Update magiskpolicy

- Generalize avtab node extraction and insertion
- Add new supported rules: type_change, type_member
- Update help message with official policy language

native/jni/magiskpolicy/api.cpp

@@ -21,16 +21,6 @@ int sepol_auditdeny(const char *s, const char *t, const char *c, const char *p)
 	return add_rule(s, t, c, p, AVTAB_AUDITDENY, 0);
 }
 
-int sepol_typetrans(const char *s, const char *t, const char *c, const char *d, const char *o) {
-	if (o == nullptr) {
-		// printf("add_trans %s %s %s %s\n", s, t, c ,d);
-		return add_transition(s, t, c, d);
-	} else {
-		// printf("add_file_trans %s %s %s %s %s\n", s, t, c ,d, o);
-		return add_file_transition(s, t, c, d, o);
-	}
-}
-
 int sepol_allowxperm(const char *s, const char *t, const char *c, const char *range) {
 	// printf("allowxperm %s %s %s %s\n", s, t, c, range);
 	return add_xperm_rule(s, t, c, range, AVTAB_XPERMS_ALLOWED, 0);
@@ -46,6 +36,21 @@ int sepol_dontauditxperm(const char *s, const char *t, const char *c, const char
 	return add_xperm_rule(s, t, c, range, AVTAB_XPERMS_DONTAUDIT, 0);
 }
 
+int sepol_typetrans(const char *s, const char *t, const char *c, const char *d) {
+	// printf("type_transition %s %s %s %s\n", s, t, c, d);
+	return add_type_rule(s, t, c, d, AVTAB_TRANSITION);
+}
+
+int sepol_typechange(const char *s, const char *t, const char *c, const char *d) {
+	// printf("type_change %s %s %s %s\n", s, t, c, d);
+	return add_type_rule(s, t, c, d, AVTAB_CHANGE);
+}
+
+int sepol_typemember(const char *s, const char *t, const char *c, const char *d) {
+	// printf("type_member %s %s %s %s\n", s, t, c, d);
+	return add_type_rule(s, t, c, d, AVTAB_MEMBER);
+}
+
 int sepol_permissive(const char *s) {
 	// printf("permissive %s\n", s);
 	return set_domain_state(s, 1);

native/jni/magiskpolicy/magiskpolicy.cpp

@@ -14,18 +14,20 @@
 
 static const char *type_msg_1 =
 "Type 1:\n"
-"\"<action> source-class target-class permission-class permission\"\n"
+"\"<rule_name> source_type target_type class perm_set\"\n"
-"Action: allow, deny, auditallow, auditdeny\n";
+"Rules: allow, deny, auditallow, auditdeny\n";
 
 static const char *type_msg_2 =
 "Type 2:\n"
-"\"<action> source-class target-class permission-class ioctl range\"\n"
+"\"<rule_name> source_type target_type class operation xperm_set\"\n"
-"Action: allowxperm, auditallowxperm, dontauditxperm\n";
+"Rules: allowxperm, auditallowxperm, dontauditxperm\n"
+"* The only supported operation is ioctl\n"
+"* The only supported xperm_set format is range ([low-high])\n";
 
 static const char *type_msg_3 =
 "Type 3:\n"
-"\"<action> class\"\n"
+"\"<rule_name> class\"\n"
-"Action: create, permissive, enforcing\n";
+"Rules: create, permissive, enforcing\n";
 
 static const char *type_msg_4 =
 "Type 4:\n"
@@ -33,7 +35,12 @@ static const char *type_msg_4 =
 
 static const char *type_msg_5 =
 "Type 5:\n"
-"\"typetrans source-class target-class permission-class default-class (optional: object-name)\"\n";
+"\"<rule_name> source_type target_type class default_type\"\n"
+"Rules: type_transition, type_change, type_member\n";
+
+static const char *type_msg_6 =
+"Type 6:\n"
+"\"name_transition source_type target_type class default_type object_name\"\n";
 
