From bcba68498f698dedfdc83687c72e0e6dd7dc0e96 Mon Sep 17 00:00:00 2001

From: Eric Blake <eblake@redhat.com>

Date: Fri, 13 Sep 2013 10:11:26 -0600

Subject: [PATCH] build: fix build with latest rawhide kernel headers

Bother those kernel developers.  In the latest rawhide, kernel

and glibc have now been unified so that <netinet/in.h> and

<linux/in6.h> no longer clash; but <linux/if_bridge.h> is still

not self-contained.  Because of the latest header change, the

build is failing with:

checking for linux/param.h... no

configure: error: You must install kernel-headers in order to compile libvirt with QEMU or LXC support

with details:

In file included from conftest.c:561:0:

/usr/include/linux/in6.h:71:18: error: field 'flr_dst' has incomplete type

  struct in6_addr flr_dst;

We need a workaround to avoid our workaround :)

* configure.ac (NETINET_LINUX_WORKAROUND): New test.

* src/util/virnetdevbridge.c (includes): Use it.

Signed-off-by: Eric Blake <eblake@redhat.com>

(cherry picked from commit e62e0094dcd0ca1484491a9cc62919473b647f11)

---

 configure.ac               | 39 +++++++++++++++++++++++++++++----------

 src/util/virnetdevbridge.c | 24 ++++++++++++++----------

 2 files changed, 43 insertions(+), 20 deletions(-)

diff --git a/configure.ac b/configure.ac

index f853e03..1956717 100644

--- a/configure.ac

+++ b/configure.ac

@@ -1003,18 +1003,37 @@ dnl check for kernel headers required by src/bridge.c

 dnl

 if test "$with_linux" = "yes"; then

   if test "$with_qemu" = "yes" || test "$with_lxc" = "yes" ; then

+    # Various kernel versions have headers that are not self-standing, but

+    # yet are incompatible with the corresponding glibc headers.  In order

+    # to guarantee compilation across a wide range of versions (from RHEL 5

+    # to rawhide), we first have to probe whether glibc and kernel can be

+    # used in tandem; and if not, provide workarounds that ensure that

+    # ABI-compatible IPv6 types are present for use by the kernel headers.

+    # These probes mirror the usage in virnetdevbridge.c

+    AC_CACHE_CHECK(

+      [whether <linux/*.h> and <netinet/*.h> headers are compatible],

+      [lv_cv_netinet_linux_compatible],

+      [AC_COMPILE_IFELSE([AC_LANG_PROGRAM([[

+        #include <netinet/in.h>

+        #include <linux/in6.h>

+      ]])],

+      [lv_cv_netinet_linux_compatible=yes],

+      [lv_cv_netinet_linux_compatible=no])])

+    if test "x$lv_cv_netinet_linux_compatible" != xyes; then

+      AC_DEFINE([NETINET_LINUX_WORKAROUND], [1],

+        [define to 1 if Linux kernel headers require a workaround to avoid

+        compilation errors when mixed with glibc netinet headers])

+    fi

     AC_CHECK_HEADERS([linux/param.h linux/sockios.h linux/if_bridge.h linux/if_tun.h],,

       [AC_MSG_ERROR([You must install kernel-headers in order to compile libvirt with QEMU or LXC support])],

-      [[/* The kernel folks broke their headers when used with particular

-         * glibc versions; although the structs are ABI compatible, the

-         * C type system doesn't like struct redefinitions.  We work around

-         * the problem here in the same manner as in virnetdevbridge.c.  */

-        #include <netinet/in.h>

-        #define in6_addr in6_addr_

-        #define sockaddr_in6 sockaddr_in6_

-        #define ipv6_mreq ipv6_mreq_

-        #define in6addr_any in6addr_any_

-        #define in6addr_loopback in6addr_loopback_

+      [[#include <netinet/in.h>

+        #if NETINET_LINUX_WORKAROUND

+        # define in6_addr in6_addr_

+        # define sockaddr_in6 sockaddr_in6_

+        # define ipv6_mreq ipv6_mreq_

+        # define in6addr_any in6addr_any_

+        # define in6addr_loopback in6addr_loopback_

+        #endif

         #include <linux/in6.h>

       ]])

   fi

diff --git a/src/util/virnetdevbridge.c b/src/util/virnetdevbridge.c

index e4daa27..1a3740a 100644

--- a/src/util/virnetdevbridge.c

+++ b/src/util/virnetdevbridge.c

@@ -39,22 +39,26 @@

 #ifdef __linux__

 # include <linux/sockios.h>

 # include <linux/param.h>     /* HZ                 */

+# if NETINET_LINUX_WORKAROUND

 /* Depending on the version of kernel vs. glibc, there may be a collision

  * between <net/in.h> and kernel IPv6 structures.  The different types

  * are ABI compatible, but choke the C type system; work around it by

  * using temporary redefinitions.  */

-# define in6_addr in6_addr_

-# define sockaddr_in6 sockaddr_in6_

-# define ipv6_mreq ipv6_mreq_

-# define in6addr_any in6addr_any_

-# define in6addr_loopback in6addr_loopback_

+#  define in6_addr in6_addr_

+#  define sockaddr_in6 sockaddr_in6_

+#  define ipv6_mreq ipv6_mreq_

+#  define in6addr_any in6addr_any_

+#  define in6addr_loopback in6addr_loopback_

+# endif

 # include <linux/in6.h>

 # include <linux/if_bridge.h> /* SYSFS_BRIDGE_ATTR  */

-# undef in6_addr

-# undef sockaddr_in6

-# undef ipv6_mreq

-# undef in6addr_any

-# undef in6addr_loopback

+# if NETINET_LINUX_WORKAROUND

+#  undef in6_addr

+#  undef sockaddr_in6

+#  undef ipv6_mreq

+#  undef in6addr_any

+#  undef in6addr_loopback

+# endif

 # define JIFFIES_TO_MS(j) (((j)*1000)/HZ)

 # define MS_TO_JIFFIES(ms) (((ms)*HZ)/1000)