/* Copyright (c) 2001 Matej Pfajfar. * Copyright (c) 2001-2004, Roger Dingledine. * Copyright (c) 2004-2006, Roger Dingledine, Nick Mathewson. * Copyright (c) 2007-2010, The Tor Project, Inc. */ /* See LICENSE for licensing information */ /** * \file connection_or.c * \brief Functions to handle OR connections, TLS handshaking, and * cells on the network. **/ #include "or.h" #include "buffers.h" #include "circuitbuild.h" #include "command.h" #include "config.h" #include "connection.h" #include "connection_or.h" #include "control.h" #include "dirserv.h" #include "geoip.h" #include "main.h" #include "networkstatus.h" #include "nodelist.h" #include "reasons.h" #include "relay.h" #include "rephist.h" #include "router.h" #include "routerlist.h" #ifdef USE_BUFFEREVENTS #include #endif static int connection_tls_finish_handshake(or_connection_t *conn); static int connection_or_process_cells_from_inbuf(or_connection_t *conn); static int connection_or_send_versions(or_connection_t *conn); static int connection_init_or_handshake_state(or_connection_t *conn, int started_here); static int connection_or_check_valid_tls_handshake(or_connection_t *conn, int started_here, char *digest_rcvd_out); static void connection_or_tls_renegotiated_cb(tor_tls_t *tls, void *_conn); #ifdef USE_BUFFEREVENTS static void connection_or_handle_event_cb(struct bufferevent *bufev, short event, void *arg); #include /*XXXX REMOVE */ #endif /**************************************************************/ /** Map from identity digest of connected OR or desired OR to a connection_t * with that identity digest. If there is more than one such connection_t, * they form a linked list, with next_with_same_id as the next pointer. */ static digestmap_t *orconn_identity_map = NULL; /** If conn is listed in orconn_identity_map, remove it, and clear * conn->identity_digest. Otherwise do nothing. */ void connection_or_remove_from_identity_map(or_connection_t *conn) { or_connection_t *tmp; tor_assert(conn); if (!orconn_identity_map) return; tmp = digestmap_get(orconn_identity_map, conn->identity_digest); if (!tmp) { if (!tor_digest_is_zero(conn->identity_digest)) { log_warn(LD_BUG, "Didn't find connection '%s' on identity map when " "trying to remove it.", conn->nickname ? conn->nickname : "NULL"); } return; } if (conn == tmp) { if (conn->next_with_same_id) digestmap_set(orconn_identity_map, conn->identity_digest, conn->next_with_same_id); else digestmap_remove(orconn_identity_map, conn->identity_digest); } else { while (tmp->next_with_same_id) { if (tmp->next_with_same_id == conn) { tmp->next_with_same_id = conn->next_with_same_id; break; } tmp = tmp->next_with_same_id; } } memset(conn->identity_digest, 0, DIGEST_LEN); conn->next_with_same_id = NULL; } /** Remove all entries from the identity-to-orconn map, and clear * all identities in OR conns.*/ void connection_or_clear_identity_map(void) { smartlist_t *conns = get_connection_array(); SMARTLIST_FOREACH(conns, connection_t *, conn, { if (conn->type == CONN_TYPE_OR) { or_connection_t *or_conn = TO_OR_CONN(conn); memset(or_conn->identity_digest, 0, DIGEST_LEN); or_conn->next_with_same_id = NULL; } }); digestmap_free(orconn_identity_map, NULL); orconn_identity_map = NULL; } /** Change conn->identity_digest to digest, and add conn into * orconn_digest_map. */ static void connection_or_set_identity_digest(or_connection_t *conn, const char *digest) { or_connection_t *tmp; tor_assert(conn); tor_assert(digest); if (!orconn_identity_map) orconn_identity_map = digestmap_new(); if (!memcmp(conn->identity_digest, digest, DIGEST_LEN)) return; /* If the identity was set previously, remove the old mapping. */ if (! tor_digest_is_zero(conn->identity_digest)) connection_or_remove_from_identity_map(conn); memcpy(conn->identity_digest, digest, DIGEST_LEN); /* If we're setting the ID to zero, don't add a mapping. */ if (tor_digest_is_zero(digest)) return; tmp = digestmap_set(orconn_identity_map, digest, conn); conn->next_with_same_id = tmp; #if 1 /* Testing code to check for bugs in representation. */ for (; tmp; tmp = tmp->next_with_same_id) { tor_assert(!memcmp(tmp->identity_digest, digest, DIGEST_LEN)); tor_assert(tmp != conn); } #endif } /** Pack the cell_t host-order structure src into network-order * in the buffer dest. See tor-spec.txt for details about the * wire format. * * Note that this function doesn't touch dst-\>next: the caller * should set it or clear it as appropriate. */ void cell_pack(packed_cell_t *dst, const cell_t *src) { char *dest = dst->body; set_uint16(dest, htons(src->circ_id)); *(uint8_t*)(dest+2) = src->command; memcpy(dest+3, src->payload, CELL_PAYLOAD_SIZE); } /** Unpack the network-order buffer src into a host-order * cell_t structure dest. */ static void cell_unpack(cell_t *dest, const char *src) { dest->circ_id = ntohs(get_uint16(src)); dest->command = *(uint8_t*)(src+2); memcpy(dest->payload, src+3, CELL_PAYLOAD_SIZE); } /** Write the header of cell into the first VAR_CELL_HEADER_SIZE * bytes of hdr_out. */ void var_cell_pack_header(const var_cell_t *cell, char *hdr_out) { set_uint16(hdr_out, htons(cell->circ_id)); set_uint8(hdr_out+2, cell->command); set_uint16(hdr_out+3, htons(cell->payload_len)); } /** Allocate and return a new var_cell_t with payload_len bytes of * payload space. */ var_cell_t * var_cell_new(uint16_t payload_len) { var_cell_t *cell = tor_malloc(sizeof(var_cell_t)+payload_len-1); cell->payload_len = payload_len; cell->command = 0; cell->circ_id = 0; return cell; } /** Release all space held by cell. */ void var_cell_free(var_cell_t *cell) { tor_free(cell); } /** We've received an EOF from conn. Mark it for close and return. */ int connection_or_reached_eof(or_connection_t *conn) { log_info(LD_OR,"OR connection reached EOF. Closing."); connection_mark_for_close(TO_CONN(conn)); return 0; } /** Handle any new bytes that have come in on connection conn. * If conn is in 'open' state, hand it to * connection_or_process_cells_from_inbuf() * (else