diff options
Diffstat (limited to 'src/common/compat_libevent.c')
| -rw-r--r-- | src/common/compat_libevent.c | 484 |
1 files changed, 23 insertions, 461 deletions
diff --git a/src/common/compat_libevent.c b/src/common/compat_libevent.c index 74b54bb855..4a3b1af922 100644 --- a/src/common/compat_libevent.c +++ b/src/common/compat_libevent.c @@ -1,16 +1,14 @@ -/* Copyright (c) 2009-2013, The Tor Project, Inc. */ +/* Copyright (c) 2009-2016, The Tor Project, Inc. */ /* See LICENSE for licensing information */ /** * \file compat_libevent.c - * \brief Wrappers to handle porting between different versions of libevent. - * - * In an ideal world, we'd just use Libevent 2.0 from now on. But as of June - * 2012, Libevent 1.4 is still all over, and some poor souls are stuck on - * Libevent 1.3e. */ + * \brief Wrappers and utility functions for Libevent. + */ #include "orconfig.h" #include "compat.h" +#define COMPAT_LIBEVENT_PRIVATE #include "compat_libevent.h" #include "crypto.h" @@ -18,54 +16,14 @@ #include "util.h" #include "torlog.h" -#ifdef HAVE_EVENT2_EVENT_H #include <event2/event.h> #include <event2/thread.h> -#ifdef USE_BUFFEREVENTS -#include <event2/bufferevent.h> -#endif -#else -#include <event.h> -#endif -/** A number representing a version of Libevent. - - This is a 4-byte number, with the first three bytes representing the - major, minor, and patchlevel respectively of the library. The fourth - byte is unused. - - This is equivalent to the format of LIBEVENT_VERSION_NUMBER on Libevent - 2.0.1 or later. For versions of Libevent before 1.4.0, which followed the - format of "1.0, 1.0a, 1.0b", we define 1.0 to be equivalent to 1.0.0, 1.0a - to be equivalent to 1.0.1, and so on. -*/ -typedef uint32_t le_version_t; - -/** @{ */ -/** Macros: returns the number of a libevent version as a le_version_t */ -#define V(major, minor, patch) \ - (((major) << 24) | ((minor) << 16) | ((patch) << 8)) -#define V_OLD(major, minor, patch) \ - V((major), (minor), (patch)-'a'+1) -/** @} */ - -/** Represetns a version of libevent so old we can't figure out what version - * it is. */ -#define LE_OLD V(0,0,0) -/** Represents a version of libevent so weird we can't figure out what version - * 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 * log messages from libevent. */ -static void +STATIC void libevent_logging_callback(int severity, const char *msg) { char buf[1024]; @@ -101,62 +59,25 @@ configure_libevent_logging(void) { event_set_log_callback(libevent_logging_callback); } + /** Ignore any libevent log message that contains <b>msg</b>. */ void 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. */ -struct event * -tor_event_new(struct event_base *base, int sock, short what, - void (*cb)(int, short, void *), void *arg) -{ - struct event *e = tor_malloc_zero(sizeof(struct event)); - event_set(e, sock, what, cb, arg); - if (! base) - base = tor_libevent_get_base(); - event_base_set(base, e); - return e; -} -/** Work-alike replacement for evtimer_new() on pre-Libevent-2.0 systems. */ -struct event * -tor_evtimer_new(struct event_base *base, - void (*cb)(int, short, void *), void *arg) -{ - return tor_event_new(base, -1, 0, cb, arg); -} -/** Work-alike replacement for evsignal_new() on pre-Libevent-2.0 systems. */ -struct event * -tor_evsignal_new(struct event_base * base, int sig, - void (*cb)(int, short, void *), void *arg) -{ - return tor_event_new(base, sig, EV_SIGNAL|EV_PERSIST, cb, arg); -} -/** Work-alike replacement for event_free() on pre-Libevent-2.0 systems. */ +/* Wrapper for event_free() that tolerates tor_event_free(NULL) */ void tor_event_free(struct event *ev) { - event_del(ev); - tor_free(ev); + if (ev == NULL) + return; + event_free(ev); } -#endif /** Global event base for use by the main thread. */ -struct event_base *the_event_base = NULL; +static struct event_base *the_event_base = NULL; /* This is what passes for version detection on OSX. We set * MACOSX_KQUEUE_IS_BROKEN to true iff we're on a version of OSX before @@ -170,17 +91,6 @@ struct