Remove workarounds for Libevent < 1.3.

This actually lets us dump a lot of old cruft that nobody had (I
hope!) tested in ages.

Closes 15248.

changes/deprecated-libevents

@@ -0,0 +1,3 @@
+  o New system requirements:
+    - Tor no longer includes workarounds for Libevent versions before 1.3e.
+      Libevent 2.0 or later is recommended. Closes ticket #15248.

configure.ac

@@ -439,15 +439,6 @@ AC_SUBST(TOR_LIB_WS32)
 AC_SUBST(TOR_LIB_GDI)
 AC_SUBST(TOR_LIB_IPHLPAPI)
 
-dnl We need to do this before we try our disgusting hack below.
-AC_CHECK_HEADERS([sys/types.h])
-
-dnl This is a disgusting hack so we safely include older libevent headers.
-AC_CHECK_TYPE(u_int64_t, unsigned long long)
-AC_CHECK_TYPE(u_int32_t, unsigned long)
-AC_CHECK_TYPE(u_int16_t, unsigned short)
-AC_CHECK_TYPE(u_int8_t, unsigned char)
-
 tor_libevent_pkg_redhat="libevent"
 tor_libevent_pkg_debian="libevent-dev"
 tor_libevent_devpkg_redhat="libevent-devel"
@@ -488,13 +479,10 @@ save_CPPFLAGS="$CPPFLAGS"
 LIBS="-levent $STATIC_LIBEVENT_FLAGS $TOR_LIB_WS32 $LIBS"
 LDFLAGS="$TOR_LDFLAGS_libevent $LDFLAGS"
 CPPFLAGS="$TOR_CPPFLAGS_libevent $CPPFLAGS"
-AC_CHECK_FUNCS([event_get_version \
-                event_get_version_number \
-                event_get_method \
-                event_set_log_callback \
+AC_CHECK_FUNCS([event_get_version_number \
                 evutil_secure_rng_set_urandom_device_file \
                 evutil_secure_rng_init \
-                event_base_loopexit])
+               ])
 AC_CHECK_MEMBERS([struct event.min_heap_idx], , ,
 [#include <event.h>
 ])

src/common/compat_libevent.c

@@ -56,11 +56,6 @@ typedef uint32_t le_version_t;
  * it is. */
 #define LE_OTHER V(0,0,99)
 
-#if 0
-static le_version_t tor_get_libevent_version(const char **v_out);
-#endif
-
-#if defined(HAVE_EVENT_SET_LOG_CALLBACK) || defined(RUNNING_DOXYGEN)
 /** A string which, if it appears in a libevent log, should be ignored. */
 static const char *suppress_msg = NULL;
 /** Callback function passed to event_set_log() so we can intercept
@@ -107,17 +102,6 @@ suppress_libevent_log_msg(const char *msg)
 {
   suppress_msg = msg;
 }
-#else
-void
-configure_libevent_logging(void)
-{
-}
-void
-suppress_libevent_log_msg(const char *msg)
-{
-  (void)msg;
-}
-#endif
 
 #ifndef HAVE_EVENT2_EVENT_H
 /** Work-alike replacement for event_new() on pre-Libevent-2.0 systems. */
@@ -275,19 +259,11 @@ tor_libevent_initialize(tor_libevent_cfg *torcfg)
     exit(1);
   }
 
-#if defined(HAVE_EVENT_GET_VERSION) && defined(HAVE_EVENT_GET_METHOD)
   /* Making this a NOTICE for now so we can link bugs to a libevent versions
    * or methods better. */
   log_info(LD_GENERAL,
       "Initialized libevent version %s using method %s. Good.",
       event_get_version(), tor_libevent_get_method());
-#else
-  log_notice(LD_GENERAL,
-      "Initialized old libevent (version 1.0b or earlier).");
-  log_warn(LD_GENERAL,
-      "You have a *VERY* old version of libevent.  It is likely to be buggy; "
-      "please build Tor with a more recent version.");
-#endif
 
 #ifdef USE_BUFFEREVENTS
   tor_libevent_set_tick_timeout(torcfg->msec_per_tick);
@@ -301,27 +277,14 @@ tor_libevent_get_base, (void))
   return the_event_base;
 }
 
-#ifndef HAVE_EVENT_BASE_LOOPEXIT
-/** Replacement for event_base_loopexit on some very old versions of Libevent
- * that we are not yet brave enough to deprecate. */
-int
-tor_event_base_loopexit(struct event_base *base, struct timeval *tv)
-{
-  tor_assert(base == the_event_base);
-  return event_loopexit(tv);
-}
-#endif
-
 /** Return the name of the Libevent backend we're using. */
 const char *
 tor_libevent_get_method(void)
 {
 #ifdef HAVE_EVENT2_EVENT_H
   return event_base_get_method(the_event_base);
-#elif defined(HAVE_EVENT_GET_METHOD)
-  return event_get_method();
 #else
-  return "<unknown>";
+  return event_get_method();
 #endif
 }
 
