view src/os/unix/ngx_freebsd_init.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 8f038068f4bc
children 56fc55e32f23
line wrap: on
line source


/*
 * Copyright (C) Igor Sysoev
 * Copyright (C) Nginx, Inc.
 */


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


/* FreeBSD 3.0 at least */
char    ngx_freebsd_kern_ostype[16];
char    ngx_freebsd_kern_osrelease[128];
int     ngx_freebsd_kern_osreldate;
int     ngx_freebsd_hw_ncpu;
int     ngx_freebsd_kern_ipc_somaxconn;
u_long  ngx_freebsd_net_inet_tcp_sendspace;

/* FreeBSD 4.9 */
int     ngx_freebsd_machdep_hlt_logical_cpus;


ngx_uint_t  ngx_freebsd_sendfile_nbytes_bug;
ngx_uint_t  ngx_freebsd_use_tcp_nopush;

ngx_uint_t  ngx_debug_malloc;


static ngx_os_io_t ngx_freebsd_io = {
    ngx_unix_recv,
    ngx_readv_chain,
    ngx_udp_unix_recv,
    ngx_unix_send,
    ngx_udp_unix_send,
#if (NGX_HAVE_SENDFILE)
    ngx_freebsd_sendfile_chain,
    NGX_IO_SENDFILE
#else
    ngx_writev_chain,
    0
#endif
};


typedef struct {
    char        *name;
    void        *value;
    size_t       size;
    ngx_uint_t   exists;
} sysctl_t;


sysctl_t sysctls[] = {
    { "hw.ncpu",
      &ngx_freebsd_hw_ncpu,
      sizeof(ngx_freebsd_hw_ncpu), 0 },

    { "machdep.hlt_logical_cpus",
      &ngx_freebsd_machdep_hlt_logical_cpus,
      sizeof(ngx_freebsd_machdep_hlt_logical_cpus), 0 },

    { "net.inet.tcp.sendspace",
      &ngx_freebsd_net_inet_tcp_sendspace,
      sizeof(ngx_freebsd_net_inet_tcp_sendspace), 0 },

    { "kern.ipc.somaxconn",
      &ngx_freebsd_kern_ipc_somaxconn,
      sizeof(ngx_freebsd_kern_ipc_somaxconn), 0 },

    { NULL, NULL, 0, 0 }
};


void
ngx_debug_init(void)
{
#if (NGX_DEBUG_MALLOC)

#if __FreeBSD_version >= 500014 && __FreeBSD_version < 1000011
    _malloc_options = "J";
#elif __FreeBSD_version < 500014
    malloc_options = "J";
#endif

    ngx_debug_malloc = 1;

#else
    char  *mo;

    mo = getenv("MALLOC_OPTIONS");

    if (mo && ngx_strchr(mo, 'J')) {
        ngx_debug_malloc = 1;
    }
#endif
}


ngx_int_t
ngx_os_specific_init(ngx_log_t *log)
{
    int         version;
    size_t      size;
    ngx_err_t   err;
    ngx_uint_t  i;

    size = sizeof(ngx_freebsd_kern_ostype);
    if (sysctlbyname("kern.ostype",
                     ngx_freebsd_kern_ostype, &size, NULL, 0) == -1) {
        ngx_log_error(NGX_LOG_ALERT, log, ngx_errno,
                      "sysctlbyname(kern.ostype) failed");

        if (ngx_errno != NGX_ENOMEM) {
            return NGX_ERROR;
        }

        ngx_freebsd_kern_ostype[size - 1] = '\0';
    }

    size = sizeof(ngx_freebsd_kern_osrelease);
    if (sysctlbyname("kern.osrelease",
                     ngx_freebsd_kern_osrelease, &size, NULL, 0) == -1) {
        ngx_log_error(NGX_LOG_ALERT, log, ngx_errno,
                      "sysctlbyname(kern.osrelease) failed");

        if (ngx_errno != NGX_ENOMEM) {
            return NGX_ERROR;
        }

        ngx_freebsd_kern_osrelease[size - 1] = '\0';
    }


    size = sizeof(int);
    if (sysctlbyname("kern.osreldate",
                     &ngx_freebsd_kern_osreldate, &size, NULL, 0) == -1) {
        ngx_log_error(NGX_LOG_ALERT, log, ngx_errno,
                      "sysctlbyname(kern.osreldate) failed");
        return NGX_ERROR;
    }

    version = ngx_freebsd_kern_osreldate;


