* This file contains basic common functions used in AppArmor
*
* Copyright (C) 1998-2008 Novell/SUSE
- * Copyright 2009-2010 Canonical Ltd.
+ * Copyright 2009-2013 Canonical Ltd.
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License as
* License.
*/
+#include <linux/ctype.h>
#include <linux/mm.h>
#include <linux/slab.h>
#include <linux/string.h>
#include <linux/vmalloc.h>
-#include "include/audit.h"
#include "include/apparmor.h"
+#include "include/audit.h"
+#include "include/label.h"
+#include "include/lib.h"
+#include "include/perms.h"
+#include "include/policy.h"
+struct aa_perms nullperms;
+struct aa_perms allperms = { .allow = ALL_PERMS_MASK,
+ .quiet = ALL_PERMS_MASK,
+ .hide = ALL_PERMS_MASK };
/**
* aa_split_fqname - split a fqname into a profile and namespace name
return name;
}
+/**
+ * skipn_spaces - Removes leading whitespace from @str.
+ * @str: The string to be stripped.
+ *
+ * Returns a pointer to the first non-whitespace character in @str.
+ * if all whitespace will return NULL
+ */
+
+const char *skipn_spaces(const char *str, size_t n)
+{
+ for (;n && isspace(*str); --n)
+ ++str;
+ if (n)
+ return (char *)str;
+ return NULL;
+}
+
+const char *aa_splitn_fqname(const char *fqname, size_t n, const char **ns_name,
+ size_t *ns_len)
+{
+ const char *end = fqname + n;
+ const char *name = skipn_spaces(fqname, n);
+ if (!name)
+ return NULL;
+ *ns_name = NULL;
+ *ns_len = 0;
+ if (name[0] == ':') {
+ char *split = strnchr(&name[1], end - &name[1], ':');
+ *ns_name = skipn_spaces(&name[1], end - &name[1]);
+ if (!*ns_name)
+ return NULL;
+ if (split) {
+ *ns_len = split - *ns_name;
+ if (*ns_len == 0)
+ *ns_name = NULL;
+ split++;
+ if (end - split > 1 && strncmp(split, "//", 2) == 0)
+ split += 2;
+ name = skipn_spaces(split, end - split);
+ } else {
+ /* a ns name without a following profile is allowed */
+ name = NULL;
+ *ns_len = end - *ns_name;
+ }
+ }
+ if (name && *name == 0)
+ name = NULL;
+
+ return name;
+}
+
/**
* aa_info_message - log a none profile related status message
* @str: message to log
void aa_info_message(const char *str)
{
if (audit_enabled) {
- struct common_audit_data sa;
- struct apparmor_audit_data aad = {0,};
- sa.type = LSM_AUDIT_DATA_NONE;
- sa.aad = &aad;
- aad.info = str;
+ DEFINE_AUDIT_DATA(sa, LSM_AUDIT_DATA_NONE, NULL);
+ aad(&sa)->info = str;
aa_audit_msg(AUDIT_APPARMOR_STATUS, &sa, NULL);
}
printk(KERN_INFO "AppArmor: %s\n", str);
}
return buffer;
}
+
+
+__counted char *aa_str_alloc(int size, gfp_t gfp)
+{
+ struct counted_str *str;
+ str = kmalloc(sizeof(struct counted_str) + size, gfp);
+ if (!str)
+ return NULL;
+
+ kref_init(&str->count);
+ return str->name;
+}
+
+void aa_str_kref(struct kref *kref)
+{
+ kfree(container_of(kref, struct counted_str, count));
+}
+
+
+const char aa_file_perm_chrs[] = "xwracd km l ";
+const char *aa_file_perm_names[] = {
+ "exec",
+ "write",
+ "read",
+ "append",
+
+ "create",
+ "delete",
+ "open",
+ "rename",
+
+ "setattr",
+ "getattr",
+ "setcred",
+ "getcred",
+
+ "chmod",
+ "chown",
+ "chgrp",
+ "lock",
+
+ "mmap",
+ "mprot",
+ "link",
+ "snapshot",
+
+ "unknown",
+ "unknown",
+ "unknown",
+ "unknown",
+
+ "unknown",
+ "unknown",
+ "unknown",
+ "unknown",
+
+ "stack",
+ "change_onexec",
+ "change_profile",
+ "change_hat",
+};
+
+/**
