From 7920ea55b8d994268d2b07f27316b0f34d8f27e5 Mon Sep 17 00:00:00 2001 From: Nick Mathewson Date: Fri, 25 Nov 2011 17:18:03 -0500 Subject: [PATCH] Refactor tor_event_base_once to do what we actually want This version avoids the timeout system entirely, gives a nicer interface, and lets us manage allocation explicitly. --- src/common/compat_libevent.c | 47 +++++++++++++++++++++++++++++++----- src/common/compat_libevent.h | 3 +-- src/common/tortls.c | 10 +++----- src/common/tortls.h | 2 +- src/common/util.c | 4 +-- src/or/connection_or.c | 4 +-- 6 files changed, 50 insertions(+), 20 deletions(-) diff --git a/src/common/compat_libevent.c b/src/common/compat_libevent.c index b709b4afd6..c3a4746b37 100644 --- a/src/common/compat_libevent.c +++ b/src/common/compat_libevent.c @@ -558,13 +558,48 @@ tor_check_libevent_header_compatibility(void) #endif } -/** Wrapper around libevent's event_base_once(). Sets a - * timeout-triggered event with no associated file descriptor. */ -int -tor_event_base_once(void (*cb)(evutil_socket_t, short, void *), - void *arg, struct timeval *timer) +typedef struct runnable_t { + struct event *ev; + void (*cb)(void *arg); + void *arg; +} runnable_t; + +/** Callback for tor_run_in_libevent_loop */ +static void +run_runnable_cb(evutil_socket_t s, short what, void *arg) { - return event_base_once(tor_libevent_get_base(), -1, EV_TIMEOUT, cb, arg, timer); + runnable_t *r = arg; + void (*cb)(void *) = r->cb; + void *cb_arg = r->arg; + (void)what; + (void)s; + event_free(r->ev); + tor_free(r); + + cb(cb_arg); +} + +/** Cause cb(arg) to run later on this iteration of the libevent loop, or in + * the next iteration of the libevent loop. This is useful for when you're + * deep inside a no-reentrant code and there's some function you want to call + * without worrying about whether it might cause reeentrant invocation. + */ +int +tor_run_in_libevent_loop(void (*cb)(void *arg), void *arg) +{ + runnable_t *r = tor_malloc(sizeof(runnable_t)); + r->cb = cb; + r->arg = arg; + r->ev = tor_event_new(tor_libevent_get_base(), -1, EV_TIMEOUT, + run_runnable_cb, r); + if (!r->ev) { + tor_free(r); + return -1; + } + /* Make the event active immediately. */ + event_active(r->ev, EV_TIMEOUT, 1); + + return 0; } /* diff --git a/src/common/compat_libevent.h b/src/common/compat_libevent.h index 897eddbbe0..3f916d16b0 100644 --- a/src/common/compat_libevent.h +++ b/src/common/compat_libevent.h @@ -46,8 +46,7 @@ void tor_event_free(struct event *ev); typedef struct periodic_timer_t periodic_timer_t; -int tor_event_base_once(void (*cb)(evutil_socket_t, short, void *), - void *arg, struct timeval *timer); +int tor_run_in_libevent_loop(void (*cb)(void *arg), void *arg); periodic_timer_t *periodic_timer_new(struct event_base *base, const struct timeval *tv, diff --git a/src/common/tortls.c b/src/common/tortls.c index 59e1bbca4f..88efa05331 100644 --- a/src/common/tortls.c +++ b/src/common/tortls.c @@ -160,7 +160,7 @@ struct tor_tls_t { /** Callback to invoke whenever a client tries to renegotiate more than once. */ - void (*excess_renegotiations_callback)(evutil_socket_t, short, void *); + void (*excess_renegotiations_callback)(void *); /** Argument to pass to negotiated_callback. */ void *callback_arg; @@ -1326,10 +1326,8 @@ tor_tls_got_client_hello(tor_tls_t *tls) callback, so we set a libevent timer that triggers in the next event loop and closes the connection. */ - struct timeval zero_seconds_timer = {0,0}; - - if (tor_event_base_once(tls->excess_renegotiations_callback, - tls->callback_arg, &zero_seconds_timer) < 0) { + if (tor_run_in_libevent_loop(tls->excess_renegotiations_callback, + tls->callback_arg) < 0) { log_warn(LD_GENERAL, "Didn't manage to set a renegotiation limiting callback."); } } @@ -1557,7 +1555,7 @@ tor_tls_set_logged_address(tor_tls_t *tls, const char *address) void tor_tls_set_renegotiate_callbacks(tor_tls_t *tls, void (*cb)(tor_tls_t *, void *arg), - void (*cb2)(evutil_socket_t, short, void *), + void (*cb2)(void *), void *arg) { tls->negotiated_callback = cb; diff --git a/src/common/tortls.h b/src/common/tortls.h index 5874881989..9f86e37127 100644 --- a/src/common/tortls.h +++ b/src/common/tortls.h @@ -63,7 +63,7 @@ tor_tls_t *tor_tls_new(int sock, int is_server); void tor_tls_set_logged_address(tor_tls_t *tls, const char *address); void tor_tls_set_renegotiate_callbacks(tor_tls_t *tls, void (*cb)(tor_tls_t *, void *arg), - void (*cb2)(evutil_socket_t, short, void *), + void (*cb2)(void *), void *arg); int tor_tls_is_server(tor_tls_t *tls); void tor_tls_free(tor_tls_t *tls); diff --git a/src/common/util.c b/src/common/util.c index efda6c07f3..ecd3b59908 100644 --- a/src/common/util.c +++ b/src/common/util.c @@ -3647,8 +3647,8 @@ tor_get_exit_code(const process_handle_t *process_handle, /* Process has not exited */ return PROCESS_EXIT_RUNNING; } else if (retval != process_handle->pid) { - log_warn(LD_GENERAL, "waitpid() failed for PID %d: %s", process_handle->pid, - strerror(errno)); + log_warn(LD_GENERAL, "waitpid() failed for PID %d: %s", + process_handle->pid, strerror(errno)); return PROCESS_EXIT_ERROR; } diff --git a/src/or/connection_or.c b/src/or/connection_or.c index c0957161d8..cbdfa44581 100644 --- a/src/or/connection_or.c +++ b/src/or/connection_or.c @@ -1157,11 +1157,9 @@ connection_or_tls_renegotiated_cb(tor_tls_t *tls, void *_conn) * tor_tls_got_client_hello() when the server receives excess * renegotiation attempts; probably indicating a DoS. */ static void -connection_or_close_connection_cb(evutil_socket_t fd, short what, void *_conn) +connection_or_close_connection_cb(void *_conn) { or_connection_t *conn = _conn; - (void) what; - (void) fd; connection_stop_reading(TO_CONN(conn)); connection_mark_for_close(TO_CONN(conn));