kdbus.h revision 607553f9306286fdccf0b356bc3d1087adfe21c4
/*
* Copyright (C) 2013 Kay Sievers
* Copyright (C) 2013 Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* Copyright (C) 2013 Linux Foundation
* Copyright (C) 2013 Lennart Poettering
* Copyright (C) 2013 Daniel Mack <daniel@zonque.org>
*
* the terms of the GNU Lesser General Public License as published by the
* Free Software Foundation; either version 2.1 of the License, or (at
* your option) any later version.
*
* "Everything should be made as simple as possible, but not simpler."
* -- Albert Einstein
*/
#ifndef _KDBUS_H_
#define _KDBUS_H_
#ifndef __KERNEL__
#endif
#define KDBUS_IOC_MAGIC 0x95
#define KDBUS_SRC_ID_KERNEL (0)
#define KDBUS_DST_ID_NAME (0)
#define KDBUS_MATCH_ID_ANY (~0ULL)
#define KDBUS_DST_ID_BROADCAST (~0ULL)
/**
* struct kdbus_notify_id_change - name registry change message
* @id: New or former owner of the name
* @flags: flags field from KDBUS_HELLO_*
*
* Sent from kernel to userspace when the owner or activator of
* a well-known name changes.
*
* Attached to:
* KDBUS_ITEM_ID_ADD
* KDBUS_ITEM_ID_REMOVE
*/
struct kdbus_notify_id_change {
};
/**
* struct kdbus_notify_name_change - name registry change message
* @old: ID and flags of former owner of a name
* @new: ID and flags of new owner of a name
* @name: Well-known name
*
* Sent from kernel to userspace when the owner or activator of
* a well-known name changes.
*
* Attached to:
* KDBUS_ITEM_NAME_ADD
* KDBUS_ITEM_NAME_REMOVE
* KDBUS_ITEM_NAME_CHANGE
*/
struct kdbus_notify_name_change {
struct kdbus_notify_id_change old;
struct kdbus_notify_id_change new;
char name[0];
};
/**
* struct kdbus_creds - process credentials
* @uid: User ID
* @gid: Group ID
* @pid: Process ID
* @tid: Thread ID
* @starttime: Starttime of the process
*
* The starttime of the process PID. This is useful to detect PID overruns
* from the client side. i.e. if you use the PID to look something up in
* /proc/$PID/ you can afterwards check the starttime field of it, to ensure
* you didn't run into a PID overrun.
*
* Attached to:
* KDBUS_ITEM_CREDS
*/
struct kdbus_creds {
};
/**
* struct kdbus_audit - audit information
* @sessionid: The audit session ID
* @loginuid: The audit login uid
*
* Attached to:
* KDBUS_ITEM_AUDIT
*/
struct kdbus_audit {
};
/**
* struct kdbus_timestamp
* @seqnum: Global per-namespace message sequence number
* @monotonic_ns: Monotonic timestamp, in nanoseconds
* @realtime_ns: Realtime timestamp, in nanoseconds
*
* Attached to:
* KDBUS_ITEM_TIMESTAMP
*/
struct kdbus_timestamp {
};
/**
* struct kdbus_vec - I/O vector for kdbus payload items
* @size: The size of the vector
* @address: Memory address for memory addresses
* @offset: Offset in the in-message payload memory,
* relative to the message head
*
* Attached to:
* KDBUS_ITEM_PAYLOAD_VEC
*/
struct kdbus_vec {
union {
};
};
/**
* struct kdbus_memfd - a kdbus memfd
* @size: The memfd's size
* @fd: The file descriptor number
* @__pad: Padding to ensure proper alignement and size
*
* Attached to:
* KDBUS_ITEM_PAYLOAD_MEMFD
*/
struct kdbus_memfd {
int fd;
};
/**
* struct kdbus_name - a registered well-known name with its flags
