PROTOCOLS

Directory

Defined in fuchsia.io/directory.fidl

Directory defines a node which is capable of containing other Objects.

AddInotifyFilter

Adds a new inotify filter for an object relative to this directory object.

• 'filter` is a mask of different inotify events that need to be watched by the server for a specific file/directory.

• path may contain multiple segments, separated by "/" characters, and should never be empty; i.e., "" is an invalid path. Paths should not contain a leading "/".

+watch_descriptor is client assigned value to identify a filter. Server shouldn't trust the client-assigned watch_descriptor. They should just send it back to the client in the socket. This value is not used by server, but it is returned back as part of InotifyEvent, to help the client correlate filter with events on this filter.

• socket is shared between different filter objects i.e every new filter will have a different server end of the socket and there will be a single client end per inotify instance on inotify init.

Request

Response

<EMPTY>

AdvisoryLock

Acquires an advisory lock on the underlying file.

The lock lasts until either this connection is closed or this method is called with |AdvisoryLockType.UNLOCK| to release the lock explicitly.

Advisory locks are purely advisory. They do not prevent actual read or write operations from occurring on the file, either through this connection or through other connections.

This method requires the following rights:

• Rights.READ_BYTES if request.type is AdvisoryLockType.READ.
• Rights.WRITE_BYTES if request.type is AdvisoryLockType.WRITE.

Errors

• ZX_ERR_BAD_STATE The specified type of lock cannot be acquired. For example, another connection might hold a conflicting lock type.
• ZX_ERR_NOT_SUPPORTED This file does not support advisory locking.
• ZX_ERR_ACCESS_DENIED This connection does not have sufficient rights to acquire the given type of lock.

Request

Response

Clone

Create another connection to the same remote object.

flags may be any of:

• OPEN_RIGHT_*
• OPEN_FLAG_APPEND
• OPEN_FLAG_NO_REMOTE
• OPEN_FLAG_DESCRIBE
• CLONE_FLAG_SAME_RIGHTS

All other flags are ignored.

The OPEN_RIGHT_* bits in flags request corresponding rights over the resulting cloned object. The cloned object must have rights less than or equal to the original object, otherwise returns ZX_ERR_ACCESS_DENIED. Alternatively, pass CLONE_FLAG_SAME_RIGHTS to inherit the rights on the source connection. It is invalid to pass any of the OPEN_RIGHT_* flags together with CLONE_FLAG_SAME_RIGHTS.

Request

Close

Terminates connection with object.

This method does not require any rights.

Request

<EMPTY>

Response

Close2

Terminates connection with object.

This method does not require any rights.

Request

<EMPTY>

Response

Describe

Returns extra information about the type of the object. If the Describe operation fails, the connection is closed.

This method does not require any rights.

Request

<EMPTY>

Response

Describe2

Returns extra connection information and auxiliary handles.

• query specifies the fields in ConnectionInfo that the caller is interested in.

• info see fuchsia.io2/ConnectionInfo for details on the fields.

When all known bits in query are set, the return value matches the one from OnConnectionInfo, as if the caller requested that event using ConnectionFlags.GET_CONNECTION_INFO.

If the Describe operation fails, the connection is closed with the associated error.

This method does not require any rights.

Request

Response

GetAttr

Acquires information about the node.

This method does not require any rights.

Request

<EMPTY>

Response

GetAttributes

Acquires information about the node.

The attributes of a node should be stable, independent of the specific protocol used to access it.

• query a bit-mask specifying which attributes to fetch. The server should not return more than necessary.

• attributes the returned attributes.

This method requires the Rights.GET_ATTRIBUTES right.

Request

Response

GetToken

Acquires a token to a Directory which can be used to identify access to it at a later point in time.

This method requires following rights: OPEN_RIGHT_WRITABLE, otherwise returns ZX_ERR_BAD_HANDLE.

Request

<EMPTY>

Response

IoToIo2Placeholder

This message should never be sent or received.

This declaration exists to let keep the Rust bindings compiling as we add and remove transitional elements from the fuchsia.io protocols. Without this declaration, the users of the Rust bindings fail to compile when there aren't any transitional protocol elements.

DEPRECATED

Request

<EMPTY>

Link

Creates a link to an object named src by the name dst, within a directory represented by token.

src must be a resolved object name. Including "/" in the string will return ZX_ERR_INVALID_ARGS.

dst must be a resolved object name. Including "/" in the string will return ZX_ERR_INVALID_ARGS.

This method requires following rights: OPEN_RIGHT_WRITABLE, otherwise returns ZX_ERR_BAD_HANDLE.

Request

Response

NodeGetFlags

Acquires the Directory.Open rights and flags used to access this file.

This method does not require any rights. This method has the same functionality as GetFlags for File and is meant as an in-progress replacement.