do nothing). */ int connection_or_process_inbuf(or_connection_t *conn) { int ret; tor_assert(conn); switch (conn->_base.state) { case OR_CONN_STATE_PROXY_HANDSHAKING: ret = connection_read_proxy_handshake(TO_CONN(conn)); /* start TLS after handshake completion, or deal with error */ if (ret == 1) { tor_assert(TO_CONN(conn)->proxy_state == PROXY_CONNECTED); if (connection_tls_start_handshake(conn, 0) < 0) ret = -1; } if (ret < 0) { connection_mark_for_close(TO_CONN(conn)); } return ret; #ifdef USE_BUFFEREVENTS case OR_CONN_STATE_TLS_SERVER_RENEGOTIATING: if (tor_tls_server_got_renegotiate(conn->tls)) connection_or_tls_renegotiated_cb(conn->tls, conn); if (conn->_base.marked_for_close) return 0; /* fall through. */ #endif case OR_CONN_STATE_OPEN: case OR_CONN_STATE_OR_HANDSHAKING: return connection_or_process_cells_from_inbuf(conn); default: return 0; /* don't do anything */ } } /** When adding cells to an OR connection's outbuf, keep adding until the * outbuf is at least this long, or we run out of cells. */ #define OR_CONN_HIGHWATER (32*1024) /** Add cells to an OR connection's outbuf whenever the outbuf's data length * drops below this size. */ #define OR_CONN_LOWWATER (16*1024) /** Called whenever we have flushed some data on an or_conn: add more data * from active circuits. */ int connection_or_flushed_some(or_connection_t *conn) { size_t datalen = connection_get_outbuf_len(TO_CONN(conn)); /* If we're under the low water mark, add cells until we're just over the * high water mark. */ if (datalen < OR_CONN_LOWWATER) { ssize_t n = CEIL_DIV(OR_CONN_HIGHWATER - datalen, CELL_NETWORK_SIZE); time_t now = approx_time(); while (conn->active_circuits && n > 0) { int flushed; flushed = connection_or_flush_from_first_active_circuit(conn, 1, now); n -= flushed; } } return 0; } /** Connection conn has finished writing and has no bytes left on * its outbuf. * * Otherwise it's in state "open": stop writing and return. * * If conn is broken, mark it for close and return -1, else * return 0. */ int connection_or_finished_flushing(or_connection_t *conn) { tor_assert(conn); assert_connection_ok(TO_CONN(conn),0); switch (conn->_base.state) { case OR_CONN_STATE_PROXY_HANDSHAKING: case OR_CONN_STATE_OPEN: case OR_CONN_STATE_OR_HANDSHAKING: break; default: log_err(LD_BUG,"Called in unexpected state %d.", conn->_base.state); tor_fragile_assert(); return -1; } return 0; } /** Connected handler for OR connections: begin the TLS handshake. */ int connection_or_finished_connecting(or_connection_t *or_conn) { int proxy_type; connection_t *conn; tor_assert(or_conn); conn = TO_CONN(or_conn); tor_assert(conn->state == OR_CONN_STATE_CONNECTING); log_debug(LD_HANDSHAKE,"OR connect() to router at %s:%u finished.", conn->address,conn->port); control_event_bootstrap(BOOTSTRAP_STATUS_HANDSHAKE, 0); proxy_type = PROXY_NONE; if (get_options()->HTTPSProxy) proxy_type = PROXY_CONNECT; else if (get_options()->Socks4Proxy) proxy_type = PROXY_SOCKS4; else if (get_options()->Socks5Proxy) proxy_type = PROXY_SOCKS5; if (proxy_type != PROXY_NONE) { /* start proxy handshake */ if (connection_proxy_connect(conn, proxy_type) < 0) { connection_mark_for_close(conn); return -1; } connection_start_reading(conn); conn->state = OR_CONN_STATE_PROXY_HANDSHAKING; return 0; } if (connection_tls_start_handshake(or_conn, 0) < 0) { /* TLS handshaking error of some kind. */ connection_mark_for_close(conn); return -1; } return 0; } /** Return 1 if identity digest id_digest is known to be a * currently or recently running relay. Otherwise return 0. */ int connection_or_digest_is_known_relay(const char *id_digest) { if (router_get_consensus_status_by_id(id_digest)) return 1; /* It's in the consensus: "yes" */ if (router_get_by_id_digest(id_digest)) return 1; /* Not in the consensus, but we have a descriptor for * it. Probably it was in a recent consensus. "Yes". */ return 0; } /** Set the per-conn read and write limits for conn. If it's a known * relay, we will rely on the global read and write buckets, so give it * per-conn limits that are big enough they'll never matter. But if it's * not a known relay, first check if we set PerConnBwRate/Burst, then * check if the consensus sets them, else default to 'big enough'. */ static void connection_or_update_token_buckets_helper(or_connection_t *conn, int reset, or_options_t *options) { int rate, burst; /* per-connection rate limiting params */ if (connection_or_digest_is_known_relay(conn->identity_digest)) { /* It's in the consensus, or we have a descriptor for it meaning it * was probably in a recent consensus. It's a recognized relay: * give it full bandwidth. */ rate = (int)options->BandwidthRate; burst = (int)options->BandwidthBurst; } else { /* Not a recognized relay. Squeeze it down based on the suggested * bandwidth parameters in the consensus, but allow local config * options to override. */ rate = options->PerConnBWRate ? (int)options->PerConnBWRate : (int)networkstatus_get_param(NULL, "perconnbwrate", (int)options->BandwidthRate); burst = options->PerConnBWBurst ? (int)options->PerConnBWBurst : (int)networkstatus_get_param(NULL, "perconnbwburst", (int)options->BandwidthBurst); } conn->bandwidthrate = rate; conn->bandwidthburst = burst; #ifdef USE_BUFFEREVENTS { const struct timeval *tick = tor_libevent_get_one_tick_timeout(); struct ev_token_bucket_cfg *cfg, *old_cfg; int rate_per_tick = rate / TOR_LIBEVENT_TICKS_PER_SECOND; cfg = ev_token_bucket_cfg_new(rate_per_tick, burst, rate_per_tick, burst, tick); old_cfg = conn->bucket_cfg; if (conn->_base.bufev) bufferevent_set_rate_limit(conn->_base.bufev, cfg); if (old_cfg) ev_token_bucket_cfg_free(old_cfg); conn->bucket_cfg = cfg; (void) reset; /* No way to do this with libevent yet. */ } #else if (reset) { /* set up the token buckets to be full */ conn->read_bucket = conn->write_bucket = burst; return; } /* If the new token bucket is smaller, take out the extra tokens. * (If it's larger, don't -- the buckets can grow to reach the