--- /dev/null
+/*
+ * Store streams in a separate subdirectory
+ *
+ * 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"
+
+#undef DBGC_CLASS
+#define DBGC_CLASS DBGC_VFS
+
+/*
+ * Excerpt from a mail from tridge:
+ *
+ * Volker, what I'm thinking of is this:
+ * /mount-point/.streams/XX/YY/aaaa.bbbb/namedstream1
+ * /mount-point/.streams/XX/YY/aaaa.bbbb/namedstream2
+ *
+ * where XX/YY is a 2 level hash based on the fsid/inode. "aaaa.bbbb"
+ * is the fsid/inode. "namedstreamX" is a file named after the stream
+ * name.
+ */
+
+static uint32_t hash_fn(DATA_BLOB key)
+{
+ uint32_t value; /* Used to compute the hash value. */
+ uint32_t i; /* Used to cycle through random values. */
+
+ /* Set the initial value from the key size. */
+ for (value = 0x238F13AF * key.length, i=0; i < key.length; i++)
+ value = (value + (key.data[i] << (i*5 % 24)));
+
+ return (1103515243 * value + 12345);
+}
+
+/*
+ * With the hashing scheme based on the inode we need to protect against
+ * streams showing up on files with re-used inodes. This can happen if we
+ * create a stream directory from within Samba, and a local process or NFS
+ * client deletes the file without deleting the streams directory. When the
+ * inode is re-used and the stream directory is still around, the streams in
+ * there would be show up as belonging to the new file.
+ *
+ * There are several workarounds for this, probably the easiest one is on
+ * systems which have a true birthtime stat element: When the file has a later
+ * birthtime than the streams directory, then we have to recreate the
+ * directory.
+ *
+ * The other workaround is to somehow mark the file as generated by Samba with
+ * something that a NFS client would not do. The closest one is a special
+ * xattr value being set. On systems which do not support xattrs, it might be
+ * an option to put in a special ACL entry for a non-existing group.
+ */
+
+#define SAMBA_XATTR_MARKER "user.SAMBA_STREAMS"
+
+static bool file_is_valid(vfs_handle_struct *handle, const char *path)
+{
+ char buf;
+
+ DEBUG(10, ("file_is_valid (%s) called\n", path));
+
+ if (SMB_VFS_NEXT_GETXATTR(handle, path, SAMBA_XATTR_MARKER,
+ &buf, sizeof(buf)) != sizeof(buf)) {
+ DEBUG(10, ("GETXATTR failed: %s\n", strerror(errno)));
+ return false;
+ }
+
+ if (buf != '1') {
+ DEBUG(10, ("got wrong buffer content: '%c'\n", buf));
+ return false;
+ }
+
+ return true;
+}
+
+static bool mark_file_valid(vfs_handle_struct *handle, const char *path)
+{
+ char buf = '1';
+ int ret;
+
+ DEBUG(10, ("marking file %s as valid\n", path));
+
+ ret = SMB_VFS_NEXT_SETXATTR(handle, path, SAMBA_XATTR_MARKER,
+ &buf, sizeof(buf), 0);
+
+ if (ret == -1) {
+ DEBUG(10, ("SETXATTR failed: %s\n", strerror(errno)));
+ return false;
+ }
+
+ return true;
+}
+
+static char *stream_dir(vfs_handle_struct *handle, const char *base_path,
