2 * Copyright (C) 2013 Kay Sievers
3 * Copyright (C) 2013 Greg Kroah-Hartman <gregkh@linuxfoundation.org>
4 * Copyright (C) 2013 Linux Foundation
5 * Copyright (C) 2013 Lennart Poettering
6 * Copyright (C) 2013 Daniel Mack <daniel@zonque.org>
8 * kdbus is free software; you can redistribute it and/or modify it under
9 * the terms of the GNU Lesser General Public License as published by the
10 * Free Software Foundation; either version 2.1 of the License, or (at
11 * your option) any later version.
13 * "Everything should be made as simple as possible, but not simpler."
21 #include <sys/ioctl.h>
22 #include <sys/types.h>
23 #include <linux/types.h>
26 #define KDBUS_IOC_MAGIC 0x95
27 #define KDBUS_SRC_ID_KERNEL (0)
28 #define KDBUS_DST_ID_NAME (0)
29 #define KDBUS_MATCH_ID_ANY (~0ULL)
30 #define KDBUS_DST_ID_BROADCAST (~0ULL)
33 * struct kdbus_notify_id_change - name registry change message
34 * @id: New or former owner of the name
35 * @flags: flags field from KDBUS_HELLO_*
37 * Sent from kernel to userspace when the owner or activator of
38 * a well-known name changes.
42 * KDBUS_ITEM_ID_REMOVE
44 struct kdbus_notify_id_change {
50 * struct kdbus_notify_name_change - name registry change message
51 * @old: ID and flags of former owner of a name
52 * @new: ID and flags of new owner of a name
53 * @name: Well-known name
55 * Sent from kernel to userspace when the owner or activator of
56 * a well-known name changes.
60 * KDBUS_ITEM_NAME_REMOVE
61 * KDBUS_ITEM_NAME_CHANGE
63 struct kdbus_notify_name_change {
64 struct kdbus_notify_id_change old;
65 struct kdbus_notify_id_change new;
70 * struct kdbus_creds - process credentials
75 * @starttime: Starttime of the process
77 * The starttime of the process PID. This is useful to detect PID overruns
78 * from the client side. i.e. if you use the PID to look something up in
79 * /proc/$PID/ you can afterwards check the starttime field of it, to ensure
80 * you didn't run into a PID overrun.
94 * struct kdbus_audit - audit information
95 * @sessionid: The audit session ID
96 * @loginuid: The audit login uid
107 * struct kdbus_timestamp
108 * @seqnum: Global per-domain message sequence number
109 * @monotonic_ns: Monotonic timestamp, in nanoseconds
110 * @realtime_ns: Realtime timestamp, in nanoseconds
113 * KDBUS_ITEM_TIMESTAMP
115 struct kdbus_timestamp {
122 * struct kdbus_vec - I/O vector for kdbus payload items
123 * @size: The size of the vector
124 * @address: Memory address for memory addresses
125 * @offset: Offset in the in-message payload memory,
126 * relative to the message head
129 * KDBUS_ITEM_PAYLOAD_VEC
140 * struct kdbus_bloom_parameter - bus-wide bloom parameters
141 * @size: Size of the bit field in bytes (m / 8)
142 * @n_hash: Number of hash functions used (k)
144 struct kdbus_bloom_parameter {
150 * struct kdbus_bloom_filter - bloom filter containing n elements
151 * @generation: Generation of the element set in the filter
152 * @data: Bit field, multiple of 8 bytes
154 struct kdbus_bloom_filter {
160 * struct kdbus_memfd - a kdbus memfd
161 * @size: The memfd's size
162 * @fd: The file descriptor number
163 * @__pad: Padding to ensure proper alignement and size
166 * KDBUS_ITEM_PAYLOAD_MEMFD
175 * struct kdbus_name - a registered well-known name with its flags
176 * @flags: flags from KDBUS_NAME_*
177 * @name: well-known name
188 * struct kdbus_policy_access - policy access item
189 * @type: One of KDBUS_POLICY_ACCESS_* types