+ * aa_perm_mask_to_str - convert a perm mask to its short string
+ * @str: character buffer to store string in (at least 10 characters)
+ * @mask: permission mask to convert
+ */
+void aa_perm_mask_to_str(char *str, const char *chrs, u32 mask)
+{
+ unsigned int i, perm = 1;
+ for (i = 0; i < 32; perm <<= 1, i++) {
+ if (mask & perm)
+ *str++ = chrs[i];
+ }
+ *str = '\0';
+}
+
+void aa_audit_perm_names(struct audit_buffer *ab, const char **names, u32 mask)
+{
+ const char *fmt = "%s";
+ unsigned int i, perm = 1;
+ bool prev = false;
+ for (i = 0; i < 32; perm <<= 1, i++) {
+ if (mask & perm) {
+ audit_log_format(ab, fmt, names[i]);
+ if (!prev) {
+ prev = true;
+ fmt = " %s";
+ }
+ }
+ }
+}
+
+void aa_audit_perm_mask(struct audit_buffer *ab, u32 mask, const char *chrs,
+ u32 chrsmask, const char **names, u32 namesmask)
+{
+ char str[33];
+
+ audit_log_format(ab, "\"");
+ if ((mask & chrsmask) && chrs) {
+ aa_perm_mask_to_str(str, chrs, mask & chrsmask);
+ mask &= ~chrsmask;
+ audit_log_format(ab, "%s", str);
+ if (mask & namesmask)
+ audit_log_format(ab, " ");
+ }
+ if ((mask & namesmask) && names)
+ aa_audit_perm_names(ab, names, mask & namesmask);
+ audit_log_format(ab, "\"");
+}
+
+/**
+ * aa_audit_perms_cb - generic callback fn for auditing perms
+ * @ab: audit buffer (NOT NULL)
+ * @va: audit struct to audit values of (NOT NULL)
+ */
+static void aa_audit_perms_cb(struct audit_buffer *ab, void *va)
+{
+ struct common_audit_data *sa = va;
+
+ if (aad(sa)->request) {
+ audit_log_format(ab, " requested_mask=");
+ aa_audit_perm_mask(ab, aad(sa)->request, aa_file_perm_chrs,
+ PERMS_CHRS_MASK, aa_file_perm_names,
+ PERMS_NAMES_MASK);
+ }
+ if (aad(sa)->denied) {
+ audit_log_format(ab, "denied_mask=");
+ aa_audit_perm_mask(ab, aad(sa)->denied, aa_file_perm_chrs,
+ PERMS_CHRS_MASK, aa_file_perm_names,
+ PERMS_NAMES_MASK);
+ }
+ audit_log_format(ab, " peer=");
+ aa_label_xaudit(ab, labels_ns(aad(sa)->label), aad(sa)->peer,
+ FLAGS_NONE, GFP_ATOMIC);
+}
+
+/**
+ * aa_apply_modes_to_perms - apply namespace and profile flags to perms
+ * @profile: that perms where computed from
+ * @perms: perms to apply mode modifiers to
+ *
+ * TODO: split into profile and ns based flags for when accumulating perms
+ */
+void aa_apply_modes_to_perms(struct aa_profile *profile, struct aa_perms *perms)
+{
+ switch (AUDIT_MODE(profile)) {
+ case AUDIT_ALL:
+ perms->audit = ALL_PERMS_MASK;
+ /* fall through */
+ case AUDIT_NOQUIET:
+ perms->quiet = 0;
+ break;
+ case AUDIT_QUIET:
+ perms->audit = 0;
+ /* fall through */
+ case AUDIT_QUIET_DENIED:
+ perms->quiet = ALL_PERMS_MASK;
+ break;
+ }
+
+ if (KILL_MODE(profile))
+ perms->kill = ALL_PERMS_MASK;
+ else if (COMPLAIN_MODE(profile))
+ perms->complain = ALL_PERMS_MASK;
+/* TODO:
+ else if (PROMPT_MODE(profile))
+ perms->prompt = ALL_PERMS_MASK;
+*/
+}
+
+static u32 map_other(u32 x)
+{
+ return ((x & 0x3) << 8) | /* SETATTR/GETATTR */
+ ((x & 0x1c) << 18) | /* ACCEPT/BIND/LISTEN */
+ ((x & 0x60) << 19); /* SETOPT/GETOPT */
+}
+
+void aa_compute_perms(struct aa_dfa *dfa, unsigned int state,
+ struct aa_perms *perms)
+{
+ perms->deny = 0;
+ perms->kill = perms->stop = 0;
+ perms->complain = perms->cond = 0;
+ perms->hide = 0;
+ perms->prompt = 0;
+ perms->allow = dfa_user_allow(dfa, state);
+ perms->audit = dfa_user_audit(dfa, state);