+ const SMB_STRUCT_STAT *base_sbuf, bool create_it)
+{
+ uint32_t hash;
+ char *result = NULL;
+ SMB_STRUCT_STAT sbuf;
+ uint8_t first, second;
+ char *tmp;
+ char *id_hex;
+ struct file_id id;
+ uint8 id_buf[16];
+
+ const char *rootdir = lp_parm_const_string(
+ SNUM(handle->conn), "streams", "directory",
+ handle->conn->connectpath);
+
+ if (base_sbuf == NULL) {
+ if (SMB_VFS_NEXT_STAT(handle, base_path, &sbuf) == -1) {
+ /*
+ * base file is not there
+ */
+ goto fail;
+ }
+ base_sbuf = &sbuf;
+ }
+
+ id = SMB_VFS_FILE_ID_CREATE(handle->conn, base_sbuf->st_dev,
+ base_sbuf->st_ino);
+
+ push_file_id_16((char *)id_buf, &id);
+
+ hash = hash_fn(data_blob_const(id_buf, sizeof(id_buf)));
+
+ first = hash & 0xff;
+ second = (hash >> 8) & 0xff;
+
+ id_hex = hex_encode(talloc_tos(), id_buf, sizeof(id_buf));
+
+ if (id_hex == NULL) {
+ errno = ENOMEM;
+ goto fail;
+ }
+
+ result = talloc_asprintf(talloc_tos(), "%s/%2.2X/%2.2X/%s", rootdir,
+ first, second, id_hex);
+
+ TALLOC_FREE(id_hex);
+
+ if (result == NULL) {
+ errno = ENOMEM;
+ return NULL;
+ }
+
+ if (SMB_VFS_NEXT_STAT(handle, result, &sbuf) == 0) {
+ char *newname;
+
+ if (!S_ISDIR(sbuf.st_mode)) {
+ errno = EINVAL;
+ goto fail;
+ }
+
+ if (file_is_valid(handle, base_path)) {
+ return result;
+ }
+
+ /*
+ * Someone has recreated a file under an existing inode
+ * without deleting the streams directory. For now, just move
+ * it away.
+ */
+
+ again:
+ newname = talloc_asprintf(talloc_tos(), "lost-%lu", random());
+ if (newname == NULL) {
+ errno = ENOMEM;
+ goto fail;
+ }
+
+ if (SMB_VFS_NEXT_RENAME(handle, result, newname) == -1) {
+ if ((errno == EEXIST) || (errno == ENOTEMPTY)) {
+ TALLOC_FREE(newname);
+ goto again;
+ }
+ goto fail;
+ }
+
+ TALLOC_FREE(newname);
+ }
+
+ if (!create_it) {
+ errno = ENOENT;
+ goto fail;
+ }
+
+ if ((SMB_VFS_NEXT_MKDIR(handle, rootdir, 0755) != 0)
+ && (errno != EEXIST)) {
+ goto fail;
+ }
+
+ tmp = talloc_asprintf(result, "%s/%2.2X", rootdir, first);
+ if (tmp == NULL) {
+ errno = ENOMEM;
+ goto fail;
+ }
+
+ if ((SMB_VFS_NEXT_MKDIR(handle, tmp, 0755) != 0)
+ && (errno != EEXIST)) {
+ goto fail;
+ }
+
+ TALLOC_FREE(tmp);
+
+ tmp = talloc_asprintf(result, "%s/%2.2X/%2.2X", rootdir, first,
+ second);
+ if (tmp == NULL) {
+ errno = ENOMEM;
+ goto fail;
+ }
+
+ if ((SMB_VFS_NEXT_MKDIR(handle, tmp, 0755) != 0)
+ && (errno != EEXIST)) {
+ goto fail;
+ }
+
+ TALLOC_FREE(tmp);
+
+ if ((SMB_VFS_NEXT_MKDIR(handle, result, 0755) != 0)
+ && (errno != EEXIST)) {
+ goto fail;
+ }
+
+ if (!mark_file_valid(handle, base_path)) {
+ goto fail;
+ }
+
+ return result;
+
+ fail:
+ TALLOC_FREE(result);
+ return NULL;
+}
+
+static char *stream_name(vfs_handle_struct *handle, const char *fname,
+ bool create_dir)
+{
+ char *base = NULL;
+ char *sname = NULL;
+ char *id_hex = NULL;
+ char *dirname, *stream_fname;
+
+ if (!NT_STATUS_IS_OK(split_ntfs_stream_name(talloc_tos(), fname,
