First (incomplete) cut of this module. Based on Volker's original work.

Jeremy.
(cherry picked from commit b1c55f5616b16a698a751a90fb209e0549332dc7)

1 files changed, 315 insertions, 0 deletions

diff --git a/source/modules/vfs_acl_xattr.c b/source/modules/vfs_acl_xattr.c
new file mode 100644
index 00000000000..31ffe340648
--- /dev/null
+++ b/source/modules/vfs_acl_xattr.c
@@ -0,0 +1,315 @@
+/*
+ * Store Windows ACLs in xattrs.
+ *
+ * Copyright (C) Volker Lendecke, 2008
+ * Copyright (C) Jeremy Allison, 2008
+ *
+ * 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; either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include "includes.h"
+#include "librpc/gen_ndr/xattr.h"
+#include "librpc/gen_ndr/ndr_xattr.h"
+
+#undef DBGC_CLASS
+#define DBGC_CLASS DBGC_VFS
+
+static NTSTATUS parse_acl_blob(const DATA_BLOB *pblob,
+				const struct timespec cts,
+				uint32 security_info,
+				struct security_descriptor **ppdesc)
+{
+	TALLOC_CTX *ctx = talloc_tos();
+	struct xattr_NTACL xacl;
+	enum ndr_err_code ndr_err;
+	size_t sd_size;
+	struct timespec ts;
+
+	ndr_err = ndr_pull_struct_blob(pblob, ctx, &xacl,
+			(ndr_pull_flags_fn_t)ndr_pull_xattr_NTACL);
+
+	if (!NDR_ERR_CODE_IS_SUCCESS(ndr_err)) {
+		DEBUG(5, ("parse_acl_blob: ndr_pull_xattr_NTACL failed: %s\n",
+			ndr_errstr(ndr_err)));
+		return ndr_map_error2ntstatus(ndr_err);;
+	}
+
+	if (xacl.version != 2) {
+		return NT_STATUS_REVISION_MISMATCH;
+	}
+
+	/*
+	 * Check that the ctime timestamp is ealier
+	 * than the stored timestamp.
+	 */
+
+	ts = nt_time_to_unix_timespec(&xacl.info.sd_ts->last_changed);
+
+	if (timespec_compare(&cts, &ts) > 0) {
+		DEBUG(5, ("parse_acl_blob: stored ACL out of date.\n"));
+		return NT_STATUS_EA_CORRUPT_ERROR;
+	}
+
+	*ppdesc = make_sec_desc(ctx, SEC_DESC_REVISION, SEC_DESC_SELF_RELATIVE,
+			(security_info & OWNER_SECURITY_INFORMATION)
+			? xacl.info.sd_ts->sd->owner_sid : NULL,
+			(security_info & GROUP_SECURITY_INFORMATION)
+			? xacl.info.sd_ts->sd->group_sid : NULL,
+			(security_info & SACL_SECURITY_INFORMATION)
+			? xacl.info.sd_ts->sd->sacl : NULL,
+			(security_info & DACL_SECURITY_INFORMATION)
+			? xacl.info.sd_ts->sd->dacl : NULL,
+			&sd_size);
+
+	TALLOC_FREE(xacl.info.sd);
+
+	return (*ppdesc != NULL) ? NT_STATUS_OK : NT_STATUS_NO_MEMORY;
+}
+
+static NTSTATUS get_acl_blob(vfs_handle_struct *handle,
+			TALLOC_CTX *ctx,
+			files_struct *fsp,
+			const char *name,
+			DATA_BLOB *pblob)
+{
+	size_t size = 1024;
+	uint8_t *val = NULL;
+	uint8_t *tmp;
+	ssize_t sizeret;
+	int saved_errno;
+
+	ZERO_STRUCTP(pblob);
+
+  again:
+
+	tmp = TALLOC_REALLOC_ARRAY(ctx, val, uint8_t, size);
+	if (tmp == NULL) {
+		TALLOC_FREE(val);
+		return NT_STATUS_NO_MEMORY;
+	}
+	val = tmp;
+
+	become_root();
+	if (fsp) {
+		sizeret = SMB_VFS_FGETXATTR(fsp, XATTR_NTACL_NAME, val, size);
+	} else {
+		sizeret = SMB_VFS_GETXATTR(handle->conn, name,
+					XATTR_NTACL_NAME, val, size);
+	}
+	if (sizeret == -1) {
+		saved_errno = errno;
+	}
+	unbecome_root();
+
+	/* Max ACL size is 65536 bytes. */
+	if (sizeret == -1) {
+		errno = saved_errno;