190 * @bits: Access to grant. One of KDBUS_POLICY_*
191 * @id: For KDBUS_POLICY_ACCESS_USER, the uid
192 * For KDBUS_POLICY_ACCESS_GROUP, the gid
195 * struct kdbus_policy
197 struct kdbus_policy_access {
198 __u64 type; /* USER, GROUP, WORLD */
199 __u64 bits; /* RECV, SEND, OWN */
200 __u64 id; /* uid, gid, 0 */
204 * struct kdbus_policy - a policy item
205 * @access: Policy access details
206 * @name: Well-known name to grant access to
209 * KDBUS_POLICY_ACCESS
210 * KDBUS_ITEM_POLICY_NAME
212 struct kdbus_policy {
214 struct kdbus_policy_access access;
220 * enum kdbus_item_type - item types to chain data in a list
221 * @_KDBUS_ITEM_NULL: Uninitialized/invalid
222 * @_KDBUS_ITEM_USER_BASE: Start of user items
223 * @KDBUS_ITEM_PAYLOAD_VEC: Vector to data
224 * @KDBUS_ITEM_PAYLOAD_OFF: Data at returned offset to message head
225 * @KDBUS_ITEM_PAYLOAD_MEMFD: Data as sealed memfd
226 * @KDBUS_ITEM_FDS: Attached file descriptors
227 * @KDBUS_ITEM_BLOOM_PARAMETER: Bus-wide bloom parameters, used with
228 * KDBUS_CMD_BUS_MAKE, carries a
229 * struct kdbus_bloom_parameter
230 * @KDBUS_ITEM_BLOOM_FILTER: Bloom filter carried with a message, used to
231 * match against a bloom mask of a connection,
232 * carries a struct kdbus_bloom_filter
233 * @KDBUS_ITEM_BLOOM_MASK: Bloom mask used to match against a message's
235 * @KDBUS_ITEM_DST_NAME: Destination's well-known name
236 * @KDBUS_ITEM_MAKE_NAME: Name of domain, bus, endpoint
237 * @KDBUS_ITEM_MEMFD_NAME: The human readable name of a memfd (debugging)
238 * @KDBUS_ITEM_ATTACH_FLAGS: Attach-flags, used for updating which metadata
239 * a connection subscribes to
240 * @_KDBUS_ITEM_ATTACH_BASE: Start of metadata attach items
241 * @KDBUS_ITEM_NAME: Well-know name with flags
242 * @KDBUS_ITEM_ID: Connection ID
243 * @KDBUS_ITEM_TIMESTAMP: Timestamp
244 * @KDBUS_ITEM_CREDS: Process credential
245 * @KDBUS_ITEM_PID_COMM: Process ID "comm" identifier
246 * @KDBUS_ITEM_TID_COMM: Thread ID "comm" identifier
247 * @KDBUS_ITEM_EXE: The path of the executable
248 * @KDBUS_ITEM_CMDLINE: The process command line
249 * @KDBUS_ITEM_CGROUP: The croup membership
250 * @KDBUS_ITEM_CAPS: The process capabilities
251 * @KDBUS_ITEM_SECLABEL: The security label
252 * @KDBUS_ITEM_AUDIT: The audit IDs
253 * @KDBUS_ITEM_CONN_NAME: The connection's human-readable name (debugging)
254 * @_KDBUS_ITEM_POLICY_BASE: Start of policy items
255 * @KDBUS_ITEM_POLICY_NAME: Policy in struct kdbus_policy
256 * @KDBUS_ITEM_POLICY_ACCESS: Policy in struct kdbus_policy
257 * @_KDBUS_ITEM_KERNEL_BASE: Start of kernel-generated message items
258 * @KDBUS_ITEM_NAME_ADD: Notify in struct kdbus_notify_name_change
259 * @KDBUS_ITEM_NAME_REMOVE: Notify in struct kdbus_notify_name_change
260 * @KDBUS_ITEM_NAME_CHANGE: Notify in struct kdbus_notify_name_change
261 * @KDBUS_ITEM_ID_ADD: Notify in struct kdbus_notify_id_change
262 * @KDBUS_ITEM_ID_REMOVE: Notify in struct kdbus_notify_id_change
263 * @KDBUS_ITEM_REPLY_TIMEOUT: Timeout has been reached
264 * @KDBUS_ITEM_REPLY_DEAD: Destination died
266 enum kdbus_item_type {
268 _KDBUS_ITEM_USER_BASE,
269 KDBUS_ITEM_PAYLOAD_VEC = _KDBUS_ITEM_USER_BASE,
270 KDBUS_ITEM_PAYLOAD_OFF,
271 KDBUS_ITEM_PAYLOAD_MEMFD,
273 KDBUS_ITEM_BLOOM_PARAMETER,
274 KDBUS_ITEM_BLOOM_FILTER,
275 KDBUS_ITEM_BLOOM_MASK,
277 KDBUS_ITEM_MAKE_NAME,
278 KDBUS_ITEM_MEMFD_NAME,
279 KDBUS_ITEM_ATTACH_FLAGS,
281 _KDBUS_ITEM_ATTACH_BASE = 0x1000,