event_base *the_event_base = NULL; #endif #endif -#ifdef USE_BUFFEREVENTS -static int using_iocp_bufferevents = 0; -static void tor_libevent_set_tick_timeout(int msec_per_tick); - -int -tor_libevent_using_iocp_bufferevents(void) -{ - return using_iocp_bufferevents; -} -#endif - /** Initialize the Libevent library and set up the event base. */ void tor_libevent_initialize(tor_libevent_cfg *torcfg) @@ -189,326 +99,73 @@ tor_libevent_initialize(tor_libevent_cfg *torcfg) /* some paths below don't use torcfg, so avoid unused variable warnings */ (void)torcfg; -#ifdef HAVE_EVENT2_EVENT_H { int attempts = 0; - int using_threads; struct event_config *cfg; - retry: ++attempts; - using_threads = 0; cfg = event_config_new(); tor_assert(cfg); -#if defined(_WIN32) && defined(USE_BUFFEREVENTS) - if (! torcfg->disable_iocp) { - evthread_use_windows_threads(); - event_config_set_flag(cfg, EVENT_BASE_FLAG_STARTUP_IOCP); - using_iocp_bufferevents = 1; - using_threads = 1; - } else { - using_iocp_bufferevents = 0; - } -#endif - - if (!using_threads) { - /* Telling Libevent not to try to turn locking on can avoid a needless - * socketpair() attempt. */ - event_config_set_flag(cfg, EVENT_BASE_FLAG_NOLOCK); - } + /* Telling Libevent not to try to turn locking on can avoid a needless + * socketpair() attempt. */ + event_config_set_flag(cfg, EVENT_BASE_FLAG_NOLOCK); -#if defined(LIBEVENT_VERSION_NUMBER) && LIBEVENT_VERSION_NUMBER >= V(2,0,7) if (torcfg->num_cpus > 0) event_config_set_num_cpus_hint(cfg, torcfg->num_cpus); -#endif -#if LIBEVENT_VERSION_NUMBER >= V(2,0,9) /* We can enable changelist support with epoll, since we don't give * Libevent any dup'd fds. This lets us avoid some syscalls. */ event_config_set_flag(cfg, EVENT_BASE_FLAG_EPOLL_USE_CHANGELIST); -#endif the_event_base = event_base_new_with_config(cfg); event_config_free(cfg); - - if (using_threads && the_event_base == NULL && attempts < 2) { - /* This could be a socketpair() failure, which can happen sometimes on - * windows boxes with obnoxious firewall rules. Downgrade and try - * again. */ -#if defined(_WIN32) && defined(USE_BUFFEREVENTS) - if (torcfg->disable_iocp == 0) { - log_warn(LD_GENERAL, "Unable to initialize Libevent. Trying again " - "with IOCP disabled."); - } else -#endif - { - log_warn(LD_GENERAL, "Unable to initialize Libevent. Trying again."); - } - - torcfg->disable_iocp = 1; - goto retry; - } } -#else - the_event_base = event_init(); -#endif if (!the_event_base) { + /* LCOV_EXCL_START */ log_err(LD_GENERAL, "Unable to initialize Libevent: cannot continue."); exit(1); + /* LCOV_EXCL_STOP */ } -#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); -#endif } /** Return the current Libevent event base that we're set up to use. */ -struct event_base * -tor_libevent_get_base(void) +MOCK_IMPL(struct event_base *, +tor_libevent_get_base, (void)) { + tor_assert(the_event_base != NULL); 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>"; -#endif -} - -/** Return the le_version_t for the version of libevent specified in the - * string <b>v</b>. If the version is very new or uses an unrecognized - * version, format, return LE_OTHER. */ -static le_version_t -tor_decode_libevent_version(const char *v) -{ - unsigned major, minor, patchlevel; - char c, e, extra; - int fields; - - /* Try the new preferred "1.4.11-stable" format. - * Also accept "1.4.14b-stable". */ - fields = tor_sscanf(v, "%u.%u.%u%c%c", &major, &minor, &patchlevel, &c, &e); - if (fields == 3 || - ((fields == 4 || fields == 5 ) && (c == '-' || c == '_')) || - (fields == 5 && TOR_ISALPHA(c) && (e == '-' || e == '_'))) { - return V(major,minor,patchlevel); - } - - /* Try the old "1.3e" format. */ - fields = tor_sscanf(v, "%u.%u%c%c", &major, &minor, &c, &extra); - if (fields == 3 && TOR_ISALPHA(c)) { - return V_OLD(major, minor, c); - } else if (fields == 2) { - return V(major, minor, 0); - } - - return LE_OTHER; -} - -/** Return an integer representing the binary interface of a Libevent library. - * Two different versions with different numbers are sure not to be binary - * compatible. Two different versions with the same numbers have a decent - * chance of binary compatibility.