sudo: add optional pam support

Configure the sudo utility to support PAM if the framework is enabled.

[Peter: use install -D, reword commit message]
Signed-off-by: James Knight <james.knight@rockwellcollins.com>
Signed-off-by: Peter Korsgaard <peter@korsgaard.com>

package/sudo/sudo.mk

@@ -16,9 +16,20 @@ SUDO_CONF_OPTS = \
 	--without-umask \
 	--with-logging=syslog \
 	--without-interfaces \
-	--without-pam \
 	--with-env-editor
 
+ifeq ($(BR2_PACKAGE_LINUX_PAM),y)
+define SUDO_INSTALL_PAM_CONF
+	$(INSTALL) -D -m 0644 package/sudo/sudo.pam $(TARGET_DIR)/etc/pam.d/sudo
+endef
+
+SUDO_DEPENDENCIES += linux-pam
+SUDO_CONF_OPTS += --with-pam
+SUDO_POST_INSTALL_TARGET_HOOKS += SUDO_INSTALL_PAM_CONF
+else
+SUDO_CONF_OPTS += --without-pam
+endif
+
 # mksigname/mksiglist needs to run on build host to generate source files
 define SUDO_BUILD_MKSIGNAME_MKSIGLIST_HOST
 	$(MAKE) $(HOST_CONFIGURE_OPTS) \

package/sudo/sudo.pam

@@ -0,0 +1,12 @@
+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