security/selinux/exports.c

   1 /*
   2  * SELinux services exported to the rest of the kernel.
   3  *
   4  * Author: James Morris <jmorris@redhat.com>
   5  *
   6  * Copyright (C) 2005 Red Hat, Inc., James Morris <jmorris@redhat.com>
   7  * Copyright (C) 2006 Trusted Computer Solutions, Inc. <dgoeddel@trustedcs.com>
   8  * Copyright (C) 2006 IBM Corporation, Timothy R. Chavez <tinytim@us.ibm.com>
   9  *
  10  * This program is free software; you can redistribute it and/or modify
  11  * it under the terms of the GNU General Public License version 2,
  12  * as published by the Free Software Foundation.
  13  */
  14 #include <linux/types.h>
  15 #include <linux/kernel.h>
  16 #include <linux/module.h>
  17 #include <linux/selinux.h>
  18 #include <linux/fs.h>
  19 #include <linux/ipc.h>
  20 #include <asm/atomic.h>
  21
  22 #include "security.h"
  23 #include "objsec.h"
  24
  25 /* SECMARK reference count */
  26 extern atomic_t selinux_secmark_refcount;
  27
  28 int selinux_sid_to_string(u32 sid, char **ctx, u32 *ctxlen)
  29 {
  30         if (selinux_enabled)
  31                 return security_sid_to_context(sid, ctx, ctxlen);
  32         else {
  33                 *ctx = NULL;
  34                 *ctxlen = 0;
  35         }
  36
  37         return 0;
  38 }
  39
  40 void selinux_get_inode_sid(const struct inode *inode, u32 *sid)
  41 {
  42         if (selinux_enabled) {
  43                 struct inode_security_struct *isec = inode->i_security;
  44                 *sid = isec->sid;
  45                 return;
  46         }
  47         *sid = 0;
  48 }
  49
  50 void selinux_get_ipc_sid(const struct kern_ipc_perm *ipcp, u32 *sid)
  51 {
  52         if (selinux_enabled) {
  53                 struct ipc_security_struct *isec = ipcp->security;
  54                 *sid = isec->sid;
  55                 return;
  56         }
  57         *sid = 0;
  58 }
  59
  60 void selinux_get_task_sid(struct task_struct *tsk, u32 *sid)
  61 {
  62         if (selinux_enabled) {
  63                 struct task_security_struct *tsec = tsk->security;
  64                 *sid = tsec->sid;
  65                 return;
  66         }
  67         *sid = 0;
  68 }
  69
  70 int selinux_string_to_sid(char *str, u32 *sid)
  71 {
  72         if (selinux_enabled)
  73                 return security_context_to_sid(str, strlen(str), sid);
  74         else {
  75                 *sid = 0;
  76                 return 0;
  77         }
  78 }
  79 EXPORT_SYMBOL_GPL(selinux_string_to_sid);
  80
  81 int selinux_secmark_relabel_packet_permission(u32 sid)
  82 {
  83         if (selinux_enabled) {
  84                 struct task_security_struct *tsec = current->security;
  85
  86                 return avc_has_perm(tsec->sid, sid, SECCLASS_PACKET,
  87                                     PACKET__RELABELTO, NULL);
  88         }
  89         return 0;
  90 }
  91 EXPORT_SYMBOL_GPL(selinux_secmark_relabel_packet_permission);
  92
  93 void selinux_secmark_refcount_inc(void)
  94 {
  95         atomic_inc(&selinux_secmark_refcount);
  96 }
  97 EXPORT_SYMBOL_GPL(selinux_secmark_refcount_inc);
  98
  99 void selinux_secmark_refcount_dec(void)
 100 {
 101         atomic_dec(&selinux_secmark_refcount);
 102 }
 103 EXPORT_SYMBOL_GPL(selinux_secmark_refcount_dec);