Request

<EMPTY>

Response

NodeSetFlags

Changes the Directory.Open flags used to access the file. Supported flags which can be turned on / off:

• OPEN_FLAG_APPEND

This method does not require any rights. This method has the same functionality as SetFlags for File and is meant as an in-progress replacement.

Request

Response

OnConnectionInfo

An event produced eagerly by the server if requested by ConnectionFlags.GET_CONNECTION_INFO. This event will be the first message from the server, and is sent exactly once.

• info See fuchsia.io2/ConnectionInfo for details on the fields. All members should be present.

Different from fuchsia.io/OnOpen, an error during open/reopen is always manifested as an epitaph.

Response

OnOpen

An event produced eagerly by a FIDL server if requested by OPEN_FLAG_DESCRIBE.

Indicates the success or failure of the open operation, and optionally describes the object. If the status is ZX_OK, info contains descriptive information about the object (the same as would be returned by Describe).

Response

Open

Opens a new object relative to this directory object.

path may contain multiple segments, separated by "/" characters, and should never be empty; i.e. "" is an invalid path. A trailing slash implies OPEN_FLAG_DIRECTORY. Components must not be empty (i.e. "foo//bar" is invalid). ".." is disallowed anywhere in the path. "." is only allowed if the path is exactly ".", but not otherwise. A leading '/' is allowed (and is treated the same way as if not present, i.e. "/foo/bar' and "foo/bar" are the same).

flags may be any of the OPEN_FLAG_* and OPEN_RIGHT_* values, bitwise ORed together. The OPEN_FLAG_DESCRIBE flag may cause an OnOpen event to be transmitted on the object handle, indicating the type of object opened.

If an unknown value is sent for flags the connection should be closed.

OPEN_RIGHT_* flags provided in flags will restrict access rights on the object channel which will be connected to the opened entity.

Rights are never increased. When you open a nested entity within a directory, you may only request the same rights as what the directory connection already has, or a subset of those. Exceeding those rights causes an access denied error to be transmitted in the OnOpen event if applicable, and the object connection closed.

The caller must specify either one or more of the OPEN_RIGHT_* flags, or the OPEN_FLAG_NODE_REFERENCE flag.

mode is only used if an object is created and indicates the type of object to be created. An unsupported mode will cause the connection to be closed. The mode type, if set, must always be consistent with the OPEN_FLAG_DIRECTORY and OPEN_FLAG_NOT_DIRECTORY flags, even if an object is not being created. If an object is not being created, mode is otherwise ignored. If an object is being created and the mode type is not set, a directory will be created if OPEN_FLAG_DIRECTORY is set (explicitly or implicitly), or otherwise a server chosen object type.

Request

Open2

Opens or creates a new node relative to this directory node.

• path identifies the node to open. If path contains multiple segments, then the directory is traversed, one segment at a time, relative to the directory represented by this connection. See fuchsia.io2/Path for what constitutes a valid path. To open another connection to the current directory, use fuchsia.io2/Node.Reopen instead.
• mode controls whether to open existing/create new etc.
• options additional options applicable to both Open and Reopen, including negotiating protocol and restricting rights. See fuchsia.io2/ConnectionOptions.
• object_request is the server end of a channel created for the new connection. The caller may proceed to send messages on the corresponding client end right away.

This method requires the following rights on the current connection:

• Rights.ENUMERATE
• Rights.TRAVERSE

Errors are presented as an epitaph on the object_request channel.

• error ZX_ERR_ACCESS_DENIED if the requested rights exceeds what is allowed.
• error ZX_ERR_BAD_PATH if path is invalid.

Request

ReadDirents

Reads a collection of variably sized dirents into a buffer. The number of dirents in a directory may be very large: akin to calling read multiple times on a file, directories have a seek offset which is updated on subsequent calls to ReadDirents. Each call to ReadDirents will only return whole dirent structures, they will not get split across ReadDirent calls.

These dirents are of the form:

struct dirent {
  // Describes the inode of the entry.
  uint64 ino;
  // Describes the length of the dirent name in bytes.
  uint8 size;
  // Describes the type of the entry. Aligned with the
  // POSIX d_type values. Use `DIRENT_TYPE_*` constants.
  uint8 type;
  // Unterminated name of entry.
  char name[0];
}

This method does not require any rights, since one could always probe for directory contents by triggering name conflicts during file creation.

Request

Response

Rename2

Renames a node named src to the name dst, in a directory represented by dst_parent_token.

src and dst must be valid node names. See fuchsia.io2/Name for what constitutes a valid name.

This method requires the following rights on both the current connection, and the connection identified by dst_parent_token:

• Rights.ENUMERATE

• Rights.MODIFY_DIRECTORY

• error ZX_ERR_INVALID_ARGS if src or dst is invalid.

Request

Response

Reopen

Creates another connection to the same node.

