Merge branch 'bug16248_027' into maint-0.2.7 (1218d731) · Commits · David Goulet / Tor

changes/bug16248

0 → 100644

+8 −0

Original line number	Diff line number	Diff line
		o Major bugfixes (dns proxy mode, crash):
		- Avoid crashing when running as a DNS proxy. Closes bug 16248; bugfix on
		0.2.0.1-alpha. Patch from 'cypherpunks'.

		o Minor features (bug-resistance):
		- Make Tor survive errors involving connections without a corresponding
		event object. Previously we'd fail with an assertion; now we produce a
		log message. Related to bug 16248.

src/or/main.c

+51 −4

Original line number	Diff line number	Diff line
		@@ -567,6 +567,45 @@ connection_is_reading(connection_t *conn)
		(conn->read_event && event_pending(conn->read_event, EV_READ, NULL));
		}

		/** Check whether <b>conn</b> is correct in having (or not having) a
		* read/write event (passed in <b>ev</b). On success, return 0. On failure,
		* log a warning and return -1. */
		static int
		connection_check_event(connection_t conn, struct event ev)
		{
		int bad;

		if (conn->type == CONN_TYPE_AP && TO_EDGE_CONN(conn)->is_dns_request) {
		/* DNS requests which we launch through the dnsserv.c module do not have
		* any underlying socket or any underlying linked connection, so they
		* shouldn't have any attached events either.
		*/
		bad = ev != NULL;
		} else {
		/* Everytyhing else should have an underlying socket, or a linked
		* connection (which is also tracked with a read_event/write_event pair).
		*/
		bad = ev == NULL;
		}

		if (bad) {
		log_warn(LD_BUG, "Event missing on connection %p [%s;%s]. "
		"socket=%d. linked=%d. "
		"is_dns_request=%d. Marked_for_close=%s:%d",
		conn,
		conn_type_to_string(conn->type),
		conn_state_to_string(conn->type, conn->state),
		(int)conn->s, (int)conn->linked,
		(conn->type == CONN_TYPE_AP && TO_EDGE_CONN(conn)->is_dns_request),
		conn->marked_for_close_file ? conn->marked_for_close_file : "-",
		conn->marked_for_close
		);
		log_backtrace(LOG_WARN, LD_BUG, "Backtrace attached.");
		return -1;
		}
		return 0;
		}

		/** Tell the main loop to stop notifying <b>conn</b> of any read events. */
		MOCK_IMPL(void,
		connection_stop_reading,(connection_t *conn))
		@@ -578,7 +617,9 @@ connection_stop_reading,(connection_t *conn))
		return;
		});

		tor_assert(conn->read_event);
		if (connection_check_event(conn, conn->read_event) < 0) {
		return;
		}

		if (conn->linked) {
		conn->reading_from_linked_conn = 0;
		@@ -603,7 +644,9 @@ connection_start_reading,(connection_t *conn))
		return;
		});

		tor_assert(conn->read_event);
		if (connection_check_event(conn, conn->read_event) < 0) {
		return;
		}

		if (conn->linked) {
		conn->reading_from_linked_conn = 1;
		@@ -643,7 +686,9 @@ connection_stop_writing,(connection_t *conn))
		return;
		});

		tor_assert(conn->write_event);
		if (connection_check_event(conn, conn->write_event) < 0) {
		return;
		}

		if (conn->linked) {
		conn->writing_to_linked_conn = 0;
		@@ -669,7 +714,9 @@ connection_start_writing,(connection_t *conn))
		return;
		});

		tor_assert(conn->write_event);
		if (connection_check_event(conn, conn->write_event) < 0) {
		return;
		}

		if (conn->linked) {
		conn->writing_to_linked_conn = 1;