 
 [[noreturn]] static void statements() {
@@ -42,9 +49,10 @@ static const char *type_msg_5 =
 		"this means a full policy statement should be enclosed in quotes;\n"
 		"multiple policy statements can be provided in a single command\n"
 		"\n"
-		"The statements has a format of \"<action> [args...]\"\n"
+		"The statements has a format of \"<rule_name> [args...]\"\n"
-		"Use '*' in args to represent every possible match.\n"
+		"Multiple types and permissions can be grouped into collections\n"
-		"Collections wrapped in curly brackets can also be used as args.\n"
+		"wrapped in curly brackets.\n"
+		"'*' represents a collection containing all valid matches.\n"
 		"\n"
 		"Supported policy statements:\n"
 		"\n"
@@ -53,20 +61,21 @@ static const char *type_msg_5 =
 		"%s\n"
 		"%s\n"
 		"%s\n"
+		"%s\n"
 		"Notes:\n"
-		"- typetrans does not support the all match '*' syntax\n"
+		"* Type 4 - 6 does not support collections\n"
-		"- permission-class cannot be collections\n"
+		"* Object classes cannot be collections\n"
-		"- source-class and target-class can also be attributes\n"
+		"* source_type and target_type can also be attributes\n"
 		"\n"
-		"Example: allow { source1 source2 } { target1 target2 } permission-class *\n"
+		"Example: allow { s1 s2 } { t1 t2 } class *\n"
 		"Will be expanded to:\n"
 		"\n"
-		"allow source1 target1 permission-class { all-permissions }\n"
+		"allow s1 t1 class { all permissions }\n"
-		"allow source1 target2 permission-class { all-permissions }\n"
+		"allow s1 t2 class { all permissions }\n"
-		"allow source2 target1 permission-class { all-permissions }\n"
+		"allow s2 t1 class { all permissions }\n"
-		"allow source2 target2 permission-class { all-permissions }\n"
+		"allow s2 t2 class { all permissions }\n"
 		"\n",
-  		type_msg_1, type_msg_2, type_msg_3, type_msg_4, type_msg_5);
+		type_msg_1, type_msg_2, type_msg_3, type_msg_4, type_msg_5, type_msg_6);
 	exit(0);
 }
 
@@ -207,6 +216,8 @@ static int parse_pattern_2(int action, const char *action_str, char *stmt) {
 				break;
 			case 3:
 				// Currently only support ioctl
+				if (strcmp(cur, "ioctl"))
+					return 1;
 				vec = nullptr;
 				break;
 			case 4:
@@ -310,11 +321,25 @@ static int parse_pattern_4(int action, const char *action_str, char *stmt) {
 	return 0;
 }
 
-// Pattern 5: action source target class default (filename)
+// Pattern 5: action source target class default
 static int parse_pattern_5(int action, const char *action_str, char *stmt) {
+	int (*action_func)(const char*, const char*, const char*, const char*);
+	switch (action) {
+		case 0:
+			action_func = sepol_typetrans;
+			break;
+		case 1:
+			action_func = sepol_typechange;
+			break;
+		case 2:
+			action_func = sepol_typemember;
+			break;
+		default:
+			return 1;
+	}
 	int state = 0;
 	char *cur;
-	char *source, *target, *cls, *def, *filename = nullptr;
+	char *source, *target, *cls, *def;
 	while ((cur = strtok_r(nullptr, " ", &stmt)) != nullptr) {
 		switch(state) {
 		case 0:
@@ -329,18 +354,48 @@ static int parse_pattern_5(int action, const char *action_str, char *stmt) {
 		case 3:
 			def = cur;
 			break;
-		case 4:
-			filename = cur;
-			break;
 		default:
 			return 1;
 		}
 		++state;
 	}
 	if (state < 4) return 1;
-	if (sepol_typetrans(source, target, cls, def, filename))
+	if (action_func(source, target, cls, def))
+		fprintf(stderr, "Error in: %s %s %s %s %s\n", action_str, source, target, cls, def);
+	return 0;
+}
+
+// Pattern 6: action source target class default filename
+static int parse_pattern_6(int action, const char *action_str, char *stmt) {
+	int state = 0;
+	char *cur;
+	char *source, *target, *cls, *def, *filename;
+	while ((cur = strtok_r(nullptr, " ", &stmt)) != nullptr) {
+		switch(state) {
+			case 0:
+				source = cur;
+				break;
+			case 1:
+				target = cur;
+				break;
+			case 2:
+				cls = cur;
+				break;
+			case 3:
+				def = cur;
+				break;
+			case 4:
+				filename = cur;
+				break;
+			default:
+				return 1;
+		}
+		++state;
+	}
+	if (state < 4) return 1;
+	if (sepol_nametrans(source, target, cls, def, filename))
 		fprintf(stderr, "Error in: %s %s %s %s %s %s\n",
-				action_str, source, target, cls, def, filename ? filename : "");
+				action_str, source, target, cls, def, filename);
 	return 0;
 }
 
