s3-vfs: initial work on posix:eadb module

This is a module that, like vfs_xattr_tdb, stores extended attributes
in a DB on disk.  This uses the format needed to support the
posix:eadb smb.conf option.

Andrew Bartlett

2 files changed, 441 insertions, 0 deletions

diff --git a/source3/modules/vfs_posix_eadb.c b/source3/modules/vfs_posix_eadb.c
new file mode 100644
index 0000000000..edc295bff0
--- /dev/null
+++ b/source3/modules/vfs_posix_eadb.c
@@ -0,0 +1,433 @@
+/*
+ * Store posix-level xattrs in a tdb (posix:eadb format)
+ *
+ * Copyright (C) Andrew Bartlett, 2011
+ *
+ * Based on vfs_xattr_tdb by
+ * Copyright (C) Volker Lendecke, 2007
+ *
+ * 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 "system/filesys.h"
+#include "smbd/smbd.h"
+#include "librpc/gen_ndr/xattr.h"
+#include "librpc/gen_ndr/ndr_xattr.h"
+#include "../librpc/gen_ndr/ndr_netlogon.h"
+#include "tdb_compat.h"
+#include "lib/tdb_wrap/tdb_wrap.h"
+#include "ntvfs/posix/posix_eadb.h"
+#include "param/param.h"
+#include "lib/param/loadparm.h"
+
+#undef DBGC_CLASS
+#define DBGC_CLASS DBGC_VFS
+
+/*
+ * Worker routine for getxattr and fgetxattr
+ */
+
+static ssize_t posix_eadb_getattr(struct tdb_wrap *db_ctx,
+				 const char *fname, int fd,
+				 const char *name, void *value, size_t size)
+{
+	ssize_t result = -1;
+	NTSTATUS status;
+	DATA_BLOB blob;
+
+	DEBUG(10, ("posix_eadb_getattr called for file %s/fd %d, name %s\n",
+		   fname, fd, name));
+
+	status = pull_xattr_blob_tdb_raw(db_ctx, talloc_tos(), name, fname, fd, size, &blob);
+
+	if (!NT_STATUS_IS_OK(status)) {
+		DEBUG(10, ("posix_eadb_fetch_attrs failed: %s\n",
+			   nt_errstr(status)));
+		errno = EINVAL;
+		return -1;
+	}
+
+	if (blob.length > size) {
+		errno = ERANGE;
+		goto fail;
+	}
+
+	memcpy(value, blob.data, blob.length);
+	result = blob.length;
+
+ fail:
+	return result;
+}
+
+static ssize_t posix_eadb_getxattr(struct vfs_handle_struct *handle,
+				  const char *path, const char *name,
+				  void *value, size_t size)
+{
+	struct tdb_wrap *db;
+
+	SMB_VFS_HANDLE_GET_DATA(handle, db, struct tdb_wrap, return -1);
+
+	return posix_eadb_getattr(db, path, -1, name, value, size);
+}
+
+static ssize_t posix_eadb_fgetxattr(struct vfs_handle_struct *handle,
+				   struct files_struct *fsp,
+				   const char *name, void *value, size_t size)
+{
+	struct tdb_wrap *db;
+
+	SMB_VFS_HANDLE_GET_DATA(handle, db, struct tdb_wrap, return -1);
+
+	return posix_eadb_getattr(db, fsp->fsp_name->base_name, fsp->fh->fd, name, value, size);
+}
+
+/*
+ * Worker routine for setxattr and fsetxattr
+ */
+
+static int posix_eadb_setattr(struct tdb_wrap *db_ctx,
+			     const char *fname, int fd, const char *name,
+			     const void *value, size_t size, int flags)
+{
+	NTSTATUS status;
+	DATA_BLOB data = data_blob_const(value, size);
+