282 KDBUS_ITEM_NAME = _KDBUS_ITEM_ATTACH_BASE,
284 KDBUS_ITEM_TIMESTAMP,
294 KDBUS_ITEM_CONN_NAME,
296 _KDBUS_ITEM_POLICY_BASE = 0x2000,
297 KDBUS_ITEM_POLICY_NAME = _KDBUS_ITEM_POLICY_BASE,
298 KDBUS_ITEM_POLICY_ACCESS,
300 _KDBUS_ITEM_KERNEL_BASE = 0x8000,
301 KDBUS_ITEM_NAME_ADD = _KDBUS_ITEM_KERNEL_BASE,
302 KDBUS_ITEM_NAME_REMOVE,
303 KDBUS_ITEM_NAME_CHANGE,
305 KDBUS_ITEM_ID_REMOVE,
306 KDBUS_ITEM_REPLY_TIMEOUT,
307 KDBUS_ITEM_REPLY_DEAD,
311 * struct kdbus_item - chain of data blocks
312 * @size: Overall data record size
313 * @type: Kdbus_item type of data
314 * @data: Generic bytes
315 * @data32: Generic 32 bit array
316 * @data64: Generic 64 bit array
317 * @str: Generic string
319 * @vec: KDBUS_ITEM_PAYLOAD_VEC
320 * @creds: KDBUS_ITEM_CREDS
321 * @audit: KDBUS_ITEM_AUDIT
322 * @timestamp: KDBUS_ITEM_TIMESTAMP
323 * @name: KDBUS_ITEM_NAME
324 * @bloom_parameter: KDBUS_ITEM_BLOOM_PARAMETER
325 * @bloom_filter: KDBUS_ITEM_BLOOM_FILTER
326 * @memfd: KDBUS_ITEM_PAYLOAD_MEMFD
327 * @name_change: KDBUS_ITEM_NAME_ADD
328 * KDBUS_ITEM_NAME_REMOVE
329 * KDBUS_ITEM_NAME_CHANGE
330 * @id_change: KDBUS_ITEM_ID_ADD
331 * KDBUS_ITEM_ID_REMOVE
332 * @policy: KDBUS_ITEM_POLICY_NAME
333 * KDBUS_ITEM_POLICY_ACCESS
345 struct kdbus_vec vec;
346 struct kdbus_creds creds;
347 struct kdbus_audit audit;
348 struct kdbus_timestamp timestamp;
349 struct kdbus_name name;
350 struct kdbus_bloom_parameter bloom_parameter;
351 struct kdbus_bloom_filter bloom_filter;
352 struct kdbus_memfd memfd;
354 struct kdbus_notify_name_change name_change;
355 struct kdbus_notify_id_change id_change;
356 struct kdbus_policy policy;
361 * enum kdbus_msg_flags - type of message
362 * @KDBUS_MSG_FLAGS_EXPECT_REPLY: Expect a reply message, used for
363 * method calls. The userspace-supplied
364 * cookie identifies the message and the
365 * respective reply carries the cookie
367 * @KDBUS_MSG_FLAGS_SYNC_REPLY: Wait for destination connection to
368 * reply to this message. The
369 * KDBUS_CMD_MSG_SEND ioctl() will block
370 * until the reply is received, and
371 * offset_reply in struct kdbus_msg will
372 * yield the offset in the sender's pool
373 * where the reply can be found.
374 * This flag is only valid if
375 * @KDBUS_MSG_FLAGS_EXPECT_REPLY is set as
377 * @KDBUS_MSG_FLAGS_NO_AUTO_START: Do not start a service, if the addressed
378 * name is not currently active
380 enum kdbus_msg_flags {
381 KDBUS_MSG_FLAGS_EXPECT_REPLY = 1 << 0,
382 KDBUS_MSG_FLAGS_SYNC_REPLY = 1 << 1,
383 KDBUS_MSG_FLAGS_NO_AUTO_START = 1 << 2,
387 * enum kdbus_payload_type - type of payload carried by message
388 * @KDBUS_PAYLOAD_KERNEL: Kernel-generated simple message
389 * @KDBUS_PAYLOAD_DBUS: D-Bus marshalling "DBusDBus"
391 enum kdbus_payload_type {
392 KDBUS_PAYLOAD_KERNEL,
393 KDBUS_PAYLOAD_DBUS = 0x4442757344427573ULL,
397 * struct kdbus_msg - the representation of a kdbus message
398 * @size: Total size of the message
399 * @flags: Message flags (KDBUS_MSG_FLAGS_*)
400 * @priority: Message queue priority value
401 * @dst_id: 64-bit ID of the destination connection
402 * @src_id: 64-bit ID of the source connection
403 * @payload_type: Payload type (KDBUS_PAYLOAD_*)
404 * @cookie: Userspace-supplied cookie, for the connection
405 * to identify its messages
406 * @timeout_ns: The time to wait for a message reply from the peer.
407 * If there is no reply, a kernel-generated message
408 * with an attached KDBUS_ITEM_REPLY_TIMEOUT item
409 * is sent to @src_id.
