security/apparmor/include/policy.h

   1 /*
   2  * AppArmor security module
   3  *
   4  * This file contains AppArmor policy definitions.
   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 #ifndef __AA_POLICY_H
  16 #define __AA_POLICY_H
  17
  18 #include <linux/capability.h>
  19 #include <linux/cred.h>
  20 #include <linux/kref.h>
  21 #include <linux/sched.h>
  22 #include <linux/slab.h>
  23 #include <linux/socket.h>
  24
  25 #include "apparmor.h"
  26 #include "audit.h"
  27 #include "capability.h"
  28 #include "domain.h"
  29 #include "file.h"
  30 #include "resource.h"
  31
  32 extern const char *const profile_mode_names[];
  33 #define APPARMOR_NAMES_MAX_INDEX 3
  34
  35 #define COMPLAIN_MODE(_profile) \
  36         ((aa_g_profile_mode == APPARMOR_COMPLAIN) || \
  37          ((_profile)->mode == APPARMOR_COMPLAIN))
  38
  39 #define KILL_MODE(_profile) \
  40         ((aa_g_profile_mode == APPARMOR_KILL) || \
  41          ((_profile)->mode == APPARMOR_KILL))
  42
  43 #define PROFILE_IS_HAT(_profile) ((_profile)->flags & PFLAG_HAT)
  44
  45 /*
  46  * FIXME: currently need a clean way to replace and remove profiles as a
  47  * set.  It should be done at the namespace level.
  48  * Either, with a set of profiles loaded at the namespace level or via
  49  * a mark and remove marked interface.
  50  */
  51 enum profile_mode {
  52         APPARMOR_ENFORCE,       /* enforce access rules */
  53         APPARMOR_COMPLAIN,      /* allow and log access violations */
  54         APPARMOR_KILL,          /* kill task on access violation */
  55 };
  56
  57 enum profile_flags {
  58         PFLAG_HAT = 1,                  /* profile is a hat */
  59         PFLAG_UNCONFINED = 2,           /* profile is an unconfined profile */
  60         PFLAG_NULL = 4,                 /* profile is null learning profile */
  61         PFLAG_IX_ON_NAME_ERROR = 8,     /* fallback to ix on name lookup fail */
  62         PFLAG_IMMUTABLE = 0x10,         /* don't allow changes/replacement */
  63         PFLAG_USER_DEFINED = 0x20,      /* user based profile - lower privs */
  64         PFLAG_NO_LIST_REF = 0x40,       /* list doesn't keep profile ref */
  65         PFLAG_OLD_NULL_TRANS = 0x100,   /* use // as the null transition */
  66
  67         /* These flags must correspond with PATH_flags */
  68         PFLAG_MEDIATE_DELETED = 0x10000, /* mediate instead delegate deleted */
  69 };
  70
  71 struct aa_profile;
  72
  73 /* struct aa_policy - common part of both namespaces and profiles
  74  * @name: name of the object
  75  * @hname - The hierarchical name
  76  * @count: reference count of the obj
  77  * @list: list policy object is on
  78  * @profiles: head of the profiles list contained in the object
  79  */
  80 struct aa_policy {
  81         char *name;
  82         char *hname;
  83         struct kref count;
  84         struct list_head list;
  85         struct list_head profiles;
  86 };
  87
  88 /* struct aa_ns_acct - accounting of profiles in namespace
  89  * @max_size: maximum space allowed for all profiles in namespace
  90  * @max_count: maximum number of profiles that can be in this namespace
  91  * @size: current size of profiles
  92  * @count: current count of profiles (includes null profiles)
  93  */
  94 struct aa_ns_acct {
  95         int max_size;
  96         int max_count;
  97         int size;
  98         int count;
  99 };
 100
 101 /* struct aa_namespace - namespace for a set of profiles
 102  * @base: common policy
 103  * @parent: parent of namespace
 104  * @lock: lock for modifying the object
 105  * @acct: accounting for the namespace
 106  * @unconfined: special unconfined profile for the namespace
 107  * @sub_ns: list of namespaces under the current namespace.
