@@ -2217,6 +2217,44 @@ static int xattr_map_client(const struct lo_data *lo, const char *client_name,
return -EPERM;
}
+/*
+ * For use with listxattr where the server fs gives us a name and we may need
+ * to sanitize this for the client.
+ * Returns a pointer to the result in *out_name
+ * This is always the original string or the current string with some prefix
+ * removed; no reallocation is done.
+ * Returns 0 on success
+ * Can return -ENODATA to indicate the name should be dropped from the list.
+ */
+static int xattr_map_server(const struct lo_data *lo, const char *server_name,
+ const char **out_name)
+{
+ size_t i;
+ const char *end;
+
+ for (i = 0; i < lo->xattr_map_nentries; i++) {
+ const XattrMapEntry *cur_entry = lo->xattr_map_list + i;
+
+ if ((cur_entry->flags & XATTR_MAP_FLAG_SERVER) &&
+ (strstart(server_name, cur_entry->prepend, &end))) {
+ if (cur_entry->flags & XATTR_MAP_FLAG_BAD) {
+ return -ENODATA;
+ }
+ if (cur_entry->flags & XATTR_MAP_FLAG_OK) {
+ *out_name = server_name;
+ return 0;
+ }
+ if (cur_entry->flags & XATTR_MAP_FLAG_PREFIX) {
+ /* Remove prefix */
+ *out_name = end;
+ return 0;
+ }
+ }
+ }
+
+ return -ENODATA;
+}
+
static void lo_getxattr(fuse_req_t req, fuse_ino_t ino, const char *in_name,
size_t size)
{
@@ -2371,8 +2409,60 @@ static void lo_listxattr(fuse_req_t req, fuse_ino_t ino, size_t size)
if (ret == 0) {
goto out;
}
+
+ if (lo->xattr_map_list) {
+ /*
+ * Map the names back, some attributes might be dropped,
+ * some shortened, but not increased, so we shouldn't
+ * run out of room.
+ */
+ size_t out_index, in_index;
+ out_index = 0;
+ in_index = 0;
+ while (in_index < ret) {
+ const char *map_out;
+ char *in_ptr = value + in_index;
+ /* Length of current attribute name */
+ size_t in_len = strlen(value + in_index) + 1;
+
+ int mapret = xattr_map_server(lo, in_ptr, &map_out);
+ if (mapret != -ENODATA && mapret != 0) {
+ /* Shouldn't happen */
+ saverr = -mapret;
+ goto out;
+ }
+ if (mapret == 0) {
+ /* Either unchanged, or truncated */
+ size_t out_len;
+ if (map_out != in_ptr) {
+ /* +1 copies the NIL */
+ out_len = strlen(map_out) + 1;
+ } else {
+ /* No change */
+ out_len = in_len;
+ }
+ /*
+ * Move result along, may still be needed for an unchanged
+ * entry if a previous entry was changed.
+ */
+ memmove(value + out_index, map_out, out_len);
+
+ out_index += out_len;
+ }
+ in_index += in_len;
+ }
+ ret = out_index;
+ if (ret == 0) {
+ goto out;
+ }
+ }
fuse_reply_buf(req, value, ret);
} else {
+ /*
+ * xattrmap only ever shortens the result,
+ * so we don't need to do anything clever with the
+ * allocation length here.
+ */
fuse_reply_xattr(req, ret);
}
out_free: