security/capability.c

   1 /*
   2  *  Capabilities Linux Security Module
   3  *
   4  *      This program is free software; you can redistribute it and/or modify
   5  *      it under the terms of the GNU General Public License as published by
   6  *      the Free Software Foundation; either version 2 of the License, or
   7  *      (at your option) any later version.
   8  *
   9  */
  10
  11 #include <linux/module.h>
  12 #include <linux/init.h>
  13 #include <linux/kernel.h>
  14 #include <linux/security.h>
  15 #include <linux/file.h>
  16 #include <linux/mm.h>
  17 #include <linux/mman.h>
  18 #include <linux/pagemap.h>
  19 #include <linux/swap.h>
  20 #include <linux/skbuff.h>
  21 #include <linux/netlink.h>
  22 #include <linux/ptrace.h>
  23 #include <linux/moduleparam.h>
  24
  25 static struct security_operations capability_ops = {
  26         .ptrace =                       cap_ptrace,
  27         .capget =                       cap_capget,
  28         .capset_check =                 cap_capset_check,
  29         .capset_set =                   cap_capset_set,
  30         .capable =                      cap_capable,
  31         .settime =                      cap_settime,
  32         .netlink_send =                 cap_netlink_send,
  33         .netlink_recv =                 cap_netlink_recv,
  34
  35         .bprm_apply_creds =             cap_bprm_apply_creds,
  36         .bprm_set_security =            cap_bprm_set_security,
  37         .bprm_secureexec =              cap_bprm_secureexec,
  38
  39         .inode_setxattr =               cap_inode_setxattr,
  40         .inode_removexattr =            cap_inode_removexattr,
  41
  42         .task_post_setuid =             cap_task_post_setuid,
  43         .task_reparent_to_init =        cap_task_reparent_to_init,
  44
  45         .syslog =                       cap_syslog,
  46
  47         .vm_enough_memory =             cap_vm_enough_memory,
  48 };
  49
  50 /* flag to keep track of how we were registered */
  51 static int secondary;
  52
  53 static int capability_disable;
  54 module_param_named(disable, capability_disable, int, 0);
  55 MODULE_PARM_DESC(disable, "To disable capabilities module set disable = 1");
  56
  57 static int __init capability_init (void)
  58 {
  59         if (capability_disable) {
  60                 printk(KERN_INFO "Capabilities disabled at initialization\n");
  61                 return 0;
  62         }
  63         /* register ourselves with the security framework */
  64         if (register_security (&capability_ops)) {
  65                 /* try registering with primary module */
  66                 if (mod_reg_security (KBUILD_MODNAME, &capability_ops)) {
  67                         printk (KERN_INFO "Failure registering capabilities "
  68                                 "with primary security module.\n");
  69                         return -EINVAL;
  70                 }
  71                 secondary = 1;
  72         }
  73         printk (KERN_INFO "Capability LSM initialized%s\n",
  74                 secondary ? " as secondary" : "");
  75         return 0;
  76 }
  77
  78 static void __exit capability_exit (void)
  79 {
  80         if (capability_disable)
  81                 return;
  82         /* remove ourselves from the security framework */
  83         if (secondary) {
  84                 if (mod_unreg_security (KBUILD_MODNAME, &capability_ops))
  85                         printk (KERN_INFO "Failure unregistering capabilities "
  86                                 "with primary module.\n");
  87                 return;
  88         }
  89
  90         if (unregister_security (&capability_ops)) {
  91                 printk (KERN_INFO
  92                         "Failure unregistering capabilities with the kernel\n");
  93         }
  94 }
  95
  96 security_initcall (capability_init);
  97 module_exit (capability_exit);
  98
  99 MODULE_DESCRIPTION("Standard Linux Capabilities Security Module");
 100 MODULE_LICENSE("GPL");