Mercurial > hg > nginx
view src/core/ngx_times.c @ 6893:a3e6d660b179 stable-1.10
Fixed trailer construction with limit on FreeBSD and macOS.
The ngx_chain_coalesce_file() function may produce more bytes to send then
requested in the limit passed, as it aligns the last file position
to send to memory page boundary. As a result, (limit - send) may become
negative. This resulted in big positive number when converted to size_t
while calling ngx_output_chain_to_iovec().
Another part of the problem is in ngx_chain_coalesce_file(): it changes cl
to the next chain link even if the current buffer is only partially sent
due to limit.
Therefore, if a file buffer was not expected to be fully sent due to limit,
and was followed by a memory buffer, nginx called sendfile() with a part
of the file buffer, and the memory buffer in trailer. If there were enough
room in the socket buffer, this resulted in a part of the file buffer being
skipped, and corresponding part of the memory buffer sent instead.
The bug was introduced in 8e903522c17a (1.7.8). Configurations affected
are ones using limits, that is, limit_rate and/or sendfile_max_chunk, and
memory buffers after file ones (may happen when using subrequests or
with proxying with disk buffering).
Fix is to explicitly check if (send < limit) before constructing trailer
with ngx_output_chain_to_iovec(). Additionally, ngx_chain_coalesce_file()
was modified to preserve unfinished file buffers in cl.
author | Maxim Dounin <mdounin@mdounin.ru> |
---|---|
date | Fri, 20 Jan 2017 21:12:48 +0300 |
parents | 40bea39731d7 |
children | 63699a40e2ff |
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/* * Copyright (C) Igor Sysoev * Copyright (C) Nginx, Inc. */ #include <ngx_config.h> #include <ngx_core.h> /* * The time may be updated by signal handler or by several threads. * The time update operations are rare and require to hold the ngx_time_lock. * The time read operations are frequent, so they are lock-free and get time * values and strings from the current slot. Thus thread may get the corrupted * values only if it is preempted while copying and then it is not scheduled * to run more than NGX_TIME_SLOTS seconds. */ #define NGX_TIME_SLOTS 64 static ngx_uint_t slot; static ngx_atomic_t ngx_time_lock; volatile ngx_msec_t ngx_current_msec; volatile ngx_time_t *ngx_cached_time; volatile ngx_str_t ngx_cached_err_log_time; volatile ngx_str_t ngx_cached_http_time; volatile ngx_str_t ngx_cached_http_log_time; volatile ngx_str_t ngx_cached_http_log_iso8601; volatile ngx_str_t ngx_cached_syslog_time; #if !(NGX_WIN32) /* * localtime() and localtime_r() are not Async-Signal-Safe functions, therefore, * they must not be called by a signal handler, so we use the cached * GMT offset value. Fortunately the value is changed only two times a year. */ static ngx_int_t cached_gmtoff; #endif static ngx_time_t cached_time[NGX_TIME_SLOTS]; static u_char cached_err_log_time[NGX_TIME_SLOTS] [sizeof("1970/09/28 12:00:00")]; static u_char cached_http_time[NGX_TIME_SLOTS] [sizeof("Mon, 28 Sep 1970 06:00:00 GMT")]; static u_char cached_http_log_time[NGX_TIME_SLOTS] [sizeof("28/Sep/1970:12:00:00 +0600")]; static u_char cached_http_log_iso8601[NGX_TIME_SLOTS] [sizeof("1970-09-28T12:00:00+06:00")]; static u_char cached_syslog_time[NGX_TIME_SLOTS] [sizeof("Sep 28 12:00:00")]; static char *week[] = { "Sun", "Mon", "Tue", "Wed", "Thu", "Fri", "Sat" }; static