410 * @cookie_reply: A reply to the requesting message with the same
411 * cookie. The requesting connection can match its
412 * request and the reply with this value
413 * @offset_reply: If KDBUS_MSG_FLAGS_WAIT_FOR_REPLY, this field will
414 * contain the offset in the sender's pool where the
416 * @items: A list of kdbus_items containing the message payload
431 struct kdbus_item items[0];
432 } __attribute__((aligned(8)));
435 * enum kdbus_recv_flags - flags for de-queuing messages
436 * @KDBUS_RECV_PEEK: Return the next queued message without
437 * actually de-queuing it, and without installing
438 * any file descriptors or other resources. It is
439 * usually used to determine the activating
440 * connection of a bus name.
441 * @KDBUS_RECV_DROP: Drop and free the next queued message and all
442 * its resources without actually receiving it.
443 * @KDBUS_RECV_USE_PRIORITY: Only de-queue messages with the specified or
444 * higher priority (lowest values); if not set,
445 * the priority value is ignored.
447 enum kdbus_recv_flags {
448 KDBUS_RECV_PEEK = 1 << 0,
449 KDBUS_RECV_DROP = 1 << 1,
450 KDBUS_RECV_USE_PRIORITY = 1 << 2,
454 * struct kdbus_cmd_recv - struct to de-queue a buffered message
455 * @flags: KDBUS_RECV_* flags
456 * @priority: Minimum priority of the messages to de-queue. Lowest
457 * values have the highest priority.
458 * @offset: Returned offset in the pool where the message is
459 * stored. The user must use KDBUS_CMD_FREE to free
460 * the allocated memory.
462 * This struct is used with the KDBUS_CMD_MSG_RECV ioctl.
464 struct kdbus_cmd_recv {
468 } __attribute__((aligned(8)));
471 * enum kdbus_policy_access_type - permissions of a policy record
472 * @_KDBUS_POLICY_ACCESS_NULL: Uninitialized/invalid
473 * @KDBUS_POLICY_ACCESS_USER: Grant access to a uid
474 * @KDBUS_POLICY_ACCESS_GROUP: Grant access to gid
475 * @KDBUS_POLICY_ACCESS_WORLD: World-accessible
477 enum kdbus_policy_access_type {
478 _KDBUS_POLICY_ACCESS_NULL,
479 KDBUS_POLICY_ACCESS_USER,
480 KDBUS_POLICY_ACCESS_GROUP,
481 KDBUS_POLICY_ACCESS_WORLD,
485 * enum kdbus_policy_access_flags - mode flags
486 * @KDBUS_POLICY_RECV: Allow receive
487 * @KDBUS_POLICY_SEND: Allow send
488 * @KDBUS_POLICY_OWN: Allow to own a well-known name
490 enum kdbus_policy_type {
491 KDBUS_POLICY_RECV = 1 << 2,
492 KDBUS_POLICY_SEND = 1 << 1,
493 KDBUS_POLICY_OWN = 1 << 0,
497 * struct kdbus_cmd_policy - a series of policies to upload
498 * @size: The total size of the structure
499 * @policies: The policies to upload
501 * A KDBUS_POLICY_NAME must always preceeds a KDBUS_POLICY_ACCESS entry.
502 * A new KDBUS_POLICY_NAME can be added after KDBUS_POLICY_ACCESS for
503 * chaining multiple policies together.
505 struct kdbus_cmd_policy {
507 struct kdbus_item policies[0];
508 } __attribute__((aligned(8)));
511 * enum kdbus_hello_flags - flags for struct kdbus_cmd_hello
512 * @KDBUS_HELLO_ACCEPT_FD: The connection allows the receiving of
513 * any passed file descriptors
514 * @KDBUS_HELLO_ACTIVATOR: Special-purpose connection which registers
515 * a well-know name for a process to be started
516 * when traffic arrives
517 * @KDBUS_HELLO_MONITOR: Special-purpose connection to monitor
520 enum kdbus_hello_flags {
521 KDBUS_HELLO_ACCEPT_FD = 1 << 0,
522 KDBUS_HELLO_ACTIVATOR = 1 << 1,
523 KDBUS_HELLO_MONITOR = 1 << 2,
527 * enum kdbus_attach_flags - flags for metadata attachments
528 * @KDBUS_ATTACH_TIMESTAMP: Timestamp
529 * @KDBUS_ATTACH_CREDS: Credentials
530 * @KDBUS_ATTACH_NAMES: Well-known names
531 * @KDBUS_ATTACH_COMM: The "comm" process identifier
532 * @KDBUS_ATTACH_EXE: The path of the executable
533 * @KDBUS_ATTACH_CMDLINE: The process command line
534 * @KDBUS_ATTACH_CGROUP: The croup membership
535 * @KDBUS_ATTACH_CAPS: The process capabilities
536 * @KDBUS_ATTACH_SECLABEL: The security label
537 * @KDBUS_ATTACH_AUDIT: The audit IDs
538 * @KDBUS_ATTACH_CONN_NAME: The human-readable connection name
540 enum kdbus_attach_flags {
541 KDBUS_ATTACH_TIMESTAMP = 1 << 0,
542 KDBUS_ATTACH_CREDS = 1 << 1,
543 KDBUS_ATTACH_NAMES = 1 << 2,
544 KDBUS_ATTACH_COMM = 1 << 3,
545 KDBUS_ATTACH_EXE = 1 << 4,
546 KDBUS_ATTACH_CMDLINE = 1 << 5,
547 KDBUS_ATTACH_CGROUP = 1 << 6,
548 KDBUS_ATTACH_CAPS = 1 << 7,
549 KDBUS_ATTACH_SECLABEL = 1 << 8,
550 KDBUS_ATTACH_AUDIT = 1 << 9,
551 KDBUS_ATTACH_CONN_NAME = 1 << 10,
555 * struct kdbus_cmd_hello - struct to say hello to kdbus
556 * @size: The total size of the structure
557 * @conn_flags: Connection flags (KDBUS_HELLO_*). The kernel will
558 * return its capabilities in that field.
