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/rhashtable.h>
  22 #include <linux/sched.h>
  23 #include <linux/slab.h>
  24 #include <linux/socket.h>
  25
  26 #include "apparmor.h"
  27 #include "audit.h"
  28 #include "capability.h"
  29 #include "domain.h"
  30 #include "file.h"
  31 #include "lib.h"
  32 #include "perms.h"
  33 #include "resource.h"
  34
  35
  36 struct aa_ns;
  37
  38 extern int unprivileged_userns_apparmor_policy;
  39
  40 extern const char *const aa_profile_mode_names[];
  41 #define APPARMOR_MODE_NAMES_MAX_INDEX 4
  42
  43 #define PROFILE_MODE(_profile, _mode)           \
  44         ((aa_g_profile_mode == (_mode)) ||      \
  45          ((_profile)->mode == (_mode)))
  46
  47 #define COMPLAIN_MODE(_profile) PROFILE_MODE((_profile), APPARMOR_COMPLAIN)
  48
  49 #define KILL_MODE(_profile) PROFILE_MODE((_profile), APPARMOR_KILL)
  50
  51 #define PROFILE_IS_HAT(_profile) ((_profile)->flags & PFLAG_HAT)
  52
  53 #define profile_is_stale(_profile) ((_profile)->flags & PFLAG_STALE)
  54
  55 #define on_list_rcu(X) (!list_empty(X) && (X)->prev != LIST_POISON2)
  56
  57 /*
  58  * FIXME: currently need a clean way to replace and remove profiles as a
  59  * set.  It should be done at the namespace level.
  60  * Either, with a set of profiles loaded at the namespace level or via
  61  * a mark and remove marked interface.
  62  */
  63 enum profile_mode {
  64         APPARMOR_ENFORCE,       /* enforce access rules */
  65         APPARMOR_COMPLAIN,      /* allow and log access violations */
  66         APPARMOR_KILL,          /* kill task on access violation */
  67         APPARMOR_UNCONFINED,    /* profile set to unconfined */
  68 };
  69
  70 enum profile_flags {
  71         PFLAG_HAT = 1,                  /* profile is a hat */
  72         PFLAG_NULL = 4,                 /* profile is null learning profile */
  73         PFLAG_IX_ON_NAME_ERROR = 8,     /* fallback to ix on name lookup fail */
  74         PFLAG_IMMUTABLE = 0x10,         /* don't allow changes/replacement */
  75         PFLAG_USER_DEFINED = 0x20,      /* user based profile - lower privs */
  76         PFLAG_NO_LIST_REF = 0x40,       /* list doesn't keep profile ref */
  77         PFLAG_OLD_NULL_TRANS = 0x100,   /* use // as the null transition */
  78         PFLAG_STALE = 0x200,            /* profile replaced/removed */
  79         PFLAG_NS_COUNT = 0x400,         /* carries NS ref count */
  80
  81         /* These flags must correspond with PATH_flags */
  82         PFLAG_MEDIATE_DELETED = 0x10000, /* mediate instead delegate deleted */
  83 };
  84
  85 struct aa_profile;
  86
  87 /* struct aa_policydb - match engine for a policy
  88  * dfa: dfa pattern match
  89  * start: set of start states for the different classes of data
  90  */
  91 struct aa_policydb {
  92         /* Generic policy DFA specific rule types will be subsections of it */
  93         struct aa_dfa *dfa;
  94         unsigned int start[AA_CLASS_LAST + 1];
  95
  96 };
  97
  98 struct aa_proxy {
  99         struct kref count;
 100         struct aa_profile __rcu *profile;
 101 };
 102
 103 /* struct aa_data - generic data structure
 104  * key: name for retrieving this data
 105  * size: size of data in bytes
 106  * data: binary data
 107  * head: reserved for rhashtable
 108  */
 109 struct aa_data {
 110         char *key;
 111         u32 size;
 112         char *data;
 113         struct rhash_head head;
 114 };
 115
 116
 117 /* struct aa_profile - basic confinement data
 118  * @base - base components of the profile (name, refcount, lists, lock ...)
