view src/os/unix/ngx_socket.c @ 7784:8cc5b0365ee5

Improved maximum errno detection. Previously, systems without sys_nerr (or _sys_nerr) were handled with an assumption that errors start at 0 and continuous. This is, however, not something POSIX requires, and not true on some platforms. Notably, on Linux, where sys_nerr is no longer available for newly linked binaries starting with glibc 2.32, there are gaps in error list, which used to stop us from properly detecting maximum errno. Further, on GNU/Hurd errors start at 0x40000001. With this change, maximum errno detection is moved to the runtime code, now able to ignore gaps, and also detects the first error if needed. This fixes observed "Unknown error" messages as seen on Linux with glibc 2.32 and on GNU/Hurd.
author Maxim Dounin <mdounin@mdounin.ru>
date Mon, 01 Mar 2021 20:00:43 +0300
parents d620f497c50f
children
line wrap: on
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/*
 * Copyright (C) Igor Sysoev
 * Copyright (C) Nginx, Inc.
 */


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


/*
 * ioctl(FIONBIO) sets a non-blocking mode with the single syscall
 * while fcntl(F_SETFL, O_NONBLOCK) needs to learn the current state
 * using fcntl(F_GETFL).
 *
 * ioctl() and fcntl() are syscalls at least in FreeBSD 2.x, Linux 2.2
 * and Solaris 7.
 *
 * ioctl() in Linux 2.4 and 2.6 uses BKL, however, fcntl(F_SETFL) uses it too.
 */


#if (NGX_HAVE_FIONBIO)

int
ngx_nonblocking(ngx_socket_t s)
{
    int  nb;

    nb = 1;

    return ioctl(s, FIONBIO, &nb);
}


int
ngx_blocking(ngx_socket_t s)
{
    int  nb;

    nb = 0;

    return ioctl(s, FIONBIO, &nb);
}

#endif


#if (NGX_FREEBSD)

int
ngx_tcp_nopush(ngx_socket_t s)
{
    int  tcp_nopush;

    tcp_nopush = 1;

    return setsockopt(s, IPPROTO_TCP, TCP_NOPUSH,
                      (const void *) &tcp_nopush, sizeof(int));
}


int
ngx_tcp_push(ngx_socket_t s)
{
    int  tcp_nopush;

    tcp_nopush = 0;

    return setsockopt(s, IPPROTO_TCP, TCP_NOPUSH,
                      (const void *) &tcp_nopush, sizeof(int));
}

#elif (NGX_LINUX)


int
ngx_tcp_nopush(ngx_socket_t s)
{
    int  cork;

    cork = 1;

    return setsockopt(s, IPPROTO_TCP, TCP_CORK,
                      (const void *) &cork, sizeof(int));
}


int
ngx_tcp_push(ngx_socket_t s)
{
    int  cork;

    cork = 0;

    return setsockopt(s, IPPROTO_TCP, TCP_CORK,
                      (const void *) &cork, sizeof(int));
}

#else

int
ngx_tcp_nopush(ngx_socket_t s)
{
    return 0;
}


int
ngx_tcp_push(ngx_socket_t s)
{
    return 0;
}

#endif