Make Smack operate on smack_known struct where it still used char*

Smack used to use a mix of smack_known struct and char* throughout its
APIs and implementation. This patch unifies the behaviour and makes it
store and operate exclusively on smack_known struct pointers when managing
labels.
Signed-off-by: Lukasz Pawelczyk <l.pawelczyk@samsung.com>

Conflicts:
	security/smack/smack_access.c
	security/smack/smack_lsm.c

security/smack/smack.h

@@ -71,11 +71,11 @@ struct smack_known {
 #define SMK_CIPSOLEN	24
 
 struct superblock_smack {
-	char		*smk_root;
-	char		*smk_floor;
-	char		*smk_hat;
-	char		*smk_default;
-	int		smk_initialized;
+	struct smack_known	*smk_root;
+	struct smack_known	*smk_floor;
+	struct smack_known	*smk_hat;
+	struct smack_known	*smk_default;
+	int			smk_initialized;
 };
 
 struct socket_smack {
@@ -88,7 +88,7 @@ struct socket_smack {
  * Inode smack data
  */
 struct inode_smack {
-	char			*smk_inode;	/* label of the fso */
+	struct smack_known	*smk_inode;	/* label of the fso */
 	struct smack_known	*smk_task;	/* label of the task */
 	struct smack_known	*smk_mmap;	/* label of the mmap domain */
 	struct mutex		smk_lock;	/* initialization lock */
@@ -112,7 +112,7 @@ struct task_smack {
 struct smack_rule {
 	struct list_head	list;
 	struct smack_known	*smk_subject;
-	char			*smk_object;
+	struct smack_known	*smk_object;
 	int			smk_access;
 };
 
@@ -123,7 +123,7 @@ struct smk_netlbladdr {
 	struct list_head	list;
 	struct sockaddr_in	smk_host;	/* network address */
 	struct in_addr		smk_mask;	/* network mask */
-	char			*smk_label;	/* label */
+	struct smack_known	*smk_label;	/* label */
 };
 
 /*
@@ -227,23 +227,23 @@ struct smk_audit_info {
 /*
  * These functions are in smack_lsm.c
  */
-struct inode_smack *new_inode_smack(char *);
+struct inode_smack *new_inode_smack(struct smack_known *);
 
 /*
  * These functions are in smack_access.c
  */
 int smk_access_entry(char *, char *, struct list_head *);
-int smk_access(struct smack_known *, char *, int, struct smk_audit_info *);
-int smk_tskacc(struct task_smack *, char *, u32, struct smk_audit_info *);
-int smk_curacc(char *, u32, struct smk_audit_info *);
+int smk_access(struct smack_known *, struct smack_known *,
+	       int, struct smk_audit_info *);
+int smk_tskacc(struct task_smack *, struct smack_known *,
+	       u32, struct smk_audit_info *);
+int smk_curacc(struct smack_known *, u32, struct smk_audit_info *);
 struct smack_known *smack_from_secid(const u32);
 char *smk_parse_smack(const char *string, int len);
 int smk_netlbl_mls(int, char *, struct netlbl_lsm_secattr *, int);
-char *smk_import(const char *, int);
 struct smack_known *smk_import_entry(const char *, int);
 void smk_insert_entry(struct smack_known *skp);
 struct smack_known *smk_find_entry(const char *);
-u32 smack_to_secid(const char *);
 
 /*
  * Shared data.
@@ -253,7 +253,7 @@ extern int smack_cipso_mapped;
 extern struct smack_known *smack_net_ambient;
 extern struct smack_known *smack_onlycap;
 extern struct smack_known *smack_syslog_label;
-extern const char *smack_cipso_option;
+extern struct smack_known smack_cipso_option;
 extern int smack_ptrace_rule;
 
 extern struct smack_known smack_known_floor;
@@ -282,9 +282,9 @@ static inline int smk_inode_transmutable(const struct inode *isp)
 }
 
 /*
- * Present a pointer to the smack label in an inode blob.
+ * Present a pointer to the smack label entry in an inode blob.
  */
-static inline char *smk_of_inode(const struct inode *isp)
+static inline struct smack_known *smk_of_inode(const struct inode *isp)
 {
 	struct inode_smack *sip = isp->i_security;
 	return sip->smk_inode;

security/smack/smack_access.c

@@ -94,7 +94,7 @@ int smk_access_entry(char *subject_label, char *object_label,
 	struct smack_rule *srp;
 
 	list_for_each_entry_rcu(srp, rule_list, list) {
-		if (srp->smk_object == object_label &&
+		if (srp->smk_object->smk_known == object_label &&
 		    srp->smk_subject->smk_known == subject_label) {
 			may = srp->smk_access;
 			break;
@@ -111,8 +111,8 @@ int smk_access_entry(char *subject_label, char *object_label,
 
