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
  20
  21 /**
  22  * aa_getprocattr - Return the profile information for @profile
  23  * @profile: the profile to print profile info about  (NOT NULL)
  24  * @string: Returns - string containing the profile info (NOT NULL)
  25  *
  26  * Returns: length of @string on success else error on failure
  27  *
  28  * Requires: profile != NULL
  29  *
  30  * Creates a string containing the namespace_name://profile_name for
  31  * @profile.
  32  *
  33  * Returns: size of string placed in @string else error code on failure
  34  */
  35 int aa_getprocattr(struct aa_profile *profile, char **string)
  36 {
  37         char *str;
  38         int len = 0, mode_len = 0, ns_len = 0, name_len;
  39         const char *mode_str = profile_mode_names[profile->mode];
  40         const char *ns_name = NULL;
  41         struct aa_namespace *ns = profile->ns;
  42         struct aa_namespace *current_ns = __aa_current_profile()->ns;
  43         char *s;
  44
  45         if (!aa_ns_visible(current_ns, ns))
  46                 return -EACCES;
  47
  48         ns_name = aa_ns_name(current_ns, ns);
  49         ns_len = strlen(ns_name);
  50
  51         /* if the visible ns_name is > 0 increase size for : :// seperator */
  52         if (ns_len)
  53                 ns_len += 4;
  54
  55         /* unconfined profiles don't have a mode string appended */
  56         if (!unconfined(profile))
  57                 mode_len = strlen(mode_str) + 3;        /* + 3 for _() */
  58
  59         name_len = strlen(profile->base.hname);
  60         len = mode_len + ns_len + name_len + 1;     /* + 1 for \n */
  61         s = str = kmalloc(len + 1, GFP_KERNEL);     /* + 1 \0 */
  62         if (!str)
  63                 return -ENOMEM;
  64
  65         if (ns_len) {
  66                 /* skip over prefix current_ns->base.hname and separating // */
  67                 sprintf(s, ":%s://", ns_name);
  68                 s += ns_len;
  69         }
  70         if (unconfined(profile))
  71                 /* mode string not being appended */
  72                 sprintf(s, "%s\n", profile->base.hname);
  73         else
  74                 sprintf(s, "%s (%s)\n", profile->base.hname, mode_str);
  75         *string = str;
  76
  77         /* NOTE: len does not include \0 of string, not saved as part of file */
  78         return len;
  79 }
  80
  81 /**
  82  * split_token_from_name - separate a string of form  <token>^<name>
  83  * @op: operation being checked
  84  * @args: string to parse  (NOT NULL)
  85  * @token: stores returned parsed token value  (NOT NULL)
  86  *
  87  * Returns: start position of name after token else NULL on failure
  88  */
  89 static char *split_token_from_name(int op, char *args, u64 * token)
  90 {
  91         char *name;
  92
  93         *token = simple_strtoull(args, &name, 16);
  94         if ((name == args) || *name != '^') {
  95                 AA_ERROR("%s: Invalid input '%s'", op_table[op], args);
  96                 return ERR_PTR(-EINVAL);
  97         }
  98
  99         name++;                 /* skip ^ */
 100         if (!*name)
 101                 name = NULL;
 102         return name;
 103 }
 104
 105 /**
 106  * aa_setprocattr_chagnehat - handle procattr interface to change_hat
 107  * @args: args received from writing to /proc/<pid>/attr/current (NOT NULL)
 108  * @size: size of the args
 109  * @test: true if this is a test of change_hat permissions
 110  *
 111  * Returns: %0 or error code if change_hat fails
 112  */
 113 int aa_setprocattr_changehat(char *args, size_t size, int test)
 114 {
 115         char *hat;
 116         u64 token;
 117         const char *hats[16];           /* current hard limit on # of names */
 118         int count = 0;
 119
 120         hat = split_token_from_name(OP_CHANGE_HAT, args, &token);
 121         if (IS_ERR(hat))
 122                 return PTR_ERR(hat);
 123
 124         if (!hat && !token) {
 125                 AA_ERROR("change_hat: Invalid input, NULL hat and NULL magic");
 126                 return -EINVAL;
 127         }
 128
 129         if (hat) {
 130                 /* set up hat name vector, args guaranteed null terminated
 131                  * at args[size] by setprocattr.
 132                  *
 133                  * If there are multiple hat names in the buffer each is
 134                  * separated by a \0.  Ie. userspace writes them pre tokenized
 135                  */
 136                 char *end = args + size;
 137                 for (count = 0; (hat < end) && count < 16; ++count) {
 138                         char *next = hat + strlen(hat) + 1;
 139                         hats[count] = hat;
 140                         hat = next;
 141                 }
 142         }
 143
 144         AA_DEBUG("%s: Magic 0x%llx Hat '%s'\n",
 145                  __func__, token, hat ? hat : NULL);
 146
 147         return aa_change_hat(hats, count, token, test);
 148 }
 149
 150 /**
 151  * aa_setprocattr_changeprofile - handle procattr interface to changeprofile
 152  * @fqname: args received from writting to /proc/<pid>/attr/current (NOT NULL)
 153  * @onexec: true if change_profile should be delayed until exec
 154  * @test: true if this is a test of change_profile permissions
 155  *
 156  * Returns: %0 or error code if change_profile fails
 157  */
 158 int aa_setprocattr_changeprofile(char *fqname, bool onexec, int test)
 159 {
 160         char *name, *ns_name;
 161
 162         name = aa_split_fqname(fqname, &ns_name);
 163         return aa_change_profile(ns_name, name, onexec, test);
 164 }
 165
 166 int aa_setprocattr_permipc(char *fqname)
 167 {
 168         /* TODO: add ipc permission querying */
 169         return -ENOTSUPP;
 170 }