Create a mac_bsdextended_check_vp function that takes a cred, a

vnode and a mode and checks if a given access mode is permitted.
This centralises the mac_bsdextended_enabled check and the GETATTR
calls and makes the implementation of the mac policy methods simple.

This should make it easier for us to match vnodes on more complex
attributes than just uid and gid in the future, but for now there
should be no functional change.

Approved/Reviewed by:	rwatson, trhodes
MFC after:	1 month

sys/security/mac_bsdextended/mac_bsdextended.c

@@ -353,11 +353,10 @@ mac_bsdextended_check(struct ucred *cred, uid_t object_uid, gid_t object_gid,
 }
 
 static int
-mac_bsdextended_check_system_swapon(struct ucred *cred, struct vnode *vp,
+mac_bsdextended_check_vp(struct ucred *cred, struct vnode *vp, int acc_mode)
-    struct label *label)
 {
-	struct vattr vap;
 	int error;
+	struct vattr vap;
 
 	if (!mac_bsdextended_enabled)
 		return (0);
@@ -365,75 +364,49 @@ mac_bsdextended_check_system_swapon(struct ucred *cred, struct vnode *vp,
 	error = VOP_GETATTR(vp, &vap, cred, curthread);
 	if (error)
 		return (error);
+
 	return (mac_bsdextended_check(cred, vap.va_uid, vap.va_gid,
-	    MBI_WRITE));
+	    acc_mode));
+}
+
+static int
+mac_bsdextended_check_system_swapon(struct ucred *cred, struct vnode *vp,
+    struct label *label)
+{
+
+	return (mac_bsdextended_check_vp(cred, vp, MBI_WRITE));
 }
 
 static int
 mac_bsdextended_check_vnode_access(struct ucred *cred, struct vnode *vp,
     struct label *label, int acc_mode)
 {
-	struct vattr vap;
-	int error;
 
-	if (!mac_bsdextended_enabled)
+	return (mac_bsdextended_check_vp(cred, vp, acc_mode));
-		return (0);
-
-	error = VOP_GETATTR(vp, &vap, cred, curthread);
-	if (error)
-		return (error);
-	return (mac_bsdextended_check(cred, vap.va_uid, vap.va_gid, acc_mode));
 }
 
 static int
 mac_bsdextended_check_vnode_chdir(struct ucred *cred, struct vnode *dvp,
     struct label *dlabel)
 {
-	struct vattr vap;
-	int error;
 
-	if (!mac_bsdextended_enabled)
+	return (mac_bsdextended_check_vp(cred, dvp, MBI_EXEC));
-		return (0);
-
-	error = VOP_GETATTR(dvp, &vap, cred, curthread);
-	if (error)
-		return (error);
-	return (mac_bsdextended_check(cred, vap.va_uid, vap.va_gid,
-	    MBI_EXEC));
 }
 
 static int
 mac_bsdextended_check_vnode_chroot(struct ucred *cred, struct vnode *dvp,
     struct label *dlabel)
 {
-	struct vattr vap;
-	int error;
 
-	if (!mac_bsdextended_enabled)
+	return (mac_bsdextended_check_vp(cred, dvp, MBI_EXEC));
-		return (0);
-
-	error = VOP_GETATTR(dvp, &vap, cred, curthread);
-	if (error)
-		return (error);
-	return (mac_bsdextended_check(cred, vap.va_uid, vap.va_gid,
-	    MBI_EXEC));
 }
 
 static int
 mac_bsdextended_check_create_vnode(struct ucred *cred, struct vnode *dvp,
     struct label *dlabel, struct componentname *cnp, struct vattr *vap)
 {
-	struct vattr dvap;
-	int error;
 
