[Buildroot] [PATCH 2/2] samba: Add support for libnss_win*.so* installation

[Thomas Petazzoni <thomas.petazzoni@free-electrons.com>]

Hello Gustavo,

Could you have a look at the below patch? It would be useful to have
some review from a person knowing Samba better than I do.

I must say I'm a bit skeptical about two things (about which probably
Beno?t can give some details) :

 * The usefulness of enabling the NSS libraries in non-glibc
   environments. Even though I agree that technically, nothing prevents
   some program from using them, in practice, the NSS libraries are
   basically only used by the glibc name resolution logic. So I would
   personally prefer to make those NSS libraries visible only in glibc
   configurations.

 * The fact that the winbindd daemon is not actually needed on the
   target to get libnss_wins/libnss_winbind working. My understanding
   is that winbindd is a daemon that will answer to the name resolution
   requests of libnss_wins/libnss_winbind, so I don't see how they can
   work without the daemon running.

Also, Beno?t, some minor comment below.

On Mon,  4 Aug 2014 20:14:17 +0200, Beno?t Th?baudeau wrote:
> The libnss_wins and libnss_winbind libraries are required in order to add
> support for the wins and winbind sources to the Name Service Switch (NSS), so
> make it possible to install them. This is useful in order to resolve NetBIOS
> names or user and group information from a Windows NT server.
> 
> These libraries are installed to /lib/ like the standard libnss_* libraries from
> (E)GLIBC.
> 
> These libraries require the --with-winbind configuration option, but not the
> files installed by BR2_PACKAGE_SAMBA_WINBINDD. That's why
> BR2_PACKAGE_SAMBA_LIBNSS_* are not made to depend on BR2_PACKAGE_SAMBA_WINBINDD.
> 
> These libraries are designed to be used by the NSS provided by (E)GLIBC, but
> nothing forbids to use them directly without (E)GLIBC. That's why
> BR2_PACKAGE_SAMBA_LIBNSS_* are not made to depend on BR2_TOOLCHAIN_USES_GLIBC.
> BR2_PACKAGE_SAMBA_WINBINDD is enabled by default, so enable
> BR2_PACKAGE_SAMBA_LIBNSS_* by default, but only if BR2_TOOLCHAIN_USES_GLIBC is
> enabled since using these libraries without (E)GLIBC is unusual.
> 
> Signed-off-by: Beno?t Th?baudeau <benoit.thebaudeau@advansee.com>
> ---
>  package/samba/Config.in | 15 +++++++++++++++
>  package/samba/samba.mk  | 22 +++++++++++++++++++++-
>  2 files changed, 36 insertions(+), 1 deletion(-)
> 
> diff --git a/package/samba/Config.in b/package/samba/Config.in
> index 8dd0bf2..8448784 100644
> --- a/package/samba/Config.in
> +++ b/package/samba/Config.in
> @@ -240,6 +240,21 @@ config BR2_PACKAGE_SAMBA_LIBSMBCLIENT
>  	  standards POSIX functions available for manipulating local
>  	  files.
>  
> +config BR2_PACKAGE_SAMBA_LIBNSS_WINS
> +	bool "libnss_wins"
> +	default y if BR2_TOOLCHAIN_USES_GLIBC
> +	help
> +	  libnss_wins is a library that permits the Name Service Switch
> +	  to resolve NetBIOS names.
> +
> +config BR2_PACKAGE_SAMBA_LIBNSS_WINBIND
> +	bool "libnss_winbind"
> +	default y if BR2_TOOLCHAIN_USES_GLIBC
> +	help
> +	  libnss_winbind is a library that permits the Name Service
> +	  Switch to resolve user and group information from a Windows
> +	  NT server.
> +
>  endmenu
>  
>  
> diff --git a/package/samba/samba.mk b/package/samba/samba.mk
> index 84e525f..20cccbc 100644
> --- a/package/samba/samba.mk
> +++ b/package/samba/samba.mk
> @@ -58,7 +58,7 @@ SAMBA_CONF_OPT = \
>  	\
>  	$(if $(BR2_PACKAGE_SAMBA_RPCCLIENT),--with-readline=$(STAGING_DIR)) \
>  	$(if $(BR2_PACKAGE_SAMBA_SMBCLIENT),--with-readline=$(STAGING_DIR)) \
> -	$(if $(BR2_PACKAGE_SAMBA_WINBINDD),--with-winbind,--without-winbind)
> +	$(if $(BR2_PACKAGE_SAMBA_WINBINDD)$(BR2_PACKAGE_SAMBA_LIBNSS_WINS)$(BR2_PACKAGE_SAMBA_LIBNSS_WINBIND),--with-winbind,--without-winbind)
>  
>  SAMBA_INSTALL_TARGET_OPT = \
>  	DESTDIR=$(TARGET_DIR) -C $(SAMBA_DIR)/$(SAMBA_SUBDIR) \
> @@ -135,6 +135,26 @@ endef
>  
>  SAMBA_POST_INSTALL_TARGET_HOOKS += SAMBA_REMOVE_UNNEEDED_BINARIES
>  
> +define SAMBA_INSTALL_LIBNSS_WINS
> +	# install libnss_wins
> +	$(INSTALL) -m 0755 -D $(@D)/nsswitch/libnss_wins.so $(TARGET_DIR)/lib/

With -D, you should specify the full destination path.

> +	ln -snf libnss_wins.so $(TARGET_DIR)/lib/libnss_wins.so.2
> +endef
> +
> +ifeq ($(BR2_PACKAGE_SAMBA_LIBNSS_WINS),y)
> +SAMBA_POST_INSTALL_TARGET_HOOKS += SAMBA_INSTALL_LIBNSS_WINS
> +endif

It would be better to have the definition of the hook function inside
the conditional.

> +
> +define SAMBA_INSTALL_LIBNSS_WINBIND
> +	# install libnss_winbind
> +	$(INSTALL) -m 0755 -D $(@D)/nsswitch/libnss_winbind.so $(TARGET_DIR)/lib/
> +	ln -snf libnss_winbind.so $(TARGET_DIR)/lib/libnss_winbind.so.2
> +endef
> +
> +ifeq ($(BR2_PACKAGE_SAMBA_LIBNSS_WINBIND),y)
> +SAMBA_POST_INSTALL_TARGET_HOOKS += SAMBA_INSTALL_LIBNSS_WINBIND
> +endif

Same comments here.

Thanks,

Thomas
-- 
Thomas Petazzoni, CTO, Free Electrons
Embedded Linux, Kernel and Android engineering
http://free-electrons.com