@@ -371,7 +426,10 @@ static void parse_statement(char *statement) {
 	add_action("permissive", 3, 1)
 	add_action("enforce", 3, 2)
 	add_action("attradd", 4, 0)
-	add_action("typetrans", 5, 0)
+	add_action("type_transition", 5, 0)
+	add_action("type_change", 5, 1)
+	add_action("type_member", 5, 2)
+	add_action("name_transition", 6, 0)
 	else { fprintf(stderr, "Unknown statement: '%s'\n\n", orig.c_str()); }
 }
 

native/jni/magiskpolicy/magiskpolicy.h

@@ -31,7 +31,10 @@ int sepol_allow(const char *s, const char *t, const char *c, const char *p);
 int sepol_deny(const char *s, const char *t, const char *c, const char *p);
 int sepol_auditallow(const char *s, const char *t, const char *c, const char *p);
 int sepol_auditdeny(const char *s, const char *t, const char *c, const char *p);
-int sepol_typetrans(const char *s, const char *t, const char *c, const char *d, const char *o);
+int sepol_typetrans(const char *s, const char *t, const char *c, const char *d);
+int sepol_typechange(const char *s, const char *t, const char *c, const char *d);
+int sepol_typemember(const char *s, const char *t, const char *c, const char *d);
+int sepol_nametrans(const char *s, const char *t, const char *c, const char *d, const char *o);
 int sepol_allowxperm(const char *s, const char *t, const char *c, const char *range);
 int sepol_auditallowxperm(const char *s, const char *t, const char *c, const char *range);
 int sepol_dontauditxperm(const char *s, const char *t, const char *c, const char *range);

native/jni/magiskpolicy/sepolicy.c

@@ -27,15 +27,6 @@
 policydb_t *policydb = NULL;
 extern int policydb_index_decls(sepol_handle_t * handle, policydb_t * p);
 
-static void *cmalloc(size_t s) {
-	void *t = calloc(s, 1);
-	if (t == NULL) {
-		LOGE("Out of memory\n");
-		exit(1);
-	}
-	return t;
-}
-
 static int get_attr(const char *type, int value) {
 	type_datum_t *attr = hashtab_search(policydb->p_types.table, type);
 	if (!attr)
@@ -44,7 +35,7 @@ static int get_attr(const char *type, int value) {
 	if (attr->flavor != TYPE_ATTRIB)
 		return 1;
 
-	return !! ebitmap_get_bit(&policydb->attr_type_map[attr->s.value-1], value-1);
+	return ebitmap_get_bit(&policydb->attr_type_map[attr->s.value - 1], value - 1) != 0;
 }
 
 static int get_attr_id(const char *type) {
@@ -74,46 +65,62 @@ static int set_attr(const char *type, int value) {
 	return 0;
 }
 
-static int __add_rule(int s, int t, int c, int p, int effect, int not) {
+static avtab_ptr_t get_avtab_node(avtab_key_t *key, avtab_extended_perms_t *xperms)  {
-	avtab_key_t key;
+	avtab_ptr_t node;
-	avtab_datum_t *av;
+	avtab_datum_t avdatum;
-	int new_rule = 0;
+	int match = 0;
 
-	key.source_type = s;
+	/* AVTAB_XPERMS entries are not necessarily unique */
-	key.target_type = t;
+	if (key->specified & AVTAB_XPERMS) {
-	key.target_class = c;
+		node = avtab_search_node(&policydb->te_avtab, key);
-	key.specified = effect;
+		while (node) {
-
+			if ((node->datum.xperms->specified == xperms->specified) &&
-	av = avtab_search(&policydb->te_avtab, &key);
+				(node->datum.xperms->driver == xperms->driver)) {
-	if (av == NULL) {
+				match = 1;
-		av = cmalloc(sizeof(*av));
+				break;
-		new_rule = 1;
+			}
+			node = avtab_search_node_next(node, key->specified);
+		}
+		if (!match)
+			node = NULL;
+	} else {
+		node = avtab_search_node(&policydb->te_avtab, key);
 	}
 
