util-linux: install PAM configuration files

Install PAM configuration files for su (with "su -" variant) and login
when the tools are enabled.
This finally fixes bug #5366 and now we can login with an util-linux
/bin/login.

Signed-off-by: Gustavo Zacarias <gustavo@zacarias.com.ar>
Signed-off-by: Peter Korsgaard <peter@korsgaard.com>

package/util-linux/login.pam

@@ -0,0 +1,11 @@
+auth		required	pam_securetty.so
+auth		required	pam_unix.so nullok
+
+account		required	pam_unix.so
+
+password	required	pam_unix.so nullok
+
+session		required	pam_limits.so
+session		required	pam_env.so
+session		required	pam_unix.so
+session		optional	pam_lastlog.so

package/util-linux/su.pam

@@ -0,0 +1,13 @@
+auth		sufficient	pam_rootok.so
+auth		required	pam_wheel.so use_uid
+auth		required	pam_env.so
+auth		required	pam_unix.so nullok
+
+account		required	pam_unix.so
+
+password	required	pam_unix.so nullok
+
+session		required	pam_limits.so
+session		required	pam_env.so
+session		required	pam_unix.so
+session		optional	pam_lastlog.so

package/util-linux/util-linux.mk

@@ -98,6 +98,20 @@ endef
 UTIL_LINUX_PRE_PATCH_HOOKS += UTIL_LINUX_DISABLE_TOOLS
 endif
 
+# Install PAM configuration files
+ifeq ($(BR2_PACKAGE_UTIL_LINUX_LOGIN_UTILS),y)
+define UTIL_LINUX_INSTALL_PAMFILES
+	$(INSTALL) -m 0644 package/util-linux/login.pam \
+		$(TARGET_DIR)/etc/pam.d/login
+	$(INSTALL) -m 0644 package/util-linux/su.pam \
+		$(TARGET_DIR)/etc/pam.d/su
+	$(INSTALL) -m 0644 package/util-linux/su.pam \
+		$(TARGET_DIR)/etc/pam.d/su-l
+endef
+endif
+
+UTIL_LINUX_POST_INSTALL_TARGET_HOOKS += UTIL_LINUX_INSTALL_PAMFILES
+
 $(eval $(autotools-package))
 $(eval $(host-autotools-package))