nmap: add option to build/install "ncat"

Ncat is a much-improved reimplementation of the venerable Netcat and is
compatible with uClibc.

So far the "nc" options available to build with uClibc were the ancient
GNU netcat and its Busybox double (the openbsd-netcat package cannot be
used because it requires GLIBC). Both lack features available in modern
netcats like IPv6, proxies, and Unix sockets.

Signed-off-by: Carlos Santos <casantos@datacom.ind.br>
------
Changes v1->v2:
  - Prevent build error
    Makefile:537: *** nmap is in the dependency chain of nc that has \
    added it to its _DEPENDENCIES variable without selecting it or \
    depending on it from Config.in.  Stop.
------
 package/Config.in                        |  3 +-
 package/nc/Config.in                     | 84 ++++++++++++++++++++++++++++++++
 package/nc/nc.mk                         |  7 +++
 package/netcat-openbsd/Config.in         | 25 ----------
 package/netcat-openbsd/netcat-openbsd.mk |  2 +
 package/netcat/Config.in                 | 13 -----
 package/netcat/netcat.mk                 |  1 +
 package/nmap/Config.in                   |  4 ++
 package/nmap/nmap.mk                     | 30 +++++++++++-
 9 files changed, 127 insertions(+), 42 deletions(-)
 create mode 100644 package/nc/Config.in
 create mode 100644 package/nc/nc.mk
---
 package/nmap/Config.in | 12 ++++++++++++
 package/nmap/nmap.mk   | 21 ++++++++++++++++++++-
 2 files changed, 32 insertions(+), 1 deletion(-)

Hi Carlos,

On Wed, Oct 04, 2017 at 09:49:20AM -0300, Carlos Santos wrote:
> Ncat is a much-improved reimplementation of the venerable Netcat and is
> compatible with uClibc.
> 
> So far the "nc" options available to build with uClibc were the ancient
> GNU netcat and its Busybox double (the openbsd-netcat package cannot be
> used because it requires GLIBC). Both lack features available in modern
> netcats like IPv6, proxies, and Unix sockets.
> 
> Signed-off-by: Carlos Santos <casantos@datacom.ind.br>
> ------
> Changes v1->v2:
>   - Prevent build error
>     Makefile:537: *** nmap is in the dependency chain of nc that has \
>     added it to its _DEPENDENCIES variable without selecting it or \
>     depending on it from Config.in.  Stop.
> ------
>  package/Config.in                        |  3 +-
>  package/nc/Config.in                     | 84 ++++++++++++++++++++++++++++++++
>  package/nc/nc.mk                         |  7 +++
>  package/netcat-openbsd/Config.in         | 25 ----------
>  package/netcat-openbsd/netcat-openbsd.mk |  2 +
>  package/netcat/Config.in                 | 13 -----
>  package/netcat/netcat.mk                 |  1 +
>  package/nmap/Config.in                   |  4 ++
>  package/nmap/nmap.mk                     | 30 +++++++++++-
>  9 files changed, 127 insertions(+), 42 deletions(-)
>  create mode 100644 package/nc/Config.in
>  create mode 100644 package/nc/nc.mk
> ---
>  package/nmap/Config.in | 12 ++++++++++++
>  package/nmap/nmap.mk   | 21 ++++++++++++++++++++-
>  2 files changed, 32 insertions(+), 1 deletion(-)
> 
> diff --git a/package/nmap/Config.in b/package/nmap/Config.in
> index 79f587afd1..7986bd6544 100644
> --- a/package/nmap/Config.in
> +++ b/package/nmap/Config.in
> @@ -11,6 +11,18 @@ config BR2_PACKAGE_NMAP
>  
>  	  http://nmap.org
>  
> +if BR2_PACKAGE_NMAP
> +
> +config BR2_PACKAGE_NMAP_NCAT
> +	bool "nmap-ncat"
> +	help
> +	  Ncat is a feature-packed networking utility which reads and
> +	  writes data across networks from the command line. Ncat was
> +	  written for the Nmap Project as a much-improved
> +	  reimplementation of the venerable Netcat.
> +
> +endif
> +
>  comment "nmap needs a toolchain w/ C++, threads"
>  	depends on BR2_USE_MMU
>  	depends on !(BR2_INSTALL_LIBSTDCPP && BR2_TOOLCHAIN_HAS_THREADS)
> diff --git a/package/nmap/nmap.mk b/package/nmap/nmap.mk
> index 9db06d1455..e41a66927c 100644
> --- a/package/nmap/nmap.mk
> +++ b/package/nmap/nmap.mk
> @@ -10,7 +10,7 @@ NMAP_SOURCE = nmap-$(NMAP_VERSION).tar.bz2
>  NMAP_DEPENDENCIES = libpcap pcre
>  NMAP_CONF_OPTS = --without-liblua --without-zenmap \
>  	--with-libdnet=included --with-liblinear=included \
> -	--with-libpcre="$(STAGING_DIR)/usr" --without-ncat
> +	--with-libpcre="$(STAGING_DIR)/usr"
>  NMAP_LICENSE = GPL-2.0
>  NMAP_LICENSE_FILES = COPYING
>  
> @@ -50,4 +50,23 @@ else
>  NMAP_CONF_OPTS += --without-ndiff
>  endif
>  
> +ifeq ($(BR2_PACKAGE_NMAP_NCAT),y)
> +
> +# If both nmap-ncat and busybox are selected, make certain coreutils

coreutils?

> +# wins the fight over who gets to have their utils actually installed.
> +ifeq ($(BR2_PACKAGE_BUSYBOX),Y)
> +NMAP_DEPENDENCIES += busybox
> +endif
> +
> +define NMAP_INSTALL_NCAT_SYMLINK
> +        ln -fs ncat $(TARGET_DIR)/usr/bin/nc
> +endef
> +NMAP_POST_INSTALL_TARGET_HOOKS += NMAP_INSTALL_NCAT_SYMLINK
> +
> +else
> +
> +NMAP_CONF_OPTS += --without-ncat
> +
> +endif
> +
>  $(eval $(autotools-package))

baruch