*/
#include <linux/types.h>
+#include <linux/slab.h>
#include <linux/fs.h>
#include <linux/sched.h>
#include "smack.h"
struct smack_known smack_known_huh = {
- .smk_next = NULL,
.smk_known = "?",
.smk_secid = 2,
.smk_cipso = NULL,
};
struct smack_known smack_known_hat = {
- .smk_next = &smack_known_huh,
.smk_known = "^",
.smk_secid = 3,
.smk_cipso = NULL,
};
struct smack_known smack_known_star = {
- .smk_next = &smack_known_hat,
.smk_known = "*",
.smk_secid = 4,
.smk_cipso = NULL,
};
struct smack_known smack_known_floor = {
- .smk_next = &smack_known_star,
.smk_known = "_",
.smk_secid = 5,
.smk_cipso = NULL,
};
struct smack_known smack_known_invalid = {
- .smk_next = &smack_known_floor,
.smk_known = "",
.smk_secid = 6,
.smk_cipso = NULL,
};
struct smack_known smack_known_web = {
- .smk_next = &smack_known_invalid,
.smk_known = "@",
.smk_secid = 7,
.smk_cipso = NULL,
};
-struct smack_known *smack_known = &smack_known_web;
+LIST_HEAD(smack_known_list);
/*
* The initial value needs to be bigger than any of the
*/
static u32 smack_next_secid = 10;
+/*
+ * what events do we log
+ * can be overwritten at run-time by /smack/logging
+ */
+int log_policy = SMACK_AUDIT_DENIED;
+
/**
* smk_access - determine if a subject has a specific access to an object
* @subject_label: a pointer to the subject's Smack label
* @object_label: a pointer to the object's Smack label
* @request: the access requested, in "MAY" format
+ * @a : a pointer to the audit data
*
* This function looks up the subject/object pair in the
* access rule list and returns 0 if the access is permitted,
* will be on the list, so checking the pointers may be a worthwhile
* optimization.
*/
-int smk_access(char *subject_label, char *object_label, int request)
+int smk_access(char *subject_label, char *object_label, int request,
+ struct smk_audit_info *a)
{
u32 may = MAY_NOT;
- struct smk_list_entry *sp;
struct smack_rule *srp;
+ int rc = 0;
/*
* Hardcoded comparisons.
* A star subject can't access any object.
*/
if (subject_label == smack_known_star.smk_known ||
- strcmp(subject_label, smack_known_star.smk_known) == 0)
- return -EACCES;
+ strcmp(subject_label, smack_known_star.smk_known) == 0) {
+ rc = -EACCES;
+ goto out_audit;
+ }
/*
* An internet object can be accessed by any subject.
* Tasks cannot be assigned the internet label.
subject_label == smack_known_web.smk_known ||
strcmp(object_label, smack_known_web.smk_known) == 0 ||
strcmp(subject_label, smack_known_web.smk_known) == 0)
- return 0;
+ goto out_audit;
/*
* A star object can be accessed by any subject.
*/
if (object_label == smack_known_star.smk_known ||
strcmp(object_label, smack_known_star.smk_known) == 0)
- return 0;
+ goto out_audit;
/*
* An object can be accessed in any way by a subject
* with the same label.
*/
if (subject_label == object_label ||
strcmp(subject_label, object_label) == 0)
- return 0;
+ goto out_audit;
/*
* A hat subject can read any object.
* A floor object can be read by any subject.
if ((request & MAY_ANYREAD) == request) {
if (object_label == smack_known_floor.smk_known ||
strcmp(object_label, smack_known_floor.smk_known) == 0)
- return 0;
+ goto out_audit;
if (subject_label == smack_known_hat.smk_known ||
strcmp(subject_label, smack_known_hat.smk_known) == 0)
- return 0;
+ goto out_audit;
}
/*
* Beyond here an explicit relationship is required.
* access (e.g. read is included in readwrite) it's
* good.
*/
- for (sp = smack_list; sp != NULL; sp = sp->smk_next) {
- srp = &sp->smk_rule;
-
+ rcu_read_lock();
+ list_for_each_entry_rcu(srp, &smack_rule_list, list) {
if (srp->smk_subject == subject_label ||
strcmp(srp->smk_subject, subject_label) == 0) {
if (srp->smk_object == object_label ||
}
}
}
+ rcu_read_unlock();
/*
* This is a bit map operation.