* @flags: flags from KDBUS_NAME_*
* @name: well-known name
*
* Attached to:
* KDBUS_ITEM_NAME
*/
struct kdbus_name {
char name[0];
};
/**
* struct kdbus_policy_access - policy access item
* @type: One of KDBUS_POLICY_ACCESS_* types
* @bits: Access to grant. One of KDBUS_POLICY_*
* @id: For KDBUS_POLICY_ACCESS_USER, the uid
* For KDBUS_POLICY_ACCESS_GROUP, the gid
*
* Embedded in:
* struct kdbus_policy
*/
struct kdbus_policy_access {
};
/**
* struct kdbus_policy - a policy item
* @access: Policy access details
* @name: Well-known name to grant access to
*
* Attached to:
* KDBUS_POLICY_ACCESS
* KDBUS_ITEM_POLICY_NAME
*/
struct kdbus_policy {
union {
struct kdbus_policy_access access;
char name[0];
};
};
/**
* enum kdbus_item_type - item types to chain data in a list
* @_KDBUS_ITEM_NULL: Uninitialized/invalid
* @_KDBUS_ITEM_USER_BASE: Start of user items
* @KDBUS_ITEM_PAYLOAD_VEC: Vector to data
* @KDBUS_ITEM_PAYLOAD_OFF: Data at returned offset to message head
* @KDBUS_ITEM_PAYLOAD_MEMFD: Data as sealed memfd
* @KDBUS_ITEM_FDS: Attached file descriptors
* @KDBUS_ITEM_BLOOM: For broadcasts, carries bloom filter
* @KDBUS_ITEM_BLOOM_SIZE: Desired bloom size, used by KDBUS_CMD_BUS_MAKE
* @KDBUS_ITEM_DST_NAME: Destination's well-known name
* @KDBUS_ITEM_MAKE_NAME: Name of namespace, bus, endpoint
* @KDBUS_ITEM_MEMFD_NAME: The human readable name of a memfd (debugging)
* @_KDBUS_ITEM_POLICY_BASE: Start of policy items
* @KDBUS_ITEM_POLICY_NAME: Policy in struct kdbus_policy
* @KDBUS_ITEM_POLICY_ACCESS: Policy in struct kdbus_policy
* @_KDBUS_ITEM_ATTACH_BASE: Start of metadata attach items
* @KDBUS_ITEM_NAME: Well-know name with flags
* @KDBUS_ITEM_ID: Connection ID
* @KDBUS_ITEM_TIMESTAMP: Timestamp
* @KDBUS_ITEM_CREDS: Process credential
* @KDBUS_ITEM_PID_COMM: Process ID "comm" identifier
* @KDBUS_ITEM_TID_COMM: Thread ID "comm" identifier
* @KDBUS_ITEM_EXE: The path of the executable
* @KDBUS_ITEM_CMDLINE: The process command line
* @KDBUS_ITEM_CGROUP: The croup membership
* @KDBUS_ITEM_CAPS: The process capabilities
* @KDBUS_ITEM_SECLABEL: The security label
* @KDBUS_ITEM_AUDIT: The audit IDs
* @KDBUS_ITEM_CONN_NAME: The connection's human-readable name (debugging)
* @_KDBUS_ITEM_KERNEL_BASE: Start of kernel-generated message items
* @KDBUS_ITEM_NAME_ADD: Notify in struct kdbus_notify_name_change
* @KDBUS_ITEM_NAME_REMOVE: Notify in struct kdbus_notify_name_change
* @KDBUS_ITEM_NAME_CHANGE: Notify in struct kdbus_notify_name_change
* @KDBUS_ITEM_ID_ADD: Notify in struct kdbus_notify_id_change
* @KDBUS_ITEM_ID_REMOVE: Notify in struct kdbus_notify_id_change
* @KDBUS_ITEM_REPLY_TIMEOUT: Timeout has been reached
* @KDBUS_ITEM_REPLY_DEAD: Destination died
*/
enum kdbus_item_type {
_KDBUS_ITEM_POLICY_BASE = 0x1000,
_KDBUS_ITEM_ATTACH_BASE = 0x2000,
_KDBUS_ITEM_KERNEL_BASE = 0x3000,
};
/**
* struct kdbus_item - chain of data blocks
* @size: Overall data record size
* @type: Kdbus_item type of data
* @data: Generic bytes
* @data32: Generic 32 bit array
* @data64: Generic 64 bit array
* @str: Generic string
* @id: Connection ID
* @vec: KDBUS_ITEM_PAYLOAD_VEC
