view src/os/unix/ngx_errno.h @ 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 a5897d360977
children 58afcd72446f
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/*
 * Copyright (C) Igor Sysoev
 * Copyright (C) Nginx, Inc.
 */


#ifndef _NGX_ERRNO_H_INCLUDED_
#define _NGX_ERRNO_H_INCLUDED_


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


typedef int               ngx_err_t;

#define NGX_EPERM         EPERM
#define NGX_ENOENT        ENOENT
#define NGX_ENOPATH       ENOENT
#define NGX_ESRCH         ESRCH
#define NGX_EINTR         EINTR
#define NGX_ECHILD        ECHILD
#define NGX_ENOMEM        ENOMEM
#define NGX_EACCES        EACCES
#define NGX_EBUSY         EBUSY
#define NGX_EEXIST        EEXIST
#define NGX_EEXIST_FILE   EEXIST
#define NGX_EXDEV         EXDEV
#define NGX_ENOTDIR       ENOTDIR
#define NGX_EISDIR        EISDIR
#define NGX_EINVAL        EINVAL
#define NGX_ENFILE        ENFILE
#define NGX_EMFILE        EMFILE
#define NGX_ENOSPC        ENOSPC
#define NGX_EPIPE         EPIPE
#define NGX_EINPROGRESS   EINPROGRESS
#define NGX_ENOPROTOOPT   ENOPROTOOPT
#define NGX_EOPNOTSUPP    EOPNOTSUPP
#define NGX_EADDRINUSE    EADDRINUSE
#define NGX_ECONNABORTED  ECONNABORTED
#define NGX_ECONNRESET    ECONNRESET
#define NGX_ENOTCONN      ENOTCONN
#define NGX_ETIMEDOUT     ETIMEDOUT
#define NGX_ECONNREFUSED  ECONNREFUSED
#define NGX_ENAMETOOLONG  ENAMETOOLONG
#define NGX_ENETDOWN      ENETDOWN
#define NGX_ENETUNREACH   ENETUNREACH
#define NGX_EHOSTDOWN     EHOSTDOWN
#define NGX_EHOSTUNREACH  EHOSTUNREACH
#define NGX_ENOSYS        ENOSYS
#define NGX_ECANCELED     ECANCELED
#define NGX_EILSEQ        EILSEQ
#define NGX_ENOMOREFILES  0
#define NGX_ELOOP         ELOOP
#define NGX_EBADF         EBADF

#if (NGX_HAVE_OPENAT)
#define NGX_EMLINK        EMLINK
#endif

#if (__hpux__)
#define NGX_EAGAIN        EWOULDBLOCK
#else
#define NGX_EAGAIN        EAGAIN
#endif


#define ngx_errno                  errno
#define ngx_socket_errno           errno
#define ngx_set_errno(err)         errno = err
#define ngx_set_socket_errno(err)  errno = err


u_char *ngx_strerror(ngx_err_t err, u_char *errstr, size_t size);
ngx_int_t ngx_strerror_init(void);


#endif /* _NGX_ERRNO_H_INCLUDED_ */