cap.) */ if (conn->read_bucket > burst) conn->read_bucket = burst; if (conn->write_bucket > burst) conn->write_bucket = burst; #endif } /** Either our set of relays or our per-conn rate limits have changed. * Go through all the OR connections and update their token buckets. */ void connection_or_update_token_buckets(smartlist_t *conns, or_options_t *options) { SMARTLIST_FOREACH(conns, connection_t *, conn, { if (connection_speaks_cells(conn)) connection_or_update_token_buckets_helper(TO_OR_CONN(conn), 0, options); }); } /** If we don't necessarily know the router we're connecting to, but we * have an addr/port/id_digest, then fill in as much as we can. Start * by checking to see if this describes a router we know. */ static void connection_or_init_conn_from_address(or_connection_t *conn, const tor_addr_t *addr, uint16_t port, const char *id_digest, int started_here) { const node_t *r = node_get_by_id(id_digest); connection_or_set_identity_digest(conn, id_digest); connection_or_update_token_buckets_helper(conn, 1, get_options()); conn->_base.port = port; tor_addr_copy(&conn->_base.addr, addr); tor_addr_copy(&conn->real_addr, addr); if (r) { tor_addr_t node_addr; node_get_addr(r, &node_addr); /* XXXX proposal 118 will make this more complex. */ if (tor_addr_eq(&conn->_base.addr, &node_addr)) conn->is_canonical = 1; if (!started_here) { /* Override the addr/port, so our log messages will make sense. * This is dangerous, since if we ever try looking up a conn by * its actual addr/port, we won't remember. Careful! */ /* XXXX arma: this is stupid, and it's the reason we need real_addr * to track is_canonical properly. What requires it? */ /* XXXX i believe the reason we did this, originally, is because * we wanted to log what OR a connection was to, and if we logged the * right IP address and port 56244, that wouldn't be as helpful. now we * log the "right" port too, so we know if it's moria1 or moria2. */ tor_addr_copy(&conn->_base.addr, &node_addr); conn->_base.port = node_get_orport(r); } conn->nickname = tor_strdup(node_get_nickname(r)); tor_free(conn->_base.address); conn->_base.address = tor_dup_addr(&node_addr); } else { const char *n; /* If we're an authoritative directory server, we may know a * nickname for this router. */ n = dirserv_get_nickname_by_digest(id_digest); if (n) { conn->nickname = tor_strdup(n); } else { conn->nickname = tor_malloc(HEX_DIGEST_LEN+2); conn->nickname[0] = '$'; base16_encode(conn->nickname+1, HEX_DIGEST_LEN+1, conn->identity_digest, DIGEST_LEN); } tor_free(conn->_base.address); conn->_base.address = tor_dup_addr(addr); } } /** Return true iff a is "better" than b for new circuits. * * A more canonical connection is always better than a less canonical * connection. That aside, a connection is better if it has circuits and the * other does not, or if it was created more recently. * * Requires that both input connections are open; not is_bad_for_new_circs, * and not impossibly non-canonical. * * If forgive_new_connections is true, then we do not call * abetter than b simply because b has no circuits, * unless b is also relatively old. */ static int connection_or_is_better(time_t now, const or_connection_t *a, const or_connection_t *b, int forgive_new_connections) { int newer; /** Do not definitively deprecate a new connection with no circuits on it * until this much time has passed. */ #define NEW_CONN_GRACE_PERIOD (15*60) if (b->is_canonical && !a->is_canonical) return 0; /* A canonical connection is better than a non-canonical * one, no matter how new it is or which has circuits. */ newer = b->_base.timestamp_created < a->_base.timestamp_created; if ( /* We prefer canonical connections regardless of newness. */ (!b->is_canonical && a->is_canonical) || /* If both have circuits we prefer the newer: */ (b->n_circuits && a->n_circuits && newer) || /* If neither has circuits we prefer the newer: */ (!b->n_circuits && !a->n_circuits && newer)) return 1; /* If one has no circuits and the other does... */ if (!b->n_circuits && a->n_circuits) { /* Then it's bad, unless it's in its grace period and we're forgiving. */ if (forgive_new_connections && now < b->_base.timestamp_created + NEW_CONN_GRACE_PERIOD) return 0; else return 1; } return 0; } /** Return the OR connection we should use to extend a circuit to the router * whose identity is digest, and whose address we believe (or have been * told in an extend cell) is target_addr. If there is no good * connection, set *msg_out to a message describing the connection's * state and our next action, and set launch_out to a boolean for * whether we should launch a new connection or not. */ or_connection_t * connection_or_get_for_extend(const char *digest, const tor_addr_t *target_addr, const char **msg_out, int *launch_out) { or_connection_t *conn, *best=NULL; int n_inprogress_goodaddr = 0, n_old = 0, n_noncanonical = 0, n_possible = 0; time_t now = approx_time(); tor_assert(msg_out); tor_assert(launch_out); if (!orconn_identity_map) { *msg_out = "Router not connected (nothing is). Connecting."; *launch_out = 1; return NULL; } conn = digestmap_get(orconn_identity_map, digest); for (; conn; conn = conn->next_with_same_id) { tor_assert(conn->_base.magic == OR_CONNECTION_MAGIC); tor_assert(conn->_base.type == CONN_TYPE_OR); tor_assert(!memcmp(conn->identity_digest, digest, DIGEST_LEN)); if (conn->_base.marked_for_close) continue; /* Never return a non-open connection. */ if (conn->_base.state != OR_CONN_STATE_OPEN) { /* If the address matches, don't launch a new connection for this * circuit. */ if (!tor_addr_compare(&conn->real_addr, target_addr, CMP_EXACT)) ++n_inprogress_goodaddr; continue; } /* Never return a connection that shouldn't be used for circs. */ if (conn->is_bad_for_new_circs) { ++n_old; continue; } /* Never return a non-canonical connection using a recent link protocol * if the address is not what we wanted. * * (For old link protocols, we can't rely on is_canonical getting * set properly if