+	DEBUG(10, ("posix_eadb_setattr called for file %s/fd %d, name %s\n",
+		   fname, fd, name));
+
+	status = push_xattr_blob_tdb_raw(db_ctx, name, fname, fd, &data);
+
+	if (!NT_STATUS_IS_OK(status)) {
+		DEBUG(10, ("push_xattr_blob_tdb_raw failed: %s\n",
+			   nt_errstr(status)));
+		return -1;
+	}
+
+	return 0;
+}
+
+static int posix_eadb_setxattr(struct vfs_handle_struct *handle,
+			      const char *path, const char *name,
+			      const void *value, size_t size, int flags)
+{
+	struct tdb_wrap *db;
+
+	SMB_VFS_HANDLE_GET_DATA(handle, db, struct tdb_wrap, return -1);
+
+	return posix_eadb_setattr(db, path, -1, name, value, size, flags);
+}
+
+static int posix_eadb_fsetxattr(struct vfs_handle_struct *handle,
+			       struct files_struct *fsp,
+			       const char *name, const void *value,
+			       size_t size, int flags)
+{
+	struct tdb_wrap *db;
+
+	SMB_VFS_HANDLE_GET_DATA(handle, db, struct tdb_wrap, return -1);
+
+	return posix_eadb_setattr(db, fsp->fsp_name->base_name, fsp->fh->fd, name, value, size, flags);
+}
+
+/*
+ * Worker routine for listxattr and flistxattr
+ */
+
+static ssize_t posix_eadb_listattr(struct tdb_wrap *db_ctx,
+				  const char *fname, int fd, char *list,
+				  size_t size)
+{
+	DATA_BLOB blob;
+	NTSTATUS status;
+
+	status = list_posix_eadb_raw(db_ctx, talloc_tos(), fname, fd, &blob);
+
+	if (!NT_STATUS_IS_OK(status)) {
+		DEBUG(10, ("posix_eadb_fetch_attrs failed: %s\n",
+			   nt_errstr(status)));
+		errno = EINVAL;
+		return -1;
+	}
+
+	if (blob.length > size) {
+		errno = ERANGE;
+		TALLOC_FREE(blob.data);
+		return -1;
+	}
+
+	memcpy(list, blob.data, blob.length);
+
+	TALLOC_FREE(blob.data);
+	return blob.length;
+}
+
+static ssize_t posix_eadb_listxattr(struct vfs_handle_struct *handle,
+				   const char *path, char *list, size_t size)
+{
+	struct tdb_wrap *db;
+
+	SMB_VFS_HANDLE_GET_DATA(handle, db, struct tdb_wrap, return -1);
+
+	return posix_eadb_listattr(db, path, -1, list, size);
+}
+
+static ssize_t posix_eadb_flistxattr(struct vfs_handle_struct *handle,
+				    struct files_struct *fsp, char *list,
+				    size_t size)
+{
+	struct tdb_wrap *db;
+
+	SMB_VFS_HANDLE_GET_DATA(handle, db, struct tdb_wrap, return -1);
+
+	return posix_eadb_listattr(db, fsp->fsp_name->base_name, fsp->fh->fd, list, size);
+}
+
+/*
+ * Worker routine for removexattr and fremovexattr
+ */
+
+static int posix_eadb_removeattr(struct tdb_wrap *db_ctx,
+				const char *fname, int fd, const char *name)
+{
+	NTSTATUS status;
+
+	status = delete_posix_eadb_raw(db_ctx, name, fname, fd);
+
+	if (!NT_STATUS_IS_OK(status)) {
+		DEBUG(10, ("delete_posix_eadb_raw failed: %s\n",
+			   nt_errstr(status)));
+		return -1;
+	}
+	return 0;
+}
+
+static int posix_eadb_removexattr(struct vfs_handle_struct *handle,
+				 const char *path, const char *name)
+{
+	struct tdb_wrap *db;
+