+	if (!node) {
+		memset(&avdatum, 0, sizeof avdatum);
+		/*
+		 * AUDITDENY, aka DONTAUDIT, are &= assigned, versus |= for
+		 * others. Initialize the data accordingly.
+		 */
+		avdatum.data = key->specified == AVTAB_AUDITDENY ? ~0U : 0U;
+		/* this is used to get the node - insertion is actually unique */
+		node = avtab_insert_nonunique(&policydb->te_avtab, key, &avdatum);
+	}
+
+	return node;
+}
+
+static int add_avrule(avtab_key_t *key, int p, int not) {
+	avtab_datum_t *datum = &get_avtab_node(key, NULL)->datum;
 	if(not) {
 		if (p < 0)
-			av->data = 0U;
+			datum->data = 0U;
 		else
-			av->data &= ~(1U << (p - 1));
+			datum->data &= ~(1U << (p - 1));
 	} else {
 		if (p < 0)
-			av->data = ~0U;
+			datum->data = ~0U;
 		else
-			av->data |= 1U << (p - 1);
+			datum->data |= 1U << (p - 1);
-	}
-
-	if (new_rule) {
-		if (avtab_insert(&policydb->te_avtab, &key, av)) {
-			LOGW("Error inserting into avtab\n");
-			return 1;
-		}
-		free(av);
 	}
 
 	return 0;
 }
 
-static int add_rule_auto(type_datum_t *src, type_datum_t *tgt, class_datum_t *cls, perm_datum_t *perm, int effect, int not) {
+static int add_rule_auto(type_datum_t *src, type_datum_t *tgt, class_datum_t *cls,
+						 perm_datum_t *perm, int effect, int not) {
+	avtab_key_t key;
 	hashtab_ptr_t cur;
 	int ret = 0;
 
@@ -130,10 +137,14 @@ static int add_rule_auto(type_datum_t *src, type_datum_t *tgt, class_datum_t *cl
 	} else if (cls == NULL) {
 		hashtab_for_each(policydb->p_classes.table, &cur) {
 			cls = cur->datum;
-			ret |= __add_rule(src->s.value, tgt->s.value, cls->s.value, -1, effect, not);
+			ret |= add_rule_auto(src, tgt, cls, perm, effect, not);
 		}
 	} else {
-		return __add_rule(src->s.value, tgt->s.value, cls->s.value, perm ? perm->s.value : -1, effect, not);
+		key.source_type = src->s.value;
+		key.target_type = tgt->s.value;
+		key.target_class = cls->s.value;
+		key.specified = effect;
+		return add_avrule(&key, perm ? perm->s.value : -1, not);
 	}
 	return ret;
 }
@@ -141,59 +152,47 @@ static int add_rule_auto(type_datum_t *src, type_datum_t *tgt, class_datum_t *cl
 #define ioctl_driver(x) (x>>8 & 0xFF)
 #define ioctl_func(x) (x & 0xFF)
 
-static int __add_xperm_rule(int s, int t, int c, uint16_t low, uint16_t high, int effect, int not) {
+static int add_avxrule(avtab_key_t *key, uint16_t low, uint16_t high, int not) {
-	avtab_key_t key;
+	avtab_datum_t *datum;
-	avtab_datum_t *av;
+	avtab_extended_perms_t xperms;
-	int new_rule = 0;
 
-	key.source_type = s;
+	memset(&xperms, 0, sizeof(xperms));
-	key.target_type = t;
+	if (ioctl_driver(low) != ioctl_driver(high)) {
-	key.target_class = c;
+		xperms.specified = AVTAB_XPERMS_IOCTLDRIVER;
-	key.specified = effect;
+		xperms.driver = 0;
-
+	} else {
-	av = avtab_search(&policydb->te_avtab, &key);
+		xperms.specified = AVTAB_XPERMS_IOCTLFUNCTION;
-	if (av == NULL) {
+		xperms.driver = ioctl_driver(low);
-		av = cmalloc(sizeof(*av));
-		av->xperms = cmalloc(sizeof(avtab_extended_perms_t));
-		new_rule = 1;
-		if (ioctl_driver(low) != ioctl_driver(high)) {
-			av->xperms->specified = AVTAB_XPERMS_IOCTLDRIVER;
-			av->xperms->driver = 0;
-		} else {
-			av->xperms->specified = AVTAB_XPERMS_IOCTLFUNCTION;
-			av->xperms->driver = ioctl_driver(low);
-		}
 	}
 