-	if (!mac_bsdextended_enabled)
+	return (mac_bsdextended_check_vp(cred, dvp, MBI_WRITE));
-		return (0);
-
-	error = VOP_GETATTR(dvp, &dvap, cred, curthread);
-	if (error)
-		return (error);
-	return (mac_bsdextended_check(cred, dvap.va_uid, dvap.va_gid,
-	    MBI_WRITE));
 }
 
 static int
@@ -441,59 +414,29 @@ mac_bsdextended_check_vnode_delete(struct ucred *cred, struct vnode *dvp,
     struct label *dlabel, struct vnode *vp, struct label *label,
     struct componentname *cnp)
 {
-	struct vattr vap;
 	int error;
 
-	if (!mac_bsdextended_enabled)
+	error = mac_bsdextended_check_vp(cred, dvp, MBI_WRITE);
-		return (0);
-
-	error = VOP_GETATTR(dvp, &vap, cred, curthread);
-	if (error)
-		return (error);
-	error = mac_bsdextended_check(cred, vap.va_uid, vap.va_gid,
-	    MBI_WRITE);
 	if (error)
 		return (error);
 
-	error = VOP_GETATTR(vp, &vap, cred, curthread);
+	return (mac_bsdextended_check_vp(cred, vp, MBI_WRITE));
-	if (error)
-		return (error);
-	return (mac_bsdextended_check(cred, vap.va_uid, vap.va_gid,
-	    MBI_WRITE));
 }
 
 static int
 mac_bsdextended_check_vnode_deleteacl(struct ucred *cred, struct vnode *vp,
     struct label *label, acl_type_t type)
 {
-	struct vattr vap;
-	int error;
 
-	if (!mac_bsdextended_enabled)
+	return (mac_bsdextended_check_vp(cred, vp, MBI_ADMIN));
-		return (0);
-
-	error = VOP_GETATTR(vp, &vap, cred, curthread);
-	if (error)
-		return (error);
-	return (mac_bsdextended_check(cred, vap.va_uid, vap.va_gid,
-	    MBI_ADMIN));
 }
 
 static int
 mac_bsdextended_check_vnode_deleteextattr(struct ucred *cred, struct vnode *vp,
     struct label *label, int attrnamespace, const char *name)
 {
-	struct vattr vap;
-	int error;
 
-	if (!mac_bsdextended_enabled)
+	return (mac_bsdextended_check_vp(cred, vp, MBI_WRITE));
-		return (0);
-
-	error = VOP_GETATTR(vp, &vap, cred, curthread);
-	if (error)
-		return (error);
-	return (mac_bsdextended_check(cred, vap.va_uid, vap.va_gid,
-	    MBI_WRITE));
 }
 
 static int
@@ -501,51 +444,24 @@ mac_bsdextended_check_vnode_exec(struct ucred *cred, struct vnode *vp,
     struct label *label, struct image_params *imgp,
     struct label *execlabel)
 {
-	struct vattr vap;
-	int error;
 
-	if (!mac_bsdextended_enabled)
+	return (mac_bsdextended_check_vp(cred, vp, MBI_READ|MBI_EXEC));
-		return (0);
-
-	error = VOP_GETATTR(vp, &vap, cred, curthread);
-	if (error)
-		return (error);
-	return (mac_bsdextended_check(cred, vap.va_uid, vap.va_gid,
-	    MBI_READ|MBI_EXEC));
 }
 
 static int
 mac_bsdextended_check_vnode_getacl(struct ucred *cred, struct vnode *vp,
     struct label *label, acl_type_t type)
 {
-	struct vattr vap;
-	int error;
 
-	if (!mac_bsdextended_enabled)
+	return (mac_bsdextended_check_vp(cred, vp, MBI_STAT));
-		return (0);
-
-	error = VOP_GETATTR(vp, &vap, cred, curthread);
-	if (error)
-		return (error);
-	return (mac_bsdextended_check(cred, vap.va_uid, vap.va_gid,
-	    MBI_STAT));
 }
 
 static int
 mac_bsdextended_check_vnode_getextattr(struct ucred *cred, struct vnode *vp,
     struct label *label, int attrnamespace, const char *name, struct uio *uio)
 {
-	struct vattr vap;
-	int error;
 
