tor-commits April 2011

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[tor/master] Detect and handle NULL returns from (gm/local)time_r
by nickm＠torproject.org 28 Apr '11

28 Apr '11

commit 51e551d3837990b7c4491253a88bedd2513fe1de Author: Nick Mathewson <nickm(a)torproject.org> Date: Tue Dec 7 14:37:50 2010 -0500 Detect and handle NULL returns from (gm/local)time_r These functions can return NULL for otherwise-valid values of time_t. Notably, the glibc gmtime manpage says it can return NULL if the year if greater than INT_MAX, and the windows MSDN gmtime page says it can return NULL for negative time_t values. Also, our formatting code is not guaranteed to correctly handle years after 9999 CE. This patch tries to correct this by detecting NULL values from gmtime/localtime_r, and trying to clip them to a reasonable end of the scale. If they are in the middle of the scale, we call it a downright error. Arguably, it's a bug to get out-of-bounds dates like this to begin with. But we've had bugs of this kind in the past, and warning when we see a bug is much kinder than doing a NULL-pointer dereference. Boboper found this one too. --- changes/gmtime_null | 6 +++ src/common/compat.c | 104 +++++++++++++++++++++++++++++++++++++++++++++------ src/common/compat.h | 9 ---- 3 files changed, 98 insertions(+), 21 deletions(-) diff --git a/changes/gmtime_null b/changes/gmtime_null new file mode 100644 index 0000000..16a2540 --- /dev/null +++ b/changes/gmtime_null @@ -0,0 +1,6 @@ + o Minor bugfixes + - On some platforms, gmtime and localtime can return NULL under + certain circumstances even for well-defined values of time_t. + Try to detect and make up for this deficiency. Possible fix for + bug 2077. Bugfix on all versions of Tor. Found by boboper. + diff --git a/src/common/compat.c b/src/common/compat.c index 27489e5..9b7c0b7 100644 --- a/src/common/compat.c +++ b/src/common/compat.c @@ -1996,14 +1996,88 @@ tor_gettimeofday(struct timeval *timeval) #define TIME_FNS_NEED_LOCKS #endif +static struct tm * +correct_tm(int islocal, const time_t *timep, struct tm *resultbuf, + struct tm *r) +{ + const char *outcome; + + if (PREDICT_LIKELY(r)) { + if (r->tm_year > 8099) { /* We can't strftime dates after 9999 CE. */ + r->tm_year = 8099; + r->tm_mon = 11; + r->tm_mday = 31; + r->tm_yday = 365; + r->tm_hour = 23; + r->tm_min = 59; + r->tm_sec = 59; + } + return r; + } + + /* If we get here, gmtime or localtime returned NULL. It might have done + * this because of overrun or underrun, or it might have done it because of + * some other weird issue. */ + if (timep) { + if (*timep < 0) { + r = resultbuf; + r->tm_year = 70; /* 1970 CE */ + r->tm_mon = 0; + r->tm_mday = 1; + r->tm_yday = 1; + r->tm_hour = 0; + r->tm_min = 0 ; + r->tm_sec = 0; + outcome = "Rounding up to 1970"; + goto done; + } else if (*timep >= INT32_MAX) { + /* Rounding down to INT32_MAX isn't so great, but keep in mind that we + * only do it if gmtime/localtime tells us NULL. */ + r = resultbuf; + r->tm_year = 137; /* 2037 CE */ + r->tm_mon = 11; + r->tm_mday = 31; + r->tm_yday = 365; + r->tm_hour = 23; + r->tm_min = 59; + r->tm_sec = 59; + outcome = "Rounding down to 2037"; + goto done; + } + } + + /* If we get here, then gmtime/localtime failed without getting an extreme + * value for *timep */ + + tor_fragile_assert(); + r = resultbuf; + memset(resultbuf, 0, sizeof(struct tm)); + outcome="can't recover"; + done: + log_warn(LD_BUG, "%s("I64_FORMAT") failed with error %s: %s", + islocal?"localtime":"gmtime", + timep?I64_PRINTF_ARG(*timep):0, + strerror(errno), + outcome); + return r; +} + + /** @{ */ /** As localtime_r, but defined for platforms that don't have it: * * Convert *timep to a struct tm in local time, and store the value in * *result. Return the result on success, or NULL on failure. */ -#ifndef HAVE_LOCALTIME_R -#ifdef TIME_FNS_NEED_LOCKS +#ifdef HAVE_LOCALTIME_R +struct tm * +tor_localtime_r(const time_t *timep, struct tm *result) +{ + struct tm *r; + r = localtime_r(timep, result); + return correct_tm(1, timep, result, r); +} +#elif defined(TIME_FNS_NEED_LOCKS) struct tm * tor_localtime_r(const time_t *timep, struct tm *result) { @@ -2013,9 +2087,10 @@ tor_localtime_r(const time_t *timep, struct tm *result) tor_assert(result); tor_mutex_acquire(m); r = localtime(timep); - memcpy(result, r, sizeof(struct tm)); + if (r) + memcpy(result, r, sizeof(struct tm)); tor_mutex_release(m); - return result; + return correct_tm(1, timep, result, r); } #else struct tm * @@ -2024,11 +2099,11 @@ tor_localtime_r(const time_t *timep, struct tm *result) struct tm *r; tor_assert(result); r = localtime(timep); - memcpy(result, r, sizeof(struct tm)); - return result; + if (r) + memcpy(result, r, sizeof(struct tm)); + return correct_tm(1, timep, result, r); } #endif -#endif /** @} */ /** @{ */ @@ -2038,7 +2113,14 @@ tor_localtime_r(const time_t *timep, struct tm *result) * *result. Return the result on success, or NULL on failure. */ #ifndef HAVE_GMTIME_R -#ifdef TIME_FNS_NEED_LOCKS +struct tm * +tor_gmtime_r(const time_t *timep, struct tm *result) +{ + struct tm *r; + r = gmtime_r(timep, result); + return correct_tm(0, timep, result, r); +} +#elif defined(TIME_FNS_NEED_LOCKS) struct tm * tor_gmtime_r(const time_t *timep, struct tm *result) { @@ -2050,7 +2132,7 @@ tor_gmtime_r(const time_t *timep, struct tm *result) r = gmtime(timep); memcpy(result, r, sizeof(struct tm)); tor_mutex_release(m); - return result; + return correct_tm(0, timep, result, r); } #else struct tm * @@ -2060,11 +2142,9 @@ tor_gmtime_r(const time_t *timep, struct tm *result) tor_assert(result); r = gmtime(timep); memcpy(result, r, sizeof(struct tm)); - return result; + return correct_tm(0, timep, result, r); } #endif -#endif -/** @} */ #if defined(USE_WIN32_THREADS) void diff --git a/src/common/compat.h b/src/common/compat.h index 550c08b..af795ff 100644 --- a/src/common/compat.h +++ b/src/common/compat.h @@ -321,17 +321,8 @@ struct timeval { void tor_gettimeofday(struct timeval *timeval); -#ifdef HAVE_LOCALTIME_R -#define tor_localtime_r localtime_r -#else struct tm *tor_localtime_r(const time_t *timep, struct tm *result); -#endif - -#ifdef HAVE_GMTIME_R -#define tor_gmtime_r gmtime_r -#else struct tm *tor_gmtime_r(const time_t *timep, struct tm *result); -#endif #ifndef timeradd /** Replacement for timeradd on platforms that do not have it: sets tvout to

