view src/os/unix/ngx_linux_config.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 c0a432c0301b
children
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/*
 * Copyright (C) Igor Sysoev
 * Copyright (C) Nginx, Inc.
 */


#ifndef _NGX_LINUX_CONFIG_H_INCLUDED_
#define _NGX_LINUX_CONFIG_H_INCLUDED_


#ifndef _GNU_SOURCE
#define _GNU_SOURCE             /* pread(), pwrite(), gethostname() */
#endif

#define _FILE_OFFSET_BITS  64

#include <sys/types.h>
#include <sys/time.h>
#include <unistd.h>
#include <stdarg.h>
#include <stddef.h>             /* offsetof() */
#include <stdio.h>
#include <stdlib.h>
#include <ctype.h>
#include <errno.h>
#include <string.h>
#include <signal.h>
#include <pwd.h>
#include <grp.h>
#include <dirent.h>
#include <glob.h>
#include <sys/vfs.h>            /* statfs() */

#include <sys/uio.h>
#include <sys/stat.h>
#include <fcntl.h>

#include <sys/wait.h>
#include <sys/mman.h>
#include <sys/resource.h>
#include <sched.h>

#include <sys/socket.h>
#include <netinet/in.h>
#include <netinet/tcp.h>        /* TCP_NODELAY, TCP_CORK */
#include <arpa/inet.h>
#include <netdb.h>
#include <sys/un.h>

#include <time.h>               /* tzset() */
#include <malloc.h>             /* memalign() */
#include <limits.h>             /* IOV_MAX */
#include <sys/ioctl.h>
#include <crypt.h>
#include <sys/utsname.h>        /* uname() */

#include <dlfcn.h>


#include <ngx_auto_config.h>


#if (NGX_HAVE_POSIX_SEM)
#include <semaphore.h>
#endif


#if (NGX_HAVE_SYS_PRCTL_H)
#include <sys/prctl.h>
#endif


#if (NGX_HAVE_SENDFILE64)
#include <sys/sendfile.h>
#else
extern ssize_t sendfile(int s, int fd, int32_t *offset, size_t size);
#define NGX_SENDFILE_LIMIT  0x80000000
#endif


#if (NGX_HAVE_POLL)
#include <poll.h>
#endif


#if (NGX_HAVE_EPOLL)
#include <sys/epoll.h>
#endif


#if (NGX_HAVE_SYS_EVENTFD_H)
#include <sys/eventfd.h>
#endif
#include <sys/syscall.h>
#if (NGX_HAVE_FILE_AIO)
#include <linux/aio_abi.h>
typedef struct iocb  ngx_aiocb_t;
#endif


#if (NGX_HAVE_CAPABILITIES)
#include <linux/capability.h>
#endif

#if (NGX_HAVE_UDP_SEGMENT)
#include <netinet/udp.h>
#endif


#define NGX_LISTEN_BACKLOG        511


#ifndef NGX_HAVE_SO_SNDLOWAT
/* setsockopt(SO_SNDLOWAT) returns ENOPROTOOPT */
#define NGX_HAVE_SO_SNDLOWAT         0
#endif


#ifndef NGX_HAVE_INHERITED_NONBLOCK
#define NGX_HAVE_INHERITED_NONBLOCK  0
#endif


#define NGX_HAVE_OS_SPECIFIC_INIT    1
#define ngx_debug_init()


extern char **environ;


#endif /* _NGX_LINUX_CONFIG_H_INCLUDED_ */