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/config.h>
  12 #include <linux/module.h>
  13 #include <linux/init.h>
  14 #include <linux/kernel.h>
  15 #include <linux/security.h>
  16 #include <linux/file.h>
  17 #include <linux/mm.h>
  18 #include <linux/mman.h>
  19 #include <linux/pagemap.h>
  20 #include <linux/swap.h>
  21 #include <linux/smp_lock.h>
  22 #include <linux/skbuff.h>
  23 #include <linux/netlink.h>
  24 #include <linux/ptrace.h>
  25 #include <linux/moduleparam.h>
  26
  27 static struct security_operations capability_ops = {
  28         .ptrace =                       cap_ptrace,
  29         .capget =                       cap_capget,
  30         .capset_check =                 cap_capset_check,
  31         .capset_set =                   cap_capset_set,
  32         .capable =                      cap_capable,
  33         .netlink_send =                 cap_netlink_send,
  34         .netlink_recv =                 cap_netlink_recv,
  35
  36         .bprm_apply_creds =             cap_bprm_apply_creds,
  37         .bprm_set_security =            cap_bprm_set_security,
  38         .bprm_secureexec =              cap_bprm_secureexec,
  39
  40         .inode_setxattr =               cap_inode_setxattr,
  41         .inode_removexattr =            cap_inode_removexattr,
  42
  43         .task_post_setuid =             cap_task_post_setuid,
  44         .task_reparent_to_init =        cap_task_reparent_to_init,
  45
  46         .syslog =                       cap_syslog,
  47
  48         .vm_enough_memory =             cap_vm_enough_memory,
  49 };
  50
  51 #define MY_NAME __stringify(KBUILD_MODNAME)
  52
  53 /* flag to keep track of how we were registered */
  54 static int secondary;
  55
  56 static int capability_disable;
  57 module_param_named(disable, capability_disable, int, 0);
  58 MODULE_PARM_DESC(disable, "To disable capabilities module set disable = 1");
  59
  60 static int __init capability_init (void)
  61 {
  62         if (capability_disable) {
  63                 printk(KERN_INFO "Capabilities disabled at initialization\n");
  64                 return 0;
  65         }
  66         /* register ourselves with the security framework */
  67         if (register_security (&capability_ops)) {
  68                 /* try registering with primary module */
  69                 if (mod_reg_security (MY_NAME, &capability_ops)) {
  70                         printk (KERN_INFO "Failure registering capabilities "
  71                                 "with primary security module.\n");
  72                         return -EINVAL;
  73                 }
  74                 secondary = 1;
  75         }
  76         printk (KERN_INFO "Capability LSM initialized%s\n",
  77                 secondary ? " as secondary" : "");
  78         return 0;
  79 }
  80
  81 static void __exit capability_exit (void)
  82 {
  83         if (capability_disable)
  84                 return;
  85         /* remove ourselves from the security framework */
  86         if (secondary) {
  87                 if (mod_unreg_security (MY_NAME, &capability_ops))
  88                         printk (KERN_INFO "Failure unregistering capabilities "
  89                                 "with primary module.\n");
  90                 return;
  91         }
  92
  93         if (unregister_security (&capability_ops)) {
  94                 printk (KERN_INFO
  95                         "Failure unregistering capabilities with the kernel\n");
  96         }
  97 }
  98
  99 security_initcall (capability_init);
 100 module_exit (capability_exit);
 101
 102 MODULE_DESCRIPTION("Standard Linux Capabilities Security Module");
 103 MODULE_LICENSE("GPL");