-	if (!mac_bsdextended_enabled)
+	return (mac_bsdextended_check_vp(cred, vp, MBI_READ));
-		return (0);
-
-	error = VOP_GETATTR(vp, &vap, cred, curthread);
-	if (error)
-		return (error);
-	return (mac_bsdextended_check(cred, vap.va_uid, vap.va_gid,
-	    MBI_READ));
 }
 
 static int
@@ -553,25 +469,13 @@ mac_bsdextended_check_vnode_link(struct ucred *cred, struct vnode *dvp,
     struct label *dlabel, struct vnode *vp, struct label *label,
     struct componentname *cnp)
 {
-	struct vattr vap;
 	int error;
 
-	if (!mac_bsdextended_enabled)
+	error = mac_bsdextended_check_vp(cred, dvp, MBI_WRITE);
-		return (0);
-
-	error = VOP_GETATTR(dvp, &vap, cred, curthread);
-	if (error)
-		return (error);
-	error = mac_bsdextended_check(cred, vap.va_uid, vap.va_gid,
-	    MBI_WRITE);
 	if (error)
 		return (error);
 
-	error = VOP_GETATTR(vp, &vap, cred, curthread);
+	error = mac_bsdextended_check_vp(cred, vp, MBI_WRITE);
-	if (error)
-		return (error);
-	error = mac_bsdextended_check(cred, vap.va_uid, vap.va_gid,
-	    MBI_WRITE);
 	if (error)
 		return (error);
 	return (0);
@@ -581,84 +485,40 @@ static int
 mac_bsdextended_check_vnode_listextattr(struct ucred *cred, struct vnode *vp,
     struct label *label, int attrnamespace)
 {
-	struct vattr vap;
-	int error;
 
-	if (!mac_bsdextended_enabled)
+	return (mac_bsdextended_check_vp(cred, vp, MBI_READ));
-		return (0);
-
-	error = VOP_GETATTR(vp, &vap, cred, curthread);
-	if (error)
-		return (error);
-	return (mac_bsdextended_check(cred, vap.va_uid, vap.va_gid,
-	    MBI_READ));
 }
 
 static int
 mac_bsdextended_check_vnode_lookup(struct ucred *cred, struct vnode *dvp,
     struct label *dlabel, struct componentname *cnp)
 {
-	struct vattr vap;
-	int error;
 
-	if (!mac_bsdextended_enabled)
+	return (mac_bsdextended_check_vp(cred, dvp, MBI_EXEC));
-		return (0);
-
-	error = VOP_GETATTR(dvp, &vap, cred, curthread);
-	if (error)
-		return (error);
-	return (mac_bsdextended_check(cred, vap.va_uid, vap.va_gid,
-	    MBI_EXEC));
 }
 
 static int
 mac_bsdextended_check_vnode_open(struct ucred *cred, struct vnode *vp,
     struct label *filelabel, int acc_mode)
 {
-	struct vattr vap;
-	int error;
 
-	if (!mac_bsdextended_enabled)
+	return (mac_bsdextended_check_vp(cred, vp, acc_mode));
-		return (0);
-
-	error = VOP_GETATTR(vp, &vap, cred, curthread);
-	if (error)
-		return (error);
-	return (mac_bsdextended_check(cred, vap.va_uid, vap.va_gid, acc_mode));
 }
 
 static int
 mac_bsdextended_check_vnode_readdir(struct ucred *cred, struct vnode *dvp,
     struct label *dlabel)
 {
-	struct vattr vap;
-	int error;
 
-	if (!mac_bsdextended_enabled)
+	return (mac_bsdextended_check_vp(cred, dvp, MBI_READ));
-		return (0);
-
-	error = VOP_GETATTR(dvp, &vap, cred, curthread);
-	if (error)
-		return (error);
-	return (mac_bsdextended_check(cred, vap.va_uid, vap.va_gid,
-	    MBI_READ));
 }
 
 static int
 mac_bsdextended_check_vnode_readdlink(struct ucred *cred, struct vnode *vp,
     struct label *label)
 {
-	struct vattr vap;
-	int error;
 