* @creds: KDBUS_ITEM_CREDS
* @audit: KDBUS_ITEM_AUDIT
* @timestamp: KDBUS_ITEM_TIMESTAMP
* @name: KDBUS_ITEM_NAME
* @memfd: KDBUS_ITEM_PAYLOAD_MEMFD
* @name_change: KDBUS_ITEM_NAME_ADD
* KDBUS_ITEM_NAME_REMOVE
* KDBUS_ITEM_NAME_CHANGE
* @id_change: KDBUS_ITEM_ID_ADD
* KDBUS_ITEM_ID_REMOVE
* @policy: KDBUS_ITEM_POLICY_NAME
* KDBUS_ITEM_POLICY_ACCESS
*/
struct kdbus_item {
union {
char str[0];
struct kdbus_creds creds;
struct kdbus_audit audit;
struct kdbus_timestamp timestamp;
struct kdbus_name name;
struct kdbus_memfd memfd;
int fds[0];
struct kdbus_notify_name_change name_change;
struct kdbus_notify_id_change id_change;
struct kdbus_policy policy;
};
};
/**
* enum kdbus_msg_flags - type of message
* @KDBUS_MSG_FLAGS_EXPECT_REPLY: Expect a reply message, used for
* method calls. The userspace-supplied
* cookie identifies the message and the
* respective reply carries the cookie
* in cookie_reply
* @KDBUS_MSG_FLAGS_SYNC_REPLY: Wait for destination connection to
* reply to this message. The
* KDBUS_CMD_MSG_SEND ioctl() will block
* until the reply is received, and
* offset_reply in struct kdbus_msg will
* yield the offset in the sender's pool
* where the reply can be found.
* This flag is only valid if
* @KDBUS_MSG_FLAGS_EXPECT_REPLY is set as
* well.
* @KDBUS_MSG_FLAGS_NO_AUTO_START: Do not start a service, if the addressed
* name is not currently active
*/
enum kdbus_msg_flags {
KDBUS_MSG_FLAGS_EXPECT_REPLY = 1 << 0,
};
/**
* enum kdbus_payload_type - type of payload carried by message
* @KDBUS_PAYLOAD_KERNEL: Kernel-generated simple message
* @KDBUS_PAYLOAD_DBUS: D-Bus marshalling "DBusDBus"
*/
enum kdbus_payload_type {
KDBUS_PAYLOAD_DBUS = 0x4442757344427573ULL,
};
/**
* struct kdbus_msg - the representation of a kdbus message
* @size: Total size of the message
* @flags: Message flags (KDBUS_MSG_FLAGS_*)
* @priority: Message queue priority value
* @dst_id: 64-bit ID of the destination connection
* @src_id: 64-bit ID of the source connection
* @payload_type: Payload type (KDBUS_PAYLOAD_*)
* @cookie: Userspace-supplied cookie, for the connection
* to identify its messages
* @timeout_ns: The time to wait for a message reply from the peer.
* If there is no reply, a kernel-generated message
* with an attached KDBUS_ITEM_REPLY_TIMEOUT item
* is sent to @src_id.
* @cookie_reply: A reply to the requesting message with the same
* cookie. The requesting connection can match its
* request and the reply with this value
* @offset_reply: If KDBUS_MSG_FLAGS_WAIT_FOR_REPLY, this field will
* contain the offset in the sender's pool where the
* reply is stored.
* @items: A list of kdbus_items containing the message payload
*/
struct kdbus_msg {
union {
};
struct kdbus_item items[0];
/**
* enum kdbus_recv_flags - flags for de-queuing messages
* @KDBUS_RECV_PEEK: Return the next queued message without
* actually de-queuing it, and without installing
* any file descriptors or other resources. It is
* usually used to determine the activating
* connection of a bus name.
* @KDBUS_RECV_DROP: Drop and free the next queued message and all
* its resources without actually receiving it.