we're talking to the right address, since we might * have an out-of-date descriptor, and we will get no NETINFO cell to * tell us about the right address.) */ if (!conn->is_canonical && conn->link_proto >= 2 && tor_addr_compare(&conn->real_addr, target_addr, CMP_EXACT)) { ++n_noncanonical; continue; } ++n_possible; if (!best) { best = conn; /* If we have no 'best' so far, this one is good enough. */ continue; } if (connection_or_is_better(now, conn, best, 0)) best = conn; } if (best) { *msg_out = "Connection is fine; using it."; *launch_out = 0; return best; } else if (n_inprogress_goodaddr) { *msg_out = "Connection in progress; waiting."; *launch_out = 0; return NULL; } else if (n_old || n_noncanonical) { *msg_out = "Connections all too old, or too non-canonical. " " Launching a new one."; *launch_out = 1; return NULL; } else { *msg_out = "Not connected. Connecting."; *launch_out = 1; return NULL; } } /** How old do we let a connection to an OR get before deciding it's * too old for new circuits? */ #define TIME_BEFORE_OR_CONN_IS_TOO_OLD (60*60*24*7) /** Given the head of the linked list for all the or_connections with a given * identity, set elements of that list as is_bad_for_new_circs as * appropriate. Helper for connection_or_set_bad_connections(). * * Specifically, we set the is_bad_for_new_circs flag on: * - all connections if force is true. * - all connections that are too old. * - all open non-canonical connections for which a canonical connection * exists to the same router. * - all open canonical connections for which a 'better' canonical * connection exists to the same router. * - all open non-canonical connections for which a 'better' non-canonical * connection exists to the same router at the same address. * * See connection_or_is_better() for our idea of what makes one OR connection * better than another. */ static void connection_or_group_set_badness(or_connection_t *head, int force) { or_connection_t *or_conn = NULL, *best = NULL; int n_old = 0, n_inprogress = 0, n_canonical = 0, n_other = 0; time_t now = time(NULL); /* Pass 1: expire everything that's old, and see what the status of * everything else is. */ for (or_conn = head; or_conn; or_conn = or_conn->next_with_same_id) { if (or_conn->_base.marked_for_close || or_conn->is_bad_for_new_circs) continue; if (force || or_conn->_base.timestamp_created + TIME_BEFORE_OR_CONN_IS_TOO_OLD < now) { log_info(LD_OR, "Marking OR conn to %s:%d as too old for new circuits " "(fd %d, %d secs old).", or_conn->_base.address, or_conn->_base.port, or_conn->_base.s, (int)(now - or_conn->_base.timestamp_created)); or_conn->is_bad_for_new_circs = 1; } if (or_conn->is_bad_for_new_circs) { ++n_old; } else if (or_conn->_base.state != OR_CONN_STATE_OPEN) { ++n_inprogress; } else if (or_conn->is_canonical) { ++n_canonical; } else { ++n_other; } } /* Pass 2: We know how about how good the best connection is. * expire everything that's worse, and find the very best if we can. */ for (or_conn = head; or_conn; or_conn = or_conn->next_with_same_id) { if (or_conn->_base.marked_for_close || or_conn->is_bad_for_new_circs) continue; /* This one doesn't need to be marked bad. */ if (or_conn->_base.state != OR_CONN_STATE_OPEN) continue; /* Don't mark anything bad until we have seen what happens * when the connection finishes. */ if (n_canonical && !or_conn->is_canonical) { /* We have at least one open canonical connection to this router, * and this one is open but not canonical. Mark it bad. */ log_info(LD_OR, "Marking OR conn to %s:%d as unsuitable for new circuits: " "(fd %d, %d secs old). It is not canonical, and we have " "another connection to that OR that is.", or_conn->_base.address, or_conn->_base.port, or_conn->_base.s, (int)(now - or_conn->_base.timestamp_created)); or_conn->is_bad_for_new_circs = 1; continue; } if (!best || connection_or_is_better(now, or_conn, best, 0)) best = or_conn; } if (!best) return; /* Pass 3: One connection to OR is best. If it's canonical, mark as bad * every other open connection. If it's non-canonical, mark as bad * every other open connection to the same address. * * XXXX This isn't optimal; if we have connections to an OR at multiple * addresses, we'd like to pick the best _for each address_, and mark as * bad every open connection that isn't best for its address. But this * can only occur in cases where the other OR is old (so we have no * canonical connection to it), or where all the connections to the OR are * at noncanonical addresses and we have no good direct connection (which * means we aren't at risk of attaching circuits to it anyway). As * 0.1.2.x dies out, the first case will go away, and the second one is * "mostly harmless", so a fix can wait until somebody is bored. */ for (or_conn = head; or_conn; or_conn = or_conn->next_with_same_id) { if (or_conn->_base.marked_for_close || or_conn->is_bad_for_new_circs || or_conn->_base.state != OR_CONN_STATE_OPEN) continue; if (or_conn != best && connection_or_is_better(now, best, or_conn, 1)) { /* This isn't the best conn, _and_ the best conn is better than it, even when we're being forgiving. */ if (best->is_canonical) { log_info(LD_OR, "Marking OR conn to %s:%d as unsuitable for new circuits: " "(fd %d, %d secs old). We have a better canonical one " "(fd %d; %d secs old).", or_conn->_base.address, or_conn->_base.port, or_conn->_base.s, (int)(now - or_conn->_base.timestamp_created), best->_base.s, (int)(now - best->_base.timestamp_created)); or_conn->is_bad_for_new_circs = 1; } else if (!tor_addr_compare(&or_conn->real_addr, &best->real_addr, CMP_EXACT)) { log_info(LD_OR, "Marking OR conn to %s:%d as unsuitable for new circuits: " "(fd %d, %d secs old). We have a better one with the " "same address (fd %d; %d secs old).", or_conn->_base.address, or_conn->_base.port, or_conn->_base.s, (int)(now - or_conn->_base.timestamp_created), best->_base.s, (int)(now - best->_base.timestamp_created)); or_conn->is_bad_for_new_circs = 1; } } } } /** Go through