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[tor/master] Correct the logic from f14754fbd for tor_gmtime_r
by nickm＠torproject.org 28 Apr '11

28 Apr '11

commit 2dc9546eef6d748245d90b288f28ace1aa9b6f14 Author: John Brooks <special(a)dereferenced.net> Date: Mon Jan 3 21:36:09 2011 -0700 Correct the logic from f14754fbd for tor_gmtime_r --- src/common/compat.c | 8 +++++--- 1 files changed, 5 insertions(+), 3 deletions(-) diff --git a/src/common/compat.c b/src/common/compat.c index 9b7c0b7..3644bd9 100644 --- a/src/common/compat.c +++ b/src/common/compat.c @@ -2112,7 +2112,7 @@ tor_localtime_r(const time_t *timep, struct tm *result) * Convert *timep to a struct tm in UTC, and store the value in * *result. Return the result on success, or NULL on failure. */ -#ifndef HAVE_GMTIME_R +#ifdef HAVE_GMTIME_R struct tm * tor_gmtime_r(const time_t *timep, struct tm *result) { @@ -2130,7 +2130,8 @@ tor_gmtime_r(const time_t *timep, struct tm *result) tor_assert(result); tor_mutex_acquire(m); r = gmtime(timep); - memcpy(result, r, sizeof(struct tm)); + if (r) + memcpy(result, r, sizeof(struct tm)); tor_mutex_release(m); return correct_tm(0, timep, result, r); } @@ -2141,7 +2142,8 @@ tor_gmtime_r(const time_t *timep, struct tm *result) struct tm *r; tor_assert(result); r = gmtime(timep); - memcpy(result, r, sizeof(struct tm)); + if (r) + memcpy(result, r, sizeof(struct tm)); return correct_tm(0, timep, result, r); } #endif

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[tor/master] Merge remote-tracking branch 'origin/maint-0.2.2'
by nickm＠torproject.org 28 Apr '11

28 Apr '11

commit 8b33928676bdf751010e5d660e6e6cca9a152389 Merge: 88638d4 2dc9546 Author: Nick Mathewson <nickm(a)torproject.org> Date: Thu Apr 28 17:15:31 2011 -0400 Merge remote-tracking branch 'origin/maint-0.2.2' changes/gmtime_null | 6 +++ src/common/compat.c | 112 ++++++++++++++++++++++++++++++++++++++++++++------- src/common/compat.h | 9 ---- 3 files changed, 103 insertions(+), 24 deletions(-)