@@ -376,54 +339,12 @@ le_versions_compatibility(le_version_t v)
     return 5;
 }
 
-#if 0
-/** Return the version number of the currently running version of Libevent.
- * See le_version_t for info on the format.
- */
-static le_version_t
-tor_get_libevent_version(const char **v_out)
-{
-  const char *v;
-  le_version_t r;
-#if defined(HAVE_EVENT_GET_VERSION_NUMBER)
-  v = event_get_version();
-  r = event_get_version_number();
-#elif defined (HAVE_EVENT_GET_VERSION)
-  v = event_get_version();
-  r = tor_decode_libevent_version(v);
-#else
-  v = "pre-1.0c";
-  r = LE_OLD;
-#endif
-  if (v_out)
-    *v_out = v;
-  return r;
-}
-#endif
-
 /** Return a string representation of the version of the currently running
  * version of Libevent. */
 const char *
 tor_libevent_get_version_str(void)
 {
-#ifdef HAVE_EVENT_GET_VERSION
   return event_get_version();
-#else
-  return "pre-1.0c";
-#endif
-}
-
-/**
- * Compare the current Libevent method and version to a list of versions
- * which are known not to work.  Warn the user as appropriate.
- */
-void
-tor_check_libevent_version(const char *m, int server,
-                           const char **badness_out)
-{
-  (void) m;
-  (void) server;
-  *badness_out = NULL;
 }
 
 #if defined(LIBEVENT_VERSION)
@@ -452,7 +373,7 @@ tor_check_libevent_header_compatibility(void)
   /* In libevent versions before 2.0, it's hard to keep binary compatibility
    * between upgrades, and unpleasant to detect when the version we compiled
    * against is unlike the version we have linked against. Here's how. */
-#if defined(HEADER_VERSION) && defined(HAVE_EVENT_GET_VERSION)
+#if defined(HEADER_VERSION)
   /* We have a header-file version and a function-call version. Easy. */
   if (strcmp(HEADER_VERSION, event_get_version())) {
     le_version_t v1, v2;
@@ -474,7 +395,7 @@ tor_check_libevent_header_compatibility(void)
     else
       log_info(LD_GENERAL, "I think these versions are binary-compatible.");
   }
-#elif defined(HAVE_EVENT_GET_VERSION)
+#else
   /* event_get_version but no _EVENT_VERSION.  We might be in 1.4.0-beta or
      earlier, where that's normal.  To see whether we were compiled with an
      earlier version, let's see whether the struct event defines MIN_HEAP_IDX.
@@ -504,9 +425,6 @@ tor_check_libevent_header_compatibility(void)
   }
 #endif
 
-#elif defined(HEADER_VERSION)
-#warn "_EVENT_VERSION is defined but not get_event_version(): Libevent is odd."
-#else
   /* Your libevent is ancient. */
 #endif
 }

src/common/compat_libevent.h

@@ -52,12 +52,7 @@ periodic_timer_t *periodic_timer_new(struct event_base *base,
              void *data);
 void periodic_timer_free(periodic_timer_t *);
 
-#ifdef HAVE_EVENT_BASE_LOOPEXIT
 #define tor_event_base_loopexit event_base_loopexit
-#else
-struct timeval;
-int tor_event_base_loopexit(struct event_base *base, struct timeval *tv);
-#endif
 
 /** Defines a configuration for using libevent with Tor: passed as an argument
  * to tor_libevent_initialize() to describe how we want to set up. */
@@ -74,8 +69,6 @@ typedef struct tor_libevent_cfg {
 void tor_libevent_initialize(tor_libevent_cfg *cfg);
 MOCK_DECL(struct event_base *, tor_libevent_get_base, (void));
 const char *tor_libevent_get_method(void);
-void tor_check_libevent_version(const char *m, int server,
-                                const char **badness_out);
 void tor_check_libevent_header_compatibility(void);
 const char *tor_libevent_get_version_str(void);
 const char *tor_libevent_get_header_version_str(void);

src/or/config.c

@@ -6695,7 +6695,6 @@ get_num_cpus(const or_options_t *options)
 static void
 init_libevent(const or_options_t *options)
 {
-  const char *badness=NULL;
   tor_libevent_cfg cfg;
 
   tor_assert(options);
@@ -6716,17 +6715,6 @@ init_libevent(const or_options_t *options)
   tor_libevent_initialize(&cfg);
 
   suppress_libevent_log_msg(NULL);
-
-  tor_check_libevent_version(tor_libevent_get_method(),
-                             server_mode(get_options()),
-                             &badness);
-  if (badness) {
-    const char *v = tor_libevent_get_version_str();
-    const char *m = tor_libevent_get_method();
-    control_event_general_status(LOG_WARN,
-        "BAD_LIBEVENT VERSION=%s METHOD=%s BADNESS=%s RECOVERED=NO",
-                                 v, m, badness);
-  }
 }
 
 /** Return a newly allocated string holding a filename relative to the data