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[tor/release-0.2.2] Make last_hid_serv_requests functions less fragile
by arma＠torproject.org 03 Jun '11

03 Jun '11

commit a1d866edc9af82c2134590f7ee3c4e18156a655c Author: Robert Ransom <rransom.8774(a)gmail.com> Date: Thu Jun 2 02:24:18 2011 -0700 Make last_hid_serv_requests functions less fragile Previously, Tor would dereference a NULL pointer and crash if lookup_last_hid_serv_request were called before the first call to directory_clean_last_hid_serv_requests. As far as I can tell, that's currently impossible, but I want that undocumented invariant to go away in case I^Wwe break it someday. --- src/or/rendclient.c | 16 +++++++++++++--- 1 files changed, 13 insertions(+), 3 deletions(-) diff --git a/src/or/rendclient.c b/src/or/rendclient.c index 29b9d26..ec6e3f2 100644 --- a/src/or/rendclient.c +++ b/src/or/rendclient.c @@ -377,7 +377,17 @@ rend_client_introduction_acked(origin_circuit_t *circ, * certain queries; keys are strings consisting of base32-encoded * hidden service directory identities and base32-encoded descriptor IDs; * values are pointers to timestamps of the last requests. */ -static strmap_t *last_hid_serv_requests = NULL; +static strmap_t *last_hid_serv_requests_ = NULL; + +/** Returns last_hid_serv_requests_, initializing it to a new strmap if + * necessary. */ +static strmap_t * +get_last_hid_serv_requests(void) +{ + if (!last_hid_serv_requests_) + last_hid_serv_requests_ = strmap_new(); + return last_hid_serv_requests_; +} /** Look up the last request time to hidden service directory hs_dir * for descriptor ID desc_id_base32. If set is non-zero, @@ -391,6 +401,7 @@ lookup_last_hid_serv_request(routerstatus_t *hs_dir, char hsdir_id_base32[REND_DESC_ID_V2_LEN_BASE32 + 1]; char hsdir_desc_comb_id[2 * REND_DESC_ID_V2_LEN_BASE32 + 1]; time_t *last_request_ptr; + 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", @@ -416,8 +427,7 @@ directory_clean_last_hid_serv_requests(void) { strmap_iter_t *iter; time_t cutoff = time(NULL) - REND_HID_SERV_DIR_REQUERY_PERIOD; - if (!last_hid_serv_requests) - last_hid_serv_requests = strmap_new(); + strmap_t *last_hid_serv_requests = get_last_hid_serv_requests(); for (iter = strmap_iter_init(last_hid_serv_requests); !strmap_iter_done(iter); ) { const char *key;

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[tor/release-0.2.2] Fix compile error in procmon.c
by arma＠torproject.org 03 Jun '11

03 Jun '11

commit 1d8bcba067ef8d96ebe022f06459d55c308343ec Author: Gisle <gvanem(a)broadpark.no> Date: Wed Jun 1 11:11:12 2011 -0400 Fix compile error in procmon.c An elusive compile-error (MingW-gcc v4.50 on Win_XP); a missing comma (!) and a typo ('err_msg' at line 277 changed to 'errmsg'). Aso changed the format for 'err_code' at line 293 into a "%ld" to suppress a warning. How did this go unnoticed for ~1 month? Btw. This is my 1st ever 'git commit', so it better work. --- src/common/procmon.c | 8 ++++---- 1 files changed, 4 insertions(+), 4 deletions(-) diff --git a/src/common/procmon.c b/src/common/procmon.c index 8fcc1af..5c10e9a 100644 --- a/src/common/procmon.c +++ b/src/common/procmon.c @@ -252,7 +252,7 @@ tor_process_monitor_poll_cb(evutil_socket_t unused1, short unused2, if (!GetExitCodeProcess(procmon->hproc, &exit_code)) { char *errmsg = format_win32_error(GetLastError()); log_warn(procmon->log_domain, "Error \"%s\" occurred while polling " - "handle for monitored process %d; assuming it's dead." + "handle for monitored process %d; assuming it's dead.", errmsg, procmon->pid); tor_free(errmsg); its_dead_jim = 1; @@ -287,12 +287,12 @@ tor_process_monitor_poll_cb(evutil_socket_t unused1, short unused2, if (!its_dead_jim) log_info(procmon->log_domain, "Failed to open handle to monitored " - "process %d, and error code %d (%s) is not 'invalid " + "process %d, and error code %lu (%s) is not 'invalid " "parameter' -- assuming the process is still alive.", procmon->pid, - err_code, err_msg); + err_code, errmsg); - tor_free(err_msg); + tor_free(errmsg); } } #else

