /** Return the circuit waiting for intro cells of the given digest. * Return NULL if no such circuit is found. */ or_circuit_t * circuit_get_intro_point(const char *digest) { return circuit_get_by_rend_token_and_purpose( CIRCUIT_PURPOSE_INTRO_POINT, digest, DIGEST_LEN); } /** Return a circuit that is open, has specified purpose, * has a timestamp_dirty value of 0, is uptime/capacity/internal * if required, and if info is defined, does not already use info * as any of its hops; or NULL if no circuit fits this description. * * If ! need_uptime, prefer returning non-uptime circuits. */ origin_circuit_t * circuit_find_to_cannibalize(uint8_t purpose, extend_info_t *info, int need_uptime, int need_capacity, int internal) { circuit_t *_circ; origin_circuit_t *best=NULL; log_debug(LD_CIRC, "Hunting for a circ to cannibalize: purpose %d, uptime %d, " "capacity %d, internal %d", purpose, need_uptime, need_capacity, internal); 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) { origin_circuit_t *circ = TO_ORIGIN_CIRCUIT(_circ); if ((!need_uptime || circ->build_state->need_uptime) && (!need_capacity || circ->build_state->need_capacity) && (internal == circ->build_state->is_internal)) { if (info) { /* need to make sure we don't duplicate hops */ crypt_path_t *hop = circ->cpath; do { if (!memcmp(hop->extend_info->identity_digest, info->identity_digest, DIGEST_LEN)) goto next; hop=hop->next; } while (hop!=circ->cpath); } if (!best || (best->build_state->need_uptime && !need_uptime)) best = circ; next: ; } } } return best; } /** Return the number of hops in circuit's path. */ int circuit_get_cpath_len(origin_circuit_t *circ) { int n = 0; if (circ && circ->cpath) { crypt_path_t *cpath, *cpath_next = NULL; for (cpath = circ->cpath; cpath_next != circ->cpath; cpath = cpath_next) { cpath_next = cpath->next; ++n; } } return n; } /** Return the hopnumth hop in circ->cpath, or NULL if there * aren't that many hops in the list. */ crypt_path_t * circuit_get_cpath_hop(origin_circuit_t *circ, int hopnum) { if (circ && circ->cpath && hopnum > 0) { crypt_path_t *cpath, *cpath_next = NULL; for (cpath = circ->cpath; cpath_next != circ->cpath; cpath = cpath_next) { cpath_next = cpath->next; if (--hopnum <= 0) return cpath; } } return NULL; } /** Go through the circuitlist; mark-for-close each circuit that starts * at us but has not yet been used. */ void circuit_mark_all_unused_circs(void) { circuit_t *circ; for (circ=global_circuitlist; circ; circ = circ->next) { if (CIRCUIT_IS_ORIGIN(circ) && !circ->marked_for_close && !circ->timestamp_dirty) circuit_mark_for_close(circ, END_CIRC_REASON_FINISHED); } } /** Go through the circuitlist; for each circuit that starts at us * and is dirty, frob its timestamp_dirty so we won't use it for any * new streams. * * This is useful for letting the user change pseudonyms, so new * streams will not be linkable to old streams. */ void circuit_expire_all_dirty_circs(void) { circuit_t *circ; or_options_t *options = get_options(); for (circ=global_circuitlist; circ; circ = circ->next) { if (CIRCUIT_IS_ORIGIN(circ) && !circ->marked_for_close && circ->timestamp_dirty) circ->timestamp_dirty -= options->MaxCircuitDirtiness; } } /** Mark circ 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. */ void _circuit_mark_for_close(circuit_t *circ, int reason, int line, const char *file) { int orig_reason = reason; /* Passed to the controller */ assert_circuit_ok(circ); tor_assert(line); tor_assert(file); if (circ->marked_for_close) { log(LOG_WARN,LD_BUG, "Duplicate call to circuit_mark_for_close at %s:%d" " (first at %s:%d)", file, line, circ->marked_for_close_file, circ->marked_for_close); return; } if (reason == END_CIRC_AT_ORIGIN) { if (!CIRCUIT_IS_ORIGIN(circ)) { log_warn(LD_BUG, "Specified 'at-origin' non-reason for ending circuit, " "but circuit was not at origin. (called %s:%d, purpose=%d)", file, line, circ->purpose); } reason = END_CIRC_REASON_NONE; } if (CIRCUIT_IS_ORIGIN(circ)) { /* We don't send reasons when closing circuits at the origin. */ reason = END_CIRC_REASON_NONE; } if (reason & END_CIRC_REASON_FLAG_REMOTE) reason &= ~END_CIRC_REASON_FLAG_REMOTE; if (reason < _END_CIRC_REASON_MIN || reason > _END_CIRC_REASON_MAX) { if (!(orig_reason & END_CIRC_REASON_FLAG_REMOTE)) log_warn(LD_BUG, "Reason %d out of range at %s:%d", reason, file, line); reason = END_CIRC_REASON_NONE; } if (circ->state == CIRCUIT_STATE_ONIONSKIN_PENDING) { onion_pending_remove(TO_OR_CIRCUIT(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)) { origin_circuit_t *ocirc = TO_ORIGIN_CIRCUIT(circ); circuit_build_failed(ocirc); /* take actions if necessary */ circuit_rep_hist_note_result(ocirc); } } if (circ->state == CIRCUIT_STATE_OR_WAIT) { if (circuits_pending_or_conns) smartlist_remove(circuits_pending_or_conns, circ); } if (CIRCUIT_IS_ORIGIN(circ)) { control_event_circuit_status(TO_ORIGIN_CIRCUIT(circ), (circ->state == CIRCUIT_STATE_OPEN)?CIRC_EVENT_CLOSED:CIRC_EVENT_FAILED, orig_reason); } if (circ->purpose == CIRCUIT_PURPOSE_C_INTRODUCE_ACK_WAIT) { origin_circuit_t *ocirc = TO_ORIGIN_CIRCUIT(circ); tor_assert(circ->state == CIRCUIT_STATE_OPEN); tor_assert(ocirc->build_state->chosen_exit); /* treat this like getting a nack from it */ log_info(LD_REND, "Failed intro circ %s to %s (awaiting ack). " "Removing from descriptor.", safe_str(ocirc->rend_query), safe_str(build_state_get_exit_nickname(ocirc->build_state))); rend_client_remove_intro_point(ocirc->build_state->chosen_exit, ocirc->rend_query); } if (circ->n_conn) connection_or_send_destroy(circ->n_circ_id, circ->n_conn, reason); if (! CIRCUIT_IS_ORIGIN(circ)) { or_circuit_t *or_circ = TO_OR_CIRCUIT(circ); edge_connection_t *conn; for (conn=or_circ->n_streams; conn; conn=conn->next_stream) connection_edge_destroy(or_circ->p_circ_id, conn); while (or_circ->resolving_streams) { conn = or_circ->resolving_streams; or_circ->resolving_streams = conn->next_stream; if (!conn->_base.marked_for_close) { /* The client will see a DESTROY, and infer that the connections * are closing because the circuit is getting torn down. No need * to send an end cell. */ conn->_base.edge_has_sent_end = 1; conn->end_reason = END_STREAM_REASON_DESTROY; conn->end_reason |= END_STREAM_REASON_FLAG_ALREADY_SENT_CLOSED; connection_mark_for_close(TO_CONN(conn)); } conn->on_circuit = NULL; } if (or_circ->p_conn) connection_or_send_destroy(or_circ->p_circ_id, or_circ->p_conn, reason); } else { origin_circuit_t *ocirc = TO_ORIGIN_CIRCUIT(circ); edge_connection_t *conn; for (conn=ocirc->p_streams; conn; conn=conn->next_stream) connection_edge_destroy(circ->n_circ_id, conn); } circ->marked_for_close = line; circ->marked_for_close_file = file; if (!CIRCUIT_IS_ORIGIN(circ)) { or_circuit_t *or_circ = TO_OR_CIRCUIT(circ); if (or_circ->rend_splice) { if (!or_circ->rend_splice->_base.marked_for_close) { /* do this after marking this circuit, to avoid infinite recursion. */ circuit_mark_for_close(TO_CIRCUIT(or_circ->rend_splice), reason); } or_circ->rend_splice = NULL; } } } /** Verify that cpath layer cp 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); tor_assert(cp); tor_assert(cp->magic == CRYPT_PATH_MAGIC); 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->dh_handshake_state); break; case CPATH_STATE_AWAITING_KEYS: /* tor_assert(cp->dh_handshake_state); */ break; default: log_fn(LOG_ERR, LD_BUG, "Unexpected state %d", cp->state); tor_assert(0); } tor_assert(cp->package_window >= 0); tor_assert(cp->deliver_window >= 0); } /** Verify that cpath cp 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 c has all of its invariants * correct. Trigger an assert if anything is invalid. */ void assert_circuit_ok(const circuit_t *c) { edge_connection_t *conn; const or_circuit_t *or_circ = NULL; const origin_circuit_t *origin_circ = NULL; circuit_t *nonconst_circ; tor_assert(c); tor_assert(c->magic == ORIGIN_CIRCUIT_MAGIC || c->magic == OR_CIRCUIT_MAGIC); tor_assert(c->purpose >= _CIRCUIT_PURPOSE_MIN && c->purpose <= _CIRCUIT_PURPOSE_MAX); /* Having a separate variable for this pleases GCC 4.2 in ways I hop I never * understand. -NM. */ nonconst_circ = (circuit_t*) c; if (CIRCUIT_IS_ORIGIN(c)) origin_circ = TO_ORIGIN_CIRCUIT(nonconst_circ); else or_circ = TO_OR_CIRCUIT(nonconst_circ); if (c->n_conn) { tor_assert(!memcmp(c->n_conn->identity_digest, c->n_conn_id_digest, DIGEST_LEN)); if (c->n_circ_id) tor_assert(c == circuit_get_by_circid_orconn(c->n_circ_id, c->n_conn)); } if (or_circ && or_circ->p_conn) { if (or_circ->p_circ_id) tor_assert(c == circuit_get_by_circid_orconn(or_circ->p_circ_id, or_circ->p_conn)); } #if 0 /* false now that rendezvous exits are attached to p_streams */ if (origin_circ) for (conn = origin_circ->p_streams; conn; conn = conn->next_stream) tor_assert(conn->_base.type == CONN_TYPE_AP); #endif if (or_circ) for (conn = or_circ->n_streams; conn; conn = conn->next_stream) tor_assert(conn->_base.type == CONN_TYPE_EXIT); tor_assert(c->deliver_window >= 0); tor_assert(c->package_window >= 0); if (c->state == CIRCUIT_STATE_OPEN) { tor_assert(!c->onionskin); if (or_circ) { tor_assert(or_circ->n_crypto); tor_assert(or_circ->p_crypto); tor_assert(or_circ->n_digest); tor_assert(or_circ->p_digest); } } if (c->state == CIRCUIT_STATE_OR_WAIT && !c->marked_for_close) { tor_assert(circuits_pending_or_conns && smartlist_isin(circuits_pending_or_conns, c)); } else { tor_assert(!circuits_pending_or_conns || !smartlist_isin(circuits_pending_or_conns, c)); } if (origin_circ && origin_circ->cpath) { assert_cpath_ok(origin_circ->cpath); } if (c->purpose == CIRCUIT_PURPOSE_REND_ESTABLISHED) { tor_assert(or_circ); if (!c->marked_for_close) { tor_assert(or_circ->rend_splice); tor_assert(or_circ->rend_splice->rend_splice == or_circ); } tor_assert(or_circ->rend_splice != or_circ); } else { tor_assert(!or_circ || !or_circ->rend_splice); } }