+	SMB_VFS_HANDLE_GET_DATA(handle, db, struct tdb_wrap, return -1);
+
+	return posix_eadb_removeattr(db, path, -1, name);
+}
+
+static int posix_eadb_fremovexattr(struct vfs_handle_struct *handle,
+				  struct files_struct *fsp, const char *name)
+{
+	struct tdb_wrap *db;
+
+	SMB_VFS_HANDLE_GET_DATA(handle, db, struct tdb_wrap, return -1);
+
+	return posix_eadb_removeattr(db, fsp->fsp_name->base_name, fsp->fh->fd, name);
+}
+
+/*
+ * Open the tdb file upon VFS_CONNECT
+ */
+
+static bool posix_eadb_init(int snum, struct tdb_wrap **p_db)
+{
+	struct tdb_wrap *db;
+	struct loadparm_context *lp_ctx;
+	const char *eadb = lp_parm_const_string(snum, "posix", "eadb", NULL);
+
+	if (!eadb) {
+		DEBUG(0, ("Can not use vfs_posix_eadb without posix:eadb set\n"));
+		return false;
+	}
+
+	lp_ctx = loadparm_init_s3(NULL, loadparm_s3_context());
+
+	become_root();
+	db = tdb_wrap_open(NULL, eadb, 50000,
+			   TDB_DEFAULT, O_RDWR|O_CREAT, 0600,
+			   lp_ctx);
+
+	unbecome_root();
+	talloc_unlink(NULL, lp_ctx);
+	/* now we know dbname is not NULL */
+
+	if (db == NULL) {
+#if defined(ENOTSUP)
+		errno = ENOTSUP;
+#else
+		errno = ENOSYS;
+#endif
+		return false;
+	}
+
+	*p_db = db;
+	return true;
+}
+
+/*
+ * On unlink we need to delete the tdb record
+ */
+static int posix_eadb_unlink(vfs_handle_struct *handle,
+			    const struct smb_filename *smb_fname)
+{
+	struct smb_filename *smb_fname_tmp = NULL;
+	NTSTATUS status;
+	int ret = -1;
+
+	struct tdb_wrap *ea_tdb;
+
+	SMB_VFS_HANDLE_GET_DATA(handle, ea_tdb, struct tdb_wrap, return -1);
+
+	status = copy_smb_filename(talloc_tos(), smb_fname, &smb_fname_tmp);
+	if (!NT_STATUS_IS_OK(status)) {
+		errno = map_errno_from_nt_status(status);
+		return -1;
+	}
+
+	if (lp_posix_pathnames()) {
+		ret = SMB_VFS_LSTAT(handle->conn, smb_fname_tmp);
+	} else {
+		ret = SMB_VFS_STAT(handle->conn, smb_fname_tmp);
+	}
+	if (ret == -1) {
+		goto out;
+	}
+
+	if (smb_fname_tmp->st.st_ex_nlink == 1) {
+		/* Only remove record on last link to file. */
+
+		if (tdb_transaction_start(ea_tdb->tdb) != 0) {
+			ret = -1;
+			goto out;
+		}
+
+		status = unlink_posix_eadb_raw(ea_tdb, smb_fname->base_name, -1);
+		if (!NT_STATUS_IS_OK(status)) {
+			tdb_transaction_cancel(ea_tdb->tdb);
+			ret = -1;
+			goto out;
+		}
+	}
+
+	ret = SMB_VFS_NEXT_UNLINK(handle, smb_fname_tmp);
+
+	if (ret == -1) {
+		tdb_transaction_cancel(ea_tdb->tdb);
+		goto out;
+	} else {
+		if (tdb_transaction_commit(ea_tdb->tdb) != 0) {
+			ret = -1;
+			goto out;
+		}
+	}
+
+out:
+	TALLOC_FREE(smb_fname_tmp);
+	return ret;
+}
+
+/*
+ * On rmdir we need to delete the tdb record
+ */
+static int posix_eadb_rmdir(vfs_handle_struct *handle, const char *path)
+{
+	NTSTATUS status;
+	struct tdb_wrap *ea_tdb;
+	int ret;
+
+	SMB_VFS_HANDLE_GET_DATA(handle, ea_tdb, struct tdb_wrap, return -1);
+
+	if (tdb_transaction_start(ea_tdb->tdb) != 0) {
