diff options
Diffstat (limited to 'src/or/rendclient.c')
| -rw-r--r-- | src/or/rendclient.c | 539 |
1 files changed, 356 insertions, 183 deletions
diff --git a/src/or/rendclient.c b/src/or/rendclient.c index 19a8cef1bf..609c45c71d 100644 --- a/src/or/rendclient.c +++ b/src/or/rendclient.c @@ -1,5 +1,5 @@ /* Copyright (c) 2004-2006, Roger Dingledine, Nick Mathewson. - * Copyright (c) 2007-2013, The Tor Project, Inc. */ + * Copyright (c) 2007-2016, The Tor Project, Inc. */ /* See LICENSE for licensing information */ /** @@ -38,6 +38,7 @@ void rend_client_purge_state(void) { rend_cache_purge(); + rend_cache_failure_purge(); rend_client_cancel_descriptor_fetches(); rend_client_purge_last_hid_serv_requests(); } @@ -51,7 +52,7 @@ rend_client_introcirc_has_opened(origin_circuit_t *circ) tor_assert(circ->cpath); log_info(LD_REND,"introcirc is open"); - connection_ap_attach_pending(); + connection_ap_attach_pending(1); } /** Send the establish-rendezvous cell along a rendezvous circuit. if @@ -64,11 +65,7 @@ rend_client_send_establish_rendezvous(origin_circuit_t *circ) tor_assert(circ->rend_data); log_info(LD_REND, "Sending an ESTABLISH_RENDEZVOUS cell"); - if (crypto_rand(circ->rend_data->rend_cookie, REND_COOKIE_LEN) < 0) { - log_warn(LD_BUG, "Internal error: Couldn't produce random cookie."); - circuit_mark_for_close(TO_CIRCUIT(circ), END_CIRC_REASON_INTERNAL); - return -1; - } + crypto_rand(circ->rend_data->rend_cookie, REND_COOKIE_LEN); /* Set timestamp_dirty, because circuit_expire_building expects it, * and the rend cookie also means we've used the circ. */ @@ -130,16 +127,6 @@ rend_client_reextend_intro_circuit(origin_circuit_t *circ) return result; } -/** Return true iff we should send timestamps in our INTRODUCE1 cells */ -static int -rend_client_should_send_timestamp(void) -{ - if (get_options()->Support022HiddenServices >= 0) - return get_options()->Support022HiddenServices; - - return networkstatus_get_param(NULL, "Support022HiddenServices", 1, 0, 1); -} - /** Called when we're trying to connect an ap conn; sends an INTRODUCE1 cell * down introcirc if possible. */ @@ -151,7 +138,7 @@ rend_client_send_introduction(origin_circuit_t *introcirc, int r, v3_shift = 0; char payload[RELAY_PAYLOAD_SIZE]; char tmp[RELAY_PAYLOAD_SIZE]; - rend_cache_entry_t *entry; + rend_cache_entry_t *entry = NULL; crypt_path_t *cpath; off_t dh_offset; crypto_pk_t *intro_key = NULL; @@ -168,8 +155,13 @@ rend_client_send_introduction(origin_circuit_t *introcirc, tor_assert(!(rendcirc->build_state->onehop_tunnel)); #endif - if (rend_cache_lookup_entry(introcirc->rend_data->onion_address, -1, - &entry) < 1) { + r = rend_cache_lookup_entry(introcirc->rend_data->onion_address, -1, + &entry); + /* An invalid onion address is not possible else we have a big issue. */ + tor_assert(r != -EINVAL); + if (r < 0 || !rend_client_any_intro_points_usable(entry)) { + /* If the descriptor is not found or the intro points are not usable + * anymore, trigger a fetch. */ log_info(LD_REND, "query %s didn't have valid rend desc in cache. " "Refetching descriptor.", @@ -181,6 +173,7 @@ rend_client_send_introduction(origin_circuit_t *introcirc, while ((conn = connection_get_by_type_state_rendquery(CONN_TYPE_AP, AP_CONN_STATE_CIRCUIT_WAIT, introcirc->rend_data->onion_address))) { + connection_ap_mark_as_non_pending_circuit(TO_ENTRY_CONN(conn)); conn->state = AP_CONN_STATE_RENDDESC_WAIT; } } @@ -189,7 +182,7 @@ rend_client_send_introduction(origin_circuit_t *introcirc, goto cleanup; } - /* first 20 bytes of payload are the hash of Bob's pk */ + /* first 20 bytes of payload are the hash of the service's pk */ intro_key = NULL; SMARTLIST_FOREACH(entry->parsed->intro_nodes, rend_intro_point_t *, intro, { @@ -251,14 +244,8 @@ rend_client_send_introduction(origin_circuit_t *introcirc, REND_DESC_COOKIE_LEN); v3_shift += 2+REND_DESC_COOKIE_LEN; } - if (rend_client_should_send_timestamp()) { - uint32_t now = (uint32_t)time(NULL); - now += 300; - now -= now % 600; - set_uint32(tmp+v3_shift+1, htonl(now)); - } else { - set_uint32(tmp+v3_shift+1, 0); - } + /* Once this held a timestamp. */ + set_uint32(tmp+v3_shift+1, 0); v3_shift += 4; } /* if version 2 only write version number */ else if (entry->parsed->protocols & (1<<2)) { @@ -370,15 +357,13 @@ rend_client_rendcirc_has_opened(origin_circuit_t *circ) } /** - * Called to close other intro circuits we launched in parallel - * due to timeout. + * Called to close other intro circuits we launched in parallel. */ static void rend_client_close_other_intros(const char *onion_address) { - circuit_t *c; /* abort parallel intro circs, if any */ - TOR_LIST_FOREACH(c, circuit_get_global_list(), head) { + SMARTLIST_FOREACH_BEGIN(circuit_get_global_list(), circuit_t *, c) { if ((c->purpose == CIRCUIT_PURPOSE_C_INTRODUCING || c->purpose == CIRCUIT_PURPOSE_C_INTRODUCE_ACK_WAIT) && !c->marked_for_close && CIRCUIT_IS_ORIGIN(c)) { @@ -389,10 +374,11 @@ rend_client_close_other_intros(const char *onion_address) log_info(LD_REND|LD_CIRC, "Closing introduction circuit %d that we " "built in parallel (Purpose %d).", oc->global_identifier, c->purpose); - circuit_mark_for_close(c, END_CIRC_REASON_TIMEOUT); + circuit_mark_for_close(c, END_CIRC_REASON_IP_NOW_REDUNDANT); } } } + SMARTLIST_FOREACH_END(c); } /** Called when get an ACK or a NAK for a REND_INTRODUCE1 cell. @@ -468,6 +454,13 @@ rend_client_introduction_acked(origin_circuit_t *circ, /* XXXX If that call failed, should we close the rend circuit, * too? */ return result; + } else { + /* Close circuit because no more intro points are usable thus not + * useful anymore. Change it's purpose before so we don't report an + * intro point failure again triggering an extra descriptor fetch. */ + circuit_change_purpose(TO_CIRCUIT(circ), + CIRCUIT_PURPOSE_C_INTRODUCE_ACKED); + circuit_mark_for_close(TO_CIRCUIT(circ), END_CIRC_REASON_FINISHED); } } return 0; @@ -479,9 +472,8 @@ rend_client_introduction_acked(origin_circuit_t *circ, /** Contains the last request times to hidden service directories for * certain queries; each key is a string consisting of the - * concatenation of a base32-encoded HS directory identity digest, a - * base32-encoded HS descriptor ID, and a hidden service address - * (without the ".onion" part); each value is a pointer to a time_t + * concatenation of a base32-encoded HS directory identity digest and + * base32-encoded HS descriptor ID; each value is a pointer to a time_t * holding the time of the last request for that descriptor ID to that * HS directory. */ static strmap_t *last_hid_serv_requests_ = NULL; @@ -497,19 +489,16 @@ get_last_hid_serv_requests(void) } #define LAST_HID_SERV_REQUEST_KEY_LEN (REND_DESC_ID_V2_LEN_BASE32 + \ - REND_DESC_ID_V2_LEN_BASE32 + \ - REND_SERVICE_ID_LEN_BASE32) + REND_DESC_ID_V2_LEN_BASE32) /** Look up the last request time to hidden service directory <b>hs_dir</b> - * for descriptor ID <b>desc_id_base32</b> for the service specified in - * <b>rend_query</b>. If <b>set</b> is non-zero, - * assign the current time <b>now</b> and return that. Otherwise, return - * the most recent request time, or 0 if no such request has been sent - * before. */ + * for descriptor ID <b>desc_id_base32</b>. If <b>set</b> is non-zero, + * assign the current time <b>now</b> and return that. Otherwise, return the + * most recent request time, or 0 if no such request has been sent before. + */ static time_t lookup_last_hid_serv_request(routerstatus_t *hs_dir, const char *desc_id_base32, - const rend_data_t *rend_query, time_t now, int set) { char hsdir_id_base32[REND_DESC_ID_V2_LEN_BASE32 + 1]; @@ -518,10 +507,9 @@ lookup_last_hid_serv_request(routerstatus_t *hs_dir, strmap_t *last_hid_serv_requests = get_last_hid_serv_requests(); base32_encode(hsdir_id_base32, sizeof(hsdir_id_base32), hs_dir->identity_digest, DIGEST_LEN); - tor_snprintf(hsdir_desc_comb_id, sizeof(hsdir_desc_comb_id), "%s%s%s", + tor_snprintf(hsdir_desc_comb_id, sizeof(hsdir_desc_comb_id), "%s%s", hsdir_id_base32, - desc_id_base32, - rend_query->onion_address); + desc_id_base32); /* XXX023 tor_assert(strlen(hsdir_desc_comb_id) == LAST_HID_SERV_REQUEST_KEY_LEN); */ if (set) { @@ -562,15 +550,23 @@ directory_clean_last_hid_serv_requests(time_t now) } } -/** Remove all requests related to the hidden service named - * <b>onion_address</b> from the history of times of requests to - * hidden service directories. */ +/** Remove all requests related to the descriptor ID <b>desc_id</b> from the + * history of times of requests to