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[tor/release-0.2.2] Refactor HS client state-clearing code into a separate function
by arma＠torproject.org 03 Jun '11

03 Jun '11

commit d7af8a2f076a38d8be32798d34049ce150c8dda0 Author: Robert Ransom <rransom.8774(a)gmail.com> Date: Thu Jun 2 02:57:29 2011 -0700 Refactor HS client state-clearing code into a separate function --- src/or/main.c | 4 +--- src/or/rendclient.c | 10 ++++++++++ src/or/rendclient.h | 2 ++ 3 files changed, 13 insertions(+), 3 deletions(-) diff --git a/src/or/main.c b/src/or/main.c index 3c84dda..bc639db 100644 --- a/src/or/main.c +++ b/src/or/main.c @@ -853,9 +853,7 @@ signewnym_impl(time_t now) circuit_expire_all_dirty_circs(); addressmap_clear_transient(); - rend_cache_purge(); - rend_client_cancel_descriptor_fetches(); - rend_client_purge_last_hid_serv_requests(); + rend_client_purge_state(); time_of_last_signewnym = now; signewnym_is_pending = 0; } diff --git a/src/or/rendclient.c b/src/or/rendclient.c index 12b54df..329b256 100644 --- a/src/or/rendclient.c +++ b/src/or/rendclient.c @@ -27,6 +27,16 @@ static extend_info_t *rend_client_get_random_intro_impl( const rend_cache_entry_t *rend_query, const int strict, const int warnings); +/** Purge all potentially remotely-detectable state held in the hidden + * service client code. Called on SIGNAL NEWNYM. */ +void +rend_client_purge_state(void) +{ + rend_cache_purge(); + rend_client_cancel_descriptor_fetches(); + rend_client_purge_last_hid_serv_requests(); +} + /** Called when we've established a circuit to an introduction point: * send the introduction request. */ void diff --git a/src/or/rendclient.h b/src/or/rendclient.h index 2bfc850..c6cf82b 100644 --- a/src/or/rendclient.h +++ b/src/or/rendclient.h @@ -12,6 +12,8 @@ #ifndef _TOR_RENDCLIENT_H #define _TOR_RENDCLIENT_H +void rend_client_purge_state(void); + void rend_client_introcirc_has_opened(origin_circuit_t *circ); void rend_client_rendcirc_has_opened(origin_circuit_t *circ); int rend_client_introduction_acked(origin_circuit_t *circ,

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[tor/release-0.2.2] Add info-level log messages during HS-client-state purge
by arma＠torproject.org 03 Jun '11

03 Jun '11

commit fc4158dad706a76acbfd3adae8b505495f1004e5 Author: Robert Ransom <rransom.8774(a)gmail.com> Date: Thu Jun 2 03:07:09 2011 -0700 Add info-level log messages during HS-client-state purge I hope these will never be useful, but having them and not needing them is better than needing them and not having them. --- changes/bug3309 | 4 ++++ src/or/rendclient.c | 1 + src/or/rendcommon.c | 4 +++- 3 files changed, 8 insertions(+), 1 deletions(-) diff --git a/changes/bug3309 b/changes/bug3309 index 5df0d9d..104056d 100644 --- a/changes/bug3309 +++ b/changes/bug3309 @@ -7,3 +7,7 @@ refuse to fetch it again for up to 15 minutes. Bugfix on 0.2.2.25-alpha; fixes bug 3309. + o Minor features: + - Log (at info level) when purging pieces of hidden-service-client + state on SIGNAL NEWNYM. + diff --git a/src/or/rendclient.c b/src/or/rendclient.c index 329b256..533dfb8 100644 --- a/src/or/rendclient.c +++ b/src/or/rendclient.c @@ -469,6 +469,7 @@ rend_client_purge_last_hid_serv_requests(void) last_hid_serv_requests_ = NULL; if (old_last_hid_serv_requests != NULL) { + log_info(LD_REND, "Purging client last-HS-desc-request-time table"); strmap_free(old_last_hid_serv_requests, _tor_free); } } diff --git a/src/or/rendcommon.c b/src/or/rendcommon.c index 4d4a90f..683e11a 100644 --- a/src/or/rendcommon.c +++ b/src/or/rendcommon.c @@ -839,8 +839,10 @@ rend_cache_clean(void) void rend_cache_purge(void) { - if (rend_cache) + if (rend_cache) { + log_info(LD_REND, "Purging client/v0-HS-authority HS descriptor cache"); strmap_free(rend_cache, _rend_cache_entry_free); + } rend_cache = strmap_new(); }

