zte's code,first commit
Change-Id: I9a04da59e459a9bc0d67f101f700d9d7dc8d681b
diff --git a/ap/os/linux/linux-3.4.x/security/smack/smack_access.c b/ap/os/linux/linux-3.4.x/security/smack/smack_access.c
new file mode 100644
index 0000000..c8115f7
--- /dev/null
+++ b/ap/os/linux/linux-3.4.x/security/smack/smack_access.c
@@ -0,0 +1,557 @@
+/*
+ * Copyright (C) 2007 Casey Schaufler <casey@schaufler-ca.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, version 2.
+ *
+ * Author:
+ * Casey Schaufler <casey@schaufler-ca.com>
+ *
+ */
+
+#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_known = "?",
+ .smk_secid = 2,
+ .smk_cipso = NULL,
+};
+
+struct smack_known smack_known_hat = {
+ .smk_known = "^",
+ .smk_secid = 3,
+ .smk_cipso = NULL,
+};
+
+struct smack_known smack_known_star = {
+ .smk_known = "*",
+ .smk_secid = 4,
+ .smk_cipso = NULL,
+};
+
+struct smack_known smack_known_floor = {
+ .smk_known = "_",
+ .smk_secid = 5,
+ .smk_cipso = NULL,
+};
+
+struct smack_known smack_known_invalid = {
+ .smk_known = "",
+ .smk_secid = 6,
+ .smk_cipso = NULL,
+};
+
+struct smack_known smack_known_web = {
+ .smk_known = "@",
+ .smk_secid = 7,
+ .smk_cipso = NULL,
+};
+
+LIST_HEAD(smack_known_list);
+
+/*
+ * The initial value needs to be bigger than any of the
+ * known values above.
+ */
+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_entry - look up matching access rule
+ * @subject_label: a pointer to the subject's Smack label
+ * @object_label: a pointer to the object's Smack label
+ * @rule_list: the list of rules to search
+ *
+ * This function looks up the subject/object pair in the
+ * access rule list and returns the access mode. If no
+ * entry is found returns -ENOENT.
+ *
+ * NOTE:
+ *
+ * Earlier versions of this function allowed for labels that
+ * were not on the label list. This was done to allow for
+ * labels to come over the network that had never been seen
+ * before on this host. Unless the receiving socket has the
+ * star label this will always result in a failure check. The
+ * star labeled socket case is now handled in the networking
+ * hooks so there is no case where the label is not on the
+ * label list. Checking to see if the address of two labels
+ * is the same is now a reliable test.
+ *
+ * Do the object check first because that is more
+ * likely to differ.
+ */
+int smk_access_entry(char *subject_label, char *object_label,
+ struct list_head *rule_list)
+{
+ int may = -ENOENT;
+ struct smack_rule *srp;
+
+ list_for_each_entry_rcu(srp, rule_list, list) {
+ if (srp->smk_object == object_label &&
+ srp->smk_subject == subject_label) {
+ may = srp->smk_access;
+ break;
+ }
+ }
+
+ return may;
+}
+
+/**
+ * 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,
+ * non zero otherwise.
+ *
+ * Smack labels are shared on smack_list
+ */
+int smk_access(char *subject_label, char *object_label, int request,
+ struct smk_audit_info *a)
+{
+ struct smack_known *skp;
+ int may = MAY_NOT;
+ int rc = 0;
+
+ /*
+ * Hardcoded comparisons.
+ *
+ * A star subject can't access any object.
+ */
+ if (subject_label == smack_known_star.smk_known) {
+ rc = -EACCES;
+ goto out_audit;
+ }
+ /*
+ * An internet object can be accessed by any subject.
+ * Tasks cannot be assigned the internet label.
+ * An internet subject can access any object.
+ */
+ if (object_label == smack_known_web.smk_known ||
+ subject_label == smack_known_web.smk_known)
+ goto out_audit;
+ /*
+ * A star object can be accessed by any subject.
+ */
+ if (object_label == smack_known_star.smk_known)
+ goto out_audit;
+ /*
+ * An object can be accessed in any way by a subject
+ * with the same label.
