Re: [PATCH] ipvsadm: fix compiling tool on distros with only libnl-1

["Ryan O'Hara" <rohara@redhat.com>]

On Thu, Aug 08, 2013 at 02:10:54PM +0200, Jesper Dangaard Brouer wrote:
> Some distros have not moved to libnl3 yet.  Add a fallback option
> for compiling on distro's with only libnl1.
> 
> Using pkg-config to detect what versions of libnl is available.
> 
> Signed-off-by: Jesper Dangaard Brouer <brouer@redhat.com>

This patch looks fine, but I think it only solves part of the
problem. The Makefile still contains following code:

ifneq (0,$(HAVE_NL))
LIBS            += -lnl
endif

First, I think the HAVE_NL conditional can be removed. But more
importantly the correct netlink library should be appended to the
LIBS variable. With the current code we'll always link against
libnl-1.

On Fedora with both libnl and libnl-3 installed:

$ pkg-config --libs libnl-3.0
-lnl-3
$ pkg-config --libs libnl-1
-lnl

Ryan


> ---
>  libipvs/Makefile  |    5 +++++
>  libipvs/libipvs.c |    5 +++++
>  2 files changed, 10 insertions(+)
> 
> diff --git a/libipvs/Makefile b/libipvs/Makefile
> index a527a7f..eafc3e5 100644
> --- a/libipvs/Makefile
> +++ b/libipvs/Makefile
> @@ -10,6 +10,11 @@ INCLUDE		+= $(shell if [ -f ../../ip_vs.h ]; then	\
>  		     echo "-I../../."; fi;)
>  DEFINES		= $(shell if [ ! -f ../../ip_vs.h ]; then	\
>  		    echo "-DHAVE_NET_IP_VS_H"; fi;)
> +DEFINES		+= $(shell if which pkg-config > /dev/null 2>&1; then \
> +			 if   pkg-config --exists libnl-3.0; then :; \
> +			 elif pkg-config --exists libnl-2.0; then :; \
> +			 elif pkg-config --exists libnl-1; \
> +			 then echo "-DFALLBACK_LIBNL1"; fi; fi)
>  
>  .PHONY		= all clean install dist distclean rpm rpms
>  STATIC_LIB	= libipvs.a
> diff --git a/libipvs/libipvs.c b/libipvs/libipvs.c
> index c3c3b0a..2b066d2 100644
> --- a/libipvs/libipvs.c
> +++ b/libipvs/libipvs.c
> @@ -32,6 +32,11 @@ static void* ipvs_func = NULL;
>  struct ip_vs_getinfo ipvs_info;
>  
>  #ifdef LIBIPVS_USE_NL
> +#ifdef FALLBACK_LIBNL1
> +#define nl_sock         nl_handle
> +#define nl_socket_alloc nl_handle_alloc
> +#define nl_socket_free  nl_handle_destroy
> +#endif
>  static struct nl_sock *sock = NULL;
>  static int family, try_nl = 1;
>  #endif
>