all the OR connections (or if digest is non-NULL, just * the OR connections with that digest), and set the is_bad_for_new_circs * flag based on the rules in connection_or_group_set_badness() (or just * always set it if force is true). */ void connection_or_set_bad_connections(const char *digest, int force) { if (!orconn_identity_map) return; DIGESTMAP_FOREACH(orconn_identity_map, identity, or_connection_t *, conn) { if (!digest || !memcmp(digest, conn->identity_digest, DIGEST_LEN)) connection_or_group_set_badness(conn, force); } DIGESTMAP_FOREACH_END; } /** conn is in the 'connecting' state, and it failed to complete * a TCP connection. Send notifications appropriately. * * reason specifies the or_conn_end_reason for the failure; * msg specifies the strerror-style error message. */ void connection_or_connect_failed(or_connection_t *conn, int reason, const char *msg) { control_event_or_conn_status(conn, OR_CONN_EVENT_FAILED, reason); if (!authdir_mode_tests_reachability(get_options())) control_event_bootstrap_problem(msg, reason); } /** Launch a new OR connection to addr:port and expect to * handshake with an OR with identity digest id_digest. * * If id_digest is me, do nothing. If we're already connected to it, * return that connection. If the connect() is in progress, set the * new conn's state to 'connecting' and return it. If connect() succeeds, * call connection_tls_start_handshake() on it. * * This function is called from router_retry_connections(), for * ORs connecting to ORs, and circuit_establish_circuit(), for * OPs connecting to ORs. * * Return the launched conn, or NULL if it failed. */ or_connection_t * connection_or_connect(const tor_addr_t *_addr, uint16_t port, const char *id_digest) { or_connection_t *conn; or_options_t *options = get_options(); int socket_error = 0; int using_proxy = 0; tor_addr_t addr; tor_assert(_addr); tor_assert(id_digest); tor_addr_copy(&addr, _addr); if (server_mode(options) && router_digest_is_me(id_digest)) { log_info(LD_PROTOCOL,"Client asked me to connect to myself. Refusing."); return NULL; } conn = or_connection_new(AF_INET); /* set up conn so it's got all the data we need to remember */ connection_or_init_conn_from_address(conn, &addr, port, id_digest, 1); conn->_base.state = OR_CONN_STATE_CONNECTING; control_event_or_conn_status(conn, OR_CONN_EVENT_LAUNCHED, 0); /* use a proxy server if available */ if (options->HTTPSProxy) { using_proxy = 1; tor_addr_copy(&addr, &options->HTTPSProxyAddr); port = options->HTTPSProxyPort; } else if (options->Socks4Proxy) { using_proxy = 1; tor_addr_copy(&addr, &options->Socks4ProxyAddr); port = options->Socks4ProxyPort; } else if (options->Socks5Proxy) { using_proxy = 1; tor_addr_copy(&addr, &options->Socks5ProxyAddr); port = options->Socks5ProxyPort; } switch (connection_connect(TO_CONN(conn), conn->_base.address, &addr, port, &socket_error)) { case -1: /* If the connection failed immediately, and we're using * a proxy, our proxy is down. Don't blame the Tor server. */ if (!using_proxy) entry_guard_register_connect_status(conn->identity_digest, 0, 1, time(NULL)); connection_or_connect_failed(conn, errno_to_orconn_end_reason(socket_error), tor_socket_strerror(socket_error)); connection_free(TO_CONN(conn)); return NULL; case 0: connection_watch_events(TO_CONN(conn), READ_EVENT | WRITE_EVENT); /* writable indicates finish, readable indicates broken link, error indicates broken link on windows */ return conn; /* case 1: fall through */ } if (connection_or_finished_connecting(conn) < 0) { /* already marked for close */ return NULL; } return conn; } /** Begin the tls handshake with conn. receiving is 0 if * we initiated the connection, else it's 1. * * Assign a new tls object to conn->tls, begin reading on conn, and * pass conn to connection_tls_continue_handshake(). * * Return -1 if conn is broken, else return 0. */ int connection_tls_start_handshake(or_connection_t *conn, int receiving) { conn->_base.state = OR_CONN_STATE_TLS_HANDSHAKING; tor_assert(!conn->tls); conn->tls = tor_tls_new(conn->_base.s, receiving); tor_tls_set_logged_address(conn->tls, // XXX client and relay? escaped_safe_str(conn->_base.address)); if (!conn->tls) { log_warn(LD_BUG,"tor_tls_new failed. Closing."); return -1; } #ifdef USE_BUFFEREVENTS if (connection_type_uses_bufferevent(TO_CONN(conn))) { const int filtering = get_options()->_UseFilteringSSLBufferevents; struct bufferevent *b = tor_tls_init_bufferevent(conn->tls, conn->_base.bufev, conn->_base.s, receiving, filtering); if (!b) { log_warn(LD_BUG,"tor_tls_init_bufferevent failed. Closing."); return -1; } conn->_base.bufev = b; if (conn->bucket_cfg) bufferevent_set_rate_limit(conn->_base.bufev, conn->bucket_cfg); connection_enable_rate_limiting(TO_CONN(conn)); connection_configure_bufferevent_callbacks(TO_CONN(conn)); bufferevent_setcb(b, connection_handle_read_cb, connection_handle_write_cb, connection_or_handle_event_cb,/* overriding this one*/ TO_CONN(conn)); } #endif connection_start_reading(TO_CONN(conn)); log_debug(LD_HANDSHAKE,"starting TLS handshake on fd %d", conn->_base.s); note_crypto_pk_op(receiving ? TLS_HANDSHAKE_S : TLS_HANDSHAKE_C); IF_HAS_BUFFEREVENT(TO_CONN(conn), { /* ???? */; }) ELSE_IF_NO_BUFFEREVENT { if (connection_tls_continue_handshake(conn) < 0) return -1; } return 0; } /** Invoked on the server side from inside tor_tls_read() when the server * gets a successful TLS renegotiation from the client. */ static void connection_or_tls_renegotiated_cb(tor_tls_t *tls, void *_conn) { or_connection_t *conn = _conn; (void)tls; /* Don't invoke this again. */ tor_tls_set_renegotiate_callback(tls, NULL, NULL); tor_tls_block_renegotiation(tls); if (connection_tls_finish_handshake(conn) < 0) { /* XXXX_TLS double-check that it's ok to do this from inside read. */ /* XXXX_TLS double-check that this verifies certificates. */ connection_mark_for_close(TO_CONN(conn)); } } /** Move forward with the tls handshake. If it finishes, hand * conn to