hidden service directories. + * <b>desc_id</b> is an unencoded descriptor ID of size DIGEST_LEN. + * + * This is called from rend_client_note_connection_attempt_ended(), which + * must be idempotent, so any future changes to this function must leave it + * idempotent too. */ static void -purge_hid_serv_from_last_hid_serv_requests(const char *onion_address) +purge_hid_serv_from_last_hid_serv_requests(const char *desc_id) { strmap_iter_t *iter; strmap_t *last_hid_serv_requests = get_last_hid_serv_requests(); - /* XXX023 tor_assert(strlen(onion_address) == REND_SERVICE_ID_LEN_BASE32); */ + char desc_id_base32[REND_DESC_ID_V2_LEN_BASE32 + 1]; + + /* Key is stored with the base32 encoded desc_id. */ + base32_encode(desc_id_base32, sizeof(desc_id_base32), desc_id, + DIGEST_LEN); for (iter = strmap_iter_init(last_hid_serv_requests); !strmap_iter_done(iter); ) { const char *key; @@ -578,9 +574,9 @@ purge_hid_serv_from_last_hid_serv_requests(const char *onion_address) strmap_iter_get(iter, &key, &val); /* XXX023 tor_assert(strlen(key) == LAST_HID_SERV_REQUEST_KEY_LEN); */ if (tor_memeq(key + LAST_HID_SERV_REQUEST_KEY_LEN - - REND_SERVICE_ID_LEN_BASE32, - onion_address, - REND_SERVICE_ID_LEN_BASE32)) { + REND_DESC_ID_V2_LEN_BASE32, + desc_id_base32, + REND_DESC_ID_V2_LEN_BASE32)) { iter = strmap_iter_next_rmv(last_hid_serv_requests, iter); tor_free(val); } else { @@ -609,59 +605,53 @@ rend_client_purge_last_hid_serv_requests(void) } } -/** Determine the responsible hidden service directories for <b>desc_id</b> - * and fetch the descriptor with that ID from one of them. Only - * send a request to a hidden service directory that we have not yet tried - * during this attempt to connect to this hidden service; on success, return 1, - * in the case that no hidden service directory is left to ask for the - * descriptor, return 0, and in case of a failure -1. */ -static int -directory_get_from_hs_dir(const char *desc_id, const rend_data_t *rend_query) +/** This returns a good valid hs dir that should be used for the given + * descriptor id. + * + * Return NULL on error else the hsdir node pointer. */ +static routerstatus_t * +pick_hsdir(const char *desc_id, const char *desc_id_base32) { smartlist_t *responsible_dirs = smartlist_new(); smartlist_t *usable_responsible_dirs = smartlist_new(); const or_options_t *options = get_options(); routerstatus_t *hs_dir; - char desc_id_base32[REND_DESC_ID_V2_LEN_BASE32 + 1]; time_t now = time(NULL); - char descriptor_cookie_base64[3*REND_DESC_COOKIE_LEN_BASE64]; - const int tor2web_mode = options->Tor2webMode; int excluded_some; - tor_assert(desc_id); - tor_assert(rend_query); - /* Determine responsible dirs. Even if we can't get all we want, - * work with the ones we have. If it's empty, we'll notice below. */ - hid_serv_get_responsible_directories(responsible_dirs, desc_id); - base32_encode(desc_id_base32, sizeof(desc_id_base32), - desc_id, DIGEST_LEN); + tor_assert(desc_id); + tor_assert(desc_id_base32); - /* Only select those hidden service directories to which we did not send - * a request recently and for which we have a router descriptor here. */ + /* Determine responsible dirs. Even if we can't get all we want, work with + * the ones we have. If it's empty, we'll notice below. */ + hid_serv_get_responsible_directories(responsible_dirs, desc_id); /* Clean request history first. */ directory_clean_last_hid_serv_requests(now); - SMARTLIST_FOREACH(responsible_dirs, routerstatus_t *, dir, { - time_t last = lookup_last_hid_serv_request( - dir, desc_id_base32, rend_query, 0, 0); - const node_t *node = node_get_by_id(dir->identity_digest); - if (last + REND_HID_SERV_DIR_REQUERY_PERIOD >= now || - !node || !node_has_descriptor(node)) { - SMARTLIST_DEL_CURRENT(responsible_dirs, dir); - continue; - } - if (! routerset_contains_node(options->ExcludeNodes, node)) { - smartlist_add(usable_responsible_dirs, dir); - } - }); + /* Only select those hidden service directories to which we did not send a + * request recently and for which we have a router descriptor here. */ + SMARTLIST_FOREACH_BEGIN(responsible_dirs, routerstatus_t *, dir) { + time_t last = lookup_last_hid_serv_request(dir, desc_id_base32, + 0, 0); + const node_t *node = node_get_by_id(dir->identity_digest); + if (last + REND_HID_SERV_DIR_REQUERY_PERIOD >= now || + !node || !node_has_descriptor(node)) { + SMARTLIST_DEL_CURRENT(responsible_dirs, dir); + continue; + } + if (!routerset_contains_node(options->ExcludeNodes, node)) { + smartlist_add(usable_responsible_dirs, dir); + } + } SMARTLIST_FOREACH_END(dir); excluded_some = smartlist_len(usable_responsible_dirs) < smartlist_len(responsible_dirs); hs_dir = smartlist_choose(usable_responsible_dirs); - if (! hs_dir && ! options->StrictNodes) + if (!hs_dir && !options->StrictNodes) { hs_dir = smartlist_choose(responsible_dirs); + } smartlist_free(responsible_dirs); smartlist_free(usable_responsible_dirs); @@ -674,23 +664,69 @@ directory_get_from_hs_dir(const char *desc_id, const rend_data_t *rend_query) "requested hidden service: they are all either down or " "excluded, and StrictNodes is set."); } - return 0; + } else { + /* Remember that we are requesting a descriptor from this hidden service + * directory now. */ + lookup_last_hid_serv_request(hs_dir, desc_id_base32, now, 1); + } + + return hs_dir; +} + +/** Determine the responsible hidden service directories for <b>desc_id</b> + * and fetch the descriptor with that ID from one of them. Only + * send a request to a hidden service directory that we have not yet tried + * during this attempt to connect to this hidden service; on success, return 1, + * in the case that no hidden service directory is left to ask for the + * descriptor, return 0, and in case of a failure -1. */ +static int +directory_get_from_hs_dir(const char *desc_id, const rend_data_t *rend_query, + routerstatus_t *rs_hsdir) +{ + routerstatus_t *hs_dir = rs_hsdir; + char *hsdir_fp; + char desc_id_base32[REND_DESC_ID_V2_LEN_BASE32 + 1]; + char descriptor_cookie_base64[3*REND_DESC_COOKIE_LEN_BASE64]; +#ifdef ENABLE_TOR2WEB_MODE + const int tor2web_mode = get_options()->Tor2webMode; + const int how_to_fetch = tor2web_mode ? DIRIND_ONEHOP : DIRIND_ANONYMOUS; +#else + const int how_to_fetch = DIRIND_ANONYMOUS; +#endif + + tor_assert(desc_id); + + base32_encode(desc_id_base32, sizeof(desc_id_base32), + desc_id, DIGEST_LEN); + + /* Automatically pick an hs dir if none given. */ + if (!rs_hsdir) { + hs_dir = pick_hsdir(desc_id, desc_id_base32); + if (!hs_dir) { + /* No suitable hs dir can be found, stop right now. */ + return 0; + } } - /* Remember that we are requesting a descriptor from this hidden service - * directory now. */ - lookup_last_hid_serv_request(hs_dir, desc_id_base32, rend_query, now, 1); + /* Add a copy of the HSDir identity digest to the query so we can track it + * on the control port. */ + hsdir_fp = tor_memdup(hs_dir->identity_digest, + sizeof(hs_dir->identity_digest)); + smartlist_add(rend_query->hsdirs_fp, hsdir_fp); - /* Encode descriptor cookie for logging purposes. */ + /* Encode descriptor cookie for logging purposes. Also, if the cookie is + * malformed, no fetch is triggered thus this needs to be done before the + * fetch request. */ if (rend_query->auth_type != REND_NO_AUTH) { if (base64_encode(descriptor_cookie_base64, sizeof(descriptor_cookie_base64), - rend_query->descriptor_cookie, REND_DESC_COOKIE_LEN)<0) { + rend_query->descriptor_cookie, REND_DESC_COOKIE_LEN, + 0)<0) { log_warn(LD_BUG, "Could not base64-encode descriptor cookie."); return 0; } - /* Remove == signs and newline. */ - descriptor_cookie_base64[strlen(descriptor_cookie_base64)-3] = '\0'; + /* Remove == signs. */ + descriptor_cookie_base64[strlen(descriptor_cookie_base64)-2] = '\0'; } else { strlcpy(descriptor_cookie_base64, "(none)", sizeof(descriptor_cookie_base64)); @@ -702,7 +738,7 @@ directory_get_from_hs_dir(const char *desc_id, const rend_data_t *rend_query) directory_initiate_command_routerstatus_rend(hs_dir, DIR_PURPOSE_FETCH_RENDDESC_V2, ROUTER_PURPOSE_GENERAL, - tor2web_mode?DIRIND_ONEHOP:DIRIND_ANONYMOUS, + how_to_fetch, desc_id_base32, NULL, 0, 0, rend_query); @@ -721,16 +757,143 @@ directory_get_from_hs_dir(const char *desc_id, const rend_data_t *rend_query) return 1; } +/** Fetch a v2 descriptor using the given descriptor id. If any hsdir(s) are + * given, they will be used instead. + * + * On success, 1 is returned. If no hidden service is left to ask, return 0. + * On error, -1 is returned. */ +static int +fetch_v2_desc_by_descid(const char *desc_id, const rend_data_t *rend_query, + smartlist_t *hsdirs) +{ + int ret; + + tor_assert(rend_query); + + if (!hsdirs) { + ret = directory_get_from_hs_dir(desc_id, rend_query, NULL); + goto end; /* either success or failure, but we're done */ + } + + /* Using the given hsdir list, trigger a fetch on each of them. */ + SMARTLIST_FOREACH_BEGIN(hsdirs, routerstatus_t *, hs_dir) { + /* This should always be a success. */ + ret = directory_get_from_hs_dir(desc_id, rend_query, hs_dir); + tor_assert(ret); + } SMARTLIST_FOREACH_END(hs_dir); + + /* Everything went well. */ + ret = 0; + + end: + return ret; +} + +/** Fetch a v2 descriptor using the onion address in the given query object. + * This will compute the descriptor id for each replicas and fetch it on the + * given hsdir(s) if any or the responsible ones that are choosen + * automatically. + * + * On success, 1 is returned. If no hidden service is left to ask, return 0. + * On error, -1 is returned. */ +static int +fetch_v2_desc_by_addr(rend_data_t *query, smartlist_t *hsdirs) +{ + char descriptor_id[DIGEST_LEN]; + int replicas_left_to_try[REND_NUMBER_OF_NON_CONSECUTIVE_REPLICAS]; + int i, tries_left, ret; + + tor_assert(query); + + /* Randomly iterate over the replicas until a descriptor can be fetched + * from one of the consecutive nodes, or no options are left. */ + for (i = 0; i < REND_NUMBER_OF_NON_CONSECUTIVE_REPLICAS; i++) { + replicas_left_to_try[i] = i; + } + + tries_left = REND_NUMBER_OF_NON_CONSECUTIVE_REPLICAS; + while (tries_left > 0) { + int rand = crypto_rand_int(tries_left); + int chosen_replica = replicas_left_to_try[rand]; + replicas_left_to_try[rand] = replicas_left_to_try[--tries_left]; + + ret = rend_compute_v2_desc_id(descriptor_id, query->onion_address, + query->auth_type == REND_STEALTH_AUTH ? + query->descriptor_cookie : NULL, + time(NULL), chosen_replica); + if (ret < 0) { + /* Normally, on failure the descriptor_id is untouched but let's be + * safe in general in case the function changes at some point. */ + goto end; + } + + if (tor_memcmp(descriptor_id, query->descriptor_id[chosen_replica], + sizeof(descriptor_id)) != 0) { + /* Not equal from what we currently have so purge the last hid serv + * request cache and update the descriptor ID with the new value. */ + purge_hid_serv_from_last_hid_serv_requests( + query->descriptor_id[chosen_replica]); + memcpy(query->descriptor_id[chosen_replica], descriptor_id, + sizeof(query->descriptor_id[chosen_replica])); + } + + /* Trigger the fetch with the computed descriptor ID. */ + ret = fetch_v2_desc_by_descid(descriptor_id, query, hsdirs); + if (ret != 0) { + /* Either on success or failure, as long as we tried a fetch we are + * done here. */ + goto end; + } + } + + /* If we come here, there are no hidden service directories left. */ + log_info(LD_REND, "Could not pick one of the responsible hidden " + "service directories to fetch descriptors, because " + "we already tried them all unsuccessfully."); + ret = 0; + + end: + memwipe(descriptor_id, 0, sizeof(descriptor_id)); + return ret; +} + +/** Fetch a v2 descriptor using the given query. If any hsdir are specified, + * use them for the fetch. + * + * On success, 1 is returned. If no hidden service is left to ask, return 0. + * On error, -1 is returned. */ +int +rend_client_fetch_v2_desc(rend_data_t *query, smartlist_t *hsdirs) +{ + int ret; + + tor_assert(query); + + /* Depending on what's available in the rend data query object, we will + * trigger a fetch by HS address or using a descriptor ID. */ + + if (query->onion_address[0] != '\0') { + ret = fetch_v2_desc_by_addr(query, hsdirs); + } else if (!tor_digest_is_zero(query->desc_id_fetch)) { + ret = fetch_v2_desc_by_descid(query->desc_id_fetch, query, hsdirs); + } else { + /* Query data is invalid. */ + ret = -1; + goto error; + } + + error: + return ret; +} + /** Unless we already have a descriptor for <b>rend_query</b> with at least * one (possibly) working introduction point in it, start a connection to a * hidden service directory to fetch a v2 rendezvous service descriptor. */ void -rend_client_refetch_v2_renddesc(const rend_data_t *rend_query) +rend_client_refetch_v2_renddesc(rend_data_t *rend_query) { - char descriptor_id[DIGEST_LEN]; - int replicas_left_to_try[REND_NUMBER_OF_NON_CONSECUTIVE_REPLICAS]; - int i, tries_left; rend_cache_entry_t *e = NULL; + tor_assert(rend_query); /* Are we configured to fetch descriptors? */ if (!get_options()->FetchHidServDescriptors) { @@ -739,7 +902,7 @@ rend_client_refetch_v2_renddesc(const rend_data_t *rend_query) return; } /* Before fetching, check if we already have a usable descriptor here. */ - if (rend_cache_lookup_entry(rend_query->onion_address, -1, &e) > 0 && + if (rend_cache_lookup_entry(rend_query->onion_address, -1, &e) == 0 && rend_client_any_intro_points_usable(e)) { log_info(LD_REND, "We would fetch a v2 rendezvous descriptor, but we " "already have a usable descriptor here. Not fetching."); @@ -747,44 +910,11 @@ rend_client_refetch_v2_renddesc(const rend_data_t *rend_query) } log_debug(LD_REND, "Fetching v2 rendezvous descriptor for service %s", safe_str_client(rend_query->onion_address)); - /* Randomly iterate over the replicas until a descriptor can be fetched - * from one of the consecutive nodes, or no options are left. */ - tries_left = REND_NUMBER_OF_NON_CONSECUTIVE_REPLICAS; - for (i = 0; i < REND_NUMBER_OF_NON_CONSECUTIVE_REPLICAS; i++) - replicas_left_to_try[i] = i; - while (tries_left > 0) { - int rand = crypto_rand_int(tries_left); - int chosen_replica = replicas_left_to_try[rand]; - replicas_left_to_try[rand] = replicas_left_to_try[--tries_left]; - - if (rend_compute_v2_desc_id(descriptor_id, rend_query->onion_address, - rend_query->auth_type == REND_STEALTH_AUTH ? - rend_query->descriptor_cookie : NULL, - time(NULL), chosen_replica) < 0) { - log_warn(LD_REND, "Internal error: Computing v2 rendezvous " - "descriptor ID did not succeed."); - /* - * Hmm, can this write anything to descriptor_id and still fail? - * Let's clear it just to be safe. - * - * From here on, any returns should goto done which clears - * descriptor_id so we don't leave key-derived material on the stack. - */ - goto done; - } - if (directory_get_from_hs_dir(descriptor_id, rend_query) != 0) - goto done; /* either success or failure, but we're done */ - } - /* If we come here, there are no hidden service directories left. */ - log_info(LD_REND, "Could not pick one of the responsible hidden " - "service directories to fetch descriptors, because " - "we already tried them all unsuccessfully."); - /* Close pending connections. */ - rend_client_desc_trynow(rend_query->onion_address); - - done: - memwipe(descriptor_id, 0, sizeof(descriptor_id)); + rend_client_fetch_v2_desc(rend_query, NULL); + /* We don't need to look the error code because either on failure or + * success, the necessary steps to continue the HS connection will be + * triggered once the descriptor arrives or if all fetch failed. */ return; } @@ -845,7 +975,7 @@ rend_client_cancel_descriptor_fetches(void) */ int rend_client_report_intro_point_failure(extend_info_t *failed_intro, - const rend_data_t *rend_query, + rend_data_t *rend_query, unsigned int failure_type) { int i, r; @@ -853,17 +983,26 @@ rend_client_report_intro_point_failure(extend_info_t *failed_intro, connection_t *conn; r = rend_cache_lookup_entry(rend_query->onion_address, -1, &ent); - if (r<0) { - log_warn(LD_BUG, "Malformed service ID %s.", - escaped_safe_str_client(rend_query->onion_address)); - return -1; - } - if (r==0) { - log_info(LD_REND, "Unknown service %s. Re-fetching descriptor.", - escaped_safe_str_client(rend_query->onion_address)); - rend_client_refetch_v2_renddesc(rend_query); - return 0; + if (r < 0) { + /* Either invalid onion address or cache entry not found. */ + switch (-r) { + case EINVAL: + log_warn(LD_BUG, "Malformed service ID %s.", + escaped_safe_str_client(rend_query->onion_address)); + return -1; + case ENOENT: + log_info(LD_REND, "Unknown service %s. Re-fetching descriptor.", + escaped_safe_str_client(rend_query->onion_address)); + rend_client_refetch_v2_renddesc(rend_query); + return 0; + default: + log_warn(LD_BUG, "Unknown cache lookup returned code: %d", r); + return -1; + } } + /* The intro points are not checked here if they are usable or not because + * this is called when an intro point circuit is closed thus there must be + * at least one intro point that