559 * @attach_flags: Mask of metadata to attach to each message sent
561 * @bus_flags: The flags field copied verbatim from the original
562 * KDBUS_CMD_BUS_MAKE ioctl. It's intended to be useful
563 * to do negotiation of features of the payload that is
564 * transferred (kernel → userspace)
565 * @id: The ID of this connection (kernel → userspace)
566 * @pool_size: Size of the connection's buffer where the received
567 * messages are placed
568 * @bloom: The bloom properties of the bus, specified
569 * by the bus creator (kernel → userspace)
570 * @id128: Unique 128-bit ID of the bus (kernel → userspace)
571 * @items: A list of items
573 * This struct is used with the KDBUS_CMD_HELLO ioctl.
575 struct kdbus_cmd_hello {
582 struct kdbus_bloom_parameter bloom;
584 struct kdbus_item items[0];
585 } __attribute__((aligned(8)));
587 /* Flags for KDBUS_CMD_{BUS,EP,NS}_MAKE */
588 enum kdbus_make_flags {
589 KDBUS_MAKE_ACCESS_GROUP = 1 << 0,
590 KDBUS_MAKE_ACCESS_WORLD = 1 << 1,
591 KDBUS_MAKE_POLICY_OPEN = 1 << 2,
595 * struct kdbus_cmd_make - struct to make a bus, an endpoint or a domain
596 * @size: The total size of the struct
597 * @flags: Properties for the bus/ep/domain to create
598 * @items: Items describing details
600 * This structure is used with the KDBUS_CMD_BUS_MAKE, KDBUS_CMD_EP_MAKE and
601 * KDBUS_CMD_DOMAIN_MAKE ioctls.
603 struct kdbus_cmd_make {
606 struct kdbus_item items[0];
607 } __attribute__((aligned(8)));
610 * enum kdbus_name_flags - properties of a well-known name
611 * @KDBUS_NAME_REPLACE_EXISTING: Try to replace name of other connections
612 * @KDBUS_NAME_ALLOW_REPLACEMENT: Allow the replacement of the name
613 * @KDBUS_NAME_QUEUE: Name should be queued if busy
614 * @KDBUS_NAME_IN_QUEUE: Name is queued
615 * @KDBUS_NAME_ACTIVATOR: Name is owned by a activator connection
617 enum kdbus_name_flags {
618 KDBUS_NAME_REPLACE_EXISTING = 1 << 0,
619 KDBUS_NAME_ALLOW_REPLACEMENT = 1 << 1,
620 KDBUS_NAME_QUEUE = 1 << 2,
621 KDBUS_NAME_IN_QUEUE = 1 << 3,
622 KDBUS_NAME_ACTIVATOR = 1 << 4,
626 * struct kdbus_cmd_name - struct to describe a well-known name
627 * @size: The total size of the struct
628 * @flags: Flags for a name entry (KDBUS_NAME_*)
629 * @owner_id: The current owner of the name. For requests,
630 * privileged users may set this field to
631 * (de)register names on behalf of other connections.
632 * @conn_flags: The flags of the owning connection (KDBUS_HELLO_*)
633 * @name: The well-known name
635 * This structure is used with the KDBUS_CMD_NAME_ACQUIRE ioctl.
637 struct kdbus_cmd_name {
643 } __attribute__((aligned(8)));
646 * enum kdbus_name_list_flags - what to include into the returned list
647 * @KDBUS_NAME_LIST_UNIQUE: All active connections
648 * @KDBUS_NAME_LIST_NAMES: All known well-known names
649 * @KDBUS_NAME_LIST_ACTIVATORS: All activator connections
650 * @KDBUS_NAME_LIST_QUEUED: All queued-up names
652 enum kdbus_name_list_flags {
653 KDBUS_NAME_LIST_UNIQUE = 1 << 0,
654 KDBUS_NAME_LIST_NAMES = 1 << 1,
655 KDBUS_NAME_LIST_ACTIVATORS = 1 << 2,
656 KDBUS_NAME_LIST_QUEUED = 1 << 3,
660 * struct kdbus_cmd_name_list - request a list of name entries
661 * @flags: Flags for the query (KDBUS_NAME_LIST_*)
662 * @offset: The returned offset in the caller's pool buffer.
