security/tomoyo/load_policy.c

   1 /*
   2  * security/tomoyo/load_policy.c
   3  *
   4  * Copyright (C) 2005-2011  NTT DATA CORPORATION
   5  */
   6
   7 #include "common.h"
   8
   9 #ifndef CONFIG_SECURITY_TOMOYO_OMIT_USERSPACE_LOADER
  10
  11 /*
  12  * Path to the policy loader. (default = CONFIG_SECURITY_TOMOYO_POLICY_LOADER)
  13  */
  14 static const char *tomoyo_loader;
  15
  16 /**
  17  * tomoyo_loader_setup - Set policy loader.
  18  *
  19  * @str: Program to use as a policy loader (e.g. /sbin/tomoyo-init ).
  20  *
  21  * Returns 0.
  22  */
  23 static int __init tomoyo_loader_setup(char *str)
  24 {
  25         tomoyo_loader = str;
  26         return 0;
  27 }
  28
  29 __setup("TOMOYO_loader=", tomoyo_loader_setup);
  30
  31 /**
  32  * tomoyo_policy_loader_exists - Check whether /sbin/tomoyo-init exists.
  33  *
  34  * Returns true if /sbin/tomoyo-init exists, false otherwise.
  35  */
  36 static bool tomoyo_policy_loader_exists(void)
  37 {
  38         struct path path;
  39         if (!tomoyo_loader)
  40                 tomoyo_loader = CONFIG_SECURITY_TOMOYO_POLICY_LOADER;
  41         if (kern_path(tomoyo_loader, LOOKUP_FOLLOW, &path)) {
  42                 printk(KERN_INFO "Not activating Mandatory Access Control "
  43                        "as %s does not exist.\n", tomoyo_loader);
  44                 return false;
  45         }
  46         path_put(&path);
  47         return true;
  48 }
  49
  50 /*
  51  * Path to the trigger. (default = CONFIG_SECURITY_TOMOYO_ACTIVATION_TRIGGER)
  52  */
  53 static const char *tomoyo_trigger;
  54
  55 /**
  56  * tomoyo_trigger_setup - Set trigger for activation.
  57  *
  58  * @str: Program to use as an activation trigger (e.g. /sbin/init ).
  59  *
  60  * Returns 0.
  61  */
  62 static int __init tomoyo_trigger_setup(char *str)
  63 {
  64         tomoyo_trigger = str;
  65         return 0;
  66 }
  67
  68 __setup("TOMOYO_trigger=", tomoyo_trigger_setup);
  69
  70 /**
  71  * tomoyo_load_policy - Run external policy loader to load policy.
  72  *
  73  * @filename: The program about to start.
  74  *
  75  * This function checks whether @filename is /sbin/init , and if so
  76  * invoke /sbin/tomoyo-init and wait for the termination of /sbin/tomoyo-init
  77  * and then continues invocation of /sbin/init.
  78  * /sbin/tomoyo-init reads policy files in /etc/tomoyo/ directory and
  79  * writes to /sys/kernel/security/tomoyo/ interfaces.
  80  *
  81  * Returns nothing.
  82  */
  83 void tomoyo_load_policy(const char *filename)
  84 {
  85         static bool done;
  86         char *argv[2];
  87         char *envp[3];
  88
  89         if (tomoyo_policy_loaded || done)
  90                 return;
  91         if (!tomoyo_trigger)
  92                 tomoyo_trigger = CONFIG_SECURITY_TOMOYO_ACTIVATION_TRIGGER;
  93         if (strcmp(filename, tomoyo_trigger))
  94                 return;
  95         if (!tomoyo_policy_loader_exists())
  96                 return;
  97         done = true;
  98         printk(KERN_INFO "Calling %s to load policy. Please wait.\n",
  99                tomoyo_loader);
 100         argv[0] = (char *) tomoyo_loader;
 101         argv[1] = NULL;
 102         envp[0] = "HOME=/";
 103         envp[1] = "PATH=/sbin:/bin:/usr/sbin:/usr/bin";
 104         envp[2] = NULL;
 105         call_usermodehelper(argv[0], argv, envp, 1);
 106         tomoyo_check_profile();
 107 }
 108
 109 #endif