* @KDBUS_RECV_USE_PRIORITY: Only de-queue messages with the specified or
* higher priority (lowest values); if not set,
* the priority value is ignored.
*/
enum kdbus_recv_flags {
KDBUS_RECV_PEEK = 1 << 0,
};
/**
* struct kdbus_cmd_recv - struct to de-queue a buffered message
* @flags: KDBUS_RECV_* flags
* @priority: Minimum priority of the messages to de-queue. Lowest
* values have the highest priority.
* @offset: Returned offset in the pool where the message is
* stored. The user must use KDBUS_CMD_FREE to free
* the allocated memory.
*
* This struct is used with the KDBUS_CMD_MSG_RECV ioctl.
*/
struct kdbus_cmd_recv {
/**
* enum kdbus_policy_access_type - permissions of a policy record
* @_KDBUS_POLICY_ACCESS_NULL: Uninitialized/invalid
* @KDBUS_POLICY_ACCESS_USER: Grant access to a uid
* @KDBUS_POLICY_ACCESS_GROUP: Grant access to gid
* @KDBUS_POLICY_ACCESS_WORLD: World-accessible
*/
enum kdbus_policy_access_type {
};
/**
* enum kdbus_policy_access_flags - mode flags
* @KDBUS_POLICY_RECV: Allow receive
* @KDBUS_POLICY_SEND: Allow send
* @KDBUS_POLICY_OWN: Allow to own a well-known name
*/
enum kdbus_policy_type {
KDBUS_POLICY_OWN = 1 << 0,
};
/**
* struct kdbus_cmd_policy - a series of policies to upload
* @size: The total size of the structure
* @policies: The policies to upload
*
* A KDBUS_POLICY_NAME must always preceeds a KDBUS_POLICY_ACCESS entry.
* A new KDBUS_POLICY_NAME can be added after KDBUS_POLICY_ACCESS for
* chaining multiple policies together.
*/
struct kdbus_cmd_policy {
struct kdbus_item policies[0];
/**
* enum kdbus_hello_flags - flags for struct kdbus_cmd_hello
* @KDBUS_HELLO_ACCEPT_FD: The connection allows the receiving of
* any passed file descriptors
* @KDBUS_HELLO_ACTIVATOR: Special-purpose connection which registers
* a well-know name for a process to be started
* when traffic arrives
* @KDBUS_HELLO_MONITOR: Special-purpose connection to monitor
* bus traffic
*/
enum kdbus_hello_flags {
KDBUS_HELLO_ACCEPT_FD = 1 << 0,
};
/**
* enum kdbus_attach_flags - flags for metadata attachments
* @KDBUS_ATTACH_TIMESTAMP: Timestamp
* @KDBUS_ATTACH_CREDS: Credentials
* @KDBUS_ATTACH_NAMES: Well-known names
* @KDBUS_ATTACH_COMM: The "comm" process identifier
* @KDBUS_ATTACH_EXE: The path of the executable
* @KDBUS_ATTACH_CMDLINE: The process command line
* @KDBUS_ATTACH_CGROUP: The croup membership
* @KDBUS_ATTACH_CAPS: The process capabilities
* @KDBUS_ATTACH_SECLABEL: The security label
* @KDBUS_ATTACH_AUDIT: The audit IDs
* @KDBUS_ATTACH_CONN_NAME: The human-readable connection name
*/
enum kdbus_attach_flags {
KDBUS_ATTACH_TIMESTAMP = 1 << 0,
};
/**
* struct kdbus_cmd_hello - struct to say hello to kdbus
* @size: The total size of the structure
* @conn_flags: Connection flags (KDBUS_HELLO_*). The kernel will
* return its capabilities in that field.
* @attach_flags: Mask of metadata to attach to each message sent
* (KDBUS_ATTACH_*)
* @bus_flags: The flags field copied verbatim from the original
* KDBUS_CMD_BUS_MAKE ioctl. It's intended to be useful
* to do negotiation of features of the payload that is
* transferred (kernel → userspace)
* @id: The ID of this connection (kernel → userspace)
* @bloom_size: The bloom filter size chosen by the owner
* (kernel → userspace)
* @pool_size: Size of the connection's buffer where the received
* messages are placed
* @id128: Unique 128-bit ID of the bus (kernel → userspace)
* @items: A list of items
*
* This struct is used with the KDBUS_CMD_HELLO ioctl.