 119  * @count: reference count of the obj
 120  * @rcu: rcu head used when removing from @list
 121  * @parent: parent of profile
 122  * @ns: namespace the profile is in
 123  * @proxy: is set to the profile that replaced this profile
 124  * @rename: optional profile name that this profile renamed
 125  * @attach: human readable attachment string
 126  * @xmatch: optional extended matching for unconfined executables names
 127  * @xmatch_len: xmatch prefix len, used to determine xmatch priority
 128  * @audit: the auditing mode of the profile
 129  * @mode: the enforcement mode of the profile
 130  * @flags: flags controlling profile behavior
 131  * @path_flags: flags controlling path generation behavior
 132  * @disconnected: what to prepend if attach_disconnected is specified
 133  * @size: the memory consumed by this profiles rules
 134  * @policy: general match rules governing policy
 135  * @file: The set of rules governing basic file access and domain transitions
 136  * @caps: capabilities for the profile
 137  * @rlimits: rlimits for the profile
 138  *
 139  * @dents: dentries for the profiles file entries in apparmorfs
 140  * @dirname: name of the profile dir in apparmorfs
 141  * @data: hashtable for free-form policy aa_data
 142  *
 143  * The AppArmor profile contains the basic confinement data.  Each profile
 144  * has a name, and exists in a namespace.  The @name and @exec_match are
 145  * used to determine profile attachment against unconfined tasks.  All other
 146  * attachments are determined by profile X transition rules.
 147  *
 148  * The @proxy struct is write protected by the profile lock.
 149  *
 150  * Profiles have a hierarchy where hats and children profiles keep
 151  * a reference to their parent.
 152  *
 153  * Profile names can not begin with a : and can not contain the \0
 154  * character.  If a profile name begins with / it will be considered when
 155  * determining profile attachment on "unconfined" tasks.
 156  */
 157 struct aa_profile {
 158         struct aa_policy base;
 159         struct kref count;
 160         struct rcu_head rcu;
 161         struct aa_profile __rcu *parent;
 162
 163         struct aa_ns *ns;
 164         struct aa_proxy *proxy;
 165         const char *rename;
 166
 167         const char *attach;
 168         struct aa_dfa *xmatch;
 169         int xmatch_len;
 170         enum audit_mode audit;
 171         long mode;
 172         long flags;
 173         u32 path_flags;
 174         const char *disconnected;
 175         int size;
 176
 177         struct aa_policydb policy;
 178         struct aa_file_rules file;
 179         struct aa_caps caps;
 180         struct aa_rlimit rlimits;
 181
 182         struct aa_loaddata *rawdata;
 183         unsigned char *hash;
 184         char *dirname;
 185         struct dentry *dents[AAFS_PROF_SIZEOF];
 186         struct rhashtable *data;
 187 };
 188
 189 extern enum profile_mode aa_g_profile_mode;
 190
 191 #define AA_MAY_LOAD_POLICY      AA_MAY_APPEND
 192 #define AA_MAY_REPLACE_POLICY   AA_MAY_WRITE
 193 #define AA_MAY_REMOVE_POLICY    AA_MAY_DELETE
 194
 195 void __aa_update_proxy(struct aa_profile *orig, struct aa_profile *new);
 196
 197 void aa_add_profile(struct aa_policy *common, struct aa_profile *profile);
 198
 199
 200 void aa_free_proxy_kref(struct kref *kref);
 201 struct aa_profile *aa_alloc_profile(const char *name, gfp_t gfp);
 202 struct aa_profile *aa_new_null_profile(struct aa_profile *parent, bool hat,
 203                                        const char *base, gfp_t gfp);
 204 void aa_free_profile(struct aa_profile *profile);
 205 void aa_free_profile_kref(struct kref *kref);
 206 struct aa_profile *aa_find_child(struct aa_profile *parent, const char *name);
 207 struct aa_profile *aa_lookupn_profile(struct aa_ns *ns, const char *hname,
 208                                       size_t n);
 209 struct aa_profile *aa_lookup_profile(struct aa_ns *ns, const char *name);
 210 struct aa_profile *aa_fqlookupn_profile(struct aa_profile *base,
 211                                         const char *fqname, size_t n);
 212 struct aa_profile *aa_match_profile(struct aa_ns *ns, const char *name);
 213