 /**
  * smk_access - determine if a subject has a specific access to an object
- * @subject_known: a pointer to the subject's Smack label entry
- * @object_label: a pointer to the object's Smack label
+ * @subject: a pointer to the subject's Smack label entry
+ * @object: a pointer to the object's Smack label entry
  * @request: the access requested, in "MAY" format
  * @a : a pointer to the audit data
  *
@@ -122,8 +122,8 @@ int smk_access_entry(char *subject_label, char *object_label,
  *
  * Smack labels are shared on smack_list
  */
-int smk_access(struct smack_known *subject_known, char *object_label,
-		int request, struct smk_audit_info *a)
+int smk_access(struct smack_known *subject, struct smack_known *object,
+	       int request, struct smk_audit_info *a)
 {
 	int may = MAY_NOT;
 	int rc = 0;
@@ -133,7 +133,7 @@ int smk_access(struct smack_known *subject_known, char *object_label,
 	 *
 	 * A star subject can't access any object.
 	 */
-	if (subject_known == &smack_known_star) {
+	if (subject == &smack_known_star) {
 		rc = -EACCES;
 		goto out_audit;
 	}
@@ -142,28 +142,28 @@ int smk_access(struct smack_known *subject_known, char *object_label,
 	 * Tasks cannot be assigned the internet label.
 	 * An internet subject can access any object.
 	 */
-	if (object_label == smack_known_web.smk_known ||
-	    subject_known == &smack_known_web)
+	if (object == &smack_known_web ||
+	    subject == &smack_known_web)
 		goto out_audit;
 	/*
 	 * A star object can be accessed by any subject.
 	 */
-	if (object_label == smack_known_star.smk_known)
+	if (object == &smack_known_star)
 		goto out_audit;
 	/*
 	 * An object can be accessed in any way by a subject
 	 * with the same label.
 	 */
-	if (subject_known->smk_known == object_label)
+	if (subject->smk_known == object->smk_known)
 		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)
+		if (object == &smack_known_floor)
 			goto out_audit;
-		if (subject_known == &smack_known_hat)
+		if (subject == &smack_known_hat)
 			goto out_audit;
 	}
 	/*
@@ -174,8 +174,8 @@ int smk_access(struct smack_known *subject_known, char *object_label,
 	 * indicates there is no entry for this pair.
 	 */
 	rcu_read_lock();
-	may = smk_access_entry(subject_known->smk_known, object_label,
-				&subject_known->smk_rules);
+	may = smk_access_entry(subject->smk_known, object->smk_known,
+			       &subject->smk_rules);
 	rcu_read_unlock();
 
 	if (may <= 0 || (request & may) != request) {
@@ -195,8 +195,8 @@ int smk_access(struct smack_known *subject_known, char *object_label,
 out_audit:
 #ifdef CONFIG_AUDIT
 	if (a)
-		smack_log(subject_known->smk_known, object_label, request,
-				rc, a);
+		smack_log(subject->smk_known, object->smk_known,
+			  request, rc, a);
 #endif
 
 	return rc;
@@ -204,8 +204,8 @@ int smk_access(struct smack_known *subject_known, char *object_label,
 
 /**
  * smk_tskacc - determine if a task has a specific access to an object
- * @tsp: a pointer to the subject task
- * @obj_label: a pointer to the object's Smack label
+ * @tsp: a pointer to the subject's task
+ * @obj_known: a pointer to the object's label entry
  * @mode: the access requested, in "MAY" format
  * @a : common audit data
  *
@@ -214,24 +214,25 @@ int smk_access(struct smack_known *subject_known, char *object_label,
  * non zero otherwise. It allows that the task may have the capability
  * to override the rules.
  */
-int smk_tskacc(struct task_smack *subject, char *obj_label,
+int smk_tskacc(struct task_smack *tsp, struct smack_known *obj_known,
 	       u32 mode, struct smk_audit_info *a)
 {
-	struct smack_known *skp = smk_of_task(subject);
+	struct smack_known *sbj_known = smk_of_task(tsp);
 	int may;
 	int rc;
 
