On Wed, Sep 4, 2013 at 6:40 AM, Ian Campbell <Ian.Campbell@citrix.com>wrote:

> On Thu, 2013-08-29 at 15:16 -0700, Shriram Rajagopalan wrote:
> > # HG changeset patch
> > # User Shriram Rajagopalan <rshriram@cs.ubc.ca>
> > # Date 1377641625 25200
> > # Node ID cc2b88cba1c67cc0e0a00c7e63a3ba97e14609cb
> > # Parent  40b079bd57dea24c3b000f233ed123763483a4d5
> > 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 40b079bd57de -r cc2b88cba1c6 config/Tools.mk.in
> > --- a/config/Tools.mk.in      Sun Aug 25 14:39:36 2013 -0700
> > +++ b/config/Tools.mk.in      Tue Aug 27 15:13:45 2013 -0700
> > @@ -35,6 +35,7 @@ PTHREAD_LDFLAGS     := @PTHREAD_LDFLAGS@
> >  PTHREAD_LIBS        := @PTHREAD_LIBS@
> >
> >  PTYFUNCS_LIBS       := @PTYFUNCS_LIBS@
> > +LIBNL3_LIBS         := @LIBNL3_LIBS@
> >
> >  # Download GIT repositories via HTTP or GIT's own protocol?
> >  # GIT's protocol is faster and more robust, when it works at all
> (firewalls
> > @@ -54,6 +55,7 @@ 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 40b079bd57de -r cc2b88cba1c6 tools/configure.ac
> > --- a/tools/configure.ac      Sun Aug 25 14:39:36 2013 -0700
> > +++ b/tools/configure.ac      Tue Aug 27 15:13:45 2013 -0700
> > @@ -208,4 +208,19 @@ 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_EXISTS([libnl-3.0 >= 3.2.8 libnl-route-3.0 >= 3.2.8
> libnl-cli-3.0 >= 3.2.8],
> > +             [libnl3_lib="y"], [libnl3_lib="n"])
> > +AC_CHECK_HEADER([netlink/route/qdisc/plug.h], [libnl3_dev="y"],
> [libnl3_dev="n"])
>
> Aren't these a bit redundant? i.e. doesn't PKG_CHECK_EXISTS cover the
> development headers?


Unfortunately, libnl3 does not have a pkgconfig .pc file for its dev
headers. So there is no standard way
to check for these headers. Debian has libnl-3-dev. OpenSUSE has
libnl3-devel, etc.


> At least on Debian libnl-3-dev contains:
> [...]
> -rw-r--r-- root/root       770 2013-05-21 22:52
> ./usr/include/libnl3/netlink/route/qdisc/plug.h
> [...]
> -rw-r--r-- root/root       239 2013-05-21 22:52
> ./usr/lib/x86_64-linux-gnu/pkgconfig/libnl-3.0.pc
> [...]
>
> > +AS_IF([test "x$libnl3" = "xn" || test "x$libnl3_dev" = "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])
>
> This should be mentioned in README too.
>
> > +         AC_SUBST(remus_netbuf, [n])
> > +         ],[
> > +         LIBNL3_LIBS="-lnl-3 -lnl-route-3"
>
> Since libnl3 uses pkg-cofnig, these should come from there I think.
> There's probably a macro in pkg-config.m4 to help?
>

None that I could find.


>
> > +         AC_SUBST(LIBNL3_LIBS)
> > +         AC_SUBST(remus_netbuf, [y])
> > +])
> > +
> >  AC_OUTPUT()
> > diff -r 40b079bd57de -r cc2b88cba1c6 tools/libxl/Makefile
> > --- a/tools/libxl/Makefile    Sun Aug 25 14:39:36 2013 -0700
> > +++ b/tools/libxl/Makefile    Tue Aug 27 15:13:45 2013 -0700
> > @@ -20,7 +20,7 @@ LIBUUID_LIBS += -luuid
> >  endif
> >
> >  LIBXL_LIBS =
> > -LIBXL_LIBS = $(LDLIBS_libxenctrl) $(LDLIBS_libxenguest)
> $(LDLIBS_libxenstore) $(LDLIBS_libblktapctl) $(PTYFUNCS_LIBS)
> $(LIBUUID_LIBS)
> > +LIBXL_LIBS = $(LDLIBS_libxenctrl) $(LDLIBS_libxenguest)
> $(LDLIBS_libxenstore) $(LDLIBS_libblktapctl) $(PTYFUNCS_LIBS)
> $(LIBUUID_LIBS) $(LIBNL3_LIBS)
>
> I think it might be time to break this long line and use
> LIBXL_LIBS  = X Y Z
> LIBXL_LIBS += A B C
> (no need for one line per lib though)
>
> >
> >  CFLAGS_LIBXL += $(CFLAGS_libxenctrl)
> >  CFLAGS_LIBXL += $(CFLAGS_libxenguest)
>
>
>