*/
struct kdbus_cmd_hello {
struct kdbus_item items[0];
/* Flags for KDBUS_CMD_{BUS,EP,NS}_MAKE */
enum kdbus_make_flags {
KDBUS_MAKE_ACCESS_GROUP = 1 << 0,
};
/**
* struct kdbus_cmd_make - struct to make a bus, an endpoint or a namespace
* @size: The total size of the struct
* @items: Items describing details
*
* This structure is used with the KDBUS_CMD_BUS_MAKE, KDBUS_CMD_EP_MAKE and
* KDBUS_CMD_NS_MAKE ioctls.
*/
struct kdbus_cmd_make {
struct kdbus_item items[0];
/**
* enum kdbus_name_flags - properties of a well-known name
* @KDBUS_NAME_REPLACE_EXISTING: Try to replace name of other connections
* @KDBUS_NAME_ALLOW_REPLACEMENT: Allow the replacement of the name
* @KDBUS_NAME_QUEUE: Name should be queued if busy
* @KDBUS_NAME_IN_QUEUE: Name is queued
* @KDBUS_NAME_ACTIVATOR: Name is owned by a activator connection
*/
enum kdbus_name_flags {
KDBUS_NAME_REPLACE_EXISTING = 1 << 0,
};
/**
* struct kdbus_cmd_name - struct to describe a well-known name
* @size: The total size of the struct
* @flags: Flags for a name entry (KDBUS_NAME_*)
* @owner_id: The current owner of the name. For requests,
* privileged users may set this field to
* (de)register names on behalf of other connections.
* @conn_flags: The flags of the owning connection (KDBUS_HELLO_*)
* @name: The well-known name
*
* This structure is used with the KDBUS_CMD_NAME_ACQUIRE ioctl.
*/
struct kdbus_cmd_name {
char name[0];
/**
* enum kdbus_name_list_flags - what to include into the returned list
* @KDBUS_NAME_LIST_UNIQUE: All active connections
* @KDBUS_NAME_LIST_NAMES: All known well-known names
* @KDBUS_NAME_LIST_ACTIVATORS: All activator connections
* @KDBUS_NAME_LIST_QUEUED: All queued-up names
*/
enum kdbus_name_list_flags {
KDBUS_NAME_LIST_UNIQUE = 1 << 0,
};
/**
* struct kdbus_cmd_name_list - request a list of name entries
* @flags: Flags for the query (KDBUS_NAME_LIST_*)
* @offset: The returned offset in the caller's pool buffer.
* The user must use KDBUS_CMD_FREE to free the
* allocated memory.
*
* This structure is used with the KDBUS_CMD_NAME_LIST ioctl.
*/
struct kdbus_cmd_name_list {
/**
* struct kdbus_name_list - information returned by KDBUS_CMD_NAME_LIST
* @size: The total size of the structure
* @names: A list of names
*
* Note that the user is responsible for freeing the allocated memory with
* the KDBUS_CMD_FREE ioctl.
*/
struct kdbus_name_list {
struct kdbus_cmd_name names[0];
};
/**
* struct kdbus_cmd_conn_info - struct used for KDBUS_CMD_CONN_INFO ioctl
* @size: The total size of the struct
* @flags: KDBUS_ATTACH_* flags
* @id: The 64-bit ID of the connection. If set to zero, passing
* @name is required. kdbus will look up the name to
* determine the ID in this case.
* @offset: Returned offset in the caller's pool buffer where the
* kdbus_conn_info struct result is stored. The user must
* use KDBUS_CMD_FREE to free the allocated memory.
* @name: The optional well-known name to look up. Only needed in
* case @id is zero.
*
* On success, the KDBUS_CMD_CONN_INFO ioctl will return 0 and @offset will
* tell the user the offset in the connection pool buffer at which to find the
* result in a struct kdbus_conn_info.