*/ -static int -le_versions_compatibility(le_version_t v) -{ - if (v == LE_OTHER) - return 0; - if (v < V_OLD(1,0,'c')) - return 1; - else if (v < V(1,4,0)) - return 2; - else if (v < V(1,4,99)) - return 3; - else if (v < V(2,0,1)) - return 4; - else /* Everything 2.0 and later should be compatible. */ - 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) -#define HEADER_VERSION LIBEVENT_VERSION -#elif defined(_EVENT_VERSION) -#define HEADER_VERSION _EVENT_VERSION -#endif - /** Return a string representation of the version of Libevent that was used * at compilation time. */ const char * tor_libevent_get_header_version_str(void) { - return HEADER_VERSION; + return LIBEVENT_VERSION; } -/** See whether the headers we were built against differ from the library we - * linked against so much that we're likely to crash. If so, warn the - * user. */ -void -tor_check_libevent_header_compatibility(void) -{ - (void) le_versions_compatibility; - (void) tor_decode_libevent_version; - - /* 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) - /* We have a header-file version and a function-call version. Easy. */ - if (strcmp(HEADER_VERSION, event_get_version())) { - le_version_t v1, v2; - int compat1 = -1, compat2 = -1; - int verybad; - v1 = tor_decode_libevent_version(HEADER_VERSION); - v2 = tor_decode_libevent_version(event_get_version()); - compat1 = le_versions_compatibility(v1); - compat2 = le_versions_compatibility(v2); - - verybad = compat1 != compat2; - - tor_log(verybad ? LOG_WARN : LOG_NOTICE, - LD_GENERAL, "We were compiled with headers from version %s " - "of Libevent, but we're using a Libevent library that says it's " - "version %s.", HEADER_VERSION, event_get_version()); - if (verybad) - log_warn(LD_GENERAL, "This will almost certainly make Tor crash."); - else - log_info(LD_GENERAL, "I think these versions are binary-compatible."); - } -#elif defined(HAVE_EVENT_GET_VERSION) - /* 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. - */ -#ifdef HAVE_STRUCT_EVENT_MIN_HEAP_IDX - /* The header files are 1.4.0-beta or later. If the version is not - * 1.4.0-beta, we are incompatible. */ - { - if (strcmp(event_get_version(), "1.4.0-beta")) { - log_warn(LD_GENERAL, "It's a little hard to tell, but you seem to have " - "Libevent 1.4.0-beta header files, whereas you have linked " - "against Libevent %s. This will probably make Tor crash.", - event_get_version()); - } - } -#else - /* Our headers are 1.3e or earlier. If the library version is not 1.4.x or - later, we're probably fine. */ - { - const char *v = event_get_version(); - if ((v[0] == '1' && v[2] == '.' && v[3] > '3') || v[0] > '1') { - log_warn(LD_GENERAL, "It's a little hard to tell, but you seem to have " - "Libevent header file from 1.3e or earlier, whereas you have " - "linked against Libevent %s. This will probably make Tor " - "crash.", event_get_version()); - } - } -#endif - -#elif defined(HEADER_VERSION) -#warn "_EVENT_VERSION is defined but not get_event_version(): Libevent is odd." -#else - /* Your libevent is ancient. */ -#endif -} - -/* - If possible, we're going to try to use Libevent's periodic timer support, - since it does a pretty good job of making sure that periodic events get - called exactly M seconds apart, rather than starting each one exactly M - seconds after the time that the last one was run. - */ -#ifdef HAVE_EVENT2_EVENT_H -#define HAVE_PERIODIC -#define PERIODIC_FLAGS EV_PERSIST -#else -#define PERIODIC_FLAGS 0 -#endif - /** Represents a timer that's run every N microseconds by Libevent. */ struct periodic_timer_t { /** Underlying event used to implement this periodic event. */ @@ -517,11 +174,6 @@ struct periodic_timer_t { void (*cb)(struct periodic_timer_t *, void *); /** User-supplied data for the callback */ void *data; -#ifndef HAVE_PERIODIC - /** If Libevent doesn't know how to invoke events every N microseconds, - * we'll need to remember the timeout interval here. */ - struct timeval tv; -#endif }; /** Libevent callback to implement a periodic event. */ @@ -531,10 +183,6 @@ periodic_timer_cb(evutil_socket_t fd, short what, void *arg) periodic_timer_t *timer = arg; (void) what; (void) fd; -#ifndef HAVE_PERIODIC - /** reschedule the event as needed. */ - event_add(timer->ev, &timer->tv); -#endif timer->cb(timer, timer->data); } @@ -552,16 +200,13 @@ periodic_timer_new(struct event_base *base, tor_assert(tv); tor_assert(cb); timer = tor_malloc_zero(sizeof(periodic_timer_t)); - if (!