view src/os/unix/ngx_freebsd_init.c @ 8018:5119c8150478

Fixed runtime handling of systems without EPOLLRDHUP support. In 7583:efd71d49bde0 (nginx 1.17.5) along with introduction of the ioctl(FIONREAD) support proper handling of systems without EPOLLRDHUP support in the kernel (but with EPOLLRDHUP in headers) was broken. Before the change, rev->available was never set to 0 unless ngx_use_epoll_rdhup was also set (that is, runtime test for EPOLLRDHUP introduced in 6536:f7849bfb6d21 succeeded). After the change, rev->available might reach 0 on systems without runtime EPOLLRDHUP support, stopping further reading in ngx_readv_chain() and ngx_unix_recv(). And, if EOF happened to be already reported along with the last event, it is not reported again by epoll_wait(), leading to connection hangs and timeouts on such systems. This affects Linux kernels before 2.6.17 if nginx was compiled with newer headers, and, more importantly, emulation layers, such as DigitalOcean's App Platform's / gVisor's epoll emulation layer. Fix is to explicitly check ngx_use_epoll_rdhup before the corresponding rev->pending_eof tests in ngx_readv_chain() and ngx_unix_recv().
author Marcus Ball <marcus.ball@live.com>
date Mon, 30 May 2022 02:38:07 +0300
parents 56fc55e32f23
children
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,
    ngx_udp_unix_sendmsg_chain,
#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);
        }
    }
}