 214 ssize_t aa_replace_profiles(struct aa_ns *view, struct aa_profile *profile,
 215                             u32 mask, struct aa_loaddata *udata);
 216 ssize_t aa_remove_profiles(struct aa_ns *view, struct aa_profile *profile,
 217                             char *name, size_t size);
 218 void __aa_profile_list_release(struct list_head *head);
 219
 220 #define PROF_ADD 1
 221 #define PROF_REPLACE 0
 222
 223 #define unconfined(X) ((X)->mode == APPARMOR_UNCONFINED)
 224
 225 #define PROFILE_MEDIATES(P, T)  ((P)->policy.start[(T)])
 226 /* safe version of POLICY_MEDIATES for full range input */
 227 static inline unsigned int PROFILE_MEDIATES_SAFE(struct aa_profile *profile,
 228                                                  unsigned char class)
 229 {
 230         if (profile->policy.dfa)
 231                 return aa_dfa_match_len(profile->policy.dfa,
 232                                         profile->policy.start[0], &class, 1);
 233         return 0;
 234 }
 235
 236 /**
 237  * aa_get_profile - increment refcount on profile @p
 238  * @p: profile  (MAYBE NULL)
 239  *
 240  * Returns: pointer to @p if @p is NULL will return NULL
 241  * Requires: @p must be held with valid refcount when called
 242  */
 243 static inline struct aa_profile *aa_get_profile(struct aa_profile *p)
 244 {
 245         if (p)
 246                 kref_get(&(p->count));
 247
 248         return p;
 249 }
 250
 251 /**
 252  * aa_get_profile_not0 - increment refcount on profile @p found via lookup
 253  * @p: profile  (MAYBE NULL)
 254  *
 255  * Returns: pointer to @p if @p is NULL will return NULL
 256  * Requires: @p must be held with valid refcount when called
 257  */
 258 static inline struct aa_profile *aa_get_profile_not0(struct aa_profile *p)
 259 {
 260         if (p && kref_get_unless_zero(&p->count))
 261                 return p;
 262
 263         return NULL;
 264 }
 265
 266 /**
 267  * aa_get_profile_rcu - increment a refcount profile that can be replaced
 268  * @p: pointer to profile that can be replaced (NOT NULL)
 269  *
 270  * Returns: pointer to a refcounted profile.
 271  *     else NULL if no profile
 272  */
 273 static inline struct aa_profile *aa_get_profile_rcu(struct aa_profile __rcu **p)
 274 {
 275         struct aa_profile *c;
 276
 277         rcu_read_lock();
 278         do {
 279                 c = rcu_dereference(*p);
 280         } while (c && !kref_get_unless_zero(&c->count));
 281         rcu_read_unlock();
 282
 283         return c;
 284 }
 285
 286 /**
 287  * aa_get_newest_profile - find the newest version of @profile
 288  * @profile: the profile to check for newer versions of
 289  *
 290  * Returns: refcounted newest version of @profile taking into account
 291  *          replacement, renames and removals
 292  *          return @profile.
 293  */
 294 static inline struct aa_profile *aa_get_newest_profile(struct aa_profile *p)
 295 {
 296         if (!p)
 297                 return NULL;
 298
 299         if (profile_is_stale(p))
 300                 return aa_get_profile_rcu(&p->proxy->profile);
 301
 302         return aa_get_profile(p);
 303 }
 304
 305 /**
 306  * aa_put_profile - decrement refcount on profile @p
 307  * @p: profile  (MAYBE NULL)
 308  */
 309 static inline void aa_put_profile(struct aa_profile *p)
 310 {
 311         if (p)
 312                 kref_put(&p->count, aa_free_profile_kref);
 313 }
 314
 315 static inline struct aa_proxy *aa_get_proxy(struct aa_proxy *p)
 316 {
 317         if (p)
 318                 kref_get(&(p->count));
 319
 320         return p;
 321 }
 322
 323 static inline void aa_put_proxy(struct aa_proxy *p)
 324 {
 325         if (p)
 326                 kref_put(&p->count, aa_free_proxy_kref);
 327 }
 328
 329 static inline int AUDIT_MODE(struct aa_profile *profile)
 330 {
 331         if (aa_g_audit != AUDIT_NORMAL)
 332                 return aa_g_audit;
 333
 334         return profile->audit;
 335 }
 336
 337 bool policy_view_capable(struct aa_ns *ns);
 338 bool policy_admin_capable(struct aa_ns *ns);
 339 int aa_may_manage_policy(struct aa_profile *profile, struct aa_ns *ns,
 340                          u32 mask);
 341
 342 #endif /* __AA_POLICY_H */