char *months[] = { "Jan", "Feb", "Mar", "Apr", "May", "Jun", "Jul", "Aug", "Sep", "Oct", "Nov", "Dec" }; void ngx_time_init(void) { ngx_cached_err_log_time.len = sizeof("1970/09/28 12:00:00") - 1; ngx_cached_http_time.len = sizeof("Mon, 28 Sep 1970 06:00:00 GMT") - 1; ngx_cached_http_log_time.len = sizeof("28/Sep/1970:12:00:00 +0600") - 1; ngx_cached_http_log_iso8601.len = sizeof("1970-09-28T12:00:00+06:00") - 1; ngx_cached_syslog_time.len = sizeof("Sep 28 12:00:00") - 1; ngx_cached_time = &cached_time[0]; ngx_time_update(); } void ngx_time_update(void) { u_char *p0, *p1, *p2, *p3, *p4; ngx_tm_t tm, gmt; time_t sec; ngx_uint_t msec; ngx_time_t *tp; struct timeval tv; if (!ngx_trylock(&ngx_time_lock)) { return; } ngx_gettimeofday(&tv); sec = tv.tv_sec; msec = tv.tv_usec / 1000; ngx_current_msec = (ngx_msec_t) sec * 1000 + msec; tp = &cached_time[slot]; if (tp->sec == sec) { tp->msec = msec; ngx_unlock(&ngx_time_lock); return; } if (slot == NGX_TIME_SLOTS - 1) { slot = 0; } else { slot++; } tp = &cached_time[slot]; tp->sec = sec; tp->msec = msec; ngx_gmtime(sec, &gmt); p0 = &cached_http_time[slot][0]; (void) ngx_sprintf(p0, "%s, %02d %s %4d %02d:%02d:%02d GMT", week[gmt.ngx_tm_wday], gmt.ngx_tm_mday, months[gmt.ngx_tm_mon - 1], gmt.ngx_tm_year, gmt.ngx_tm_hour, gmt.ngx_tm_min, gmt.ngx_tm_sec); #if (NGX_HAVE_GETTIMEZONE) tp->gmtoff = ngx_gettimezone(); ngx_gmtime(sec + tp->gmtoff * 60, &tm); #elif (NGX_HAVE_GMTOFF) ngx_localtime(sec, &tm); cached_gmtoff = (ngx_int_t) (tm.ngx_tm_gmtoff / 60); tp->gmtoff = cached_gmtoff; #else ngx_localtime(sec, &tm); cached_gmtoff = ngx_timezone(tm.ngx_tm_isdst); tp->gmtoff = cached_gmtoff; #endif p1 = &cached_err_log_time[slot][0]; (void) ngx_sprintf(p1, "%4d/%02d/%02d %02d:%02d:%02d", tm.ngx_tm_year, tm.ngx_tm_mon, tm.ngx_tm_mday, tm.ngx_tm_hour, tm.ngx_tm_min, tm.ngx_tm_sec); p2 = &cached_http_log_time[slot][0]; (void) ngx_sprintf(p2, "%02d/%s/%d:%02d:%02d:%02d %c%02i%02i", tm.ngx_tm_mday, months[tm.ngx_tm_mon - 1], tm.ngx_tm_year, tm.ngx_tm_hour, tm.ngx_tm_min, tm.ngx_tm_sec, tp->gmtoff < 0 ? '-' : '+', ngx_abs(tp->gmtoff / 60), ngx_abs(tp->gmtoff % 60)); p3 = &cached_http_log_iso8601[slot][0]; (void) ngx_sprintf(p3, "%4d-%02d-%02dT%02d:%02d:%02d%c%02i:%02i", tm.ngx_tm_year, tm.ngx_tm_mon, tm.ngx_tm_mday, tm.ngx_tm_hour, tm.ngx_tm_min, tm.ngx_tm_sec, tp->gmtoff < 0 ? '-' : '+', ngx_abs(tp->gmtoff / 60), ngx_abs(tp->gmtoff % 60)); p4 = &cached_syslog_time[slot][0]; (void) ngx_sprintf(p4, "%s %2d %02d:%02d:%02d", months[tm.ngx_tm_mon - 1], tm.ngx_tm_mday, tm.ngx_tm_hour, tm.ngx_tm_min, tm.ngx_tm_sec); ngx_memory_barrier(); ngx_cached_time = tp; ngx_cached_http_time.data = p0; ngx_cached_err_log_time.data = p1; ngx_cached_http_log_time.data = p2; ngx_cached_http_log_iso8601.data = p3; ngx_cached_syslog_time.data = p4; ngx_unlock(&ngx_time_lock); } #if !(NGX_WIN32) void ngx_time_sigsafe_update(void) { u_char *p, *p2; ngx_tm_t tm; time_t sec; ngx_time_t *tp; struct timeval tv; if (!ngx_trylock(&ngx_time_lock)) { return; } ngx_gettimeofday(&tv); sec = tv.tv_sec; tp = &cached_time[slot]; if (tp->sec == sec) { ngx_unlock(&ngx_time_lock); return; } if (slot == NGX_TIME_SLOTS - 1) { slot = 0; } else { slot++; } tp = &cached_time[slot]; tp->sec = 0; ngx_gmtime(sec + cached_gmtoff * 60, &tm); p = &cached_err_log_time[slot][0]; (void) ngx_sprintf(p, "%4d/%02d/%02d %02d:%02d:%02d", tm.ngx_tm_year, tm.ngx_tm_mon, tm.ngx_tm_mday, tm.ngx_tm_hour, tm.ngx_tm_min, tm.ngx_tm_sec); p2 = &cached_syslog_time[slot][0]; (void) ngx_sprintf(p2, "%s %2d %02d:%02d:%02d", months[tm.ngx_tm_mon - 1], tm.ngx_tm_mday, tm.ngx_tm_hour, tm.ngx_tm_min, tm.ngx_tm_sec); ngx_memory_barrier(); ngx_cached_err_log_time.data = p; ngx_cached_syslog_time.data = p2; ngx_unlock(&ngx_time_lock); } #endif u_char * ngx_http_time(u_char *buf, time_t t) { ngx_tm_t tm; ngx_gmtime(t, &tm); return ngx_sprintf(buf, "%s, %02d %s %4d %02d:%02d:%02d GMT", week[tm.ngx_tm_wday], tm.ngx_tm_mday, months[tm.ngx_tm_mon - 1], tm.ngx_tm_year, tm.ngx_tm_hour, tm.ngx_tm_min, tm.ngx_tm_sec); } u_char * ngx_http_cookie_time(u_char *buf, time_t t) { ngx_tm_t tm; ngx_gmtime(t, &tm); /* * Netscape 3.x does not understand 4-digit years at all and * 2-digit years more than "37" */ return ngx_sprintf(buf, (tm.ngx_tm_year > 2037) ? "%s, %02d-%s-%d %02d:%02d:%02d GMT": "%s, %02d-%s-%02d %02d:%02d:%02d GMT", week[tm.ngx_tm_wday], tm.ngx_tm_mday, months[tm.ngx_tm_mon - 1], (tm.ngx_tm_year > 2037) ? tm.ngx_tm_year: tm.ngx_tm_year % 100, tm.ngx_tm_hour, tm.ngx_tm_min, tm.ngx_tm_sec); } void ngx_gmtime(time_t t, ngx_tm_t *tp) { ngx_int_t yday; ngx_uint_t n, sec, min, hour, mday, mon, year, wday, days, leap; /* the calculation is valid for positive time_t only */ n = (ngx_uint_t) t; days = n / 86400; /* January 1, 1970 was Thursday */ wday = (4 + days) % 7; n %= 86400; hour = n / 3600; n %= 3600; min = n / 60; sec = n % 60; /* * the algorithm based on Gauss' formula, * see src/http/ngx_http_parse_time.c */ /* days since March 1, 1 BC */ days = days - (31 + 28) + 719527; /* * The "days" should be adjusted to 1 only, however, some March 1st's go * to previous year, so we adjust them to 2. This causes also shift of the * last February days to next year, but we catch the case when "yday" * becomes negative. */ year = (days + 2) * 400 / (365 * 400 + 100 - 4 + 1); yday = days - (365 * year + year / 4 - year / 100 + year / 400); if (yday < 0) { leap = (year % 4 == 0) && (year % 100 || (year % 400 == 0)); yday = 365 + leap + yday; year--; } /* * The empirical formula that maps "yday" to month. * There are at least 10 variants, some of them are: * mon = (yday + 31) * 15 / 459 * mon = (yday + 31) * 17 / 520 * mon = (yday + 31) * 20 / 612 */ mon = (yday + 31) * 10 / 306; /* the Gauss' formula that evaluates days before the month */ mday = yday - (367 * mon / 12 - 30) + 1; if (yday >= 306) { year++; mon -= 10; /* * there is no "yday" in Win32 SYSTEMTIME * * yday -= 306; */ } else { mon += 2; /* * there is no "yday" in Win32 SYSTEMTIME * * yday += 31 + 28 + leap; */ } tp->ngx_tm_sec = (ngx_tm_sec_t) sec; tp->ngx_tm_min = (ngx_tm_min_t) min; tp->ngx_tm_hour = (ngx_tm_hour_t) hour; tp->ngx_tm_mday = (ngx_tm_mday_t) mday; tp->ngx_tm_mon = (ngx_tm_mon_t) mon; tp->ngx_tm_year = (ngx_tm_year_t) year; tp->ngx_tm_wday = (ngx_tm_wday_t) wday; } time_t ngx_next_time(time_t when) { time_t now, next; struct tm tm; now = ngx_time(); ngx_libc_localtime(now, &tm); tm.tm_hour = (int) (when / 3600); when %= 3600; tm.tm_min = (int) (when / 60); tm.tm_sec = (int) (when % 60); next = mktime(&tm); if (next == -1) { return -1; } if (next - now > 0) { return next; } tm.tm_mday++; /* mktime() should normalize a date (Jan 32, etc) */ next = mktime(&tm); if (next != -1) { return next; } return -1; }