is usable and is about to be flagged. */ for (i = 0; i < smartlist_len(ent->parsed->intro_nodes); i++) { rend_intro_point_t *intro = smartlist_get(ent->parsed->intro_nodes, i); @@ -876,6 +1015,9 @@ rend_client_report_intro_point_failure(extend_info_t *failed_intro, tor_fragile_assert(); /* fall through */ case INTRO_POINT_FAILURE_GENERIC: + rend_cache_intro_failure_note(failure_type, + (uint8_t *)failed_intro->identity_digest, + rend_query->onion_address); rend_intro_point_free(intro); smartlist_del(ent->parsed->intro_nodes, i); break; @@ -891,6 +1033,10 @@ rend_client_report_intro_point_failure(extend_info_t *failed_intro, intro->unreachable_count, zap_intro_point ? " Removing from descriptor.": ""); if (zap_intro_point) { + rend_cache_intro_failure_note( + failure_type, + (uint8_t *) failed_intro->identity_digest, + rend_query->onion_address); rend_intro_point_free(intro); smartlist_del(ent->parsed->intro_nodes, i); } @@ -908,9 +1054,11 @@ rend_client_report_intro_point_failure(extend_info_t *failed_intro, rend_client_refetch_v2_renddesc(rend_query); /* move all pending streams back to renddesc_wait */ + /* NOTE: We can now do this faster, if we use pending_entry_connections */ while ((conn = connection_get_by_type_state_rendquery(CONN_TYPE_AP, AP_CONN_STATE_CIRCUIT_WAIT, rend_query->onion_address))) { + connection_ap_mark_as_non_pending_circuit(TO_ENTRY_CONN(conn)); conn->state = AP_CONN_STATE_RENDDESC_WAIT; } @@ -946,9 +1094,9 @@ rend_client_rendezvous_acked(origin_circuit_t *circ, const uint8_t *request, circ->base_.timestamp_dirty = time(NULL); /* From a path bias point of view, this circuit is now successfully used. - * Waiting any longer opens us up to attacks from Bob. He could induce - * Alice to attempt to connect to his hidden service and never reply - * to her rend requests */ + * Waiting any longer opens us up to attacks from malicious hidden services. + * They could induce the client to attempt to connect to their hidden + * service and never reply to the client's rend requests */ pathbias_mark_use_success(circ); /* XXXX This is a pretty brute-force approach. It'd be better to @@ -956,11 +1104,11 @@ rend_client_rendezvous_acked(origin_circuit_t *circ, const uint8_t *request, * than trying to attach them all. See comments bug 743. */ /* If we already have the introduction circuit built, make sure we send * the INTRODUCE cell _now_ */ - connection_ap_attach_pending(); + connection_ap_attach_pending(1); return 0; } -/** Bob sent us a rendezvous cell; join the circuits. */ +/** The service sent us a rendezvous cell; join the circuits. */ int rend_client_receive_rendezvous(origin_circuit_t *circ, const uint8_t *request, size_t request_len) @@ -985,7 +1133,8 @@ rend_client_receive_rendezvous(origin_circuit_t *circ, const uint8_t *request, log_info(LD_REND,"Got RENDEZVOUS2 cell from hidden service."); - /* first DH_KEY_LEN bytes are g^y from bob. Finish the dh handshake...*/ + /* first DH_KEY_LEN bytes are g^y from the service. Finish the dh + * handshake...*/ tor_assert(circ->build_state); tor_assert(circ->build_state->pending_final_cpath); hop = circ->build_state->pending_final_cpath; @@ -1014,7 +1163,7 @@ rend_client_receive_rendezvous(origin_circuit_t *circ, const uint8_t *request, circuit_change_purpose(TO_CIRCUIT(circ), CIRCUIT_PURPOSE_C_REND_JOINED); hop->state = CPATH_STATE_OPEN; /* set the windows to default. these are the windows - * that alice thinks bob has. + * that the client thinks the service has. */ hop->package_window = circuit_initial_package_window(); hop->deliver_window = CIRCWINDOW_START; @@ -1062,7 +1211,7 @@ rend_client_desc_trynow(const char *query) continue; assert_connection_ok(base_conn, now); if (rend_cache_lookup_entry(rend_data->onion_address, -1, - &entry) == 1 && + &entry) == 0 && rend_client_any_intro_points_usable(entry)) { /* either this fetch worked, or it failed but there was a * valid entry from before which we should reuse */ @@ -1075,35 +1224,34 @@ rend_client_desc_trynow(const char *query) base_conn->timestamp_lastread = now; base_conn->timestamp_lastwritten = now; - if (connection_ap_handshake_attach_circuit(conn) < 0) { - /* it will never work */ - log_warn(LD_REND,"Rendezvous attempt failed. Closing."); - if (!base_conn->marked_for_close) - connection_mark_unattached_ap(conn, END_STREAM_REASON_CANT_ATTACH); - } + connection_ap_mark_as_pending_circuit(conn); } else { /* 404, or fetch didn't get that far */ log_notice(LD_REND,"Closing stream for '%s.onion': hidden service is " "unavailable (try again later).", safe_str_client(query)); connection_mark_unattached_ap(conn, END_STREAM_REASON_RESOLVEFAILED); - rend_client_note_connection_attempt_ended(query); + rend_client_note_connection_attempt_ended(rend_data); } } SMARTLIST_FOREACH_END(base_conn); } -/** Clear temporary state used only during an attempt to connect to - * the hidden service named <b>onion_address</b>. Called when a - * connection attempt has ended; may be called occasionally at other - * times, and should be reasonably harmless. */ +/** Clear temporary state used only during an attempt to connect to the + * hidden service with <b>rend_data</b>. Called when a connection attempt + * has ended; it is possible for this to be called multiple times while + * handling an ended connection attempt, and any future changes to this + * function must ensure it remains idempotent. */ void -rend_client_note_connection_attempt_ended(const char *onion_address) +rend_client_note_connection_attempt_ended(const rend_data_t *rend_data) { + unsigned int have_onion = 0; rend_cache_entry_t *cache_entry = NULL; - rend_cache_lookup_entry(onion_address, -1, &cache_entry); - log_info(LD_REND, "Connection attempt for %s has ended; " - "cleaning up temporary state.", - safe_str_client(onion_address)); + if (*rend_data->onion_address != '\0') { + /* Ignore return value; we find an entry, or we don't. */ + (void) rend_cache_lookup_entry(rend_data->onion_address, -1, + &cache_entry); + have_onion = 1; + } /* Clear the timed_out flag on all remaining intro points for this HS. */ if (cache_entry != NULL) { @@ -1113,7 +1261,20 @@ rend_client_note_connection_attempt_ended(const char *onion_address) } /* Remove the HS's entries in last_hid_serv_requests. */ - purge_hid_serv_from_last_hid_serv_requests(onion_address); + if (have_onion) { + unsigned int replica; + for (replica = 0; replica < ARRAY_LENGTH(rend_data->descriptor_id); + replica++) { + const char *desc_id = rend_data->descriptor_id[replica]; + purge_hid_serv_from_last_hid_serv_requests(desc_id); + } + log_info(LD_REND, "Connection attempt for %s has ended; " + "cleaning up temporary state.", + safe_str_client(rend_data->onion_address)); + } else { + /* We only have an ID for a fetch. Probably used by HSFETCH. */ + purge_hid_serv_from_last_hid_serv_requests(rend_data->desc_id_fetch); + } } /** Return a newly allocated extend_info_t* for a randomly chosen introduction @@ -1123,13 +1284,17 @@ rend_client_note_connection_attempt_ended(const char *onion_address) extend_info_t * rend_client_get_random_intro(const rend_data_t *rend_query) { + int ret; extend_info_t *result; rend_cache_entry_t *entry; - if (rend_cache_lookup_entry(rend_query->onion_address, -1, &entry) < 1) { - log_warn(LD_REND, - "Query '%s' didn't have valid rend desc in cache. Failing.", - safe_str_client(rend_query->onion_address)); + ret = rend_cache_lookup_entry(rend_query->onion_address, -1, &entry); + if (ret < 0 || !rend_client_any_intro_points_usable(entry)) { + log_warn(LD_REND, + "Query '%s' didn't have valid rend desc in cache. Failing.", + safe_str_client(rend_query->onion_address)); + /* XXX: Should we refetch the descriptor here if the IPs are not usable + * anymore ?. */ return NULL; } @@ -1200,11 +1365,19 @@ rend_client_get_random_intro_impl(const rend_cache_entry_t *entry, smartlist_del(usable_nodes, i); goto again; } +#ifdef ENABLE_TOR2WEB_MODE + new_extend_info = extend_info_from_node(node, options->Tor2webMode); +#else new_extend_info = extend_info_from_node(node, 0); +#endif if (!new_extend_info) { + const char *alternate_reason = ""; +#ifdef ENABLE_TOR2WEB_MODE + alternate_reason = ", or we cannot connect directly to it"; +#endif log_info(LD_REND, "We don't have a descriptor for the intro-point relay " - "'%s'; trying another.", - extend_info_describe(intro->extend_info)); + "'%s'%s; trying another.", + extend_info_describe(intro->extend_info), alternate_reason); smartlist_del(usable_nodes, i); goto again; } else { |