#if (NGX_HAVE_SENDFILE)

    /*
     * The determination of the sendfile() "nbytes bug" is complex enough.
     * There are two sendfile() syscalls: a new #393 has no bug while
     * an old #336 has the bug in some versions and has not in others.
     * Besides libc_r wrapper also emulates the bug in some versions.
     * There is no way to say exactly if syscall #336 in FreeBSD circa 4.6
     * has the bug.  We use the algorithm that is correct at least for
     * RELEASEs and for syscalls only (not libc_r wrapper).
     *
     * 4.6.1-RELEASE and below have the bug
     * 4.6.2-RELEASE and above have the new syscall
     *
     * We detect the new sendfile() syscall available at the compile time
     * to allow an old binary to run correctly on an updated FreeBSD system.
     */

#if (__FreeBSD__ == 4 && __FreeBSD_version >= 460102) \
    || __FreeBSD_version == 460002 || __FreeBSD_version >= 500039

    /* a new syscall without the bug */

    ngx_freebsd_sendfile_nbytes_bug = 0;

#else

    /* an old syscall that may have the bug */

    ngx_freebsd_sendfile_nbytes_bug = 1;

#endif

#endif /* NGX_HAVE_SENDFILE */


    if ((version < 500000 && version >= 440003) || version >= 500017) {
        ngx_freebsd_use_tcp_nopush = 1;
    }


    for (i = 0; sysctls[i].name; i++) {
        size = sysctls[i].size;

        if (sysctlbyname(sysctls[i].name, sysctls[i].value, &size, NULL, 0)
            == 0)
        {
            sysctls[i].exists = 1;
            continue;
        }

        err = ngx_errno;

        if (err == NGX_ENOENT) {
            continue;
        }

        ngx_log_error(NGX_LOG_ALERT, log, err,
                      "sysctlbyname(%s) failed", sysctls[i].name);
        return NGX_ERROR;
    }

    if (ngx_freebsd_machdep_hlt_logical_cpus) {
        ngx_ncpu = ngx_freebsd_hw_ncpu / 2;

    } else {
        ngx_ncpu = ngx_freebsd_hw_ncpu;
    }

    if (version < 600008 && ngx_freebsd_kern_ipc_somaxconn > 32767) {
        ngx_log_error(NGX_LOG_ALERT, log, 0,
                      "sysctl kern.ipc.somaxconn must be less than 32768");
        return NGX_ERROR;
    }

    ngx_tcp_nodelay_and_tcp_nopush = 1;

    ngx_os_io = ngx_freebsd_io;

    return NGX_OK;
}


void
ngx_os_specific_status(ngx_log_t *log)
{
    u_long      value;
    ngx_uint_t  i;

    ngx_log_error(NGX_LOG_NOTICE, log, 0, "OS: %s %s",
                  ngx_freebsd_kern_ostype, ngx_freebsd_kern_osrelease);

#ifdef __DragonFly_version
    ngx_log_error(NGX_LOG_NOTICE, log, 0,
                  "kern.osreldate: %d, built on %d",
                  ngx_freebsd_kern_osreldate, __DragonFly_version);
#else
    ngx_log_error(NGX_LOG_NOTICE, log, 0,
                  "kern.osreldate: %d, built on %d",
                  ngx_freebsd_kern_osreldate, __FreeBSD_version);
#endif

    for (i = 0; sysctls[i].name; i++) {
        if (sysctls[i].exists) {
            if (sysctls[i].size == sizeof(long)) {
                value = *(long *) sysctls[i].value;

            } else {
                value = *(int *) sysctls[i].value;
            }

            ngx_log_error(NGX_LOG_NOTICE, log, 0, "%s: %l",
                          sysctls[i].name, value);
        }
    }
}