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