connection_tls_finish_handshake(). * * Return -1 if conn is broken, else return 0. */ int connection_tls_continue_handshake(or_connection_t *conn) { int result; check_no_tls_errors(); again: if (conn->_base.state == OR_CONN_STATE_TLS_CLIENT_RENEGOTIATING) { // log_notice(LD_OR, "Renegotiate with %p", conn->tls); result = tor_tls_renegotiate(conn->tls); // log_notice(LD_OR, "Result: %d", result); } else { tor_assert(conn->_base.state == OR_CONN_STATE_TLS_HANDSHAKING); // log_notice(LD_OR, "Continue handshake with %p", conn->tls); result = tor_tls_handshake(conn->tls); // log_notice(LD_OR, "Result: %d", result); } switch (result) { CASE_TOR_TLS_ERROR_ANY: log_info(LD_OR,"tls error [%s]. breaking connection.", tor_tls_err_to_string(result)); return -1; case TOR_TLS_DONE: if (! tor_tls_used_v1_handshake(conn->tls)) { if (!tor_tls_is_server(conn->tls)) { if (conn->_base.state == OR_CONN_STATE_TLS_HANDSHAKING) { // log_notice(LD_OR,"Done. state was TLS_HANDSHAKING."); conn->_base.state = OR_CONN_STATE_TLS_CLIENT_RENEGOTIATING; goto again; } // log_notice(LD_OR,"Done. state was %d.", conn->_base.state); } else { /* improved handshake, but not a client. */ tor_tls_set_renegotiate_callback(conn->tls, connection_or_tls_renegotiated_cb, conn); conn->_base.state = OR_CONN_STATE_TLS_SERVER_RENEGOTIATING; connection_stop_writing(TO_CONN(conn)); connection_start_reading(TO_CONN(conn)); return 0; } } return connection_tls_finish_handshake(conn); case TOR_TLS_WANTWRITE: connection_start_writing(TO_CONN(conn)); log_debug(LD_OR,"wanted write"); return 0; case TOR_TLS_WANTREAD: /* handshaking conns are *always* reading */ log_debug(LD_OR,"wanted read"); return 0; case TOR_TLS_CLOSE: log_info(LD_OR,"tls closed. breaking connection."); return -1; } return 0; } #ifdef USE_BUFFEREVENTS static void connection_or_handle_event_cb(struct bufferevent *bufev, short event, void *arg) { struct or_connection_t *conn = TO_OR_CONN(arg); /* XXXX cut-and-paste code; should become a function. */ if (event & BEV_EVENT_CONNECTED) { if (conn->_base.state == OR_CONN_STATE_TLS_HANDSHAKING) { if (tor_tls_finish_handshake(conn->tls) < 0) { log_warn(LD_OR, "Problem finishing handshake"); connection_mark_for_close(TO_CONN(conn)); return; } } if (! tor_tls_used_v1_handshake(conn->tls)) { if (!tor_tls_is_server(conn->tls)) { if (conn->_base.state == OR_CONN_STATE_TLS_HANDSHAKING) { conn->_base.state = OR_CONN_STATE_TLS_CLIENT_RENEGOTIATING; tor_tls_unblock_renegotiation(conn->tls); if (bufferevent_ssl_renegotiate(conn->_base.bufev)<0) { log_warn(LD_OR, "Start_renegotiating went badly."); connection_mark_for_close(TO_CONN(conn)); } tor_tls_unblock_renegotiation(conn->tls); return; /* ???? */ } } else if (tor_tls_get_num_server_handshakes(conn->tls) == 1) { /* improved handshake, as a server. Only got one handshake, so * wait for the next one. */ tor_tls_set_renegotiate_callback(conn->tls, connection_or_tls_renegotiated_cb, conn); conn->_base.state = OR_CONN_STATE_TLS_SERVER_RENEGOTIATING; /* return 0; */ return; /* ???? */ } else { const int handshakes = tor_tls_get_num_server_handshakes(conn->tls); tor_assert(handshakes >= 2); if (handshakes == 2) { /* improved handshake, as a server. Two handshakes happened already, * so we treat renegotiation as done. */ connection_or_tls_renegotiated_cb(conn->tls, conn); } else { log_warn(LD_OR, "More than two handshakes done on connection. " "Closing."); connection_mark_for_close(TO_CONN(conn)); } return; } } connection_watch_events(TO_CONN(conn), READ_EVENT|WRITE_EVENT); if (connection_tls_finish_handshake(conn) < 0) connection_mark_for_close(TO_CONN(conn)); /* ???? */ return; } if (event & BEV_EVENT_ERROR) { unsigned long err; while ((err = bufferevent_get_openssl_error(bufev))) { tor_tls_log_one_error(conn->tls, err, LOG_WARN, LD_OR, "handshaking (with bufferevent)"); } } connection_handle_event_cb(bufev, event, arg); } #endif /** Return 1 if we initiated this connection, or 0 if it started * out as an incoming connection. */ int connection_or_nonopen_was_started_here(or_connection_t *conn) { tor_assert(conn->_base.type == CONN_TYPE_OR); if (!conn->tls) return 1; /* it's still in proxy states or something */ if (conn->handshake_state) return conn->handshake_state->started_here; return !tor_tls_is_server(conn->tls); } /** Conn just completed its handshake. Return 0 if all is well, and * return -1 if he is lying, broken, or otherwise something is wrong. * * If we initiated this connection (started_here is true), make sure * the other side sent a correctly formed certificate. If I initiated the * connection, make sure it's the right guy. * * Otherwise (if we _didn't_ initiate this connection), it's okay for * the certificate to be weird or absent. * * If we return 0, and the certificate is as expected, write a hash of the * identity key into digest_rcvd_out, which must have DIGEST_LEN * space in it. * If the certificate is invalid or missing on an incoming connection, * we return 0 and set digest_rcvd_out to DIGEST_LEN NUL bytes. * (If we return -1, the contents of this buffer are undefined.) * * As side effects, * 1) Set conn->circ_id_type according to tor-spec.txt. * 2) If we're an authdirserver and we initiated the connection: drop all * descriptors that claim to be on that IP/port but that aren't * this guy; and note that this guy is reachable. * 3) If this is a bridge and we didn't configure its identity * fingerprint, remember the keyid we just learned. */ static int connection_or_check_valid_tls_handshake(or_connection_t *conn, int started_here, char *digest_rcvd_out) { crypto_pk_env_t *identity_rcvd=NULL; or_options_t *options = get_options(); int severity = server_mode(options) ? LOG_PROTOCOL_WARN : LOG_WARN; const char *safe_address = started_here ? conn->_base.address : safe_str_client(conn->_base.address); const char *conn_type = started_here ? "outgoing" : "incoming"; crypto_pk_env_t *our_identity = started_here ? get_tlsclient_identity_key() : get_server_identity_key(); int has_cert = 