2 * AppArmor security module
4 * This file contains basic common functions used in AppArmor
6 * Copyright (C) 1998-2008 Novell/SUSE
7 * Copyright 2009-2010 Canonical Ltd.
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
15 #include <linux/ctype.h>
17 #include <linux/slab.h>
18 #include <linux/string.h>
19 #include <linux/vmalloc.h>
21 #include "include/audit.h"
22 #include "include/apparmor.h"
23 #include "include/lib.h"
24 #include "include/perms.h"
25 #include "include/policy.h"
27 struct aa_perms nullperms;
28 struct aa_perms allperms = { .allow = ALL_PERMS_MASK,
29 .quiet = ALL_PERMS_MASK,
30 .hide = ALL_PERMS_MASK };
33 * aa_split_fqname - split a fqname into a profile and namespace name
34 * @fqname: a full qualified name in namespace profile format (NOT NULL)
35 * @ns_name: pointer to portion of the string containing the ns name (NOT NULL)
37 * Returns: profile name or NULL if one is not specified
39 * Split a namespace name from a profile name (see policy.c for naming
40 * description). If a portion of the name is missing it returns NULL for
43 * NOTE: may modify the @fqname string. The pointers returned point
44 * into the @fqname string.
46 char *aa_split_fqname(char *fqname, char **ns_name)
48 char *name = strim(fqname);
52 char *split = strchr(&name[1], ':');
53 *ns_name = skip_spaces(&name[1]);
55 /* overwrite ':' with \0 */
57 if (strncmp(split, "//", 2) == 0)
59 name = skip_spaces(split);
61 /* a ns name without a following profile is allowed */
64 if (name && *name == 0)
71 * skipn_spaces - Removes leading whitespace from @str.
72 * @str: The string to be stripped.
74 * Returns a pointer to the first non-whitespace character in @str.
75 * if all whitespace will return NULL
78 const char *skipn_spaces(const char *str, size_t n)
80 for (; n && isspace(*str); --n)
87 const char *aa_splitn_fqname(const char *fqname, size_t n, const char **ns_name,
90 const char *end = fqname + n;
91 const char *name = skipn_spaces(fqname, n);
100 char *split = strnchr(&name[1], end - &name[1], ':');
101 *ns_name = skipn_spaces(&name[1], end - &name[1]);
105 *ns_len = split - *ns_name;
109 if (end - split > 1 && strncmp(split, "//", 2) == 0)
111 name = skipn_spaces(split, end - split);
113 /* a ns name without a following profile is allowed */
115 *ns_len = end - *ns_name;
118 if (name && *name == 0)
125 * aa_info_message - log a none profile related status message
126 * @str: message to log
128 void aa_info_message(const char *str)
131 DEFINE_AUDIT_DATA(sa, LSM_AUDIT_DATA_NONE, NULL);
133 aad(&sa)->info = str;
134 aa_audit_msg(AUDIT_APPARMOR_STATUS, &sa, NULL);
136 printk(KERN_INFO "AppArmor: %s\n", str);
139 __counted char *aa_str_alloc(int size, gfp_t gfp)
141 struct counted_str *str;
143 str = kmalloc(sizeof(struct counted_str) + size, gfp);
147 kref_init(&str->count);
151 void aa_str_kref(struct kref *kref)
153 kfree(container_of(kref, struct counted_str, count));
157 const char aa_file_perm_chrs[] = "xwracd km l ";
158 const char *aa_file_perm_names[] = {
201 * aa_perm_mask_to_str - convert a perm mask to its short string
202 * @str: character buffer to store string in (at least 10 characters)
203 * @mask: permission mask to convert
205 void aa_perm_mask_to_str(char *str, const char *chrs, u32 mask)
207 unsigned int i, perm = 1;
209 for (i = 0; i < 32; perm <<= 1, i++) {
216 void aa_audit_perm_names(struct audit_buffer *ab, const char **names, u32 mask)
218 const char *fmt = "%s";
219 unsigned int i, perm = 1;
222 for (i = 0; i < 32; perm <<= 1, i++) {
224 audit_log_format(ab, fmt, names[i]);
233 void aa_audit_perm_mask(struct audit_buffer *ab, u32 mask, const char *chrs,
234 u32 chrsmask, const char **names, u32 namesmask)
238 audit_log_format(ab, "\"");
239 if ((mask & chrsmask) && chrs) {
240 aa_perm_mask_to_str(str, chrs, mask & chrsmask);
