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