Second pass commit to introduce new ACL and Extended Attribute system

calls, vnops, vfsops, both in /kern, and to individual file systems that
require a vfsop_ array entry.

Reviewed by:	eivind

1 files changed, 281 insertions, 0 deletions

diff --git a/sys/kern/kern_acl.c b/sys/kern/kern_acl.c
new file mode 100644
index 0000000..5df8d6a
--- /dev/null
+++ b/sys/kern/kern_acl.c
@@ -0,0 +1,281 @@
+/*-
+ * Copyright (c) 1999 Robert N. M. Watson
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ *
+ * $FreeBSD$
+ */
+
+/*
+ * Generic routines to support file system ACLs, at a syntactic level
+ * Semantics are the responsibility of the underlying file system
+ */
+
+#include <sys/param.h>
+#include <sys/systm.h>
+#include <sys/sysproto.h>
+#include <sys/kernel.h>
+#include <sys/malloc.h>
+#include <sys/vnode.h>
+#include <sys/lock.h>
+#include <sys/namei.h>
+#include <sys/file.h>
+#include <sys/proc.h>
+#include <sys/sysent.h>
+#include <sys/errno.h>
+#include <sys/stat.h>
+#include <sys/acl.h>
+#include <vm/vm_zone.h>
+
+static MALLOC_DEFINE(M_ACL, "acl", "access control list");
+
+static int vacl_set_acl(struct proc *p, struct vnode *vp, acl_type_t type,
+    struct acl *aclp);
+static int vacl_get_acl(struct proc *p, struct vnode *vp, acl_type_t type,
+    struct acl *aclp);
+static int vacl_aclcheck(struct proc *p, struct vnode *vp, acl_type_t type,
+    struct acl *aclp);
+
+/*
+ * These calls wrap the real vnode operations, and are called by the 
+ * syscall code once the syscall has converted the path or file
+ * descriptor to a vnode (unlocked).  The aclp pointer is assumed
+ * still to point to userland, so this should not be consumed within
+ * the kernel except by syscall code.  Other code should directly
+ * invoke VOP_{SET,GET}ACL.
+ */
+
+/*
+ * Given a vnode, set its ACL.
+ */
+static int
+vacl_set_acl(struct proc *p, struct vnode *vp, acl_type_t type,
+       struct acl *aclp)
+{
+	struct acl inkernacl;
+	int error;
+
+	error = copyin(aclp, &inkernacl, sizeof(struct acl));
+	if (error)
+		return(error);
+	VOP_LEASE(vp, p, p->p_ucred, LEASE_WRITE);
+	vn_lock(vp, LK_EXCLUSIVE | LK_RETRY, p);
+	error = VOP_SETACL(vp, type, &inkernacl, p->p_ucred, p);
+	VOP_UNLOCK(vp, 0, p);
+	return(error);
+}
+
+/*
+ * Given a vnode, get its ACL.
+ */
+static int
+vacl_get_acl(struct proc *p, struct vnode *vp, acl_type_t type,
+    struct acl *aclp)
+{
+	struct acl inkernelacl;
+	int error;
+
+	error = VOP_GETACL(vp, type, &inkernelacl, p->p_ucred, p);
+	if (error == 0)
+		error = copyout(&inkernelacl, aclp, sizeof(struct acl));
+	return (error);
+}
+
+/*
+ * Given a vnode, delete its ACL.
+ */
+static int
+vacl_delete(struct proc *p, struct vnode *vp, acl_type_t type)
+{
+	int error;
+
+	VOP_LEASE(vp, p, p->p_ucred, LEASE_WRITE);
+	vn_lock(vp, LK_EXCLUSIVE | LK_RETRY, p);
+	error = VOP_SETACL(vp, ACL_TYPE_DEFAULT, 0, p->p_ucred, p);
+	VOP_UNLOCK(vp, 0, p);
+	return (error);
+}
+
+/*
+ * Given a vnode, check whether an ACL is appropriate for it
+ */
+static int
+vacl_aclcheck(struct proc *p, struct vnode *vp, acl_type_t type,
+    struct acl *aclp)
+{
+	struct acl inkernelacl;
+	int error;
+
+	error = copyin(aclp, &inkernelacl, sizeof(struct acl));
+	if (error)
+		return(error);
+	error = VOP_ACLCHECK(vp, type, &inkernelacl, p->p_ucred, p);
+	return (error);
+}
+