-	if (!mac_bsdextended_enabled)
+	return (mac_bsdextended_check_vp(cred, vp, MBI_READ));
-		return (0);
-
-	error = VOP_GETATTR(vp, &vap, cred, curthread);
-	if (error)
-		return (error);
-	return (mac_bsdextended_check(cred, vap.va_uid, vap.va_gid,
-	    MBI_READ));
 }
 
 static int
@@ -666,24 +526,12 @@ mac_bsdextended_check_vnode_rename_from(struct ucred *cred, struct vnode *dvp,
     struct label *dlabel, struct vnode *vp, struct label *label,
     struct componentname *cnp)
 {
-	struct vattr vap;
 	int error;
 
-	if (!mac_bsdextended_enabled)
+	error = mac_bsdextended_check_vp(cred, dvp, MBI_WRITE);
-		return (0);
-
-	error = VOP_GETATTR(dvp, &vap, cred, curthread);
 	if (error)
 		return (error);
-	error = mac_bsdextended_check(cred, vap.va_uid, vap.va_gid,
+	error = mac_bsdextended_check_vp(cred, vp, MBI_WRITE);
-	    MBI_WRITE);
-	if (error)
-		return (error);
-	error = VOP_GETATTR(vp, &vap, cred, curthread);
-	if (error)
-		return (error);
-	error = mac_bsdextended_check(cred, vap.va_uid, vap.va_gid,
-	    MBI_WRITE);
 
 	return (error);
 }
@@ -693,27 +541,14 @@ mac_bsdextended_check_vnode_rename_to(struct ucred *cred, struct vnode *dvp,
     struct label *dlabel, struct vnode *vp, struct label *label, int samedir,
     struct componentname *cnp)
 {
-	struct vattr vap;
 	int error;
 
-	if (!mac_bsdextended_enabled)
+	error = mac_bsdextended_check_vp(cred, dvp, MBI_WRITE);
-		return (0);
-
-	error = VOP_GETATTR(dvp, &vap, cred, curthread);
-	if (error)
-		return (error);
-	error = mac_bsdextended_check(cred, vap.va_uid, vap.va_gid,
-	    MBI_WRITE);
 	if (error)
 		return (error);
 
-	if (vp != NULL) {
+	if (vp != NULL)
-		error = VOP_GETATTR(vp, &vap, cred, curthread);
+		error = mac_bsdextended_check_vp(cred, vp, MBI_WRITE);
-		if (error)
-			return (error);
-		error = mac_bsdextended_check(cred, vap.va_uid, vap.va_gid,
-		    MBI_WRITE);
-	}
 
 	return (error);
 }
@@ -722,136 +557,64 @@ static int
 mac_bsdextended_check_vnode_revoke(struct ucred *cred, struct vnode *vp,
     struct label *label)
 {
-	struct vattr vap;
-	int error;
 
-	if (!mac_bsdextended_enabled)
+	return (mac_bsdextended_check_vp(cred, vp, MBI_ADMIN));
-		return (0);
-
-	error = VOP_GETATTR(vp, &vap, cred, curthread);
-	if (error)
-		return (error);
-	return (mac_bsdextended_check(cred, vap.va_uid, vap.va_gid,
-	    MBI_ADMIN));
 }
 
 static int
 mac_bsdextended_check_setacl_vnode(struct ucred *cred, struct vnode *vp,
     struct label *label, acl_type_t type, struct acl *acl)
 {
-	struct vattr vap;
-	int error;
 