+		return -1;
+	}
+
+	status = unlink_posix_eadb_raw(ea_tdb, path, -1);
+	if (!NT_STATUS_IS_OK(status)) {
+		tdb_transaction_cancel(ea_tdb->tdb);
+	}
+
+	ret = SMB_VFS_NEXT_RMDIR(handle, path);
+
+	if (ret == -1) {
+		tdb_transaction_cancel(ea_tdb->tdb);
+	} else {
+		if (tdb_transaction_commit(ea_tdb->tdb) != 0) {
+			return -1;
+		}
+	}
+
+	return ret;
+}
+
+/*
+ * Destructor for the VFS private data
+ */
+
+static void close_xattr_db(void **data)
+{
+	struct tdb_wrap **p_db = (struct tdb_wrap **)data;
+	TALLOC_FREE(*p_db);
+}
+
+static int posix_eadb_connect(vfs_handle_struct *handle, const char *service,
+			  const char *user)
+{
+	char *sname = NULL;
+	int res, snum;
+	struct tdb_wrap *db;
+
+	res = SMB_VFS_NEXT_CONNECT(handle, service, user);
+	if (res < 0) {
+		return res;
+	}
+
+	snum = find_service(talloc_tos(), service, &sname);
+	if (snum == -1 || sname == NULL) {
+		/*
+		 * Should not happen, but we should not fail just *here*.
+		 */
+		return 0;
+	}
+
+	if (!posix_eadb_init(snum, &db)) {
+		DEBUG(5, ("Could not init xattr tdb\n"));
+		lp_do_parameter(snum, "ea support", "False");
+		return 0;
+	}
+
+	lp_do_parameter(snum, "ea support", "True");
+
+	SMB_VFS_HANDLE_SET_DATA(handle, db, close_xattr_db,
+				struct tdb_wrap, return -1);
+
+	return 0;
+}
+
+static struct vfs_fn_pointers vfs_posix_eadb_fns = {
+	.getxattr_fn = posix_eadb_getxattr,
+	.fgetxattr_fn = posix_eadb_fgetxattr,
+	.setxattr_fn = posix_eadb_setxattr,
+	.fsetxattr_fn = posix_eadb_fsetxattr,
+	.listxattr_fn = posix_eadb_listxattr,
+	.flistxattr_fn = posix_eadb_flistxattr,
+	.removexattr_fn = posix_eadb_removexattr,
+	.fremovexattr_fn = posix_eadb_fremovexattr,
+	.unlink_fn = posix_eadb_unlink,
+	.rmdir_fn = posix_eadb_rmdir,
+	.connect_fn = posix_eadb_connect,
+};
+
+NTSTATUS vfs_posix_eadb_init(void);
+NTSTATUS vfs_posix_eadb_init(void)
+{
+	return smb_register_vfs(SMB_VFS_INTERFACE_VERSION, "posix_eadb",
+				&vfs_posix_eadb_fns);
+}
diff --git a/source3/modules/wscript_build b/source3/modules/wscript_build
index d59e29ccd9..32c32fa224 100644
--- a/source3/modules/wscript_build
+++ b/source3/modules/wscript_build
@@ -186,6 +186,14 @@ bld.SAMBA3_MODULE('vfs_xattr_tdb',
                  internal_module=bld.SAMBA3_IS_STATIC_MODULE('vfs_xattr_tdb'),
                  enabled=bld.SAMBA3_IS_ENABLED_MODULE('vfs_xattr_tdb'))
 
+bld.SAMBA3_MODULE('vfs_posix_eadb',
+                 subsystem='vfs',
+                 source='vfs_posix_eadb.c',
+                 deps='tdb-wrap posix_eadb',
+                 init_function='',
+                 internal_module=bld.SAMBA3_IS_STATIC_MODULE('vfs_posix_eadb'),
+                 enabled=bld.SAMBA3_IS_ENABLED_MODULE('vfs_posix_eadb'))
+
 bld.SAMBA3_MODULE('vfs_posixacl',
                  subsystem='vfs',
                  source=VFS_POSIXACL_SRC,