+/*
+ * syscalls -- convert the path/fd to a vnode, and call vacl_whatever.
+ * Don't need to lock, as the vacl_ code will get/release any locks
+ * required.
+ */
+
+/*
+ * Given a file path, get an ACL for it
+ */
+int
+acl_syscall_get_file(struct proc *p, struct acl_syscall_get_file_args *uap)
+{
+	struct nameidata nd;
+	int error;
+
+	/* what flags are required here -- possible not LOCKLEAF? */
+	NDINIT(&nd, LOOKUP, FOLLOW, UIO_USERSPACE, SCARG(uap, path), p);
+	error = namei(&nd);
+	if (error)
+		return(error);
+	error = vacl_get_acl(p, nd.ni_vp, SCARG(uap, type), SCARG(uap, aclp));
+	NDFREE(&nd, 0);
+	return (error);
+}
+
+/*
+ * Given a file path, set an ACL for it
+ */
+int
+acl_syscall_set_file(struct proc *p, struct acl_syscall_set_file_args *uap)
+{
+	struct nameidata nd;
+	int error;
+
+	NDINIT(&nd, LOOKUP, FOLLOW, UIO_USERSPACE, SCARG(uap, path), p);
+	error = namei(&nd);
+	if (error)
+		return(error);
+	error = vacl_set_acl(p, nd.ni_vp, SCARG(uap, type), SCARG(uap, aclp));
+	NDFREE(&nd, 0);
+	return (error);
+}
+
+/*
+ * Given a file descriptor, get an ACL for it
+ */
+int
+acl_syscall_get_fd(struct proc *p, struct acl_syscall_get_fd_args *uap)
+{
+	struct file *fp;
+	int error;
+
+	error = getvnode(p->p_fd, SCARG(uap, filedes), &fp);
+	if (error)
+		return(error);
+	return vacl_get_acl(p, (struct vnode *)fp->f_data, SCARG(uap, type),
+	    SCARG(uap, aclp));
+}
+
+/*
+ * Given a file descriptor, set an ACL for it
+ */
+int
+acl_syscall_set_fd(struct proc *p, struct acl_syscall_set_fd_args *uap)
+{
+	struct file *fp;
+	int error;
+
+	error = getvnode(p->p_fd, SCARG(uap, filedes), &fp);
+	if (error)
+		return(error);
+	return vacl_set_acl(p, (struct vnode *)fp->f_data, SCARG(uap, type),
+	    SCARG(uap, aclp));
+}
+
+/*
+ * Given a file path, delete an ACL from it.
+ */
+int
+acl_syscall_delete_file(struct proc *p,
+			struct acl_syscall_delete_file_args *uap)
+{
+	struct nameidata nd;
+	int error;
+
+	NDINIT(&nd, LOOKUP, FOLLOW, UIO_USERSPACE, SCARG(uap, path), p);
+	error = namei(&nd);
+	if (error)
+		return(error);
+	error = vacl_delete(p, nd.ni_vp, SCARG(uap, type));
+	NDFREE(&nd, 0);
+	return (error);
+}
+
+/*
+ * Given a file path, delete an ACL from it.
+ */
+int
+acl_syscall_delete_fd(struct proc *p,
+    struct acl_syscall_delete_fd_args *uap)
+{
+	struct file *fp;
+	int error;
+
+	error = getvnode(p->p_fd, SCARG(uap, filedes), &fp);
+	if (error)
+		return(error);
+	error = vacl_delete(p, (struct vnode *)fp->f_data, SCARG(uap, type));
+	return (error);
+}
+
+/*
+ * Given a file path, check an ACL for it
+ */
+int
+acl_syscall_aclcheck_file(struct proc *p,
+			  struct acl_syscall_aclcheck_file_args *uap)
+{
+	struct nameidata	nd;
+	int	error;
+
+	NDINIT(&nd, LOOKUP, FOLLOW, UIO_USERSPACE, SCARG(uap, path), p);
+	error = namei(&nd);
+	if (error)
+		return(error);
+	error = vacl_aclcheck(p, nd.ni_vp, SCARG(uap, type), SCARG(uap, aclp));
+	NDFREE(&nd, 0);
+	return (error);
+}
+
+/*
+ * Given a file descriptor, check an ACL for it
+ */
+int
+acl_syscall_aclcheck_fd(struct proc *p,
+    struct acl_syscall_aclcheck_fd_args *uap)
+{
+	struct file *fp;
+	int error;
+
+	error = getvnode(p->p_fd, SCARG(uap, filedes), &fp);
+	if (error)
+		return(error);
+	return vacl_aclcheck(p, (struct vnode *)fp->f_data, SCARG(uap, type),
+	    SCARG(uap, aclp));
+}