663 * The user must use KDBUS_CMD_FREE to free the
666 * This structure is used with the KDBUS_CMD_NAME_LIST ioctl.
668 struct kdbus_cmd_name_list {
671 } __attribute__((aligned(8)));
674 * struct kdbus_name_list - information returned by KDBUS_CMD_NAME_LIST
675 * @size: The total size of the structure
676 * @names: A list of names
678 * Note that the user is responsible for freeing the allocated memory with
679 * the KDBUS_CMD_FREE ioctl.
681 struct kdbus_name_list {
683 struct kdbus_cmd_name names[0];
687 * struct kdbus_cmd_conn_info - struct used for KDBUS_CMD_CONN_INFO ioctl
688 * @size: The total size of the struct
689 * @flags: KDBUS_ATTACH_* flags
690 * @id: The 64-bit ID of the connection. If set to zero, passing
691 * @name is required. kdbus will look up the name to
692 * determine the ID in this case.
693 * @offset: Returned offset in the caller's pool buffer where the
694 * kdbus_conn_info struct result is stored. The user must
695 * use KDBUS_CMD_FREE to free the allocated memory.
696 * @name: The optional well-known name to look up. Only needed in
699 * On success, the KDBUS_CMD_CONN_INFO ioctl will return 0 and @offset will
700 * tell the user the offset in the connection pool buffer at which to find the
701 * result in a struct kdbus_conn_info.
703 struct kdbus_cmd_conn_info {
709 } __attribute__((aligned(8)));
712 * struct kdbus_conn_info - information returned by KDBUS_CMD_CONN_INFO
713 * @size: The total size of the struct
714 * @id: The connection's 64-bit ID
715 * @flags: The connection's flags
716 * @items: A list of struct kdbus_item
718 * Note that the user is responsible for freeing the allocated memory with
719 * the KDBUS_CMD_FREE ioctl.
721 struct kdbus_conn_info {
725 struct kdbus_item items[0];
729 * struct kdbus_cmd_conn_update - update flags of a connection
730 * @size: The total size of the struct
731 * @items: A list of struct kdbus_item
733 * This struct is used with the KDBUS_CMD_CONN_UPDATE ioctl.
735 struct kdbus_cmd_conn_update {
737 struct kdbus_item items[0];
738 } __attribute__((aligned(8)));
741 * struct kdbus_cmd_match - struct to add or remove matches
742 * @size: The total size of the struct
743 * @owner_id: Privileged users may (de)register matches on behalf
745 * @cookie: Userspace supplied cookie. When removing, the cookie
746 * identifies the match to remove
747 * @items: A list of items for additional information
749 * This structure is used with the KDBUS_CMD_ADD_MATCH and
750 * KDBUS_CMD_REMOVE_MATCH ioctl.
752 struct kdbus_cmd_match {
756 struct kdbus_item items[0];
757 } __attribute__((aligned(8)));
760 * struct kdbus_cmd_memfd_make - create a kdbus memfd
761 * @size: The total size of the struct
762 * @file_size: The initial file size
763 * @fd: The returned file descriptor number
764 * @__pad: Padding to ensure proper alignement
765 * @items: A list of items for additional information
767 * This structure is used with the KDBUS_CMD_MEMFD_NEW ioctl.
769 struct kdbus_cmd_memfd_make {
774 struct kdbus_item items[0];
775 } __attribute__((aligned(8)));
778 * enum kdbus_ioctl_type - Ioctl API
779 * @KDBUS_CMD_BUS_MAKE: After opening the "control" device node, this
780 * command creates a new bus with the specified
781 * name. The bus is immediately shut down and
782 * cleaned up when the opened "control" device node
784 * @KDBUS_CMD_DOMAIN_MAKE: Similar to KDBUS_CMD_BUS_MAKE, but it creates a
786 * @KDBUS_CMD_EP_MAKE: Creates a new named special endpoint to talk to
787 * the bus. Such endpoints usually carry a more
788 * restrictive policy and grant restricted access
789 * to specific applications.
790 * @KDBUS_CMD_HELLO: By opening the bus device node a connection is
791 * created. After a HELLO the opened connection
792 * becomes an active peer on the bus.
793 * @KDBUS_CMD_BYEBYE: Disconnect a connection. If the connection's
794 * message list is empty, the calls succeeds, and
795 * the handle is rendered unusable. Otherwise,
796 * -EAGAIN is returned without any further side-
798 * @KDBUS_CMD_MSG_SEND: Send a message and pass data from userspace to
800 * @KDBUS_CMD_MSG_RECV: Receive a message from the kernel which is
801 * placed in the receiver's pool.