-	if (av->xperms->specified == AVTAB_XPERMS_IOCTLDRIVER) {
+	if (xperms.specified == AVTAB_XPERMS_IOCTLDRIVER) {
-		for (unsigned i = ioctl_driver(low); i <= ioctl_driver(high); ++i) {
+		for (int i = ioctl_driver(low); i <= ioctl_driver(high); ++i) {
 			if (not)
-				xperm_clear(i, av->xperms->perms);
+				xperm_clear(i, xperms.perms);
 			else
-				xperm_set(i, av->xperms->perms);
+				xperm_set(i, xperms.perms);
 		}
 	} else {
-		for (unsigned i = ioctl_func(low); i <= ioctl_func(high); ++i) {
+		for (int i = ioctl_func(low); i <= ioctl_func(high); ++i) {
 			if (not)
-				xperm_clear(i, av->xperms->perms);
+				xperm_clear(i, xperms.perms);
 			else
-				xperm_set(i, av->xperms->perms);
+				xperm_set(i, xperms.perms);
 		}
 	}
 
-	if (new_rule) {
+	datum = &get_avtab_node(key, &xperms)->datum;
-		if (avtab_insert(&policydb->te_avtab, &key, av)) {
-			LOGW("Error inserting into avtab\n");
-			return 1;
-		}
-		free(av);
-	}
 
+	if (datum->xperms == NULL)
+		datum->xperms = xmalloc(sizeof(xperms));
+
+	memcpy(datum->xperms, &xperms, sizeof(xperms));
 	return 0;
 }
 
 static int add_xperm_rule_auto(type_datum_t *src, type_datum_t *tgt, class_datum_t *cls,
 			uint16_t low, uint16_t high, int effect, int not) {
+	avtab_key_t key;
 	hashtab_ptr_t cur;
 	int ret = 0;
 
@@ -210,10 +209,14 @@ static int add_xperm_rule_auto(type_datum_t *src, type_datum_t *tgt, class_datum
 	} else if (cls == NULL) {
 		hashtab_for_each(policydb->p_classes.table, &cur) {
 			cls = cur->datum;
-			ret |= __add_xperm_rule(src->s.value, tgt->s.value, cls->s.value, low, high, effect, not);
+			ret |= add_xperm_rule_auto(src, tgt, cls, low, high, effect, not);
 		}
 	} else {
-		return __add_xperm_rule(src->s.value, tgt->s.value, cls->s.value, low, high, effect, not);
+		key.source_type = src->s.value;
+		key.target_type = tgt->s.value;
+		key.target_class = cls->s.value;
+		key.specified = effect;
+		return add_avxrule(&key, low, high, not);
 	}
 	return ret;
 }
@@ -227,7 +230,7 @@ int load_policydb(const char *filename) {
 	if (policydb)
 		destroy_policydb();
 
-	policydb = cmalloc(sizeof(*policydb));
+	policydb = xcalloc(sizeof(*policydb), 1);
 
 	mmap_ro(filename, &map, &size);
 
@@ -417,59 +420,7 @@ int set_domain_state(const char *s, int state) {
 	return 0;
 }
 
