dropbear: add options to disable wtmp / lastlog logging

Buildroot does not have wtmp or lastlog support by default so allow dropbear
to be configured to stop using them and hence to stop generating system log
error messages.

[Peter: invert to positive options, and disable by default]
Signed-off-by: Will Moore <will.moore@beraninstruments.com>
Signed-off-by: Peter Korsgaard <jacmet@sunsite.dk>

package/dropbear/Config.in

@@ -23,3 +23,17 @@ config BR2_PACKAGE_DROPBEAR_SMALL
 
 	  Tradeoffs are slower hashes and ciphers, and disabling of the
 	  blowfish cipher and zlib.
+
+config BR2_PACKAGE_DROPBEAR_WTMP
+	bool "log dropbear access to wtmp"
+	depends on BR2_PACKAGE_DROPBEAR
+	help
+	  Enable logging of dropbear access to wtmp. Notice that
+	  Buildroot does not generate wtmp by default.
+
+config BR2_PACKAGE_DROPBEAR_LASTLOG
+	bool "log dropbear access to lastlog"
+	depends on BR2_PACKAGE_DROPBEAR
+	help
+	  Enable logging of dropbear access to lastlog. Notice that
+	  Buildroot does not generate lastlog by default.

package/dropbear/dropbear.mk

@@ -46,6 +46,14 @@ DROPBEAR_POST_EXTRACT_HOOKS += DROPBEAR_BUILD_FEATURED
 DROPBEAR_DEPENDENCIES += zlib
 endif
 
+ifneq ($(BR2_PACKAGE_DROPBEAR_WTMP),y)
+DROPBEAR_CONF_OPT += --disable-wtmp
+endif
+
+ifneq ($(BR2_PACKAGE_DROPBEAR_LASTLOG),y)
+DROPBEAR_CONF_OPT += --disable-lastlog
+endif
+
 define DROPBEAR_INSTALL_TARGET_CMDS
 	$(INSTALL) -m 755 $(@D)/dropbearmulti $(TARGET_DIR)/usr/sbin/dropbear
 	for f in $(DROPBEAR_TARGET_BINS); do \