 108  *
 109  * An aa_namespace defines the set profiles that are searched to determine
 110  * which profile to attach to a task.  Profiles can not be shared between
 111  * aa_namespaces and profile names within a namespace are guaranteed to be
 112  * unique.  When profiles in separate namespaces have the same name they
 113  * are NOT considered to be equivalent.
 114  *
 115  * Namespaces are hierarchical and only namespaces and profiles below the
 116  * current namespace are visible.
 117  *
 118  * Namespace names must be unique and can not contain the characters :/\0
 119  *
 120  * FIXME TODO: add vserver support of namespaces (can it all be done in
 121  *             userspace?)
 122  */
 123 struct aa_namespace {
 124         struct aa_policy base;
 125         struct aa_namespace *parent;
 126         rwlock_t lock;
 127         struct aa_ns_acct acct;
 128         struct aa_profile *unconfined;
 129         struct list_head sub_ns;
 130 };
 131
 132 /* struct aa_policydb - match engine for a policy
 133  * dfa: dfa pattern match
 134  * start: set of start states for the different classes of data
 135  */
 136 struct aa_policydb {
 137         /* Generic policy DFA specific rule types will be subsections of it */
 138         struct aa_dfa *dfa;
 139         unsigned int start[AA_CLASS_LAST + 1];
 140
 141 };
 142
 143 /* struct aa_profile - basic confinement data
 144  * @base - base components of the profile (name, refcount, lists, lock ...)
 145  * @parent: parent of profile
 146  * @ns: namespace the profile is in
 147  * @replacedby: is set to the profile that replaced this profile
 148  * @rename: optional profile name that this profile renamed
 149  * @xmatch: optional extended matching for unconfined executables names
 150  * @xmatch_len: xmatch prefix len, used to determine xmatch priority
 151  * @sid: the unique security id number of this profile
 152  * @audit: the auditing mode of the profile
 153  * @mode: the enforcement mode of the profile
 154  * @flags: flags controlling profile behavior
 155  * @path_flags: flags controlling path generation behavior
 156  * @size: the memory consumed by this profiles rules
 157  * @policy: general match rules governing policy
 158  * @file: The set of rules governing basic file access and domain transitions
 159  * @caps: capabilities for the profile
 160  * @rlimits: rlimits for the profile
 161  *
 162  * The AppArmor profile contains the basic confinement data.  Each profile
 163  * has a name, and exists in a namespace.  The @name and @exec_match are
 164  * used to determine profile attachment against unconfined tasks.  All other
 165  * attachments are determined by profile X transition rules.
 166  *
 167  * The @replacedby field is write protected by the profile lock.  Reads
 168  * are assumed to be atomic, and are done without locking.
 169  *
 170  * Profiles have a hierarchy where hats and children profiles keep
 171  * a reference to their parent.
 172  *
 173  * Profile names can not begin with a : and can not contain the \0
 174  * character.  If a profile name begins with / it will be considered when
 175  * determining profile attachment on "unconfined" tasks.
