[PATCH 3/3] add disable param to capabilities module

[Chris Wright <chrisw@osdl.org>]

Add disable param to capabilities module.  Similar to the SELinux param
for disabling at boot time.  This allows vendors to ship single binary
image with capabilities compiled statically, and disable it if they
provide another security model compiled as module.

--- linus-2.5/security/capability.c~disable	2004-05-11 16:14:36.121676768 -0700
+++ linus-2.5/security/capability.c	2004-05-11 16:19:25.906622760 -0700
@@ -22,6 +22,7 @@
 #include <linux/skbuff.h>
 #include <linux/netlink.h>
 #include <linux/ptrace.h>
+#include <linux/moduleparam.h>
 
 static struct security_operations capability_ops = {
 	.ptrace =			cap_ptrace,
@@ -52,9 +53,16 @@
 /* flag to keep track of how we were registered */
 static int secondary;
 
+static int capability_disable;
+module_param_named(disable, capability_disable, int, 0);
+MODULE_PARM_DESC(disable, "To disable capabilities module set disable = 1");
 
 static int __init capability_init (void)
 {
+	if (capability_disable) {
+		printk(KERN_INFO "Capabilities disabled at initialization\n");
+		return 0;
+	}
 	/* register ourselves with the security framework */
 	if (register_security (&capability_ops)) {
 		/* try registering with primary module */
@@ -72,6 +80,8 @@
 
 static void __exit capability_exit (void)
 {
+	if (capability_disable)
+		return;
 	/* remove ourselves from the security framework */
 	if (secondary) {
 		if (mod_unreg_security (MY_NAME, &capability_ops))