samhain: fix server startup failure on systemd-based systems

Fix two issues preventing samhain-server (yule) from starting:

1. The compiled-in PID file path /var/run/samhain.pid fails because
   /var/run is a symlink to /run on systemd-based systems, and
   samhain's security check rejects symlinks for PID directories.
   Add SetLockfilePath = /run/yule.pid to yulerc.template, following
   the same approach used in 0004-Set-the-PID-Lock-path-for-samhain.pid
   for the standalone/client configuration.

2. The init scripts unconditionally source /etc/default/rcS which does
   not exist on systemd-based systems, producing a confusing error
   message. Source it conditionally instead.

Signed-off-by: Bin Cao <bin.cao.cn@windriver.com>
(adapted against prior 4.5.3 upgrade)
Signed-off-by: Scott Murray <scott.murray@konsulko.com>

recipes-ids/samhain/files/0013-yulerc-set-SetLockfilePath-to-run-yule.pid.patch

@@ -0,0 +1,41 @@
+From 7070832b4652f3cdaa2e37325fc6f9456859cb5d Mon Sep 17 00:00:00 2001
+From: Bin Cao <bin.cao.cn@windriver.com>
+Date: Mon, 25 May 2026 14:55:37 +0800
+Subject: [PATCH] yulerc: set SetLockfilePath to /run/yule.pid
+
+On systemd-based systems, /var/run is a symlink to /run. Samhain's
+security-hardened code uses lstat() to verify the PID file directory
+is a real directory and rejects symlinks. This causes yule (the samhain
+server) to fail to start with "Path of PID directory refers to a
+non-directory object".
+
+Set SetLockfilePath explicitly to /run/yule.pid to bypass the
+compiled-in default of /var/run/samhain.pid.
+
+This is the same approach used in 0004-Set-the-PID-Lock-path-for-
+samhain.pid.patch for the standalone/client configuration.
+
+Upstream-Status: Inappropriate [OE-specific configuration]
+Signed-off-by: Bin Cao <bin.cao.cn@windriver.com>
+---
+ yulerc.template | 4 ++++
+ 1 file changed, 4 insertions(+)
+
+diff --git a/yulerc.template b/yulerc.template
+index 512bc0d..24b437c 100644
+--- a/yulerc.template
++++ b/yulerc.template
+@@ -173,6 +173,10 @@ Daemon=yes
+ # SetLoopTime = 60
+ SetLoopTime = 600
+ 
++## Path to the PID file
++#
++SetLockfilePath = /run/yule.pid
++
+ ## Normally, client messages are regarded as data within a
+ ## server message of fixed severity. The following two
+ ## options cause the server to use the original severity/class
+-- 
+2.34.1
+

recipes-ids/samhain/files/samhain-client.init

@@ -13,7 +13,8 @@ DAEMON=/usr/sbin/samhain
 RETVAL=0
 PIDFILE=/var/run/samhain.pid
 
-. /etc/default/rcS
+# Source rcS only if it exists (not present on systemd-based systems)
+[ -f /etc/default/rcS ] && . /etc/default/rcS
 
 . /etc/default/samhain-client
 

recipes-ids/samhain/files/samhain-server.init

@@ -13,7 +13,8 @@ DAEMON=/usr/sbin/yule
 RETVAL=0
 PIDFILE=/var/run/yule.pid
 
-. /etc/default/rcS
+# Source rcS only if it exists (not present on systemd-based systems)
+[ -f /etc/default/rcS ] && . /etc/default/rcS
 
 . /etc/default/samhain-server
 

recipes-ids/samhain/samhain.inc

@@ -20,6 +20,7 @@ SRC_URI = "https://la-samhna.de/archive/samhain_signed-${PV}.tar.gz \
            file://0009-fix-build-with-new-version-attr.patch \
            file://0010-Fix-initializer-element-is-not-constant.patch \
            file://0001-Format-test-output-to-match-Automake-standards.patch \
+           file://0013-yulerc-set-SetLockfilePath-to-run-yule.pid.patch \
            "
 
 SRC_URI[sha256sum] = "e7837adfde3d59a23c59e1bf3ebacdf71bce018619194cfad938cd30cbb9d15b"