(timer->ev = tor_event_new(base, -1, PERIODIC_FLAGS, + if (!(timer->ev = tor_event_new(base, -1, EV_PERSIST, periodic_timer_cb, timer))) { tor_free(timer); return NULL; } timer->cb = cb; timer->data = data; -#ifndef HAVE_PERIODIC - memcpy(&timer->tv, tv, sizeof(struct timeval)); -#endif event_add(timer->ev, (struct timeval *)tv); /*drop const for old libevent*/ return timer; } @@ -576,72 +221,19 @@ periodic_timer_free(periodic_timer_t *timer) tor_free(timer); } -#ifdef USE_BUFFEREVENTS -static const struct timeval *one_tick = NULL; -/** - * Return a special timeout to be passed whenever libevent's O(1) timeout - * implementation should be used. Only use this when the timer is supposed - * to fire after msec_per_tick ticks have elapsed. -*/ -const struct timeval * -tor_libevent_get_one_tick_timeout(void) -{ - tor_assert(one_tick); - return one_tick; -} - -/** Initialize the common timeout that we'll use to refill the buckets every - * time a tick elapses. */ -static void -tor_libevent_set_tick_timeout(int msec_per_tick) -{ - struct event_base *base = tor_libevent_get_base(); - struct timeval tv; - - tor_assert(! one_tick); - tv.tv_sec = msec_per_tick / 1000; - tv.tv_usec = (msec_per_tick % 1000) * 1000; - one_tick = event_base_init_common_timeout(base, &tv); -} - -static struct bufferevent * -tor_get_root_bufferevent(struct bufferevent *bev) -{ - struct bufferevent *u; - while ((u = bufferevent_get_underlying(bev)) != NULL) - bev = u; - return bev; -} - -int -tor_set_bufferevent_rate_limit(struct bufferevent *bev, - struct ev_token_bucket_cfg *cfg) -{ - return bufferevent_set_rate_limit(tor_get_root_bufferevent(bev), cfg); -} - -int -tor_add_bufferevent_to_rate_limit_group(struct bufferevent *bev, - struct bufferevent_rate_limit_group *g) -{ - return bufferevent_add_to_rate_limit_group(tor_get_root_bufferevent(bev), g); -} -#endif - int tor_init_libevent_rng(void) { int rv = 0; -#ifdef HAVE_EVUTIL_SECURE_RNG_INIT char buf[256]; if (evutil_secure_rng_init() < 0) { rv = -1; } - /* Older libevent -- manually initialize the RNG */ crypto_rand(buf, 32); +#ifdef HAVE_EVUTIL_SECURE_RNG_ADD_BYTES evutil_secure_rng_add_bytes(buf, 32); - evutil_secure_rng_get_bytes(buf, sizeof(buf)); #endif + evutil_secure_rng_get_bytes(buf, sizeof(buf)); return rv; } @@ -691,33 +283,3 @@ tor_gettimeofday_cache_set(const struct timeval *tv) #endif #endif -/** - * As tor_gettimeofday_cached, but can never move backwards in time. - * - * The returned value may diverge from wall-clock time, since wall-clock time - * can trivially be adjusted backwards, and this can't. Don't mix wall-clock - * time with these values in the same calculation. - * - * Depending on implementation, this function may or may not "smooth out" huge - * jumps forward in wall-clock time. It may or may not keep its results - * advancing forward (as opposed to stalling) if the wall-clock time goes - * backwards. The current implementation does neither of of these. - * - * This function is not thread-safe; do not call it outside the main thread. - * - * In future versions of Tor, this may return a time does not have its - * origin at the Unix epoch. - */ -void -tor_gettimeofday_cached_monotonic(struct timeval *tv) -{ - struct timeval last_tv = { 0, 0 }; - - tor_gettimeofday_cached(tv); - if (timercmp(tv, &last_tv, <)) { - memcpy(tv, &last_tv, sizeof(struct timeval)); - } else { - memcpy(&last_tv, tv, sizeof(struct timeval)); - } -} - |