-int add_transition(const char *s, const char *t, const char *c, const char *d) {
+int sepol_nametrans(const char *s, const char *t, const char *c, const char *d, const char *o) {
-	type_datum_t *src, *tgt, *def;
-	class_datum_t *cls;
-
-	avtab_key_t key;
-	avtab_datum_t *av;
-	int new_rule = 0;
-
-	src = hashtab_search(policydb->p_types.table, s);
-	if (src == NULL) {
-		LOGW("source type %s does not exist\n", s);
-		return 1;
-	}
-	tgt = hashtab_search(policydb->p_types.table, t);
-	if (tgt == NULL) {
-		LOGW("target type %s does not exist\n", t);
-		return 1;
-	}
-	cls = hashtab_search(policydb->p_classes.table, c);
-	if (cls == NULL) {
-		LOGW("class %s does not exist\n", c);
-		return 1;
-	}
-	def = hashtab_search(policydb->p_types.table, d);
-	if (def == NULL) {
-		LOGW("default type %s does not exist\n", d);
-		return 1;
-	}
-
-	key.source_type = src->s.value;
-	key.target_type = tgt->s.value;
-	key.target_class = cls->s.value;
-	key.specified = AVTAB_TRANSITION;
-	av = avtab_search(&policydb->te_avtab, &key);
-	if (av == NULL) {
-		av = cmalloc(sizeof(*av));
-		new_rule = 1;
-	}
-
-	av->data = def->s.value;
-
-	if (new_rule) {
-		if (avtab_insert(&policydb->te_avtab, &key, av)) {
-			LOGW("Error inserting into avtab\n");
-			return 1;
-		}
-		free(av);
-	}
-	return 0;
-}
-
-int add_file_transition(const char *s, const char *t, const char *c, const char *d,
-						const char *filename) {
 	type_datum_t *src, *tgt, *def;
 	class_datum_t *cls;
 
@@ -498,13 +449,13 @@ int add_file_transition(const char *s, const char *t, const char *c, const char
 	trans_key.stype = src->s.value;
 	trans_key.ttype = tgt->s.value;
 	trans_key.tclass = cls->s.value;
-	trans_key.name = (char *) filename;
+	trans_key.name = (char *) o;
 
 	filename_trans_datum_t *trans_datum;
 	trans_datum = hashtab_search(policydb->p_types.table, (hashtab_key_t) &trans_key);
 
 	if (trans_datum == NULL) {
-		trans_datum = cmalloc(sizeof(*trans_datum));
+		trans_datum = xcalloc(sizeof(*trans_datum), 1);
 		hashtab_insert(policydb->filename_trans, (hashtab_key_t) &trans_key, trans_datum);
 	}
 
@@ -634,3 +585,42 @@ int add_xperm_rule(const char *s, const char *t, const char *c, const char *rang
 
 	return add_xperm_rule_auto(src, tgt, cls, low, high, effect, n);
 }
+
+int add_type_rule(const char *s, const char *t, const char *c, const char *d, int effect) {
+	type_datum_t *src, *tgt, *def;
+	class_datum_t *cls;
+
+	avtab_key_t key;
+	avtab_datum_t *av;
+
+	src = hashtab_search(policydb->p_types.table, s);
+	if (src == NULL) {
+		LOGW("source type %s does not exist\n", s);
+		return 1;
+	}
+	tgt = hashtab_search(policydb->p_types.table, t);
+	if (tgt == NULL) {
+		LOGW("target type %s does not exist\n", t);
+		return 1;
+	}
+	cls = hashtab_search(policydb->p_classes.table, c);
+	if (cls == NULL) {
+		LOGW("class %s does not exist\n", c);
+		return 1;
+	}
+	def = hashtab_search(policydb->p_types.table, d);
+	if (def == NULL) {
+		LOGW("default type %s does not exist\n", d);
+		return 1;
+	}
+
+	key.source_type = src->s.value;
+	key.target_type = tgt->s.value;
+	key.target_class = cls->s.value;
+	key.specified = effect;
+
+	av = &get_avtab_node(&key, NULL)->datum;
+	av->data = def->s.value;
+
+	return 0;
+}

native/jni/magiskpolicy/sepolicy.h

@@ -21,12 +21,12 @@ extern policydb_t *policydb;
 // sepolicy manipulation functions
 int create_domain(const char *d);
 int set_domain_state(const char *s, int state);
-int add_transition(const char *s, const char *t, const char *c, const char *d);
 int add_file_transition(const char *s, const char *t, const char *c, const char *d,
-						const char *filename);
+						const char *o);
 int add_typeattribute(const char *domainS, const char *attr);
 int add_rule(const char *s, const char *t, const char *c, const char *p, int effect, int n);
 int add_xperm_rule(const char *s, const char *t, const char *c, const char *range, int effect, int n);
+int add_type_rule(const char *s, const char *t, const char *c, const char *d, int effect);
 
 #ifdef __cplusplus
 };