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[tor/release-0.2.2] Clear last_hid_serv_requests on SIGNAL NEWNYM
by arma＠torproject.org 03 Jun '11

03 Jun '11

commit b0e7925c0205a68d730025cc8832110c1675cfd7 Author: Robert Ransom <rransom.8774(a)gmail.com> Date: Thu Jun 2 02:46:04 2011 -0700 Clear last_hid_serv_requests on SIGNAL NEWNYM Fixes bug #3309. --- changes/bug3309 | 9 +++++++++ src/or/main.c | 1 + src/or/rendclient.c | 19 +++++++++++++++++++ src/or/rendclient.h | 1 + 4 files changed, 30 insertions(+), 0 deletions(-) diff --git a/changes/bug3309 b/changes/bug3309 new file mode 100644 index 0000000..5df0d9d --- /dev/null +++ b/changes/bug3309 @@ -0,0 +1,9 @@ + o Minor bugfixes: + - Clear the table recording the time of the last request for each + hidden service descriptor from each HS directory on SIGNAL + NEWNYM. Previously, we would clear our HS descriptor cache on + SIGNAL NEWNYM, but if we had previously retrieved a descriptor + (or tried to) from every directory responsible for it, we would + refuse to fetch it again for up to 15 minutes. Bugfix on + 0.2.2.25-alpha; fixes bug 3309. + diff --git a/src/or/main.c b/src/or/main.c index adbde90..3c84dda 100644 --- a/src/or/main.c +++ b/src/or/main.c @@ -855,6 +855,7 @@ signewnym_impl(time_t now) addressmap_clear_transient(); rend_cache_purge(); rend_client_cancel_descriptor_fetches(); + rend_client_purge_last_hid_serv_requests(); time_of_last_signewnym = now; signewnym_is_pending = 0; } diff --git a/src/or/rendclient.c b/src/or/rendclient.c index ec6e3f2..12b54df 100644 --- a/src/or/rendclient.c +++ b/src/or/rendclient.c @@ -444,6 +444,25 @@ directory_clean_last_hid_serv_requests(void) } } +/** Purge the history of request times to hidden service directories, + * so that future lookups of an HS descriptor will not fail because we + * accessed all of the HSDir relays responsible for the descriptor + * recently. */ +void +rend_client_purge_last_hid_serv_requests(void) +{ + /* Don't create the table if it doesn't exist yet (and it may very + * well not exist if the user hasn't accessed any HSes)... */ + strmap_t *old_last_hid_serv_requests = last_hid_serv_requests_; + /* ... and let get_last_hid_serv_requests re-create it for us if + * necessary. */ + last_hid_serv_requests_ = NULL; + + if (old_last_hid_serv_requests != NULL) { + strmap_free(old_last_hid_serv_requests, _tor_free); + } +} + /** Determine the responsible hidden service directories for desc_id * and fetch the descriptor belonging to that ID from one of them. Only * send a request to hidden service directories that we did not try within diff --git a/src/or/rendclient.h b/src/or/rendclient.h index 6910c1a..2bfc850 100644 --- a/src/or/rendclient.h +++ b/src/or/rendclient.h @@ -19,6 +19,7 @@ int rend_client_introduction_acked(origin_circuit_t *circ, size_t request_len); void rend_client_refetch_v2_renddesc(const rend_data_t *rend_query); void rend_client_cancel_descriptor_fetches(void); +void rend_client_purge_last_hid_serv_requests(void); int rend_client_remove_intro_point(extend_info_t *failed_intro, const rend_data_t *rend_query); int rend_client_rendezvous_acked(origin_circuit_t *circ,