242 audit_log_format(ab, "%s", str);
243 if (mask & namesmask)
244 audit_log_format(ab, " ");
246 if ((mask & namesmask) && names)
247 aa_audit_perm_names(ab, names, mask & namesmask);
248 audit_log_format(ab, "\"");
252 * aa_audit_perms_cb - generic callback fn for auditing perms
253 * @ab: audit buffer (NOT NULL)
254 * @va: audit struct to audit values of (NOT NULL)
256 static void aa_audit_perms_cb(struct audit_buffer *ab, void *va)
258 struct common_audit_data *sa = va;
260 if (aad(sa)->request) {
261 audit_log_format(ab, " requested_mask=");
262 aa_audit_perm_mask(ab, aad(sa)->request, aa_file_perm_chrs,
263 PERMS_CHRS_MASK, aa_file_perm_names,
266 if (aad(sa)->denied) {
267 audit_log_format(ab, "denied_mask=");
268 aa_audit_perm_mask(ab, aad(sa)->denied, aa_file_perm_chrs,
269 PERMS_CHRS_MASK, aa_file_perm_names,
272 audit_log_format(ab, " peer=");
273 aa_label_xaudit(ab, labels_ns(aad(sa)->label), aad(sa)->peer,
274 FLAGS_NONE, GFP_ATOMIC);
278 * aa_apply_modes_to_perms - apply namespace and profile flags to perms
279 * @profile: that perms where computed from
280 * @perms: perms to apply mode modifiers to
282 * TODO: split into profile and ns based flags for when accumulating perms
284 void aa_apply_modes_to_perms(struct aa_profile *profile, struct aa_perms *perms)
286 switch (AUDIT_MODE(profile)) {
288 perms->audit = ALL_PERMS_MASK;
296 case AUDIT_QUIET_DENIED:
297 perms->quiet = ALL_PERMS_MASK;
301 if (KILL_MODE(profile))
302 perms->kill = ALL_PERMS_MASK;
303 else if (COMPLAIN_MODE(profile))
304 perms->complain = ALL_PERMS_MASK;
307 * else if (PROMPT_MODE(profile))
308 * perms->prompt = ALL_PERMS_MASK;
312 static u32 map_other(u32 x)
314 return ((x & 0x3) << 8) | /* SETATTR/GETATTR */
315 ((x & 0x1c) << 18) | /* ACCEPT/BIND/LISTEN */
316 ((x & 0x60) << 19); /* SETOPT/GETOPT */
319 void aa_compute_perms(struct aa_dfa *dfa, unsigned int state,
320 struct aa_perms *perms)
323 perms->kill = perms->stop = 0;
324 perms->complain = perms->cond = 0;
327 perms->allow = dfa_user_allow(dfa, state);
328 perms->audit = dfa_user_audit(dfa, state);
329 perms->quiet = dfa_user_quiet(dfa, state);
331 /* for v5 perm mapping in the policydb, the other set is used
332 * to extend the general perm set
334 perms->allow |= map_other(dfa_other_allow(dfa, state));
335 perms->audit |= map_other(dfa_other_audit(dfa, state));
336 perms->quiet |= map_other(dfa_other_quiet(dfa, state));
337 // perms->xindex = dfa_user_xindex(dfa, state);
341 * aa_perms_accum_raw - accumulate perms with out masking off overlapping perms
342 * @accum - perms struct to accumulate into
343 * @addend - perms struct to add to @accum
345 void aa_perms_accum_raw(struct aa_perms *accum, struct aa_perms *addend)
347 accum->deny |= addend->deny;
348 accum->allow &= addend->allow & ~addend->deny;
349 accum->audit |= addend->audit & addend->allow;
350 accum->quiet &= addend->quiet & ~addend->allow;
351 accum->kill |= addend->kill & ~addend->allow;
352 accum->stop |= addend->stop & ~addend->allow;
353 accum->complain |= addend->complain & ~addend->allow & ~addend->deny;
354 accum->cond |= addend->cond & ~addend->allow & ~addend->deny;
355 accum->hide &= addend->hide & ~addend->allow;
356 accum->prompt |= addend->prompt & ~addend->allow & ~addend->deny;
360 * aa_perms_accum - accumulate perms, masking off overlapping perms
361 * @accum - perms struct to accumulate into
362 * @addend - perms struct to add to @accum
364 void aa_perms_accum(struct aa_perms *accum, struct aa_perms *addend)
366 accum->deny |= addend->deny;
367 accum->allow &= addend->allow & ~accum->deny;
368 accum->audit |= addend->audit & accum->allow;
369 accum->quiet &= addend->quiet & ~accum->allow;
370 accum->kill |= addend->kill & ~accum->allow;
371 accum->stop |= addend->stop & ~accum->allow;
372 accum->complain |= addend->complain & ~accum->allow & ~accum->deny;