0, has_identity=0; check_no_tls_errors(); has_cert = tor_tls_peer_has_cert(conn->tls); if (started_here && !has_cert) { log_info(LD_HANDSHAKE,"Tried connecting to router at %s:%d, but it didn't " "send a cert! Closing.", safe_address, conn->_base.port); return -1; } else if (!has_cert) { log_debug(LD_HANDSHAKE,"Got incoming connection with no certificate. " "That's ok."); } check_no_tls_errors(); if (has_cert) { int v = tor_tls_verify(started_here?severity:LOG_INFO, conn->tls, &identity_rcvd); if (started_here && v<0) { log_fn(severity,LD_HANDSHAKE,"Tried connecting to router at %s:%d: It" " has a cert but it's invalid. Closing.", safe_address, conn->_base.port); return -1; } else if (v<0) { log_info(LD_HANDSHAKE,"Incoming connection gave us an invalid cert " "chain; ignoring."); } else { log_debug(LD_HANDSHAKE, "The certificate seems to be valid on %s connection " "with %s:%d", conn_type, safe_address, conn->_base.port); } check_no_tls_errors(); } if (identity_rcvd) { has_identity = 1; crypto_pk_get_digest(identity_rcvd, digest_rcvd_out); if (crypto_pk_cmp_keys(our_identity, identity_rcvd)<0) { conn->circ_id_type = CIRC_ID_TYPE_LOWER; } else { conn->circ_id_type = CIRC_ID_TYPE_HIGHER; } crypto_free_pk_env(identity_rcvd); } else { memset(digest_rcvd_out, 0, DIGEST_LEN); conn->circ_id_type = CIRC_ID_TYPE_NEITHER; } if (started_here && tor_digest_is_zero(conn->identity_digest)) { connection_or_set_identity_digest(conn, digest_rcvd_out); tor_free(conn->nickname); conn->nickname = tor_malloc(HEX_DIGEST_LEN+2); conn->nickname[0] = '$'; base16_encode(conn->nickname+1, HEX_DIGEST_LEN+1, conn->identity_digest, DIGEST_LEN); log_info(LD_HANDSHAKE, "Connected to router %s at %s:%d without knowing " "its key. Hoping for the best.", conn->nickname, conn->_base.address, conn->_base.port); /* if it's a bridge and we didn't know its identity fingerprint, now * we do -- remember it for future attempts. */ learned_router_identity(&conn->_base.addr, conn->_base.port, digest_rcvd_out); } if (started_here) { int as_advertised = 1; tor_assert(has_cert); tor_assert(has_identity); if (memcmp(digest_rcvd_out, conn->identity_digest, DIGEST_LEN)) { /* I was aiming for a particular digest. I didn't get it! */ char seen[HEX_DIGEST_LEN+1]; char expected[HEX_DIGEST_LEN+1]; base16_encode(seen, sizeof(seen), digest_rcvd_out, DIGEST_LEN); base16_encode(expected, sizeof(expected), conn->identity_digest, DIGEST_LEN); log_fn(severity, LD_HANDSHAKE, "Tried connecting to router at %s:%d, but identity key was not " "as expected: wanted %s but got %s.", conn->_base.address, conn->_base.port, expected, seen); entry_guard_register_connect_status(conn->identity_digest, 0, 1, time(NULL)); control_event_or_conn_status(conn, OR_CONN_EVENT_FAILED, END_OR_CONN_REASON_OR_IDENTITY); if (!authdir_mode_tests_reachability(options)) control_event_bootstrap_problem("foo", END_OR_CONN_REASON_OR_IDENTITY); as_advertised = 0; } if (authdir_mode_tests_reachability(options)) { /* We initiated this connection to address:port. Drop all routers * with the same address:port and a different key. */ dirserv_orconn_tls_done(conn->_base.address, conn->_base.port, digest_rcvd_out, as_advertised); } if (!as_advertised) return -1; } return 0; } /** The tls handshake is finished. * * Make sure we are happy with the person we just handshaked with. * * If he initiated the connection, make sure he's not already connected, * then initialize conn from the information in router. * * If all is successful, call circuit_n_conn_done() to handle events * that have been pending on the _base.address)); directory_set_dirty(); if (connection_or_check_valid_tls_handshake(conn, started_here, digest_rcvd) < 0) return -1; circuit_build_times_network_is_live(&circ_times); if (tor_tls_used_v1_handshake(conn->tls)) { conn->link_proto = 1; if (!started_here) { connection_or_init_conn_from_address(conn, &conn->_base.addr, conn->_base.port, digest_rcvd, 0); } tor_tls_block_renegotiation(conn->tls); return connection_or_set_state_open(conn); } else { conn->_base.state = OR_CONN_STATE_OR_HANDSHAKING; if (connection_init_or_handshake_state(conn, started_here) < 0) return -1; if (!started_here) { connection_or_init_conn_from_address(conn, &conn->_base.addr, conn->_base.port, digest_rcvd, 0); } return connection_or_send_versions(conn); } } /** Allocate a new connection handshake state for the connection * conn. Return 0 on success, -1 on failure. */ static int connection_init_or_handshake_state(or_connection_t *conn, int started_here) { or_handshake_state_t *s; s = conn->handshake_state = tor_malloc_zero(sizeof(or_handshake_state_t)); s->started_here = started_here ? 1 : 0; return 0; } /** Free all storage held by state. */ void or_handshake_state_free(or_handshake_state_t *state) { if (!state) return; memset(state, 0xBE, sizeof(or_handshake_state_t)); tor_free(state); } /** Set conn's state to OR_CONN_STATE_OPEN, and tell other subsystems * as appropriate. Called when we are done with all TLS and OR handshaking. */ int connection_or_set_state_open(or_connection_t *conn) { int started_here = connection_or_nonopen_was_started_here(conn); time_t now = time(NULL); conn->_base.state = OR_CONN_STATE_OPEN; control_event_or_conn_status(conn, OR_CONN_EVENT_CONNECTED, 0); if (started_here) { circuit_build_times_network_is_live(&circ_times); rep_hist_note_connect_succeeded(conn->identity_digest, now); if (entry_guard_register_connect_status(conn->identity_digest, 1, 0, now) < 0) { /* Close any circuits pending on this conn. We leave it in state * 'open' though, because it didn't actually *fail* -- we just * chose not to use it. (Otherwise * connection_about_to_close_connection() will call a big pile of * functions to indicate we shouldn't try it again.) */ log_debug(LD_OR, "New entry guard was reachable, but closing this " "connection so we can retry the earlier entry guards."); circuit_n_conn_done(conn, 0); return -1; } router_set_status(conn->identity_digest, 1); } else { /* only report it to the geoip module if it's not a known router */ if (!router_get_by_id_digest(conn->identity_digest)) { if (tor_addr_family(&TO_CONN(conn)->addr) == AF_INET) { /*XXXX IP6 support ipv6 geoip.