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[tor/release-0.2.2] Fix unit test failure in dir/formats
by arma＠torproject.org 03 Jun '11

03 Jun '11

commit df42eb0a18a9f6fe4b729a1c9a63bb6ab247f631 Author: Sebastian Hahn <sebastian(a)torproject.org> Date: Thu Jun 2 13:30:32 2011 +0200 Fix unit test failure in dir/formats options->DirPort is 0 in the unit tests, so router_get_advertised_dir_port() would return 0 so we wouldn't pick a dirport. This isn't what we want for the unit tests. Fixes bug introduced in 95ac3ea5946. --- src/or/connection.c | 4 ++-- src/or/dirserv.c | 5 +++-- src/or/router.c | 18 +++++++++++------- src/or/router.h | 3 ++- 4 files changed, 18 insertions(+), 12 deletions(-) diff --git a/src/or/connection.c b/src/or/connection.c index 3dcb573..3f4ca1d 100644 --- a/src/or/connection.c +++ b/src/or/connection.c @@ -1952,7 +1952,7 @@ retry_all_listeners(smartlist_t *replaced_conns, or_options_t *options = get_options(); int retval = 0; const uint16_t old_or_port = router_get_advertised_or_port(options); - const uint16_t old_dir_port = router_get_advertised_dir_port(options); + const uint16_t old_dir_port = router_get_advertised_dir_port(options, 0); if (retry_listeners(CONN_TYPE_OR_LISTENER, options->ORListenAddress, options->ORPort, "0.0.0.0", @@ -1998,7 +1998,7 @@ retry_all_listeners(smartlist_t *replaced_conns, return -1; if (old_or_port != router_get_advertised_or_port(options) || - old_dir_port != router_get_advertised_dir_port(options)) { + old_dir_port != router_get_advertised_dir_port(options, 0)) { /* Our chosen ORPort or DirPort is not what it used to be: the * descriptor we had (if any) should be regenerated. (We won't * automatically notice this because of changes in the option, diff --git a/src/or/dirserv.c b/src/or/dirserv.c index e9355fe..d114d86 100644 --- a/src/or/dirserv.c +++ b/src/or/dirserv.c @@ -2705,7 +2705,7 @@ dirserv_generate_networkstatus_vote_obj(crypto_pk_env_t *private_key, voter->sigs = smartlist_create(); voter->address = hostname; voter->addr = addr; - voter->dir_port = router_get_advertised_dir_port(options); + voter->dir_port = router_get_advertised_dir_port(options, 0); voter->or_port = router_get_advertised_or_port(options); voter->contact = tor_strdup(contact); if (options->V3AuthUseLegacyKey) { @@ -2812,7 +2812,8 @@ generate_v2_networkstatus_opinion(void) "dir-options%s%s%s%s\n" "%s" /* client version line, server version line. */ "dir-signing-key\n%s", - hostname, ipaddr, (int)router_get_advertised_dir_port(options), + hostname, ipaddr, + (int)router_get_advertised_dir_port(options, 0), fingerprint, contact, published, diff --git a/src/or/router.c b/src/or/router.c index 30a340a..68e29bb 100644 --- a/src/or/router.c +++ b/src/or/router.c @@ -704,7 +704,7 @@ init_keys(void) ds = router_get_trusteddirserver_by_digest(digest); if (!ds) { ds = add_trusted_dir_server(options->Nickname, NULL, - router_get_advertised_dir_port(options), + router_get_advertised_dir_port(options, 0), router_get_advertised_or_port(options), digest, v3_digest, @@ -802,7 +802,7 @@ decide_to_advertise_dirport(or_options_t *options, uint16_t dir_port) return 0; if (!check_whether_dirport_reachable()) return 0; - if (!router_get_advertised_dir_port(options)) + if (!router_get_advertised_dir_port(options, dir_port)) return 0; /* Section two: reasons to publish or not publish that the user @@ -1184,12 +1184,16 @@ router_get_advertised_or_port(or_options_t *options) return options->ORPort; } -/** Return the port that we should advertise as our DirPort; this is either - * the one configured in the DirPort option, or the one we actually bound to - * if DirPort is "auto". */ +/** Return the port that we should advertise as our DirPort; + * this is one of three possibilities: + * The one that is passed as dirport if the DirPort option is 0, or + * the one configured in the DirPort option, + * or the one we actually bound to if DirPort is "auto". */ uint16_t -router_get_advertised_dir_port(or_options_t *options) +router_get_advertised_dir_port(or_options_t *options, uint16_t dirport) { + if (!options->DirPort) + return dirport; if (options->DirPort == CFG_AUTO_PORT) { connection_t *c = connection_get_by_type(CONN_TYPE_DIR_LISTENER); if (c) @@ -1440,7 +1444,7 @@ router_rebuild_descriptor(int force) ri->nickname = tor_strdup(options->Nickname); ri->addr = addr; ri->or_port = router_get_advertised_or_port(options); - ri->dir_port = router_get_advertised_dir_port(options); + ri->dir_port = router_get_advertised_dir_port(options, 0); ri->cache_info.published_on = time(NULL); ri->onion_pkey = crypto_pk_dup_key(get_onion_key()); /* must invoke from * main thread */ diff --git a/src/or/router.h b/src/or/router.h index a27c1d9..3733099 100644 --- a/src/or/router.h +++ b/src/or/router.h @@ -51,7 +51,8 @@ int authdir_mode_tests_reachability(or_options_t *options); int authdir_mode_bridge(or_options_t *options); uint16_t router_get_advertised_or_port(or_options_t *options); -uint16_t router_get_advertised_dir_port(or_options_t *options); +uint16_t router_get_advertised_dir_port(or_options_t *options, + uint16_t dirport); int server_mode(or_options_t *options); int public_server_mode(or_options_t *options);