+ &base, &sname))) {
+ DEBUG(10, ("split_ntfs_stream_name failed\n"));
+ errno = ENOMEM;
+ goto fail;
+ }
+
+ dirname = stream_dir(handle, base, NULL, create_dir);
+
+ if (dirname == NULL) {
+ goto fail;
+ }
+
+ stream_fname = talloc_asprintf(talloc_tos(), "%s/:%s", dirname, sname);
+
+ if (stream_fname == NULL) {
+ errno = ENOMEM;
+ goto fail;
+ }
+
+ DEBUG(10, ("stream filename = %s\n", stream_fname));
+
+ TALLOC_FREE(base);
+ TALLOC_FREE(sname);
+ TALLOC_FREE(id_hex);
+
+ return stream_fname;
+
+ fail:
+ DEBUG(5, ("stream_name failed: %s\n", strerror(errno)));
+ TALLOC_FREE(base);
+ TALLOC_FREE(sname);
+ TALLOC_FREE(id_hex);
+ return NULL;
+}
+
+static NTSTATUS walk_streams(vfs_handle_struct *handle,
+ const char *fname,
+ const SMB_STRUCT_STAT *sbuf,
+ char **pdirname,
+ bool (*fn)(const char *dirname,
+ const char *dirent,
+ void *private_data),
+ void *private_data)
+{
+ char *dirname;
+ SMB_STRUCT_DIR *dirhandle = NULL;
+ char *dirent;
+
+ dirname = stream_dir(handle, fname, sbuf, false);
+
+ if (dirname == NULL) {
+ if (errno == ENOENT) {
+ /*
+ * no stream around
+ */
+ return NT_STATUS_OK;
+ }
+ return map_nt_error_from_unix(errno);
+ }
+
+ DEBUG(10, ("walk_streams: dirname=%s\n", dirname));
+
+ dirhandle = SMB_VFS_NEXT_OPENDIR(handle, dirname, NULL, 0);
+
+ if (dirhandle == NULL) {
+ TALLOC_FREE(dirname);
+ return map_nt_error_from_unix(errno);
+ }
+
+ while ((dirent = vfs_readdirname(handle->conn, dirhandle)) != NULL) {
+
+ if (ISDOT(dirent) || ISDOTDOT(dirent)) {
+ continue;
+ }
+
+ DEBUG(10, ("walk_streams: dirent=%s\n", dirent));
+
+ if (!fn(dirname, dirent, private_data)) {
+ break;
+ }
+ }
+
+ SMB_VFS_NEXT_CLOSEDIR(handle, dirhandle);
+
+ if (pdirname != NULL) {
+ *pdirname = dirname;
+ }
+ else {
+ TALLOC_FREE(dirname);
+ }
+
+ return NT_STATUS_OK;
+}
+
+static int streams_depot_stat(vfs_handle_struct *handle, const char *fname,
+ SMB_STRUCT_STAT *sbuf)
+{
+ char *stream_fname;
+ int ret = -1;
+
+ DEBUG(10, ("streams_depot_stat called for [%s]\n", fname));
+
+ if (!is_ntfs_stream_name(fname)) {
+ return SMB_VFS_NEXT_STAT(handle, fname, sbuf);
+ }
+
+ stream_fname = stream_name(handle, fname, false);
+ if (stream_fname == NULL) {
+ goto done;
+ }
+
+ ret = SMB_VFS_NEXT_STAT(handle, stream_fname, sbuf);
+
+ done:
+ TALLOC_FREE(stream_fname);
+ return ret;
+}
+
+static int streams_depot_lstat(vfs_handle_struct *handle, const char *fname,
+ SMB_STRUCT_STAT *sbuf)
+{
+ char *stream_fname;
+ int ret = -1;
+
+ if (!is_ntfs_stream_name(fname)) {
+ return SMB_VFS_NEXT_LSTAT(handle, fname, sbuf);
+ }
+
+ stream_fname = stream_name(handle, fname, false);
+ if (stream_fname == NULL) {
+ goto done;
+ }
+
+ ret = SMB_VFS_NEXT_LSTAT(handle, stream_fname, sbuf);
+
+ done:
+ TALLOC_FREE(stream_fname);
+ return ret;
+}
+
+static int streams_depot_open(vfs_handle_struct *handle, const char *fname,
