From 9b5ce27c3b517c501bb13a534d50476e11751262 Mon Sep 17 00:00:00 2001
From: Max Kellermann <max@duempel.org>
Date: Thu, 16 Oct 2008 14:59:26 +0200
Subject: [PATCH] configure.ac: check if "struct ucred" is available
By default, glibc 2.8 hides struct ucred behind the _GNU_SOURCE
macro. I don't want to enable that globally, because it may encourage
the use of non-portable functions. Test if "struct ucred" is
available, and enable _GNU_SOURCE if required.
For details about that issue, see glib's bug database:
http://sources.redhat.com/bugzilla/show_bug.cgi?id=6545
---
configure.ac | 1 +
m4/ucred.m4 | 32 ++++++++++++++++++++++++++++++++
src/listen.c | 4 ++--
3 files changed, 35 insertions(+), 2 deletions(-)
create mode 100644 m4/ucred.m4
diff --git a/configure.ac b/configure.ac
index eceedaf09..ce50de896 100644
--- a/configure.ac
+++ b/configure.ac
@@ -308,6 +308,7 @@ fi
if test x$enable_un = xyes; then
AC_DEFINE(HAVE_UN, 1, [Define if unix domain socket support is enabled])
+ STRUCT_UCRED
fi
enable_osx=no
diff --git a/m4/ucred.m4 b/m4/ucred.m4
new file mode 100644
index 000000000..3a8245245
--- /dev/null
+++ b/m4/ucred.m4
@@ -0,0 +1,32 @@
+# Check if "struct ucred" is available. If not, try harder with
+# _GNU_SOURCE.
+#
+# Author: Max Kellermann <max@duempel.org>
+
+AC_DEFUN([STRUCT_UCRED],[
+ AC_MSG_CHECKING([for struct ucred])
+ AC_CACHE_VAL(mpd_cv_have_struct_ucred, [
+ AC_TRY_COMPILE([#include <sys/socket.h>],
+ [struct ucred cred;],
+ mpd_cv_have_struct_ucred=yes,
+ mpd_cv_have_struct_ucred=no)
+ if test x$mpd_cv_have_struct_ucred = xno; then
+ # glibc 2.8 forces _GNU_SOURCE on us
+ AC_TRY_COMPILE(
+ [#define _GNU_SOURCE
+ #include <sys/socket.h>],
+ [struct ucred cred;],
+ mpd_cv_have_struct_ucred=yes,
+ mpd_cv_have_struct_ucred=no)
+ if test x$mpd_cv_have_struct_ucred = xyes; then
+ # :(
+ MPD_CFLAGS="$MPD_CFLAGS -D_GNU_SOURCE"
+ fi
+ fi
+ ])
+
+ AC_MSG_RESULT($mpd_cv_have_struct_ucred)
+ if test x$mpd_cv_have_struct_ucred = xyes; then
+ AC_DEFINE(HAVE_STRUCT_UCRED, 1, [Define if struct ucred is present from sys/socket.h])
+ fi
+])
diff --git a/src/listen.c b/src/listen.c
index 1a52202ac..ab74f8d02 100644
--- a/src/listen.c
+++ b/src/listen.c
@@ -97,7 +97,7 @@ static int establishListen(int pf, const struct sockaddr *addrp,
if (listen(sock, 5) < 0)
FATAL("problems listen'ing: %s\n", strerror(errno));
-#if defined(HAVE_UN) && defined(SO_PASSCRED)
+#ifdef HAVE_UCRED
setsockopt(sock, SOL_SOCKET, SO_PASSCRED, &passcred, sizeof(passcred));
#endif
@@ -265,7 +265,7 @@ void freeAllListenSockets(void)
static int get_remote_uid(int fd)
{
-#if defined(HAVE_UN) && defined(SO_PEERCRED)
+#ifdef HAVE_UCRED
struct ucred cred;
socklen_t len = sizeof (cred);