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[tor/release-0.2.2] Merge remote-tracking branch 'arma/bug3321' into maint-0.2.2
by arma＠torproject.org 03 Jun '11

03 Jun '11

commit 385c59798af80e2609b66afb2998acb508060f95 Merge: df42eb0 7039c34 Author: Nick Mathewson <nickm(a)torproject.org> Date: Thu Jun 2 12:55:56 2011 -0400 Merge remote-tracking branch 'arma/bug3321' into maint-0.2.2 changes/bug3321 | 7 +++++++ src/or/circuitbuild.c | 17 ++++++++++++----- 2 files changed, 19 insertions(+), 5 deletions(-)

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[tor/release-0.2.2] Add an "auto" option to UseBridges
by arma＠torproject.org 03 Jun '11

03 Jun '11

commit 507c1257a4d9c629fefc2adbad8db73607749734 Author: Nick Mathewson <nickm(a)torproject.org> Date: Mon May 30 23:32:38 2011 -0400 Add an "auto" option to UseBridges UseBridges 1 now means "connect only to bridges; if you know no bridges, don't make connections." UseBridges auto means "Use bridges if they are known, and we have no EntryNodes set, and we aren't a server." UseBridges 0 means "don't use bridges." --- src/or/config.c | 19 +++++++++++++++---- src/or/or.h | 12 +++++++++++- 2 files changed, 26 insertions(+), 5 deletions(-) diff --git a/src/or/config.c b/src/or/config.c index 6635cac..44cecf3 100644 --- a/src/or/config.c +++ b/src/or/config.c @@ -376,7 +376,7 @@ static config_var_t _option_vars[] = { V(TransPort, PORT, "0"), V(TunnelDirConns, BOOL, "1"), V(UpdateBridgesFromAuthority, BOOL, "0"), - V(UseBridges, BOOL, "0"), + VAR("UseBridges", STRING, UseBridges_, "auto"), V(UseEntryGuards, BOOL, "1"), V(User, STRING, NULL), VAR("V1AuthoritativeDirectory",BOOL, V1AuthoritativeDir, "0"), @@ -3232,6 +3232,19 @@ options_validate(or_options_t *old_options, or_options_t *options, "of the Internet, so they must not set Reachable*Addresses " "or FascistFirewall."); + /* XXX023 use autobool instead. */ + if (!strcmp(options->UseBridges_, "auto")) { + options->UseBridges = (options->Bridges && + !server_mode(options) && + !options->EntryNodes); + } else if (!strcmp(options->UseBridges_, "0")) { + options->UseBridges = 0; + } else if (!strcmp(options->UseBridges_, "1")) { + options->UseBridges = 1; + } else { + REJECT("UseBridges must be 0, 1, or auto"); + } + if (options->UseBridges && server_mode(options)) REJECT("Servers must be able to freely connect to the rest " @@ -3566,10 +3579,8 @@ options_validate(or_options_t *old_options, or_options_t *options, if (validate_dir_authorities(options, old_options) < 0) REJECT("Directory authority line did not parse. See logs for details."); - if (options->UseBridges && !options->Bridges) - REJECT("If you set UseBridges, you must specify at least one bridge."); if (options->UseBridges && !options->TunnelDirConns) - REJECT("If you set UseBridges, you must set TunnelDirConns."); + REJECT("TunnelDirConns set to 0 only works with UseBridges set to 0"); if (options->Bridges) { for (cl = options->Bridges; cl; cl = cl->next) { if (parse_bridge_line(cl->value, 1)<0) diff --git a/src/or/or.h b/src/or/or.h index 97fecd1..456dce2 100644 --- a/src/or/or.h +++ b/src/or/or.h @@ -2480,7 +2480,17 @@ typedef struct { * when doing so. */ char *BridgePassword; - int UseBridges; /**< Boolean: should we start all circuits with a bridge? */ + /** Whether we should start all circuits with a bridge. "1" means strictly + * yes, "0" means strictly no, and "auto" means that we do iff any bridges + * are configured, we are not running a server and have not specified a list + * of entry nodes. */ + char *UseBridges_; + /** Effective value of UseBridges. Will be set equally for UseBridges set to + * 1 or 0, but for 'auto' it will be set to 1 iff any bridges are + * configured, we are not running a server and have not specified a list of + * entry nodes. */ + int UseBridges; + config_line_t *Bridges; /**< List of bootstrap bridge addresses. */ int BridgeRelay; /**< Boolean: are we acting as a bridge relay? We make