• options options applicable to both Open and Reopen, including negotiating protocol and restricting rights. See fuchsia.io2/ConnectionOptions.
• object_request is the server end of a channel created for the new connection. The caller may proceed to send messages on the corresponding client end right away.

For files, the cloned connection and the original connection have independent seek offsets.

Request

Rewind

Resets the directory seek offset.

This method does not require any rights, similar to ReadDirents.

Request

<EMPTY>

Response

SetAttr

Updates information about the node. flags may be any of NODE_ATTRIBUTE_FLAG_*.

This method requires following rights: OPEN_RIGHT_WRITABLE, otherwise returns ZX_ERR_BAD_HANDLE.

Request

Response

Sync

Synchronizes updates to the node to the underlying media, if it exists.

This method does not require any rights.

Request

<EMPTY>

Response

Sync2

Synchronizes updates to the node to the underlying media, if it exists.

This method will return when the filesystem server has flushed the relevant updates to the underlying media, but does not guarantee the underlying media has persisted the information, nor that any information is committed to hardware. Clients may use Sync to ensure ordering between operations.

This method does not require any rights.

Request

<EMPTY>

Response

Unlink

Removes a child node from the this directory's list of entries.

Note: this does not guarantee that the underlying object is destroyed. Although the link will be removed from the containing directory, objects with multiple references (such as files which are still open) will not actually be destroyed until all references are closed.

• error ZX_ERR_ACCESS_DENIED if the connection does not have Rights.WRITE_BYTES.
• error ZX_ERR_NOT_SUPPORTED if the underlying filesystem does not support writing.
• error ZX_ERR_BAD_PATH if name is invalid.
• error ZX_ERR_NOT_EMPTY if name refers to a non-empty directory.
• error ZX_ERR_UNAVAILABLE if name refers to a mount point, containing a remote channel.
• error ZX_ERR_NOT_DIR if the options requested a directory but something other than a directory was found.

Other errors may be returned for filesystem-specific reasons.

This method requires the following rights:

• Rights.ENUMERATE
• Rights.MODIFY_DIRECTORY

Request

Response

UpdateAttributes

Updates information about the node.

• attributes the presence of a table field in attributes indicates the intent to update the corresponding attribute.

This method requires the Rights.UPDATE_ATTRIBUTES right.

Request

Response

Watch

Watches a directory, receiving events of added messages on the watcher request channel.

The watcher handle will send messages of the form:

struct {
  uint8 event;
  uint8 len;
  char name[];
};

Where names are NOT null-terminated.

This API is unstable; in the future, watcher will be a DirectoryWatcher client.

Mask specifies a bitmask of events to observe. Options must be zero; it is reserved.

This method does not require any rights, similar to ReadDirents.

Request

Response

DirectoryWatcher

Defined in fuchsia.io/directory.fidl

DirectoryWatcher transmits messages from a filesystem server about events happening in the filesystem. Clients can register new watchers using the Directory.Watch method, where they can filter which events they want to receive notifications for.

OnEvent

Request

File

Defined in fuchsia.io/file.fidl

File defines the interface of a node which contains a flat layout of data.

AdvisoryLock

Acquires an advisory lock on the underlying file.

The lock lasts until either this connection is closed or this method is called with |AdvisoryLockType.UNLOCK| to release the lock explicitly.

Advisory locks are purely advisory. They do not prevent actual read or write operations from occurring on the file, either through this connection or through other connections.

This method requires the following rights:

• Rights.READ_BYTES if request.type is AdvisoryLockType.READ.
• Rights.WRITE_BYTES if request.type is AdvisoryLockType.WRITE.

Errors

• ZX_ERR_BAD_STATE The specified type of lock cannot be acquired. For example, another connection might hold a conflicting lock type.
• ZX_ERR_NOT_SUPPORTED This file does not support advisory locking.
• ZX_ERR_ACCESS_DENIED This connection does not have sufficient rights to acquire the given type of lock.

Request

Response

Clone

Create another connection to the same remote object.

flags may be any of:

• OPEN_RIGHT_*
• OPEN_FLAG_APPEND
• OPEN_FLAG_NO_REMOTE
• OPEN_FLAG_DESCRIBE
• CLONE_FLAG_SAME_RIGHTS

All other flags are ignored.

The OPEN_RIGHT_* bits in flags request corresponding rights over the resulting cloned object. The cloned object must have rights less than or equal to the original object, otherwise returns ZX_ERR_ACCESS_DENIED. Alternatively, pass CLONE_FLAG_SAME_RIGHTS to inherit the rights on the source connection. It is invalid to pass any of the OPEN_RIGHT_* flags together with CLONE_FLAG_SAME_RIGHTS.

Request

Close

Terminates connection with object.

This method does not require any rights.

Request

<EMPTY>

Response

Close2

Terminates connection with object.

This method does not require any rights.

