[PATCH libnfnetlink v3 2/2] Make it clear that this library is deprecated

[Duncan Roe <duncan_roe@xxxxxxxxxxxxxxx>]

 src/iftable.c: Update group description

 src/libnfnetlink.c: - Re-work main page (which was based on the misconception
                       that this library always gets used)
                     - Update group description

Signed-off-by: Duncan Roe <duncan_roe@xxxxxxxxxxxxxxx>
---
 src/iftable.c      |  6 +++++-
 src/libnfnetlink.c | 17 ++++++++++++++---
 2 files changed, 19 insertions(+), 4 deletions(-)

diff --git a/src/iftable.c b/src/iftable.c
index 6d1d135..aab59b3 100644
--- a/src/iftable.c
+++ b/src/iftable.c
@@ -25,7 +25,11 @@
 #include "linux_list.h"
 
 /**
- * \defgroup iftable Functions in iftable.c
+ * \defgroup iftable Functions in iftable.c [DEPRECATED]
+ * This documentation is provided for the benefit of maintainers of legacy code.
+ *
+ * New applications should use
+ * [libmnl](https://netfilter.org/projects/libmnl/doxygen/html/).
  * @{
  */
 
diff --git a/src/libnfnetlink.c b/src/libnfnetlink.c
index 3db21e0..1cb6a82 100644
--- a/src/libnfnetlink.c
+++ b/src/libnfnetlink.c
@@ -55,12 +55,23 @@
 /**
  * \mainpage
  *
- * libnfnetlink is the bottom-level communication between the kernel and
- * userspace
+ * Deprecated
+ * ---
+ * New applications should use
+ * [libmnl](https://netfilter.org/projects/libmnl/doxygen/html/).
+ *
+ * [libnetfilter_queue]
+ * (https://netfilter.org/projects/libnetfilter_queue/doxygen/html/)
+ * now provides a set of helpers for libmnl, in addition to those it provides
+ * for libnfnetlink (which are now deprecated).
  */
 
 /**
- * \defgroup libnfnetlink Functions in libnfnetlink.c
+ * \defgroup libnfnetlink Functions in libnfnetlink.c [DEPRECATED]
+ * This documentation is provided for the benefit of maintainers of legacy code.
+ *
+ * New applications should use
+ * [libmnl](https://netfilter.org/projects/libmnl/doxygen/html/).
  * @{
  */
 
-- 
2.14.5