*/
if ((request & may) == request)
- return 0;
-
- return -EACCES;
+ goto out_audit;
+
+ rc = -EACCES;
+out_audit:
+#ifdef CONFIG_AUDIT
+ if (a)
+ smack_log(subject_label, object_label, request, rc, a);
+#endif
+ return rc;
}
/**
* smk_curacc - determine if current has a specific access to an object
- * @object_label: a pointer to the object's Smack label
- * @request: the access requested, in "MAY" format
+ * @obj_label: a pointer to the object's Smack label
+ * @mode: the access requested, in "MAY" format
+ * @a : common audit data
*
* This function checks the current subject label/object label pair
* in the access rule list and returns 0 if the access is permitted,
* non zero otherwise. It allows that current may have the capability
* to override the rules.
*/
-int smk_curacc(char *obj_label, u32 mode)
+int smk_curacc(char *obj_label, u32 mode, struct smk_audit_info *a)
{
int rc;
+ char *sp = current_security();
- rc = smk_access(current_security(), obj_label, mode);
+ rc = smk_access(sp, obj_label, mode, NULL);
if (rc == 0)
- return 0;
+ goto out_audit;
/*
* Return if a specific label has been designated as the
* have that label.
*/
if (smack_onlycap != NULL && smack_onlycap != current->cred->security)
- return rc;
+ goto out_audit;
if (capable(CAP_MAC_OVERRIDE))
return 0;
+out_audit:
+#ifdef CONFIG_AUDIT
+ if (a)
+ smack_log(sp, obj_label, mode, rc, a);
+#endif
return rc;
}
+#ifdef CONFIG_AUDIT
+/**
+ * smack_str_from_perm : helper to transalate an int to a
+ * readable string
+ * @string : the string to fill
+ * @access : the int
+ *
+ */
+static inline void smack_str_from_perm(char *string, int access)
+{
+ int i = 0;
+ if (access & MAY_READ)
+ string[i++] = 'r';
+ if (access & MAY_WRITE)
+ string[i++] = 'w';
+ if (access & MAY_EXEC)
+ string[i++] = 'x';
+ if (access & MAY_APPEND)
+ string[i++] = 'a';
+ string[i] = '\0';
+}
+/**
+ * smack_log_callback - SMACK specific information
+ * will be called by generic audit code
+ * @ab : the audit_buffer
+ * @a : audit_data
+ *
+ */
+static void smack_log_callback(struct audit_buffer *ab, void *a)
+{
+ struct common_audit_data *ad = a;
+ struct smack_audit_data *sad = &ad->smack_audit_data;
+ audit_log_format(ab, "lsm=SMACK fn=%s action=%s",
+ ad->smack_audit_data.function,
+ sad->result ? "denied" : "granted");
+ audit_log_format(ab, " subject=");
+ audit_log_untrustedstring(ab, sad->subject);
+ audit_log_format(ab, " object=");
+ audit_log_untrustedstring(ab, sad->object);
+ audit_log_format(ab, " requested=%s", sad->request);
+}
+
+/**
+ * smack_log - Audit the granting or denial of permissions.
+ * @subject_label : smack label of the requester
+ * @object_label : smack label of the object being accessed
+ * @request: requested permissions
+ * @result: result from smk_access
+ * @a: auxiliary audit data
+ *
+ * Audit the granting or denial of permissions in accordance
+ * with the policy.