Request

<EMPTY>

Response

Describe

Returns extra information about the type of the object. If the Describe operation fails, the connection is closed.

This method does not require any rights.

Request

<EMPTY>

Response

Describe2

Returns extra connection information and auxiliary handles.

• query specifies the fields in ConnectionInfo that the caller is interested in.

• info see fuchsia.io2/ConnectionInfo for details on the fields.

When all known bits in query are set, the return value matches the one from OnConnectionInfo, as if the caller requested that event using ConnectionFlags.GET_CONNECTION_INFO.

If the Describe operation fails, the connection is closed with the associated error.

This method does not require any rights.

Request

Response

GetAttr

Acquires information about the node.

This method does not require any rights.

Request

<EMPTY>

Response

GetAttributes

Acquires information about the node.

The attributes of a node should be stable, independent of the specific protocol used to access it.

• query a bit-mask specifying which attributes to fetch. The server should not return more than necessary.

• attributes the returned attributes.

This method requires the Rights.GET_ATTRIBUTES right.

Request

Response

GetBackingMemory

Acquires a zx.handle:VMO representing this file, if there is one, with the requested access rights.

• request flags a VmoFlags indicating the desired mode of access.

• response vmo the requested zx.handle:VMO.

• error a zx.status value indicating the failure.

This method requires the following rights:

• Rights.READ_BYTES if flags includes VmoFlags.READ.
• Rights.WRITE_BYTES if flags includes VmoFlags.WRITE.
• Rights.EXECUTE if flags includes VmoFlags.EXECUTE.

Request

Response

GetBuffer

Acquires a buffer representing this file, if there is one, with the requested access rights.

flags may be any of VMO_FLAG_*.

This method requires following rights:

• OPEN_RIGHT_WRITABLE if flags includes VMO_FLAG_WRITE.
• OPEN_RIGHT_READABLE if flags includes VMO_FLAG_READ or VMO_FLAG_EXEC.
• OPEN_RIGHT_EXECUTABLE if flags includes VMO_FLAG_EXEC.

Request

Response

GetFlags

Acquires the Directory.Open rights and flags used to access this file.

This method does not require any rights.

Request

<EMPTY>

Response

IoToIo2Placeholder

This message should never be sent or received.

This declaration exists to let keep the Rust bindings compiling as we add and remove transitional elements from the fuchsia.io protocols. Without this declaration, the users of the Rust bindings fail to compile when there aren't any transitional protocol elements.

DEPRECATED

Request

<EMPTY>

NodeGetFlags

Acquires the Directory.Open rights and flags used to access this file.

This method does not require any rights. This method has the same functionality as GetFlags for File and is meant as an in-progress replacement.

Request

<EMPTY>

Response

NodeSetFlags

Changes the Directory.Open flags used to access the file. Supported flags which can be turned on / off:

• OPEN_FLAG_APPEND

This method does not require any rights. This method has the same functionality as SetFlags for File and is meant as an in-progress replacement.

Request

Response

OnConnectionInfo

An event produced eagerly by the server if requested by ConnectionFlags.GET_CONNECTION_INFO. This event will be the first message from the server, and is sent exactly once.

• info See fuchsia.io2/ConnectionInfo for details on the fields. All members should be present.

Different from fuchsia.io/OnOpen, an error during open/reopen is always manifested as an epitaph.

Response

OnOpen

An event produced eagerly by a FIDL server if requested by OPEN_FLAG_DESCRIBE.

Indicates the success or failure of the open operation, and optionally describes the object. If the status is ZX_OK, info contains descriptive information about the object (the same as would be returned by Describe).

Response

Read

Reads up to count bytes at the seek offset. The seek offset is moved forward by the number of bytes read.

This method requires the following rights: OPEN_RIGHT_READABLE, otherwise returns ZX_ERR_BAD_HANDLE.

Returns ZX_ERR_OUT_OF_RANGE if count is greater than MAX_BUF.

Request

Response

Read2

Reads up to 'count' bytes at the seek offset. The seek offset is moved forward by the number of bytes read.

Invariants

• The returned data.length will never be greater than count.
• If data.length is less than count, it means that the seek offset has reached the end of file as part of this operation.
• If data.length is zero while count is not, it means that the seek offset is already at or beyond the end of file, and no data could be read.
• If count is zero, the server should perform all the checks ensuring read access without actually read anything, and return an empty data vector.

This method requires the Rights.READ_BYTES right.

Returns ZX_ERR_OUT_OF_RANGE if count is greater than MAX_TRANSFER_SIZE.

Request

Response

ReadAt

Reads up to count bytes at the provided offset. Does not affect the seek offset.

This method requires the following rights: OPEN_RIGHT_READABLE, otherwise returns ZX_ERR_BAD_HANDLE.

Returns ZX_ERR_OUT_OF_RANGE if count is greater than MAX_BUF.