*/
struct kdbus_cmd_conn_info {
char name[0];
/**
* struct kdbus_conn_info - information returned by KDBUS_CMD_CONN_INFO
* @size: The total size of the struct
* @id: The connection's 64-bit ID
* @flags: The connection's flags
* @items: A list of struct kdbus_item
*
* Note that the user is responsible for freeing the allocated memory with
* the KDBUS_CMD_FREE ioctl.
*/
struct kdbus_conn_info {
struct kdbus_item items[0];
};
/**
* struct kdbus_cmd_match - struct to add or remove matches
* @size: The total size of the struct
* @owner_id: Privileged users may (de)register matches on behalf
* of other peers
* @cookie: Userspace supplied cookie. When removing, the cookie
* identifies the match to remove
* @items: A list of items for additional information
*
* This structure is used with the KDBUS_CMD_ADD_MATCH and
* KDBUS_CMD_REMOVE_MATCH ioctl.
*/
struct kdbus_cmd_match {
struct kdbus_item items[0];
/**
* struct kdbus_cmd_memfd_make - create a kdbus memfd
* @size: The total size of the struct
* @file_size: The initial file size
* @fd: The returned file descriptor number
* @__pad: Padding to ensure proper alignement
* @items: A list of items for additional information
*
* This structure is used with the KDBUS_CMD_MEMFD_NEW ioctl.
*/
struct kdbus_cmd_memfd_make {
int fd;
struct kdbus_item items[0];
/**
* enum kdbus_ioctl_type - Ioctl API
* @KDBUS_CMD_BUS_MAKE: After opening the "control" device node, this
* command creates a new bus with the specified
* name. The bus is immediately shut down and
* cleaned up when the opened "control" device node
* is closed.
* @KDBUS_CMD_NS_MAKE: Similar to KDBUS_CMD_BUS_MAKE, but it creates a
* new kdbus namespace.
* @KDBUS_CMD_EP_MAKE: Creates a new named special endpoint to talk to
* the bus. Such endpoints usually carry a more
* restrictive policy and grant restricted access
* to specific applications.
* @KDBUS_CMD_HELLO: By opening the bus device node a connection is
* created. After a HELLO the opened connection
* becomes an active peer on the bus.
* @KDBUS_CMD_BYEBYE: Disconnect a connection. If the connection's
* message list is empty, the calls succeeds, and
* the handle is rendered unusable. Otherwise,
* -EAGAIN is returned without any further side-
* effects.
* @KDBUS_CMD_MSG_SEND: Send a message and pass data from userspace to
* the kernel.
* @KDBUS_CMD_MSG_RECV: Receive a message from the kernel which is
* placed in the receiver's pool.
* @KDBUS_CMD_FREE: Release the allocated memory in the receiver's
* pool.
* @KDBUS_CMD_NAME_ACQUIRE: Request a well-known bus name to associate with
* the connection. Well-known names are used to
* address a peer on the bus.
* @KDBUS_CMD_NAME_RELEASE: Release a well-known name the connection
* currently owns.
* @KDBUS_CMD_NAME_LIST: Retrieve the list of all currently registered
* well-known and unique names.
* @KDBUS_CMD_CONN_INFO: Retrieve credentials and properties of the
* initial creator of the connection. The data was
* stored at registration time and does not
* necessarily represent the connected process or
* the actual state of the process.
* @KDBUS_CMD_MATCH_ADD: Install a match which broadcast messages should
* be delivered to the connection.
* @KDBUS_CMD_MATCH_REMOVE: Remove a current match for broadcast messages.
* @KDBUS_CMD_EP_POLICY_SET: Set the policy of an endpoint. It is used to
* restrict the access for endpoints created with
* KDBUS_CMD_EP_MAKE.
* @KDBUS_CMD_MEMFD_NEW: Return a new file descriptor which provides an
* anonymous shared memory file and which can be
* used to pass around larger chunks of data.
* Kdbus memfd files can be sealed, which allows
* the receiver to trust the data it has received.