 	/*
 	 * Check the global rule list
 	 */
-	rc = smk_access(skp, obj_label, mode, NULL);
+	rc = smk_access(sbj_known, obj_known, 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(skp->smk_known, obj_label,
-					&subject->smk_rules);
+		may = smk_access_entry(sbj_known->smk_known,
+				       obj_known->smk_known,
+				       &tsp->smk_rules);
 		if (may < 0)
 			goto out_audit;
 		if ((mode & may) == mode)
@@ -248,14 +249,15 @@ int smk_tskacc(struct task_smack *subject, char *obj_label,
 out_audit:
 #ifdef CONFIG_AUDIT
 	if (a)
-		smack_log(skp->smk_known, obj_label, mode, rc, a);
+		smack_log(sbj_known->smk_known, obj_known->smk_known,
+			  mode, 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
+ * @obj_known: a pointer to the object's Smack label entry
  * @mode: the access requested, in "MAY" format
  * @a : common audit data
  *
@@ -264,11 +266,12 @@ int smk_tskacc(struct task_smack *subject, char *obj_label,
  * 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)
+int smk_curacc(struct smack_known *obj_known,
+	       u32 mode, struct smk_audit_info *a)
 {
 	struct task_smack *tsp = current_security();
 
-	return smk_tskacc(tsp, obj_label, mode, a);
+	return smk_tskacc(tsp, obj_known, mode, a);
 }
 
 #ifdef CONFIG_AUDIT
@@ -561,27 +564,6 @@ struct smack_known *smk_import_entry(const char *string, int len)
 	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
@@ -608,19 +590,3 @@ struct smack_known *smack_from_secid(const u32 secid)
 	rcu_read_unlock();
 	return &smack_known_invalid;
 }
-
-/**
- * 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 = smk_find_entry(smack);
-
-	if (skp == NULL)
-		return 0;
-	return skp->smk_secid;
-}

security/smack/smackfs.c

@@ -131,14 +131,17 @@ LIST_HEAD(smack_rule_list);
 
 struct smack_parsed_rule {
 	struct smack_known	*smk_subject;
-	char			*smk_object;
+	struct smack_known	*smk_object;
 	int			smk_access1;
 	int			smk_access2;
 };
 
 static int smk_cipso_doi_value = SMACK_CIPSO_DOI_DEFAULT;
 
-const char *smack_cipso_option = SMACK_CIPSO_OPTION;
+struct smack_known smack_cipso_option = {
+	.smk_known	= SMACK_CIPSO_OPTION,
+	.smk_secid	= 0,
+};
 
 /*
  * Values for parsing cipso rules
@@ -339,7 +342,7 @@ static int smk_fill_rule(const char *subject, const char *object,
 		if (rule->smk_subject == NULL)
 			return -EINVAL;
 
-		rule->smk_object = smk_import(object, len);
+		rule->smk_object = smk_import_entry(object, len);
 		if (rule->smk_object == NULL)
 			return -EINVAL;
 	} else {
@@ -359,7 +362,7 @@ static int smk_fill_rule(const char *subject, const char *object,
 		kfree(cp);
 		if (skp == NULL)
 			return -ENOENT;
-		rule->smk_object = skp->smk_known;
+		rule->smk_object = skp;
 	}
 
 	rule->smk_access1 = smk_perm_from_str(access1);
@@ -598,13 +601,15 @@ static void smk_rule_show(struct seq_file *s, struct smack_rule *srp, int max)
 	 * anything you read back.
 	 */
 	if (strlen(srp->smk_subject->smk_known) >= max ||
-	    strlen(srp->smk_object) >= max)
+	    strlen(srp->smk_object->smk_known) >= max)
 		return;
 
 	if (srp->smk_access == 0)
 		return;
 
-	seq_printf(s, "%s %s", srp->smk_subject->smk_known, srp->smk_object);
+	seq_printf(s, "%s %s",
+		   srp->smk_subject->smk_known,
+		   srp->smk_object->smk_known);
 
 	seq_putc(s, ' ');
 