Request

Response

ReadAt2

Reads up to 'count' bytes at the provided offset. Does not affect the seek offset.

Invariants

• The returned data.length will never be greater than count.
• If data.length is less than count, it means that ReadAt has hit the end of file as part of this operation.
• If data.length is zero while count is not, it means that offset is at or past the end of file, and no data can be read.
• If count is zero, the server should perform all the checks ensuring read access without actually reading anything, and return an empty data vector.

This method requires the Rights.READ_BYTES right.

Returns ZX_ERR_OUT_OF_RANGE if count is greater than MAX_TRANSFER_SIZE.

Request

Response

Reopen

Creates another connection to the same node.

• options options applicable to both Open and Reopen, including negotiating protocol and restricting rights. See fuchsia.io2/ConnectionOptions.
• object_request is the server end of a channel created for the new connection. The caller may proceed to send messages on the corresponding client end right away.

For files, the cloned connection and the original connection have independent seek offsets.

Request

Resize

Shrinks or grows the file size to 'length' bytes.

If file size is reduced by this operation, the extra trailing data' is discarded. If file size is increased by this operation, the extended area appears as if it was zeroed.

This method requires the Rights.WRITE_BYTES right.

Request

Response

Seek

Moves the offset at which the next invocation of Read() or Write() will occur.

This method does not require any rights.

Request

Response

Seek2

Moves the offset at which the next invocation of Read or Write will occur. The seek offset is specific to each file connection.

• request origin the reference point where offset will be based on.
• request offset the number of bytes to seek.

• response offset_from_start the adjusted seek offset, from the start of the file.

This method does not require any rights.

Request

Response

SetAttr

Updates information about the node. flags may be any of NODE_ATTRIBUTE_FLAG_*.

This method requires following rights: OPEN_RIGHT_WRITABLE, otherwise returns ZX_ERR_BAD_HANDLE.

Request

Response

SetFlags

Changes the Directory.Open flags used to access the file. Supported flags which can be turned on / off:

• OPEN_FLAG_APPEND

This method does not require any rights.

Request

Response

Sync

Synchronizes updates to the node to the underlying media, if it exists.

This method does not require any rights.

Request

<EMPTY>

Response

Sync2

Synchronizes updates to the node to the underlying media, if it exists.

This method will return when the filesystem server has flushed the relevant updates to the underlying media, but does not guarantee the underlying media has persisted the information, nor that any information is committed to hardware. Clients may use Sync to ensure ordering between operations.

This method does not require any rights.

Request

<EMPTY>

Response

Truncate

Shrinks the file size to 'length' bytes.

This method requires following rights: OPEN_RIGHT_WRITABLE, otherwise returns ZX_ERR_BAD_HANDLE.

Request

Response

UpdateAttributes

Updates information about the node.

• attributes the presence of a table field in attributes indicates the intent to update the corresponding attribute.

This method requires the Rights.UPDATE_ATTRIBUTES right.

Request

Response

Write

Writes data at the seek offset. The seek offset is moved forward by the number of bytes written.

This method requires following rights: OPEN_RIGHT_WRITABLE, otherwise returns ZX_ERR_BAD_HANDLE.

Request

Response

Write2

Writes data at the seek offset. The seek offset is moved forward by the number of bytes written. If the file is in append mode, the seek offset is first set to the end of the file, followed by the write, in one atomic step.

The file size may grow if the seek offset plus data.length is beyond the current end of file.

• request data the byte buffer to write to the file.

• response actual_count the number of bytes written.

Invariants

• The returned actual_count will never be greater than data.length.
• If the server is unable to write all the data due to e.g. not enough space, actual_count may be less than data.length.
• If data.length is zero, the server should perform all the checks ensuring write access without mutating the file. The seek offset is still updated if in append mode.

This method requires the Rights.WRITE_BYTES right.

Request

Response

WriteAt

Writes data to the provided offset. Does not affect the seek offset.

This method requires following rights: OPEN_RIGHT_WRITABLE, otherwise returns ZX_ERR_BAD_HANDLE.

Request

Response

WriteAt2

Writes data at the provided offset. Does not affect the seek offset.

The file size may grow if offset plus data.length is past the current end of file.

• request data the byte buffer to write to the file.
• request offset the offset from start of the file to begin writing.

• response actual_count the number of bytes written.

Invariants

• The returned actual_count will never be greater than data.length.
• If the server is unable to write all the data due to e.g. not enough space, actual_count may be less than data.length.
• If data.length is zero, the server should perform all the checks ensuring write access without mutating the file.

This method requires the Rights.WRITE_BYTES right.

Request

Response

Node

Defined in fuchsia.io/node.fidl

Node defines the minimal interface for entities which can be accessed in a filesystem.