* Kdbus memfd files expose only very limited
* operations, they can be mmap()ed, seek()ed,
* (p)read(v)() and (p)write(v)(); most other
* common file operations are not implemented.
* Special caution needs to be taken with
* read(v)()/write(v)() on a shared file; the
* underlying file position is always shared
* between all users of the file and race against
* each other, pread(v)()/pwrite(v)() avoid these
* issues.
* @KDBUS_CMD_MEMFD_SIZE_GET: Return the size of the underlying file, which
* changes with write().
* @KDBUS_CMD_MEMFD_SIZE_SET: Truncate the underlying file to the specified
* size.
* @KDBUS_CMD_MEMFD_SEAL_GET: Return the state of the file sealing.
* @KDBUS_CMD_MEMFD_SEAL_SET: Seal or break a seal of the file. Only files
* which are not shared with other processes and
* which are currently not mapped can be sealed.
* The current process needs to be the one and
* single owner of the file, the sealing cannot
* be changed as long as the file is shared.
*/
enum kdbus_ioctl_type {
};
/*
* errno - api error codes
* @E2BIG: A message contains too many records or items.
* @EADDRINUSE: A well-known bus name is already taken by another
* connection.
* @EADDRNOTAVAIL: A message flagged not to activate a service, addressed
* a service which is not currently running.
* @EAGAIN: No messages are queued at the moment.
* @EBADF: File descriptors passed with the message are not valid.
* @EBADFD: A bus connection is in a corrupted state.
* @EBADMSG: Passed data contains a combination of conflicting or
* inconsistent types.
* @EBUSY: The user tried to say BYEBYE to a connection, but the
* connection had a non-empty message list.
* @ECONNRESET: A connection is shut down, no further operations are
* possible.
* @ECOMM: A peer does not accept the file descriptors addressed
* to it.
* @EDESTADDRREQ: The well-known bus name is required but missing.
* @EDOM: The size of data does not match the expectations. Used
* for the size of the bloom filter bit field.
* @EEXIST: A requested namespace, bus or endpoint with the same
* name already exists. A specific data type, which is
* only expected once, is provided multiple times.
* @EFAULT: The supplied memory could not be accessed, or the data
* is not properly aligned.
* @EINVAL: The provided data does not match its type or other
* expectations, like a string which is not NUL terminated,
* or a string length that points behind the first
* \0-byte in the string.
* @EMEDIUMTYPE: A file descriptor which is not a kdbus memfd was
* refused to send as KDBUS_MSG_PAYLOAD_MEMFD.
* @EMFILE: Too many file descriptors have been supplied with a
* message.
* @EMLINK: Too many requests from this connection to other peers
* are queued and waiting for a reply
* @EMSGSIZE: The supplied data is larger than the allowed maximum
* size.
* @ENAMETOOLONG: The requested name is larger than the allowed maximum
* size.
* @ENOBUFS: There is no space left for the submitted data to fit
* into the receiver's pool.
* @ENOENT: The name to query information about is currently not on
* the bus.
* @ENOMEM: Out of memory.
* @ENOMSG: The queue is not empty, but no message with a matching
* priority is currently queued.
* @ENOSYS: The requested functionality is not available.
* @ENOTSUPP: The feature negotiation failed, a not supported feature
* was requested, or an unknown item type was received.
* @ENOTTY: An unknown ioctl command was received.
* @ENOTUNIQ: A specific data type was addressed to a broadcast
* address, but only direct addresses support this kind of
* data.
* @ENXIO: A unique address does not exist, or an offset in the
* receiver's pool does not represent a queued message.
* @EPERM: The policy prevented an operation. The requested
* resource is owned by another entity.
* @ESHUTDOWN: A namespace or endpoint is currently shutting down;
* no further operations will be possible.
* @ESRCH: A requested well-known bus name is not found.
* @ETXTBSY: A kdbus memfd file cannot be sealed or the seal removed,
* because it is shared with other processes or still
* mmap()ed.
* @EXFULL: The size limits in the pool are reached, no data of
* the size tried to submit can be queued.
*/
#endif