@@ -1073,7 +1078,7 @@ static int netlbladdr_seq_show(struct seq_file *s, void *v)
 	for (maskn = 0; temp_mask; temp_mask <<= 1, maskn++);
 
 	seq_printf(s, "%u.%u.%u.%u/%d %s\n",
-		hp[0], hp[1], hp[2], hp[3], maskn, skp->smk_label);
+		hp[0], hp[1], hp[2], hp[3], maskn, skp->smk_label->smk_known);
 
 	return 0;
 }
@@ -1153,10 +1158,10 @@ static void smk_netlbladdr_insert(struct smk_netlbladdr *new)
 static ssize_t smk_write_netlbladdr(struct file *file, const char __user *buf,
 				size_t count, loff_t *ppos)
 {
-	struct smk_netlbladdr *skp;
+	struct smk_netlbladdr *snp;
 	struct sockaddr_in newname;
 	char *smack;
-	char *sp;
+	struct smack_known *skp;
 	char *data;
 	char *host = (char *)&newname.sin_addr.s_addr;
 	int rc;
@@ -1219,15 +1224,15 @@ static ssize_t smk_write_netlbladdr(struct file *file, const char __user *buf,
 	 * If smack begins with '-', it is an option, don't import it
 	 */
 	if (smack[0] != '-') {
-		sp = smk_import(smack, 0);
-		if (sp == NULL) {
+		skp = smk_import_entry(smack, 0);
+		if (skp == NULL) {
 			rc = -EINVAL;
 			goto free_out;
 		}
 	} else {
 		/* check known options */
-		if (strcmp(smack, smack_cipso_option) == 0)
-			sp = (char *)smack_cipso_option;
+		if (strcmp(smack, smack_cipso_option.smk_known) == 0)
+			skp = &smack_cipso_option;
 		else {
 			rc = -EINVAL;
 			goto free_out;
@@ -1250,9 +1255,9 @@ static ssize_t smk_write_netlbladdr(struct file *file, const char __user *buf,
 	nsa = newname.sin_addr.s_addr;
 	/* try to find if the prefix is already in the list */
 	found = 0;
-	list_for_each_entry_rcu(skp, &smk_netlbladdr_list, list) {
-		if (skp->smk_host.sin_addr.s_addr == nsa &&
-		    skp->smk_mask.s_addr == mask.s_addr) {
+	list_for_each_entry_rcu(snp, &smk_netlbladdr_list, list) {
+		if (snp->smk_host.sin_addr.s_addr == nsa &&
+		    snp->smk_mask.s_addr == mask.s_addr) {
 			found = 1;
 			break;
 		}
@@ -1260,26 +1265,26 @@ static ssize_t smk_write_netlbladdr(struct file *file, const char __user *buf,
 	smk_netlabel_audit_set(&audit_info);
 
 	if (found == 0) {
-		skp = kzalloc(sizeof(*skp), GFP_KERNEL);
-		if (skp == NULL)
+		snp = kzalloc(sizeof(*snp), GFP_KERNEL);
+		if (snp == NULL)
 			rc = -ENOMEM;
 		else {
 			rc = 0;
-			skp->smk_host.sin_addr.s_addr = newname.sin_addr.s_addr;
-			skp->smk_mask.s_addr = mask.s_addr;
-			skp->smk_label = sp;
-			smk_netlbladdr_insert(skp);
+			snp->smk_host.sin_addr.s_addr = newname.sin_addr.s_addr;
+			snp->smk_mask.s_addr = mask.s_addr;
+			snp->smk_label = skp;
+			smk_netlbladdr_insert(snp);
 		}
 	} else {
 		/* we delete the unlabeled entry, only if the previous label
 		 * wasn't the special CIPSO option */
-		if (skp->smk_label != smack_cipso_option)
+		if (snp->smk_label != &smack_cipso_option)
 			rc = netlbl_cfg_unlbl_static_del(&init_net, NULL,
-					&skp->smk_host.sin_addr, &skp->smk_mask,
+					&snp->smk_host.sin_addr, &snp->smk_mask,
 					PF_INET, &audit_info);
 		else
 			rc = 0;
-		skp->smk_label = sp;
+		snp->smk_label = skp;
 	}
 
 	/*
@@ -1287,10 +1292,10 @@ static ssize_t smk_write_netlbladdr(struct file *file, const char __user *buf,
 	 * this host so that incoming packets get labeled.
 	 * but only if we didn't get the special CIPSO option
 	 */
-	if (rc == 0 && sp != smack_cipso_option)
+	if (rc == 0 && skp != &smack_cipso_option)
 		rc = netlbl_cfg_unlbl_static_add(&init_net, NULL,
-			&skp->smk_host.sin_addr, &skp->smk_mask, PF_INET,
-			smack_to_secid(skp->smk_label), &audit_info);
+			&snp->smk_host.sin_addr, &snp->smk_mask, PF_INET,
+			snp->smk_label->smk_secid, &audit_info);
 
 	if (rc == 0)
 		rc = count;