[PATCH] dropbear: allow disabling support for scp

[Paul Spooren]

Hi Rui,

I imagine it could be helpful if you use sstrip[0] on the created 
binaries to give a clearer size comparison.

[0]: https://github.com/BR903/ELFkickers/blob/master/sstrip/

Best,
Paul

On 22.07.20 03:31, Rui Salvaterra wrote:
> If not needed, disabling scp allows for a nice size reduction.
>
> Dropbear executable size comparison:
>
> 153621 bytes (baseline)
> 133077 bytes (without scp)
>
> In other words, we trim a total of 20544 bytes.
>
> [Note: This patch is on top of
> "dropbear: fix ssh alternative when dbclient isn't built"]
>
> Signed-off-by: Rui Salvaterra <rsalvaterra at gmail.com>
> ---
>   package/network/services/dropbear/Config.in | 4 ++++
>   package/network/services/dropbear/Makefile  | 8 +++++---
>   2 files changed, 9 insertions(+), 3 deletions(-)
>
> diff --git a/package/network/services/dropbear/Config.in b/package/network/services/dropbear/Config.in
> index 0ac84ee206..b9ecbc815b 100644
> --- a/package/network/services/dropbear/Config.in
> +++ b/package/network/services/dropbear/Config.in
> @@ -102,4 +102,8 @@ config DROPBEAR_DBCLIENT
>   	bool "Build dropbear with dbclient"
>   	default y
>   
> +config DROPBEAR_SCP
> +	bool "Build dropbear with scp"
> +	default y
> +
>   endmenu
> diff --git a/package/network/services/dropbear/Makefile b/package/network/services/dropbear/Makefile
> index edd20909b1..8b57b214ae 100644
> --- a/package/network/services/dropbear/Makefile
> +++ b/package/network/services/dropbear/Makefile
> @@ -31,7 +31,7 @@ PKG_CONFIG_DEPENDS:= \
>   	CONFIG_DROPBEAR_RSA CONFIG_DROPBEAR_CURVE25519 CONFIG_DROPBEAR_ZLIB \
>   	CONFIG_DROPBEAR_ED25519 CONFIG_DROPBEAR_CHACHA20POLY1305 \
>   	CONFIG_DROPBEAR_UTMP CONFIG_DROPBEAR_PUTUTLINE \
> -	CONFIG_DROPBEAR_DBCLIENT
> +	CONFIG_DROPBEAR_DBCLIENT CONFIG_DROPBEAR_SCP
>   
>   include $(INCLUDE_DIR)/package.mk
>   
> @@ -53,7 +53,9 @@ define Package/dropbear
>     CATEGORY:=Base system
>     TITLE:=Small SSH2 client/server
>     DEPENDS:= +DROPBEAR_ZLIB:zlib
> -  ALTERNATIVES:=100:/usr/bin/scp:/usr/sbin/dropbear
> +  ALTERNATIVES:=
> +  $(if $(CONFIG_DROPBEAR_SCP),ALTERNATIVES+= \
> +	  100:/usr/bin/scp:/usr/sbin/dropbear,)
>     $(if $(CONFIG_DROPBEAR_DBCLIENT),ALTERNATIVES+= \
>   	  100:/usr/bin/ssh:/usr/sbin/dropbear,)
>   
> @@ -149,7 +151,7 @@ endef
>   define Build/Compile
>   	+$(MAKE) $(PKG_JOBS) -C $(PKG_BUILD_DIR) \
>   		$(TARGET_CONFIGURE_OPTS) \
> -		PROGRAMS="dropbear $(if $(CONFIG_DROPBEAR_DBCLIENT),dbclient,) dropbearkey scp" \
> +		PROGRAMS="dropbear $(if $(CONFIG_DROPBEAR_DBCLIENT),dbclient,) dropbearkey $(if $(CONFIG_DROPBEAR_SCP),scp,)" \
>   		MULTI=1 SCPPROGRESS=1
>   	+$(MAKE) $(PKG_JOBS) -C $(PKG_BUILD_DIR) \
>   		$(TARGET_CONFIGURE_OPTS) \