commit a77a366b87fb04a878392284241fe72850b4dd88 Author: Nick Mathewson nickm@torproject.org Date: Tue Feb 6 11:02:41 2018 -0500
Warn on zstd header/library version mismatch
If we're going to potentially degrade performance in this case, we may as well tell people so. --- src/common/compress.c | 10 ++++++++++ src/common/compress.h | 1 + src/common/compress_zstd.c | 46 ++++++++++++++++++++++++++++++++++++++-------- src/common/compress_zstd.h | 1 + src/or/main.c | 2 ++ 5 files changed, 52 insertions(+), 8 deletions(-)
diff --git a/src/common/compress.c b/src/common/compress.c index 47c93cf6a..cb1549f1a 100644 --- a/src/common/compress.c +++ b/src/common/compress.c @@ -663,3 +663,13 @@ tor_compress_init(void) tor_zstd_init(); }
+/** Warn if we had any problems while setting up our compression libraries. + * + * (This isn't part of tor_compress_init, since the logs aren't set up yet.) + */ +void +tor_compress_log_init_warnings(void) +{ + tor_zstd_warn_if_version_mismatched(); +} + diff --git a/src/common/compress.h b/src/common/compress.h index 952102bf9..65d63a438 100644 --- a/src/common/compress.h +++ b/src/common/compress.h @@ -87,6 +87,7 @@ void tor_compress_free_(tor_compress_state_t *state); size_t tor_compress_state_size(const tor_compress_state_t *state);
void tor_compress_init(void); +void tor_compress_log_init_warnings(void);
#endif /* !defined(TOR_COMPRESS_H) */
diff --git a/src/common/compress_zstd.c b/src/common/compress_zstd.c index 02469ced9..96906efb9 100644 --- a/src/common/compress_zstd.c +++ b/src/common/compress_zstd.c @@ -58,21 +58,29 @@ tor_zstd_method_supported(void) #endif }
+/** Format a zstd version number as a string in <b>buf</b>. */ +static void +tor_zstd_format_version(char *buf, size_t buflen, unsigned version_number) +{ + tor_snprintf(buf, buflen, + "%u.%u.%u", + version_number / 10000 % 100, + version_number / 100 % 100, + version_number % 100); +} + +#define VERSION_STR_MAX_LEN 16 /* more than enough space for 99.99.99 */ + /** Return a string representation of the version of the currently running * version of libzstd. Returns NULL if Zstandard is unsupported. */ const char * tor_zstd_get_version_str(void) { #ifdef HAVE_ZSTD - static char version_str[16]; - size_t version_number; + static char version_str[VERSION_STR_MAX_LEN];
- version_number = ZSTD_versionNumber(); - tor_snprintf(version_str, sizeof(version_str), - "%d.%d.%d", - (int) version_number / 10000 % 100, - (int) version_number / 100 % 100, - (int) version_number % 100); + tor_zstd_format_version(version_str, sizeof(version_str), + ZSTD_versionNumber());
return version_str; #else /* !(defined(HAVE_ZSTD)) */ @@ -487,6 +495,27 @@ tor_zstd_init(void) atomic_counter_init(&total_zstd_allocation); }
+/** Warn if the header and library versions don't match. */ +void +tor_zstd_warn_if_version_mismatched(void) +{ +#ifdef HAVE_ZSTD + if (! tor_zstd_can_use_static_apis()) { + char header_version[VERSION_STR_MAX_LEN]; + char runtime_version[VERSION_STR_MAX_LEN]; + tor_zstd_format_version(header_version, sizeof(header_version), + ZSTD_VERSION_NUMBER); + tor_zstd_format_version(runtime_version, sizeof(runtime_version), + ZSTD_versionNumber()); + + log_warn(LD_GENERAL, + "Tor was compiled with zstd %s, but is running with zstd %s. " + "For safety, we'll avoid using advanced zstd functionality.", + header_version, runtime_version); + } +#endif +} + #ifdef TOR_UNIT_TESTS /** Testing only: disable usage of static-only APIs, so we can make sure that * we still work without them. */ @@ -496,3 +525,4 @@ tor_zstd_set_static_apis_disabled_for_testing(int disabled) static_apis_disable_for_testing = disabled; } #endif + diff --git a/src/common/compress_zstd.h b/src/common/compress_zstd.h index 8882617c9..bd42cf65c 100644 --- a/src/common/compress_zstd.h +++ b/src/common/compress_zstd.h @@ -43,6 +43,7 @@ size_t tor_zstd_compress_state_size(const tor_zstd_compress_state_t *state); size_t tor_zstd_get_total_allocation(void);
void tor_zstd_init(void); +void tor_zstd_warn_if_version_mismatched(void);
#ifdef TOR_UNIT_TESTS void tor_zstd_set_static_apis_disabled_for_testing(int disabled); diff --git a/src/or/main.c b/src/or/main.c index 98566c0c9..894b12cc3 100644 --- a/src/or/main.c +++ b/src/or/main.c @@ -3323,6 +3323,8 @@ tor_init(int argc, char *argv[]) if (strstr(version, "alpha") || strstr(version, "beta")) log_notice(LD_GENERAL, "This version is not a stable Tor release. " "Expect more bugs than usual."); + + tor_compress_log_init_warnings(); }
#ifdef HAVE_RUST