802 * @KDBUS_CMD_MSG_CANCEL: Cancel a pending request of a message that
803 * blocks while waiting for a reply. The parameter
804 * denotes the cookie of the message in flight.
805 * @KDBUS_CMD_FREE: Release the allocated memory in the receiver's
807 * @KDBUS_CMD_NAME_ACQUIRE: Request a well-known bus name to associate with
808 * the connection. Well-known names are used to
809 * address a peer on the bus.
810 * @KDBUS_CMD_NAME_RELEASE: Release a well-known name the connection
812 * @KDBUS_CMD_NAME_LIST: Retrieve the list of all currently registered
813 * well-known and unique names.
814 * @KDBUS_CMD_CONN_INFO: Retrieve credentials and properties of the
815 * initial creator of the connection. The data was
816 * stored at registration time and does not
817 * necessarily represent the connected process or
818 * the actual state of the process.
819 * @KDBUS_CMD_CONN_UPDATE: Update the properties of a connection. Used to
820 * update the metadata subscription.
821 * @KDBUS_CMD_MATCH_ADD: Install a match which broadcast messages should
822 * be delivered to the connection.
823 * @KDBUS_CMD_MATCH_REMOVE: Remove a current match for broadcast messages.
824 * @KDBUS_CMD_EP_POLICY_SET: Set the policy of an endpoint. It is used to
825 * restrict the access for endpoints created with
827 * @KDBUS_CMD_MEMFD_NEW: Return a new file descriptor which provides an
828 * anonymous shared memory file and which can be
829 * used to pass around larger chunks of data.
830 * Kdbus memfd files can be sealed, which allows
831 * the receiver to trust the data it has received.
832 * Kdbus memfd files expose only very limited
833 * operations, they can be mmap()ed, seek()ed,
834 * (p)read(v)() and (p)write(v)(); most other
835 * common file operations are not implemented.
836 * Special caution needs to be taken with
837 * read(v)()/write(v)() on a shared file; the
838 * underlying file position is always shared
839 * between all users of the file and race against
840 * each other, pread(v)()/pwrite(v)() avoid these
842 * @KDBUS_CMD_MEMFD_SIZE_GET: Return the size of the underlying file, which
843 * changes with write().
844 * @KDBUS_CMD_MEMFD_SIZE_SET: Truncate the underlying file to the specified
846 * @KDBUS_CMD_MEMFD_SEAL_GET: Return the state of the file sealing.
847 * @KDBUS_CMD_MEMFD_SEAL_SET: Seal or break a seal of the file. Only files
848 * which are not shared with other processes and
849 * which are currently not mapped can be sealed.
850 * The current process needs to be the one and
851 * single owner of the file, the sealing cannot
852 * be changed as long as the file is shared.
854 enum kdbus_ioctl_type {
855 KDBUS_CMD_BUS_MAKE = _IOW (KDBUS_IOC_MAGIC, 0x00, struct kdbus_cmd_make),
856 KDBUS_CMD_DOMAIN_MAKE = _IOW (KDBUS_IOC_MAGIC, 0x10, struct kdbus_cmd_make),
857 KDBUS_CMD_EP_MAKE = _IOW (KDBUS_IOC_MAGIC, 0x20, struct kdbus_cmd_make),
859 KDBUS_CMD_HELLO = _IOWR(KDBUS_IOC_MAGIC, 0x30, struct kdbus_cmd_hello),
860 KDBUS_CMD_BYEBYE = _IO (KDBUS_IOC_MAGIC, 0x31),
862 KDBUS_CMD_MSG_SEND = _IOWR(KDBUS_IOC_MAGIC, 0x40, struct kdbus_msg),
863 KDBUS_CMD_MSG_RECV = _IOWR(KDBUS_IOC_MAGIC, 0x41, struct kdbus_cmd_recv),
864 KDBUS_CMD_MSG_CANCEL = _IOW (KDBUS_IOC_MAGIC, 0x42, __u64 *),
865 KDBUS_CMD_FREE = _IOW (KDBUS_IOC_MAGIC, 0x43, __u64 *),
867 KDBUS_CMD_NAME_ACQUIRE = _IOWR(KDBUS_IOC_MAGIC, 0x50, struct kdbus_cmd_name),
868 KDBUS_CMD_NAME_RELEASE = _IOW (KDBUS_IOC_MAGIC, 0x51, struct kdbus_cmd_name),
869 KDBUS_CMD_NAME_LIST = _IOWR(KDBUS_IOC_MAGIC, 0x52, struct kdbus_cmd_name_list),
871 KDBUS_CMD_CONN_INFO = _IOWR(KDBUS_IOC_MAGIC, 0x60, struct kdbus_cmd_conn_info),
872 KDBUS_CMD_CONN_UPDATE = _IOW (KDBUS_IOC_MAGIC, 0x61, struct kdbus_cmd_conn_update),
874 KDBUS_CMD_MATCH_ADD = _IOW (KDBUS_IOC_MAGIC, 0x70, struct kdbus_cmd_match),
875 KDBUS_CMD_MATCH_REMOVE = _IOW (KDBUS_IOC_MAGIC, 0x71, struct kdbus_cmd_match),
877 KDBUS_CMD_EP_POLICY_SET = _IOW (KDBUS_IOC_MAGIC, 0x80, struct kdbus_cmd_policy),
879 KDBUS_CMD_MEMFD_NEW = _IOWR(KDBUS_IOC_MAGIC, 0xc0, struct kdbus_cmd_memfd_make),
880 KDBUS_CMD_MEMFD_SIZE_GET = _IOR (KDBUS_IOC_MAGIC, 0xc1, __u64 *),
881 KDBUS_CMD_MEMFD_SIZE_SET = _IOW (KDBUS_IOC_MAGIC, 0xc2, __u64 *),
882 KDBUS_CMD_MEMFD_SEAL_GET = _IOR (KDBUS_IOC_MAGIC, 0xc3, int *),
883 KDBUS_CMD_MEMFD_SEAL_SET = _IO (KDBUS_IOC_MAGIC, 0xc4),
887 * errno - api error codes
888 * @E2BIG: A message contains too many records or items.