373 accum->cond |= addend->cond & ~accum->allow & ~accum->deny;
374 accum->hide &= addend->hide & ~accum->allow;
375 accum->prompt |= addend->prompt & ~accum->allow & ~accum->deny;
378 void aa_profile_match_label(struct aa_profile *profile, struct aa_label *label,
379 int type, u32 request, struct aa_perms *perms)
381 /* TODO: doesn't yet handle extended types */
384 state = aa_dfa_next(profile->policy.dfa,
385 profile->policy.start[AA_CLASS_LABEL],
387 aa_label_match(profile, label, state, false, request, perms);
391 /* currently unused */
392 int aa_profile_label_perm(struct aa_profile *profile, struct aa_profile *target,
393 u32 request, int type, u32 *deny,
394 struct common_audit_data *sa)
396 struct aa_perms perms;
398 aad(sa)->label = &profile->label;
399 aad(sa)->peer = &target->label;
400 aad(sa)->request = request;
402 aa_profile_match_label(profile, &target->label, type, request, &perms);
403 aa_apply_modes_to_perms(profile, &perms);
404 *deny |= request & perms.deny;
405 return aa_check_perms(profile, &perms, request, sa, aa_audit_perms_cb);
409 * aa_check_perms - do audit mode selection based on perms set
410 * @profile: profile being checked
411 * @perms: perms computed for the request
412 * @request: requested perms
413 * @deny: Returns: explicit deny set
414 * @sa: initialized audit structure (MAY BE NULL if not auditing)
415 * @cb: callback fn for tpye specific fields (MAY BE NULL)
417 * Returns: 0 if permission else error code
419 * Note: profile audit modes need to be set before calling by setting the
420 * perm masks appropriately.
422 * If not auditing then complain mode is not enabled and the
423 * error code will indicate whether there was an explicit deny
424 * with a positive value.
426 int aa_check_perms(struct aa_profile *profile, struct aa_perms *perms,
427 u32 request, struct common_audit_data *sa,
428 void (*cb)(struct audit_buffer *, void *))
432 u32 denied = request & (~perms->allow | perms->deny);
434 if (likely(!denied)) {
435 /* mask off perms that are not being force audited */
436 request &= perms->audit;
440 type = AUDIT_APPARMOR_AUDIT;
445 if (denied & perms->kill)
446 type = AUDIT_APPARMOR_KILL;
447 else if (denied == (denied & perms->complain))
448 type = AUDIT_APPARMOR_ALLOWED;
450 type = AUDIT_APPARMOR_DENIED;
452 if (denied & perms->stop)
454 if (denied == (denied & perms->hide))
457 denied &= ~perms->quiet;
463 aad(sa)->label = &profile->label;
464 aad(sa)->request = request;
465 aad(sa)->denied = denied;
466 aad(sa)->error = error;
467 aa_audit_msg(type, sa, cb);
470 if (type == AUDIT_APPARMOR_ALLOWED)
478 * aa_policy_init - initialize a policy structure
479 * @policy: policy to initialize (NOT NULL)
480 * @prefix: prefix name if any is required. (MAYBE NULL)
481 * @name: name of the policy, init will make a copy of it (NOT NULL)
482 * @gfp: allocation mode
484 * Note: this fn creates a copy of strings passed in
486 * Returns: true if policy init successful
488 bool aa_policy_init(struct aa_policy *policy, const char *prefix,
489 const char *name, gfp_t gfp)
493 /* freed by policy_free */
495 hname = aa_str_alloc(strlen(prefix) + strlen(name) + 3, gfp);
497 sprintf(hname, "%s//%s", prefix, name);
499 hname = aa_str_alloc(strlen(name) + 1, gfp);
505 policy->hname = hname;
506 /* base.name is a substring of fqname */
507 policy->name = basename(policy->hname);
508 INIT_LIST_HEAD(&policy->list);
509 INIT_LIST_HEAD(&policy->profiles);
515 * aa_policy_destroy - free the elements referenced by @policy
516 * @policy: policy that is to have its elements freed (NOT NULL)
518 void aa_policy_destroy(struct aa_policy *policy)
520 AA_BUG(on_list_rcu(&policy->profiles));
521 AA_BUG(on_list_rcu(&policy->list));
523 /* don't free name as its a subset of hname */
524 aa_put_str(policy->hname);