diff options
| -rw-r--r-- | src/xtime.c | 62 | ||||
| -rw-r--r-- | tests/xtime.c | 34 |
2 files changed, 55 insertions, 41 deletions
diff --git a/src/xtime.c b/src/xtime.c index 5b259ab..bcf6dd3 100644 --- a/src/xtime.c +++ b/src/xtime.c @@ -69,73 +69,77 @@ static int month_length(int year, int month) { } int xtimegm(struct tm *tm, time_t *timep) { - tm->tm_isdst = 0; + struct tm copy = *tm; + copy.tm_isdst = 0; - if (wrap(&tm->tm_sec, 60, &tm->tm_min) != 0) { + if (wrap(©.tm_sec, 60, ©.tm_min) != 0) { goto overflow; } - if (wrap(&tm->tm_min, 60, &tm->tm_hour) != 0) { + if (wrap(©.tm_min, 60, ©.tm_hour) != 0) { goto overflow; } - if (wrap(&tm->tm_hour, 24, &tm->tm_mday) != 0) { + if (wrap(©.tm_hour, 24, ©.tm_mday) != 0) { goto overflow; } // In order to wrap the days of the month, we first need to know what // month it is - if (wrap(&tm->tm_mon, 12, &tm->tm_year) != 0) { + if (wrap(©.tm_mon, 12, ©.tm_year) != 0) { goto overflow; } - if (tm->tm_mday < 1) { + if (copy.tm_mday < 1) { do { - --tm->tm_mon; - if (wrap(&tm->tm_mon, 12, &tm->tm_year) != 0) { + --copy.tm_mon; + if (wrap(©.tm_mon, 12, ©.tm_year) != 0) { goto overflow; } - tm->tm_mday += month_length(tm->tm_year, tm->tm_mon); - } while (tm->tm_mday < 1); + copy.tm_mday += month_length(copy.tm_year, copy.tm_mon); + } while (copy.tm_mday < 1); } else { while (true) { - int days = month_length(tm->tm_year, tm->tm_mon); - if (tm->tm_mday <= days) { + int days = month_length(copy.tm_year, copy.tm_mon); + if (copy.tm_mday <= days) { break; } - tm->tm_mday -= days; - ++tm->tm_mon; - if (wrap(&tm->tm_mon, 12, &tm->tm_year) != 0) { + copy.tm_mday -= days; + ++copy.tm_mon; + if (wrap(©.tm_mon, 12, ©.tm_year) != 0) { goto overflow; } } } - tm->tm_yday = 0; - for (int i = 0; i < tm->tm_mon; ++i) { - tm->tm_yday += month_length(tm->tm_year, i); + copy.tm_yday = 0; + for (int i = 0; i < copy.tm_mon; ++i) { + copy.tm_yday += month_length(copy.tm_year, i); } - tm->tm_yday += tm->tm_mday - 1; + copy.tm_yday += copy.tm_mday - 1; int leap_days; // Compute floor((year - 69)/4) - floor((year - 1)/100) + floor((year + 299)/400) without overflows - if (tm->tm_year >= 0) { - leap_days = floor_div(tm->tm_year - 69, 4) - floor_div(tm->tm_year - 1, 100) + floor_div(tm->tm_year - 101, 400) + 1; + if (copy.tm_year >= 0) { + leap_days = floor_div(copy.tm_year - 69, 4) - floor_div(copy.tm_year - 1, 100) + floor_div(copy.tm_year - 101, 400) + 1; } else { - leap_days = floor_div(tm->tm_year + 3, 4) - floor_div(tm->tm_year + 99, 100) + floor_div(tm->tm_year + 299, 400) - 17; + leap_days = floor_div(copy.tm_year + 3, 4) - floor_div(copy.tm_year + 99, 100) + floor_div(copy.tm_year + 299, 400) - 17; } - long long epoch_days = 365LL * (tm->tm_year - 70) + leap_days + tm->tm_yday; - tm->tm_wday = (epoch_days + 4) % 7; - if (tm->tm_wday < 0) { - tm->tm_wday += 7; + long long epoch_days = 365LL * (copy.tm_year - 70) + leap_days + copy.tm_yday; + copy.tm_wday = (epoch_days + 4) % 7; + if (copy.tm_wday < 0) { + copy.tm_wday += 7; } - long long epoch_time = tm->tm_sec + 60 * (tm->tm_min + 60 * (tm->tm_hour + 24 * epoch_days)); - *timep = (time_t)epoch_time; - if ((long long)*timep != epoch_time) { + long long epoch_time = copy.tm_sec + 60 * (copy.tm_min + 60 * (copy.tm_hour + 24 * epoch_days)); + time_t time = (time_t)epoch_time; + if ((long long)time != epoch_time) { goto overflow; } + + *tm = copy; + *timep = time; return 0; overflow: diff --git a/tests/xtime.c b/tests/xtime.c index c8dc00b..ec499d8 100644 --- a/tests/xtime.c +++ b/tests/xtime.c @@ -137,6 +137,24 @@ static bool check_one_xtimegm(const struct tm *tm) { return ret; } +/** Check an overflowing xtimegm() call. */ +static bool check_xtimegm_overflow(const struct tm *tm) { + struct tm copy = *tm; + time_t time = 123; + + bool ret = true; + ret &= bfs_check(xtimegm(©, &time) == -1 && errno == EOVERFLOW); + ret &= bfs_check(tm_equal(©, tm)); + ret &= bfs_check(time == 123); + + if (!ret) { + bfs_diag("xtimegm(): " TM_FORMAT, TM_PRINTF(copy)); + bfs_diag("(input): " TM_FORMAT, TM_PRINTF(*tm)); + } + + return ret; +} + /** xtimegm() tests. */ static bool check_xtimegm(void) { bool ret = true; @@ -144,7 +162,6 @@ static bool check_xtimegm(void) { struct tm tm = { .tm_isdst = -1, }; - time_t time; // Check equivalence with mktime() for (tm.tm_year = 10; tm.tm_year <= 200; tm.tm_year += 10) @@ -157,17 +174,10 @@ static bool check_xtimegm(void) { } // Check integer overflow cases - tm = (struct tm){ .tm_sec = INT_MAX, .tm_min = INT_MAX }; - ret &= bfs_check(xtimegm(&tm, &time) == -1 && errno == EOVERFLOW); - - tm = (struct tm){ .tm_min = INT_MAX, .tm_hour = INT_MAX }; - ret &= bfs_check(xtimegm(&tm, &time) == -1 && errno == EOVERFLOW); - - tm = (struct tm){ .tm_hour = INT_MAX, .tm_mday = INT_MAX }; - ret &= bfs_check(xtimegm(&tm, &time) == -1 && errno == EOVERFLOW); - - tm = (struct tm){ .tm_mon = INT_MAX, .tm_year = INT_MAX }; - ret &= bfs_check(xtimegm(&tm, &time) == -1 && errno == EOVERFLOW); + check_xtimegm_overflow(&(struct tm) { .tm_sec = INT_MAX, .tm_min = INT_MAX }); + check_xtimegm_overflow(&(struct tm) { .tm_min = INT_MAX, .tm_hour = INT_MAX }); + check_xtimegm_overflow(&(struct tm) { .tm_hour = INT_MAX, .tm_mday = INT_MAX }); + check_xtimegm_overflow(&(struct tm) { .tm_mon = INT_MAX, .tm_year = INT_MAX }); return ret; } |