LXR linux/security/apparmor/procattr.c

   1/*
   2 * AppArmor security module
   3 *
   4 * This file contains AppArmor /proc/<pid>/attr/ interface functions
   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 "include/apparmor.h"
  16#include "include/context.h"
  17#include "include/policy.h"
  18#include "include/domain.h"
  19#include "include/procattr.h"
  20
  21
  22/**
  23 * aa_getprocattr - Return the profile information for @profile
  24 * @profile: the profile to print profile info about  (NOT NULL)
  25 * @string: Returns - string containing the profile info (NOT NULL)
  26 *
  27 * Returns: length of @string on success else error on failure
  28 *
  29 * Requires: profile != NULL
  30 *
  31 * Creates a string containing the namespace_name://profile_name for
  32 * @profile.
  33 *
  34 * Returns: size of string placed in @string else error code on failure
  35 */
  36int aa_getprocattr(struct aa_profile *profile, char **string)
  37{
  38        char *str;
  39        int len = 0, mode_len = 0, ns_len = 0, name_len;
  40        const char *mode_str = aa_profile_mode_names[profile->mode];
  41        const char *ns_name = NULL;
  42        struct aa_namespace *ns = profile->ns;
  43        struct aa_namespace *current_ns = __aa_current_profile()->ns;
  44        char *s;
  45
  46        if (!aa_ns_visible(current_ns, ns))
  47                return -EACCES;
  48
  49        ns_name = aa_ns_name(current_ns, ns);
  50        ns_len = strlen(ns_name);
  51
  52        /* if the visible ns_name is > 0 increase size for : :// seperator */
  53        if (ns_len)
  54                ns_len += 4;
  55
  56        /* unconfined profiles don't have a mode string appended */
  57        if (!unconfined(profile))
  58                mode_len = strlen(mode_str) + 3;        /* + 3 for _() */
  59
  60        name_len = strlen(profile->base.hname);
  61        len = mode_len + ns_len + name_len + 1;     /* + 1 for \n */
  62        s = str = kmalloc(len + 1, GFP_KERNEL);     /* + 1 \0 */
  63        if (!str)
  64                return -ENOMEM;
  65
  66        if (ns_len) {
  67                /* skip over prefix current_ns->base.hname and separating // */
  68                sprintf(s, ":%s://", ns_name);
  69                s += ns_len;
  70        }
  71        if (unconfined(profile))
  72                /* mode string not being appended */
  73                sprintf(s, "%s\n", profile->base.hname);
  74        else
  75                sprintf(s, "%s (%s)\n", profile->base.hname, mode_str);
  76        *string = str;
  77
  78        /* NOTE: len does not include \0 of string, not saved as part of file */
  79        return len;
  80}
  81
  82/**
  83 * split_token_from_name - separate a string of form  <token>^<name>
  84 * @op: operation being checked
  85 * @args: string to parse  (NOT NULL)
  86 * @token: stores returned parsed token value  (NOT NULL)
  87 *
  88 * Returns: start position of name after token else NULL on failure
  89 */
  90static char *split_token_from_name(int op, char *args, u64 * token)
  91{
  92        char *name;
  93
  94        *token = simple_strtoull(args, &name, 16);
  95        if ((name == args) || *name != '^') {
  96                AA_ERROR("%s: Invalid input '%s'", op_table[op], args);
  97                return ERR_PTR(-EINVAL);
  98        }
  99
 100        name++;                 /* skip ^ */
 101        if (!*name)
 102                name = NULL;
 103        return name;
 104}
 105
 106/**
 107 * aa_setprocattr_chagnehat - handle procattr interface to change_hat
 108 * @args: args received from writing to /proc/<pid>/attr/current (NOT NULL)
 109 * @size: size of the args
 110 * @test: true if this is a test of change_hat permissions
 111 *
 112 * Returns: %0 or error code if change_hat fails
 113 */
 114int aa_setprocattr_changehat(char *args, size_t size, int test)
 115{
 116        char *hat;
 117        u64 token;
 118        const char *hats[16];           /* current hard limit on # of names */
 119        int count = 0;
 120
 121        hat = split_token_from_name(OP_CHANGE_HAT, args, &token);
 122        if (IS_ERR(hat))
 123                return PTR_ERR(hat);
 124
 125        if (!hat && !token) {
 126                AA_ERROR("change_hat: Invalid input, NULL hat and NULL magic");
 127                return -EINVAL;
 128        }
 129
 130        if (hat) {
 131                /* set up hat name vector, args guaranteed null terminated
 132                 * at args[size] by setprocattr.
 133                 *
 134                 * If there are multiple hat names in the buffer each is
 135                 * separated by a \0.  Ie. userspace writes them pre tokenized
 136                 */
 137                char *end = args + size;
 138                for (count = 0; (hat < end) && count < 16; ++count) {
 139                        char *next = hat + strlen(hat) + 1;
 140                        hats[count] = hat;
 141                        hat = next;
 142                }
 143        }
 144
 145        AA_DEBUG("%s: Magic 0x%llx Hat '%s'\n",
 146                 __func__, token, hat ? hat : NULL);
 147
 148        return aa_change_hat(hats, count, token, test);
 149}
 150
 151/**
 152 * aa_setprocattr_changeprofile - handle procattr interface to changeprofile
 153 * @fqname: args received from writting to /proc/<pid>/attr/current (NOT NULL)
 154 * @onexec: true if change_profile should be delayed until exec
 155 * @test: true if this is a test of change_profile permissions
 156 *
 157 * Returns: %0 or error code if change_profile fails
 158 */
 159int aa_setprocattr_changeprofile(char *fqname, bool onexec, int test)
 160{
 161        char *name, *ns_name;
 162
 163        name = aa_split_fqname(fqname, &ns_name);
 164        return aa_change_profile(ns_name, name, onexec, test);
 165}
 166