*/ uint32_t a = tor_addr_to_ipv4h(&TO_CONN(conn)->addr); geoip_note_client_seen(GEOIP_CLIENT_CONNECT, a, now); } } } or_handshake_state_free(conn->handshake_state); conn->handshake_state = NULL; IF_HAS_BUFFEREVENT(TO_CONN(conn), { connection_watch_events(TO_CONN(conn), READ_EVENT|WRITE_EVENT); }) ELSE_IF_NO_BUFFEREVENT { connection_start_reading(TO_CONN(conn)); } circuit_n_conn_done(conn, 1); /* send the pending creates, if any. */ return 0; } /** Pack cell into wire-format, and write it onto conn's outbuf. * For cells that use or affect a circuit, this should only be called by * connection_or_flush_from_first_active_circuit(). */ void connection_or_write_cell_to_buf(const cell_t *cell, or_connection_t *conn) { packed_cell_t networkcell; tor_assert(cell); tor_assert(conn); cell_pack(&networkcell, cell); connection_write_to_buf(networkcell.body, CELL_NETWORK_SIZE, TO_CONN(conn)); if (cell->command != CELL_PADDING) conn->timestamp_last_added_nonpadding = approx_time(); } /** Pack a variable-length cell into wire-format, and write it onto * conn's outbuf. Right now, this DOES NOT support cells that * affect a circuit. */ void connection_or_write_var_cell_to_buf(const var_cell_t *cell, or_connection_t *conn) { char hdr[VAR_CELL_HEADER_SIZE]; tor_assert(cell); tor_assert(conn); var_cell_pack_header(cell, hdr); connection_write_to_buf(hdr, sizeof(hdr), TO_CONN(conn)); connection_write_to_buf(cell->payload, cell->payload_len, TO_CONN(conn)); if (cell->command != CELL_PADDING) conn->timestamp_last_added_nonpadding = approx_time(); } /** See whether there's a variable-length cell waiting on or_conn's * inbuf. Return values as for fetch_var_cell_from_buf(). */ static int connection_fetch_var_cell_from_buf(or_connection_t *or_conn, var_cell_t **out) { connection_t *conn = TO_CONN(or_conn); IF_HAS_BUFFEREVENT(conn, { struct evbuffer *input = bufferevent_get_input(conn->bufev); return fetch_var_cell_from_evbuffer(input, out, or_conn->link_proto); }) ELSE_IF_NO_BUFFEREVENT { return fetch_var_cell_from_buf(conn->inbuf, out, or_conn->link_proto); } } /** Process cells from conn's inbuf. * * Loop: while inbuf contains a cell, pull it off the inbuf, unpack it, * and hand it to command_process_cell(). * * Always return 0. */ static int connection_or_process_cells_from_inbuf(or_connection_t *conn) { var_cell_t *var_cell; while (1) { log_debug(LD_OR, "%d: starting, inbuf_datalen %d (%d pending in tls object).", conn->_base.s,(int)connection_get_inbuf_len(TO_CONN(conn)), tor_tls_get_pending_bytes(conn->tls)); if (connection_fetch_var_cell_from_buf(conn, &var_cell)) { if (!var_cell) return 0; /* not yet. */ circuit_build_times_network_is_live(&circ_times); command_process_var_cell(var_cell, conn); var_cell_free(var_cell); } else { char buf[CELL_NETWORK_SIZE]; cell_t cell; if (connection_get_inbuf_len(TO_CONN(conn)) < CELL_NETWORK_SIZE) /* whole response available? */ return 0; /* not yet */ circuit_build_times_network_is_live(&circ_times); connection_fetch_from_buf(buf, CELL_NETWORK_SIZE, TO_CONN(conn)); /* retrieve cell info from buf (create the host-order struct from the * network-order string) */ cell_unpack(&cell, buf); command_process_cell(&cell, conn); } } } /** Write a destroy cell with circ ID circ_id and reason reason * onto OR connection conn. Don't perform range-checking on reason: * we may want to propagate reasons from other cells. * * Return 0. */ int connection_or_send_destroy(circid_t circ_id, or_connection_t *conn, int reason) { cell_t cell; tor_assert(conn); memset(&cell, 0, sizeof(cell_t)); cell.circ_id = circ_id; cell.command = CELL_DESTROY; cell.payload[0] = (uint8_t) reason; log_debug(LD_OR,"Sending destroy (circID %d).", circ_id); connection_or_write_cell_to_buf(&cell, conn); return 0; } /** Array of recognized link protocol versions. */ static const uint16_t or_protocol_versions[] = { 1, 2 }; /** Number of versions in or_protocol_versions. */ static const int n_or_protocol_versions = (int)( sizeof(or_protocol_versions)/sizeof(uint16_t) ); /** Return true iff v is a link protocol version that this Tor * implementation believes it can support. */ int is_or_protocol_version_known(uint16_t v) { int i; for (i = 0; i < n_or_protocol_versions; ++i) { if (or_protocol_versions[i] == v) return 1; } return 0; } /** Send a VERSIONS cell on conn, telling the other host about the * link protocol versions that this Tor can support. */ static int connection_or_send_versions(or_connection_t *conn) { var_cell_t *cell; int i; tor_assert(conn->handshake_state && !conn->handshake_state->sent_versions_at); cell = var_cell_new(n_or_protocol_versions * 2); cell->command = CELL_VERSIONS; for (i = 0; i < n_or_protocol_versions; ++i) { uint16_t v = or_protocol_versions[i]; set_uint16(cell->payload+(2*i), htons(v)); } connection_or_write_var_cell_to_buf(cell, conn); conn->handshake_state->sent_versions_at = time(NULL); var_cell_free(cell); return 0; } /** Send a NETINFO cell on conn, telling the other server what we know * about their address, our address, and the current time. */ int connection_or_send_netinfo(or_connection_t *conn) { cell_t cell; time_t now = time(NULL); const routerinfo_t *me; int len; char *out; memset(&cell, 0, sizeof(cell_t)); cell.command = CELL_NETINFO; /* Timestamp. */ set_uint32(cell.payload, htonl((uint32_t)now)); /* Their address. */ out = cell.payload + 4; len = append_address_to_payload(out, &conn->_base.addr); if (len<0) return -1; out += len; /* My address. */ if ((me = router_get_my_routerinfo())) { tor_addr_t my_addr; *out++ = 1; /* only one address is supported. */ tor_addr_from_ipv4h(&my_addr, me->addr); len = append_address_to_payload(out, &my_addr); if (len < 0) return -1; out += len; } else { *out++ = 0; } connection_or_write_cell_to_buf(&cell, conn); return 0; }