+ perms->quiet = dfa_user_quiet(dfa, state);
+
+ /* for v5 perm mapping in the policydb, the other set is used
+ * to extend the general perm set
+ */
+ perms->allow |= map_other(dfa_other_allow(dfa, state));
+ perms->audit |= map_other(dfa_other_audit(dfa, state));
+ perms->quiet |= map_other(dfa_other_quiet(dfa, state));
+// perms->xindex = dfa_user_xindex(dfa, state);
+}
+
+/**
+ * aa_perms_accum_raw - accumulate perms with out masking off overlapping perms
+ * @accum - perms struct to accumulate into
+ * @addend - perms struct to add to @accum
+ */
+void aa_perms_accum_raw(struct aa_perms *accum, struct aa_perms *addend)
+{
+ accum->deny |= addend->deny;
+ accum->allow &= addend->allow & ~addend->deny;
+ accum->audit |= addend->audit & addend->allow;
+ accum->quiet &= addend->quiet & ~addend->allow;
+ accum->kill |= addend->kill & ~addend->allow;
+ accum->stop |= addend->stop & ~addend->allow;
+ accum->complain |= addend->complain & ~addend->allow & ~addend->deny;
+ accum->cond |= addend->cond & ~addend->allow & ~addend->deny;
+ accum->hide &= addend->hide & ~addend->allow;
+ accum->prompt |= addend->prompt & ~addend->allow & ~addend->deny;
+}
+
+/**
+ * aa_perms_accum - accumulate perms, masking off overlapping perms
+ * @accum - perms struct to accumulate into
+ * @addend - perms struct to add to @accum
+ */
+void aa_perms_accum(struct aa_perms *accum, struct aa_perms *addend)
+{
+ accum->deny |= addend->deny;
+ accum->allow &= addend->allow & ~accum->deny;
+ accum->audit |= addend->audit & accum->allow;
+ accum->quiet &= addend->quiet & ~accum->allow;
+ accum->kill |= addend->kill & ~accum->allow;
+ accum->stop |= addend->stop & ~accum->allow;
+ accum->complain |= addend->complain & ~accum->allow & ~accum->deny;
+ accum->cond |= addend->cond & ~accum->allow & ~accum->deny;
+ accum->hide &= addend->hide & ~accum->allow;
+ accum->prompt |= addend->prompt & ~accum->allow & ~accum->deny;
+}
+
+void aa_profile_match_label(struct aa_profile *profile, struct aa_label *label,
+ int type, u32 request, struct aa_perms *perms)
+{
+ /* TODO: doesn't yet handle extended types */
+ unsigned int state;
+ state = aa_dfa_next(profile->policy.dfa,
+ profile->policy.start[AA_CLASS_LABEL],
+ type);
+ aa_label_match(profile, label, state, false, request, perms);
+}
+
+
+/* currently unused */
+int aa_profile_label_perm(struct aa_profile *profile, struct aa_profile *target,
+ u32 request, int type, u32 *deny,
+ struct common_audit_data *sa)
+{
+ struct aa_perms perms;
+ aad(sa)->label = &profile->label;
+ aad(sa)->peer = &target->label;
+ aad(sa)->request = request;
+
+ aa_profile_match_label(profile, &target->label, type, request, &perms);
+ aa_apply_modes_to_perms(profile, &perms);
+ *deny |= request & perms.deny;
+ return aa_check_perms(profile, &perms, request, sa, aa_audit_perms_cb);
+}
+
+/**
+ * aa_check_perms - do audit mode selection based on perms set
+ * @profile: profile being checked
+ * @perms: perms computed for the request
+ * @request: requested perms
+ * @deny: Returns: explicit deny set
+ * @sa: initialized audit structure (MAY BE NULL if not auditing)
+ * @cb: callback fn for tpye specific fields (MAY BE NULL)
+ *
+ * Returns: 0 if permission else error code
+ *
+ * Note: profile audit modes need to be set before calling by setting the
+ * perm masks appropriately.