+ */
+ if (subject_label == object_label)
+ 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)
+ goto out_audit;
+ if (subject_label == smack_known_hat.smk_known)
+ goto out_audit;
+ }
+ /*
+ * Beyond here an explicit relationship is required.
+ * If the requested access is contained in the available
+ * access (e.g. read is included in readwrite) it's
+ * good. A negative response from smk_access_entry()
+ * indicates there is no entry for this pair.
+ */
+ skp = smk_find_entry(subject_label);
+ rcu_read_lock();
+ may = smk_access_entry(subject_label, object_label, &skp->smk_rules);
+ rcu_read_unlock();
+
+ if (may > 0 && (request & may) == request)
+ 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
+ * @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, struct smk_audit_info *a)
+{
+ struct task_smack *tsp = current_security();
+ char *sp = smk_of_task(tsp);
+ int may;
+ int rc;
+
+ /*
+ * Check the global rule list
+ */
+ rc = smk_access(sp, obj_label, mode, NULL);
+ if (rc == 0) {
+ /*
+ * If there is an entry in the task's rule list
+ * it can further restrict access.
+ */
+ may = smk_access_entry(sp, obj_label, &tsp->smk_rules);
+ if (may < 0)
+ goto out_audit;
+ if ((mode & may) == mode)
+ goto out_audit;
+ rc = -EACCES;
+ }
+
+ /*
+ * Return if a specific label has been designated as the
+ * only one that gets privilege and current does not
+ * have that label.
+ */
+ if (smack_onlycap != NULL && smack_onlycap != sp)
+ goto out_audit;
+
+ if (capable(CAP_MAC_OVERRIDE))
+ rc = 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;
+
+ sad = a->smack_audit_data;
+
+ if (sad->function == NULL)
+ sad->function = "unknown";
+
+ /* end preparing the audit data */
+ smack_str_from_perm(request_buffer, request);
+ sad->subject = subject_label;
+ sad->object = object_label;
+ sad->request = request_buffer;
+ sad->result = result;
+
+ common_lsm_audit(a, smack_log_callback, NULL);
+}
+#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);
+
+/**
+ * smk_find_entry - find a label on the list, return the list entry
+ * @string: a text string that might be a Smack label
+ *
+ * Returns a pointer to the entry in the label list that
+ * matches the passed string.
+ */
+struct smack_known *smk_find_entry(const char *string)
+{
+ struct smack_known *skp;
+
+ list_for_each_entry_rcu(skp, &smack_known_list, list) {
+ if (strncmp(skp->smk_known, string, SMK_MAXLEN) == 0)
+ return skp;
+ }
+
+ return NULL;
+}
+
+/**
+ * smk_parse_smack - parse smack label from a text string
+ * @string: a text string that might contain a Smack label
+ * @len: the maximum size, or zero if it is NULL terminated.
+ * @smack: parsed smack label, or NULL if parse error
+ */
+void smk_parse_smack(const char *string, int len, char *smack)
+{
+ int found;
+ int i;
+
+ if (len <= 0 || len > SMK_MAXLEN)
+ len = SMK_MAXLEN;
+
+ for (i = 0, found = 0; i < SMK_LABELLEN; i++) {
+ if (found)
+ smack[i] = '\0';
+ else if (i >= len || string[i] > '~' || string[i] <= ' ' ||
+ string[i] == '/' || string[i] == '"' ||
+ string[i] == '\\' || string[i] == '\'') {
+ smack[i] = '\0';
+ found = 1;
+ } else
+ smack[i] = string[i];
+ }
+}
+
+/**
+ * smk_import_entry - import a label, return the list entry
+ * @string: a text string that might be a Smack label
+ * @len: the maximum size, or zero if it is NULL terminated.
+ *
+ * Returns a pointer to the entry in the label list that
+ * matches the passed string, adding it if necessary.
