Stub out connection_handle_oos() and call it from places we can change the... (34d9d021) · Commits · The Tor Project / Core / Tor

src/or/config.c

+3 −0

Original line number	Diff line number	Diff line
		@@ -1358,6 +1358,9 @@ options_act_reversible(const or_options_t old_options, char *msg)
		options->ConnLimit, options->ConnLimit_,
		options->ConnLimit_high_thresh,
		options->ConnLimit_low_thresh);

		/* Give the OOS handler a chance with the new thresholds */
		connection_handle_oos(get_n_open_sockets(), 0);
		}

		goto done;

src/or/connection.c

+107 −1

Original line number	Diff line number	Diff line
		@@ -1090,6 +1090,7 @@ connection_listener_new(const struct sockaddr *listensockaddr,
		int start_reading = 0;
		static int global_next_session_group = SESSION_GROUP_FIRST_AUTO;
		tor_addr_t addr;
		int exhaustion = 0;

		if (listensockaddr->sa_family == AF_INET \|\|
		listensockaddr->sa_family == AF_INET6) {
		@@ -1108,6 +1109,11 @@ connection_listener_new(const struct sockaddr *listensockaddr,
		int e = tor_socket_errno(s);
		if (ERRNO_IS_RESOURCE_LIMIT(e)) {
		warn_too_many_conns();
		/*
		* We'll call the OOS handler at the error exit, so set the
		* exhaustion flag for it.
		*/
		exhaustion = 1;
		} else {
		log_warn(LD_NET, "Socket creation failed: %s",
		tor_socket_strerror(e));
		@@ -1226,6 +1232,11 @@ connection_listener_new(const struct sockaddr *listensockaddr,
		int e = tor_socket_errno(s);
		if (ERRNO_IS_RESOURCE_LIMIT(e)) {
		warn_too_many_conns();
		/*
		* We'll call the OOS handler at the error exit, so set the
		* exhaustion flag for it.
		*/
		exhaustion = 1;
		} else {
		log_warn(LD_NET,"Socket creation failed: %s.", strerror(e));
		}
		@@ -1344,6 +1355,12 @@ connection_listener_new(const struct sockaddr *listensockaddr,
		dnsserv_configure_listener(conn);
		}

		/*
		* Normal exit; call the OOS handler since connection count just changed;
		* the exhaustion flag will always be zero here though.
		*/
		connection_handle_oos(get_n_open_sockets(), 0);

		return conn;

		err:
		@@ -1352,6 +1369,9 @@ connection_listener_new(const struct sockaddr *listensockaddr,
		if (conn)
		connection_free(conn);

		/* Call the OOS handler, indicate if we saw an exhaustion-related error */
		connection_handle_oos(get_n_open_sockets(), exhaustion);

		return NULL;
		}

		@@ -1442,21 +1462,34 @@ connection_handle_listener_read(connection_t *conn, int new_type)
		if (!SOCKET_OK(news)) { /* accept() error */
		int e = tor_socket_errno(conn->s);
		if (ERRNO_IS_ACCEPT_EAGAIN(e)) {
		return 0; /* they hung up before we could accept(). that's fine. */
		/*
		* they hung up before we could accept(). that's fine.
		*
		* give the OOS handler a chance to run though
		*/
		connection_handle_oos(get_n_open_sockets(), 0);
		return 0;
		} else if (ERRNO_IS_RESOURCE_LIMIT(e)) {
		warn_too_many_conns();
		/* Exhaustion; tell the OOS handler */
		connection_handle_oos(get_n_open_sockets(), 1);
		return 0;
		}
		/* else there was a real error. */
		log_warn(LD_NET,"accept() failed: %s. Closing listener.",
		tor_socket_strerror(e));
		connection_mark_for_close(conn);
		/* Tell the OOS handler about this too */
		connection_handle_oos(get_n_open_sockets(), 0);
		return -1;
		}
		log_debug(LD_NET,
		"Connection accepted on socket %d (child of fd %d).",
		(int)news,(int)conn->s);