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[tor/release-0.2.2] Merge remote-tracking branch 'rransom-tor/bug3309' into maint-0.2.2
by arma＠torproject.org 03 Jun '11

03 Jun '11

commit 80038b545359e5156fde6d6be4015bdf7f80e779 Merge: 385c597 fc4158d Author: Nick Mathewson <nickm(a)torproject.org> Date: Thu Jun 2 15:06:04 2011 -0400 Merge remote-tracking branch 'rransom-tor/bug3309' into maint-0.2.2 changes/bug3309 | 13 +++++++++++++ src/or/main.c | 3 +-- src/or/rendclient.c | 46 +++++++++++++++++++++++++++++++++++++++++++--- src/or/rendclient.h | 3 +++ src/or/rendcommon.c | 4 +++- 5 files changed, 63 insertions(+), 6 deletions(-)

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[tor/release-0.2.2] Update man page for new UseBridges tristate behaviour.
by arma＠torproject.org 03 Jun '11

03 Jun '11

commit 40cfad1b5ae90b06eb74861a4fdc1310f8611111 Author: anonym <anonym(a)lavabit.com> Date: Mon May 30 23:52:02 2011 +0200 Update man page for new UseBridges tristate behaviour. --- doc/tor.1.txt | 10 +++++++--- 1 files changed, 7 insertions(+), 3 deletions(-) diff --git a/doc/tor.1.txt b/doc/tor.1.txt index 1815a8d..8aa32e8 100644 --- a/doc/tor.1.txt +++ b/doc/tor.1.txt @@ -708,10 +708,14 @@ The following options are useful only for clients (that is, if from the configured bridge authorities when feasible. It will fall back to a direct request if the authority responds with a 404. (Default: 0) -**UseBridges** **0**|**1**:: - When set, Tor will fetch descriptors for each bridge listed in the "Bridge" +**UseBridges** **0**|**1**|**auto**:: + Make Tor fetch descriptors for each bridge listed in the "Bridge" config lines, and use these relays as both entry guards and directory - guards. (Default: 0) + guards. If the option is 1, bridges must be used and if no bridges are + configured Tor will not make any connections until a bridge is configured; + if it's "auto", Tor will use bridges if any are configured, otherwise it + will connect directly to the Tor network; if it's 0, bridges are not used + at all. (Defaults to auto) **UseEntryGuards** **0**|**1**:: If this option is set to 1, we pick a few long-term entry servers, and try

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