 176  */
 177 struct aa_profile {
 178         struct aa_policy base;
 179         struct aa_profile *parent;
 180
 181         struct aa_namespace *ns;
 182         struct aa_profile *replacedby;
 183         const char *rename;
 184
 185         struct aa_dfa *xmatch;
 186         int xmatch_len;
 187         u32 sid;
 188         enum audit_mode audit;
 189         enum profile_mode mode;
 190         u32 flags;
 191         u32 path_flags;
 192         int size;
 193
 194         struct aa_policydb policy;
 195         struct aa_file_rules file;
 196         struct aa_caps caps;
 197         struct aa_rlimit rlimits;
 198 };
 199
 200 extern struct aa_namespace *root_ns;
 201 extern enum profile_mode aa_g_profile_mode;
 202
 203 void aa_add_profile(struct aa_policy *common, struct aa_profile *profile);
 204
 205 bool aa_ns_visible(struct aa_namespace *curr, struct aa_namespace *view);
 206 const char *aa_ns_name(struct aa_namespace *parent, struct aa_namespace *child);
 207 int aa_alloc_root_ns(void);
 208 void aa_free_root_ns(void);
 209 void aa_free_namespace_kref(struct kref *kref);
 210
 211 struct aa_namespace *aa_find_namespace(struct aa_namespace *root,
 212                                        const char *name);
 213
 214 static inline struct aa_policy *aa_get_common(struct aa_policy *c)
 215 {
 216         if (c)
 217                 kref_get(&c->count);
 218
 219         return c;
 220 }
 221
 222 /**
 223  * aa_get_namespace - increment references count on @ns
 224  * @ns: namespace to increment reference count of (MAYBE NULL)
 225  *
 226  * Returns: pointer to @ns, if @ns is NULL returns NULL
 227  * Requires: @ns must be held with valid refcount when called
 228  */
 229 static inline struct aa_namespace *aa_get_namespace(struct aa_namespace *ns)
 230 {
 231         if (ns)
 232                 kref_get(&(ns->base.count));
 233
 234         return ns;
 235 }
 236
 237 /**
 238  * aa_put_namespace - decrement refcount on @ns
 239  * @ns: namespace to put reference of
 240  *
 241  * Decrement reference count of @ns and if no longer in use free it
 242  */
 243 static inline void aa_put_namespace(struct aa_namespace *ns)
 244 {
 245         if (ns)
 246                 kref_put(&ns->base.count, aa_free_namespace_kref);
 247 }
 248
 249 struct aa_profile *aa_alloc_profile(const char *name);
 250 struct aa_profile *aa_new_null_profile(struct aa_profile *parent, int hat);
 251 void aa_free_profile_kref(struct kref *kref);
 252 struct aa_profile *aa_find_child(struct aa_profile *parent, const char *name);
 253 struct aa_profile *aa_lookup_profile(struct aa_namespace *ns, const char *name);
 254 struct aa_profile *aa_match_profile(struct aa_namespace *ns, const char *name);
 255
 256 ssize_t aa_replace_profiles(void *udata, size_t size, bool noreplace);
 257 ssize_t aa_remove_profiles(char *name, size_t size);
 258
 259 #define PROF_ADD 1
 260 #define PROF_REPLACE 0
 261
 262 #define unconfined(X) ((X)->flags & PFLAG_UNCONFINED)
 263
 264 /**
 265  * aa_newest_version - find the newest version of @profile
 266  * @profile: the profile to check for newer versions of (NOT NULL)
 267  *
 268  * Returns: newest version of @profile, if @profile is the newest version
 269  *          return @profile.
 270  *
 271  * NOTE: the profile returned is not refcounted, The refcount on @profile
 272  * must be held until the caller decides what to do with the returned newest
 273  * version.
 274  */
 275 static inline struct aa_profile *aa_newest_version(struct aa_profile *profile)
 276 {
 277         while (profile->replacedby)
 278                 profile = profile->replacedby;
 279
 280         return profile;
 281 }
 282
 283 /**
 284  * aa_get_profile - increment refcount on profile @p
 285  * @p: profile  (MAYBE NULL)
 286  *
 287  * Returns: pointer to @p if @p is NULL will return NULL
 288  * Requires: @p must be held with valid refcount when called
 289  */
 290 static inline struct aa_profile *aa_get_profile(struct aa_profile *p)
 291 {
 292         if (p)
 293                 kref_get(&(p->base.count));
 294
 295         return p;
 296 }
 297
 298 /**
 299  * aa_put_profile - decrement refcount on profile @p
 300  * @p: profile  (MAYBE NULL)
 301  */
 302 static inline void aa_put_profile(struct aa_profile *p)
 303 {
 304         if (p)
 305                 kref_put(&p->base.count, aa_free_profile_kref);
 306 }
 307
 308 static inline int AUDIT_MODE(struct aa_profile *profile)
 309 {
 310         if (aa_g_audit != AUDIT_NORMAL)
 311                 return aa_g_audit;
 312
 313         return profile->audit;
 314 }
 315
 316 bool aa_may_manage_policy(int op);
 317
 318 #endif /* __AA_POLICY_H */