view src/os/unix/ngx_time.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 d620f497c50f
children
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/*
 * Copyright (C) Igor Sysoev
 * Copyright (C) Nginx, Inc.
 */


#include <ngx_config.h>
#include <ngx_core.h>


/*
 * FreeBSD does not test /etc/localtime change, however, we can workaround it
 * by calling tzset() with TZ and then without TZ to update timezone.
 * The trick should work since FreeBSD 2.1.0.
 *
 * Linux does not test /etc/localtime change in localtime(),
 * but may stat("/etc/localtime") several times in every strftime(),
 * therefore we use it to update timezone.
 *
 * Solaris does not test /etc/TIMEZONE change too and no workaround available.
 */

void
ngx_timezone_update(void)
{
#if (NGX_FREEBSD)

    if (getenv("TZ")) {
        return;
    }

    putenv("TZ=UTC");

    tzset();

    unsetenv("TZ");

    tzset();

#elif (NGX_LINUX)
    time_t      s;
    struct tm  *t;
    char        buf[4];

    s = time(0);

    t = localtime(&s);

    strftime(buf, 4, "%H", t);

#endif
}


void
ngx_localtime(time_t s, ngx_tm_t *tm)
{
#if (NGX_HAVE_LOCALTIME_R)
    (void) localtime_r(&s, tm);

#else
    ngx_tm_t  *t;

    t = localtime(&s);
    *tm = *t;

#endif

    tm->ngx_tm_mon++;
    tm->ngx_tm_year += 1900;
}


void
ngx_libc_localtime(time_t s, struct tm *tm)
{
#if (NGX_HAVE_LOCALTIME_R)
    (void) localtime_r(&s, tm);

#else
    struct tm  *t;

    t = localtime(&s);
    *tm = *t;

#endif
}


void
ngx_libc_gmtime(time_t s, struct tm *tm)
{
#if (NGX_HAVE_LOCALTIME_R)
    (void) gmtime_r(&s, tm);

#else
    struct tm  *t;

    t = gmtime(&s);
    *tm = *t;

#endif
}