Clone

Create another connection to the same remote object.

flags may be any of:

• OPEN_RIGHT_*
• OPEN_FLAG_APPEND
• OPEN_FLAG_NO_REMOTE
• OPEN_FLAG_DESCRIBE
• CLONE_FLAG_SAME_RIGHTS

All other flags are ignored.

The OPEN_RIGHT_* bits in flags request corresponding rights over the resulting cloned object. The cloned object must have rights less than or equal to the original object, otherwise returns ZX_ERR_ACCESS_DENIED. Alternatively, pass CLONE_FLAG_SAME_RIGHTS to inherit the rights on the source connection. It is invalid to pass any of the OPEN_RIGHT_* flags together with CLONE_FLAG_SAME_RIGHTS.

Request

Close

Terminates connection with object.

This method does not require any rights.

Request

<EMPTY>

Response

Close2

Terminates connection with object.

This method does not require any rights.

Request

<EMPTY>

Response

Describe

Returns extra information about the type of the object. If the Describe operation fails, the connection is closed.

This method does not require any rights.

Request

<EMPTY>

Response

Describe2

Returns extra connection information and auxiliary handles.

• query specifies the fields in ConnectionInfo that the caller is interested in.

• info see fuchsia.io2/ConnectionInfo for details on the fields.

When all known bits in query are set, the return value matches the one from OnConnectionInfo, as if the caller requested that event using ConnectionFlags.GET_CONNECTION_INFO.

If the Describe operation fails, the connection is closed with the associated error.

This method does not require any rights.

Request

Response

GetAttr

Acquires information about the node.

This method does not require any rights.

Request

<EMPTY>

Response

GetAttributes

Acquires information about the node.

The attributes of a node should be stable, independent of the specific protocol used to access it.

• query a bit-mask specifying which attributes to fetch. The server should not return more than necessary.

• attributes the returned attributes.

This method requires the Rights.GET_ATTRIBUTES right.

Request

Response

IoToIo2Placeholder

This message should never be sent or received.

This declaration exists to let keep the Rust bindings compiling as we add and remove transitional elements from the fuchsia.io protocols. Without this declaration, the users of the Rust bindings fail to compile when there aren't any transitional protocol elements.

DEPRECATED

Request

<EMPTY>

NodeGetFlags

Acquires the Directory.Open rights and flags used to access this file.

This method does not require any rights. This method has the same functionality as GetFlags for File and is meant as an in-progress replacement.

Request

<EMPTY>

Response

NodeSetFlags

Changes the Directory.Open flags used to access the file. Supported flags which can be turned on / off:

• OPEN_FLAG_APPEND

This method does not require any rights. This method has the same functionality as SetFlags for File and is meant as an in-progress replacement.

Request

Response

OnConnectionInfo

An event produced eagerly by the server if requested by ConnectionFlags.GET_CONNECTION_INFO. This event will be the first message from the server, and is sent exactly once.

• info See fuchsia.io2/ConnectionInfo for details on the fields. All members should be present.

Different from fuchsia.io/OnOpen, an error during open/reopen is always manifested as an epitaph.

Response

OnOpen

An event produced eagerly by a FIDL server if requested by OPEN_FLAG_DESCRIBE.

Indicates the success or failure of the open operation, and optionally describes the object. If the status is ZX_OK, info contains descriptive information about the object (the same as would be returned by Describe).

Response

Reopen

Creates another connection to the same node.

• options options applicable to both Open and Reopen, including negotiating protocol and restricting rights. See fuchsia.io2/ConnectionOptions.
• object_request is the server end of a channel created for the new connection. The caller may proceed to send messages on the corresponding client end right away.

For files, the cloned connection and the original connection have independent seek offsets.

Request

SetAttr

Updates information about the node. flags may be any of NODE_ATTRIBUTE_FLAG_*.

This method requires following rights: OPEN_RIGHT_WRITABLE, otherwise returns ZX_ERR_BAD_HANDLE.

Request

Response

Sync

Synchronizes updates to the node to the underlying media, if it exists.

This method does not require any rights.

Request

<EMPTY>

Response

Sync2

Synchronizes updates to the node to the underlying media, if it exists.

This method will return when the filesystem server has flushed the relevant updates to the underlying media, but does not guarantee the underlying media has persisted the information, nor that any information is committed to hardware. Clients may use Sync to ensure ordering between operations.

This method does not require any rights.

Request

<EMPTY>

Response

UpdateAttributes

Updates information about the node.

• attributes the presence of a table field in attributes indicates the intent to update the corresponding attribute.

This method requires the Rights.UPDATE_ATTRIBUTES right.

