From 10c6c566a9ca136abf916c172fe13a91ee6f4b7a Mon Sep 17 00:00:00 2001
From: Dmitry Kurochkin <dmitry.kurochkin@measurement-factory.com>
Date: Mon, 4 Jun 2012 04:52:56 -0600
Subject: [PATCH] Bug #3380: Mac OSX compile errors with CMSG_SPACE

---
 compat/Makefile.am    |  1 +
 compat/cmsg.h         | 18 ++++++++++++++++++
 compat/os/macosx.h    |  2 ++
 configure.ac          | 14 ++++++++++++++
 src/ipc/TypedMsgHdr.h |  4 +++-
 5 files changed, 38 insertions(+), 1 deletion(-)
 create mode 100644 compat/cmsg.h

diff --git a/compat/Makefile.am b/compat/Makefile.am
index a483647cbc..d69d5dbb91 100644
--- a/compat/Makefile.am
+++ b/compat/Makefile.am
@@ -13,6 +13,7 @@ noinst_LIBRARIES = libcompat-squid.a
 libcompat_squid_a_SOURCES = \
 	assert.cc \
 	assert.h \
+	cmsg.h \
 	compat.cc \
 	compat.h \
 	compat_shared.h \
diff --git a/compat/cmsg.h b/compat/cmsg.h
new file mode 100644
index 0000000000..a433f77f55
--- /dev/null
+++ b/compat/cmsg.h
@@ -0,0 +1,18 @@
+#ifndef SQUID_COMPAT_CMSG_H
+#define SQUID_COMPAT_CMSG_H
+
+// CMSG_SPACE is not constant on some systems (in particular Max OS X),
+// provide a replacement that can be used at build time in that case
+
+#if HAVE_SYS_SOCKET_H
+#include <sys/socket.h>
+#endif
+
+#if HAVE_CONSTANT_CMSG_SPACE
+#define SQUID_CMSG_SPACE CMSG_SPACE
+#else
+// add 16 bytes for header and data alignment
+#define SQUID_CMSG_SPACE(len) (sizeof(struct cmsghdr) + (len) + 16)
+#endif
+
+#endif /* SQUID_COMPAT_CMSG_H */
diff --git a/compat/os/macosx.h b/compat/os/macosx.h
index e601614f11..4baf2dc848 100644
--- a/compat/os/macosx.h
+++ b/compat/os/macosx.h
@@ -18,5 +18,7 @@
 //#define s6_addr16 __u6_addr.__u6_addr16
 #define s6_addr32 __u6_addr.__u6_addr32
 
+#include "compat/cmsg.h"
+
 #endif /* _SQUID_APPLE_ */
 #endif /* SQUID_OS_MACOSX_H */
diff --git a/configure.ac b/configure.ac
index 8ad7d2a186..b5f81f8e59 100644
--- a/configure.ac
+++ b/configure.ac
@@ -3246,6 +3246,20 @@ if test "x$squid_cv_resuid_works" = "xyes" ; then
   AC_DEFINE(HAVE_SETRESUID,1,[Yay! Another Linux brokenness. Knowing that setresuid() exists is not enough, because RedHat 5.0 declares setresuid() but does not implement it.])
 fi
 
+AC_MSG_CHECKING([for constant CMSG_SPACE])
+AC_COMPILE_IFELSE([AC_LANG_SOURCE([[
+  #if HAVE_SYS_SOCKET_H
+  #include <sys/socket.h>
+  #endif
+
+  int a[CMSG_SPACE(int)];
+]])], [
+  AC_MSG_RESULT(yes)
+  AC_DEFINE(HAVE_CONSTANT_CMSG_SPACE, 1, [Define to 1 if CMSG_SPACE is constant])
+], [
+  AC_MSG_RESULT(no)
+])
+
 SQUID_CHECK_FUNC_STRNSTR
 SQUID_CHECK_FUNC_VACOPY
 SQUID_CHECK_FUNC___VACOPY
diff --git a/src/ipc/TypedMsgHdr.h b/src/ipc/TypedMsgHdr.h
index 95afe00dd6..a3ca266171 100644
--- a/src/ipc/TypedMsgHdr.h
+++ b/src/ipc/TypedMsgHdr.h
@@ -8,6 +8,7 @@
 #ifndef SQUID_IPC_TYPED_MSG_HDR_H
 #define SQUID_IPC_TYPED_MSG_HDR_H
 
+#include "compat/cmsg.h"
 #if HAVE_SYS_SOCKET_H
 #include <sys/socket.h>
 #endif
@@ -90,7 +91,8 @@ private:
     } data; ///< same as .msg_iov[0].iov_base
 
     struct CtrlBuffer {
-        char raw[CMSG_SPACE(sizeof(int))]; ///< control buffer space for one fd
+        /// control buffer space for one fd
+        char raw[SQUID_CMSG_SPACE(sizeof(int))];
     } ctrl; ///< same as .msg_control
 
     /// data offset for the next get/put*() to start with
-- 
2.47.2