+		if ((errno == ERANGE) && (size != 65536)) {
+			/* Too small, try again. */
+			size = 65536;
+			goto again;
+		}
+
+		/* Real error - exit here. */
+		TALLOC_FREE(val);
+		return map_nt_error_from_unix(errno);
+	}
+
+	pblob->data = val;
+	pblob->length = sizeret;
+	return NT_STATUS_OK;
+}
+
+static int mkdir_acl_xattr(vfs_handle_struct *handle,  const char *path, mode_t mode)
+{
+	return SMB_VFS_NEXT_MKDIR(handle, path, mode);
+}
+
+static int rmdir_acl_xattr(vfs_handle_struct *handle,  const char *path)
+{
+	return SMB_VFS_NEXT_RMDIR(handle, path);
+}
+
+static int open_acl_xattr(vfs_handle_struct *handle,  const char *fname, files_struct *fsp, int flags, mode_t mode)
+{
+	return SMB_VFS_NEXT_OPEN(handle, fname, fsp, flags, mode);
+}
+
+static int unlink_acl_xattr(vfs_handle_struct *handle,  const char *fname)
+{
+	return SMB_VFS_NEXT_UNLINK(handle, fname);
+}
+
+static NTSTATUS get_nt_acl_xattr_internal(vfs_handle_struct *handle,
+					files_struct *fsp,
+					const char *name,
+				        uint32 security_info,
+					SEC_DESC **ppdesc)
+{
+	TALLOC_CTX *ctx = talloc_tos();
+	DATA_BLOB blob;
+	SMB_STRUCT_STAT sbuf;
+	NTSTATUS status;
+
+	if (fsp && name == NULL) {
+		name = fsp->fsp_name;
+	}
+
+	DEBUG(10, ("get_nt_acl_xattr_internal: name=%s\n", name));
+
+	status = get_acl_blob(ctx, handle, fsp, name, &blob);
+	if (!NT_STATUS_IS_OK(status)) {
+		DEBUG(10, ("get_acl_blob returned %s\n", nt_errstr(status)));
+		return status;
+	}
+
+	if (fsp && fsp->fh->fd != -1) {
+		if (SMB_VFS_FSTAT(fsp, &sbuf) == -1) {
+			return map_nt_error_from_unix(errno);
+		}
+	} else {
+		if (SMB_VFS_STAT(handle->conn, name, &sbuf) == -1) {
+			return map_nt_error_from_unix(errno);
+		}
+	}
+
+	status = parse_acl_blob(&blob, get_ctimespec(&sbuf),
+			security_info, ppdesc);
+	if (!NT_STATUS_IS_OK(status)) {
+		DEBUG(10, ("parse_acl_blob returned %s\n",
+				nt_errstr(status)));
+		return status;
+	}
+
+	TALLOC_FREE(blob.data);
+	return status;
+}
+
+static NTSTATUS fget_nt_acl_xattr(vfs_handle_struct *handle, files_struct *fsp,
+        uint32 security_info, SEC_DESC **ppdesc)
+{
+	NTSTATUS status = get_nt_acl_xattr_internal(handle, fsp,
+				NULL, security_info, ppdesc);
+	if (NT_STATUS_IS_OK(status)) {
+		return NT_STATUS_OK;
+	}
+	return SMB_VFS_NEXT_FGET_NT_ACL(handle, fsp,
+			security_info, ppdesc);
+}
+
+static NTSTATUS get_nt_acl_xattr(vfs_handle_struct *handle,
+        const char *name, uint32 security_info, SEC_DESC **ppdesc)
+{
+	NTSTATUS status = get_nt_acl_xattr_internal(handle, NULL,
+				name, security_info, ppdesc);
+	if (NT_STATUS_IS_OK(status)) {
+		return NT_STATUS_OK;
+	}
+	return SMB_VFS_NEXT_GET_NT_ACL(handle, name,
+			security_info, ppdesc);
+}
+
+static NTSTATUS create_acl_blob(SEC_DESC *psd, DATA_BLOB *pblob)
+{
+	struct xattr_NTACL xacl;
+	enum ndr_err_code ndr_err;
+	TALLOC_CTX *ctx = talloc_tos();
+	struct timespec curr = timespec_current();
+
+	/* Horrid hack as setting an xattr changes the ctime
+ 	 * on Linux. This gives a race of 1 second during
+ 	 * which we would not see a POSIX ACL set.
