[PATCH 1 of 5 V3] remus: add libnl3 dependency to autoconf scripts

[Shriram Rajagopalan <rshriram@cs.ubc.ca>]

# HG changeset patch
# User Shriram Rajagopalan <rshriram@cs.ubc.ca>
# Date 1381540581 25200
# Node ID 357655a1598cba8f8460758714885563dd2b4a9c
# Parent  808aba98084edee7b6dc78c7333da71d2be70386
remus: add libnl3 dependency to autoconf scripts

Libnl3 is required for controlling Remus network buffering.
This patch adds dependency on libnl3 (>= 3.2.8) to autoconf scripts.
Also provide ability to configure tools without libnl3 support, that
is without network buffering support.

Signed-off-by: Shriram Rajagopalan <rshriram@cs.ubc.ca>

diff -r 808aba98084e -r 357655a1598c config/Tools.mk.in
--- a/config/Tools.mk.in	Fri Oct 11 18:16:11 2013 -0700
+++ b/config/Tools.mk.in	Fri Oct 11 18:16:21 2013 -0700
@@ -37,6 +37,8 @@ PTHREAD_LIBS        := @PTHREAD_LIBS@
 
 PTYFUNCS_LIBS       := @PTYFUNCS_LIBS@
 
+LIBNL3_LIBS         := @LIBNL3_LIBS@
+LIBNL3_CFLAGS       := @LIBNL3_CFLAGS@
 # Download GIT repositories via HTTP or GIT's own protocol?
 # GIT's protocol is faster and more robust, when it works at all (firewalls
 # may block it). We make it the default, but if your GIT repository downloads
@@ -55,6 +57,7 @@ CONFIG_QEMU_TRAD    := @qemu_traditional
 CONFIG_QEMU_XEN     := @qemu_xen@
 CONFIG_XEND         := @xend@
 CONFIG_BLKTAP1      := @blktap1@
+CONFIG_REMUS_NETBUF := @remus_netbuf@
 
 #System options
 ZLIB                := @zlib@
diff -r 808aba98084e -r 357655a1598c tools/configure.ac
--- a/tools/configure.ac	Fri Oct 11 18:16:11 2013 -0700
+++ b/tools/configure.ac	Fri Oct 11 18:16:21 2013 -0700
@@ -219,6 +219,24 @@ AC_SUBST(libiconv)
 # Checks for header files.
 AC_CHECK_HEADERS([yajl/yajl_version.h sys/eventfd.h])
 
+# Check for libnl3 >=3.2.8. If present enable remus network buffering.
+PKG_CHECK_MODULES(LIBNL3, [libnl-3.0 >= 3.2.8 libnl-route-3.0 >= 3.2.8],
+		[libnl3_lib="y"], [libnl3_lib="n"])
+
+# Check for libnl3 command line utilities
+PKG_CHECK_EXISTS([libnl-cli-3.0 >= 3.2.8], [libnl3_cli="y"], [libnl3_cli="n"])
+
+AS_IF([test "x$libnl3_lib" = "xn" || test "x$libnl3_cli" = "xn"], [
+	    AC_MSG_WARN([Disabling support for Remus network buffering.
+	    Please install libnl3 libraries, command line tools and devel
+	    headers - version 3.2.8 or higher])
+	    AC_SUBST(remus_netbuf, [n])
+	    ],[
+	    AC_SUBST(LIBNL3_LIBS)
+	    AC_SUBST(LIBNL3_CFLAGS)
+	    AC_SUBST(remus_netbuf, [y])
+])
+
 AC_OUTPUT()
 
 AS_IF([test "x$xend" = "xy" ], [
diff -r 808aba98084e -r 357655a1598c tools/libxl/Makefile
--- a/tools/libxl/Makefile	Fri Oct 11 18:16:11 2013 -0700
+++ b/tools/libxl/Makefile	Fri Oct 11 18:16:21 2013 -0700
@@ -21,11 +21,13 @@ endif
 
 LIBXL_LIBS =
 LIBXL_LIBS = $(LDLIBS_libxenctrl) $(LDLIBS_libxenguest) $(LDLIBS_libxenstore) $(LDLIBS_libblktapctl) $(PTYFUNCS_LIBS) $(LIBUUID_LIBS)
+LIBXL_LIBS += $(LIBNL3_LIBS)
 
 CFLAGS_LIBXL += $(CFLAGS_libxenctrl)
 CFLAGS_LIBXL += $(CFLAGS_libxenguest)
 CFLAGS_LIBXL += $(CFLAGS_libxenstore)
 CFLAGS_LIBXL += $(CFLAGS_libblktapctl) 
+CFLAGS_LIBXL += $(LIBNL3_CFLAGS)
 CFLAGS_LIBXL += -Wshadow
 
 CFLAGS += $(PTHREAD_CFLAGS)
diff -r 808aba98084e -r 357655a1598c tools/remus/README
--- a/tools/remus/README	Fri Oct 11 18:16:11 2013 -0700
+++ b/tools/remus/README	Fri Oct 11 18:16:21 2013 -0700
@@ -2,3 +2,9 @@ Remus provides fault tolerance for virtu
 checkpoints to a backup, which will activate if the target VM fails.
 
 See the website at http://nss.cs.ubc.ca/remus/ for details.
+
+Using Remus with libxl on Xen 4.4 and higher:
+ To enable network buffering, you need libnl 3.2.8
+ or higher along with the development headers and command line utilities.
+ If your distro does not have the appropriate libnl3 version, you can find
+ the latest source tarball of libnl3 at http://www.carisma.slowglass.com/~tgr/libnl/