-	if (!mac_bsdextended_enabled)
+	return (mac_bsdextended_check_vp(cred, vp, MBI_ADMIN));
-		return (0);
-
-	error = VOP_GETATTR(vp, &vap, cred, curthread);
-	if (error)
-		return (error);
-	return (mac_bsdextended_check(cred, vap.va_uid, vap.va_gid,
-	    MBI_ADMIN));
 }
 
 static int
 mac_bsdextended_check_vnode_setextattr(struct ucred *cred, struct vnode *vp,
     struct label *label, int attrnamespace, const char *name, struct uio *uio)
 {
-	struct vattr vap;
-	int error;
 
-	if (!mac_bsdextended_enabled)
+	return (mac_bsdextended_check_vp(cred, vp, MBI_WRITE));
-		return (0);
-
-	error = VOP_GETATTR(vp, &vap, cred, curthread);
-	if (error)
-		return (error);
-	return (mac_bsdextended_check(cred, vap.va_uid, vap.va_gid,
-	    MBI_WRITE));
 }
 
 static int
 mac_bsdextended_check_vnode_setflags(struct ucred *cred, struct vnode *vp,
     struct label *label, u_long flags)
 {
-	struct vattr vap;
-	int error;
 
-	if (!mac_bsdextended_enabled)
+	return (mac_bsdextended_check_vp(cred, vp, MBI_ADMIN));
-		return (0);
-
-	error = VOP_GETATTR(vp, &vap, cred, curthread);
-	if (error)
-		return (error);
-	return (mac_bsdextended_check(cred, vap.va_uid, vap.va_gid,
-	    MBI_ADMIN));
 }
 
 static int
 mac_bsdextended_check_vnode_setmode(struct ucred *cred, struct vnode *vp,
     struct label *label, mode_t mode)
 {
-	struct vattr vap;
-	int error;
 
-	if (!mac_bsdextended_enabled)
+	return (mac_bsdextended_check_vp(cred, vp, MBI_ADMIN));
-		return (0);
-
-	error = VOP_GETATTR(vp, &vap, cred, curthread);
-	if (error)
-		return (error);
-	return (mac_bsdextended_check(cred, vap.va_uid, vap.va_gid,
-	    MBI_ADMIN));
 }
 
 static int
 mac_bsdextended_check_vnode_setowner(struct ucred *cred, struct vnode *vp,
     struct label *label, uid_t uid, gid_t gid)
 {
-	struct vattr vap;
-	int error;
 
-	if (!mac_bsdextended_enabled)
+	return (mac_bsdextended_check_vp(cred, vp, MBI_ADMIN));
-		return (0);
-
-	error = VOP_GETATTR(vp, &vap, cred, curthread);
-	if (error)
-		return (error);
-	return (mac_bsdextended_check(cred, vap.va_uid, vap.va_gid,
-	   MBI_ADMIN));
 }
 
 static int
 mac_bsdextended_check_vnode_setutimes(struct ucred *cred, struct vnode *vp,
     struct label *label, struct timespec atime, struct timespec utime)
 {
-	struct vattr vap;
-	int error;
 
-	if (!mac_bsdextended_enabled)
+	return (mac_bsdextended_check_vp(cred, vp, MBI_ADMIN));
-		return (0);
-
-	error = VOP_GETATTR(vp, &vap, cred, curthread);
-	if (error)
-		return (error);
-	return (mac_bsdextended_check(cred, vap.va_uid, vap.va_gid,
-	    MBI_ADMIN));
 }
 
 static int
 mac_bsdextended_check_vnode_stat(struct ucred *active_cred,
     struct ucred *file_cred, struct vnode *vp, struct label *label)
 {
-	struct vattr vap;
-	int error;
 
-	if (!mac_bsdextended_enabled)
+	return (mac_bsdextended_check_vp(active_cred, vp, MBI_STAT));
-		return (0);
-
-	error = VOP_GETATTR(vp, &vap, active_cred, curthread);
-	if (error)
-		return (error);
-	return (mac_bsdextended_check(active_cred, vap.va_uid, vap.va_gid,
-	    MBI_STAT));
 }
 
 static struct mac_policy_ops mac_bsdextended_ops =