security/apparmor/lib.c

   1 /*
   2  * AppArmor security module
   3  *
   4  * This file contains basic common functions used in AppArmor
   5  *
   6  * Copyright (C) 1998-2008 Novell/SUSE
   7  * Copyright 2009-2010 Canonical Ltd.
   8  *
   9  * This program is free software; you can redistribute it and/or
  10  * modify it under the terms of the GNU General Public License as
  11  * published by the Free Software Foundation, version 2 of the
  12  * License.
  13  */
  14
  15 #include <linux/mm.h>
  16 #include <linux/slab.h>
  17 #include <linux/string.h>
  18 #include <linux/vmalloc.h>
  19
  20 #include "include/audit.h"
  21 #include "include/apparmor.h"
  22
  23
  24 /**
  25  * aa_split_fqname - split a fqname into a profile and namespace name
  26  * @fqname: a full qualified name in namespace profile format (NOT NULL)
  27  * @ns_name: pointer to portion of the string containing the ns name (NOT NULL)
  28  *
  29  * Returns: profile name or NULL if one is not specified
  30  *
  31  * Split a namespace name from a profile name (see policy.c for naming
  32  * description).  If a portion of the name is missing it returns NULL for
  33  * that portion.
  34  *
  35  * NOTE: may modify the @fqname string.  The pointers returned point
  36  *       into the @fqname string.
  37  */
  38 char *aa_split_fqname(char *fqname, char **ns_name)
  39 {
  40         char *name = strim(fqname);
  41
  42         *ns_name = NULL;
  43         if (name[0] == ':') {
  44                 char *split = strchr(&name[1], ':');
  45                 *ns_name = skip_spaces(&name[1]);
  46                 if (split) {
  47                         /* overwrite ':' with \0 */
  48                         *split++ = 0;
  49                         if (strncmp(split, "//", 2) == 0)
  50                                 split += 2;
  51                         name = skip_spaces(split);
  52                 } else
  53                         /* a ns name without a following profile is allowed */
  54                         name = NULL;
  55         }
  56         if (name && *name == 0)
  57                 name = NULL;
  58
  59         return name;
  60 }
  61
  62 /**
  63  * aa_info_message - log a none profile related status message
  64  * @str: message to log
  65  */
  66 void aa_info_message(const char *str)
  67 {
  68         if (audit_enabled) {
  69                 struct common_audit_data sa;
  70                 struct apparmor_audit_data aad = {0,};
  71                 sa.type = LSM_AUDIT_DATA_NONE;
  72                 sa.aad = &aad;
  73                 aad.info = str;
  74                 aa_audit_msg(AUDIT_APPARMOR_STATUS, &sa, NULL);
  75         }
  76         printk(KERN_INFO "AppArmor: %s\n", str);
  77 }
  78
  79 /**
  80  * __aa_kvmalloc - do allocation preferring kmalloc but falling back to vmalloc
  81  * @size: how many bytes of memory are required
  82  * @flags: the type of memory to allocate (see kmalloc).
  83  *
  84  * Return: allocated buffer or NULL if failed
  85  *
  86  * It is possible that policy being loaded from the user is larger than
  87  * what can be allocated by kmalloc, in those cases fall back to vmalloc.
  88  */
  89 void *__aa_kvmalloc(size_t size, gfp_t flags)
  90 {
  91         void *buffer = NULL;
  92
  93         if (size == 0)
  94                 return NULL;
  95
  96         /* do not attempt kmalloc if we need more than 16 pages at once */
  97         if (size <= (16*PAGE_SIZE))
  98                 buffer = kmalloc(size, flags | GFP_NOIO | __GFP_NOWARN);
  99         if (!buffer) {
 100                 /* see kvfree for why size must be at least work_struct size
 101                  * when allocated via vmalloc
 102                  */
 103                 if (size < sizeof(struct work_struct))
 104                         size = sizeof(struct work_struct);
 105                 if (flags & __GFP_ZERO)
 106                         buffer = vzalloc(size);
 107                 else
 108                         buffer = vmalloc(size);
 109         }
 110         return buffer;
 111 }
 112
 113 /**
 114  * kvfree - free an allocation do by kvmalloc
 115  * @buffer: buffer to free (MAYBE_NULL)
 116  *
 117  * Free a buffer allocated by kvmalloc
 118  */
 119 void kvfree(void *buffer)
 120 {
 121         if (is_vmalloc_addr(buffer))
 122                 vfree(buffer);
 123         else
 124                 kfree(buffer);
 125 }