Prevent a "try forever to download an unobtainable descriptor" bug. Still... (d118d506) · Commits · The Tor Project / Core / Tor

doc/TODO

+3 −2

Original line number	Diff line number	Diff line
		@@ -133,7 +133,7 @@ R - check reachability as soon as you hear about a new server
		X By 'if-newer-than' (Does the spec require this??)
		o Support compression.
		N - Alice acts on network-status objects
		. Alice downloads descriptors as needed.
		o Alice downloads descriptors as needed.
		o Figure out what's needed
		o Store it
		o Implement store
		@@ -146,7 +146,8 @@ N - Alice acts on network-status objects
		o Call directory_has_arrived as needed; rename it.
		o Set has_fetched_directory properly.
		o Retry descriptors on failure
		- Give up after a while.
		o Give up after a while.
		- But try again after a long while (???)
		- Check software versions according to some sane plan.
		o Alice sets descriptor status from network-status
		o Implement

src/or/directory.c

+10 −3

Original line number	Diff line number	Diff line
		@@ -283,7 +283,7 @@ connection_dir_request_failed(connection_t *conn)
		log_fn(LOG_INFO, "Giving up on directory server at '%s'; retrying",
		conn->address);
		connection_dir_download_networkstatus_failed(conn);
		} else if (conn->purpose == DIR_PURPOSE_FETCH_NETWORKSTATUS) {
		} else if (conn->purpose == DIR_PURPOSE_FETCH_SERVERDESC) {
		log_fn(LOG_INFO, "Giving up on directory server at '%s'; retrying",
		conn->address);
		connection_dir_download_routerdesc_failed(conn);
		@@ -320,7 +320,8 @@ connection_dir_download_networkstatus_failed(connection_t *conn)
		static void
		connection_dir_download_routerdesc_failed(connection_t *conn)
		{
		/* try again. */
		/* Try again. */
		/XXXX011 plays poorly with multiple conns. /
		update_router_descriptor_downloads(time(NULL));
		}

		@@ -1547,7 +1548,13 @@ dir_networkstatus_download_failed(smartlist_t *failed)
		static void
		dir_routerdesc_download_failed(smartlist_t *failed)
		{
		/* XXXX writeme! Give up after a while! */
		SMARTLIST_FOREACH(failed, const char *, cp,
		{
		routerstatus_t *rs = router_get_combined_status_by_digest(cp);
		if (!rs \|\| rs->n_download_failures >= MAX_ROUTERDESC_DOWNLOAD_FAILURES)
		continue;
		++rs->n_download_failures;
		});
		}

		/* DOCDOC */

src/or/or.h

+6 −1

Original line number	Diff line number	Diff line
		@@ -805,6 +805,9 @@ typedef struct routerstatus_t {
		* recent descriptor. */
		} routerstatus_t;

		/XXXX001 make this configurable! /
		#define MAX_ROUTERDESC_DOWNLOAD_FAILURES 16

		/** Contents of a (v2 or later) network status object. */
		typedef struct networkstatus_t {
		/** When did we receive the network-status document? */
		@@ -2107,11 +2110,13 @@ void add_trusted_dir_server(const char *addr, uint16_t port,
		const char *digest, int supports_v1);
		void clear_trusted_dir_servers(void);
		networkstatus_t networkstatus_get_by_digest(const char digest);
		routerstatus_t router_get_combined_status_by_digest(const char digest);
		void update_networkstatus_cache_downloads(time_t now);
		void update_networkstatus_client_downloads(time_t now);
		void update_router_descriptor_downloads(time_t now);
		void routers_update_all_from_networkstatus(void);
		void routers_update_status_from_networkstatus(smartlist_t *routers);
		void routers_update_status_from_networkstatus(smartlist_t *routers,
		int reset_failures);
		smartlist_t *router_list_superseded(void);
		int router_have_minimum_dir_info(void);
		void networkstatus_list_update_recent(time_t now);

src/or/routerlist.c

+13 −9

Original line number	Diff line number	Diff line
		@@ -29,7 +29,6 @@ static trusted_dir_server_t *router_pick_trusteddirserver_impl(
		static void mark_all_trusteddirservers_up(void);
		static int router_nickname_is_in_list(routerinfo_t router, const char list);
		static int router_nickname_matches(routerinfo_t router, const char nickname);
		static routerstatus_t router_get_combined_status_by_digest(const char d);
		static void routerstatus_list_update_from_networkstatus(time_t now);