1 0

[tor/maint-0.2.2] Correct the logic from f14754fbd for tor_gmtime_r
by nickm＠torproject.org 28 Apr '11

28 Apr '11

1 0

[tor/maint-0.2.2] Detect and handle NULL returns from (gm/local)time_r
by nickm＠torproject.org 28 Apr '11

28 Apr '11

1 0

[tor/master] Merge remote-tracking branch 'origin/maint-0.2.2'
by nickm＠torproject.org 28 Apr '11

28 Apr '11

commit 88638d40ca08057e006c0dd6604a4255371acc75 Merge: 32918e9 3055acb Author: Nick Mathewson <nickm(a)torproject.org> Date: Thu Apr 28 16:05:59 2011 -0400 Merge remote-tracking branch 'origin/maint-0.2.2' changes/ticket2497 | 4 ++++ src/or/rephist.c | 14 ++++++++++++-- 2 files changed, 16 insertions(+), 2 deletions(-)

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[tor/master] Don't report empty bw-history lines in extrainfo
by nickm＠torproject.org 28 Apr '11

28 Apr '11

commit c1927d7d5f5dff5b8d7da5bd4e7a743eb06bcbb3 Author: Sebastian Hahn <sebastian(a)torproject.org> Date: Sat Apr 16 16:01:36 2011 +0200 Don't report empty bw-history lines in extrainfo Some tor relays would report lines like these in their extrainfo documents: dirreq-write-history 2011-03-14 16:46:44 (900 s) This was confusing to some people who look at the stats. It would happen whenever a relay first starts up, or when a relay has dirport disabled. Change this so that lines without actual bw entries are omitted. Implements ticket 2497. --- changes/ticket2497 | 4 ++++ src/or/rephist.c | 14 ++++++++++++-- 2 files changed, 16 insertions(+), 2 deletions(-) diff --git a/changes/ticket2497 b/changes/ticket2497 new file mode 100644 index 0000000..5117141 --- /dev/null +++ b/changes/ticket2497 @@ -0,0 +1,4 @@ + o Minor features: + - Ensure that no empty [dirreq-](read|write)-history lines are added + to an extrainfo document. Implements ticket 2497. + diff --git a/src/or/rephist.c b/src/or/rephist.c index 9b7eefe..b55797a 100644 --- a/src/or/rephist.c +++ b/src/or/rephist.c @@ -1524,10 +1524,15 @@ rep_hist_get_bandwidth_lines(void) size_t len; /* opt [dirreq-](read|write)-history yyyy-mm-dd HH:MM:SS (n s) n,n,n... */ - len = (67+21*NUM_TOTALS)*4; +/* The n,n,n part above. Largest representation of a uint64_t is 20 chars + * long, plus the comma. */ +#define MAX_HIST_VALUE_LEN 21*NUM_TOTALS + len = (67+MAX_HIST_VALUE_LEN)*4; buf = tor_malloc_zero(len); cp = buf; for (r=0;r<4;++r) { + char tmp[MAX_HIST_VALUE_LEN]; + size_t slen; switch (r) { case 0: b = write_array; @@ -1547,11 +1552,16 @@ rep_hist_get_bandwidth_lines(void) break; } tor_assert(b); + slen = rep_hist_fill_bandwidth_history(tmp, MAX_HIST_VALUE_LEN, b); + /* If we don't have anything to write, skip to the next entry. */ + if (slen == 0) + continue; format_iso_time(t, b->next_period-NUM_SECS_BW_SUM_INTERVAL); tor_snprintf(cp, len-(cp-buf), "%s %s (%d s) ", desc, t, NUM_SECS_BW_SUM_INTERVAL); cp += strlen(cp); - cp += rep_hist_fill_bandwidth_history(cp, len-(cp-buf), b); + strlcat(cp, tmp, len-(cp-buf)); + cp += slen; strlcat(cp, "\n", len-(cp-buf)); ++cp; }

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[tor/master] Merge remote-tracking branch 'sebastian/bug2497' into maint-0.2.2
by nickm＠torproject.org 28 Apr '11

28 Apr '11

commit 3055acbdbe914c31ca4825ed60b4cce6676bd61e Merge: 2c0258b c1927d7 Author: Nick Mathewson <nickm(a)torproject.org> Date: Thu Apr 28 16:05:34 2011 -0400 Merge remote-tracking branch 'sebastian/bug2497' into maint-0.2.2 changes/ticket2497 | 4 ++++ src/or/rephist.c | 14 ++++++++++++-- 2 files changed, 16 insertions(+), 2 deletions(-)

1 0

[tor/maint-0.2.2] Don't report empty bw-history lines in extrainfo
by nickm＠torproject.org 28 Apr '11

28 Apr '11

1 0

[tor/maint-0.2.2] Merge remote-tracking branch 'sebastian/bug2497' into maint-0.2.2
by nickm＠torproject.org 28 Apr '11

28 Apr '11

1 0

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tor-commits April 2011