Request

Response

STRUCTS

DatagramSocket resource

Defined in fuchsia.io/node.fidl

Device resource

Defined in fuchsia.io/node.fidl

DirectoryObject

Defined in fuchsia.io/node.fidl

<EMPTY>

Directory_Rename2_Response

Defined in fuchsia.io/directory.fidl

<EMPTY>

Directory_Unlink_Response

Defined in fuchsia.io/directory.fidl

<EMPTY>

FileObject resource

Defined in fuchsia.io/node.fidl

File_GetBackingMemory_Response resource

Defined in fuchsia.io/file.fidl

File_Read2_Response

Defined in fuchsia.io/file.fidl

File_ReadAt2_Response

Defined in fuchsia.io/file.fidl

File_Resize_Response

Defined in fuchsia.io/file.fidl

<EMPTY>

File_Seek2_Response

Defined in fuchsia.io/file.fidl

File_Write2_Response

Defined in fuchsia.io/file.fidl

File_WriteAt2_Response

Defined in fuchsia.io/file.fidl

NodeAttributes

Defined in fuchsia.io/node.fidl

NodeAttributes defines generic information about a filesystem node.

Node_Close2_Response

Defined in fuchsia.io/node.fidl

<EMPTY>

Node_GetAttributes_Response

Defined in fuchsia.io/node.fidl

Node_Sync2_Response

Defined in fuchsia.io/node.fidl

<EMPTY>

Node_UpdateAttributes_Response

Defined in fuchsia.io/node.fidl

<EMPTY>

Pipe resource

Defined in fuchsia.io/node.fidl

RawSocket resource

Defined in fuchsia.io/node.fidl

RightsRequest

Defined in fuchsia.io/connection-options.fidl

Options for requesting rights on the new connection. Because opening a new connection may involve multiple hops through directory proxies, we require the client to set an upper bound and lower bound on the rights request, and intermediate proxies to refine these bounds.

The rights manipulation should be implemented mechanically without knowledge of any specific rights, and servers should propagate unknown bits members, to gracefully handle future rights extensions.

Implementation Notes

It could be common for a client to request an exact set of rights. We recommend client libraries to define a helper function like follows:

fn Exact(exact_rights: Rights) -> RightsRequest {
    RightsRequest {
        at_most: exact_rights,
        at_least: exact_rights,
        resolution: RightsResolution.MAXIMIZE,
    }
}

at_most ⊋ {}
at_most ⊃ at_least
rights_on_connection_where_open_is_received ⊋ {}
rights_on_connection_where_open_is_received ⊃ at_least

Service

Defined in fuchsia.io/node.fidl

<EMPTY>

StreamSocket resource

Defined in fuchsia.io/node.fidl

Tty resource

Defined in fuchsia.io/node.fidl

Vmofile resource

Defined in fuchsia.io/node.fidl

WatchedEvent

Defined in fuchsia.io/directory.fidl

WatchedEvent describes events returned from a DirectoryWatcher.

ENUMS

OpenMode strict

Type: uint32

Defined in fuchsia.io/directory.fidl

Options related to node creation during Directory.Open.

RightsResolution strict

Type: uint32

Defined in fuchsia.io/connection-options.fidl

When an Open/Reopen request reaches its final remote server, it should assign rights on the new connection based on one of these modes.

SeekOrigin strict

Type: uint32

Defined in fuchsia.io/file.fidl

The reference point for updating the seek offset. See File.Seek.

This enum matches the zx_stream_seek_origin_t enum.

TABLES

ConnectionInfo resource

Defined in fuchsia.io/connection-info.fidl

Returns run-time information about a node that is specific to the current connection.

ConnectionOptions

Defined in fuchsia.io/connection-options.fidl

Options for Directory.Open and Node.Reopen.

RightsRequest {
    at_most: r,
    at_least: 0,
    resolution: RightsResolution.MAXIMIZE,
}

ConnectorInfo resource

Defined in fuchsia.io/connection-info.fidl

Auxiliary data for the connector representation of a node, used for protocol discovery and connection.

It supports connecting to arbitrary protocols exported by the filesystem server at a path, including ones that do not compose fuchsia.io2/Node.

DatagramSocketInfo resource

Defined in fuchsia.io/connection-info.fidl

The connection composes fuchsia.posix.socket/DatagramSocket.

DebuglogInfo resource

Defined in fuchsia.io/connection-info.fidl

The debuglog representation of a node. The selection of this variant in Representation implies that the connection speaks the fuchsia.io2/Debuglog protocol.

DeviceInfo resource

Defined in fuchsia.io/connection-info.fidl

The object may be cast to the shared interface of devices.

DEPRECATED - devices will be services in the future

DirectoryInfo resource

Defined in fuchsia.io/connection-info.fidl

Auxiliary data for the directory representation of a node. The selection of this variant in Representation implies that the connection speaks the fuchsia.io2/Directory protocol.

FileInfo resource

Defined in fuchsia.io/connection-info.fidl

Auxiliary data for the file representation of a node. The selection of this variant in Representation implies that the connection speaks the fuchsia.io2/File protocol.