+ files_struct *fsp, int flags, mode_t mode)
+{
+ TALLOC_CTX *frame;
+ char *base = NULL;
+ SMB_STRUCT_STAT base_sbuf;
+ char *stream_fname;
+ int ret = -1;
+
+ if (!is_ntfs_stream_name(fname)) {
+ return SMB_VFS_NEXT_OPEN(handle, fname, fsp, flags, mode);
+ }
+
+ frame = talloc_stackframe();
+
+ if (!NT_STATUS_IS_OK(split_ntfs_stream_name(talloc_tos(), fname,
+ &base, NULL))) {
+ errno = ENOMEM;
+ goto done;
+ }
+
+ ret = SMB_VFS_NEXT_STAT(handle, base, &base_sbuf);
+
+ if (ret == -1) {
+ goto done;
+ }
+
+ TALLOC_FREE(base);
+
+ stream_fname = stream_name(handle, fname, true);
+ if (stream_fname == NULL) {
+ goto done;
+ }
+
+ ret = SMB_VFS_NEXT_OPEN(handle, stream_fname, fsp, flags, mode);
+
+ done:
+ TALLOC_FREE(frame);
+ return ret;
+}
+
+static int streams_depot_unlink(vfs_handle_struct *handle, const char *fname)
+{
+ int ret = -1;
+ SMB_STRUCT_STAT sbuf;
+
+ DEBUG(10, ("streams_depot_unlink called for %s\n", fname));
+
+ if (is_ntfs_stream_name(fname)) {
+ char *stream_fname;
+
+ stream_fname = stream_name(handle, fname, false);
+ if (stream_fname == NULL) {
+ return -1;
+ }
+
+ ret = SMB_VFS_NEXT_UNLINK(handle, stream_fname);
+
+ TALLOC_FREE(stream_fname);
+ return ret;
+ }
+
+ /*
+ * We potentially need to delete the per-inode streams directory
+ */
+
+ if (SMB_VFS_NEXT_STAT(handle, fname, &sbuf) == -1) {
+ return -1;
+ }
+
+ if (sbuf.st_nlink == 1) {
+ char *dirname = stream_dir(handle, fname, &sbuf, false);
+
+ if (dirname != NULL) {
+ SMB_VFS_NEXT_RMDIR(handle, dirname);
+ }
+ TALLOC_FREE(dirname);
+ }
+
+ return SMB_VFS_NEXT_UNLINK(handle, fname);
+}
+
+static bool add_one_stream(TALLOC_CTX *mem_ctx, unsigned int *num_streams,
+ struct stream_struct **streams,
+ const char *name, SMB_OFF_T size,
+ SMB_OFF_T alloc_size)
+{
+ struct stream_struct *tmp;
+
+ tmp = TALLOC_REALLOC_ARRAY(mem_ctx, *streams, struct stream_struct,
+ (*num_streams)+1);
+ if (tmp == NULL) {
+ return false;
+ }
+
+ tmp[*num_streams].name = talloc_strdup(tmp, name);
+ if (tmp[*num_streams].name == NULL) {
+ return false;
+ }
+
+ tmp[*num_streams].size = size;
+ tmp[*num_streams].alloc_size = alloc_size;
+
+ *streams = tmp;
+ *num_streams += 1;
+ return true;
+}
+
+struct streaminfo_state {
+ TALLOC_CTX *mem_ctx;
+ vfs_handle_struct *handle;
+ unsigned int num_streams;
+ struct stream_struct *streams;
+ NTSTATUS status;
+};
+
+static bool collect_one_stream(const char *dirname,
+ const char *dirent,
+ void *private_data)
+{
+ struct streaminfo_state *state =
+ (struct streaminfo_state *)private_data;
+ char *full_sname;
+ SMB_STRUCT_STAT sbuf;
+
+ if (asprintf(&full_sname, "%s/%s", dirname, dirent) == -1) {
+ state->status = NT_STATUS_NO_MEMORY;
+ return false;
+ }
+ if (SMB_VFS_NEXT_STAT(state->handle, full_sname, &sbuf) == -1) {
+ DEBUG(10, ("Could not stat %s: %s\n", full_sname,
+ strerror(errno)));
+ SAFE_FREE(full_sname);