889 * @EADDRINUSE: A well-known bus name is already taken by another
891 * @EADDRNOTAVAIL: A message flagged not to activate a service, addressed
892 * a service which is not currently running.
893 * @EAGAIN: No messages are queued at the moment.
894 * @EBADF: File descriptors passed with the message are not valid.
895 * @EBADFD: A bus connection is in a corrupted state.
896 * @EBADMSG: Passed data contains a combination of conflicting or
897 * inconsistent types.
898 * @EBUSY: The user tried to say BYEBYE to a connection, but the
899 * connection had a non-empty message list.
900 * @ECANCELED: A synchronous message sending was cancelled.
901 * @ECONNRESET: A connection is shut down, no further operations are
903 * @ECOMM: A peer does not accept the file descriptors addressed
905 * @EDESTADDRREQ: The well-known bus name is required but missing.
906 * @EDOM: The size of data does not match the expectations. Used
907 * for bloom bit field sizes.
908 * @EEXIST: A requested domain, bus or endpoint with the same
909 * name already exists. A specific data type, which is
910 * only expected once, is provided multiple times.
911 * @EFAULT: The supplied memory could not be accessed, or the data
912 * is not properly aligned.
913 * @EINVAL: The provided data does not match its type or other
914 * expectations, like a string which is not NUL terminated,
915 * or a string length that points behind the first
916 * \0-byte in the string.
917 * @EMEDIUMTYPE: A file descriptor which is not a kdbus memfd was
918 * refused to send as KDBUS_MSG_PAYLOAD_MEMFD.
919 * @EMFILE: Too many file descriptors have been supplied with a
921 * Too many connections or buses are created for a given
923 * @EMLINK: Too many requests from this connection to other peers
924 * are queued and waiting for a reply
925 * @EMSGSIZE: The supplied data is larger than the allowed maximum
927 * @ENAMETOOLONG: The requested name is larger than the allowed maximum
929 * @ENOBUFS: There is no space left for the submitted data to fit
930 * into the receiver's pool.
931 * @ENOENT: The name to query information about is currently not on
933 * @ENOMEM: Out of memory.
934 * @ENOMSG: The queue is not empty, but no message with a matching
935 * priority is currently queued.
936 * @ENOSYS: The requested functionality is not available.
937 * @ENOTSUPP: The feature negotiation failed, a not supported feature
938 * was requested, or an unknown item type was received.
939 * @ENOTTY: An unknown ioctl command was received.
940 * @ENOTUNIQ: A specific data type was addressed to a broadcast
941 * address, but only direct addresses support this kind of
943 * @ENXIO: A unique address does not exist, or an offset in the
944 * receiver's pool does not represent a queued message.
945 * @EPERM: The policy prevented an operation. The requested
946 * resource is owned by another entity.
947 * @EPIPE: When sending a message, a synchronous reply from the
948 * receiving connection was expected but the connection
949 * died before answering.
950 * @ESHUTDOWN: A domain or endpoint is currently shutting down;
951 * no further operations will be possible.
952 * @ESRCH: A requested well-known bus name is not found.
953 * @ETIMEDOUT: A synchronous wait for a message reply did not arrive
954 * within the specified time frame.
955 * @ETXTBSY: A kdbus memfd file cannot be sealed or the seal removed,
956 * because it is shared with other processes or still
958 * @EXFULL: The size limits in the pool are reached, no data of
959 * the size tried to submit can be queued.