MemoryInfo resource

Defined in fuchsia.io/connection-info.fidl

Auxiliary data for the memory object representation of a node. The node is a file which is represented as a VMO. The selection of this variant in Representation implies that the connection speaks the fuchsia.io2/Memory protocol.

NodeAttributes2

Defined in fuchsia.io/node-attributes.fidl

Objective information about a filesystem node. See Node.GetAttributes and Node.UpdateAttributes.

The attributes of a node should be stable, independent of the specific protocol used to access it.

If a particular attribute is not applicable or not supported, filesystems should leave the corresponding field absent.

PipeInfo resource

Defined in fuchsia.io/connection-info.fidl

The pipe representation of a node. A pipe is a data streaming interface, commonly used for standard in/out. There is no universal requirement as to if it is uni- or bi-directional. The selection of this variant in Representation implies that the connection speaks the fuchsia.io2/Pipe protocol.

RawSocketInfo resource

Defined in fuchsia.io/connection-info.fidl

The connection composes fuchsia.posix.socket.raw/Socket.

StreamSocketInfo resource

Defined in fuchsia.io/connection-info.fidl

The connection composes fuchsia.posix.socket/StreamSocket.

TtyInfo resource

Defined in fuchsia.io/connection-info.fidl

The object may be cast to a Tty interface.

DEPRECATED - tty functionalities may be covered by a tty service

UNIONS

Directory_Rename2_Result strict

Defined in fuchsia.io/directory.fidl

Directory_Unlink_Result strict

Defined in fuchsia.io/directory.fidl

File_GetBackingMemory_Result strict resource

Defined in fuchsia.io/file.fidl

File_Read2_Result strict

Defined in fuchsia.io/file.fidl

File_ReadAt2_Result strict

Defined in fuchsia.io/file.fidl

File_Resize_Result strict

Defined in fuchsia.io/file.fidl

File_Seek2_Result strict

Defined in fuchsia.io/file.fidl

File_Write2_Result strict

Defined in fuchsia.io/file.fidl

File_WriteAt2_Result strict

Defined in fuchsia.io/file.fidl

NodeInfo strict resource

Defined in fuchsia.io/node.fidl

Connection information.

Refer to Node.Describe and Node.OnOpen for usage.

Node_Close2_Result strict

Defined in fuchsia.io/node.fidl

Node_GetAttributes_Result strict

Defined in fuchsia.io/node.fidl

Node_Sync2_Result strict

Defined in fuchsia.io/node.fidl

Node_UpdateAttributes_Result strict

Defined in fuchsia.io/node.fidl

Representation flexible resource

Defined in fuchsia.io/connection-info.fidl

Describes how the connection should be handled, and provides auxiliary handles and information for the connection where applicable. Refer to Node.Describe and Node.OnConnectionInfo.

If handles are returned which offer alternative ways of access to the node, the rights on the handles should correspond to the rights on the connection.

If the client specified more than one protocol in protocols during Directory.Open or Node.Reopen, the Representation xunion carries additionally the result of the connection-time negotiation via its tag.

The elements have one-to-one correspondence with the members of NodeProtocols.

BITS

ConnectionFlags strict

Type: uint64

Defined in fuchsia.io/connection-options.fidl

Flags applicable to both Directory.Open and Node.Reopen.

ConnectionInfoQuery strict

Type: uint64

Defined in fuchsia.io/connection-info.fidl

Set the relevant bit to one to fetch the corresponding field during fuchsia.io2/Node.Describe.

NodeAttributesQuery strict

Type: uint64

Defined in fuchsia.io/node-attributes.fidl

When calling Node.GetAttributes, set the corresponding bit to one to query that particular attribute. The elements here correspond one-to-one with NodeAttributes.

NodeProtocols strict

Type: uint64

Defined in fuchsia.io/connection-info.fidl

A node may have multiple supported representations when opening, even though it may have a fixed underlying identity.

Today, a file is accessed via the fuchsia.io2/File protocol, and sends a Representation.FileInfo when opened with GET_CONNECTION_INFO. However, in the future we might introduce a more sophisticated FileV2 protocol, or a more efficient SuperFastFile backed by a specialized kernel object. New clients can request the more advanced representations by specifying the corresponding bits in NodeProtocols, whereas existing clients would continue to talk to the node via the old representation.

NodeProtocols enables forward-compatibility through a form of protocol negotiation.

The elements have one-to-one correspondence with the members of Representation.

Operations strict

Type: uint64

Defined in fuchsia.io/rights-abilities.fidl

The common members definition behind Rights and Abilities. Note that Directory operations are distinct from File operations, with the exception of some common operations (e.g. GET_ATTRIBUTES) defined on the underlying fuchsia.io2/Node.

VmoFlags strict

Type: uint64

Defined in fuchsia.io/file.fidl

CONSTANTS

TYPE ALIASES