+ *
+ * If not auditing then complain mode is not enabled and the
+ * error code will indicate whether there was an explicit deny
+ * with a positive value.
+ */
+int aa_check_perms(struct aa_profile *profile, struct aa_perms *perms,
+ u32 request, struct common_audit_data *sa,
+ void (*cb) (struct audit_buffer *, void *))
+{
+ int type, error;
+ bool stop = false;
+ u32 denied = request & (~perms->allow | perms->deny);
+ if (likely(!denied)) {
+ /* mask off perms that are not being force audited */
+ request &= perms->audit;
+ if (!request || !sa)
+ return 0;
+
+ type = AUDIT_APPARMOR_AUDIT;
+ error = 0;
+ } else {
+ error = -EACCES;
+
+ if (denied & perms->kill)
+ type = AUDIT_APPARMOR_KILL;
+ else if (denied == (denied & perms->complain))
+ type = AUDIT_APPARMOR_ALLOWED;
+ else
+ type = AUDIT_APPARMOR_DENIED;
+
+ if (denied & perms->stop)
+ stop = true;
+ if (denied == (denied & perms->hide))
+ error = -ENOENT;
+
+ denied &= ~perms->quiet;
+ if (!sa || !denied)
+ return error;
+ }
+
+ if (sa) {
+ aad(sa)->label = &profile->label;
+ aad(sa)->request = request;
+ aad(sa)->denied = denied;
+ aad(sa)->error = error;
+ aa_audit_msg(type, sa, cb);
+ }
+
+ if (type == AUDIT_APPARMOR_ALLOWED)
+ error = 0;
+
+ return error;
+}
+
+const char *aa_imode_name(umode_t mode)
+{
+ switch(mode & S_IFMT) {
+ case S_IFSOCK:
+ return "sock";
+ case S_IFLNK:
+ return "link";
+ case S_IFREG:
+ return "reg";
+ case S_IFBLK:
+ return "blkdev";
+ case S_IFDIR:
+ return "dir";
+ case S_IFCHR:
+ return "chrdev";
+ case S_IFIFO:
+ return "fifo";
+ }
+ return "unknown";
+}
+
+/**
+ * aa_policy_init - initialize a policy structure
+ * @policy: policy to initialize (NOT NULL)
+ * @prefix: prefix name if any is required. (MAYBE NULL)
+ * @name: name of the policy, init will make a copy of it (NOT NULL)
+ * @gfp: allocation mode
+ *
+ * Note: this fn creates a copy of strings passed in
+ *
+ * Returns: true if policy init successful
+ */
+bool aa_policy_init(struct aa_policy *policy, const char *prefix,
+ const char *name, gfp_t gfp)
+{
+ char *hname;
+
+ /* freed by policy_free */
+ if (prefix) {
+ hname = aa_str_alloc(strlen(prefix) + strlen(name) + 3, gfp);
+ if (hname)
+ sprintf(hname, "%s//%s", prefix, name);
+ } else {
+ hname = aa_str_alloc(strlen(name) + 1, gfp);
+ if (hname)
+ strcpy(hname, name);
+ }
+ if (!hname)
+ return 0;
+ policy->hname = hname;
+ /* base.name is a substring of fqname */
+ policy->name = (char *) basename(policy->hname);
+ INIT_LIST_HEAD(&policy->list);
+ INIT_LIST_HEAD(&policy->profiles);
+
+ return 1;
+}
+
+/**
+ * aa_policy_destroy - free the elements referenced by @policy
+ * @policy: policy that is to have its elements freed (NOT NULL)
+ */
+void aa_policy_destroy(struct aa_policy *policy)
+{
+ AA_BUG(on_list_rcu(&policy->profiles));
+ AA_BUG(on_list_rcu(&policy->list));
+
+ /* don't free name as its a subset of hname */
+ aa_put_str(policy->hname);
+}
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