		/* We accepted a new conn; run OOS handler */
		connection_handle_oos(get_n_open_sockets(), 0);

		if (make_socket_reuseable(news) < 0) {
		if (tor_socket_errno(news) == EINVAL) {
		/* This can happen on OSX if we get a badly timed shutdown. */
		@@ -1661,12 +1694,18 @@ connection_connect_sockaddr,(connection_t *conn,

		s = tor_open_socket_nonblocking(protocol_family, SOCK_STREAM, proto);
		if (! SOCKET_OK(s)) {
		/*
		* Early OOS handler calls; it matters if it's an exhaustion-related
		* error or not.
		*/
		*socket_error = tor_socket_errno(s);
		if (ERRNO_IS_RESOURCE_LIMIT(*socket_error)) {
		warn_too_many_conns();
		connection_handle_oos(get_n_open_sockets(), 1);
		} else {
		log_warn(LD_NET,"Error creating network socket: %s",
		tor_socket_strerror(*socket_error));
		connection_handle_oos(get_n_open_sockets(), 0);
		}
		return -1;
		}
		@@ -1676,6 +1715,13 @@ connection_connect_sockaddr,(connection_t *conn,
		tor_socket_strerror(errno));
		}

		/*
		* We've got the socket open; give the OOS handler a chance to check
		* against configuured maximum socket number, but tell it no exhaustion
		* failure.
		*/
		connection_handle_oos(get_n_open_sockets(), 0);

		if (bindaddr && bind(s, bindaddr, bindaddr_len) < 0) {
		*socket_error = tor_socket_errno(s);
		log_warn(LD_NET,"Error binding network socket: %s",
		@@ -4454,6 +4500,66 @@ connection_reached_eof(connection_t *conn)
		}
		}

		/** Out-of-Sockets handler; n_socks is the current number of open
		* sockets, and failed is non-zero if a socket exhaustion related
		* error immediately preceded this call. This is where to do
		* circuit-killing heuristics as needed.
		*/
		void
		connection_handle_oos(int n_socks, int failed)
		{
		int target_n_socks = 0;

		/* Sanity-check args */
		tor_assert(n_socks >= 0);

		/*
		* Make some log noise; keep it at debug level since this gets a chance
		* to run on every connection attempt.
		*/
		log_debug(LD_NET,
		"Running the OOS handler (%d open sockets, %s)",
		n_socks, (failed != 0) ? "exhaustion seen" : "no exhaustion");

		/*
		* Check if we're really handling an OOS condition, and if so decide how
		* many sockets we want to get down to.
		*/
		if (n_socks > get_options()->ConnLimit_high_thresh) {
		/* Try to get down to the low threshold */
		target_n_socks = get_options()->ConnLimit_low_thresh;
		log_notice(LD_NET,
		"Current number of sockets %d is greater than configured "
		"limit %d; OOS handler trying to get down to %d",
		n_socks, get_options()->ConnLimit_high_thresh,
		target_n_socks);
		} else if (failed) {
		/*
		* If we're not at the limit but we hit a socket exhaustion error, try to
		* drop some (but not as aggressively as ConnLimit_low_threshold, which is
		* 3/4 of ConnLimit_)
		*/
		target_n_socks = (n_socks * 9) / 10;
		log_notice(LD_NET,
		"We saw socket exhaustion at %d open sockets; OOS handler "
		"trying to get down to %d",
		n_socks, target_n_socks);
		}

		if (target_n_socks > 0) {
		/*
		* It's an OOS!
		*
		* TODO count moribund sockets; it'll be important that anything we decide
		* to get rid of here but don't immediately close get counted as moribund
		* on subsequent invocations so we don't try to kill too many things if
		* this gets called multiple times.
		*/

		/* TODO pick what to try to close */
		}
		}

		/** Log how many bytes are used by buffers of different kinds and sizes. */
		void
		connection_dump_buffer_mem_stats(int severity)

src/or/connection.h

+2 −0

Original line number	Diff line number	Diff line
		@@ -247,6 +247,8 @@ void clock_skew_warning(const connection_t *conn, long apparent_skew,
		int trusted, log_domain_mask_t domain,
		const char received, const char source);

		void connection_handle_oos(int n_socks, int failed);

		#ifdef CONNECTION_PRIVATE
		STATIC void connection_free_(connection_t *conn);