Simon Josefsson wrote:
> no objection from me.
OK, I've added the module and applied the support for old kernels:
2009-08-24 Bruno Haible <br...@clisp.org>
Tolerate declared but missing accept4 syscall.
* lib/accept4.c (accept4): Invoke original accept4 function first, if
available.
* lib/sys_socket.in.h (accept4): If the function is already present,
override it.
* m4/accept4.m4 (gl_FUNC_ACCEPT4): Remove AC_LIBOBJ invocation.
* modules/accept4 (Makefile.am): Compile accept4.c always.
Reported by Paolo Bonzini and Eric Blake.
--- lib/accept4.c.orig 2009-08-25 02:25:10.000000000 +0200
+++ lib/accept4.c 2009-08-25 02:22:35.000000000 +0200
@@ -33,6 +33,26 @@
{
int fd;
+#if HAVE_ACCEPT4
+# undef accept4
+ /* Try the system call first, if it exists. (We may be running with a glibc
+ that has the function but with an older kernel that lacks it.) */
+ {
+ /* Cache the information whether the system call really exists. */
+ static int have_accept4_really; /* 0 = unknown, 1 = yes, -1 = no */
+ if (have_accept4_really >= 0)
+ {
+ int result = accept4 (sockfd, addr, addrlen, flags);
+ if (!(result < 0 && errno == ENOSYS))
+ {
+ have_accept4_really = 1;
+ return result;
+ }
+ have_accept4_really = -1;
+ }
+ }
+#endif
+
/* Check the supported flags. */
if ((flags & ~(SOCK_CLOEXEC | O_TEXT | O_BINARY)) != 0)
{
--- lib/sys_socket.in.h.orig 2009-08-25 02:25:10.000000000 +0200
+++ lib/sys_socket.in.h 2009-08-25 02:23:26.000000000 +0200
@@ -428,15 +428,16 @@
#endif
#if @GNULIB_ACCEPT4@
-# if !...@have_accept4@
/* Accept a connection on a socket, with specific opening flags.
The flags are a bitmask, possibly including O_CLOEXEC (defined in <fcntl.h>)
and O_TEXT, O_BINARY (defined in "binary-io.h").
See also the Linux man page at
<http://www.kernel.org/doc/man-pages/online/pages/man2/accept4.2.html>. */
+# if @HAVE_ACCEPT4@
+# define accept4 rpl_accept4
+# endif
extern int accept4 (int sockfd, struct sockaddr *addr, socklen_t *addrlen,
int flags);
-# endif
#elif defined GNULIB_POSIXCHECK
# undef accept4
# define accept4(s,a,l,f) \
--- m4/accept4.m4.orig 2009-08-25 02:25:10.000000000 +0200
+++ m4/accept4.m4 2009-08-25 02:23:48.000000000 +0200
@@ -1,4 +1,4 @@
-# accept4.m4 serial 1
+# accept4.m4 serial 2
dnl Copyright (C) 2009 Free Software Foundation, Inc.
dnl This file is free software; the Free Software Foundation
dnl gives unlimited permission to copy and/or distribute it,
@@ -14,6 +14,5 @@
AC_CHECK_FUNCS_ONCE([accept4])
if test $ac_cv_func_accept4 != yes; then
HAVE_ACCEPT4=0
- AC_LIBOBJ([accept4])
fi
])
--- modules/accept4.orig 2009-08-25 02:25:10.000000000 +0200
+++ modules/accept4 2009-08-25 02:24:04.000000000 +0200
@@ -17,6 +17,7 @@
gl_SYS_SOCKET_MODULE_INDICATOR([accept4])
Makefile.am:
+lib_SOURCES += accept4.c
Include:
<sys/socket.h>