+ return true;
+ }
+
+ SAFE_FREE(full_sname);
+
+ if (!add_one_stream(state->mem_ctx,
+ &state->num_streams, &state->streams,
+ dirent, sbuf.st_size,
+ get_allocation_size(
+ state->handle->conn, NULL, &sbuf))) {
+ state->status = NT_STATUS_NO_MEMORY;
+ return false;
+ }
+
+ return true;
+}
+
+static NTSTATUS streams_depot_streaminfo(vfs_handle_struct *handle,
+ struct files_struct *fsp,
+ const char *fname,
+ TALLOC_CTX *mem_ctx,
+ unsigned int *pnum_streams,
+ struct stream_struct **pstreams)
+{
+ SMB_STRUCT_STAT sbuf;
+ int ret;
+ NTSTATUS status;
+ struct streaminfo_state state;
+
+ if ((fsp != NULL) && (fsp->fh->fd != -1)) {
+ if (is_ntfs_stream_name(fsp->fsp_name)) {
+ return NT_STATUS_INVALID_PARAMETER;
+ }
+ ret = SMB_VFS_NEXT_FSTAT(handle, fsp, &sbuf);
+ }
+ else {
+ if (is_ntfs_stream_name(fname)) {
+ return NT_STATUS_INVALID_PARAMETER;
+ }
+ ret = SMB_VFS_NEXT_STAT(handle, fname, &sbuf);
+ }
+
+ if (ret == -1) {
+ return map_nt_error_from_unix(errno);
+ }
+
+ state.streams = NULL;
+ state.num_streams = 0;
+
+ if (!S_ISDIR(sbuf.st_mode)) {
+ if (!add_one_stream(mem_ctx,
+ &state.num_streams, &state.streams,
+ "::$DATA", sbuf.st_size,
+ get_allocation_size(handle->conn, fsp,
+ &sbuf))) {
+ return NT_STATUS_NO_MEMORY;
+ }
+ }
+
+ state.mem_ctx = mem_ctx;
+ state.handle = handle;
+ state.status = NT_STATUS_OK;
+
+ status = walk_streams(handle, fname, &sbuf, NULL, collect_one_stream,
+ &state);
+
+ if (!NT_STATUS_IS_OK(status)) {
+ TALLOC_FREE(state.streams);
+ return status;
+ }
+
+ if (!NT_STATUS_IS_OK(state.status)) {
+ TALLOC_FREE(state.streams);
+ return state.status;
+ }
+
+ *pnum_streams = state.num_streams;
+ *pstreams = state.streams;
+ return NT_STATUS_OK;
+}
+
+static int streams_depot_statvfs(struct vfs_handle_struct *handle,
+ const char *path,
+ struct vfs_statvfs_struct *statbuf)
+{
+ int ret;
+
+ ret = SMB_VFS_NEXT_STATVFS(handle, path, statbuf);
+ statbuf->FsCapabilities |= FILE_NAMED_STREAMS;
+ return ret;
+
+}
+
+/* VFS operations structure */
+
+static vfs_op_tuple streams_depot_ops[] = {
+ {SMB_VFS_OP(streams_depot_statvfs), SMB_VFS_OP_STATVFS,
+ SMB_VFS_LAYER_TRANSPARENT},
+ {SMB_VFS_OP(streams_depot_open), SMB_VFS_OP_OPEN,
+ SMB_VFS_LAYER_TRANSPARENT},
+ {SMB_VFS_OP(streams_depot_stat), SMB_VFS_OP_STAT,
+ SMB_VFS_LAYER_TRANSPARENT},
+ {SMB_VFS_OP(streams_depot_lstat), SMB_VFS_OP_LSTAT,
+ SMB_VFS_LAYER_TRANSPARENT},
+ {SMB_VFS_OP(streams_depot_unlink), SMB_VFS_OP_UNLINK,
+ SMB_VFS_LAYER_TRANSPARENT},
+ {SMB_VFS_OP(streams_depot_streaminfo), SMB_VFS_OP_STREAMINFO,
+ SMB_VFS_LAYER_OPAQUE},
+ {SMB_VFS_OP(NULL), SMB_VFS_OP_NOOP, SMB_VFS_LAYER_NOOP}
+};
+
+NTSTATUS vfs_streams_depot_init(void);
+NTSTATUS vfs_streams_depot_init(void)
+{
+ return smb_register_vfs(SMB_VFS_INTERFACE_VERSION, "streams_depot",
+ streams_depot_ops);
+}
git.samba.org / kamenim / samba.git / commitdiff