+ 	 */
+	curr.tv_sec += 1;
+
+	xacl.version = 2;
+	xacl.info.sd_ts->sd = psd;
+	unix_timespec_to_nt_time(&xacl.info.sd_ts->last_changed, curr);
+
+	ndr_err = ndr_push_struct_blob(
+			pblob, ctx, &xacl,
+			(ndr_push_flags_fn_t)ndr_push_xattr_NTACL);
+
+	if (!NDR_ERR_CODE_IS_SUCCESS(ndr_err)) {
+		DEBUG(5, ("create_acl_blob: ndr_push_xattr_NTACL failed: %s\n",
+			ndr_errstr(ndr_err)));
+		return ndr_map_error2ntstatus(ndr_err);;
+	}
+
+	return NT_STATUS_OK;
+}
+
+static NTSTATUS store_acl_blob(files_struct *fsp,
+				DATA_BLOB *pblob)
+{
+	int ret;
+	int saved_errno;
+
+	become_root();
+	ret = SMB_VFS_FSETXATTR(fsp, XATTR_NTACL_NAME,
+			pblob->data, pblob->length, 0);
+	if (ret) {
+		saved_errno = errno;
+	}
+	unbecome_root();
+	if (ret) {
+		errno = saved_errno;
+		DEBUG(5, ("store_acl_blob: fsetxattr failed for file %s "
+			"with error %s\n",
+			fsp->fsp_name,
+			strerror(errno) ));
+		return map_nt_error_from_unix(errno);
+	}
+	return NT_STATUS_OK;
+}
+
+static NTSTATUS fset_nt_acl_xattr(vfs_handle_struct *handle, files_struct *fsp,
+        uint32 security_info_sent, SEC_DESC *psd)
+{
+	NTSTATUS status;
+	DATA_BLOB blob;
+
+	status = SMB_VFS_NEXT_FSET_NT_ACL(handle, fsp, security_info_sent, psd);
+	if (!NT_STATUS_IS_OK(status)) {
+		return status;
+	}
+
+	create_acl_blob(psd, &blob);
+	store_acl_blob(fsp, &blob);
+
+	return NT_STATUS_OK;
+}
+
+/* VFS operations structure */
+
+static vfs_op_tuple skel_op_tuples[] =
+{
+	{SMB_VFS_OP(mkdir_acl_xattr), SMB_VFS_OP_MKDIR, SMB_VFS_LAYER_TRANSPARENT},
+	{SMB_VFS_OP(rmdir_acl_xattr), SMB_VFS_OP_RMDIR, SMB_VFS_LAYER_TRANSPARENT},
+	{SMB_VFS_OP(open_acl_xattr),  SMB_VFS_OP_OPEN,  SMB_VFS_LAYER_TRANSPARENT},
+	{SMB_VFS_OP(unlink_acl_xattr),SMB_VFS_OP_UNLINK,SMB_VFS_LAYER_TRANSPARENT},
+
+        /* NT File ACL operations */
+
+	{SMB_VFS_OP(fget_nt_acl_xattr),SMB_VFS_OP_FGET_NT_ACL,SMB_VFS_LAYER_TRANSPARENT},
+	{SMB_VFS_OP(get_nt_acl_xattr), SMB_VFS_OP_GET_NT_ACL, SMB_VFS_LAYER_TRANSPARENT},
+	{SMB_VFS_OP(fset_nt_acl_xattr),SMB_VFS_OP_FSET_NT_ACL,SMB_VFS_LAYER_TRANSPARENT},
+
+        {SMB_VFS_OP(NULL), SMB_VFS_OP_NOOP, SMB_VFS_LAYER_NOOP}
+};
+
+NTSTATUS vfs_acl_xattr_init(void)
+{
+	return smb_register_vfs(SMB_VFS_INTERFACE_VERSION, "acl_xattr", skel_op_tuples);
+}