+ */
+void smack_log(char *subject_label, char *object_label, int request,
+ int result, struct smk_audit_info *ad)
+{
+ char request_buffer[SMK_NUM_ACCESS_TYPE + 1];
+ struct smack_audit_data *sad;
+ struct common_audit_data *a = &ad->a;
+
+ /* check if we have to log the current event */
+ if (result != 0 && (log_policy & SMACK_AUDIT_DENIED) == 0)
+ return;
+ if (result == 0 && (log_policy & SMACK_AUDIT_ACCEPT) == 0)
+ return;
+
+ if (a->smack_audit_data.function == NULL)
+ a->smack_audit_data.function = "unknown";
+
+ /* end preparing the audit data */
+ sad = &a->smack_audit_data;
+ smack_str_from_perm(request_buffer, request);
+ sad->subject = subject_label;
+ sad->object = object_label;
+ sad->request = request_buffer;
+ sad->result = result;
+ a->lsm_pre_audit = smack_log_callback;
+
+ common_lsm_audit(a);
+}
+#else /* #ifdef CONFIG_AUDIT */
+void smack_log(char *subject_label, char *object_label, int request,
+ int result, struct smk_audit_info *ad)
+{
+}
+#endif
+
static DEFINE_MUTEX(smack_known_lock);
/**
if (found)
smack[i] = '\0';
else if (i >= len || string[i] > '~' || string[i] <= ' ' ||
- string[i] == '/') {
+ string[i] == '/' || string[i] == '"' ||
+ string[i] == '\\' || string[i] == '\'') {
smack[i] = '\0';
found = 1;
} else
mutex_lock(&smack_known_lock);
- for (skp = smack_known; skp != NULL; skp = skp->smk_next)
- if (strncmp(skp->smk_known, smack, SMK_MAXLEN) == 0)
+ found = 0;
+ list_for_each_entry_rcu(skp, &smack_known_list, list) {
+ if (strncmp(skp->smk_known, smack, SMK_MAXLEN) == 0) {
+ found = 1;
break;
+ }
+ }
- if (skp == NULL) {
+ if (found == 0) {
skp = kzalloc(sizeof(struct smack_known), GFP_KERNEL);
if (skp != NULL) {
- skp->smk_next = smack_known;
strncpy(skp->smk_known, smack, SMK_MAXLEN);
skp->smk_secid = smack_next_secid++;
skp->smk_cipso = NULL;
* Make sure that the entry is actually
* filled before putting it on the list.
*/
- smp_mb();
- smack_known = skp;
+ list_add_rcu(&skp->list, &smack_known_list);
}
}
{
struct smack_known *skp;
+ /* labels cannot begin with a '-' */
+ if (string[0] == '-')
+ return NULL;
skp = smk_import_entry(string, len);
if (skp == NULL)
return NULL;
{
struct smack_known *skp;
- for (skp = smack_known; skp != NULL; skp = skp->smk_next)
- if (skp->smk_secid == secid)
+ rcu_read_lock();
+ list_for_each_entry_rcu(skp, &smack_known_list, list) {
+ if (skp->smk_secid == secid) {
+ rcu_read_unlock();
return skp->smk_known;
+ }
+ }
/*
* If we got this far someone asked for the translation
* of a secid that is not on the list.
*/
+ rcu_read_unlock();
return smack_known_invalid.smk_known;
}
{
struct smack_known *skp;
- for (skp = smack_known; skp != NULL; skp = skp->smk_next)
- if (strncmp(skp->smk_known, smack, SMK_MAXLEN) == 0)
+ rcu_read_lock();
+ list_for_each_entry_rcu(skp, &smack_known_list, list) {
+ if (strncmp(skp->smk_known, smack, SMK_MAXLEN) == 0) {
+ rcu_read_unlock();
return skp->smk_secid;
+ }
+ }
+ rcu_read_unlock();
return 0;
}
struct smack_known *kp;
char *final = NULL;
- for (kp = smack_known; final == NULL && kp != NULL; kp = kp->smk_next) {
+ rcu_read_lock();
+ list_for_each_entry(kp, &smack_known_list, list) {
if (kp->smk_cipso == NULL)
continue;
spin_unlock_bh(&kp->smk_cipsolock);
}
+ rcu_read_unlock();
if (final == NULL)
final = smack_known_huh.smk_known;
strncpy(result, final, SMK_MAXLEN);
int smack_to_cipso(const char *smack, struct smack_cipso *cp)
{
struct smack_known *kp;
+ int found = 0;
- for (kp = smack_known; kp != NULL; kp = kp->smk_next)
+ rcu_read_lock();
+ list_for_each_entry_rcu(kp, &smack_known_list, list) {
if (kp->smk_known == smack ||
- strcmp(kp->smk_known, smack) == 0)
+ strcmp(kp->smk_known, smack) == 0) {
+ found = 1;
break;
+ }
+ }
+ rcu_read_unlock();
- if (kp == NULL || kp->smk_cipso == NULL)
+ if (found == 0 || kp->smk_cipso == NULL)
return -ENOENT;
memcpy(cp, kp->smk_cipso, sizeof(struct smack_cipso));
git://ftp.safe.ca / safe / jmp / linux-2.6 / blobdiff