+ */
+struct smack_known *smk_import_entry(const char *string, int len)
+{
+ struct smack_known *skp;
+ char smack[SMK_LABELLEN];
+
+ smk_parse_smack(string, len, smack);
+ if (smack[0] == '\0')
+ return NULL;
+
+ mutex_lock(&smack_known_lock);
+
+ skp = smk_find_entry(smack);
+
+ if (skp == NULL) {
+ skp = kzalloc(sizeof(struct smack_known), GFP_KERNEL);
+ if (skp != NULL) {
+ strncpy(skp->smk_known, smack, SMK_MAXLEN);
+ skp->smk_secid = smack_next_secid++;
+ skp->smk_cipso = NULL;
+ INIT_LIST_HEAD(&skp->smk_rules);
+ spin_lock_init(&skp->smk_cipsolock);
+ mutex_init(&skp->smk_rules_lock);
+ /*
+ * Make sure that the entry is actually
+ * filled before putting it on the list.
+ */
+ list_add_rcu(&skp->list, &smack_known_list);
+ }
+ }
+
+ mutex_unlock(&smack_known_lock);
+
+ return skp;
+}
+
+/**
+ * smk_import - import a smack label
+ * @string: a text string that might be a Smack label
+ * @len: the maximum size, or zero if it is NULL terminated.
+ *
+ * Returns a pointer to the label in the label list that
+ * matches the passed string, adding it if necessary.
+ */
+char *smk_import(const char *string, int len)
+{
+ 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;
+ return skp->smk_known;
+}
+
+/**
+ * smack_from_secid - find the Smack label associated with a secid
+ * @secid: an integer that might be associated with a Smack label
+ *
+ * Returns a pointer to the appropriate Smack label if there is one,
+ * otherwise a pointer to the invalid Smack label.
+ */
+char *smack_from_secid(const u32 secid)
+{
+ struct smack_known *skp;
+
+ 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;
+}
+
+/**
+ * smack_to_secid - find the secid associated with a Smack label
+ * @smack: the Smack label
+ *
+ * Returns the appropriate secid if there is one,
+ * otherwise 0
+ */
+u32 smack_to_secid(const char *smack)
+{
+ struct smack_known *skp;
+
+ 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;
+}
+
+/**
+ * smack_from_cipso - find the Smack label associated with a CIPSO option
+ * @level: Bell & LaPadula level from the network
+ * @cp: Bell & LaPadula categories from the network
+ *
+ * This is a simple lookup in the label table.
+ *
+ * Return the matching label from the label list or NULL.
+ */
+char *smack_from_cipso(u32 level, char *cp)
+{
+ struct smack_known *kp;
+ char *final = NULL;
+
+ rcu_read_lock();
+ list_for_each_entry(kp, &smack_known_list, list) {
+ if (kp->smk_cipso == NULL)
+ continue;
+
+ spin_lock_bh(&kp->smk_cipsolock);
+
+ if (kp->smk_cipso->smk_level == level &&
+ memcmp(kp->smk_cipso->smk_catset, cp, SMK_LABELLEN) == 0)
+ final = kp->smk_known;
+
+ spin_unlock_bh(&kp->smk_cipsolock);
+
+ if (final != NULL)
+ break;
+ }
+ rcu_read_unlock();
+
+ return final;
+}
+
+/**
+ * smack_to_cipso - find the CIPSO option to go with a Smack label
+ * @smack: a pointer to the smack label in question
+ * @cp: where to put the result
+ *
+ * Returns zero if a value is available, non-zero otherwise.
+ */
+int smack_to_cipso(const char *smack, struct smack_cipso *cp)
+{
+ struct smack_known *kp;
+ int found = 0;
+
+ rcu_read_lock();
+ list_for_each_entry_rcu(kp, &smack_known_list, list) {
+ if (kp->smk_known == smack ||
+ strcmp(kp->smk_known, smack) == 0) {
+ found = 1;
+ break;
+ }
+ }
+ rcu_read_unlock();
+
+ if (found == 0 || kp->smk_cipso == NULL)
+ return -ENOENT;
+
+ memcpy(cp, kp->smk_cipso, sizeof(struct smack_cipso));
+ return 0;
+}