view src/os/unix/ngx_darwin_init.c @ 8867:5119c8150478

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


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


char    ngx_darwin_kern_ostype[16];
char    ngx_darwin_kern_osrelease[128];
int     ngx_darwin_hw_ncpu;
int     ngx_darwin_kern_ipc_somaxconn;
u_long  ngx_darwin_net_inet_tcp_sendspace;

ngx_uint_t  ngx_debug_malloc;


static ngx_os_io_t ngx_darwin_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_darwin_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_darwin_hw_ncpu,
      sizeof(ngx_darwin_hw_ncpu), 0 },

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

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

    { NULL, NULL, 0, 0 }
};


void
ngx_debug_init(void)
{
#if (NGX_DEBUG_MALLOC)

    /*
     * MacOSX 10.6, 10.7:  MallocScribble fills freed memory with 0x55
     *                     and fills allocated memory with 0xAA.
     * MacOSX 10.4, 10.5:  MallocScribble fills freed memory with 0x55,
     *                     MallocPreScribble fills allocated memory with 0xAA.
     * MacOSX 10.3:        MallocScribble fills freed memory with 0x55,
     *                     and no way to fill allocated memory.
     */

    setenv("MallocScribble", "1", 0);

    ngx_debug_malloc = 1;

#else

    if (getenv("MallocScribble")) {
        ngx_debug_malloc = 1;
    }

#endif
}


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

    size = sizeof(ngx_darwin_kern_ostype);
    if (sysctlbyname("kern.ostype", ngx_darwin_kern_ostype, &size, NULL, 0)
        == -1)
    {
        err = ngx_errno;

        if (err != NGX_ENOENT) {

            ngx_log_error(NGX_LOG_ALERT, log, err,
                          "sysctlbyname(kern.ostype) failed");

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

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

    size = sizeof(ngx_darwin_kern_osrelease);
    if (sysctlbyname("kern.osrelease", ngx_darwin_kern_osrelease, &size,
                     NULL, 0)
        == -1)
    {
        err = ngx_errno;

        if (err != NGX_ENOENT) {

            ngx_log_error(NGX_LOG_ALERT, log, err,
                          "sysctlbyname(kern.osrelease) failed");

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

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

    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;
    }

    ngx_ncpu = ngx_darwin_hw_ncpu;

    if (ngx_darwin_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_darwin_io;

    return NGX_OK;
}


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

    if (ngx_darwin_kern_ostype[0]) {
        ngx_log_error(NGX_LOG_NOTICE, log, 0, "OS: %s %s",
                      ngx_darwin_kern_ostype, ngx_darwin_kern_osrelease);
    }

    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);
        }
    }
}