		/****************************************************************************/
		@@ -1292,7 +1291,7 @@ router_load_routers_from_string(const char *s, int from_cache,

		router_parse_list_from_string(&s, routers);

		routers_update_status_from_networkstatus(routers);
		routers_update_status_from_networkstatus(routers, !from_cache);

		SMARTLIST_FOREACH(routers, routerinfo_t *, ri,
		{
		@@ -1554,7 +1553,8 @@ networkstatus_find_entry(networkstatus_t ns, const char digest)
		_compare_digest_to_routerstatus_entry);
		}

		static routerstatus_t *
		/DOCDOC/
		routerstatus_t *
		router_get_combined_status_by_digest(const char *digest)
		{
		if (!routerstatus_list)
		@@ -1563,7 +1563,6 @@ router_get_combined_status_by_digest(const char *digest)
		_compare_digest_to_routerstatus_entry);
		}


		/* XXXX These should be configurable, perhaps? NM */
		#define AUTHORITY_NS_CACHE_INTERVAL 10*60
		#define NONAUTHORITY_NS_CACHE_INTERVAL 15*60
		@@ -1995,7 +1994,7 @@ routers_update_all_from_networkstatus(void)
		if (networkstatus_list_has_changed)
		routerstatus_list_update_from_networkstatus(now);

		routers_update_status_from_networkstatus(routerlist->routers);
		routers_update_status_from_networkstatus(routerlist->routers, 0);

		me = router_get_my_routerinfo();
		if (me) {
		@@ -2003,7 +2002,7 @@ routers_update_all_from_networkstatus(void)
		* dirservers list us as named, valid, etc. */
		smartlist_t *lst = smartlist_create();
		smartlist_add(lst, me);
		routers_update_status_from_networkstatus(lst);
		routers_update_status_from_networkstatus(lst, 1);
		if (me->is_verified == 0) {
		log_fn(LOG_WARN, "Many directory servers list us as unverified. Please consider sending your identity fingerprint to the tor-ops.");
		have_warned_about_unverified_status = 1;
		@@ -2179,7 +2178,7 @@ routerstatus_list_update_from_networkstatus(time_t now)
		* is_named, is_verified, and is_running fields according to our current
		* networkstatus_t documents. */
		void
		routers_update_status_from_networkstatus(smartlist_t *routers)
		routers_update_status_from_networkstatus(smartlist_t *routers, int reset_failures)
		{
		trusted_dir_server_t *ds;
		routerstatus_t *rs;
		@@ -2198,6 +2197,9 @@ routers_update_status_from_networkstatus(smartlist_t *routers)
		if (!rs)
		continue;

		if (reset_failures)
		rs->n_download_failures = 0;

		if (!namingdir)
		router->is_named = rs->is_named;

		@@ -2250,8 +2252,10 @@ router_list_downloadable(void)
		// log_fn(LOG_NOTICE, "No status for %s", fp);
		continue;
		}
		if (!memcmp(ri->signed_descriptor_digest,rs->descriptor_digest,DIGEST_LEN)
		\|\| rs->published_on <= ri->published_on) {
		/XXXX001 reset max_routerdesc_download_failures somewhere! /
		if (rs->n_download_failures >= MAX_ROUTERDESC_DOWNLOAD_FAILURES \|\|
		!memcmp(ri->signed_descriptor_digest,rs->descriptor_digest,DIGEST_LEN)\|\|
		rs->published_on <= ri->published_on) {
		/* Same digest, or earlier. No need to download it. */
		// log_fn(LOG_NOTICE, "Up-to-date status for %s", fp);
		strmap_remove(status_map, fp);

src/or/routerparse.c

+0 −2

Original line number	Diff line number	Diff line
		@@ -692,8 +692,6 @@ router_parse_list_from_string(const char *s, smartlist_t dest)
		smartlist_add(routers, router);
		}

		routers_update_status_from_networkstatus(routers);

		smartlist_add_all(dest, routers);

		return 0;